bims-toxgon Biomed News
on Toxoplasma gondii metabolism
Issue of 2024–12–01
forty-six papers selected by
Lakesh Kumar, BITS Pilani
  1. TgATG9 is required for autophagosome biogenesis and maintenance of chronic infection in Toxoplasma gondii.
  2. Recent advances in identifying and characterizing secretory proteins of Toxoplasma gondii by CRISPR-based screening.
  3. Perforation of the host cell plasma membrane during Toxoplasma gondii invasion requires rhoptry exocytosis.
  4. The Toxoplasma gondii homolog of ATPase inhibitory factor 1 is critical for mitochondrial cristae maintenance and stress response.
  5. IL-36 Gamma: A Novel Adjuvant Cytokine Enhancing Protective Immunity Induced by DNA Immunization with TGIST and TGNSM Against Toxoplasma gondii Infection in Mice.
  6. Comprehensive Insights into the Development of Antitoxoplasmosis Drugs: Current Advances, Obstacles, and Future Perspectives.
  7. The microneme protein1 (MIC1) of Chinese 1 Toxoplasma regulates pyroptosis through the TLR4/NLRP3 pathway in macrophages.
  8. TcCARP3 modulates compartmentalized cAMP signals involved in osmoregulation, infection of mammalian cells, and colonization of the triatomine vector in the human pathogen Trypanosoma cruzi.
  9. The dynamin-related protein PfDyn2 is essential for both apicoplast and mitochondrial fission in Plasmodium falciparum.
  10. Apigeninidin chloride disrupts Toxoplasma gondii Mitochondrial membrane potential and induce reactive oxygen species and metabolites production.
  11. Toxoplasma gondii-Derived Exosomes: A Potential Immunostimulant and Delivery System for Tumor Immunotherapy Superior to Toxoplasma gondii.
  12. Diseases Caused by and Behaviors Associated with Toxoplasma gondii Infection.
  13. Slow-Binding and Covalent HDAC Inhibition: A New Paradigm?
  14. Nucleo-cytosolic acetyl-CoA drives tumor immune evasion by regulating PD-L1 in melanoma.
  15. Hit Identification and Functional Validation of Novel Dual Inhibitors of HDAC8 and Tubulin Identified by Combining Docking and Molecular Dynamics Simulations.
  16. Nuclear mTORC1 Live-Cell Sensor nTORSEL Reports Differential Nuclear mTORC1 Activity in Cell Lines.
  17. The Role of Polo-Like Kinase 1 (PLK1) O-GlcNAcylation in Mitosis.
  18. ACSS1-dependent acetate utilization rewires mitochondrial metabolism to support AML and melanoma tumor growth and metastasis.
  19. Function of the alternative electron transport chain in the Cryptosporidium parvum mitosome.
  20. Mapping of Nuclear Localization Signal in Secreted Liver-Specific Protein 2 of Plasmodium falciparum.
  21. Epigenetic modifications control CYP1A1 Inducibility in human and rat keratinocytes.
  22. Proteasome associated function of UCH37 is evolutionarily conserved in Plasmodium parasites.
  23. Recombinant SAG2A Protein from Toxoplasma gondii Modulates Immune Profile and Induces Metabolic Changes Associated with Reduced Tachyzoite Infection in Peritoneal Exudate Cells from Susceptible C57BL/6 Mice.
  24. Regulating Histone Deacetylases and Carbonic Anhydrases by Metal Complexes: A Potent Strategy for Treating Cancers.
  25. Mechanisms of growth-dependent regulation of the Gin4 kinase.
  26. Hydrogen Sulfide and Gut Microbiota: Their Synergistic Role in Modulating Sirtuin Activity and Potential Therapeutic Implications for Neurodegenerative Diseases.
  27. Toxoplasmosis in a case with multiple serous effusions and severe aplastic anemia.
  28. Liver-gut axis signaling regulates circadian energy metabolism in shift workers.
  29. Epigenetic maneuvering: an emerging strategy for mycobacterial intracellular survival.
  30. In silico identification of Histone Deacetylase inhibitors using Streamlined Masked Transformer-based Pretrained features.
  31. The Cwr1 protein kinase localizes to the plasma membrane and mediates resistance to cell wall stress in Candida albicans.
  32. The J Domain Proteins of Plasmodium knowlesi, a Zoonotic Malaria Parasite of Humans.
  33. Cannabidiol Enhances Mitochondrial Metabolism and Antioxidant Defenses in Human Intestinal Epithelial Caco-2 Cells.
  34. DNA Methylation and Histone Acetylation Contribute to the Maintenance of LTP in the Withdrawal Behavior Interneurons in Terrestrial Snails.
  35. New-to-nature CO2-dependent acetyl-CoA assimilation enabled by an engineered B12-dependent acyl-CoA mutase.
  36. Treponema Pallidum protein Tp47 triggers macrophage inflammatory senescence via PKM2-mediated metabolic reprogramming.
  37. Clinical trial landscape for histone deacetylation inhibitors in breast cancer: a dawn in the darkness?
  38. Lactate metabolism and histone lactylation in the central nervous system disorders: impacts and molecular mechanisms.
  39. From Microcirculation to Aging-Related Diseases: A Focus on Endothelial SIRT1.
  40. My path to citrin deficiency.
  41. Structural insights into the advancements of mobile colistin resistance enzymes.
  42. Identification of new inhibitors of Plasmodium falciparum hypoxanthine-guanine-xanthine Phosphoribosyltransferase (HG(X)PRT): An outlook towards the treatment of malaria.
  43. Arginyltransferase1 drives a mitochondria-dependent program to induce cell death.
  44. Metabolomics and 13C labelled glucose tracing to identify carbon incorporation into aberrant cell membrane glycans in cancer.
  45. N-acetylaspartate mitigates pro-inflammatory responses in microglial cells by intersecting lipid metabolism and acetylation processes.
  46. Fluorescent probes for sensing peroxynitrite: biological applications.
  1. Autophagy Rep. 2024 ;pii: 2418256. [Epub ahead of print]3(1):
    TgATG9 is required for autophagosome biogenesis and maintenance of chronic infection in Toxoplasma gondii.
    Pariyamon Thaprawat, Zhihai Zhang, Eric C Rentchler, Fengrong Wang, Shreya Chalasani, Christopher J Giuliano, Sebastian Lourido, Manlio Di Cristina, Daniel J Klionsky, Vern B Carruthers.
      Toxoplasma gondii is a ubiquitous protozoan parasite that can reside long-term within hosts as intracellular tissue cysts comprised of chronic stage bradyzoites. To perturb chronic infection requires a better understanding of the cellular processes that mediate parasite persistence. Macroautophagy/autophagy is a catabolic and homeostatic pathway that is required for T. gondii chronic infection, although the molecular details of this process remain poorly understood. A key step in autophagy is the initial formation of the phagophore that sequesters cytoplasmic components and matures into a double-membraned autophagosome for delivery of the cargo to a cell's digestive organelle for degradative recycling. While T. gondii appears to have a reduced repertoire of autophagy proteins, it possesses a putative phospholipid scramblase, TgATG9. Through structural modeling and complementation assays, we show herein that TgATG9 can partially rescue bulk autophagy in atg9Δ yeast. We demonstrated the importance of TgATG9 for proper autophagosome dynamics at the subcellular level using three-dimensional live cell lattice light sheet microscopy. Conditional knockdown of TgATG9 in T. gondii after bradyzoite differentiation resulted in markedly reduced parasite viability. Together, our findings provide insights into the molecular dynamics of autophagosome biogenesis within an early-branching eukaryote and pinpoint the indispensable role of autophagy in maintaining T. gondii chronic infection.
    Keywords:  Apicomplexa; autophagy; bradyzoite; conditional knockdown; lattice light sheet microscopy; yeast complementation
    DOI:  https://doi.org/10.1080/27694127.2024.2418256
  2. Parasitol Int. 2024 Nov 23. pii: S1383-5769(24)00148-X. [Epub ahead of print]105 102997
    Recent advances in identifying and characterizing secretory proteins of Toxoplasma gondii by CRISPR-based screening.
    Yuta Tachibana, Masahiro Yamamoto.
      The apicomplexan parasite, Toxoplasma gondii, develops unique secretory organelles, such as micronemes, rhoptries, and dense granules, which do not exist in other well-studied eukaryotic organisms. These secretory organelles are key features of apicomplexan parasites and discharge various proteins that are essential for invasion, replication, egress, host-parasite interactions, and virulence. Many studies have therefore focused on identifying and characterizing the proteins secreted by T. gondii that play essential roles in pathology and that can be targeted for therapeutics and vaccine development. The recent development of functional genetic screens based on CRISPR/Cas9 technology has revolutionized this field and has enabled the identification of genes that contribute to parasite fitness in vitro and in vivo. Consequently, characterization of genes identified by unbiased CRISPR screens has revealed novel aspects of apicomplexan biology. In this review, we describe the development of CRIPSR-based screening technology for T. gondii, and recent advances in our understanding of secretory proteins identified and characterized by CRISPR-based screening.
    Keywords:  CRISPR screen; Dense granule; Microneme; Rhoptry; Secretome; Secretory proteins; Toxoplasma gondii
    DOI:  https://doi.org/10.1016/j.parint.2024.102997
  3. bioRxiv. 2024 Nov 11. pii: 2024.10.12.618018. [Epub ahead of print]
    Perforation of the host cell plasma membrane during Toxoplasma gondii invasion requires rhoptry exocytosis.
    Frances Male, Yuto Kegawa, Paul S Blank, Irene Jiménez-Munguía, Saima M Sidik, Dylan Valleau, Sebastian Lourido, Maryse Lebrun, Joshua Zimmerberg, Gary E Ward.
      Toxoplasma gondii is an obligate intracellular parasite, and the delivery of effector proteins from the parasite into the host cell during invasion is critical for invasion itself and for parasite virulence. The effector proteins are released from specialized apical secretory organelles known as rhoptries. While much has been learned recently about the structure and composition of the rhoptry exocytic machinery and the function of individual rhoptry effector proteins that are exocytosed, virtually nothing is known about how the released proteins are translocated across the host cell plasma membrane. Previous electrophysiology experiments reported an unanticipated observation that invasion by T. gondii is preceded by a transient increase in host cell plasma membrane conductance. Here, we confirm this electrophysiological observation and propose that the conductance transient represents a parasite-induced perforation in the host cell plasma membrane through which rhoptry proteins are delivered. As a first step towards testing this hypothesis, and to provide higher throughput than patch clamp electrophysiology, we developed an alternative assay to detect the perforation. This assay utilizes high-speed, multi-wavelength fluorescence imaging to enable simultaneous visualization of host cell perforation and parasite invasion. Using this assay, we interrogated a panel of mutant parasites conditionally depleted of key invasion-related proteins. Parasites lacking signaling proteins involved in triggering rhoptry secretion ( e.g. , CLAMP) or components of the rhoptry exocytic machinery ( e.g. , Nd9, RASP2) are defective in their ability to induce the perforation. These data are consistent with a model in which the perforating agents that disrupt host cell membrane integrity during invasion - and may thereby provide the conduit for delivery of rhoptry effector proteins - are stored within the rhoptries themselves and released upon contact with the host cell.
    DOI:  https://doi.org/10.1101/2024.10.12.618018
  4. Mol Biol Cell. 2024 Nov 27. mbcE24080344
    The Toxoplasma gondii homolog of ATPase inhibitory factor 1 is critical for mitochondrial cristae maintenance and stress response.
    Madelaine M Usey, Anthony A Ruberto, Kaelynn V Parker, Diego Huet.
      The production of energy in the form of ATP by the mitochondrial ATP synthase must be tightly controlled. One well-conserved form of regulation is mediated via ATPase inhibitory factor 1 (IF1), which governs ATP synthase activity and gene expression patterns through a cytoprotective process known as mitohormesis. In apicomplexans, the processes regulating ATP synthase activity are not fully elucidated. Using the model apicomplexan Toxoplasma gondii, we found that knockout and overexpression of TgIF1, the structural homolog of IF1, significantly affected gene expression. Additionally, TgIF1 overexpression resulted in the formation of a stable TgIF1 oligomer and increased the presence of higher order ATP synthase oligomers. We also show that parasites lacking TgIF1 exhibit reduced mitochondrial cristae density, and that while TgIF1 levels do not affect growth in conventional culture conditions, they are crucial for parasite survival under hypoxia. Interestingly, TgIF1 overexpression enhances recovery from oxidative stress, suggesting a mitohormetic function. In summary, while TgIF1 does not appear to play a role in ATP synthase regulation under conventional growth conditions, our work uncovers its potential role in adapting to the stressors faced by T. gondii and other apicomplexans throughout their intricate life cycles.
    DOI:  https://doi.org/10.1091/mbc.E24-08-0344
  5. Microorganisms. 2024 Nov 07. pii: 2258. [Epub ahead of print]12(11):
    IL-36 Gamma: A Novel Adjuvant Cytokine Enhancing Protective Immunity Induced by DNA Immunization with TGIST and TGNSM Against Toxoplasma gondii Infection in Mice.
    Ying Tan, Jingqi Mu, Jia Chen.
       BACKGROUND: Toxoplasma gondii can cause congenital infections and abortions in humans. TgIST and TgNSM play critical roles in intracellular cyst formation and chronic infection. However, no studies have explored their potential to induce protective immunity against T. gondii infection.
    OBJECTIVE: To evaluate the immune efficacy of DNA vaccines encoding TgNSM and TgIST genes against T. gondii infection, using the acute and chronic ME49 strain (Type II).
    METHODS: DNA vaccines, including eukaryotic plasmids pVAX-IST and pVAX-NSM, were constructed. A cocktail DNA vaccine combining these two genes was formulated. The expression and immunogenicity were determined using the indirect immunofluorescence assay (IFA). Mice were immunized with DNA vaccines encoding either TgIST or TgNSM, as well as with the cocktail DNA vaccine. Humoral and cellular immune responses were analyzed by detecting antibody levels, cytotoxic T cell (CTL) responses, cytokines, and lymphocyte surface markers. Mouse survival and brain cyst counts were assessed 1 to 2 months post-vaccination in experimental toxoplasmosis models. The adjuvant efficacy of plasmid pVAX-IL-36γ in enhancing DNA vaccine-induced protective immunity was also evaluated.
    RESULTS: DNA immunization with pVAX-IST and pVAX-NSM elicited strong humoral and cellular immune responses, characterized by increased Toxoplasma-specific IgG2a titers, Th1 responses (including production of IFN-γ, IL-2, IL-12p40, and IL-12p70), and cell-mediated activity with elevated frequencies of CD8+ and CD4+ T cells, and CTL responses. This provided significant protective efficacy against acute and chronic T. gondii infection. Mice immunized with the two-gene cocktail (pVAX-IST + pVAX-NSM) showed greater protection than those immunized with single-gene vaccines. Co-administration of the molecular adjuvant pVAX-IL-36γ further enhanced the protective immunity induced by the cocktail DNA vaccine.
    CONCLUSIONS: TgIST and TgNSM induce effective immunity against T. gondii infection, making them promising vaccine candidates against toxoplasmosis. Additionally, IL-36γ is a promising genetic adjuvant that enhances protective immunity in a vaccine setting against T. gondii, and it should be evaluated in strategies against other apicomplexan parasites.
    Keywords:  DNA vaccine; IL-36γ; Kunming mice; TgIST; TgNSM; Toxoplasma gondii; protective immunity
    DOI:  https://doi.org/10.3390/microorganisms12112258
  6. J Med Chem. 2024 Nov 26.
    Comprehensive Insights into the Development of Antitoxoplasmosis Drugs: Current Advances, Obstacles, and Future Perspectives.
    Siyang Liu, Minghao Cai, Zhendi Liu, Weixin Gao, Junjie Li, Yuxueqing Li, Xiayire Abudouxukuer, Jili Zhang.
      Current therapies for toxoplasmosis rely on a few drugs, most of which have severe side effects, and seeking ideal therapies for different types of toxoplasmosis is a long-term and challenging mission. Research and development (R&D) of novel drugs against Toxoplasma gondii (T. gondii) has focused on two main directions, the structural modification of lead compounds and natural products. Here we summarize the recent advances in the development of anti-T. gondii drugs from these two perspectives and provide comprehensive insights, reflecting on the advantages and selected molecules in each field. This review also focuses on the current obstacles to the development of novel anti-T. gondii agents, proposes comprehensive solutions, and facilitates future development.
    DOI:  https://doi.org/10.1021/acs.jmedchem.4c01733
  7. Parasit Vectors. 2024 Nov 29. 17(1): 495
    The microneme protein1 (MIC1) of Chinese 1 Toxoplasma regulates pyroptosis through the TLR4/NLRP3 pathway in macrophages.
    Wenze Sun, Fan Zhang, Jinjin Zhu, Yanxia Yu, Yang Wang, Qingli Luo, Li Yu.
       BACKGROUND: TgMIC1, a soluble adhesion protein that typically facilitates parasite invasion, exhibited varying expression levels among distinct virulence strains of Chinese 1 Toxoplasma. This study aims to explore its role in immunological regulation and its association with diverse postinfection outcomes in Toxoplasma infection.
    METHODS: First, the mic1 knockout strain Wh3Δmic1 was generated and assessed for its virulence and proliferative capacity. Subsequently, the serum inflammation levels were examined in mice infected with Wh3Δmic1, Wh3, and Wh6. Furthermore, rMIC1 and rMIC1-T126A/T220A, which lack binding sites to N-glycan in TLR4, were produced for coculture with bone marrow-derived macrophages (BMDMs) to investigate their impact on pyroptosis.
    RESULTS: Our data showed Wh3Δmic1 exhibited a significant reduction in invasion efficiency, limited growth, and attenuated inflammatory responses in mice. Additionally, it displayed a decreased capacity to induce pyroptosis when compared with Wh3-infected BMDMs. Moreover, rMIC1 but not rMIC1-T126A/T220A was found to be able to upregulate NOD-like receptor pyrin domain-containing protein 3 (NLRP3) and activate GSDMD and caspase-1 in BMDMs but not in TLR4-/- and NLRP3-/- BMDMs.
    CONCLUSIONS: TgMIC1 is implicated in both parasite invasion and the modulation of macrophage pyroptosis via the TLR4/NLRP3 pathway. This investigation indicates that TgMIC1 serves diverse functions in Toxoplasma gondii infection, thereby enhancing comprehension of the immune regulatory mechanisms of the parasite.
    Keywords:   Toxoplasma gondii ; NLRP3; Pyrptosis; TLR4; TgMIC1
    DOI:  https://doi.org/10.1186/s13071-024-06584-z
  8. bioRxiv. 2024 Nov 21. pii: 2024.11.20.624561. [Epub ahead of print]
    TcCARP3 modulates compartmentalized cAMP signals involved in osmoregulation, infection of mammalian cells, and colonization of the triatomine vector in the human pathogen Trypanosoma cruzi.
    Joshua Carlson, Milad Ahmed, Riley Hunter, Syeda Farjana Hoque, Joshua B Benoit, Miguel A Chiurillo, Noelia Lander.
      Trypanosoma cruzi is the causative agent of Chagas disease, a zoonotic infectious disease considered a leading cause of cardiomyopathy, disability, and premature death in the Americas. This parasite spends its life between a mammalian host and an arthropod vector, undergoing essential transitions among different developmental forms. How T. cruzi senses microenvironmental changes that trigger cellular responses necessary for parasite survival has remained largely unknown. Cyclic AMP (cAMP) is a universal second messenger that has been shown to regulate key cellular processes in trypanosomes, in which cyclic AMP response proteins (CARPs) have been proposed to be modulators or effectors of a PKA-independent signaling pathway. In this study we aimed to investigate the role of TcCARP3 in cAMP signaling throughout T. cruzi life cycle. Our results show that TcCARP3 shares a dual localization (flagellar tip and contractile vacuole complex) with adenylate cyclase 1 (TcAC1) in the main developmental stages of the parasite. We also found that TcCARP3 directly interacts with several TcACs, modulating the intracellular content of cAMP. Through generation of TcCARP3 knockout, addback, and overexpression cell lines we showed that modulation of gene expression affects the parasite's ability to differentiate, respond to osmotic stress, invade mammalian cells and replicate within them, and colonize the hindgut of the triatomine vector. In addition, we identified several signaling proteins interacting with TcCARP3 in what we propose are cAMP signaling microdomains. Our results unveil a key role for TcCARP3 as modulator of cAMP signals necessary for parasite differentiation and survival throughout T. cruzi life cycle.
    IMPORTANCE: Cyclic AMP signaling pathways are poorly understood in the stercorarian parasite Trypanosoma cruzi . Specifically, the mechanisms driving the activation of TcACs in response to microenvironmental stress are completely unknown. This study unveils the role of TcCARP3 in modulating the content of cAMP through the interaction with several TcACs and putative cAMP effectors in T. cruzi . Particularly, TcCARP3 interacts with TcAC1 in the main developmental stages of this parasite's life cycle, where both proteins display a dual localization pattern. These results provide new evidence supporting the compartmentalization of cAMP signals in trypanosomes. Moreover, our data unequivocally demonstrates that TcCARP3 is required for key cellular processes for parasite survival, such as response to osmotic stress, host cell invasion, intracellular replication, and the ability to colonize the hindgut of the triatomine vector. In summary, we found that TcCARP3 is an adenylate cyclase regulator, necessary for the life cycle progression of T. cruzi .
    DOI:  https://doi.org/10.1101/2024.11.20.624561
  9. mBio. 2024 Nov 29. e0303624
    The dynamin-related protein PfDyn2 is essential for both apicoplast and mitochondrial fission in Plasmodium falciparum.
    Alexander A Morano, Wei Xu, Francesca M Navarro, Neeta Shadija, Jeffrey D Dvorin, Hangjun Ke.
      Dynamins, or dynamin-related proteins (DRPs), are large mechano-sensitive GTPases that mediate membrane dynamics or organellar fission/fusion events. Plasmodium falciparum encodes three dynamin-like proteins whose functions are poorly understood. Here, we demonstrate that one of these dynamin-related proteins, PfDyn2, is required to divide both the apicoplast and the mitochondrion, a striking divergence from the biology of related parasites. Using super-resolution and ultrastructure expansion microscopy (U-ExM), we show that PfDyn2 is expressed in dividing schizonts, and that it localizes to both the apicoplast and the mitochondrion. Our use of long-term, live-cell microscopy allows for the visualization of apicoplast and mitochondrial division in live parasites at super resolution for the first time, and demonstrates that in PfDyn2-deficient parasites, while the apicoplast and mitochondrion increase in size and complexity, they do not undergo fission. We also show that these organellar fission defects prevent successful individualization of the schizont mass and the formation of new daughter cells, or merozoites because the basal complex, the cytokinetic ring of Plasmodium, cannot fully contract in PfDyn2-deficient parasites, a phenotype secondary to physical blockage by undivided organelles occluding the ring. PfDyn2's singular role in mediating both apicoplast and mitochondrial fission has not been observed in other organisms possessing two endosymbiotic organelles, including other Apicomplexans, thus reflecting a unique, potentially exploitable method of organellar division in P. falciparum.IMPORTANCEPlasmodium falciparum remains a significant global pathogen, causing over 200 million infections and over 600,000 deaths per year. One significant obstacle to the control of malaria is increasing resistance to first-line artemisinin-based antimalarials. Another is a lack of basic knowledge about the cell biology of the parasite. Along with the mitochondrion, Plasmodium contains a second organelle descended from an endosymbiotic event, the apicoplast. Both organelles are common targets for antimalarials, but because many proteins involved in organellar fission are not conserved in Plasmodium, until now, the mechanisms underlying apicoplast and mitochondrial division have been unknown. In this study, we demonstrate that PfDyn2, a dynamin-related protein (DRP), is required for the division of both organelles. We also show that defects in organellar division hinder segmentation of the schizont and formation of invasive merozoites by preventing full contraction of the basal complex. By demonstrating its necessity for the proper division of both the apicoplast and the mitochondria, this study highlights PfDyn2 as a potential target for new antimalarials.
    Keywords:  PfDyn2; Plasmodium falciparum; apicoplast; apicoplast fission; basal complex; dynamin; dynamin-related protein; malaria; mitochondria; mitochondrial fission; residual body; schizogony
    DOI:  https://doi.org/10.1128/mbio.03036-24
  10. Front Cell Infect Microbiol. 2024 ;14 1368019
    Apigeninidin chloride disrupts Toxoplasma gondii Mitochondrial membrane potential and induce reactive oxygen species and metabolites production.
    Miya Janelle Moon, Japhet Senyo Kamasah, Homa Nath Sharma, Boakai K Robertson, Daniel A Abugri.
       Introduction: Apigeninidin chloride (APi) is a form of 3-deoxyanthrocyanidins (3-DAs) abundantly produced by the red Sorghum bicolor plant. It has been previously reported to be effective against Toxoplasma gondii (T. gondii) tachyzoites grown in vitro with less cytotoxic effect. However, its possible mechanism(s) of action has not been elucidated. Biochemically, we discovered that APi induced high reactive oxygen species (ROS) and mitochondria superoxide (MitoSOX) productions in tachyzoites, leading to mitochondrial membrane potential (MMP) disruption in vitro.
    Methods: To confirm our biochemical results at the molecular level, we performed a liquid chromatography-mass spectrometry (LC-MS) analysis on APi-treated parasites to assess any metabolite and lipid alterations often associated with high ROS/MitoSOX production in cells.
    Results: Noteworthy is that we detected several important oxidative stress-induced metabolites such as hexanal, aldehydes, methyl undeo10-enoate, butadiynyl phenyl ketone, 16-hydroxyhexadecanoic acid (16-OH, 16:0), 2-hydroxytricosanoic acid (C23:0; O), 3-oxodecanosanoic acid (C22:1; O), 2-hydroxypropylsterate, and furan fatty acids F6 (19FU-FA).
    Discussion: These metabolites are associated with lipid, protein, and nucleic acid disruptions. Using atovaquone (Atov) as a control, we observed that it disrupted intracellular tachyzoites' mitochondrial membrane potential, increased ROS and MitoSOX production, and altered metabolite and lipid production similar to what was observed with our experimental compound APi. Overall, our results indicated that APi targets T. gondii tachyzoite growth through inducing oxidative stress, mitochondrial dysfunction, and eventually parasite death.
    Keywords:  3-DAs; T. gondii; in vitro; mitochondrial membrane potential; oxidative-stress metabolites; reactive oxygen species; tachyzoites
    DOI:  https://doi.org/10.3389/fcimb.2024.1368019
  11. Int J Nanomedicine. 2024 ;19 12421-12438
    Toxoplasma gondii-Derived Exosomes: A Potential Immunostimulant and Delivery System for Tumor Immunotherapy Superior to Toxoplasma gondii.
    Lai-Xi Zhao, Qiong Sun, Chong Wang, Jia-Jia Liu, Xiao-Rong Yan, Meng-Ci Shao, Li Yu, Wen-Hua Xu, Rui Xu.
      Immunotherapies such as immune checkpoint blockade (ICB) therapy and chimeric antigen receptor T-cell (CAR-T) therapy have ushered in a new era of tumor treatment. However, most patients do not benefit from immunotherapy due to limitations such as narrow indications, low response rates, and high rates of adverse effects. Toxoplasma gondii (T. gondii), a specialized intracellular protozoan, can modulate host immune responses by inhibiting or stimulating cytokines. The ability of T. gondii to enhance an organism's immune response was found to have a direct anti-tumor effect and enhance the sensitivity of patients with tumors to ICB therapy. However, the application of T. gondii for tumor therapy faces several challenges, such as biosafety concerns. Exosomes, a subtype of extracellular vesicle that contains active components such as proteins, nucleic acids, and lipids, have become effective therapeutic tools for various diseases, including tumors. Parasites, such as T. gondii, mediate the communication of pathogens with immune cells and modulate host cellular immune responses through exosomes. Growing evidence indicates that T. gondii-derived exosomes mediate communication between pathogens and immune cells, modulate host immune responses, and have great potential as new tools for tumor therapy. In this review, we highlight recent advances in isolation and identification techniques, profiling analysis, host immunomodulatory mechanisms, and the role of T. gondii-derived exosomes in tumor immunotherapy. Additionally, we emphasize the potential of T. gondii-derived exosomes as delivery platform to enhance anti-tumor efficacy in combination with other therapies. This review proposes that T. gondii-derived exosomes may serve as a novel tool for tumor immunotherapy owing to their ability to activate host immune function and properties such as high modifiability, stability, and low toxicity. This work will assist in promoting the application of parasite exosomes in tumor therapy.
    Keywords:  Toxoplasma gondii; exosomes; immune regulation; immunotherapy; tumor
    DOI:  https://doi.org/10.2147/IJN.S483626
  12. Pathogens. 2024 Nov 06. pii: 968. [Epub ahead of print]13(11):
    Diseases Caused by and Behaviors Associated with Toxoplasma gondii Infection.
    Ginger K H Akins, João M Furtado, Justine R Smith.
      Toxoplasma gondii is an Apicomplexan parasite that is estimated to infect at least one-third of the global human population. T. gondii infection may be transmitted horizontally or vertically. The main risk factors for transmission to humans are related to diet, especially the consumption of undercooked meat, along with soil contact. In immunocompetent persons, the acute infection may go undetected as it typically produces minor, non-specific symptoms that are self-limited. After infection is established, recurrent retinochoroiditis is the most common clinical disease. In contrast, severe systemic or cerebral toxoplasmosis may be life-threatening for immunocompromised individuals. Furthermore, congenital toxoplasmosis acquired in utero may have devastating consequences if not recognized and promptly treated. A growing body of research has identified associations between latent T. gondii infection, and personality traits and risk-taking behaviors. Other studies have documented associations between latent infection and psychiatric conditions that include schizophrenia and bipolar affective disorder. With no current treatment regimens being curative of T. gondii infection, effective prevention measures at both the public health and individual levels are vitally important.
    Keywords:  Toxoplasma gondii; bipolar disorder; cerebral toxoplasmosis; congenital toxoplasmosis; ocular toxoplasmosis; personality; risky behavior; schizophrenia
    DOI:  https://doi.org/10.3390/pathogens13110968
  13. JACS Au. 2024 Nov 25. 4(11): 4148-4161
    Slow-Binding and Covalent HDAC Inhibition: A New Paradigm?
    Yasir S Raouf, Carlos Moreno-Yruela.
      The dysregulated post-translational modification of proteins is an established hallmark of human disease. Through Zn2+-dependent hydrolysis of acyl-lysine modifications, histone deacetylases (HDACs) are key regulators of disease-implicated signaling pathways and tractable drug targets in the clinic. Early targeting of this family of 11 enzymes (HDAC1-11) afforded a first generation of broadly acting inhibitors with medicinal applications in oncology, specifically in cutaneous and peripheral T-cell lymphomas and in multiple myeloma. However, first-generation HDAC inhibitors are often associated with weak-to-modest patient benefits, dose-limited efficacies, pharmacokinetic liabilities, and recurring clinical toxicities. Alternative inhibitor design to target single enzymes and avoid toxic Zn2+-binding moieties have not overcome these limitations. Instead, recent literature has seen a shift toward noncanonical mechanistic approaches focused on slow-binding and covalent inhibition. Such compounds hold the potential of improving the pharmacokinetic and pharmacodynamic profiles of HDAC inhibitors through the extension of the drug-target residence time. This perspective aims to capture this emerging paradigm and discuss its potential to improve the preclinical/clinical outlook of HDAC inhibitors in the coming years.
    DOI:  https://doi.org/10.1021/jacsau.4c00828
  14. Cell Rep. 2024 Nov 26. pii: S2211-1247(24)01366-4. [Epub ahead of print]43(12): 115015
    Nucleo-cytosolic acetyl-CoA drives tumor immune evasion by regulating PD-L1 in melanoma.
    Huina Wang, Xiuli Yi, Xiangxu Wang, Yuqi Yang, Hengxiang Zhang, Hao Wang, Jianru Chen, Baolu Zhang, Sen Guo, Lili Wu, Juan Du, Yuhan Chen, Ningyue Sun, Tianwen Gao, Rui Zhang, Huijie Bian, Lintao Jia, Chunying Li, Weinan Guo.
      Acetyl coenzyme A (acetyl-CoA), a versatile central metabolite, plays a critical role in various metabolic processes and protein acetylation. While its impact on tumor cell properties is well established, the connection between acetyl-CoA metabolism and immune evasion in tumors remains unclear. Here, we uncover a mechanism by which nucleo-cytosolic acetyl-CoA contributes to immune evasion through regulation of programmed death ligand 1 (PD-L1). Specifically, bioinformatics analysis reveals a negative correlation between acetyl-CoA metabolism and anti-tumor immunity across multiple cancers. Inhibition of the acetyl-CoA-producing enzyme ATP-citrate lyase (ACLY) leads to a re-invigoration of cytotoxic T cells and enhances the efficacy of immunotherapy. Mechanistically, nucleo-cytosolic acetyl-CoA promotes PD-L1 transcription via P300-dependent histone H3K27 acetylation at the promoter region of CD274. The ACLY-H3K27ac-PD-L1 axis is verified in clinical specimens and predicts poor immunotherapy response. Our findings suggest that targeting acetyl-CoA metabolism may act as a promising strategy to overcome immune evasion and improve the outcomes of cancer immunotherapy.
    Keywords:  ACLY; Acetyl-CoA; CP: Cancer; PD-L1; histone acetylation; immune evasion; melanoma; metabolism
    DOI:  https://doi.org/10.1016/j.celrep.2024.115015
  15. Antioxidants (Basel). 2024 Nov 20. pii: 1427. [Epub ahead of print]13(11):
    Hit Identification and Functional Validation of Novel Dual Inhibitors of HDAC8 and Tubulin Identified by Combining Docking and Molecular Dynamics Simulations.
    Antonio Curcio, Roberta Rocca, Federica Chiera, Maria Eugenia Gallo Cantafio, Ilenia Valentino, Ludovica Ganino, Pierpaolo Murfone, Angela De Simone, Giulia Di Napoli, Stefano Alcaro, Nicola Amodio, Anna Artese.
      Chromatin organization, which is under the control of histone deacetylases (HDACs), is frequently deregulated in cancer cells. Amongst HDACs, HDAC8 plays an oncogenic role in different neoplasias by acting on both histone and non-histone substrates. Promising anti-cancer strategies have exploited dual-targeting drugs that inhibit both HDAC8 and tubulin. These drugs have shown the potential to enhance the outcome of anti-cancer treatments by simultaneously targeting multiple pathways critical to disease onset and progression. In this study, a structure-based virtual screening (SBVS) of 96403 natural compounds was performed towards the four Class I HDAC isoforms and tubulin. Using molecular docking and molecular dynamics simulations (MDs), we identified two molecules that could selectively interact with HDAC8 and tubulin. CNP0112925 (arundinin), bearing a polyphenolic structure, was confirmed to inhibit HDAC8 activity and tubulin organization, affecting breast cancer cell viability and triggering mitochondrial superoxide production and apoptosis.
    Keywords:  HDAC8; docking; epigenetics; molecular dynamics; multi-targets; tubulin; virtual screening
    DOI:  https://doi.org/10.3390/antiox13111427
  16. Int J Mol Sci. 2024 Nov 12. pii: 12117. [Epub ahead of print]25(22):
    Nuclear mTORC1 Live-Cell Sensor nTORSEL Reports Differential Nuclear mTORC1 Activity in Cell Lines.
    Yifan Wang, Canrong Li, Yingyi Ouyang, Xiaoduo Xie.
      The mammalian or mechanistic target of rapamycin complex 1 (mTORC1) is activated on the surface of lysosomes and phosphorylates substrates at various subcellular locations, including the lysosome, cytosol, and nucleus. However, the signaling and biological functions of nuclear mTORC1 (nmTORC1) are not well understood, primarily due to limited tools for monitoring mTORC1 activity in the nucleus. In this study, we developed a genetically encoded nmTORC1 sensor, termed nTORSEL, based on the phosphorylation of the eukaryotic initiation factor 4E (eIF4E) binding protein 1 (4EBP1) by mTORC1 within the nucleus. nTORSEL, like its predecessor TORSEL, exhibits a fluorescent punctate pattern in the nucleus through multivalent protein-protein interactions between oligomerized 4EBP1 and eIF4E when nmTORC1 activity is low. We validated nTORSEL using biochemical analyses and imaging techniques across representative cell lines with varying levels of nmTORC1 activity. Notably, nTORSEL specifically detects physiological, pharmacological, and genetic inhibition of nmTORC1 in mouse embryonic fibroblast (MEF) cells but not in HEK293T cells. Therefore, nTORSEL is an effective tool for investigating nuclear mTORC1 signaling in cell lines.
    Keywords:  PI3K-AKT-mTOR pathway; amino acid; fluorescent reporter; live-cell sensor; nuclear mTORC1
    DOI:  https://doi.org/10.3390/ijms252212117
  17. Methods Mol Biol. 2025 ;2874 127-137
    The Role of Polo-Like Kinase 1 (PLK1) O-GlcNAcylation in Mitosis.
    Jie Li, Guangcan Shao, Bin Peng, Xingzhi Xu, Meng-Qiu Dong, Jing Li.
      Polo-like kinase 1 (PLK1) is a crucial mitotic kinase that is implicated in various aspects of cell cycle. Many post-translational modifications have been identified on PLK1 to regulate its activation, stability, and localization. PLK1 has been shown previously to colocalize with the O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT), and OGT regulates PLK1 stability. In our recent work, we show that PLK1 is O-GlcNAcylated by click chemistry. Using stepped collisional energy/higher energy collision dissociation mass spectrometry, we mapped the PLK1 O-GlcNAc site to be T291. We further utilized fluorescent activated cell sorting and time-lapse microscopy to assess the mitotic defects of PLK1 O-GlcNAc mutants. In vivo studies in mouse xenograft demonstrated that it promoted uterine cancer tumorigenesis. In this chapter, we delineate the methodologies we used in studying PLK1 O-GlcNAcylation, including click chemistry, stepped collisional energy/higher energy collision dissociation mass spectrometry, fluorescent activated cell sorting, time-lapse microscopy, and mouse xenograft assays.
    Keywords:  Mass spectrometry; Mitosis; O-GlcNAcylation; PLK1; Uterine carcinoma
    DOI:  https://doi.org/10.1007/978-1-0716-4236-8_11
  18. Cell Rep. 2024 Nov 21. pii: S2211-1247(24)01339-1. [Epub ahead of print]43(12): 114988
    ACSS1-dependent acetate utilization rewires mitochondrial metabolism to support AML and melanoma tumor growth and metastasis.
    Sabina I Hlavaty, Kelsey N Salcido, Katherine A Pniewski, Dzmitry Mukha, Weili Ma, Toshitha Kannan, Joel Cassel, Yellamelli V V Srikanth, Qin Liu, Andrew Kossenkov, Joseph M Salvino, Qing Chen, Zachary T Schug.
      Cancer cells often use alternative nutrient sources to support their metabolism and proliferation. One important alternative nutrient source for many cancers is acetate. Acetate is metabolized into acetyl-coenzyme A (CoA) by acetyl-CoA synthetases 1 and 2 (ACSS1 and ACSS2), which are found in the mitochondria and cytosol, respectively. We show that ACSS1 and ACSS2 are differentially expressed in cancer. Melanoma, breast cancer, and acute myeloid leukemia cells expressing ACSS1 readily use acetate for acetyl-CoA biosynthesis and to fuel mitochondrial metabolism. ACSS1-dependent acetate metabolism decreases the relative contributions of glucose and glutamine to the tricarboxylic acid (TCA) cycle and alters the pentose phosphate pathway and redox state of cancer cells. ACSS1 knockdown decreases acute myeloid leukemia burden in vivo and inhibits melanoma tumor and metastatic growth. Our study highlights a key role for ACSS1-dependent acetate metabolism for cancer growth, raising the potential for ACSS1-targeting therapies in cancer.
    Keywords:  ACSS1; ACSS2; ACSS2 inhibitor; AML; CP: Cancer; CP: Metabolism; acetate; cancer; melanoma; metabolism; metastasis
    DOI:  https://doi.org/10.1016/j.celrep.2024.114988
  19. bioRxiv. 2024 Oct 01. pii: 2024.10.01.616074. [Epub ahead of print]
    Function of the alternative electron transport chain in the Cryptosporidium parvum mitosome.
    Silu Deng, L David Sibley.
      Cryptosporidium parvum and C. hominis possess a remanent mitochondrion called the mitosome, which lacks DNA, the tricarboxylic acid cycle, a conventional electron transport chain, and ATP synthesis. The mitosome retains ubiquinone and iron sulfur cluster biosynthesis pathways, both of which require protein import that relies on the membrane potential. It was previously proposed that the membrane potential is generated by electrons transferred through an alternative respiratory pathway coupled to a transhydrogenase (TH) that pumps hydrogens out of the mitosome. This pathway relies on an alternative oxidase (AOX) and type II NADH dehydrogenase (NDH2), which also exists in plants, some fungi, and several protozoan parasites. To examine this model, we determined the location and function of AOX and NDH2 in C. parvum . Surprisingly, we observed that NDH2 was localized to parasite surface membranes instead of the mitosome. Furthermore, a Δ ndh2 knockout (KO) strain was readily obtained, indicating that this protein is not essential for parasite growth. Although, AOX exhibited a mitosome-like staining pattern, we readily obtained an Δ aox knockout strain, indicating that AOX is also dispensable for parasite growth. The growth of the Δ aox strain was inhibited by the AOX inhibitors SHAM and 8-HQ to the same extent as wild type, indicating that AOX is not the target of these inhibitors in C. parvum . Collectively, our studies indicate that NDH2 and AOX are non-essential genes in C. parvum , necessitating an alternative mechanism for maintaining the mitosome membrane potential.
    Importance: Cryptosporidiosis is the leading cause of diarrhea in young children and immunocompromised individuals, particularly AIDS/HIV patients. The only FDA approved drug against cryptosporidiosis, nitazoxanide, has limited effectivity in immunocompromised patients and is not approved for usage in children under 1 year old. Genomic analysis and previous studies proposed an alternative respiration pathway involving alternative oxidase (AOX) and type II NAD(P)H dehydrogenase (NDH2), which are thought to generate the mitosome membrane potential in C. parvum . Additionally, AOX and NDH2 were nominated as potential drug targets, based on their absence in mammalian hosts and sensitivity of parasite growth to known inhibitors of AOX. However, our study demonstrated that NDH2 is not localized in mitosome, AOX non-essential for parasite growth, and knockout lines lacking this enzyme are equally sensitive to AOX inhibitors. These findings indicate that AOX and NDH2 are not ideal candidates for future drug development against cryptosporidiosis and force a re-evaluation for models of how the mitosome generate its membrane potential.
    DOI:  https://doi.org/10.1101/2024.10.01.616074
  20. ACS Infect Dis. 2024 Nov 27.
    Mapping of Nuclear Localization Signal in Secreted Liver-Specific Protein 2 of Plasmodium falciparum.
    Akshaykumar Nanaji Shrikondawar, Kiranmai Chennoju, Debasish Kumar Ghosh, Akash Ranjan.
      The secretory proteome of Plasmodium exhibits differential spatial and functional activity within host cells. Plasmodium secretes proteins that translocate into the human host cell nucleus. Liver-specific protein 2 of Plasmodium falciparum (Pf-LISP2) shows nuclear accumulation in human hepatocytes during the late liver stage of malaria parasite development. However, the nuclear translocation mechanism for Pf-LISP2 remains largely uncharacterized. Here, we identified a classical bipartite nuclear localization signal (NLS) located in the C-terminal region of Pf-LISP2. Phylogenetic analysis revealed that this NLS is unique to Plasmodium falciparum and its close relative Plasmodium reichenowi, suggesting an evolutionary adaptation linked to their shared primate hosts. Functional assays confirmed the NLS's nuclear import activity, as fusion constructs of the Pf-LISP2 NLS with Pf-aldolase (Pf-aldolase-NLS-EGFP) localized exclusively to the nucleus of HepG2 cells. Mutation analysis of key lysine and arginine residues in the bipartite NLS demonstrated that the basic amino acid clusters are essential for nuclear localization. Importin-α/β interaction was found to be crucial for Pf-LISP2 nuclear transport, as coexpression of the NLS constructs with the importin-α/β inhibitor mCherry-Bimax2 significantly blocked nuclear translocation. Specific interactions between the lysine and arginine residues of Pf-LISP2's NLS and the conserved tryptophan and asparagine residues of human importin-α1 facilitate the cytosol-to-nuclear translocation of Pf-LISP2. Additionally, LISP2 lacks any nuclear export signal. These results provide new insights into the mechanisms of nuclear transport in Plasmodium falciparum, potentially contributing to the understanding of its pathogenicity and host-cell interactions during liver-stage infection.
    Keywords:  LISP2; Plasmodium falciparum; bipartite NLS; evolutionary adaptation; importin-α/β; liver-stage infection; nuclear translocation
    DOI:  https://doi.org/10.1021/acsinfecdis.4c00715
  21. Toxicol Appl Pharmacol. 2024 Nov 22. pii: S0041-008X(24)00362-4. [Epub ahead of print]494 117163
    Epigenetic modifications control CYP1A1 Inducibility in human and rat keratinocytes.
    Lo-Wei Lin, Allison K Ehrlich, Robert H Rice.
      Serially passaged rat keratinocytes exhibit dramatically attenuated induction of Cyp1a1 by aryl hydrocarbon receptor ligands such as TCDD. However, the sensitivity to induction can be restored by protein synthesis inhibition. Previous work revealed that the functionality of the receptor was not affected by passaging. The present work explored the possibility of epigenetic silencing on CYP1A1 inducibility in both rat and human cells. Use of an array of small molecule epigenetic modulators demonstrated that inhibition of histone deacetylases mimicked the effect of protein synthesis inhibition. Consistent with this finding, cycloheximide treatment also reduced histone deacetylase activity. More importantly, when compared to human CYP1A1, rat Cyp1a1 exhibited much greater sensitivity toward epigenetic modulators, particularly inhibitors of histone deacetylases. Other genes in the aryl hydrocarbon receptor domain showed variable and less dramatic responses to histone deacetylase inhibitors. These findings highlight a potential species difference in epigenetics that must be considered when extrapolating results from rodent models to humans and has implications for xenobiotic- or drug-drug interactions where CYP1A1 activity plays an important role.
    Keywords:  Aryl hydrocarbon receptor; Cycloheximide; HDAC inhibitors; Superinduction; TCDD
    DOI:  https://doi.org/10.1016/j.taap.2024.117163
  22. Sci Rep. 2024 11 27. 14(1): 29428
    Proteasome associated function of UCH37 is evolutionarily conserved in Plasmodium parasites.
    Mohsen Hajisadeghian, Annie M Geiger, Carla Briggs, Cameron Smith, Katerina Artavanis Tsakonas.
      Ubiquitin C-terminal hydrolase 37 (UCH37 also known as UCHL5) is a conserved deubiquitinating enzyme (DUB) with dual roles in proteasomal degradation and chromatin remodeling in humans. Its Plasmodium falciparum ortholog, PfUCH37, is unusual in that it possesses both DUB and deneddylating activities. While PfUCH37 is enriched in proteasome preparations, its direct interaction and broader functions in Plasmodium remain unclear, particularly given the absence of the chromatin remodeling complex INO80 homologs. This study utilizes transgenic parasites and proteomics to identify PfUCH37-associating proteins. We confirm a direct interaction with the proteasome and demonstrate that the interaction mechanism is evolutionarily conserved. Notably, we discover a divergence in localization compared to the human enzyme and identify novel interacting partners, suggesting alternative functions for PfUCH37 in Plasmodium. These findings provide insights into the unique biology of this enzyme in malaria parasites, potentially opening avenues for targeted therapeutic interventions.
    DOI:  https://doi.org/10.1038/s41598-024-80433-y
  23. Microorganisms. 2024 Nov 20. pii: 2366. [Epub ahead of print]12(11):
    Recombinant SAG2A Protein from Toxoplasma gondii Modulates Immune Profile and Induces Metabolic Changes Associated with Reduced Tachyzoite Infection in Peritoneal Exudate Cells from Susceptible C57BL/6 Mice.
    Thaíse Anne Rocha Dos Santos, Mário Cézar de Oliveira, Edson Mario de Andrade Silva, Uener Ribeiro Dos Santos, Monaliza Macêdo Ferreira, Ana Luísa Corrêa Soares, Neide Maria Silva, Tiago Antônio de Oliveira Mendes, Jamilly Azevedo Leal-Sena, Jair Pereira da Cunha-Júnior, Tiago Wilson Patriarca Mineo, José Roberto Mineo, Érica Araújo Mendes, Jane Lima-Santos, Carlos Priminho Pirovani.
      Toxoplasmosis is a neglected disease that represents a significant public health problem. The antigenic profile of T. gondii is complex, and the immune response can lead to either susceptibility or resistance. Some antigens, such as surface antigen glycoprotein (SAG), are expressed on the surface of tachyzoite stages and interact with the host immune cells. In this study, we investigated the potential of the recombinant SAG2A protein of T. gondii to control parasitism and modulate the immune response in the peritoneal exudate cells (PECs) of both susceptible (C57BL/6) and resistant (BALB/c) mice using an in vitro infection model, gene expression, proteomic analysis, and bioinformatic tools. Our results showed that rSAG2A-treated PECs presented a lower parasitism in C57BL/6 mice but not in the PECs from BALB/c mice, and induced a pro-inflammatory cytokine profile in C57BL/6 mice (iNOS, TNF-α, and IL-6). rSAG2A modulated different exclusive proteins in each mouse lineage, with PECs from the C57BL/6 mice being more sensitive to modulation by rSAG2A. Additionally, biological processes crucial to parasite survival and immune response were modulated by rSAG2A in the C57BL/6 PECs, including fatty acid beta-oxidation, reactive oxygen species metabolism, interferon production, and cytokine-mediated signaling pathways. Together, our study indicates that rSAG2A controls T. gondii parasitism in susceptible C57BL/6 PECs through the modulation of pro-inflammatory cytokines and enhanced expression of proteins involved in the cytotoxic response.
    Keywords:  Toxoplasma gondii; cytokine; inflammation; macrophages; rSAG2A
    DOI:  https://doi.org/10.3390/microorganisms12112366
  24. Discov Med. 2024 Nov;36(190): 2152-2174
    Regulating Histone Deacetylases and Carbonic Anhydrases by Metal Complexes: A Potent Strategy for Treating Cancers.
    Yen Thi Nguyen, Namdoo Kim, Hyuck Jin Lee.
      Utilizing metal complexes to inhibit histone deacetylases (HDACs) and carbonic anhydrases (CAs) highlights their therapeutic potential, particularly in anticancer strategies. The metal complexes, with their unique three-dimensional structures, fit adequately into the active sites of the enzymes, not only improving selectivity but also providing facile coordination with amino acid residues to enhance their inhibitory ability. This review emphasizes the role of metal complexes in the selective inhibition of HDACs and CAs along with details of their mechanism of action. Additionally, we summarize the inhibition ability and cytotoxicity of metal complexes targeting HDACs and CAs, as well as the therapeutic implications that can lead to the invention and development of metal complexes as potent anticancer agents.
    Keywords:  cancers; carbonic anhydrases; histone deacetylases; metal complexes; metalloenzymes
    DOI:  https://doi.org/10.24976/Discov.Med.202436190.198
  25. bioRxiv. 2024 Nov 21. pii: 2024.11.20.624605. [Epub ahead of print]
    Mechanisms of growth-dependent regulation of the Gin4 kinase.
    Francisco Mendez Diaz, David Sanchez Godinez, Francisco Solano, Akshi Jasani, Maria Alcaide, Douglas R Kellogg.
      Cell cycle progression is dependent upon cell growth. Cells must therefore translate growth into a proportional signal that can be used to determine when there has been sufficient growth for cell cycle progression. In budding yeast, the protein kinase Gin4 is required for normal control of cell growth and undergoes gradual hyperphosphorylation and activation that are dependent upon growth and proportional to the extent of growth, which suggests that Gin4 could function in mechanisms that measure cell growth. However, the molecular mechanisms that drive hyperphosphorylation of Gin4 are poorly understood. Here, we used biochemical reconstitution and genetic analysis to test hypotheses for the mechanisms that drive phosphorylation of Gin4. We ruled out a previous model in which phosphatidylserine delivered to sites of plasma membrane growth binds Gin4 to initiate autophosphorylation. Instead, we show that Elm1, a homolog of the mammalian Lkb1 tumor suppressor kinase, is sufficient to promote hyperphosphorylation of Gin4 in vitro, likely via initiation of Gin4 autophosphorylation. Furthermore, we show that casein kinase I is required for growth-dependent hyperphosphorylation of Gin4 and also for normal regulation of Elm1. Together, these discoveries lead to new insight into mechanisms that link cell cycle progression to cell growth.
    DOI:  https://doi.org/10.1101/2024.11.20.624605
  26. Pharmaceuticals (Basel). 2024 Nov 04. pii: 1480. [Epub ahead of print]17(11):
    Hydrogen Sulfide and Gut Microbiota: Their Synergistic Role in Modulating Sirtuin Activity and Potential Therapeutic Implications for Neurodegenerative Diseases.
    Constantin Munteanu, Gelu Onose, Mădălina Poștaru, Marius Turnea, Mariana Rotariu, Anca Irina Galaction.
      The intricate relationship between hydrogen sulfide (H2S), gut microbiota, and sirtuins (SIRTs) can be seen as a paradigm axis in maintaining cellular homeostasis, modulating oxidative stress, and promoting mitochondrial health, which together play a pivotal role in aging and neurodegenerative diseases. H2S, a gasotransmitter synthesized endogenously and by specific gut microbiota, acts as a potent modulator of mitochondrial function and oxidative stress, protecting against cellular damage. Through sulfate-reducing bacteria, gut microbiota influences systemic H2S levels, creating a link between gut health and metabolic processes. Dysbiosis, or an imbalance in microbial populations, can alter H2S production, impair mitochondrial function, increase oxidative stress, and heighten inflammation, all contributing factors in neurodegenerative diseases such as Alzheimer's and Parkinson's. Sirtuins, particularly SIRT1 and SIRT3, are NAD+-dependent deacetylases that regulate mitochondrial biogenesis, antioxidant defense, and inflammation. H2S enhances sirtuin activity through post-translational modifications, such as sulfhydration, which activate sirtuin pathways essential for mitigating oxidative damage, reducing inflammation, and promoting cellular longevity. SIRT1, for example, deacetylates NF-κB, reducing pro-inflammatory cytokine expression, while SIRT3 modulates key mitochondrial enzymes to improve energy metabolism and detoxify reactive oxygen species (ROS). This synergy between H2S and sirtuins is profoundly influenced by the gut microbiota, which modulates systemic H2S levels and, in turn, impacts sirtuin activation. The gut microbiota-H2S-sirtuin axis is also essential in regulating neuroinflammation, which plays a central role in the pathogenesis of neurodegenerative diseases. Pharmacological interventions, including H2S donors and sirtuin-activating compounds (STACs), promise to improve these pathways synergistically, providing a novel therapeutic approach for neurodegenerative conditions. This suggests that maintaining gut microbiota diversity and promoting optimal H2S levels can have far-reaching effects on brain health.
    Keywords:  gut microbiota; hydrogen sulfide; neurodegenerative diseases; pharmacological intervention; sirtuins
    DOI:  https://doi.org/10.3390/ph17111480
  27. BMC Infect Dis. 2024 Nov 28. 24(1): 1361
    Toxoplasmosis in a case with multiple serous effusions and severe aplastic anemia.
    Xiaoning Wang, Hao Li, Le Ma, Juan Ren, Fatahichegeni Mahsa, Ansarian Mohammad Amin, Jing Zhao, Mei Zhang, Pengcheng He.
      Toxoplasmosis, a parasitic disease, can cause fatal multi-organ failure in immunocompromised patients. The lack of specificity in the symptoms and the need to confirm a diagnosis of tachyzoites in fluids or tissues through microscopic examination leads to a delay in reaching a diagnosis. A 28-year-old woman with severe aplastic anemia received stem cell transplantation seven months ago, presented with fever. Computed Tomography scan and ultrasonography showed moderate pleural, pericardial, peritoneal, and pelvic effusions. Metagenomic next-generation sequencing of blood and alveolar lavage fluid was done, 11,082 and 17,154 sequence readings of Toxoplasma gondii were detected, accounting for 1.34% and 17.09% of genome coverage, respectively. Then, marrow aspirate smears showed Toxoplasma gondii tachyzoites and pseudocyst. This case report alerts clinicians about Toxoplasma gondii infection in stem cell transplantation patients with multiple serous effusions and fever. Clinical trial: Not applicable.
    Keywords:   Toxoplasma gondii ; Multiple serous effusions; Severe aplastic anemia; Stem cell transplantation
    DOI:  https://doi.org/10.1186/s12879-024-10249-8
  28. FASEB J. 2024 Nov 30. 38(22): e70203
    Liver-gut axis signaling regulates circadian energy metabolism in shift workers.
    Zhenning Yang, Helmut Zarbl, Bo Kong, Rulaiha Taylor, Kathleen Black, Howard Kipen, Veronia Basaly, Mingzhu Fang, Grace L Guo.
      Circadian rhythm is critical to maintaining the whole-body metabolic homeostasis of an organism. Chronic disruption of circadian rhythm by shift work is an important risk factor for metabolic diseases. Fibroblast growth factor 15/19 (FGF15/19), a key component in the liver-gut axis, potently suppresses bile acid (BA) synthesis and improves insulin sensitivity. FGF15/19 emerges as a novel pharmaceutical target for prevention and treatment of metabolic diseases. The nicotinamide adenine dinucleotide (NAD+)-dependent sirtuin 1 (SIRT1) deacetylase plays an important role in the maintenance of hepatic homeostasis by linking hepatic metabolism to circadian rhythm. Here, our clinical study identified that circadian rhythmicity and levels of plasma FGF19 and BA profiling, and cellular NAD+-dependent SIRT1 signaling were disturbed in night shift (NS, n = 10) compared to day shift (DS, n = 12) nurses. Our in vitro data showed that recombinant FGF19 protein rescued cellular circadian rhythm disrupted by SIRT1 inhibitors. Furthermore, we determined the effect of FGF15 on circadian rhythm and hepatic metabolism in wild-type (WT), Fgf15 knockout (KO), and Fgf15 transgenic (TG) mice. The expressions of circadian-controlled genes (CCGs) involved in SIRT1 signaling, BA and lipid metabolism, and inflammation were disrupted in Fgf15 KO compared to WT and/or Fgf15 TG mice. Moreover, systemic FGF15 deficiency led to the circadian disturbance of NAD+-dependent SIRT1 signaling and significant reduction during nighttime in mice. These findings suggest that FGF15/19 regulates the circadian energy metabolism, which warrants further studies as a putative prognostic biomarker and pharmaceutical target for preventing against metabolic diseases associated with chronic shift work.
    Keywords:  circadian clock; fibroblast growth factor 15/19 (FGF15/19); shift work; sirtuin 1 (SIRT1)
    DOI:  https://doi.org/10.1096/fj.202402102R
  29. Trends Microbiol. 2024 Nov 28. pii: S0966-842X(24)00281-6. [Epub ahead of print]
    Epigenetic maneuvering: an emerging strategy for mycobacterial intracellular survival.
    Prakruti R Singh, Valakunja Nagaraja.
      Mycobacterium tuberculosis (Mtb) has elaborated numerous mechanisms for its pathogenesis. Mtb manipulates host signaling pathways to interfere with the immune response and cell death pathways. By employing virulence factors - of which secretory proteins are emerging as significant components - it ensures successful survival in the host. In this review, we discuss advances made on the largely unexplored secretory modifiers of Mtb that alter the host epigenome to impact host pathways for the pathogen's advantage. We highlight the findings on the Mtb-encoded modification enzymes and their role in maneuvering the host machinery. We also provide pointers to the gaps that still exist in this area and approaches to address these questions for a better appreciation of the uncanny success of Mtb as an intracellular pathogen.
    Keywords:  Mycobacterium tuberculosis; acetylation; chromatin remodeling; histone modifications; kinases and phosphatases; methylation
    DOI:  https://doi.org/10.1016/j.tim.2024.10.007
  30. Methods. 2024 Nov 23. pii: S1046-2023(24)00246-9. [Epub ahead of print]234 1-9
    In silico identification of Histone Deacetylase inhibitors using Streamlined Masked Transformer-based Pretrained features.
    Tuan Vinh, Thanh-Hoang Nguyen-Vo, Viet-Tuan Le, Xuan-Phuc Phan-Nguyen, Binh P Nguyen.
      Histone Deacetylases (HDACs) are enzymes that regulate gene expression by removing acetyl groups from histones. They are involved in various diseases, including neurodegenerative, cardiovascular, inflammatory, and metabolic disorders, as well as fibrosis in the liver, lungs, and kidneys. Successfully identifying potent HDAC inhibitors may offer a promising approach to treating these diseases. In addition to experimental techniques, researchers have introduced several in silico methods for identifying HDAC inhibitors. However, these existing computer-aided methods have shortcomings in their modeling stages, which limit their applications. In our study, we present a Streamlined Masked Transformer-based Pretrained (SMTP) encoder, which can be used to generate features for downstream tasks. The training process of the SMTP encoder was directed by masked attention-based learning, enhancing the model's generalizability in encoding molecules. The SMTP features were used to develop 11 classification models identifying 11 HDAC isoforms. We trained SMTP, a lightweight encoder, with only 1.9 million molecules, a smaller number than other known molecular encoders, yet its discriminant ability remains competitive. The results revealed that machine learning models developed using the SMTP feature set outperformed those developed using other feature sets in 8 out of 11 classification tasks. Additionally, chemical diversity analysis confirmed the encoder's effectiveness in distinguishing between two classes of molecules.
    Keywords:  Attention; Deep learning; Histone deacetylases; Machine learning; Molecular encoder; Molecular graph; Transformer
    DOI:  https://doi.org/10.1016/j.ymeth.2024.11.009
  31. mSphere. 2024 Nov 29. e0039124
    The Cwr1 protein kinase localizes to the plasma membrane and mediates resistance to cell wall stress in Candida albicans.
    Shamoon Naseem, Jakub Zahumenský, Carla E Lanze, Lois M Douglas, Jan Malínský, James B Konopka.
      The plasma membrane is critical for the virulence of the human fungal pathogen Candida albicans. In addition to functioning as a protective barrier, the plasma membrane plays dynamic roles in a wide range of functions needed for virulence including nutrient uptake, cell wall synthesis, morphogenesis, resistance to stress, and invasive hyphal growth. Screening a collection of C. albicans mutants identified an understudied gene that is important for invasive hyphal growth, which we have termed CWR1 (Cell Wall Regulatory kinase). A mutant strain lacking CWR1 displayed defects in resisting stressful conditions that exacerbate cell wall defects. The Cwr1 protein shows strong similarity to protein kinases, suggesting it plays a regulatory role in coordinating plasma membrane and cell wall functions. A Cwr1-green fluorescent protein (GFP) fusion protein localized to punctate patches associated with the plasma membrane that partially overlapped Membrane Compartment of Can1 (MCC)/eisosome domains. In contrast to the static MCC/eisosome domains, the Cwr1-GFP patches were very dynamic. Truncation mutants lacking C-terminal sequences distal to the protein kinase domain failed to show detectable localization at the plasma membrane. Surprisingly, these mutant strains did not show the defects of a cwr1Δ mutant, suggesting that localization to punctate patches associated with the plasma membrane is not essential for Cwr1 function. Altogether, these data indicate that Cwr1 contributes to the regulation of plasma membrane functions that promote proper morphogenesis and resistance to cell wall stress, both of which are important for C. albicans virulence.
    IMPORTANCE: The ability of Candida albicans to grow invasively in the host and resist stress is critical for it to be an effective human pathogen. Identifying the genes that promote these processes is important for developing new strategies to block infection. Therefore, genetic methods were used in this study to identify a novel gene that is needed for invasive growth and stress resistance (Cell Wall Regulatory kinase [CWR1]). Interestingly, the Cwr1 protein localized to punctate patches in the plasma membrane, some of which co-localized with specialized subdomains of the plasma membrane known as eisosomes that are known to promote stress resistance and invasive growth in the host. Thus, these studies identified a novel regulator of traits that are critical for C. albicans pathogenesis.
    Keywords:  C2_04360W; MCC domain; ORF19.4518; Ypl150w; eisosome; eisosomes; hyphal morphogenesis; stress resistance
    DOI:  https://doi.org/10.1128/msphere.00391-24
  32. Int J Mol Sci. 2024 Nov 16. pii: 12302. [Epub ahead of print]25(22):
    The J Domain Proteins of Plasmodium knowlesi, a Zoonotic Malaria Parasite of Humans.
    Michael O Daniyan, Harpreet Singh, Gregory L Blatch.
      Plasmodium knowlesi is a zoonotic form of human malaria, the pathology of which is poorly understood. While the J domain protein (JDP) family has been extensively studied in Plasmodium falciparum, and shown to contribute to malaria pathology, there is currently very limited information on the P. knowlesi JDPs (PkJDPs). This review provides a critical analysis of the literature and publicly available data on PkJDPs. Interestingly, the P. knowlesi genome encodes at least 31 PkJDPs, with well over half belonging to the most diverse types which contain only the signature J domain (type IIIs, 19) or a corrupted version of the J domain (type IVs, 2) as evidence of their membership. The more typical PkJDPs containing other domains typical of JDPs in addition to the J domain are much fewer in number (type IIs, 8; type Is, 2). This study indentifies PkJDPs that are potentially involved in: folding of newly synthesized or misfolded proteins within the P. knowlesi cytosol (a canonical type I and certain typical type IIs); protein translocation (a type III) and folding (a type II) in the ER; and protein import into mitochondria (a type III). Interestingly, a type II PkJDP is potentially exported to the host cell cytosol where it may recruit human HSP70 for the trafficking and folding of other exported P. knowlesi proteins. Experimental studies are required on this fascinating family of proteins, not only to validate their role in the pathology of knowlesi malaria, but also because they represent potential anti-malarial drug targets.
    Keywords:  HSP40; HSP70; HSP90; J domain protein; Plasmodium knowlesi; heat shock proteins; molecular chaperones; protein folding; zoonotic malaria
    DOI:  https://doi.org/10.3390/ijms252212302
  33. Nutrients. 2024 Nov 09. pii: 3843. [Epub ahead of print]16(22):
    Cannabidiol Enhances Mitochondrial Metabolism and Antioxidant Defenses in Human Intestinal Epithelial Caco-2 Cells.
    Alejandro Bravo Iniguez, Qi Sun, Qiaorong Cui, Min Du, Mei-Jun Zhu.
       BACKGROUND: The reintroduction of hemp production has resulted in increased consumption of cannabidiol (CBD) products, particularly CBD oil, yet their effects on intestinal health are not fully understood. Proper mitochondrial function and antioxidant defenses are vital for maintaining the intestinal epithelial barrier. AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator (PGC)1α are key mediators of mitochondrial metabolism.
    METHODS & RESULTS: Using Caco-2 cells, we found that CBD oil promoted AMPK phosphorylation, upregulated differentiation markers, and enhanced PGC1α/SIRT3 mitochondrial signaling. CBD oil reduced reactive oxygen species production and increased antioxidant enzymes. Moreover, CBD oil also increased levels of citrate, malate, and succinate-key metabolites of the tricarboxylic acid cycle-alongside upregulation of pyruvate dehydrogenase and isocitrate dehydrogenase 1. Similarly, pure CBD induced metabolic and antioxidant signaling.
    CONCLUSIONS: CBD enhances mitochondrial metabolic activity and antioxidant defense in Caco-2 cells, making it a promising candidate for treating intestinal dysfunction.
    Keywords:  AMPK; antioxidant activity; cannabidiol; intestinal epithelium; mitochondria
    DOI:  https://doi.org/10.3390/nu16223843
  34. Cells. 2024 Nov 08. pii: 1850. [Epub ahead of print]13(22):
    DNA Methylation and Histone Acetylation Contribute to the Maintenance of LTP in the Withdrawal Behavior Interneurons in Terrestrial Snails.
    Alena Zuzina, Daria Kolotova, Pavel Balaban.
      Accumulated data indicate that epigenetic regulations, including histone modifications and DNA methylation, are important means for adjusting the expression of genes in response to various stimuli. In contrast to the success in studying the role of DNA methylation in laboratory rodents, the role of DNA methylation in the terrestrial snail Helix lucorum has been studied only in behavioral experiments. This prompted us to further investigate the role of DNA methylation and the interaction between DNA methylation and histone acetylation in the mechanisms of neuroplasticity in terrestrial snails using in vitro experiments. Dysregulation of DNA methylation by the DNMT inhibitor RG108 significantly suppressed the long-term potentiation (LTP) of synaptic inputs in identified neurons. We then tested whether the RG108-induced weakening of potentiation can be reversed under co-application of histone deacetylase inhibitors sodium butyrate or trichostatin A. It was found that increased histone acetylation significantly compensated for RG108-induced LTP deficiency. These data bring important insights into the functional role of DNA methylation as an important regulatory mechanism and a necessary condition for the development and maintenance of long-term synaptic changes in withdrawal interneurons of terrestrial snails. Moreover, these results support the idea of the interaction of DNA methylation and histone acetylation in the epigenetic regulation of synaptic plasticity.
    Keywords:  DNA methylation/demethylation; epigenetics; gastropods; histone acetylation; synaptic plasticity
    DOI:  https://doi.org/10.3390/cells13221850
  35. Nat Commun. 2024 Nov 26. 15(1): 10235
    New-to-nature CO2-dependent acetyl-CoA assimilation enabled by an engineered B12-dependent acyl-CoA mutase.
    Helena Schulz-Mirbach, Philipp Wichmann, Ari Satanowski, Helen Meusel, Tong Wu, Maren Nattermann, Simon Burgener, Nicole Paczia, Arren Bar-Even, Tobias J Erb.
      Acetyl-CoA is a key metabolic intermediate and the product of various natural and synthetic one-carbon (C1) assimilation pathways. While an efficient conversion of acetyl-CoA into other central metabolites, such as pyruvate, is imperative for high biomass yields, available aerobic pathways typically release previously fixed carbon in the form of CO2. To overcome this loss of carbon, we develop a new-to-nature pathway, the Lcm module, in this study. The Lcm module provides a direct link between acetyl-CoA and pyruvate, is shorter than any other oxygen-tolerant route and notably fixes CO2, instead of releasing it. The Lcm module relies on the new-to-nature activity of a coenzyme B12-dependent mutase for the conversion of 3-hydroxypropionyl-CoA into lactyl-CoA. We demonstrate Lcm activity of the scaffold enzyme 2-hydroxyisobutyryl-CoA mutase from Bacillus massiliosenegalensis, and further improve catalytic efficiency 10-fold by combining in vivo targeted hypermutation and adaptive evolution in an engineered Escherichia coli selection strain. Finally, in a proof-of-principle, we demonstrate the complete Lcm module in vitro. Overall, our work demonstrates a synthetic CO2-incorporating acetyl-CoA assimilation route that expands the metabolic solution space of central carbon metabolism, providing options for synthetic biology and metabolic engineering.
    DOI:  https://doi.org/10.1038/s41467-024-53762-9
  36. Int J Biol Macromol. 2024 Nov 22. pii: S0141-8130(24)08802-0. [Epub ahead of print] 137991
    Treponema Pallidum protein Tp47 triggers macrophage inflammatory senescence via PKM2-mediated metabolic reprogramming.
    Jia-Wen Xie, Yin-Feng Guo, Shu-Hao Fan, Ying Zheng, Hui-Lin Zhang, Yan Zhang, Yi Zhang, Li-Rong Lin.
      Syphilis is a sexually transmitted disease caused by Treponema pallidum. The mechanisms enabling T. pallidum to persist despite macrophage eradication efforts in syphilis remain unclear. Pathogens can exploit senescent cells to enhance host susceptibility, and cellular senescence can be induced by pyroptosis, which known as inflammatory senescence. While recent studies have linked metabolic reprogramming to inflammatory senescence, their role in syphilis remained to be clarified. This study investigated the mechanisms of Tp47 on metabolic reprogramming and inflammatory senescence in macrophages. The results demonstrated that Tp47 triggered NLRP3 inflammasome-mediated pyroptosis by activating the phosphorylation of EIF2AK2 (a protein kinase), increasing senescence-associated pro-inflammatory cytokines secretion and leading to inflammatory senescence in macrophages. Additionally, Tp47 competitively bound to pyruvate kinase M2 (PKM2) with STUB1(a ubiquitin ligase), thereby inhibiting PKM2 ubiquitination degradation. By promoting the Y105 phosphorylation of PKM2, Tp47 modulated the intracellular function of PKM2, and facilitated PKM2-mediated metabolic reprogramming, which produced lactate that subsequently led to EIF2AK2 phosphorylation. Furthermore, inhibitors targeting EIF2AK2, lactate, glycolysis, and PKM2 effectively suppressed the inflammatory senescence induced by Tp47. In conclusion, Tp47 could mediate immune metabolic reprogramming through interaction with PKM2 to trigger macrophage inflammatory senescence. These discoveries offer a novel perspective for targeted therapies against syphilis.
    Keywords:  Inflammatory senescence; Metabolic reprogramming; Syphilis
    DOI:  https://doi.org/10.1016/j.ijbiomac.2024.137991
  37. J Transl Med. 2024 Nov 28. 22(1): 1081
    Clinical trial landscape for histone deacetylation inhibitors in breast cancer: a dawn in the darkness?
    Jiajun Li, Yining Yan, Feng Chen.
      
    DOI:  https://doi.org/10.1186/s12967-024-05911-3
  38. J Neuroinflammation. 2024 Nov 28. 21(1): 308
    Lactate metabolism and histone lactylation in the central nervous system disorders: impacts and molecular mechanisms.
    Yao Wang, Ping Li, Yuan Xu, Linyu Feng, Yongkang Fang, Guini Song, Li Xu, Zhou Zhu, Wei Wang, Qi Mei, Minjie Xie.
      Brain takes up approximately 20% of the total body oxygen and glucose consumption due to its relatively high energy demand. Glucose is one of the major sources to generate ATP, the process of which can be realized via glycolysis, oxidative phosphorylation, pentose phosphate pathways and others. Lactate serves as a hub molecule amid these metabolic pathways, as it may function as product of glycolysis, substrate of a variety of enzymes and signal molecule. Thus, the roles of lactate in central nervous system (CNS) diseases need to be comprehensively elucidated. Histone lactylation is a novel lactate-dependent epigenetic modification that plays an important role in immune regulation and maintaining homeostasis. However, there's still a lack of studies unveiling the functions of histone lactylation in the CNS. In this review, we first comprehensively reviewed the roles lactate plays in the CNS under both physiological and pathological conditions. Subsequently, we've further discussed the functions of histone lactylation in various neurological diseases. Furthermore, future perspectives regarding histone lactylation and its therapeutic potentials in stroke are also elucidated, which may possess potential clinical applications.
    Keywords:  CNS diseases; Histone lactylation; Inflammation; Lactate
    DOI:  https://doi.org/10.1186/s12974-024-03303-4
  39. Pharmaceuticals (Basel). 2024 Nov 07. pii: 1495. [Epub ahead of print]17(11):
    From Microcirculation to Aging-Related Diseases: A Focus on Endothelial SIRT1.
    Martin Law, Pei-Chun Wang, Zhong-Yan Zhou, Yu Wang.
      Silent information regulator sirtuin 1 (SIRT1) is an NAD+-dependent deacetylase with potent anti-arterial aging activities. Its protective function in aging-related diseases has been extensively studied. In the microcirculation, SIRT1 plays a crucial role in preventing microcirculatory endothelial senescence by suppressing inflammation and oxidative stress while promoting mitochondrial function and optimizing autophagy. It suppresses hypoxia-inducible factor-1α (HIF-1α)-mediated pathological angiogenesis while promoting healthy, physiological capillarization. As a result, SIRT1 protects against microvascular dysfunction, such as diabetic microangiopathy, while enhancing exercise-induced skeletal muscle capillarization and energy metabolism. In the brain, SIRT1 upregulates tight junction proteins and strengthens their interactions, thus maintaining the integrity of the blood-brain barrier. The present review summarizes recent findings on the regulation of microvascular function by SIRT1, the underlying mechanisms, and various approaches to modulate SIRT1 activity in microcirculation. The importance of SIRT1 as a molecular target in aging-related diseases, such as diabetic retinopathy and stroke, is underscored, along with the need for more clinical evidence to support SIRT1 modulation in the microcirculation.
    Keywords:  angiogenesis; artery aging; capillarization; endothelium; microcirculation
    DOI:  https://doi.org/10.3390/ph17111495
  40. J Inherit Metab Dis. 2024 Nov 24.
    My path to citrin deficiency.
    John E Walker.
      Citrin belongs to the SLC25 transport protein family found mostly in inner mitochondrial membranes. The family prototype, the ADP-ATP carrier, delivers ATP made inside mitochondria to the cellular cytoplasm and returns ADP to the mitochondrion for resynthesis of ATP. In pre-genomic 1981, I noticed that the protein sequence of the bovine ADP-ATP carrier consists of three related sequences, each containing two transmembrane α-helices traveling in opposite senses. Colleagues and I demonstrated that two other mitochondrial carriers had similar features. From emergent genomic sequences, it became apparent that they represented a large family of transport proteins with the same characteristic threefold repeats. The human genome encodes 53 members, but the functions of many were unknown. So, colleagues and I determined how to make these proteins in Escherichia coli and introduce them into liposomes to allow exploration of their transport functions. The 27 human family members to have been thus identified include citrin and the closely related protein aralar. Both exchange aspartate from the mitochondrial matrix for cytosolic glutamate plus a proton. Citrin is expressed predominantly in liver and non-excitable tissues, whereas aralar is the dominant form in the brain. Each has a membrane extrinsic N-terminal Ca2+-binding domain, a transport domain, and a C-terminal amphipathic α-helix. Human mutations in citrin impair the urea cycle, malate-aspartate shuttle, gluconeogenesis, amino acid breakdown, and energy metabolism leading to citrin deficiency. Currently, the complex etiology of this condition is poorly understood and new knowledge would help to improve diagnosis, therapies, and finding a cure. My aims are to seek a basic understanding of the etiology of citrin deficiency and to use that knowledge in improving diagnostic procedures and in developing new treatments and a cure.
    Keywords:  citrin deficiency; cure; diagnosis; mitochondria; treatment; urea cycle
    DOI:  https://doi.org/10.1002/jimd.12818
  41. Microbiol Res. 2024 Nov 26. pii: S0944-5013(24)00384-7. [Epub ahead of print]291 127983
    Structural insights into the advancements of mobile colistin resistance enzymes.
    Qi Zhang.
      The plasmid-encoded mobile colistin resistance enzyme (MCR) is challenging the clinical efficacy of colistin as a last-resort antibiotic against multidrug-resistant bacteria. This transferase catalyzes the addition of positively charged phosphoethanolamine to lipid A, and its catalytic domain in the periplasm has been elucidated. To date, there are many works on the catalytic domain and function of this enzyme class. However, the roles of unreported soluble or inter-membrane domains remain undefined, which might cause an inaccurate or even incorrect understanding of substrate recognition and binding. In this review, MCR-1 is first compared and analyzed from the perspective of the full-length alpha-fold MCR-1. Specifically, some disputed issues, especially in its architecture and catalytic mechanism are discussed independently. Meanwhile, the structure-based insights into MCRs variants, their evolutions, and the balance between colistin-resistance and survival costs, are also critically analyzed. Importantly, by comparing it with the full-length MCR-1, several potential pockets for drug design have been re-identified. Finally, recent advancements in inhibitors targeting MCR-1 are also in-depth summarized. These details offer a new perspective on MCRs and serve as a valuable foundation for drug development.
    Keywords:  Antimicrobial resistance; Colistin; Inhibitor development; MCRs; Structure
    DOI:  https://doi.org/10.1016/j.micres.2024.127983
  42. Int J Biol Macromol. 2024 Nov 25. pii: S0141-8130(24)08727-0. [Epub ahead of print] 137917
    Identification of new inhibitors of Plasmodium falciparum hypoxanthine-guanine-xanthine Phosphoribosyltransferase (HG(X)PRT): An outlook towards the treatment of malaria.
    Laleen Hammal, Sumaira Javaid, Atia-Tul Wahab, Humaira Zafar, Noor Rahman, Aftab Ahmed, M Iqbal Choudhary.
      Plasmodium, a protozoan parasite responsible for causing malaria relies on the purine salvage pathway to synthesize purine as they are incapable of synthesizing them de novo. This pathway is crucial for the survival of the parasite and hence enzymes of this pathway can serve as antimalarial drug targets. One of the enzymes of this pathway is hypoxanthine guanine (xanthine) phosphoribosyltransferase [HG(X)PRT] that serves as novel target, potentially less prone to existing resistance mechanisms seen with the use of traditional antimalarial drugs. HGXPRT inhibition disrupts the parasite's ability to synthesize nucleotides, essential for its growth and replication. In this regard, the current study was designed to identify the inhibitors of HGXPRT. For this purpose, the enzyme was produced through recombinant technology and purified with 10 mg/ L yield. Followed this, UV-based enzyme inhibition assay was optimized and >200 fully characterized compounds were evaluated for their HGXPRT inhibitory activity. Out of them fourteen compounds 1-14 showed significant to weak inhibition of HGXPRT enzyme with IC50 values in the range of 15.7 to 229.6 μM, as compared to the standard inhibitor i.e. 9-deazaguanine (IC50 = 12 ± 1.0 μM). In- silico and biophysical studies were further performed on active compounds to get structural insights into enzyme-inhibitor complex at the atomic level. Docking studies predicted that these inhibitors accommodate the purine binding site of enzyme and interacted with critical residues such as Asp148, Phe197, and Val198. Biophysical studies showed that these identified inhibitors interacted with HGXPRT enzyme in a non-ambiguous manner. Furthermore, these inhibitors were found to be non-cytotoxic against human fibroblast cell lines (BJ). Hence, this study identified 14 hits that could lead to further research towards anti-malarial drug design and development.
    Keywords:  Anti-malarial agents; HGXPRT; Plasmodium falciparam; Purine salvage pathway; STD-NMR
    DOI:  https://doi.org/10.1016/j.ijbiomac.2024.137917
  43. bioRxiv. 2024 Nov 23. pii: 2024.11.22.624728. [Epub ahead of print]
    Arginyltransferase1 drives a mitochondria-dependent program to induce cell death.
    Akhilesh Kumar, Corin R O'Shea, Vikas K Yadav, Ganapathi Kandasamy, Balaji T Moorthy, Evan A Ambrose, Aliya Mulati, Flavia Fontanesi, Fangliang Zhang.
      Cell death regulation is essential for stress adaptation and/or signal response. Past studies have shown that eukaryotic cell death is mediated by an evolutionarily conserved enzyme, arginyltransferase1 (Ate1). The downregulation of Ate1, as seen in many types of cancer, prominently increases cellular tolerance to a variety of stressing conditions. Conversely, in yeast and mammalian cells, Ate1 is elevated under acute oxidative stress conditions and this change appears to be essential for triggering cell death. However, studies of Ate1 were conventionally focused on its function in inducing protein degradation via the N-end rule pathway in the cytosol, leading to an incomplete understanding of the role of Ate1 in cell death. Our recent investigation shows that Ate1 dually exists in the cytosol and mitochondria, the latter of which has an established role in cell death initiation. Here, by using budding yeast as a model organism, we found that mitochondrial translocation of Ate1 is promoted by the presence of oxidative stressors and is essential for inducing cell death with characteristics of apoptosis. Also, we found that Ate1-induced cell death is dependent on the formation of the mitochondrial permeability pore and at least partly dependent on the action of mitochondria-contained factors including the apoptosis-inducing factor, but is not directly dependent on mitochondrial electron transport chain activity or its derived reactive oxygen species (ROS). Furthermore, our evidence suggests that, contrary to widespread assumptions, the cytosolic protein degradation pathways including ubiquitin-proteasome, autophagy, or endoplasmic reticulum (ER) stress response has little or negligible impacts on Ate1-induced cell death. We conclude that Ate1 controls the mitochondria-dependent cell death pathway.
    DOI:  https://doi.org/10.1101/2024.11.22.624728
  44. Commun Biol. 2024 Nov 26. 7(1): 1576
    Metabolomics and 13C labelled glucose tracing to identify carbon incorporation into aberrant cell membrane glycans in cancer.
    Alfredo Reyes-Oliveras, Abigail E Ellis, Ryan D Sheldon, Brian Haab.
      Cell membrane glycans contribute to immune recognition, signaling, and cellular adhesion and migration, and altered membrane glycosylation is a feature of cancer cells that contributes to cancer progression. The uptake and metabolism of glucose and other nutrients essential for glycan synthesis could underlie altered membrane glycosylation, but the relationship between shifts in nutrient metabolism and the effects on glycans have not been directly examined. We developed a method that combines stable isotope tracing with metabolomics to enable direct observations of glucose allocation to nucleotide sugars and cell-membrane glycans. We compared the glucose allocation to membrane glycans of two pancreatic cancer cell lines that are genetically identical but have differing energy requirements. The 8988-S cells had higher glucose allocation to membrane glycans and intracellular pathways relating to glycan synthesis, but the 8988-T cells had higher glucose uptake and commitment of glucose to non-glycosylation pathways. The cell lines differed in the requirements of glucose for energy production, resulting in differences in glucose bioavailability for glycan synthesis. The workflow demonstrated here enables studies on the effects of metabolic shifts on the commitment of nutrients to cell-membrane glycans. The results suggest that cell-membrane glycans are remodeled through shifts in glucose commitment to non-glycosylation pathways.
    DOI:  https://doi.org/10.1038/s42003-024-07277-0
  45. Cell Commun Signal. 2024 Nov 25. 22(1): 564
    N-acetylaspartate mitigates pro-inflammatory responses in microglial cells by intersecting lipid metabolism and acetylation processes.
    Federica Felice, Pamela De Falco, Martina Milani, Serena Castelli, Antonella Ragnini-Wilson, Giacomo Lazzarino, Nadia D'Ambrosi, Fabio Ciccarone, Maria Rosa Ciriolo.
       BACKGROUND: Microglia play a crucial role in brain development and repair by facilitating processes such as synaptic pruning and debris clearance. They can be activated in response to various stimuli, leading to either pro-inflammatory or anti-inflammatory responses associated with specific metabolic alterations. The imbalances between microglia activation states contribute to chronic neuroinflammation, a hallmark of neurodegenerative diseases. N-acetylaspartate (NAA) is a brain metabolite predominantly produced by neurons and is crucial for central nervous system health. Alterations in NAA metabolism are observed in disorders such as Multiple Sclerosis and Canavan disease. While NAA's role in oligodendrocytes and astrocytes has been investigated, its impact on microglial function remains less understood.
    METHODS: The murine BV2 microglial cell line and primary microglia were used as experimental models. Cells were treated with exogenous NAA and stimulated with LPS/IFN-γ to reproduce the pro-inflammatory phenomenon. HPLC and immunofluorescence analysis were used to study lipid metabolism following NAA treatment. Automated fluorescence microscopy was used to analyze phagocytic activity. The effects on the pro-inflammatory response were evaluated by analysis of protein/mRNA expression and ChIP assay of typical inflammatory markers.
    RESULTS: NAA treatment promotes an increase in both lipid synthesis and degradation, and enhances the phagocytic activity of BV2 cells, thus fostering surveillant microglia characteristics. Importantly, NAA decreases the pro-inflammatory state induced by LPS/IFN-γ via the activation of histone deacetylases (HDACs). These findings were validated in primary microglial cells, highlighting the impact on cellular metabolism and inflammatory responses.
    CONCLUSIONS: The study highlighted the role of NAA in reinforcing the oxidative metabolism of surveillant microglial cells and, most importantly, in buffering the inflammatory processes characterizing reactive microglia. These results suggest that the decreased levels of NAA observed in neurodegenerative disorders can contribute to chronic neuroinflammation.
    Keywords:  Anti-inflammatory response; Histone deacetylases; Lipid turnover; Microglial polarization; NAA; Oxidative metabolism
    DOI:  https://doi.org/10.1186/s12964-024-01947-6
  46. Redox Rep. 2024 Dec;29(1): 2430157
    Fluorescent probes for sensing peroxynitrite: biological applications.
    Yan Yang, Jinting Shang, Yiyuan Xia, Yuran Gui.
      Peroxynitrite (ONOO-) is a quintessential reactive oxygen species (ROS) and reactive nitrogen species (RNS), renowned for its potent oxidizing and nitrifying capabilities. Under normal physiological conditions, a baseline level of ONOO- is present within the body. However, its production escalates significantly in response to oxidative stress. ONOO- is highly reactive with various biomolecules in vivo, particularly proteins, lipids, and nucleic acids, thereby playing a role in a spectrum of physiological and pathological processes, such as inflammation, cancer, neurodegenerative diseases, and cardiovascular diseases. Consequently, detecting ONOO- in vivo is of paramount importance for understanding the etiology of various diseases and facilitating early diagnosis. Fluorescent probes have become a staple in the identification of biomolecules due to their ease of use, convenience, and superior sensitivity and specificity. This review highlights the recent advancements in the development of fluorescent probes for the detection of ONOO- in diverse disease models and provides an in-depth examination of their design and application.
    Keywords:  Peroxynitrite; animal imaging; bio-application; bio-imaging; biocompatibility; cellular imaging; fluorescent probe; reactive oxygen species
    DOI:  https://doi.org/10.1080/13510002.2024.2430157
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