bims-toxgon 2025-03-16 papers

bims-toxgon

Biomed News

on Toxoplasma gondii metabolism

Issue of 2025–03–16
thirty-one papers selected by
Lakesh Kumar, BITS Pilani

mSphere of Influence: Toxoplasma gondii tissue cysts-who are you calling dormant?
Toxoplasma survives the loss of key enzymes of peroxide and glutathione metabolism.
Finding the brakes on the Toxoplasma life cycle.
N-Glycoproteomics of the Apicomplexan Parasite Toxoplasma gondii.
Bacillus subtilis spores displaying Toxoplasma gondii GRA12 induce immunity against acute toxoplasmosis.
SARM regulates cell apoptosis and inflammation during Toxoplasma gondii infection through a multistep mechanism.
Involvement of Toxoplasma gondii natural antisense transcripts in cellular stress responses.
Assessing the Therapeutic Potential of Silicon Dioxide Nanoparticles in Acute and Chronic Toxoplasmosis in BALB/c mice.
Role of Protein Lysine Acetylation in the Pathogenesis and Treatment of Obesity and Metabolic Syndrome.
Class I histone deacetylases catalyze lysine lactylation.
Anticancer efficacy of Spiruchostatin A: current insights into histone deacetylase inhibition and oncologic applications.
SIRT2 Regulates Apoptosis Signaling in Hyperoxic Acute Lung Injury.
Parasite evolution: Coral-infecting apicomplexans disrupt our understanding of the pathways to parasitism.
Mitochondrial ACSS1-K635 acetylation knock-in mice exhibit altered liver lipid metabolism on a ketogenic diet.
An enzyme-linked immunosorbent assay (ELISA)-based activity assay for AMP-activated protein kinase (AMPK).
Endogenous structure of antimalarial target Pf ATP4 reveals new class of apicomplexan P-type ATPase modulators.
Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization.
Characterization of substrate distribution and functional implication of lysine acylations in Staphylococcus aureus.
PARASITOPHYSIOART: EXPLORING THE INTERSECTION OF ART, PHYSIOLOGY, AND PARASITOLOGY ON STUDENTS´ PERCEPTION AND MOTIVATION.
Phosphorylation-driven regulation of SIRT1 in muscle senescence: Insights from molecular dynamics simulation and experimental validation.
Monoselective Histone Deacetylase 6 PROTAC Degrader Shows In Vivo Tractability.
Acetylation: a new target for protein degradation in cancer.
Inhibitors of Type II NADH Dehydrogenase Enzyme: A Review.
Electron Microscopy to Visualize and Quantify Mitochondrial Structure and Organellar Interactions in Cultured Cells During Senescence.
HDAC11 in ovarian granulosa cells coordinates LH in the maturation of oocytes in Tan sheep.
Structure and mechanism of the plastid/parasite ATP/ADP translocator.
Sirt3 Rescues Porphyromonas gingivalis-Impaired Cementogenesis via SOD2 Deacetylation.
Mitochondrial fatty acid oxidation regulates adult muscle stem cell function through modulating metabolic flux and protein acetylation.
SENP1-SIRT3 axis mediates glycolytic reprogramming to suppress inflammation during Listeria monocytogenes infection.
The role of protein lactylation: A kaleidoscopic post-translational modification in cancer.
Crystal structure of the S-adenosylmethionine-dependent mycolic acid synthase UmaA from Mycobacterium tuberculosis.

mSphere. 2025 Mar 12. e0002825

mSphere of Influence: Toxoplasma gondii tissue cysts-who are you calling dormant?

Robyn S Kent.

  Robyn Kent studies how Toxoplasma gondii chronic infections can persist in different tissues in the host and how latency is controlled to enable maintenance, transmission, and reactivation of the parasite. In this mSphere of Influence article, she reflects on how two papers from the laboratories of Dr. A. P. Sinai and Dr. L. D. Sibley have impacted her thinking on the chronic stage of T. gondii infections.

Keywords:  Toxoplasma gondii; apicomplexa; latency; parasitology

DOI:  https://doi.org/10.1128/msphere.00028-25
FASEB J. 2025 Mar 15. 39(5): e70416

Toxoplasma survives the loss of key enzymes of peroxide and glutathione metabolism.

Qinghong Guo, Jiajia Pan, Xuefang Guo, Meng Zhao, Huiyu Du, Mengting Wang, Marcel Deponte, Xinhua Zhong, Lihua Xiao, Yaoyu Feng, Ningbo Xia.

  Toxoplasma gondii is an obligate intracellular protozoan parasite that replicates rapidly in a variety of host cells. The parasite encodes diverse enzymes of glutathione and peroxide metabolism, but their physiological roles remain poorly understood. Herein, we shed a new perspective on the functions and relevance of the peroxiredoxin and glutathione metabolism in the zoonotic pathogen T. gondii. We show that two cytosolic peroxidases (TgPRX1, TgPRX2), a mitochondrial peroxiredoxin (TgPRX3), and the cytosolic glutathione reductase (TgGR2), glutamate-cysteine ligase (TgGCL), and glutathione synthetase (TgGS) are not required for the lytic cycle of T. gondii under standard growth conditions. However, mutants lacking the gene for either TgPRX1 or TgGR2 exhibited increased susceptibility to exogenous hydrogen peroxide compared to wild-type parasites. Furthermore, we found that the combined deletion of TgPRX1 and TgPRX2 led to a notable impairment of parasite growth, suggesting a functional redundancy between the two peroxidases. Finally, our results show that the apicoplast glutathione reductase (TgGR1) is required for normal parasite growth in vitro and in vivo but is not essential for parasite survival. Our findings highlight that the redox metabolism of Toxoplasma is surprisingly robust and flexible, allowing the parasite to survive under the loss of several key enzymes of peroxide and glutathione metabolism.

Keywords:  apicomplexan parasites; glutamate‐cysteine ligase; glutathione reductase; glutathione synthetase; peroxidases

DOI:  https://doi.org/10.1096/fj.202402341R
Trends Parasitol. 2025 Mar 07. pii: S1471-4922(25)00045-5. [Epub ahead of print]

Finding the brakes on the Toxoplasma life cycle.

Alice L Herneisen, Sebastian Lourido.

  Toxoplasma gondii motility is an all-or-nothing response. Claywell et al. identify negative-feedback loops in cyclic-nucleotide signaling that allow parasites to turn off motility and commit to intracellular replication. Feedback mechanisms and bistability are useful frameworks for describing, modeling, and testing T. gondii motility signaling pathways.

Keywords:  Toxoplasma; cyclic nucleotide; feedback loop; kinase

DOI:  https://doi.org/10.1016/j.pt.2025.02.010
Proteomics. 2025 Mar 12. e202400239

N-Glycoproteomics of the Apicomplexan Parasite Toxoplasma gondii.

Vanessa Horn, Patricia Zarnovican, Birgit Tiemann, Andreas Pich, Hans Bakker, Françoise H Routier.

  Protein N-glycosylation influences protein folding, stability, and trafficking, and has prominent functions in cell-cell adhesion and recognition. For the parasite Toxoplasma gondii, N-glycosylation of proteins is crucial for initial adhesion to host cells, parasite motility, and consequently, its ability to invade host cells. However, the glycoproteome of T. gondii remains largely unknown. In this study, we used the α-mannose-specific Burkholderia cenocepacia lectin A (BC2L-A) to enrich glycopeptides from T. gondii tachyzoites and analysed them by tandem mass spectrometry. The data enable the identification of over 100 N-glycoproteins with the glycosylation site(s) and the composition of the N-glycans at each site. T. gondii glycoproteins include known virulence factors, vaccine candidates as well as numerous uncharacterised proteins. These data provide ground knowledge to deepen our understanding of the role of glycoproteins in invasion and assist the rational design of vaccines.

Keywords:  BC2L‐A lectin; N‐glycosylation; apicomplexa; parasite

DOI:  https://doi.org/10.1002/pmic.202400239
Front Immunol. 2025 ;16 1457560

Bacillus subtilis spores displaying Toxoplasma gondii GRA12 induce immunity against acute toxoplasmosis.

Hong-Chao Sun, Xiu-Fang Yuan, Wei Zhou, Zhi-Jin Zhou, Fei Su, Yuan Fu, Li-Li Hao, Xin Liu, Xin Zhou, Shi-Yi Ye, Li-Hua Xu, Bin Yu, Jun-Xing Li, Tuan-Yuan Shi.

   Background: Toxoplasma gondii (T. gondii) is a widely prevalent intracellular parasite that infects almost all warm-blooded animals and causes serious public health problems. The drugs currently used to treat toxoplasmosis have the disadvantage of being toxic and prone to the development of resistance, and the only licensed vaccine entails a risk of virulence restoration. The development of a safe and effective vaccine against T. gondii is urgently needed. Bacillus subtilis (B. subtilis) has been used as a potential vaccine expression vector for the treatment and prevention of various diseases. T. gondii GRA12 is a key virulence factor that resists host innate immunity and exhibits good antigenicity with several excellent B and T cell epitopes.
Methods: A recombinant spore named rBS-GRA12 was constructed by fusing the T. gondii GRA12 protein to the B. subtilis coat protein B (CotB). rBS-GRA12 spores were identified by PCR, western blotting, immunofluorescence assays, amylase activity, and ultrastructural analysis. Immunological experiments were then conducted to assess the immunoprotective effects of rBS-GRA12. Groups of mice immunized with rBS-GRA12 (106, 108, or 1010 colony-forming units), GRA12 protein emulsified with Freund's adjuvant (FA+GRA12), Freund's adjuvant alone (FA), phosphate buffered saline (PBS), or wild-type B. subtilis spores (WT). Splenocyte proliferation, antibodies, and cytokine expression levels were used to assess immune responses induced by the immunizations. All groups were inoculated with T. gondii RH strain, and survival times and parasite loads in tissues were used to assess protective effects against T. gondii infection.
Results: Amylase activity assays confirmed the generation of recombinant B. subtilis. PCR, western blotting and immunofluorescence assays confirmed that the rBS-GRA12 spores expressed GRA12. Observation of rBS-GRA12 spores via transmission and scanning electron microscopy indicated that GRA12 expression had no effect on spore morphology or structure. Splenocyte proliferation was significantly greater in all three rBS-GRA12 groups than in the FA+GRA12 group, and IgG and IgG2a subclass titers were higher. Substantial production of interferon gamma (IFN-γ), interleukin (IL)-12, and an increase in IL-4 production were evident in the rBS-GRA12-108 group. Secretory sIgA levels were significantly elevated in all three rBS-GRA12 groups than in the FA+GRA12 group and the control groups. Brain and liver tissues parasite loads were significantly lower in the three rBS-GRA12 groups than in any other group. Compared to all other groups, mice in the three rBS-GRA12 groups exhibited longer survival times when challenged with acute T. gondii infection.
Conclusion: Mice immunized with rBS-GRA12 exhibited higher levels of cellular, humoral, and mucosal immune responses than control mice. These results provide a new perspective for the development of T. gondii vaccines.

Keywords:  Bacillus subtilis; GRA12; protective efficacy; toxoplasmosis; vaccine

DOI:  https://doi.org/10.3389/fimmu.2025.1457560
Parasit Vectors. 2025 Mar 12. 18(1): 103

SARM regulates cell apoptosis and inflammation during Toxoplasma gondii infection through a multistep mechanism.

Shumin Gao, Min Gao, Huanhui Du, Lingyu Li, Xudian An, Yongyu Shi, Xiaoyan Wang, Hua Cong, Bing Han, Chunxue Zhou, Huaiyu Zhou.

   BACKGROUND: The sterile alpha and HEAT/Armadillo motif (SARM) is the fifth Toll-like receptor (TLR) adaptor protein containing the Toll/interleukin-1 receptor (TIR) domain, which is highly enriched in the brain. Toxoplasma gondii (T. gondii) is an obligate intracellular parasitic protozoan that causes zoonotic toxoplasmosis, resulting in threats to human health, such as brain damage. Previous studies have shown that SARM plays crucial roles in cell death and triggers specific transcription programs of innate immunity in response to cell stress, viral, and bacterial infections. However, whether SARM is involved in T. gondii infection remains unclear.
METHODS: In this report, quantitative real-time polymerase chain reaction (qPCR), western blot, flow cytometry, ethynyldeoxyuridine (EdU) assay, and enzyme-linked immunosorbent assay (ELISA) were used to explore the relationship between SARM and T. gondii.
RESULTS: Here, we showed that T. gondii infection increased the expression of SARM in vitro and in vivo. SARM induced cell apoptosis during T. gondii infection, activating the mitochondrial apoptotic pathway, the endoplasmic reticulum stress (ER) pathway, and the mitogen-activated protein kinase (MAPK) signaling pathway, and prompting the production of reactive oxygen species (ROS). Furthermore, SARM participated in the regulation of the inflammatory response through the nod-like receptor pyrin domain 3 (NLRP3) inflammasome signaling pathway during T. gondii in vitro infection.
CONCLUSIONS: These results elucidate the relationship between SARM and T. gondii infection, suggesting that SARM may represent a potential target for T. gondii control.

Keywords:   Toxoplasma gondii ; Apoptosis; Infection; Inflammation; SARM

DOI:  https://doi.org/10.1186/s13071-025-06721-2
Exp Parasitol. 2025 Mar 12. pii: S0014-4894(25)00036-0. [Epub ahead of print] 108931

Involvement of Toxoplasma gondii natural antisense transcripts in cellular stress responses.

Yue Gou, Laura Agudelo Vallejo, Ana Podadera, Kenneth Ng, Sirinart Ananvoranich.

  Natural antisense transcripts (NATs), as a major subset of long non-coding RNAs (lncRNAs), are derived from every chromosome of Toxoplasma gondii, with the highest occurrence from ChrIa (18.4 NATs per Mbp) and the lowest from ChrIX (3.9 NATs per Mbp). GO analysis indicates that genes, which mRNA-NAT pairs are derived, are important for house-keeping and essential activities of T. gondii. Approximately half of protein encoding genes, whose loci also generate NATs, are involved in biological processes of metabolic processes and protein biochemistry and have canonical catalytic or binding activities. Using NAT of ubiquitin-like protease 1 (TgUlp1-NAT) as our study model, we showed that TgUlp1-NAT expression is part of cellular stress responses. Using a nanoluc reporter system, we confirmed that electroporation or membrane destabilization significantly induced TgUlp1-NAT expression. When the extracellular parasites were exposed to media containing high potassium, high sodium or altered osmotic pressure, TgUlp1-NAT expression was significantly down-regulated. In addition, two TgUlp1-NAT variants were detected in stressed T. gondii. One is an intron-retained variant, and the other is a spliced variant, referred to as TgUlp1-NATa and TgUlp1-NATb, respectively. The intronic sequence is 368 nts long, where regulatory small ncRNAs were derived. Taken together, we have confirmed that NAT expressions and functions are involved in cellular adaptation that allows T. gondii recover from stresses.

Keywords:  Alternative splicing; Natural antisense transcripts; Stress response; Toxoplasma gondii; Ubiquitin-like protease; lncRNAs; sncRNAs

DOI:  https://doi.org/10.1016/j.exppara.2025.108931
Acta Trop. 2025 Mar 07. pii: S0001-706X(25)00054-3. [Epub ahead of print] 107576

Assessing the Therapeutic Potential of Silicon Dioxide Nanoparticles in Acute and Chronic Toxoplasmosis in BALB/c mice.

Ahmad Nematoollahi, Monireh Khordadmehr, Parisa Shahbazi, Reyhaneh Moghaddami, Kimia Moradi, Deniz Armanmanesh, Misagh Yaghubinejad, Ata Moghimi, Ehsan Ahmadpour.

  Toxoplasmosis, an infection caused by the obligate intracellular parasite Toxoplasma gondii, represents a significant global health concern, particularly for immunocompromised individuals. This study aimed to evaluate the therapeutic effects of silicon dioxide nanoparticles (SiO2-NPs) against both acute (T. gondii RH strain) and chronic (T. gondii PRU strain) infections in BALB/c mice. In the acute infection model, mice (n=40) were infected with 104 T. gondii tachyzoites, while the chronic infection model (n=40) involved the injection of 50 active cysts. Mice were treated with SiO2-NPs or pyrimethamine. Evaluations of parasite load and histopathological changes were conducted. The results showed that SiO2-NPs significantly reduced the number of cysts in the brain, indicating their effectiveness in controlling T. gondii proliferation. In cases of acute infection, there was a statistically significant decrease in parasite load (p<0.01). Although there was no significant difference between the pyrimethamine and SiO2-NPs groups (p>0.05), nanoparticles exhibited greater efficacy than pyrimethamine in acute infection. Furthermore, histopathological analysis revealed that mice were treated with SiO2-NPs displayed less severe lesions compared to the positive control group. The findings suggest that SiO2-NPs may offer a dual therapeutic advantage by reducing parasite load while also mitigating tissue damage. Further research is needed to explore the mechanisms behind the effectiveness of SiO2-NPs and to assess their long-term effects on T. gondii infections.

Keywords:  Histopathology; Parasite load; SiO2-NPs; Toxoplasma gondii; Treatment

DOI:  https://doi.org/10.1016/j.actatropica.2025.107576
Curr Obes Rep. 2025 Mar 13. 14(1): 24

Role of Protein Lysine Acetylation in the Pathogenesis and Treatment of Obesity and Metabolic Syndrome.

Zhaopeng Li, Yancheng Song, Zhao Li, Shuguang Liu, Song Yi, Zhuoli Zhang, Tao Yu, Yu Li.

   PURPOSE OF REVIEW: This review aimed to highlight the known role of histone deacetylases (HDACs) and lysine acetyltransferases (KATs) in individuals with obesity, better understand the role of HDACs and KATs enzymes in obesity and related metabolic disorders.
RECENT FINDINGS: Numerous cellular activities, including DNA replication, DNA repair, cell cycle regulation, RNA splicing, signal transmission, metabolic function, protein stability, transportation, and transcriptional regulation, are influenced by lysine acetylation. Protein lysine acetylation serves several purposes, which not only contribute to the development of metabolic disorders linked to obesity but also hold promise for therapeutic approaches. The current study demonstrates that HDACs and KATs control lysine acetylation. This review details the advancements made in the study of obesity, related metabolic diseases, and protein lysine acetylation. It contributes to our understanding of the function and mechanism of protein lysine acetylation in obesity and MS and offers a fresh method for treating these diseases.

Keywords:  Epigenetic modification; Histone deacetylases; Lysine acetylation; Lysine acetyltransferase; Metabolic syndrome; Obesity

DOI:  https://doi.org/10.1007/s13679-025-00615-1
bioRxiv. 2025 Feb 28. pii: 2025.02.25.640220. [Epub ahead of print]

Class I histone deacetylases catalyze lysine lactylation.

Takeshi Tsusaka, Mohd Altaf Najar, Isha Sharma, Mariola M Marcinkiewicz, Claudia Veronica Da Silva Crispim, Nathaniel W Snyder, George M Burslem, Emily L Goldberg.

Metabolism and post-translational modifications (PTMs) are intrinsically linked and the number of identified metabolites that can covalently modify proteins continues to increase. This metabolism/PTM crosstalk is especially true for lactate, the product of anaerobic metabolism following glycolysis. Lactate forms an amide bond with the ε-amino group of lysine, a modification known as lysine lactylation, or Kla. Multiple independent mechanisms have been proposed in the formation of Kla, including p300/CBP-dependent transfer from lactyl-CoA, via a high-energy intermediate lactoylglutathione species that non-enzymatically lactylates proteins, and several enzymes are reported to have lactyl transferase capability. We recently discovered that class I histone deacetylases (HDACs) 1, 2, and 3 can all reverse their canonical chemical reaction to catalyze lysine β-hydroxybutyrylation. Here we tested the hypothesis that HDACs can also catalyze Kla formation. Using biochemical, pharmacological, and genetic approaches, we found that HDAC-catalyzed lysine lactylation accounts for the majority of Kla formation in cells. Dialysis experiments confirm this is a reversible reaction that depends on lactate concentration. We also directly quantified intracellular lactyl-CoA and found that Kla abundance can be uncoupled from lactyl-CoA levels. Therefore, we propose a model in which the majority of Kla is formed through enzymatic addition of lactate by HDACs 1, 2, and 3.

DOI: https://doi.org/10.1101/2025.02.25.640220
Eur J Med Res. 2025 Mar 14. 30(1): 169

Anticancer efficacy of Spiruchostatin A: current insights into histone deacetylase inhibition and oncologic applications.

Saooda Ibrahim, Muhammad Umer Khan, Iqra Khurram, Muhammad Usman Ghani, Javad Sharifi-Rad, Daniela Calina.

  Spiruchostatin A also referred to as YM753 and OBP801, a cyclic peptide-based natural product derived from Pseudomonas sp., is distinguished by its potent inhibition of Class I histone deacetylases (HDACs). The modulation of epigenetic mechanisms by HDAC inhibitors is fundamental for altering gene expression related to cell growth, apoptosis, and differentiation, highlighting their potential in oncologic therapies. This updated review assesses the antitumor efficacy of Spiruchostatin A across diverse cellular and animal models, scrutinizing its viability as a therapeutic agent against various cancers. A systematic literature review was executed by searching databases such as PubMed/MedLine, Scopus, and Web of Science from October 2022 to February 2023. The inclusion criteria focused on studies involving Spiruchostatin A in the context of cancer treatment, including in vitro and in vivo models. The review concentrated on the compound's mechanistic action, biological activity, and clinical applicability. Spiruchostatin A has demonstrated significant antitumor activities, including inducing apoptosis and inhibiting tumor growth effectively in multiple models. Its therapeutic potential is particularly noted in synergistic applications with other anticancer agents, enhancing its efficacy. Mechanistically, the compound facilitates chromatin relaxation and transcriptional activation of key tumor suppressor genes through increased histone acetylation. Spiruchostatin A exhibits substantial potential as an anticancer agent through effective HDAC inhibition and subsequent epigenetic modifications of cancer cell biology. However, comprehensive clinical trials are imperative to validate its efficacy and safety profiles comprehensively. Future research is warranted to elucidate detailed molecular mechanisms and to develop biomarkers for predicting treatment response. Comprehensive longitudinal clinical studies are also critical to establish Spiruchostatin A's role within the broader oncological therapeutic regimen, along with the exploration of its analogs for improved therapeutic outcomes.

Keywords:  Anticancer; Epigenetics; HDAC inhibitor; Histone deacetylase; Spiruchostatin A; Therapeutic potential

DOI:  https://doi.org/10.1186/s40001-025-02401-0
Lung. 2025 Mar 11. 203(1): 41

SIRT2 Regulates Apoptosis Signaling in Hyperoxic Acute Lung Injury.

Yu Jin Lee, Mi Na Kim, Eun Gyul Kim, Chang Hyun Park, Joo Yeon Cho, Byung Chan Ko, Min Jung Kim, Yoon Hee Kim, Soon Min Lee, Kyung Won Kim, Tae Won Song, Myung Hyun Sohn.

   PURPOSE: Oxygen therapy is helpful for patients with breathing difficulties; however, sustained supplementation with high-concentration oxygen can cause hyperoxic acute lung injury. Sirtuin 2 (SIRT2), a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase, has been shown to be involved in pulmonary fibrosis, apoptosis, and inflammation. Here, we elucidated the role of SIRT2 in hyperoxic acute lung injury.
METHODS: Wild-type (WT) mice and SIRT2-deficient (SIRT2-/-) mice were exposed to room air or hyperoxia for 72 h. Thereafter, changes in hyperoxia-induced responses were evaluated in WT and SIRT2-/- mice.
RESULTS: SIRT2 expression was elevated in WT mice after hyperoxic exposure. We also observed that the levels of SIRT2 were higher in tracheal aspirates from newborns with bronchopulmonary dysplasia (BPD) than in those without BPD. Hyperoxia-induced inflammation and apoptosis were more considerably attenuated in SIRT2-/- mice than in WT mice. We also observed an interaction between SIRT2 and forkhead box O3 (FOXO3), and that SIRT2 deficiency was associated with altered acetylation levels of FOXO3 and changes in the expression of its downstream targets. Further investigation of the therapeutic effect of SIRT2 showed that hyperoxic acute lung injury was alleviated when AGK2, a SIRT2 inhibitor, was administered.
CONCLUSION: Taken together, SIRT2 plays a critical role in the pathogenesis of hyperoxic acute lung injury by regulating apoptotic signaling. These findings indicated that SIRT2 is potentially a novel therapeutic strategy for hyperoxic acute lung injury.

Keywords:  Acute lung injury; Apoptosis; Deacetylation; FOXO3; Hyperoxia; SIRT2

DOI:  https://doi.org/10.1007/s00408-025-00794-7
Curr Biol. 2025 Mar 10. pii: S0960-9822(24)01718-4. [Epub ahead of print]35(5): R175-R177

Parasite evolution: Coral-infecting apicomplexans disrupt our understanding of the pathways to parasitism.

Benjamin H Jenkins, Ross F Waller.

The discovery of chlorophyll biosynthesis genes in a cryptic apicomplexan partner of corals has disrupted, once again, our understanding of how this infamous group of parasites evolved.

DOI: https://doi.org/10.1016/j.cub.2024.12.050
Free Radic Biol Med. 2025 Mar 10. pii: S0891-5849(25)00159-5. [Epub ahead of print]

Mitochondrial ACSS1-K635 acetylation knock-in mice exhibit altered liver lipid metabolism on a ketogenic diet.

Guogang Xu, Joseph R Schell, Songhua Quan, Yucheng Gao, Sung-Jen Wei, Meixia Pan, Xianlin Han, Guiming Li, Daohong Zhou, Haiyan Jiang, Felix F Dong, Erin Munkácsy, Nobuo Horikoshi, David Gius.

  Acetyl-CoA Synthetase Short Chain Family Member-1 (ACSS1) catalyzes the ligation of acetate and coenzyme A to generate acetyl-CoA in the mitochondria to produce ATP through the tricarboxylic acid (TCA) cycle. We recently generated an ACSS1-acetylation (Ac) mimic knock-in mouse, where lysine 635 was mutated to glutamine (K635Q), which structurally and biochemically mimics an acetylated lysine. ACSS1 enzymatic activity is regulated, at least in part, through the acetylation of lysine 635 in mice (lysine 642 in humans), a Sirtuin 3 deacetylation target. We challenged our Acss1K635Q knock-in mice with a three-week ketogenic diet. While both wild-type and Acss1K635Q knock-in mice were in ketosis with similar blood glucose levels, the Acss1K635Q mice exhibited elevated blood acetate and liver acetyl-CoA. In addition, and importantly, compared to wild-type mice, the liver in the Acss1K635Q mice displayed a much more predominant liver steatosis morphology and accumulation of lipid drops, as measured by H&E and Oil Red O staining. RNAseq analysis identified that genes related to mitochondrial respiratory chain complexes and oxidative stress were significantly overexpressed in the Acss1K635Q mice on a KD. Finally, lipidomics analysis revealed very different lipid profiles for these groups, including a dramatic increase in triacylglycerides (TAGs), phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and cardiolipins in the Acss1K635Q liver.

Keywords:  Acetate; Acetyl-CoA Synthetase; Ketogenic Diet; Lipid Metabolism; Steatosis

DOI:  https://doi.org/10.1016/j.freeradbiomed.2025.03.009
FEBS Open Bio. 2025 Mar 11.

An enzyme-linked immunosorbent assay (ELISA)-based activity assay for AMP-activated protein kinase (AMPK).

Trezze P Nguyen, Shangze Lyu, Yang Liu.

  AMP-activated protein kinase (AMPK) is the master regulator of cellular and organismal energy homeostasis, playing an essential role in modulating metabolism and other cellular processes. Substantial efforts have been made to develop pharmacological modulators of AMPK activity due to their therapeutic potential against various diseases. Measuring AMPK activity in vitro is a fundamental step for testing AMPK activators and inhibitors. Here, we report an enzyme-linked immunosorbent assay (ELISA)-based AMPK activity assay with simple steps and high sensitivity. This assay offers a robust, in-house alternative to the traditional radioactive methods and other approaches that rely on specialized reagents or commercial kits.

Keywords:  AMPK; ELISA; kinase activity

DOI:  https://doi.org/10.1002/2211-5463.70017
bioRxiv. 2025 Feb 25. pii: 2025.02.25.640208. [Epub ahead of print]

Endogenous structure of antimalarial target Pf ATP4 reveals new class of apicomplexan P-type ATPase modulators.

Meseret T Haile, Anurag Shukla, James Zhen, Michael W Mather, Suyash Bhatnagar, Zhening Zhang, Akhil B Vaidya, Chi-Min Ho.

The Plasmodium falciparum sodium efflux pump Pf ATP4 is a leading antimalarial target, but suffers from a lack of high-resolution structural information needed to identify functionally important features in conserved regions and guide rational design of next generation inhibitors. Here, we determine a 3.7Å cryoEM structure of Pf ATP4 purified from CRISPR-engineered P. falciparum parasites, revealing a previously unknown, apicomplexan-specific binding partner, Pf ABP, which forms a conserved, likely modulatory interaction with Pf ATP4. The discovery of Pf ABP presents a new avenue for designing novel Pf ATP4 inhibitors.

DOI: https://doi.org/10.1101/2025.02.25.640208
Cells. 2025 Feb 27. pii: 342. [Epub ahead of print]14(5):

Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization.

Adeline M Luperchio, Daniel J Salamango.

  The family of forkhead box O (FoxO) transcription factors regulate cellular processes involved in glucose metabolism, stress resistance, DNA damage repair, and tumor suppression. FoxO transactivation activity is tightly regulated by a complex network of signaling pathways and post-translational modifications. While it has been well established that phosphorylation promotes FoxO cytoplasmic retention and inactivation, the mechanism underlying dephosphorylation and nuclear translocation is less clear. Here, we investigate the role of protein phosphatase 2A (PP2A) in regulating this process. We demonstrate that PP2A and AMP-activated protein kinase (AMPK) combine to regulate nuclear translocation of multiple FoxO family members following inhibition of metabolic signaling or induction of oxidative stress. Moreover, chemical inhibitor studies indicate that nuclear accumulation of FoxO proteins occurs through inhibition of nuclear export as opposed to promoting nuclear import as previously speculated. Functional, genetic, and biochemical studies combine to identify the PP2A complexes that regulate FoxO nuclear translocation, and the binding motif required. Mutating the FoxO-PP2A interface to enhance or diminish PP2A binding alters nuclear translocation kinetics accordingly. Together, these studies shed light on the molecular mechanisms regulating FoxO nuclear translocation and provide insights into how FoxO regulation is integrated with metabolic and stress-related stimuli.

Keywords:  AKT; FoxO; PI3K; PP2A; subcellular localization; transcription factor; tumor suppressors

DOI:  https://doi.org/10.3390/cells14050342
J Proteomics. 2025 Mar 06. pii: S1874-3919(25)00046-6. [Epub ahead of print]316 105419

Characterization of substrate distribution and functional implication of lysine acylations in Staphylococcus aureus.

Yunxu Bian, Zunli Hu, Rongzhen Wang, Shuyu Xie, Yewen Sun, Tianqi Liu, Shaojie Ma, Bin Liu, Minjia Tan, Jun-Yu Xu.

  Staphylococcus aureus (S. aureus) is a major pathogen whose post-translational modifications (PTMs) regulate key biological processes that exert a substantial impact on protein function within this pathogen. In this study, we comprehensively analyzed the overall patterns of three lysine acylation in S. aureus including acetylation, succinylation, and malonylation. Using mass spectrometry, we identified 1249 acetylated, 871 succinylated, and 67 malonylated sites. Bioinformatic analysis furtherly revealed that both lysine acetylation and succinylation exhibited a preferential association with glutamate residues near the modified lysine positions. Pathway enrichment showed that modified substrates were associated with ribosomes and metabolic functions. Additional functional exploration showed that lysine succinylation significantly regulates the enzymatic activity of Glutamyl-tRNA amidotransferase and Carbamoyl phosphate synthase. In conclusion, our study enhanced the comprehension of lysine succinylation in S. aureus and highlights potential targets related to its pathogenicity at the post-translational modification level. SIGNIFICANCE NEW: Lysine acylations play important roles in regulating bacterial survival and pathogenicity in Staphylococcus aureus. However, comprehensive and systematic investigations of the lysine acylomes in S. aureus remain insufficient. In this study, we conducted a comprehensive analysis of three lysine acylation modifications in Staphylococcus aureus subspecies aureus ATCC 25923 using mass spectrometry-based proteomic techniques. The objective was to investigate the potential impact of these modifications on protein function. Our bioinformatics analysis identified a significant correlation between lysine acylations and both ribosomal and metabolic pathways. Through additional experimental validation, we have substantiated that lysine succinylation plays a significant regulatory role in the activities of Glutamyl-tRNA amidinotransferase and Carbamoyl phosphate synthetase, consequently exerting a profound impact on cellular energy metabolism and protein synthesis in S. aureus. Collectively, our study underscores the pivotal role of lysine acylation modifications in S. aureus in modulating enzyme function, thereby offering valuable insights into the biology of S. aureus and informing potential therapeutic strategies.

Keywords:  Acetylation; Malonylation; Post-translational modifications; Staphylococcus aureus; Succinylation

DOI:  https://doi.org/10.1016/j.jprot.2025.105419
Adv Physiol Educ. 2025 Mar 08.

PARASITOPHYSIOART: EXPLORING THE INTERSECTION OF ART, PHYSIOLOGY, AND PARASITOLOGY ON STUDENTS´ PERCEPTION AND MOTIVATION.

Maria Victória Patrício da Silva, Pedro Henricke Oliveira de Souza, Ana Luíza Rocha Teixeira Faria Fernandes, Marcos Ruan Sousa Lima, Camilly Cristinne do Nascimento Silva, Fabiola da Cruz Nunes, Josiane Campos Cruz.

  This study explores the impact of integrating art into the teaching of physiology and parasitology to enhance student engagement, motivation, and perception. Thirty-seven biotechnology students from the Federal University of Paraíba, Brazil, enrolled in human physiology and parasitology courses and participated in the innovative ParasitoPhysioart project. The students were tasked with recreating artworks illustrating key parasitology concepts and their physiological effects on the human body. For instance, one group reinterpreted Wassily Kandinsky's "Several Circles" to represent the lifecycle of Toxoplasma gondii and its effect on the eyes, highlighting how the parasite, transmitted through contaminated soil or food, can invade various organs, including the retina and choroid, potentially leading to blindness. Another group reimagined Clovis Jr.'s "Nossa Senhora Aparecida," replacing the original branches with drawings of Ascaris lumbricoides, a parasite transmitted through contaminated fruits or vegetables. The artwork emphasized the parasite's impact on the lungs, which can cause symptoms such as cough, dyspnea, and hemoptysis. A voluntary survey answered after the project revealed that 62% of students (n=39) considered physiology challenging. However, about 86% reported that the multidisciplinary approach of combining art with scientific concepts motivated them to study and helped them better understand the disciplines. Results suggest that the artistic reinterpretations vividly illustrated the intersection of parasitology and physiology, highlighting this interdisciplinary approach's educational and creative potential.

Keywords:  Parasitology; Physiology; active learning; art education; multidisciplinary

DOI:  https://doi.org/10.1152/advan.00165.2024
Int J Biol Macromol. 2025 Mar 06. pii: S0141-8130(25)02285-8. [Epub ahead of print]306(Pt 4): 141734

Phosphorylation-driven regulation of SIRT1 in muscle senescence: Insights from molecular dynamics simulation and experimental validation.

Siyao Liu, Liang Shan, Yue Li, Jinbao Xiang, Hansi Zhang.

  Sirtuin 1 (SIRT1) is a key regulator of mitochondrial function and inflammatory responses, both of which are critical in the progression of muscle aging and sarcopenia. While SIRT1's activity is known to be regulated by post-translational modifications, the specific role of Ser46 phosphorylation has not been fully elucidated. In this study, we explored the effects of Ser46 phosphorylation on SIRT1's structural stability, subcellular localization, and downstream signaling in the context of muscle cell senescence. Using a combination of molecular dynamics (MD) simulations and in vitro assays with C2C12 myoblasts, we demonstrated that phosphorylation at Ser46 enhances SIRT1's structural stability by reducing flexibility in its nuclear localization signal (NLS) and catalytic domains. This modification promotes nuclear translocation of SIRT1 and is associated with a reduction in PGC-1α expression and mitochondrial membrane potential. Additionally, Ser46 phosphorylation activates NF-κB-mediated inflammatory pathways and is associated with increased p53 expression and SA-β-gal activity, hallmarks of cellular senescence. JC-1 staining further revealed that Ser46 phosphorylation compromises mitochondrial membrane potential. These findings reveal a previously unrecognized mechanism by which Ser46 phosphorylation shifts SIRT1's function toward promoting inflammation and muscle senescence, providing a potential target for therapeutic interventions in age-related muscle degeneration.

Keywords:  Nuclear localization; Phosphorylation; SIRT1; Sarcopenia

DOI:  https://doi.org/10.1016/j.ijbiomac.2025.141734
J Med Chem. 2025 Mar 10.

Monoselective Histone Deacetylase 6 PROTAC Degrader Shows In Vivo Tractability.

Harsimran K Garcha, Olasunkanmi O Olaoye, Abootaleb Sedighi, Daniel Pölöske, Pearla Hariri, Wenlong Yu, Diaaeldin I Abdallah, Richard Moriggl, Elvin D de Araujo, Patrick T Gunning.

Herein, we report a potent HDAC6 PROTAC, TO-1187, which selectively degrades HDAC6 in cellulo and demonstrates in vivo efficacy. The design of TO-1187 was achieved by linking our previously reported HDAC6 inhibitor, TO-317, to the cereblon (CRBN) E3 ligase ligand, pomalidomide. TO-1187 achieved monoselective HDAC6 degradation in human multiple myeloma cells, MM.1S, with a Dmax of 94% and a DC50 of 5.81 nM after 6 h. Importantly, at concentrations up to 25 μM, TO-1187 exhibited no cellular degradation of other HDACs. Proteomic evaluation confirmed a highly selective proteome-wide degradation profile, with HDAC6 the only protein observed to be depleted. Notably, TO-1187 did not impact the abundance of well-known CRBN neosubstrates, like IKZF1, IKZF3, CK1α, SALL4, and GSPT1. In vivo evaluation confirmed that TO-1187 efficiently degraded HDAC6 in mouse tissues, measured 6 h after intravenous injection. In summary, TO-1187 represents a viable candidate for advanced preclinical evaluation of HDAC6 biology.

DOI: https://doi.org/10.1021/acs.jmedchem.4c02021
Trends Cancer. 2025 Mar 06. pii: S2405-8033(25)00014-7. [Epub ahead of print]

Acetylation: a new target for protein degradation in cancer.

Callie E W Crawford, George M Burslem.

  Acetylation is an increasing area of focus for cancer research as it is closely related to a variety of cellular processes through modulation of histone and non-histone proteins. However, broadly targeting acetylation threatens to yield nonselective toxic effects owing to the vital role of acetylation in cellular function. There is thus a pressing need to elucidate and characterize the specific cancer-relevant roles of acetylation for future therapeutic design. Acetylation-mediated protein homeostasis is an example of selective acetylation that affects a myriad of proteins as well as their correlated functions. We review recent examples of acetylation-mediated protein homeostasis that have emerged as key contributors to tumorigenesis, tumor proliferation, metastasis, and/or drug resistance, and we discuss their implications for future exploration of this intriguing phenomenon.

Keywords:  acetylation; cancer; degradation; heterobifunctional; ubiquitination

DOI:  https://doi.org/10.1016/j.trecan.2025.01.013
Curr Protein Pept Sci. 2025 Mar 10.

Inhibitors of Type II NADH Dehydrogenase Enzyme: A Review.

Guangzhou Sun, Quanshan Shi, Yuting Song, Lingkai Tang, Siyao Li, Tiantian Yang, Kaixuan Hu, Liang Ma, Xiaodong Shi, Jianping Hu.

  Mitochondria are organelles in eukaryotic organisms with an electron transport chain consisting of four complexes (i.e., CI, CII, CIII, and CIV) on the inner membrane, which have functions such as providing energy, electron transport, and generating proton gradients. NADH dehydrogenase type 2 (NDH-2), widely found in bacterial, plant, fungal and protist mitochondria, is a nonproton-pumping single-subunit enzyme bound to the surface of the inner mitochondrial membrane that partially replaces NDH-1. NDH-2 has a crucial role in the energy metabolism of pathogenic microorganisms, and the lack of NDH-2 or its homologs in humans makes NDH-2 an essential target for the development of antimicrobial drugs. There is a wide variety of pathogenic microorganisms that invade the human body and cause diseases; therefore, more and more inhibitors targeting NDH-2 of different pathogenic microorganisms continue to be reported. This paper first reviews the structure and function of NDH-2 and summarizes the classification of compounds targeting NDH-2. Given the relative paucity of inhibition mechanisms for NDH-2, which has greatly hindered the development of targeted drugs, the article concludes with a summary of two possible mechanisms in action: allosteric inhibition and competitive inhibition. This review will provide theoretical support for the subsequent molecular design and modification of drugs targeting the pathogenic microorganism NDH-2.

Keywords:  Mitochondria; NDH-2; inhibition mechanism; inhibitor; molecular design.

DOI:  https://doi.org/10.2174/0113892037350396250213115109
Methods Mol Biol. 2025 ;2906 229-242

Electron Microscopy to Visualize and Quantify Mitochondrial Structure and Organellar Interactions in Cultured Cells During Senescence.

Christina Glytsou.

  Mitochondria are multifunctional organelles that play a crucial role in numerous cellular processes, including oncogene-induced senescence. Recent studies have demonstrated that mitochondria undergo notable morphological and functional changes during senescence, with mitochondria dysregulation being a critical factor contributing to the induction of this state. To elucidate the intricate and dynamic structure of these organelles, high-resolution visualization techniques are imperative. Electron microscopy offers nanometer-scale resolution images, enabling the comprehensive study of organelles' architecture. This chapter provides a detailed guide for preparing fixed samples from cultured cells for electron microscopy imaging. It also describes various quantification methods to accurately assess organellar parameters, including morphometric measurements of mitochondrial shape, cristae structure, and mitochondria-endoplasmic reticulum contact sites. These analyses yield valuable insights into the status of subcellular organelles, advancing our understanding of their involvement in cellular senescence and disease.

Keywords:  EM sample preparation; Electron microscopy; MERCs; Mitochondria visualization; Mitochondrial structure

DOI:  https://doi.org/10.1007/978-1-0716-4426-3_13
Acta Biochim Biophys Sin (Shanghai). 2025 Mar 10.

HDAC11 in ovarian granulosa cells coordinates LH in the maturation of oocytes in Tan sheep.

Jiaqi Shi, Donghuan Lv, Yaxiu Xu, Xiangyan Wang, Zhipeng Qi, Yujie Yan, Jinghua Wang, Hongyuan Song, Hui Yang, Luguo Jin, Zhengyi Yang, Xiaoning Yang, Xiumei Kang, Xinfeng Liu, Zhuming Zhang, Chao Wang.

  Oocyte maturation plays an important role in supporting mammalian reproduction. Histone deacetylase 11 (HDAC11), the only member of the class IV histone deacetylase family and the smallest histone deacetylases (HDACs), has been shown to regulate oocyte maturation in mice and pigs. However, the epigenetic effects of HDACs in follicular granulosa cells in response to LH induction remain elusive in sheep. In this study, the effects of follicular somatic cell-derived HDAC11 on oocyte maturation in Tan sheep are evaluated. The expression changes of HDAC11 and related proteins are detected by means of immunofluorescence, immunohistochemistry, western blot analysis and enzyme-linked immunosorbent assay. Our results indicate that the level of HDAC11 in follicular granulosa cells as well as oocytes in Tan sheep increases with the growth and maturation of the follicles. Specific inhibition of HDAC11 by SIS17 remarkably reduces the oocyte maturation rate under LH supplementation in vitro. Accordingly, the acetylation level of H3K9 in granulosa cells is increased, while the EGF-like growth factor AREG is remarkably decreased. Furthermore, inhibition of HDAC11 markedly decreases the level of YAP1, which is a negative regulator of AREG in granulosa cells. Conclusively, HDAC11 in the granulosa cells of Tan sheep contributes to the LH induced production of AREG during oocyte in vitro maturation by decreasing the level of H3K9 acetylation and increasing the level of YAP1.

Keywords:  AREG; H3K9ac; HDAC11; YAP1; granulosa cell; oocyte maturation

DOI:  https://doi.org/10.3724/abbs.2025036
Nature. 2025 Mar 12.

Structure and mechanism of the plastid/parasite ATP/ADP translocator.

Huajian Lin, Jian Huang, Tianming Li, Wenjuan Li, Yutong Wu, Tianjiao Yang, Yuwei Nian, Xiang Lin, Jiangqin Wang, Ruiying Wang, Xiaohui Zhao, Nannan Su, Jinru Zhang, Xudong Wu, Minrui Fan.

Adenosine triphosphate (ATP) is the principal energy currency of all living cells1,2. Metabolically impaired obligate intracellular parasites, such as the human pathogens Chlamydia trachomatis and Rickettsia prowazekii, can acquire ATP from their host cells through a unique ATP/adenosine diphosphate (ADP) translocator, which mediates the import of ATP into and the export of ADP and phosphate out of the parasite cells, thus allowing the exploitation of the energy reserves of host cells (also known as energy parasitism). This type of ATP/ADP translocator also exists in the obligate intracellular endosymbionts of protists and the plastids of plants and algae and has been implicated to play an important role in endosymbiosis3-31. The plastid/parasite type of ATP/ADP translocator is phylogenetically and functionally distinct from the mitochondrial ATP/ADP translocator, and its structure and transport mechanism are still unknown. Here we report the cryo-electron microscopy structures of two plastid/parasite types of ATP/ADP translocators in the apo and substrate-bound states. The ATP/ADP-binding pocket is located at the interface between the N and C domains of the translocator, and a conserved asparagine residue within the pocket is critical for substrate specificity. The translocator operates through a rocker-switch alternating access mechanism involving the relative rotation of the two domains as rigid bodies. Our results provide critical insights for understanding ATP translocation across membranes in energy parasitism and endosymbiosis and offer a structural basis for developing drugs against obligate intracellular parasites.

DOI: https://doi.org/10.1038/s41586-025-08743-3
Cell Prolif. 2025 Mar 11. e70022

Sirt3 Rescues Porphyromonas gingivalis-Impaired Cementogenesis via SOD2 Deacetylation.

Xin Huang, Huiqing Gou, Jirong Xie, Yonglin Guo, Yifei Deng, Yan Xu, Zhengguo Cao.

  The keystone pathogen Porphyromonas gingivalis (P.g.) is responsible for cementum resorption in periodontitis; however, the mechanism involved in it remains unclear. Sirtuin 3 (Sirt3) is a NAD+-dependent protein deacetylase contributing to mitochondrial homeostasis and various cell functions. In this study, the expression of Sirt3 in cementoblasts was found to be increased during cementoblast mineralisation and cementum development, while it decreased gradually under P.g. infection in a multiplicity of infection-dependent manner. Compared with wild type mice, the Sirt3 knockout mice showed less cellular cementum and lower mineralisation capacity with decreased expression of Runx2 and OCN in cementoblasts. Sirt3 inhibition by 3-TYP or Sirt3 silencing by lentivirus infection both confirmed the impaired cementogenesis. Conversely, honokiol (HKL) was simulated to bind Sirt3 and was applied to activate Sirt3 in cementoblasts. HKL-mediated Sirt3 activation facilitated cementoblast mineralisation and rescued P.g.-suppressed cementoblast mineralisation markedly. Superoxide dismutase 2 (SOD2), the downstream molecule of Sirt3, showed a similar expression pattern to Sirt3 under different conditions. Silencing of SOD2 was demonstrated to restrain cementoblast mineralisation. The pan acetylation was detected to decrease under Sirt3-upregulating conditions and increase under Sirt3-downregulating conditions. The binding of Sirt3 and SOD2 in cementoblasts was also verified. Furthermore, SOD2 acetylation and specific SOD2-K68 acetylation were found to be upregulated under P.g. or Sirt3 silencing conditions and downregulated by HKL stimulation. Moreover, K68Q mutation simulating acetylation decreased cementoblast mineralisation, while K68R mutation simulating deacetylation increased it. Altogether, Sirt3 deacetylates SOD2 via K68 to orchestrate P.g.-perturbed cementogenesis, and HKL is a Sirt3-targeted treatment candidate.

Keywords:   porphyromonas gingivalis ; acetylation; cementogenesis; cementum; sirtuin3; superoxide dismutase

DOI:  https://doi.org/10.1111/cpr.70022
EMBO J. 2025 Mar 10.

Mitochondrial fatty acid oxidation regulates adult muscle stem cell function through modulating metabolic flux and protein acetylation.

Feng Yue, Lijie Gu, Jiamin Qiu, Stephanie N Oprescu, Linda M Beckett, Jessica M Ellis, Shawn S Donkin, Shihuan Kuang.

  During homeostasis and regeneration, satellite cells, the resident stem cells of skeletal muscle, have distinct metabolic requirements for fate transitions between quiescence, proliferation and differentiation. However, the contribution of distinct energy sources to satellite cell metabolism and function remains largely unexplored. Here, we uncover a role of mitochondrial fatty acid oxidation (FAO) in satellite cell integrity and function. Single-cell RNA sequencing revealed progressive enrichment of mitochondrial FAO and downstream pathways during activation, proliferation and myogenic commitment of satellite cells. Deletion of Carnitine palmitoyltransferase 2 (Cpt2), the rate-limiting enzyme in FAO, hampered muscle stem cell expansion and differentiation upon acute muscle injury, markedly delaying regeneration. Cpt2 deficiency reduces acetyl-CoA levels in satellite cells, impeding the metabolic flux and acetylation of selective proteins including Pax7, the central transcriptional regulator of satellite cells. Notably, acetate supplementation restored cellular metabolic flux and partially rescued the regenerative defects of Cpt2-null satellite cells. These findings highlight an essential role of fatty acid oxidation in controlling satellite cell function and suggest an integration of lipid metabolism and protein acetylation in adult stem cells.

Keywords:  CPT2; Fatty Acid Oxidation; Muscle Regeneration; Muscle Satellite Cell; Protein Acetylation

DOI:  https://doi.org/10.1038/s44318-025-00397-1
mBio. 2025 Mar 12. e0252424

SENP1-SIRT3 axis mediates glycolytic reprogramming to suppress inflammation during Listeria monocytogenes infection.

Yan Xiong, Yongliang Du, Feng Lin, Beibei Fu, Dong Guo, Zhou Sha, Rong Tian, Rui Yao, Lulu Wang, Zixuan Cong, Bohao Li, Xiaoyuan Lin, Haibo Wu.

  Listeria monocytogenes, a foodborne pathogen, has the ability to invade intestinal mucosal cells, undergo intracellular proliferation, activate host immune responses, and induce diseases such as colitis. We have demonstrated that sentrin-specific protease 1 (SENP1) functions as a protective gene in the host, suppressing the inflammatory response triggered by Listeria monocytogenes. The host's SENP1-SIRT3 axis plays a critical role in regulating inflammation during Listeria monocytogenes infection. Our findings reveal that overexpression of SENP1, particularly under Listeria monocytogenes infection conditions (MOI = 20), effectively suppresses inflammation through modulation of glycolysis. Mechanistically, during Listeria monocytogenes infection, SENP1 accumulates in the mitochondria, facilitating the de-SUMOylation and activation of sirtuin 3 (SIRT3). Activated SIRT3 then regulates the deacetylation of pyruvate kinase M2 (PKM2), leading to a decrease in glycolytic intermediates, downregulation of glycolysis-related gene expression, and suppression of inflammation. Taken together, our study provides a deeper understanding of the mechanistic role of the SENP1-SIRT3 axis in the regulation of inflammation, offering novel insights, and strategies for the treatment and prevention of inflammatory diseases.
IMPORTANCE: Sentrin-specific protease 1 (SENP1)-sirtuin 3 (SIRT3) has never been reported in the regulation of bacteria-induced inflammation. Our study demonstrated that SENP1 acted as a protective factor against Listeria-induced inflammation by promoting SIRT3 activation and subsequent metabolic reprogramming. The SENP1-SIRT3 axis served not only as an essential signaling pathway for regulating mitochondrial metabolic responses to metabolic stress but also responds to bacterial invasion and plays a protective role in the organism. Our findings provide a basis for further research into targeting the SENP1-SIRT3 signaling pathway for the treatment of bacterial infections.

Keywords:  Listeria monocytogenes; PKM2; SENP1-SIRT3 axis; SUMO; glycolysis

DOI:  https://doi.org/10.1128/mbio.02524-24
Mol Cell. 2025 Mar 05. pii: S1097-2765(25)00142-X. [Epub ahead of print]

The role of protein lactylation: A kaleidoscopic post-translational modification in cancer.

Marta Iozzo, Elisa Pardella, Elisa Giannoni, Paola Chiarugi.

  The recently discovered lysine lactylation represents a critical post-translational modification with widespread implications in epigenetics and cancer biology. Initially identified on histones, lysine lactylation has been also described on non-histone proteins, playing a pivotal role in transcriptional activation, protein function, and cellular processes. Two major sources of the lactyl moiety have been currently distinguished: L-lactyl-CoA (precursor of the L-lactyl moiety) and S-D-lactylglutathione (precursor of the D-lactyl moiety), which enable enzymatic and non-enzymatic mechanisms of lysine lactylation, respectively. Although the specific writers, erasers, and readers of this modification are still unclear, acetyltransferases and deacetylases have been proposed as crucial mediators of lysine lactylation. Remarkably, lactylation exerts significant influence on critical cancer-related pathways, thereby shaping cellular behavior during malignant transformation and the metastatic cascade. Hence, as recent insights into lysine lactylation underscore its growing potential in tumor biology, targeting this modification is emerging as a significant opportunity for cancer treatment.

Keywords:  cancer aggressiveness; histone lactylation; lactyl-CoA; lactylglutathione; non-histone protein lactylation

DOI:  https://doi.org/10.1016/j.molcel.2025.02.011
Acta Crystallogr F Struct Biol Commun. 2025 Apr 01.

Crystal structure of the S-adenosylmethionine-dependent mycolic acid synthase UmaA from Mycobacterium tuberculosis.

Sean Teng, Jie Wang, Collin D Sroge, Jan Abendroth, Donald D Lorimer, Peter S Horanyi, Thomas E Edwards, Logan Tillery, Justin K Craig, Wesley C Van Voorhis, Peter J Myler, Craig L Smith.

  Mycobacterium tuberculosis is a Gram-positive bacillus that causes tuberculosis and is a leading cause of mortality worldwide. This disease is a growing health threat due to the occurrence of multidrug resistance. Mycolic acids are essential for generating cell walls and their modification is important to the virulence and persistence of M. tuberculosis. A family of S-adenosylmethionine-dependent mycolic acid synthases modify mycolic acids and represent promising drug targets. UmaA is currently the least-understood member of this family. This paper describes the crystal structure of UmaA. UmaA is a monomer composed of two domains: a structurally conserved SAM-binding domain and a variable substrate-binding auxiliary domain. Fortuitously, our structure contains a nitrate in the active site, a structural mimic of carbonate, which is a known general base in cyclopropane-adding synthases. Further investigation indicated that the structure of the N-terminus is highly flexible. Finally, we have identified S-adenosyl-N-decyl-aminoethyl as a promising potential inhibitor.

Keywords:  Mycobacterium tuberculosis; S-adenosylmethionine-dependent methyltransferases; SAM-dependent mycolic acid synthase; Seattle Structural Genomics Center for Infectious Disease; UmaA; short-chain fatty-acid modification; structural genomics

DOI:  https://doi.org/10.1107/S2053230X25001530