bims-toxgon 2025-08-03 papers

bims-toxgon

Biomed News

on Toxoplasma gondii metabolism

Issue of 2025–08–03
24 papers selected by
Lakesh Kumar, BITS Pilani

Comprehensive analysis of Toxoplasma gondii migration routes and tissue dissemination in the host.
Elucidating the Role of Toxoplasma gondii's Mitochondrial Superoxide Dismutase.
Toltrazuril inhibits Toxoplasma gondii by potentially targeting pyrimidine metabolism.
In vitro and in vivo activity of quisinostat against Toxoplasma gondii.
Proline dehydrogenase, a rate-limiting catabolic enzyme, affecting the growth and pathogenicity of Toxoplasma gondii tachyzoites by regulating the proline metabolism and mitochondrial function of the parasite.
Correction: Sexually aggressive behavior triggered by parasitic infection - how parasites can influence our personality.
Quantitative proteomic analysis of the Toxoplasma gondii cytoskeleton and bioinformatic identification of highly antigenic proteins.
IL-24 Is a Promising Molecular Adjuvant for Enhancing Protective Immunity Induced by DNA Vaccination Against Toxoplasma gondii.
Pyroptosis Drives the Impairment of Colonic Barrier Integrity During Toxoplasma Gondii Chronic Infection.
[Generation of a dense granule protein 3 gene-deficient strain of Toxoplasma gondii and its virulence testing].
Quantitative Structure-Activity Relationship Modeling and Molecular Docking Studies of TgCDPK1 Inhibitors in Toxoplasma gondii.
Catechin gallate triggers metabolomic and lipidomic alteration in Toxoplasma gondii.
Isolation of Toxoplasma gondii from the placenta of northern fur seals (Callorhinus ursinus) and potential transplacental transmission of the parasite.
Evaluating The Therapeutic Effect of 2-Nitroimidazole on Toxoplasma gondii: An In vitro and In vivo Study Using BALB/c Mice.
Low Tenacity of Toxoplasma gondii Tachyzoites In Vitro.
Placental Expression of Sirtuins in Women with Gestational Diabetes.
Unraveling the roles of mitochondrial sirtuins in aging-related diseases: From mechanistic insights to therapeutic strategies.
Sirtuins Contribute to the Migraine-Stroke Connection.
SIRT3 deficiency aggravates mitochondrial metabolic disorder and podocyte injury in DKD via MPC2 acetylation.
Histone deacetylase 6 deacetylates and ubiquitinates ATG3 to regulate autophagy.
Human toxoplasmosis: current advances in the field.
Mitochondrial Calcium Uniporter Links Acetyl-CoA Metabolism and H3K27 Acetylation to Maintain Glioblastoma Stem Cells.
Amino Acid Metabolism and Photoreceptor Degenerative Diseases: Mechanisms, Early Diagnosis, and Therapeutic Prospects.
Epigenetic regulation of cancer stemness.

PLoS Negl Trop Dis. 2025 Jul;19(7): e0013369

Comprehensive analysis of Toxoplasma gondii migration routes and tissue dissemination in the host.

Carlos J Ramírez-Flores, Ricardo Mondragón-Flores.

Toxoplasma gondii is a highly adaptable intracellular parasite capable of infecting a wide range of warm-blooded animals, including humans. Following the ingestion of cysts and oocysts, the parasites rapidly emerge and transmigrate through the bloodstream, initiating a complex infection process. Despite reports on the parasite's dissemination, the mechanisms behind its migration remain unclear. Recent advances using innovative 3D models and various host systems are beginning to shed light on the migratory routes and strategies employed by T. gondii. This review compiles current knowledge on the migration and dissemination of T. gondii, from its initial interactions in the gut to its invasion of immune-privileged organs. This review provides a comprehensive understanding of how T. gondii establishes its infection crossing the most impermeable biological barriers within the host.

DOI: https://doi.org/10.1371/journal.pntd.0013369
Biomolecules. 2025 Jul 07. pii: 972. [Epub ahead of print]15(7):

Elucidating the Role of Toxoplasma gondii's Mitochondrial Superoxide Dismutase.

James Alexander Tirtorahardjo, Christopher I-H Ma, Areej Shaikh, Rosa M Andrade.

  Toxoplasma gondii is an Apicomplexan parasite that possesses a well-developed system of scavengers of reactive oxygen species (ROS). Among its components, T. gondii mitochondrial superoxide dismutase (TgSOD2) is essential, as predicted by the CRISPR phenotype index and evidenced by the non-viability of its constitutive knockouts. As an obligate intracellular parasite, TgSOD2 is upregulated during extracellular stages. Herein, we generated a viable TgSOD2 knockdown mutant using an inducible auxin-degron system to explore the biological role of TgSOD2 in T. gondii. Depletion of TgSOD2 led to impaired parasite growth and replication, reduced mitochondrial membrane potential (MMP), abnormalities in the distribution of ATP synthase within its mitochondrial electron transport chain (mETC), and increased susceptibility to mETC inhibitors. Through a proximal biotinylation approach, we identified the interactions of TgSOD2 with complexes IV and V of its mETC, suggesting that these sites are sensitive to ROS. Our study provides the first insights into the role of TgSOD2 in maintaining its mitochondrial redox homeostasis and subsequent parasite replication fitness. Significance:Toxoplasma gondii infects nearly a third of the world population and can cause fetal miscarriages or life-threatening complications in vulnerable patients. Current therapies do not eradicate the parasite from the human hosts, rendering them at risk of recurrence during their lifetimes. T. gondii has a single mitochondrion, which is well-known for its susceptibility to oxidative damage that leads to T. gondii's death. Therefore, targeting T. gondii mitochondrion remains an attractive therapeutic strategy for drug development. T. gondii's mitochondrial superoxide dismutase is an antioxidant protein in the parasite mitochondrion and is essential for its survival. Understanding its biological role could reveal mitochondrial vulnerabilities in T. gondii and provide new leads for the development of effective treatments for T. gondii infections.

Keywords:  ATP synthase; Toxoplasma; electron transport chain; mitochondria; superoxide dismutase

DOI:  https://doi.org/10.3390/biom15070972
Pestic Biochem Physiol. 2025 Sep;pii: S0048-3575(25)00237-8. [Epub ahead of print]213 106524

Toltrazuril inhibits Toxoplasma gondii by potentially targeting pyrimidine metabolism.

An Yan, Kai He, Mingjun Xiong, Xu Wang, Wanxiao Jin, Ruibin Wu, Bolin Xia, Weiwei Sun, Baoliang Pan.

  Toxoplasma gondii is a significant zoonotic pathogen that infects nearly all warm-blooded animals. Available drugs for clinical treatment of toxoplasmosis are limited, creating an urgent need for development of new compounds. Toltrazuril (TOL) is a highly effective and broad-spectrum drug against parasites in Apicomplexa. In the hosts, TOL is metabolized to toltrazuril sulfone (TOLSO2) and toltrazuril sulfoxide (TOLSO), which also show potency against Apicomplexa protozoa. However, the knowledge about the effects of these metabolites on T. gondii remains unknown. The present study demonstrated that toltrazuril and its two metabolites, TOLSO and TOLSO2, markedly inhibited the invasion and proliferation of T. gondii in cells. Transmission electron microscopy revealed that these drugs substantially negatively affected the membrane structure of T. gondii. Furthermore, transcriptome and metabolome analyses indicated that toltrazuril reduces the transcription levels of dUTP pyrophosphatase (dUTPase) and thymidylate kinase (TMK), as well as the levels of dozens of metabolites, including dTMP and dUMP, potentially disrupting the stability of the pyrimidine network. More importantly, animal experiments have demonstrated that toltrazuril can completely protect mice against T. gondii infection. Taken together, the present findings demonstrate toltrazuril is a promising therapeutic candidate for toxoplasmosis.

Keywords:  Pyrimidine metabolism; Thymidylate kinase; Toltrazuril; Toxoplasma gondii; dUTPase

DOI:  https://doi.org/10.1016/j.pestbp.2025.106524
Antimicrob Agents Chemother. 2025 Jul 31. e0181924

In vitro and in vivo activity of quisinostat against Toxoplasma gondii.

Hui-Jie Qiu, Wen-Bin Zheng, Ting Zeng, Shu-Feng Yang, Dai-Ang Liu, Li-Yan Wang, Zhi-Rong Liu, Xing-Quan Zhu, Chun-Xue Zhou.

  Toxoplasma gondii, an opportunistic pathogen, poses severe threats to immunocompromised individuals and fetuses of newly infected pregnant women. The current gold-standard treatment, a combination of pyrimethamine and sulfadiazine, is limited by severe adverse events, necessitating the development of novel therapeutic agents. In vitro, a CCK8 assay demonstrated that quisinostat inhibited HeLa cell proliferation in a dose-dependent manner, with a CC50 of 8.22 nM. Regarding T. gondii tachyzoites, quisinostat exhibited time-dependent inhibition of extracellular parasite activity and suppressed intracellular parasite proliferation, with an EC50 of 25.84 pM, and a high selectivity index (SI = 318.11). Quisinostat disrupted the T. gondii lytic cycle by decreasing invasion rates, inducing G1 cell cycle arrest, reducing replication, and shrinking plaque size. Ultrastructural analysis indicated that quisinostat treatment led to membrane damage, enhanced lactate dehydrogenase (LDH) release, and apoptotic cell death in tachyzoites, whereas no significant change in reactive oxygen species (ROS) levels was detected. Proteome analysis identified 77 upregulated and 205 downregulated proteins, which were enriched in functions associated with protein dephosphorylation and ion transport, as well as pathways, such as non-homologous end-joining. Molecular docking studies revealed a strong interaction between quisinostat and T. gondii HDAC3. In vivo, treatment with quisinostat increased the survival time of mice infected with virulent RH strain. In mice infected with low-virulent ME49 tachyzoites, quisinostat treatment decreased parasite burden in multiple organs and increased the survival to 80%. Taken together, these findings demonstrate that quisinostat has potent anti-Toxoplasma activity both in vitro and in vivo, which offers promise for treatment of human toxoplasmosis.

Keywords:  EC50; Toxoplasma gondii; mouse; proteome; quisinostat

DOI:  https://doi.org/10.1128/aac.01819-24
Parasit Vectors. 2025 Jul 29. 18(1): 309

Proline dehydrogenase, a rate-limiting catabolic enzyme, affecting the growth and pathogenicity of Toxoplasma gondii tachyzoites by regulating the proline metabolism and mitochondrial function of the parasite.

Xiao-Ling Geng, Jing-Yu Li, Huan-Yu Xu, Jiang-Ping Wu, De-Liang Tao, Jin-Ming Chen, Ying-Ying Fan, Xin Yang, Jun-Ke Song, Guang-Hui Zhao.

   BACKGROUND: The pathogenicity of Toxoplasma gondii is closely associated with its intracellular lytic cycle in host cells. Currently, the mechanisms by which T. gondii completes the lytic cycle remain unclear. The proline metabolism has been reported to be crucial for intracellular growth of pathogens by providing energy and nutrients. However, it remains unclear whether the intracellular growth and pathogenicity of T. gondii are related to proline metabolism.
METHODS: The gene-edited strains of proline dehydrogenase (Tgprodh) were constructed by using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR-Cas9) technology. The effects of the Tgprodh gene on the growth in vitro and pathogenicity in vivo of the tachyzoites for T. gondii were studied through proliferation, plaque, invasion, egress and virulence assays. The effects of the Tgprodh gene on mitochondrial function were studied by using reactive oxygen species (ROS), mitochondrial membrane potential (∆Ψm), adenosine triphosphate (ATP) assay kits, mitochondrial DNA (mtDNA) copy numbers, transmission electron microscopy (TEM) analysis, and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). The effects of the Tgprodh gene on proline metabolism were studied by using L-proline (L-Pro), L-glutamic acid (L-Glu), L-glutamine (L-Gln) assay kits, and RT-qPCR.
RESULTS: TgPRODH, the first rate-limiting enzyme in proline metabolism, was identified to be encoded by T. gondii and localized in the cytoplasm of T. gondii. Deletion of the Tgprodh gene resulted in significant growth inhibition in vitro and reduced pathogenicity in vivo of T. gondii. Further study found that deletion of the Tgprodh gene caused damage to the mitochondrial morphology, decreased membrane potential, mtDNA copy numbers, and the production of ATP and ROS. The expression of genes for maintaining mitochondrial integrity was downregulated in the Tgprodh-knockout strain of T. gondii, while complementation of the Tgprodh gene restored these defects in this parasite. Meantime, the deletion of the Tgprodh gene resulted in the accumulation of proline, reduced the contents of glutamate and glutamine, and affected the expression of genes related to proline catabolism in T. gondii.
CONCLUSIONS: The present study found the significance of the Tgprodh gene for the intracellular growth and pathogenicity of T. gondii through regulating mitochondrial function and the proline metabolism and provided a novel insight to reveal intracellular survival strategies of T. gondii.

Keywords:   Tgprodh ; Toxoplasma gondii ; Growth; Mitochondrial function; Proline metabolism

DOI:  https://doi.org/10.1186/s13071-025-06966-x
Front Psychiatry. 2025 ;16 1639610

Correction: Sexually aggressive behavior triggered by parasitic infection - how parasites can influence our personality.

Marco Goczol.

  [This corrects the article DOI: 10.3389/fpsyt.2025.1555024.].

Keywords:  Toxoplasma gondii; neuropsychiatric; parasitic infection; personality change; psychological behavior; sexual aggression

DOI:  https://doi.org/10.3389/fpsyt.2025.1639610
J Proteomics. 2025 Jul 25. pii: S1874-3919(25)00136-8. [Epub ahead of print]321 105509

Quantitative proteomic analysis of the Toxoplasma gondii cytoskeleton and bioinformatic identification of highly antigenic proteins.

Karina Araujo-Ruiz, Daniel Ignacio López-Flores, María Karla Martínez-Muné, Brenda Yomara García-Sánchez, Carlos J Ramírez-Flores, Francisco Ernesto Sandoval-Rodríguez, Emmanuel Ríos-Castro, Mónica Edith Mondragón-Castelán, Sirenia González-Pozos, Ricardo Mondragón-Flores.

  The Toxoplasma gondii cytoskeleton is a highly organized structure essential for parasite motility, replication, and host cell invasion. To identify its components, a highly enriched fraction of tachyzoite cytoskeletons was obtained and quantitatively analyzed by mass spectrometry. We identified 623 proteins classified into 18 functional groups, including 30 IMC proteins, 34 cytoskeleton proteins, and 14 uncharacterized proteins. A comprehensive bioinformatic analysis was conducted to assess protein abundance (fmol), antigenicity, accessibility, interactome, and homology, with the aim of identifying immunogenic targets. Among the top vaccine candidates were -GRA12, IMC1, ROP8, and -IMC4, with ROP8 emerging as the most promising based on epitope prediction. Data are available via ProteomeXchange with identifier PXD063409. SIGNIFICANCE: Toxoplasma gondii represents one of the most virulent and successful parasites in human and veterinary pathogenesis. Since T. gondii is a highly dynamic parasite that depends on its cytoskeleton to invade and disseminate through tissues, knowledge of its cytoskeleton composition is essential for understanding the biological mechanisms involved in parasite-host interactions and for the design of pharmaceutical and vaccination strategies. Quantitative proteomic analysis of the T. gondii cytoskeleton provided new and extensive information on its composition and, through bioinformatics approaches, allowed us to suggest several candidate molecules for future immunoprotective design.

Keywords:  Cytoskeleton; Immunogenic peptides; Quantitative mass spectrometry; Toxoplasma gondii

DOI:  https://doi.org/10.1016/j.jprot.2025.105509
Microorganisms. 2025 Jul 14. pii: 1661. [Epub ahead of print]13(7):

IL-24 Is a Promising Molecular Adjuvant for Enhancing Protective Immunity Induced by DNA Vaccination Against Toxoplasma gondii.

Bohuai Xu, Xiuqiang Zhang, Yaowen Wang, Jia Chen.

  Toxoplasma gondii, a parasitic protozoan, causes zoonotic infections with severe health impacts in humans and warm-blooded animals, underscoring the urgent need for effective vaccines to control these infections. In this study, a DNA vaccine encoding TgROP5, TgROP18, TgGRA7, TgGRA15, and TgMIC6 was formulated using the eukaryotic expression vector pVAX I. IL-24 was delivered as a molecular adjuvant using plasmid pVAX-IL-24. BALB/c, C57BL/6, and Kunming mouse strains received the DNA immunization, after which antibody levels, cytokine production, and lymphocyte surface markers were analyzed to assess immune responses. Additionally, survival rates and brain cyst counts were measured 1 to 2 months post-vaccination in experimental models of toxoplasmosis. As a result, compared to controls, the DNA vaccine cocktail significantly increased serum IgG levels, Th1 cytokine production, and proportions of CD4+/CD8+ T cells, leading to extended survival and reduced brain cyst counts post-challenge with T. gondii ME49. Furthermore, the five-gene DNA vaccine cocktail conferred greater protection compared to single-gene immunizations. Co-administration of IL-24 significantly enhanced the immune efficacy of the multi-gene DNA vaccination. Our findings suggest that IL-24 is an effective molecular adjuvant, enhancing the protective immunity of DNA vaccines against T. gondii, supporting its potential role in vaccine strategies targeting other apicomplexan parasites.

Keywords:  T-cell activation; Th1 immunity; protective efficacy; protozoan vaccine; serological markers

DOI:  https://doi.org/10.3390/microorganisms13071661
Immunology. 2025 Jul 31.

Pyroptosis Drives the Impairment of Colonic Barrier Integrity During Toxoplasma Gondii Chronic Infection.

Xiaokang Tian, Yihui Xing, Yumeng Zhou, Yingting Huang, Yongsheng Zhang, Jiaxin Guo, Qingling Wang, Linlin Fu, Zhen Shi, Xiaoying Yang, Wei Pan, Fenfen Sun.

  Toxoplasma gondii (T. gondii) impairs gut barrier integrity in hosts, which helps the establishment of long-term infection and is closely associated with disease progression. However, the precise mechanisms remain largely unclear. This study investigated whether pyroptosis, a form of inflammatory programmed cell death, contributes to the impairment of colonic barrier integrity induced by T. gondii chronic infection in mice. We found that the infection resulted in pronounced pathological damage in the colon, characterised by reduced colon length, decreased expression of tight junction proteins, and elevated serum LPS levels. Interestingly, the infection activated the pyroptosis pathway, supported by the higher expression of NLRP3 (NOD-like receptor thermal protein domain associated protein 3), Caspase-1, gasdermin D (GSDMD), GSDMD-N, as well as IL-1β and IL-18. In addition, dimethyl fumarate, an anti-pyroptogenic drug, significantly attenuated the infection-induced pyroptosis and colonic pathology. Notably, macrophages exhibited pyroptosis post T. gondii infection, which was attenuated by DMF treatment. Overall, our results uncover that pyroptosis is vital for the impairments of gut barrier integrity post T. gondii chronic infection.

Keywords:   toxoplasma gondii ; dimethyl fumarate; gut barrier integrity damage; pyroptosis

DOI:  https://doi.org/10.1111/imm.70023
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2025 Jun 04. 37(3): 304-309

[Generation of a dense granule protein 3 gene-deficient strain of Toxoplasma gondii and its virulence testing].

P Wang, M Wu, J Du.

   OBJECTIVE: To generate a dense granule protein 3 (GRA3) gene-deficient mutant of the Toxoplasma gondii ME49 strain and to test the virulence of the mutant.
METHODS: Gene-deficient parasites were generated with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system. Guide RNA (gRNA) was designed using the E-CRISPR software, and mutated on the pSAG1::Cas9-U6::sgUPRT plasmid using the Q5 site-directed mutagenesis kit to generate the pSAG1::Cas9-U6::sgGRA3 plasmid. A GRA3 donor plasmid containing GRA3 gene upstream sequences, pyrimethamine resistant gene dihydrofolate reductase-thymidylate synthase (DHFR-TS) and GRA3 gene downstream sequence was generated, and GRA3 donor DNA was amplified using PCR assay. The pSAG1::Cas9-U6::sgGRA3 plasmid and GRA3 donor DNA were electroporated into tachyzoites of the wild-type T. gondii ME49 strain. Then, parasite suspensions were inoculated into human foreskin fibroblast (HFF) cells and screened with pyrimethamine to yield pyrimethamine-resistant parasites for monoclonal screening. The GRA3 gene deficient monoclonal strain (ME49Δgra3) of T. gondii was identified using PCR and Western blotting assays, and the expression of GRA3 protein was determined in the T. gondii ME49Δgra3 strain using Western blotting. Subsequently, 1 000 freshly lysed tachyzoites of T. gondii ME49 and ME49Δgra3 strains were transferred to 12-well plates seeded with HFF cells, and incubated at 37 °C containing 5% CO2 for 7 days, and the number of plaques was counted by staining with crystal violet solutions. HFF cells infected with tachyzoites of T. gondii ME49 and ME49Δgra3 strains were stained using Giemsa solutions, and the numbers of cells containing 1, 2, 4, and > 4 T. gondii parasitophorous vacuoles were counted. In addition, the survival rates of C57BL/6 mice infected with T. gondii ME49 and ME49Δgra3 strains were compared 35 days post-infection.
RESULTS: PCR assay revealed successful amplification of both the upstream and downstream homologous arm bands of the DHFR-TS gene in the T. gondii ME49Δgra3 strain, and no corresponding bands were amplified in the ME49 strain. The GRA3 band was amplified in the ME49 strain, and the DHFR-TS band, rather than GRA3 band, was amplified in the ME49Δgra3 strain. Western blotting determined absence of GRA3 protein expression in the ME49Δgra3 strain. Crystal violet staining showed that the T. gondii ME49 strain produced more plaques than the ME49Δgra3 strain [(352.67 ± 26.39) plaques vs. (235.00 ± 26.29) plaques; t = 5.472, P < 0.01], and Giemsa staining revealed that the proportion of T. gondii parasitophorous vacuoles containing at least four T. gondii tachyzoites was higher in HFF cells infected with the ME49 strain than in those infected with the T. gondii ME49Δgra3 strain [(75.67 ± 2.52)% vs. (59.67 ± 2.31)%; t = 8.113, P < 0.01], and the proportion of T. gondii parasitophorous vacuoles containing at least 1 or 2 T. gondii tachyzoites was higher in HFF cells infected with the T. gondii ME49 strain than in those infected with the T. gondii ME49Δgra3 strain [(24.33 ± 2.52)% vs. (40.33 ± 2.31)%; t = -8.113, P < 0.01]. In addition, mice infected with the T. gondii ME49 and ME49Δgra3 strains started to die 8 and 9 days post-infection, and the 35-day mortality rates of mice infected with T. gondii ME49 and ME49Δgra3 strains were 10.00% and 70.00% post-infection (χ2 = 6.762, P < 0.01).
CONCLUSIONS: The T. gondii ME49Δgra3 strain has been successfully generated, and GRA3 protein may increase the virulence of the T. gondii ME49 strain.

Keywords:  Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9; Dense granule protein 3; Gene deficiency; Toxoplasma gondii; Virulence

DOI:  https://doi.org/10.16250/j.32.1915.2024293
Microbiologyopen. 2025 Aug;14(4): e70039

Quantitative Structure-Activity Relationship Modeling and Molecular Docking Studies of TgCDPK1 Inhibitors in Toxoplasma gondii.

Sara Lesani, Mehdi Tavalla, Gilda Eslami, Mohammad J Boozhmehrani.

  Toxoplasma gondii is a globally prevalent protozoan parasite responsible for severe health complications, particularly in immunocompromised individuals and during congenital infections. Existing treatments are limited by suboptimal efficacy and significant side effects, highlighting the urgent need for novel therapeutic strategies. Calcium-dependent protein kinase 1 (TgCDPK1) has emerged as a promising drug target due to its critical role in T. gondii pathogenesis and structural divergence from human kinases. This study integrates quantitative structure-activity relationship (QSAR) modeling and molecular docking to identify and prioritize potent TgCDPK1 inhibitors. A robust QSAR model was developed from a data set of 152 ligands, leveraging a systematic feature selection process to identify 23 key molecular descriptors predictive of inhibitory activity (R = 0.895, R² = 0.802). Molecular docking studies further characterized the binding interactions of top-ranked ligands, revealing strong binding affinities and favorable ADMET profiles. Notably, compound L03, identified as a substituted imidazopyrimidine derivative, demonstrated exceptional binding energy (-176.794 kcal/mol) and stability within the TgCDPK1 active site. Key interactions with Asp210(A) through hydrogen bonds and hydrophobic contacts were instrumental in its high binding affinity, underscoring its potential as a lead compound. These findings provide a comprehensive framework for rational drug design, combining computational approaches to accelerate the discovery of selective and efficacious anti-toxoplasma agents targeting TgCDPK1. This integrated methodology represents a significant advancement toward addressing the unmet clinical needs of toxoplasmosis treatment.

Keywords:  QSAR modeling; TgCDPK1 inhibitors; molecular docking; structure–activity relationship; toxoplasmosis drug discovery

DOI:  https://doi.org/10.1002/mbo3.70039
Parasit Vectors. 2025 Jul 31. 18(1): 317

Catechin gallate triggers metabolomic and lipidomic alteration in Toxoplasma gondii.

Jazmyn R Greggs, Homa Nath Sharma, Daniel A Abugri.

   BACKGROUND: Toxoplasma gondii is a zoonotic parasite, the causative agent of toxoplasmosis, which has global importance owing to its significant socioeconomic, public health, and veterinary burdens. Toxoplasmosis is currently treated with a combination of pyrimethamine and sulfadiazine. These drugs have treatment failures and toxicity and are ineffective against the bradyzoite stage. Hence, there is a need for new inhibitors against T. gondii. Catechin gallate (CG) is a known antioxidant with demonstrated antiparasitic properties. However, little is known about its anti-Toxoplasma gondii activity and mechanism of action.
METHODS: Here, we assess the effect of CG on human telomerase reverse transcriptase immortalized foreskin fibroblast (hTERT) cells, cytotoxicity, and inhibitory activity of the RH-RFP (type I) strain of T. gondii tachyzoite. Inhibitory and cytotoxicity activities were measured by a fluorescent plate reader, and the data were analyzed using Graph Pad Prism software. In addition, to predict the possible mechanism of CG action, hTERT cells were cultured in a T25 flask and infected with RH-RFP parasites, followed by CG administration and incubation for 48 h. Parasites were quenched under ice, and the parasites were purified from host cells and extracted with chloroform-methanol. The extracts containing the lipids and metabolites were analyzed using liquid chromatography-mass spectrometry (LC-MS).
RESULTS: To address this research question, we tested the in vitro inhibitory activity of CG against parasite growth at 48 h and 72 h. The half-maximal inhibitory concentration (IC50) values against tachyzoite growth were calculated to be 10.07 (8.31-12.20) µM and 7.057 (5.98-8.32) µM for 48 h and 72 h, respectively. We identified 5-formyl-tetrahydromethanopterin; 5-(6-hydroxy-6-methyloctyl)-2,5-dihydrofuran-2-one; trans-3-indoleacrylic acid; 5,5-dimethyl-2-{[(2-phenylacetyl)amino]methyl}-1,3-thiazolane-4-carboxylic acid; 5'-S-Ethyl-5'-thioadenosine; L-Norleucine; and norepinephrine sulfate as the most produced during the CG treatment. For the lipidomics analysis, we identified the production of several sphingolipid species, including ceramides, dihydroceramide, and sphingosine, which are associated with apoptosis and autophagy. The limited number of sphingomyelin and sphingosine-1-phosphate identified, which are known to promote proliferation, suggests that CG may be affecting T. gondii parasites' proliferation. In addition, oxidized fatty acids (3-hydroxypropyl stearate and (R)-3-hydroxy myristic acid) were observed in both treatments with low production, which confers oxidative stress induction on parasites.
CONCLUSIONS: The study showed that CG had inhibitory activity against T. gondii growth and caused metabolite and lipid alterations in T. gondii. This requires future studies on the enzymes associated with the biosynthesis of these metabolite/lipid pathways that are altered in these in vitro studies.

Keywords:   T. gondii ; Catechin gallate; In vitro; Lipidomics; Metabolomics

DOI:  https://doi.org/10.1186/s13071-025-06869-x
Parasite. 2025 ;32 48

Isolation of Toxoplasma gondii from the placenta of northern fur seals (Callorhinus ursinus) and potential transplacental transmission of the parasite.

Gaohui Mao, Bingyan Guo, Shanshan Xie, Yurong Yang.

  Toxoplasma gondii infects almost all warm-blooded animals, including marine mammals. Toxoplasmosis has been reported in wild and captive marine mammals in North America; however, no viable T. gondii strains have been isolated from northern fur seals. In this study, reproduction and T. gondii infection status were investigated in 10 northern fur seals (Callorhinus ursinus), from tissues collected from 2012 to 2024 in China. Toxoplasma gondii infections were determined by the modified agglutination test (MAT), PCR, immunohistochemical (IHC) staining, and isolation of the parasite by bioassay in mice. MAT was performed using placenta or tissue exudates to detect anti-T. gondii IgG antibodies. Four of the 10 seals had anti-T. gondii antibodies; Toxoplasma gondii DNA was detected by PCR in placenta tissues of two of these four animals, and T. gondii antibody positive reactions were observed in four seals by IHC. A viable T. gondii strain, TgFurSealCHn1, was isolated from placenta of one seal by bioassay in mice. In all, five seals had signs of T. gondii infection, and three of them had fetal stillbirth. One stillborn fetus had T. gondii nucleic acid detected by PCR, indicating potential vertical transmission of the parasite. Multilocus genetic typing of the TgFurSealCHn1 isolate revealed ToxoDB #5 genotype, which had demonstrated avirulence in Swiss Webster outbred mice, and the ROP18/ROP5 type was 2/2. ToxoDB #5 is the dominant genotype of wild terrestrial and marine mammals in North America. This is the first report of a viable T. gondii strain isolated from northern fur seal placenta.

Keywords:  Avirulence; Fur seal (Callorhinus ursinus); Isolation; ToxoDB#5; Toxoplasma gondii

DOI:  https://doi.org/10.1051/parasite/2025045
Iran J Pharm Res. 2025 Jan-Dec;24(1):24(1): e157086

Evaluating The Therapeutic Effect of 2-Nitroimidazole on Toxoplasma gondii: An In vitro and In vivo Study Using BALB/c Mice.

Elaheh Ghiasipour, Javid Sadraei, Fatemeh Ghaffarifar.

   Background: Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, remains a significant health concern due to its widespread prevalence and severe impact on immunocompromised individuals. Current treatments are limited, necessitating the exploration of new therapeutic agents.
Objectives: This study aimed to evaluate the efficacy and safety of 2-nitroimidazole as a potential treatment for toxoplasmosis in BALB/c mice, comparing its effects with the standard treatment, sulfadiazine.
Methods: In vitro assays were conducted to determine the half-maximal inhibitory concentration (IC50) of 2-nitroimidazole and sulfadiazine against T. gondii tachyzoites. The MTT assay was used to assess the cytotoxicity of 2-nitroimidazole on macrophages. In vivo experiments involved treating BALB/c mice infected with T. gondii with either 2-nitroimidazole or sulfadiazine, monitoring survival rates and therapeutic outcomes.
Results: In vitro results revealed IC50 values of 5.43 μM for 2-nitroimidazole and 2.99 μM for sulfadiazine, indicating potent anti-tachyzoite activity. The MTT assay showed that 2-nitroimidazole had low cytotoxicity, with significant cell viability even at higher concentrations. Based on the MTT assay findings, 40 μM of 2-nitroimidazole showed the highest level of toxicity towards macrophages. Furthermore, flow cytometry analysis revealed that this compound induced apoptosis in approximately 58.9% of tachyzoites. In vivo, all mice in the control group died by the eighth day. Treatment with sulfadiazine resulted in two mice surviving until the 14th day, while 2-nitroimidazole treatment saw one mouse surviving to the same day. These findings suggest that 2-nitroimidazole has comparable efficacy to sulfadiazine with potentially fewer side effects.
Conclusions: The study demonstrates that 2-nitroimidazole is a promising candidate for the treatment of toxoplasmosis, exhibiting strong anti-parasitic activity and low cytotoxicity. Further research is warranted to optimize dosing regimens and explore combination therapies to enhance its therapeutic potential.

Keywords:  2-Nitroimidazole; In vitro; In vivo; Sulfadiazine; Tachyzoite; Toxoplasma gondii

DOI:  https://doi.org/10.5812/ijpr-157086
Microorganisms. 2025 Jun 29. pii: 1517. [Epub ahead of print]13(7):

Low Tenacity of Toxoplasma gondii Tachyzoites In Vitro.

Thomas Grochow, Mirjam Kalusa, Pauline Tonndorf-Martini, Nicole Röhrmann, Simone A Fietz, Lea-Christina Murnik.

  Toxoplasma gondii, an obligate intracellular protozoan, poses significant risks to public health due to its widespread distribution and potential for severe congenital and neurological complications. The fast-replicating tachyzoite stage is crucial for acute infection and laboratory studies, yet effective inactivation methods remain inadequately explored. This study evaluates various chemical and physical approaches to inactivate T. gondii tachyzoites in vitro. Using a combination of GFP fluorescence and viability assays, we demonstrated the complete inactivation of tachyzoites with ethanol (≥30%), hydrogen peroxide (≥3%), o-hydroxydiphenyl fatty acid eutectic with peracetic acid (≥1%), and heat treatment at 60 °C for 30 min. Our findings highlight the importance of concentration, solvent choice, and exposure time in disinfection efficacy, providing a framework for improving laboratory safety protocols. These results contribute to the refinement of inactivation strategies, supporting safer handling and research on T. gondii in vitro while reducing reliance on animal models.

Keywords:  Toxoplasma gondii; cell culture; chemical treatment; disinfection; heat inactivation; in vitro; tachyzoites; tenacity

DOI:  https://doi.org/10.3390/microorganisms13071517
Genes (Basel). 2025 Jul 20. pii: 844. [Epub ahead of print]16(7):

Placental Expression of Sirtuins in Women with Gestational Diabetes.

Michał Czerewaty, Łukasz Ustianowski, Kajetan Kiełbowski, Estera Bakinowska, Krzysztof Safranow, Maciej Tarnowski, Tomasz Sroczyński, Andrzej Pawlik.

   BACKGROUND/OBJECTIVES: Gestational diabetes mellitus (GDM) is a common metabolic disorder in pregnant women. It can lead to several complications, such as preterm delivery, macrosomia, or metabolic disorders in newborns. Studies have revealed morphological and transcriptional differences between the placentas of patients with GDM and women with normal glucose tolerance. Sirtuins (SIRTs) are nicotinamide adenine dinucleotide-dependent deacetylases that interact with and regulate the activity of numerous proteins. However, little is known about their role in the pathogenesis of GDM. This study was performed to analyze the placental expression of SIRTs and investigate their correlations with clinical parameters.
METHODS: GDM was diagnosed based on the 75 g oral glucose tolerance test in accordance with the criteria developed by the International Association of Diabetes and Pregnancy Study Groups. Placental tissues were collected, and the expression of SIRT1,-3,-4 and a reference gene (β-2 microglobulin) was analyzed.
RESULTS: The placental expression of SIRT1 and SIRT3 was elevated in women with GDM. However, there was no significant difference in SIRT4 expression between women with GDM and those with normal glucose tolerance. Furthermore, we found no significant correlations between SIRT1, SIRT3, and SIRT4 expression and clinical parameters.
CONCLUSIONS: The findings of this study demonstrate elevated expression of SIRT1 and SIRT3 in the placentas of women with GDM. Further studies are required to confirm our observations and demonstrate the precise role of these enzymes in GDM.

Keywords:  gestational diabetes mellitus; placenta; sirtuin

DOI:  https://doi.org/10.3390/genes16070844
Metabolism. 2025 Jul 24. pii: S0026-0495(25)00225-2. [Epub ahead of print]172 156356

Unraveling the roles of mitochondrial sirtuins in aging-related diseases: From mechanistic insights to therapeutic strategies.

Yanyan Cao, Yan Wang, Na Zhao, Ziyue Yuan, Lan Zhang, Peng Jin.

  Mitochondrial sirtuins, including SIRT3, SIRT4, and SIRT5, play pivotal roles in maintaining mitochondrial homeostasis by regulating oxidative phosphorylation, energy metabolism, and redox balance. Dysregulation of these enzymes is closely associated with the pathogenesis of aging-related diseases such as neurodegenerative diseases, metabolic diseases, and cardiovascular diseases. SIRT3 has been the most extensively studied, demonstrating protective effects against oxidative stress and metabolic dysregulation. In contrast, while SIRT4 and SIRT5 are less characterized, they are critical for the regulation of insulin sensitivity, nitrogen metabolism, and mitochondrial function. This review focuses on the involvement of mitochondrial sirtuins in modulating cellular metabolism, redox balance, and mitochondrial homeostasis, highlighting their roles in the development and progression of aging-related diseases. Furthermore, we provide an overview of small-molecule modulators targeting mitochondrial sirtuins, which aim to restore cellular function, attenuate aging processes, and offer novel therapeutic strategies for treating aging-related diseases.

Keywords:  Aging-related diseases; Mechanism; Mitochondrial sirtuins; Small-molecule compounds

DOI:  https://doi.org/10.1016/j.metabol.2025.156356
Int J Mol Sci. 2025 Jul 10. pii: 6634. [Epub ahead of print]26(14):

Sirtuins Contribute to the Migraine-Stroke Connection.

Jan Krekora, Michal Fila, Maria Mitus-Kenig, Elzbieta Pawlowska, Justyna Ciupinska, Janusz Blasiak.

  The prevalence of stroke in patients with migraine is higher than in the general population, suggesting certain shared mechanisms of pathogenesis. Migrainous infarction is a pronounced example of the migraine-stroke connection. Some cases of migraine with aura may be misdiagnosed as stroke, with subsequent mistreatment. Therefore, it is important to identify these shared mechanisms of pathogenesis contributing to the migraine-stroke connection to improve diagnosis and treatment. Sirtuins (SIRTs) are a seven-member family of NAD+-dependent histone deacetylases that can epigenetically regulate gene expression. Sirtuins possess antioxidant properties, making them a first-line defense against oxidative stress, which is important in the pathogenesis of migraine and stroke. Mitochondrial localization of SIRT2, SIRT3, and SIRT4 supports this function, as most reactive oxygen and nitrogen species are produced in mitochondria. In this narrative review, we present arguments that sirtuins may link migraine with stroke through their involvement in antioxidant defense, mitochondrial quality control, neuroinflammation, and autophagy. We also indicate mediators of this involvement that can be, along with sirtuins, therapeutic targets to ameliorate migraine and prevent stroke.

Keywords:  migraine; migraine–stroke connection; oxidative stress; sirtuins; stroke

DOI:  https://doi.org/10.3390/ijms26146634
Cell Signal. 2025 Jul 29. pii: S0898-6568(25)00444-9. [Epub ahead of print]135 112029

SIRT3 deficiency aggravates mitochondrial metabolic disorder and podocyte injury in DKD via MPC2 acetylation.

Jun Feng, Ling Feng, Yu Yan, Huiluan Ye, Kaiyue Tang, Xiaohua Guo, Yiqiong Ma.

   BACKGROUND: Diabetic kidney disease (DKD) is a chronic disease characterized by high prevalence and mortality rates. Podocyte injury and mitochondrial metabolic disorder are crucial in its progression. Sirtuin3 (SIRT3), a mitochondrial NAD+-dependent deacetylase, exerts renoprotective effects in various kidney pathologies by modulating the acetylation status and activity of energy metabolism related substrates. However, its specific roles in podocytes homeostasis during DKD progression remain unclear. We previously reported the role and acetylation level of mitochondrial pyruvate carrier 2 (MPC2) in DKD, but the regulatory mechanism between SIRT3 and MPC2 has not been elucidated. This study aims to investigate the effect of SIRT3 on mitochondrial reprogramming in podocytes and explore the association between SIRT3 and MPC2 during DKD progression.
RESULT: SIRT3 expression was downregulated in hyperglycemia-induced podocytes in vivo and in vitro. SIRT3 deficiency aggravated podocyte apoptosis and mitochondrial homeostasis dysregulation, as evidenced by increased ROS production, decreased mitochondrial membrane potential and diminished ATP level. However, the overexpression of SIRT3 alleviated these alterations. In addition, we identified a binding interaction between SIRT3 and MPC2. SIRT3 deacetylated MPC2 at lysine K19/K27, mechanistically implicated in the podocyte injury in the process of DKD.
CONCLUSION: This study validated that hyperglycemia-induced SIRT3-mediated MPC2 acetylation contributes to mitochondrial dysfunction and cellular apoptosis.

Keywords:  Acetylation; Diabetic kidney disease; MPC2; Mitochondria; Podocytes; SIRT3

DOI:  https://doi.org/10.1016/j.cellsig.2025.112029
Cell Death Differ. 2025 Jul 30.

Histone deacetylase 6 deacetylates and ubiquitinates ATG3 to regulate autophagy.

Jiayu Yao, Ziyang Zhao, Yousheng Chen, Xuan Xu, Ying Yang, Weiying Yue, Xingjuan Shi.

ATG3 (autophagy-related gene 3), an E2 like enzyme, plays a vital role in autophagy by regulating the lipidation modification of LC3 (microtubule-associated protein 1A/1B-light chain 3). Although the level of ATG3 can be reduced by the ubiquitin-proteasome pathway, the detailed mechanisms of this regulation remain elusive. Histone deacetylase 6 (HDAC6) is involved in multiple cellular activities by regulating acetylation of its substrates such as α-tubulin and cortactin. Here, we revealed a novel function of HDAC6 in autophagy regulation by mediating the post-translational modifications of ATG3. We found that HDAC6 interacts with ATG3 and deacetylates ATG3. In addition, HDAC6 acts its ubiquitin E3 ligase activity and ubiquitinates ATG3 at lysine 272, leading to ATG3 degradation. Intriguingly, lysine 272 of ATG3 is targeted for deacetylation as well as ubiquitination by HDAC6. Further study showed that HDAC6 participates in autophagy by mediating ATG3 degradation. Taken together, our findings uncover a novel role of HDAC6 in autophagy regulation by mediating the protein modification and degradation of ATG3.

DOI: https://doi.org/10.1038/s41418-025-01553-0
Curr Opin Infect Dis. 2025 Aug 01.

Human toxoplasmosis: current advances in the field.

Anna Beltrame, Kami Kim, Louis M Weiss.

   PURPOSE OF REVIEW: Human toxoplasmosis remains a significant, yet often underrecognized, global health concern. This review highlights emerging advances in prevention and management, offering timely updates for clinicians and researchers.
RECENT FINDINGS: Recent venison-associated outbreaks in the United States have emphasized the risk of ocular toxoplasmosis and severe disease in immune competent individuals and the need for heightened clinical suspicion. Updated guidelines for hematopoietic stem cell transplant (HSCT) recipients now recommend systematic screening, qPCR monitoring, and prophylaxis to reduce mortality from Toxoplasma gondii reactivation. Emerging evidence suggests that chronic T. gondii infection may contribute to adverse pregnancy outcomes, challenging the long-held assumption that chronic infection is protective against these complications. Although the potential association between chronic T. gondii infection and neuropsychiatric disorders remains debated, its public health relevance warrants further investigation.
SUMMARY: Improved clinical awareness, applied preventive strategies, and expanded research are essential to mitigate the broader health impact of chronic T. gondii infection. Future well designed studies and rigorous analyses are critical to defining maternal-fetal risks and potential neuropsychiatric effects, providing the evidence needed to update clinical guidelines and inform public health policies.

Keywords:  ; chronic infection; qPCR; transplantation; venison

DOI:  https://doi.org/10.1097/QCO.0000000000001130
Cancer Res. 2025 Jul 25.

Mitochondrial Calcium Uniporter Links Acetyl-CoA Metabolism and H3K27 Acetylation to Maintain Glioblastoma Stem Cells.

Guangqin Liu, Haoqian Zhang, Siqi Chen, Jun Gao, Haixin Zhao, Yan Dong, Changwei Liu, Xuechen Wei, Ting Li, Chang Lu, Haizhen Zhu, Dingyi Lu, Shiyu Feng, Teng Li, Weina Zhang, Qing Xia, Jianghong Man, Tao Zhou, Jiayi Chen, Ailing Li, Xin Pan.

Glioblastoma stem cells (GSCs) exhibit remarkable metabolic and epigenetic adaptability, contributing to therapeutic resistance and tumor recurrence. The mechanisms underlying this plasticity represent potential targetable vulnerabilities to improve glioblastoma treatment. Here, we identified a critical metabolic-epigenetic axis centered on the mitochondrial calcium uniporter (MCU) that governs GSC survival and tumor initiation. MCU was preferentially expressed in GSCs, and loss of MCU significantly impaired GSC self-renewal and viability. Mechanistically, MCU enhanced mitochondrial calcium uptake, promoting acetyl-CoA production via pyruvate dehydrogenase activation. Elevated acetyl-CoA levels drove histone H3K27 acetylation at the TRIB3 locus to maintain GSC growth. In glioblastoma patients, higher MCU expression was correlated with increased acetyl-CoA levels, elevated H3K27 acetylation, enhanced TRIB3 expression, higher tumor grade, and poorer survival. Pharmacological inhibition of MCU with berberine suppressed GSC growth and extended survival in mouse GBM models. These findings establish MCU as a critical link between mitochondrial metabolism and epigenetic regulation, highlighting its potential as a therapeutic target for glioblastoma.

DOI: https://doi.org/10.1158/0008-5472.CAN-25-0419
Exp Eye Res. 2025 Jul 29. pii: S0014-4835(25)00334-3. [Epub ahead of print] 110563

Amino Acid Metabolism and Photoreceptor Degenerative Diseases: Mechanisms, Early Diagnosis, and Therapeutic Prospects.

Qin Zhang, Bintao Xie, Liujun Ding, Lue Xiang, Jing Wang, Jineng Lv, Qi Chen.

  Photoreceptor degeneration is a key characteristic of degenerative retinal diseases, leading to severe visual impairment and adversely affecting the quality of life of patients. Amino acid metabolism is closely related to cellular protein synthesis, lipid metabolism, and energy metabolism. These processes work synergistically to maintain normal photoreceptor functions. Recently, interruptions in amino acid metabolism have been found to play a pivotal role in photoreceptor degeneration, triggering or exacerbating retinal lesions. To understand the regulatory mechanisms and potential therapeutic targets of amino acid metabolism in photoreceptor degeneration, this study reviewed the functions of various amino acid metabolites (glutamate and taurine), metabolic pathways (branched-chain amino acid catabolism and aminoacyl-tRNA biosynthesis), and key enzymes (arginase-1 and glutamine synthetase), as well as the consequences of their dysregulation on photoreceptors.

Keywords:  Amino acid metabolism; Metabolic dysregulation; Photoreceptors; Retinal degenerative diseases

DOI:  https://doi.org/10.1016/j.exer.2025.110563
Signal Transduct Target Ther. 2025 Aug 01. 10(1): 243

Epigenetic regulation of cancer stemness.

Claudia Galassi, Gwenola Manic, Manel Esteller, Lorenzo Galluzzi, Ilio Vitale.

Gene expression is finely controlled by the abundance and activation status of transcription factors and their regulators, as well as by a number of reversible modifications of DNA and histones that are commonly referred to as epigenetic marks. Such alterations (i.e., methylation, acetylation, and ubiquitination) are catalyzed by an array of dedicated enzymes with antagonistic activity, including methyltransferases and demethylases, acetyltransferases and deacetylases, as well as ubiquitin ligases and deubiquitinating enzymes. The epigenetic control of transcription is critical not only for embryonic and postembryonic development but also for the preservation of homeostasis in all adult tissues. In line with this notion, epigenetic defects have been associated with a variety of human disorders, including (but not limited to) congenital conditions as well as multiple hematological and solid tumors. Here, we provide an in-depth discussion of the impact of epigenetic alterations on cancer stemness, i.e., the ability of a small population of poorly differentiated malignant cells to (1) self-renew while generating a more differentiated progeny, and (2) exhibit superior tumor initiating/repopulating potential along with exceptional plasticity and improved resistance to environmental and therapy-elicited stress. Moreover, we critically evaluate the potential and limitations of targeting epigenetic modifiers as a means to eradicate cancer stem cells for therapeutic purposes.

DOI: https://doi.org/10.1038/s41392-025-02340-6