Complex I inhibition collapses host bioenergetics and activates p53‐dependent apoptosis in Theileria annulata infected cells
- 1National Institute of Animal Biotechnology , ,
- 2Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER) , ,
- 3Laboratory of Infectious Diseases, Centre for DNA Fingerprinting and Diagnostics (CDFD) , ,
Abstract
Introduction: Protozoan parasites continue to impose a major burden on human and veterinary health, while emerging drug resistance increasingly limits treatment options. Identifying conserved biological vulnerabilities shared across diverse parasites may facilitate the development of new therapeutic strategies. Here, we investigated whether mitochondrial electron transport represents a common metabolic vulnerability in drug-resistant protozoan pathogens.
Methods: The Medicines for Malaria Venture Global Health Priority Box (GHPB) was screened against Theileria annulata-infected cells to identify compounds affecting parasite survival. Rotenone was evaluated using cell viability assays, flow cytometry, mitochondrial membrane potential, reactive oxygen species (ROS) detection, apoptosis assays, transcriptomic profiling, drug combination studies, and comparative bioinformatic analyses.
Results: Rotenone selectively inhibited T. annulata-infected cells (IC50 = 1.30 ± 0.27 μM) while sparing uninfected cells, retained efficacy against buparvaquone-resistant cells, and showed activity against Leishmania donovani (IC50 = 10.12 ± 0.98 μM), Entamoeba histolytica (IC50 = 32.94 ± 0.27μM), and Naegleria fowleri (44.27 ± 4.02% mortality at 20μM). suggesting a conserved mitochondrial vulnerability across evolutionarily distinct protozoan pathogens. Mitochondrial electron transportdisruption induced membrane depolarization, elevated ROS, γH2AX-associated DNA damage, phospho-p53 (Ser15) activation, G2/M-phase arrest, and caspase-9/-3-dependent apoptosis. Transcriptomic profiling revealed oxidative and proteotoxic stress with suppression of metabolic and translational pathways. Synergism between inhibitors of mitochondrial complexes I and III further supported mitochondrial electron transport as a therapeutically exploitable pathway.
Discussion: These findings reveal mitochondria‐dependent vulnerabilities as exploitable weaknesses across protozoa. Rotenone, though unsuitable for clinical use due to systemic toxicity, serves as a prototype compound that demonstrates mitochondrial metabolic vulnerability beyond lineage boundaries. By establishing mitochondrial bioenergetics as a resistance‐independent therapeutic node, this work provides a foundation for designing safer, broad‐spectrum antiparasitic agents that selectively exploit mitochondrial pathways.
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BibTeX
@article{subudhi2026complex,
title = {{Complex I inhibition collapses host bioenergetics and activates p53‐dependent apoptosis in Theileria annulata infected cells}},
author = {Madhusmita Subudhi and Siva Singothu and Vasundhra Bhandari and Umarani Brahma and Kuldeep Verma and Padavala Navyaka and Akash Suresh and Sakshi Singh and Paresh Sharma},
journal = {Frontiers in cellular and infection microbiology},
year = {2026},
month = oct,
doi = {10.3389/fcimb.2026.1908136},
url = {https://europepmc.org/article/PMC/PMC13724478},
note = {CC BY},
}
RIS
TY - JOUR
TI - Complex I inhibition collapses host bioenergetics and activates p53‐dependent apoptosis in Theileria annulata infected cells
AU - Madhusmita Subudhi
AU - Siva Singothu
AU - Vasundhra Bhandari
AU - Umarani Brahma
AU - Kuldeep Verma
AU - Padavala Navyaka
AU - Akash Suresh
AU - Sakshi Singh
AU - Paresh Sharma
PY - 2026
DA - 2026/10/19
JO - Frontiers in cellular and infection microbiology
DO - 10.3389/fcimb.2026.1908136
UR - https://europepmc.org/article/PMC/PMC13724478
AB - Introduction: Protozoan parasites continue to impose a major burden on human and veterinary health, while emerging drug resistance increasingly limits treatment options. Identifying conserved biological vulnerabilities shared across diverse parasites may facilitate the development of new therapeutic strategies. Here, we investigated whether mitochondrial electron transport represents a common metabolic vulnerability in drug-resistant protozoan pathogens. Methods: The Medicines for Malaria Venture Global Health Priority Box (GHPB) was screened against Theileria annulata-infected cells to identify compounds affecting parasite survival. Rotenone was evaluated using cell viability assays, flow cytometry, mitochondrial membrane potential, reactive oxygen species (ROS) detection, apoptosis assays, transcriptomic profiling, drug combination studies, and comparative bioinformatic analyses. Results: Rotenone selectively inhibited T. annulata-infected cells (IC50 = 1.30 ± 0.27 μM) while sparing uninfected cells, retained efficacy against buparvaquone-resistant cells, and showed activity against Leishmania donovani (IC50 = 10.12 ± 0.98 μM), Entamoeba histolytica (IC50 = 32.94 ± 0.27μM), and Naegleria fowleri (44.27 ± 4.02% mortality at 20μM). suggesting a conserved mitochondrial vulnerability across evolutionarily distinct protozoan pathogens. Mitochondrial electron transportdisruption induced membrane depolarization, elevated ROS, γH2AX-associated DNA damage, phospho-p53 (Ser15) activation, G2/M-phase arrest, and caspase-9/-3-dependent apoptosis. Transcriptomic profiling revealed oxidative and proteotoxic stress with suppression of metabolic and translational pathways. Synergism between inhibitors of mitochondrial complexes I and III further supported mitochondrial electron transport as a therapeutically exploitable pathway. Discussion: These findings reveal mitochondria‐dependent vulnerabilities as exploitable weaknesses across protozoa. Rotenone, though unsuitable for clinical use due to systemic toxicity, serves as a prototype compound that demonstrates mitochondrial metabolic vulnerability beyond lineage boundaries. By establishing mitochondrial bioenergetics as a resistance‐independent therapeutic node, this work provides a foundation for designing safer, broad‐spectrum antiparasitic agents that selectively exploit mitochondrial pathways.
SN - 2235-2988
ER -