Mitochondrial perturbation is a key event in chemical-induced organ toxicities that is incompletely understood. Here, we studied how electron transport chain (ETC) complex I, II, or III (CI, CII and CIII) inhibitors affect mitochondrial functionality, stress response activation, and cell viability using a combination of high-content imaging and TempO-Seq in HepG2 hepatocyte cells. CI and CIII inhibitors perturbed mitochondrial membrane potential (MMP) and mitochondrial and cellular ATP levels in a concentration- and time-dependent fashion and, under conditions preventing a switch to glycolysis attenuated cell viability, whereas CII inhibitors had no effect. TempO-Seq analysis of changes in mRNA expression pointed to a shared cellular response to CI and CIII inhibition. First, to define specific ETC inhibition responses, a gene set responsive toward ETC inhibition (and not to genotoxic, oxidative, or endoplasmic reticulum stress) was identified using targeted TempO-Seq in HepG2. Silencing of one of these genes, NOS3, exacerbated the impact of CI and CIII inhibitors on cell viability, indicating its functional implication in cellular responses to mitochondrial stress. Then by monitoring dynamic responses to ETC inhibition using a HepG2 GFP reporter panel for different classes of stress response pathways and applying pathway and gene network analysis to TempO-Seq data, we looked for downstream cellular events of ETC inhibition and identified the amino acid response (AAR) as being triggered in HepG2 by ETC inhibition. Through in silico approaches we provide evidence indicating that a similar AAR is associated with exposure to mitochondrial toxicants in primary human hepatocytes. Altogether, we (i) unravel quantitative, time- and concentration-resolved cellular responses to mitochondrial perturbation, (ii) identify a gene set associated with adaptation to exposure to active ETC inhibitors, and (iii) show that ER stress and an AAR accompany ETC inhibition in HepG2 and primary hepatocytes.
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http://dx.doi.org/10.1007/s00204-021-03160-7 | DOI Listing |
Sci Rep
December 2024
Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka, 422-8526, Shizuoka, Japan.
The cell painting assay is useful for understanding cellular phenotypic changes and drug effects. To identify other aspects of well-known chemicals, we screened 258 compounds with the cell painting assay and focused on a mitochondrial punctate phenotype seen with disulfiram. To elucidate the reason for this punctate phenotype, we looked for clues by examining staining steps and gene knockdown as well as examining protein solubility and comparing cell lines.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, People's Republic of China.
Fibroblast-mediated oxidative stress is a pivotal factor in the pathogenesis of skin photoaging, predominantly induced by UVA radiation. Diverging from traditional strategies that concentrate on the reduction of reactive oxygen species (ROS), the present study implements mitochondrial transplantation as an innovative therapeutic approach. The objective of this study is to reestablish the oxidative microenvironment and to effectively rejuvenate cellular functionality through the direct introduction of healthy and vibrant mitochondria.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Virus and Cellular Stress Unit, Department of Virology, Université Paris Cité, Institut Pasteur, 28 rue du Dr. Roux, F-75724 Paris cedex 15, France. Electronic address:
Perturbation of the deoxyribonucleotide triphosphate (dNTP) pool is recognized for contributing to the mutagenic processes involved in oncogenesis. The RAS gene family encodes well characterized oncoproteins whose structure and function are among the most frequently altered in several cancers. In this work, we show that fluctuation of the dNTP pool induces CG->TA mutations across the whole genome, including RAS gene at codons for glycine 12 and 13, known hotspots in cancers.
View Article and Find Full Text PDFEnviron Int
December 2024
Key Laboratory of Environmental Medicine Engineering of Ministry of Education, School of Public Health, Southeast University, Nanjing, Jiangsu 210009, China; Department of Toxicology, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China. Electronic address:
Fine particulate matter (PM2.5) is increasingly recognized for its detrimental effects on human health, with substantial evidence linking exposure to various forms of cell death and dysfunction across multiple organ systems. This review examines key cell death mechanisms triggered by PM2.
View Article and Find Full Text PDFBiomaterials
May 2025
Department of Dental Materials & Dental Medical Devices Testing Center & NMPA Key Laboratory for Dental Materials & Beijing Key Laboratory of Digital Stomatology, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & National Center for Stomatology & National Clinical Research Center for Oral Diseases & NHC Research Center of Engineering and Technology for Computerized Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China; Institute of Advanced Clinical Medicine, Peking University, Beijing, 100191, China. Electronic address:
The hemostatic, inflammatory, proliferative, and remodeling phases of healing require precise spatiotemporal coordination and orchestration of numerous biological processes. As the primary energy generators in the cell, mitochondria play multifunctional roles in regulating metabolism, stress reactions, immunity, and cell density during the process of tissue regeneration. Mitochondrial dynamics involves numerous crucial processes, fusion, fission, autophagy, and translocation, which are all necessary for preserving mitochondrial function, distributing energy throughout cells, and facilitating cellular signaling.
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