title: Establishment of HK-2 Cells as a Relevant Model to Study Tenofovir-Induced Cytotoxicity.
abstract: Tenofovir (TFV) is an antiviral drug approved for treating Human Immunodeficiency Virus (HIV) and Hepatitis B. TFV is administered orally as the prodrug tenofovir disoproxil fumarate (TDF) which then is deesterified to the active drug TFV. TFV induces nephrotoxicity characterized by renal failure and Fanconi Syndrome. The mechanism of this toxicity remains unknown due to limited experimental models. This study investigated the cellular mechanism of cytotoxicity using a human renal proximal tubular epithelial cell line (HK-2). HK-2 cells were grown for 48 h followed by 24 to 72 h exposure to 0-28.8 μM TFV or vehicle, phosphate buffered saline (PBS). MTT (MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) and Trypan blue indicated that TFV diminished cell viability at 24-72 h. TFV decreased ATP levels at 72 h when compared to vehicle, reflecting mitochondrial dysfunction. TFV increased the oxidative stress biomarkers of protein carbonylation and 4-hydroxynonenol (4-HNE) adduct formation. Tumor necrosis factor alpha (TNFα) was released into the media following exposure to 14.5 and 28.8 μM TFV. Caspase 3 and 9 cleavage was induced by TFV compared to vehicle at 72 h. These studies show that HK-2 cells are a sensitive model for TFV cytotoxicity and suggest that mitochondrial stress and apoptosis occur in HK-2 cells treated with TFV.
authors.affiliation: Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA. murphyrachel63@gmail.com.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Murphy
authors.affiliation: Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA. stafford34@marshall.edu.
authors.forename: Reagan M
authors.initials: RM
authors.lastname: Stafford
authors.affiliation: Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA. bpetrasovits2010@aol.com.
authors.forename: Brooke A
authors.initials: BA
authors.lastname: Petrasovits
authors.affiliation: West Virginia Wesleyan College, Buckhannon, WV 26201, USA. boone.195@osu.edu.
authors.forename: Megann A
authors.initials: MA
authors.lastname: Boone
authors.affiliation: Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA. valentov@marshall.edu.
authors.forename: Monica A
authors.initials: MA
authors.lastname: Valentovic
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology* / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D001205:Ascorbic Acid / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D007687:Kidney Tubules, Proximal / Q000166:cytology; D008928:Mitochondria / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D000068698:Tenofovir / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D019380:Anti-HIV Agents; D000068698:Tenofovir; D001205:Ascorbic Acid
keywords: Fanconi Syndrome; HK-2 cells; nephrotoxicity; tenofovir; tenofovir disoproxil fumarate