Affiliation:
1. Division of Clinical Immunology, Hannover Medical School, Hannover, Germany
2. Department for Paediatric Kidney and Liver Diseases and Metabolic Disorders, Hannover Medical School, Hannover, Germany
Abstract
ObjectiveTo study the impact of adipocyte differentiation on nucleoside reverse transcriptase inhibitor (NRTI)-mediated mitochondrial DNA (mtDNA) depletion and to correlate mtDNA depletion with the activity of the respiratory chain complexes.MethodsWe studied adipocyte phenotype, viability, differentiation (CCAAT/enhancer-binding protein [C/EBP]-α and peroxisome proliferator-activated receptor [PPAR]-γ expression), adiponectin production, mtDNA content, activity of respiratory chain complexes and citrate synthase activity in 3T3–L1 adipocytes. Cells were exposed to zidovudine (6 μM or 180 μM), stavudine (3 μM or 90 μM), and zalcitabine (0.1 μM or 3 μM) at different developmental stages for up to 2 months.ResultsZidovudine and stavudine impaired adiponectin production in vitro at therapeutic Cmaxconcentrations, but none of the tested NRTIs had a negative impact on adipocyte differentiation or led to mtDNA depletion at these concentrations. Susceptibility of preadipocytes to mtDNA depletion was dependent on cell proliferation and differentiation, and mtDNA depletion occurred only after exposure to high drug concentrations. Under these conditions, stavudine led to up to 80% mtDNA depletion in both dividing and differentiating preadipocytes, whereas zidovudine affected mtDNA only in the differentiating cells. Despite mtDNA depletion by NRTIs, activity of the respiratory chain complexes was found to be unimpaired.ConclusionsWe found mtDNA depletion in adipocytes but proliferation and/or differentiation of the cells seems to be a prerequisite for this phenomenon. Depletion of mtDNA up to 80%, however, was not associated with impaired respiratory chain activity in 3T3-L1 preadipocytes.
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology