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Updated: Jul 14, 2026
High-Throughput Image-Based Quantification of Mitochondrial DNA Synthesis and Distribution
Published on: May 5, 2023
Relationship of mitochondrial DNA depletion and respiratory chain activity in preadipocytes treated with nucleoside
Metodi V Stankov1, Thomas Lücke, Anibh M Das
1Division of Clinical Immunology, Hannover Medical School, Hannover, Germany.
Objective:
To 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.
Methods:
We studied adipocyte phenotype, viability, differentiation (CCAAT/enhancer-binding protein [C/EBP]-alpha and peroxisome proliferator-activated receptor [PPAR]-gamma expression), adiponectin production, mtDNA content, activity of respiratory chain complexes and citrate synthase activity in 3T3-L1 adipocytes. Cells were exposed to zidovudine (6 microM or 180 microM), stavudine (3 microM or 90 microM), and zalcitabine (0.1 microM or 3 microM) at different developmental stages for up to 2 months.
Results:
Zidovudine and stavudine impaired adiponectin production in vitro at therapeutic Cmax concentrations, 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.
Conclusions:
We 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.
Insights
Nucleoside reverse transcriptase inhibitors (NRTIs) can cause mitochondrial DNA (mtDNA) depletion in adipocytes, particularly during cell proliferation and differentiation. However, significant mtDNA depletion did not impair respiratory chain complex activity in these cells.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Nucleoside reverse transcriptase inhibitors (NRTIs) are crucial in HIV treatment.
- NRTI use can lead to mitochondrial toxicity, including mitochondrial DNA (mtDNA) depletion.
- Adipocytes play a role in energy metabolism and drug response.
Purpose of the Study:
- To investigate the effect of adipocyte differentiation on NRTI-induced mtDNA depletion.
- To determine if NRTI-mediated mtDNA depletion impacts respiratory chain complex activity.
Main Methods:
- 3T3-L1 adipocytes were treated with various NRTIs (zidovudine, stavudine, zalcitabine) at different concentrations and developmental stages.
- Assessed adipocyte differentiation, viability, adiponectin production, mtDNA content, and respiratory chain complex activity.
- Citrate synthase activity was measured as a mitochondrial marker.
Main Results:
- NRTIs did not impair adipocyte differentiation or cause mtDNA depletion at therapeutic concentrations.
- High NRTI concentrations induced significant mtDNA depletion, dependent on cell proliferation and differentiation.
- Stavudine caused up to 80% mtDNA depletion in dividing and differentiating cells; zidovudine affected only differentiating cells.
- Despite substantial mtDNA depletion, respiratory chain complex activity remained unimpaired.
Conclusions:
- Adipocyte proliferation and/or differentiation are prerequisites for NRTI-induced mtDNA depletion.
- Significant NRTI-mediated mtDNA depletion in 3T3-L1 preadipocytes does not compromise respiratory chain complex activity.
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