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Updated: May 13, 2026
High-Throughput Image-Based Quantification of Mitochondrial DNA Synthesis and Distribution
Published on: May 5, 2023
Vitamin D attenuates nucleoside reverse transcriptase inhibitor induced human skeletal muscle mitochondria DNA
Grant R Campbell1, Zachary T Pallack, Stephen A Spector
1Department of Pediatrics, Division of Infectious Diseases, University of California San Diego, La Jolla, California 92093-0672, USA.
Objective:
To evaluate the impact of the active metabolite of vitamin D, 1α,25-dihydroxycholecalciferol (1,25D3), on nucleoside reverse transcriptase inhibitor (NRTI) induced mitochondrial DNA (mtDNA) depletion in human skeletal muscle myoblasts and myotubes.
Design:
mtDNA was quantified in human skeletal muscle myoblasts and myotubes following 1,25D3 and NRTI treatment using real-time PCR.
Methods:
Human skeletal muscle myoblasts and myotubes were treated with didanosine (ddI), stavudine (d4T), zidovudine (ZDV), lamivudine (3TC) and abacavir (ABC) alone or in combination either in the presence or absence of 1,25D3 for 5 days. Cells were harvested, DNA extracted and mtDNA quantified.
Results:
ddI and ddI-d4T significantly decreased both myoblast and myotube mtDNA in the absence of 1,25D3 compared with untreated controls (P≤0.029). In addition, the ZDV-3TC combination resulted in a 47% decrease in myotube mtDNA (P=0.005). 1,25D3 increased myotube mtDNA levels in ddI, ZDV, 3TC, ABC, ddI-d4T, d4T-3TC, ZDV-3TC, ZDV-ABC and ZDV-3TC-ABC-containing regimens and myoblast mtDNA levels in ddI, d4T, ZDV, 3TC, ddI-d4T, ZDV-3TC and ZDV-ABC-containing regimens. Of note, 1,25D3 protected against myotube mtDNA depletion following ZDV-3TC treatment, rendering them similar to 1,25D3 untreated controls (P=0.62), and increased both myotube and myoblast mtDNA two to three-fold in ddI-containing regimens (P<0.05).
Conclusion:
1,25D3 confers a protective effect against NRTI-induced mitochondrial toxicity in skeletal muscle myoblasts and myotubes. These findings support a protective role for vitamin D in preventing mitochondrial toxicity and suggest that supplemental vitamin D may protect against NRTI-associated mitochondrial toxicity.
Insights
The active metabolite of vitamin D, 1α,25-dihydroxycholecalciferol (1,25D3), protects skeletal muscle cells from mitochondrial DNA depletion caused by nucleoside reverse transcriptase inhibitors (NRTIs). Vitamin D supplementation may prevent NRTI-associated mitochondrial toxicity.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Mitochondrial toxicity, including mitochondrial DNA (mtDNA) depletion, is a significant side effect of nucleoside reverse transcriptase inhibitors (NRTIs) used in antiretroviral therapy.
- Skeletal muscle is particularly vulnerable to NRTI-induced mitochondrial dysfunction, potentially leading to myopathy.
- The role of vitamin D in mitigating drug-induced cellular damage requires further investigation.
Purpose of the Study:
- To investigate the protective effects of 1α,25-dihydroxycholecalciferol (1,25D3), the active form of vitamin D, against NRTI-induced mitochondrial DNA (mtDNA) depletion.
- To determine if 1,25D3 can prevent or reduce mtDNA depletion in human skeletal muscle cells exposed to various NRTIs.
Main Methods:
- Human skeletal muscle myoblasts and myotubes were treated with a panel of NRTIs (didanosine, stavudine, zidovudine, lamivudine, abacavir) alone or in combination.
- Cells were co-treated with or without 1,25D3 for five days.
- Mitochondrial DNA (mtDNA) levels were quantified using real-time PCR.
Main Results:
- Several NRTIs, including didanosine and the zidovudine-lamivudine combination, significantly depleted mtDNA in skeletal muscle cells.
- 1,25D3 demonstrated a protective effect, increasing mtDNA levels in myoblasts and myotubes treated with various NRTI regimens.
- Specifically, 1,25D3 prevented significant myotube mtDNA depletion with the zidovudine-lamivudine combination and markedly increased mtDNA levels in didanosine-containing regimens.
Conclusions:
- 1,25D3 confers a significant protective effect against NRTI-induced mitochondrial toxicity in human skeletal muscle cells.
- These findings highlight a potential therapeutic role for vitamin D in managing or preventing NRTI-associated mitochondrial damage.
- Supplemental vitamin D may be beneficial for patients receiving NRTI therapy to mitigate skeletal muscle mitochondrial toxicity.
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