title: Vitamin D attenuates nucleoside reverse transcriptase inhibitor induced human skeletal muscle mitochondria DNA depletion.
abstract: 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.
  
  
  METHODS
  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).
  
  
  CONCLUSIONS
  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.
authors: Department of Pediatrics, Division of Infectious Diseases, University of California San Diego, La Jolla, California 92093-0672, USA.
authors: Grant R
authors: GR
authors: Campbell
authors: Zachary T
authors: ZT
authors: Pallack
authors: Stephen A
authors: SA
authors: Spector
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology; D002117:Calcitriol / Q000627:therapeutic use*; D004272:DNA, Mitochondrial / Q000378:metabolism*; D016049:Didanosine / Q000494:pharmacology; D004359:Drug Therapy, Combination; D005260:Female; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors*; D006801:Humans; D007223:Infant; D019259:Lamivudine / Q000494:pharmacology; D008931:Mitochondria, Muscle / Q000187:drug effects*; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects*; D032446:Myoblasts / Q000187:drug effects / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D018119:Stavudine / Q000494:pharmacology; D014815:Vitamins / Q000627:therapeutic use*; D015215:Zidovudine / Q000494:pharmacology
chemical_list: D019380:Anti-HIV Agents; D004272:DNA, Mitochondrial; D018894:Reverse Transcriptase Inhibitors; D014815:Vitamins; D019259:Lamivudine; D015215:Zidovudine; D018119:Stavudine; D054303:HIV Reverse Transcriptase; D002117:Calcitriol; D016049:Didanosine