Combined effect of C-reactive protein and stavudine on adipogenesis.
BACKGROUND
Subcutaneous fat wasting in HIV therapy is primarily associated with the use of stavudine (d4T) and zidovudine (AZT). We hypothesized that C-reactive protein (CRP) might have an additive effect on nucleoside reverse transcriptase inhibitor (NRTI)-mediated peripheral fat loss.


METHODS
3T3-F442A cells were exposed to AZT (6 microM), d4T (3 microM) and/or CRP (0.5 microg/ml) during differentiation. Differentiation was assessed by real-time PCR measurement of peroxisome proliferator-activated receptor (PPAR)gamma and CCAAT/enhancer-binding protein (C/EBP)alpha, by quantification of triglyceride accumulation and by determination of adiponectin expression and secretion. In addition, parameters of lipid accumulation, lipolysis, cell viability and apoptosis were examined.


RESULTS
When preadipocytes were induced to differentiate in the presence of only AZT, d4T or CRP, only AZT significantly impaired adipogenic differentiation. When combined, d4T+CRP also led to reduced triacylglycerol accumulation, an effect not explained by CRP-induced apoptosis or cell death, but instead confirmed by reduced PPARgamma and C/EBPalpha expression and decreased expression of factors involved in lipogenesis, such as fatty acid synthase and acetyl-coenzyme A carboxylase. We observed further reduction in adiponectin expression and secretion when adipocytes were differentiated in the presence of AZT or d4T together with CRP. Addition of rosiglitazone (1 microM) had no effect on reduced adipogenesis, but partially rescued the effects of d4T and d4T+CRP on adiponectin production.


CONCLUSIONS
We conclude that CRP at levels circulating in patients with HIV infection might promote the anti-adipogenic potential of d4T, a cooperative effect that could account for the in vivo observed variability in the development of lipoatrophy.
Stankov
Metodi V
MV
Clinic for Immunology and Rheumatology, Hannover Medical School, Hannover, Germany.
Schmidt
Reinhold E
RE
Behrens
Georg M N
GM
D016475:3T3 Cells; D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000008:administration & dosage / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D051379:Mice; D018119:Stavudine / Q000008:administration & dosage / Q000494:pharmacology*; D015215:Zidovudine / Q000008:administration & dosage / Q000494:pharmacology
D019380:Anti-HIV Agents; D015415:Biomarkers; D015215:Zidovudine; D002097:C-Reactive Protein; D018119:Stavudine