Antiretroviral drugs with adverse effects on adipocyte lipid metabolism and survival alter the expression and secretion of proinflammatory cytokines and adiponectin in vitro.
OBJECTIVE
The lipodystrophy syndrome is a major adverse effect of highly active antiretroviral therapy (HAART), associated with altered circulating levels and adipose tissue mRNA expression of proinflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor (TNF)alpha, and adiponectin. Proinflammatory cytokines and adiponectin, which are secreted by adipose tissue, regulate fat metabolism, insulin sensitivity and adipose cell apoptosis. We examined the direct effects of individual antiretrovirals on lipid metabolism and cytokine and adiponectin production by cultured adipocytes.


METHODS
Differentiating 3T3-F442A cells and differentiated 3T3-L1 adipocytes were treated for 12 or 4 days, respectively, with protease inhibitors (PIs) indinavir, nelfinavir, amprenavir, lopinavir and ritonavir, or nucleoside reverse transcriptase inhibitors (NRTIs) stavudine and zidovudine, at near-Cmax concentrations. Lipid metabolism was estimated by Oil Red O staining of intracellular lipids, mRNA expression of fatty acid synthase and adipocyte lipid binding protein 2, and insulin activation of lipogenesis. Apoptosis was estimated by flow cytometry. The expression and secretion of proinflammatory cytokines (IL-6, TNFalpha and IL-1beta) and adiponectin were evaluated by real-time reverse transcription PCR and ELISA.


RESULTS
Chronic treatment of 3T3-F442A differentiating adipocytes and differentiated 3T3-L1 adipocytes with PIs and NRTIs reduced lipid accumulation, mRNA expression of lipid markers and insulin-induced lipogenesis. IL-6, TNFalpha, IL-1beta and adiponectin expression and secretion were markedly altered in differentiating 3T3-F442A adipocytes. PIs had either no effect on differentiated 3T3-L1 adipocytes (TNFalpha expression and sucretion) or their effect was less marked than in 3T3-F442A cells. Indinavir and amprenavir did not alter cytokine secretion and expression by mature adipocytes. The effects of stavudine and zidovudine on differentiating and mature adipocytes were similar, despite the difference in treatment procedure. The drugs with the strongest effect on TNFalpha expression also increased adipocyte apoptosis, in contrast to the drugs that only moderately increased TNFalpha expression.


CONCLUSIONS
These results suggest that increased cytokine and decreased adiponectin secretion and expression induced by some PIs and NRTIs may contribute to the adipose tissue loss (via apoptosis and lipid leakage) and insulin resistance associated with the lipodystrophy syndrome.
Lagathu
Claire
C
INSERM U402 and IFR65 Saint-Antoine Faculty of Medicine and Biochemistry Department, Tenon Hospital, University Pierre et Marie Curie, Paris, France.
Bastard
Jean-Philippe
JP
Auclair
Martine
M
Maachi
Mustapha
M
Kornprobst
Michel
M
Capeau
Jacqueline
J
Caron
Martine
M
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D000818:Animals; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis*; D004359:Drug Therapy, Combination; D017320:HIV Protease Inhibitors / Q000009:adverse effects* / Q000494:pharmacology; D039682:HIV-Associated Lipodystrophy Syndrome; D006801:Humans; D007333:Insulin Resistance; D050356:Lipid Metabolism; D051379:Mice; D018894:Reverse Transcriptase Inhibitors / Q000009:adverse effects* / Q000494:pharmacology
D019380:Anti-HIV Agents; D016207:Cytokines; D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors