Objective: To elucidate the pathogenesis of HAART-associated lipodystrophy, by investigating the effects of antiretroviral drugs on adipocyte differentiation and gene expression profile.
Design and methods: Analysis of gene expression profile by DNA microarrays and quantitative RT–PCR of 3T3-L1 preadipocytes treated with the nucleoside reverse transcriptase inhibitors (NRTI) lamivudine, zidovudine, stavudine, and zalcitabine, and with the protease inhibitors (PI) indinavir, saquinavir, and lopinavir during maturation into adipocytes.
Results: Under standard adipogenic differentiation protocols, PI significantly inhibited adipocyte differentiation, as demonstrated by cell viability assay and Oil Red O staining and quantification, whereas NRTI had mild effects on adipogenesis. Gene expression profile analysis showed that treatment with NRTI modulated the expression of transcription factors, such as Aebp1, Pou5f1 and Phf6, which could play a key role in the determination of the adipocyte phenotype. PI also modulated gene expression toward inhibition of adipocyte differentiation, with up-regulation of the Wnt signaling gene Wnt10a and down-regulation of the expression of genes encoding master adipogenic transcription factors (e.g., C/EBPα and PPARγ), oestrogen receptor β, and adipocyte-specific markers (e.g., Adiponectin, Leptin, Mrap, Cd36, S100A8).
Conclusions: This study identifies new genes modulated by PI and NRTI in differentiating adipocytes. Abnormal expression of these genes, which include master adipogenic transcription factors and genes involved in lipid metabolism and cell cycle control, could contribute to the understanding of the pathogenesis of HAART-associated lipodystrophy.
From the aDepartment of Histology, Microbiology and Medical Biotechnologies, University of Padova, Padova, Italy
bDepartment of Medical and Surgical Sciences, University of Padova, Padova, Italy
cCIVEN (Coordinamento Interuniversitario Veneto per le Nanotecnologie), Mestre, Venezia, Italy.
1Note: Monia Pacenti and Luisa Barzon equally contributed to this work.
Received 22 November, 2005
Revised 6 January, 2006
Accepted 12 January, 2006
Correspondence to L. Barzon and G. Palù, Department of Histology, Microbiology and Medical Biotechnologies, University of Padova, Via A. Gabelli 63, I-35121 Padova, Italy. Tel: +39 049 8218946; fax: +39 049 8272355; e-mail: email@example.com; firstname.lastname@example.org