mRNA expression profile of adipose tissue in HIV-1 positive subjects with art-related lipoatrophy

BACKGROUND. Since the introduction of highly active antiretroviral therapy (HAART), the life expectancy of patients infected with human immunodeficiency virus 1 (HIV-1) remarkably increased. Despite the clinical benefits, the long-term HAART is associated with a complex spectrum of untoward metabolic effects, including dyslipidemia and insulin resistance that lead to higher risk of developing cardiovascular diseases and diabetes mellitus, and lipodystrophy syndrome. However, these side effects do not occur in all treated patients, and there is a very large interindividual variability in the emergence and severity of the symptoms. METHODS. 28 HIV-positive patients (57,1% male and 42,9% female) attending the Clinic of Infectious Diseases and Tropical Medicine at the University of Milan, with HAART-related lipodystrophy and 11 healthy donors (HC) (36,4% female and 63,6% male) were enrolled in the study. Subcutaneous adipose tissue specimens from the supra-iliac region were obtained using a 4-mm punch biopsy needle. Fat biopsies were rapidly frozen and stored at – 80°C. RNA was extracted using standard methods, the cDNA was generated by reverse transcription using transcriptor first strand cDNA synthesis kit (Applied Biosystem) following the manufacturer’s instructions. We have compared the mRNA expression profile of adipocytes in the HIV-1 positive with lipodystrophy and healthy donors, using TaqMan LDA microfluidic card technology (Applied Biosystem). Relative gene expression analyses including statistical analyses were performed utilizing web-free software (REST 2008). A written informed consent was obtained from all the participants. RESULTS. 48 different genes were analyzed (47 for the study and one as housekeeping gene). The genes with significantly different expression between the studied groups was enhancer binding protein (EBP). EBP is more expressed in healthy donors (mRNA expression in AU: 2.52 in HC and 1,54 in HIV-1 positive patients; p=0,034). Adiponectin is also less expressed in HIV-1 positive patients but did not reach statistical significance (mRNA expression in arbitrary units (AU): 0,98 in HIV-1 positive vs 1,58 in HC; p= 0,062). In our HIV-1 population we observed a different mRNA expression profile between females and males in regard to 3 genes. Adiponectin (mRNA expression in AU: 1,8 for females and 1,05 for males p=0,009), PCK-1 (mRNA expression in AU: for 2,2 females and 0,7 for males p=0,017) and GLUT4 (mRNA expression in AU: 3,3 for females and 1 for males p=0,007). In males only we also evidenced lower expression for 3 genes in HIV-1 infected compared to healthy controls: adiponectin, C/EBP and PCK-1 (p=0.006, p= 0.034 and p=0-004, respectively). CONCLUSIONS. With the limitations of an investigation in a relatively small population, our study suggests a role for CEBP and adiponectin in lipoatrophy. In antiretroviral treated HIV infected patients, CEBP deficiency might lead to defective development of adipose tissue leading to lipoatrophy. Differential gene expression in subcutaneous adipose tissue between males and females seems to emerge and might account for the different prevalence and time to appearance of lipodystrophy between sexes.