Changes in subcutaneous adipose tissue microRNA expression in HIV-infected patients

We evaluated the possibility that a pattern of abnormal microRNA (miRNA) expression could be fuelling the mechanisms causing HIV-associated lipodystrophy (HAL). In this case-control study, samples of subcutaneous adipose tissue from eight consecutive HIV-infected patients on combination antiretroviral therapy with HAL (cases) were compared with those of eight HIV-negative subjects (controls). Human miRNA microarrays were used to probe the transcriptomes of the samples. Analysis of differentially expressed miRNAs was performed using DataAssist v2.0 software, applying a paired Student's t-test. Data showed that 21 miRNAs out of 754 were overexpressed in the patient group. Ten of these (i.e. miR-186, miR-199a-3p, miR-214, miR-374a, miR-487b, miR-532-5p, miR-628-5p, miR-874, miR-125-b-1* and miR-374b*) were up-regulated to a significant degree (fold change > 2.5; PaEuroS < aEuroS0.01). Eleven other miRNAs (i.e. miR-let-7d, miR-24, miR-30c, miR-125a-3p, miR-149, miR-191, miR-196-b, miR-218, miR-342-3p, miR-452 and miR-454*) were 2- to 2.5-fold more expressed in HIV+ samples than in controls. Levels of mRNA for lipin 1, the target of miR-218, were significantly lower in subcutaneous adipose tissue from HIV patients. In adipocytes of HIV-infected patients, the up-regulation of specific miRNAs could lead to an increased 'activation' that might contribute to the pathogenesis of HAL by increasing cell turnover and/or promotion of apoptosis.