Methodological considerations in human studies of gene expression in HIV-associated lipodystrophy

In the majority of cases, HIV-associated lipodystrophy, lipoatrophy in particular, becomes clinically apparent only after months or years of continuous exposure to antiretroviral medications and, once developed, is difficult to reverse. Many lipid-related side effects of antiretroviral medications result from drug-induced changes in gene expression. As our understanding of the pathogenic mechanisms underlying HIV-associated lipodystrophy improves, it is important to be able to explore changes at a molecular level in order to fully elucidate the mechanisms whereby antiretroviral drugs exert their toxicities. Monitoring changes in gene expression in vivo may enable physicians to identify, predict or prevent drug toxicities early, before irreversible changes in body composition occur. However, monitoring changes in gene expression at a population level presents many methodological challenges that need to be addressed, over and above the considerable intra- and inter-individual variability inherent in the cellular expression of any gene. Careful collection and processing of adequate biological samples, robust laboratory processes and assays, and appropriate study design can help overcome many of these difficulties

Cutis Verticis Gyrata in Men Affected by HIV-Related Lipodystrophy

We report the occurrence of cutis verticis gyrata (CVG), a disfiguring dermatological condition, in four patients with HIV-related lipodystrophy (HIVLD). These four patients had abnormal metabolic and hormonal lab values which we compare with metabolic and hormonal perturbations cited in previous HIVLD cohorts. In addition, we describe the sole use of poly-L-lactic acid as a potential treatment for decreasing the appearance of CVG-associated ridges

Cutis Verticis Gyrata in Men Affected by HIV-Related Lipodystrophy

We report the occurrence of cutis verticis gyrata (CVG), a disfiguring dermatological condition, in four patients with HIV-related lipodystrophy (HIVLD). These four patients had abnormal metabolic and hormonal lab values which we compare with metabolic and hormonal perturbations cited in previous HIVLD cohorts. In addition, we describe the sole use of poly-L-lactic acid as a potential treatment for decreasing the appearance of CVG-associated ridges

Cutis Verticis Gyrata in Men Affected by HIV-Related Lipodystrophy.

We report the occurrence of cutis verticis gyrata (CVG), a disfiguring dermatological condition, in four patients with HIV-related lipodystrophy (HIVLD). These four patients had abnormal metabolic and hormonal lab values which we compare with metabolic and hormonal perturbations cited in previous HIVLD cohorts. In addition, we describe the sole use of poly-L-lactic acid as a potential treatment for decreasing the appearance of CVG-associated ridges

In vivo, nucleoside reverse‐transcriptase inhibitors alter expression of both mitochondrial and lipid metabolism genes in the absence of depletion of mitochondrial DNA

Background: Nucleoside reverse-transcriptase inhibitors (NRTIs), which are used to treat human immunodeficiency virus (HIV) infection, can cause mitochondrial dysfunction and have been associated with lipoatrophy. The effects of this mitochondrial dysfunction on lipid metabolism, at a molecular level in vivo, have not been described. Methods: We examined early changes (by 2 weeks after initiation of therapy) in expression of mitochondrial and nuclear genes in adipose tissue from 20 HIV-negative subjects randomized to receive dual-NRTI therapy (zidovudine/lamivudine or stavudine/lamivudine) for 6 weeks. Results: We observed decreased transcription of mitochondrial (mt) RNA without significant depletion of mtDNA. Decreases in mtRNA coincided with simultaneous up-regulation of nuclear genes involved in transcriptional regulation of mtRNA (NRF1 and TFAM) and oxidation of fatty acids (PPARA and LPL), whereas PPARG, which is important for differentiation of adipose tissue, was down-regulated. Many nuclear changes correlated with changes in peroxisome proliferator–activated receptor–g coactivator–1 (PGC1), suggesting a central role for PGC1 in nuclear responses to mitochondrial dysfunction. Expression of peripheral blood monocyte mtRNA also decreased, suggesting that monocytes may be surrogates for NRTI-induced mitochondrial dysfunction in other tissues. Conclusions: Independent of HIV, NRTIs decrease transcription of mtRNA in vivo. The absence of depletion of mtDNA suggests that NRTIs cause mitochondrial dysfunction by means other than through inhibition of DNA polymerase-g, whereas disruption of expression of lipid metabolism genes offers an explanation forNRTI-induced lipoatrophy

Effect of rosiglitazone on peroxisome proliferator‐activated receptor γ gene expression in human adipose tissue is limited by antiretroviral drug–induced mitochondrial dysfunction

Background. Treatment of human immunodeficiency virus (HIV)-1 with thymidine-analogue nucleoside reverse-transcriptase inhibitors (tNRTIs) causes lipoatrophy, mitochondrial toxicity, and lower adipose tissue expression of peroxisome proliferator-activated receptor γ (PPARγ [PPARG gene]) . Rosiglitazone (RSG), a PPARγ agonist, improves congenital lipoatrophy but not HIV lipoatrophy. Methods. Serial fat biopsies were taken from HIV-infected, lipoatrophic men randomized to receive RSG or placebo for 48 weeks. Adipose tissue mitochondrial and nuclear gene expression and mitochondrial DNA content were quantified by real-time polymerase chain reaction. Nonparametric analyses were applied. Results. Subjects receiving tNRTI-containing antiretroviral therapy had lower baseline mitochondrial RNA expression and DNA content. In subjects receiving tNRTIs, exposure to RSG did not affect PPARG expression at either week 2 or 48. At week 2, RSG increased PPARG expression only in subjects not treated with tNRTIs, whereas at week 48, increased PPARG expression was observed in subjects not treated with tNRTIs, regardless of RSG use. Similar findings were observed for the PPARG-responsive gene fatty acid-binding protein 4. Changes in PPARG expression were associated with increases in limb fat mass. Conclusions. These data suggest that in HIV-infected, lipoatrophic men, adipose PPARG expression and function are dependent on intact mitochondrial function. These data support a direct link between mitochondrial toxicity and adipose tissue PPARG expression and help explain the poor clinical response to RSG observed in clinical trials

CD57 expression and cytokine production by T cells in lesional and unaffected skin from patients with psoriasis.

BACKGROUND: The immunopathogenic mechanisms leading to psoriasis remain unresolved. CD57 is a marker of replicative inability and immunosenescence on CD8+ T cells and the proportion of CD57 expressing CD8+ T cells is increased in a number of inflammatory conditions. METHODOLOGY: We examined the expression of CD57 on T cells in the skin of patients affected with psoriasis, comparing lesional and unaffected skin. We also assessed functionality of the T cells by evaluating the secretion of several inflammatory cytokines (IL-17A, IFN-gamma, IL-2, IL-33, TNF-alpha, IL-21, IL-22, and IL-27), from cell-sorted purified CD4+ and CD8+ T cells isolated from lesional and unaffected skin biopsies of psoriasis patients. PRINCIPAL FINDINGS: We observed that the frequency of CD57+CD4+ and CD57+CD8+ T cells was significantly higher in unaffected skin of psoriasis patients compared to lesional skin. Sorted CD4+ T cells from psoriatic lesional skin produced higher levels of IL-17A, IL-22, and IFN-gamma compared to unaffected skin, while sorted CD8+ T cells from lesional skin produced higher levels of IL-17, IL-22, IFN-gamma, TNF-alpha, and IL-2 compared to unaffected skin. CONCLUSIONS/SIGNIFICANCE: These findings suggest that T cells in unaffected skin from psoriasis patients exhibit a phenotype compatible with replicative inability. As they have a lower replicative capacity, CD57+ T cells are less frequent in lesional tissue due to the high cellular turnover