Polymorphisms in adiponectin receptor genes are associated with lipodystrophy-related phenotypes in HIV-infected patients receiving antiretroviral therapy

miRNA Expression Profiling in Subcutaneous Adipose Tissue of Monozygotic Twins Discordant for HIV Infection: Validation of Differentially Expressed miRNA and Bioinformatic Analysis

Combined AntiRetroviral Treatments (cARTs) used for HIV infection may result in varied metabolic complications, which in some cases, may be related to patient genetic factors, particularly microRNAs. The use of monozygotic twins, differing only for HIV infection, presents a unique and powerful model for the controlled analysis of potential alterations of miRNAs regulation consequent to cART treatment. Profiling of 2578 mature miRNA in the subcutaneous (SC) adipose tissue and plasma of monozygotic twins was investigated by the GeneChip® miRNA 4.1 array. Real-time PCR and ddPCR experiments were performed in order to validate differentially expressed miRNAs. Target genes of deregulated miRNAs were predicted by the miRDB database (prediction score > 70) and enrichment analysis was carried out with g:Profiler. Processes in SC adipose tissue most greatly affected by miRNA up-regulation included (i) macromolecular metabolic processes, (ii) regulation of neurogenesis, and (iii) protein phosphorylation. Furthermore, KEGG analysis revealed miRNA up-regulation involvement in (i) insulin signaling pathways, (ii) neurotrophin signaling pathways, and (iii) pancreatic cancer. By contrast, miRNA up-regulation in plasma was involved in (i) melanoma, (ii) p53 signaling pathways, and (iii) focal adhesion. Our findings suggest a mechanism that may increase the predisposition of HIV+ patients to insulin resistance and cancer.

Pharmacogenetics of HIV therapy: State of the art in Latin American countries

The use of combined antiretroviral therapy (cART) has resulted in a remarkable reduction in morbidity and mortality of people living with HIV worldwide. Nevertheless, interindividual variations in drug response often impose a challenge to cART effectiveness. Although personalized therapeutic regimens may help overcome incidence of adverse reactions and therapeutic failure attributed to host factors, pharmacogenetic studies are often restricted to a few populations. Latin American countries accounted for 2.1 million people living with HIV and 1.4 million undergoing cART in 2020-21. The present review describes the state of art of HIV pharmacogenetics in this region and highlights that such analyses remain to be given the required relevance. A broad analysis of pharmacogenetic markers in Latin America could not only provide a better understanding of genetic structure of these populations, but might also be crucial to develop more informative dosing algorithms, applicable to non-European populations.

Severe insulin resistance syndromes

Severe insulin resistance syndromes are a heterogeneous group of rare disorders characterized by profound insulin resistance, substantial metabolic abnormalities, and a variety of clinical manifestations and complications. The etiology of these syndromes may be hereditary or acquired, due to defects in insulin potency and action, cellular responsiveness to insulin, and/or aberrations in adipose tissue function or development. Over the past decades, advances in medical technology, particularly in genomic technologies and genetic analyses, have provided insights into the underlying pathophysiological pathways and facilitated the more precise identification of several of these conditions. However, the exact cellular and molecular mechanisms of insulin resistance have not yet been fully elucidated for all syndromes. Moreover, in clinical practice, many of the syndromes are often misdiagnosed or underdiagnosed. The majority of these disorders associate with an increased risk of severe complications and mortality; thus, early identification and personalized clinical management are of the essence. This Review aims to categorize severe insulin resistance syndromes by disease process, including insulin receptor defects, signaling defects, and lipodystrophies. We also highlight several complex syndromes and emphasize the need to identify patients, investigate underlying disease mechanisms, and develop specific treatment regimens.

Investigation of SIRT1 gene variants in HIV-associated lipodystrophy and metabolic syndrome

HIV-infected individuals on chronic use of highly active antiretroviral therapy (HAART) are more likely to develop adipose tissue and metabolic disorders, such as lipodystrophy (LD) and metabolic syndrome (MetS). The development of these phenotypes is known to be multifactorial. Thus, variants in genes implicated in adipogenesis and lipid metabolism may increase susceptibility to LD and MetS. Sirtuin 1 (SIRT1) may influence the outcome of these disturbances due to its role in the regulation of transcription factors involved in energy regulation. Therefore, we genotyped four polymorphisms located in SIRT1 (rs2273773 T>C, rs12413112 G>A, rs7895833 A>G, rs12049646 T>C) in 832 HIV-infected patients receiving HAART by real-time polymerase chain reaction. The prevalence of LD was 55.8% and MetS was 35.3%. Lipoatrophy was the most prevalent subtype in all samples (38.0%) and showed significant difference between white and non-white individuals (P = 0.002). None of the genetic variants investigated in SIRT1 was associated with LD and MetS. White individuals and those in longer time of HAART use were more likely to develop LD. We concluded that these SIRT1 polymorphisms are not predictive factors to the development of lipodystrophy and metabolic syndrome in HIV-infected individuals from Brazil.

Association of adiponectin and adiponectin receptor gene polymorphisms with rheumatoid arthritis in a Chinese population

PURPOSE

To explore the association of adiponectin (AD) and adiponectin receptor (ADR) gene single-nucleotide polymorphisms (SNPs) with genetic susceptibility to rheumatoid arthritis (RA) in a Chinese population.

STUDY DESIGN

Five AD SNPs (rs266729, rs2241766, rs1063537, rs2082940 and rs1063539) and two ADR SNPs (rs7539542 and rs12342) were genotyped in a cohort of 617 patients with RA and 639 healthy controls. Seven SNPs were genotyped using TaqMan genotyping assays on the Fluidigm 192.24 system. The concentration of AD in plasma was examined by ELISA.

RESULTS

Patients with RA showed a considerably lower plasma level of AD than healthy controls (p=0.002). No significant differences were observed for the distribution of allele and genotype frequencies of rs266729, rs2241766, rs2082940, rs1063539, rs7539542 and rs12342 SNPs between patients with RA and controls. The genotype effects of recessive and dominant models were also analysed, but no marked evidence for association was found. However, further analysis in female patients with RA showed that the frequency of the AD gene rs1063539 GG genotype was nominally significantly higher in patients who were anti-cyclic citrullinated peptide (anti-CCP) antibody-positive (p=0.040). No significant differences in serum AD level were observed in patients with RA with different genotypes.

CONCLUSIONS

rs266729, rs2241766, rs2082940 and rs1063539 in the AD gene and rs7539542 and rs12342 in the ADR gene are possibly not associated with genetic susceptibility to RA, but the A D gene rs1063539 locus was possibly associated with anti-CCP in RA female patients.

Adiponectin Receptor gene Polymorphisms are Associated with Kidney Function in Elderly Japanese Populations

Aim: Adiponectin exhibits its biological effects through adiponectin receptors (AdipoR1 and AdipoR2), which are distributed in the kidneys, and activation of those receptors could prevent or ameliorate diabetic nephropathy. This study aimed to evaluate the associations between AdipoR single nucleotide polymorphisms (SNPs) and kidney function in an elderly Japanese population.

Methods: A total of 271 elderly Japanese volunteers underwent anthropometric and laboratory tests (cystatin C-based eGFR and total and high molecular weight adiponectin levels at baseline and a follow-up visit). Genotype data were obtained for the selected 7 and 5 AdipoR1 and AdipoR2 SNPs, respectively.

Results: In a cross-sectional analysis at baseline, we found a significant association between the AdipoR2 SNP rs12230440 and kidney function; eGFRcys tended to increase as the number of carriers of T alleles increased after adjustment for covariates and Bonferroni correction, although the association of the SNP and annual eGFR decline could not be identified in the longitudinal data. Regarding the variants rs16850797, rs11061925, and rs10773983, each of the allele G, allele C, and allele G showed nominally significant associations with higher eGFRcys. However, this failed to reach significance after Bonferroni correction.

Conclusion: Here, an AdipoR2 SNP was associated with kidney function, suggesting that the effects of this polymorphism on adiponectin receptor may affect kidney function in the elderly Japanese population.

Variations in ADIPOR1 But Not ADIPOR2 are Associated With Hypertriglyceridemia and Diabetes in an Admixed Latin American Population

BACKGROUND

Adiponectin is a hormone secreted by adipose tissue. It regulates glycolysis and lipolysis and is involved in the pathophysiology of diabetes and related disorders. Its activity is mainly mediated by the transmembrane receptors AdipoR1 and AdipoR2, which are encoded by ADIPOR1 (1q32.1) and ADIPOR2 (12p13.33) genes, respectively. In genetic association studies, single nucleotide polymorphisms (SNPs) in or near these genes have been associated with metabolic alterations. However, these relationships are still controversial.

AIM

The aim of this work was to analyze possible associations between ADIPOR1/2 and diabetes and other metabolic disorders.

METHODS

A genetic association study was carried out in an admixed Latin American population. A sample of 200 adults was analyzed. Clinical and serum-biochemical characteristics were measured to diagnose obesity, abdominal obesity, hypertension, hyperglycemia, hypertriglyceridemia, low HDLc, insulin resistance (HOMA-IR), and diabetes. Three SNPs were genotyped in ADIPOR1 (rs10494839, rs12733285, and rs2275737) and ADIPOR2 (rs11061937, rs11612383, and rs2286383). For the association analysis, an additive model was assessed through logistic regression. An admixture adjustment was performed using a Monte-Carlo-Markov-Chain method, assuming a three-hybrid substructure (k = 3).

RESULTS

Two SNPs in ADIPOR1 were associated with diabetes: rs10494839 (OR = 3.88, adjusted p < 0.03) and rs12733285 (OR = 4.72, adjusted p < 0.03). Additionally, rs10494839 was associated with hypertriglyceridemia (OR = 2.16, adjusted p < 0.01). None of the SNPs in ADIPOR2 were associated with metabolic disorders.

CONCLUSIONS

ADIPOR1 was consistently associated with diabetes and hypertriglyceridemia. This association was maintained even after adjusting for genetic stratification. There were no significant associations involving ADIPOR2.

Adiponectin, Leptin and Inflammatory Markers in HIV-associated Metabolic Syndrome in Children and Adolescents

BACKGROUND

Metabolic syndrome (MetS) is more common in HIV-infected adults and children than in the general population. Adipocytokines and inflammatory markers may contribute to the pathophysiology of this condition and could be useful indices for monitoring MetS. The objective of this study was to provide information on the prevalence of MetS and investigate the role of adipocytokines and other biomarkers in this syndrome in HIV-infected pediatric patients.

METHODS

A cross-sectional study was conducted between October 2013 and March 2014 in the outpatient clinics of 2 tertiary pediatric referral hospitals. Fifty-four HIV-infected children and adolescents were included. MetS was defined according to the International Diabetes Federation and modified National Cholesterol Education Program Adult Treatment Panel III criteria. Measurements included anthropometry, waist circumference, blood pressure, fasting lipids, glucose and insulin, adiponectin, leptin, interleukin-6, vitamin D and C-reactive protein and clinical lipodystrophy assessment.

RESULTS

Among the total, 3.7% of patients met the International Diabetes Federation criteria for MetS and 7.4% met the National Cholesterol Education Program Adult Treatment Panel III criteria. C-reactive protein and leptin levels were significantly higher and adiponectin level significantly lower in patients with MetS, regardless of the criteria used. Insulin resistance was observed in 40.7% of patients; abnormal quantitative insulin sensitivity check index values were found in 88.9%. Eighteen patients (33.3%) had vitamin D deficiency.

CONCLUSIONS

The prevalence of MetS was similar to that observed in larger cohorts of HIV-infected patients in our setting. Adipocytokine dysregulation seems to be related to MetS in HIV-infected children. A high percentage of patients showed insulin resistance, which should be strictly monitored.

Deciphering the molecular mechanisms involved in HIV-associated lipoatrophy by transcriptomics: a pilot study

HIV-associated lipoatrophy (LA) has considerable implications for risk of metabolic diseases, quality of life, and adherence to treatments. Although it has decreased in high-income countries, it is still very common in resource-limited countries. Understanding the pathophysiological mechanisms of LA can open the possibility to explore new ways to treat or prevent this condition. To identify new markers for an accurate and quick diagnosis will be also of interest. Thus, we aimed to examine functional classes of genes implicated in LA and to identify potential new markers for an accurate/quick diagnosis of LA and future complications. Eighteen participants were recruited: seven healthy volunteers, five non-LA-HIV patients, and six LA-HIV subjects. Clinical lipoatrophy was considered when changes in fat volume in the cheeks next to the nose, lateral aspect of the face, legs, arms, and buttocks were observed by the physicians. mRNA was isolated from peripheral blood mononuclear cells (PBMCs) to perform a transcriptomic and Gene Ontology analysis. To confirm RNA sequencing results, qPCRs were developed. A total of 55 genes were differentially expressed between LA and non-LA patients. Thirty-seven genes were overexpressed, whereas 18 genes were repressed. Functional analysis showed that overexpressed genes were involved in lymphocyte/neutrophil activation, inflammation, and atherogenesis. Several lymphoma markers and members of the lipocalin and aquaporin families were also found more expressed in LA patients. In contrast, most of the genes found less expressed in LA subjects were involved in angiogenesis and protection against myocardial infarction. Our results demonstrated a distinct transcriptomic signature in PBMCs of LA patients in comparison with non-LA-HIV subjects and, therefore, provided novel insights to the pathogenesis of HIV-associated lipoatrophy. Our study also highlights the potential usage of some of these genes as early markers of future complications.

Pharmacogenetic considerations in the treatment of HIV

After the introduction of highly active antiretroviral therapy in the 1990s, the perception of the diagnosis of HIV infection gradually shifted from a 'death sentence' to a chronic disease requiring long-term treatment. The host genetic variability has been shown to play a relevant role in both antiretroviral drugs bioavailability and adverse effects susceptibility. Knowledge about pharmacogenetics role in HIV infection treatment has largely increased over the last years, and is reviewed in the present report, as well as future perspectives for the inclusion of pharmacogenetics information in the directing of HIV infection treatment.