Variants in adiponectin signaling pathway genes show little association with subclinical CVD in the diabetes heart study

Association of Adiponectin Receptors with Metabolic and Immune Homeostasis Parameters in Colorectal Cancer: In Silico Analysis and Observational Findings

Adiponectin (ADIPOQ) as both a regulator of metabolic homeostasis and a protein involved in immune response might be of particular interest to contemporary laboratory medicine, especially in terms of minimally invasive diagnostics. The diverse roles of ADIPOQ with regard to the immune and metabolic aspects of colorectal carcinogenesis have been proposed. However, the expression of its receptors ADIPOR1 and ADIPOR2 is scarcely explored in peripheral blood mononuclear cells (PBMCs). Moreover, ADIPORs' relationships with the immune response mediator TNF-α have not been previously investigated in the PBMCs of CRC patients. This study used both in silico and observational case-control analyses with the aim of exploring the association of ADIPOR gene expression and ADIPOQ single nucleotide polymorphisms (SNPs) with the inflammatory marker TNF-α and lipid status parameters in patients with CRC. Publicly available transcriptomic datasets (GSE47756, GSE44076) obtained from analyses of monocytes and CRC tissue samples were employed for the in silico evaluation of ADIPORs' specific genetic traits. GSE47756 and GSE44076 datasets were processed with GSEA software to provide a genetic fingertip of different signaling pathways associated with ADIPORs' mRNA levels. The case-control aspect of the study included the PBMC samples of 73 patients diagnosed with CRC and 80 healthy volunteers. The PCR method was carried out for the PBMC gene expression analysis (ADIPOR1, ADIPOR2, TNF-α mRNA levels) and for the subjects' genotyping (ADIPOQ rs266729, ADIPOR1 rs7539542). GSEA showed significant associations of ADIPOR mRNA expression with gene sets related to metabolic and immune homeostasis in both datasets. The case-control study revealed the association of ADIPOR1 rs7539542 with reduced lipid status parameters in CRC. In addition, PBMC ADIPOR1 mRNA levels decreased in CRC (p < 0.001), whereas ADIPOR2 mRNA did not differ between the groups (p = 0.442). A reduction in PBMC TNF-α mRNA levels was noted in CRC (p < 0.05). Our results indicate that ADIPOR1 and ADIPOR2 play a significant role in the alteration of both metabolic and immune homeostasis during the progression of CRC. For the first time, ADIPOR1 is shown to be a specific receptor for mediating ADIPOQ's effects in the PBMCs of CRC patients.

Analysis of APPL1 Gene Polymorphisms in Patients with a Phenotype of Maturity Onset Diabetes of the Young

The APPL1 gene encodes a protein mediating the cross-talk between adiponectin and insulin signaling. Recently, it was found that APPL1 mutations can cause maturity onset diabetes of the young, type 14. Here, an analysis of APPL1 was performed in patients with a maturity-onset diabetes of the young (MODY) phenotype, and prevalence of these mutations was estimated in a Russian population, among type 2 diabetes mellitus (T2DM) and MODY patients. Whole-exome sequencing or targeted sequencing was performed on 151 probands with a MODY phenotype, with subsequent association analysis of one of identified variants, rs11544593, in a white population of Western Siberia (276 control subjects and 169 T2DM patients). Thirteen variants were found in APPL1, three of which (rs79282761, rs138485817, and rs11544593) are located in exons. There were no statistically significant differences in the frequencies of rs11544593 alleles and genotypes between T2DM patients and the general population. In the MODY group, AG rs11544593 genotype carriers were significantly more frequent (AG vs. AA + GG: odds ratio 1.83, confidence interval 1.15-2.90, p = 0.011) compared with the control group. An association of rs11544593 with blood glucose concentration was revealed in the MODY group. The genotyping data suggest that rs11544593 may contribute to carbohydrate metabolism disturbances.

Type 2 Diabetes-Associated Genetic Polymorphisms as Potential Disease Predictors

Diabetes is a major cause of mortality worldwide. There are several types of diabetes, with type 2 diabetes mellitus (T2DM) being the most common. Many factors, including environmental and genetic factors, are involved in the etiology of the disease. Numerous studies have reported the role of genetic polymorphisms in the initiation and development of T2DM. While genome-wide association studies have identified around more than 200 susceptibility loci, it remains unclear whether these loci are correlated with the pathophysiology of the disease. The present review aimed to elucidate the potential genetic mechanisms underlying T2DM. We found that some genetic polymorphisms were related to T2DM, either in the form of single-nucleotide polymorphisms or direct amino acid changes in proteins. These polymorphisms are potential predictors for the management of T2DM.

The relationship between circulating adiponectin, ADIPOQ variants and incident cardiovascular disease in type 2 diabetes: The Fremantle Diabetes Study

AIMS

To investigate the relationship between serum adiponectin, ADIPOQ variants and haplotypes, and cardiovascular disease (CVD) in type 2 diabetes (T2D).

METHODS

Baseline data including serum total adiponectin and 21 ADIPOQ polymorphisms were available for 1076 participants (mean age 64.0 years, 49.4% males) in a community-based cohort followed for an average of 12 years.

RESULTS

During 8843 patient-years of follow-up for coronary heart disease (CHD), 13,494 patient-years for ischaemic stroke (IS) and 12,028 patient-years for heart failure (HF), 40.4%, 11.8% and 31.9% of patients experienced a first episode of CHD, IS or HF, respectively. In Cox regression after adjustment for the most parsimonious models, log_e(serum adiponectin) and the ADIPOQ variant rs12495941 were inversely associated with incident CHD (hazard ratio [95% confidence interval] 0.79 [0.65-0.98] and 0.64 [0.44-0.94], respectively), while rs1648707 was positively associated with incident IS (2.05 [1.37-3.06]; all P ≤ 0.028). In males, rs9860747 and rs17366568 predicted CHD (0.22 [0.05-0.92] and 1.50 [1.01-2.20]; P ≤ 0.042), while rs1648707 and rs1063537 predicted IS (2.36 [1.32-4.23] and 2.09 [1.17-3.72]; P ≤ 0.012). In females, rs10937273 predicted CHD via an interaction with serum adiponectin (0.43 [0.21-0.91]; P = 0.027), while rs864265 predicted IS (0.43 [0.21-0.88], P = 0.021). The associations between ADIPOQ variants and outcomes were supported by haplotype block analysis. Neither serum adiponectin nor ADIPOQ variants predicted HF.

CONCLUSIONS

Serum total adiponectin and gender-specific ADIPOQ variants predict CHD and IS, but not HF, independently of other risk factors in community-based patients with T2D. In contrast to some previous studies, there was no relationship between a high serum total adiponectin and CVD.

Translating the biology of adipokines in atherosclerosis and cardiovascular diseases: Gaps and open questions

AIM

Critically discuss the available data, to identify the current gaps and to provide key concepts that will help clinicians in translating the biology of adipokines in the context of atherosclerosis and cardio-metabolic diseases.

DATA SYNTHESIS

Adipose tissue is nowadays recognized as an active endocrine organ, a function related to the ability to secrete adipokines (such as leptin and adiponectin) and pro-inflammatory cytokines (tumor necrosis factor alpha and resistin). Studies in vitro and in animal models have observed that obesity status presents a chronic low-grade inflammation as the consequence of the immune cells infiltrating the adipose tissue as well as adipocytes. This inflammatory signature is often related to the presence of cardiovascular diseases, including atherosclerosis and thrombosis. These links are less clear in humans, where the role of adipokines as prognostic marker and/or player in cardiovascular diseases is not as clear as that observed in experimental models. Moreover, plasma adipokine levels might reflect a condition of adipokine-resistance in which adipokine redundancy occurs. The investigation of the cardio-metabolic phenotype of carriers of single nucleotide polymorphisms affecting the levels or function of a specific adipokine might help determine their relevance in humans. Thus, the aim of the present review is to critically discuss the available data, identify the current gaps and provide key concepts that will help clinicians translate the biology of adipokines in the context of atherosclerosis and cardio-metabolic diseases.

Analysis of the Relationship Between ADIPOR1 Variants and the Susceptibility of Chronic Metabolic Diseases in a Northeast Han Chinese Population

Objective: Shared genetic variants in ADIPOR1 have been identified as closely related to coronary artery disease (CAD), type 2 diabetes (T2D), and T2D with CAD susceptibility, suggesting that these variants are strong candidates for the common soil hypothesis. Therefore, it is essential to analyze the relationship between ADIPOR1 variants and the susceptibility to CAD, T2D, and T2D with CAD in other populations.

Materials and Methods: A case–control study was conducted which included three case cohorts [CAD (n = 316), T2D (n = 295), T2D with CAD (n = 302)], and a control cohort (n = 268) from a population in northeast China. Six ADIPOR1 single-nucleotide polymorphisms were genotyped by high-resolution melting and polymerase chain reaction–restriction fragment length polymorphism.

Results: We confirmed that the shared variant, rs3737884*G, in ADIPOR1 is associated with CAD, T2D, and T2D with CAD (p-value range: 6.54E-6–1.82E-5, odds ratio [OR] range: 1.770–1.844) and that rs16850797*C is associated with T2D and T2D with CAD (p-value range: 0.001–0.001, OR range: 1.529–1.571). We also found that a novel shared variant, rs7514221*C, is associated with an increased susceptibility to CAD, T2D, and T2D with CAD (p-value range: 0.002–0.004, OR range: 1.194–2.382) in this population.

Conclusions:ADPOR1 variants, rs3737884*G and rs7514221*C, may be shared risk factors associated with CAD, T2D, and T2D with CAD in a population of northeast China.

Relation between ADIPOQ Gene Polymorphisms and Type 2 Diabetes

OBJECTIVE

The manuscript investigates the relation between adiponectin gene (ADIPOQ) polymorphisms and type 2 diabetes mellitus (T2DM) in a Chinese population.

METHODS

We designed a case-control study involving 340 normal glucose tolerant (NGT) subjects and 340 type 2 diabetes patients. Three SNPs (rs182052, rs1501299, and rs7627128) were genotyped by TaqMan methods.

RESULTS

We found that rs7627128, rs1501299 and rs182052 were significantly associated with T2DM. Haplotypes analysis indicated that the frequency of the haplotypes A-A-T was frequent in T2DM patients (OR = 2.10; 95%CI: 1.44-2.90; p < 0.001), but G-A-T was more frequent in the control group than in the T2DM group (OR = 0.66; 95%CI: 0.54-0.81; p < 0.001).

CONCLUSION

The ADIPOQ genetic polymorphisms were associated with type 2 diabetes in a Chinese population.

Variants in the Atherogenic ALOX5AP, THBD, and KNG1 Genes Potentiate the Risk of Ischemic Stroke via a Genetic Main Effect and Epistatic Interactions in a Chinese Population

BACKGROUND

Ischemic stroke (IS) is a multifactorial disease that displays a strong genetic predisposition. However, the genetic architecture of IS has yet to be fully elucidated. It was hypothesized that epistasis between genes in multiple atherothrombotic pathways may play a vital role in determining the susceptibility to IS. The aim of the present study was to investigate the contributions of the hypothesized genetic factors to IS and the interactions between these genetic factors in a Chinese population.

METHODS

In this study, 351 cases with IS and 417 control subjects from a Chinese population were genotyped for single-nucleotide polymorphisms (SNPs) in 12 genes hypothesized to be involved in atherosclerosis, coagulation, and related pathways. We examined SNP main effects and epistatic interactions between these polymorphic loci.

RESULTS

rs710446 of the KNG1 gene was associated with IS susceptibility based on an additive genetic model (rs710446: P = .012; odds ratio [OR], 1.247; 95% confidence interval [CI], 1.050-1.481) after adjusting for covariates. Furthermore, an epistatic interaction between the ALOX5AP, THBD, and KNG1 gene was also identified in association with stroke susceptibility (P < .001 after 1000 permutations). Based on the chi-squared test, the OR of the high-risk combination of the three-locus model increased the risk of IS by 2.53-fold (95% CI, 1.60-4.01; P < .0001).

CONCLUSIONS

Our findings support the association of the epistatic interactions of ALOX5AP, THBD, and KNG1 and present novel evidence for the main effect of KNG1 gene on IS susceptibility, suggesting a modulation of stroke risk by a genetic main effect and gene-gene interactions.