Monocyte chemoattractant protein-1 (MCP-1) g.-2518A>G polymorphism and susceptibility to type 2 diabetes (T2D) and end stage renal disease (ESRD) in the North-West Indian population of Punjab

Integrating Common Risk Factors with Polygenic Scores Improves the Prediction of Type 2 Diabetes

We tested associations between 13 established genetic variants and type 2 diabetes (T2D) in 1371 study participants from the Volga-Ural region of the Eurasian continent, and evaluated the predictive ability of the model containing polygenic scores for the variants associated with T2D in our dataset, alone and in combination with other risk factors such as age and sex. Using logistic regression analysis, we found associations with T2D for the CCL20 rs6749704 (OR = 1.68, P_FDR = 3.40 × 10^-5), CCR5 rs333 (OR = 1.99, P_FDR = 0.033), ADIPOQ rs17366743 (OR = 3.17, P_FDR = 2.64 × 10^-4), TCF7L2 rs114758349 (OR = 1.77, P_FDR = 9.37 × 10^-5), and CCL2 rs1024611 (OR = 1.38, P_FDR = 0.033) polymorphisms. We showed that the most informative prognostic model included weighted polygenic scores for these five loci, and non-genetic factors such as age and sex (AUC 85.8%, 95%CI 83.7-87.8%). Compared to the model containing only non-genetic parameters, adding the polygenic score for the five T2D-associated loci showed improved net reclassification (NRI = 37.62%, 1.39 × 10^-6). Inclusion of all 13 tested SNPs to the model with age and sex did not improve the predictive ability compared to the model containing five T2D-associated variants (NRI = -17.86, p = 0.093). The five variants associated with T2D in people from the Volga-Ural region are linked to inflammation (CCR5, CCL2, CCL20) and glucose metabolism regulation (TCF7L, ADIPOQ2). Further studies in independent groups of T2D patients should validate the prognostic value of the model and elucidate the molecular mechanisms of the disease development.

Association of eNOS and MCP-1 Genetic Variants with Type 2 Diabetes and Diabetic Nephropathy Susceptibility: A Case-Control and Meta-Analysis Study

Type 2 diabetes (T2D) and its secondary complications result from the complex interplay of genetic and environmental factors. To understand the role of these factors on disease susceptibility, the present study was conducted to assess the association of eNOS and MCP-1 variants with T2D and diabetic nephropathy (DN) in two ethnically and geographically different cohorts from North India. A total of 1313 subjects from two cohorts were genotyped for eNOS (rs2070744, rs869109213 and rs1799983) and MCP-1 (rs1024611 and rs3917887) variants. Cohort-I (Punjab) comprised 461 T2D cases (204 T2D with DN and 257 T2D without DN) and 315 healthy controls. Cohort-II (Jammu and Kashmir) included 337 T2D (150 T2D with DN and 187 T2D without DN) and 200 controls. Allele, genotype and haplotype frequencies were compared among the studied participants, and phenotype-genotype interactions were determined. Meta-analysis was performed to investigate the association between the selected variants and disease susceptibility. All three eNOS variants were associated with 1.5-4.0-fold risk of DN in both cohorts. MCP-1 rs1024611 conferred twofold risk towards DN progression in cohort-II, while rs3917887 provided twofold risk for both T2D and DN in both cohorts. eNOS and MCP-1 haplotypes conferred risk for T2D and DN susceptibility. Phenotype-genotype interactions showed significant associations between the studied variants and anthropometric and biochemical parameters. In meta-analysis, all eNOS variants conferred risk towards DN progression, whereas no significant association was observed for MCP-1 rs1024611. We show evidences for an association of eNOS and MCP-1 variants with T2D and DN susceptibility.

The Role of Chemokines and Chemokine Receptors in Diabetic Nephropathy

Kidney function decline is one of the complications of diabetes mellitus and may be indicated as diabetic nephropathy (DN). DN is a chronic inflammatory disease featuring proteinuria and a decreasing glomerular filtration rate. Despite several therapeutic options being currently available, DN is still the major cause of end-stage renal disease. Accordingly, widespread innovation is needed to improve outcomes in patients with DN. Chemokines and their receptors are critically involved in the inflammatory progression in the development of DN. Although recent studies have shown multiple pathways related to the chemokine system, the specific and direct effects of chemokines and their receptors remain unclear. In this review, we provide an overview of the potential role and mechanism of chemokine systems in DN proposed in recent years. Chemokine system-related mechanisms may provide potential therapeutic targets in DN.

Chemokine gene polymorphisms association with increased risk of type 2 diabetes mellitus in Tatar ethnic group, Russia

Recent studies have shown that chemokines play an important role in the development of chronic inflammation in adipose tissue, obesity pathogenesis, glucose intolerance and type 2 diabetes. It has also been revealed that some SNPs in chemokine genes are associated with obesity, insulin resistance, type 2 diabetes and diabetes complications in different ethnic groups. The aim of this study was to determine the associations between SNPs in chemokine genes and type 2 diabetes in participants of Tatar ethnic group, living in Bashkortostan. Case-control and cross-sectional study were included in our study design. Five SNPs were genotyped in 440 type 2 diabetes (160 men and 280 women), 58.8 ± 9.2 years old (mean ± SD), BMI 29.3 ± 3.9 kg/m² (mean ± SD) patients of Tatar ethnicity, and a control group of 500 Tatars (180 men and 320 women), 55.2 ± 11.6 years old (mean ± SD), BMI 25.9 ± 4.3 kg/m² (mean ± SD). The SNPs rs6749704 in CCL20 [odds ratio (OR) = 2.77 (95% CI 1.81-4.25), р = 0.0001], rs2107538 in CCL5 [odds ratio (OR) = 1.80 (95% CI 1.46-2.22), p = 0.0001] were significantly associated with type 2 diabetes. Regression analysis revealed that rs1696941 in CCL11 was associated with the onset age and duration of type 2 diabetes as well as with HbA_1c level (p = 0.034, p = 0.036 and p = 0.0054, respectively). The SNPs rs223828 in CCL17 and rs6749704 in CCL20 were correlated with obesity as estimated by BMI (p = 0.0004, p = 0.029, respectively). Rs223828 in CCL17 revealed the association with postprandial glucose level (p = 0.024) and HbA_1c (p = 0.008). These data demonstrate that variants of chemokine genes are associated with type 2 diabetes and obesity of Tatar ethnic group inhabiting Bashkortostan Republic. Novel associations of the polymorphic loci in CCL20 (rs6749704) and CCL5 (rs2107538) genes with type 2 diabetes had been identified as a result of the conducted research.

Association between MCP-1 2518 A>G gene polymorphism and chronic kidney disease

Monocyte chemoattractant protein-1 (MCP-1) is involved in the pathogenesis of chronic kidney diseases (CKD). MCP-1 2518 A>G gene polymorphism is associated with MCP-1 status. We performed a meta-analysis to assess the association between MCP-1 2518 A>G gene polymorphism and CKD risk. The eligible studies regarding the relationship between MCP-1 2518 A>G gene polymorphism and CKD risk were searched through electronic databases. The pooled odds ratios (ORs) and its 95% confidence intervals (CIs) were calculated by using a fixed-effects model, or in the presence of heterogeneity, a random-effects model. A total of 2415 cases and 2011 controls were recruited in our investigation. A allele/GG genotype was not associated with CKD risk in overall populations, Asians, Caucasians, and Africans. AA/AG genotype was not associated with the risk of CKD in overall populations, Asians, Caucasians, and Africans. AA genotype was associated with a lower risk of CKD in Caucasians (OR 0.816, 95% CI 0.703-0.947). AG genotype was associated with a higher risk of CKD in Caucasians (OR 1.230, 95% CI 1.042-1.452). There was no marked publication bias. In conclusion, AA genotype may be a protective factor against CKD susceptibility in Caucasians. AG genotype may be a risk factor for CKD risk in Caucasians. However, more studies are needed in the future.

Association of MCP-1 rs1024611 polymorphism with diabetic foot ulcers

Monocyte chemotactant protein-1 (MCP-1), a pro-inflammatory cytokine, plays an important role in inflammatory process. In present study, we evaluated the association of MCP-1 gene rs1024611 polymorphism with risk and clinical characteristics of diabetic foot ulcers (DFUs).This study recruited 116 patients with DFUs, 135 patients with diabetes mellitus (DM) without complications (non-DFU), and 149 healthy controls (HCs). MCP-1 gene rs1024611 polymorphism was genotyped by direct sequencing. The expression of MCP-1 was analyzed using quantitative real-time polymerase chain reaction. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assume the association strength.Individuals with rs1024611 AG and GG genotypes exhibited significantly higher susceptibility to DFUs, in the comparison with HCs (AG vs AA, OR = 2.364, 95% CI = 1.021-5.470; GG vs AA, OR = 2.686, 95% CI = 1.154-6.255). Meanwhile, G allele was associated with increased DFUs susceptibility (OR = 1.457, 95% CI = 1.014-2.093). Besides, rs1024611 SNP was slightly correlated with increased DFUs susceptibility in patients with DM. GG genotype of rs1024611 was significantly correlated with higher epidermal thickness and lower dermis thickness in patients with DFUs (P < .01). Patients with DFU exhibited upregulation of MCP-1 mRNA, and GG genotype was correlated with enhanced MCP-1 expression in DFU and non-DFU groups.Rs1024611 polymorphism was significantly associated with MCP-1 expression and individual susceptibility to DFUs.

The association between MCP-1, VEGF polymorphisms and their serum levels in patients with diabetic foot ulcer

The purpose of the present study was to investigate distribution of monocyte chemoattractant protein-1 (MCP-1) -2518A/G and vascular endothelial growth factor (VEGF) -634G/C polymorphisms in type 2 diabetes melitus patients (T2DM) presenting diabetic foot ulcer (DFU). Additionally, we evaluated the effects of these 2 polymorphisms on serum levels of MCP-1 and VEGF in the study population.Patients diagnosed with T2DM without or with DFU were recruited in the study. The distribution of MCP-1 -2518A/G and VEGF -634G/C polymorphisms was investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Enzyme-linked immunosorbent assay (ELISA) was applied to detect the protein levels of MCP-1 and VEGF. The comparisons of protein levels in DFU patients were performed by student t test according to their genotypes.The frequencies of GG genotype and G allele of MCP-1 -2518A/G was increased in DFU patients, compared with T2DM patients (odds ratio [OR] = 2.60, 95% confidence interval [CI] = 1.23-5.50, P = .011 and OR = 1.72, 95% CI = 1.18-2.50, P = .005, respectively). Moreover, the increased frequency of GG was significantly associated with up-regulated MCP-1 level in DFU patients (P < .001). Analysis for VEGF -634G/C polymorphisms indicated that the prevalence of CC genotype and C allele of the polymorphisms was decreased in DFU patients, compared with T2DM patients (OR = 0.36, 95% CI = 0.17-0.77, P = .008 and OR = 0.63, 95% CI = 0.43-0.91, P = .015, respectively). DFU patients carrying CC genotype had a higher level of VEGF than those with other genotypes (P = .007).MCP-1 -2518A/G and VEGF -634G/C polymorphisms may involve in occurrence and progress of DFU through regulating transcription activity of the genes.

The MCP-1 Gene A-2518G Polymorphism Confers an Increased Risk of Vascular Complications in Type 2 Diabetes Mellitus Patients

OBJECTIVE

We aimed to evaluate the correlation of the monocyte chemoattractant protein 1 (MCP-1) A-2518G polymorphism with type 2 diabetes mellitus (T2DM) and vascular complications in T2DM, to aid in understanding its role in pathogenesis.

METHODS

A total of 150 T2DM patients and 50 healthy controls (group A) were enrolled. The T2DM patients were divided into three groups based on the absence of complications (group B) presence of microvascular disease (group C) or macrovascular disease (group D). DNA of all enrolled subjects was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the MCP-1 A-2518G polymorphism. Serum MCP-1 levels were measured by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Participants in group D had increased serum MCP-1 levels relative to group B, group C, and group A (all p<0.01). Compared with group A, the frequencies of the MCP-1 A-2518G G/G genotype and G allele were significantly higher in group C and group D (all p<0.05). In contrast to group B, group C had higher frequencies of the G/G genotype and G allele, while group D had higher G allele frequencies (all p<0.05). Logistic regression analysis showed that lower body-mass index (BMI) and free cholesterol (FC), as well as higher high-density lipoprotein cholesterol (HDL-C) levels may be the protective factors for T2DM, while higher levels of triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and G/G genotype frequency were independent risk factors for T2DM.

CONCLUSIONS

Our data indicates a correlation between the MCP-1 A-2518G polymorphism with macrovascular complications in T2DM patients; lower BMI and FC, as well as higher HDL-C levels may be the protective factors for T2DM, while higher levels of TG, LDL-C, and G/G genotype frequency were independent risk factors for T2DM.

Association of Transforming Growth Factor Beta-1 (TGF-β1) Genetic Variation with Type 2 Diabetes and End Stage Renal Disease in Two Large Population Samples from North India

Geographic and ethnic differences impart an immense influence on the genetic susceptibility to Type 2 diabetes (T2D) and diabetic nephropathy (DN). Transforming growth factor-beta1 (TGF-β1), a ubiquitously expressed pro-fibrotic cytokine plays a pivotal role in mediating the hypertrophic and fibrotic manifestations of DN. The present study is aimed to study the association of TGF-β1 g.869T>C (rs1800470) and g.-509C>T (rs1800469) polymorphism in T2D and end stage renal disease (ESRD) cases from the two geographically and ethnically different populations from North India. A total of 1313 samples comprising 776 samples from Punjab (204 with ESRD, 257 without ESRD, and 315 healthy controls) and 537 samples from Jammu and Kashmir (150 with ESRD, 187 without ESRD, and 200 controls) were genotyped for TGF-β1 (rs1800470 and rs1800469) using ARMS-PCR. The CC genotype of rs1800470 increased ESRD risk by 3.1-4.5-fold in both populations. However, for rs1800469, the TT genotype provided 5.5-fold risk towards ESRD cases from Jammu and Kashmir and no risk for the cases from Punjab. The haplotype C-T conferred nearly a 2-3-fold risk towards T2D and ESRD and diplotype CC-CT conferred a 4-fold risk towards ESRD. Our results conclude that TGF-β1 (rs1800470) may increase the risk of both ESRD and T2D in both populations, but TGF-β1 (rs1800469) provided risk for only ESRD in the population of Jammu and Kashmir. The present study is one of the large sample sized genetic association studies of T2D and ESRD from Indian population and adds to the scholarship on global health omics.