CD36 gene variants and their association with type 2 diabetes in an Indian population

Pharmacogenetic impact of SLC22A1 gene variant rs628031 (G/A) in newly diagnosed Indian type 2 diabetes patients undergoing metformin monotherapy

OBJECTIVES

Type 2 diabetes (T2D) imposes an enormous burden all over the world in both developed and developing countries. Inter-individual differences are attributed to polymorphisms in candidate genes resulting in altered absorption, transportation, distribution, and metabolism of oral antidiabetic drugs (OADs). Hence, the present study was undertaken to evaluate the pharmacogenetic impact of SLC22A1 gene variant rs628031 (G/A) on metformin monotherapy in newly diagnosed untreated T2D patients.

METHODS

Newly diagnosed T2D patients ( n  = 500) were enrolled according to inclusion/exclusion criteria. Initially, enrolled subjects were prescribed metformin monotherapy and followed up for at least 12 weeks. Response to metformin was evaluated in 478 patients who revisited for follow-up by measuring HbA1c.

RESULT

Out of 478 patients, 373 were responders to metformin monotherapy while 105 were non-responders. The pharmacogenetic impact was evaluated by genotype, haplotype, and pharmacogenetic analyses. 'GG' genotype and 'G' allele of SLC22A1 rs628031 G/A were observed in 48.8% and 67.7% of Met responders, respectively, while 20.9% and 49.1 % were in non-responders. Therefore, there was a 2.18-fold increase in the success rate of Met therapeutics.

CONCLUSION

Individuals carrying the 'GG' genotype or 'G' allele for SLC22A1 gene variant rs628031 G/A are better responders for Metformin monotherapy.

Association of cluster determinant 36, scavenger receptor class B type 1, and major facilitator superfamily domain containing the 2a genetic polymorphism with serum lipid profile in aging population with type 2 diabetes mellitus

Background

Lipid metabolism disorder commonly happens in subjects with Type 2 diabetes mellitus (T2DM) which may be linked to genetic variants of lipid metabolism-related genes. However, few studies have explored the relationship between lipid metabolism-related gene polymorphism and serum lipid profile in aging subjects with T2DM. The present study was designed to explore the impact of genetic polymorphism of cluster determinant 36 (CD36) (rs1049673, rs1054516, rs2151916), scavenger receptor class B type 1 (SCARB1) (rs5888), and major facilitator superfamily domain containing the 2a (MFSD2A) (rs12083239, rs4233508, rs12072037) on the relationship between circulating lipids in aging subjects with T2DM.

Methods

205 T2DM patients and 205 age and gender matched control subjects were recruited. Information on demographic characteristics was collected by using a self-administered questionnaire. Fasting venous blood samples were taken for lipid-related gene genotyping and serum lipid profile measurement. The Chi-square test was used to compare percentage differences and to calculate P-value for Hardy-Weinberg equilibrium. Logistic regression and multiple linear regression were used to explore the risk or correlation between variables, and general linear model (GLM) was used to compare the means of serum lipids between the groups.

Results

In T2DM group, CD36 rs1054516 and MFSD2A rs12072037 were correlated with serum TC level. In control group, CD36 rs1049673 was correlated with serum HDL-C level. Meanwhile, T2DM subjects with MFSD2A rs12083239 (CG), MFSD2A rs4233508 (TT), and MFSD2A rs12072037 (AA) had higher TG level than control subjects. T2DM subjects with CD36 rs1049673 (CG, GG), CD36 rs1054516 (CT), CD36 rs2151916 (TT, CT), SCARB1 rs5888 (GG), MFSD2A rs12083239 (GG, CG), MFSD2A rs4233508 (TT), and MFSD2A rs12072037 (CA, AA) had lower HDL-C level than control subjects. T2DM subjects with MFSD2A rs12072037 (AA) had lower LDL-C level than control subjects. In dominant model, major genotype (GG) of SCARB1 gene was associated with the risk of T2DM (OR = 0.636, P = 0.032).

Conclusion

The genetic polymorphism of CD36 (rs1049673, rs1054516, rs2151916), SCARB1 (rs5888), and MFSD2A (rs12083239, rs4233508, rs12072037) were associated with serum lipids in T2DM subjects. The SCARB1 rs5888 major genotype (GG) was a protective factor for T2DM. Large scale cohort study is required to determine the relationship between lipid metabolism-related gene polymorphism, serum lipid profile and T2DM in aging subjects.

CD36 favours fat sensing and transport to govern lipid metabolism

CD36, located on the cell membrane, transports fatty acids in response to dietary fat. It is a critical fatty acid sensor and regulator of lipid metabolism. The interaction between CD36 and lipid dysmetabolism and obesity has been identified in various models and human studies. Nevertheless, the mechanisms by which CD36 regulates lipid metabolism and the role of CD36 in metabolic diseases remain obscure. Here, we summarize the latest research on the role of membrane CD36 in fat metabolism, with emphasis on CD36-mediated fat sensing and transport. This review also critically discusses the factors affecting the regulation of CD36-mediated fat dysfunction. Finally, we review previous clinical evidence of CD36 in metabolic diseases and consider the path forward.

Investigating the association of CD36 gene polymorphisms (rs1761667 and rs1527483) with T2DM and dyslipidemia: Statistical analysis, machine learning based prediction, and meta-analysis

CD36 (cluster of differentiation 36) is a membrane protein involved in lipid metabolism and has been linked to pathological conditions associated with metabolic disorders, such as diabetes and dyslipidemia. A case-control study was conducted and included 177 patients with type-2 diabetes mellitus (T2DM) and 173 control subjects to study the involvement of CD36 gene rs1761667 (G>A) and rs1527483 (C>T) polymorphisms in the pathogenesis of T2DM and dyslipidemia among Jordanian population. Lipid profile, blood sugar, gender and age were measured and recorded. Also, genotyping analysis for both polymorphisms was performed. Following statistical analysis, 10 different neural networks and machine learning (ML) tools were used to predict subjects with diabetes or dyslipidemia. Towards further understanding of the role of CD36 protein and gene in T2DM and dyslipidemia, a protein-protein interaction network and meta-analysis were carried out. For both polymorphisms, the genotypic frequencies were not significantly different between the two groups (p > 0.05). On the other hand, some ML tools like multilayer perceptron gave high prediction accuracy (≥ 0.75) and Cohen's kappa (κ) (≥ 0.5). Interestingly, in K-star tool, the accuracy and Cohen's κ values were enhanced by including the genotyping results as inputs (0.73 and 0.46, respectively, compared to 0.67 and 0.34 without including them). This study confirmed, for the first time, that there is no association between CD36 polymorphisms and T2DM or dyslipidemia among Jordanian population. Prediction of T2DM and dyslipidemia, using these extensive ML tools and based on such input data, is a promising approach for developing diagnostic and prognostic prediction models for a wide spectrum of diseases, especially based on large medical databases.

Contribution of rs3211938 polymorphism at CD36 to glucose levels, oxidized low-density lipoproteins, insulin resistance, and body mass index in Mexican mestizos with type-2 diabetes from western Mexico

Introduction

Background: type-2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia, insulin resistance (IR), and abnormal fatty acid metabolism in which the CD36 receptor has been implicated in glucose and lipid dysregulation. Objective: to evaluate the contribution of polymorphism CD36 rs3211938 to metabolic profile in T2DM Mexican mestizos from western Mexico. Methods: we included 115 individuals classified as non-T2DM (NT2DM) adults and T2DM patients. Polymorphism CD36 rs3211938 was assessed by PCR-RFLP. Anthropometric and metabolic markers were measured by routine methods, and insulin and oxidized LDL (ox-LDL) were measured by ELISA. Results: the distribution of genotypes between NT2DM and T2DM patients was different (p < 0.001), as was the allele frequency (p = 0.002). NT2DM TG carriers showed the lowest levels of basal insulin and HOMA-IR index in comparison with TT carriers (p < 0.05 and p < 0.05, respectively). In the T2DM group TG carriers showed high BMI, WHR, and weight values (p = 0.001; p ≤ 0.05 and p < 0.05, respectively), and the highest levels of basal glucose, HDL-cholesterol, ox-LDL, and HOMA-IR (p < 0.001; p < 0.001; p < 0.001, and p = 0.001, respectively) in comparison with diabetic TT carriers. Conclusion: the CD36 rs3211938 TG genotype is associated with high levels of glucose, ox-LDL, HDL-cholesterol, and IR, and with increased BMI in Mexican mestizo T2DM patients from western Mexico.

The Role of CD36 in Type 2 Diabetes Mellitus: β-Cell Dysfunction and Beyond

Impaired β-cell function is the key pathophysiology of type 2 diabetes mellitus, and chronic exposure of nutrient excess could lead to this tragedy. For preserving β-cell function, it is essential to understand the cause and mechanisms about the progression of β-cells failure. Glucotoxicity, lipotoxicity, and glucolipotoxicity have been suggested to be a major cause of β-cell dysfunction for decades, but not yet fully understood. Fatty acid translocase cluster determinant 36 (CD36), which is part of the free fatty acid (FFA) transporter system, has been identified in several tissues such as muscle, liver, and insulin-producing cells. Several studies have reported that induction of CD36 increases uptake of FFA in several cells, suggesting the functional interplay between glucose and FFA in terms of insulin secretion and oxidative metabolism. However, we do not currently know the regulating mechanism and physiological role of CD36 on glucolipotoxicity in pancreatic β-cells. Also, the downstream and upstream targets of CD36 related signaling have not been defined. In the present review, we will focus on the expression and function of CD36 related signaling in the pancreatic β-cells in response to hyperglycemia and hyperlipidemia (ceramide) along with the clinical studies on the association between CD36 and metabolic disorders.

Anti‑glycolipid disorder effect of epigallocatechin‑3‑gallate on high‑fat diet and STZ‑induced T2DM in mice

Epigallocatechin-3-gallate (EGCG) is beneficial for inhibiting dyslipidemia and reducing hyperlipidemic risk. The purpose of the present study was to investigate the glycolipid regulatory effects and potential mechanisms of EGCG in a high-fat diet and streptozotocin-induced type 2 diabetes mellitus (T2DM) mouse model. The results demonstrated that EGCG can decrease blood glucose levels and increase insulin resistance in T2DM mice. In addition, EGCG can regulate serum lipid levels, including those of total cholesterol, triglyceride and low-density lipoprotein receptor (LDL-r), and reduce lipid deposition in vascular endothelial cells in a dose-dependent manner. In addition, the gene and protein expression of related scavenger receptors, including cluster of differentiation 36, sterol regulatory element binding protein 2 (SREBP), SREBP cleavage-activating protein and LDL-r, were downregulated in a dose-dependent manner. The present study noted that EGCG possesses potential as a natural product for preventing and treating metabolic hyperlipidemia syndrome, probably by reducing the blood lipid levels, alleviating vascular endothelial cell damage, maintaining normal lipid metabolism in blood vessels and ameliorating glycolipid disorders.

Interaction of antioxidant gene variants and susceptibility to type 2 diabetes mellitus

Background: Diabetes is the seventh most common disease leading to death with a global estimate of 425 million diabetics, expected to be 629 million in 2045. The role of reactive metabolites and antioxidants, such as glutathione, glutathione peroxidase, superoxide dismutase and catalase in type 2 diabetes mellitus (T2DM) provides an opportunity for identifying gene variants and risk genotypes. We hypothesised that certain antioxidant gene-gene interactions are linked with T2DM and can model disease risk prediction.Materials and methods: Genotyping of single nucleotide polymorphisms (SNPs) in antioxidant genes for glutathione (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) was performed in 558 T2DMs and 410 age and sex matched healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), routine lab indices by standard techniques.Results: The null/null allele combination of GSTM1del and GSTT1del increased disease risk up to 1.7-fold. The combination of SNPs in GSTM1del, GSTT1del, GSTP1 + 313A/G and in CAT-21A/T, SOD2 + 47C/T, GPx1 + 599C/T increased the risk of diabetes 13.5 and 2.1-fold, respectively. Interaction of SNPs GSTM1del, GSTT1del, GSTP1 + 313A/G (105Ile/Val), CAT-21A/T, SOD2 + 47C/T, GPx1 + 599C/T were significantly linked with disease risk >5 × 10³ fold.Conclusion: As the number of gene combinations increase, there is a rise in the odds ratio of disease risk, suggesting that gene-gene interaction plays an important role in T2DM susceptibility. Individuals who possess the GSTM1del, GSTT1del, GSTP1 105I/V(+313A/G), CAT-21A/T, SOD2 + 47C/T and GPx1 + 599C/T are at very high risk of developing T2DM.

Atherosclerotic Cardiovascular Disease in South Asians in the United States: Epidemiology, Risk Factors, and Treatments: A Scientific Statement From the American Heart Association

South Asians (from Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan, and Sri Lanka) make up one quarter of the world's population and are one of the fastest-growing ethnic groups in the United States. Although native South Asians share genetic and cultural risk factors with South Asians abroad, South Asians in the United States can differ in socioeconomic status, education, healthcare behaviors, attitudes, and health insurance, which can affect their risk and the treatment and outcomes of atherosclerotic cardiovascular disease (ASCVD). South Asians have higher proportional mortality rates from ASCVD compared with other Asian groups and non-Hispanic whites, in contrast to the finding that Asian Americans (Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese) aggregated as a group are at lower risk of ASCVD, largely because of the lower risk observed in East Asian populations. Literature relevant to South Asian populations regarding demographics and risk factors, health behaviors, and interventions, including physical activity, diet, medications, and community strategies, is summarized. The evidence to date is that the biology of ASCVD is complex but is no different in South Asians than in any other racial/ethnic group. A majority of the risk in South Asians can be explained by the increased prevalence of known risk factors, especially those related to insulin resistance, and no unique risk factors in this population have been found. This scientific statement focuses on how ASCVD risk factors affect the South Asian population in order to make recommendations for clinical strategies to reduce disease and for directions for future research to reduce ASCVD in this population.

CD36 gene variants is associated with type 2 diabetes mellitus through the interaction of obesity in rural Chinese adults

BACKGROUND

Evidences show that cluster determinant 36 (CD36) protein plays a role in lipid metabolism and insulin resistance, and the expression of CD36 is inducible in obesity. The present study evaluated the association of CD36 variants and the interaction with obesity on type 2 diabetes mellitus (T2DM) risk.

METHODS

We performed a case-control study nested in the Rural Chinese Cohort Study. We included 546 incident T2DM cases matched with non-T2DM controls in a 1:1 ratio by sex, age (within 2 years), marital status, and residence village. Four loci in CD36 (rs1194197, rs2151916, rs3211956, and rs7755) were genotyped by SNPscan^TM Genotyping system.

RESULTS

After adjusting for potential confounding, we observed no statistically significant association between the CD36 polymorphisms and T2DM risk. Compared to wild-type homozygous carriers with normal weight, overweight/obesity participants carrying the mutational allele rs7755 showed increased risk of T2DM, by 114% (OR = 2.14, 95% CI: 1.33-3.46; P_interaction = 0.007); abdominal obesity participants carrying the mutational allele rs7755 showed increased risk of T2DM, by 133% (OR = 2.33, 95% CI: 1.48-3.66; P_interaction = 0.002). Furthermore, rs2151916 polymorphism was associated with triglycerides level (P = 0.019), and the rs1194197 variant was related to systolic blood pressure (P = 0.023) within the group of controls.

CONCLUSIONS

CD36 genotypes were not associated with the progression to T2DM independently. However, our results suggested a positive interaction between the CD36 variants and obesity on T2DM susceptibility, which might be through a cardiometabolic disorder.

Study and evaluation the impact of vitamin D receptor variants on the risk of type 2 diabetes mellitus in Han Chinese

BACKGROUND

Vitamin D and the vitamin D receptor (VDR) are associated with susceptibility to type 2 diabetes mellitus (T2DM). The purpose of the present study was to screen more single nucleotide polymorphisms (SNPs) of VDR and assess their effects on the risk of T2DM in Han Chinese.

METHOD

Four SNPs were genotyped in 1191 individuals (397 cases, 794 controls). Allele frequencies and genotype distributions were analyzed. Effects were investigated by evaluating genotype distribution with regard to phenotypes, insulin resistance, and β-cell function. Haplotype analysis and gene risk score (GRS) were used to evaluate the combined and additive roles of VDR SNPs on T2DM pathogenesis.

RESULTS

There was a significant association between rs739837 and T2DM in two models and allele frequency distribution. The novel locus rs2239179 differed significantly between cases and controls, especially in males and those aged >55 years, in three models and allele frequency distribution. The TT genotype of rs739837 was associated with higher triglyceride than GG and TG genotypes, and higher total cholesterol levels than the GG genotype. Compared with the GTGA haplotype, the GCGG haplotype reduced the risk of T2DM. Trend Chi-squared tests showed that there was significant association between the weighted GRS and the risk of T2DM (P_trend  = 0.034).

CONCLUSION

This study provides novel evidence that rs739837 is associated with lipid metabolism in T2DM patients. The rs739837 and rs2239179 SNPs were associated with the risk of T2DM in Han Chinese. The VDR SNPs had combined and additive effects on the risk of T2DM.

Pharmacogenetic studies update in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a silent progressive polygenic metabolic disorder resulting from ineffective insulin cascading in the body. World-wide, about 415 million people are suffering from T2DM with a projected rise to 642 million in 2040. T2DM is treated with several classes of oral antidiabetic drugs (OADs) viz. biguanides, sulfonylureas, thiazolidinediones, meglitinides, etc. Treatment strategies for T2DM are to minimize long-term micro and macro vascular complications by achieving an optimized glycemic control. Genetic variations in the human genome not only disclose the risk of T2DM development but also predict the personalized response to drug therapy. Inter-individual variability in response to OADs is due to polymorphisms in genes encoding drug receptors, transporters, and metabolizing enzymes for example, genetic variants in solute carrier transporters (SLC22A1, SLC22A2, SLC22A3, SLC47A1 and SLC47A2) are actively involved in glycemic/HbA1c management of metformin. In addition, CYP gene encoding Cytochrome P450 enzymes also play a crucial role with respect to metabolism of drugs. Pharmacogenetic studies provide insights on the relationship between individual genetic variants and variable therapeutic outcomes of various OADs. Clinical utility of pharmacogenetic study is to predict the therapeutic dose of various OADs on individual basis. Pharmacogenetics therefore, is a step towards personalized medicine which will greatly improve the efficacy of diabetes treatment.

Soluble CD36 in plasma and urine: a plausible prognostic marker for diabetic nephropathy

AIMS

This study was designed to analyze the level of soluble CD36 (sCD36) in both plasma and urine of type 2 diabetic patients with and without microalbuminuria/macroalbuminuria.

METHODS

Study subjects (n=20 each) comprised of those with normal glucose tolerance, type 2 diabetes (T2DM) with normoalbuminiria, T2DM with microalbuminuria and T2DM with macroalbuminuria. The biochemical parameters were analyzed using auto-analyzer, and the level of sCD36 was estimated using an in-house Sandwich ELISA.

RESULTS

The presence of sCD36 has been identified for the first time in the urine sample. Significant increase in the level of sCD36 was observed in both plasma and urine of diabetic patients with microalbuminuria (P<0.01) and macroalbuminuria (P<0.001). Positive correlation of sCD36 with the kidney markers such as urea, creatinine and eGFR confirmed the association of sCD36 with kidney damage in diabetic patients. Microalbuminuria, which is clinically used as a biomarker for nephropathy showed a strong positive correlation with urine sCD36 (r=0.642; P<0.001) and plasma sCD36 (r=0.498; P<0.001) in Pearson correlation analysis, which was further substantiated in stepwise multiple regression analysis.

CONCLUSIONS

Our study implies a plausible prognostic/adjuvant biomarker role of soluble CD36 for diabetic nephropathy.

CD36 gene variants in early prediction of type 2 diabetes mellitus

Type 2 diabetes (T2DM) is a noncommunicable disease affecting huge populations in India and abroad. Single-nucleotide polymorphisms (SNPs) in CD36, a macrophage scavenger receptor, have been implicated in the pathogenesis of T2DM and its complications. Eleven SNPs in the CD36 gene and their association with 100 each of control subjects and T2DM patients were investigated in the present study. The haplotype analysis of a few significant SNPs was carried out in individuals from families with diabetic history to evaluate its utility in disease prediction. Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping. Ten families with a family history of diabetes were identified and blood samples were collected from as many family members as possible. Genotyping of three SNPs, namely rs1761667 (G>A) in exon 1 A, rs3211938 (T>G) in exon 10, and rs3212018 (16 bp del) in exon 14, was performed in all samples. Our results suggested that individuals having a GATTC1 haplotype might be at risk of developing T2DM (p<0.001) and, therefore, might be susceptible to related complications. Moreover, the presence of A, G, and G alleles of SNPs rs1761667 (G>A), rs3211938 (T>G), and rs1984112 (T>G) tends to have increased BMI, respectively. Such studies may be helpful for disease prediction in individuals at risk of T2DM. The predictive potential of CD36 variants can be explored with more families in the study population to use this as a genetic marker.