CD36 gene variants in early prediction of type 2 diabetes mellitus

Circadian Gene Variants: Effects in Overweight and Obese Pregnant Women

Obesity and overweight are common and complex conditions influenced by multiple genetic and environmental factors. Several genetic variants located in the genes involved in clock systems and fat taste perception can affect metabolic health. In particular, the polymorphisms in CLOCK and BMAL1 genes were reported to be significantly related to cardiovascular disease, metabolic syndrome, sleep reduction, and evening preference. Moreover, genetic variants in the CD36 gene have been shown to be involved in lipid metabolism, regulation of fat intake, and body weight regulation. The aim of this study is to evaluate, for the first time, the association between variants in some candidate genes (namely, BMAL1 rs7950226 (G>A), CLOCK rs1801260 (A>G), CLOCK rs4864548 (G>A), CLOCK rs3736544 (G>A), CD36 rs1984112 (A>G), CD36 rs1761667 (G>A)) and overweight/obesity (OB) in pregnant women. A total of 163 normal-weight (NW) and 128 OB participants were included. A significant correlation was observed between A-allele in CLOCK rs4864548 and an increased risk of obesity (OR: 1.97; 95% CI 1.22-3.10, p = 0.005). In addition, we found that subjects carrying the haplotype of rs1801260-A, rs4864548-A, and rs3736544-G are likely to be overweight or obese (OR 1.47, 95% CI 1.03-2.09, p = 0.030), compared with those with other haplotypes. Moreover, a significant relation was observed between third-trimester lipid parameters and genetic variants-namely, CD36 rs1984112, CD36 rs1761667, BMAL1 rs7950226, and CLOCK rs1801260. A multivariate logistic regression model revealed that CLOCK rs4864548 A-allele carriage was a strong risk factor for obesity (OR 2.05, 95% CI 1.07-3.93, p = 0.029); on the other hand, greater adherence to Mediterranean diet (OR 0.80, 95% CI 0.65-0.98, p = 0.038) and higher HDL levels (OR 0.96, 95% CI 0.94-0.99, p = 0.021) were related to a reduced risk of obesity. Interestingly, an association between maternal CLOCK rs4864548 and neonatal birthweight was detected (p = 0.025). These data suggest a potential role of the polymorphisms in clock systems and in fat taste perception in both susceptibility to overweight/obesity and influencing the related metabolic traits in pregnant women.

Genetic Variants in CD36 Involved in Fat Taste Perception: Association with Anthropometric and Clinical Parameters in Overweight and Obese Subjects Affected by Type 2 Diabetes or Dysglycemia-A Pilot Study

Obesity and overweight represent a growing health problem worldwide. Genes regulating the intake and metabolism of different nutrients can positively or negatively influence the efficacy of nutritional interventions against obesity and its complications. The aim of this study was to assess changes in anthropometric and clinical parameters and the adherence to a Mediterranean diet (MedDiet) over time in relation to nutrigenetic variants in overweight or obese subjects affected by Type 2 Diabetes (T2D) or dysglycemia, who were included in a nutritional program. A total of 23 subjects were included in this study. Clinical parameters, physical activity levels, and the adherence to a MedDiet were evaluated at baseline, at 6 (T6), and at 12 months (T12) during and after a diet/lifestyle intervention. In a single blood sample from each subject, rs1984112 (A>G) and rs1761667 (G>A) in CD36; rs7950226 (G>A) in BMAL1; and rs1801260 (A>G), rs4864548 (A>G), and rs3736544 (G>A) in CLOCK were genotyped with Real-Time PCR. Significant associations were observed between CD36 rs1761667 and weight (p = 0.025), hip circumference (p = 0.042), triglycerides (p = 0.047), and HbA1c (p = 0.012) at baseline. Moreover, the genotype AA in CD36 rs1761667 was significantly associated with a lower BMI when compared to G carriers at baseline, at T6, and also at T12. In addition, subjects with the AA genotype at CD36 rs1984112 had significantly lower levels of HbA1c (p = 0.027) than the GG and AG genotypes at baseline. These results show that variants in CD36 can have an impact on anthropometric and clinical parameters in overweight or obese subjects affected by T2D or dysglycemia, and that it might influence the success of the diet/lifestyle intervention.

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.

Association between polymorphisms and hypermethylation of CD36 gene in obese and obese diabetic Senegalese females

BACKGROUND

Obesity and related metabolic disorders are associated with genetic and epigenetic alterations. In this study, we have examined the association between polymorphisms and hypermethylation of the CD36 gene promoter with obesity in Senegalese females with or without type 2 diabetes mellitus to identify novel molecular markers of these pathologies (obesity and type 2 diabetes mellitus).

MATERIALS AND METHODS

The study was conducted in Senegal with healthy lean control, obese, and obese diabetic (age; 49.98 years ± 7.52 vs 50.50 years ± 8.76 vs 51.06 ± 5.78, and body mass index (BMI); 24.19 kg/m² ± 2.74 vs 34.30 kg/m² ± 4.41 vs 33.09 kg/m² ± 4.30). We determined three genetic polymorphisms of CD36 i.e., rs1761667, rs1527483, and rs3211867 by real-time polymerase chain reaction, and methylation of CPG islands of CD36 was assessed by methylation-specific polymerase chain reaction (MS-PCR) in DNA isolated from peripheral blood of each participant. Plasma sCD36 levels and DNA methyltransferase 3a (DNMT3a) levels were determined by enzyme-linked immunosorbent assay (ELISA). According to the standard laboratory protocol, all biochemical parameters were analyzed from fasting serum or plasma.

RESULTS

For rs1761667, obese and obese diabetic subjects had statistically significant different parameters depending on the genotypic distribution. These were waist size for obese and HDL cholesterol for obese diabetic, they were significantly higher in subjects harboring GG genotype of rs1761667 (respectively p = 0.04 and p = 0.04). For rs3211867, obese subjects harboring the AA/AC genotype had significantly higher BMI (p = 0.02) and total cholesterol (p = 0.03) than obese subjects harboring the CC genotype. At the same time, the obese diabetic subjects harboring the AA/AC genotype had total cholesterol levels significantly higher than the obese diabetic subjects harboring the CC genotype (p = 0.03). For rs1527483, only the control subjects had statistically significant different parameters depending on the genotypic distribution. The control subjects harboring the GG genotype had a significantly higher BMI than the control subjects harboring the AA/AG genotype (p = 0.003). The CD36 gene methylation was significantly 1.36 times more frequent in obese and obese diabetic compared to lean control (RR = 1.36; p = 0.04). DNMT3a levels were higher in subjects with CD36 gene methylation than in subjects without CD36 gene methylation in each group. Obese diabetic subjects with CD36 gene methylation had significantly fewer plasmas sCD36 (p = 0.03) and more LDL-cholesterol (p = 0.01) than obese diabetic subjects without CD36 gene methylation. In the control group, an increase in sCD36 levels would be associated with a decrease in total cholesterol and triglyceride levels (coef = -7647.56 p = 0.01 and coef = -2528.50 p = 0.048, respectively) would be associated with an increase in LDL cholesterol levels. For the obese group, an increase in sCD36 levels would be associated with an increase in fasting insulin levels (coef = 490.99 p = 0.02) and a decrease in glycated hemoglobin levels (coef = -1196.26 p = 0.03). An increase in the sCD36 levels would be associated with an increase in the triglyceride levels in the obese diabetic group (coef = 9937.41 p = 0.02). The AA/AC genotype of SNP rs3211867 polymorphism was significantly associated with CD36 gene methylation in the control and obese diabetic groups (respectively p = 0.05, p = 0.002; 95% CI).

CONCLUSION

These observations suggest that polymorphisms and epigenetic changes in CD36 gene promoters may be implicated in the onset of obesity and its related complication type 2 diabetes mellitus.

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.

Multi-Ethnic Genome-Wide Association Study of Decomposed Cardioelectric Phenotypes Illustrates Strategies to Identify and Characterize Evidence of Shared Genetic Effects for Complex Traits

BACKGROUND

We examined how expanding electrocardiographic trait genome-wide association studies to include ancestrally diverse populations, prioritize more precise phenotypic measures, and evaluate evidence for shared genetic effects enabled the detection and characterization of loci.

METHODS

We decomposed 10 seconds, 12-lead electrocardiograms from 34 668 multi-ethnic participants (15% Black; 30% Hispanic/Latino) into 6 contiguous, physiologically distinct (P wave, PR segment, QRS interval, ST segment, T wave, and TP segment) and 2 composite, conventional (PR interval and QT interval) interval scale traits and conducted multivariable-adjusted, trait-specific univariate genome-wide association studies using 1000-G imputed single-nucleotide polymorphisms. Evidence of shared genetic effects was evaluated by aggregating meta-analyzed univariate results across the 6 continuous electrocardiographic traits using the combined phenotype adaptive sum of powered scores test.

RESULTS

We identified 6 novels (CD36, PITX2, EMB, ZNF592, YPEL2, and BC043580) and 87 known loci (adaptive sum of powered score test P<5×10-9). Lead single-nucleotide polymorphism rs3211938 at CD36 was common in Blacks (minor allele frequency=10%), near monomorphic in European Americans, and had effects on the QT interval and TP segment that ranked among the largest reported to date for common variants. The other 5 novel loci were observed when evaluating the contiguous but not the composite electrocardiographic traits. Combined phenotype testing did not identify novel electrocardiographic loci unapparent using traditional univariate approaches, although this approach did assist with the characterization of known loci.

CONCLUSIONS

Despite including one-third as many participants as published electrocardiographic trait genome-wide association studies, our study identified 6 novel loci, emphasizing the importance of ancestral diversity and phenotype resolution in this era of ever-growing genome-wide association studies.

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.

CD36 - a plausible modifier of disease phenotype in familial adenomatous polyposis

Background

Familial adenomatous polyposis (FAP) is a well characterised genetic predisposition to early onset colorectal cancer (CRC) that is characterised by polyposis of the colon and rectum. Animal models have consistently suggested the role of modifier genes in determining disease phenotype, yet none have been substantiated in the human population. The mouse homologue of cluster of differentiation 36 (CD36) has been proposed as a modifier of disease in the MIN mouse model of FAP.

Methods

Three single nucleotide polymorphisms (SNPs); rs1049673, rs1761667 and rs1984112 in CD36, have been investigated in 275 FAP patients to determine if they were associated with age of polyposis or risk of developing disease.

Results

The results revealed a substantially lower age of polyposis diagnosis for patients belonging to the severe FAP group (harbouring adenomatous polyposis coli (APC) variants in the mutation cluster region (MCR)) and high age for patients in the attenuated familial adenomatous polyposis (AFAP) group for SNPs rs1761667 and rs1984112.

Conclusions

This study provides evidence for patients belonging to the MCR and AFAP groups harbouring specific genotypes for SNPs in CD36 to initiate screening/treatment for FAP at much earlier (MCR) and much later (AFAP) ages than the norm in today’s clinical practice. The findings need to be verified in an independent FAP patient cohort.

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.

The rs1527483, but not rs3212018, CD36 polymorphism associates with linoleic acid detection and obesity in Czech young adults

Recent evidence has raised the possibility of the existence of a sixth taste modality – that is, taste for fat – which is mediated by lingual CD36 and plays a role in obesity. Consequently, the genetic polymorphism of CD36 has been shown to be associated with altered oro-sensory detection of dietary lipids. In the present study, we investigated the relationship between oro-sensory perception of linoleic acid (LA), two CD36 polymorphisms (rs1527483 and rs3212018), obesity parameters and craving habits for dietary lipids in young Czech adults. We also sequenced 5 and 6 exons of CD36 to trace out any new mutation that might be responsible for the difference in taste perception. We observed that craving for dietary lipids was correlated with anthropometric parameters (P<0·05) and LA detection threshold (P=0·033). The participants with the CC genotype of the rs1527483 polymorphism had lower BMI (P=0·011), waist circumference (P=0·005), waist:height ratio (P=0·010) and higher sensitivity for LA (P=0·037) than the participants with the CT and TT genotypes. Interestingly, we did not observe any association between the rs3212018 polymorphism and the studied parameters. Moreover, we did not observe any mutation in exons 5 and 6 of the CD36 gene in these subjects. Finally, we can state that rs1527483, but not rs3212018, is associated with high body weight in young Czech subjects.

Current Advances in the Biochemical and Physiological Aspects of the Treatment of Type 2 Diabetes Mellitus with Thiazolidinediones

The present review summarizes the current advances in the biochemical and physiological aspects in the treatment of type 2 diabetes mellitus (DM2) with thiazolidinediones (TZDs). DM2 is a metabolic disorder characterized by hyperglycemia, triggering the abnormal activation of physiological pathways such as glucose autooxidation, polyol's pathway, formation of advance glycation end (AGE) products, and glycolysis, leading to the overproduction of reactive oxygen species (ROS) and proinflammatory cytokines, which are responsible for the micro- and macrovascular complications of the disease. The treatment of DM2 has been directed toward the reduction of hyperglycemia using different drugs such as insulin sensitizers, as the case of TZDs, which are able to lower blood glucose levels and circulating triglycerides by binding to the nuclear peroxisome proliferator-activated receptor gamma (PPARγ) as full agonists. When TZDs interact with PPARγ, the receptor regulates the transcription of different genes involved in glucose homeostasis, insulin resistance, and adipogenesis. However, TZDs exhibit some adverse effects such as fluid retention, weight gain, hepatotoxicity, plasma-volume expansion, hemodilution, edema, bone fractures, and congestive heart failure, which limits their use in DM2 patients.

Association between rs1761667 polymorphism of CD36 gene and risk of coronary atherosclerosis in Egyptian population

BACKGROUND

Recent studies have demonstrated that CD36 is involved in the progression of atherosclerosis. Associations between rs1761667 polymorphisms of the CD36 gene and susceptibility to coronary artery disease (CAD) are not obvious.

METHODS

We studied the relationship between single nucleotide polymorphisms (SNPs), rs1761667 of CD36 gene and the risk of coronary atherosclerosis in a case-control study composed of 71 CAD patients and 76 healthy controls by assessment of allele frequencies and genotype distributions using real-time polymerase chain reaction (PCR) and the allele discrimination technique. Additionally, we detected CD36 expression by flow cytometry.

RESULTS

The distribution of rs1761667 genotypes between the two groups was significantly different (P<0.001), with the frequency of the AG genotype being significantly higher in the CAD group than in the control group (P<0.001). The expression level of CD36 in the CAD group was significantly higher than that in the control group (P<0.001), with significant differences in the CAD patients with an AG genotype compared with those with an AA and GG genotype (P<0.001). The plasma levels (mg/dL) of low-density lipoprotein (LDL) in the CAD group were much higher than that in the control group (P<0.001). On the other hand, the plasma LDL levels in CAD patients with the AG genotype were remarkably higher than those with the GG and AA genotypes (P=0.046) and AG genotype was significantly more prevalent among type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) patients (P<0.05). After adjusted logistic regression analysis, the AG genotype of rs1761667 was associated with an increased risk of CAD (OR=17.97, 95% CI, 3.19-87.85, P=0.001).

CONCLUSIONS

The AG genotype of the rs1761667 polymorphism in the CD36 gene may be involved in CAD pathogenesis as well as increased body mass index (BMI), T2DM and MetS in the Sohag population of Egypt.