Association of single nucleotide polymorphisms of miRNAs involved in the GLUT4 pathway in T2DM in a Chinese population

Role of metformin in functional endometrial hyperplasia and polycystic ovary syndrome involves the regulation of MEG3/miR‑223/GLUT4 and SNHG20/miR‑4486/GLUT4 signaling

Metformin (MET) can effectively treat endometrial hyperplasia (EH), and the expression of glucose transporter type 4 insulin-responsive (GLUT4) is closely associated with the development of EH. The present study aimed to verify the effect of MET in functional EH and polycystic ovary syndrome (PCOS). H&E staining was performed to analyze the severity of EH, and immunohistochemistry was performed to evaluate the expression of GLUT4 in the endometrium of PCOS rats. Reverse transcription-quantitative PCR was used to calculate the expression of long non-coding (lnc)RNA-maternally expressed gene 3 (MEG3), lncRNA-small nucleolar RNA host gene 20 (SNHG20), GLUT4 mRNA, microRNA (miR)-223 and miR-4486. Sequence analysis and luciferase assays were performed to explore the regulatory relationship among certain lncRNAs, miRNAs and target genes. EH in PCOS rats was efficiently inhibited by MET administration. The increased expression of GLUT4 in PCOS rats was attenuated by MET treatment. Moreover, the expression levels of lncRNA-MEG3 and lncRNA-SNHG20 were significantly inhibited in the endometrium of PCOS rats. MET treatment also showed remarkable efficiency in restoring the expression of lncRNA-MEG3 and lncRNA-SNHG20. Meanwhile, the expression levels of miR-223 and miR-4486 were notably elevated in the endometrium of PCOS rats, while MET treatment reduced the expression of miR-223 and miR-4486 in PCOS rats. Furthermore, a luciferase assay confirmed the inhibitory relationship between miR-223 and lncRNA-MEG3/GLUT4 expression, as well as between miR-4486 and lncRNA-SNHG20/GLUT4 expression. GLUT4 knockdown restored the decreased viability of HCC-94 cells induced by overexpression of lncRNA-MEG3. To conclude, MET exhibited a therapeutic effect in the treatment of EH by modulating the lncRNA-MEG3/miR-223/GLUT4 and lncRNA-SNHG20/miR-4486/GLUT4 signaling pathways. This work provides mechanistic insight into the development of EH.

Insulin Resistance Is Cheerfully Hitched with Hypertension

Cardiovascular diseases and type 2 diabetes mellitus (T2DM) have risen steadily worldwide, particularly in low-income and developing countries. In the last hundred years, deaths caused by cardiovascular diseases increased rapidly to 35-40%, becoming the most common cause of mortality worldwide. Cardiovascular disease is the leading cause of morbidity and mortality in type 2 diabetes mellitus (T2DM), which is aggravated by hypertension. Hypertension and diabetes are closely interlinked since they have similar risk factors such as endothelial dysfunction, vascular inflammation, arterial remodeling, atherosclerosis, dyslipidemia, and obesity. Patients with high blood pressure often show insulin resistance and have a higher risk of developing diabetes than normotensive individuals. It has been observed that over the last 30 years, the prevalence of insulin resistance (IR) has increased significantly. Accordingly, hypertension and insulin resistance are strongly related to an increased risk of impaired glucose tolerance, diabetes, cardiovascular diseases (CVD), and endocrine disorders. Common mechanisms, for instance, upregulation of the renin-angiotensin-aldosterone system, oxidative stress, inflammation, and activation of the immune system, possibly have a role in the association between diabetes and hypertension. Altogether these abnormalities significantly increase the risk of developing type 2 diabetes.

Differences in Liver microRNA profiling in pigs with low and high feed efficiency

Feed cost is the main factor affecting the economic benefits of pig industry. Improving the feed efficiency (FE) can reduce the feed cost and improve the economic benefits of pig breeding enterprises. Liver is a complex metabolic organ which affects the distribution of nutrients and regulates the efficiency of energy conversion from nutrients to muscle or fat, thereby affecting feed efficiency. MicroRNAs (miRNAs) are small non-coding RNAs that can regulate feed efficiency through the modulation of gene expression at the post-transcriptional level. In this study, we analyzed miRNA profiling of liver tissues in High-FE and Low-FE pigs for the purpose of identifying key miRNAs related to feed efficiency. A total 212~221 annotated porcine miRNAs and 136~281 novel miRNAs were identified in the pig liver. Among them, 188 annotated miRNAs were co-expressed in High-FE and Low-FE pigs. The 14 miRNAs were significantly differentially expressed (DE) in the livers of high-FE pigs and low-FE pigs, of which 5 were downregulated and 9 were upregulated. Kyoto Encyclopedia of Genes and Genomes analysis of liver DE miRNAs in high-FE pigs and low-FE pigs indicated that the target genes of DE miRNAs were significantly enriched in insulin signaling pathway, Gonadotropin-releasing hormone signaling pathway, and mammalian target of rapamycin signaling pathway. To verify the reliability of sequencing results, 5 DE miRNAs were randomly selected for quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR results of miRNAs were confirmed to be consistent with sequencing data. DE miRNA data indicated that liver-specific miRNAs synergistically acted with mRNAs to improve feed efficiency. The liver miRNAs expression analysis revealed the metabolic pathways by which the liver miRNAs regulate pig feed efficiency.

The Single Nucleotide Polymorphisms (rs1292037 and rs13137) in miR-21 Were Associated with T2DM in a Chinese Population

BACKGROUND

Insulin receptor (INSR), insulin receptor substrate (IRS) and glucose transporter 4 (GLUT4) play important roles in the insulin resistance pathway. The microRNA (miRNA or miR) involved in INSR, IRS or GLUT4 could be associated with the development of type 2 diabetes (T2DM).

METHODS

The aim of this study was to investigate the association of T2DM with 12 single nucleotide polymorphisms (SNPs) in 7 miRNAs (miR-195, miR-126, miR-144, miR-155, miR-21, miR-93 and miR-222) involved in the insulin resistance pathway. A total of 1593 subjects with T2DM and 1656 nondiabetic subjects were genotyped. Then, the associations of these SNPs with the development of T2DM and individual metabolic traits were evaluated, such as fasting plasma glucose (FPG) and glycosylated haemoglobin (HbA1C).

RESULTS

Our data showed that the C allele of rs1292037 in miR-21 could increase the risk of developing T2DM (P = 0.002, OR = 1.17; 95% CI: 1.06-1.29). In addition, the T allele of rs13137 in miR-21 could be a risk factor for T2DM (P = 0.003, OR = 1.16; 95% CI: 1.05-1.28). According to inheritance mode analysis, compared with the T/T-T/C genotype, the C/C genotype of rs1292037 showed a risk effect in T2DM in the recessive mode (P = 0.001, OR = 1.35; 95% CI: 1.13-1.63). For rs13137, compared with the A/A-A/T genotype, the T/T genotype also showed a risk effect in T2DM in the recessive mode (P = 0.001, OR = 1.35; 95% CI: 1.13-1.62). Moreover, in the nondiabetic group, compared with the rs78312845 A/G (FPG = 5.177±0.488mmol/L; HbA1C = 5.147±0.293%) and A/A genotypes (FPG = 5.155±0.486mmol/L; HbA1C = 5.136±0.299%), the G/G genotype (FPG = 4.887±0.482mmol/L; HbA1C = 4.960±0.397%) was associated with lower FPG (P = 0.012 and 0.019) and HbA1C (P = 0.008 and 0.011).

CONCLUSION

Our results revealed that rs1292037 and rs13137 in miR-21 were associated with T2DM susceptibility in a Han Chinese population. Moreover, the rs78312845 in miR-195 contributed to the level of FPG and HbA1C in nondiabetic group in the Han Chinese population.

Diabetic patients with chronic kidney disease: Non-invasive assessment of cardiovascular risk

The prevalence and burden of diabetes mellitus and chronic kidney disease on global health and socioeconomic development is already heavy and still rising. Diabetes mellitus by itself is linked to adverse cardiovascular events, and the presence of concomitant chronic kidney disease further amplifies cardiovascular risk. The culmination of traditional (male gender, smoking, advanced age, obesity, arterial hypertension and dyslipidemia) and non-traditional risk factors (anemia, inflammation, proteinuria, volume overload, mineral metabolism abnormalities, oxidative stress, etc.) contributes to advanced atherosclerosis and increased cardiovascular risk. To decrease the morbidity and mortality of these patients due to cardiovascular causes, timely and efficient cardiovascular risk assessment is of huge importance. Cardiovascular risk assessment can be based on laboratory parameters, imaging techniques, arterial stiffness parameters, ankle-brachial index and 24 h blood pressure measurements. Newer methods include epigenetic markers, soluble adhesion molecules, cytokines and markers of oxidative stress. In this review, the authors present several non-invasive methods of cardiovascular risk assessment in patients with diabetes mellitus and chronic kidney disease.

Evidence of association between single-nucleotide polymorphisms in lipid metabolism-related genes and type 2 diabetes mellitus in a Chinese population

Background: Type 2 diabetes mellitus (T2DM) is a complex chronic metabolic disorder triggered by insulin resistance in peripheral tissues. Evidence has shown that lipid metabolism and related genetic factors lead to insulin resistance. Hence, it is meaningful to investigate the association between single-nucleotide polymorphisms (SNPs) in lipid metabolism-related genes and T2DM. Methods: A total of 1,194 subjects with T2DM and 1,274 Non-diabetic subjects (NDM) were enrolled. Five SNPs in three genes (rs864745 in JAZF1, rs35767 in IGF1, and rs4376068, rs4402960, and rs6769511 in IGF2BP2) that contribute to insulin resistance involving lipid metabolism were genotyped using the MassArray method in a Chinese population. Results: The allele and genotypes of rs6769511 in IGF2BP2 were associated with T2DM (P=0.009 and P=0.002, respectively). In inheritance model analysis, compared with the T/T-C/T genotype, the C/C genotype of rs6769511 in IGF2BP2 was a risk factor for the development of T2DM (P<0.001, odds ratio [OR] =1.76; 95% confidence interval [CI]: 1.29-2.42). Haplotype analysis revealed associations of the rs4376068-rs4402960-rs6769511 haplotypes in IGF2BP2 with the development of T2DM (P=0.015). Additionally, rs4376068C-rs4402960T-rs6769511C was a risk haplotype for T2DM (OR=1.179; 95% CI: 1.033-1.346). Conclusion: The rs6769511 in IGF2BP2 was associated with T2DM susceptibility, and the rs4376068-rs4402960-rs6769511 haplotypes in IGF2BP2 was associated with the development of T2DM in a Chinese population.

Association of microRNA gene polymorphisms with Type 2 diabetes mellitus: A systematic review and meta-analysis

Background:

Type 2 diabetes mellitus (T2DM) is a metabolic disorder with growing prevalence and increasing economic burden. Based on the role of genetics and epigenetic factors on T2DM, we aimed to carry a systematic review and meta-analysis for all miRNA gene polymorphisms and risk of T2DM.

Materials and Methods:

A computerized literature search was carried out on PubMed, Web of Science, Scopus, Embase, as well as references of relevant review/meta-analysis. Key search terms were “Diabetes Mellitus, Type 2,” “MicroRNAs,” and “Polymorphism, Single Nucleotide.” All types of observational studies from January 1, 1992, to November 30, 2019, were included, without language restriction. Data analysis was performed using R programming language (3.5.2). Level of heterogeneity was obtained by Cochran's Q test (P < 0.05), and subgroup analysis was performed based on ethnicity.

Results:

Thirty-two polymorphisms from fifteen articles were included. Meta-analysis was carried out based on minor allele frequencies. Seven studies with 2193 cases and 3963 controls were included for rs2910164 polymorphism. In subgroup analysis, there were significant results in Caucasian population in dominant model (odds ratio [OR] =1.12; 95% confidence interval [CI]: 0.83–1.51), homozygote model (OR = 1.78; 95% CI: 1.06–3.00), heterozygote model (OR = 1.77; 95% CI: 1.03–3.05), and recessive model (OR = 1.78; 95% CI: 1.07–2.96). Four studies with 2085 cases and 1933 controls were included for rs895819 polymorphism. Overall, there was no significant result for association with rs895819, but subgroup analysis revealed that minor allele significantly decreased the risk of T2DM in Caucasians by recessive model (OR = 0.34; 95% CI: 0.18–0.66), dominant model (OR = 0.70; 95% CI: 0.52–0.94), homozygote model (OR = 0.32; 95% CI: 0.16–0.62), heterozygote model (OR = 0.37; 95% CI: 0.19–0.74), allelic model (OR = 0.67; 95% CI: 0.52–0.85).

Conclusion:

The minor allele of rs2910164 may increase the risk of T2DM by leading to lower level of miR-146a. In contrast, minor allele of rs895819 may decrease the risk of T2DM by leading to higher level of miR-27a.

Polycyclic aromatic hydrocarbon exposure, miRNA genetic variations, and associated leukocyte mitochondrial DNA copy number: A cross-sectional study in China

Mitochondria DNA was preferentially attacked by the exogenous carcinogens including polycyclic aromatic hydrocarbons (PAHs) relative to nuclear DNA, and nuclear gene variants may account for variability in the mitochondrial DNA copy number (mtDNAcn). However, it remains unclear whether miRNA genetic variations are associated with mitochondrial DNA damage in the PAH-exposed workers. Therefore, we measured the leukocyte mtDNAcn, urinary 1-hydroxypyrene (1-OHPYR), environmental PAH exposure, and miRNA genetic polymorphisms among 544 coke oven workers and 238 healthy control participants. We found that the mtDNAcn in the exposure group (0.60 ± 0.29) was significantly lower than that in the control group (1.03 ± 0.31) (t = 18.931, P < 0.001). Spearman correlation analysis showed that the peripheral blood leukocyte mtDNAcn had significantly negative correlations with the levels of 1-OHPYR and environmental PAH exposure (P < 0.001). Covariance analysis indicated that miR-210 rs11246190 AA, miR-210 rs7395206 CC, and miR-126 rs2297538 GG probably promoted a decrease in leukocyte mtDNAcn in the exposure or control groups (P < 0.05). In generalized linear model, miR-210 rs11246190 GG was a protective factor of mtDNAcn, and environmental PAH exposure was the risk factor of the mtDNAcn. In conclusion, the decrease of leukocyte mtDNAcn is the result of a combination of environmental and genetic factors.

Association Between Single Nucleotide Polymorphisms in CDKAL1 and HHEX and Type 2 Diabetes in Chinese Population

PURPOSE

Type 2 diabetes mellitus (T2DM) has a high global prevalence, and the interaction of environmental factors and genetic factors may contribute to the risk of T2DM. We aimed to investigate the association between T2DM and the single nucleotide polymorphisms (SNPs) in genes (CDKAL1 and HHEX) associated with insulin secretion.

SUBJECTS AND METHODS

T2DM (n=1,169) and nondiabetic (NDM) (n=1,277) subjects were enrolled and the eight SNPs in CDKAL1 and HHEX genes associated with insulin secretion were genotyped in a Chinese population using MassARRAY. Then, the association of these SNPs with T2DM was analyzed.

RESULTS

Our results revealed that four SNPs (rs4712524, rs10946398, rs7754840 in CDKAL1, and rs5015480 in HHEX) showed significantly different distributions between the T2DM and NDM groups (P<0.00625). The G allele of rs4712524 (P=0.004, OR=1.184; 95% CI=1.057-1.327), C allele of rs10946398 (P<0.001, OR=1.247; 95% CI=1.112-1.398), and C allele of rs775480 in CDKAL1 (P<0.001, OR=1.229; 95% CI=1.096-1.387) functioned as risk alleles of T2DM. The C allele of rs5015480 in HHEX (P<0.001, OR=1.295; 95% CI=1.124-1.493) was also the risk factor for T2DM. The haplotype analysis revealed that CDKAL1 haplotype rs4712524G-rs10946398C-rs7754840C-rs9460546G (P=0.001, OR=1.210; 95% CI=1.076-1.360) and HHEX haplotype rs1111875C-rs5015480C (P<0.001, OR=1.364; 95% CI=1.180-1.576) were the risk factors of T2DM.

CONCLUSION

Our results revealed that genetic variations in CDKAL1 and HHEX were associated with T2DM susceptibility in Chinese population.

Identifying the association between single nucleotide polymorphisms in KCNQ1, ARAP1, and KCNJ11 and type 2 diabetes mellitus in a Chinese population

Background: Type 2 diabetes mellitus (T2DM) has a high global prevalence, and insufficient insulin secretion is one of the major reasons for its development. Therefore, investigating the association between T2DM and the single nucleotide polymorphisms (SNPs) in genes associated with insulin secretion is necessary. Methods: T2DM (1,194) and nondiabetic (NDM) (1,292) subjects were enrolled and the ten single nucleotide polymorphisms (SNPs) in KCNQ1, ARAP1, and KCNJ11 associated with insulin secretion were genotyped in a Chinese population. Results: Our data revealed that the rs2237897T allele in KCNQ1 is the protective allele for T2DM (P<0.001, OR=0.793; 95%CI: 0.705-0.893). However, the A allele of rs1552224 in ARAP1 may be a risk factor for T2DM (P=0.002, OR=12.070; 95% CI: 1.578-92.337). The haplotype analysis revealed that rs151290-rs2237892CC and rs2237895-rs2237897CC in KCNQ1 constitute the risk haplotype in T2DM development (P=0.010, OR=1.160; 95% CI: 1.037-1.299 and P=0.004, OR=1.192; 95% CI: 1.057-1.344). Moreover, rs2237895-rs2237897AT in KCNQ1 constitutes the protective haplotype in T2DM (P=0.001, OR=0.819; 95% CI: 0.727-0.923). In the inheritance models analysis, the rs2283228 (C/A-C/C) genotype is the protective factor compared to the A/A genotype (P=0.005, OR=0.79; 95% CI: 0.68-0.93). For rs2237897, the C/T-T/T genotype is the protective factor compared to the C/C genotype (P<0.001, OR=0.74; 95% CI: 0.63-0.87). Furthermore, when compared with the rs2237897 (C/T-T/T) genotype, rs2237897C/C genotype showed higher HbA1C levels (8.731±2.697 vs 9.282±2.921, P=0.001). Conclusion: Our results revealed that genetic variations in KCNQ1 and ARAP1 were associated with T2DM susceptibility in a Chinese population.

Association of single nucleotide polymorphisms of miRNAs involved in the GLUT4 pathway in T2DM in a Chinese population

Background

The insulin/insulin receptor substrate (IRS)/phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (Akt)/GLUT4 pathway plays a crucial role in insulin resistance and is closely associated with T2DM. Accumulating evidence indicates that miRNAs (such as miR‐135a, let‐7d, miR‐107, miR‐96, miR‐29a, miR‐23a, miR‐126, miR‐133a, and miR‐106b) influence the GLUT4 pathway.

Methods

A total of 784 subjects with T2DM and 846 nondiabetic subjects were enrolled and 12 single nucleotide polymorphisms (SNPs) in miRNAs (rs10459194 in miR‐135a‐2, rs10993081 and rs7045890 in let‐7d, rs2296616 in miR‐107, rs2402959 and rs6965643 in miR‐96, rs24168 in miR‐29a, rs3745453 in miR‐23a, rs4636297 in miR‐126, rs8089787 and rs9948906 in miR‐133a‐1 and rs999885 in miR‐106b) involved in the GLUT4 pathway were genotyped using the MassArray method in a Chinese population.

Results

Our data showed that the A allele of rs2402959 in miR‐96 may increase the risk of developing T2DM (p = .002, OR = 1.266; 95% CI: 1.089–1.471). The genotypes of rs3745453 in miR‐23a showed the difference between T2DM and control groups (p < .001). Moreover, for rs2402959, compared with the A/A genotype, the (G/A–G/G) genotype shows a protective effect in T2DM (p = .001, OR = 0.71; 95% CI: 0.58–0.87). For rs3745453, compared with the (A/A–A/G) genotype, the G/G genotype increases the risk of T2DM (p < .001, OR = 1.95; 95% CI: 1.38–2.77). In addition, we also found that rs4636297G/G genotype was associated with lower TC in T2DM group.

Conclusion

Our results revealed that genetic variations in the miRNAs involved in the GLUT4 pathway were associated with T2DM susceptibility in a Chinese population, and these results emphasize the need to study the functional effects of these variations in the miRNAs involved in the GLUT4 pathway on the risk of developing T2DM.