TLR4 Polymorphisms (896A>G and 1196C>T) Affect the Predisposition to Diabetic Nephropathy in Type 2 Diabetes Mellitus

Molecular Effect of Variants in Toll-like Receptor 4 Gene in Saudi Patients with Type 2 Diabetes Mellitus

Single-nucleotide polymorphisms (SNPs) in the Toll-like receptor 4 (TLR4) gene have been documented in type 2 diabetes mellitus (T2DM) and other diseases in the Saudi population. We investigated the relationship between rs11536889, rs4986790, and rs4986791 SNPs in the TLR4 gene and T2DM in the Saudi population; 105 patients with T2DM and 105 healthy controls were analyzed. The TLR4 gene was amplified through PCR, followed by restriction fragment length polymorphism analysis for rs4986791 and Sanger sequencing for rs11536889 and rs4986790 SNPs. The clinical and biochemical characteristics were associated with T2DM (p < 0.05). The rs11536889, rs4986790, and rs4986791 SNPs in control subjects followed the Hardy-Weinberg equilibrium (p > 0.05). Alleles were associated with rs11536889, rs4986791, heterozygous codominant, and dominant models (p < 0.05). However, the rs4986790 SNP was not associated with T2DM (p > 0.05). Logistic regression analysis showed that high-density lipoprotein cholesterol (HDLc) levels were associated with T2DM (p < 0.001). Analysis of variance showed that waist (p = 0.0005) and hip circumferences (p = 0.002) in rs4986790 and rs4986791 SNPs, in SBP (p = 0.001), DBP (p = 0.002), and HDLc levels (p = 0.003), were associated with T2DM subjects. T2DM was also associated with the haplotype (p < 0.001) but not with linkage disequilibrium. The gene-gene interaction was associated with the three SNPs studied in patients with T2DM according to the generalized multifactor dimensionality reduction model (p < 0.0001). Dendrogram and graphical depletion analysis revealed a moderate association in patients with T2DM. The results suggest that rs11536889 and rs4986790 SNPs are genotypically and allelically associated with T2DM in Saudi patients. Future functional studies are recommended to validate the genetic roles of these SNPs in the pathogenesis and progression of diseases.

TLR4 polymorphism and haplotype are associated with obesity and lipid profile in young population: a pilot study

BACKGROUND

The single nucleotide polymorphisms in the TLR4 gene can decrease or increase the response to lipopolysaccharide, increasing the susceptibility to inflammatory diseases, affecting the expression or receptor function by inducing a low-grade chronic inflammatory response.

PURPOSE

The objective of this study was to evaluate the association of SNPs - 2570 A > G (rs2737190), - 2081 G > A (rs10983755), 896 A > G (rs 4986790), and 1196 C > T (rs4986791) of the TLR4 gene with obesity and metabolic alterations in the young population.

RESULTS

In this study, it was found that the carriers of the heterozygous genotype of the SNPs - 2081 G > A, 896 A > G, and 1196 C > T confer a higher risk of developing obesity (OR = 3.73, p = 0.018; OR = 5.66, p = 0.014, and OR = 8.95, p = 0.014, respectively). Also, with the lipid profile, the SNP - 2081 G > A was associated with total cholesterol (TC) ≥ 200 mg/dL (OR = 3.91, p = 0.020) and Kannel index > 3% (OR = 4.00, p = 0.008). The SNP 896 A > G was associated with LDL-c ≥ 100 mg/dL (OR = 3.64, p = 0.040) and Kannel index > 3% (OR = 4.33, p = 0.016), and the SNP 1196 C > T was associated with TC ≥ 200 mg/dL (OR = 4.37, p = 0.048), Castelli index > 4.5/> 5% (OR = 5.33, p = 0.016), and Kannel index > 3% (OR = 16.00, p = 0.001). Finally, the AGGT haplotype was associated with Castelli index > 4.5/> 5% (OR = 5.40, p = 0.015) and Kannel index > 3% (OR = 10.46, p < 0.001), and the AAAC haplotype was associated with obesity (OR = 3.56, p = 0.020), TC ≥ 200 mg/dL (OR = 4.04, p = 0.007), LDL-c ≥ 100 mg/dL (OR = 2.98, p = 0.030) and Kannel index > 3% (OR = 4.20, p = 0.002).

CONCLUSION

The heterozygous genotype of the SNPs - 2081 G > A, 896 A > G and 1196 C > T of the TLR4 gene was associated with altered lipid profile and development of obesity in young university students of Guerrero State, Mexico.

lncRNA MALAT1 Promotes Diabetic Nephropathy Progression via miR-15b-5p/TLR4 Signaling Axis

Objective

The long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) are closely associated with the pathogenesis of diabetic nephropathy (DN). But a complete mechanism for MALAT1 in DN has yet to be identified. This study investigated the effect of MALAT1 on DN through the regulation of miR-15b-5p/TLR4 signaling.

Method

Renal tissues were collected from DN patients. Human renal tubular epithelial cells (HK-2) were used as a model of DN induced by high glucose (HG). We then measured the viability, apoptosis, and inflammatory cytokine levels of HK-2 cells using the corresponding assays. Following transfections of si-MALAT1, si-MALAT1+miR-15b-5p inhibitor, or si-MALAT1+vector TLR4 into HG-stimulated HK-2 cells, cell viability, apoptosis, and inflammatory cytokines were again measured. Furthermore, dual-luciferase reporter assay validated the interactions of MALAT1/miR-15b-5p and miR-15b-5p/TLR4. In addition, the interaction between MALAT1 and miR-15b-5p was investigated by RNA immunoprecipitation (RIP).

Results

A significant upregulation of MALAT1 was observed in DN kidney tissues, as well as in HG-stimulated HK-2 cells. MALAT1 knockdown attenuates the inhibition of cell viability, apoptosis, and inflammatory response induced by HG in HK-2 cells. Moreover, a miR-15b-5p inhibitor or TLR4 overexpression reversed the above effects induced by MALAT1 knockdown.

Conclusion

These results indicate that reduced MALAT1 ameliorates HG-stimulated HK-2 cell damage through an inhibition of the miR-15b-5p/TLR4 axis. MALAT1 may serve as a biomarker and potential therapeutic target for DN.

Toll like receptor 4 gene Asp299Gly polymorphism increases the risk of diabetic microvascular complications: a meta analysis

OBJECTIVE

The relationship between Toll like receptor 4(TLR4) gene Asp299Gly polymorphism and diabetic microvascular complications (DMI) is unclear. Therefore, the aim of this meta analysis was to explore the relationship between TLR4 Asp299Gly polymorphism and DMI.

METHODS

System search PubMed, Web of science, Springer, Cochrane library, ELSEVIER, Wanfang database, VIP, CNKI, a case-control study of the correlation between TLR4 gene Asp299Gly polymorphism and DMI published before June 2020 was collected.

RESULTS

We included 6 articles, a total of 11 studies involving patients with type 2 diabetes mellitus (T2DM) complicated by microvascular complications 1834 cases, without corresponding microvascular complications 4069 cases. TLR4 gene Asp299Gly polymorphism increased the risk of microvascular complications in T2DM (dominant model OR = 1.52, 95% CI 1.10-2.09, p = 0.01; allelic model OR = 1.42, 95% CI 1.02-1.96, p = 0.04). Subgroup analysis by race and different type of microvascular complications, we found that TLR4 gene Asp299Gly polymorphism was associated with increased risk of microvascular complications in the Caucasian population (dominant model OR = 1.69, 95% CI 1.22-2.35, P = 0.002; allelic model OR = 1.56, 95% CI 1.10-2.21, P = 0.01) and increased the risk of retinopathy in patients with T2DM(dominant model OR = 1.81, 95% CI 1.04-3.14, P = 0.03; allelic model OR = 1.77, 95% CI 1.05-2.98, P = 0.03).

CONCLUSION

TLR4 gene Asp299Gly polymorphism was associated with increased risk of microvascular complications in patients with T2DM, especially diabetic retinopathy (DR).

Toll-Like Receptor 4 Polymorphisms (896A/G and 1196C/T) as an Indicator of COVID-19 Severity in a Convenience Sample of Egyptian Patients

Background

The clinical spectrum of COVID-19 is extremely variable. Thus, it is likely that the heterogeneity in the genetic make-up of the host may contribute to disease severity. Toll‐like receptor (TLR)-4 plays a vital role in the innate immune response to SARS-CoV-2 infection. The susceptibility of humans to severe COVID-19 concerning TLR-4 single nucleotide polymorphisms (SNPs) has not been well examined.

Objective

The goal of this research was to investigate the association between TLR-4 (Asp299Gly and Thr399Ile) SNPs and COVID-19 severity and progression as well as the cytokine storm in Egyptian patients.

Methods

We genotyped 300 adult COVID-19 Egyptian patients for TLR-4 (Asp299Gly and Thr399Ile) SNPs using PCR-restriction fragment length polymorphism (PCR-RFLP). We also measured interleukin (IL)-6 levels by enzyme-linked immunosorbent assay (ELISA) as an indicator of the cytokine storm.

Results

The minor 299Gly (G) and 399Ile (T) alleles were associated with a significant (P < 0.001) positive risk of severe COVID-19 (OR = 3.14; 95% CI = 2.02–4.88 and OR = 2.75; 95% CI = 1.66–4.57), their frequency in the severe group were 71.8% (84/150) and 70.7% (58/150), respectively. We detected significant differences between TLR-4 (Asp299Gly, Thr399Ile) genotypes with regard to serum levels of IL-6. Levels of IL-6 increased significantly with the presence of the mutant 299Gly (G) and 399Ile (T) alleles to reach the highest levels in the Gly299Gly (GG) and the Ile399Ile (TT) genotypes (170 pg/mL (145–208.25) and 112 pg/mL (24–284.75), respectively).

Conclusion

The TLR-4 (Asp299Gly and Thr399Ile) minor alleles 299Gly (G) and 399Ile (T) are associated with COVID-19 severity, mortality, and the cytokine storm.

Quantitative assessment of TLR4 gene polymorphisms and T2DM risk: A meta-analysis

BACKGROUND

Numerous studies have evaluated the association between TLR4 gene polymorphisms and T2DM risk. However, the findings were inconsistent and controversial.

METHODS

In order to drive a more precise estimation, we carried out a meta-analysis based on 41 studies involving 23,250 cases and 24,760 controls. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of association.

RESULTS

Our meta-analysis provides evidence that rs4986790 polymorphism was associated with an increased risk of T2DM in Asian (AG vs. AA, OR = 1.23, 95% CI = 1.01-1.50, p = 0.042; G vs. A, OR = 1.21, 95% CI = 1.01-1.44, p = 0.041). Rs4986791 polymorphism was related to an increased risk of T2DM both in Asian (AG vs. AA, OR = 1.76, 95% CI = 1.11-2.80, p = 0.017; G vs. A, OR = 1.63, 95% CI = 1.04-2.55, p = 0.034) and Caucasian (GG vs. AA, OR = 2.42, 95% CI = 1.23-4.75, p = 0.010). Rs11536889 polymorphism may have a protective effect on T2DM in Chinese populations (CC vs. GG, OR = 0.62, 95% CI = 0.40-0.96, p = 0.031; GC vs. GG, OR = 0.77, 95% CI = 0.61-0.98, p = 0.034; CC vs. GC/GG, OR = 0.81, 95% CI = 0.69-0.96, p = 0.013; C vs. G, OR = 0.76, 95% CI = 0.59-0.97, p = 0.027), whereas rs1927911 may have no impact.

CONCLUSIONS

These findings supported that rs4986790, rs4986791, and rs11536889 may contribute to the risk of T2DM.