Expression of JAZF1, ABCC8, KCNJ11and Notch2 genes and vitamin D receptor polymorphisms in type 2 diabetes, and their association with microvascular complications

N6-methylation of RNA-bound adenosine regulator HNRNPC promotes vascular endothelial dysfunction in type 2 diabetes mellitus by activating the PSEN1-mediated Notch pathway

AIM

The regulatory mechanism of m6A regulators in vascular endothelial function of type 2 diabetes mellitus (T2DM) remains largely unknown. We addressed this issue based on the data retrieved Gene Expression Omnibus (GEO) database and experimental validations.

METHODS

Expression of m6A methylation regulators was evaluated in T2DM samples of GSE76894 dataset and GSE156341 dataset. Further analysis of candidate m6A methylation regulators was conducted in the thoracic aorta of db/db mice and high glucose (HG)-induced human umbilical vein endothelial cells (HUVECs). Ectopic expression and depletion experiments were conducted to detect effects of m6A methylation regulators on vascular endothelial function in T2DM.

RESULTS

It emerged that three m6A methylation regulators (HNRNPC, RBM15B, and ZC3H13) were highly expressed in T2DM, which were related to vascular EC function, showing diagnostic values for T2DM. HNRNPC expression in the thoracic aorta of db/db mice was higher than that in heterozygous db mice, and HNRNPC expression in HG-induced HUVECs was upregulated when compared with normal glucose-exposed HUVECs. Furthermore, HNRNPC activated PSEN1-dependent Notch pathway to induce eNOS inactivation and NO production decrease, thereby causing vascular endothelial dysfunction in T2DM.

CONCLUSIONS

HNRNPC impaired vascular endothelial function to enhance the development of vascular complications in T2DM through PSEN1-mediated Notch signaling pathway.

Regulatory T cells differentiation in visceral adipose tissues contributes to insulin resistance by regulating JAZF-1/PPAR-γ pathway

Regulatory T cell (Treg) activity and differentiation in visceral adipose tissue (VAT) play an important role in inhibiting chronic inflammation and insulin resistance. Whether JAZF-1 and PPAR-γ mediate VAT Treg differentiation to promote the inhibition of chronic inflammation and insulin resistance remains unclear. Here, we investigated the roles of JAZF-1 and PPAR-γ in VAT Treg differentiation, inflammation and insulin resistance using a transgenic mouse model. First, we determined that the levels of glucose and insulin biochemical markers in the JAZF-1 transgenic general feeding or high-fat groups were lower than those in the wild-type general feeding or high-fat groups. Second, the levels of CD4⁺ , CD25⁺ , and FOXP3⁺ differentiation markers in the JAZF-1 transgenic general feeding or high-fat groups were significantly higher than those in the wild-type groups. PPAR-γ inhibition was associated with low levels of CD4⁺ , CD25⁺ and FOXP3⁺ differentiation markers. Third, the levels of TNF-α, IL-1β and IL-6 in the JAZF-1 transgenic groups were lower than those in the wild-type groups, whereas IL-10 and TGF-β levels were higher in the JAZF-1 transgenic groups than in the wild-type groups. After using the PPAR-γ inhibitor, we observed that TNF-α, IL-1β and IL-6 increased, while IL-10 and TGF-β decreased. We found that JAZF-1 and PPAR-γ could promote Tregs differentiation and regulate insulin resistance by synergistically decreasing the expression levels of TNF-α, IL-1β and IL-6 and increasing those of IL-10 and TGF-β.

Vitamin D Status, Vitamin D Receptor Polymorphisms, and Risk of Microvascular Complications Among Individuals With Type 2 Diabetes: A Prospective Study

OBJECTIVE

Evidence is limited regarding the associations between vitamin D status and microvascular complications in individuals with type 2 diabetes (T2D), among whom vitamin D deficiency or insufficiency is particularly common. In this study we aimed to prospectively investigate the associations of serum 25-hydroxyvitamin D [25(OH)D] and vitamin D receptor (VDR) polymorphisms with risk of diabetic microvascular complications.

RESEARCH DESIGN AND METHODS

This analysis included 14,709 participants with T2D who were free of microvascular complications from the UK Biobank. Incidence of diabetic microvascular complications was ascertained via electronic health records. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Median serum 25(OH)D concentration was 40.7 nmol/L (interquartile range 27.5, 56.4). During a median of 11.2 years of follow-up, 1,370 people developed diabetic microvascular complications. Compared with participants with 25(OH)D <25 nmol/L, individuals with 25(OH)D ≥75 nmol/L had a multivariable-adjusted HR of 0.65 (95% CI 0.51, 0.84) for composite diabetic microvascular complications, 0.62 (0.40, 0.95) for diabetic retinopathy, 0.56 (0.40, 0.79) for diabetic nephropathy, and 0.48 (0.26, 0.89) for diabetic neuropathy. In addition, in comparisons with participants with 25(OH)D <25 nmol/L and minor allele homozygotes (TT of rs1544410 and GG of rs731236), the multivariable-adjusted HRs of composite diabetic microvascular complications were 0.54 (0.38, 0.78) and 0.55 (0.38, 0.80) for participants with serum 25(OH)D ≥50 nmol/L and major allele homozygotes (CC and AA), respectively, although no significant interaction was observed.

CONCLUSIONS

Higher serum 25(OH)D concentrations were significantly associated with lower risk of diabetic microvascular complications, including diabetic retinopathy, diabetic nephropathy, and diabetic neuropathy. Our findings suggest a potential beneficial role of maintaining adequate vitamin D status in the prevention of diabetic microvascular complications.

ADCY5, CAPN10 and JAZF1 Gene Polymorphisms and Placental Expression in Women with Gestational Diabetes

Gestational diabetes mellitus (GDM) is carbohydrate intolerance that occurs during pregnancy. This disease may lead to various maternal and neonatal complications; therefore, early diagnosis is very important. Because of the similarity in pathogenesis of type 2 diabetes and GDM, the genetic variants associated with type 2 diabetes are commonly investigated in GDM. The aim of the present study was to examine the associations between the polymorphisms in the ADCY5 (rs11708067, rs2877716), CAPN10 (rs2975760, rs3792267), and JAZF1 (rs864745) genes and GDM as well as to determine the expression of these genes in the placenta. This study included 272 pregnant women with GDM and 348 pregnant women with normal glucose tolerance. The diagnosis of GDM was based on a 75 g oral glucose tolerance test (OGTT) at 24–28 weeks gestation, according to International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. There were no statistically significant differences in the distribution of the ADCY5 gene (rs11708067, rs2877716) and CAPN10 gene (rs2975760, rs3792267) polymorphisms between pregnant women with normal carbohydrate tolerance and pregnant women with GDM. We have shown a lower frequency of JAZF1 gene rs864745 C allele carriers among women with GDM CC + CT vs. TT (OR = 0.60, 95% CI = 0.41–0.87, p = 0.006), and C vs. T (OR = 0.75, 95% CI = 0.60–0.95, p = 0.014). In addition, ADCY5 and JAZF1 gene expression was statistically significantly increased in the placentas of women with GDM compared with that of healthy women. The expression of the CAPN10 gene did not differ significantly between women with and without GDM. Our results indicate increased expression of JAZF1 and ADCY5 genes in the placentas of women with GDM as well as a protective effect of the C allele of the JAZF1 rs864745 gene polymorphism on the development of GDM in pregnant women.

Evaluation of association studies and a systematic review and meta-analysis of VDR polymorphisms in type 2 diabetes mellitus risk

ABSTRACT

Numerous original studies and 4 published meta-analyses have reported the association between the Vitamin D receptor (VDR) BsmI, FokI, ApaI, and TaqI polymorphisms and type 2 diabetes mellitus (T2DM) risk. However, the results were inconsistent. Therefore, an updated meta-analysis was performed to further explore these issues.To further explore the association between the VDR BsmI, FokI, ApaI, and TaqI polymorphisms and T2DM risk.PubMed, EMBASE, Scopus, and Wanfang databases were searched. The following search strategy were used: (VDR OR vitamin D receptor) AND (polymorphism OR variant OR mutation) AND (diabetes OR mellitus OR diabetes mellitus). Pooled crude odds ratios with 95% confidence intervals were applied to evaluate the strength of association in 5 genetic models. Statistical heterogeneity, the test of publication bias, and sensitivity analysis were carried out using the STATA software (Version 12.0). To evaluate the credibility of statistically significant associations, we applied the false-positive report probabilities (FPRP) and Bayesian false discovery probability (BFDP) test.Overall, the VDR BsmI polymorphism was associated with a significantly decreased T2DM risk in Asians; the VDR FokI polymorphism was associated with a significantly decreased T2DM risk in Asians, African countries, and Asian countries; the VDR ApaI polymorphism was associated with a significantly decreased T2DM risk in Caucasians and North American countries.On the VDR ApaI polymorphism, a significantly increased T2DM risk was found in a mixed population. However, when we further performed a sensitivity analysis, FPRP, and BFDP test, less-credible positive results were identified (all FPRP > 0.2 and BFDP > 0.8) in any significant association.In summary, this study strongly indicates that all significant associations were less credible positive results, rather than from true associations.

Novel Reclassification of Adult Diabetes Is Useful to Distinguish Stages of β-Cell Function Linked to the Risk of Vascular Complications: The DOLCE Study From Northern Ukraine

Background

Presently, persons with diabetes are classified as having type 1 (T1D) or type 2 diabetes (T2D) based on clinical diagnosis. However, adult patients exhibit diverse clinical representations and this makes treatment approaches challenging to personalize. A recent Scandinavian study proposed a novel classification of adult diabetes into five clusters based on disease pathophysiology and risk of vascular complications. The current study aimed to characterize new subgroups of adult diabetes using this strategy in a defined population from northern Ukraine.

Methods

We analyzed 2,140 patients with established diabetes from the DOLCE study (n = 887 with new-onset diabetes and n = 1,253 with long duration). We used the k-means approach to perform clustering analyses using BMI, age at onset of diabetes, HbA_1c, insulin secretion (HOMA2-B), and insulin resistance (HOMA2-IR) indices and glutamic acid decarboxylase antibodies (GADA) levels. Risks of macro- (myocardial infarction or stroke) and microvascular [retinopathy, chronic kidney disease (CKD) and neuropathy] complications and associations of genetic variants with specific clusters were studied using logistic regression adjusted for age, sex, and diabetes duration.

Results

Severe autoimmune diabetes (SAID, 11 and 6%) and severe insulin-deficient diabetes (SIDD, 25 and 14%) clusters were twice as prevalent in patients with long-term as compared to those with new-onset diabetes. Patients with long duration in both SAID and SIDD clusters had highest risks of proliferative retinopathy, and elevated risks of CKD. Long-term insulin-resistant obese diabetes 1 (IROD1) subgroup had elevated risks of CKD, while insulin-resistant obese diabetes 2 (IROD2) cluster exhibited the highest HOMA2-B, lowest HbA_1c, and lower prevalence of all microvascular complications as compared to all other clusters. Genetic analyses of IROD2 subgroup identified reduced frequency of the risk alleles in the TCF7L2 gene as compared to all other clusters, cumulatively and individually (p = 0.0001).

Conclusion

The novel reclassification algorithm of patients with adult diabetes was reproducible in this population from northern Ukraine. It may be beneficial for the patients in the SIDD subgroup to initiate earlier insulin treatment or other anti-diabetic modalities to preserve β-cell function. Long-term diabetes cases with preserved β-cell function and lower risk for microvascular complications represent an interesting subgroup of patients for further investigations of protective mechanisms.

Vitamin D Receptor gene polymorphisms and susceptibility to type 2 diabetes: evidence from a meta-regression and meta-analysis based on 47 studies

BACKGROUND

Evidence from various studies suggest that vitamin D receptor (VDR) gene polymorphisms are associated with type 2 diabetes (T2D); However, these results have been disputable. Here we conducted a meta-analysis to comprehensively evaluate the effect of VDR gene polymorphisms and susceptibility to T2D.

METHODS

All relevant studies reporting the association between VDR gene polymorphisms and susceptibility to T2D published up to August 2020 were identified by comprehensive systematic database search in web of science, Scopus, and Medline. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure strength of association. The methodological quality of each study was assessed according to the Newcastle-Ottawa Scale. Subgroup and meta-regression analysis were also performed.

RESULTS

A total of 47 case-control studies were included in this meta-analysis. The overall population results revealed a significant association between FokI, and BsmI (heterozygote model) polymorphisms and T2D in the overall analysis. However, no association was found with the TaqI and ApaI polymorphisms. Moreover, the pooled results of subgroup analysis by ethnicity suggested significant association between FokI, TaqI, and BsmI polymorphisms and T2D in some subgroups. Meta-regression analyses indicated that none of the publication year, ethnicity, and genotyping method were the source of heterogenicity in all four polymorphisms.

CONCLUSIONS

This meta-analysis suggested a significant association between VDR gene FokI, and BsmI (heterozygote model) polymorphisms and T2D susceptibility in overall population and ethnic-specific analysis.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-020-00704-z.

Relationship of serum vitamin D levels with diabetic microvascular complications in patients with type 2 diabetes mellitus

Background:

Vitamin D deficiency has been reported to be associated with diabetic microvascular complications, but previous studies have only focused on the relationship between vitamin D and specific complications. Therefore, we aimed to explore the relationship between vitamin D level and diabetic microvascular complications in general, including diabetic retinopathy (DR), diabetic nephropathy (DN), and diabetic peripheral neuropathy (DPN).

Methods:

This was a cross-sectional study of 815 patients with type 2 diabetes mellitus (T2DM). Clinical information and laboratory results were collected from the medical records. The relationship between vitamin D and the three diabetic microvascular complications was investigated.

Results:

The serum 25-hydroxyvitamin D (25 [OH] D) level of patients with DPN and/or DN was significantly lower than that of T2DM patients without any microvascular complications (P < 0.01). Univariate analysis showed that the 25 (OH) D level was related to DPN and DN, but not DR. After adjustment, the 25 (OH) D level was confirmed to be an independent protective factor for DPN (odds ratio [OR]: 0.968, P = 0.004]) and DN (OR: 0.962, P = 0.006). The prevalence of DPN and DN increased significantly as the serum 25 (OH) D levels decreased. Furthermore, patients with both DPN and DN had the lowest concentration of serum 25 (OH) D (P < 0.001), and the prevalence of macroalbuminuria increased more abruptly than that of microalbuminuria across the 25 (OH) D tertiles. Among the patients with vitamin D insufficiency, those with DPN presented more comorbid macroalbuminuria than those without DPN (15.32% vs. 4.91%; P = 0.001).

Conclusions:

Vitamin D deficiency is independently associated with higher risk of DPN and DN, but not DR, in T2DM patients. Further, it may be a potential predictor for both the occurrence and severity of DPN and DN.

Vitamin D supplementation in the treatment of type 2 diabetic microangiopathy: A protocol for a systematic review and meta-analysis

BACKGROUND

The number of people with diabetes is growing exponentially.Human studies have shown that vitamin D supplementation is beneficial for type 2 diabetic microangiopathy. However, owing to the low quality, small sample size, and methodological heterogeneity of these studies, this conclusion is not convincing. Consequently, in order to determine whether vitamin D supplementation is effective and safe in type 2 diabetic microangiopathy, it is necessary to conduct a meta-analysis of high-quality clinical trials.

METHODS

We will search each database from the built-in until March 2020. The English literature mainly searches Cochrane Library, PubMed, EMBASE, and Web of Science, while the Chinese literature comes from CNKI, CBM, VIP, and Wangfang database. Simultaneously we will retrieval clinical registration tests and grey literatures. In this study, only the clinical randomized controlled trials were selected to evaluate the efficacy and safety of vitamin D in the treatment of type 2 diabetic microangiopathy. The two researchers independently conducted literature selection, data extraction and quality assessment. Statistical heterogeneity among studies will be evaluated using the Cochran Q test (x) and the I statistical value. We will utilize the Review Manage software V5.3.0 (The Nordic Cochrane Center, The Cochrane Collaboration, 2014, Copenhagen, Denmark) to statistically analyze all data.

ETHICS AND DISSEMINATION

Ethics and dissemination: This study is a systematic review of vitamin D supplementation as a treatment of type 2 diabetic microangiopathy.

RESULTS

This study will provide high-quality synthesis of effectiveness and safety of vitamin D supplementation for type 2 diabetic microangiopathy.

CONCLUSION

This systematic review aims to provide new options for vitamin D treatment of type 2 diabetic microangiopathy in terms of its efficacy and safety.

REGISTRATION NUMBER

LNPLASY202050055.

Effects of Adenovirus-Mediated Overexpression of JAZF1 on Chronic Inflammation: An In Vitro and In Vivo Study

BACKGROUND Insulin sensitivity and inflammation can be affected by juxtaposition with another zinc finger gene 1 (JAZF1), but its precise role in chronic inflammation is unclear. In this study, JAZF1-overexpression adenovirus plasmids were transfected into macrophages, CD4⁺ T cells, and C57BL/6J mice to assess the role of JAZF1 in chronic inflammation. MATERIAL AND METHODS JAZF1 was cloned into an adenovirus skeleton plasmid and transfected in HEK293 cells to package and enrich the virus particles. In vitro, the JAZF1 overexpression adenovirus vector (PAD-JAZF1) was cultured with peritoneal macrophages and peripheral blood CD4⁺ T cells of C57BL/6J mice, and samples were evaluated using flow cytometry. In vivo, PAD-JAZF1 was introduced into C57BL/6J mice, and livers were collected to evaluate factors related to inflammation by hematoxylin & eosin and immunohistochemical staining. RESULTS In vitro, PAD-JAZF1 decreased total macrophages, CD11c⁺ macrophages, and the secretion of proinflammatory cytokines, but increased CD206⁺ macrophages. It also decreased total CD4⁺T cells, active T cells, memory T cells, and the secretion of IL-6, IL-10, and IFN-γ, but increased Treg cells and restrictive T cells. In vivo, compared to those in the control group transfected with the adenovirus skeleton vector, mice transfected with the PAD-JAZF1 recombinant adenovirus had fewer CD11c⁺ ATMs and CD4⁺ T cells, lower levels of TNF-alpha and IL-6, and higher IL-10 concentrations in the liver. CONCLUSIONS These findings indicate that JAZF1 limits chronic inflammation by reducing macrophage and CD4⁺T cell populations, altering subtype differentiation, and regulating the secretion of immune-related factors.

Up-regulation of miR-139-5p protects diabetic mice from liver tissue damage and oxidative stress through inhibiting Notch signaling pathway

The occurrence and development of diabetes seriously threaten the health of patients. Therefore, the mechanism exploration of diabetes is of great significance for more effective control of this disease. In this study, we aimed to investigate the regulatory mechanism of miR-139-5p and Notch signaling pathway on liver damage and oxidative stress in diabetic mice. The mouse model of diabetes was established, and the mice were divided into normal group, model group, negative control (NC) group, miR-139-5p mimic group, miR-139-5p inhibitor group, DAPT group, and miR-139-5p inhibitor + DAPT group. The mRNA expressions of miR-139-5p, Notch1, Jagged1, and NICD1, and the protein expressions of Notch1, Jagged1, and NICD1 were detected. In addition, HepG2 cells were cultured for high glucose induction, and cell cycle distribution and apoptosis were detected by flow cytometry. The results showed that the body weights of mice in the model, NC, miR-139-5p mimic, miR-139-5p inhibitor, DAPT, and miR-139-5p inhibitor + DAPT groups were all lower than that in the normal group. Co-localization of miR-139-5p and Notch1 was observed in the fluorescence in situ hybridization assay, and miR-139-5p was found to negatively regulate Notch1. Furthermore, reduced blood glucose level and inhibited liver oxidative stress were observed in mice with miR-139-5p overexpression or DAPT treatment. DAPT treatment reversed the increase of blood glucose level and oxidative stress injury caused by miR-139-5p silencing. In conclusion, up-regulation of miR-139-5p expression can protect liver tissue from oxidative stress injury in diabetic mice, and its mechanism may be related to the inhibition of Notch signaling pathway.

Rare Variants of Putative Candidate Genes Associated With Sporadic Meniere's Disease in East Asian Population

Objectives: The cause of Meniere's disease (MD) is unclear but likely involves genetic and environmental factors. The aim of this study was to investigate the genetic basis underlying MD by screening putative candidate genes for MD.

Methods: Sixty-eight patients who met the diagnostic criteria for MD of the Barany Society were included. We performed targeted gene sequencing using next generation sequencing (NGS) panel composed of 45 MD-associated genes. We identified the rare variants causing non-synonymous amino acid changes, stop codons, and insertions/deletions in the coding regions, and excluded the common variants with minor allele frequency >0.01 in public databases. The pathogenicity of the identified variants was analyzed by various predictive tools and protein structural modeling.

Results: The average read depth for the targeted regions was 1446.3-fold, and 99.4% of the targeted regions were covered by 20 or more reads, achieving the high quality of the sequencing. After variant filtering, annotation, and interpretation, we identified a total of 15 rare heterozygous variants in 12 (17.6%) sporadic patients. Among them, four variants were detected in familial MD genes (DTNA, FAM136A, DPT), and the remaining 11 in MD-associated genes (PTPN22, NFKB1, CXCL10, TLR2, MTHFR, SLC44A2, NOS3, NOTCH2). Three patients had the variants in two or more genes. All variants were not detected in our healthy controls (n = 100). No significant differences were observed between patients with and without a genetic variant in terms of sex, mean age of onset, bilaterality, the type of MD, and hearing threshold at diagnosis.

Conclusions: Our study identified rare variants of putative candidate genes in some of MD patients. The genes were related to the formation of inner ear structures, the immune-associated process, or systemic hemostasis derangement, suggesting the multiple genetic predispositions in the development of MD.

The Impact of Vitamin D Receptor Gene Polymorphisms on the Susceptibility of Diabetic Vascular Complications: A Meta-Analysis

Background: To determine whether vitamin D receptor (VDR) gene polymorphisms are correlated with susceptibility to diabetic vascular complications. Methods: We included all eligible studies, and used Stata12.0 to calculate the pooled results. Results: Eight thousand eleven diabetic patients and 1635 normal controls from 27 studies were included. Our results showed that there was no correlation between VDR gene TaqI variants and diabetic nephropathy (DN) or diabetic retinopathy (DR) susceptibility. In comparison with diabetic patients without DN, there was a link between the VDR gene ApaI variant and DN susceptibility under allelic model (p = 0.029) in all populations. In addition, the VDR gene BsmI variant correlated with DN under both dominant (p = 0.005) and allelic (p = 0.003) models in Asian populations. The VDR gene FokI variant was also correlated with DN susceptibility under the recessive model (p = 0.027) in the Asian subgroup. In comparison with diabetic patients without DR, we identified a link between the VDR gene ApaI variant and DR susceptibility under the dominant model (p = 0.034) in all populations. Also, the VDR gene FokI variant was correlated with DR under the recessive (p = 0.016), the allelic (p = 0.001), and the dominant (p < 0.001) models in all populations. When compared with healthy controls, the VDR gene BsmI variant was associated with DR under the additive (p = 0.014), the allelic (p = 0.033), and the dominant (p < 0.001) models in Indian populations. Conclusions: The VDR gene BsmI, ApaI, and FokI gene variants are associated with DN and DR susceptibility. No association was found between the VDR gene TaqI gene variants and diabetic vascular complications.

Diminished 25-OH vitamin D3 levels and vitamin D receptor variants are associated with susceptibility to type 2 diabetes with coronary artery diseases

Background

Role of plasma vitamin D and genetic variants of its receptor (VDR) in susceptibility to different diseases has been documented. Various studies in different populations have been highlighted strong associations with diabetes and cardiovascular diseases. Vitamin D deficiency has been linked with the development of type 2 diabetes (T2D) and the onset of coronary artery diseases (CAD). However, the role of vitamin D in predisposition to CAD in patients with T2D is ill‐defined.

Materials and Methods

We enrolled 674 Chinese T2D patients, and based on clinical phenotype, patients were further categorized into patients with (n = 138) or without coronary artery disease (n = 536). Five hundred twenty‐one healthy subjects from similar geographical areas, free from diabetic or coronary disorders, were enrolled as controls. Serum levels of 25‐OH vitamin D were quantified by ELISA. Common VDR (FokI, TaqI, BsmI, and ApaI) polymorphisms were genotyped by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP).

Results

Patients with T2D displayed lower levels of 25‐OH vitamin D compared with healthy controls. Furthermore, T2D patients with CAD clinical phenotype had the lowest levels of vitamin D. Prevalence of FokI and TaqI mutants was significantly higher in diabetic patients when compared to controls. Interestingly, Tt genotype was more frequent in the artery disease group in comparison with T2D patients without heart involvement. Combined analysis of VDR polymorphisms and serum levels of vitamin D revealed a significant role in predisposition to T2D with or without CAD.

Conclusions

Lower vitamin D levels and variants of VDR polymorphisms (FokI and TaqI) are associated with susceptibility to T2D and clinical manifestation.

Over-expression of JAZF1 promotes cardiac microvascular endothelial cell proliferation and angiogenesis via activation of the Akt signaling pathway in rats with myocardial ischemia-reperfusion

Myocardial ischemia-reperfusion (I/R) injury is caused by endothelial dysfunction and enhanced oxidative stress. The overexpression of JAZF1, a zinc finger protein, has been reported to promote cell proliferation and suppress myogenic differentiation in type 2 diabetes. However, the involvement of JAZF1 in myocardial I/R injury remains to be unclear. The current study aims to investigate the role by which JAZF1 influences cardiac microvascular endothelial cells (CMECs) in a rat model of myocardial I/R injury. A total of 50 rats were established as a myocardial I/R model to isolate CMECs, with alterations in JAZF1 expression. After that, the gain- or loss-function of JAZF1 on the proliferation, apoptosis and tube formation ability of CMECs were evaluated by a series of in vitro experiments. Results indicated that JAZF1 was down-regulated in CMECs of rats with myocardial I/R injury. After treatment with JAZF1, the levels of VEGF, Bcl-2, PDGF and p-Akt/Akt were all increased; however, the expression of Bax, caspase-3, caspase-9, p-Bad/Bad, c-caspase-3/caspase-3, c-caspase-9/caspase-9, and p-FKHR/FKHR exhibited decreased levels; CMEC proliferation and angiogenesis were increased, while cell apoptosis was attenuated. CMECs transfected with JAZF1 shRNA exhibited the contrary tendencies. The key findings of this study suggest that the over-expression of JAZF1 alleviates myocardial I/R injury by enhancing proliferation and angiogenesis of CMECs and in turn inhibiting apoptosis of CMECs via the activation of the Akt signaling pathway.

The influence of SLC22A1 rs622342 and ABCC8 rs757110 genetic variants on the efficacy of metformin and glimepiride combination therapy in Egyptian patients with type 2 diabetes

Background: The incidence of Type 2 Diabetes Mellitus (T2DM) in Egypt is considered one of the highest in the world. Metformin and Sulfonylureas are usually prescribed together due to their efficacy and their relatively low cost. Organic cation transport 1, encoded by SLC22A1 gene, is the main transporter of metformin into hepatocytes, which is considered metformin site of action. Sulfonylureas enhance insulin release from pancreatic B-cells through binding to sulfonylurea receptor 1, encoded by ABCC8 gene. Single nucleotide polymorphisms in the SLC22A1 and ABCC8 genes might affect the response of each drug.

Aims: To investigate the influence of SLC22A1 rs622342 (A>C) and ABCC8 rs757110 (A>C) genetic variants on the efficacy of metformin and glimepiride combination therapy in Egyptian T2DM patients.

Methods: Observational cross-sectional study in which patients receiving metformin and glimepiride combination therapy for at least 6 months were included for genotyping and classified into either responders or non-responders, based on their HbA1C level.

Results: A total of 127 patients were included and genotyped. They were divided into 93 responders (HbA1C<7%) and 34 non-responders (HbA1C≥7%). Minor allele frequencies for rs622342 and rs757110 were 0.189 and 0.271, respectively. Only SLC22A1 rs622342 variant was found to be associated with the response of combination therapy, in which AA alleles carriers were 2.7-times more responsive to metformin than C allele carriers (Recessive model, odds ratio = 2.718, p = 0.025, 95% CI = 1.112–6.385).

Conclusion: Genotyping of rs622342 can be useful in predicting the response to metformin in combination therapy in Egyptian T2DM patients.

The dominant models of KCNJ11 E23K and KCNMB1 E65K are associated with essential hypertension (EH) in Asian: Evidence from a meta-analysis

BACKGROUND

The K channel, subfamily J, member-11 (KCNJ11) E23K and β1 subunit of large-conductance Ca-activated K channel (KCNMB1) E65K polymorphisms were shown to be associated with the risk of essential hypertension (EH). However, the results were inconclusive with relatively small sample size. Thus, we carried out a meta-analysis to investigate the genetic association between KCNJ11 E23K and KCNMB1 E65K polymorphisms and essential hypertension risk.

METHODS

Relative studies were collected using PubMed, Web of Science, the Cochrane Library databases, Chinese National Knowledge Infrastructure and Embase databases. Pooled odds ratios with 95% confidence intervals were used to assess the strength of associations.

RESULTS

The dominant models of KCNJ11 E23K (P = .006, OR [95%CI] = 0.45 [0.25, 0.79]) and KCNMB1 E65K (P = .04, OR [95%CI] = 0.91 [0.83, 1.00]) were significantly associated with essential hypertension risk. No significant association was detected between the allelic and recessive models of KCNJ11 E23K and KCNMB1 E65K and the susceptibility of EH. Subgroup analysis stratified by ethnicity showed that the dominant model of KCNMB1 E65K was associated with EH risk in Asian population (P = .003, OR [95%CI] = 0.83 [0.74, 0.94]), but not in Caucasian (P = .74, OR [95%CI] = 1.02 [0.89, 1.18]).

CONCLUSIONS

The dominant model of KCNJ11 E23K and KCNMB1 E65K might be susceptible factors for essential hypertension. To confirm this result, large-scale case-control studies with more subjects are necessary.