The Relation between eNOS -786 C/T, 4 a/b, MMP-13 rs640198 G/T, Eotaxin 426 C/T, -384 A/G, and 67 G/A Polymorphisms and Long-Term Outcome in Patients with Coronary Artery Disease

Coronary Heart Disease in Type 2 Diabetes Mellitus: Genetic Factors and Their Mechanisms, Gene-Gene, and Gene-Environment Interactions in the Asian Populations

Asians are more susceptible to type 2 diabetes mellitus (T2D) and its coronary heart disease (CHD) complications than the Western populations, possibly due to genetic factors, higher degrees of obesity, insulin resistance, and endothelial dysfunction that could occur even in healthy individuals. The genetic factors and their mechanisms, along with gene-gene and gene-environment interactions associated with CHD in T2D Asians, are yet to be explored. Therefore, the objectives of this paper were to review the current evidence of genetic factors for CHD, summarize the proposed mechanisms of these genes and how they may associate with CHD risk, and review the gene-gene and gene-environment interactions in T2D Asians with CHD. The genetic factors can be grouped according to their involvement in the energy and lipoprotein metabolism, vascular and endothelial pathology, antioxidation, cell cycle regulation, DNA damage repair, hormonal regulation of glucose metabolism, as well as cytoskeletal function and intracellular transport. Meanwhile, interactions between single nucleotide polymorphisms (SNPs) from different genes, SNPs within a single gene, and genetic interaction with environmental factors including obesity, smoking habit, and hyperlipidemia could modify the gene's effect on the disease risk. Collectively, these factors illustrate the complexities of CHD in T2D, specifically among Asians.

T-786C variation in the promoter sequence of human eNOS gene markedly influences its expression level

This study investigated the role of the T-786C polymorphism (SNP) in the 5'-flanking sequence of the endothelial nitric oxide synthase gene (eNOS) on its expression level in vascular endothelium with the ultimate goal of shedding more light on the mechanisms by which genetic variations of eNOS might affect the vascular level of nitric oxide (NO). Sequences in the 5'-flanking region of eNOS gene were PCR-amplified using genomic DNA templates isolated from blood samples collected from cardiovascular disease (CVD) patients. Two sequence-versions carrying the same SNP site were used; a short (345 bp) and an extended one (1,594 bp), numbered relative to the translational start site. All sequences were cloned into a promoter-less vector (pGL3-basic), which carries the firefly luciferase gene as a reporter. Genotyping of the T-786C polymorphism was performed using Sanger sequencing of the insert region. Luminescence levels were then recorded 24-48 h after transfecting human endothelial cell line (EA.hy926). Three genotypes were identified in the subject samples; TT, TC, or CC. The highest expression levels associated with the TT genotype, followed by the TC genotype, then the CC genotype. The extended sequence version produced higher expression levels compared to the shorter version. Our results provide evidence that the T allele at the T-786C SNP site of the eNOS gene results in increased expression of the enzyme, and consequently might provide a protective mechanism from CVD. The extended promoter sequence of eNOS resulted in higher expression of the gene, suggesting the presence of some essential binding sites for transcription enhancing proteins.

Association of MMP9-1562C/T and MMP13-77A/G Polymorphisms with Non-Small Cell Lung Cancer in Southern Chinese Population

Background: Matrix metalloproteinases (MMPs) are capable of degrading and modifying most components of the extracellular matrix (ECM) and the basal membrane (BM), and play crucial roles in cancer invasion and metastasis. MMP gene expressions were regulated primarily at the transcriptional level, which was associated with tumor spread and patient prognosis. Polymorphisms in MMPs have been reported to be associated with non-small cell lung cancer (NSCLC). The objective of this study aim to evaluate the serum levels and polymorphisms of MMP-9 and MMP-13 in non-small cell lung cancer patients compared to normal subjects and their correlation to non-small cell lung cancer histopathology findings in Southern Chinese people. Methods: This case–control study included 245 patients with NSCLC and 258 healthy controls. Genomic DNA was extracted by using DNA extraction kit, genotyping was confirmed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct DNA sequencing, and serum levels of MMP-9 and MMP-13 were measured by using a specific ELISA, Human Matrix Metalloproteinase Enzyme Immunoassay Kits. Statistical analysis was carried out using the SPSS 23.0 software package. Results: The subjects carrying the TT genotype had a decreased risk of lung cancer in MMP9-1562C/T comparing with the CC genotype (p = 0.00, OR = 0.45, 95% CI = 0.29–0.68), and the MMP13-77 AA genotype was associated with a decreased risk of NSCLC by comparing with the GG genotype (p = 0.03, OR = 0.56, 95% CI = 0.33–0.94). Moreover, the C allele of MMP9-1562C/T could increase serum level of NSCLC in compared with the A allele (OR = 1.19, 95% CI = 0.75–1.89). Similarly, the AA genotype of MMP13 might be a marker of decreased serum level of lung cancer (OR = 0.76, 95% CI = 0.51–1.14). Conclusions: The results of these analyses underline the support of the notion that the CC genotype of MMP9-1562C/T and GG genotypes of MMP13-77G/A were associated with the increased risk NSCLC, and the serum levels of MMP9 and MMP13 were consistent with the results of the SNP analysis. MMP13 and MMP9 might be function as a key oncogene in NSCLC with a Southern Chinese population. Combined detection of SNP and enzyme activity between MMP9 and MMP13 are expected to be a potential diagnostic method of non-small cell lung cancer.

T786C Mutation in the Endothelial Nitric Oxide Synthase Gene in Patients With Primary Osteonecrosis

Mutations in the T786C endothelial nitric oxide synthase gene (eNOS) are associated with osteonecrosis and Prinzmetal's angina. Nitric oxide is necessary for bone health and ameliorates Prinzmetal's angina. This study compared mutations of T786C eNOS in 146 patients with primary osteonecrosis, 114 patients with Prinzmetal's angina, and 83 normal control subjects. Patients with osteonecrosis had more mutant eNOS alleles than control subjects (42% vs 22%, respectively; P<.0001) but had the same number of mutant alleles as patients with Prinzmetal's angina (42% vs 41%, respectively; P=.7), who in turn had more mutant eNOS alleles than control subjects (41% vs 22%, respectively; P=.0001). Of 146 patients with primary osteonecrosis, 65 (45%) had none of the 5 thrombophilias (Factor V Leiden heterozygosity, high levels of Factors VIII and XI, anticardiolipin antibody immunoglobulin M, and homocysteine) that otherwise distinguished patients with osteonecrosis from control subjects (P<.05). No associations were found between eNOS hetero-homozygosity and the 5 major thrombophilias in primary osteonecrosis. Of the 65 patients who had osteonecrosis but no major thrombophilias, for 41 (28% of the total sample of 146), eNOS hetero-homozygosity was the only abnormality. Normalization of nitric oxide levels with l-arginine 9 g/d or l-citrulline 800 mg/d, both of which relieve vasospastic angina in Prinzmetal's angina, which has the same eNOS genotype as primary osteonecrosis, may slow or stop the progression of osteonecrosis. Placebo-controlled trials of patients with primary osteonecrosis who are hetero-homozygous for the T786C eNOS mutation and have no major thrombophilias are needed to assess the safety and efficacy of this treatment. [Orthopedics. 2017; 40(5):e898-e903.].

Assessment of the role of plasma nitric oxide levels, T-786C genetic polymorphism, and gene expression levels of endothelial nitric oxide synthase in the development of coronary artery disease

Background:

Reduced bioavailability of nitric oxide (NO) and the T-786C polymorphism of endothelial nitric oxide synthase (eNOS) gene have been reported as risk factors for the development of coronary artery disease (CAD) with conflicting results. We investigated the association of plasma NO levels, T-786C genetic polymorphism, and gene expression levels of eNOS with CAD risk in an Iranian subpopulation.

Materials and Methods:

Studied population included 100 patients with angiographically verified CAD and 100 ethnically matched controls. Analysis of T-786C genetic polymorphism and gene expression levels of eNOS was conducted by polymerase chain reaction (PCR) restriction fragment length polymorphism and real-time reverse transcription-PCR methods, respectively. Plasma levels of NO were measured using Griess method.

Results:

The CC genotype distribution (15% vs. 6%, P = 0.011) and minor C allele frequency (36.5% vs. 21.5%, P = 0.001) of eNOS T-786C polymorphism differed significantly between CAD patients and control. Furthermore, eNOS T-786C polymorphism was more common among smoker than nonsmoker CAD patients (27.7% vs. 7.8%, P = 0.044). The association of the eNOS T-786C polymorphism with the severity of CAD (number of diseased vessel) was significant (P < 0.05). The gene expression levels of eNOS were significantly lower in the heterozygote (0.49 ± 0.1, P = 0.023) and mutant homozygote (0.36 ± 0.09, P = 0.011) genotypes than that of wild-type genotype (P < 0.05). In addition, NO levels were significantly lower in CAD patients compared with control subjects (42.62 ± 12.26 vs. 55.48 ± 16.57, P = 0.002) and showed intergenotypic variation in the CAD patients.

Conclusion:

Our study indicated that reduced NO levels and eNOS T-786C genetic polymorphism are significant risk factors for the development and severity of CAD in the Iranian population.