Association between T174M polymorphism in the angiotensinogen gene and risk of coronary artery disease: a meta-analysis

Summary of Known Genetic and Epigenetic Modification Contributed to Hypertension

Hypertension is a multifactorial disease due to a complex interaction among genetic, epigenetic, and environmental factors. Characterized by raised blood pressure (BP), it is responsible for more than 7 million deaths per annum by acting as a leading preventable risk factor for cardiovascular disease. Reports suggest that genetic factors are estimated to be involved in approximately 30 to 50% of BP variation, and epigenetic marks are known to contribute to the initiation of the disease by influencing gene expression. Consequently, elucidating the genetic and epigenetic mediators associated with hypertension is essential for better discernment of its pathophysiology. By deciphering the unprecedented molecular hypertension basis, it could help to unravel an individual's inclination towards hypertension which eventually could result in an arrangement of potential strategies for prevention and therapy. In the present review, we discuss known genetic and epigenetic drivers that contributed to the hypertension development and summarize the novel variants that have currently been identified. The effect of these molecular alterations on endothelial function was also presented.

The effect of polymorphisms (M235T and T174M) on the angiotensinogen gene (AGT) in coronary artery disease in the Eastern Asian population: A systematic review and meta-analysis

BACKGROUND

It is thought that genetic factors may play an important role in the development of coronary artery disease (CAD). Several studies report that AGT polymorphism is implicated in CAD susceptibility, but these results contradict those of the other studies with the associations being unclear in the Eastern Asian population. Therefore, meta-analysis was performed to evaluate this relationship.

METHODS

Publication databases were used to search for eligible relevant studies and valid data were extracted from studies meeting the inclusion criteria. Subsequently, odds ratios (ORs) with 95 % confidence intervals (CIs), were used to assess the strength of the association between AGT polymorphism and CAD risk.

RESULTS

Seven eligible studies published only in English were included in the present meta-analysis. In the Eastern Asian population, CAD susceptibility was shown to be related to AGT M235T under the heterozygote model (OR = 0.19). Stratified analysis indicated there was a significant relationship between AGT M235T and CAD risk in China under allelic (OR = 1.34), dominant (OR = 1.43), and heterozygote (OR = 1.62) models. The results showed that the T174M polymorphism was significantly associated with CAD risk in recessive (OR = 2.28) and homozygote (OR = 2.37) models in the Eastern Asian population.

CONCLUSIONS

In the Eastern Asian population, especially the Chinese, the M235T of AGT is associated with CAD susceptibility. The T174M polymorphisms were associated with CAD risk in the Eastern Asian population.

The Renin-Angiotensin System: A Key Role in SARS-CoV-2-Induced COVID-19

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), was first identified in Eastern Asia (Wuhan, China) in December 2019. The virus then spread to Europe and across all continents where it has led to higher mortality and morbidity, and was declared as a pandemic by the World Health Organization (WHO) in March 2020. Recently, different vaccines have been produced and seem to be more or less effective in protecting from COVID-19. The renin-angiotensin system (RAS), an essential enzymatic cascade involved in maintaining blood pressure and electrolyte balance, is involved in the pathogenicity of COVID-19, since the angiotensin-converting enzyme II (ACE2) acts as the cellular receptor for SARS-CoV-2 in many human tissues and organs. In fact, the viral entrance promotes a downregulation of ACE2 followed by RAS balance dysregulation and an overactivation of the angiotensin II (Ang II)-angiotensin II type I receptor (AT1R) axis, which is characterized by a strong vasoconstriction and the induction of the profibrotic, proapoptotic and proinflammatory signalizations in the lungs and other organs. This mechanism features a massive cytokine storm, hypercoagulation, an acute respiratory distress syndrome (ARDS) and subsequent multiple organ damage. While all individuals are vulnerable to SARS-CoV-2, the disease outcome and severity differ among people and countries and depend on a dual interaction between the virus and the affected host. Many studies have already pointed out the importance of host genetic polymorphisms (especially in the RAS) as well as other related factors such age, gender, lifestyle and habits and underlying pathologies or comorbidities (diabetes and cardiovascular diseases) that could render individuals at higher risk of infection and pathogenicity. In this review, we explore the correlation between all these risk factors as well as how and why they could account for severe post-COVID-19 complications.

Gene polymorphism associated with angiotensinogen (M235T), endothelial lipase (584C/T) and susceptibility to coronary artery disease: a meta-analysis

OBJECTIVE

To explore the association between the variant M235T locus of angiotensinogen (AGT) gene, 584C/T locus of Endothelial lipase (EL) gene, and coronary artery disease (CAD) by meta-analysis.

METHODS

The case-control studies on the association between AGT/EL gene polymorphism and CAD were collected through searching PubMed, Excerpta Medica Database (EMBASE), Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases up to 1 March 2020. Stata 15.0 software was used for analysis.

RESULTS

A total of 29 articles met the inclusion criteria. After analyzing, it was found that the M235T polymorphism of AGT gene was associated with the occurrence of CAD. In the allele model (T vs. M), OR = 1.38 (P<v0.05). In other heredity, there was also statistical significance. Subgroup analysis indicated that except the heterozygous genetic model of the Chinese population, other genetic models of the Caucasian and Chinese population were also statistically significant. The 584C/T polymorphism of EL gene was associated with the occurrence of CAD, with OR = 0.83 (P<0.05) in the allele model (T vs. C) and OR = 0.80 (P<0.05) in the dominant gene model. Also, in the allele model of Caucasian subgroup, OR = 0.83 (P<0.05), while in Asian subgroup, there was no statistically significant genetic model.

CONCLUSION

AGT M235T and EL 584C/T polymorphisms are associated with CAD susceptibility. The genotype TT, TC or allele T of AGT M235T and genotype CC or allele C of EL 584C/T might be the genetic risk factors for the development of CAD.

Association between angiotensinogen T174M polymorphism and ischemic stroke: A meta-analysis

BACKGROUND

Numerous studies have evaluated the association between the angiotensinogen (AGT) T174M polymorphism and ischemic stroke(IS) risk. However, the specific association is still controversial.

MATERIALS AND METHODS

In order to explore this association more deeply, we performed a meta-analysis. All of the relevant studies were identified from PubMed, Embase, and Chinese National Knowledge Infrastructure database up to October 2014. Statistical analyses were conducted with STATA 12.0 software. Odds ratio (OR) with 95% confidence interval (CI) values were applied to evaluate the strength of the association.

RESULTS

Six studies with 1290 cases and 1125 controls were included. No significant variation in IS risk was detected in any of the genetic models in the overall (MM vs. TT: OR = 1.64, 95% CI = 0.51-5.28; MT vs. TT: OR = 0.93, 95% CI = 0.66-1.31; dominant model: OR = 1.08, 95% CI = 0.69-1.72; recessive model: OR = 0.61,95% CI = 0.20-1.91). Taking into account the effect of ethnicity, further stratified analyses were performed. The results showed that AGT gene T174M polymorphism might be associated with IS risk in Asians (MM vs. TT: OR = 3.28, 95% CI = 1.79-6.02; recessive model: OR = 0.31, 95% CI = 0.17-0.57).

CONCLUSION

In conclusion, the AGT T174M polymorphism may be a susceptible predictor of the risk of IS in Asians. Further, large and well-designed studies are needed to confirm this conclusion.

Intercellular adhesion molecule-1 K469E and angiotensinogen T207M polymorphisms in coronary slow flow

OBJECTIVE

To investigate intercellular adhesion molecule-1 (ICAM1) and angiotensinogen (AGT) gene polymorphisms, as related to atherosclerosis and endothelial dysfunction, in coronary slow flow (CSF).

SUBJECTS AND METHODS

The participants in this study were 48 patients with CSF and 67 patients with normal coronary flow as controls. The K469E polymorphism of ICAM1 (rs5498) and the T207M polymorphism of AGT (rs4762) were determined using the polymerase chain reaction amplification method.

RESULTS

Baseline demographic parameters were similar in both groups. The mean thrombolysis in myocardial infarction frame count was significantly higher in patients with CSF (23.8 ± 5.1) compared to the controls (13.3 ± 2.6, p < 0.001). A significant association was found between the ICAM1 K allele and CSF (OR: 1.96, 95% CI: 1.15-3.35, p = 0.013). There was no difference in the frequency of AGT T207M genotypes in the patients with CSF and the control subjects.

CONCLUSION

This study showed that K469E polymorphisms of ICAM1 that play a role in atherosclerotic pathogenesis are related to CSF.