Association between the ACE I/D polymorphism and risk of ischemic stroke: an updated meta-analysis of 47,026 subjects from 105 case-control studies

Angiotensin-Converting Enzyme Insertion/Deletion Polymorphism and the Risk of Leukoaraiosis in a South Chinese Han Population: A Case-Control Study

Leukoaraiosis (LA) appears as white matter hyperintensities on T2-weighted brain magnetic resonance imaging scans. Age and hypertension are considered the primary risk factors for LA, but its pathogenesis remains uncertain. This study aims to investigate the correlation between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and LA. A total of 140 patients with LA and 136 neuroimaging alteration-free controls were recruited in a case-control study. ACE I/D polymorphism was determined using the polymerase chain reaction method. The allele and genotype distributions of the ACE I/D polymorphism were significantly different between subjects with and without LA. Significant difference was observed in the genotypic distribution between LA patients and controls for recessive and additive models. A statistically significant association remained apparent after adjusting for potential risk factors (D/D vs. I/D + I/I: adjusted OR 3.251, 95% CI 1.185-8.918; D/D vs. I/I: adjusted OR 3.277, 95% CI 1.187-9.047). Our results indicate that the D/D genotype and D allele are important risk factors for LA. Future studies with larger populations are needed to validate our results.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and risk of ischemic stroke complication among patients with hypertension in the Ethiopian population

Background

Ischemic stroke is a complicated, multifaceted condition brought on by a confluence of vascular, environmental, and genetic variables. The burden of ischemic stroke is currently rising in terms of death, morbidity, and disability worldwide. Genetic variables also play significant roles in the pathophysiology of hypertension and ischemic stroke in addition to the greatest effects of demographic, clinical, and behavioral risk factors. The key functional variation of the ACE gene that has drawn the most interest is the ACE I/D variant. Even though the ACE gene I/D polymorphism has been widely studied, the findings of investigations on the involvement of this polymorphism in ischemic stroke were contradictory and provide conflicting data. The goal of this study was to look into the effect of the ACE gene I/D polymorphism on the risk of ischemic stroke in patients with hypertension.

Methods

A hospital-based case-control study was carried out in 36 cases of patients with hypertensive IS and 36 age- and sex-matched healthy controls. Clinical and biochemical parameters were measured to assess the associated risk factors. The DNA was isolated from blood samples, and the ACE I/D genotypes were identified using polymerase chain reaction and analyzed by agarose gel electrophoresis.

Results

The ACE-DD genotype (OR = 3.71, 95% CI = 1.02-13.5; P < 0.05) and D allele (OR = 2.07, 95% CI = 1.06-4.03; P < 0.05) were significantly more common in patients than in controls, indicating that it is a risk factor for the development of ischemic stroke in hypertensive individuals.

Conclusion

There is a significant correlation between the ACE gene I/D polymorphism and the development of ischemic stroke in patients with a history of hypertension in the Ethiopian population.

Angiotensin-Converting Enzyme (ACE) Insertion/Deletion (I/D) Polymorphism as a Conjoint Regulator of Coagulation, Fibrinolytic, and RAAS Pathway in Infertility and Associated Pregnancy Complications

Despite the increase in assisted reproductive technologies, the high rates of infertility and pregnancy complications are a major concern to infertility specialists worldwide. Infertility may be attributed to pregnancy complications like thrombophilia, preeclampsia and fibrin-induced recurrent pregnancy loss (RPL). Renin-angiotensin-aldosterone system (RAAS) directly or indirectly causes preeclampsia and thrombophilia through the fibrinolytic pathway that ultimately leads to RPL or infertility. The underlying mechanisms of this interaction are still unclear. The present comprehensive review is intended to demonstrate the role and interaction of RAAS and fibrinolytic pathways in pregnancy complications. How this interaction can induce pregnancy complications, and ultimately infertility, is also discussed in the light of current evidence. This study also presents common markers that link RAAS and fibrinolytic processes in developing thrombophilia, preeclampsia and RPL. The common link in these pathways is ACE gene I/D polymorphism. Apart from ACE, PAI-1, VIIa, XIIa, AT1R, AT1AA, and TF are common molecules that can delineate the underlying causes of pregnancy complications and infertility.

Genetic Polymorphisms in a Familial Hypercholesterolemia Population from North-Eastern Europe

(1) Background: Familial hypercholesterolemia (FH) is one of the most prevalent inherited metabolic disorders. The purpose of the study was to investigate the role in cardiovascular disease (CVD) of PAI-1, ACE, ApoB-100, MTHFR A1298C, and C677T. (2) Methods: From a group of 1499 patients, we included 52 patients diagnosed with FH phenotype and 17 patients in a control group. (3) Results: Most of the FH patients had multiple comorbidities compared to the control group, such as atherosclerosis (48.1% vs. 17.6%), atherosclerotic cardiovascular disease (ASCVD 32.7% vs. 11.8%), and metabolic syndrome (MetS, 40.4% vs. 11.8%). In total, 66.7% of the FH patients had PAI-1 4G/5G genotype and MetS. Between 4G/5G and 4G/4G, a statistically significant difference was observed (p = 0.013). FH patients with ApoB R3500Q polymorphism were correlated with ASCVD (p = 0.031). Both MTHFR C677T and A1298C polymorphisms had a significant correlation with gender, alcohol consumption, and smoking status. ACE polymorphism was associated with ATS in FH patients, statistically significant differences being observed between heterozygous and homozygous D genotype (p = 0.036) as well as between heterozygous and homozygous I genotype (p = 0.021). (4) Conclusions: A link between these polymorphisms was demonstrated in the FH group for ATS, ASCVD, and MetS.

Association of laboratory parameters and genetic polymorphisms with ischemic stroke in Chinese Han population

Numerous genetic polymorphisms and clinical laboratory parameters are associated with ischemic stroke (IS). However, the results of such studies have frequently been inconsistent. The aim of the present study was to evaluate associations between clinical laboratory parameters with genetic polymorphisms that influence the risk of IS in a Chinese Han population. Clinical laboratory parameters were measured by an automatic biochemical analyzer. Genotype and allele frequencies of the polymorphisms angiotensin-converting enzyme (ACE) D/I, methylene tetrahydrofolate reductase (MTHFR) C677T and β-fibrinogen (β-Fg) A/G, 455/148T/C were characterized by restriction fragment length polymorphism-PCR. Furthermore, the gene polymorphisms plasminogen activator inhibitor (PAI)-1-4G/5G and apolipoprotein E (ApoE) ε2,3,4 were characterized by allele-specific PCR. The associations of genotype and allele frequencies of the six risk genes in different groups with clinical laboratory parameters were analyzed by chi-square tests. The distribution maps of the polymorphisms of the six genes and clinical laboratory parameters were compared between a control group of 336 healthy individuals and 762 patients with IS. Certain laboratory parameters were associated with ACE I/D, β-Fg-455 A/G and PAI-1 4G/5G. The D allele of ACE I/D was associated with high levels of total cholesterol and low-density lipoprotein cholesterol (LDL-C). Furthermore, high levels of fasting blood glucose, triglyceride and LDL-C were risk factors for IS. There were significant differences in the genotype frequencies of ACE I/D, β-Fg-455 A/G and β-Fg-148 T/C between the IS and the control group. In conclusion, clinical laboratory parameters were associated with the risk of polymorphisms of IS-related genes. The present results support the determination of a range of control values of clinical laboratory parameters for common genotypes in patients with diabetes and hyperlipidemia as a strategy for the early prevention of IS.

Omics era in forensic medicine: towards a new age

Background/aim

Forensic medicine and sciences is a multidisciplinary branch of science, which frequently benefit from novel technologies. State of the art omics technologies have begun to be performed in forensic medicine and sciences, particularly in postmortem interval, intoxication, drugs of abuse, diagnosis of diseases and cause of death. This review aims to discuss the role and use of great omics (metabolomics, proteomics, genomics and transcriptomics) in forensic sciences, in detail.

Materials and methods

A detailed review of related literature was performed, and studies were subdivided as per the type of omics.

Results and conclusion

Omics seems as a revolutionary step in forensic science and sure carries it towards a new age. The number of forensic studies utilizing omics steadily increases in last years. Omics strategies should be used together in order to gather more accurate and certain data. Additional studies need to be performed to incorporate omics into routine forensic methodology.

Cross-Talk Between Key Players in Patients with COVID-19 and Ischemic Stroke: A Review on Neurobiological Insight of the Pandemic

The global pandemic of novel coronavirus disease 2019 (COVID-19) has taken the entire human race by surprise and led to an unprecedented number of mortalities worldwide so far. Current clinical studies have interpreted that angiotensin-converting enzyme 2 (ACE2) is the host receptor for severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). In addition, ACE2 is the major component of the renin-angiotensin system. ACE2 deteriorates angiotensin II, a peptide that is responsible for the promotion of stroke. The downregulation of ACE2 further activates an immunological cascade. Thus, researchers need to explore and examine the possible links between COVID-19 and ischemic stroke (IS). Human ACE2 expression level and pattern in various tissues might be decisive for the vulnerability, symptoms, and treatment outcomes of the SARS-CoV-2 infection. The swift increase in the knowledge of SARS-CoV-2 has given creditable evidence that SARS-CoV-2 infected patients also encounter neurological deficits. As the SARS-CoV-2 binds to ACE2, it will hamper the activity of ACE2 in providing neuroprotection, especially in the case of stroke patients. Due to the downregulation of ACE2, the inflammatory response is activated in the ischemic penumbra. The COVID-19 pandemic has affected people with various pre-existing diseases, including IS, in such a way that these patients need special care and attention for their survival. Several clinical trials are currently ongoing worldwide as well as many other projects are in different stages of conceptualization and planning to facilitate the effective management of stroke patients with COVID-19 infection.

Influence of Angiotensin-converting Enzyme Insertion/Deletion Gene Polymorphism in Progression of Chagas Heart Disease

INTRODUCTION

Chagas disease (CD) is a neglected disease caused by the parasite Trypanosoma cruzi. One-third of infected patients will develop the cardiac form, which may progress to heart failure (HF). However, the factors that determine disease progression remain unclear. Increased angiotensin II activity is a key player in the pathophysiology of HF. A functional polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with plasma enzyme activity. In CD, ACE inhibitors have beneficial effects supporting the use of this treatment in chagasic cardiomyopathy.

METHODS

We evaluated the association of ACE I/D polymorphism with HF, performing a case-control study encompassing 343 patients with positive serology for CD staged as non-cardiomyopathy (stage A; 100), mild (stage B1; 144), and severe (stage C; 99) forms of Chagas heart disease. For ACE I/D genotyping by PCR, groups were compared using unconditional logistic regression analysis and adjusted for nongenetic covariates: age, sex, and trypanocidal treatment.

RESULTS

A marginal, but not significant (p=0.06) higher prevalence of ACE I/D polymorphism was observed in patients in stage C compared with patients in stage A. Patients in stage C (CD with HF), were compared with patients in stages A and B1 combined into one group (CD without HF); DD genotype/D carriers were prevalent in the HF patients (OR = 2; CI = 1.013.96; p = 0.04).

CONCLUSIONS

Our results of this cohort study, comprising a population from the Northeast region of Brazil, suggest that ACE I/D polymorphism is more prevalent in the cardiac form of Chagas disease with HF.

ACE-Triggered Hypertension Incites Stroke: Genetic, Molecular, and Therapeutic Aspects

Stroke is the second largest cause of death worldwide. Angiotensin converting enzyme (ACE) gene has emerged as an important player in the pathogenesis of hypertension and consequently stroke. It encodes ACE enzyme that converts the inactive decapeptide angiotensin I to active octapeptide, angiotensin II (Ang II). Dysregulation in the expression of ACE gene, on account of genetic variants or regulation by miRNAs, alters the levels of ACE in the circulation. Variable expression of ACE affects the levels of Ang II. Ang II acts through different signal transduction pathways via various tyrosine kinases (receptor/non-receptor) and protein serine/threonine kinases, initiating a downstream cascade of molecular events. In turn these activated molecular pathways might lead to hypertension and inflammation thereby resulting in cardiovascular and cerebrovascular diseases including stroke. In order to regulate the overexpression of ACE, many ACE inhibitors and blockers have been developed, some of which are still under clinical trials.

Association Between the Angiotensin-Converting Enzyme Gene Insertion/Deletion Polymorphism and Avascular Necrosis of the Femoral Head

Objective: This study investigated the association between the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and avascular necrosis of the femoral head (ANFH). Materials and Methods: The ACE gene I/D polymorphism was determined in 279 nontraumatic, ANFH Han Chinese patients (divided into idiopathic and steroid- and alcohol-induced subgroups) and 276 age- and gender-matched healthy controls using the polymerase chain reaction. Results: The frequencies of the ACE DD genotype and D allele were significantly higher among the ANFH patients as a whole and also in the idiopathic and steroid- and alcohol-induced ANFH subgroups compared to healthy controls (p < 0.05 for all). Additionally, the DD genotype, compared with the ID+II, ID, and II genotypes, conferred a higher risk of developing ANFH across all clinical subgroups (p < 0.001, odds ratio [OR] = 2.508; p < 0.001, OR = 2.072; p < 0.001, OR = 3.684, respectively) as well in each of the subgroups examined individually, including the idiopathic subgroup (p < 0.001, OR = 2.579; p < 0.001, OR = 2.091; p < 0.001, OR = 3.994, respectively), the steroid-induced subgroup (p = 0.005, OR = 2.345; p = 0.031, OR = 2.050; p = 0.007, OR = 3.000, respectively), and the alcohol-induced subgroup (p < 0.001, OR = 2.488; p = 0.012, OR = 2.050; p = 0.011, OR = 2.659, respectively) of ANFH patients. The ID genotype, compared with the II genotype, conferred a higher risk across all subtypes analyzed together, and in the idiopathic subgroup (p = 0.013, OR = 1.778; p = 0.028, OR = 1.910) analyzed separately. Additionally, the D allele, in comparison with the I allele, conferred a relatively higher risk across all subgroups (p < 0.001, OR = 2.101) as well as in each of the three subgroups examined individually (idiopathic: p < 0.001, OR = 2.178; steroid-induced: p = 0.003, OR = 1.910; and alcohol-induced: p < 0.001, OR = 2.094). Conclusion: The ACE DD and ID genotypes and D allele may be risk factors for susceptibility to ANFH in the Chinese population.

Advances in Understanding the Pathophysiology of Lacunar Stroke: A Review

Importance

Stroke is the second leading cause of death in the world, and nearly one-third of ischemic strokes are lacunar strokes (LSs) or small subcortical infarcts. Although smaller in size, they create large problems, leaving many patients with intellectual and physical disabilities. Because there are limitations in understanding the underlying pathophysiology of LS, the development of novel therapies has been slow.

Observations

When the term lacune was described in the 1800s, its underlying pathophysiological basis was obscure. In the 1960s, C. Miller Fisher, MD, performed autopsy studies that showed that vessels supplying lacunes displayed segmental arteriolar disorganization, characterized by vessel enlargement, hemorrhage, and fibrinoid deposition. For these pathologic changes, he coined the term lipohyalinosis. Since that time, few attempts have been made to reconcile this pathologic description with modern mechanisms of cerebral small vessel disease (CSVD). During the past 6 years, progress has been made in understanding the clinical mechanisms, imaging characteristics, and genetic basis of LS.

Conclusions and Relevance

Questions persist regarding the order of events related to the initiation and progression of CSVD, how LS is related to other sequelae of CSVD, and whether LS is part of a systemic disease process. The relative roles of aging, oxidative stress, mechanical stress, genetic predisposition, and other vascular risk factors should be further studied, especially in the era of widespread antihypertensive use. Although understanding of endothelial dysfunction has increased, future work on the role of media and adventitial dysfunction should be explored. Recent advances in mapping the brain vasculome may generate new hypotheses. The investigation of new therapeutic targets, aimed at reversing CSVD processes and promoting neural repair after LS, depends upon further understanding these basic mechanisms.

The combination of ACE I/D and ACE2 G8790A polymorphisms revels susceptibility to hypertension: A genetic association study in Brazilian patients

BACKGROUND

Systemic arterial hypertension (SAH) is a multifactorial condition that already affects one third of the worldwide population. The identification of candidate genes for hypertension is a challenge for the next years. Nevertheless, the small contribution of each individual genetic factor to the disease brings the necessity of evaluate genes in an integrative manner and taking into consideration the physiological interaction of functions. Angiotensin I-converting enzymes, ACE and ACE2, are key regulators of blood pressure that have counterbalance roles by acting on vasoactive peptides from Renin-Angiotensin-Aldosterone System (RAAS). Insertion/deletion (I/D) polymorphism of ACE gene and single nucleotide polymorphism G8790A of ACE2 gene have been associated with susceptibility to SAH, but the literature is controversial. We proposed to evaluate these two polymorphisms jointly exploring the combined effects of ACE and ACE2 genotypes on SAH susceptibility, an approach that have not been done yet for ACE and ACE2 polymorphisms.

METHODS AND FINDINGS

This genetic association study included 117 hypertensive (mean age 59.7 years) patients and 123 normotensive and diabetes-free controls (mean age 57.5 years). ACE and ACE2 polymorphisms were genotyped by SYBR Green real-time PCR and RFLP-PCR, respectively. Crude and adjusted odds ratio (OR) values were calculated to estimate the susceptibility to SAH development. It was obtained homogeneity regarding distribution by sex, age range, smoking, alcohol consumption and body mass index (BMI) between case and control groups. No-association was verified for each gene individually, but the combination of ACE and ACE2 polymorphisms on female gender revealed a significative association for DD/G_ carriers who had a 3-fold increased risk to SAH development (p = 0.03), with a stronger susceptibility on DD/GG carriers (7-fold increased risk, p = 0.01). The D allele of ACE showed association with altered levels of lipid profile variables on case group (VLDL-cholesterol, p = 0.01) and DD genotype in all individuals analysis (triglycerides, p = 0.01 and VLDL-cholesterol, p = 0.01).

CONCLUSION

These findings indicate that the combination of ACE and ACE2 polymorphisms effects may play a role in SAH predisposition been the DD/G_ genotype the susceptibility profile. This result allowed us to raise the hypothesis that an increased activity of ACE (prohypertensive effects) in conjunction with reduced ACE2 activity (antihypertensive effects) could be the underlining mechanism. The association of ACE D allele with lipid alterations indicate that this can be a marker of poor prognostic on SAH evolution and contribute to CVD development. Although these preliminary findings must be confirmed by further researches with larger sample size, we could observe that the integrative analysis of ACE and ACE2 can be an informative tool in hypertension understanding that needs to be explored in new studies.

Shared genetic risk factors for depression and stroke

BACKGROUND

The comorbidity of major depressive disorder (MDD) and stroke are common in clinic. There is a growing body of evidence suggesting a bi-directional relationship between stroke and depression. However, the mechanisms underlying the relationship between MDD and stroke are poorly investigated. Considering that both MDD and stroke can be heritable and are influenced by multiple risk genes, shared genetic risk factors between MDD and stroke may exist.

OBJECTIVE

The objective is to review the existing evidence for common genetic risk factors for both MDD and stroke and to outline the possible pathophysiological mechanisms mediating this association.

METHODS

A systematic review and meta-analysis was performed. Gene association studies regarding stroke and depression were searched in the database PubMed, CNKI, and Chinese Biomedical Literature Database before December 2018. Statistical analysis was performed using the software Revman 5.3.

RESULTS

Genetic polymorphisms of 4 genes, methylenetetrahydrofolate reductase (MTHFR) and apolipoprotein E (ApoE) have been demonstrated to associate with the increased risk for both MDD and stroke, while the association between identified polymorphisms in angiotensin converting enzyme (ACE) and serum paraoxonase (PON1) with depression is still under debate, for the existing studies are insufficient in sample size. These results suggest the possible pathophysiological mechanisms that are common to these two disorders, including immune-inflammatory imbalance, increased oxidative and nitrative stress, dysregulation of lipoprotein and lipid metabolism, and changes of cerebrovascular morphology and function. Other associated genes with few or conflicting results have also been included, and a few studies have investigated the effects of the described polymorphisms on MDD and stroke comorbidity, such as post stroke depression.

CONCLUSION

These findings suggest that shared genetic pathways may contribute to the comorbidity of MDD and stroke. Studies to evaluate the shared genetic variations between MDD and stroke may provide insights into the molecular mechanisms that trigger disease progression.

Effects of Interactions among Gene Polymorphisms of the Renin–Angiotensin-Aldosterone System on Hypertension in Turkish People from Southeast Anatolia

Introduction: Hypertension (HT) is characterized by high blood pressure. The reninangiotensin-aldosterone system (RAAS) plays a crucial role in blood pressure (BP) regulation by maintaining vascular tone and the water-sodium balance. We aimed to investigate whether there is any relation between AGT (M235T), ACE (I/D), and AGTR1 (A1166C) genetic polymorphisms and hypertension among Turkish people from Southeast Anatolia.

Method and Results: A total of 210 individuals, consisting of 102 healthy controls and 108 patients with essential hypertension admitted to the Cardiology Department of the Adıyaman University Research and Application Hospital were included the study. DNA isolation was performed from the blood samples via commercial kit. Genotype determination was determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Statistically significant differences were found between the control and patient groups in terms of genotype distribution and allelic frequencies of ACE I/D polymorphisms. Significant differences were found in the frequencies of ICM, DCM, DCT, DAT between the patient and control groups.

Conclusions: In this study, we found a significant association of ACE I/D polymorphism with HT, and we showed that the I allele can increase the risk of HT in Turkish people from Southeast Anatolia. Although we did not find any association between independent AGT M235T and AGT1R A1166C polymorphisms and HT, we observed that the DCM, DCT, and DAT haplotypes of ACE/AGT1R/AGT polymorphisms reduced the risk of hypertension, while the ICM haplotype increased it.

Role of angiotensin-converting enzyme insertion/deletion polymorphism in sudden cardiac arrest

OBJECTIVE

This study aimed to investigate the relationship between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and to understand sudden cardiac arrest (SCA) in the Chinese population.

METHODS

In this study, 232 patients were divided into the SCA group and the coronary disease group with coronary disease, but no SCA occurred during the treatment period. After comparing the genotype frequencies of the two groups, all patients were further divided into three groups as the II homozygotes, ID heterozygotes, and DD homozygotes to investigate the relationship in ACE I/D polymorphism and other risk factors of SCA.

RESULTS

The frequencies of DD genotype in the SCA group were significantly higher than the coronary disease group, as well as the D allele frequencies in the SCA group were high when compared with the coronary disease group. According to the genotypes of the ACE I/D polymorphism, the distribution of patients' characteristics had no significant differences among all the characteristics. Both, the patients who survived SCA, with II genotype and the ones who died of SCA, with DD genotype had significant higher percentages.

CONCLUSION

The DD genotype was associated with a higher prevalence of SCA and might be a risk factor of survival rate in sudden cardiac death.

ALUminating the Path of Atherosclerosis Progression: Chaos Theory Suggests a Role for Alu Repeats in the Development of Atherosclerotic Vascular Disease

Atherosclerosis (ATH) and coronary artery disease (CAD) are chronic inflammatory diseases with an important genetic background; they derive from the cumulative effect of multiple common risk alleles, most of which are located in genomic noncoding regions. These complex diseases behave as nonlinear dynamical systems that show a high dependence on their initial conditions; thus, long-term predictions of disease progression are unreliable. One likely possibility is that the nonlinear nature of ATH could be dependent on nonlinear correlations in the structure of the human genome. In this review, we show how chaos theory analysis has highlighted genomic regions that have shared specific structural constraints, which could have a role in ATH progression. These regions were shown to be enriched with repetitive sequences of the Alu family, genomic parasites that have colonized the human genome, which show a particular secondary structure and are involved in the regulation of gene expression. Here, we show the impact of Alu elements on the mechanisms that regulate gene expression, especially highlighting the molecular mechanisms via which the Alu elements alter the inflammatory response. We devote special attention to their relationship with the long noncoding RNA (lncRNA); antisense noncoding RNA in the INK4 locus (ANRIL), a risk factor for ATH; their role as microRNA (miRNA) sponges; and their ability to interfere with the regulatory circuitry of the (nuclear factor kappa B) NF-κB response. We aim to characterize ATH as a nonlinear dynamic system, in which small initial alterations in the expression of a number of repetitive elements are somehow amplified to reach phenotypic significance.

Review and meta-analysis of genetic polymorphisms associated with exceptional human longevity

BACKGROUND

Many factors contribute to exceptional longevity, with genetics playing a significant role. However, to date, genetic studies examining exceptional longevity have been inconclusive. This comprehensive review seeks to determine the genetic variants associated with exceptional longevity by undertaking meta-analyses.

METHODS

Meta-analyses of genetic polymorphisms previously associated with exceptional longevity (85+) were undertaken. For each variant, meta-analyses were performed if there were data from at least three independent studies available, including two unpublished additional cohorts.

RESULTS

Five polymorphisms, ACE rs4340, APOE ε2/3/4, FOXO3A rs2802292, KLOTHO KL-VS and IL6 rs1800795 were significantly associated with exceptional longevity, with the pooled effect sizes (odds ratios) ranging from 0.42 (APOE ε4) to 1.45 (FOXO3A males).

CONCLUSION

In general, the observed modest effect sizes of the significant variants suggest many genes of small influence play a role in exceptional longevity, which is consistent with results for other polygenic traits. Our results also suggest that genes related to cardiovascular health may be implicated in exceptional longevity. Future studies should examine the roles of gender and ethnicity and carefully consider study design, including the selection of appropriate controls.

The D allele of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism is associated with worse functional outcome of ischaemic stroke

PURPOSE

Insertion/deletion polymorphism in ACE gene (ACE I/D) is known to be associated with the occurrence of ischaemic stroke through its effect on pathogenesis of atherosclerosis and hypertension. This study was aimed to examine the association between this polymorphism with functional outcome of ischaemic stroke.

METHOD

This was a cross-sectional study. The subjects were patients with ischaemic stroke in a reference hospital in Yogyakarta, Indonesia. Data on demographic characteristics, stroke risk factors, comorbidities and stroke severity were assessed on admission. The functional outcome, Barthel index (BI), was assessed when the patients were discharged from the hospital. ACE I/D genotypes of the patients were identified by polymerase chain reaction (PCR).

RESULT

In total, 61 patients were included. Of these, 38 patients (62.3%) had II polymorphism, 22 patients (36.1%) had ID polymorphism and 1 patient (1.6%) had DD polymorphism in the ACE gene. There were significant differences in the functional outcomes between patients without D allele (II polymorphisms) and patients with D allele (ID and DD polymorphism) (mean BI on discharge: 75 ± 23.57 and 60.65 ± 27.15, respectively; p = 0.034). Multiple linear regression model showed that the availability of D allele is an independent variable negatively associated with functional outcome as assessed by BI (β = -0.232, p = 0.024).

CONCLUSION

This study showed that the D allele in ACE I/D polymorphism is associated with worse functional outcomes. This highlights the possibility of further research to improve functional outcomes of ischaemic stroke by inhibiting the ACE system.

Up-regulation of angiotensin-converting enzyme in response to acute ischemic stroke via ERK/NF-κB pathway in spontaneously hypertensive rats

Cerebral ischemic stroke is usually caused by a temporary or permanent decrease in blood supply to the brain. Despite general progress in diagnosis and treatment, the prognosis of stroke is still unsatisfactory, and more detailed potential mechanisms are needed to investigate underlying the pathological process. Here, we showed that serum angiotensin-converting enzyme (ACE) concentration was positively correlated with infarct volume after acute ischemic stroke (AIS). Moreover, using a permanent middle cerebral artery occlusion rat model, we indicated for the first time that increased ACE expression in response to AIS was regulated by the ERK/NF-κB pathway in peri-infarct regions. More importantly, we disclosed that angiotensin II type 1 receptors were implicated in up-regulation of ACE expression in peri-infarct regions. These findings offer insight into ACE expression and activity in response to stroke, and further our understanding of ACE mechanisms.

Genomics of Atrial Fibrillation

Atrial fibrillation (AF) is a common clinical arrhythmia that appears to be highly heritable, despite representing a complex interplay of several disease processes that generally do not manifest until later in life. In this manuscript, we will review the genetic basis of this complex trait established through studies of familial AF, linkage and candidate gene studies of common AF, genome wide association studies (GWAS) of common AF, and transcriptomic studies of AF. Since AF is associated with a five-fold increase in the risk of stroke, we also review the intersection of common genetic factors associated with both of these conditions. Similarly, we highlight the intersection of common genetic markers associated with some risk factors for AF, such as hypertension and obesity, and AF. Lastly, we describe a paradigm where genetic factors predispose to the risk of AF, but which may require additional stress and trigger factors in older age to allow for the clinical manifestation of AF.

The effect of angiotensin-converting enzyme polymorphism on hemodynamic response to endotracheal intubation in hypertensive patients

Endotracheal intubation elicits a hemodynamic response associated with increased heart rate and blood pressure that is influenced by the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) genetic polymorphism which may be of importance also for the pressure response to anesthesia. A total of 337 patients underwent abdominal surgery in general anesthesia and 16% were D/D-homozygotes, 45% were I/D heterozygotes and 39% of the patients were I/I homozygotes. Before surgery most patients were in treatment for arterial hypertension. Systolic and diastolic pressure, heart rate and concentrations of catecholamines in blood were determined before and after induction of anesthesia and for up to 10 minutes following endotracheal intubation. Anesthesia decreased blood pressure and for patients presenting ID and DD, blood pressure and heart rate reached similar levels but compared to II-homozygotes, D-carriers demonstrated significantly higher levels for systolic pressure and heart rate before and after intubation (p < 0.05). The blood levels of catercholamines were similar in the three genotype groups. The incidence of ECG-determined myocardial ischemia was higher in D-allele carriers compared to I-allele homozygotes (DD 22%, ID 25% vs. II 5%). In response to anesthesia and intubation and independent of sympathetic nervous activity, D-allele carriers for ACE polymorphism increased blood pressure response and higher risk for development of cardiovascular complications compared to patients homozygous for the I-allele.

ACE Insertion/Deletion Polymorphism Associated with Caries in Permanent but Not Primary Dentition in Czech Children

OBJECTIVE

Dental caries is a multifactorial, infectious disease where genetic predisposition plays an important role. Insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) has very recently been associated with caries in Polish children. The aim of this study was to analyze ACE I/D polymorphism in a group of caries-free children versus subjects affected by dental caries in the Czech population.

MATERIALS AND METHODS

In this case-control study, 182 caries-free children (with decayed/missing/filled teeth, DMFT = 0), 561 subjects with dental caries (DMFT ≥1) aged 13-15 years and 220 children aged 2-6 years with early childhood caries (ECC, dmft ≥1) were included. Genotype determination of ACE I/D polymorphism in intron 16 was based on the TaqMan method.

RESULTS

Although no significant differences in the allele or genotype frequencies between the caries-free children and those affected by dental caries were observed, statistically significant differences between the children with DMFT = 0 and the subgroup of 179 patients with high caries experience (DMFT ≥4; p < 0.01 and p < 0.05, respectively) were detected. The comparison of DD versus II+ID genotype frequencies between the patients with DMFT ≥1 or DMFT ≥4 and healthy children also showed significant differences (31.5% or 35.6% vs. 23.6%, p < 0.05 or p < 0.01, respectively). A gender-based analysis identified a significant difference in the DD versus II+ID genotype frequencies only in girls (p < 0.05). In contrast, no significant association of ACE I/D polymorphism with ECC in young children was found (p > 0.05).

CONCLUSIONS

ACE I/D polymorphism may be associated with caries in permanent but not primary dentition, especially in girls in the Czech population.

Neuroprotective Effect of Scutellarin on Ischemic Cerebral Injury by Down-Regulating the Expression of Angiotensin-Converting Enzyme and AT1 Receptor

Background and Purpose

Previous studies have demonstrated that angiotensin-converting enzyme (ACE) is involved in brain ischemic injury. In the present study, we investigated whether Scutellarin (Scu) exerts neuroprotective effects by down-regulating the Expression of Angiotensin-Converting Enzyme and AT1 receptor in a rat model of permanent focal cerebral ischemia.

Methods

Adult Sprague–Dawley rats were administrated with different dosages of Scu by oral gavage for 7 days and underwent permanent middle cerebral artery occlusion (pMCAO). Blood pressure was measured 7 days after Scu administration and 24 h after pMCAO surgery by using a noninvasive tail cuff method. Cerebral blood flow (CBF) was determined by Laser Doppler perfusion monitor and the neuronal dysfunction was evaluated by analysis of neurological deficits before being sacrificed at 24 h after pMCAO. Histopathological change, cell apoptosis and infarct area were respectively determined by hematoxylin–eosin staining, terminal deoxynucleotidyl transfer-mediated dUTP nick end labeling (TUNEL) analysis and 2,3,5-triphenyltetrazolium chloride staining. Tissue angiotensin II (Ang II) and ACE activity were detected by enzyme-linked immunosorbent assays. The expression levels of ACE, Ang II type 1 receptor (AT1R), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) were measured by Western blot and real-time PCR. ACE inhibitory activity of Scu in vitro was detected by the photometric determination.

Results

Scu treatment dose-dependently decreased neurological deficit score, infarct area, cell apoptosis and morphological changes induced by pMCAO, which were associated with reductions of ACE and AT1R expression and the levels of Ang II, TNF-α, IL-6, and IL-1β in ischemic brains. Scu has a potent ACE inhibiting activity.

Conclusion

Scu protects brain from acute ischemic injury probably through its inhibitory effect on the ACE/Ang II/AT1 axis, CBF preservation and proinflammation inhibition.

Insertion/Insertion Genotype of Angiotensin I-Converting-Enzyme Gene Predicts Risk of Myocardial Infarction in North East India

Myocardial infarction (MI) is common in India and the disease occurs at a relatively younger age. We wanted to look for association of Angiotensin I-converting enzyme (ACE) gene with MI in North East India. We also wanted to examine possible environmental interaction of ACE gene with established cardiovascular risk factors in causation of MI. In the study carried out in Assam Medical College, 200 consecutive confirmed cases of MI were recruited. Equal numbers of age- and sex-matched control subjects from hospital workers and patients attending the hospital for diseases unrelated to cardiovascular disease were enrolled. Structured questionnaires were used to note demographic and clinical factors. Cardiovascular risk factors were determined from history, physical examination and biochemical investigations. ACE insertion/deletion (I/D) polymorphism was determined by PCR method. Interaction of ACE gene with other risk factors was noted. The study identified ACE II genotype (odds ratio = 3.02; 95% CI 1.40-6.51), smoking, hypertension, diabetes and serum triglyceride > 150 mg/dl as independent risk factors for MI. ACE II genotype showed greater risk in non-smokers, non-hypertensives, non-diabetics and in subjects with LDL-C < 130 mg/dl. Low HDL cholesterol enhanced the genetic risk. Subjects with ACE II genotype have an independent risk of developing MI, specially in low cardiovascular risk subjects.

Variants in the Atherogenic ALOX5AP, THBD, and KNG1 Genes Potentiate the Risk of Ischemic Stroke via a Genetic Main Effect and Epistatic Interactions in a Chinese Population

BACKGROUND

Ischemic stroke (IS) is a multifactorial disease that displays a strong genetic predisposition. However, the genetic architecture of IS has yet to be fully elucidated. It was hypothesized that epistasis between genes in multiple atherothrombotic pathways may play a vital role in determining the susceptibility to IS. The aim of the present study was to investigate the contributions of the hypothesized genetic factors to IS and the interactions between these genetic factors in a Chinese population.

METHODS

In this study, 351 cases with IS and 417 control subjects from a Chinese population were genotyped for single-nucleotide polymorphisms (SNPs) in 12 genes hypothesized to be involved in atherosclerosis, coagulation, and related pathways. We examined SNP main effects and epistatic interactions between these polymorphic loci.

RESULTS

rs710446 of the KNG1 gene was associated with IS susceptibility based on an additive genetic model (rs710446: P = .012; odds ratio [OR], 1.247; 95% confidence interval [CI], 1.050-1.481) after adjusting for covariates. Furthermore, an epistatic interaction between the ALOX5AP, THBD, and KNG1 gene was also identified in association with stroke susceptibility (P < .001 after 1000 permutations). Based on the chi-squared test, the OR of the high-risk combination of the three-locus model increased the risk of IS by 2.53-fold (95% CI, 1.60-4.01; P < .0001).

CONCLUSIONS

Our findings support the association of the epistatic interactions of ALOX5AP, THBD, and KNG1 and present novel evidence for the main effect of KNG1 gene on IS susceptibility, suggesting a modulation of stroke risk by a genetic main effect and gene-gene interactions.