Aldehyde dehydrogenase 2 gene is a risk factor for myocardial infarction in Japanese men

ALDH2 deficiency augments atherosclerosis through the USP14-cGAS-dependent polarization of proinflammatory macrophages

The aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism commonly exists in the East Asian populations and is associated with high risks of cardiovascular disease (CVD). However, the cellular and molecular mechanisms that underlie the ALDH2 rs671 mutant-linked high CVD remain elusive. Here, we show that macrophages derived from human ALDH2 rs671 carriers and ALDH2 knockout mice exhibited an enhanced pro-inflammatory macrophage phenotype and an impaired anti-inflammatory macrophage phenotype. Transplanting bone marrow from ALDH2-/-ApoE-/- to ApoE-/- mice significantly increased atherosclerotic plaque growth and pro-inflammatory macrophage polarization in vivo. Mechanistically, ALDH2 inhibited activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in macrophages. Pharmacological inhibition of cGAS by RU.521 completely neutralized ALDH2-deficiency-induced macrophage polarization. In-depth mechanistic investigation showed that ALDH2 accelerated cGAS K48-linked polyubiquitination degradation at lysine 282 in macrophages by reducing the interaction between ubiquitin-specific protease 14 (USP14) and cGAS, mainly through its enzymatic role in mitigating 4-hydroxy-2-nonenal (4-HNE) accumulation. Consistently, USP14 knockdown in bone marrow cells alleviated proinflammatory responses in macrophages and protected against atherosclerosis. Our findings provide new mechanistic insights of ALDH2 deficiency-associated proinflammation and atherosclerosis and new therapeutic and preventive paradigms for treatment of atherosclerosis-associated CVD.

Aldehyde Dehydrogenase 2 rs671 G/A and a/A Genotypes are Associated with the Risk of Acute Myocardial Infarction

Background

Aldehyde dehydrogenase 2 (ALDH2) is a key catalytic enzyme involved in the aldehyde metabolism that plays an important role in the occurrence and development of acute myocardial infarction (AMI). However, the relationship of ALDH2 polymorphism and susceptibility to AMI may differ among different regions and populations, and it has not yet been reported in Hakka population. The purpose of the present study was to investigate it in this population.

Methods

Four hundred and nineteen AMI patients and 636 individuals without AMI were included in the present study. The ALDH2 rs671 polymorphism was genotyped using polymerase chain reaction (PCR)-microarray. Differences in ALDH2 rs671 genotypes and alleles between patients and controls were compared, and the relationship between ALDH2 rs671 genotypes and AMI risk was analyzed.

Results

Patients with AMI had a lower frequency of ALDH2 rs671 G/G genotype (43.2% vs 52.7%, p=0.003), and a higher G/A genotype (45.6% vs 38.5%, p=0.025) than controls. And AMI patients had a lower frequency of ALDH2 rs671 G allele (66.0% vs 71.9%), and a higher A allele (34.0% vs 28.1%) (p=0.004) than controls. Logistic regression analysis showed that overweight (body mass index (BMI)≥24.0 kg/m2 vs BMI 18.5-23.9 kg/m2: odds ratio (OR) 2.046, 95% confidence interval (CI): 1.520-2.754, p<0.001), history of hypertension (yes vs no: OR 3.464, 95% CI: 2.515-4.770, p<0.001), ALDH2 rs671 G/A genotype (G/A vs G/G: OR 1.476, 95% CI: 1.102-1.976, p=0.009), and A/A genotype (A/A vs G/G: OR 1.656, 95% CI: 1.027-2.668, p=0.038) maybe the independent risk factors for AMI.

Conclusion

Overweight (BMI≥24.0 kg/m2), a history of hypertension, and ALDH2 rs671 G/A or A/A genotypes increased the risk of developing AMI in Hakka population.

ALDH2 polymorphism and myocardial infarction: From alcohol metabolism to redox regulation

Acute myocardial infarction (AMI) remains a leading cause of death worldwide. Increased formation of reactive oxygen species (ROS) during the early reperfusion phase is thought to trigger lipid peroxidation and disrupt redox homeostasis, leading to myocardial injury. Whilst the mitochondrial enzyme aldehyde dehydrogenase 2 (ALDH2) is chiefly recognised for its central role in ethanol metabolism, substantial experimental evidence suggests an additional cardioprotective role for ALDH2 independent of alcohol intake, which mitigates myocardial injury by detoxifying breakdown products of lipid peroxidation including the reactive aldehydes, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Epidemiological evidence suggests that an ALDH2 mutant variant with reduced activity that is highly prevalent in the East Asian population increases AMI risk. Additional studies have uncovered a strong association between coronary heart disease and this ALDH2 mutant variant. It appears this enzyme polymorphism (in particular, in ALDH2*2/2 carriers) has the potential to have wide-ranging effects on thiol reactivity, redox tone and therefore numerous redox-related signaling processes, resilience of the heart to cope with lifestyle-related and environmental stressors, and the ability of the whole body to achieve redox balance. In this review, we summarize the journey of ALDH2 from a mitochondrial reductase linked to alcohol metabolism, via pre-clinical studies aimed at stimulating ALDH2 activity to reduce myocardial injury to clinical evidence for its protective role in the heart.

The ALDH2 gene rs671 polymorphism is associated with cardiometabolic risk factors in East Asian population: an updated meta-analysis

Introduction

Acetaldehyde dehydrogenase 2 (ALDH2) had reported as a prominent role in the development of cardiometabolic diseases among Asians. Our study aims to investigate the relationship between ALDH2 polymorphism and cardiometabolic risk factors in East Asian population.

Method

We searched databases of PubMed, Web of Science, and Embase updated to Oct 30th, 2023. We extracted data of BMI, Hypertension, SBP, DBP, T2DM, FBG, PPG, HbA1c, TG, TC, LDL-C and HDL-C.

Result

In total, 46 studies were finally included in our meta-analysis, containing, 54068 GG and, 36820 GA/AA participants. All outcomes related to blood pressure revealed significant results (hypertension OR=0.83 [0.80, 0.86]; SBP MD=-1.48 [-1.82, -1.14]; DBP MD=-1.09 [-1.58, -0.61]). FBG showed a significant difference (MD=-0.10 [-0.13, -0.07]), and the lipid resulted significantly in some outcomes (TG MD=-0.07 [-0.09, -0.04]; LDL-C MD=-0.04 [-0.05, -0.02]). As for subgroups analysis, we found that in populations without severe cardiac-cerebral vascular diseases (CCVDs), GG demonstrated a significantly higher incidence of T2DM (T2DM OR=0.88 [0.79, 0.97]), while the trend was totally opposite in population with severe CCVDs (T2DM OR=1.29 [1.00, 1.66]) with significant subgroup differences.

Conclusion

Our updated meta-analysis demonstrated that ALDH2 rs671 GG populations had significantly higher levels of BMI, blood pressure, FBG, TG, LDL-C and higher risk of hypertension than GA/AA populations. Besides, to the best of our knowledge, we first report GG had a higher risk of T2DM in population without severe CCVDs, and GA/AA had a higher risk of T2DM in population with severe CCVDs.Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023389242.

Aldehyde Dehydrogenase 2 (ALDH2) Deficiency, Obesity, and Atrial Fibrillation Susceptibility: Unraveling the Connection

Atrial fibrillation (AF), characterized by structural remodeling involving atrial myocardial degradation and fibrosis, is linked with obesity and transforming growth factor beta 1 (TGF-β1). Aldehyde dehydrogenase 2 (ALDH2) deficiency, highly prevalent in East Asian people, is paradoxically associated with a lower AF risk. This study investigated the impact of ALDH2 deficiency on diet-induced obesity and AF vulnerability in mice, exploring potential compensatory upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme-oxygenase 1 (HO-1). Wild-type (WT) and ALDH2*2 knock-in (KI) mice were administered a high-fat diet (HFD) for 16 weeks. Despite heightened levels of reactive oxygen species (ROS) post HFD, the ALDH2*2 KI mice did not exhibit a greater propensity for AF compared to the WT controls. The ALDH2*2 KI mice showed equivalent myofibril degradation in cardiomyocytes compared to WT after chronic HFD consumption, indicating suppressed ALDH2 production in the WT mice. Atrial fibrosis did not proportionally increase with TGF-β1 expression in ALDH2*2 KI mice, suggesting compensatory upregulation of the Nrf2 and HO-1 pathway, attenuating fibrosis. In summary, ALDH2 deficiency did not heighten AF susceptibility in obesity, highlighting Nrf2/HO-1 pathway activation as an adaptive mechanism. Despite limitations, these findings reveal a complex molecular interplay, providing insights into the paradoxical AF-ALDH2 relationship in the setting of obesity.

The role of aldehyde dehydrogenase 2 in cardiovascular disease

Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme involved in the detoxification of alcohol-derived acetaldehyde and endogenous aldehydes. The inactivating ALDH2 rs671 polymorphism, present in up to 8% of the global population and in up to 50% of the East Asian population, is associated with increased risk of cardiovascular conditions such as coronary artery disease, alcohol-induced cardiac dysfunction, pulmonary arterial hypertension, heart failure and drug-induced cardiotoxicity. Although numerous studies have attributed an accumulation of aldehydes (secondary to alcohol consumption, ischaemia or elevated oxidative stress) to an increased risk of cardiovascular disease (CVD), this accumulation alone does not explain the emerging protective role of ALDH2 rs671 against ageing-related cardiac dysfunction and the development of aortic aneurysm or dissection. ALDH2 can also modulate risk factors associated with atherosclerosis, such as cholesterol biosynthesis and HDL biogenesis in hepatocytes and foam cell formation and efferocytosis in macrophages, via non-enzymatic pathways. In this Review, we summarize the basic biology and the clinical relevance of the enzymatic and non-enzymatic, tissue-specific roles of ALDH2 in CVD, and discuss the future directions in the research and development of therapeutic strategies targeting ALDH2. A thorough understanding of the complex roles of ALDH2 in CVD will improve the diagnosis, management and prognosis of patients with CVD who harbour the ALDH2 rs671 polymorphism.

BIGKnock: fine-mapping gene-based associations via knockoff analysis of biobank-scale data

We propose BIGKnock (BIobank-scale Gene-based association test via Knockoffs), a computationally efficient gene-based testing approach for biobank-scale data, that leverages long-range chromatin interaction data, and performs conditional genome-wide testing via knockoffs. BIGKnock can prioritize causal genes over proxy associations at a locus. We apply BIGKnock to the UK Biobank data with 405,296 participants for multiple binary and quantitative traits, and show that relative to conventional gene-based tests, BIGKnock produces smaller sets of significant genes that contain the causal gene(s) with high probability. We further illustrate its ability to pinpoint potential causal genes at [Formula: see text] of the associated loci.

Effects of intracardiac delivery of aldehyde dehydrogenase 2 gene in myocardial salvage

Intrinsic activity of aldehyde dehydrogenase (ALDH)2, a cardiac mitochondrial enzyme, is vital in detoxifying 4-hydroxy-2-nonenal (4HNE) like cellular reactive carbonyl species (RCS) and thereby conferring cardiac protection against pathological stress. It was also known that a single point mutation (E487K) in ALDH2 (prevalent in East Asians) known as ALDH2*2 reduces its activity intrinsically and was associated with increased cardiovascular diseases. We and others have shown that ALDH2 activity is reduced in several pathologies in WT animals as well. Thus, exogenous augmentation of ALDH2 activity is a good strategy to protect the myocardium from pathologies. In this study, we will test the efficacy of intracardiac injections of the ALDH2 gene in mice. We injected both wild type (WT) and ALDH2*2 knock-in mutant mice with ALDH2 constructs, AAv9-cTNT-hALDH2-HA tag-P2A-eGFP or their control constructs, AAv9-cTNT-eGFP. We found that intracardiac ALDH2 gene transfer increased myocardial levels of ALDH2 compared to GFP alone after 1 and 3 weeks. When we subjected the hearts of these mice to 30 min global ischemia and 90 min reperfusion (I-R) using the Langendorff perfusion system, we found reduced infarct size in the hearts of mice with ALDH2 gene vs GFP alone. A single time injection has shown increased myocardial ALDH2 activity for at least 3 weeks and reduced myocardial 4HNE adducts and infarct size along with increased contractile function of the hearts while subjected to I-R. Thus, ALDH2 overexpression protected the myocardium from I-R injury by reducing 4HNE protein adducts implicating increased 4HNE detoxification by ALDH2. In conclusion, intracardiac ALDH2 gene transfer is an effective strategy to protect the myocardium from pathological insults.

Effects of the genetic variants of alcohol-metabolizing enzymes on lipid levels in Asian populations: a systematic review and meta-analysis

CONTEXT

Emerging evidence indicates that variants of alcohol-metabolizing enzymes may influence lipid metabolism.

OBJECTIVE

This study aimed to investigate whether the rs671 and rs1229984 variants affect lipid levels in East Asian individuals.

DATA SOURCES

PubMed, Foreign Medical Journal Service, Embase, Cochrane Library, Scopus, MEDLINE, Web of Science, Web of Knowledge, Wanfang, and Chinese Biomedical Literature databases were searched until December 31, 2021.

DATA EXTRACTION

Meta-analyses of studies that examined the effects of alcohol-metabolizing enzyme variants on lipid levels, as well as the interaction with alcohol intake, were selected. Data extraction was conducted independently by two investigators and confirmed by the third.

DATA ANALYSIS

In total, 86 studies (179 640 individuals) were analyzed. The A allele of rs671 (a functional variant in the ALDH2 gene) was linked to higher levels of low-density lipoprotein cholesterol (LDL-C) and lower levels of triglycerides and high-density lipoprotein cholesterol. In contrast, the A allele of the rs1229984 (a functional variant in the ADH2 gene) was associated only with lower levels of LDL-C. The effects of rs671 and rs1229984 on lipid levels were much stronger in Japanese than in Chinese individuals and in males than in females. Regression analysis indicated that the effects of rs671 on lipid levels were independent of alcohol intake in an integrated East Asian population (ie, Japanese, Chinese, and Korean individuals). Intriguingly, alcohol intake had a statistical influence on lipid levels when the sample analyzed was restricted to Japanese individuals or to males.

CONCLUSIONS

The rs671 and rs1229984 variants of alcohol-metabolizing enzymes have significant effects on lipid levels and may serve as genetic markers for lipid dyslipidemia in East Asian populations. Circulating lipid levels in Japanese individuals and in males were modulated by the interaction between rs671 and alcohol intake.

Bioinformatics analysis to screen for genes related to myocardial infarction

Myocardial infarction (MI) is an acute and persistent myocardial ischemia caused by coronary artery disease. This study screened potential genes related to MI. Three gene expression datasets related to MI were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were screened using the MetaDE package. Afterward, the modules and genes closely related to MI were screened and a gene co-expression network was constructed. A support vector machine (SVM) classification model was then constructed based on the GSE61145 dataset using the e1071 package in R. A total of 98 DEGs were identified in the MI samples. Next, three modules associated with MI were screened and an SVM classification model involving seven genes was constructed. Among them, BCL6, CEACAM8, and CUGBP2 showed co-interactions in the gene co-expression network. Therefore, ACOX1, BCL6, CEACAM8, and CUGBP2, in addition to GPX7, might be feature genes related to MI.

Alcohol consumption and subclinical and clinical coronary heart disease: A Mendelian randomization analysis

AIMS

The potential effect of alcohol consumption on coronary heart disease (CHD) remains unclear. We used the variant rs671 in the aldehyde dehydrogenase 2 gene (ALDH2) as an instrument to investigate the causal role of alcohol intake in subclinical and clinical CHD.

METHODS

We conducted two Mendelian randomization studies: a cross-sectional study of coronary artery calcification (CAC) on computed tomography of 1029 healthy men (mean age, 63.8 years) and a case-control study of 421 men with CHD (acute coronary syndrome [ACS] or stable angina pectoris) who underwent coronary revascularization and 842 age-matched male controls.

RESULTS

In the CAC study, medians (25%tiles, 75%tiles) of alcohol consumption by ALDH2-rs671 *2 homozygotes (n = 86 [8.4%]), *1*2 heterozygotes (n = 397 [38.5%]), and *1 homozygotes (n = 546 [53.1%]) were 0.0 (0.0, 0.0), 28.0 (0.0, 129.0), and 224.0 (84.0, 350.0) g/week, respectively. In age-adjusted Poisson regression with robust error variance, compared with *2 homozygotes, relative risks for prevalent CAC score >0, ≥100, and ≥300 in *1 homozygotes were 1.29 (95% confidence interval, 1.06-1.57), 1.76 (1.05-2.96), and 1.81 (0.80-4.09), respectively. In age-adjusted ordinal logistic regression for CAC distributions, we observed higher odds among *1 homozygotes (odds ratio, 2.19 [1.39-3.46]) and even among *1*2 heterozygotes (1.77 [1.11-2.82]) compared with *2 homozygotes. In the case-control study, conditional logistic regression revealed lower prevalence of *1 homozygotes among men with CHD (odds ratio, 0.54 [0.35-0.82]), especially ACS (0.46 [0.27-0.77]), than controls.

CONCLUSION

Our findings indicate a positive association of alcohol consumption with CAC burden but an inverse association with clinical CHD, especially ACS.

Macrophage ALDH2 (Aldehyde Dehydrogenase 2) Stabilizing Rac2 Is Required for Efferocytosis Internalization and Reduction of Atherosclerosis Development

BACKGROUND

Clinical studies show that the most common single-point mutation in humans, ALDH2 (aldehyde dehydrogenase 2) rs671 mutation, is a risk factor for the development and poor prognosis of atherosclerotic cardiovascular diseases, but the underlying mechanism remains unclear. Apoptotic cells are phagocytosed and eliminated by macrophage efferocytosis during atherosclerosis, and enhancement of arterial macrophage efferocytosis reduces atherosclerosis development.

METHODS

Plaque areas, necrotic core size, apoptosis, and efferocytosis in aortic lesions were investigated in APOE-/- mice with bone marrow transplanted from APOE-/-ALDH2-/- and APOE-/- mice. RNA-seq, proteomics, and immunoprecipitation experiments were used to screen and validate signaling pathways affected by ALDH2. Efferocytosis and protein levels were verified in human macrophages from wild-type and rs671 mutation populations.

RESULTS

We found that transplanting bone marrow from APOE-/-ALDH2-/- to APOE-/- mice significantly increased atherosclerosis plaques compared with transplanting bone marrow from APOE-/- to APOE-/- mice. In addition to defective efferocytosis in plaques of APOE-/- mice bone marrow transplanted from APOE-/-ALDH2-/- mice in vivo, macrophages from ALDH2-/- mice also showed significantly impaired efferocytotic activity in vitro. Subsequent RNA-seq, proteomics, and immunoprecipitation experiments showed that wild-type ALDH2 directly interacted with Rac2 and attenuated its degradation due to decreasing the K48-linked polyubiquitination of lysine 123 in Rac2, whereas the rs671 mutant markedly destabilized Rac2. Furthermore, Rac2 played a more crucial role than other Rho GTPases in the internalization process in which Rac2 was up-regulated, activated, and clustered into dots. Overexpression of wild-type ALDH2 in ALDH2-/- macrophages, rather than the rs671 mutant, rescued Rac2 degradation and defective efferocytosis. More importantly, ALDH2 rs671 in human macrophages dampened the apoptotic cells induced upregulation of Rac2 and subsequent efferocytosis.

CONCLUSIONS

Our study has uncovered a pivotal role of the ALDH2-Rac2 axis in mediating efferocytosis during atherosclerosis, highlighting a potential therapeutic strategy in cardiovascular diseases, especially for ALDH2 rs671 mutation carriers.

ALDH2, ADCY3 and BCMO1 polymorphisms and lifestyle-induced traits are jointly associated with CAD risk in Chinese Han people

BACKGROUNDS

To investigate associations of genetic and environmental factors with coronary artery disease (CAD), we collected medical reports, lifestyle details, and blood samples of 2113 individuals, and then used the polymerase chain reaction (PCR)-ligase detection reaction (LDR) to genotype the targeted 102 SNPs.

METHODS

We adopted elastic net algorithm to build an association model that considered simultaneously genetic and lifestyle/clinical factors associated with CAD in Chinese Han population.

RESULTS

In this study, we developed an all covariates-based model to explain the risk of CAD, which incorporated 8 lifestyle/clinical factors and a gene-score variable calculated from 3 significant SNPs (rs671, rs6751537 and rs11641677), attaining an area under the curve (AUC) value of 0.71. It was found that, in terms of genetic variants, the AA genotype of rs671 in the additive (adjusted odds ratio (OR) = 2.51, p = 0.008) and recessive (adjusted OR = 2.12, p = 0.021) models, the GG genotype of rs6751537 in the additive (adjusted OR = 3.36, p = 0.001) and recessive (adjusted OR = 3.47, p = 0.001) models were associated with increased risk of CAD, while GG genotype of rs11641677 in additive model (adjusted OR = 0.39, p = 0.044) was associated with decreased risk of CAD. In terms of lifestyle/clinical factors, the history of hypertension (unadjusted OR = 2.37, p < 0.001) and dyslipidemia (unadjusted OR = 1.82, p = 0.007), age (unadjusted OR = 1.07, p < 0.001) and waist circumference (unadjusted OR = 1.02, p = 0.05) would significantly increase the risk of CAD, while height (unadjusted OR = 0.97, p = 0.006) and regular intake of chicken (unadjusted OR = 0.78, p = 0.008) reduced the risk of CAD. A significantinteraction was foundbetween rs671 and dyslipidemia (the relative excess risk due to interaction (RERI) = 3.36, p = 0.05).

CONCLUSION

In this study, we constructed an association model and identified a set of SNPs and lifestyle/clinical risk factors of CAD in Chinese Han population. By considering both genetic and non-genetic risk factors, the built model may provide implications for CAD pathogenesis and clues for screening tool development in Chinese Han population.

Diabetic Aldehyde Dehydrogenase 2 Mutant (ALDH2*2) Mice Are More Susceptible to Cardiac Ischemic-Reperfusion Injury Due to 4-Hydroxy-2-Nonenal Induced Coronary Endothelial Cell Damage

Background

Aldehyde dehydrogenase‐2 (ALDH2), a mitochondrial enzyme, detoxifies reactive aldehydes such as 4‐hydroxy‐2‐nonenal (4HNE). A highly prevalent E487K mutation in ALDH2 (ALDH2*2) in East Asian people with intrinsic low ALDH2 activity is implicated in diabetic complications. 4HNE‐induced cardiomyocyte dysfunction was studied in diabetic cardiac damage; however, coronary endothelial cell (CEC) injury in myocardial ischemia‐reperfusion injury (IRI) in diabetic mice has not been studied. Therefore, we hypothesize that the lack of ALDH2 activity exacerbates 4HNE‐induced CEC dysfunction which leads to cardiac damage in ALDH2*2 mutant diabetic mice subjected to myocardial IRI.

Methods and Results

Three weeks after diabetes mellitus (DM) induction, hearts were subjected to IRI either in vivo via left anterior descending artery occlusion and release or ex vivo IRI by using the Langendorff system. The cardiac performance was assessed by conscious echocardiography in mice or by inserting a balloon catheter in the left ventricle in the ex vivo model. Just 3 weeks of DM led to an increase in cardiac 4HNE protein adducts and, cardiac dysfunction, and a decrease in the number of CECs along with reduced myocardial ALDH2 activity in ALDH2*2 mutant diabetic mice compared with their wild‐type counterparts. Systemic pretreatment with Alda‐1 (10 mg/kg per day), an activator of both ALDH2 and ALDH2*2, led to a reduction in myocardial infarct size and dysfunction, and coronary perfusion pressure upon cardiac IRI by increasing CEC population and coronary arteriole opening.

Conclusions

Low ALDH2 activity exacerbates 4HNE‐mediated CEC injury and thereby cardiac dysfunction in diabetic mouse hearts subjected to IRI, which can be reversed by ALDH2 activation.

Interaction between ALDH2 rs671 and life habits affects the risk of hypertension in Koreans: A STROBE observational study

Aldehyde dehydrogenase-2 (ALDH2) is associated with the risk of hypertension, and the effects of lifestyle factors on blood pressure vary according to genotype. Among the Han Chinese, the risk of hypertension is lower in the group with the rs671 A allele than in the group with the G allele, and there is a significant association between the frequency of fried food consumption and hypertension. However, the A allele significantly increases the risk of hypertension with increased fried food intake. This study aimed to investigate the effect of the relationship between ALDH2 polymorphism and complex lifestyle habits (fried food consumption and exercise) on hypertension.rs671 polymorphisms of ALDH2 were examined using Korean genome and epidemiology data from 8157 hypertensive cases and 9550 controls. Further, we investigated whether the A allele is protective against hypertension in Koreans and explored the effect of the combination of fried food intake and exercise habits on hypertension by genotype.The genotype frequencies of rs671, which is specific to East Asia, were 2.51% AA, 26.66% GA, and 70.83% GG in the Korean population. The group with inactive aldehyde dehydrogenase-2 had a low odds ratio [OR = 0.75 (95% CI:0.69-0.80), P = 4.35 × 10-14] of hypertension, and low metabolism of acetaldehyde. Subjects carrying the A allele exhibited an increased risk of hypertension with increased fried food intake without exercise [OR = 2.256 (95% CI:1.094-4.654), P = .028].ALDH2 polymorphism and complex lifestyle habits (fried food consumption and exercise) are associated with the risk of hypertension. Further, the A allele is associated with a low risk of hypertension, but it increases the risk of hypertension as fried food intake without exercise increases.

East Asian variant aldehyde dehydrogenase type 2 genotype exacerbates ischemia/reperfusion injury with ST-elevation myocardial infarction in men: possible sex differences

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) detoxifies toxic aldehydes generated during ischemia/reperfusion (I/R) injury in ST-elevation myocardial infarction (STEMI). The deficient variant ALDH2 genotype (ALDH2*2) is prevalent among East Asians. Whether ALDH2*2 exacerbates I/R injury of in patients with STEMI is not known. The study subjects comprised 218 Japanese patients with STEMI (158 men and 60 women, mean age 67.9 ± 11.9) who underwent successful percutaneous coronary intervention. Of these, 120 (55.0%) were the carriers of variant ALDH2*2 and 98 (45.0%) those of wild ALDH2*1/*1 on genotyping. There were no differences in clinical characteristics between the ALDH2*2 and ALDH2*1/*1 group except lower alcohol habit (14.2% vs 46.3%, P < 0.001) in the ALDH2*2 group. The peak plasma levels of creatine phosphokinase myocardial binding (CKMB), a marker of myocardial injury, however, were significantly higher in the patients with ALDH2*2 than in those with ALDH2*1/*1 [a median 275.0 (175.8-407.5) vs 177.5 (126.9-344.3) U/L, P = 0.001] among men but not among women (P = 0.811). There was a significant interaction between men (male sex) and ALDH2*2 for I/R injury (χ2 = 4.425, P = 0.040). The variant ALDH2*2 was associated with more severe I/R injury than the wild ALDH2*1/*1 in STEMI patients in men with possible sex differences.

Association of Aldehyde Dehydrogenase 2 Gene Polymorphism with Myocardial Infarction

Objective

This study explored the correlation between myocardial infarction (MI) and the Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene in the Qingyuan area.

Methods

The Glu504Lys polymorphism of the ALDH2 gene was analyzed using the polymerase chain reaction and deoxyribonucleic acid microarray analysis for 468 patients diagnosed with MI for the first time and 132 healthy subjects.

Results

There was a significant difference in the distribution of the ALDH2 genotype between the MI group and the control group (P = 0.0492), but there was no significant difference in allele frequency between the two groups (P = 0.1363). The clinical data showed that there were statistically significant differences (P < 0.05) in the two groups’ gender and age distributions, rates of diabetes and hypertension, levels of alcohol and tobacco use, serological levels of heart markers, blood lipids and glucose. The subgroup analysis of ALDH2 genotypes found that alcohol consumption, high levels of myoglobin, and low levels of high-density lipoprotein cholesterol were significantly associated with a higher incidence of MI (P < 0.05). After adjusting for gender, hypertension, diabetes, and other related influencing factors, logistic regression analysis showed that the ALDH2 genotype GA/AA was an independent risk factor for MI (P < 0.05, OR = 1.479, 95% CI = 1.003–2.179).

Conclusion

The presence of risk alleles with the genetic effect (ALDH2 genotype GA/AA) is an independent risk factor for MI.

Alcohol Consumption, Cardiovascular-Related Conditions, and ALDH2*2 Ethnic Group Prevalence in Asian Americans

BACKGROUND

Little is known about the relationships between alcohol consumption and cardiovascular disease (CVD) and related chronic conditions in Asian Americans and how such risk relationships vary among their subgroups. We examine these relationships in Asian Americans and their moderation by ethnic prevalence of a variant the aldehyde dehydrogenase gene: ALDH2*2.

METHODS

Multiple logistic regression modeling was performed using a nationally representative sample of Asian-American adults aged 30 to 70 (n = 1,720) from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) Waves 2 (2004 to 2005) and 3 (2012 to 2013). Outcomes considered were diabetes, hypertension, high cholesterol, CVD, any of the 3 conditions (i.e., diabetes, high cholesterol, and CVD) documented to have a J-shaped relationship with drinking (CVDRC3), and any of the CVD-related conditions (ANYCVD). Demographic and socioeconomic characteristics, health insurance coverage, and other lifestyle risk factors (smoking and obesity/overweight) were adjusted. Analyses were stratified by gender.

RESULTS

Alcohol consumption level was positively associated only with hypertension in Asian males, with consuming 7 to 14 drinks per week associated with more than double the risk of lifetime abstinence. For females, alcohol consumption had a dose-response relationship with high cholesterol and CVDRC3. Membership in the higher ALDH2*2 ethnic group overall was associated with lower risk of CVD-related conditions. However, compared to abstainers in lower ALDH2*2 group, females in the higher ALDH2*2 group who consumed more than 7 drinks per week had a higher risk of diabetes, hypertension, CVDRC3, and ANYCVD.

CONCLUSIONS

Asian Americans may have increased risk of CVD-related conditions at relatively low alcohol consumption levels. Among Asian-American females, in particular, any amount of drinking may increase risk for high cholesterol or any of the CVD-related conditions previously documented to have a curvilinear relationship with drinking. These risks may be particularly elevated for those in ethnic groups with a high prevalence of ALDH2*2.

Precision Medicine Considerations for the Management of Heart Disease and Stroke in East Asians

Heart disease is the leading cause of death in Asian Americans. Importantly, people of East Asian descent are more likely to carry a loss-of-function point mutation in aldehyde dehydrogenase 2 (ALDH2), ALDH2*2, which reduces ALDH2 enzymatic activity by at least 40% relative to wild type ALDH2. Given the role of ALDH2 in removing toxic aldehydes from the cell, ALDH2 is intimately involved in the cardioprotective mechanisms of ischemic preconditioning and the pathophysiology of ischemia reperfusion injury. The ALDH2*2 variant is associated with an increased incidence of coronary artery disease, myocardial infarction, and stroke. Furthermore, this variant is associated with insensitivity to nitroglycerin, which is commonly prescribed in patients with cardiovascular disease. In this review, we discuss the genetic susceptibility and pathophysiology associated with the ALDH2*2 variant in regards to cardiovascular disease. We also present the considerations for the management of heart disease and stroke specific to East Asians carrying the ALDH2*2 genetic variant.

Aldehyde Dehydrogenase 2 Ameliorates Chronic Alcohol Consumption-Induced Atrial Fibrillation through Detoxification of 4-HNE

Aldehyde dehydrogenase 2 (ALDH2) is an enzyme that detoxifies reactive oxygen species (ROS)-generated aldehyde adducts such as 4-hydroxy-trans-2-nonenal (4-HNE). Previous meta-analyses have shown an increase in the risk of atrial fibrillation (AF) in patients with chronic alcohol consumption. ALDH2*2, a common dysfunctional polymorphism in the ALDH2 gene, has been linked to an increased risk of cancer and heart disease. We tested the effect of ALDH2 deficiency on alcohol-induced AF in a murine model of chronic-binge ethanol feeding, with ALDH2*2 knock-in (KI) mice generated by a CRISPR/CAS9 system. In addition, right atrial appendages were obtained from eight patients with AF undergoing open heart surgery. The results showed that burst atrial pacing induced a greater susceptibility to AF in ALDH2*2 KI mice exposed to chronic ethanol intoxication than in wild-type mice, resulting from a higher degree of 4-HNE accumulation and collagen deposition in their atria. Alda-1 attenuated transforming growth factor beta 1 (TGF-β1) expression and collagen deposition in the atria and reduced AF inducibility. Patients with AF and the ALDH2*2 allele exhibited greater oxidative stress and substrate remodeling in their atria than non-carriers. In conclusion, ALDH2 deficiency may increase the risk of chronic alcohol and tachypacing-induced AF through the accumulation of 4-HNE and increased ROS production.

Acetaldehyde Dehydrogenase 2 rs671 Polymorphism Affects Hypertension Susceptibility and Lipid Profiles in a Chinese Population

Previous studies revealed that the rs671 polymorphism in the acetaldehyde dehydrogenase 2 (ALDH2) genes is correlated with alcohol consumption in Japanese population. The ALDH2 gene variants and drinking are associated with hypertension and dyslipidemia. However, it remains unclear whether there might be potent relationships among ALDH2 rs671 polymorphism, alcohol consumption, hypertension, and dyslipidemia in Shandong population. A total of 467 male volunteers from Shandong area were enrolled in this study. The ALDH2 rs671 polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism. The concentrations of total cholesterol (TC), triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) in serum were measured using commercial kits. SPSS 23.0 was used for statistical analysis. The significance of differences between subgroups was determined using chi-square test, and multiple comparisons were performed with the least-significant difference method. The ALDH2 variant frequencies were 80.5% with GG, 17.1% with GA, and 2.4% with AA. The ALDH2 genotypes had significant correlations with alcohol consumption (p = 0.001), whereas the GA genotype was associated with a decreased risk of alcohol consumption (odds ratio = 0.27; 95% confidence interval = 0.130-0.539; p = 0.001). The ALDH2 genotypes frequencies and drinking habits were significantly different between hypertension and healthy individuals (p = 0.034; p = 0.044). The ALDH2 GG genotype individuals have high average lipids levels, and the proportion of TC disorder among GG individuals was higher than that of GA individuals (p = 0.006). Individuals who had drinking habits have a high average lipids levels; especially average TC levels (p = 0.048), and had high proportions of dyslipidemia (TC and HDL; p = 0.016 and p = 0.033, respectively). The frequencies of ALDH2 variants were evaluated according to the Hardy-Weinberg equilibrium among enrolled population. Our study suggested that the individuals with ALDH2 rs671 GA genotype were less prone to developing a drinking habit in Shandong population. The ALDH2 genotypes and drinking habit were associated with hypertension and lipid profiles especially TC profile in Shandong province. The ALDH2 rs671 genotypes indicated that the gene-related drinking habit and gene variant altogether may affect hypertension and dyslipidemia.

Appropriate dose of ethanol exerts anti-senescence and anti-atherosclerosis protective effects by activating ALDH2

Moderate alcohol consumption has been shown to reduce atherosclerosis-associated diseases. As shown in our earlier works, ethanol has a dose-dependent protective effects against endothelial cellular senescence by activating aldehyde dehydrogenase 2 (ALDH2) in vitro. However, whether ethanol administration possesses anti-atherosclerosis properties and whether ALDH2 is involved in the underlying mechanisms are unknown. In the present study, we revealed that the appropriate dose of ethanol reduced atherosclerotic plaque formation, and upregulated ALDH2 expression and activity in ApoE^-/- mice. ALDH2 deficiency blocked the protection of ethanol against atherosclerotic plaque formation by inhibiting endothelium senescence. In contrast, Alda-1, which is a specific enzymatic agonist of ALDH2, enhanced the anti-senescence and anti-atherosclerosis effects of the appropriate dose of ethanol. Furthermore, following ALDH2 knockdown, resveratrol (an anti-aging compound) recovered the beneficial effects of ethanol against endothelial senescence in vitro. Thus, these results suggest that the appropriate dose of ethanol has protective effects against endothelial senescence and atherosclerosis by activating ALDH2.

Association of East Asian Variant Aldehyde Dehydrogenase 2 Genotype (ALDH2*2*) with Coronary Spasm and Acute Myocardial Infarction

Coronary spasm plays an important role in the pathogenesis of ischemic heart disease, including angina pectoris, acute myocardial infarction (AMI), silent myocardial ischemia, and sudden death. The prevalence of coronary spasm is higher among East Asians probably due to genetic as well as environmental factors. ALDH2 eliminates toxic aldehydes including 4-hydroxy-2-nonenal (4-HNE) derived from lipid peroxidation and acrolein in tobacco smoking as well as ethanol-derived acetaldehyde and thereby protects tissues and cells from oxidative damage. Deficient variant ALDH2*2 genotype is prevalent among East Asians and is a significant risk factor for both coronary spasm and AMI through accumulation of toxic aldehydes, thereby contributing to oxidative stress, endothelial damage, vasoconstriction, and thrombosis. Toxic aldehydes are thus identified as risk factors to be targeted for the treatment of coronary spasm and AMI.

Mitochondrial Aldehyde Dehydrogenase in Myocardial Ischemic and Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion (IR) injury during acute myocardial infarction or open-heart surgery would promote oxidative stress, leading to the accumulation of reactive aldehydes that cause cardiac damage. It has been well demonstrated that aldehyde dehydrogenase (ALDH)-2 is an important cardioprotective enzyme for its central role in the detoxification of reactive aldehydes. ALDH2 activation by small molecule activators is a promising approach for cardioprotection for myocardial IR injury.

Interactions between ALDH2 rs671 polymorphism and lifestyle behaviors on coronary artery disease risk in a Chinese Han population with dyslipidemia: A guide to targeted heart health management

BACKGROUND

Both aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism and lifestyle behaviors are involved in coronary artery disease (CAD), while the interaction between them is currently unknown.

METHODS

A nested case-control study was conducted in 161 patients with CAD and 495 controls in dyslipidemia population in Yinzhou District, Ningbo, Zhejiang Province, China, in August 2013. Anthropometric data and blood samples were collected, demographic characteristics and lifestyle behaviors information were obtained by a face-to-face interview, dietary intake was assessed by a food frequency questionnaire, and genomic DNA was genotyped.

RESULTS

Carriers with increasing number of A alleles had an elevated CAD risk compared with G allele carriers (adjusted OR = 1.483, 95% CI = 1.114-1.974). Carriers of rs671 A/G and A/A genotypes had a higher CAD risk than carriers of G/G genotype (adjusted OR = 1.492, 95% CI = 1.036-2.148). Similarly, individuals with rs671 A/A genotype had a higher CAD risk than individuals with A/G and G/G genotypes (adjusted OR = 2.161, 95% CI = 1.139-4.101). We found a borderline additive interaction between regular fried food intake and A/A and A/G genotypes, and a significantly additive interaction between sedentary/light physical activity and A/A and A/G genotypes.

CONCLUSIONS

Individuals with A/A or A/G genotypes of rs671 have a higher CAD risk, if they lack physical activity and take fried food regularly, than individuals with G/G genotypes. These findings can help to provide a guide to targeted heart health management.

Identification of three novel loci of ALDH2 Gene for Serum Folate levels in a Male Chinese Population by Genome-Wide Association Study

BACKGROUND

Serum folate is important in clinical researches and DNA synthesis and methylation. Some loci and genes that are associated with folate levels had been detected by genome-wide association studies (GWAS), such as rs1801133 in MTHFR and rs1979277 in SHMT1. Nevertheless, only a small part of variants has been clearly identified for serum folate. Hence, we conducted a GWAS to discover new inherited susceptibility and gene-environment interactions on serum folate concentration.

MATERIALS AND METHODS

In a healthy Chinese population of 1999 men, genotyping was performed using Illumina HumanOmni1-Quad BeadChip. Serum folate levels were measured by enzyme-linked immunosorbent assay (ELISA), pathway enrichment analysis and statistical analysis were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID) and Statistic Package for Social Science (SPSS).

RESULTS

We validated that rs1801133 in MTHFR was significantly involved in serum folate (P = 4.21 × 10^-19). Surprisingly, we discovered three novel loci rs3782886, rs671, and rs4646776 of ALDH2 gene were suggestively significantly associated with folate serum folate levels in the male population studied (P = 2.17 × 10^-7, P = 3.60 × 10^-7, P = 3.99 × 10^-7, respectively) after adjusting for population stratification, BMI and age. Men with the AA genotype had significantly higher serum folate levels compared with men with the GG/AG genotype. But we found ALDH2 gene mutation no relation to part of environmental factors on serum folate levels.

CONCLUSION

In a male Chinese population, genome-wide association study discovered that three novel SNPs rs3782886, rs671 and rs4646776 of ALDH2 gene were suggestively significantly associated with serum folate levels.

Type-2 diabetic aldehyde dehydrogenase 2 mutant mice (ALDH 2*2) exhibiting heart failure with preserved ejection fraction phenotype can be determined by exercise stress echocardiography

E487K point mutation of aldehyde dehydrogenase (ALDH) 2 (ALDH2*2) in East Asians intrinsically lowers ALDH2 activity. ALDH2*2 is associated with diabetic cardiomyopathy. Diabetic patients exhibit heart failure of preserved ejection fraction (HFpEF) i.e. while the systolic heart function is preserved in them, they may exhibit diastolic dysfunction, implying a jeopardized myocardial health. Currently, it is challenging to detect cardiac functional deterioration in diabetic mice. Stress echocardiography (echo) in the clinical set-up is a procedure used to measure cardiac reserve and impaired cardiac function in coronary artery diseases. Therefore, we hypothesized that high-fat diet fed type-2 diabetic ALDH2*2 mutant mice exhibit HFpEF which can be measured by cardiac echo stress test methodology. We induced type-2 diabetes in 12-week-old male C57BL/6 and ALDH2*2 mice through a high-fat diet. At the end of 4 months of DM induction, we measured the cardiac function in diabetic and control mice of C57BL/6 and ALDH2*2 genotypes by conscious echo. Subsequently, we imposed exercise stress by allowing the mice to run on the treadmill until exhaustion. Post-stress, we measured their cardiac function again. Only after treadmill running, but not at rest, we found a significant decrease in % fractional shortening and % ejection fraction in ALDH2*2 mice with diabetes compared to C57BL/6 diabetic mice as well as non-diabetic (control) ALDH2*2 mice. The diabetic ALDH2*2 mice also exhibited poor maximal running speed and distance. Our data suggest that high-fat fed diabetic ALDH2*2 mice exhibit HFpEF and treadmill exercise stress echo test is able to determine this HFpEF in the diabetic ALDH2*2 mice.

Biomarkers: Delivering on the expectation of molecularly driven, quantitative health

Biomarkers are the pillars of precision medicine and are delivering on expectations of molecular, quantitative health. These features have made clinical decisions more precise and personalized, but require a high bar for validation. Biomarkers have improved health outcomes in a few areas such as cancer, pharmacogenetics, and safety. Burgeoning big data research infrastructure, the internet of things, and increased patient participation will accelerate discovery in the many areas that have not yet realized the full potential of biomarkers for precision health. Here we review themes of biomarker discovery, current implementations of biomarkers for precision health, and future opportunities and challenges for biomarker discovery. Impact statement Precision medicine evolved because of the understanding that human disease is molecularly driven and is highly variable across patients. This understanding has made biomarkers, a diverse class of biological measurements, more relevant for disease diagnosis, monitoring, and selection of treatment strategy. Biomarkers' impact on precision medicine can be seen in cancer, pharmacogenomics, and safety. The successes in these cases suggest many more applications for biomarkers and a greater impact for precision medicine across the spectrum of human disease. The authors assess the status of biomarker-guided medical practice by analyzing themes for biomarker discovery, reviewing the impact of these markers in the clinic, and highlight future and ongoing challenges for biomarker discovery. This work is timely and relevant, as the molecular, quantitative approach of precision medicine is spreading to many disease indications.

Aldehyde dehydrogenase 2 inhibits inflammatory response and regulates atherosclerotic plaque

Previous studies demonstrated that aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which eliminates ALDH2 activity down to 1%-6%, is a susceptibility gene for coronary disease. Here we investigated the underlying mechanisms based on our prior clinical and experimental studies. Male apoE-/- mice were transfected with GFP, ALDH2-overexpression and ALDH2-RNAi lentivirus respectively (n=20 each) after constrictive collars were placed around the right common carotid arteries. Consequently, ALDH2 gene silencing led to an increased en face plaque area, more unstable plaque with heavier accumulation of lipids, more macrophages, less smooth muscle cells and collagen, which were associated with aggravated inflammation. However, ALDH2 overexpression displayed opposing effects. We also found that ALDH2 activity decreased in atherosclerotic plaques of human and aged apoE-/- mice. Moreover, in vitro experiments with human umbilical vein endothelial cells further illustrated that, inhibition of ALDH2 activity resulted in elevating inflammatory molecules, an increase of nuclear translocation of NF-κB, and enhanced phosphorylation of NF-κB p65, AP-1 c-Jun, Jun-N terminal kinase and p38 MAPK, while ALDH2 activation could trigger contrary effects. These findings suggested that ALDH2 can influence plaque development and vulnerability, and inflammation via MAPK, NF-κB and AP-1 signaling pathways.

Activation of aldehyde dehydrogenase 2 slows down the progression of atherosclerosis via attenuation of ER stress and apoptosis in smooth muscle cells

Aldehyde dehydrogenase 2 (ALDH2) is a key mitochondrial enzyme in the metabolism of aldehydes and may have beneficial cardiovascular effects for conditions such as cardiac hypertrophy, heart failure, myocardial I/R injury, reperfusion, arrhythmia, coronary heart disease and atherosclerosis. In this study we investigated the role of ALDH2 in the progression of atherosclerosis and the underlying mechanisms, with a focus on endoplasmic reticulum (ER) stress. A clinical study was performed in 248 patients with coronary heart disease. The patients were divided into two groups according to their ALDH2 genotype. Baseline clinical characteristics and coronary angiography were recorded, and the coronary artery Gensini score was calculated. Serum levels of 4-hydroxy-2-nonenal (4-HNE) were detected. The clinical study revealed that the mutant ALDH2 genotype was an independent risk factor for coronary heart disease. ALDH2 gene polymorphism is closely associated with atherosclerosis and the severity of coronary artery stenosis. Serum levels of 4-HNE were significantly higher in patients with the mutant ALDH2 genotype than in patients with the wild-type ALDH2 genotype. As an in vitro model of atherosclerosis, rat smooth muscle cells (SMCs) were treated with oxygenized low-density lipoprotein (ox-LDL), which significantly elevated the levels of ER markers glucose-regulated protein78 (GRP78), protein kinase R-like ER kinase (PERK), phosphorylated eukaryotic translation initiation factor α subunit (p-eIF2α), activating transcription factor-4 (ATF-4), CEBP homologous protein (CHOP) and 4-HNE in the cells. All the ox-LDL-induced responses were significantly attenuated in the presence of Alda-1 (an ALDH2 activating agent), and accentuated in the presence of daidzin (an ALDH2 inhibitor). Furthermore, pretreatment with ALDH2 activator Alda-1 significantly decreased ox-LDL-induced apoptosis. Similarly, overexpression of ALDH2 protected SMCs against ox-LDL-induced ER stress as well as ER stress-induced apoptosis. These findings suggest that ALDH2 may slow the progression of atherosclerosis via the attenuation of ER stress and apoptosis in smooth muscle cells.

Could ALDH2*2 be the reason for low incidence and mortality of ovarian cancer for East Asia women?

It is curious that East Asian women have a low incidence and mortality of ovarian cancer in various epidemiological studies. Although different explanations were given, they appear unsubstantial. We notice that East Asian population usually are inactive aldehyde dehydrogenase 2 mutation (ALDH2 ^* 2) carriers, and ALDH plays an important role in the resistance of ovarian cancer to chemotherapeutics, especially in ovarian cancer stem cells. Therefore, we hypothesize whether ALDH2 mutation is the major reason for low incidence and mortality of ovarian cancer in East Asian women, and use the evidence from literature, transcriptomic data with average 5-year overall survival to confirm our hypothesis.

Impact of Alcohol Intake and Drinking Patterns on Mortality From All Causes and Major Causes of Death in a Japanese Population

BACKGROUND

We examined the associations of alcohol consumption and liver holidays with all-cause mortality and with mortality due to cancer, heart disease, cerebrovascular disease, respiratory disease, and injury using a large-scale prospective study in Japan.

METHODS

We followed 102,849 Japanese who were aged between 40 and 69 years at baseline for 18.2 years on average, during which 15,203 deaths were reported. Associations between alcohol intake and mortality risk were assessed using a Cox proportional hazards model, with analysis by the number of liver holidays (in which a person abstains from drinking for several days a week).

RESULTS

A J-shaped association was observed between alcohol intake and total mortality in men (nondrinkers: reference; occasional drinkers: hazard ratio [HR] 0.74; 95% confidence interval [CI], 0.68-0.80; 1-149 g/week: HR 0.76; 95% CI, 0.71-0.81; 150-299 g/week: HR 0.75; 95% CI, 0.70-0.80; 300-449 g/week: HR 0.84; 95% CI, 0.78-0.91; 450-599 g/week: HR 0.92; 95% CI, 0.83-1.01; and ≥600 g/week: HR 1.19; 95% CI, 1.07-1.32) and in women (nondrinkers: reference; occasional: HR 0.75; 95% CI, 0.70-0.82; 1-149 g/week: HR 0.80; 95% CI, 0.73-0.88; 150-299 g/week: HR 0.91; 95% CI, 0.74-1.13; 300-449 g/week: HR 1.04; 95% CI, 0.73-1.48; and ≥450 g/week: HR 1.59; 95% CI, 1.07-2.38). In current drinkers, alcohol consumption was associated with a linear, positive increase in mortality risk from all causes, cancer, and cerebrovascular disease in both men and women, but not heart disease in men. Taking of liver holidays was associated with a lower risk of cancer and cerebrovascular disease mortality in men.

CONCLUSIONS

Alcohol intake showed J-shaped associations with the risk of total mortality and three leading causes of death. However, heavy drinking increases the risk of mortality, which highlights the necessity of drinking in moderation coupled with liver holidays.

Human heart disease: lessons from human pluripotent stem cell-derived cardiomyocytes

Technical advances in generating and phenotyping cardiomyocytes from human pluripotent stem cells (hPSC-CMs) are now driving their wider acceptance as in vitro models to understand human heart disease and discover therapeutic targets that may lead to new compounds for clinical use. Current literature clearly shows that hPSC-CMs recapitulate many molecular, cellular, and functional aspects of human heart pathophysiology and their responses to cardioactive drugs. Here, we provide a comprehensive overview of hPSC-CMs models that have been described to date and highlight their most recent and remarkable contributions to research on cardiovascular diseases and disorders with cardiac traits. We conclude discussing immediate challenges, limitations, and emerging solutions.

Aldehyde Dehydrogenase 2 (ALDH2) Glu504Lys Polymorphism Affects Collateral Circulation and Short-Term Prognosis of Acute Cerebral Infarction Patients

Background

Acute cerebral infarction is a major clinical subtype of ischemic stroke that has become a leading cause of death and disability worldwide. Aldehyde dehydrogenase 2 (ALDH2) is an important oxidative enzyme in alcohol metabolism. The polymorphism of ALDH2 Glu504Lys polymorphism modifies the activity of this enzyme. However, the potential association between the allelic variation of ALDH2 Glu504Lys with collateral circulation and short-term prognosis of acute cerebral infarction remains unclear.

Material/Methods

A total of 394 patients with acute cerebral infarction were recruited for ALDH2 genotyping using direct sequencing. Cerebrovascular stenosis and collateral circulation were evaluated by digital subtraction angiography (DSA). Short-term prognosis was assessed in accordance with the modified Ranking Scale (mRS).

Results

We identified 297 as EAS and 394 as IAS. There were more patients with occluded blood vessel in the opened group and far fewer in the unopened group. ALDH2 polymorphism was significantly different among the primary, secondary, and tertiary opened groups. ALDH2 gene Glu504Lys was significantly associated with short-term prognosis. The genotype GA+AA of ALDH2 gene Glu504Lys locus was an independent risk factor of poor 90-day prognosis.

Conclusions

ALDH2 Glu504Lys could be a risk factor for collateral circulation and a negative predictor for short-term prognosis in acute cerebral infarction in Han Chinese. ALDH2 Glu504Lys could be a new therapeutic target for patients with acute cerebral infarction.

Associations between aldehyde dehydrogenase 2 (ALDH2) rs671 genetic polymorphisms, lifestyles and hypertension risk in Chinese Han people

Hypertension is a multiple factor disease which was influenced by gene, environment, and lifestyle. Several studies confirmed that the ALDH2 rs671 polymorphism is associated with hypertension. However, the evidence remains inconclusive. Whether lifestyle affects blood pressure in different genotype groups have not been clarified, either. The subjects were adult Chinese Han people who received health examination in the period from December 2014 to December 2015. Detection of the ALDH2 r671 polymorphism was determined by polymerase chain reaction. Lifestyle data were collected using self-administered questionnaires. Basic characteristics and fasting venous blood sample were collected at baseline. 4018 subjects were eligible for participation.The frequencies of the ALDH2 rs671 genotype were 68.67% (GG), 28.67%(GL), 2.66%(LL), respectively. Pepole who harbored the L allele were less likely to develop incident hypertension. There was a significant association between food frequency and hypertension in the L genotype group. Fried food intake was significantly increased the risk of hypertension in the L genotype group. Our study suggested that ALDH2 rs671 L-genotypes are protective factors for hypertension in Han Chinese. Consumption of fried food accelerated the development of hypertension in individuals with poor metabolism of acetaldehyde.

Enzymes and signal pathways in the pathogenesis of alcoholic cardiomyopathy

Owing to its acute psychotropic effects, ethanol is the most frequently consumed toxic agent worldwide. However, excessive alcohol intake results in an array of health, social, and economic consequences, which are related to its property as an addictive substance. It has been well established that exposure to high levels of alcohol for a long period leads to the onset and progression of nonischemic cardiomyopathy through direct toxic mechanisms of ethanol and its metabolite, acetaldehyde. Excessive alcohol ingestion causes myocardial damage including disruptions of the myofibrillar architecture and is associated with reduced myocardial contractility and decreased ejection volumes. Key features of alcoholic cardiomyopathy are cardiac hypertrophy and ventricular dilatation, and the disease is manifested mainly as cardiomegaly, congestive heart failure, and even cardiac death. Mechanisms that have been postulated to underlie the pathogenesis of alcoholic cardiomyopathy include apoptosis, mitochondrial alterations, acetaldehyde protein adduct formation, oxidative stress, and imbalances in fatty acid metabolism. In the following, we give a brief overview of the molecular effects of ethanol-metabolizing enzymes and their impact on myocardial signal transduction pathways.

Association between Carotid Intima-media Thickness and Aldehyde Dehydrogenase 2 Glu504Lys Polymorphism in Chinese Han with Essential Hypertension

BACKGROUND

Aldehyde dehydrogenase 2 (ALDH2) is involved in the pathophysiological processes of cardiovascular diseases. Recent studies showed that mutant ALDH2 could increase oxidative stress and is a susceptible factor for hypertension. In addition, wild-type ALDH2 could improve the endothelial functions, therefore reducing the risk of developing atherosclerosis. The aim of the present study was to explore the frequency of the Glu504Lys polymorphism of the ALDH2 gene and its relation to carotid intima-media thickness (CIMT) in a group of patients with essential hypertension (EH) and to investigate the association between the Glu504Lys polymorphism and CIMT in Chinese Han patients with EH.

METHODS

In this study, 410 Chinese Han patients with EH who received physical examinations at the People's Hospital of Sichuan Province (China) were selected. DNA microarray chip was used for the genotyping of the Glu504Lys polymorphism of the ALDH2 gene. The differences in CIMT among patients with different Glu504Lys ALDH2 genotypes were analyzed.

RESULTS

The mean CIMT of the patients carrying AA/AG and GG genotypes was 1.02 ± 0.31 mm and 0.78 ± 0.28 mm, respectively. One-way ANOVA showed that the CIMT of the patients carrying the AA/AG genotype was significantly higher than in the ones carrying the GG genotype (P < 0.001). Multivariate logistic regression showed that the Glu504Lys AA/AG genotype of the ALDH2 gene was one of the major factors influencing the CIMT in patients with EH (odds ratio = 3.731, 95% confidence interval = 1.589-8.124, P = 0.001).

CONCLUSIONS

The Glu504Lys polymorphism of the ALDH2 gene is associated with the CIMT of Chinese Han patients with EH in Sichuan, China.

Human Second Window Pre-Conditioning and Post-Conditioning by Nitrite Is Influenced by a Common Polymorphism in Mitochondrial Aldehyde Dehydrogenase

Pre-conditioning is an exciting physiological phenomenon that, despite great efforts, has so far resisted translation to mainstream clinical medicine. Many potential triggers (e.g., ischemia of the organ in question or a remote organ, many different drugs) have been investigated, but recent work has implicated activation of mitochondrial aldehyde dehydrogenase (ALDH2) as central to the process. A genetic polymorphism, known as ALDH2*2, is common worldwide (present in up to 40% of Han Chinese people) and produces a functionally different enzyme. The authors used a variety of protocols in the human ischemic forearm model, in participants with both enzyme types, to assess cytoprotection with low-dose sodium nitrite and attempt to further elucidate the role of ALDH2.

Targeting acetaldehyde dehydrogenase 2 (ALDH2) in heart failure-Recent insights and perspectives

Heart failure is one of the major causes of the ever-rising mortality globally. ALDH2 rs671 polymorphism is proven to be closely related to the prevalence of CAD, hypertension, diabetes mellitus and alcoholism, which are etiological factors of heart failure. In addition, growing evidence supports a possible role for ALDH2 in different forms of heart failure. In this mini-review, we will review the recent insights regarding the effects of ALDH2 polymorphism on etiological factors of heart failure and underlying mechanisms involved. In addition, we will also discuss the booming epigenetic information in this field which will greatly improve our understanding of the cardiovascular effect of ALDH2. This article is part of a Special Issue entitled: Genetic and epigenetic control of heart failure edited by Dr. Jun Ren & Yingmei Zhang.

Characterization of the molecular mechanisms underlying increased ischemic damage in the aldehyde dehydrogenase 2 genetic polymorphism using a human induced pluripotent stem cell model system

Nearly 8% of the human population carries an inactivating point mutation in the gene that encodes the cardioprotective enzyme aldehyde dehydrogenase 2 (ALDH2). This genetic polymorphism (ALDH2*2) is linked to more severe outcomes from ischemic heart damage and an increased risk of coronary artery disease (CAD), but the underlying molecular bases are unknown. We investigated the ALDH2*2 mechanisms in a human model system of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) generated from individuals carrying the most common heterozygous form of the ALDH2*2 genotype. We showed that the ALDH2*2 mutation gave rise to elevated amounts of reactive oxygen species and toxic aldehydes, thereby inducing cell cycle arrest and activation of apoptotic signaling pathways, especially during ischemic injury. We established that ALDH2 controls cell survival decisions by modulating oxidative stress levels and that this regulatory circuitry was dysfunctional in the loss-of-function ALDH2*2 genotype, causing up-regulation of apoptosis in cardiomyocytes after ischemic insult. These results reveal a new function for the metabolic enzyme ALDH2 in modulation of cell survival decisions. Insight into the molecular mechanisms that mediate ALDH2*2-related increased ischemic damage is important for the development of specific diagnostic methods and improved risk management of CAD and may lead to patient-specific cardiac therapies.

Variant Aldehyde Dehydrogenase 2 (ALDH2*2) Is a Risk Factor for Coronary Spasm and ST-Segment Elevation Myocardial Infarction

BACKGROUND

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) plays a key role in removing toxic aldehydes. Deficient variant ALDH2*2 genotype is prevalent in up to 40% of the East Asians and reported to be associated with acute myocardial infarction (AMI). To elucidate the mechanisms underlying the association of ALDH2*2 with AMI, we compared the clinical features of AMI patients with ALDH2*2 to those with wild-type ALDH2*1/*1.

METHODS AND RESULTS

The study subjects consisted of 202 Japanese patients with acute ST-segment elevation myocardial infarction (STEMI) (156 men and 46 women; mean age, 67.3±12.0) who underwent primary percutaneous coronary intervention (PCI). In 85 patients, provocation test for coronary spasm was also done 6 month post-PCI. ALDH2 genotyping was performed by direct application of the TaqMan polymerase chain system. Of the 202 patients, 103 (51.0%) were carriers of ALDH2*2 and 99 (49.0%) those of ALDH2*1/*1. There were no differences in clinical features between ALDH2*2 and ALDH2*1/*1 carrier groups except higher frequencies of coronary spasm and alcohol flush syndrome (AFS) (88.6% vs 56.1%; P=0.001 and 94.3% vs 17.6%; P<0.001), less-frequent alcohol habit (14.6% vs 51.5%; P<0.001), and higher peak plasma creatine phophokinase levels (2224 vs 1617 mg/dL; P=0.002) in the ALDH2*2 than the ALDH2*1/*1 carrier group.

CONCLUSIONS

ALDH2*2 is prevalent (51.0%) among Japanese STEMI patients, and those with ALDH2*2 had higher frequencies of coronary spasm and AFS and more-severe myocardial injury compared to those with ALDH2*1/*1.

Oxidative stress and lipotoxicity

The α,β polyunsaturated lipid aldehydes are potent lipid electrophiles that covalently modify lipids, proteins, and nucleic acids. Recent work highlights the critical role these lipids play under both physiological and pathological conditions. Protein carbonylation resulting from nucleophilic attack of lysine, histidine, and cysteine residues is a major outcome of oxidative stress and functions as a redox-sensitive signaling mechanism with roles in autophagy, cell proliferation, transcriptional control, and apoptosis. In addition, protein carbonylation is implicated as an initiating factor in mitochondrial dysfunction and endoplasmic reticulum stress, providing a mechanistic connection between oxidative stress and metabolic disease. In this review, we discuss the generation and metabolism of reactive lipid aldehydes, as well as their signaling roles.

Relationships of alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase 2 (ALDH2) genotypes with alcohol sensitivity, drinking behavior and problem drinking in Japanese older men

OBJECTIVES

Many East Asians have the genetic polymorphisms rs1229984 in alcohol dehydrogenase 1B (ADH1B) and rs671 in aldehyde dehydrogenase 2 (ALDH2). Here we analyzed the relationships of the two genotypes with alcohol sensitivity, drinking behavior and problem drinking among older and younger men living in rural areas of Japan.

METHODS

The subjects were 718 Japanese men aged 63.3 ± 10.8 (mean ± SD), categorized into the older (≥65 years, n = 357) and younger (<65 years, n = 361) groups. Facial flushing frequency, drinking behavior and positive CAGE results were compared among the genotypes using Bonferroni-corrected χ(2) test and a multivariate logistic regression analysis adjusting for age, BMI and lifestyle factors.

RESULTS

The frequency of 'always' facial flushing among the ADH1B*1/*2 carriers was significantly lower than that among the ADH1B*2/*2 carriers in the older group (P < 0.01). The alcohol consumption (unit/day) in the ADH1B*1/*2 carriers tended to be higher compared with that in the ADH1B*2/*2 carriers among the older group (P = 0.050). In the younger group, no significant differences in alcohol sensitivity and drinking habits were generally found among the ADH1B genotypes. The ADH1B*1/*1 genotype tended to be positively associated with problem drinking in the older group (P = 0.080) but not in the younger group. The ALDH2 genotypes consistently and strongly affected the alcohol sensitivity, drinking behavior and problem drinking in both the younger and older group.

CONCLUSIONS

We for the first time observed a significant difference in alcohol sensitivity between ADH1B*1/*2 and ADH1B*2/*2 in older men aged 65 and above.

Association of Genetically Determined Aldehyde Dehydrogenase 2 Activity with Diabetic Complications in Relation to Alcohol Consumption in Japanese Patients with Type 2 Diabetes Mellitus: The Fukuoka Diabetes Registry

Aldehyde dehydrogenase 2 (ALDH2) detoxifies aldehyde produced during ethanol metabolism and oxidative stress. A genetic defect in this enzyme is common in East Asians and determines alcohol consumption behaviors. We investigated the impact of genetically determined ALDH2 activity on diabetic microvascular and macrovascular complications in relation to drinking habits in Japanese patients with type 2 diabetes mellitus. An ALDH2 single-nucleotide polymorphism (rs671) was genotyped in 4,400 patients. Additionally, the relationship of clinical characteristics with ALDH2 activity (ALDH2 *1/*1 active enzyme activity vs. *1/*2 or *2/*2 inactive enzyme activity) and drinking habits (lifetime abstainers vs. former or current drinkers) was investigated cross-sectionally (n = 691 in *1/*1 abstainers, n = 1,315 in abstainers with *2, n = 1,711 in *1/*1 drinkers, n = 683 in drinkers with *2). The multiple logistic regression analysis for diabetic complications was adjusted for age, sex, current smoking habits, leisure-time physical activity, depressive symptoms, diabetes duration, body mass index, hemoglobin A1c, insulin use, high-density lipoprotein cholesterol, systolic blood pressure and renin-angiotensin system inhibitors use. Albuminuria prevalence was significantly lower in the drinkers with *2 than that of other groups (odds ratio [95% confidence interval (CI)]: *1/*1 abstainers as the referent, 0.94 [0.76-1.16] in abstainers with *2, 1.00 [0.80-1.26] in *1/*1 drinkers, 0.71 [0.54-0.93] in drinkers with *2). Retinal photocoagulation prevalence was also lower in drinkers with ALDH2 *2 than that of other groups. In contrast, myocardial infarction was significantly increased in ALDH2 *2 carriers compared with that in ALDH2 *1/*1 abstainers (odds ratio [95% CI]: *1/*1 abstainers as the referent, 2.63 [1.28-6.13] in abstainers with *2, 1.89 [0.89-4.51] in *1/*1 drinkers, 2.35 [1.06-5.79] in drinkers with *2). In summary, patients with type 2 diabetes and ALDH2 *2 displayed a lower microvascular complication prevalence associated with alcohol consumption but a higher macrovascular complication prevalence irrespective of alcohol consumption.

Exploring causal associations of alcohol with cardiovascular and metabolic risk factors in a Chinese population using Mendelian randomization analysis

Observational studies suggest that moderate alcohol consumption may be protective for cardiovascular disease, but results may be biased by confounding and reverse causality. Mendelian randomization, which uses genetic variants as proxies for exposures, can minimise these biases and therefore strengthen causal inference. Using a genetic variant in the ALDH2 gene associated with alcohol consumption, rs671, we performed a Mendelian randomization analysis in 1,712 diabetes cases and 2,076 controls from Nantong, China. Analyses were performed using linear and logistic regression, stratified by sex and diabetes status. The A allele of rs671 was strongly associated with reduced odds of being an alcohol drinker in all groups, but prevalence of alcohol consumption amongst females was very low. The A allele was associated with reduced systolic and diastolic blood pressure and decreased total and HDL cholesterol in males. The A allele was also associated with decreased triglyceride levels, but only robustly in diabetic males. There was no strong evidence for associations between rs671 and any outcomes in females. Our results suggest that associations of alcohol consumption with blood pressure and HDL-cholesterol are causal. Alcohol also appeared to have adverse effects on triglyceride levels, although this may be restricted to diabetics.