ALDH2, a novel protector against stroke?
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ABSTRACT:
SUBMITTER: Sun A
PROVIDER: S-EPMC3698642 | BioStudies | 2013-01-01
SECONDARY ACCESSION(S): 10.1038/cr.2013.76
REPOSITORIES: biostudies
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Project description:Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that metabolizes ethanol and toxic aldehydes such as 4-hydroxy-2-nonenal (4-HNE). Using an unbiased proteomic search, we identified ALDH2 deficiency in stroke-prone spontaneously hypertensive rats (SHR-SP) as compared with spontaneously hypertensive rats (SHR). We concluded the causative role of ALDH2 deficiency in neuronal injury as overexpression or activation of ALDH2 conferred neuroprotection by clearing 4-HNE in in vitro studies. Further, ALDH2-knockdown rats revealed the absence of neuroprotective effects of PKC?. Moderate ethanol administration that is known to exert protection against stroke was shown to enhance the detoxification of 4-HNE, and to protect against ischemic cerebral injury through the PKC?-ALDH2 pathway. In SHR-SP, serum 4-HNE level was persistently elevated and correlated inversely with the lifespan. The role of 4-HNE in stroke in humans was also suggested by persistent elevation of its plasma levels for at least 6 months after stroke. Lastly, we observed that 21 of 1 242 subjects followed for 8 years who developed stroke had higher initial plasma 4-HNE levels than those who did not develop stroke. These findings suggest that activation of the ALDH2 pathway may serve as a useful index in the identification of stroke-prone subjects, and the ALDH2 pathway may be a potential target of therapeutic intervention in stroke.
2013-01-01 | S-EPMC3698638 | BioStudies
Project description:Recent studies have demonstrated the protective effect of mitochondrial aldehyde dehydrogenase 2 (ALDH2) in cardiovascular diseases. Increased levels of the potential ALDH2 substrate 4-hydroxynonenal (4-HNE) are involved in myocardial/cerebral ischemia accompanied by a high level of oxidative stress. In this investigation, we first performed a case-control study to explore the potential association of ALDH2 rs671 polymorphism and post-stroke epilepsy (PSE). Then, we performed an in vitro study to determine whether the overexpression of ALDH2 could decrease the level of oxidative stress and the apoptosis ratio induced by 4-HNE. There was a significant difference in the distribution of the allele and genotype frequencies of the rs671 polymorphism between PSE patients and ischemic stroke (IS) patients. Individuals with the rs671 A allele showed significantly higher levels of plasma 4-HNE. The overexpression of ALDH2 partially blocked the increased levels of malondialdehyde (MDA), reactive oxygen species (ROS) and apoptosis ratio induced by 4-HNE and also partially restored the ALDH2 activity in PC12 cells; these effects were reversed in the presence of ?V1-2. Our results suggest that the ALDH2 rs671 polymorphism is associated with PSE susceptibility and affects the 4-HNE levels. Targeting ALDH2 might be a useful strategy for the treatment or prevention of PSE.
2014-01-01 | S-EPMC4196934 | BioStudies
Project description:Previous studies have shown that aldehyde dehydrogenase 2 (ALDH2) plays a role in ischemic stroke progression. In recent years, the activation of the ALDH2 pathway have been reported serving as a useful index in the identification of stroke-prone participants, and the ALDH2 pathway may be a potential target for the therapeutic intervention in ischemic stroke.We evaluated six tagging single-nucleotide polymorphisms (SNPs) of the ALDH2 gene in a case-control study from Hainan of China (488 cases, 503 controls). We used SPSS version 17.0 statistical software, Excel software and other analysis software to explore associations between SNPs and the risk of ischemic stroke various genetic models (additive, dominant, and recessive).Through statistical analysis, we found that ALDH2 rs886205 [odds ratio (OR) = 6.39; 95% confidence interval (CI) = 1.19-34.38; p = 0.03] and rs7296651 (OR = 9.29; 95% CI = 1.37-63.21; p = 0.02) were associated with increased risk of ischemic stroke in recessive model analysis. In addition, we established that the "AA" genotype (OR = 5.99; 95% CI = 1.11-32.23; p = 0.037) for rs886205 and the "AA" genotype (OR = 8.93; 95% CI = 1.31-60.78; p = 0.025) for rs7296651 were associated with increased ischemic stroke risk.Our results provide evidence that variants of ALDH2 gene polymorphisms influence the risk of developing ischemic stroke in Han Chinese population.
2017-01-01 | S-EPMC5731925 | BioStudies
Project description:Oxidative stress induced by lipid peroxidation products (LPP) accompanies aging and has been hypothesized to exacerbate the secondary cascade in traumatic brain injury (TBI). Increased oxidative stress is a contributor to loss of neural reserve that defines the ability to maintain healthy cognitive function despite the accumulation of neuropathology. ALDH2-/- mice are unable to clear aldehyde LPP by mitochondrial aldehyde dehydrogenase-2 (Aldh2) detoxification and provide a model to study mild TBI (mTBI), therapeutic interventions, and underlying mechanisms. The ALDH2-/- mouse model presents with elevated LPP-mediated protein modification, lowered levels of PSD-95, PGC1-?, and SOD-1, and mild cognitive deficits from 4 months of age. LPP scavengers are neuroprotective in vitro and in ALDH2-/- mice restore cognitive performance. A single-hit, closed skull mTBI failed to elicit significant effects in WT mice; however, ALDH2-/- mice showed a significant inflammatory cytokine surge in the ipsilateral hemisphere 24 h post-mTBI, and increased GFAP cleavage, a biomarker for TBI. Known neuroprotective agents, were able to reverse the effects of mTBI. This new preclinical model of mTBI, incorporating significant perturbations in behavior, inflammation, and clinically relevant biomarkers, allows mechanistic study of the interaction of LPP and neurotrauma in loss of neural reserve.
2020-01-01 | S-EPMC7063127 | BioStudies
Project description:Aldehyde dehydrogenase (ALDH) gene superfamily consists of 19 isozymes. They are present in various organs and involved in metabolizing aldehydes that are biologically generated. For instance, ALDH2, a cardiac mitochondrial ALDH isozyme, is known to detoxify 4-hydroxy-2-nonenal, a reactive aldehyde produced upon lipid peroxidation in diabetic conditions. We hypothesized that inhibition of ALDH leads to the accumulation of unmetabolized 4HNE and consequently exacerbates injury in cells subjected to high glucose stress. H9C2 cardiomyocyte cell lines were pretreated with 10??M disulfiram (DSF), an inhibitor of ALDH2 or vehicle (DMSO) for 2 hours, and then subjected to high glucose stress {33?mM D-glucose (HG) or 33?mM D-mannitol as an osmotic control (Ctrl)} for 24?hrs. The decrease in ALDH2 activity with DSF pretreatment was higher in HG group when compared to Ctrl group. Increased 4HNE adduct formation with DSF pretreatment was higher in HG group compared to Ctrl group. Pretreatment with DSF leads to potentiated HG-induced cell death in cultured H9C2 cardiomyocytes by lowering mitochondrial membrane potential. Our results indicate that ALDH2 activity is important in preventing high glucose induced cellular dysfunction.
2016-01-01 | S-EPMC5110883 | BioStudies
Project description:Mitochondrial aldehyde dehydrogenase 2 (ALDH2) in the liver removes toxic aldehydes including acetaldehyde, an intermediate of ethanol metabolism. Nearly 40% of East Asians inherit an inactive ALDH2*2 variant, which has a lysine-for-glutamate substitution at position 487 (E487K), and show a characteristic alcohol flush reaction after drinking and a higher risk for gastrointestinal cancers. Here we report the characterization of knockin mice in which the ALDH2(E487K) mutation is inserted into the endogenous murine Aldh2 locus. These mutants recapitulate essentially all human phenotypes including impaired clearance of acetaldehyde, increased sensitivity to acute or chronic alcohol-induced toxicity, and reduced ALDH2 expression due to a dominant-negative effect of the mutation. When treated with a chemical carcinogen, these mutants exhibit increased DNA damage response in hepatocytes, pronounced liver injury, and accelerated development of hepatocellular carcinoma (HCC). Importantly, ALDH2 protein levels are also significantly lower in patient HCC than in peritumor or normal liver tissues. Our results reveal that ALDH2 functions as a tumor suppressor by maintaining genomic stability in the liver, and the common human ALDH2 variant would present a significant risk factor for hepatocarcinogenesis. Our study suggests that the ALDH2*2 allele-alcohol interaction may be an even greater human public health hazard than previously appreciated.
2015-01-01 | S-EPMC4517197 | BioStudies
Project description:The present study was designed to examine the mechanism involved in mitochondrial aldehyde dehydrogenase (ALDH2)-induced cardioprotection against ischaemia/reperfusion (I/R) injury with a focus on autophagy.Wild-type (WT), ALDH2 overexpression, and knockout (KO) mice (n = 4-6 for each index measured) were subjected to I/R, and myocardial function was assessed using echocardiographic, Langendroff, and edge-detection systems. Western blotting was used to evaluate AMP-dependent protein kinase (AMPK), Akt, autophagy, and the AMPK/Akt upstream signalling LKB1 and PTEN.ALDH2 overexpression and KO significantly attenuated and accentuated, respectively, infarct size, factional shortening, and recovery of post-ischaemic left ventricular function following I/R as well as hypoxia/reoxygenation-induced cardiomyocyte contractile dysfunction. Autophagy was induced during ischaemia and remained elevated during reperfusion. ALDH2 significantly promoted autophagy during ischaemia, which was accompanied by AMPK activation and mammalian target of rapamycin (mTOR) inhibition. On the contrary, ALDH2 overtly inhibited autophagy during reperfusion accompanied by the activation of Akt and mTOR. Inhibition and induction of autophagy mitigated ALDH2-induced protection against cell death in hypoxia and reoxygenation, respectively. In addition, levels of the endogenous toxic aldehyde 4-hydroxy-2-nonenal (4-HNE) were elevated by ischaemia and reperfusion, which was abrogated by ALDH2. Furthermore, ALDH2 ablated 4-HNE-induced cardiomyocyte dysfunction and protein damage, whereas 4-HNE directly decreased pan and phosphorylated LKB1 and PTEN expression.Our data suggest a myocardial protective effect of ALDH2 against I/R injury possibly through detoxification of toxic aldehyde and a differential regulation of autophagy through AMPK- and Akt-mTOR signalling during ischaemia and reperfusion, respectively.
1000-01-01 | S-EPMC3076664 | BioStudies
Project description:Limited data are available about the role of common variants at the aldehyde dehydrogenase 2 gene (ALDH2) on the clinical outcome in Chinese patients with coronary heart disease (CHD) undergoing percutaneous coronary intervention (PCI). In the present study, a total of 1089 patients were consecutively enrolled from January 2012 and July 2013. Six common variants at ALDH2 gene, including rs2339840, rs4648328, rs4767939, rs11066028, rs16941669, and rs671, were selected to test the associations of those polymorphisms with the cardiovascular outcome in patients with CHD after PCI. The clinical endpoints included cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. The composite of clinical endpoints was defined as the primary endpoint, and every endpoint alone was considered as the secondary endpoints. The median follow-up time was 38.27 months. Our results showed that the common variant rs2339840 was independently associated with a lower risk of stroke in patients with CHD after PCI (codominant model, HR = 0.32, 95% CI, 0.11-0.91, P = .074 for heterozygotes; HR = 0.25, 95% CI, 0.06-1.14, P = .033 for homozygotes; dominant model, HR = 0.32, 95% CI, 0.14-0.74, P = .007). However, no significant associations were found between other 5 single nucleotide polymorphisms (SNPs) and the clinical endpoints. For the first time, the common variant rs2339840 was reported to be a protective factor against stroke in CHD patients with PCI.
2018-01-01 | S-EPMC5959384 | BioStudies
Project description:In last decades, many scholars have studied the relationship between aldehyde dehydrogenase 2 (ALDH2) rs671 and ischemic stroke (IS), however, the results obtained from these studies were inconclusive. The purpose of this study was to investigate the association between rs671 and the risk of IS by systematically review.Two researchers independently screened relevant published literatures, derived data and estimated the risk of bias of the research in Pubmed, Embase, Ovid, China National Knowledge Infrastructure (CNKI), Cochrane Library and China Biomedical Literature Database throughout March 29, 2020. All statistical analyses were performed with the Stata 12.0 software. The data of the study was analyzed using fixed and random effects models. The results were expressed by odds ratio (OR) and 95% confidence interval (95%CI).A total of 10 articles were included this study. The total number of samples for all studies was 5265, including 2762 cases and 2503 controls. Statistical results indicated statistical differences between ALDH2 rs671 polymorphism and IS under dominant model (AA vs. AG?+?GG) and allelic model (A vs G), ORs (95% CI) were 1.66 (1.27-2.17) (P?=?.00) and 1.34 (1.05-1.71) (P?=?.02), respectively. But there was no statistical difference under recessive model (AA?+?AG vs GG), OR (95% CI) was 1.40 (0.99-1.97), P?=?.06.ALDH2 rs671 polymorphism was related to IS risk for Chinese population and the A allele of rs671 may be a risk factor of IS.
2020-01-01 | S-EPMC7249896 | BioStudies
Project description:The ALDH2 gene encodes the mitochondrial aldehyde dehydrogenase 2 (ALDH2), a critical enzyme involved in ethanol clearance through acetaldehyde metabolism. ALDH2 also catalyzes the metabolism of other bioreactive aldehydes, including propionaldehyde, butyraldehyde, and 4-hydroxykenals (4-HNE). Increased levels of 4-HNE in adipose tissue positively correlate with obesity and insulin resistance. However, it remains unclear whether ALDH2 is involved in regulation of adipocyte differentiation. Here, we found that ALDH2 protein levels were lower in white adipose tissue of high-fat diet-fed mice and ob/ob mice relative to lean mice. Knockdown of ALDH2 expression in 3T3-L1 preadipocytes caused an increase in intracellular 4-HNE, thereby attenuated adipocyte differentiation. By contrast, an ALDH2 activator, Alda-1, significantly accelerated adipogenesis, which was accompanied by an increase in adipogenic gene expression. Consistently, adipogenesis was reduced when protein kinase C ? (PKC?), an ALDH2 phosphorylating activator, was silenced in 3T3-L1 preadipocytes, whereas treatment with a PKC? agonist in 3T3-L1 preadipocytes enhanced adipogenesis. Whole-genome microarray profiling of Alda-1-treated cells demonstrated several upregulated transcripts encoding proteins involved in metabolism and the majority of these transcripts are for proteins involved in PPAR signaling pathways. Furthermore, PKC?-ALDH2 interaction alleviates 4-HNE induced aberrant PPAR? regulation on adipogenesis. Taken together, these results demonstrate that ALDH2 activation enhances adipogenesis and signaling pathways involving PPAR?. Thus, activation of PKC?-ALDH2 regulatory axis may be a therapeutic target for treating obesity and type 2 diabetes.
2016-01-01 | S-EPMC5004862 | BioStudies