Multi-Omics profiling identifies aldehyde dehydrogenase 2 as a critical mediator in the crosstalk between Treg-mediated immunosuppression microenvironment and hepatocellular carcinoma.

Dysregulation of the aldehyde dehydrogenase (ALDH) family has been implicated in various pathological conditions, including cancer. However, a systematic evaluation of ALDH alterations and their therapeutic relevance in hepatocellular carcinoma (HCC) remains lacking. Herein, we found that 15 of 19 ALDHs were transcriptionally dysregulated in HCC tissues compared to normal liver tissues. A four gene signature, including ALDH2, ALDH5A1, ALDH6A1, and ALDH8A1, robustly predicted prognosis and defined a high-risk subgroup exhibiting immunosuppressive features like regulatory T cell (Tregs) infiltration. Single-cell profiling revealed selective overexpression of tumor necrosis factor receptor superfamily member 18 (TNFRSF18) on Tregs, upregulated in high-risk HCC patients. We identified ALDH2 as a tumor suppressor in HCC, with three novel phosphorylation sites mediated by protein kinase C zeta that enhanced enzymatic activity. Mechanistically, ALDH2 suppressed Tregs differentiation by inhibiting ß-catenin/TGF-ß1 signaling in HCC. Collectively, our integrated multi-omics analysis defines an ALDH-Tregs-TNFRSF18 axis that contributes to HCC pathogenesis and represents potential therapeutic targets for this aggressive malignancy.

Effectiveness of genetic feedback on alcohol metabolism to reduce alcohol consumption in young adults: an open-label randomized controlled trial.

BACKGROUND: It is unclear whether brief interventions using the combined classification of alcohol-metabolizing enzymes aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 1B (ADH1B) together with behavioral changes in alcohol use can reduce excessive alcohol consumption. This study aimed to examine the effects of a brief intervention based on the screening of ALDH2 and ADH1B gene polymorphisms on alcohol consumption in Japanese young adults. METHODS: In this open-label randomized controlled trial, we enrolled adults aged 20-30 years who had excessive drinking behavior (average amount of alcohol consumed: men, ≥ 4 drinks/per day and women, ≥ 2 drinks/per day; 1 drink = 10 g of pure alcohol equivalent). Participants were randomized into intervention or control group using a simple random number table. The intervention group underwent saliva-based genotyping of alcohol-metabolizing enzymes (ALDH2 and ADH1B), which were classified into five types. A 30-min in-person or online educational counseling was conducted approximately 1 month later based on genotyping test results and their own drinking records. The control group received traditional alcohol education. Average daily alcohol consumption was calculated based on the drinking diary, which was recorded at baseline and at 3 and 6 months of follow-up. The primary endpoint was average daily alcohol consumption, and the secondary endpoints were the alcohol-use disorder identification test for consumption (AUDIT-C) score and behavioral modification stages assessed using a transtheoretical model. RESULTS: Participants were allocated to the intervention (n = 100) and control (n = 96) groups using simple randomization. Overall, 28 (29.2%) participants in the control group and 21 (21.0%) in the intervention group did not complete the follow-up. Average alcohol consumption decreased significantly from baseline to 3 and 6 months in the intervention group but not in the control group. The reduction from baseline alcohol consumption values and AUDIT-C score at 3 months were greater in the intervention group than in the control group (p < 0.001). In addition, the behavioral modification stages were significantly changed by the intervention (p < 0.001). CONCLUSIONS: Genetic testing for alcohol-metabolizing enzymes and health guidance on type-specific excessive drinking may be useful for reducing sustained average alcohol consumption associated with behavioral modification. TRIAL REGISTRATION: R000050379, UMIN000044148, Registered on June 1, 2021.

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.

Unlocking the potential: A novel prognostic index signature for acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aggressive malignancy characterized by challenges in treatment, including drug resistance and frequent relapse. Recent research highlights the crucial roles of tumor microenvironment (TME) in assisting tumor cell immune escape and promoting tumor aggressiveness. This study delves into the interplay between AML and TME. Through the exploration of potential driver genes, we constructed an AML prognostic index (AMLPI). Cross-platform data and multi-dimensional internal and external validations confirmed that the AMLPI outperforms existing models in terms of areas under the receiver operating characteristic curves, concordance index values, and net benefits. High AMLPIs in AML patients were indicative of unfavorable prognostic outcomes. Immune analyses revealed that the high-AMLPI samples exhibit higher expression of HLA-family genes and immune checkpoint genes (including PD1 and CTLA4), along with lower T cell infiltration and higher macrophage infiltration. Genetic variation analyses revealed that the high-AMLPI samples associate with adverse variation events, including TP53 mutations, secondary NPM1 co-mutations, and copy number deletions. Biological interpretation indicated that ALDH2 and SPATS2L contribute significantly to AML patient survival, and their abnormal expression correlates with DNA methylation at cg12142865 and cg11912272. Drug response analyses revealed that different AMLPI samples tend to have different clinical selections, with low-AMLPI samples being more likely to benefit from immunotherapy. Finally, to facilitate broader access to our findings, a user-friendly and publicly accessible webserver was established and available at http://bioinfor.imu.edu.cn/amlpi. This server provides tools including TME-related AML driver genes mining, AMLPI construction, multi-dimensional validations, AML patients risk assessment, and figures drawing.

The effect of metabolism-related lifestyle and clinical risk factors on digestive system cancers in East Asian populations: a two-sample Mendelian randomization analysis.

Metabolic factors play a critical role in the development of digestive system cancers (DSCs), and East Asia has the highest incidence of malignant tumors in the digestive system. We performed a two-sample Mendelian randomization analysis to explore the associations between 19 metabolism-related lifestyle and clinical risk factors and DSCs, including esophageal, gastric, colorectal, hepatocellular, biliary tract, and pancreatic cancer. The causal association was explored for all combinations of each risk factor and each DSC. We gathered information on the instrumental variables (IVs) from various sources and retrieved outcome information from Biobank Japan (BBJ). The data were all from studies of east Asian populations. Finally, 17,572 DSCs cases and 195,745 controls were included. Our analysis found that genetically predicted alcohol drinking was a strong indicator of gastric cancer (odds ratio (OR) = 0.95; 95% confidence interval (CI): 0.93-0.98) and hepatocellular carcinoma (OR = 1.11; 95% CI: 1.05-1.18), whereas coffee consumption had a potential protective effect on hepatocellular carcinoma (OR = 0.69; 95% CI: 0.53-0.90). Triglyceride was potentially associated with a decreased risk of biliary tract cancer (OR = 0.53; 95% CI: 0.34-0.81), and uric acid was associated with pancreatic cancer risk (OR = 0.59; 95% CI: 0.37-0.96). Metabolic syndrome (MetS) was associated with esophageal and gastric cancer. Additionally, there was no evidence for a causal association between other risk factors, including body mass index, waist circumference, waist-to-hip ratio, educational levels, lipoprotein cholesterol, total cholesterol, glycine, creatinine, gout, and Graves' disease, and DSCs. The leave-one-out analysis revealed that the single nucleotide polymorphism (SNP) rs671 from the ALDH2 gene has a disproportionately high contribution to the causal association between alcohol drinking and gastric cancer and hepatocellular carcinoma, as well as the association between coffee consumption and hepatocellular carcinoma. The present study revealed multiple metabolism-related lifestyle and clinical risk factors and a valuable SNP rs671 for DSCs, highlighting the significance of metabolic factors in both the prevention and treatment of DSCs.

ALDH2 as an immunological and prognostic biomarker: Insights from pan-cancer analysis.

Aldehyde dehydrogenase 2 (ALDH2) plays a critical role in safeguarding cells against acetaldehyde toxicity and is closely linked to human metabolism. Nevertheless, the involvement of ALDH2 in cancer remains enigmatic. This investigation seeks to comprehensively assess ALDH2's significance in pan-cancer. We conducted an all-encompassing analysis of pan-cancer utilizing multiple databases, including TCGA, linkedomicshs, UALCAN, and Kaplan-Meier plotter. We employed diverse algorithms such as EPIC, MCPCOUNTER, TIDTIMER, xCell, MCP-counter, CIBERSORT, quanTIseq, and EPIC to examine the connection between ALDH2 expression and immune cell infiltration. Single-cell sequencing analysis furnished insights into ALDH2's functional status in pan-cancer. Immunohistochemical staining was performed to validate ALDH2 expression in cancer tissues. In a comprehensive assessment, we observed that tumor tissues demonstrated diminished ALDH2 expression levels compared to normal tissues across 16 different cancer types. ALDH2 expression exhibited a significant positive correlation with the infiltration of immune cells, including CD4 + T cells, CD8 + T cells, neutrophils, B cells, and macrophages, in various tumor types. Moreover, this study explored the association between ALDH2 and patient survival, examined the methylation patterns of ALDH2 in normal and primary tumor tissues, and delved into genetic variations and mutations of ALDH2 in tumors. The findings suggest that ALDH2 could serve as a valuable prognostic biomarker in pan-cancer, closely linked to the tumor's immune microenvironment.

Myocardial reperfusion injury exacerbation due to ALDH2 deficiency is mediated by neutrophil extracellular traps and prevented by leukotriene C4 inhibition.

BACKGROUND AND AIMS: The Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene is closely associated with myocardial ischaemia/reperfusion injury (I/RI). The effects of ALDH2 on neutrophil extracellular trap (NET) formation (i.e. NETosis) during I/RI remain unknown. This study aimed to investigate the role of ALDH2 in NETosis in the pathogenesis of myocardial I/RI. METHODS: The mouse model of myocardial I/RI was constructed on wild-type, ALDH2 knockout, peptidylarginine deiminase 4 (Pad4) knockout, and ALDH2/PAD4 double knockout mice. Overall, 308 ST-elevation myocardial infarction patients after primary percutaneous coronary intervention were enrolled in the study. RESULTS: Enhanced NETosis was observed in human neutrophils carrying the ALDH2 genetic mutation and ischaemic myocardium of ALDH2 knockout mice compared with controls. PAD4 knockout or treatment with NETosis-targeting drugs (GSK484, DNase1) substantially attenuated the extent of myocardial damage, particularly in ALDH2 knockout. Mechanistically, ALDH2 deficiency increased damage-associated molecular pattern release and susceptibility to NET-induced damage during myocardial I/RI. ALDH2 deficiency induced NOX2-dependent NETosis via upregulating the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/leukotriene C4 (LTC4) pathway. The Food and Drug Administration-approved LTC4 receptor antagonist pranlukast ameliorated I/RI by inhibiting NETosis in both wild-type and ALDH2 knockout mice. Serum myeloperoxidase-DNA complex and LTC4 levels exhibited the predictive effect on adverse left ventricular remodelling at 6 months after primary percutaneous coronary intervention in ST-elevation myocardial infarction patients. CONCLUSIONS: ALDH2 deficiency exacerbates myocardial I/RI by promoting NETosis via the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/LTC4/NOX2 pathway. This study hints at the role of NETosis in the pathogenesis of myocardial I/RI, and pranlukast might be a potential therapeutic option for attenuating I/RI, particularly in individuals with the ALDH2 mutation.

Aldehyde Dehydrogenase 2 (ALDH2): A novel sorafenib target in hepatocellular carcinoma unraveled by the proteome-wide cellular thermal shift assay.

Sorafenib is a multikinase inhibitor indicated for first-line treatment of unresectable hepatocellular carcinoma. Despite its widespread use in the clinic, the existing knowledge of sorafenib mode-of-action remains incomplete. To build upon the current understanding, we used the Cellular Thermal Shift Assay (CETSA) coupled to Mass Spectrometry (CETSA-MS) to monitor compound binding to its target proteins in the cellular context on a proteome-wide scale. Among the potential sorafenib targets, we identified aldehyde dehydrogenase 2 (ALDH2), an enzyme that plays a major role in alcohol metabolism. We validated the interaction of sorafenib with ALDH2 by orthogonal methods using pure recombinant protein, proving that this interaction is not mediated by other cellular components. Moreover, we showed that sorafenib inhibits ALDH2 activity, supporting a functional role for this interaction. Finally, we were able to demonstrate that both ALDH2 protein expression and activity were reduced in sorafenib-resistant cells compared to the parental cell line. Overall, our study allowed the identification of ALDH2 as a novel sorafenib target and sheds light on its potential role in both hepatocellular carcinoma and sorafenib resistance condition.

A genome-wide association study based on the China Kadoorie Biobank identifies genetic associations between snoring and cardiometabolic traits.

Despite the high prevalence of snoring in Asia, little is known about the genetic etiology of snoring and its causal relationships with cardiometabolic traits. Based on 100,626 Chinese individuals, a genome-wide association study on snoring was conducted. Four novel loci were identified for snoring traits mapped on SLC25A21, the intergenic region of WDR11 and FGFR, NAA25, ALDH2, and VTI1A, respectively. The novel loci highlighted the roles of structural abnormality of the upper airway and craniofacial region and dysfunction of metabolic and transport systems in the development of snoring. In the two-sample bi-directional Mendelian randomization analysis, higher body mass index, weight, and elevated blood pressure were causal for snoring, and a reverse causal effect was observed between snoring and diastolic blood pressure. Altogether, our results revealed the possible etiology of snoring in China and indicated that managing cardiometabolic health was essential to snoring prevention, and hypertension should be considered among snorers.

Rational design of soluble expressed human aldehyde dehydrogenase 2 with high stability and activity in pepsin and trypsin.

Acetaldehyde dehydrogenase 2 (ALDH2) is a crucial enzyme in alcohol metabolism, and oral administration of ALDH2 is a promising method for alcohol detoxification. However, recombinant ALDH2 is susceptible to hydrolysis by digestive enzymes in the gastrointestinal tract and is expressed as inactive inclusion bodies in E. coli. In this study, we performed three rounds of rational design to address these issues. Specifically, the surface digestive sites of pepsin and trypsin were replaced with other polar amino acids, while hydrophobic amino acids were incorporated to reshape the catalytic cavity of ALDH2. The resulting mutant DE2-852 exhibited a 45-fold increase in soluble expression levels, while its stability against trypsin and pepsin increased by eightfold and twofold, respectively. Its catalytic efficiency (kcat/Km) at pH 7.2 and 3.2 improved by more than four and five times, respectively, with increased Vmax and decreased Km values. The enhanced properties of DE2-852 were attributed to the D457Y mutation, which created a more compact protein structure and facilitated a faster collision between the substrate and catalytic residues. These results laid the foundation for the oral administration and mass preparation of highly active ALDH2 and offered insights into the oral application of other proteins.

Research Progress on the Correlation between Acetaldehyde Dehydrogenase 2 and Hepatocellular Carcinoma Development.

Hepatocellular carcinoma (HCC) is the predominant pathologic type of primary liver cancer. It is a malignant tumor of liver epithelial cells. There are many ways to treat HCC, but the survival rate for HCC patients remains low. Therefore, understanding the underlying mechanisms by which HCC occurs and develops is critical to explore new therapeutic targets. Aldehyde dehydrogenase 2 (ALDH2) is an important player in the redox reaction of ethanol with endogenous aldehyde products released by lipid peroxidation. Increasing evidence suggests that ALDH2 is a crucial regulator of human tumor development, including HCC. Therefore, clarifying the relationship between ALDH2 and HCC is helpful for formulating rational treatment strategies. This review highlights the regulatory roles of ALDH2 in the development of HCC, elucidates the multiple potential mechanisms by which ALDH2 regulates the development of HCC, and summarizes the progress of research on ALDH2 gene polymorphisms and HCC susceptibility. Meanwhile, we envision viable strategies for targeting ALDH2 in the treatment of HCC SIGNIFICANCE STATEMENT: Numerous studies have aimed to explore novel therapeutic targets for HCC, and ALDH2 has been reported to be a critical regulator of HCC progression. This review discusses the functions, molecular mechanisms, and clinical significance of ALDH2 in the development of HCC and examines the prospects of ALDH2-based therapy for HCC.

The aldehyde dehydrogenase 2 rs671 variant enhances amyloid ß pathology.

In the ALDH2 rs671 variant, a guanine changes to an adenine, resulting in a dramatic decrease in the catalytic activity of the enzyme. Population-based data are contradictory about whether this variant increases the risk of Alzheimer's disease. In East Asian populations, the prevalence of the ALDH2 rs671 variant is 30-50%, making the National Human Brain Bank for Development and Function (the largest brain bank in East Asia) an important resource to explore the link between the ALDH2 rs671 polymorphism and Alzheimer's disease pathology. Here, using 469 postmortem brains, we find that while the ALDH2 rs671 variant is associated with increased plaque deposits and a higher Aß40/42 ratio, it is not an independent risk factor for Alzheimer's disease. Mechanistically, we show that lower ALDH2 activity leads to 4-HNE accumulation in the brain. The (R)-4-HNE enantiomer adducts to residue Lys53 of C99, favoring Aß40 generation in the Golgi apparatus. Decreased ALDH2 activity also lowers inflammatory factor secretion, as well as amyloid ß phagocytosis and spread in brains of patients with Alzheimer's disease. We thus define the relationship between the ALDH2 rs671 polymorphism and amyloid ß pathology, and find that ALDH2 rs671 is a key regulator of Aß40 or Aß42 generation.

Neutrophil ALDH2 is a new therapeutic target for the effective treatment of sepsis-induced ARDS.

Acetaldehyde dehydrogenase 2 (ALDH2) mutations are commonly found in a subgroup of the Asian population. However, the role of ALDH2 in septic acute respiratory distress syndrome (ARDS) remains unknown. Here, we showed that human subjects carrying the ALDH2rs671 mutation were highly susceptible to developing septic ARDS. Intriguingly, ALDH2rs671-ARDS patients showed higher levels of blood cell-free DNA (cfDNA) and myeloperoxidase (MPO)-DNA than ALDH2WT-ARDS patients. To investigate the mechanisms underlying ALDH2 deficiency in the development of septic ARDS, we utilized Aldh2 gene knockout mice and Aldh2rs671 gene knock-in mice. In clinically relevant mouse sepsis models, Aldh2-/- mice and Aldh2rs671 mice exhibited pulmonary and circulating NETosis, a specific process that releases neutrophil extracellular traps (NETs) from neutrophils. Furthermore, we discovered that NETosis strongly promoted endothelial destruction, accelerated vascular leakage, and exacerbated septic ARDS. At the molecular level, ALDH2 increased K48-linked polyubiquitination and degradation of peptidylarginine deiminase 4 (PAD4) to inhibit NETosis, which was achieved by promoting PAD4 binding to the E3 ubiquitin ligase CHIP. Pharmacological administration of the ALDH2-specific activator Alda-1 substantially alleviated septic ARDS by inhibiting NETosis. Together, our data reveal a novel ALDH2-based protective mechanism against septic ARDS, and the activation of ALDH2 may be an effective treatment strategy for sepsis.

Asian flush is a potential protective factor against COVID-19: a web-based retrospective survey in Japan.

BACKGROUND: Coronavirus disease 2019 (COVID-19), first reported in December 2019, spread worldwide in a short period, resulting in numerous cases and associated deaths; however, the toll was relatively low in East Asia. A genetic polymorphism unique to East Asians, Aldehyde dehydrogenase 2 rs671, has been reported to confer protection against infections. METHOD: We retrospectively investigated the association between the surrogate marker of the rs671 variant, the skin flushing phenomenon after alcohol consumption, and the timing of COVID-19 incidence using a web-based survey tool to test any protective effects of rs671 against COVID-19. RESULTS: A total of 807 valid responses were received from 362 non-flushers and 445 flushers. During the 42 months, from 12/1/2019 to 5/31/2023, 40.6% of non-flushers and 35.7% of flushers experienced COVID-19. Flushers tended to have a later onset (Spearman's partial rank correlation test, p = 0.057, adjusted for sex and age). Similarly, 2.5% of non-flushers and 0.5% of flushers were hospitalized because of COVID-19. Survival analysis estimated lower risks of COVID-19 and associated hospitalization among flushers (p = 0.03 and <0.01, respectively; generalized Wilcoxon test). With the Cox proportional hazards model covering 21 months till 8/31/2021, when approximately half of the Japanese population had received two doses of COVID-19 vaccine, the hazard ratio (95% confidence interval) of COVID-19 incidence was estimated to be 0.21 (0.10-0.46) for flusher versus non-flusher, with adjustment for sex, age, steroid use, and area of residence. CONCLUSIONS: Our study suggests an association between the flushing phenomenon after drinking and a decreased risk of COVID-19 morbidity and hospitalization, suggesting that the rs671 variant is a protective factor. This study provides valuable information for infection control and helps understand the unique constitutional diversity of East Asians.

LncRNA CHKB-DT Downregulation Enhances Dilated Cardiomyopathy Through ALDH2.

BACKGROUND: Human cardiac long noncoding RNA (lncRNA) profiles in patients with dilated cardiomyopathy (DCM) were previously analyzed, and the long noncoding RNA CHKB (choline kinase beta) divergent transcript (CHKB-DT) levels were found to be mostly downregulated in the heart. In this study, the function of CHKB-DT in DCM was determined. METHODS: Long noncoding RNA expression levels in the human heart tissues were measured via quantitative reverse transcription-polymerase chain reaction and in situ hybridization assays. A CHKB-DT heterozygous or homozygous knockout mouse model was generated using the clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 system, and the adeno-associated virus with a cardiac-specific promoter was used to deliver the RNA in vivo. Sarcomere shortening was performed to assess the primary cardiomyocyte contractility. The Seahorse XF cell mitochondrial stress test was performed to determine the energy metabolism and ATP production. Furthermore, the underlying mechanisms were explored using quantitative proteomics, ribosome profiling, RNA antisense purification assays, mass spectrometry, RNA pull-down, luciferase assay, RNA-fluorescence in situ hybridization, and Western blotting. RESULTS: CHKB-DT levels were remarkably decreased in patients with DCM and mice with transverse aortic constriction-induced heart failure. Heterozygous knockout of CHKB-DT in cardiomyocytes caused cardiac dilation and dysfunction and reduced the contractility of primary cardiomyocytes. Moreover, CHKB-DT heterozygous knockout impaired mitochondrial function and decreased ATP production as well as cardiac energy metabolism. Mechanistically, ALDH2 (aldehyde dehydrogenase 2) was a direct target of CHKB-DT. CHKB-DT physically interacted with the mRNA of ALDH2 and fused in sarcoma (FUS) through the GGUG motif. CHKB-DT knockdown aggravated ALDH2 mRNA degradation and 4-HNE (4-hydroxy-2-nonenal) production, whereas overexpression of CHKB-DT reversed these molecular changes. Furthermore, restoring ALDH2 expression in CHKB-DT+/- mice alleviated cardiac dilation and dysfunction. CONCLUSIONS: CHKB-DT is significantly downregulated in DCM. CHKB-DT acts as an energy metabolism-associated long noncoding RNA and represents a promising therapeutic target against DCM.

Polymorphisms in drug-metabolizing genes and urinary bladder cancer susceptibility and prognosis: Possible impacts and future management.

Epidemiological studies have shown the association of genetic variants with risks of occupational and environmentally induced cancers, including bladder (BC). The current review summarizes the effects of variants in genes encoding phase I and II enzymes in well-designed studies to highlight their contribution to BC susceptibility and prognosis. Polymorphisms in genes codifying drug-metabolizing proteins are of particular interest because of their involvement in the metabolism of exogenous genotoxic compounds, such as tobacco and agrochemicals. The prognosis between muscle-invasive and non-muscle-invasive diseases is very different, and it is difficult to predict which will progress worse. Web of Science, PubMed, and Medline were searched to identify studies published between January 1, 2010, and February 2023. We included 73 eligible studies, more than 300 polymorphisms, and 46 genes/loci. The most studied candidate genes/loci of phase I metabolism were CYP1B1, CYP1A1, CYP1A2, CYP3A4, CYP2D6, CYP2A6, CYP3E1, and ALDH2, and those in phase II were GSTM1, GSTT1, NAT2, GSTP1, GSTA1, GSTO1, and UGT1A1. We used the 46 genes to construct a network of proteins and to evaluate their biological functions based on the Reactome and KEGG databases. Lastly, we assessed their expression in different tissues, including normal bladder and BC samples. The drug-metabolizing pathway plays a relevant role in BC, and our review discusses a list of genes that could provide clues for further exploration of susceptibility and prognostic biomarkers.

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-ß1). 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-ß1 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.

ALDH2 is a novel biomarker and exerts an inhibitory effect on melanoma.

Melanoma is a malignant skin tumor. This study aimed to explore and assess the effect of novel biomarkers on the progression of melanoma. Differently expressed genes (DEGs) were screened from GSE3189 and GSE46517 datasets of Gene Expression Omnibus database using GEO2R. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted based on the identified DEGs. Hub genes were identified and assessed using protein-protein interaction networks, principal component analysis, and receiver operating characteristic curves. Quantitative real-time polymerase chain reaction was employed to measure the mRNA expression levels. TIMER revealed the association between aldehyde dehydrogenase 2 (ALDH2) and tumor immune microenvironment. The viability, proliferation, migration, and invasion were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, wound healing, and transwell assays. Total 241 common DEGs were screened out from GSE3189 and GSE46517 datasets. We determined 6 hub genes with high prediction values for melanoma, which could distinguish tumor samples from normal samples. ALDH2, ADH1B, ALDH3A2, DPT, EPHX2, and GATM were down-regulated in A375 and SK-MEL-2 cells, compared with the human normal melanin cell line (PIG1 cells). ALDH2 was selected as the candidate gene in this research, presenting a high diagnostic and predictive value for melanoma. ALDH2 had a positive correlation with the infiltrating levels of immune cells in melanoma microenvironment. Overexpression of ALDH2 inhibited cell viability, proliferation, migration, and invasion of A375/SK-MEL-2 cells. ALDH2 is a new gene biomarker of melanoma, which exerts an inhibitory effect on melanoma.

Aldehyde Dehydrogenase 2 (ALDH2) rs671 Polymorphism is a Predictor of Pulmonary Hypertension Due to Left Heart Disease.

AIM: Pulmonary hypertension due to left heart disease (PH-LHD) is commonly seen in patients with heart failure (HF), but there are limited treatment options. Recent studies have shown an association between aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphisms and pulmonary hypertension (PH). Therefore, this study aimed to investigate the occurrence of ALDH2 rs671 polymorphisms, and the association between ALDH2 and risk of PH-LHD in patients with HF. It also investigated different ALDH2 genotypes and examined their association with cardiac structure and function in HF patients with PH-LHD. METHODS: A total of 178 HF patients were consecutively enrolled in this study: 102 without PH-LHD and 76 with PH-LHD. Clinical data, parameters of echocardiography, and relevant biochemical indexes were recorded in both groups. Differences in data obtained between groups were compared, and the risk of variant ALDH2 polymorphisms with PH-LHD in HF patients was analysed using univariate and multivariate logistic regression. RESULTS: The prevalence of ALDH2 rs671 GA/AA polymorphisms (variant ALDH2) was 24 of 102 patients (23.53%) in the HF without PH-LHD group, and 32 of 76 patients (42.10%) in the HF with PH-LHD group, with a statistically significant difference. Univariate and multivariate logistical regression showed that variant ALDH2 is an independent risk factor for HF combined with PH-LHD. A higher proportion of patients with variant ALDH2 in the HF with PH-LHD group had a tricuspid regurgitation velocity >2.8 m/s, and they had higher values of peak early diastolic velocity of the mitral orifice/peak velocity of the early diastolic wave of the mitral orifice, maximum frequency shift of pulmonary valve flow, and pulmonary artery stiffness. CONCLUSIONS: Variant ALDH2 may be an independent risk factor for HF combined with PH-LHD. Variant ALDH2 may also be involved in pulmonary artery remodelling and is a potential new target for clinical treatment of PH-LHD.