A prognostic model of idiopathic pulmonary fibrosis constructed based on macrophage and mitochondria-related genes

BACKGROUND

Studies have shown that mitochondrial function and macrophages may play a role in the development of idiopathic pulmonary fibrosis (IPF). However, the understanding of the interactions and specific mechanisms between mitochondrial function and macrophages in pulmonary fibrosis is still very limited.

METHODS

To construct a prognostic model for IPF based on Macrophage- related genes (MaRGs) and Mitochondria-related genes (MitoRGs), differential analysis was performed to achieve differentially expressed genes (DEGs) between IPF and Control groups in the GSE28042 dataset. Then, MitoRGs, MaRGs and DEGs were overlapped to screen out the signature genes. The univariate Cox analysis and the least absolute shrinkage and selection operator (LASSO) algorithm were implemented to achieve key genes. Furthermore, the independent prognostic analysis was employed. The ingenuity pathway analysis (IPA) was employed to further understand the molecular mechanisms of key genes.Next, the immune infiltration analysis was implemented to identify differential immune cells between two risk subgroups.

RESULTS

There were 4791 DEGs between IPF and Control groups. Furthermore, 26 signature genes were achieved by the intersection processing. Three key genes including ALDH2, MCL1, and BCL2A1 were achieved, and the risk model based on the key genes was created. In addition, a nomogram for survival forecasting of IPF patients was created based on riskScore, Age, and Gender, and we found that key genes were associated with classical pathways including 'Apoptosis Signaling', 'PI3K/AKT Signaling', and so on. Next, two differential immune cells including Monocytes and CD8 T cells were identified between two risk subgroups. Moreover, we found that MIR29B2CHG and hsa-mir-1-3p could regulate the expression of ALDH2.

CONCLUSION

We achieved 3 key genes including ALDH2, MCL1,, and BCL2A1 associated with IPF, providing a new theoretical basis for clinical treatment of IPF.

Inhibiting apoptosis and GSDME-mediated pyroptosis attenuates hepatic injury in septic mice

BACKGROUND

Sepsis is characterized by severe inflammation and organ dysfunction resulting from a dysregulated organismal response to infection. Although pyroptosis has been presumably shown to be a major cause of multiple organ failure and septic death, whether gasdermin E (GSDME)-mediated pyroptosis occurs in septic liver injury and whether inhibiting apoptosis and GSDME-mediated pyroptosis can attenuate septic liver injury remain unclear. This study investigated the role of apoptosis and GSDME-mediated pyroptosis in septic liver injury.

METHODS

Adult male C57BL/6 mice were randomly divided into four groups: sham, cecal ligation puncture (CLP), CLP + Z-DEVD-FMK (a caspase-3 inhibitor, 5 mg/kg), and CLP + Ac-DMLD-CMK (a GSDME inhibitor, 5 mg/kg). Sepsis severity was assessed using the murine sepsis score (MSS). Hepatic tissue damage was observed by the hematoxylin-eosin staining method, the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the levels of malondialdehyde (MDA), the concentrations of interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were measured according to the related kits, and the changes in the hepatic tissue reactive oxygen species (ROS) levels were detected by immunofluorescence (IF). The protein expression levels of cleaved caspase-3, GSDME-N, IL-1β, B-cell lymphoma-2 (Bcl-2), cytochrome C (Cyt-c), and acetaldehyde dehydrogenase 2 (ALDH2) were detected using western blotting. GSDME expression was detected by immunohistochemistry.

RESULTS

Compared with the Sham group, CLP mice showed high sepsis scores and obvious liver damage. However, in the CLP + Z-DEVD-FMK and CLP + Ac-DMLD-CMK groups, the sepsis scores were reduced and liver injury was alleviated. Compared with the Sham group, the serum ALT and AST activities, MDA and ROS levels, and IL-1β and TNF-α concentrations were increased in the CLP group, as well as the protein expression of cleaved caspase-3, GSDME-N, IL-1β, Cyt-c, and GSDME positive cells (P < 0.05). However, the expression levels of Bcl-2 and ALDH2 protein were decreased (P < 0.05). Compared with the CLP group, the CLP + Z-DEVD-FMK and CLP + Ac-DMLD-CMK groups showed low sepsis scores, ALT and AST activities, MDA and ROS levels, decreased IL-1β and TNF-α concentrations, and decreased expression of cleaved caspase-3, GSDME-N, IL-1β protein expression, and GSDME positive cells (P < 0.05). The expression levels of Bcl-2 and ALDH2 protein were increased (P < 0.05).

CONCLUSION

Apoptosis and GSDME-mediated pyroptosis are involved in the development of sepsis-induced hepatic injury. Inhibition of apoptosis and GSDME-mediated pyroptosis attenuates injury. ALDH2 plays a protective role by inhibiting apoptosis and pyroptosis.

Exploring patterns of alcohol use and alcohol use disorder among Asian Americans with a finer lens

BACKGROUND

National survey data suggest Asian Americans (AA) are less likely to consume alcohol and develop AUD than Americans in other groups. However, it is common for AA to be born outside of the US and carry gene variants that alter alcohol metabolism, both of which can lead to lower levels of alcohol involvement. The current study examined differences in alcohol use and AUD between AA and other groups before and after controlling for birth location and gene variants.

DESIGN

Past year alcohol measures were examined from adults 18+ (N=22,848) in the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions III before and after controlling for birth location (inside or outside of the US) and gene variants (ALDH2*2 and ADH1B*2/ADH1B*3). Gender gaps in alcohol measures also were assessed.

RESULTS

Before adjustments, AA were less likely than White Americans to drink in the previous year (OR=0.50, 95% CI 0.41-0.62), binge (OR=0.68, 95% CI 0.52-0.88), engage in frequent heavy drinking (OR=0.55, 95% CI 0.42-0.73), and reach criteria for AUD (OR=0.71, 95% CI 0.53-0.94). After controlling for birth location and gene variants, AA remained less likely to drink in the past year (OR=0.54, 95% CI 0.41-0.70) but all other differences disappeared. Gender gaps were only observed for AA born outside of the US, highlighting the importance of experience rather than racial category per se.

CONCLUSIONS

Findings indicate that heterogeneity among AA leads to spurious generalizations regarding alcohol use and AUD and challenge the model minority myth.

SNP-based and haplotype-based genome-wide association on drug dependence in Han Chinese

BACKGROUND

Drug addiction is a serious problem worldwide and is influenced by genetic factors. The present study aimed to investigate the association between genetics and drug addiction among Han Chinese.

METHODS

A total of 1000 Chinese users of illicit drugs and 9693 healthy controls were enrolled and underwent single nucleotide polymorphism (SNP)-based and haplotype-based association analyses via whole-genome genotyping.

RESULTS

Both single-SNP and haplotype tests revealed associations between illicit drug use and several immune-related genes in the major histocompatibility complex (MHC) region (SNP association: log10BF = 15.135, p = 1.054e-18; haplotype association: log10BF = 20.925, p = 2.065e-24). These genes may affect the risk of drug addiction via modulation of the neuroimmune system. The single-SNP test exclusively reported genome-wide significant associations between rs3782886 (SNP association: log10BF = 8.726, p = 4.842e-11) in BRAP and rs671 (SNP association: log10BF = 7.406, p = 9.333e-10) in ALDH2 and drug addiction. The haplotype test exclusively reported a genome-wide significant association (haplotype association: log10BF = 7.607, p = 3.342e-11) between a region with allelic heterogeneity on chromosome 22 and drug addiction, which may be involved in the pathway of vitamin B12 transport and metabolism, indicating a causal link between lower vitamin B12 levels and methamphetamine addiction.

CONCLUSIONS

These findings provide new insights into risk-modeling and the prevention and treatment of methamphetamine and heroin dependence, which may further contribute to potential novel therapeutic approaches.

Effects of Hovenia dulcis fruit and peduncle extract on alcohol metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit and peduncle of Hovenia dulcis Thunberg (Rhamnaceae) (HD) has been used as a folk medicine to treat liver disease, detoxify alcoholism, and prevent and cure hangovers.

AIM OF THE STUDY

We investigated the pharmacology of HD on the kinetics of EtOH and on the enzymes related to alcohol metabolism to seek the scientific evidence of HD to prevent hangover, the effectiveness as a folk medicine.

MATERIALS AND METHODS

EtOH was orally administered 30 min after oral administration of HD boiling water extract in rats. Then, the profiles of blood EtOH concentrations were measured. Mice were reared with food containing powdered HD for 7 days, and the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in liver were measured. Hepa1c1c7 cells were cultured with the medium containing HD extract, and the activities of ADH and ALDH were measured.

RESULTS

HD extract reduced the blood EtOH concentrations in rats and induced the activities of ADH and ALDH and mRNA and protein expressions of ADH1B, ALDH1A1, and ALDH2 in the liver of mice and Hepa1c1c7 cells. Dihydromyricetin, one of the ingredients of HD, significantly induced the activities of ADH and ALDH in Hepa1c1c7 cells, however, the fractions containing hydrophilic organic compounds with small molecular weight contributed the most of the activities of HD extract.

CONCLUSIONS

We clarified the experimental pharmacological evidences of HD as a folk medicine to detoxify alcoholism and prevent hangovers.

CD163-Mediated Small-Vessel Injury in Alzheimer's Disease: An Exploration from Neuroimaging to Transcriptomics

Patients with Alzheimer's disease (AD) often present with imaging features indicative of small-vessel injury, among which, white-matter hyperintensities (WMHs) are the most prevalent. However, the underlying mechanism of the association between AD and small-vessel injury is still obscure. The aim of this study is to investigate the mechanism of small-vessel injury in AD. Differential gene expression analyses were conducted to identify the genes related to WMHs separately in mild cognitive impairment (MCI) and cognitively normal (CN) subjects from the ADNI database. The WMH-related genes identified in patients with MCI were considered to be associated with small-vessel injury in early AD. Functional enrichment analyses and a protein-protein interaction (PPI) network were performed to explore the pathway and hub genes related to the mechanism of small-vessel injury in MCI. Subsequently, the Boruta algorithm and support vector machine recursive feature elimination (SVM-RFE) algorithm were performed to identify feature-selection genes. Finally, the mechanism of small-vessel injury was analyzed in MCI from the immunological perspectives; the relationship of feature-selection genes with various immune cells and neuroimaging indices were also explored. Furthermore, 5×FAD mice were used to demonstrate the genes related to small-vessel injury. The results of the logistic regression analyses suggested that WMHs significantly contributed to MCI, the early stage of AD. A total of 276 genes were determined as WMH-related genes in patients with MCI, while 203 WMH-related genes were obtained in CN patients. Among them, only 15 genes overlapped and were thus identified as the crosstalk genes. By employing the Boruta and SVM-RFE algorithms, CD163, ALDH3B1, MIR22HG, DTX2, FOLR2, ALDH2, and ZNF23 were recognized as the feature-selection genes linked to small-vessel injury in MCI. After considering the results from the PPI network, CD163 was finally determined as the critical WMH-related gene in MCI. The expression of CD163 was correlated with fractional anisotropy (FA) values in regions that are vulnerable to small-vessel injury in AD. The immunostaining and RT-qPCR results from the verifying experiments demonstrated that the indicators of small-vessel injury presented in the cortical tissue of 5×FAD mice and related to the upregulation of CD163 expression. CD163 may be the most pivotal candidates related to small-vessel injury in early AD.

Prognosis prediction and risk stratification of breast cancer patients based on a mitochondria-related gene signature

As the malignancy with the highest global incidence, breast cancer represents a significant threat to women's health. Recent advances have shed light on the importance of mitochondrial function in cancer, particularly in metabolic reprogramming within tumors. Recognizing this, we developed a novel risk signature based on mitochondrial-related genes to improve prognosis prediction and risk stratification in breast cancer patients. In this study, transcriptome data and clinical features of breast cancer samples were extracted from two sources: the TCGA, serving as the training set, and the METABRIC, used as the independent validation set. We developed the signature using LASSO-Cox regression and assessed its prognostic efficacy via ROC curves. Furthermore, the signature was integrated with clinical features to create a Nomogram model, whose accuracy was validated through clinical calibration curves and decision curve analysis. To further elucidate prognostic variations between high and low-risk groups, we conducted functional enrichment and immune infiltration analyses. Additionally, the study encompassed a comparison of mutation landscapes and drug sensitivity, providing a comprehensive understanding of the differing characteristics in these groups. Conclusively, we established a risk signature comprising 8 mitochondrial-related genes-ACSL1, ALDH2, MTHFD2, MRPL13, TP53AIP1, SLC1A1, ME3, and BCL2A1. This signature was identified as an independent risk predictor for breast cancer patient survival, exhibiting a significant high hazard ratio (HR = 3.028, 95%CI 2.038-4.499, P < 0.001). Patients in the low-risk group showed a more favorable prognosis, with enhanced immune infiltration, distinct mutation landscapes, and greater sensitivity to anti-tumor drugs. In contrast, the high-risk group exhibited an adverse trend in these aspects. This risk signature represents a novel and effective prognostic indicator, suggesting valuable insights for patient stratification in breast cancer.

A new prognostic risk model for acute myeloid leukemia patients based on telomere-related genes

Telomere maintenance is critical to ensure unlimited cancer cell proliferation, but the role of telomere-related genes in acute myeloid leukemia (AML) has not yet been thoroughly discussed. This study aims to develop a new prognostic risk model based on telomere-related genes and analyze potential mechanisms and targets. Cox regression analyses were used to build the prognostic risk model. Kaplan-Meier (KM) survival analysis and receiver operating characteristic (ROC) curve were used to assess the model performance. At the same time, we analyzed the relationship between the risk score and chemotherapy and immunotherapy and preliminarily explored possible mechanisms of immune resistance. The real-time polymerase chain reaction (PCR) was used to detect the prognosis gene expression levels. Finally, a prognostic signature of six telomere-related genes (TGPS6) including ALDH2, CDK18, DNMT3B, FRAT2, LGALSL, and RBL2 was constructed. The TGPS6 score was confirmed as an independent prognostic factor (HR 2.74, CI [2.13-3.53], p < 0.001) in AML and the five-year area under the ROC curve (AUC) value of the score in the training and validation set reached 0.74, 0.81 respectively. In addition, the TGPS6 perfected the European LeukemiaNet (ELN) 2017 prognosis risk stratification and performed well in both AML and cytogenetically normal AML (CN-AML) cohorts. The TGPS6 score also provided a reference for chemotherapy and immunotherapy in patients with AML.

Alcohol intake and cause-specific mortality: conventional and genetic evidence in a prospective cohort study of 512 000 adults in China

BACKGROUND

Genetic variants that affect alcohol use in East Asian populations could help assess the causal effects of alcohol consumption on cause-specific mortality. We aimed to investigate the associations between alcohol intake and cause-specific mortality using conventional and genetic epidemiological methods among more than 512 000 adults in China.

METHODS

The prospective China Kadoorie Biobank cohort study enrolled 512 724 adults (210 205 men and 302 519 women) aged 30-79 years, during 2004-08. Residents with no major disabilities from ten diverse urban and rural areas of China were invited to participate, and alcohol use was self-reported. During 12 years of follow-up, 56 550 deaths were recorded through linkage to death registries, including 23 457 deaths among 168 050 participants genotyped for ALDH2-rs671 and ADH1B-rs1229984. Adjusted hazard ratios (HRs) for cause-specific mortality by self-reported and genotype-predicted alcohol intake were estimated using Cox regression.

FINDINGS

33% of men drank alcohol most weeks. In conventional observational analyses, ex-drinkers, non-drinkers, and heavy drinkers had higher risks of death from most major causes than moderate drinkers. Among current drinkers, each 100 g/week higher alcohol intake was associated with higher mortality risks from cancers (HR 1·18 [95% CI 1·14-1·22]), cardiovascular disease (CVD; HR 1·19 [1·15-1·24]), liver diseases (HR 1·51 [1·27-1·78]), non-medical causes (HR 1·15 [1·08-1·23]), and all causes (HR 1·18 [1·15-1·20]). In men, ALDH2-rs671 and ADH1B-rs1229984 genotypes predicted 60-fold differences in mean alcohol intake (4 g/week in the lowest group vs 255 g/week in the highest). Genotype-predicted alcohol intake was uniformly and positively associated with risks of death from all causes (n=12 939; HR 1·07 [95% CI 1·05-1·10]) and from pre-defined alcohol-related cancers (n=1274; 1·12 [1·04-1·21]), liver diseases (n=110; 1·31 [1·02-1·69]), and CVD (n=6109; 1·15 [1·10-1·19]), chiefly due to stroke (n=3285; 1·18 [1·12-1·24]) rather than ischaemic heart disease (n=2363; 1·06 [0·99-1·14]). Results were largely consistent using a polygenic score to predict alcohol intake, with higher intakes associated with higher risks of death from alcohol-related cancers, CVD, and all causes. Approximately 2% of women were current drinkers, and although power was low to assess observational associations of alcohol with mortality, the genetic evidence suggested that the excess risks in men were due to alcohol, not pleiotropy.

INTERPRETATION

Higher alcohol intake increased the risks of death overall and from major diseases for men in China. There was no genetic evidence of protection from moderate drinking for all-cause and cause-specific mortality, including CVD.

FUNDING

Kadoorie Charitable Foundation, National Natural Science Foundation of China, British Heart Foundation, Cancer Research UK, GlaxoSmithKline, Wellcome Trust, Medical Research Council, and Chinese Ministry of Science and Technology.

ALDH2 activation attenuates oxygen-glucose deprivation/reoxygenation-induced cell apoptosis, pyroptosis, ferroptosis and autophagy

PURPOSE

It is previously reported that aldehyde dehydrogenase 2 family member (ALDH2) shows neuroprotective effects in cerebral ischemia/reperfusion injury. However, whether the protective effects are through mediating the programmed cell death is yet to be fully elucidated.

METHODS

In vitro oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in HT22 cells and mouse cortical neurons. Subsequently, ALDH2 expression were assessed by qRT-PCR and western blot. The methylation status was examined by methylation-specific PCR (MS-PCR). Then, ALDH2 expression was promoted and suppressed to explore the role of ALDH2 in OGD/R-treated cells. CCK-8 assay was applied to detect cell viability, and flow cytometry was applied to evaluate cell apoptosis. Western blot was applied to detect the apoptosis-related proteins (Caspase 3, Bcl-2 and Bax), necroptosis-related proteins (RIP3 and MLKL), pyroptosis-related proteins (NLRP3 and GSDMD), ferroptosis-related protein (ACSL4 and GPX4), and autophagy-related proteins (LC3B, and p62). IL-1β and IL-18 production was evaluated by ELISA assay. Reactive oxygen species production and Fe2+ content were evaluated by the corresponding detection kit.

RESULTS

In OGD/R-treated cells, ALDH2 expression was decreased, which was due to the hypermethylation of ALDH2 in the promoter region. ALDH2 overexpression improved cell viability and ALDH2 knockdown suppressed cell viability in OGD/R-treated cells. We also found that ALDH2 overexpression attenuated OGD/R-induced cell apoptosis, pyroptosis, ferroptosis and autophagy, while ALDH2 knockdown facilitated the OGD/R-induced cell apoptosis, pyroptosis, ferroptosis and autophagy.

CONCLUSIONS

Collectively, our results implied that ALDH2 attenuated OGD/R-induced cell apoptosis, pyroptosis, ferroptosis and autophagy to promote cell viability in HT22 cells and mouse cortical neurons.

[Research on the mechanism of Miao ethnicity medicine formula of Oxalis corniculata against chronic non-bacterial prostatitis]

Objective： To explore the mechanism of Miao ethnicity medicine formula of Oxalis corniculata against chronic non-bacterial prostatitis. Methods: The rat model of chronic abacterial prostatitis was induced by stimulation with 2% sterile carrageenan solution. After modeling, the rats were randomly divided into two groups, Model control group (Model group) and oxalis group. Another normal control group was set up. The rats in the Model group and the normal control group were given 0.01ml/g normal saline by gavage, and the rats in the oxalis alis group were given 1ml/100g (1 g/kg) of Oxalis corniculata L warm water decoction by gavage once a day for 28 days. Twenty-four hours after the last administration, 10ml blood was collected from the abdominal aorta of the rats, and prostate tissue samples were collected from the rats. hematoxylin-eosin (HE) staining was used to observe the morphological structure of the prostate in normal and prostatitis rats. ELISA was used to detect the levels of serum and prostate cytokines. The protein expressions of 4-HNE , ALDH2 and FGF2 were detected by Western blot. Results: Compared with the blank group, the model group showed obvious hyperplasia of fibrous tissue in the interstitium of the prostate tissue, disordered glandular structure, papillary hyperplasia of epithelial cells in the acini, infiltration of a small amount of lymphocytes, monocytes and other inflammatory cells in the acini, and increased pathological scores. The protein expressions of 4-HNE , ALDH2 , MCP-1 and FGF2 in prostate tissue were significantly increased. Compared with the model group, the prostate tissue of the oxalis group was slightly damaged, with a small amount of fibrous hyperplasia and inflammatory cell infiltration. The protein expressions of 4-HNE , ALDH2 , MCP-1 and FGF2 were decreased in prostate tissue. Conclusion： Oxalis corniculata L can effectively repair the pathological morphology of prostate tissue in rats with CNP, and its mechanism may be related to activating 4-HNE protein and reducing oxidative stress injury of prostate tissue in rats.

A novel telomere-related gene prognostic signature for survival and drug treatment efficiency prediction in lung adenocarcinoma

OBJECTIVE

Telomere-related genes (TRGs) play a critical role in various types of tumors. However, there is a lack of comprehensive exploration of their relevance in lung cancer. This research aimed to verify the relationship between TRGs gene expression and the prognosis of patients with lung adenocarcinoma (LUAD), as well as the prediction of drug treatment efficiency.

METHODS

A total of 2093 TRGs were acquired from TelNet. The clinical information including age, tumor stage, follow up and outcome (death/survival) and TRGs expression profile of LUAD were obtained from the patients in The Cancer Genome Atlas (TCGA) database and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database. The two databases were used to construct and verify a prognostic model based on the expression of hubTRGs. The tumor mutation burden, immune infiltration and subtypes, as well as IC50 prediction of multiple targeted drugs were also evaluated in TRGs-divided risk groups.

RESULTS

A total of 335 TRGs were significantly differentially expressed in LUAD as compared with normal control. Among them, 9 TRGs (ABCC2, ABCC8, ALDH2, FOXP3, GNMT, JSRP1, MACF1, PLCD3, SULT4A1) were finally identified as hubGenes and used to construct a TRG risk score. The TRG risk score showed favorable performance in constructing a prognostic nomogram in predicting survival of LUAD, and the ROC curves at 1, 3 and 5 years were plotted and the AUROC values were 0.743, 0.754 and 0.735, respectively. Higher TRGs risk score correlated with worse immune subtypes and higher tumor mutation burden in LUAD tissues. In addition, the patients in TRG high risk group harbored a lower TIDE score which indicated potentially better response to immunotherapy.

CONCLUSION

This study proposed a broad molecular signature of telomere-related genes that can be used in further functional and therapeutic investigations, and also represents an integrated modality for characterizing critical molecules when exploring novel targets for lung cancer immunotherapy.

DNMT1 mediates the disturbed flow-induced endothelial to mesenchymal transition through disrupting β-alanine and carnosine homeostasis

Background: Increasing evidence suggests that hemodynamic disturbed flow induces endothelial dysfunction via a complex biological process so-called endothelial to mesenchymal transition (EndoMT). Recently, DNA methyltransferases (DNMTs) was reported as a key molecular mediator to promote EndoMT. Our understanding of how DNMTs, particularly the maintenance DNMTs, DNMT1, coordinate EndoMT is still lacking. Methods: A parallel-plate flow apparatus and perfusion devices were used to apply fluid with endothelial protective pulsatile shear (PS, to mimic the laminar flow) or harmful oscillatory shear (OS, to mimic the disturbed flow) to cultured endothelial cells (ECs). Endothelial lineage tracing mice and conditional EC Dnmt1 knockout mice were subjected to a surgery of carotid partial ligation to generate the flow-accelerated atherogenesis models. Western blotting, quantitative RT-PCR, immunofluorescent staining, methylation-specific PCR, chromatin immunoprecipitation, endothelial functional assays, and assessments for neointimal formation and atherosclerosis were performed. Results: Inhibition of DNMTs with 5-aza-2'-deoxycytidine (5-Aza) suppressed the disturbed flow/OS-induced EndoMT, both in cultured cells and the endothelial lineage tracing mice. 5-Aza also ameliorated the downregulation of aldehyde dehydrogenases (ALDHs) and β-alanine biosynthesis caused by disturbed flow/OS. Knockdown of the ALDH family proteins, ALDH2, ALDH3A1, and ALDH6A1, showed an EndoMT-induction effect as OS. Supplementation of cells with the functional metabolites of β-alanine, carnosine and acetyl-CoA (acetate), reversed EndoMT, likely via inhibiting the phosphorylation of Smad2/3. Endothelial-specific knockout of Dnmt1 protected the vasculature from disturbed flow-induced remodeling and atherosclerosis. Conclusions: Endothelial DNMT1 acts as one of the key epigenetic factors to mediate the hemodynamically regulated EndoMT at least through repressing the expression of ALDH2, ALDH3A1, and ALDH6A1. Supplementation with carnosine and acetate may have a great potential in the prevention and treatment of atherosclerosis.

Development of tryptophan metabolism patterns to predict prognosis and immunotherapeutic responses in hepatocellular carcinoma

Tryptophan metabolism is associated with tumorigenesis and tumor immune response in various cancers. Liver is the main place where tryptophan catabolism is performed. However, the role of tryptophan metabolism in hepatocellular carcinoma (HCC) has not been well clarified. In the present study, we described the mutations of 42 tryptophan metabolism-related genes (TRPGs) in HCC cohorts. Then, HCC patients were well distributed into two subtypes based on the expression profiles of the 42 TRPGs. The clinicopathological characteristics and tumor microenvironmental landscape of the two subtypes were profiled. We also established a TRPGs scoring system and identified four hallmark TRPGs, including ACSL3, ADH1B, ALDH2, and HADHA. Univariate and multivariate Cox regression analysis revealed that the TRPG signature was an independent prognostic indicator for HCC patients. Besides, the predictive accuracy of the TRPG signature was assessed by the receiver operating characteristic curve (ROC) analysis. These results showed that the TRPG risk model had an excellent capability in predicting survival in both TCGA and GEO HCC cohorts. Moreover, we discovered that the TRPG signature was significantly related to the different immune infiltration and therapeutic drug sensitivity. The functional experiments and immunohistochemistry staining analysis also validated the results above. Our comprehensive analysis enhanced our understanding of TRPGs in HCC. A novel predictive model based on TRPGs was built, which may be considered as a beneficial tool for predicting the clinical outcomes of HCC patients.

Dissecting the alternation landscape of mitochondrial metabolism-related genes in lung adenocarcinoma and their latent mechanisms

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer with high incidence and unsatisfactory prognosis. The majority of LUAD patients eventually succumb to local and/or distinct metastatic recurrence. Genomic research of LUAD has broadened our understanding of this disease's biology and improved target therapies. However, the alternation landscape and characteristics of mitochondrial metabolism-related genes (MMRGs) in LUAD progression remain poorly understood. We performed a comprehensive analysis to identify the function and mechanism of MMRGs in LUAD based on the TCGA and GEO databases, which might offer therapeutic values for clinical researchers. Then, we figured out three hub prognosis-associated MMRGs (also termed as PMMRGs: ACOT11, ALDH2, and TXNRD1) that were engaged in the evolution of LUAD. To investigate the correlation between clinicopathological characteristics and MMRGs, we divided LUAD samples into two clusters (C1 and C2) based on key MMRGs. In addition, important pathways and the immune infiltration landscape affected by LUAD clusters were also delineated. Further, we nominated potential regulatory mechanisms underlying the MMRGs in LUAD development and progression. In conclusion, our integrative analysis enables a more comprehensive understanding of the mutation landscape of MMRGs in LUAD and provides an opportunity for more precise treatment.

Identifying novel proteins underlying loneliness by integrating GWAS summary data with human brain proteomes

Enduring loneliness is associated with mental disorders and physical diseases. Although genome-wide association studies (GWAS) have identified risk loci associated with loneliness, how these loci confer the risk remains largely unknown. In the current study, we aimed to investigate key proteins underlying loneliness in the brain by integrating human brain proteomes and transcriptomes with loneliness GWAS to perform a discovery proteome-wide association study (PWAS), followed by a confirmatory PWAS, transcriptome-wide association analysis (TWAS), Mendelian randomization (MR), Steigering filtering analysis and Bayesian colocalization analysis. Moreover, given the fact that loneliness is associated with mental disorders, we explored the shared genetic architecture between loneliness and mental disorders. Totally, we identified 18 genes to be associated with loneliness via their cis-regulated brain protein abundance. Eleven of the 18 genes (61.1%) were replicated in the confirmatory PWAS, and mRNA levels of 4 genes were further validated to be associated with loneliness.MR and genetic colocalization analysis further confirmed that the increased protein abundance of ALDH2 and ICA1L was protective against loneliness, while the increased protein abundance of GPX1 was a risk for developing loneliness. Furthermore, we found genetic correlations, bidirectional causal associations and overlapping phenotype-associated protein profiles between loneliness and mental disorders including major depression and schizophrenia. In summary, our findings provided clues about the brain-related molecular basis underlying loneliness, which warrants further investigation.

The Generation of Nitric Oxide from Aldehyde Dehydrogenase-2: The Role of Dietary Nitrates and Their Implication in Cardiovascular Disease Management

Reduced bioavailability of the nitric oxide (NO) signaling molecule has been associated with the onset of cardiovascular disease. One of the better-known and effective therapies for cardiovascular disorders is the use of organic nitrates, such as glyceryl trinitrate (GTN), which increases the concentration of NO. Unfortunately, chronic use of this therapy can induce a phenomenon known as "nitrate tolerance", which is defined as the loss of hemodynamic effects and a reduction in therapeutic effects. As such, a higher dosage of GTN is required in order to achieve the same vasodilatory and antiplatelet effects. Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a cardioprotective enzyme that catalyzes the bio-activation of GTN to NO. Nitrate tolerance is accompanied by an increase in oxidative stress, endothelial dysfunction, and sympathetic activation, as well as a loss of the catalytic activity of ALDH2 itself. On the basis of current knowledge, nitrate intake in the diet would guarantee a concentration of NO such as to avoid (or at least reduce) treatment with GTN and the consequent onset of nitrate tolerance in the course of cardiovascular diseases, so as not to make necessary the increase in GTN concentrations and the possible inhibition/alteration of ALDH2, which aggravates the problem of a positive feedback mechanism. Therefore, the purpose of this review is to summarize data relating to the introduction into the diet of some natural products that could assist pharmacological therapy in order to provide the NO necessary to reduce the intake of GTN and the phenomenon of nitrate tolerance and to ensure the correct catalytic activity of ALDH2.

Differentially expressed genes and miRNAs in female osteoporosis patients

Osteoporosis is characterized by lowing bone mineral density. This study aimed to investigate the genes, miRNAs, pathways, and miRNA-gene interaction pairs involved in the pathogenesis of female osteoporosis. The differentially expressed genes (DEGs, GSE62402), differentially expressed miRNAs (DEmiRNAs, GSE63446), and differentially methylated genes (GSE62588) between females with low- and high-hip bone mineral density were identified. Genes common to DEGs, differentially methylated genes, DEmiRNAs' targets, and osteoporosis-related genes were retained and used to construct the miRNA-mRNA-pathway regulatory network. The expression of hub nodes was validated in microarray datasets (genes in GSE56116 and miRNAs in GSE93883). Thirty-four DEmiRNAs and 179 DEGs with opposite expression-methylation profiles were identified. Functional enrichment analysis showed that DEGs were associated with pathways including "hsa00380:Tryptophan metabolism," "hsa04670:Leukocyte transendothelial migration," "hsa04630:Jak-STAT signaling pathway," and "hsa04062:Chemokine signaling pathway." The miRNA-mRNA-pathway network included 10 DEGs, 9 miRNAs, and 4 osteoporosis-related pathways. The miRNA-gene-pathway axes including hsa-miR-27b-5p/3p-IFNAR1-hsa04630, hsa-miR-30a-5p/3p-IFNAR1-hsa04630, hsa-miR-30a-5p/3p-ALDH2-hsa00380, and hsa-miR-194-5p/3p-NCF2-hsa04670 were included in the network. Microarray validation showed that IFNAR1, NCF2, and ALDH2 were upregulated, and hsa-miR-30a-3p/5p, hsa-miR-194-3p/5p, hsa-miR-27b-3p/5p, and hsa-miR-34a-3p were downregulated in osteoporotic samples compared with control. Axes including hsa-miR-27b/30a-IFNAR1-Jak-STAT signaling pathway, hsa-miR-30a-ALDH2-Tryptophan metabolism, and hsa-miR-194-NCF2-Leukocyte transendothelial migration were involved in osteoporosis pathogenesis.

Influence of alcohol sensitivity on bone metastases and skeletal-related events in primary operable breast cancer: A retrospective cohort study

Background

Bone metastases in breast cancer patients are a common concern for medical doctors and dentists. Bone-modifying agents, which are necessary to prevent skeletal-related events (SREs), are associated with osteonecrosis of the jaw as an adverse side effect. Hypersensitivity to alcohol is an unfavorable response caused by deficiency of aldehyde dehydrogenase-2 (ALDH2) activity. Inactive ALDH2 is associated with osteoporosis, but its influence on bone metastases is unclear. The aim of our study was to evaluate the effects of alcohol sensitivity on bone metastases and SREs in primary operable breast cancer patients.

Methods

We retrospectively analyzed patients who were administered docetaxel, an anti-tumor agent, for histologically diagnosed breast cancer between April 2004 and September 2015. Alcohol sensitivity was assessed based on medical records of hypersensitivity to alcohol. The primary endpoint was time to bone metastases and the secondary endpoint was time to first SRE from the initial docetaxel administration. Data were stratified by alcohol sensitivity and tumor stages, and differences were estimated by the Kaplan-Meier method. Prognostic risk factors were analyzed by the multivariate Cox proportional hazards model.

Results

The median follow-up period of patients with high sensitivity to alcohol (n = 45) was 54 months and that for those with low sensitivity (n = 287) was 64 months. Stratification by alcohol sensitivity revealed that tumor stage exhibited significant correlations with the cumulative incidence of bone metastases in low-sensitivity patients; however, no differences were found in high-sensitivity patients. In multivariate analysis, alcohol sensitivity was a significant prognostic risk factor for bone metastases (HR 2.721, 95% CI 1.268–5.841, P = 0.010).

Conclusion

Alcohol sensitivity may be a prognostic risk factor for bone metastases. More detailed genetic investigations and metabolic analyses are needed.

[New insights into inherited bone marrow failure syndrome]

Inherited bone marrow failure syndromes (IBMFS) are a heterogeneous group of genetic disorders characterized by bone marrow failure, congenital anomalies, and increased risk of malignant disease. Next generation sequencing methods have greatly facilitated the discovery of genetic etiology in IBMFS. Recently, de novo mutations activating TP53 were detected in patients with BMFS, mimicking Diamond-Blackfan anemia (DBA), using whole exome sequencing, and these patients were recognized as having a novel disorder. This discovery provides important insights into the previously postulated connection between p53 activation and IBMFS. Furthermore, a novel IBMFS, aldehyde degradation deficiency syndrome, was found in patients with aplastic anemia resembling Fanconi anemia (FA). This disorder is caused by combined inactivating mutations in ADH5 and ALDH2 coding formaldehyde-detoxifying enzymes. In this review, we highlight recent studies on DBA, FA, and their related diseases in Japan.

Transformed ALDH2-/- hepatocytes by ethanol could serve as a useful tool for studying alcoholic hepatocarcinogenesis

Alcohol is a well-recognized hepatic carcinogen. Alcohol is metabolized into genotoxic acetaldehyde in hepatocytes, which is catalyzed by aldehyde dehydrogenase 2 (ALDH2). The detailed underlying mechanisms of alcohol-related hepatocellular carcinoma (HCC) remains unclear, at least partially, due to the absence of appropriate experimental models. Current studies suggest that rodents are not good models of the most common liver diseases that trigger HCC including alcoholic liver injury. We hypothesize that ethanol could induce transformation of immortalized normal liver cells, which may serve as a versatile tool for studying alcoholic HCC. Besides, we believe that knockout of ALDH2 will help to shorten the time course of transformation, as ALDH2 deficiency will significantly increase the accumulation of acetaldehyde in hepatocytes. Using this model, the dynamic changes of carcinogenesis-related molecular events could be easily examined. Furthermore, the transformed cells isolated from soft agar could be inoculated to mice for studying invasion, metastasis, and also for screening prophylactics.

Disruption of the aldehyde dehydrogenase 2 gene increases the bone anabolic response to intermittent PTH treatment in an ovariectomized mouse model

Aldehyde dehydrogenase 2 (ALDH2) is the enzyme that oxidizes the acetaldehyde produced by alcohol metabolism. This variant not only affects the response to alcohol but is also associated with several diseases, such as esophageal cancer, myocardial infarction, and particularly osteoporosis. In our previous study, we reported that compared to wild-type (WT) mice, Aldh2 knockout (KO) mice naturally have a strong bone formation ability, and high expression of parathyroid hormone receptor (PTHR1) in osteocytes. The effect of the Aldh2 gene on bone metabolism in response to intermittent PTH treatment is unknown. The purpose of this study was to clarify the effect of the Aldh2 gene on the bone anabolic response to intermittent PTH treatment in ovariectomized mice. Female KO and WT mice were ovariectomized at 8 weeks of age. At 14 weeks of age, the KO and WT mice were divided into vehicle-treated (Veh) and PTH-treated (PTH) groups (i.e., the WT-Veh, WT-PTH, KO-Veh and KO-PTH groups). PTH (1-34) and vehicle were subcutaneously administered to each group at a dose of 40 μg/kg body weight (BW) five times per week for 4 weeks. Micro-CT showed that the bone volume (BV), trabecular number (Tb.N), connectivity density (Conn.D), and cortical thickness (Ct.Th) values in the KO-PTH mice were significantly higher than those in the KO-Veh mice. Histomorphometric analysis showed that the BV, Tb.N, and mineral apposition rate (MAR) values in the KO-PTH group were significantly higher than those in the KO-Veh group. The mRNA expression level of PTHR1 in the KO-PTH group was significantly increased and that of p21 in the KO-PTH group was significantly decreased compared with the levels in the KO-Veh group. The expression of PTHR in osteocytes from the KO-PTH group was also significantly increased compared with that in osteocytes from the KO-Veh group. Furthermore, cell cultures revealed that the ALP⁺CFU-f/total CFU-f percentage was significantly higher in the KO-PTH group than in the KO-Veh group. We concluded that in ovariectomized Aldh2 KO mice, the bone anabolic response to intermittent PTH treatment was significantly enhanced compared to that in WT mice, which may be mediated by the high expression level of PTHR1.

The mitochondrial aldehyde dehydrogenase OsALDH2b negatively regulates tapetum degeneration in rice

Timely degradation of anther tapetal cells is a prerequisite for normal pollen development in flowering plants. Although several genes involved in tapetum development have been identified, the molecular basis of tapetum degeneration regulation remains poorly understood. In this study, we identified and characterized the nucleus-encoded, conserved mitochondrial aldehyde dehydrogenase OsALDH2b as a key regulator of tapetum degeneration in rice (Oryza sativa). OsALDH2b was highly expressed in anthers from meiosis to the early microspore stage. Mutation of OsALDH2b resulted in excess malonaldehyde accumulation and earlier programmed cell death in the tapetum, leading to premature tapetum degeneration and abnormal microspore development. These results demonstrate that OsALDH2b negatively regulates tapetal programmed cell death and is required for male reproductive development, providing insights into the regulation of tapetum development in plants.

Recent Efforts to Dissect the Genetic Basis of Alcohol Use and Abuse

Alcohol use disorder (AUD) is defined by several symptom criteria, which can be dissected further at the genetic level. Over the past several years, our understanding of the genetic factors influencing alcohol use and abuse has progressed tremendously; numerous loci have been implicated in different aspects of alcohol use. Previously known associations with alcohol-metabolizing enzymes (ADH1B, ALDH2) have been replicated definitively. In addition, novel associations with loci containing the genes KLB, GCKR, CRHR1, and CADM2 have been reported. Downstream analyses have leveraged these genetic findings to reveal important relationships between alcohol use behaviors and both physical and mental health. AUD and aspects of alcohol misuse have been shown to overlap strongly with psychiatric disorders, whereas aspects of alcohol consumption have shown stronger links to metabolism. These results demonstrate that the genetic architecture of alcohol consumption only partially overlaps with the genetics of clinically defined AUD. We discuss the limitations of using quantitative measures of alcohol use as proxy measures for AUD, and we outline how future studies will require careful phenotype harmonization to properly capture the genetic liability to AUD.

Activation of ALDH2 attenuates high glucose induced rat cardiomyocyte fibrosis and necroptosis

Necroptosis is one of a regulated programmed death mode, fibrosis is closely related with cell death. It has been reported that inhibition of necroptosis can play the protective role in cardiac ischemia and reperfusion injury, stroke and other diseases, but the mechanisms of aldehyde dehydrogenases 2 (ALDH2) against high glucose induced neonatal rat ventricular primary cardiomyocytes fibrosis and necroptosis had not been elucidated clearly. This study was to observe the effect of ALDH2 on high glucose (HG) induced myocardial fibrosis and necroptosis in primary rat cardiomyocytes model. In contrast to normal glucose group, in HG group, with the decreases of ALDH2 activity, mRNA and protein levels, the cardiomyocytes viability was decreased, reactive oxygen species (ROS), the inflammation factors - tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) levels, collagen I (col I) and col III mRNA expressions and tissue inhibitors of matrix metalloproteinase 4 (TIMP4) protein expression were increased, while matrix metalloproteinase 14 (MMP14) protein level, the ratio of MMP14/TIMP4 were decreased, and the necroptosis key factors - the receptor interacting protein 1 (RIP1), RIP3 and mixed lineage kinase domain-like protein (MLKL) at mRNA and protein expressions were increased, the inflammasome core proteins - NLRP3 and ASC protein expressions were also increased, the apoptosis rate and necrosis rate were also increased. When the cardiomyocytes were treated with Alda-1 (the ALDH2 agonist) in HG intervention, the cell viability, ALDH2 activity, mRNA and protein levels, MMP14 protein level, the ratio of MMP14/TIMP4 were higher, ROS and TNF-α, IL-6, IL-1β levels, RIP1, RIP3, MLKL, NLRP3 and ASC expressions, col I and col III, TIMP4 expressions, the apoptosis rate and necrosis rate were lower than in HG group. Daidzin, the antagonist of ALDH2 abolished the role of Alda-1. In summary, ALDH2 maybe is a key regulator in high glucose induced cardiomyocytes injury. Activation of ALDH2 prevented the happening of fibrosis, apoptosis and necroptosis in high glucose induced primary cardiomyocytes injury model, the protective effects were related to the inhibiting of oxidative stress and inflammation, changing of MMP14 and TIMP4, then inhibiting the happening of fibrosis, apoptosis and necroptosis. These findings advance our understanding of the intensive mechanisms of ALDH2's cardioprotection, and provide the targeted basis for clinical diabetes treatment.

[Effects of activation of mitochondrial aldehyde dehydrogenase 2 on inflammasome production in high glucose induced A549 cells]

OBJECTIVE

To investigate the effects of activation of mitochondrial aldehyde dehydrogenase 2(ALDH2) on high glucose-induced inflammasome production in alveolar epithelial A549 cells.

METHODS

The alveolar epithelial A549 cells were cultured with 25 mmol/L high glucose complete medium and divided into 4 groups: Control group, ALDH2 agonist 20 μmol/L Alda-1 group, ALDH2 antagonist 60 μmol/L Daidzin group, 20 μmol/L Alda-1 + 60 μmol/L Daidzin group. After the cells treated for 24 h, the cell proliferation activity was measured by thiazolyl blue tetrazolium bromide(MTT) colorimetric assaymethod, and the cellular reactive oxygen species(ROS) level were detected by dihydroethidium(DHE) fluorescent staining method, the cell migration ability was performed by cell scratching experiments, the protein expressions of ALDH2 and the core components of inflammasome, nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC) and cysteinyl aspartate specific protease-1(caspase-1) were detected by western blot.

RESULTS

Compared with the control group, after Alda-1 activated ALDH2 specifically, the cell proliferation activity did not change significantly, but the oxidative stress level and cell migration rate were significantly decreased(P<0.05). ALDH2 protein expression was significantly increased(P<0.05), the protein expressions of NLRP3, ASC and caspase-1 were significantly decreased(P<0.05). After Daidzin blocked ALDH2 specifically, there were no significant changes in cell proliferation, oxidative stress, cell migration rate, ALDH2 and ASC protein expressions, while NLRP3 protein expression was significantly increased(P<0.05), and caspase-1 protein expression was significantly decreased(P<0.05). Compared with Alda-1 group, there was no significant changes in cell proliferation and oxidative stress in Alda-1+Daidzin group, cell migration rate was significantly increased(P<0.05), ALDH2 protein expression was decreased(P<0.05), and the protein expressions of NLRP3, ASC and caspase-1 were significantly increased(P<0.05).

CONCLUSION

Increasing ALDH2 expression in alveolar epithelial A549 cells may attenuate high glucose-induced cellular inflammatory reaction, possibly through reducing cellular ROS level and reducing inflammasome expression.

Not just correlative: a new pathway defines how an ALDH2 SNP contributes to atherosclerosis

Individuals with the rs671 SNP in the gene encoding aldehyde dehydrogenase 2 (ALDH2) are at increased risk of cardiovascular disease (CVD); however, it has been unclear if this mutation contributes to CVD development. In this issue of the JCI, Zhong et al. perform an elegant set of experiments that reveal a pathway wherein the ALDH2 rs671 mutant is phosphorylated by AMPK and translocates to the nucleus where it represses the transcription of a lysosomal H+ pump subunit that is critical for lipid degradation and foam cell formation, as occurs in atherosclerosis. The discovery of this pathway may explain how subjects harboring ALDH2 rs671 are at a greater risk for numerous other disease states and thereby provide new targets for therapeutic intervention.

Genetic variants in ALDH1B1 and alcohol dependence risk in a British and Irish population: A bioinformatic and genetic study

Alcohol is metabolized in the liver via the enzymes alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Polymorphisms in the genes encoding these enzymes, which are common in East Asian populations, can alter enzyme kinetics and hence the risk of alcohol dependence and its sequelae. One of the most important genetic variants, in this regards, is the single nucleotide polymorphism (SNP) rs671 in ALDH2, the gene encoding the primary acetaldehyde metabolizing enzyme ALDH2. However, the protective allele of rs671 is absent in most Europeans although ALDH1B1, which shares significant sequence homology with ALDH2, contains several, potentially functional, missense SNPs that do occur in European populations. The aims of this study were: (i) to use bioinformatic techniques to characterize the possible effects of selected variants in ALDH1B1 on protein structure and function; and, (ii) to genotype three missense and one stop-gain, protein-altering, non-synonymous SNPs in 1478 alcohol dependent cases and 1254 controls of matched British and Irish ancestry. No significant allelic associations were observed between the three missense SNPs and alcohol dependence risk. The minor allele frequency of rs142427338 (Gln378Ter) was higher in alcohol dependent cases than in controls (allelic P = 0.19, OR = 2.98, [0.62–14.37]) but as this SNP is very rare the study was likely underpowered to detect an association with alcohol dependence risk. This potential association will needs to be further evaluated in other large, independent European populations.

Effects of long-term ethanol consumption and Aldh1b1 depletion on intestinal tumourigenesis in mice

Ethanol and its metabolite acetaldehyde have been classified as carcinogens for the upper aerodigestive tract, liver, breast, and colorectum. Whereas mechanisms related to oxidative stress and Cyp2e1 induction seem to prevail in the liver, and acetaldehyde has been proposed to play a crucial role in the upper aerodigestive tract, pathological mechanisms in the colorectum have not yet been clarified. Moreover, all evidence for a pro-carcinogenic role of ethanol in colorectal cancer is derived from correlations observed in epidemiological studies or from rodent studies with additional carcinogen application or tumour suppressor gene inactivation. In the current study, wild-type mice and mice with depletion of aldehyde dehydrogenase 1b1 (Aldh1b1), an enzyme which has been proposed to play an important role in acetaldehyde detoxification in the intestines, received ethanol in drinking water for 1 year. Long-term ethanol consumption led to intestinal tumour development in wild-type and Aldh1b1-depleted mice, but no intestinal tumours were observed in water-treated controls. Moreover, a significant increase in DNA damage was detected in the large intestinal epithelium of ethanol-treated mice of both genotypes compared with the respective water-treated groups, along with increased proliferation of the small and large intestinal epithelium. Aldh1b1 depletion led to increased plasma acetaldehyde levels in ethanol-treated mice, to a significant aggravation of ethanol-induced intestinal hyperproliferation, and to more advanced features of intestinal tumours, but it did not affect intestinal tumour incidence. These data indicate that ethanol consumption can initiate intestinal tumourigenesis without any additional carcinogen treatment or tumour suppressor gene inactivation, and we provide evidence for a role of Aldh1b1 in protection of the intestines from ethanol-induced damage, as well as for both carcinogenic and tumour-promoting functions of acetaldehyde, including increased progression of ethanol-induced tumours. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Alcohol consumption and prostate cancer incidence and progression: A Mendelian randomisation study

Prostate cancer is the most common cancer in men in developed countries, and is a target for risk reduction strategies. The effects of alcohol consumption on prostate cancer incidence and survival remain unclear, potentially due to methodological limitations of observational studies. In this study, we investigated the associations of genetic variants in alcohol-metabolising genes with prostate cancer incidence and survival. We analysed data from 23,868 men with prostate cancer and 23,051 controls from 25 studies within the international PRACTICAL Consortium. Study-specific associations of 68 single nucleotide polymorphisms (SNPs) in 8 alcohol-metabolising genes (Alcohol Dehydrogenases (ADHs) and Aldehyde Dehydrogenases (ALDHs)) with prostate cancer diagnosis and prostate cancer-specific mortality, by grade, were assessed using logistic and Cox regression models, respectively. The data across the 25 studies were meta-analysed using fixed-effect and random-effects models. We found little evidence that variants in alcohol metabolising genes were associated with prostate cancer diagnosis. Four variants in two genes exceeded the multiple testing threshold for associations with prostate cancer mortality in fixed-effect meta-analyses. SNPs within ALDH1A2 associated with prostate cancer mortality were rs1441817 (fixed effects hazard ratio, HRfixed  = 0.78; 95% confidence interval (95%CI):0.66,0.91; p values = 0.002); rs12910509, HRfixed  = 0.76; 95%CI:0.64,0.91; p values = 0.003); and rs8041922 (HRfixed  = 0.76; 95%CI:0.64,0.91; p values = 0.002). These SNPs were in linkage disequilibrium with each other. In ALDH1B1, rs10973794 (HRfixed  = 1.43; 95%CI:1.14,1.79; p values = 0.002) was associated with prostate cancer mortality in men with low-grade prostate cancer. These results suggest that alcohol consumption is unlikely to affect prostate cancer incidence, but it may influence disease progression.

Aldehyde dehydrogenase activity is necessary for beta cell development and functionality in mice

AIMS/HYPOTHESIS

Pancreatic beta cells maintain glucose homeostasis and beta cell dysfunction is a major risk factor in developing diabetes. Therefore, understanding the developmental regulatory networks that define a fully functional beta cell is important for elucidating the genetic origins of the disease. Aldehyde dehydrogenase activity has been associated with stem/progenitor cells and we have previously shown that Aldh1b1 is specifically expressed in pancreas progenitor pools. Here we address the hypothesis that Aldh1b1 may regulate the timing of the appearance and eventual functionality of beta cells.

METHODS

We generated an Aldh1b1-knockout mouse line (Aldh1b1 (tm1lacZ)) and used this to study pancreatic development, beta cell functionality and glucose homeostasis in the absence of Aldh1b1 function.

RESULTS

Differentiation in the developing pancreas of Aldh1b1 (tm1lacZ) null mice was accelerated. Transcriptome analyses of newborn and adult islets showed misregulation of key beta cell transcription factors and genes crucial for beta cell function. Functional analyses showed that glucose-stimulated insulin secretion was severely compromised in islets isolated from null mice. Several key features of beta cell functionality were affected, including control of oxidative stress, glucose sensing, stimulus-coupling secretion and secretory granule biogenesis. As a result of beta cell dysfunction, homozygous mice developed glucose intolerance and age-dependent hyperglycaemia.

CONCLUSIONS/INTERPRETATION

These findings show that Aldh1b1 influences the timing of the transition from the pancreas endocrine progenitor to the committed beta cell and demonstrate that changes in the timing of this transition lead to beta cell dysfunction and thus constitute a diabetes risk factor later in life. Gene Expression Omnibus (GEO) accession: GSE58025.

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.

[Verification and Validation on Single Nucleotide Polymorphism Analysis of Alcohol Metabolism-Related Genes ADH1B and ALDH2, Using Dried-Saliva Samples]

We have developed a new method for unprocessed biological specimens as templates directly into the TaqMan assay. Saliva was needed to be put on a water-soluble paper and dried, because foreign substances, such as a filter paper, hinder fluorescence detection through the assay. Genotyping of alcohol metabolism-related genes ADH1B (rs1229984) and ALDH2 (rs671) polymorphisms was, subsequently, performed by TaqMan PCR assay using dried saliva in the present investigation. The optimized technique was tested on 114 samples of alcoholic patients. The PCR-RFLP methods with purified DNA from blood samples were employed for validation of the assay. Upon validation, complete concordance was observed between the two independent results. These results highlight the ability of TaqMan PCR assays using dried saliva on water-soluble paper in genotyping of ADH1B and ALDH2 genes. Our results showed a rapid, simple, reliable, and cost-effective method for SNP genotyping of mutations in ADH1B and ALDH2 genes. This will be very useful for large-scale association studies in various fields. [Original].

Alcohol Use and Gamma-Glutamyltransferase Using a Mendelian Randomization Design in the Guangzhou Biobank Cohort Study

Background

Observational studies and small intervention studies suggest alcohol raises gamma-glutamyltransferase (GGT). We used Mendelian randomization to assess the causal effect of alcohol use on GGT in older Chinese people.

Methods

An instrumental variable (IV) analysis in 2,321 men and 2,757 women aged 50+ years from phase 3 of the Guangzhou Biobank Cohort Study with ALDH2 (rs671) genotyped, alcohol use and GGT available was used to assess the causal effect of alcohol use on GGT. Rs671 was used as an IV and F-statistics was used to test for weak instrument hypothesis. An F-statistic of ≥10 indicates the IV is not weak.

Results

In men, the F-statistic for rs671 on alcohol use was 70. Using IV analysis alcohol use increased GGT by 10.60 U/L per alcohol unit (10 gram ethanol) per day (95% confidence interval (CI) 6.58 to 14.62). The estimate was lower in observational multivariate regression: 3.48 U/L GGT per alcohol unit per day (95% CI 2.84 to 4.11) adjusted for age, education, physical activity and smoking. In women, rs671 was not associated with alcohol or GGT and the F-statistic was 7 precluding IV analysis.

Conclusion

In Mendelian randomization, we found confirmative evidence that alcohol use increases GGT among Southern Chinese men. Moreover, we found that the ALDH2 variant rs671 was not associated with GGT among Southern Chinese women who generally consume very low levels of alcohol. Taken together our findings strongly suggest that alcohol increases GGT, although we cannot rule out the possibility that other unknown factors may cause a different relation between alcohol and GGT in other populations.

Alcohol Dehydrogenase-1B (rs1229984) and Aldehyde Dehydrogenase-2 (rs671) Genotypes Are Strong Determinants of the Serum Triglyceride and Cholesterol Levels of Japanese Alcoholic Men

BACKGROUND

Elevated serum triglyceride (TG) and high-density-lipoprotein cholesterol (HDL-C) levels are common in drinkers. The fast-metabolizing alcohol dehydrogenase-1B encoded by the ADH1B*2 allele (vs. ADH1B*1/*1 genotype) and inactive aldehyde dehydrogenase-2 encoded by the ALDH2*2 allele (vs. ALDH2*1/*1 genotype) modify ethanol metabolism and are prevalent (≈90% and ≈40%, respectively) in East Asians. We attempted to evaluate the associations between the ADH1B and ALDH2 genotypes and lipid levels in alcoholics.

METHODS

The population consisted of 1806 Japanese alcoholic men (≥40 years) who had undergone ADH1B and ALDH2 genotyping and whose serum TG, total cholesterol, and HDL-C levels in the fasting state had been measured within 3 days after admission.

RESULTS

High serum levels of TG (≥150 mg/dl), HDL-C (>80 mg/dl), and low-density-lipoprotein cholesterol (LDL-C calculated by the Friedewald formula ≥140 mg/dl) were observed in 24.3%, 16.8%, and 15.6%, respectively, of the subjects. Diabetes, cirrhosis, smoking, and body mass index (BMI) affected the serum lipid levels. Multivariate analysis revealed that the presence of the ADH1B*2 allele and the active ALDH2*1/*1 genotype increased the odds ratio (OR; 95% confidence interval) for a high TG level (2.22 [1.67-2.94] and 1.39 [0.99-1.96], respectively), and decreased the OR for a high HDL-C level (0.37 [0.28-0.49] and 0.51 [0.37-0.69], respectively). The presence of the ADH1B*2 allele decreased the OR for a high LDL-C level (0.60 [0.45-0.80]). The ADH1B*2 plus ALDH2*1/*1 combination yielded the highest ORs for high TG levels and lowest OR for a high HDL-C level. The genotype effects were more prominent in relation to the higher levels of TG (≥220 mg/dl) and HDL-C (≥100 mg/dl).

CONCLUSIONS

The fast-metabolizing ADH1B and active ALDH2, and especially a combination of the two were strongly associated with higher serum TG levels and lower serum HDL-C levels of alcoholics. The fast-metabolizing ADH1B was associated with lower serum LDL-C levels.

Evaluation of Moderate Alcohol Use With QT Interval and Heart Rate Using Mendelian Randomization Analysis Among Older Southern Chinese Men in the Guangzhou Biobank Cohort Study

Western observational studies show that moderate alcohol use is associated with lower cardiovascular disease (CVD) risk, but these associations may be confounded by the healthier attributes of moderate users in these settings. Mendelian randomization analysis may help to ascertain the causal effect of moderate alcohol use on specific factors related to CVD and thereby clarify the role of alcohol. We used Mendelian randomization analysis with the aldehyde dehydrogenase 2 gene (ALDH2) as an instrumental variable to examine the association of alcohol units (10 g of ethanol) per day with heart rate-corrected QT interval and heart rate assessed from electrocardiogram among 4,588 older southern Chinese men in the Guangzhou Biobank Cohort Study (2003-2008). The F statistic was 77 for ALDH2 on alcohol use, suggesting little weak-instrument bias. Instrumental variable analysis showed that alcohol units were not associated with the corrected QT interval, with β = 1.04 (95% confidence interval: -0.61, 2.70) milliseconds, but they were associated with increased heart rate, with β = 0.98 (95% confidence interval: 0.04, 1.92) beat per minute. This study suggests that moderate alcohol use in men is not beneficial for heart function via QT interval or heart rate but could be detrimental. Future studies using specific cardiovascular outcomes may elucidate how alcohol affects different aspects of the cardiovascular system and, hence, the overall effects of alcohol on CVD can be estimated.

Effects of Alda-1, an Aldehyde Dehydrogenase-2 Agonist, on Hypoglycemic Neuronal Death

Hypoglycemic encephalopathy (HE) is caused by a lack of glucose availability to neuronal cells, and no neuroprotective drugs have been developed as yet. Studies on the pathogenesis of HE and the development of new neuroprotective drugs have been conducted using animal models such as the hypoglycemic coma model and non-coma hypoglycemia model. However, both models have inherent problems, and establishment of animal models that mimic clinical situations is desirable. In this study, we first developed a short-term hypoglycemic coma model in which rats could be maintained in an isoelectric electroencephalogram (EEG) state for 2 min and subsequent hyperglycemia without requiring anti-seizure drugs and an artificial ventilation. This condition caused the production of 4-hydroxy-2-nonenal (4-HNE), a cytotoxic aldehyde, in neurons of the hippocampus and cerebral cortex, and a marked increase in neuronal death as evaluated by Fluoro-Jade B (FJB) staining. We also investigated whether N-(1,3-benzodioxole-5-ylmethyl)-2,6-dichlorobenzamide (Alda-1), a small-molecule agonist of aldehyde dehydrogenase-2, could attenuate 4-HNE levels and reduce hypoglycemic neuronal death. After confirming that EEG recordings remained isoelectric for 2 min, Alda-1 (8.5 mg/kg) or vehicle (dimethyl sulfoxide; DMSO) was administered intravenously with glucose to maintain a blood glucose level of 250 to 270 mg/dL. Fewer 4-HNE and FJB-positive cells were observed in the cerebral cortex of Alda-1-treated rats than in DMSO-treated rats 24 h after glucose administration (P = 0.002 and P = 0.020). Thus, activation of the ALDH2 pathway could be a molecular target for HE treatment, and Alda-1 is a potentially neuroprotective agent that exerts a beneficial effect on neurons when intravenously administered simultaneously with glucose.

Interaction of DRD2TaqI, COMT, and ALDH2 genes associated with bipolar II disorder comorbid with anxiety disorders in Han Chinese in Taiwan

It is hypothesized that dopaminergic genes-dopamine type-2 receptor (DRD2), aldehyde dehydrogenase 2 (ALDH2), and catechol-O-methyltransferase (COMT)-are associated with bipolar disorder (BP) and anxiety disorder (AD). Bipolar II (BP-II) is reported to be highly comorbid with AD. We examined whether interactions among these three genes are susceptibility factors in BP-II with AD (BP-II(+AD)) and without AD (BP-II(-AD)). In this study, we hypothesize that the interaction of the dopaminergic genes between BP-II(+AD) and BP-II(-AD) is significant different. We recruited 1260 participants: 495 with BP-II(-AD), 170 with BP-II(+AD), and 595 healthy controls without BP-II or AD. Genotyping was done using polymerase chain reactions plus restriction fragment length polymorphism analysis. Genotypic frequencies of the DRD2TaqIA, COMT, and ALDH2 polymorphisms between the two BP-II groups were nonsignificant. In logistic regression, the ALDH2 and DRD2TaqIA genes showed a main effect that was protective against BP-II(-AD) (odds ratio [OR] = 0.497, p = 0.010, and OR = 0.415, p = 0.017, respectively). The interaction of DRD2TaqIA A1/A1 and ALDH2*1/*1 had a significant risk effect on the BP-II(-AD) group (OR = 7.177, p < 0.001). However, the interaction of DRD2TaqIA A1/A1, ALDH2*1/*1, and COMTMet/Met&Val/Met become a weak protective factor against BP-II(-AD) (OR = 0.205, p = 0.047). All of the significant results described above are found only in BP-II(-AD). This study supports the hypothesis the interaction of the dopaminergic genes between BP-II(+AD) and BP-II(-AD) is significant different,, and provides additional evidence that the DRD2TaqIA A1/A1, ALDH2*1/*1 and COMT genes interact in BP-II(-AD) but not in BP-II(+AD).

ALDH1B1 Is Crucial for Colon Tumorigenesis by Modulating Wnt/β-Catenin, Notch and PI3K/Akt Signaling Pathways

In the normal human colon, aldehyde dehydrogenase 1B1 (ALDH1B1) is expressed only at the crypt base, along with stem cells. It is also highly expressed in the human colonic adenocarcinomas. This pattern of expression corresponds closely to that observed for Wnt/β-catenin signaling activity. The present study examines the role of ALDH1B1 in colon tumorigenesis and signalling pathways mediating its effects. In a 3-dimensional spheroid growth model and a nude mouse xenograft tumor model, shRNA-induced suppression of ALDH1B1 expression decreased the number and size of spheroids formed in vitro and the size of xenograft tumors formed in vivo by SW 480 cells. Six binding elements for Wnt/β-catenin signalling transcription factor binding elements (T-cell factor/lymphoid enhancing factor) were identified in the human ALDH1B1 gene promoter (3 kb) but shown by dual luciferase reporter assay to not be necessary for ALDH1B1 mRNA expression in colon adenocarcinoma cell lines. We examined Wnt-reporter activity and protein/mRNA expression for Wnt, Notch and PI3K/Akt signaling pathways. Wnt/β-catenin, Notch and PI3K/Akt-signaling pathways were down-regulated in SW 480 cells in which ALDH1B1 expression had been suppressed. In summary, our data demonstrate that ALDH1B1 may promote colon cancer tumorigenesis by modulating the Wnt/β-catenin, Notch and PI3K/Akt signaling pathways. Selective targeting of ALDH1B1 may represent a novel means to prevent or treat colon cancer.

Effects of ALDH2 genotype, PPI treatment and L-cysteine on carcinogenic acetaldehyde in gastric juice and saliva after intragastric alcohol administration

Acetaldehyde (ACH) associated with alcoholic beverages is Group 1 carcinogen to humans (IARC/WHO). Aldehyde dehydrogenase (ALDH2), a major ACH eliminating enzyme, is genetically deficient in 30-50% of Eastern Asians. In alcohol drinkers, ALDH2-deficiency is a well-known risk factor for upper aerodigestive tract cancers, i.e., head and neck cancer and esophageal cancer. However, there is only a limited evidence for stomach cancer. In this study we demonstrated for the first time that ALDH2 deficiency results in markedly increased exposure of the gastric mucosa to acetaldehyde after intragastric administration of alcohol. Our finding provides concrete evidence for a causal relationship between acetaldehyde and gastric carcinogenesis. A plausible explanation is the gastric first pass metabolism of ethanol. The gastric mucosa expresses alcohol dehydrogenase (ADH) enzymes catalyzing the oxidation of ethanol to acetaldehyde, especially at the high ethanol concentrations prevailing in the stomach after the consumption of alcoholic beverages. The gastric mucosa also possesses the acetaldehyde-eliminating ALDH2 enzyme. Due to decreased mucosal ALDH2 activity, the elimination of ethanol-derived acetaldehyde is decreased, which results in its accumulation in the gastric juice. We also demonstrate that ALDH2 deficiency, proton pump inhibitor (PPI) treatment, and L-cysteine cause independent changes in gastric juice and salivary acetaldehyde levels, indicating that intragastric acetaldehyde is locally regulated by gastric mucosal ADH and ALDH2 enzymes, and by oral microbes colonizing an achlorhydric stomach. Markedly elevated acetaldehyde levels were also found at low intragastric ethanol concentrations corresponding to the ethanol levels of many foodstuffs, beverages, and dairy products produced by fermentation. A capsule that slowly releases L-cysteine effectively eliminated acetaldehyde from the gastric juice of PPI-treated ALDH2-active and ALDH2-deficient subjects. These results provide entirely novel perspectives for the prevention of gastric cancer, especially in established risk groups.

Genotyping on ALDH2: comparison of four different technologies

Objectives

This study aimed to compare the accuracy and performance of four genotyping methods for detecting single nucleotide polymorphisms (SNPs) in aldehyde dehydrogenase-2 (ALDH2), which is the principal enzyme involved in alcohol metabolism.

Design and Methods

We genotyped rs671 of ALDH2 in 96 coronary heart disease (CHD) patients with four methods including high resolution melting analysis (HRM), TaqMan allelic discrimination assay (TaqMan), allele-specific PCR (AS-PCR) and pyrosequencing. Meanwhile, we compared the accuracy and performance of these methods.

Results

All selected patients were successfully genotyped with referred methods. The results of these four assays showed 100% concordant results and had 100% accuracy as verified by Sanger sequencing.

Conclusions

All of the referred methods can be used for genotyping ALDH2 rs671 with the same accuracy compared to Sanger sequencing. In small size of clinical samples, HRM and AS-PCR outperform over others due to their lower cost and less hands-on operation, which are suitable for clinical application.

Aldehyde dedydrogenase-2 plays a beneficial role in ameliorating chronic alcohol-induced hepatic steatosis and inflammation through regulation of autophagy

BACKGROUND & AIMS

Mitochondrial aldehyde dehydrogenase (ALDH2) plays a critical role in the detoxification of the ethanol metabolite acetaldehyde. This study was designed to examine the impact of global ALDH2 overexpression on alcohol-induced hepatic steatosis.

METHODS

Wild type Friend virus B (FVB) and ALDH2 transgenic mice were placed on a 4% alcohol or control diet for 12 weeks. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin and cholesterol, hepatic triglyceride, steatosis, fat metabolism-related proteins, pro-inflammatory cytokines, glutathione (GSH), oxidized glutathione (GSSG), autophagy and autophagy signalling were examined. The role of autophagy was evaluated in alcohol dehydrogenase 1 (ADH1)-transfected human hepatocellular liver carcinoma cells (VA-13) treated with or without the autophagy inducer rapamycin and lysosomal inhibitors.

RESULTS

Chronic alcohol intake led to elevated AST-, ALT-levels, bilirubin, AST/ALT ratio, cholesterol, hepatic triglycerides and hepatic fat deposition as evidenced by H&E and Oil Red O staining. Hepatic fat deposition was associated with disturbed levels of fat metabolism-related proteins (fatty acid synthase, SCD1), upregulated interleukin-6, TNF-α, cyclooxygenase, oxidative stress, and loss of autophagy, effects which were attenuated or ablated by the ALDH2 transgene. Moreover, ethanol (100 mM) and acetaldehyde (100 and 500 μM) increased levels of IL-6 and IFN-γ, and suppressed autophagy in VA-13 cells, effects which were markedly alleviated by rapamycin. In addition, lysosomal inhibitors mimicked ethanol-induced p62 accumulation with little additive effect with ethanol. Ethanol significantly suppressed LC3 conversion in the presence of lysosomal inhibitors.

CONCLUSIONS

In summary, our results revealed that ALDH2 plays a beneficial role in ameliorating chronic alcohol intake-induced hepatic steatosis and inflammation through regulation of autophagy.

Association between Glu504Lys polymorphism of ALDH2 gene and cancer risk: a meta-analysis

Background

The association of the aldehyde dehydrogenases-2 (ALDH2) Glu504Lys polymorphism (also named Glu487Lys, or rs671) and cancers has been investigated. This meta-analysis aims to comprehensively assess the influence of this polymorphism on the overall cancer risk.

Methods

Eligible publications were retrieved according to inclusion/exclusion criteria and the data were analyzed using the Review Manager software (V5.2).

Results

A meta-analysis based on 51 case-control studies consisting of 16774 cases and 32060 controls was performed to evaluate the association between the ALDH2 Glu504Lys polymorphism and cancer risk. The comparison of genotypes Lys+ (Lys/Lys and Lys/Glu) with Glu/Glu yielded a significant 20% increased cancer risk (OR = 1.20, 95%CI: 1.03–1.39, P = 0.02, I² = 92%). Subgroup analysis by cancer type indicated a significantly increased UADT cancer risk (OR = 1.39, 95%CI: 1.11–1.73, P = 0.004, I² = 94%) in individuals with the Lys+ genotypes. Subgroup analysis by country indicated that individuals from Japan with the Lys+ genotypes had a significant 38% increased cancer risk (OR = 1.38, 95%CI: 1.12–1.71, P = 0.003, I² = 93%).

Conclusions

Our results indicated that the ALDH2 Glu504Lys polymorphism is a susceptible loci associated with overall cancers, especially esophageal cancer and among Japanese population.

Genetic polymorphisms modify bladder cancer recurrence and survival in a USA population-based prognostic study

OBJECTIVE

To identify genetic variants that modify bladder cancer prognosis focusing on genes involved in major biological carcinogenesis processes (apoptosis, proliferation, DNA repair, hormone regulation, immune surveillance, and cellular metabolism), as nearly half of patients with bladder cancer experience recurrences reliable predictors of this recurrent phenotype are needed to guide surveillance and treatment.

PATIENTS AND METHODS

We analysed variant genotypes hypothesised to modify these processes in 563 patients with urothelial-cell carcinoma enrolled in a population-based study of incident bladder cancer conducted in New Hampshire, USA. After diagnosis, patients were followed over time to ascertain recurrence and survival status, making this one of the first population-based studies with detailed prognosis data. Cox proportional hazards regression was used to assess the relationship between single nucleotide polymorphisms (SNPs) and prognosis endpoints.

RESULTS

Patients with aldehyde dehydrogenase 2 (ALDH2) variants had a shorter time to first recurrence (adjusted non-invasive hazard ratio [HR] 1.90, 95% confidence interval [CI] 1.29-2.78). There was longer survival among patients with non-invasive tumours associated with DNA repair X-ray repair cross-complementing protein 4 (XRCC4) heterozygous genotype compared with wild-type (adjusted HR 0.53, 95% CI 0.38-0.74). Time to recurrence was shorter for patients who had a variant allele in vascular cellular adhesion molecule 1 (VCAM1) and were treated with immunotherapy (P interaction < 0.001).

CONCLUSIONS

Our analysis suggests candidate prognostic SNPs that could guide personalised bladder cancer surveillance and treatment.

miR-28 promotes cardiac ischemia by targeting mitochondrial aldehyde dehydrogenase 2 (ALDH2) in mus musculus cardiac myocytes

OBJECTIVE

Aldehyde dehydrogenase 2 (ALDH2) is a crucial enzyme involved in protecting the heart from ischemic. MicroRNAs (miRNAs) are involved in gene down-regulation. However, this mechanism is unclear. The aim of this study was to investigate the role of miR-28 in the regulation of ALDH2 and to explore the mechanism of miR-28 in musculus of myocardial ischemia.

MATERIALS AND METHODS

To evaluate the role of miR-28, we assessed cellular apoptosis. In addition, the regulation of ALDH2 by miR-199b was evaluated by Western blotting and luciferase assay.

RESULTS

MiR-28 was up-regulated, while ALDH2 expression decreased in a time-dependent manner under normoxic conditions. The miR-28-transfected cells showed a significant decrease in the cellular apoptosis. Compared with the negative control 1 precursor molecules, miR-28 over-expression caused about 55% increase in myocardial apoptosis under hypoxic conditions, and miR-28 silencing by anti-miR-28 attenuated a 41% decreasing in apoptosis. MiR-28 and pGL3-ALDH2 vector-transfected cells showed that ALDH2 protein expression was suppressed and luciferase activity was reduced.

CONCLUSIONS

These findings suggest that miR-28 promotes myocardial ischemia through the inhibition of ALDH2 expression in mus. miRNAs is as a probable index in identification of myocardial ischemia after acute myocardial infarction.

Remote ischemic conditioning: from experimental observation to clinical application: report from the 8th Biennial Hatter Cardiovascular Institute Workshop

In 1993, Przyklenk and colleagues made the intriguing experimental observation that ‘brief ischemia in one vascular bed also protects remote, virgin myocardium from subsequent sustained coronary artery occlusion’ and that this effect ‘…. may be mediated by factor(s) activated, produced, or transported throughout the heart during brief ischemia/reperfusion’. This seminal study laid the foundation for the discovery of ‘remote ischemic conditioning’ (RIC), a phenomenon in which the heart is protected from the detrimental effects of acute ischemia/reperfusion injury (IRI), by applying cycles of brief ischemia and reperfusion to an organ or tissue remote from the heart. The concept of RIC quickly evolved to extend beyond the heart, encompassing inter-organ protection against acute IRI. The crucial discovery that the protective RIC stimulus could be applied non-invasively, by simply inflating and deflating a blood pressure cuff placed on the upper arm to induce cycles of brief ischemia and reperfusion, has facilitated the translation of RIC into the clinical setting. Despite intensive investigation over the last 20 years, the underlying mechanisms continue to elude researchers. In the 8th Biennial Hatter Cardiovascular Institute Workshop, recent developments in the field of RIC were discussed with a focus on new insights into the underlying mechanisms, the diversity of non-cardiac protection, new clinical applications, and large outcome studies. The scientific advances made in this field of research highlight the journey that RIC has made from being an intriguing experimental observation to a clinical application with patient benefit.

Somatic mutations of amino acid metabolism-related genes in gastric and colorectal cancers and their regional heterogeneity--a short report

BACKGROUND

Metabolic reprogramming is an emerging topic in cancer research. However, genetic alterations in genes encoding enzymes involved in amino acid metabolism are largely unknown. The aim of this study was to explore whether genes known to be involved in amino acid metabolism are mutated in gastric cancer (GC) and/or colorectal cancer (CRC).

METHODS

Through a public database search, we found that a number of genes known to be involved in amino acid metabolism, i.e., AGXT, ALDH2, APIP, MTR, DNMT1, ASH1L, ASPA, CAD, DDC, GCDH, DLD, LAP3, MCEE and MUT, harbor mononucleotide repeats that may serve as mutation targets in cancers exhibiting microsatellite instability (MSI). We assessed these genes for the presence of the mutations in 79 GCs and 124 CRCs using single-strand conformation polymorphism (SSCP) and direct sequencing analyses.

RESULTS

Using SSCP in conjunction with DNA sequencing we detected frameshift mutations in AGXT (17 cases), ALDH2 (3 cases), APIP (4 cases), MTR (5 cases), DNMT1 (1 case), ASH1L (1 case), ASPA (2 cases), CAD (2 cases), DDC (1 case), GCDH (3 cases), DLD (1 case), LAP3 (1 case), MCEE (5 cases) and MUT (1 case). These mutations were exclusively detected in MSI-high (MSI-H), and not in MSI-low or MSI-stable (MSI-L/MSS) cases. In addition, we analyzed 16 CRCs for the presence of intra-tumor heterogeneity (ITH) and found that two CRCs harbored regional ITH for GCDH frameshift mutations.

CONCLUSIONS

Our data indicate that genes known to be involved in amino acid metabolism recurrently acquire somatic mutations in MSH-H GCs and MSH-H CRCs and that, in addition, mutation ITH does occur in at least some of these tumors. Together, these data suggest that metabolic reprogramming may play a role in the etiology of MSI-H GCs and CRCs. Our data also suggest that ultra-regional mutation analysis is required for a more comprehensive evaluation of the mutation status in these tumors.

Genetic variation in alcohol metabolizing enzymes among Inuit and its relation to drinking patterns

BACKGROUND

Variation in genes involved in alcohol metabolism is associated with drinking patterns worldwide. We compared variation in these genes among the Inuit with published results from the general population of Denmark and, due to the Asian ancestry of the Inuit, with Han Chinese. We analyzed the association between gene variations and drinking patterns among the Inuit.

METHODS

We genotyped 4162 Inuit participants from two population health surveys. Information on drinking patterns was available for 3560. Seven single nucleotide polymorphisms (SNPs) were examined: ADH1B arg48his, ADH1C ile350val, ADH1C arg272gln, ALDH2 glu504lys, ALDH2 5'-UTR A-357G, ALDH1B1 ala86val and ALDH1B1 arg107leu.

RESULTS

The allele distribution differed significantly between Inuit and the general population of Denmark. A protective effect on heavy drinking was found for the TT genotype of the ALDH1B1 arg107leu SNP (OR=0.59; 95% CI 0.37-0.92), present in 3% of pure Inuit and 37% of Danes. The ADH1C GG genotype was associated with heavy drinking and a positive CAGE test (OR 1.34; 95% CI 1.05-1.72). It was present in 27% of Inuit and 18% of Danes. The Asian genotype pattern with a high frequency of the ADH1B A allele and an ALDH2 gene coding for an inactive enzyme was not present in Greenland.

CONCLUSIONS

ADH1C and ALDH1B1 arg107leu SNPs play a role in the shaping of drinking patterns among the Inuit in Greenland. A low frequency of the ALDH1B1 arg107leu TT genotype compared with the general population in Denmark deserves further study. This genotype was protective of heavy drinking among the Inuit.