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Graphic Medicine Review 2024Nearly 540 million people world-wide have facial flushing and an increased heart rate after consuming alcohol. Known as the alcohol flushing response, this reaction to...
Nearly 540 million people world-wide have facial flushing and an increased heart rate after consuming alcohol. Known as the alcohol flushing response, this reaction to alcohol is a result of a genetic variant in an enzyme aldehyde dehydrogenase 2 (ALDH2), known as ALDH2*2. Mainly carried by those of East Asian descent, the genetic variant is likely the most common genetic variant carried in the world. Carrying this ALDH2*2 genetic variant has important health implications with respect cancer risk which is increased when carriers of the ALDH2*2 genetic variant frequently use of alcohol or tobacco products. This comic explains the alcohol flush response and the health risks associated with alcohol and tobacco use for those who carry an ALDH2*2 variant.
PubMed: 38895023
DOI: 10.7191/gmr.807 -
Research Square Aug 2023The mechanisms underlying alcohol-induced breast carcinogenesis are not fully understood but may involve hormonal changes.
BACKGROUND
The mechanisms underlying alcohol-induced breast carcinogenesis are not fully understood but may involve hormonal changes.
METHODS
We investigated cross-sectional associations between self-reported alcohol intake and serum or plasma concentrations of oestradiol, oestrone, progesterone (in pre-menopausal women only), testosterone, androstenedione, DHEAS (dehydroepiandrosterone sulphate) and SHBG (sex hormone binding globulin) in 45 431 pre-menopausal and 173 476 post-menopausal women. We performed multivariable linear regression separately for UK Biobank, EPIC (European Prospective Investigation into Cancer and Nutrition) and EHBCCG (Endogenous Hormones and Breast Cancer Collaborative Group), and meta-analysed the results. For testosterone and SHBG, we also conducted two-sample Mendelian Randomization (MR) and colocalisation using the (Alcohol Dehydrogenase 1B) variant (rs1229984).
RESULTS
Alcohol intake was positively, though weakly, associated with all hormones (except progesterone in pre-menopausal women), with increments in concentrations per 10 g/day increment in alcohol intake ranging from 1.7% for luteal oestradiol to 6.6% for post-menopausal DHEAS. There was an inverse association of alcohol with SHBG in post-menopausal women but a small positive association in pre-menopausal women. MR identified positive associations of alcohol intake with total testosterone (difference per 10 g/day increment: 4.1%; 95% CI: 0.6%, 7.6%) and free testosterone (7.8%; 4.1%, 11.5%), and an inverse association with SHBG (-8.1%; -11.3%, -4.9%). Colocalisation suggested a shared causal locus at between alcohol intake and higher free testosterone and lower SHBG (PP4: 0.81 and 0.97 respectively).
CONCLUSIONS
Alcohol intake was associated with small increases in sex hormone concentrations, including bioavailable fractions, which may contribute to its effect on breast cancer risk.
PubMed: 37645769
DOI: 10.21203/rs.3.rs-3249588/v1 -
Frontiers in Aging Neuroscience 2023Aldehyde dehydrogenase 2 (ALDH2) is an enzyme found in the mitochondrial matrix that plays a central role in alcohol and aldehyde metabolism. A common ALDH2 polymorphism... (Review)
Review
Aldehyde dehydrogenase 2 (ALDH2) is an enzyme found in the mitochondrial matrix that plays a central role in alcohol and aldehyde metabolism. A common ALDH2 polymorphism in East Asians descent (called ALDH2*2 or E504K missense variant, SNP ID: rs671), present in approximately 8% of the world's population, has been associated with a variety of diseases. Recent meta-analyses support the relationship between this ALDH2 polymorphism and Alzheimer's disease (AD). And AD-like pathology observed in ALDH2 null mice and ALDH2*2 overexpressing transgenic mice indicate that ALDH2 deficiency plays an important role in the pathogenesis of AD. Recently, the worldwide increase in alcohol consumption has drawn attention to the relationship between heavy alcohol consumption and AD. Of potential clinical significance, chronic administration of alcohol in ALDH2*2/*2 knock-in mice exacerbates the pathogenesis of AD-like symptoms. Therefore, ALDH2 polymorphism and alcohol consumption likely play an important role in the onset and progression of AD. Here, we review the data on the relationship between ALDH2 polymorphism, alcohol, and AD, and summarize what is currently known about the role of the common ALDH2 inactivating mutation, ALDH2*2, and alcohol in the onset and progression of AD.
PubMed: 37693648
DOI: 10.3389/fnagi.2023.1223977 -
Blood Jul 2023Sickle cell disease (SCD) is a chronic hemolytic and systemic hypoxia condition with constant oxidative stress and significant metabolic alterations. However, little is...
Sickle cell disease (SCD) is a chronic hemolytic and systemic hypoxia condition with constant oxidative stress and significant metabolic alterations. However, little is known about the correlation between metabolic alterations and the pathophysiological symptoms. Here, we report that Nrf2, a master regulator of cellular antioxidant responses, regulates the production of the metabolite l-2-hydroxyglutarate (L2HG) to mediate epigenetic histone hypermethylation for gene expression involved in metabolic, oxidative, and ferroptotic stress responses in SCD. Mechanistically, Nrf2 was found to regulate the expression of L2HG dehydrogenase (L2hgdh) to mediate L2HG production under hypoxia. Gene expression profile analysis indicated that reactive oxygen species (ROS) and ferroptosis responses were the most significantly affected signaling pathways after Nrf2 ablation in SCD. Nrf2 silencing and L2HG supplementation sensitize human sickle erythroid cells to ROS and ferroptosis stress. The absence of Nrf2 and accumulation of L2HG significantly affect histone methylation for chromatin structure modification and reduce the assembly of transcription complexes on downstream target genes to regulate ROS and ferroptosis responses. Furthermore, pharmacological activation of Nrf2 was found to have protective effects against ROS and ferroptosis stress in SCD mice. Our data suggest a novel mechanism by which Nrf2 regulates L2HG levels to mediate SCD severity through ROS and ferroptosis stress responses, suggesting that targeting Nrf2 is a viable therapeutic strategy for ameliorating SCD symptoms.
Topics: Ferroptosis; Glutarates; NF-E2-Related Factor 2; Anemia, Sickle Cell; Chromatin; Epigenesis, Genetic; Methylation; Alcohol Oxidoreductases; Animals; Mice; Reactive Oxygen Species; Transcription, Genetic; Gene Expression Profiling
PubMed: 37267508
DOI: 10.1182/blood.2022018159 -
BMC Genomics Oct 2023Although it is known that variation in the aldehyde dehydrogenase 2 (ALDH2) gene family influences the East Asian alcohol flushing response, knowledge about other... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Although it is known that variation in the aldehyde dehydrogenase 2 (ALDH2) gene family influences the East Asian alcohol flushing response, knowledge about other genetic variants that affect flushing symptoms is limited.
METHODS
We performed a genome-wide association study meta-analysis and heritability analysis of alcohol flushing in 15,105 males of East Asian ancestry (Koreans and Chinese) to identify genetic associations with alcohol flushing. We also evaluated whether self-reported flushing can be used as an instrumental variable for alcohol intake.
RESULTS
We identified variants in the region of ALDH2 strongly associated with alcohol flushing, replicating previous studies conducted in East Asian populations. Additionally, we identified variants in the alcohol dehydrogenase 1B (ADH1B) gene region associated with alcohol flushing. Several novel variants were identified after adjustment for the lead variants (ALDH2-rs671 and ADH1B-rs1229984), which need to be confirmed in larger studies. The estimated SNP-heritability on the liability scale was 13% (S.E. = 4%) for flushing, but the heritability estimate decreased to 6% (S.E. = 4%) when the effects of the lead variants were controlled for. Genetic instrumentation of higher alcohol intake using these variants recapitulated known associations of alcohol intake with hypertension. Using self-reported alcohol flushing as an instrument gave a similar association pattern of higher alcohol intake and cardiovascular disease-related traits (e.g. stroke).
CONCLUSION
This study confirms that ALDH2-rs671 and ADH1B-rs1229984 are associated with alcohol flushing in East Asian populations. Our findings also suggest that self-reported alcohol flushing can be used as an instrumental variable in future studies of alcohol consumption.
Topics: Humans; Male; Alcohol Dehydrogenase; Alcohol Drinking; Aldehyde Dehydrogenase, Mitochondrial; East Asian People; Genome-Wide Association Study; Polymorphism, Single Nucleotide; Flushing
PubMed: 37875790
DOI: 10.1186/s12864-023-09721-7 -
Alcohol and Alcoholism (Oxford,... Jan 2024Ethanol metabolism plays an essential role in how the body perceives and experiences alcohol consumption, and evidence suggests that modulation of ethanol metabolism can... (Review)
Review
Ethanol metabolism plays an essential role in how the body perceives and experiences alcohol consumption, and evidence suggests that modulation of ethanol metabolism can alter the risk for alcohol use disorder (AUD). In this review, we explore how ethanol metabolism, mainly via alcohol dehydrogenase and aldehyde dehydrogenase 2 (ALDH2), contributes to drinking behaviors by integrating preclinical and clinical findings. We discuss how alcohol dehydrogenase and ALDH2 polymorphisms change the risk for AUD, and whether we can harness that knowledge to design interventions for AUD that alter ethanol metabolism. We detail the use of disulfiram, RNAi strategies, and kudzu/isoflavones to inhibit ALDH2 and increase acetaldehyde, ideally leading to decreases in drinking behavior. In addition, we cover recent preclinical evidence suggesting that strategies other than increasing acetaldehyde-mediated aversion can decrease ethanol consumption, providing other potential metabolism-centric therapeutic targets. However, modulating ethanol metabolism has inherent risks, and we point out some of the key areas in which more data are needed to mitigate these potential adverse effects. Finally, we present our opinions on the future of treating AUD by the modulation of ethanol metabolism.
Topics: Humans; Alcoholism; Ethanol; Aldehyde Dehydrogenase, Mitochondrial; Aldehyde Dehydrogenase; Alcohol Dehydrogenase; Alcohol Drinking; Acetaldehyde
PubMed: 37950904
DOI: 10.1093/alcalc/agad077 -
The Journal of Nutrition Jul 2023Elevated serum erythritol concentration is a predictive biomarker of diabetes and cardiovascular incidence and complications. Erythritol is synthesized endogenously from...
BACKGROUND
Elevated serum erythritol concentration is a predictive biomarker of diabetes and cardiovascular incidence and complications. Erythritol is synthesized endogenously from glucose, but little is known regarding the origin of elevated circulating erythritol in vivo.
OBJECTIVES
In vitro evidence indicates that intracellular erythritol is elevated by high-glucose cell culture conditions and that final step of erythritol synthesis is catalyzed by the enzymes sorbitol dehydrogenase (SORD) and alcohol dehydrogenase (ADH) 1. The purpose of this study was to determine whether dietary intake and/or diet-induced obesity affect erythritol synthesis in mice and whether this relationship is modified by the loss of the enzymes SORD or ADH1.
METHODS
First, 8-wk-old male Sord, Sord, Adh1, and Adh1 mice were fed either low-fat diet (LFD) with 10% fat-derived calories or diet-induced obesity high-fat diet (HFD) with 60% fat-derived calories for 8 wk. Plasma and tissue erythritol concentrations were measured using gas chromatography-mass spectrometry. Second, male wild-type 8-wk-old C57BL/6J mice were fed LFD or HFD with plain drinking water or 30% sucrose water for 8 wk. Blood glucose and plasma and urinary erythritol concentrations were measured in nonfasted and fasted samples. Tissue erythritol was measured after killing. Finally, male Sord and Sord mice were fed LFD with 30% sucrose water for 2 wk; then, nonfasted plasma, urine, and tissue erythritol concentrations were quantified.
RESULTS
Plasma and tissue erythritol concentrations were not affected by loss of Sord or Adh1 in mice fed LFD or HFD. In wild-type mice, consumption of 30% sucrose water significantly elevated plasma and urinary erythritol concentrations on both LFD-fed and HFD-fed mice compared with that of plain water. Sord genotype did not affect plasma or urinary erythritol concentration in response to sucrose feeding, but Sord mice had reduced kidney erythritol content compared with wild-type littermates in response to sucrose.
CONCLUSIONS
Sucrose intake, not HFD, elevates erythritol synthesis and excretion in mice. Loss of ADH1 or SORD does not significantly affect erythritol concentration in mice.
Topics: Mice; Male; Animals; Dietary Fats; Erythritol; Mice, Inbred C57BL; Obesity; Diet, High-Fat; Glucose; Sucrose
PubMed: 37245661
DOI: 10.1016/j.tjnut.2023.05.022 -
Experimental Cell Research Dec 2023Alcohol dehydrogenase 1 (ADH1) is an alcohol-oxidizing enzyme with poorlydefined biology. Here we report that ADH1 is highly expressed in kidneys of mice with lethal...
Alcohol dehydrogenase 1 (ADH1) is an alcohol-oxidizing enzyme with poorlydefined biology. Here we report that ADH1 is highly expressed in kidneys of mice with lethal endotoxemia and is transcriptionally upregulated in tubular cells by lipopolysaccharide (LPS) stimuli through TLR4/NF-κB cascade. The Adh1 knockout (Adh1) mice with lethal endotoxemia displayed increased susceptibility to acute kidney injury (AKI) but not systemic inflammatory response. Adh1 mice develop more severe tubular cell apoptosis in comparison to Adh1 wild-type (Adh1) mice during course of lethal endotoxemia. ADH1 deficiency facilitates the LPS-induced tubular cell apoptosis in a caspase-dependent manner. Mechanistically, ADH1 deficiency dampens tubular mitophagy that relies on PINK1-Parkin pathway characterized by the reduced membrane potential, reactive oxygen species (ROS) and release of fragmented mtDNA to cytosol. Kidney-specific overexpression of PINK1 and Parkin by adeno-associated viral vector 9 (AAV9) delivery ameliorates AKI exacerbation in Adh1 mice with lethal endotoxemia. Our study supports the notion that ADH1 is critical for blockade of tubular apoptosis mediated by mitophagy, allowing the rapid identification and targeting of alcohol-metabolic route applicable to septic AKI.
Topics: Animals; Male; Mice; Acute Kidney Injury; Alcohol Dehydrogenase; Apoptosis; Endotoxemia; Kidney Tubules; Lipopolysaccharides; Mice, Inbred C57BL; Mice, Knockout; Mitophagy; Protein Kinases; Reactive Oxygen Species; Sepsis; Ubiquitin-Protein Ligases
PubMed: 37806378
DOI: 10.1016/j.yexcr.2023.113804 -
Cancer Medicine Oct 2023Previous studies have shown that ALDH2 and ADH1B genes may be associated with alcohol metabolism and the risk of esophageal squamous cell carcinoma (ESCC), with... (Meta-Analysis)
Meta-Analysis
Relationship between esophageal squamous cell carcinoma risk and alcohol-related ALDH2 and ADH1B polymorphisms: Evidence from a meta-analysis and Mendelian randomization analysis.
BACKGROUND
Previous studies have shown that ALDH2 and ADH1B genes may be associated with alcohol metabolism and the risk of esophageal squamous cell carcinoma (ESCC), with inconsistent results. This meta-analysis aimed at comprehensively assessing the associations between ALDH2 and ADH1B polymorphisms and the risk of ESCC to synthesize and clarify the evidence.
METHODS
We calculated summary estimates of the associations between four genetic variants (rs671 and rs674 in ALDH2, and rs1229984 and rs1042026 in ADH1B) and the ESCC risk across 23 publications in the additive model and allelic model. Venice criteria, Bayesian false discovery probability (BFDP), and false-positive reporting probability (FPRP) were used to assess the strength of epidemiological evidence. Heterogeneity among studies was evaluated by using the Higgin's I statistic, and publication bias was assessed by using funnel plots and Begg's test. A Mendelian randomization (MR) analysis was performed to determine the causal association between alcohol intake and esophageal cancer risk. Data from the HaploReg v4.1 and PolyPhen-2 were analyzed for functional annotations.
RESULTS
Of the four genetic variants, rs671 of ALDH2 was associated with a significantly reduced risk of ESCC (OR: 0.60, 95% CI: 0.50-0.73), whereas rs1229984 of ADH1B was associated with a significantly increased risk (2.50, 95% CI: 1.70-3.69) in the additive model. In the allelic model, the variant rs1229984 of ADH1B also increased the risk of ESCC (OR: 1.50; 95% CI: 1.21-1.87). The result for the variant rs671 was considered as strong epidemiological evidence. Functional annotations identified that the four variants were related to the enhancer histone marks and motif changes. The other two variants were not associated with the ESCC risk (rs674 of ALDH2 OR: 1.22, 95% CI: 0.71-2.12; rs1042026 of ADH1B OR: 1.28, 95% CI: 0.52-3.14) in the additive model. The MR analysis did not find a causal effect of alcohol on the esophageal cancer risk.
CONCLUSIONS
The results showed that ADH1B rs1229984 was significantly associated with an increased the risk of ESCC.
Topics: Humans; Esophageal Squamous Cell Carcinoma; Mendelian Randomization Analysis; Esophageal Neoplasms; Bayes Theorem; Risk Factors; Genetic Predisposition to Disease; Aldehyde Dehydrogenase, Mitochondrial; Alcohol Drinking; Ethanol; Genotype; Polymorphism, Single Nucleotide
PubMed: 37795758
DOI: 10.1002/cam4.6610 -
Cancer Medicine Sep 2023Single-nucleotide polymorphisms (SNPs) in PNPLA3 and hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) genes are associated with fatty liver disease (FLD) progression...
AIM
Single-nucleotide polymorphisms (SNPs) in PNPLA3 and hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) genes are associated with fatty liver disease (FLD) progression and carcinogenesis. In the present study, we evaluated the characteristics of Japanese FLD patients according to HSD17B13 polymorphisms.
METHODS
We enrolled 402 patients who were clinically and pathologically diagnosed with FLD (alcoholic: 63 cases, nonalcoholic: 339 cases) at our hospital in 1990-2018 (228 males; median age: 54.9 [14.6-83.6] years). FLD patients with HSD17B13 A/A (212 cases) and others (A/AA or AA/AA; 190 cases) were compared.
RESULTS
Compared to patients with HSD17B13 A/A and others, those with the A/A genotype showed increased incidence of hepatocellular carcinoma (HCC) (A/A vs. others; 18.4% vs. 9.5%, p = 0.01), cardiovascular diseases (14.2% vs. 4.2%, p < 0.01), and hypertension (56.6% vs. 47.4%, p = 0.06). In patients without A/A, the HCC incidence was significantly reduced in those with alcohol-related FLD, fibrosis-4 index <2.67, and the PNPLA3 CC genotype; however, there was no significant difference in nonalcoholic-FLD. Patients without HSD17B13 A/A showed severe steatosis (77% vs. 88.6%, p < 0.01). New HCC developed in 11 cases and the 5-year incidence rate of HCC was 3.3% in patients with both PNPLA3 GG/GC and HSD17B13 A/A, which was significantly higher than the rate for those with other SNP profiles (0.6%, p = 0.03).
CONCLUSIONS
Inhibiting HSD17B13 activity may prevent HCC development, particularly in alcohol-related FLD and low-risk patients. Therefore, combinations of SNPs and other risk factors can be used for screening FLD-HCC.
Topics: Male; Humans; Middle Aged; Carcinoma, Hepatocellular; Liver Neoplasms; Case-Control Studies; Non-alcoholic Fatty Liver Disease; Fatty Liver, Alcoholic; Polymorphism, Single Nucleotide; Genetic Predisposition to Disease
PubMed: 37644826
DOI: 10.1002/cam4.6410