Aldehyde dehydrogenase deficiency as cause of facial flushing reaction to alcohol in Japanese

Associations of ADH1B and ALDH2 genotypes and alcohol flushing with drinking history, withdrawal symptoms, and ICD-10 criteria in Japanese alcohol-dependent men

OBJECTIVES

Given the high prevalence of fast-metabolizing alcohol dehydrogenase-1B*2 (ADH1B*2 ) and inactive aldehyde dehydrogenase-2*2 (ALDH2*2 ) alleles in East Asians, we evaluated how the ADH1B / ALDH2 genotypes and alcohol flushing might affect the development of alcohol dependence (AD).

METHODS

We evaluated how the ADH1B / ALDH2 genotypes and self-reported alcohol flushing affected history of drinking events and withdrawal symptoms and ICD-10 criteria in 4116 Japanese AD men.

RESULTS

The ADH1B*1/*1 group and ALDH2*1/*1 group were 1-5 years younger than the ADH1B*2 (+) and ALDH2*1/*2 groups, respectively, for all of the ages at onset of habitual drinking, blackouts, daytime drinking, uncontrolled drinking, withdrawal symptoms, and first treatment for AD, and the current age. Blackouts were more common in the ADH1B*1/*1 group and ALDH2*1/*1 group. Daytime drinking, uncontrolled drinking, and withdrawal symptoms, such as hand tremor, sweating, convulsions, and delirium tremens/hallucinations were more common in the ADH1B*1/*1 group. The ADH1B*1/*1 was positively associated with the ICD-10 criteria for 'tolerance' and 'withdrawal symptoms'. The ADH1B*1/*1 group and ALDH2*1/*2 group had a larger ICD-10 score. Never flushing was reported by 91.7% and 35.2% of the ALDH2*1/*1 and ALDH2*1/*2 carriers, respectively. After a 1-2-year delay in the onset of habitual drinking in the former-/current-flushing group, no differences in the ages of the aforementioned drinking milestones were found according to the flushing status.

CONCLUSION

The ADH1B*1/*1 and ALDH2*1/*1 accelerated the development of drinking events and withdrawal symptoms in Japanese AD patients. ICD-10 score was larger in the ADH1B*1/*1 group and ALDH2*1/*2 group. The effects of alcohol flushing on drinking events were limited.

Preparation of antiviral multispray with cationic antimicrobial dialkyldimethyl ammonium salt and sulfobetaine against new coronaviruses (SARS-CoV-2)

The novel sudden acute respiratory syndrome coronavirus 2 is an enveloped virus currently causing severe illness and death worldwide. Common antiseptics such as alcohol have some efficacy in disinfecting everyday surroundings, but development of more effective disinfectants is imperative. A series of studies focusing on cationic antimicrobials resulted in the development of a safe and effective novel coronavirus disinfectant, DEA-171, which provides ≥99.98 % inhibition of all novel coronavirus variants within 1 min.

Risk of newly developed atrial fibrillation by alcohol consumption differs according to genetic predisposition to alcohol metabolism: a large-scale cohort study with UK Biobank

BACKGROUND

The predictive relationship between mild-to-moderate alcohol consumption and the risk of incident atrial fibrillation (AF) remains controversial.

OBJECTIVE

We investigated whether the relationship between alcohol consumption and the risk of incident AF could be associated with the genetic predisposition to alcohol metabolism.

METHODS

A total of 399,329 subjects with genetic data from the UK Biobank database, enrolled between 2006 and 2010, were identified and followed for incident AF until 2021. Genetic predisposition to alcohol metabolism was stratified according to the polygenic risk score (PRS) tertiles. Alcohol consumption was categorized as non-drinkers, mild-to-moderate drinkers (< 30 g/day), and heavy drinkers (≥ 30 g/day).

RESULTS

During the follow-up (median 12.2 years), 19,237 cases of AF occurred. When stratified by PRS tertiles, there was a significant relationship between genetic predisposition to alcohol metabolism and actual alcohol consumption habits (P < 0.001). Mild-to-moderate drinkers showed a decreased risk of AF (HR 0.96, 95% CI 0.92-0.99), and heavy drinkers showed an increased risk of AF (HR 1.06, 95% CI 1.02-1.10) compared to non-drinkers. When stratified according to PRS tertiles for genetic predisposition to alcohol metabolism, mild-to-moderate drinkers had equivalent AF risks, and heavy drinkers showed increased AF risk in the low PRS tertile group. However, mild-to-moderate drinkers had decreased AF risks and heavy drinkers showed similar risks of AF in the middle/high PRS tertile groups.

CONCLUSIONS

Differential associations between alcohol consumption habits and incident AF across genetic predisposition to alcohol metabolism were observed; individuals with genetic predisposition to low alcohol metabolism were more susceptible to AF.

Genetic influences on alcohol flushing in East Asian populations

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.

Aldehyde-Associated Mutagenesis─Current State of Knowledge

Aldehydes are widespread in the environment, with multiple sources such as food and beverages, industrial effluents, cigarette smoke, and additives. The toxic effects of exposure to several aldehydes have been observed in numerous studies. At the molecular level, aldehydes damage DNA, cross-link DNA and proteins, lead to lipid peroxidation, and are associated with increased disease risk including cancer. People genetically predisposed to aldehyde sensitivity exhibit severe health outcomes. In various diseases such as Fanconi's anemia and Cockayne syndrome, loss of aldehyde-metabolizing pathways in conjunction with defects in DNA repair leads to widespread DNA damage. Importantly, aldehyde-associated mutagenicity is being explored in a growing number of studies, which could offer key insights into how they potentially contribute to tumorigenesis. Here, we review the genotoxic effects of various aldehydes, focusing particularly on the DNA adducts underlying the mutagenicity of environmentally derived aldehydes. We summarize the chemical structures of the aldehydes and their predominant DNA adducts, discuss various methodologies, in vitro and in vivo, commonly used in measuring aldehyde-associated mutagenesis, and highlight some recent studies looking at aldehyde-associated mutation signatures and spectra. We conclude the Review with a discussion on the challenges and future perspectives of investigating aldehyde-associated mutagenesis.

Health-Related Habits and Health Promotion Behaviors in People With Alcohol Flushing

There is limited investigation on health-related behaviors by alcohol flushing. A nationwide cross-sectional study was conducted using data from the Korea Community Health Survey. The final analysis included 130 192 adults with available information on alcohol flushing assessed by a self-reported questionnaire. About a quarter of participants were classified into alcohol flushers. After considering demographics, comorbidities, mental health, and perceived health status, multivariable logistic regression analysis revealed that flushers smoked or drank less and received vaccination or screening more than nonflushers. In conclusion, flushers have healthier behaviors than nonflushers.

Factors associated with the development of second primary tumours in head and neck cancer patients

INTRODUCTION

The development of second primary tumours (SPTs) is one of the main causes of low survival in patients with head and neck cancer (HNC). The aim of this study was to review the evidence about factors associated with developing SPTs in patients with HNC.

METHODS

An updated systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, and the search was performed in Pubmed and Scopus. Only original articles with a cohort or case-control design were included. Article quality was assessed with the Newcastle-Ottawa scale.

RESULTS

Thirty-six and two case-control studies were included, with quality medium (n = 5) to high (n = 33). Tobacco showed a significant association with SPT development, with risks ranging from 1.41 (95%CI: 1.04-1.91) to 5.52 (95%CI: 2.91-10.49). Regarding alcohol, risks ranged from 1.46 (95%CI: 1.12-1.91) to 21.3 (95%CI: 2.9-156). Location of the index tumour in the hypopharynx/oropharynx, absence of human papillomavirus and presence of a premalignant lesion also increased the risk of SPTs. More controversy was found for sex, age and other clinical factors of the tumour.

CONCLUSION

Toxic lifestyle habits and clinical factors were associated with the risk of SPTs in HNC patients. These findings may improve individualised prevention strategies in its follow-up.

E-cigarette aerosol exacerbates cardiovascular oxidative stress in mice with an inactive aldehyde dehydrogenase 2 enzyme

BACKGROUND

E-cigarette aerosol containing aldehydes, including acetaldehyde, are metabolized by the enzyme aldehyde dehydrogenase 2 (ALDH2). However, little is known how aldehyde exposure from e-cigarettes, when coupled with an inactivating ALDH2 genetic variant, ALDH2*2 (present in 8% of the world population), affects cardiovascular oxidative stress.

OBJECTIVES

The study was to determine how e-cigarette aerosol exposure, coupled with genetics, impacts cardiovascular oxidative stress in wild type ALDH2 and ALDH2*2 knock-in mice.

METHODS

Using selective ion flow mass spectrometry, we determined e-cigarette aerosol contains acetaldehyde levels 10-fold higher than formaldehyde or acrolein. Based on this finding, we tested how isolated ALDH2*2 primary cardiomyocytes respond to acetaldehyde and how intact ALDH2*2 knock-in rodents instrumented with telemeters respond physiologically and at the molecular level to 10 days of e-cigarette aerosol exposure relative to wild type ALDH2 rodents.

RESULTS

For ALDH2*2 isolated cardiomyocytes, acetaldehyde (1 μM) caused a 4-fold greater peak calcium influx, 2-fold increase in ROS production and 2-fold increase in 4-HNE-induced protein adducts relative to wild-type ALDH2 cardiomyocytes. The heart rate in ALDH2*2 mice increased ∼200 beats/min, while, heart rate in ALDH2 mice increased ∼150 beats/min after 10 days of e-cigarette exposure, relative to air-exposed mice. E-cigarette aerosol exposure triggered ∼1.3 to 2-fold higher level of protein carbonylation, lipid peroxidation, and phosphorylation of NF-κB for both strains of mice, with this response exacerbated for ALDH2*2 mice.

CONCLUSIONS

Our findings indicate people carrying an ALDH2*2 genetic variant may be more susceptible to increases in cardiovascular oxidative stress from e-cigarette aerosol exposure.

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.

ALDH2 variance in disease and populations

The ALDH2*2 missense variant that commonly causes alcohol flushing reactions is the single genetic polymorphism associated with the largest number of traits in humans. The dysfunctional ALDH2 variant affects nearly 8% of the world population and is highly concentrated among East Asians. Carriers of the ALDH2*2 variant commonly present alterations in a number of blood biomarkers, clinical measurements, biometrics, drug prescriptions, dietary habits and lifestyle behaviors, and they are also more susceptible to aldehyde-associated diseases, such as cancer and cardiovascular disease. However, the interaction between alcohol and ALDH2-related pathology is not clearly delineated. Furthermore, genetic evidence indicates that the ALDH2*2 variant has been favorably selected for in the past 2000-3000 years. It is therefore necessary to consider the disease risk and mechanism associated with ALDH2 deficiency, and to understand the possible beneficial or protective effect conferred by ALDH2 deficiency and whether the pleiotropic effects of ALDH2 variance are all mediated by alcohol use.

Aldh2 is a lineage-specific metabolic gatekeeper in melanocyte stem cells

Melanocyte stem cells (McSCs) in zebrafish serve as an on-demand source of melanocytes during growth and regeneration, but metabolic programs associated with their activation and regenerative processes are not well known. Here, using live imaging coupled with scRNA-sequencing, we discovered that, during regeneration, quiescent McSCs activate a dormant embryonic neural crest transcriptional program followed by an aldehyde dehydrogenase (Aldh) 2 metabolic switch to generate progeny. Unexpectedly, although ALDH2 is well known for its aldehyde-clearing mechanisms, we find that, in regenerating McSCs, Aldh2 activity is required to generate formate – the one-carbon (1C) building block for nucleotide biosynthesis – through formaldehyde metabolism. Consequently, we find that disrupting the 1C cycle with low doses of methotrexate causes melanocyte regeneration defects. In the absence of Aldh2, we find that purines are the metabolic end product sufficient for activated McSCs to generate progeny. Together, our work reveals McSCs undergo a two-step cell state transition during regeneration, and that the reaction products of Aldh2 enzymes have tissue-specific stem cell functions that meet metabolic demands in regeneration.

Summary: In zebrafish melanocyte regeneration, quiescent McSCs respond by re-expressing a neural crest identity, followed by an Aldh2-dependent metabolic switch to generate progeny.

Association between changes in facial flushing and hypertension across drinking behavior patterns in South Korean adults

Heavy alcohol drinking has been reported to be associated with hypertension. Moreover, when drinking alcohol, individuals may experience symptoms such as facial flushing. Therefore, this study aimed to examine the association between changes in facial flushing and hypertension across different drinking behavior patterns in South Korean adults. Data from the Korea Community Health Survey conducted in 2019 were used, and 118 129 (51 047 men and 67 082 women) participants were included. The participants were divided into five groups based on the change in facial flushing (non-drinking, non-flushing to non-flushing, flushing to flushing, non-flushing to flushing, flushing to non-flushing). The risk of hypertension in each facial flushing group was analyzed by multiple logistic regression. Men in the non-flushing to flushing group had a significantly higher association with hypertension than other groups (men: odds ratio (OR) 1.42, confidence interval (CI) 1.14-1.76). According to the level of alcohol use disorder, the non-flushing to flushing group showed a significantly increased odds of hypertension compared to all levels of drinking (men: mild drinking: OR 1.95, CI 1.40-2.71; moderate drinking: OR 2.02, CI 1.41-2.90; women: moderate drinking: OR 1.71, CI 1.16-2.52; heavy drinking: OR 1.90, CI 1.19-3.04). This study found a significant association between changes in facial flushing and hypertension among adults in South Korea. In particular, individuals who changed from non-flushing to flushing reactions had an increased association with hypertension than the other groups. Compared to people at the same drinking level, people with non-flushing to flushing reactions were highly associated with hypertension at moderate drinking level.

Alcohol Consumption, ALDH2 Polymorphism as Risk Factors for Upper Aerodigestive Tract Cancer Progression and Prognosis

The upper aerodigestive tract (UADT) is highly susceptible to multiple primary cancers originated from squamous epithelia and constitutes a field of cancerization. Patients with head and neck cancer (head and neck squamous cell carcinoma, HNSCC) are at high risk of developing multiple cancers in the esophagus (esophageal squamous cell carcinoma, ESCC). Conversely, esophageal cancer patients are prone to develop multiple primary tumors in the head and neck region. The East Asian-specific dysfunctional ALDH2*2 missense mutation is a genetic risk factor for UADT cancer. It is not only associated with increased incidences of UADT cancer, but is also implicated in faster cancer progression and poorer prognosis. Alcohol use is a major lifestyle risk factor which causes UADT cancer among ALDH2*2 carriers. The accumulation of the immediate metabolite of alcohol, acetaldehyde, is likely the genotoxic agents that is involved in the process of tumorigenesis. This review summarizes recent publications on the risk and association of ALDH2*2 mutation, alcohol consumption in synchronous, metachronous UADT cancer. Possible molecular mechanisms involved in cancer initiation, progress and prognosis are discussed. The review also highlights a need for precision medicine-based preventive and therapeutic strategies by integrating lifestyle and genetic risk factors, such as alcohol consumption, genotypes of the alcohol metabolizing genes, ADH1B and ALDH2, into a risk assessment model for better screening, surveillance and treatment outcome.

Effect of the ALDH2 Variant on the Prevalence of Atrial Fibrillation in Habitual Drinkers

Background

Alcohol—a risk factor for atrial fibrillation (AF)—is metabolized by aldehyde dehydrogenase 2 (ALDH2). Dysfunctional alleles of ALDH2 (ALDH2-deficient variants) are prevalent among East Asians.

Objectives

Because the prevalence of AF is estimated to be high in ALDH2-deficient variant carriers, we investigated the correlation between AF and ALDH2-deficient variant carriers, including the association with habitual alcohol consumption.

Methods

A total of 656 consecutive patients were included in this investigation. ALDH2 genotypes were divided into ALDH2 homozygous wild-type (∗1/∗1), ALDH2 heterozygous-deficient allele (∗1/∗2), and ALDH2 homozygous-deficient allele (∗2/∗2). Multivariate analyses were applied to determine the correlation between ALDH2 genotype and AF.

Results

ALDH2∗1/∗2 and ALDH2∗2/∗2 carriers who were ALDH2-deficient variant carriers comprised 199 (30.3%) and 27 (4.1%) patients, respectively. Among these patients, the proportions of habitual alcohol consumption were 26.1% and 0%, respectively. Multivariate analysis revealed that ALDH2∗1/∗2 itself was not a risk factor for AF (odds ratio [OR]: 1.28; P = 0.21). However, habitual alcohol consumption in ALDH2∗1/∗2 carriers was an independent risk factor of AF (OR: 4.13; P = 0.001). Contrary to expectations, ALDH2∗2/∗2 itself had a lower incidence of AF among other risk factors (OR: 0.37; P = 0.03).

Conclusions

Although the ALDH2∗1/∗2 itself was not associated with AF, ALDH2∗1/∗2 carriers with habitual alcohol consumption could experience AF because of slow alcohol metabolism. In contrast, ALDH2∗2/∗2 itself had a lower incidence of AF. This might be related to the absence to habitual alcohol consumption in ALDH2∗2/∗2 carriers because of the negligible activity of ALDH2. Thus, abstaining from alcohol consumption might prevent the development of AF in patients who are ALDH2∗1/∗2 carriers.

FACTORS CONTRIBUTING TO THE ESCALATION OF ALCOHOL CONSUMPTION

Understanding factors that contribute to the escalation of alcohol consumption is key to understanding how an individual transitions from non/social drinking to AUD and to providing better treatment. In this review, we discuss how the way ethanol is consumed as well as individual and environmental factors contribute to the escalation of ethanol consumption from intermittent low levels to consistently high levels. Moreover, we discuss how these factors are modelled in animals. It is clear a vast array of complex, interacting factors influence changes in alcohol consumption. Some of these factors act early in the acquisition of ethanol consumption and initial escalation, while others contribute to escalation of ethanol consumption at a later stage and are involved in the development of alcohol dependence. There is considerable need for more studies examining escalation associated with the formation of dependence and other hallmark features of AUD, especially studies examining mechanisms, as it is of considerable relevance to understanding and treating AUD.

Whole-Genome Sequencing of a 900-Year-Old Human Skeleton Supports Two Past Migration Events from the Russian Far East to Northern Japan

Recent studies on paleogenomics have reported some Paleolithic and Neolithic genomes that have provided new insights into the human population history in East and Northeast Asia. However, there remain some cases where more recent migration events need to be examined to elucidate the detailed formation process of local populations. Although the area around northern Japan is one of the regions archaeologically suggested to have been affected by migration waves after the Neolithic period, the genetic source of these migrations are still unclear. Thus, genomic data from such past migrant populations would be highly informative to clarify the detailed formation process of local populations in this region. Here, we report the genome sequence of a 900-year-old adult female (NAT002) belonging to the prehistoric Okhotsk people, who have been considered to be the past migrants to northern Japan after the Neolithic period. We found a close relationship between NAT002 and modern Lower Amur populations and past admixture events between the Amur, Jomon, and Kamchatka ancestries. The admixture dating suggested migration of Amur-related ancestry at approximately 1,600 BP, which is compatible with the archaeological evidence regarding the settlement of the Okhotsk people. Our results also imply migration of Kamchatka-related ancestry at approximately 2,000 BP. In addition, human leukocyte antigen (HLA) typing detected the HLA-B*40 allele, which is reported to increase the risk of arthritis, suggesting the genetic vulnerability of NAT002 to hyperostosis, which was observed around her chest clavicle.

Biochemical Mechanisms Associating Alcohol Use Disorders with Cancers

Simple Summary

Of all yearly deaths attributable to alcohol consumption globally, approximately 12% are due to cancers, representing approximately 0.4 million deceased individuals. Ethanol metabolism disturbs cell biochemistry by targeting the structure and function of essential biomolecules (proteins, nucleic acids, and lipids) and by provoking alterations in cell programming that lead to cancer development and cancer malignancy. A better understanding of the metabolic and cell signaling realm affected by ethanol is paramount to designing effective treatments and preventive actions tailored to specific neoplasias.

Abstract

The World Health Organization identifies alcohol as a cause of several neoplasias of the oropharynx cavity, esophagus, gastrointestinal tract, larynx, liver, or female breast. We review ethanol’s nonoxidative and oxidative metabolism and one-carbon metabolism that encompasses both redox and transfer reactions that influence crucial cell proliferation machinery. Ethanol favors the uncontrolled production and action of free radicals, which interfere with the maintenance of essential cellular functions. We focus on the generation of protein, DNA, and lipid adducts that interfere with the cellular processes related to growth and differentiation. Ethanol’s effects on stem cells, which are responsible for building and repairing tissues, are reviewed. Cancer stem cells (CSCs) of different origins suffer disturbances related to the expression of cell surface markers, enzymes, and transcription factors after ethanol exposure with the consequent dysregulation of mechanisms related to cancer metastasis or resistance to treatments. Our analysis aims to underline and discuss potential targets that show more sensitivity to ethanol’s action and identify specific metabolic routes and metabolic realms that may be corrected to recover metabolic homeostasis after pharmacological intervention. Specifically, research should pay attention to re-establishing metabolic fluxes by fine-tuning the functioning of specific pathways related to one-carbon metabolism and antioxidant processes.

A regionally specific drinking custom 'Otōri' and its association with alcohol consumption/alcohol use disorders: a cross-sectional study

OBJECTIVES

The primary objective was to describe the characteristics of Otōri, a regionally specific drinking custom in the Miyakojima region of Okinawa, Japan, and its participants. The secondary objective was to clarify the distribution of alcohol consumption/alcohol use disorders as measured by the Alcohol Use Disorders Identification Test (AUDIT) and its association with the frequency of engagement in Otōri per month.

DESIGN

Cross-sectional study.

SETTING

Tarama Island, a remote island in Okinawa, Japan.

PARTICIPANTS

Individuals who lived on Tarama Island, participated in a mass general health check or mass influenza vaccination programme, were aged ≥20 years and had decision-making capacity were eligible to participate.

PRIMARY OUTCOME MEASURES

Alcohol consumption/alcohol use disorders as measured by the AUDIT, frequency of engagement in Otōri per month, settings in which people engage in Otōri and attitudes toward Otōri.

RESULTS

Among 478 eligible participants, 401 answered the questionnaire. Approximately 15% reported attitudes toward Otōri of 'like' or 'somewhat like'; around 80% of these participants were middle-aged to older adult men. Compared with the national average, a higher percentage of people (9.2% and 40.9% of women and men, respectively) had AUDIT scores indicating 'hazardous drinking or more', which was associated with 'low or intermediate frequency' and 'high frequency' of engagement in Otōri per month (ORs of 7.626 and 20.321, respectively).

CONCLUSIONS

Social obligation generated by some community members could pressure most of the population into participating in Otōri, possibly leading to a higher percentage of people engaging in hazardous/harmful alcohol consumption and alcohol dependence. However, healthcare professionals should carefully consider the beneficial and detrimental effects of the custom on biomedical and social conditions and avoid advocating to promote or abolish the custom by only highlighting one aspect.

Genome-wide association study of epilepsy in a Japanese population identified an associated region at chromosome 12q24

OBJECTIVE

Although a number of genes responsible for epilepsy have been identified through Mendelian genetic approaches, and genome-wide association studies (GWASs) have implicated several susceptibility loci, the role of ethnic-specific markers remains to be fully explored. We aimed to identify novel genetic associations with epilepsy in a Japanese population.

METHODS

We conducted a GWAS on 1825 patients with a variety of epilepsies and 7975 control individuals. Expression quantitative trait locus (eQTL) analysis of epilepsy-associated single nucleotide polymorphisms (SNPs) was performed using Japanese eQTL data.

RESULTS

We identified a novel region, which is ~2 Mb (lead SNP rs149212747, p = 8.57 × 10^-10 ), at chromosome 12q24 as a risk for epilepsy. Most of these loci were polymorphic in East Asian populations including Japanese, but monomorphic in the European population. This region harbors 24 transcripts including genes expressed in the brain such as CUX2, ATXN2, BRAP, ALDH2, ERP29, TRAFD1, HECTD4, RPL6, PTPN11, and RPH3A. The eQTL analysis revealed that the associated SNPs are also correlated to differential expression of genes at 12q24.

SIGNIFICANCE

These findings suggest that a gene or genes in the CUX2-RPH3A ~2-Mb region contribute to the pathology of epilepsy in the Japanese population.

The toxic side of one-carbon metabolism and epigenetics

One-carbon metabolism is a central metabolic hub that provides one-carbon units for essential biosynthetic reactions and for writing epigenetics marks. The leading role in this hub is performed by the one-carbon carrier tetrahydrofolate (THF), which accepts formaldehyde usually from serine generating one-carbon THF intermediates in a set of reactions known as the folate or one-carbon cycle. THF derivatives can feed one-carbon units into purine and thymidine synthesis, and into the methionine cycle that produces the universal methyl-donor S-adenosylmethionine (AdoMet). AdoMet delivers methyl groups for epigenetic methylations and it is metabolized to homocysteine (Hcy), which can enter the transsulfuration pathway for the production of cysteine and lastly glutathione (GSH), the main cellular antioxidant. This vital role of THF comes to an expense. THF and other folate derivatives are susceptible to oxidative breakdown releasing formaldehyde, which can damage DNA -a consequence prevented by the Fanconi Anaemia DNA repair pathway. Epigenetic demethylations catalysed by lysine-specific demethylases (LSD) and Jumonji histone demethylases can also release formaldehyde, constituting a potential threat for genome integrity. In mammals, the toxicity of formaldehyde is limited by a metabolic route centred on the enzyme alcohol dehydrogenase 5 (ADH5/GSNOR), which oxidizes formaldehyde conjugated to GSH, lastly generating formate. Remarkably, this formate can be a significant source of one-carbon units, thus defining a formaldehyde cycle that likely restricts the toxicity of one-carbon metabolism and epigenetic demethylations. This work describes recent advances in one-carbon metabolism and epigenetics, focusing on the steps that involve formaldehyde flux and that might lead to cytotoxicity affecting human health.

Formaldehyde Causes Bone Marrow Failure Linked to Transcriptional Reprogramming or Metabolic Deficiency

Two new studies in this issue of Molecular Cell demonstrate that bone marrow failure, in mice and humans, can be induced by formaldehyde generated either from defective metabolism (Dingler et al., 2020) or during the process of transcriptional reprogramming (Shen et al., 2020).

Two Aldehyde Clearance Systems Are Essential to Prevent Lethal Formaldehyde Accumulation in Mice and Humans

Reactive aldehydes arise as by-products of metabolism and are normally cleared by multiple families of enzymes. We find that mice lacking two aldehyde detoxifying enzymes, mitochondrial ALDH2 and cytoplasmic ADH5, have greatly shortened lifespans and develop leukemia. Hematopoiesis is disrupted profoundly, with a reduction of hematopoietic stem cells and common lymphoid progenitors causing a severely depleted acquired immune system. We show that formaldehyde is a common substrate of ALDH2 and ADH5 and establish methods to quantify elevated blood formaldehyde and formaldehyde-DNA adducts in tissues. Bone-marrow-derived progenitors actively engage DNA repair but also imprint a formaldehyde-driven mutation signature similar to aging-associated human cancer mutation signatures. Furthermore, we identify analogous genetic defects in children causing a previously uncharacterized inherited bone marrow failure and pre-leukemic syndrome. Endogenous formaldehyde clearance alone is therefore critical for hematopoiesis and in limiting mutagenesis in somatic tissues.

Association between the incidence of hypertension and alcohol consumption pattern and the alcohol flushing response: A 12-year follow-up study

BACKGROUND

Alcohol consumption is associated with hypertension, and this association depends on the alcohol consumption pattern and alcohol flushing response. In this 12-year follow-up study, we investigated the relationship between the alcohol consumption pattern and incidence of hypertension in the Korean population.

METHODS

We analyzed 1,366 Korean participants in the Ansung-Ansan cohort study without hypertension at baseline. The subjects were classified into four alcohol consumption patterns: never-drinking, light alcohol consumption, moderate alcohol consumption, and heavy alcohol consumption, and as flushers or non-flushers in response to alcohol.

RESULTS

In flushers, moderate and heavy alcohol consumption patterns increased the risk of incident hypertension compared with never-drinkers [moderate: HR 1.811 (95% CI 1.084-3.028); heavy: HR 2.494 (95% CI 1.185-5.247)], but non-flushers were not associated with increased risk of incident hypertension according to the alcohol consumption pattern. In addition, a heavy alcohol consumption pattern increased the risk of hypertension among flushers compared with non-flushers [HR 2.232 (95% CI 1.054-4.728)].

CONCLUSION

In this 12-year follow-up study, we observed that moderate and heavy alcohol consumption was associated with an increased risk of hypertension in flushers. Especially, a heavy alcohol consumption pattern in flushers markedly increased the risk of hypertension.

Digenic mutations in ALDH2 and ADH5 impair formaldehyde clearance and cause a multisystem disorder, AMeD syndrome

Rs671 in the aldehyde dehydrogenase 2 gene (ALDH2) is the cause of Asian alcohol flushing response after drinking. ALDH2 detoxifies endogenous aldehydes, which are the major source of DNA damage repaired by the Fanconi anemia pathway. Here, we show that the rs671 defective allele in combination with mutations in the alcohol dehydrogenase 5 gene, which encodes formaldehyde dehydrogenase (ADH5FDH ), causes a previously unidentified disorder, AMeD (aplastic anemia, mental retardation, and dwarfism) syndrome. Cellular studies revealed that a decrease in the formaldehyde tolerance underlies a loss of differentiation and proliferation capacity of hematopoietic stem cells. Moreover, Adh5-/-Aldh2 E506K/E506K double-deficient mice recapitulated key clinical features of AMeDS, showing short life span, dwarfism, and hematopoietic failure. Collectively, our results suggest that the combined deficiency of formaldehyde clearance mechanisms leads to the complex clinical features due to overload of formaldehyde-induced DNA damage, thereby saturation of DNA repair processes.

ALDH2 genotype modulates the association between alcohol consumption and AST/ALT ratio among middle-aged Japanese men: a genome-wide G × E interaction analysis

Liver tests (LT), especially to measure AST, ALT and GGT levels, are widely used to evaluate the risk of alcohol-related liver disease (ALD). In this study, we investigated the potential genetic factors that modulate the association between LTs and alcohol consumption. We conducted a genome-wide interaction meta-analysis in 7856 Japanese subjects from Tohoku Medical Megabank Community-Based Cohort (TMM CommCohort) study recruited in 2013, and identified 2 loci (12q24 and 2p16) with genome-wide significance (P > 5 × 10-8). The significant variants in the 12q24 included rs671, a variant associated with alcohol intolerance and located at a coding exon of ALDH2. We found that the amount of alcohol consumption was associated with increased level AST/ALT ratio among the subjects with the rs671 GA genotype. The elevated AST/ALT ratio among subjects with moderate-to-high levels of drinking behavior and the rs671 GA genotype was due to decreased levels of ALT, which was not accompanied with significant differences in AST levels. Although the interaction effect was significant in both men and women, the effect was much larger in men. Our results suggest that the impact of alcohol consumption on LT varies according to the ALDH2 genotype, providing an insight for the accurate screening of ALD in drinkers with the rs671 GA genotype.

The impact of frequency, pattern, intensity, and type of alcohol consumption, and its combined effect with smoking on inflammation, lipid profile, and the risk of myocardial infarction

Aim

To determine the risk of myocardial infarction (MI) associated with pattern, frequency, and intensity of alcohol consumption, type of alcoholic beverage, and the combined effect of alcohol and smoking on risk of MI, inflammation, and lipid profile.

Method

A total of 423 cases with a first MI and 465 controls from the Maltese Acute Myocardial Infarction (MAMI) Study were analysed. Data was collected through an extensive interviewer-led questionnaire, along with measurements of various blood parameters. Medians and the Mann–Whitney test were used to assess effect of different drinking patterns, frequency, intensity, and smoking and drinking combinations on hs-CRP and lipid profile. Odds ratios, adjusted for the conventional risk factors of MI (AdjORs), were calculated as an estimate of the relative risk of MI.

Results

Regular alcohol consumption protected against MI [AdjOR 0.6 (95% CI 0.4–0.9)] while daily binge drinking increased risk [AdjOR 5.0 (95% CI 1.6–15.0)] relative to regular drinkers who did not binge drink. Whereas moderate weekly consumption of wine protected against MI, high weekly consumption of beer conveyed a deleterious effect. Alcohol consumption decreased risk of MI independent of smoking status. Frequent alcohol consumption was associated with higher HDL-, non-HDL-, total cholesterol and triglycerides, and lower hs-CRP. Total and HDL-cholesterol increased and BMI decreased with increasing quantity of weekly alcohol consumption relative to the non-regular drinkers. The effect of smoking on lipid profile and hs-CRP was less pronounced in current drinkers than in those who were non-regular drinkers.

Conclusion

The protective effect of alcohol consumption was dependent on the pattern, frequency, type, and intensity of alcohol consumed. Alcohol modified the effects of smoking on the lipid profile. Regular drinking attenuated the effect of smoking on hs-CRP and lipid profile.

Effect of ALDH2 on Sleep Disturbances in Patients with Parkinson's Disease

Monoamine neurotransmitters play essential roles in the regulation of arousal and sleep. Impaired metabolism of monoamine neurotransmitters could result in the accumulation of neurotoxic aldehyde metabolites and, hence, neuronal degeneration. Aldehyde dehydrogenases play an important role in the metabolism of the neurotoxic aldehyde metabolites, including the aldehyde metabolites of dopamine, serotonin, and noradrenaline. Deficient aldehyde dehydrogenase 2 (ALDH2) has been suggested to result in the accumulation of these biogenic aldehydes. An ALDH2 single nucleotide polymorphism (SNP), rs671 (A), results in significantly reduced ALDH2 enzyme activity. A total of 83 Parkinson’s disease (PD) patients were recruited in this study. In addition to the genotypes of rs671, the patients were assessed with the PD sleep scale-2nd version (PDSS-2) and the Epworth sleepiness scale (ESS) for symptoms of daytime and nocturnal sleep disturbances. The patients carrying rs671 (A) had more frequent dozing while lying down to rest in the afternoon (ESS item5) (F = 7.308, p = 0.008) than the rs671 (GG) patients. The patients with rs671 (A) reported a trend toward more frequent difficulty staying asleep than the patients with rs671 (GG). (F = 3.278, p = 0.074). The results indicate that patients carrying allele rs671 (A) are more likely to experience impairment in the regulation of arousal and sleep. The results also support the hypothesis that the accumulation of neurotoxic monoamine neurotransmitter aldehyde metabolites secondary to reduced ALDH2 enzyme activity may cause more severe monoaminergic neuronal loss and, hence, more severe symptoms in the regulation of wakefulness and sleep.

Aldh2 Attenuates Stem Cell Factor/Kit-Dependent Signaling and Activation in Mast Cells

Mitochondrial aldehyde dehydrogenase (ALDH2) metabolizes endogenous and exogenous aldehydes and protects cells against oxidative injury. Inactivating genetic polymorphisms in humans are common and associate with alcohol flush reactions. However, whether mast cell Aldh2 activity impacts normal mast cell responses is unknown. Using bone marrow-derived mast cells from Aldh2 knockout mice, we found evidence for a role of mast cell Aldh2 in Kit-mediated responses. Aldh2-deficient mast cells showed enhanced Kit tyrosine kinase phosphorylation and activity after stimulation with its ligand (stem cell factor) and augmentation of downstream signaling pathways, including Stat4, MAPKs, and Akt. The activity of the phosphatase Shp-1, which attenuates Kit activity, was reduced in Aldh2^−/− mast cells, along with an increase in reactive oxygen species, known to regulate Shp-1. Reduced Shp-1 activity concomitant with sustained Kit signaling resulted in greater proliferation following Kit engagement, and increased mediator and cytokine release when Aldh2^−/− mast cells were co-stimulated via Kit and FcεRI. However, FcεRI-mediated signaling and responses were unaffected. Therefore, our findings reveal a functional role for mast cell intrinsic Aldh2 in the control of Kit activation and Kit-mediated responses, which may lead to a better understanding of mast cell reactivity in conditions related to ALDH2 polymorphisms.

Idiopathic anaphylaxis yardstick: Practical recommendations for clinical practice

Anaphylaxis is considered idiopathic when there is no known trigger. The signs and symptoms of idiopathic anaphylaxis (IA) are identical to those of anaphylaxis because of a known cause and can include cutaneous, circulatory, respiratory, gastrointestinal, and neurologic symptoms. Idiopathic anaphylaxis can be a frustrating disease for patients and health care providers. Episodes are unpredictable, and differential diagnosis is challenging. Current anaphylaxis guidelines have little specific guidance regarding differential diagnosis and long-term management of IA. Therefore, the objective of the Idiopathic Anaphylaxis Yardstick is to use published data and the authors' combined clinical experience to provide practical recommendations for the diagnosis and management of patients with IA.

Psychosocial Motivators for Moderate Drinking among Young Asian Flushers in Singapore

Asians are more susceptible to alcohol flush syndrome and its associated health risks because they are genetically predisposed towards it. Guided by the theory of planned behaviour, this research examined the psychosocial factors associated with moderate alcohol consumption, in order to inform the development of a health campaign targeting young Asian "flushers" in Singapore. We employed a mixed-method design comprising an online survey and focus group discussions. The survey results identified perceived behavioural control as the most salient belief associated with moderate drinking intentions, particularly for Asian flushers. Although Asian flushers had more positive attitudes towards, and perceived behavioural control about drinking in moderation, they were more likely to consider that their peers disapprove of such a practice, compared to non-flushers. Additionally, Asian flushers did not consider themselves as having a higher risk of long-term health effects from alcohol consumption than non-Flushers despite their actual high-risk status. Focus group findings suggest that young Asian flushers have poor knowledge of, and skills associated with moderate drinking, in addition to feeling self-imposed social pressure. The study findings provide practical insights into bridging the information gap on Asian flush and promoting Asian flushers' drinking in moderation.

Validation of Alcohol Flushing Questionnaire to Identify ALDH2 Status in a Case-Control Study of Head and Neck Cancer

BACKGROUND

Carriers of the ALDH2*2 allele have impaired alcohol metabolism and are more susceptible to the development of alcohol-related cancers, including head and neck cancer (HNC). Screening for ALDH2*2 allele may identify high-risk individuals for alcohol health education. Although genotyping of ALDH2 is the most accurate way to identify ALDH2 deficiency, it may not be practical due to the cost and requirement for genotyping service.

METHODS

This study evaluated the accuracy of the alcohol flushing questionnaire to identify ALDH2 deficiency in a case-control study of HNC conducted in Taiwan using data collected from 904 patients with HNC and 1,078 controls.

RESULTS

Overall, alcohol flushing questionnaire had a high sensitivity (89%) of identifying ALDH2*2 carriers among the control subjects and a good sensitivity (79%) among the patients with HNC. The sensitivity of the alcohol flushing questionnaire in identifying ALDH2*2 carriers was affected by alcohol use, with a lower sensitivity among individuals who consumed alcohol, particularly among current regular (drinking alcohol once per week or more) alcohol drinkers.

CONCLUSIONS

The current validation study showed that the alcohol flushing questionnaire may be a reasonable method to identify ALDH2-deficient individuals. However, current regular users of alcohol who reported no alcohol flushing may need to undergo genotyping of ALDH2 for a more accurate assessment of the ALDH2 status.

The prevalence of ADH1B and OPRM1 alleles predisposing for alcohol consumption are increased in the Hungarian psoriasis population

Alcohol intake affects in great the symptoms and life of  psoriasis patients, although the association of SNPs related to increased alcohol consumption with psoriasis has not been elucidated. Therefore, to investigate the association of psoriasis with established alcohol consumption and dependence-related gene variants we conducted a population-based case-control study including 3743 subjects (776 psoriasis cases and 2967 controls from the general Hungarian population). Genotyping of 23 SNPs at ADH1B, ADH1C, ALDH1A1, ALDH2, SLC6A3, DDC, GABRA2, GABRG1, HTR1B, MAOA, TPH2, CHRM2, GRIN2A, POMC, OPRM1, OPRK1 and BDNF were determined and differences in genotype and allele distributions were investigated. Multiple logistic regression analyses were implemented. Analysis revealed association between C allele of the rs1229984 polymorphism (ADH1B gene) and psoriasis risk (OR_additive = 1.58, 95% CI 1.23-2.03, p < 0.001, OR_recessive = 1.58, 95% CI 1.22-2.04, p = 0.001). Furthermore, the G allele of rs1799971 polymorphism (OPRM1 gene) increased the risk of familial aggregation (OR_additive = 1.99, 95% CI 1.36-2.91, p < 0.001 OR_dominant = 2.01, 95% CI 1.35-3.01, p < 0.001). In subgroups of psoriatic patients with history of early onset and familial aggregation effect allele 'C' of rs1229984 showed association in the additive and recessive models (OR_additive = 2.41, 95% CI 1.26-4.61, p < 0.01, OR_recessive = 2.42, 95% CI 1.26-4.68, p < 0.01). While effect allele 'G' of rs1799971 (OPRM1) also associated with increased risk of early onset and familial aggregation of psoriasis in the additive and dominant models (OR_additive = 1.75, 95% CI 1.27-2.43, p = 0.001, OR_dominant = 1.82, 95% CI 1.26-2.63, p = 0.001). Our results suggest that genetically defined high-risk individuals for alcohol consumption are more common in the psoriasis population.

Aldehyde dehydrogenase 2 genotype in tolerability of alcohol contained in paclitaxel in Japanese breast cancer patients

BACKGROUND

Paclitaxel (PTX) is an essential anticancer drug used to treat breast cancer. Because it contains alcohol as a solvent, it is contraindicated in many Japanese breast cancer patients when they are suspected of alcohol intolerance. Aldehyde dehydrogenase 2 (ALDH2) is one of several enzymes that catalyzes dehydrogenation of aldehydes, and plays an important role in ethanol metabolism. Deficiency of this isozyme is believed to be responsible for facial flushing and other unpleasant symptoms following ethanol intake. In this study, we examined the safety of PTX for patients with the ALDH2 GA genotype.

METHODS

We performed ALDH2 genotyping on 25 patients with various cancers who were suspected to be intolerant to alcohol based on an interview using a simple question. Ten patients with the ALDH2 GA genotype, including 5 breast cancer patients, underwent chemotherapy containing PTX up to 100 mg/m2 (range 80-100 mg/m2), and were questioned about 16 alcohol-related symptoms at 11 timepoints to evaluate sensitivity to alcohol.

RESULTS

All patients completed the first course of planned chemotherapy with either no or grade 1 alcohol-related symptoms.

CONCLUSIONS

Our study suggests that PTX up to 100 mg/m2 can be used safely for patients with the ALDH2 GA genotype. To confirm the necessity of a genotyping test for ALDH2, further studies evaluating alcohol sensitivity in response to PTX among patients with the ALDH2 AA genotype are required.

Telomere shortening in alcohol dependence: Roles of alcohol and acetaldehyde

Heavy drinking leads to premature aging and precipitates the onset of age-related diseases. Acetaldehyde (AcH), a toxic metabolite of ethanol, has been implicated in various types of cancer. However, whether alcohol accelerates biological aging at a cellular level is controversial and the mechanism involved is unclear. We addressed these questions by measuring telomere length (TL) in peripheral blood leukocytes of Japanese patients with alcohol dependence (AD) and examined the association between TL, genetic variants of alcohol dehydrogenase (ADH)1B and aldehyde dehydrogenase (ALDH)2, and other clinical characteristics. A total of 134 male AD patients and 121 age- and sex-matched healthy controls were evaluated. All patients received endoscopic screening for cancer of the upper aerodigestive tract (UADT). TL was almost 50% shorter in AD patients relative to controls. There were no significant differences in TL between AD patients with and without UADT cancer, and no associations between ADH1B and ALDH2 genotypes and TL. AD patients with thiamine (vitamin B1) deficiency at admission had significantly shorter TL than those with normal thiamine status. Although the exact mechanism underlying the shorter TL in AD patients remain unclear, our findings suggest that alcohol rather than AcH is associated with telomere shortening in AD, which may be accelerated by thiamine deficiency. Future studies should also focus on the association between telomere shortening and TD in the context of oxidative stress.

An Asian consensus on standards of diagnostic upper endoscopy for neoplasia

BACKGROUND

This is a consensus developed by a group of expert endoscopists aiming to standardise the preparation, process and endoscopic procedural steps for diagnosis of early upper gastrointestinal (GI) cancers.

METHOD

The Delphi method was used to develop consensus statements through identification of clinical questions on diagnostic endoscopy. Three consensus meetings were conducted to consolidate the statements and voting. We conducted a systematic literature search on evidence for each statement. The statements were presented in the second consensus meeting and revised according to comments. The final voting was conducted at the third consensus meeting on the level of evidence and agreement.

RESULTS

Risk stratification should be conducted before endoscopy and high risk endoscopic findings should raise an index of suspicion. The presence of premalignant mucosal changes should be documented and use of sedation is recommended to enhance detection of superficial upper GI neoplasms. The use of antispasmodics and mucolytics enhanced visualisation of the upper GI tract, and systematic endoscopic mapping should be conducted to improve detection. Sufficient examination time and structured training on diagnosis improves detection. Image enhanced endoscopy in addition to white light imaging improves detection of superficial upper GI cancer. Magnifying endoscopy with narrow-band imaging is recommended for characterisation of upper GI superficial neoplasms. Endoscopic characterisation can avoid unnecessary biopsy.

CONCLUSION

This consensus provides guidance for the performance of endoscopic diagnosis and characterisation for early gastric and oesophageal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early upper GI cancers.

Role of Alcohol Oxidative Metabolism in Its Cardiovascular and Autonomic Effects

Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.

Alcohol Dehydrogenases, Aldehyde Dehydrogenases, and Alcohol Use Disorders: A Critical Review

Alcohol use disorders (AUDs) are complex traits, meaning that variations in many genes contribute to the risk, as does the environment. Although the total genetic contribution to risk is substantial, most individual variations make only very small contributions. By far the strongest contributors are functional variations in 2 genes involved in alcohol (ethanol [EtOH]) metabolism. A functional variant in alcohol dehydrogenase 1B (ADH1B) is protective in people of European and Asian descent, and a different functional variant in the same gene is protective in those of African descent. A strongly protective variant in aldehyde dehydrogenase 2 (ALDH2) is essentially only found in Asians. This highlights the need to study a wide range of populations. The likely mechanism of protection against heavy drinking and AUDs in both cases is alteration in the rate of metabolism of EtOH that at least transiently elevates acetaldehyde. Other ADH and ALDH variants, including functional variations in ADH1C, have also been implicated in affecting drinking behavior and risk for alcoholism. The pattern of linkage disequilibrium in the ADH region and the differences among populations complicate analyses, particularly of regulatory variants. This critical review focuses upon the ADH and ALDH genes as they affect AUDs.

Allergic and intolerance reactions to wine

Hypersensitivity reactions to alcoholic beverages (particularly red wine) are relatively frequent, affecting 10% of the general population. Hypersensitivity reactions due to alcoholic drinks, mainly in the form of airway reactions (rhinitis and asthma), occur significantly more frequently in persons with pre-existing rhinitis and asthma. In terms of pathogenesis, it has to be differentiated between immunologic, mainly IgE-mediated, hypersensitivity reactions (wine allergies), and intolerance reactions in which no causative allergen-specific immune mechanisms can be detected. Allergens responsible for wine allergy could be: grape (Vitis vinifera) proteins (particularly the major allergen lipid transfer protein Vit v1), proteins and ingredients used for the fining of wines such as fish gelatin or isinglass (swim bladder of the fish huso, family of sturgeons), ovalbumin, dairy (casein) products, gum arabic, enzymes (lysozyme, pectinase, glucanase, cellulase, glucosidase, urease, aromatic enzymes), molds (particularly Botrytis cinerea) responsible for the noble rot in wines, yeasts and proteins from insects that contaminated the mash. Type 1 allergic reactions (positive prick tests) have been described for inorganic components like ethanol, acetaldehyde, acetic acid and sulfites, but no specific IgE could be detected in the serum. Ethanol, acetaldehyde and acetic acid, flavonoids (anthocyanins and chatechines), sulfites, histamine and other biogenic amines are the main causative agents of intolerance reactions (pseudoallergic reactions) to wine. After a short historic review of viticulture and the importance of wine in classical antiquity, we go into the chemical processes of alcoholic fermentation and the genetically inherited “flush syndrome” caused by an acetaldehyde dehydrogenase 2 polymorphism, subsequently we focus on the different etiologic factors of allergies and intolerance reactions to wine. The most frequent intolerance reactions to sulfites occur particularly after the ingestion of white wine and in asthma patients. Intolerance reactions to histamine and other biogenic amines occur mainly after ingestion of red wine and in persons with diamine oxidase (DAO) deficiency.

Genetic variants of ALDH2-rs671 and CYP2E1-rs2031920 contributed to risk of hepatocellular carcinoma susceptibility in a Chinese population

Objective

Acetaldehyde dehydrogenase 2 (ALDH2) and cytochrome P450 2E1 (CYP2E1) have been associated with hepatocellular carcinoma (HCC) susceptibility and prognosis. The polymorphisms ALDH2 rs671 and CYP2E1 rs2031920 are reportedly correlated with the prevalence of HCC in other countries. The aim of this study was to investigate associations between ALDH2 and CYP2E1, and HCC susceptibility in a population of Guangxi, southern China, an area with a high incidence of HCC.

Patients and methods

The study cohort included 300 HCC cases, 292 healthy controls for HCC susceptibility analysis, and another 20 HCC cases and 10 healthy controls for ascertainment. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method.

Results

The study results demonstrated that mutant genotypes of ALDH2 (G/A and A/A) led to significant differences in HCC susceptibility, as compared with the wild genotype (G/G) with the same C1/C1 genotype in non-drinking individuals (adjusted P=0.010, OR=0.20, 95% CI=0.06–0.68). The mutant genotypes of CYP2E1 (C1/C2 and C2/C2) brought about significant differences in HCC susceptibility, as compared with the wild genotype (C1/C1) and the same G/G genotype (adjusted P=0.025, OR=0.42, 95% CI=0.20–0.90). Drinking plays a role in HCC susceptibility in the same G/G genotype individuals (adjusted P=0.004, OR=0.32, 95% CI=0.15–0.69), but had no impact when combined with CYP2E1 for analysis (all P>0.05).

Conclusion

These results suggest that the mutant genotypes of ALDH2 and CYP2E1 may be protective factors for HCC susceptibility in Guangxi province, China.

Facial flushing after alcohol intake as a predictor for a high risk of synchronous or metachronous cancer of the upper gastrointestinal tract

Background

In Japan, there has been a lot of reports showing an association between facial flushing after light alcohol consumption and heterozygosity for inactive aldehyde dehydrogenase-2 (ALDH2). Persons with inactive ALDH2 may have a higher risk of alcohol-related oral, pharyngeal and esophageal cancers, compared with those with wild-type ALDH2. The purpose of this study was to examine whether flushers with oral or pharyngeal squamous cell carcinoma have an increased risk of synchronous or metachronous cancer of the upper gastrointestinal (UGI) tract.

Methods

A retrospective study was performed by medical chart review and through a questionnaire sent to 285 patients treated for oral and pharyngeal cancer. Responses were obtained from 150 patients (52.6%), who were classified as flushers or non-flushers, smokers (≥20 pack-year; 1 pack-years = number of cigarettes/20 per day) or non-smokers, and drinkers (≥14 units of alcohol consumption per week; 1 unit = 22 g) or non-drinkers. Relationships of these factors with occurrence of second primary cancers (SPCs) in the UGI tract were investigated.

Results

In Kaplan-Meier analysis, there was a significantly higher rate of SPC at 5 years in flushers and drinkers, but no relationship with smoking. In multivariate analyses, a history of flushing was significantly associated with SPC in the UGI tract (HR 2.64, 95% CI 1.25-5.52, P = 0.0109), but not with smoking or alcohol consumption.

Conclusions

A simple interview on history of facial flushing after alcohol intake can be useful for identifying patients at high risk for synchronous or metachronous cancers of the UGI tract.

Genomewide Association Study of Alcohol Dependence and Related Traits in a Thai Population

BACKGROUND

Alcohol use (both quantity and dependence) is moderately heritable, and genomewide association studies (GWAS) have identified risk genes in European, African, and Asian populations. The most reproducibly identified risk genes affect alcohol metabolism. Well-known functional variants at the gene encoding alcohol dehydrogenase B and other alcohol dehydrogenases affect risk in European and African ancestry populations. Similarly, variants mapped to these same genes and a well-known null variant that maps to the gene that encodes aldehyde dehydrogenase 2 (ALDH2) also affect risk in various Asian populations. In this study, we completed the first GWAS for 3 traits related to alcohol use in a Thai population recruited initially for studies of methamphetamine dependence.

METHODS

All subjects were evaluated with the Thai version of the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA). A total of 1,045 subjects were available for analysis. Three traits were analyzed: flushing, maximum number of alcoholic beverages consumed in any lifetime 24-hour period ("MAXDRINKS"), and DSM-IV alcohol dependence criterion count. We also conducted a pleiotropy analysis with major depression, the only other psychiatric trait where summary statistics from a large-scale Asian-population GWAS are available.

RESULTS

All 3 traits showed genomewide significant association with variants near ALDH2, with significance ranging from 2.01 × 10^-14 (for flushing; lead single nucleotide polymorphism (SNP) PTPN11* rs143894582) to p_meta  = 5.80 × 10^-10 (for alcohol dependence criterion count; lead SNP rs149212747). These lead SNPs flank rs671 and span a region of over a megabase, illustrating the need for prior biological information in identifying the actual effect SNP, rs671. We also identified significant pleiotropy between major depression and flushing.

CONCLUSIONS

These results are consistent with prior findings in Asian populations and add new information regarding alcohol use-depression pleiotropy.

Fanconi anaemia and cancer: an intricate relationship

Fanconi anaemia (FA) is a genetic disorder that is characterized by bone marrow failure (BMF), developmental abnormalities and predisposition to cancer. Together with other proteins involved in DNA repair processes and cell division, the FA proteins maintain genome homeostasis, and germline mutation of any one of the genes that encode FA proteins causes FA. Monoallelic inactivation of some FA genes, such as FA complementation group D1 (FANCD1; also known as the breast and ovarian cancer susceptibility gene BRCA2), leads to adult-onset cancer predisposition but does not cause FA, and somatic mutations in FA genes occur in cancers in the general population. Carcinogenesis resulting from a dysregulated FA pathway is multifaceted, as FA proteins monitor multiple complementary genome-surveillance checkpoints throughout interphase, where monoubiquitylation of the FANCD2-FANCI heterodimer by the FA core complex promotes recruitment of DNA repair effectors to chromatin lesions to resolve DNA damage and mitosis. In this Review, we discuss how the FA pathway safeguards genome integrity throughout the cell cycle and show how studies of FA have revealed opportunities to develop rational therapeutics for this genetic disease and for malignancies that acquire somatic mutations within the FA pathway.

The aldehyde dehydrogenase 2 polymorphisms on neuropsychological performance in bipolar II disorder with or without comorbid anxiety disorder

Anxiety disorders (ADs), the most common comorbid illnesses with bipolar disorder (BP) has been reported to associate with dopamine system. Dopamine, metabolized to 3,4-dihydroxyphenylacetic acid (DOPAC) by aldehyde dehydrogenase 2 (ALDH2), and the distribution of the ALDH2*1/*1, and ALDH2*1/*2+ALDH*2/*2 alleles in the Han Chinese general population is relatively equal. The association between dopamine metabolic enzymes and cognitive performance in patients with bipolar II disorder (BP-II) comorbid with AD is unclear. This study proposed to explore the role of ALDH2 polymorphisms on neuropsychological performance between BP-II comorbid with or without AD. One hundred ninety-seven BP-II patients with and without a comorbid AD were recruited and compared with 130 healthy controls (HCs). A polymerase chain reaction and a restriction fragment length polymorphism analysis were used to determine genotypes for ALDH2, and study participants underwent neuropsychological tests. An interaction between AD comorbidity and the ALDH2 polymorphisms was found in different domain of cognitive dysfunction in the BP-II patients. The ALDH2 polymorphisms might have different effects on the neuropsychological performance of BP-II patients with and without comorbid AD.

HPV, KRAS mutations, alcohol consumption and tobacco smoking effects on esophageal squamous-cell carcinoma carcinogenesis

Esophageal squamous-cell carcinoma (ESCC) is an invasive neoplastic disease generally associated with poor survival rates. The incidence of ESCC is characterized by marked geographic variation, with highest rates noted in developing Southeastern African, Central and Eastern Asian countries. In the developed Western European and North American regions where there is a low disease incidence, heavy alcohol and cigarette consumption constitute major risk factors. The toxic effects of both these risk factors cause chronic irritation and inflammation of the esophageal mucosa, while at the cellular level they further confer mutagenic effects by the activation of oncogenes (e.g., RAS mutations), inhibition of tumor-suppressor genes, and profound DNA damage. Viral infections, particularly with human papillomavirus, may activate specific antiapoptotic, proliferative and malignant cellular responses that may be intensified in combination with the effects of alcohol and tobacco. In countries with a high ESCC incidence, low socioeconomic status and an inadequate diet of poorly preserved food are combined with basic nutritional deficiencies and inadequate medical treatment. These conditions are favorable to the above-mentioned risk factors implicated in ESCC development, which may be present and/or habitually used in certain populations. New perspectives in epidemiological studies of ESCC development and its risk factors allow genome-wide research involving specific environments and habits. Such research should consist of adequately large and representative samples, should use newly designed informative genetic markers, and apply genomic variation analysis of the functional transcripts involved in malignant cell cycle regulation and neoplastic transformation in the multi-step process of ESCC carcinogenesis.