Association of polymorphism in the alcohol dehydrogenase 2 gene with alcohol-related organ injuries, especially liver cirrhosis

Association analysis among polymorphisms of the various genes and chronic alcoholic pancreatitis

Chronic and excessive consumption of alcohol is an important factor responsible for the onset of pancreatitis. However, the incidence of chronic pancreatitis in heavy drinkers differs in individuals, suggesting that these individual differences may involve various genetic and environmental factors. In the present study, we investigated an association of alcoholic pancreatitis with polymorphisms of the various genes related to metabolism of the oxidative compounds. We analyzed polymorphisms of NADPH-quinone oxidoreductase 2 (NQO2), multidrug resistance 1 (MDR1), alcohol dehydrogenase 1B (ADH1B) and lipoprotein lipase (LPL). The subjects consisted of 53 patients with chronic alcoholic pancreatitis (AlCP), 54 alcoholic patients without pancreatic dysfunction (Alc), and 42 healthy individuals. DNA samples were prepared from the peripheral blood of all subjects, and the genetic mutations were analyzed by polymerase chain reaction and restriction fragment length polymorphism methods. The ADH1B gene frequencies were significantly different between healthy controls and Alc patients (P < 0.001), and also between AlCP and Alc patients (P < 0.05). However, no significant difference was found between healthy controls and AlCP patients. The gene frequencies of MDR1 (3435C > T) and MDR1 (2677G > A/T) of patients with AlCP or Alc were different when compared with healthy controls, although the difference was not significant. The NQO2 and LPL genes showed no relation with Alc and AlCP patients. The ADH1B*1 gene frequency in AlCP was significantly lower compared with Alc. We speculate that the ADH1B*1 gene may function by reducing vulnerability to the onset of alcoholic pancreatitis. Other genes analyzed in the present study lacked association with AlCP.

Genetic polymorphisms of ADH2, ADH3, CYP4502E1 Dra-I and Pst-I, and ALDH2 in Spanish men: lack of association with alcoholism and alcoholic liver disease

BACKGROUND/AIMS

The relationship between polymorphisms at the alcohol dehydrogenase 2 (ADH(2)), ADH(3), CYP(450)2E1 and aldehyde dehydrogenase 2 (ALDH(2)) loci and the individual predisposition to alcoholism and alcoholic liver disease in Caucasians is controversial.

METHODS

We determined the genotypes of ADH(2), ADH(3), CYP(450)2E1 (Pst-I and Dra-I) and ALDH(2) in 519 male Spaniards: 264 alcoholic subjects (47 without liver disease, 118 with non-cirrhotic liver disease and 99 with cirrhosis) and 255 non-alcoholic subjects (64 healthy controls, 110 with non-cirrhotic non-alcoholic liver disease and 81 with cirrhosis unrelated to alcohol). Genotyping was performed using PCR-RFLP methods on white cell DNA.

RESULTS

The distribution of the allelic variants (allele *1 and allele *2) in the whole subjects analyzed was: ADH(2) 93.1% and 6.9%; ADH(3) 55.7 and 44.3%; CYP(450)2E1 Dra-I 11.2 and 88.8%; CYP(450)2E1 Pst-I 96.2 and 3.8% and ALDH2 100 and 0%, respectively. No differences were observed in the allelic distributions of the alcoholic and non-alcoholic subjects for the loci examined. Allele distribution in alcoholics with no liver disease, with alcoholic steatosis or hepatitis, and with cirrhosis was also similar.

CONCLUSIONS

ADH(2), ADH(3), and CYP(450)2E1 Pst-I and Dra-I genetic variations are not related to alcoholism or susceptibility to alcoholic liver disease in our male population. ALDH(2) locus is monomorphic.

The role of acetaldehyde in the actions of alcohol (update 2000)

BACKGROUND

Recent advances in the field of acetaldehyde (AcH) research have raised the need for a comprehensive review on the role of AcH in the actions of alcohol. This update is an attempt to summarize the available AcH research.

METHODS

The descriptive part of this article covers not only recent research but also the development of the field. Special emphasis is placed on mechanistic analyses, new hypotheses, and conclusions.

RESULTS

Elevated AcH during alcohol intoxication causes alcohol sensitivity, which involves vasodilation associated with increased skin temperature, subjective feelings of hotness and facial flushing, increased heart and respiration rate, lowered blood pressure, sensation of dry mouth or throat associated with bronchoconstriction and allergy reactions, nausea and headache, and also reinforcing reactions like euphoria. These effects seem to involve catecholamine, opiate peptide, prostaglandin, histamine, and/or kinin mechanisms. The contribution of AcH to the pathological consequences of chronic alcohol intake is well established for different forms of cancer in the digestive tract and the upper airways. AcH seems to play a role in the etiology of liver cirrhosis. AcH may have a role in other pathological developments, which include brain damage, cardiomyopathy, pancreatitis, and fetal alcohol syndrome. AcH creates both unpleasant aversive reactions that protect against excessive alcohol drinking and euphoric sensations that may reinforce alcohol drinking. The protective effect of AcH may be used in future treatments that involve gene therapy with or without liver transplantation.

CONCLUSIONS

AcH plays a role in most of the actions of alcohol. The individual variability in these AcH-mediated actions will depend on the genetic polymorphism, not only for the alcohol and AcH-metabolizing enzymes but also for the target sites for AcH actions. The subtle balance between aversive and reinforcing, protecting and promoting factors will determine the overall behavioral and pathological developments.

Polymorphism of tumor necrosis factor-beta and alcohol dehydrogenase genes and alcoholic brain atrophy in Japanese patients

BACKGROUND

Alcohol abuse can induce brain atrophy, but it only occurs in some alcoholics. Many inflammatory cytokines such as tumor necrosis factor (TNF) are produced rapidly in the brain by experimental or clinical injury.

METHOD

To investigate whether genetic polymorphism of TNF was related to alcoholic brain atrophy, we determined restriction fragment-length polymorphisms of the TNF-beta genes in 72 male alcoholics. Computed tomography was used to determine the severity of brain atrophy.

RESULTS

Digestion with NcoI and MspI after polymerase chain reaction amplification showed that the TNFB1 allele frequency was significantly higher in patients with brain atrophy than in those without brain atrophy (chi2 = 10.20, p = 0.0034). A multivariate analysis that included age, total alcohol intake, ADH2 genotype, and TNF-beta genotype showed that the ADH21/21 genotype and TNFB1/B1 genotype are independently associated with alcoholic brain atrophy. These findings suggest that the TNFB1 allele may be associated with alcoholic brain atrophy.

Homozygosity for alanine in the mitochondrial targeting sequence of superoxide dismutase and risk for severe alcoholic liver disease

BACKGROUND & AIMS

For similar ethanol consumption, some subjects only develop macrovacuolar steatosis whereas others develop severe liver lesions. A genetic dimorphism encodes for either alanine or valine in the mitochondrial targeting sequence of manganese superoxide dismutase and could modulate its mitochondrial import.

METHODS

The DNA of 71 white patients with alcoholic liver disease and 79 white blood donors was amplified and genotyped.

RESULTS

The frequency of the alanine-encoding allele and the percentage of alanine homozygotes were higher in all patients than in controls and increased with the severity of liver lesions. The percentage of alanine homozygotes was 19% in controls, 17% in alcoholic patients with macrovacuolar steatosis, 43% in patients with microvesicular steatosis, 58% in patients with alcoholic hepatitis, and 69% in patients with cirrhosis. Alcohol consumption in alcoholics was similar whatever the genotype. Alanine homozygosity did not change the risk of developing macrovacuolar steatosis in alcoholics, but increased by 3-fold that of microvesicular steatosis, and 6- and 10-fold that of alcoholic hepatitis and cirrhosis.

CONCLUSIONS

Homozygosity for alanine in the mitochondrial targeting sequence of manganese superoxide does not modify alcohol consumption and the risk of macrovacuolar steatosis in alcoholics but is a major risk factor for severe alcoholic liver disease.

The role of acetaldehyde in the actions of alcohol (update 2000)

BACKGROUND

Recent advances in the field of acetaldehyde (AcH) research have raised the need for a comprehensive review on the role of AcH in the actions of alcohol. This update is an attempt to summarize the available AcH research.

METHODS

The descriptive part of this article covers not only recent research but also the development of the field. Special emphasis is placed on mechanistic analyses, new hypotheses, and conclusions.

RESULTS

Elevated AcH during alcohol intoxication causes alcohol sensitivity, which involves vasodilation associated with increased skin temperature, subjective feelings of hotness and facial flushing, increased heart and respiration rate, lowered blood pressure, sensation of dry mouth or throat associated with bronchoconstriction and allergy reactions, nausea and headache, and also reinforcing reactions like euphoria. These effects seem to involve catecholamine, opiate peptide, prostaglandin, histamine, and/or kinin mechanisms. The contribution of AcH to the pathological consequences of chronic alcohol intake is well established for different forms of cancer in the digestive tract and the upper airways. AcH seems to play a role in the etiology of liver cirrhosis. AcH may have a role in other pathological developments, which include brain damage, cardiomyopathy, pancreatitis, and fetal alcohol syndrome. AcH creates both unpleasant aversive reactions that protect against excessive alcohol drinking and euphoric sensations that may reinforce alcohol drinking. The protective effect of AcH may be used in future treatments that involve gene therapy with or without liver transplantation.

CONCLUSIONS

AcH plays a role in most of the actions of alcohol. The individual variability in these AcH-mediated actions will depend on the genetic polymorphism, not only for the alcohol and AcH-metabolizing enzymes but also for the target sites for AcH actions. The subtle balance between aversive and reinforcing, protecting and promoting factors will determine the overall behavioral and pathological developments.

Genetic polymorphism of alcohol dehydrogenase in europeans: the ADH2*2 allele decreases the risk for alcoholism and is associated with ADH3*1

Polymorphism at the ADH2 and ADH3 loci of alcohol dehydrogenase (ADH) has been shown to have an effect on the predisposition to alcoholism in Asian individuals. However, the results are not conclusive for white individuals. We have analyzed the ADH genotype of 876 white individuals from Spain (n = 251), France (n = 160), Germany (n = 184), Sweden (n = 88), and Poland (n = 193). Peripheral blood samples from healthy controls and groups of patients with viral cirrhosis and alcohol-induced cirrhosis, as well as alcoholics with no liver disease, were collected on filter paper. Genotyping of the ADH2 and ADH3 loci was performed using polymerase chain reaction-restriction fragment length polymorphism methods on white cell DNA. In healthy controls, ADH2*2 frequencies ranged from 0% (France) to 5.4% (Spain), whereas ADH3*1 frequencies ranged from 47. 6% (Germany) to 62.5% (Sweden). Statistically significant differences were not found, however, between controls from different countries, nor between patients with alcoholism and/or liver disease. When all individuals were grouped in nonalcoholics (n = 451) and alcoholics (n = 425), ADH2*2 frequency was higher in nonalcoholics (3.8%) than in alcoholics (1.3%) (P =.0016), whereas the ADH3 alleles did not show differences. Linkage disequilibrium was found between ADH2 and ADH3, resulting in an association of the alleles ADH2*2 and ADH3*1, both coding for the most active enzymatic forms. In conclusion, the ADH2*2 allele decreases the risk for alcoholism, whereas the ADH2*2 and ADH3*1 alleles are found to be associated in the European population.

Serum ubiquitin levels in patients with alcoholic liver disease

Serum concentrations of free ubiquitin and multiubiquitin chain as determined by immunoassays were compared between 10 healthy subjects, and 11 patients with alcoholic hepatic fibrosis, 10 with alcoholic cirrhosis, and 6 with viral liver cirrhosis. All measurements of multiubiquitin chains were expressed in terms of a standard multiubiquitin chain reference preparation 1. Serum concentrations (mean +/- SD) of free ubiquitin and multiubiquitin chains were significantly higher in patients with alcoholic cirrhosis (63.5 +/- 33.7 ng/ml and 7.5 +/- 4.6 ng/ml) than in the normal subjects (29.6 +/- 6.6 ng/ml, p < 0.05 and 4.1 +/- 1.7 ng/ml, p < 0.05), and those with alcoholic hepatic fibrosis (34.8 +/- 16.3 ng/ml, p < 0.05 and 3.0 +/- 0.7 ng/ml, p < 0.05) and viral liver cirrhosis (28.8 +/- 7.5 ng/ml, p < 0.05 and 4.2 +/- 1.3 ng/ml, p < 0.05). Serum levels of both forms of ubiquitin in six patients with alcoholic cirrhosis showed a tendency to decline after 3 months of abstinence. In a total of 14 patients with alcoholic liver damage, 11 with brain atrophy had significantly higher serum levels of both ubiquitin forms than did three patients without brain atrophy (p < 0.05). No correlation was seen between serum concentrations of either form of ubiquitin and liver function test results in the patients with alcoholic liver damage. However, serum levels of both forms of ubiquitin levels correlated significantly with cumulative alcohol intake (p < 0.05). A significant correlation (p < 0.05) also was observed between serum levels of multiubiquitin chains and mean corpuscular volume, a marker of alcohol consumption. These results suggest that the serum concentrations of ubiquitin, especially multiubiquitin chain is a good marker for the diagnosis of alcoholic cirrhosis.

Genotypes of alcohol-metabolizing enzymes in relation to alcoholic chronic pancreatitis in Japan

Long-term consumption of large amounts of alcohol is the main cause of chronic pancreatitis. All heavy drinkers, however, do not contract chronic pancreatitis. Although genetic predisposition to alcoholism and alcoholic liver disease has been reported, genetic susceptibility to alcoholic pancreatitis is still a matter of debate. To determine the relation between genotypes of alcohol-metabolizing enzymes and chronic alcoholic pancreatitis, we examined genotype patterns of aldehyde dehydrogenase 2 (ALDH 2), alcohol dehydrogenase 2 (ADH 2) and cytochrome P-4502E1 (CYP2E1) in 54 patients with chronic alcoholic pancreatitis who were diagnosed in general hospitals in all over Japan and compared with those in 30 patients with chronic nonalcoholic pancreatitis or in 46 alcoholics with normal pancreatic function. There were no significant differences in the distribution of genotypes of ALDH 2 and CYP2E1 among those three groups. As for the ADH 2 genotype, distribution of 2(1)/2(1), 2(1)/2(2), and 2(2)/2(2) was 35%, 30%, and 35% in alcoholics with normal pancreatic function; 4%, 39%, and 57% in the chronic alcoholic pancreatitis group; and 0%, 50%, and 50% in the chronic nonalcoholic pancreatitis group, respectively. The frequency of ADH 2(2) allele was significantly higher in the chronic alcoholic pancreatitis group, compared with alcoholics with normal pancreatic function; but, it was not significantly different from that in the chronic nonalcoholic pancreatitis group. We also examined the relation between pancreatic fibrosis or pancreatitis histologically diagnosed and genotypes of alcohol-metabolizing enzymes in alcoholic autopsy cases. Twenty of 31 cases showed moderate or severe pancreatic fibrosis and showed intralobular + interlobular fibrosis, which is characteristic in alcoholic pancreatitis or intralobular fibrosis. ADH 2(2) allele tended to show a high frequency in the intralobular + interlobular fibrosis group, compared with that in the intralobular fibrosis group (75.0% vs. 41.7%, p < 0.1). The chronic pancreatitis group had a significantly higher frequency of the ADH 2(2) allele than that in cases without such findings (87.5% vs. 58.7%, p < 0.05). However, the ALDH 2 and CYP2E1 genotypes showed no significant relation to the findings of pancreatic fibrosis or histological pancreatitis. These data suggest that the risk of chronic alcoholic pancreatitis diagnosed clinically and pathologically seems to be associated with the ADH 2(2) allele in the genotypes of alcohol-metabolizing enzymes.