Blood Leukocyte Counts and Genetic Polymorphisms of Alcohol Dehydrogenase-1B and Aldehyde Dehydrogenase-2 in Japanese Alcoholic Men

Acetaldehyde exposure underlies functional defects in monocytes induced by excessive alcohol consumption

Increased intestinal permeability and hepatic macrophage activation by endotoxins are involved in alcohol-induced liver injury pathogenesis. Long-term alcohol exposure conversely induces endotoxin immune tolerance; however, the precise mechanism and reversibility are unclear. Seventy-two alcohol-dependent patients with alcohol dehydrogenase-1B (ADH1B, rs1229984) and aldehyde dehydrogenase-2 (ALDH2, rs671) gene polymorphisms admitted for alcohol abstinence were enrolled. Blood and fecal samples were collected on admission and 4 weeks after alcohol cessation and were sequentially analyzed. Wild-type and ALDH2*2 transgenic mice were used to examine the effect of acetaldehyde exposure on liver immune responses. The productivity of inflammatory cytokines of peripheral CD14⁺ monocytes in response to LPS stimulation was significantly suppressed in alcohol dependent patients on admission relative to that in healthy controls, which was partially restored by alcohol abstinence with little impact on the gut microbiota composition. Notably, immune suppression was associated with ALDH2/ADH1B gene polymorphisms, and patients with a combination of ALDH2*1/*2 and ADH1B*2 genotypes, the most acetaldehyde-exposed group, demonstrated a deeply suppressed phenotype, suggesting a direct role of acetaldehyde. In vitro LPS and malondialdehyde-acetaldehyde adducted protein stimulation induced direct cytotoxicity on monocytes derived from healthy controls, and a second LPS stimulation suppressed the inflammatory cytokines production. Consistently, hepatic macrophages of ethanol-administered ALDH2*2 transgenic mice exhibited suppressed inflammatory cytokines production in response to LPS compared to that in wild-type mice, reinforcing the contribution of acetaldehyde to liver macrophage function. These results collectively provide new perspectives on the systemic influence of excessive alcohol consumption based on alcohol-metabolizing enzyme genetic polymorphisms.

Effects of circadian variation, lifestyle and environment on hematological parameters: A narrative review

The complete blood count (CBC) is the most widely prescribed laboratory test. It plays a key role in screening, diagnosing, and monitoring a variety of medical disorders. Preanalytical and analytical variables are responsible for more than 50% of laboratory errors that may lead to spurious CBC results. The effects of blood sampling, transport, storage, and analytical errors on hematological parameters have been well described. Circadian variation and changes in lifestyle and environment can also affect blood cells. It has been extensively studied in the past, but highly variable methodology and the presence of confounding factors have provided scattered and inconsistent results. We have investigated the literature to define the impact of circadian variation, modification of the sleep-wake cycle, acute and chronic exercise, eating habits, alcohol, tobacco, drugs of abuse, high-altitude, heat/cold exposure, and air pollution on CBC results. The affected cell type along with the intensity and duration of changes are detailed for each condition. We aim at providing a comprehensive overview of which situations may induce clinically significant changes and have to be taken into account by healthcare professionals before considering a hematological parameter as pathological and requesting complementary tests.

Effect of silibinin on ethanol- or acetaldehyde-induced damge of mouse primary hepatocytes in vitro

Silibinin, one of the flavonoids isolated from milk thistle seeds of Silybum marianum, has hepatoprotective properties against toxins in clinical. However, the detailed mechanisms have remained unclear. This study investigates the underlying mechanism of silibinin in the protection against ethanol- or acetaldehyde-induced damage of neonatal mouse primary hepatocytes in vitro. The results show that ethanol inhibited proliferation of hepatocytes in a time (12, 24, 36 h) and dose-dependent (0-800 mM) manner. However, silibinin did not show protective effect on ethanol (500 mM)-induced suppression of hepatocyte proliferation. Acetaldehyde, the toxic metabolite of ethanol, appearing immediately in individuals after drink also inhibited the proliferation of hepatocytes in a dose-dependent (0-12 mM) manner. Surprisingly, silibinin significantly increased the cell viability and reduced the leakage of alanine amino transferase (ALT) and aspartate amino transferase (AST) in acetaldehyde-treated hepatocytes, suggesting that silibinin protected cell injury caused by acetaldehyde treatment. The apoptosis-inducing effect of acetaldehyde was demonstrated by the increased number of cells in sub-G1 phase as well as caspase-3 activation. Further study shows that acetaldehyde induced autophagy in the hepatocytes. The autophagy inhibitors, 3-Methyladenine (3-MA) and chloroquine (CQ), further decreased the viability of cells treated with acetaldehyde, suggesting that autophagy plays a protective role against apoptosis. Consistently, silibinin (20 μM) significantly reduced the activation of caspase 3 or apoptosis and increased the conversion of LC3-I to LC3-II or autophagy. Taken together, it is concluded that silibinin does not repress the ethanol- induced hepatocyte injury, whereas silibinin reduces acetaldehyde-caused hepatocyte injury through down-regulation of apoptosis and up-regulation of autophagy.

ADH1B: From alcoholism, natural selection, and cancer to the human phenome

The ADH1B (Alcohol Dehydrogenase 1B (class I), Beta Polypeptide) gene and its best-known functional alleles, Arg48His (rs1229984, ADH1B*2) and Arg370Cys (rs2066702, ADH1B*3), have been investigated in relation to many phenotypic traits; most frequently including alcohol metabolism and alcohol drinking behaviors, but also human evolution, liver function, cancer, and, recently, the comprehensive human phenome. To understand ADH1B functions and consequences, we provide here a bioinformatic analysis of its gene regulation and molecular functions, literature review of studies focused on this gene, and a discussion regarding future research perspectives. Certain ADH1B alleles have large effects on alcohol metabolism, and this relationship particularly encourages further investigations in relation to alcoholism and alcohol-associated cancer to understand better the mechanisms by which alcohol metabolism contributes to alcohol abuse and carcinogenesis. We also observed that ADH1B has complex mechanisms that regulate its expression across multiple human tissues, and these may be involved in cardiac and metabolic traits. Evolutionary data strongly suggest that the selection signatures at the ADH1B locus are primarily related to effects other than those on alcohol metabolism. This is also supported by the involvement of ADH1B in multiple molecular pathways and by the findings of our recent phenome-wide association study. Accordingly, future studies should also investigate other functions of ADH1B potentially relevant for the human phenome. © 2017 Wiley Periodicals, Inc.

Recovery from anemia and leukocytopenia after abstinence in Japanese alcoholic men and their genetic polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2

BACKGROUND

The combination of the fast-metabolizing alcohol dehydrogenase-1B (ADH1B*2 allele) and inactive heterozygous aldehyde dehydrogenase-2 (ALDH2*1/*2) increases susceptibility to macrocytic anemia and leukocytopenia in alcoholics due to severe acetaldehydemia. More than half of Japanese drinkers with esophageal cancer have this genotype combination.

METHODS

To assess the recovery of hematologic abnormalities after drinking cessation, changes in blood erythrocyte indices and leukocyte count during 8-week hospital stay were evaluated in 925 Japanese alcoholic men. We used four categories in ascending order for high blood acetaldehyde exposure from drinking: A, ADH1B*1/*1 plus ALDH2*1/*1; B, ADH1B*2 plus ALDH2*1/*1; C, ADH1B*1/*1 plus ALDH2*1/*2; and D, ADH1B*2 plus ALDH2*1/*2.

RESULTS

Mean values of hemoglobin and hematocrit were the lowest, and those of mean corpuscular volume (MCV) were markedly the highest in the D group on admission, and returning toward normal after abstinence, but the inter-group differences remained significant throughout the 8 weeks. The mean leukocyte count was the lowest in the D group on admission, but increased during 4-week abstinence when the inter-group differences were no longer significant. Frequencies of MCV ≥110 fl (50.5%), hemoglobin levels <11.5 g/dL (32.7%), hemoglobin levels <10.0 g/dL (9.9%) and leukocytopenia <4000/μL (22.8%) were the highest in the D group on the admission day and decreased at the 4-week abstinence (28.7%, 18.8%, 4.0% and 7.9%, respectively). The inter-group differences in frequencies of the severe anemia and leukocytopenia disappeared after 4-week abstinence.

CONCLUSIONS

Drinking cessation before surgery and/or chemoradiation treatment for esophageal cancer may be effective for recovery from anemia and leukocytopenia in drinkers belonging to the D group.

Platelet Counts and Genetic Polymorphisms of Alcohol Dehydrogenase-1B and Aldehyde Dehydrogenase-2 in Japanese Alcoholic Men

BACKGROUND

Thrombocytopenia during intoxication, rebound thrombocytosis during 1 to 3 weeks of abstinence, and subsequent normalization of the platelet count are common in alcoholics.

METHODS

We evaluated 989 Japanese alcoholic men to identify the effects of genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B; rs1229984) and aldehyde dehydrogenase-2 (ALDH2; rs671) on platelet counts during an 8-week in-hospital abstinence period.

RESULTS

Thrombocytopenia (<15 × 10⁴ /μl) was observed in 25.9% of the subjects upon admission. The platelet counts increased from 21.4 ± 0.3 × 10⁴ /μl (mean ± SE) to 27.6 ± 0.3 × 10⁴ /μl, and a rebound platelet increase of  ≥10 × 10⁴ /μl was observed in 28.6% of the patients during the first 2 weeks after admission. By 4 weeks, the mean platelet counts had returned to intermediate levels and remained stable thereafter. The reversible suppression and rebound increase in the platelet counts were more prominent in the slow-metabolizing ADH1B*1/*1 group than in the fast-metabolizing ADH1B*2 group. Throughout the 8 weeks, the mean platelet counts of the active ALDH2*1/*1 group were consistently lower than those in the inactive ALDH2*1/*2 group. Cirrhosis was a strong determinant of a lower platelet count. After adjustments for nongenetic factors including cirrhosis, multiple linear regression analyses showed that the ADH1B*1/*1 genotype was associated with a lower platelet count (partial regression coefficient = -1.3 × 10⁴ /μl) on the admission day, but subsequently had a positive effect on the platelet count at 1 and 2 weeks after admission (+1.5 and +3.8 × 10⁴ /μl, respectively). The ALDH2*1/*1 genotype was associated with a lower platelet count (-2.1 to -3.9 × 10⁴ /μl) consistently throughout the 8 weeks. Multiple logistic regression analyses showed that the ADH1B*1/*1 genotype increased the risk of thrombocytopenia upon admission (odds ratio [95% confidence interval] = 1.61 [1.14 to 2.27]) and of a rebound platelet increase during the first 2 weeks (3.86 [2.79 to 5.34]). The ALDH2*1/*1 genotype increased the risk of thrombocytopenia upon admission (1.73 [1.06 to 2.82]).

CONCLUSIONS

In alcoholics, the ADH1B*1/*1 genotype increased the risk of thrombocytopenia upon admission and of a rebound platelet increase 2 weeks thereafter, while the ALDH2*1/*1 genotype was associated with lower platelet counts throughout the 8-week hospital stay.