Alcohol-induced ketonemia is associated with lowering of blood glucose, downregulation of gluconeogenic genes, and depletion of hepatic glycogen in type 2 diabetic db/db mice

Lysine β-hydroxybutyrylation promotes lipid accumulation in alcoholic liver disease

Continuous (chronic or sub-chronic) alcohol consumption induces a metabolic byproduct known as ketone bodies, and the accumulation of ketones leads to a life-threatening syndrome called alcoholic ketoacidosis. However, the mechanism underlining the physiological effects of ketone accumulation in alcoholic liver disease (ALD) is still in its infancy. Here, we discovered that mitochondrial acetyl-CoA accumulation was diverted into the ketogenesis pathway in ethanol-fed mice and ethanol-exposed hepatocytes. Unexpectedly, global protein lysine β-hydroxybutyrylation (Kbhb) was induced in response to increased ketogenesis-derived β-hydroxybutyrate (BHB) levels both in hepatocytes and in livers of mice. Focusing on the solute carrier family (SLCs), we found that SLC25A5 presented obvious Kbhb at lysine residues 147 and 166. Kbhb modifications at these two lysine residues stabilized SLC25A5 expression by blocking ubiquitin-proteasome pathway. Subsequent mutation analysis revealed that Kbhb of SLC25A5 at K147 and K166 had site-specific regulatory roles by increasing peroxisome proliferator activated receptor gamma (PPARγ) expression, which further promoting lipogenesis. Additionally, 3-hydroxy-3-methylglutaryl-coenzyme A synthase 2 (HMGCS2), a rate-limiting enzyme for BHB production, was profoundly induced by ethanol exposure, and knockout of Hmgcs2 with CRISPR/Cas9 attenuated SLC25A5 Kbhb. Together, our study demonstrated a widespread Kbhb landscape under ethanol exposure and clarified a physiological effect of Kbhb modification on liver lipid accumulation.

Comprehensive insights into berberine's hypoglycemic mechanisms: A focus on ileocecal microbiome in db/db mice

The efficacy of berberine in managing diabetes through modulation of gut microbiome has been established through fecal sample analyses. However, relying solely on fecal materials constrains our comprehension of berberine's effects on diverse gastrointestinal locations. This study specifically explores the ileocecal region, a segment characterized by higher microbial diversity than fecal samples. Berberine exhibits a robust hypoglycemic impact by significantly reducing glucose levels in blood and urine. Beyond glycemic control, berberine ameliorates various diabetes-related symptoms in serum, including increased insulin and leptin, but decreased NEFA and MDA. Notably, berberine demonstrates liver-protective functions by alleviating oxidative stress and enhancing hepatic glycogen abundance. These outcomes prompted a high-throughput sequencing analysis of the ileocecal microbiome, revealing an augmentation of beneficial bacterial genera (four genera in the Lachnospiraceae family, Erysipelatoclostridium, and Escherichia-Shigella), along with a reduction in harmful bacterial genera (Romboutsia). Additionally, we predicted the impact of the ileocecal microbiome on clinically relevant factors associated with diabetes. These findings elucidate the multi-pathway mechanisms of berberine in treating T2D, underscoring its potential as a natural anti-diabetic agent or functional food, particularly through the modulation of the gut microbiota.

Morphological and Transcriptomic Analysis of the Supplemental Boron in the Liver of Ostrich Chicks

African ostrich chicks (Struthio camelus) were divided into six groups, and each received different levels of boric acid (source of boron) in the drinking water (0, 40, 80, 160, 320, and 640 mg/L respectively) to examine the histological, apoptotic, biochemical, and transcriptomic parameters. Morphological analysis in different groups was assessed by hematoxylin and eosin (H&E) staining, periodic acid Schiff (PAS) staining, and terminal deoxynucleotide transferase dUTP Nick-End Labeling (TUNEL) assay. The biochemical profile was evaluated spectrophotometrically. Detailed RNA-Seq of the data was performed using the transcriptomic method. H&E staining showed well-developed liver structure up to the 160 mg/L boric acid (BA) supplement groups, while BA doses (320 mg/L and 640 mg/L) caused changes in hepatocytes and portal triads. PAS staining showed that glycogen levels were optimal in the 80 mg/L BA dose group, but a reduction in glycogen levels was observed after this group, particularly in the 640 mg/L BA supplement group. Cellular apoptosis showed a biphasic pattern, and the BA dose above 160 mg/L enhanced cell death. In addition, serum analysis showed that doses of 80-160 mg BA were beneficial for ostrich liver. Then, the transcriptome analysis of the 80 mg dose also showed mainly positive effects on the liver. These results demonstrated that chronic BA exposure (320-640 mg) can cause significant histological, apoptotic, and biochemical changes in African ostrich liver, while the adequate dose of supplementation (particularly 80 mg BA) promotes liver growth.

Hepatic COX-2 expression protects mice from an alcohol-high fat diet-induced metabolic disorder by involving protein acetylation related energy metabolism

PURPOSE

A diet high in fat and ethanol often results in chronic metabolic disorder, hepatic steatosis, and liver inflammation. Constitutive hepatic cyclooxygenase-2 (COX-2) expression could protect from high fat-induced metabolism disturbance in a murine model. In this study, we explored the influence of hCOX-2 transgenic [TG] to high fat with ethanol-induced metabolic disorder and liver injury using a mouse animal model.

METHODS

12-week-old male hepatic hCOX-2 transgenic (TG) or wild type mice (WT) were fed either a high fat and ethanol liquid diet (HF+Eth) or a regular control diet (RCD) for 5 weeks (four groups: RCD/WT, RCD/TG; HF+Eth/TG, HF+Eth/WT). We assessed metabolic biomarkers, cytokine profiles, histomorphology, and gene expression to study the impact of persistent hepatic COX-2 expression on diet-induced liver injury.

RESULTS

In the HF+Eth diet, constitutively hepatic human COX-2 expression protects mice from body weight gain and white adipose tissue accumulation, accompanied by improved IPGTT response, serum triglyceride/cholesterol levels, and lower levels of serum and liver inflammatory cytokines. Histologically, hCOX-2 mice showed decreased hepatic lipid droplets accumulation, decreased hepatocyte ballooning, and improved steatosis scores. Hepatic hCOX-2 overexpression enhanced AKT insulin signaling and increased fatty acid synthesis in both RCD and HF+Eth diet groups. The anti-lipogenic effect of hCOX-2 TG in the HF+Eth diet animals was mediated by increasing lipid disposal through enhanced β-oxidation via elevations in the expression of PPARα and PPARγ, and increased hepatic autophagy as assessed by the ratio of autophagy markers LC3 II/I in hepatic tissue. Various protein acetylation pathway components, including HAT, HDAC1, SIRT1, and SNAIL1, were modulated in hCOX-2 TG mice in either RCD or HF+Eth diet.

CONCLUSIONS

Hepatic human COX-2 expression protected mice from the metabolic disorder and liver injury induced by a high fat and ethanol diet by enhancing hepatic lipid expenditure. Epigenetic reprogramming of diverse metabolic genes might be involved in the anti-lipogenic effect of COX-2.

Serum Glycated Albumin Levels Are Affected by Alcohol in Men of the Jinuo Ethnic Group in China

AIM

To investigate the effects of alcohol on serum glycated albumin (GA) levels in Chinese men.

METHODS

A total of 2314 male subjects from the Jinuo ethnic group in China were enrolled. Of these, 986 subjects drank alcohol frequently and 404 subjects did not. Lifestyle information was gathered by using a questionnaire, and measurements of blood pressure, body mass index, blood glucose level, liver function, and kidney function were collected. GA was measured by using an enzymatic method. Frequent drinking was defined as a history of drinking ethanol > 80 g/d within the past two weeks. Nondrinking was defined as no alcohol consumption in the past three months. Subjects with an alcohol intake between 0 and 80 g/d in the past two weeks were included in the drinking-occasionally group. Analysis of variance (ANOVA), correlation analysis, and linear regression were used to evaluate the effects of drinking on serum GA levels. Decision tree regression (DTR) algorithm was used to evaluate the effect of features (variables) on GA levels.

RESULTS

We found that male subjects who drank frequently had significantly lower serum GA levels than subjects who did not drink (13.0 ± 1.7 vs. 14.1 ± 3.7, p < 0.05). Spearman's correlation analysis calculated a coefficient of -0.152 between drinking and GA (p < 0.005). Linear regression established that drinking was an independent predictor for GA levels with a standardized regression coefficient of -0.144 (p < 0.05). Decision tree regression showed that the effect of drinking on GA levels (0.0283) is five times higher than that of smoking (0.0057).

CONCLUSIONS

Frequent alcohol consumption could result in decreased GA levels in men of the Jinuo ethnic group in China.

Alcoholic hepatitis and metabolic disturbance in female mice: a more tractable model than Nrf2-/- animals

Alcoholic hepatitis (AH) is the dramatic acute presentation of alcoholic liver disease, with a 15% mortality rate within 28 days in severe cases. Research into AH has been hampered by the lack of effective and reproducible murine models that can be operated under different regulatory frameworks internationally. The liquid Lieber-deCarli (LdC) diet has been used as a means of ad libitum delivery of alcohol but without any additional insult, and is associated with relatively mild liver injury. The transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) protects against oxidative stress, and mice deficient in this molecule are suggested to be more sensitive to alcohol-induced injury. We have established a novel model of AH in mice and compared the nature of liver injury in C57/BL6 wild-type (WT) versus Nrf2-/- mice. Our data showed that both WT and Nrf2-/- mice demonstrate robust weight loss, and an increase in serum transaminase, steatosis and hepatic inflammation when exposed to diet and ethanol. This is accompanied by an increase in peripheral blood and hepatic myeloid cell populations, fibrogenic response and compensatory hepatocyte regeneration. We also noted characteristic disturbances in hepatic carbohydrate and lipid metabolism. Importantly, use of Nrf2-/- mice did not increase hepatic injury responses in our hands, and female WT mice exhibited a more-reproducible response. Thus, we have demonstrated that this simple murine model of AH can be used to induce an injury that recreates many of the key human features of AH - without the need for challenging surgical procedures to administer ethanol. This will be valuable for understanding of the pathogenesis of AH, for testing new therapeutic treatments or devising metabolic approaches to manage patients whilst in medical care.This article has an associated First Person interview with the joint first authors of the paper.