Draft genome sequence analysis of a mcr-1-producing Klebsiella pneumoniae ST661 isolated from a mink in China.

OBJECTIVES: Klebsiella pneumoniae is a major opportunistic pathogen that is a member of the Enterobacteriaceae. Klebsiella pneumoniae causes pneumonia in mink and has become the primary infectious disease that limits mink farming. In this study, we report the draft genome sequence of a multidrug-resistant (MDR) strain of K. pneumoniae that harbours the mcr-1 gene isolated from a mink in China. METHODS: The agar microdilution method was used to determine the minimum inhibitory concentration of the strain. The entire genomic DNA was sequenced using an Illumina MiSeq platform. A multilocus sequence type (MLST) and a core genome SNP phylogenetic tree analysis with a heatmap of the resistance genes and virulence genes were performed. RESULTS: The size of the genome was 5451.826 kb, and it included one chromosome and one plasmid. The draft genome of K. pneumoniae indicated that the isolate was a member of MLST 661. Four types of virulence genes were detected. The results of antimicrobial susceptibility testing showed multiple drug resistance, and 17 resistance genes were identified. CONCLUSION: The genome sequence reported in this study will help to reveal the key role of antibiotic resistance and pathogenic mechanisms. It will provide useful information for the role of mobile genetic elements in the adaptive translocation and spread of antimicrobial resistance.

Alterations in metabolome and microbiome: new clues on cathelicidin-related antimicrobial peptide alleviates acute ulcerative colitis.

Ulcerative colitis (UC) is a chronic and recurrent inflammatory disease of the gastrointestinal tract. This study aimed to determine the effect of cathelicidin-related antimicrobial peptide (Cramp) on dextran sulfate sodium (DSS)-induced acute experimental colitis in mice and to investigate the underlying mechanisms. Acute UC was induced in C57BL/6 mice with 3% DSS for 7 days, 4 mg/kg b.w. synthetic Cramp peptide was administrated once daily starting on day 4 of the experimental period. Mice were evaluated for body weight, colon length, colon histopathology, and inflammatory cytokines in colon tissue. Using 16 s rRNA sequencing, the composition structure of gut microbiota was characterized. Metabolomic profiling of the serum was performed. The results showed that DSS treatment significantly induced intestinal damage as reflected by disease activity index, histopathological features, and colon length, while Cramp treatment significantly prevented these trends. Meanwhile, Cramp treatment decreased the levels of inflammatory cytokines in both serum and colonic tissue on DSS-induced colitis. It was also observed that DSS damaged the integrity of the intestinal epithelial barrier, whereas Cramp also played a protective role by attenuating these deteriorated effects. Furthermore, Cramp treatment reversed the oxidative stress by increasing the antioxidant enzymes of GSH-PX and decreasing the oxidant content of MDA. Notably, compared to the DSS group, Cramp treatment significantly elevated the abundance of Verrucomicrobiota at the phylum level. Furthermore, at the genus level, Parasutterella and Mucispirllum abundance was increased significantly in response to Cramp treatment, although Roseburia and Enterorhabdus reduced remarkably. Metabolic pathway analysis of serum metabolomics showed that Cramp intervention can regulate various metabolic pathways such as α-linolenic acid, taurine and hypotaurine, sphingolipid, and arachidonic acid metabolism. The study concluded that Cramp significantly ameliorated DSS-induced colonic injury, colonic inflammation, and intestinal barrier dysfunction in mice. The underlying mechanism is closely related to the metabolic alterations derived from gut microbiota.

Physical exercise habits are related with reduced prevalence of falling among elderly women in China.

BACKGROUND: Although some studies have examined the association between exercise and falls, most have focused on specific exercises, and the results have been inconsistent. In addition, there is a lack of evidence on elderly Chinese women who have different living and exercise habits compared to those in other countries. Therefore, this study aimed to investigate whether physical exercise is associated with falls in elderly Chinese women. METHODS: This cross-sectional study included 1429 elderly Chinese women with a mean age of 69.2 years. Information on physical exercise habits and fall experiences was collected using a self-report questionnaire. Logistic regression models were used to analyze the association between physical exercise habits and falls. RESULTS: The results showed that 15% participants had a fall in the past year. After adjusting for confounding factors, the odd ratios (ORs) and 95% Confidence Intervals (CIs) for fall experiences across categories of exercise frequency were as follow: 1 (reference) for no exercise behavior, 0.50 (0.29, 0.85) for exercise 1 to 5 times a week, and 0.37 (0.25, 0.55) for exercise more than 6 times a week. Furthermore, the ORs (95% CIs) across categories of exercise insistence were 1 (reference) for less than 1 year, 0.78 (0.37, 1.65) for 1 to 3 years, and 0.38 (0.20, 0.74) for more than 3 years. In terms of exercise duration, the ORs (95% CIs) for < 1 h/day, 1-2 h/day, and > 2 h/day were 1 (reference), 0.85 (0.53, 1.36), and 2.80 (1.30, 6.05). Unlike other variables, longer exercise duration was associated unfavorably with falls. CONCLUSION: Physical exercise habits were associated with falls in elderly Chinese women. Keeping a proper exercise habit may contribute to lower risk of falling in elderly women.

Genome-Assisted Probiotic Characterization and Application of Lactiplantibacillus plantarum 18 as a Candidate Probiotic for Laying Hen Production.

Probiotics gained significant attention for their potential to improve gut health and enhance productivity in animals, including poultry. This comprehensive study focused on the genetic analysis of Lactiplantibacillus plantarum 18 (LP18) to understand its survival and colonization characteristics in the gastrointestinal tract. LP18 was supplemented in the late-stage diet of laying hens to investigate its impact on growth performance, egg quality, and lipid metabolism. The complete genome sequence of LP18 was determined, consisting of 3,275,044 base pairs with a GC content of 44.42% and two circular plasmids. Genomic analysis revealed genes associated with adaptability, adhesion, and gastrointestinal safety. LP18 supplementation significantly improved the daily laying rate (p < 0.05) during the late-production phase and showed noteworthy advancements in egg quality, including egg shape index (p < 0.05), egg albumen height (p < 0.01), Haugh unit (p < 0.01), and eggshell strength (p < 0.05), with notable improvements in eggshell ultrastructure. Additionally, LP18 supplementation resulted in a significant reduction in serum lipid content, including LDL (p < 0.01), FFA (p < 0.05), and Gly (p < 0.05). These findings provide valuable insights into the genomic characteristics of LP18 and the genes that support its survival and colonization in the gastrointestinal tract. Importantly, this study highlights the potential of LP18 as a probiotic candidate to enhance productivity, optimize egg quality, and modulate lipid metabolism in poultry production.

Comparative analysis of ankle injury kinematics and dynamics in basketball players: forefoot landing vs. rearfoot landing modes.

OBJECTIVE: To compare the differences in ankle joint parameters of basketball athletes between the forefoot and rearfoot landing and to investigate the injury mechanism of ankle joints in different landing modes. METHODS: Twenty level II male basketball athletes were selected as subjects in this study. The landing movements of these athletes were assigned into a forefoot landing mode and a rearfoot landing mode. The former includes movements such as running emergency stop, two-leg jump and forefoot landing, while the latter includes actions such as running emergency stop, two-leg jump and rearfoot landing. The motion capture system and three-dimensional force measuring table were used for collecting the kinematic and dynamic data of the subjects. RESULTS: The initial landing angles, including ankle dorsiflexion and medial ankle rotation of the forefoot were larger than those of the rearfoot (all P<0.05). Compared to those in the rearfoot landing mode, the forefoot landing exhibited a greater peak angle of ankle plantar flexion and ankle varus, as well as a smaller peak angle of ankle dorsiflexion and ankle internal rotation (all P<0.05). In comparison to the rearfoot landing mode, the forefoot landing showed a larger range of ankle varus and valgus, as well as a smaller range of ankle dorsiflexion and plantar flexion (all P<0.05). The ankle plantar flexion torque of forefoot landing was higher than that of rearfoot landing, while the peak ankle dorsiflexion torque of forefoot landing was smaller than that of rearfoot landing (all P<0.05). Compared to those in the rearfoot landing mode, the outward peak ground reaction force was smaller and the forward peak ground reaction was larger in forefoot landing mode (all P<0.05). No obvious differences were observed in other indicators between two landing modes. CONCLUSIONS: There are kinematic and dynamic differences between the forefoot and rearfoot landing. Forefoot landing may increase the risk of ankle injury during landing.

Effects of dietary Lactobacillus rhamnosus GG supplementation on the production performance, egg quality, eggshell ultrastructure, and lipid metabolism of late-phase laying hens.

BACKGROUND: Toward the late phase of laying, the production performance of laying hens decreases, egg quality deteriorates, lipid metabolism weakens, and hepatic lipid accumulation is exacerbated. Probiotics as an alternative to antimicrobials have been employed in poultry-related industries. Lactobacillus rhamnosus GG (LGG) is currently the most researched and clinically validated probiotic, showing promising effects in multiple application areas. However, few studies have been conducted on livestock (including poultry) production. RESULTS: Compared with the CON group, the feed conversion ratio (P < 0.01) declined significantly in the LGG group. Eggshell strength (P < 0.001) and eggshell thickness (P < 0.001) were significantly increased by supplementation with LGG in the diet. The height (P < 0.001) and proportion (P < 0.05) of the effective layer and the mammillary knob density (P < 0.01) in the eggshell ultrastructure of the LGG group increased significantly, while the mammillary layer (P < 0.05) and knob width (P < 0.01) decreased significantly. The LGG-treated hens had significantly lower serum concentrations of low-density lipoprotein (P < 0.05), free fatty acids (P < 0.01), and liver triglyceride (P < 0.05) levels than those in the CON group. CONCLUSIONS: LGG supplementation significantly decreases the feed conversion ratio, improves eggshell quality by altering the ultrastructure, and improves lipid metabolism in the late laying period.

Lactiplantibacillus plantarum LPJZ-658 Improves Non-Alcoholic Steatohepatitis by Modulating Bile Acid Metabolism and Gut Microbiota in Mice.

Non-alcoholic steatohepatitis (NASH) is one of the most prevalent diseases worldwide; it is characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Here, a Western diet combined with low-dose weekly carbon tetrachloride was fed to C57BL/6J mice for 12 weeks to build a NASH model to investigate the attenuating effects and possible mechanisms of Lactiplantibacillus plantarum LPJZ-658. Hepatic pathology, lipid profiles, and gene expression were assessed. The metabolomic profiling of the serum was performed. The composition structure of gut microbiota was profiled using 16s rRNA sequencing. The results show that LPJZ-658 treatment significantly attenuated liver injury, steatosis, fibrosis, and inflammation in NASH mice. Metabolic pathway analysis revealed that several pathways, such as purine metabolism, glycerophospholipid metabolism, linoleic acid metabolism, and primary bile acid biosynthesis, were associated with NASH. Notably, we found that treatment with LPJZ-658 regulated the levels of bile acids (BAs) in the serum. Moreover, LPJZ-658 restored NASH-induced gut microbiota dysbiosis. The correlation analysis deduced obvious interactions between BAs and gut microbiota. The current study indicates that LPJZ-658 supplementation protects against NASH progression, which is accompanied by alternating BA metabolic and modulating gut microbiota.

FGF21 Depletion Attenuates Colitis through Intestinal Epithelial IL-22-STAT3 Activation in Mice.

Fibroblast growth factor 21 (FGF21) is a glucose and lipid metabolic regulator. Recent research revealed that FGF21 was also induced by inflammatory stimuli. Its role in inflammatory bowel disease (IBD) has not been investigated. In this study, an experimental IBD model was established in FGF21 knockout (KO) and wild-type (WT) mice by adding 2.5% (wt/vol) dextran sodium sulfate (DSS) to their drinking water for 7 days. The severity of the colitis and the inflammation of the mouse colon tissues were analyzed. In WT mice, acute DSS treatment induced an elevation in plasma FGF21 and a significant loss of body weight in a time-dependent manner. Surprisingly, the loss of body weight and the severity of the colitis induced by DSS treatment in WT mice were significantly attenuated in FGF21 KO mice. Colon and circulating pro-inflammatory factors were significantly lower in the FGF21 KO mice compared to the WT mice. As shown by BrdU staining, the FGF21 KO mice demonstrated increased colonic epithelial cell proliferation. DSS treatment reduced intestinal Paneth cell and goblet cell numbers in the WT mice, and this effect was attenuated in the FGF21 KO mice. Mechanistically, FGF21 deficiency significantly increased the signal transducer and activator of transcription (STAT)-3 activation in intestinal epithelial cells and increased the expression of IL-22. Further study showed that the expression of suppressor of cytokine signaling-2/3 (SOCS 2/3), a known feedback inhibitor of STAT3, was significantly inhibited in the DSS-treated FGF2 KO mice compared to the WT mice. We conclude that FGF21 deficiency attenuated the severity of DSS-induced acute colitis, which is likely mediated by enhancing the activation of the IL-22-STAT3 signaling pathway in intestinal epithelial cells.

Effects of Lactiplantibacillus plantarum LPJZ-658 Supplementation on the Production, Meat Quality, Intestinal Morphology, and Cecal Microbiota of Broilers Chickens.

This study aimed to investigate the effects of L. plantarum LPJZ-658 on the production, meat quality, intestinal morphology, and cecal microbiota of broilers. White-feathered broilers (1 day old, n = 600) were randomly assigned to two groups and raised for six weeks. The individuals in the LPJZ-658 group were supplemented with 2.6 × 109 cfu/g LPJZ-658. The growth performance, meat quality, intestinal epithelium morphology, and cecal microbiota were observed. The results showed that the average daily gain, average daily feed intake, and feed conversion ratio of broilers in the LPJZ-658 group were significantly improved. In addition, the LPJZ-658 groups had a higher thigh muscle (TM) yield, TM color, TMpH24h, breast muscle (BM) pH24h, and BM color24h, while the BM cooking loss was significantly lower than the CON group. Moreover, supplementation with LPJZ-658 increased ileum and cecum length, duodenum and ileum villus height, and ileum villus height/crypt depth ratio. Furthermore, 16S rRNA sequencing revealed the dietary LPJZ-658 supplementation modulated the diversity and composition of cecal microflora. At the phylum level, the relative abundances of Proteobacteria, Actinobacteria, Verrucomicrobiota, and Acidobacteriota were significantly higher. In addition, LPJZ-658 substantially decreased the genus relative abundances of Streptococcus, Veillonella, Neisseria, and Haemophilus compared with the CON group and facilitated the growth and colonization of beneficial cecal bacteria, such as OBacteroides, Phascolarctobacterium, Bacillus, and Akkermansia. It was concluded that LPJZ-658 supplementation significantly increased growth production, improved meat quality and intestinal status, and modulated the intestinal microbiota in the broilers.

Genome Sequence and Evaluation of Safety and Probiotic Potential of Lactiplantibacillus plantarum LPJZ-658.

This study aims to systematically evaluate the safety of a novel L. plantarum LPJZ-658 explored on whole-genome sequence analysis, safety, and probiotic properties assessment. Whole genome sequencing results demonstrated that L. plantarum LPJZ-658 consists of 3.26 Mbp with a GC content of 44.83%. A total of 3254 putative ORFs were identified. Of note, a putative bile saline hydrolase (BSH) (identity 70.4%) was found in its genome. In addition, the secondary metabolites were analyzed, and one secondary metabolite gene cluster was predicted to consist of 51 genes, which verified its safety and probiotic properties at the genome level. Additionally, L. plantarum LPJZ-658 exhibited non-toxic and non-hemolytic activity and was susceptible to various tested antibiotics, indicating that L. plantarum LPJZ-658 was safe for consumption. Moreover, the probiotic properties tests confirm that L. plantarum LPJZ-658 also exhibits tolerance to acid and bile salts, preferably hydrophobicity and auto-aggregation, and excellent antimicrobial activity against both Gram-positive and Gram-negative gastrointestinal pathogens. In conclusion, this study confirmed the safety and probiotic properties of L. plantarum LPJZ-658, suggesting it can be used as a potential probiotic candidate for human and animal applications.

Cathelicidin-related antimicrobial peptide alleviates alcoholic liver disease through inhibiting inflammasome activation.

Alcoholic liver disease (ALD) is associated with gut dysbiosis and hepatic inflammasome activation. While it is known that antimicrobial peptides (AMPs) play a critical role in the regulation of bacterial homeostasis in ALD, the functional role of AMPs in the alcohol-induced inflammasome activation is unclear. The aim of this study was to determine the effects of cathelicidin-related antimicrobial peptide (CRAMP) on inflammasome activation in ALD. CRAMP knockout (Camp-/-) and wild-type (WT) mice were subjected to binge-on-chronic alcohol feeding and synthetic CRAMP peptide was administered. Serum/plasma and hepatic tissue samples from human subjects with alcohol use disorder and/or alcoholic hepatitis were analyzed. CRAMP deficiency exacerbated ALD with enhanced inflammasome activation as shown by elevated serum interleukin (IL)-1ß levels. Although Camp-/- mice had comparable serum endotoxin levels compared to WT mice after alcohol feeding, hepatic lipopolysaccharide (LPS) binding protein (LBP) and cluster of differentiation (CD) 14 were increased. Serum levels of uric acid (UA), a Signal 2 molecule in inflammasome activation, were positively correlated with serum levels of IL-1ß in alcohol use disorder patients with ALD and were increased in Camp-/- mice fed alcohol. In vitro studies showed that CRAMP peptide inhibited LPS binding to macrophages and inflammasome activation stimulated by a combination of LPS and UA. Synthetic CRAMP peptide administration decreased serum UA and IL-1ß concentrations and rescued the liver from alcohol-induced damage in both WT and Camp-/- mice. In summary, CRAMP exhibited a protective role against binge-on-chronic alcohol-induced liver damage via regulation of inflammasome activation by decreasing LPS binding and UA production. CRAMP administration may represent a novel strategy for treating ALD. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Fibroblast growth factor 21 is required for the therapeutic effects of Lactobacillus rhamnosus GG against fructose-induced fatty liver in mice.

OBJECTIVES: High fructose feeding changes fibroblast growth factor 21 (FGF21) regulation. Lactobacillus rhamnosus GG (LGG) supplementation reduces fructose-induced non-alcoholic fatty liver disease (NAFLD). The aim of this study was to determine the role of FGF21 and underlying mechanisms in the protective effects of LGG. METHODS: FGF21 knockout (KO) mice and C57BL/6 wild type (WT) mice were fed 30% fructose for 12 weeks. LGG was administered to the mice in the last 4 weeks during fructose feeding. FGF21-adiponectin (ADPN)-mediated hepatic lipogenesis and inflammation were investigated. RESULTS: FGF21 expression was robustly increased after 5-weeks of feeding and significantly decreased after 12-weeks of feeding in fructose-induced NAFLD mice. LGG administration reversed the depressed FGF21 expression, increased adipose production of ADPN, and reduced hepatic fat accumulation and inflammation in the WT mice but not in the KO mice. Hepatic nuclear carbohydrate responsive-element binding protein (ChREBP) was increased by fructose and reduced by LGG, resulting in a reduction in the expression of lipogenic genes. The methylated form of protein phosphatase 2A (PP2A) C, which dephosphorylates and activates ChREBP, was upregulated by fructose and normalized by LGG. Leucine carboxyl methyltransferase-1, which methylates PP2AC, was also increased by fructose and decreased by LGG. However, those beneficial effects of LGG were blunted in the KO mice. Hepatic dihydrosphingosine-1-phosphate, which inhibits PP2A, was markedly increased by LGG in the WT mice but attenuated in the KO mice. LGG decreased adipose hypertrophy and increased serum levels of ADPN, which regulates sphingosine metabolism. This beneficial effect was decreased in the KO mice. CONCLUSION: LGG administration increases hepatic FGF21 expression and serum ADPN concentration, resulting in a reduced ChREBP activation through dihydrosphingosine-1-phosphate-mediated PP2A deactivation, and subsequently reversed fructose-induced NAFLD. Thus, our data suggest that FGF21 is required for the beneficial effects of LGG in reversal of fructose-induced NAFLD.

Intestinal HIF-1α deletion exacerbates alcoholic liver disease by inducing intestinal dysbiosis and barrier dysfunction.

BACKGROUND & AIMS: Alcoholic liver disease (ALD) is characterized by gut dysbiosis and increased gut permeability. Hypoxia inducible factor 1α (HIF-1α) has been implicated in transcriptional regulation of intestinal barrier integrity and inflammation. We aimed to test the hypothesis that HIF-1α plays a critical role in gut microbiota homeostasis and the maintenance of intestinal barrier integrity in a mouse model of ALD. METHODS: Wild-type (WT) and intestinal epithelial-specific Hif1a knockout mice (IEhif1α-/-) were pair-fed modified Lieber-DeCarli liquid diet containing 5% (w/v) alcohol or isocaloric maltose dextrin for 24 days. Serum levels of alanine aminotransferase and endotoxin were determined. Fecal microbiota were assessed. Liver steatosis and injury, and intestinal barrier integrity were evaluated. RESULTS: Alcohol feeding increased serum levels of alanine aminotransferase and lipopolysaccharide, hepatic triglyceride concentration, and liver injury in the WT mice. These deleterious effects were exaggerated in IEhif1α-/- mice. Alcohol exposure resulted in greater reduction of the expression of intestinal epithelial tight junction proteins, claudin-1 and occludin, in IEhif1α-/- mice. In addition, cathelicidin-related antimicrobial peptide and intestinal trefoil factor were further decreased by alcohol in IEhif1α-/- mice. Metagenomic analysis showed increased gut dysbiosis and significantly decreased Firmicutes/Bacteroidetes ratio in IEhif1α-/- mice compared to the WT mice exposed to alcohol. An increased abundance of Akkermansia and a decreased level of Lactobacillus in IEhif1α-/- mice were also observed. Non-absorbable antibiotic treatment reversed the liver steatosis in both WT and IEhif1α-/- mice. CONCLUSION: Intestinal HIF-1α is essential for the adaptative response to alcohol-induced changes in intestinal microbiota and barrier function associated with elevated endotoxemia and hepatic steatosis and injury. LAY SUMMARY: Alcohol consumption alters gut microbiota and multiple intestinal barrier protecting factors that are regulated by intestinal hypoxia-inducible factor 1α (HIF-1α). Absence of intestinal HIF-1α exacerbates gut leakiness leading to an increased translocation of bacteria and bacterial products to the liver, consequently causing alcoholic liver disease. Intestinal specific upregulation of HIF-1α could be developed as a novel approach for the treatment of alcoholic liver disease.

FGF 21 deficiency slows gastric emptying and reduces initial blood alcohol concentration in mice exposed to acute alcohol in fasting state.

Excess alcohol consumption can lead to alcoholic liver disease. Fibroblast growth factor 21 (FGF21) is a metabolic regulator with multiple physiologic functions. Previous study demonstrated that FGF21 deficiency exacerbated alcohol-induced liver injury and exogenous FGF21 administration protected liver from chronic alcohol-induced injury. In this study, we aimed to explore the role of FGF21 in alcohol metabolism in mice. FGF21 knockout (KO) mice and the wild type(WT) control mice were divided into two groups and fasted for 24 h followed by a bonus of alcohol treatment at a dose of 5 g/kg body weight via gavage. Serum alcohol concentration was measured after gavage at 0.5, 2, 3, 4 and 6 h, respectively. At the end, gastric and liver tissues were collected. Serum alcohol concentration of KO mice was significantly lower than that of WT at 0.5 h after alcohol expose. There were no significant differences in alcohol dehydrogenase (ADH) activity and aldehyde dehydrogenase 2 (ALDH2) activity in gastric and liver tissues between WT and the KO mice. However, gastric emptying time of KO mice was much longer than that of WT mice. In addition, the intestinal permeability and serum GLP-1 level of KO mice were significantly higher than that of WT mice. These results suggest that FGF21 deficiency slow gastric emptying rate and indirectly influence initial alcohol metabolism in mice exposed to acute alcohol. Our findings provide additional information for understanding the gastrointestinal mechanism of alcoholic liver disease and other alcohol use disorders.

Activation of autophagy attenuates EtOH-LPS-induced hepatic steatosis and injury through MD2 associated TLR4 signaling.

Autophagy serves as a protective mechanism to degrade damaged organelles and proteins. Acute alcohol exposure is known to activate the hepatic autophagy response, whereas chronic alcohol exposure slows autophagosome formation along with an elevation of gut-derived endotoxin. In the current study, we examined whether lipopolysaccharide (LPS) administration decreased autophagic response in the liver of mice treated by short-term alcohol and whether activation of autophagy by rapamycin attenuates EtOH-LPS-induced liver steatosis and injury. We demonstrated that ten-day alcohol feeding primed the liver to LPS-induced lipid accumulation and liver injury with significantly increased hepatic steatosis and serum AST level as well as hepatic cellular NF-κB activation. LPS increased alcohol-mediated reactive oxygen species (ROS) formation while reducing autophagy activation. These deleterious effects were attenuated by rapamycin administration in mice. The protective effects of rapamycin are associated with decreased cellular MD2/TLR4 expression and interaction in Raw264.7 cells. Taken together, our results demonstrated that enhanced gut-derived LPS decreases the hepatic autophagosome numbers in response to alcohol exposure, and activation of autophagy by rapamycin protects from EtOH-LPS-induced liver injury, probably through reduced macrophage expression and interaction of TLR4/MD2 signaling complex.

Fibroblast Growth Factor 21 Deficiency Attenuates Experimental Colitis-Induced Adipose Tissue Lipolysis.

AIMS: Nutrient deficiencies are common in patients with inflammatory bowel disease (IBD). Adipose tissue plays a critical role in regulating energy balance. Fibroblast growth factor 21 (FGF21) is an important endocrine metabolic regulator with emerging beneficial roles in lipid homeostasis. We investigated the impact of FGF21 in experimental colitis-induced epididymal white adipose tissue (eWAT) lipolysis. METHODS: Mice were given 2.5% dextran sulfate sodium (DSS) ad libitum for 7 days to induce colitis. The role of FGF21 was investigated using antibody neutralization or knockout (KO) mice. Lipolysis index and adipose lipolytic enzymes were determined. In addition, 3T3-L1 cells were pretreated with IL-6, followed by recombinant human FGF21 (rhFGF21) treatment; lipolysis was assessed. RESULTS: DSS markedly decreased eWAT/body weight ratio and increased serum concentrations of free fatty acid (FFA) and glycerol, indicating increased adipose tissue lipolysis. eWAT intracellular lipolytic enzyme expression/activation was significantly increased. These alterations were significantly attenuated in FGF21 KO mice and by circulating FGF21 neutralization. Moreover, DSS treatment markedly increased serum IL-6 and FGF21 levels. IL-6 pretreatment was necessary for the stimulatory effect of FGF21 on adipose lipolysis in 3T3-L1 cells. CONCLUSIONS: Our results demonstrate that experimental colitis induces eWAT lipolysis via an IL-6/FGF21-mediated signaling pathway.

Fibroblast growth factor 21 deficiency exacerbates chronic alcohol-induced hepatic steatosis and injury.

Fibroblast growth factor 21 (FGF21) is a hepatokine that regulates glucose and lipid metabolism in the liver. We sought to determine the role of FGF21 in hepatic steatosis in mice exposed to chronic alcohol treatment and to discern underlying mechanisms. Male FGF21 knockout (FGF21 KO) and control (WT) mice were divided into groups that were fed either the Lieber DeCarli diet containing 5% alcohol or an isocaloric (control) diet for 4 weeks. One group of WT mice exposed to alcohol received recombinant human FGF21 (rhFGF21) in the last 5 days. Liver steatosis and inflammation were assessed. Primary mouse hepatocytes and AML-12 cells were incubated with metformin or rhFGF21. Hepatic genes and the products involved in in situ lipogenesis and fatty acid ß-oxidation were analyzed. Alcohol exposure increased circulating levels and hepatic expression of FGF21. FGF21 depletion exacerbated alcohol-induced hepatic steatosis and liver injury, which was associated with increased activation of genes involved in lipogenesis mediated by SREBP1c and decreased expression of genes involved in fatty acid ß-oxidation mediated by PGC1α. rhFGF21 administration reduced alcohol-induced hepatic steatosis and inflammation in WT mice. These results reveal that alcohol-induced FGF21 expression is a hepatic adaptive response to lipid dysregulation. Targeting FGF21 signaling could be a novel treatment approach for alcoholic steatohepatitis.

FGF21 mediates alcohol-induced adipose tissue lipolysis by activation of systemic release of catecholamine in mice.

Alcohol consumption leads to adipose tissue lipoatrophy and mobilization of FFAs, which contributes to hepatic fat accumulation in alcoholic liver disease. This study aimed to investigate the role of fibroblast growth factor (FGF)21, a metabolic regulator, in the regulation of chronic-binge alcohol-induced adipose tissue lipolysis. FGF21 KO mice were subjected to chronic-binge alcohol exposure, and epididymal white adipose tissue lipolysis and liver steatosis were investigated. Alcohol exposure caused adipose intracellular cAMP elevation and activation of lipolytic enzymes, leading to FFA mobilization in both WT and FGF21 KO mice. However, alcohol-induced systemic elevation of catecholamine, which is known to be a major player in adipose lipolysis by binding to the ß-adrenergic receptor, was markedly inhibited in KO mice. Supplementation with recombinant human FGF21 to alcohol-exposed FGF21 KO mice resulted in an increase in fat loss in parallel with an increase of circulating norepinephrine concentration. Furthermore, alcohol consumption-induced fatty liver was blunted in the KO mice, indicating an inhibition of fatty acid reverse transport from adipose to the liver in the KO mice. Taken together, our studies demonstrate that FGF21 KO mice are protected from alcohol-induced adipose tissue excess-lipolysis through a mechanism involving systemic catecholamine release.

Inhibition of miR122a by Lactobacillus rhamnosus GG culture supernatant increases intestinal occludin expression and protects mice from alcoholic liver disease.

Alcoholic liver disease (ALD) has a high morbidity and mortality. Chronic alcohol consumption causes disruption of intestinal microflora homeostasis, intestinal tight junction barrier dysfunction, increased endotoxemia, and eventually liver steatosis/steatohepatitis. Probiotic Lactobacillus rhamnosus GG (LGG) and the bacteria-free LGG culture supernatant (LGGs) have been shown to promote intestinal epithelial integrity and protect intestinal barrier function in ALD. However, little is known about how LGGs mechanistically works to increase intestinal tight junction proteins. Here we show that chronic ethanol exposure increased intestinal miR122a expression, which decreased occludin expression leading to increased intestinal permeability. Moreover, LGGs supplementation decreased ethanol-elevated miR122a level and attenuated ethanol-induced liver injury in mice. Similar to the effect of ethanol exposure, overexpression of miR122a in Caco-2 monolayers markedly decreased occludin protein levels. In contrast, inhibition of miR122a increased occludin expression. We conclude that LGGs supplementation functions in intestinal integrity by inhibition of miR122a, leading to occludin restoration in mice exposed to chronic ethanol.