Cholesterol gallstone disease is a worldwide common disease. Cholesterol supersaturation in gallbladder bile is the prerequisite for its pathogenesis, while the mechanism is not completely understood. In this study, we find enrichment of gut microbiota (especially Desulfovibrionales) in patients with gallstone disease. Fecal transplantation of gut microbiota from gallstone patients to gallstone-resistant strain of mice can induce gallstone formation. Carrying Desulfovibrionales is associated with enhanced cecal secondary bile acids production and increase of bile acid hydrophobicity facilitating intestinal cholesterol absorption. Meanwhile, the metabolic product of Desulfovibrionales, H2S increase and is shown to induce hepatic FXR and inhibit CYP7A1 expression. Mice carrying Desulfovibrionales present induction of hepatic expression of cholesterol transporters Abcg5/g8 to promote biliary secretion of cholesterol as well. Our study demonstrates the role of gut microbiota, Desulfovibrionales, as an environmental regulator contributing to gallstone formation through its influence on bile acid and cholesterol metabolism.

BackgroundThe gut microbiome exerts extensive roles in metabolism of nutrients, pharmaceuticals, organic chemicals. Little has been known for the role of gut microbiota in regulating cholesterol and bile acids in association with gallstone formation. This study investigated the changes in the composition of gut microbiota in mice fed with lithogenic diet (LD).MethodsAdult male C57BL/6 J mice were fed with either lithogenic diet (1.25% cholesterol and 0.5% cholic acid) or chow diet as control for 56 days. The fecal microbiota were determined by 16S rRNA gene sequencing.ResultsLD led to formation of cholesterol gallstone in mice. The richness and alpha diversity of gut microbial reduced in mice fed with LD. Firmicutes was significantly decreased from 59.71% under chow diet to 31.45% under LD, P < 0.01, as well as the ratio of Firmicutes to Bacteroidetes. Differences in gut microbiota composition were also observed at phylum, family and genus levels between the two groups.ConclusionOur results suggested that gut microbiota dysbiosis might play an important role in the pathogenesis of cholesterol gallstone formation in mice.Electronic supplementary materialThe online version of this article (doi:10.1186/s12876-017-0629-2) contains supplementary material, which is available to authorized users.

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Excessive cholesterol contributes to the development of cardiovascular diseases. Berberine (BBR) has been reported to regulate cholesterol homeostasis. Here, we found that BBR could ameliorate the hepatic autophagic flux blockade caused by cholesterol overloading. The underlying mechanism included lowering hepatic cholesterol level, modulating the cholesterol distribution targeting the plasma membrane by decreasing sterol carrier protein 2 expression and inhibiting cyclooxygenase 2-mediated production of prostaglandin metabolites, which decreased the phosphorylation of Akt/mTOR. Our study provides evidences that BBR could be a therapeutic agent for protecting liver under cholesterol overloading via the regulation of autophagic flux.

BackgroundOrganochlorine pesticides (OCPs) are one kind of persistent organic pollutants. Although they are reported to be associated with metabolic disorders, the underlying mechanism is unclear. We explored the association of OCPs with gallstone disease and its influence on hepatic lipid metabolism.Materials and MethodsOCPs levels in omentum adipose tissues from patients with and without gallstone disease between 2008 and 2011 were measured by GC-MS. Differences of gene expression involved in hepatic lipid metabolism and hepatic lipids content were compared in liver biopsies between groups with high and low level of OCPs. Using HepG2 cell lines, the influence on hepatic lipid metabolism by individual OCP was evaluated in vitro.ResultsIn all patients who were from non-occupational population, there were high levels of β-hexachlorocyclohexane (β-HCH) and p',p'-dichloroethylene (p',p'-DDE) accumulated in adipose tissues. Both β-HCH and p', p'-DDE levels were significantly higher in adipose tissues from patients with gallstone disease (294.3± 313.5 and 2222± 2279 ng/g of lipid) than gallstone-free controls (282.7± 449.0 and 2025±2664 ng/g of lipid, P< 0.01) and they were strongly related with gallstone disease (P for trend = 0.0004 and 0.0138). Furthermore, higher OCPs in adipose tissue led to increase in the expression of hepatic cholesterol transporters ABCG5 and G8 (+34% and +27%, P< 0.01) and higher cholesterol saturation index in gallbladder bile, and induced hepatic fatty acids synthesis, which was further confirmed in HepG2 cells.ConclusionOCPs might enhance hepatic secretion of cholesterol into bile via ABCG5/G8 which promoting gallstone disease as well as lipogenesis.

2,4-Dichlorophenoxyacetic acid is one of the most widely used herbicides. Its impact on health is increasingly attracting great attentions. This study aimed to investigate the effect of 2,4-dichlorophenoxyacetic acid on glucose metabolism in HepG2 cells and the underlying mechanism. After 24 h exposure to 2,4-dichlorophenoxyacetic acid, glycogen was measured by PAS staining and glucose by ELISA in HepG2 cells. The expression of genes involved in glucose metabolism was measured by real-time PCR, Western blotting, and immunofluorescence. HepG2 cells presented more extracellular glucose consumption and glycogen content after exposed to 2,4-dichlorophenoxyacetic acid. Expression of gluconeogenesis-related genes, FoxO1, and CREB is significantly elevated. Moreover, PPARβ was up-regulated dose-dependently. SiRNA knockdown of PPARβ completely rescued the increase of glycogen accumulation and glucose uptake, and the up-regulation of FOXO1 and CREB expression. Our findings propose novel mechanisms that 2,4-dichlorophenoxyacetic acid causes glucose metabolism dysfunction through PPARβ in HepG2 cells.

Breast cancer (BC) is the most common cancer affecting women and the leading cause of cancer-related deaths worldwide. Compelling evidence indicates that pyroptosis is inextricably involved in the development of cancer and may activate tumor-specific immunity and/or enhance the effectiveness of existing therapies. We constructed a novel prognostic prediction model for BC, based on pyroptosis-related clusters, according to RNA-seq and clinical data downloaded from TCGA. The proportions of tumor-infiltrating immune cells differed significantly in the two pyroptosis clusters, which were determined according to 38 pyroptosis-related genes, and the immune-related pathways were activated according to GO and KEGG enrichment analysis. A 56-gene signature, constructed using univariate and multivariate Cox regression, was significantly associated with progression-free interval (PFI), disease-specific survival (DSS), and overall survival (OS) of patients with BC. Cox analysis revealed that the signature was significantly associated with the PFI and DSS of patients with BC. The signature could efficiently distinguish high- and low-risk patients and exhibited high sensitivity and specificity when predicting the prognosis of patients using KM and ROC analysis. Combined with clinical risk, patients in both the gene and clinical low-risk subgroup who received adjuvant chemotherapy had a significantly lower incidence of the clinical event than those who did not. This study presents a novel 56-gene prognostic signature significantly associated with PFI, DSS, and OS in patients with BC, which, combined with the TNM stage, might be a potential therapeutic strategy for individualized clinical decision-making.