Project description:Per- and polyfluoroalkyl substances (PFAS) are pervasive in the environment resulting in nearly universal detection in people. Human serum PFAS concentrations are strongly associated with increased serum low-density lipoprotein cholesterol (LDL-C), and growing evidence suggests an association with serum triacylglycerides (TG). Here, we tested the hypothesis that perfluorooctanoic acid (PFOA) dysregulates liver and serum triacylglycerides in human peroxisome proliferator activated receptor α (hPPARα)-expressing mice fed an American diet. Mice were exposed to PFOA (3.5 mg/L) in drinking water for 6 weeks resulting in a serum concentration of 48 ± 9 μg/ml. In male and female hPPARα mice, PFOA increased total liver TG and TG substituted with saturated and monounsaturated fatty acids. Lack of expression of PPARα alone also increased total liver TG, and PFOA treatment had little effect on liver TG in PPARα null mice. In hPPARα mice, PFOA neither significantly increased nor decreased serum TG; however, there was a modest increase in TG associated with very low-density cholesterol particles in both sexes. Intriguingly, in female PPARα null mice, PFOA significantly increased serum TG, with a similar trend in males. PFOA also modified fatty acid and TG homeostasis-related gene expression in liver, in a hPPARα-dependent manner, but not in adipose. The results of our study and others reveal the importance of context (serum concentration and genotype) in determining the effect of PFOA on lipid homeostasis.
Project description:Purpose: Neutrophils and cytokines play a major role in the pathogenesis of acute-on-chronic liver failure (ACLF). We aimed to determine whether chemokine (CXC) ligand 1 (CXCL1), a key marker of neutrophil recruitment and activation, could predict the severity and prognosis of hepatitis B virus-related ACLF (HBV-ACLF). Methods: Hospitalized patients with HBV-ACLF were enrolled in a prospective study and stratified as survivors (alive at 28 days) and nonsurvivors (deceased at 28 days). Serum CXCL1 levels were measured in healthy controls, patients with chronic HBV, patients with HBV-related compensated cirrhosis, and patients with HBV-ACLF. Univariate and multivariable logistic analyses, Pearson correlation analysis, area under the receiver operating characteristic curve (AUROC), and Z tests were used to evaluate the performance of CXCL1 as a marker in HBV-ACLF. Results: Patients with HBV-ACLF had significantly higher serum levels of CXCL1 and neutrophil count than healthy controls and patients with chronic HBV or HBV-related compensated cirrhosis (P < 0.01, respectively). Among patients with HBV-ACLF, survivors had lower serum CXCL1 levels and neutrophil count than those of nonsurvivors (P < 0.001, P < 0.05, respectively). Serum CXCL1 level was positively correlated with neutrophil count (r = 0.256, P = 0.001), ACLF grade (r = 0.295, P < 0.001) and organ failure, including coagulation (r = 0.21, P = 0.005) and brain failure (r = 0.198, P = 0.008). Multivariable logistic analyses showed serum CXCL1 [OR (95% CI) = 1.017 (1.009-1.025), P < 0.001] was an independent risk factor for 28-day mortality in HBV-ACLF. Meanwhile, the AUROC analysis demonstrated that serum CXCL1 [0.741 (0.669-0.804)] might be a reliable prognostic biomarker for patients with HBV-ACLF. Conclusions: Overall, serum CXCL1 can serve as a biomarker indicating the severity of disease and prognosis for patients with HBV-ACLF. CXCL1 might also be a therapeutic target in this disease.
Project description:Background/Aim: We investigated alterations in the expression of serum exosomal miRNAs with the progression of liver fibrosis and evaluated their clinical applicability as biomarkers. Methods: This study prospectively enrolled 71 patients who underwent liver biopsy at an academic hospital in Korea. Exosomes were extracted from serum samples, followed by next-generation sequencing (NGS) of miRNAs and targeted real-time quantitative polymerase chain reaction. A model was derived to discriminate advanced fibrosis based on miRNA levels and the performance of this model was evaluated. Validation of the effect of miRNA on liver fibrosis in vitro was followed. Methods: This study prospectively enrolled 71 patients who underwent liver biopsy at an academic hospital in Korea. Exosomes were extracted from serum samples, followed by next-generation sequencing (NGS) of miRNAs and targeted real-time quantitative polymerase chain reaction. A model was derived to discriminate advanced fibrosis based on miRNA levels and the performance of this model was evaluated. Validation of the effect of miRNA on liver fibrosis in vitro was followed. Results: NGS data revealed that exosomal miR-660-5p, miR-125a-5p, and miR-122 expression were changed significantly with the progression of liver fibrosis, of which miR-122 exhibited high read counts enough to be used as a biomarker. The level of exosomal miR-122 decreased as the pathologic fibrosis grade progressed and patients with biopsy-proven advanced fibrosis had significantly lower levels of exosomal miR-122 (P < 0.001) than those without advanced fibrosis. Exosomal miR-122 exhibited a fair performance in discriminating advanced fibrosis especially in combination with fibrosis-4 score and transient elastography. In a subgroup of patients with a non-viral etiology of liver disease, the performance of exosomal miR-122 as a biomarker was greatly improved. Inhibition of miR-122 expression increased the proliferation of the human hepatic stellate cell line, LX-2, and upregulated the expression of various fibrosis related proteins. Conclusion: Exosomal miR-122 may serve as a useful non-invasive biomarker for liver fibrosis, especially in patients with non-viral etiologies of chronic liver disease.
Project description:Background/aimWe investigated alterations in the expression of serum exosomal miRNAs with the progression of liver fibrosis and evaluated their clinical applicability as biomarkers.MethodsThis study prospectively enrolled 71 patients who underwent liver biopsy at an academic hospital in Korea. Exosomes were extracted from serum samples, followed by next-generation sequencing (NGS) of miRNAs and targeted real-time quantitative polymerase chain reaction. A model was derived to discriminate advanced fibrosis based on miRNA levels and the performance of this model was evaluated. Validation of the effect of miRNA on liver fibrosis in vitro was followed.ResultsNGS data revealed that exosomal miR-660-5p, miR-125a-5p, and miR-122 expression were changed significantly with the progression of liver fibrosis, of which miR-122 exhibited high read counts enough to be used as a biomarker. The level of exosomal miR-122 decreased as the pathologic fibrosis grade progressed and patients with biopsy-proven advanced fibrosis had significantly lower levels of exosomal miR-122 (P < 0.001) than those without advanced fibrosis. Exosomal miR-122 exhibited a fair performance in discriminating advanced fibrosis especially in combination with fibrosis-4 score and transient elastography. In a subgroup of patients with a non-viral etiology of liver disease, the performance of exosomal miR-122 as a biomarker was greatly improved. Inhibition of miR-122 expression increased the proliferation of the human hepatic stellate cell line, LX-2, and upregulated the expression of various fibrosis related proteins.ConclusionExosomal miR-122 may serve as a useful non-invasive biomarker for liver fibrosis, especially in patients with non-viral etiologies of chronic liver disease.
Project description:Background/aimsSarcopenia is an independent prognostic factor of liver cirrhosis (LC). However, the association between LC-related systemic inflammation and sarcopenia is unclear.MethodsSprague-Dawley rats were treated with thioacetamide (TAA) or saline as a control. Rifaximin was administered to TAA-induced LC rats. Enzyme-linked immunosorbent assay was performed to measure inflammatory mediators in rat serum. RT-PCR was performed to measure the molecular expression in tissues. Hematoxylin and eosin (H&E) staining and immunohistochemistry were performed to investigate tissue pathology. Serum tumor necrosis factor-α levels, liver stiffness (LS), and the L3 skeletal muscle index (L3SMI) were measured in 60 patients with chronic liver disease.ResultsLC and sarcopenia were successfully induced by TAA. Serum TNF-α levels were increased in LC rats and correlated with myostatin expression, muscle weight, and myofiber diameter. The expression of intestinal occludin and zona occludens-1 was reduced in LC rats and associated with serum TNF-α levels and sarcopenia. In patients with LS ≥7 kPa or sarcopenia, serum TNF-α levels were significantly increased, which was also confirmed when we raised the LS cutoff to 10 kPa. The L3SMI was inversely correlated with serum TNF-α levels in patients with LS ≥7 kPa. TNF-α was reduced by rifaximin, which might have resulted in reduced expression of muscular MuRF1 and myostatin and improvements in myofiber diameters within muscle tissues.ConclusionThese results suggest that serum TNF-α is associated with LC-related sarcopenia. Rifaximin might be effective in reducing serum TNF-α levels and improving sarcopenia in LC, but these results need to be validated in future studies.
Project description:BackgroundThe metabolic regulator Fibroblast Growth Factor 21 (FGF21) is highly expressed in the acinar pancreas, but its role in pancreatic function is obscure. It appears to play a protective role in acute experimental pancreatitis in mice. The aim of this study was to define an association between FGF21 and the course and resolution of acute pancreatitis in humans.Methods and principal findingsTwenty five subjects with acute pancreatitis admitted from May to September 2012 to the Beth Israel Deaconess Medical Center (BIDMC) were analyzed. Serial serum samples were collected throughout hospitalization and analyzed for FGF21 levels by ELISA. Twenty healthy subjects sampled three times over a four week period were used as controls. We found that, in patients with pancreatitis, serum FGF21 rises significantly and peaks four to six days after the maximum lipase level, before slowly declining. Maximum FGF21 levels were significantly greater than baseline levels for acute pancreatitis subjects (1733 vs. 638 pg/mL, P = 0.003). This maximum value was significantly greater than the highest value observed for our control subjects (1733 vs. 322 pg/mL, P = 0.0002). The ratio of active to total FGF21 did not change during the course of the disease (42.5% vs. 44.4%, P = 0.58). Fold increases in FGF21 were significantly greater in acute pancreatitis subjects than the fold difference seen in healthy subjects (4.7 vs. 2.0, P = 0.01). Higher fold changes were also seen in severe compared to mild pancreatitis (18.2 vs. 4.4, P = 0.01). The timing of maximum FGF21 levels correlated with day of successful return to oral intake (R2 = 0.21, P = 0.04).ConclusionsOur results demonstrate that serum FGF21 rises significantly in humans with acute pancreatitis. The pancreas may be contributing to increased FGF21 levels following injury and FGF21 may play a role in the recovery process.