N-glycosylation of CREBH improves lipid metabolism and attenuates lipotoxicity in NAFLD by modulating PPARα and SCD-1.

INTRODUCTION: Cyclic adenosine monophosphate (AMP)-responsive element-binding protein H (CREBH), an endoplasmic reticulum-anchored transcription factor essential for lipid metabolism and inflammation in nonalcoholic fatty liver disease (NAFLD), is covalently modified by N-acetylglucosamine. Glycosylation is a ubiquitous type of protein involved in posttranslational modifications, and plays a critical role in various biological processes. However, the mechanism of glycosylated CREBH remains poorly understood in NAFLD. METHODS: CREBH glycosylation mutants were obtained by site-mutation methods. After transfection with plasmids, AML-12, LO2, or HepG2 cells were treated with palmitic acid (PA) proteolysis, tunicamycin (Tm), or their combination. Glycosyltransferase V (GnT-V) was used induce hyperglycosylation to further understand the effect of CREBH. In addition, glycosylation mutant mice and hyperglycosylated mice were generated by lentivirus injection to construct two kinds of NAFLD animal models. The expression of NAFLD-related factors was detected to further verify the role of N-linked glycosylation of CREBH in lipid and sterol metabolism, inflammation, and lipotoxicity. RESULTS: N-glycosylation enhanced the ability of CREBH to activate transcription and modulated the production of peroxisome proliferator-activated receptor alpha (PPARα) and stearoyl-CoA desaturase-1 (SCD-1) activity by affecting their promoter-driven transcription activity and protein interactions, leading to reduce lipid deposition and attenuate lipotoxicity. Deglycosylation of CREBH induced by Tm could inhibit the proteolysis of CREBH induced by PA. The addition of unglycosylated CREBH to cells upregulates gene and protein expression of lipogenesis, lipotoxicity, and inflammation, and aggravates liver damage by preventing glycosylation in cells, as well as in mouse models of NAFLD. Furthermore, increased N-glycosylation of CREBH, as achieved by overexpressing GnT-V could significantly improve liver lesion caused by unglycosylation of CREBH. CONCLUSION: These findings have important implications for the role of CREBH N-glycosylation in proteolytic activation, and they provide the first link between N-glycosylation of CREBH, lipid metabolism, and lipotoxicity processes in the liver by modulating PPARα and SCD-1. These results provide novel insights into the N-glycosylation of CREBH as a therapeutic target for NAFLD.

Efficacy of serum miRNA test as a non-invasive method to diagnose nonalcoholic steatohepatitis: a systematic review and meta-analysis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a key turning point during the progression of nonalcoholic fatty liver disease (NAFLD). Recent studies have shown that serum miRNA tests may be effective in the diagnosis of NAFLD. We conducted a meta-analysis to assess the evidence for the diagnostic efficacy of serum miRNAs in patients with NAFLD and its subtype, NASH, in particular. METHODS: After a systematic review, sensitivity, specificity, and area under the receiver operating characteristics curve (AUROC) were pooled to determine the efficacy of serum miRNA test for the diagnosis of NAFLD and NASH. Clinical utility was evaluated by Fagan's nomogram and likelihood ratio scattergram. Heterogeneity was evaluated by subgroup analysis and meta-regression. Publication bias was detected by Deeks' funnel plot. RESULTS: We included 27 trials containing 1775 NAFLD patients (including simple steatosis and NASH) and 586 NASH patients. For NAFLD vs NASH, the pooled sensitivity, specificity, and AUROC were (0.71 vs. 0.74), (0.76 vs. 0.85) and (0.80 vs. 0.86), respectively. Serum miRNA had high accuracy for distinguishing NASH from simple steatosis, with an AUROC of 0.91. Among the most commonly studied serum miRNAs, miRNA-34a showed moderate diagnostic accuracy for NAFLD and the lowest heterogeneity (sensitivity I2 = 5.73%, specificity I2 = 33.16%, AUROC = 0.85). According to subgroup analysis and meta-regression, a lower BMI (< 30 kg/m2) might be a crucial source of heterogeneity. CONCLUSIONS: As a novel non-invasive method, serum miRNA test exhibited robust diagnostic efficacy for NASH. Among these well-studied miRNAs, miRNA-34a was more available for diagnosis. Diagnosis of NAFLD by serum miRNA is more likely to be accurate in patients with BMI ≥ 30 kg/m2.

USP10 Alleviates Palmitic Acid-induced Steatosis through Autophagy in HepG2 Cells.

Background and Aims: Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease caused by over-nutrition. Impaired autophagy is closely related to NAFLD progression. Recently, ubiquitin-specific peptidase-10 (USP10) was reported to ameliorate hepatic steatosis, but the underlying mechanism is still unclear. In view of the potential effects of USP10 on autophagy, we investigated whether USP10 alleviated steatosis through autophagy. Methods: HepG2 cells were treated with palmitic acid (PA) to model NAFLD in vitro. Lentivirus was used to regulate USP10 level in cells. Autophagic regulators were used to autophagic progression in cells. Western blotting, real-time fluorescence quantitative polymerase chain reaction, lipid drop staining and immunofluorescent staining were performed to determine the effect of USP10 on lipid autophagy. Student's t-test and Tukey's post hoc test were used to compare the means among groups. Results: PA induced cellular steatosis with dependance on autophagy. USP10 overexpression alleviated PA-induced steatosis, restored autophagic activity, promoted autophagic flux, including synthesis and degradation of autophagosomes, and lipid-targeted autophagy. In the presence of autophagy inhibitors, the protective effectiveness of USP10 on steatosis decreased. Furthermore, the specific inhibitor to C-jun N-terminal protein kinase-1 (JNK1), DB07268, abolished USP10-induced autophagy. However, during early stage inhibition of JNK1, compensatory expression of tuberous sclerosis complex-2 (TSC2) maintained autophagy. The degree of TSC2-to-JNK1 compensation was positively associated with USP10 level. Functionally, JNK1 and TSC2 were involved in the lipid-lowering effect of USP10. Conclusions: USP10 alleviated hepatocellular steatosis in autophagy-dependent manner. JNK1/TSC2 signaling pathways were required for USP10-induced autophagy.

Ubiquitin-specific peptidase 10 ameliorates hepatic steatosis in nonalcoholic steatohepatitis model by restoring autophagic activity.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a critical event in the progression of nonalcoholic fatty liver disease (NAFLD). Steatosis induces lipotoxicity, driving the transition of simple fatty liver (NAFL) to NASH. Autophagy affects NAFLD by improving steatosis. AIM: To investigate whether ubiquitin-specific peptidase (USP)10 alleviates hepatic steatosis through autophagy. METHODS: A methionine-choline-deficient diet (MCDD) and choline-deficient diet (CDD) were used to model rodent NASH and NAFL, respectively. HepG2 cells were treated with palmitic acid to model hepatocellular steatosis. A viral carrier was used to regulate the USP10 level. Real-time fluorescence quantitative polymerase chain reaction, western blotting, histology, and electron microscopy were used to detect autophagic activity and steatosis. RESULTS: In vivo, a time-dependent correlation of USP10 and autophagic activity in the liver was found during NAFLD (including NAFL and NASH) modeling. After 8 weeks of modeling, the autophagic activity of NASH was lower than that of the healthy controls and those with NAFL. USP10 could promote autophagy-related pathways and molecules and increase the synthesis of autophagosomes in NASH, improving steatosis, inflammation, and fibrosis. In vitro, autophagy inhibitors reversed the lipid-lowering effect of USP10 without decreasing the level of fatty acid ß-oxidation. CONCLUSION: USP10 ameliorated histological steatosis, inflammation, and fibrosis. USP10 alleviated hepatic steatosis in NASH in an autophagy-dependent manner.

A case report of hepatitis B virus reactivation 19 months after cessation of chemotherapy with rituximab.

A 72-year-old woman presented to our hospital with elevation of serum transaminases. Her blood tests showed the hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) negative. Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were given for the diffuse large B-cell lymphoma. She didn't receive anti- hepatitis B virus (HBV) drug for the isolated HBcAb positive. HBV reactivation confirmed based on the serum HBV DNA detectable until 19 months after stopping R-CHOP regimen. HBV DNA became undetectable after 4 weeks therapy with Tenofovir alafenamide fumarate (TAF). Serum transaminases went down to normal 3 months later after receiving TAF. HBV reactivation is a substantial risk for patients with isolated HBcAb positive receiving rituximab-containing chemotherapy without anti- HBV drug. Regular monitoring with a frequency of 1-3 months is the basis for timely diagnosis and treatment of HBV reactivation. Serum transaminases abnormalities may be the initial manifestation of HBV reactivation.

Zhikang Capsule Ameliorates Inflammation, Drives Polarization to M2 Macrophages, and Inhibits Apoptosis in Lipopolysaccharide-induced RAW264.7 Cells.

OBJECTIVE: To explore the anti-inflammatory effect of the traditional Chinese medicine Zhikang capsule (ZKC) on lipopolysaccharide (LPS)-induced RAW264.7 cells. METHODS: Safe concentrations of ZKC (0.175, 0.35, and 0.7 mg/mL) were used after the half-maximal inhibitory concentration (IC50) of RAW264.7 cells was calculated through the CCK-8 assay. In addition, the optimal intervention duration of ZKC (0.7 mg/mL) on RAW264.7 cells was determined to be 6 h, since all proinflammatory mediators [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), inteleukin-6 (IL-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and monocyte chemotactic protein-1 (MCP-1)] had a decreasing tendency and relatively down-regulated mRNA expression levels as compared with other durations (4, 8, and 12 h). RAW264.7 cells were pretreated with ZKC at various concentrations (0.175, 0.35 and 0.7 mg/mL) for 6 h and then stimulated with LPS (1 µg/mL) for an additional 12 h. RESULTS: In terms of inflammation, ZKC could reverse LPS-induced upregulation of TNF-α, IL-1ß, IL-6, COX-2, iNOS, and MCP-1 at both the mRNA and protein levels in RAW264.7 cells in a dose-dependent manner. In terms of the NF-κB signaling pathway, ZKC could reduce phosphorylated p65 and promote M2 polarization of RAW264.7 cells under LPS stimulation in a dose-dependent manner. Moreover, ZKC exhibited a protective effect on macrophages from apoptosis. CONCLUSION: ZKC exhibited obvious antiinflammatory and anti-apoptotic effects on LPS-induced RAW264.7 cells at the cellular level, and a weakened NF-κB signaling pathway may be a potential significant target.

Abnormal Liver Function Tests of Patients with Coronavirus Disease 2019 in Mainland China: A Systematic Review and Meta- Analysis.

AIMS: Comparing the risk of abnormal liver function tests between severe and non-severe patients with coronavirus disease 2019 (COVID-19) by meta-analysis. METHODS: A literature search was conducted using the databases PubMed, Embase, and Cochrane Library. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using fixed- or random-effects models. Publication bias was detected by the Harbord test. RESULTS: We included 8 articles comprising 7,467 COVID-19 patients. When compared between severe and non-severe COVID-19 patients, the pooled ORs of elevated alanine aminotransferase, aspartate aminotransferase, total bilirubin, and lactate dehydrogenase levels were 2.35 (95% CI 1.38-3.98), 3.21 (95% CI 2.59-3.98), 1.87 (95% CI 1.32-2.65), and 4.83 (95% CI 2.90-8.05), respectively. CONCLUSIONS: The severity of COVID-19 is associated with liver damage, and can be a risk factor for abnormal liver function tests.

Scoparone improves hepatic inflammation and autophagy in mice with nonalcoholic steatohepatitis by regulating the ROS/P38/Nrf2 axis and PI3K/AKT/mTOR pathway in macrophages.

BACKGROUND AND AIMS: Scoparone has been shown to ameliorate many forms of liver disease, and several underlying molecular mechanisms involved have been previously revealed. However, the potential role of scoparone in autophagy, which is dysregulated in nonalcoholic fatty liver disease-nonalcoholic steatohepatitis (NAFLD-NASH), has not been evaluated. In the current study, we investigated the effect and potential mechanisms of scoparone in hepatic autophagy in mice with NASH. METHODS: In vivo, mice were fed a methionine-choline deficient (MCD) diet to establish a NASH model and then subjected to treatment with or without scoparone for 4 weeks. In vitro, scoparone was applied in a hepatocellular lipid overload model in AML12 cells challenged with palmitic acid (PA) and in lipopolysaccharide (LPS)-induced RAW264.7 cells. RESULTS: Scoparone improved impaired autophagy and several key features of NASH in mice fed an MCD diet. In vitro, scoparone had an effect on the autophagy of macrophages but not hepatocytes. In RAW264.7 cells, scoparone reduced the LPS-induced accumulation of autophagosomes and autophagy substrates, the production of reactive oxygen species (ROS) and the inflammatory response. Scoparone inhibited the upregulation of p62 transcription, which is mediated by the ROS/P38/Nrf2 axis. Chloroquine (CQ), an inhibitor of autophagic flux, significantly inhibited scoparone-mediated protection against inflammation. In addition, scoparone suppressed activation of the PI3K/AKT/mTOR pathway, and MHY1485 (an mTOR activator that inhibits autophagy) inhibited the anti-inflammatory effect of scoparone. CONCLUSIONS: In LPS-induced macrophages, scoparone regulates autophagy and further suppresses inflammation by inhibiting the ROS/P38/Nrf2 axis and PI3K/AKT/mTOR pathway and enhancing autophagic flux. Scoparone may improve hepatic autophagy and NASH partly through enhancing autophagy in macrophages but not hepatocytes. Scoparone is expected to become a novel therapeutic drug for NASH or diseases associated with dysregulated autophagy in macrophages.

Diallyl disulfide attenuates non­alcoholic steatohepatitis by suppressing key regulators of lipid metabolism, lipid peroxidation and inflammation in mice.

Non­alcoholic steatohepatitis (NASH) is a common clinicopathological condition. Currently, the pathogenesis of NASH remains unknown, and no optimal therapy option currently exists. It has previously been demonstrated that diallyl disulfide (DADS) was capable of attenuating liver dysfunction, as DADS supplementation had a positive impact on liver regeneration, proliferation and oxidative damage. Thus, DADS could serve as a potential therapeutic agent that can protect against the effects of NASH. The present study aimed to evaluate the effect of DADS on NASH and to understand the associated underlying molecular mechanisms. A methionine­ and choline­deficient diet (MCD) and high­fat diet (HFD) are the two common animal models that induce NASH. C57BL/6J mice were fed an MCD for 4 weeks, or an HFD for 20 weeks, in the present study. The mice were treated with or without DADS (20, 50 and 100 mg/kg) for 4 or 20 weeks. For the histopathological examination, hematoxylin and eosin staining, oil red O staining and immunohistochemical analyses were performed using the liver sections. Biochemical assays and ELISA were performed to measure the serum biochemical indicators of hepatic function and inflammatory indicators, respectively. Reverse transcription­quantitative PCR, immunofluorescence and western blotting were used to detect expression levels of the genes involved in the molecular mechanisms underlying DADS protection. MCD or HFD induced the histological features of NASH in mice, including significant vacuolated hepatocytes, marked inflammatory cell infiltration and severe micro­ and macro­vesicular steatosis. Serum alanine transferase and aspartate aminotransferase levels, as well as the contents of liver triglyceride and total cholesterol, were significantly increased in these two models. DADS attenuated these histological and biochemical changes. DADS ameliorated hepatic steatosis by regulating sterol regulatory element­binding transcription factor 1, apolipoprotein A1, cyclic AMP­responsive element­binding protein H and fibroblast growth factor 21. Furthermore, DADS was revealed to prevent lipotoxicity via peroxisome proliferator­activated receptor α elevation and stearoyl­coenzyme A desaturase 1 inhibition in HFD­fed mice. In addition, DADS markedly inhibited lipid peroxidation by modulating malondialdehyde and superoxide dismutase, and it also decreased tumor necrosis factor­α production, interleukin­6 production and macrophage influx, as well as suppressing nuclear factor­κB activation, indicating suppression of MCD­induced hepatic inflammation. Taken together, the results have shown that DADS exerts beneficial effects on MCD­ or HFD­induced NASH by suppressing key regulators of lipid metabolism, lipid peroxidation and inflammation.

The association of two common polymorphisms in miRNAs with diabetes mellitus: A meta-analysis.

BACKGROUND: MicroRNAs (miRNAs) are small noncoding single-stranded RNAs with a length of ∼21 nucleotides. Single nucleotide polymorphisms (SNPs) may affect the function of miRNAs, resulting in a variety of disorders in vivo. Recently, diabetes mellitus (DM) has become a global healthcare problem, and several studies have reported that 2 common polymorphisms (miRNA 146a rs2910164 and miRNA 27a rs895819) are related to susceptibility to diabetes. Given that no consensus had been reached regarding the association of the 2 polymorphisms with diabetes, we conducted this meta-analysis. METHODS: Four databases (PubMed, EMBASE, Cochrane, and Web of Science) were searched up to January 9, 2019. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the association strength. Subgroup and sensitivity analyses were also performed. RESULTS: Six studies involving 2585 cases and 2435 controls for miR146a rs2910164 and 5 studies involving 2922 cases and 2781 controls for miR27a rs895819 were ultimately analyzed in our meta-analysis. Based on pooled results, no statistical significance in association between rs2910164 and diabetes in Caucasians, Asians, or type 2 diabetes was observed in any genetic models. Nevertheless, we found a significant correlation between miRNA27a rs895819 and diabetes in the homozygote model (CC vs TT: OR = 0.58, 95%CI [0.35,0.98]) and recessive model (CC vs CT + TT: OR = 0.59, 95%CI [0.36,0.97]). By performing subgroup analysis, we also observed that C allele conveyed a significant protective effect against diabetes development in Caucasians (C vs T: OR = 0.67, 95%CI [0.52,0.85]). CONCLUSION: In conclusion, this meta-analysis indicated that miRNA27a rs895819 might play a protective role in diabetes, and miRNA146a rs2910164 likely had no association with diabetes.

Scoparone alleviates inflammation, apoptosis and fibrosis of non-alcoholic steatohepatitis by suppressing the TLR4/NF-κB signaling pathway in mice.

Scoparone, a naturally-occurring, bioactive compound isolated from the Chinese herb Artemisia capillaria, has been shown to ameliorate hepatotoxicity and cholestasis in liver diseases. However, the pharmacological effect of scoparone in non-alcoholic steatohepatitis (NASH) has not been elucidated. In this study, we investigated the protective effects and mechanisms of scoparone in NASH. In vivo, the NASH model was established in mice fed a methionine and choline-deficient (MCD) diet for 4weeks, with or without simultaneous scoparone treatment. In vitro, RAW264.7 cells induced by lipopolysaccharide (LPS) were pretreated with or without different concentrations of scoparone. Hepatic triglycerides and serum AST and ALT levels were examined by biochemical assays. Hepatic histology was assessed by H&E, oil red O and Masson's trichrome staining methods, which were applied to analyze the protective effects of scoparone in NASH. To further explore the underlying mechanism of scoparone, immunohistochemistry, TUNEL, qRT-PCR, and Western blotting assays were applied to liver tissue or LPS-induced RAW264.7 cells. We found that scoparone can effectively improve hepatic steatosis, apoptosis, inflammation, and fibrosis in an MCD diet-induced NASH murine model. Mechanistically, we demonstrated that scoparone treatment alleviates NASH- and lipopolysaccharide (LPS)-induced immune responses in macrophages partly by blocking TLR-4/NF-κB signaling in a dose-dependent manner. Taken together, our results present the potential protective effects and mechanism of scoparone in NASH, suggesting a potentially beneficial drug treatment for NASH.

Baicalin attenuates non-alcoholic steatohepatitis by suppressing key regulators of lipid metabolism, inflammation and fibrosis in mice.

AIMS: Baicalin (BA), an active flavonoid compound originating from the herb of Scutellaria baicalensis Georgi, has been previously shown to exert anti-inflammation and anti-oxidant effects in liver diseases. However, the potential role of BA in the regulation of non-alcoholic steatohepatitis (NASH) remains elusive. In this study, we newly explored the hepatoprotective effects of BA in MCD diet-induced NASH by ameliorating hepatic steatosis, inflammation, fibrosis and apoptosis. MAIN METHODS: NASH was induced in mice fed a methionine and choline-deficient (MCD) diet for 4weeks. The mice were simultaneously treated with or without BA for 4weeks. Serum liver functional markers and inflammatory indicators were assessed by biochemical and ELISA methods, respectively. The livers were histologically examined using H&E, Oil Red O and Masson's trichrome staining methods. The qRT-PCR, IHC and Western blotting assays were applied to analyze mechanisms underlying BA protection. KEY FINDINGS: BA treatment significantly attenuated MCD diet-induced hepatic lipid accumulation partly through regulating the expression of SREBP-1c, FASN, PPARα and CPT1a. BA treatment dramatically suppressed MCD diet-induced hepatic inflammation, which was associated with decrease in serum TNF-α, IL-1ß and MCP-1 production, macrophage influx and suppression of nuclear factor-κB activation. Additionally, BA was proved to prevent liver fibrosis, which appears to be mediated by inhibition of α-SMA, TGF-ß1 and Col1A1. Furthermore, BA markedly inhibited hepatocyte apoptosis and cleaved caspase-3 protein expression in MCD diet-induced mice. SIGNIFICANCE: These results provide a possible basis of the underlying mechanism for the application of BA in the treatment of NASH.