Sclareol attenuates liver fibrosis through SENP1-mediated VEGFR2 SUMOylation and inhibition of downstream STAT3 signaling.

Liver fibrosis is a key global health care burden. Sclareol, isolated from Salvia sclarea, possesses various biological activities. Its effect on liver fibrosis remains unknown. This study was proposed to evaluate the antifibrotic activity of sclareol (SCL) and explore its underlying mechanisms. Stimulated hepatic stellate cells served as an in vitro liver fibrosis model. The expression of fibrotic markers was assessed by western blot and real-time PCR. Two classical animal models, bile duct-ligated rats and carbon tetrachloride-treated mice, were utilized for the in vivo experiments. The liver function and fibrosis degree were determined by serum biochemical and histopathological analyses. VEGFR2 SUMOylation was analyzed using coimmunoprecipitation assay. Our results indicated that SCL treatment restricted the profibrotic propensity of activated HSCs. In fibrotic rodents, SCL administration alleviated hepatic injury and reduced collagen accumulation. Mechanistic studies indicated that SCL downregulated the protein level of SENP1 and enhanced VEGFR2 SUMOylation in LX-2 cells, which affected its intracellular trafficking. Blockade of the interaction between VEGFR2 and STAT3 was observed, resulting in the suppression of downstream STAT3 phosphorylation. Our findings demonstrated that SCL has therapeutic efficacy against liver fibrosis through mediating VEGFR2 SUMOylation, suggesting that SCL may be a potential candidate compound for its treatment.

Tripartite motif-containing 25 facilitates immunosuppression and inhibits apoptosis of glioma via activating NF-κB.

As a crucial tumor type of the central nervous system, gliomas are characterized by a dismal prognosis. Tripartite motif-containing 25 (TRIM25), an essential E3 ubiquitin ligase, participates in various biological processes. This study sought to demonstrate its functional role in gliomas. Data obtained from publicly available databases - including The Cancer Genome Atlas (TCGA), the Chinese Glioma Genome Atlas (CGGA), and the Repository for Molecular Brain Neoplasia Data (REMBRANDT) - were employed. TRIM25 expression pattern and its association with different clinical characteristics were analyzed. Kaplan-Meier analysis was utilized to compare different TRIM25 expressions with glioma patients' survival. Subsequently, we performed bioinformatic analyses to investigate the biological functions of TRIM25, which were further validated by in vitro experiments, CIBERSORT algorithm, and ESTIMATE evaluation. TRIM25 expression was upregulated in glioma patients and can predict an unfavorable prognosis. Bioinformatic results indicated the involvement of TRIM25 in apoptosis and immune regulation. TRIM25 was associated with programmed death-ligand 1 (PD-L1) related and macrophage-induced immune suppression in gliomas. Meanwhile, silencing TRIM25 promoted apoptosis in glioma cells, which is attributed to its regulation of NF-κB. Therefore, TRIM25 contributed to the glioma malignant progression and suppressive immune microenvironments via NF-κB activation, which may play a therapeutic role in gliomas.

Dehydromevalonolactone ameliorates liver fibrosis and inflammation by repressing activation of NLRP3 inflammasome.

Liver fibrosis is an important process in chronic liver disease and is strongly related to poor prognosis. Dehydromevalonolactone (C8) is a natural product isolated from a fungus of Fusarium sp. CPCC 401218, and its pharmacological activity has never been reported before. In this study, the potential of C8 as an anti-hepatic fibrosis agent was investigated. In human hepatic stellate cell (HSC) line LX-2, C8 suppressed the increased expression of COL1A1 and α-SMA induced by TGFß1, which indicated that C8 could repress the activation of HSCs. In bile duct ligated rats, C8 administration (100 mg/kg, i.p.) markedly attenuated liver injury, fibrosis, and inflammation, and suppressed the expression of the macrophage surface marker F4/80. In terms of mechanism, C8 treatment blocked the activation of the NLRP3 inflammasome, which was stimulated by LPS and nigericin in bone marrow-derived macrophages (BMDMs) and companied by the release of active IL-1ß. In addition, the activation of LX-2 cells induced by IL-1ß released from BMDMs was also inhibited after C8 administration, which indicated that C8 repressed HSCs activation by inhibiting the activation of NLRP3 inflammasome in macrophages. Furthermore, C8 exhibited the effects of anti-fibrosis and inhibiting the expression of NLRP3 inflammasome in non-alcoholic steatohepatitis (NASH) mice. Finally, C8 can be commendably absorbed in vivo and was safe for mice at the concentration of 1000 mg/kg (p.o.). In summary, our study reveals that C8 ameliorates HSCs activation and liver fibrosis in cholestasis rats and NASH mice by inhibiting NLRP3 inflammasome in macrophages, and C8 might be a safe and effective candidate for the treatment of liver fibrosis.

Pantoprazole ameliorates liver fibrosis and suppresses hepatic stellate cell activation in bile duct ligation rats by promoting YAP degradation.

Liver fibrosis is one of the most severe pathologic consequences of chronic liver diseases, and effective therapeutic strategies are urgently needed. Proton pump inhibitors (PPIs) are H+/K+-ATPase inhibitors and currently used to treat acid-related diseases such as gastric ulcers, which have shown other therapeutic effects in addition to inhibiting acid secretion. However, few studies have focused on PPIs from the perspective of inhibiting hepatic fibrosis. In the present study, we investigated the effects of pantoprazole (PPZ), a PPI, against liver fibrosis in a bile duct ligation (BDL) rat model, human hepatic stellate cell (HSC) line LX-2 and mouse primary HSCs (pHSCs), and explored the potential mechanisms underlying the effects of PPZ in vitro and in vivo. In BDL rats, administration of PPZ (150 mg· kg-1· d-1, i.p. for 14 d) significantly attenuated liver histopathological injury, collagen accumulation, and inflammatory responses, and suppressed fibrogenesis-associated gene expression including Col1a1, Acta2, Tgfß1, and Mmp-2. In LX-2 cells and mouse pHSCs, PPZ (100-300 µM) dose-dependently suppressed the levels of fibrogenic markers. We conducted transcriptome analysis and subsequent validation in PPZ-treated LX-2 cells, and revealed that PPZ inhibited the expression of Yes-associated protein (YAP) and its downstream targets such as CTGF, ID1, survivin, CYR61, and GLI2. Using YAP overexpression and silencing, we demonstrated that PPZ downregulated hepatic fibrogenic gene expression via YAP. Furthermore, we showed that PPZ promoted the proteasome-dependent degradation and ubiquitination of YAP, thus inhibiting HSC activation. Additionally, we showed that PPZ destabilized YAP by disrupting the interaction between a deubiquitinating enzyme OTUB2 and YAP, and subsequently blocked the progression of hepatic fibrosis.

Costunolide represses hepatic fibrosis through WW domain-containing protein 2-mediated Notch3 degradation.

BACKGROUND AND PURPOSE: This study investigates the antifibrotic activities and potential mechanisms of costunolide (COS), a natural sesquiterpene compound. EXPERIMENTAL APPROACH: Rats subjected to bile duct ligation and mice challenged with CCl4 were used to study the antifibrotic effects of COS in vivo. Mouse primary hepatic stellate cells (pHSCs) and human HSC line LX-2 also served as an in vitro liver fibrosis models. The expression of fibrogenic genes and signaling proteins in the neurogenic locus notch homologue protein 3 (Notch3)-hairy/enhancer of split-1 (HES1) pathway was examined using western blot and/or real-time PCR. Notch3 degradation was analysed using immunofluorescence and coimmunoprecipitation. KEY RESULTS: In animals, COS administration attenuated hepatic histopathological injury and collagen accumulation and reduced the expression of fibrogenic genes. COS time- and dose-dependently suppressed the levels of fibrotic markers in LX-2 cells and mouse pHSCs. Mechanistic studies showed COS destabilized Notch3 and subsequently inhibited the Notch3-HES1 pathway, thus inhibiting HSC activation. Furthermore, COS blocked the WW domain-containing protein 2 (WWP2)/protein phosphatase 1G (PPM1G) interaction and enhanced the effect of WWP2 on Notch3 degradation. CONCLUSIONS AND IMPLICATIONS: COS exerted potent antifibrotic effects in vitro and in vivo by disrupting the WWP2/PPM1G complex, promoting Notch3 degradation and inhibiting the Notch3/HES1 pathway. This indicates that COS may be a potential therapeutic candidate for the treatment of liver fibrosis.

Advances in understanding the regulatory mechanism of cholesterol 7α-hydroxylase.

The conversion of cholesterol to bile acids (BAs) contributes to the elimination of total cholesterol from the body. In addition, manipulating BA homeostasis by modulating cholesterol 7α-hydroxylase (CYP7A1) may affect the metabolic processing of cholesterol, exerting therapeutic effects on hypercholesterolemia and cardiovascular diseases. Multiple mechanisms (such as various nuclear receptors and regulatory factors) are involved in CYP7A1 modulation. Recently, microRNAs, protein degradation pathways, and the gut microbiota have been identified to participate in these sophisticated networks. In this review, research progress on the regulatory mechanism of CYP7A1 is summarized.

A novel ASBT inhibitor, IMB17-15, repressed nonalcoholic fatty liver disease development in high-fat diet-fed Syrian golden hamsters.

The manipulation of bile acid (BA) homeostasis by blocking the ileal apical Na+-dependent bile salt transporter (ASBT/SLC10A2) may have therapeutic effects in nonalcoholic fatty liver disease. We developed a novel ASBT inhibitor, an N-(3,4-o-dichlorophenyl)-2-(3-trifluoromethoxy) benzamide derivative referred to as IMB17-15, and investigated its therapeutic effects and the molecular mechanisms underlying the effects. Syrian golden hamsters were challenged with high-fat diet (HFD) to induce NAFLD and were subsequently administered 400 mg/kg IMB17-15 by gavage daily for 21 days. Serum, liver, and fecal samples were collected for further analysis. Plasma concentration-time profiles of IMB17-15 were also constructed. The human hepatocyte cell line HL-7702 was treated with Oleic acid (OA) with or without IMB17-15. Western blotting and real-time PCR were used to study the molecular mechanisms of IMB17-15. We found that IMB17-15 inhibited ASBT and subsequently suppressed ileal farnesoid X receptor (FXR) and FXR-activated fibroblast growth factor15/19 (FGF15/19) expression, which reduced the hepatic phosphorylated extracellular regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) levels and upregulated the cholesterol 7α-hydroxylase (CYP7A1) activity. Additionally, IMB17-15 stimulated adenosine monophosphate (AMP)-activated protein kinase (AMPKα) phosphorylation and enhanced peroxisome proliferator activated receptor α (PPARα) expression and thus promoted triglyceride (TG) oxidation and high-density lipoprotein cholesterol (HDL-c) metabolism through an ASBT-independent mechanism. In conclusion, a novel ASBT inhibitor known as IMB17-15 protected hamsters against HFD-induced NFALD by manipulating BA and lipid homeostasis. IMB17-15 also reduced lipid deposition in human hepatic cell lines, indicating that it may be useful as a therapy for NAFLD patients.

D-chiro-inositol effectively attenuates cholestasis in bile duct ligated rats by improving bile acid secretion and attenuating oxidative stress.

Cholestatic liver diseases are important causes of liver cirrhosis and liver transplantation, but few drugs are available for treatment. D-chiro-inositol (DCI), an isomer of inositol found in many Leguminosae plants and in animal viscera, is used clinically for the treatment of polycystic ovary syndrome (PCOS) and diabetes mellitus. In this study, we investigated whether DCI exerted an anti-cholestatic effect and its underlying mechanisms. A cholestatic rat model was established via bile duct ligation (BDL). After the surgery, the rats were given DCI (150 mg·kg-1·d-1) in drinking water for 2 weeks. Oral administration of DCI significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and attenuated bile duct proliferation, parenchymal necrosis and fibrosis in BDL rats. Furthermore, DCI treatment significantly increased the serum and bile levels of total bile acid (TBA), and decreased TBA levels in the liver. Moreover, DCI treatment significantly increased expression of the genes encoding bile acid transporters BSEP (Abcb11) and MRP2 (Abcc2) in liver tissues. DCI treatment also markedly decreased hepatic CD68 and NF-kappaB (NF-κB) levels, significantly decreased the serum and hepatic MDA levels, markedly increased superoxide dismutase activity in both serum and liver tissues. Using whole-genome oligonucleotide microarray, we revealed that DCI treatment altered the expression profiles of oxidation reduction-related genes in liver tissues. Collectively, DCI effectively attenuates BDL-induced hepatic bile acid accumulation and decreases the severity of injury and fibrosis by improving bile acid secretion, repressing inflammation and decreasing oxidative stress. The results suggest that DCI might be beneficial for patients with cholestatic disorders.

Recent progression in the utilization of autophagy-regulating nature compound as anti-liver fibrosis agents.

Hepatic fibrosis is a wound-healing response to chronic liver injury caused by various pathogenesis, such as hepatitis virus infection, drugs toxicity and autoimmune imbalances. Autophagy, a cellular process degrading damaged organelles or aggregative proteins, participates in multiple human diseases including hepatic fibrosis. However, the precise role of autophagy in the pathogenesis of hepatic fibrosis is yet to be elucidated. Accumulated evidences indicate that several nature compounds exhibit anti-fibrotic potential through modulating autophagy activity. For a better understanding of the relationships among autophagy, hepatic fibrosis, and autophagy-regulating nature compounds, this review highlights the recent advancement of nature compounds treating hepatic fibrosis through regulating autophagy.

[Advances in studies of ileal apical sodium-dependent bile acid transporter].

Bile acids play critical roles in the regulation of metabolism and absorption of lipids. The ileal apical sodium-dependent bile acid transporter (ASBT) located at the enterocyte brush border is responsible for the reuptake of bile acids and the maintenance of bile acid homeostasis. Recently, a number of investigations have been made concerning the regulation and control of ASBT and the relationship between ASBT and intestinal inflammation, tumorigenesis, diabetes mellitus and hyperlipemia, which suggests ASBT as a potential therapeutic target of these diseases. In this review, advances in the study of above-mentioned issues were summarized.