Protein tyrosine phosphatase 1b deficiency protects against hepatic fibrosis by modulating nadph oxidases

Hepatoprotective effect of astaxanthin against cholestasis liver fibrosis induced by bile duct ligation in adult Wistar rats

In this study, we evaluated the hepatoprotective effects of astaxanthin, a natural carotenoid, against the cholestatic liver fibrosis induced by bile duct ligation (BDL). Toward this end, male rats were subjected to BDL and treated with astaxanthin for 35 days. Afterwards, their serum and liver biochemical factors were assessed. Also, histopathological and immunohistochemical analyses were performed to determine the fibrosis and the expression levels of alpha-smooth muscle actin (α-SMA) and transforming growth factor beta (TGF-ß1) in the liver tissue. Based on the results, BDL caused a significant increase in liver enzyme levels, blood lipids, and bilirubin, while decreasing the activity of superoxide dismutase(SOD), catalase (CAT), and glutathione (GSH) enzymes. Also, in the BDL rats, hepatocyte necrosis, infiltration of inflammatory lymphocytes, and hyperplasia of bile ducts were detected, along with a significant increase in α-SMA and TGF-ß1 expression. Astaxanthin, however, significantly prevented the BDL's detrimental effects. In all, 10 mg/kg of this drug maintained the bilirubin and cholesterol serum levels of BDL rats at normal levels. It also reduced the liver enzymes' activity and serum lipids, while increasing the SOD, CAT, and GSH activity in BDL rats. The expression of α-SMA and TGF-ß1 in the BDL rats treated with 10 mg/kg of astaxanthin was moderate (in 34%-66% of cells) and no considerable cholestatic fibrosis was observed in this group. However, administrating the 20 mg/kg of astaxanthin was not effective in this regard. These findings showed that astaxanthin could considerably protect the liver from cholestatic damage by improving the biochemical features and regulating the expression of related proteins.

Formononetin attenuates hepatic injury in diabetic mice by regulating macrophage polarization through the PTP1B/STAT6 axis

BACKGROUND

Formononetin (FNT) is an isoflavone known for its anti-inflammatory properties and has been shown to reduce insulin resistance in Type 2 Diabetes Mellitus (T2DM). However, its effects and the underlying mechanisms in diabetic liver injury remain largely unexplored.

METHODS

We established a T2DM-induced liver injury mouse model by feeding high-fat diet, followed by injecting streptozotocin. The mice were then treated with FNT and the liver function in these mice was assessed. Macrophage markers in FNT-treated T2DM mice or human THP-1 cells were evaluated using flow cytometry, RT-qPCR, and Western blotting. The expression of PTP1B and STAT6 in mouse liver tissues and THP-1 cells was analyzed. Molecular docking predicted the interaction between PTP1B and STAT6, which was validated via co-immunoprecipitation (Co-IP) and phos-tag analysis. Microscale thermophoresis (MST) assessed the binding affinity of FNT to PTP1B.

RESULTS

FNT treatment significantly ameliorated blood glucose levels, hepatocyte apoptosis, inflammatory response, and liver dysfunction in T2DM mice. Moreover, FNT facilitated M2 macrophage polarization in both T2DM mice and high glucose (HG)-induced THP-1-derived macrophages. The PTP1B/STAT6 axis, deregulated in T2DM mice, was normalized by FNT treatment, which counteracted the T2DM-induced upregulation of PTP1B and downregulation of phosphorylated STAT6. Molecular docking and subsequent analyses revealed that PTP1B binds to and dephosphorylates STAT6 at the S325A site. In contrast, FNT strongly binds to PTP1B and influences its expression at the K116A site, promoting M2 polarization of THP-1 cells via downregulation of PTP1B.

CONCLUSION

Formononetin mitigates diabetic hepatic injury by fostering M2 macrophage polarization via the PTP1B/STAT6 axis.

Recent Developments in the Role of Protein Tyrosine Phosphatase 1B (PTP1B) as a Regulator of Immune Cell Signalling in Health and Disease

Protein tyrosine phosphatase 1B (PTP1B) is a non-receptor tyrosine phosphatase best known for its role in regulating insulin and leptin signalling. Recently, knowledge on the role of PTP1B as a major regulator of multiple signalling pathways involved in cell growth, proliferation, viability and metabolism has expanded, and PTP1B is recognised as a therapeutic target in several human disorders, including diabetes, obesity, cardiovascular diseases and hematopoietic malignancies. The function of PTP1B in the immune system was largely overlooked until it was discovered that PTP1B negatively regulates the Janus kinase-a signal transducer and activator of the transcription (JAK/STAT) signalling pathway, which plays a significant role in modulating immune responses. PTP1B is now known to determine the magnitude of many signalling pathways that drive immune cell activation and function. As such, PTP1B inhibitors are being developed and tested in the context of inflammation and autoimmune diseases. Here, we provide an up-to-date summary of the molecular role of PTP1B in regulating immune cell function and how targeting its expression and/or activity has the potential to change the outcomes of immune-mediated and inflammatory disorders.

Uncovering a Novel Functional Interaction Between Adult Hepatic Progenitor Cells, Inflammation and EGFR Signaling During Bile Acids-Induced Injury

Chronic cholestatic damage is associated to both accumulation of cytotoxic levels of bile acids and expansion of adult hepatic progenitor cells (HPC) as part of the ductular reaction contributing to the regenerative response. Here, we report a bile acid-specific cytotoxic response in mouse HPC, which is partially impaired by EGF signaling. Additionally, we show that EGF synergizes with bile acids to trigger inflammatory signaling and NLRP3 inflammasome activation in HPC. Aiming at understanding the impact of this HPC specific response on the liver microenvironment we run a proteomic analysis of HPC secretome. Data show an enrichment in immune and TGF-β regulators, ECM components and remodeling proteins in HPC secretome. Consistently, HPC-derived conditioned medium promotes hepatic stellate cell (HSC) activation and macrophage M1-like polarization. Strikingly, EGF and bile acids co-treatment leads to profound changes in the secretome composition, illustrated by an abolishment of HSC activating effect and by promoting macrophage M2-like polarization. Collectively, we provide new specific mechanisms behind HPC regulatory action during cholestatic liver injury, with an active role in cellular interactome and inflammatory response regulation. Moreover, findings prove a key contribution for EGFR signaling jointly with bile acids in HPC-mediated actions.

Specific targeting of the NRF2/β-TrCP axis promotes beneficial effects in NASH

Non-alcoholic steatohepatitis (NASH) is a common chronic liver disease that compromises liver function, for which there is not a specifically approved medicine. Recent research has identified transcription factor NRF2 as a potential therapeutic target. However, current NRF2 activators, designed to inhibit its repressor KEAP1, exhibit unwanted side effects. Alternatively, we previously introduced PHAR, a protein-protein interaction inhibitor of NRF2/β-TrCP, which induces a mild NRF2 activation and selectively activates NRF2 in the liver, close to normal physiological levels. Herein, we assessed the effect of PHAR in protection against NASH and its progression to fibrosis. We conducted experiments to demonstrate that PHAR effectively activated NRF2 in hepatocytes, Kupffer cells, and stellate cells. Then, we used the STAM mouse model of NASH, based on partial damage of endocrine pancreas and insulin secretion impairment, followed by a high fat diet. Non-invasive analysis using MRI revealed that PHAR protects against liver fat accumulation. Moreover, PHAR attenuated key markers of NASH progression, including liver steatosis, hepatocellular ballooning, inflammation, and fibrosis. Notably, transcriptomic data indicate that PHAR led to upregulation of 3 anti-fibrotic genes (Plg, Serpina1a, and Bmp7) and downregulation of 6 pro-fibrotic (including Acta2 and Col3a1), 11 extracellular matrix remodeling, and 8 inflammatory genes. Overall, our study suggests that the mild activation of NRF2 via the protein-protein interaction inhibitor PHAR holds promise as a strategy for addressing NASH and its progression to liver fibrosis.

Targeting Protein Phosphatases for the Treatment of Chronic Liver Disease

There exists a huge number of patients suffering from chronic liver disease worldwide. As a disease with high incidence and mortality worldwide, strengthening the research on the pathogenesis of chronic liver disease and the development of novel drugs is an important issue related to the health of all human beings. Phosphorylation modification of proteins plays a crucial role in cellular signal transduction, and phosphatases are involved in the development of liver diseases. Therefore, this article summarized the important role of protein phosphatases in chronic liver disease with the aim of facilitating the development of drugs targeting protein phosphatases for the treatment of chronic liver disease.

Hypothalamic JNK1-hepatic fatty acid synthase axis mediates a metabolic rewiring that prevents hepatic steatosis in male mice treated with olanzapine via intraperitoneal: Additional effects of PTP1B inhibition

Olanzapine (OLA), a widely used second-generation antipsychotic (SGA), causes weight gain and metabolic alterations when administered orally to patients. Recently, we demonstrated that, contrarily to the oral treatment which induces weight gain, OLA administered via intraperitoneal (i.p.) in male mice resulted in body weight loss. This protection was due to an increase in energy expenditure (EE) through a mechanism involving the modulation of hypothalamic AMPK activation by higher OLA levels reaching this brain region compared to those of the oral treatment. Since clinical studies have shown hepatic steatosis upon chronic treatment with OLA, herein we further investigated the role of the hypothalamus-liver interactome upon OLA administration in wild-type (WT) and protein tyrosine phosphatase 1B knockout (PTP1B-KO) mice, a preclinical model protected against metabolic syndrome. WT and PTP1B-KO male mice were fed an OLA-supplemented diet or treated via i.p. Mechanistically, we found that OLA i.p. treatment induces mild oxidative stress and inflammation in the hypothalamus in a JNK1-independent and dependent manner, respectively, without features of cell dead. Hypothalamic JNK activation up-regulated lipogenic gene expression in the liver though the vagus nerve. This effect concurred with an unexpected metabolic rewiring in the liver in which ATP depletion resulted in increased AMPK/ACC phosphorylation. This starvation-like signature prevented steatosis. By contrast, intrahepatic lipid accumulation was observed in WT mice treated orally with OLA; this effect being absent in PTP1B-KO mice. We also demonstrated an additional benefit of PTP1B inhibition against hypothalamic JNK activation, oxidative stress and inflammation induced by chronic OLA i.p. treatment, thereby preventing hepatic lipogenesis. The protection conferred by PTP1B deficiency against hepatic steatosis in the oral OLA treatment or against oxidative stress and neuroinflammation in the i.p. treatment strongly suggests that targeting PTP1B might be also a therapeutic strategy to prevent metabolic comorbidities in patients under OLA treatment in a personalized manner.

Identification of Hub Genes and Biological Mechanisms Associated with Non-Alcoholic Fatty Liver Disease and Triple-Negative Breast Cancer

The relationship between non-alcoholic fatty liver disease (NAFLD) and triple-negative breast cancer (TNBC) has been widely recognized, but the underlying mechanisms are still unknown. The objective of this study was to identify the hub genes associated with NAFLD and TNBC, and to explore the potential co-pathogenesis and prognostic linkage of these two diseases. We used GEO, TCGA, STRING, ssGSEA, and Rstudio to investigate the common differentially expressed genes (DEGs), conduct functional and signaling pathway enrichment analyses, and determine prognostic value between TNBC and NAFLD. GO and KEGG enrichment analyses of the common DEGs showed that they were enriched in leukocyte aggregation, migration and adhesion, apoptosis regulation, and the PPAR signaling pathway. Fourteen candidate hub genes most likely to mediate NAFLD and TNBC occurrence were identified and validation results in a new cohort showed that ITGB2, RAC2, ITGAM, and CYBA were upregulated in both diseases. A univariate Cox analysis suggested that high expression levels of ITGB2, RAC2, ITGAM, and CXCL10 were associated with a good prognosis in TNBC. Immune infiltration analysis of TNBC samples showed that NCF2, ICAM1, and CXCL10 were significantly associated with activated CD8 T cells and activated CD4 T cells. NCF2, CXCL10, and CYBB were correlated with regulatory T cells and myeloid-derived suppressor cells. This study demonstrated that the redox reactions regulated by the NADPH oxidase (NOX) subunit genes and the transport and activation of immune cells regulated by integrins may play a central role in the co-occurrence trend of NAFLD and TNBC. Additionally, ITGB2, RAC2, and ITGAM were upregulated in both diseases and were prognostic protective factors of TNBC; they may be potential therapeutic targets for treatment of TNBC patients with NAFLD, but further experimental studies are still needed.

The PTP1B inhibitor MSI-1436 ameliorates liver insulin sensitivity by modulating autophagy, ER stress and systemic inflammation in Equine metabolic syndrome affected horses

BACKGROUND

Equine metabolic syndrome (EMS) is a multifactorial pathology gathering insulin resistance, low-grade inflammation and past or chronic laminitis. Among the several molecular mechanisms underlying EMS pathogenesis, increased negative insulin signalling regulation mediated by protein tyrosine phosphatase 1 B (PTP1B) has emerged as a critical axis in the development of liver insulin resistance and general metabolic distress associated to increased ER stress, inflammation and disrupted autophagy. Thus, the use of PTP1B selective inhibitors such as MSI-1436 might be considered as a golden therapeutic tool for the proper management of EMS and associated conditions. Therefore, the present investigation aimed at verifying the clinical efficacy of MSI-1436 systemic administration on liver metabolic balance, insulin sensitivity and inflammatory status in EMS affected horses. Moreover, the impact of MSI-1436 treatment on liver autophagy machinery and associated ER stress in liver tissue has been analysed.

METHODS

Liver explants isolated from healthy and EMS horses have been treated with MSI-1436 prior to gene and protein expression analysis of main markers mediating ER stress, mitophagy and autophagy. Furthermore, EMS horses have been intravenously treated with a single dose of MSI-1436, and evaluated for their metabolic and inflammatory status.

RESULTS

Clinical application of MSI-1436 to EMS horses restored proper adiponectin levels and attenuated the typical hyperinsulinemia and hyperglycemia. Moreover, administration of MSI-1436 further reduced the circulating levels of key pro-inflammatory mediators including IL-1β, TNF-α and TGF-β and triggered the Tregs cells activation. At the molecular level, PTP1B inhibition resulted in a noticeable mitigation of liver ER stress, improvement of mitochondrial dynamics and consequently, a regulation of autophagic response. Similarly, short-term ex vivo treatment of EMS liver explants with trodusquemine (MSI-1436) substantially enhanced autophagy by upregulating the levels of HSC70 and Beclin-1 at both mRNA and protein level. Moreover, the PTP1B inhibitor potentiated mitophagy and associated expression of MFN2 and PINK1. Interestingly, inhibition of PTP1B resulted in potent attenuation of ER stress key mediators' expression namely, CHOP, ATF6, HSPA5 and XBP1.

CONCLUSION

Presented findings shed for the first time promising new insights in the development of an MSI-1436-based therapy for proper equine metabolic syndrome intervention and may additionally find potential translational application to human metabolic syndrome treatment.

TCMSID: a simplified integrated database for drug discovery from traditional chinese medicine

Traditional Chinese Medicine (TCM) has been widely used in the treatment of various diseases for millennia. In the modernization process of TCM, TCM ingredient databases are playing more and more important roles. However, most of the existing TCM ingredient databases do not provide simplification function for extracting key ingredients in each herb or formula, which hinders the research on the mechanism of actions of the ingredients in TCM databases. The lack of quality control and standardization of the data in most of these existing databases is also a prominent disadvantage. Therefore, we developed a Traditional Chinese Medicine Simplified Integrated Database (TCMSID) with high storage, high quality and standardization. The database includes 499 herbs registered in the Chinese pharmacopeia with 20,015 ingredients, 3270 targets as well as corresponding detailed information. TCMSID is not only a database of herbal ingredients, but also a TCM simplification platform. Key ingredients from TCM herbs are available to be screened out and regarded as representatives to explore the mechanism of TCM herbs by implementing multi-tool target prediction and multilevel network construction. TCMSID provides abundant data sources and analysis platforms for TCM simplification and drug discovery, which is expected to promote modernization and internationalization of TCM and enhance its international status in the future. TCMSID is freely available at https://tcm.scbdd.com .

Ptpn1 deletion protects oval cells against lipoapoptosis by favoring lipid droplet formation and dynamics

Activation of oval cells (OCs) has been related to hepatocyte injury during chronic liver diseases including non-alcoholic fatty liver disease (NAFLD). However, OCs plasticity can be affected under pathological environments. We previously found protection against hepatocyte cell death by inhibiting protein tyrosine phosphatase 1B (PTP1B). Herein, we investigated the molecular and cellular processes involved in the lipotoxic susceptibility in OCs expressing or not PTP1B. Palmitic acid (PA) induced apoptotic cell death in wild-type (Ptpn1+/+) OCs in parallel to oxidative stress and impaired autophagy. This lipotoxic effect was attenuated in OCs lacking Ptpn1 that showed upregulated antioxidant defences, increased unfolded protein response (UPR) signaling, higher endoplasmic reticulum (ER) content and elevated stearoyl CoA desaturase (Scd1) expression and activity. These effects in Ptpn1-/- OCs concurred with an active autophagy, higher mitochondrial efficiency and a molecular signature of starvation, favoring lipid droplet (LD) formation and dynamics. Autophagy blockade in Ptpn1-/- OCs reduced Scd1 expression, mitochondrial fitness, LD formation and restored lipoapoptosis, an effect also recapitulated by Scd1 silencing. PTP1B immunostaining was detected in OCs from mouse liver and, importantly, LDs were found in OCs from Ptpn1-/- mice with NAFLD. In conclusion, we demonstrated that Ptpn1 deficiency restrains lipoapoptosis in OCs through a metabolic rewiring towards a "starvation-like" fate, favoring autophagy, mitochondrial fitness and LD formation. Dynamic LD-lysosomal interations likely ensure lipid recycling and, overall, these adaptations protect against lipotoxicity. The identification of LDs in OCs from Ptpn1-/- mice with NAFLD opens therapeutic perspectives to ensure OC viability and plasticity under lipotoxic liver damage.

Modulation of hypothalamic AMPK phosphorylation by olanzapine controls energy balance and body weight

BACKGROUND

Second-generation antipsychotics (SGAs) are a mainstay therapy for schizophrenia. SGA-treated patients present higher risk for weight gain, dyslipidemia and hyperglycemia. Herein, we evaluated the effects of olanzapine (OLA), widely prescribed SGA, in mice focusing on changes in body weight and energy balance. We further explored OLA effects in protein tyrosine phosphatase-1B deficient (PTP1B-KO) mice, a preclinical model of leptin hypersensitivity protected against obesity.

METHODS

Wild-type (WT) and PTP1B-KO mice were fed an OLA-supplemented diet (5 mg/kg/day, 7 months) or treated with OLA via intraperitoneal (i.p.) injection or by oral gavage (10 mg/kg/day, 8 weeks). Readouts of the crosstalk between hypothalamus and brown or subcutaneous white adipose tissue (BAT and iWAT, respectively) were assessed. The effects of intrahypothalamic administration of OLA with adenoviruses expressing constitutive active AMPKα1 in mice were also analyzed.

RESULTS

Both WT and PTP1B-KO mice receiving OLA-supplemented diet presented hyperphagia, but weight gain was enhanced only in WT mice. Unexpectedly, all mice receiving OLA via i.p. lost weight without changes in food intake, but with increased energy expenditure (EE). In these mice, reduced hypothalamic AMPK phosphorylation concurred with elevations in UCP-1 and temperature in BAT. These effects were also found by intrahypothalamic OLA injection and were abolished by constitutive activation of AMPK in the hypothalamus. Additionally, OLA i.p. treatment was associated with enhanced Tyrosine Hydroxylase (TH)-positive innervation and less sympathetic neuron-associated macrophages in iWAT. Both central and i.p. OLA injections increased UCP-1 and TH in iWAT, an effect also prevented by hypothalamic AMPK activation. By contrast, in mice fed an OLA-supplemented diet, BAT thermogenesis was only enhanced in those lacking PTP1B. Our results shed light for the first time that a threshold of OLA levels reaching the hypothalamus is required to activate the hypothalamus BAT/iWAT axis and, therefore, avoid weight gain.

CONCLUSION

Our results have unraveled an unexpected metabolic rewiring controlled by hypothalamic AMPK that avoids weight gain in male mice treated i.p. with OLA by activating BAT thermogenesis and iWAT browning and a potential benefit of PTP1B inhibition against OLA-induced weight gain upon oral treatment.

NOX as a Therapeutic Target in Liver Disease

The nicotinamide adenine dinucleotide phosphate hydrogen oxidase (NADPH oxidase or NOX) plays a critical role in the inflammatory response and fibrosis in several organs such as the lungs, pancreas, kidney, liver, and heart. In the liver, NOXs contribute, through the generation of reactive oxygen species (ROS), to hepatic fibrosis by acting through multiple pathways, including hepatic stellate cell activation, proliferation, survival, and migration of hepatic stellate cells; hepatocyte apoptosis, enhancement of fibrogenic mediators, and mediation of an inflammatory cascade in both Kupffer cells and hepatic stellate cells. ROS are overwhelmingly produced during malignant transformation and hepatic carcinogenesis (HCC), creating an oxidative microenvironment that can cause different and various types of cellular stress, including DNA damage, ER stress, cell death of damaged hepatocytes, and oxidative stress. NOX1, NOX2, and NOX4, members of the NADPH oxidase family, have been linked to the production of ROS in the liver. This review will analyze some diseases related to an increase in oxidative stress and its relationship with the NOX family, as well as discuss some therapies proposed to slow down or control the disease's progression.

Neurotrophic factors stimulate the activation of hepatic stellate cells in liver fibrosis

BACKGROUND AND AIMS

Patients with liver fibrosis who have pain in the liver region may have changed nerve factors. The expression of neurokines and hepatic nerves in liver fibrosis, however, was little understood. In order to better understand how liver fibrosis develops, we plan to look into the hepatic nerve and neurokine changes and how they relate to hepatic stellate cells (HSCs).

METHODS

The expression of neurokines in liver samples from 55 chronic hepatitis B patients and the carbon tetrachloride (CCl₄) animal model were studied. The co-staining of Nissl and α-SMA allowed us to investigate the neurons and their interaction with α-SMA in fibrotic livers, as well as the expression of the glial cell marker glial fibrillary acidic protein (GFAP) and its relationship with α-SMA, a marker of HSCs. SH-SY5Y cells were treated with a fibrotic serum to imitate the hepatic microenvironment on neuronal cells. We also used brain-derived neurotrophic factor (BDNF) to stimulate mouse primary HSCs and LX2.

RESULTS

The levels of mRNA for neurokines such as BDNF, GFAP, and growth-associated protein (GAP43) are significantly increased in both human and animal liver fibrosis. As liver fibrosis advances, we found that Nissl bodies and α-SMA may co-localize, suggesting a connection between hepatic nerves and HSCs. Human fibrotic serum may increase neurkines, notably BDNF, in SH-SY5Y cells. We also found that BDNF increased pro-inflammatory cytokines and fibrogenic markers in hHSCs.

CONCLUSIONS

Patients with hepatic fibrosis had significantly higher levels of BDNF, GFAP, GAP43, and nerve fibers. HSC and nerve fibers interact, and nerves also create neurogenic substances that promote liver fibrosis and HSC activation.

Bryodulcosigenin attenuates bleomycin-induced pulmonary fibrosis via inhibiting AMPK-mediated mesenchymal epithelial transition and oxidative stress

Fibrosis is a pathological result of a dysfunctional repair response to tissue injury and occurs in several organs, including the lungs. Bryodulcosigenin (BDG) is a cucurbitane-type triterpene isolated from Siratia grosvenori and has clear-cut anti-inflammatory effects, yet its benefit of pulmonary fibrosis (PF) remains unclear. In this study, we investigated the protective effects of BDG (10 mg/kg/day, for 14 days) against TGF-β1-stimulated mouse alveolar epithelial MLE-12 cells and bleomycin (BLM)-induced PF mice. In vitro experiments showed that BDG could inhibit epithelial-mesenchymal transition (EMT) and oxidative stress. In vivo experiments indicated that BDG could ameliorate BLM-induced PF in mice as evidenced by characteristic structural changes in histopathology, increased collagen deposition and reduced survival and weight of mice. The abnormal increased expressions of TGF-β1, p-Smad2/3, α-SMA, COL-I, and NOX4 and decreased expressions for Sirt1 and p-AMPK were improved in BDG treatment. But these beneficial effects could be eliminated by co-treatment with Compound C (CC, a selective AMPK inhibitor). Molecular docking technology also revealed the potential of BDG to activate AMPK. In summary, AMPK activation modulated by BDG not only ameliorated TGF-β1/Smad2/3 signaling pathways but also partially mediated the suppression effects on EMT and oxidative stress, thus mediating the anti-fibrotic effects.

Diagnosis and staging of HCV associated fibrosis, cirrhosis and hepatocellular carcinoma with target identification for miR-650, 552-3p, 676-3p, 512-5p and 147b

BACKGROUND: Chronic HCV infection progresses to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The latter represents the third most common cause for cancer mortality. Currently, there is no reliable non-invasive biomarker for diagnosis of HCV mediated disorders. OBJECTIVE: Profiling expression signature for circulatory miRNAs in the plasma of 167 Egyptian patients (40 healthy, 48 HCV fibrotic, 39 HCV cirrhotic and 40 HCV-HCC cases). METHODS: QRTPCR was used to quantify expression signature for circulatory miRNAs. RESULTS: MiR-676 and miR-650 were powerful in discriminating cirrhotic and late fibrosis from HCC. MiR-650 could distinguish mild (f0-f1) and advanced (f2-f3) fibrosis from HCC cases. MiR-650 and miR-147b could distinguish early fibrosis from healthy controls meanwhile miR-676 and miR-147b could effectively distinguish between mild chronic and (f1-f3) cases from healthy individuals. All studied miRNAs, except miR-512, can differentiate between (f0-f3) cases and healthy controls. Multivariate logistic regression revealed three potential miRNA panels for effective differentiation of HCC, cirrhotic and chronic liver cases. MiR-676-3p and miR-512-5p were significantly correlated in (f1-f3) fibrosis meanwhile miR-676 and miR-512 could differentiate between cirrhosis and (f0-f3) cases. Both miR-650 and miR-512-5p were positively correlated in the cirrhotic group and in (f0-f4) group. Putative targets for investigated miRNAs were also determined. CONCLUSIONS: Investigated miRNAs could assist in staging and diagnosis of HCV associated disorders.

Baihe Wuyao decoction ameliorates CCl4-induced chronic liver injury and liver fibrosis in mice through blocking TGF-β1/Smad2/3 signaling, anti-inflammation and anti-oxidation effects

ETHNOPHARMACOLOGICAL RELEVANCE

Baihe Wuyao decoction (BWD), a prescription of Traditional Chinese Medicines, composed of Lilium brownii var. viridulum Baker.(Lilii Bulbus) and Lindera aggregata (Sims) Kosterm. (Linderae Radix), has been used to treat epigastric pain and superficial gastritis for hundreds of years in China. Recently, some compounds obtained from Lilii Bulbus and Linderae Radix had active effects of hepatic protection or liver fibrosis alleviation. Thus, we aim to evaluate the effects of BWD on treatment of chronic liver injury and liver fibrosis induced by carbon tetrachloride (CCl₄) and to elucidate the possible molecular mechanism.

MATERIALS AND METHODS

Mice were treated with BWD (low, medium and high dose), diammonium glycyrrhizinate or vehicle by oral gavage once daily, simultaneously intraperitoneal injected with a single dose of CCl₄ (1 μl/g body weight) twice a week for consecutive 6 weeks. Next, all mice were sacrificed after fasted 12 h, and serums and liver tissues were harvested for analysis. The hepatic injury was detected by serum biomarker assay, including aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The hepatic histology and collagen were illustrated by hematoxylin-eosin staining and Sirius red staining respectively. The antioxidant capacity of liver tissues was evaluated by the contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenization. The mRNA gene or protein expressions related to fibrosis, oxidative stress and inflammation molecules were performed by real-time quantitative PCR (RT-PCR) or Western-blot.

RESULTS

BWD exhibited a good hepatic protection with ameliorating liver histological changes, decreasing serum AST and ALT contents, and reducing hepatic fibrosis with stimulation ECMs (such as Collagen1 and Collagen3) degradation. BWD inhibited hepatic stellate cells (HSCs) activation, promoted matrix metalloproteinase-2 (MMP2), MMP9, and MMP12 while suppressing tissue inhibitors of matrix metalloproteinase-1 (TIMP1) expression, and blocked traditional fibrosis TGF-β1/Smad2/3 signal pathway. Moreover, BWD exhibited anti-inflammation effect proved by the reduction of liver Interleukin-1β (IL-1β), TNF-α, IL-11 mRNA levels and promoted anti-oxidation effects determined by inhibition of liver MDA and iNOS levels while promoting liver SOD and Mn-SOD.

CONCLUSION

BWD ameliorates CCl₄-induced CLI and liver fibrosis which is correlated to its blocking TGF-β1/Smad2/3 signaling, anti-inflammation, and anti-oxidation effects. BWD, as a small traditional prescription, is a promising treatment for CLI and liver fibrosis through multiple pharmacological targets.

Hepatic protein-tyrosine phosphatase 1B disruption and pharmacological inhibition attenuate ethanol-induced oxidative stress and ameliorate alcoholic liver disease in mice

Alcoholic liver disease (ALD) is a major health problem and a significant cause of liver-related death. Currently, the mainstay for ALD therapy is alcohol abstinence highlighting the need to develop pharmacotherapeutic approaches. Protein-tyrosine phosphatase 1B (PTP1B) is an established regulator of hepatic functions, but its role in ALD is mostly unexplored. In this study, we used mice with liver-specific PTP1B disruption as well as pharmacological inhibition to investigate the in vivo function of this phosphatase in ALD. We report upregulation of hepatic PTP1B in the chronic plus binge mouse model and, importantly, in liver biopsies of alcoholic hepatitis patients. Also, mice with hepatic PTP1B disruption attenuated ethanol-induced injury, inflammation, and steatosis compared with ethanol-fed control animals. Moreover, PTP1B deficiency was associated with decreased ethanol-induced oxidative stress in vivo and ex vivo. Further, pharmacological modulation of oxidative balance in hepatocytes identified diminished oxidative stress as a contributor to the salutary effects of PTP1B deficiency. Notably, PTP1B pharmacological inhibition elicited beneficial effects and mitigated hepatic injury, inflammation, and steatosis caused by ethanol feeding. In summary, these findings causally link hepatic PTP1B and ALD and define a potential therapeutic target for the management of this disease.

Protein tyrosine phosphatase 1B as a therapeutic target for Graves' orbitopathy in an in vitro model

Graves' orbitopathy (GO) is characterised in early stages by orbital fibroblast inflammation, which can be aggravated by oxidative stress and often leads to fibrosis. Protein tyrosine protein 1B (PTP1B) is a regulator of inflammation and a therapeutic target in diabetes. We investigated the role of PTP1B in the GO mechanism using orbital fibroblasts from GO and healthy non-GO subjects. After 24 hours of transfection with PTPN1 siRNA, the fibroblasts were exposed to interleukin (IL)-1β, cigarette smoke extract (CSE), H2O2, and transforming growth factor (TGF)-β stimulations. Inflammatory cytokines and fibrosis-related proteins were analysed using western blotting and/or enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) release was detected using an oxidant-sensitive fluorescent probe. IL-1β, tumor necrosis factor (TNF)-α, bovine thyroid stimulating hormone (bTSH), high-affinity human stimulatory monoclonal antibody of TSH receptor (M22), and insulin-like growth factor-1 (IGF-1) significantly increased PTP1B protein production in GO and non-GO fibroblasts. PTPN1 silencing significantly blocked IL-1β-induced inflammatory cytokine production, CSE- and H2O2-induced ROS synthesis, and TGF-β-induced expression of collagen Iα, α-smooth muscle actin (SMA), and fibronectin in GO fibroblasts. Silencing PTPN1 also decreased phosphorylation levels of Akt, p38, and c-Jun N-terminal kinase (JNK) and endoplasmic reticulum (ER)-stress response proteins in GO cells. PTP1B may be a potential therapeutic target of anti-inflammatory, anti-oxidant and anti-fibrotic treatment of GO.

The peripheral CB1 receptor antagonist JD5037 attenuates liver fibrosis via a CB1 receptor/β-arrestin1/Akt pathway

BACKGROUND AND PURPOSE

Liver fibrosis is a serious cause of morbidity and mortality worldwide and has no adequate treatment. Accumulating evidence suggests that cannabinoid CB₁ receptors regulate a variety of physiological and pathological processes in the liver, and blockage of CB₁ receptor signalling shows promise as a new therapy for several liver diseases. The aim of this study was to investigate the potential therapeutic effects of CB₁ receptors and a peripheral CB₁ receptor antagonist JD5037 in liver fibrogenesis.

EXPERIMENTAL APPROACH

Liver samples from both humans and mouse models were investigated. The peripheral CB₁ receptor antagonist JD5037, β-arr1 wild type (β-arr1-WT) and β-arr1 knockout (β-arr1-KO) littermate models, and primary hepatic stellate cells (HSCs) were also used. The mechanisms underlying CB₁ receptor-regulated HSCs activation in fibrosis and the therapeutic potential of JD5037 were further analysed.

KEY RESULTS

CB₁ receptors were induced in samples from patients with liver fibrosis and from mouse models. These receptors promoted activation of HSCs in liver fibrosis via recruiting β-arrestin1 and Akt signalling, while blockage of CB₁ receptors with JD5037 attenuated CB₁ receptor-regulated HSCs activation and liver fibrosis by suppressing β-arrestin1/Akt signalling.

CONCLUSIONS AND IMPLICATIONS

CB₁ receptors promote the activation of HSCs and liver fibrosis via the β-arrestin1/Akt signalling pathway. The peripheral CB₁ receptor antagonist JD5037 blocked this pathway, the activation of HSCs and liver fibrosis. This compound and the associated pathway may be a novel approach to the treatment of liver fibrosis.

Design and synthesis of tricyclic terpenoid derivatives as novel PTP1B inhibitors with improved pharmacological property and in vivo antihyperglycaemic efficacy

Overexpression of protein tyrosine phosphatase 1B (PTP1B) induces insulin resistance in various basic and clinical research. In our previous work, a synthetic oleanolic acid (OA) derivative C10a with PTP1B inhibitory activity has been reported. However, C10a has some pharmacological defects and cytotoxicity. Herein, a structure-based drug design approach was used based on the structure of C10a to elaborate the smaller tricyclic core. A series of tricyclic derivatives were synthesised and the compounds 15, 28 and 34 exhibited the most PTP1B enzymatic inhibitory potency. In the insulin-resistant human hepatoma HepG2 cells, compound 25 with the moderate PTP1B inhibition and preferable pharmaceutical properties can significantly increase insulin-stimulated glucose uptake and showed the insulin resistance ameliorating effect. Moreover, 25 showed the improved in vivo antihyperglycaemic potential in the nicotinamide–streptozotocin-induced T2D. Our study demonstrated that these tricyclic derivatives with improved molecular architectures and antihyperglycaemic activity could be developed in the treatment of T2D.