11Beta-hydroxysteroid dehydrogenase-1 deficiency or inhibition enhances hepatic myofibroblast activation in murine liver fibrosis

Angiotensin II depends on hippo/YAP signaling to reprogram angiogenesis and promote liver fibrosis

Liver fibrosis is a chronic pathological process in which the abnormal proliferation of connective tissue is induced by various pathogenic factors. During the process of fibrosis, excessive angiogenesis is observed. Physiological angiogenesis has the potential to impede the progression of liver fibrosis through augmenting matrix metalloenzyme activity; however, pathological angiogenesis can exacerbate liver fibrosis by promoting collagen accumulation. Therefore, a key scientific research focus in the treatment of liver diseases is to search for the "on-off" mechanism that regulates angiogenesis from normal proliferation to pathological proliferation. In this study, we found that excessive angiogenesis appeared during the initial phase of hepatic fibrosis without mesenchymal characteristics. In addition, angiogenesis accompanied by significant endothelial-to-mesenchymal transition (EndMT) was observed in mice after the intraperitoneal injection of angiotensin II (Ang II). Interestingly, the changes in Yes-associated protein (YAP) activity in endothelial cells (ECs) can affect the regulation of angiogenesis by Ang II. The results of in vitro experiments revealed that the regulatory influence of Ang II on ECs was significantly attenuated upon suppression of YAP activity. Furthermore, the function of Ang II in regulating angiogenesis during fibrosis was investigated in liver-specific transgenic mice. The results revealed that Ang II gene deletion could restrain liver fibrosis and EndMT. Meanwhile, Ang II deletion downregulated the profibrotic YAP signaling pathway in ECs. The small molecule AT1R agonist olmesartan targeting Ang II-YAP signaling could also alleviate liver fibrosis. In conclusion, this study identified Ang II as a pivotal regulator of EndMT during the progression of liver fibrosis and evaluated the therapeutic effect of the Ang II-targeted drug olmesartan on liver fibrosis.

Halogenated bisphenol A derivatives potently inhibit human and rat 11β-hydroxysteroid dehydrogenase 1: Structure-activity relationship and molecular docking

Chlorinated bisphenol A (BPA) derivatives are formed during chlorination process of drinking water, whereas bisphenol S (BPS) and brominated BPA and BPS (TBBPA and TBBPS) were synthesized for many industrial uses such as fire retardants. However, the effect of halogenated BPA and BPS derivatives on glucocorticoid metabolizing enzyme 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) remains unclear. The inhibitory effects of 6 BPA derivatives in the inhibition of human and rat 11β-HSD1 were investigated. The potencies for inhibition on human 11β-HSD1 were TBBPA (IC50, 3.87 μM) = monochloro BPA (MCBPA, 4.08 μM) = trichloro BPA (TrCBPA, 4.41 μM) > tetrachloro BPA (TCBPA, 9.75 μM) > TBBPS (>100 μM) = BPS (>100 μM), and those for rat 11β-HSD1 were TrCBPA (IC50, 2.76 μM) = MCBPA (3.75 μM) > TBBPA (39.58 μM) > TCBPA = TBBPS = BPS. All these BPA derivatives are mixed/competitive inhibitors of both human and rat enzymes. Molecular docking studies predict that MCBPA, TrCBPA, TCBPA, and TBBPA all bind to the active site of human 11β-HSD1, forming hydrogen bonds with catalytic residue Ser170 except TCBPA. Regression of the lowest binding energy with IC50 values revealed a significant inverse linear regression. In conclusion, halogenated BPA derivatives are mostly potent inhibitors of human and rat 11β-HSD1, and there is structure-dependent inhibition.

Distinct inhibitory strength of bisphenol A analogues on human and rat 11β-hydroxysteroid dehydrogenase 1: 3D quantitative structure-activity relationship and in silico molecular docking analysis

Bisphenol A (BPA) analogues are developed to replace BPA usage. However, their effects on 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) are largely unknown. The inhibitory effects of BPA and 10 BPA analogues with the substituents on the bridge moiety on human and rat 11β-HSD1 were explored in human and rat liver microsomes. The strength of inhibiting human 11β-HSD1 was bisphenol FL (IC50, 3.87 μM) > bisphenol Z (6.86 μM) > bisphenol AF (9.42 μM) > bisphenol C (16.14 μM) > bisphenol AP (32.14 μM) = bisphenol B (32.34 μM) > 4,4'-thiodiphenol (67.35 μM) > BPA (297.35 μM) > other BPA analogues (ineffective at 100 μM). The strength of inhibiting rat 11β-HSD1 was bisphenol Z (IC50, 14.44 μM) > 4,4'-thiodiphenol (19.01 μM) > bisphenol B (20.13 μM) > bisphenol F (22.10 μM) > bisphenol E (33.04 μM) > bisphenol AF (49.67 μM) > bisphenol C > (56.97 μM) > bisphenol AP (62.71 μM) >bisphenol FL (96.31 μM) > other BPA analogues (ineffective at 100 μM). Bisphenol A, AF, AP, B, C, F, FL, Z, and 4,4'-thiodiphenol bind to the active sites of human and rat 11β-HSD1. Regression of LogP and molecular weight with IC50 values revealed distinct inhibitory pattern (negative correlation for human 11β-HSD1 vs. positive correlation for rat enzyme). Regression of the lowest binding energy with IC50 values revealed a significant positive regression. 3D QSAR pharmacophore analysis showed one hydrogen bond acceptor and two hydrogen bond donors for human 11β-HSD1. In conclusion, most BPA analogues are more potent inhibitors of human and rat 11β-HSD1 enzymes and there is structure-dependent and species-dependent inhibition.

Contribution of local regeneration of glucocorticoids to tissue steroid pools

11β-Hydroxysteroid dehydrogenase 1 (11βHSD1) is a drug target to attenuate adverse effects of chronic glucocorticoid excess. It catalyses intracellular regeneration of active glucocorticoids in tissues including brain, liver and adipose tissue (coupled to hexose-6-phosphate dehydrogenase, H6PDH). 11βHSD1 activity in individual tissues is thought to contribute significantly to glucocorticoid levels at those sites, but its local contribution vs glucocorticoid delivery via the circulation is unknown. Here, we hypothesised that hepatic 11βHSD1 would contribute significantly to the circulating pool. This was studied in mice with Cre-mediated disruption of Hsd11b1 in liver (Alac-Cre) vs adipose tissue (aP2-Cre) or whole-body disruption of H6pdh. Regeneration of [9,12,12-2H3]-cortisol (d3F) from [9,12,12-2H3]-cortisone (d3E), measuring 11βHSD1 reductase activity was assessed at steady state following infusion of [9,11,12,12-2H4]-cortisol (d4F) in male mice. Concentrations of steroids in plasma and amounts in liver, adipose tissue and brain were measured using mass spectrometry interfaced with matrix-assisted laser desorption ionisation or liquid chromatography. Amounts of d3F were higher in liver, compared with brain and adipose tissue. Rates of appearance of d3F were ~6-fold slower in H6pdh-/- mice, showing the importance for whole-body 11βHSD1 reductase activity. Disruption of liver 11βHSD1 reduced the amounts of d3F in liver (by ~36%), without changes elsewhere. In contrast disruption of 11βHSD1 in adipose tissue reduced rates of appearance of circulating d3F (by ~67%) and also reduced regenerated of d3F in liver and brain (both by ~30%). Thus, the contribution of hepatic 11βHSD1 to circulating glucocorticoid levels and amounts in other tissues is less than that of adipose tissue.

Stretch regulates alveologenesis and homeostasis via mesenchymal Gαq/11-mediated TGFβ2 activation

Alveolar development and repair require tight spatiotemporal regulation of numerous signalling pathways that are influenced by chemical and mechanical stimuli. Mesenchymal cells play key roles in numerous developmental processes. Transforming growth factor-β (TGFβ) is essential for alveologenesis and lung repair, and the G protein α subunits Gαq and Gα11 (Gαq/11) transmit mechanical and chemical signals to activate TGFβ in epithelial cells. To understand the role of mesenchymal Gαq/11 in lung development, we generated constitutive (Pdgfrb-Cre+/-;Gnaqfl/fl;Gna11-/-) and inducible (Pdgfrb-Cre/ERT2+/-;Gnaqfl/fl;Gna11-/-) mesenchymal Gαq/11 deleted mice. Mice with constitutive Gαq/11 gene deletion exhibited abnormal alveolar development, with suppressed myofibroblast differentiation, altered mesenchymal cell synthetic function, and reduced lung TGFβ2 deposition, as well as kidney abnormalities. Tamoxifen-induced mesenchymal Gαq/11 gene deletion in adult mice resulted in emphysema associated with reduced TGFβ2 and elastin deposition. Cyclical mechanical stretch-induced TGFβ activation required Gαq/11 signalling and serine protease activity, but was independent of integrins, suggesting an isoform-specific role for TGFβ2 in this model. These data highlight a previously undescribed mechanism of cyclical stretch-induced Gαq/11-dependent TGFβ2 signalling in mesenchymal cells, which is imperative for normal alveologenesis and maintenance of lung homeostasis.

Glucocorticoid activation by HSD11B1 limits T cell-driven interferon signaling and response to PD-1 blockade in melanoma

BACKGROUND

Immune responses against tumors are subject to negative feedback regulation. Immune checkpoint inhibitors (ICIs) blocking Programmed cell death protein 1 (PD-1), a receptor expressed on T cells, or its ligand PD-L1 have significantly improved the treatment of cancer, in particular malignant melanoma. Nevertheless, responses and durability are variables, suggesting that additional critical negative feedback mechanisms exist and need to be targeted to improve therapeutic efficacy.

METHODS

We used different syngeneic melanoma mouse models and performed PD-1 blockade to identify novel mechanisms of negative immune regulation. Genetic gain-of-function and loss-of-function approaches as well as small molecule inhibitor applications were used for target validation in our melanoma models. We analyzed mouse melanoma tissues from treated and untreated mice by RNA-seq, immunofluorescence and flow cytometry to detect changes in pathway activities and immune cell composition of the tumor microenvironment. We analyzed tissue sections of patients with melanoma by immunohistochemistry as well as publicly available single-cell RNA-seq data and correlated target expression with clinical responses to ICIs.

RESULTS

Here, we identified 11-beta-hydroxysteroid dehydrogenase-1 (HSD11B1), an enzyme that converts inert glucocorticoids into active forms in tissues, as negative feedback mechanism in response to T cell immunotherapies. Glucocorticoids are potent suppressors of immune responses. HSD11B1 was expressed in different cellular compartments of melanomas, most notably myeloid cells but also T cells and melanoma cells. Enforced expression of HSD11B1 in mouse melanomas limited the efficacy of PD-1 blockade, whereas small molecule HSD11B1 inhibitors improved responses in a CD8+ T cell-dependent manner. Mechanistically, HSD11B1 inhibition in combination with PD-1 blockade augmented the production of interferon-γ by T cells. Interferon pathway activation correlated with sensitivity to PD-1 blockade linked to anti-proliferative effects on melanoma cells. Furthermore, high levels of HSD11B1, predominantly expressed by tumor-associated macrophages, were associated with poor responses to ICI therapy in two independent cohorts of patients with advanced melanomas analyzed by different methods (scRNA-seq, immunohistochemistry).

CONCLUSION

As HSD11B1 inhibitors are in the focus of drug development for metabolic diseases, our data suggest a drug repurposing strategy combining HSD11B1 inhibitors with ICIs to improve melanoma immunotherapy. Furthermore, our work also delineated potential caveats emphasizing the need for careful patient stratification.

Diverse effector and regulatory functions of fibro/adipogenic progenitors during skeletal muscle fibrosis in muscular dystrophy

Fibrosis is a prominent pathological feature of skeletal muscle in Duchenne muscular dystrophy (DMD). The commonly used disease mouse model, mdx ^5cv , displays progressive fibrosis in the diaphragm but not limb muscles. We use single-cell RNA sequencing to determine the cellular expression of the genes involved in extracellular matrix (ECM) production and degradation in the mdx ^5cv diaphragm and quadriceps. We find that fibro/adipogenic progenitors (FAPs) are not only the primary source of ECM but also the predominant cells that express important ECM regulatory genes, including Ccn2, Ltbp4, Mmp2, Mmp14, Timp1, Timp2, and Loxs. The effector and regulatory functions are exerted by diverse FAP clusters which are different between diaphragm and quadriceps, indicating their activation by different tissue microenvironments. FAPs are more abundant in diaphragm than in quadriceps. Our findings suggest that the development of anti-fibrotic therapy for DMD should target not only the ECM production but also the pro-fibrogenic regulatory functions of FAPs.

Inhibition of 11β-hydroxysteroid dehydrogenase 1 relieves fibrosis through depolarizing of hepatic stellate cell in NASH

11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) is a key enzyme that catalyzes the intracellular conversion of cortisone to physiologically active cortisol. Although 11βHSD1 has been implicated in numerous metabolic syndromes, such as obesity and diabetes, the functional roles of 11βHSD1 during progression of nonalcoholic steatohepatitis (NASH) and consequent fibrosis have not been fully elucidated. We found that pharmacological and genetic inhibition of 11βHSD1 resulted in reprogramming of hepatic stellate cell (HSC) activation via inhibition of p-SMAD3, α-SMA, Snail, and Col1A1 in a fibrotic environment and in multicellular hepatic spheroids (MCHSs). We also determined that 11βHSD1 contributes to the maintenance of NF-κB signaling through modulation of TNF, TLR7, ITGB3, and TWIST, as well as regulating PPARα signaling and extracellular matrix accumulation in activated HSCs during advanced fibrogenesis in MCHSs. Of great interest, the 11βHSD1 inhibitor J2H-1702 significantly attenuated hepatic lipid accumulation and ameliorated liver fibrosis in diet- and toxicity-induced NASH mouse models. Together, our data indicate that J2H-1702 is a promising new clinical candidate for the treatment of NASH.

mRNA and lncRNA expression profiles of liver tissues in children with biliary atresia

Progressive liver fibrosis is the most common phenotype in biliary atresia (BA). A number of pathways contribute to the fibrosis process so comprehensive understanding the mechanisms of liver fibrosis in BA will pave the way to improve patient's outcome after operation. In this study, the differentially expressed profiles of mRNAs and long non-coding RNAs from BA and choledochal cyst (CC) liver tissues were investigated and analyzed, which may provide potential clues to clarify hepatofibrosis mechanism in BA. A total of two BA and two CC liver tissue specimens were collected, the expression level of mRNAs and lncRNAs was detected by RNA sequencing. Differentially expressed mRNAs (DEmRNAs) were functionally annotated and protein-protein interaction networks (PPI) was established to predict the biological roles and interactive relationships. Differentially expressed lncRNAs (DElncRNAs) nearby targeted DEmRNA network and DElncRNA-DEmRNA co-expression network were constructed to further explore the roles of DElncRNAs in BA pathogenesis. The expression profiles of significant DEmRNAs were validated in Gene Expression Omnibus database. A total of 2,086 DEmRNAs and 184 DElncRNAs between BA and CC liver tissues were obtained. DEmRNAs were enriched in 521 Gene Ontology terms and 71 Kyoto Encyclopedia of Genes and Genomes terms which were mainly biological processes and metabolic pathways related to immune response and inflammatory response. A total of five hub proteins (TYRO protein tyrosine kinase binding protein, C-X-C motif chemokine ligand 8, pleckstrin, Toll-like receptor 8 and C-C motif chemokine receptor 5) were found in the PPI networks. A total of 31 DElncRNA-nearby-targeted DEmRNA pairs and 2,337 DElncRNA-DEmRNA co-expression pairs were obtained. The expression of DEmRNAs obtained from RNA sequencing were verified in GSE46960 dataset, generally. The present study identified key genes and lncRNAs participated in BA associated liver fibrosis, which may present a new avenue for understanding the patho-mechanism for hepatic fibrosis in BA.

Narrative Review: Glucocorticoids in Alcoholic Hepatitis—Benefits, Side Effects, and Mechanisms

Alcoholic hepatitis is a major health and economic burden worldwide. Glucocorticoids (GCs) are the only first-line drugs recommended to treat severe alcoholic hepatitis (sAH), with limited short-term efficacy and significant side effects. In this review, I summarize the major benefits and side effects of GC therapy in sAH and the potential underlying mechanisms. The review of the literature and data mining clearly indicate that the hepatic signaling of glucocorticoid receptor (GR) is markedly impaired in sAH patients. The impaired GR signaling causes hepatic down-regulation of genes essential for gluconeogenesis, lipid catabolism, cytoprotection, and anti-inflammation in sAH patients. The efficacy of GCs in sAH may be compromised by GC resistance and/or GC’s extrahepatic side effects, particularly the side effects of intestinal epithelial GR on gut permeability and inflammation in AH. Prednisolone, a major GC used for sAH, activates both the GR and mineralocorticoid receptor (MR). When GC non-responsiveness occurs in sAH patients, the activation of MR by prednisolone might increase the risk of alcohol abuse, liver fibrosis, and acute kidney injury. To improve the GC therapy of sAH, the effort should be focused on developing the biomarker(s) for GC responsiveness, liver-targeting GR agonists, and strategies to overcome GC non-responsiveness and prevent alcohol relapse in sAH patients.

Update on Non-Alcoholic Fatty Liver Disease-Associated Single Nucleotide Polymorphisms and Their Involvement in Liver Steatosis, Inflammation, and Fibrosis: A Narrative Review

Genetic factors are involved in the development, progression, and severity of NAFLD. Polymorphisms in genes regulating liver functions may increase liver susceptibility to NAFLD. Therefore, we conducted this literature study to present recent findings on NAFLD-associated polymorphisms from published articles in PubMed from 2016 to 2021. From 69 selected research articles, 20 genes and 34 SNPs were reported to be associated with NAFLD. These mutated genes affect NAFLD by promoting liver steatosis (PNPLA3, MBOAT7, TM2SF6, PTPRD, FNDC5, IL-1B, PPARGC1A, UCP2, TCF7L2, SAMM50, IL-6, AGTR1, and NNMT), inflammation (PNPLA3, TNF-α, AGTR1, IL-17A, IL-1B, PTPRD, and GATAD2A), and fibrosis (IL-1B, PNPLA3, MBOAT7, TCF7L2, GATAD2A, IL-6, NNMT, UCP, AGTR1, and TM2SF6). The identification of these genetic factors helps to better understand the pathogenesis pathways of NAFLD

Crosstalk of hepatocyte nuclear factor 4a and glucocorticoid receptor in the regulation of lipid metabolism in mice fed a high-fat-high-sugar diet

Background

Hepatocyte nuclear factor 4α (HNF4α) and glucocorticoid receptor (GR), master regulators of liver metabolism, are down-regulated in fatty liver diseases. The present study aimed to elucidate the role of down-regulation of HNF4α and GR in fatty liver and hyperlipidemia.

Methods

Adult mice with liver-specific heterozygote (HET) and knockout (KO) of HNF4α or GR were fed a high-fat-high-sugar diet (HFHS) for 15 days. Alterations in hepatic and circulating lipids were determined with analytical kits, and changes in hepatic mRNA and protein expression in these mice were quantified by real-time PCR and Western blotting. Serum and hepatic levels of bile acids were quantified by LC-MS/MS. The roles of HNF4α and GR in regulating hepatic gene expression were determined using luciferase reporter assays.

Results

Compared to HFHS-fed wildtype mice, HNF4α HET mice had down-regulation of lipid catabolic genes, induction of lipogenic genes, and increased hepatic and blood levels of lipids, whereas HNF4α KO mice had fatty liver but mild hypolipidemia, down-regulation of lipid-efflux genes, and induction of genes for uptake, synthesis, and storage of lipids. Serum levels of chenodeoxycholic acid and deoxycholic acid tended to be decreased in the HNF4α HET mice but dramatically increased in the HNF4α KO mice, which was associated with marked down-regulation of cytochrome P450 7a1, the rate-limiting enzyme for bile acid synthesis. Hepatic mRNA and protein expression of sterol-regulatory-element-binding protein-1 (SREBP-1), a master lipogenic regulator, was induced in HFHS-fed HNF4α HET mice. In reporter assays, HNF4α cooperated with the corepressor small heterodimer partner to potently inhibit the transactivation of mouse and human SREBP-1C promoter by liver X receptor. Hepatic nuclear GR proteins tended to be decreased in the HNF4α KO mice. HFHS-fed mice with liver-specific KO of GR had increased hepatic lipids and induction of SREBP-1C and PPARγ, which was associated with a marked decrease in hepatic levels of HNF4α proteins in these mice. In reporter assays, GR and HNF4α synergistically/additively induced lipid catabolic genes.

Conclusions

induction of lipid catabolic genes and suppression of lipogenic genes by HNF4α and GR may mediate the early resistance to HFHS-induced fatty liver and hyperlipidemia.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01654-6.

TargetTox: A Feature Selection Pipeline for Identifying Predictive Targets Associated with Drug Toxicity

In silico assessment of drug toxicity is becoming a critical step in drug development. Conventional ligand-based models are limited by low accuracy and lack of interpretability. Further, they often fail to explain cellular mechanisms underlying structure-toxicity associations. We addressed these limitations by incorporating target profile as an intermediate connecting structure to toxicity. To accommodate for high-dimensional feature space, we developed a pipeline named TargetTox that can identity a subset of predictive features. We implemented TargetTox to study 569 targets and 815 adverse events. The features identified by TargetTox comprise less than 10% of the original feature space; nevertheless, they accurately predicted binding outcomes for 377 targets and toxicity outcomes for 36 adverse events. We demonstrated that predictive targets tend to be differentially expressed in the tissue of toxicity. We also rediscovered key cellular functions associated with cardiotoxicity from the predictive targets, as well as markers of skin and liver diseases. Furthermore, we found evidence supporting diagnostic and therapeutic applications of some predictive targets in hepatotoxicity and nephrotoxicity. Our findings highlighted the critical role of predictive targets in cellular mechanisms leading to toxicity. In general, our study improved the interpretability of toxicity prediction without sacrificing accuracy. Our novel pipeline may benefit future studies of high-dimensional data sets.

The Role and Mechanism of Oxidative Stress and Nuclear Receptors in the Development of NAFLD

The overproduction of reactive oxygen species (ROS) and consequent oxidative stress contribute to the pathogenesis of acute and chronic liver diseases. It is now acknowledged that nonalcoholic fatty liver disease (NAFLD) is characterized as a redox-centered disease due to the role of ROS in hepatic metabolism. However, the underlying mechanisms accounting for these alternations are not completely understood. Several nuclear receptors (NRs) are dysregulated in NAFLD, and have a direct influence on the expression of a set of genes relating to the progress of hepatic lipid homeostasis and ROS generation. Meanwhile, the NRs act as redox sensors in response to metabolic stress. Therefore, targeting NRs may represent a promising strategy for improving oxidation damage and treating NAFLD. This review summarizes the link between impaired lipid metabolism and oxidative stress and highlights some NRs involved in regulating oxidant/antioxidant turnover in the context of NAFLD, shedding light on potential therapies based on NR-mediated modulation of ROS generation and lipid accumulation.

Selective Inhibition of 11β-Hydroxysteroid Dehydrogenase Type 1 Attenuates High-Fat Diet-Induced Hepatic Steatosis in Mice

Introduction

The effect of 11β-hydroxysteroid dehydrogenase type1 (11β-HSD1) inhibition on hepatic steatosis is incompletely understood. Here, we aimed to determine the therapeutic effect of BVT.2733, a selective 11β-HSD1 inhibitor, on hepatic steatosis.

Materials and Methods

C57B/6J mice were randomly divided into a low-fat diet (LFD) fed group and a high-fat diet (HFD) fed group. Mice were fed with HFD for 28 weeks which induced obesity and severe hepatic steatosis. The two groups were further divided into four groups as follows: LFD, LFD with BVT.2733, HFD, and HFD with BVT.2733. Mice in LFD+BVT and HFD+BVT groups were intraperitoneally injected with BVT.2733 daily for 30 days. Effects of BVT.2733 on mice body weight, serum lipid profile, serum free fatty acids (FFAs), glucocorticoid levels, gene expression in adipose and liver tissues were assessed.

Results

Injection of a low dose of BVT.2733 (50 mg/kg/day) reduced body weight and hyperlipidemia, but did not improve glucose tolerance and insulin resistance in diet-induced obese mice. The low dose of BVT.2733 attenuated hepatic steatosis, liver injury, and liver lipolytic gene expression in diet-induced obese mice. Besides, the low dose of BVT.2733 reduced fat mass and lipolysis in visceral adipose tissues, hepatic FFAs, and serum corticosterone levels in diet-induced obese mice.

Conclusion

Our study shows that moderate inhibition of 11β-HSD1 by BVT.2733 reduces FFAs and corticosterone synthesis in fatty tissues, thereby attenuates the delivery of corticosterone and FFAs to the liver. Collectively, this prevents high-fat diet-induced hepatic steatosis.

Addressing the role of 11β-hydroxysteroid dehydrogenase type 1 in the development of polycystic ovary syndrome and the putative therapeutic effects of its selective inhibition in a preclinical model

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common metabolic and endocrine disorder among reproductive-age women, and the leading cause of anovulatory infertility. 11β-hydroxysteroid dehydrogenases-1 (11β-HSD1) catalysing the conversion of inactive cortisone to active cortisol plays a crucial role in various metabolic diseases. However, whether 11β-HSD1 is associated with the pathogenesis of PCOS and whether 11β-HSD1 can be a treating target of PCOS remain unknown.

METHODS

This study was first designed to explore the role of 11β-HSD1 in PCOS development and the effect of selective 11β-HSD1 inhibitor administration on PCOS treatment. Follicular fluid and granulosa cells (GCs) were collected from 32 non-PCOS patients and 37 patients with PCOS to measure cortisol and 11β-HSDs levels. Female Sprague-Dawley rats (3-week-old) were injected with dehydroepiandrosterone (DHEA) to induce PCOS and their ovaries were collected to measure the abundance of corticosterone (CORT) and 11β-HSDs. To determine the role of 11β-HSD1 in PCOS development, we overexpressed 11β-HSD1 in the ovaries of female rats (5-week-old) or knocked down the expression of 11β-HSD1 in the ovaries from PCOS rats via lentivirus injection. After lentivirus infection, the body weights, ovarian weights, estrous cycles, reproductive hormones and morphology of the ovary were analysed in rats from different experimental groups. Then to figure out the translational potential of the selective 11β-HSD1 inhibitor in treating PCOS, PCOS rats were treated with BVT.2733, a selective 11β-HSD1 inhibitor and a cluster of PCOS-like traits were analysed, including insulin sensitivity, ovulatory function and fertility of rats from the Control, PCOS and PCOS+BVT groups. Rat ovarian explants and human GCs were used to explore the effect of CORT or cortisol on ovarian extracellular matrix remodelling.

RESULTS

The elevated expression of 11β-HSD1 contributed to the increased cortisol and corticosterone (CORT) concentrations observed in the ovaries of PCOS patients and PCOS rats respectively. Our results showed that ovarian overexpression of 11β-HSD1 induced a cluster of PCOS phenotypes in rats including irregular estrous cycles, reproductive hormone dysfunction and polycystic ovaries. While knockdown of ovarian 11β-HSD1 of PCOS rats reversed these PCOS-like changes. Additionally, the selective 11β-HSD1 inhibitor BVT.2733 alleviated PCOS symptoms such as insulin resistance (IR), irregular estrous cycles, reproductive hormone dysfunction, polycystic ovaries, ovulatory dysfunction and subfertility. Moreover, we showed that cortisol target ovarian insulin signalling pathway and ovarian extracellular matrix (ECM) remodelling in vivo, in ovarian explants and in GCs.

CONCLUSION

Elevated 11β-HSD1 abundance in ovarian is involved in the pathogenesis of PCOS by impairing insulin signalling pathway and ECM remodelling. Selective inhibition of 11β-HSD1 ameliorates a cluster of PCOS phenotypes. Our study demonstrates the selective 11β-HSD1 inhibitor as a novel and promising strategy for the treatment of PCOS.

11β‑hydroxysteroid dehydrogenase‑1 is associated with the activation of hepatic stellate cells in the development of hepatic fibrosis

Hepatic fibrosis (HF) is a common complication of numerous chronic liver diseases, but predominantly results from persistent liver inflammation or injury. If left untreated, HF can progress and develop into liver cirrhosis and even hepatocellular carcinoma. However, the underlying molecular mechanisms of HF remain unknown. The present study aimed to investigate the role of 11β-hydroxysteroid dehydrogenase-1 (11β-HSD1) during the development of hepatic fibrosis. An experimental rat model of liver fibrosis was induced using porcine serum. 11β-HSD1 gene expression levels and enzyme activity during hepatic fibrogenesis were assessed. 11β-HSD1 gene knockdown using small interfering RNA and overexpression were performed in LX2-human hepatic stellate cells (HSCs). HSCs were stimulated with transforming growth factor-β1 (TGF-β1). Cell cycle distribution, proliferation, collagen secretion and 11β-HSD1 gene activity in HSCs were compared before and after stimulation. As hepatic fibrosis progressed, 11β-HSD1 gene expression and activity increased, indicating a positive correlation with typical markers of liver fibrosis. 11β-HSD1 inhibition markedly reduced the degree of fibrosis. The cell proliferation was increased, the number of cells in the G₀/G₁ phase decreased and the number of cells in the S and G₂/M phases increased in the pSuper transfected group compared with the N group. In addition, the overexpression of 11β-HSD1 enhanced the TGF-β1-induced activation of LX2-HSCs and enzyme activity of connective tissue growth factor. 11β-HSD1 knockdown suppressed cell proliferation by blocking the G₀/G₁ phase of the cell cycle, which was associated with HSC stimulation and inhibition of 11β-HSD1 enzyme activity. In conclusion, increased 11β-HSD1 expression in the liver may be partially responsible for hepatic fibrogenesis, which is potentially associated with HSC activation and proliferation.

Epigenetic silencing of LncRNA ANRIL enhances liver fibrosis and HSC activation through activating AMPK pathway

Long non‐coding RNAs (LncRNAs) and DNA methylation are important epigenetic mark play a key role in liver fibrosis. Currently, how DNA methylation and LncRNAs control the hepatic stellate cell (HSC) activation and fibrosis has not yet been fully characterized. Here, we explored the role of antisense non‐coding RNA in the INK4 locus (ANRIL) and DNA methylation in HSC activation and fibrosis. The expression levels of DNA methyltransferases 3A (DNMT3A), ANRIL, α‐Smooth muscle actin (α‐SMA), Type I collagen (Col1A1), adenosine monophosphate‐activated protein kinase (AMPK) and p‐AMPK in rat and human liver fibrosis were detected by immunohistochemistry, qRT‐PCR and Western blotting. Liver tissue histomorphology was examined by haematoxylin and eosin (H&E), Sirius red and Masson staining. HSC was transfected with DNMT3A‐siRNA, over‐expressing ANRIL and down‐regulating ANRIL. Moreover, cell proliferation ability was examined by CCK‐8, MTT and cell cycle assay. Here, our study demonstrated that ANRIL was significantly decreased in activated HSC and liver fibrosis tissues, while Col1A1, α‐SMA and DNMT3A were significantly increased in activated HSC and liver fibrosis tissues. Further, we found that down‐regulating DNMT3A expression leads to inhibition of HSC activation. Reduction in DNMT3A elevated ANRIL expression in activated HSC. Furthermore, we performed the over expression ANRIL suppresses HSC activation and AMPK signalling pathways. In sum, our study found that epigenetic DNMT3A silencing of ANRIL enhances liver fibrosis and HSC activation through activating AMPK pathway. Targeting epigenetic modulators DNMT3A and ANRIL, and offer a novel approach for liver fibrosis therapy.

Camellia oil (Camellia oleifera Abel.) attenuates CCl4-induced liver fibrosis via suppressing hepatocyte apoptosis in mice

Liver fibrosis is a common part of the pathological development of many chronic liver diseases.

Betulinic acid attenuates liver fibrosis by inducing autophagy via the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway

The present study was designed to investigate the effects of betulinic acid on human hepatic stellate cells in vitro and C57BL/6 mice in vivo, as well as the signaling pathways involved. In this study, we explored the effects of betulinic acid on expression of alpha smooth muscle actin and autophagy-related proteins. Betulinic acid reduced pathological damage associated with liver fibrosis, as well as serum platelet-derived growth factor and serum hydroxyproline levels. Furthermore, betulinic acid downregulated the expression of alpha smooth muscle actin and type I collagen in mouse liver and upregulated the expression of microtubule-associated protein light chain 3B and autophagy-related gene 7 at the gene and protein levels. LC3II expression was increased and alpha smooth muscle actin expression was decreased in betulinic acid-treated hepatic stellate cells. Interventions with bafilomycin A1 and mCherry-GFP-LC3 adenoviruses promoted the formation of autophagosomes in hepatic stellate cells and the development of autophagic flow. Our study found that mitogen-activated protein kinase/extracellular signal-regulated kinase may be involved in the effects of betulinic acid on liver fibrosis. The present study suggests that betulinic acid has anti-hepatic fibrosis activity by inducing autophagy and could serve as a promising new agent for treating hepatic fibrosis.