Salvianolic acid B-induced microRNA-152 inhibits liver fibrosis by attenuating DNMT1-mediated Patched1 methylation

Progress in clinical and basic research of fuzheng Huayu formula for the treatment of liver fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine has great potential and advantages in the treatment of liver fibrosis, with Fuzheng Huayu formula (FZHY) serving as a prime example due to its remarkable efficacy in delaying and reversing liver fibrosis while simultaneously improving clinical symptoms for patients.

AIM OF THE REVIEW

In this paper, we present a comprehensive review of recent studies on the therapeutic potential of FZHY and its components/ingredients in the treatment of liver fibrosis and cirrhosis, with the aim of providing insights for future research endeavors.

MATERIALS AND METHODS

A comprehensive literature search was conducted on FZHY, TCM319, traditional Chinese medicine 319, liver fibrosis and cirrhosis using multiple internationally recognized databases including PubMed, Embase, Springer, Web of science, SciVerse ScienceDirect, Clinical Trails. Gov, CNKI, Wanfang, and VIP.

RESULTS

FZHY is widely used clinically for liver fibrosis and cirrhosis caused by various chronic liver diseases, with the effects of improving serum liver function, liver pathological histology, serological indices related to liver fibrosis, decreasing liver stiffness values and portal hypertension, as well as reducing the incidence of hepatocellular carcinoma and morbidity/mortality in patients with cirrhosis. Numerous in vivo and in vitro experiments have demonstrated that FZHY possesses anti-fibrotic effects by inhibiting hepatic stellate cell activation, reducing inflammation, protecting hepatocytes, inhibiting hepatic sinusoidal capillarization and angiogenesis, promoting extracellular matrix degradation, and facilitating liver regeneration. In recent years, there has been a growing focus on investigating the primary active components/ingredients of FZHY, and significant strides have been made in comprehending their synergistic mechanisms that enhance efficacy.

CONCLUSION

FZHY is a safe and effective drug for treating liver fibrosis. Future research on FZHY should focus on its active components/ingredients and their synergistic effects, as well as the development of modern cocktail drugs based on its components/ingredients. This will facilitate a more comprehensive understanding of the molecular mechanisms and targets of FZHY in treating liver fibrosis, thereby further guide clinical applications and drug development.

Differential DNA methylation landscape of miRNAs genes in mice liver fibrosis

BACKGROUND

Patients with chronic liver disease were found nearly all to have liver fibrosis, which is characterized by excess accumulation of extracellular matrix (ECM) proteins. While ECM accumulation can prevent liver infection and injury, it can destroy normal liver function and architecture. miRNA's own regulation was involved in DNA methylation change. The purpose of this study is to detect DNA methylation landscape of miRNAs genes in mice liver fibrosis tissues.

METHODS

Male mice (10-12 weeks) were injected CCl4 from abdominal cavity to induced liver fibrosis. 850 K BeadChips were used to examine DNA methylation change in whole genome. The methylation change of 16 CpG dinucleotides located in promoter regions of 4 miRNA genes were detected by bisulfite sequencing polymerase chain reaction (BSP) to verify chip data accuracy, and these 4 miRNA genes' expressions were detected by RT-qPCR methods.

RESULTS

There are 769 differential methylation sites (DMS) in total between fibrotic liver tissue and normal mice liver tissue, which were related with 148 different miRNA genes. Chips array data were confirmed by bisulfite sequencing polymerase chain reaction (R = 0.953; P < 0.01). GO analysis of the target genes of 2 miRNA revealed that protein binding, cytoplasm and chromatin binding activity were commonly enriched; KEGG pathway enrichment analysis displayed that TGF-beta signaling pathway was commonly enriched.

CONCLUSION

The DNA of 148 miRNA genes was found to have methylation change in liver fibrosis tissue. These discoveries in miRNA genes are beneficial to future miRNA function research in liver fibrosis.

Epigenetic modification in liver fibrosis: Promising therapeutic direction with significant challenges ahead

Liver fibrosis, characterized by scar tissue formation, can ultimately result in liver failure. It's a major cause of morbidity and mortality globally, often associated with chronic liver diseases like hepatitis or alcoholic and non-alcoholic fatty liver diseases. However, current treatment options are limited, highlighting the urgent need for the development of new therapies. As a reversible regulatory mechanism, epigenetic modification is implicated in many biological processes, including liver fibrosis. Exploring the epigenetic mechanisms involved in liver fibrosis could provide valuable insights into developing new treatments for chronic liver diseases, although the current evidence is still controversial. This review provides a comprehensive summary of the regulatory mechanisms and critical targets of epigenetic modifications, including DNA methylation, histone modification, and RNA modification, in liver fibrotic diseases. The potential cooperation of different epigenetic modifications in promoting fibrogenesis was also highlighted. Finally, available agonists or inhibitors regulating these epigenetic mechanisms and their potential application in preventing liver fibrosis were discussed. In summary, elucidating specific druggable epigenetic targets and developing more selective and specific candidate medicines may represent a promising approach with bright prospects for the treatment of chronic liver diseases.

Epigenetic Regulation of EMP/EMT-Dependent Fibrosis

Fibrosis represents a process characterized by excessive deposition of extracellular matrix (ECM) proteins. It often represents the evolution of pathological conditions, causes organ failure, and can, in extreme cases, compromise the functionality of organs to the point of causing death. In recent years, considerable efforts have been made to understand the molecular mechanisms underlying fibrotic evolution and to identify possible therapeutic strategies. Great interest has been aroused by the discovery of a molecular association between epithelial to mesenchymal plasticity (EMP), in particular epithelial to mesenchymal transition (EMT), and fibrogenesis, which has led to the identification of complex molecular mechanisms closely interconnected with each other, which could explain EMT-dependent fibrosis. However, the result remains unsatisfactory from a therapeutic point of view. In recent years, advances in epigenetics, based on chromatin remodeling through various histone modifications or through the intervention of non-coding RNAs (ncRNAs), have provided more information on the fibrotic process, and this could represent a promising path forward for the identification of innovative therapeutic strategies for organ fibrosis. In this review, we summarize current research on epigenetic mechanisms involved in organ fibrosis, with a focus on epigenetic regulation of EMP/EMT-dependent fibrosis.

Salvianolic Acid B Alleviates High Glucose-Induced Vascular Smooth Muscle Cell Inflammation by Upregulating the miR-486a-5p Expression

The macrovascular complications of diabetes cause high mortality and disability in patients with type 2 diabetes mellitus (T2DM). The inflammatory response of vascular smooth muscle cell (VSMC) runs through its pathophysiological process. Salvianolic acid B (Sal B) exhibits beneficial effects on the cardiovascular system. However, its role and mechanism in diabetic vascular inflammatory response remain unclear. In this study, we found that Sal B reduced vascular inflammation in diabetic mice and high glucose- (HG-) induced VSMC inflammation. Subsequently, we found that Sal B reduced HG-induced VSMC inflammation by downregulating FOXO1. Furthermore, miR-486a-5p expression was obviously reduced in HG-treated VSMC. Sal B attenuated HG-induced VSMC inflammation by upregulating miR-486a-5p. Loss- and gain-of-function experiments had proven that the transfection of the miR-486a-5p mimic inhibited HG-induced VSMC inflammation whereas that of the miR-486a-5p inhibitor promoted HG-induced VSMC inflammation, thereby leading to the amelioration of vascular inflammation in the diabetic mice. Furthermore, studies had shown that miR-486a-5p inhibited FOXO1 expression by directly targeting its 3'-UTR. In conclusion, Sal B alleviates the inflammatory response of VSMC by upregulating miR-486a-5p and aggravating its inhibition of FOXO1 expression. Sal B exerts a significant anti-inflammatory effect in HG-induced VSMC inflammation by modulating the miR-486a-5p/FOXO1 axis.

Research Progress Regarding the Effect and Mechanism of Dietary Polyphenols in Liver Fibrosis

The development of liver fibrosis is a result of chronic liver injuries may progress to liver cirrhosis and liver cancer. In recent years, liver fibrosis has become a major global problem, and the incidence rate and mortality are increasing year by year. However, there are currently no approved treatments. Research on anti-liver-fibrosis drugs is a top priority. Dietary polyphenols, such as plant secondary metabolites, have remarkable abilities to reduce lipid metabolism, insulin resistance and inflammation, and are attracting more and more attention as potential drugs for the treatment of liver diseases. Gradually, dietary polyphenols are becoming the focus for providing an improvement in the treatment of liver fibrosis. The impact of dietary polyphenols on the composition of intestinal microbiota and the subsequent production of intestinal microbial metabolites has been observed to indirectly modulate signaling pathways in the liver, thereby exerting regulatory effects on liver disease. In conclusion, there is evidence that dietary polyphenols can be therapeutically useful in preventing and treating liver fibrosis, and we highlight new perspectives and key questions for future drug development.

Molecular pathogenesis of subretinal fibrosis in neovascular AMD focusing on epithelial-mesenchymal transformation of retinal pigment epithelium

Age-related macular degeneration (AMD) is a leading cause of vision loss among elderly people in developed countries. Neovascular AMD (nAMD) accounts for more than 90% of AMD-related vision loss. At present, intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) is widely used as the first-line therapy to decrease the choroidal and retinal neovascularizations, and thus to improve or maintain the visual acuity of the patients with nAMD. However, about 1/3 patients still progress to irreversible visual impairment due to subretinal fibrosis even with adequate anti-VEGF treatment. Extensive literatures support the critical role of epithelial-mesenchymal transformation (EMT) of retinal pigment epithelium (RPE) in the pathogenesis of subretinal fibrosis in nAMD, but the underlying mechanisms still remain largely unknown. This review summarized the molecular pathogenesis of subretinal fibrosis in nAMD, especially focusing on the transforming growth factor-β (TGF-β)-induced EMT pathways. It was also discussed how these pathways crosstalk and respond to signals from the microenvironment to mediate EMT and contribute to the progression of nAMD-related subretinal fibrosis. Targeting EMT signaling pathways might provide a promising and effective therapeutic strategy to treat subretinal fibrosis secondary to nAMD.

Salvianolic acid B inhibits hepatic stellate cell activation and liver fibrosis by targeting PDGFRβ

Liver fibrosis is a reversible pathological process and a wound healing response to liver injury. As an early stage of various liver diseases, liver fibrosis can develop into cirrhosis, liver failure, and even liver cancer if not controlled in time. Salvia miltiorrhiza is a medicinal plant with hepatoprotective effects. Salvianolic acid B (Sal B) is the representative component of S. miltiorrhiza. Many studies have reported the anti-liver fibrosis effects and mechanisms of Sal B. However, the direct anti-fibrotic targets of Sal B have not yet been reported. Platelet-derived growth factor receptor β (PDGFRβ) is one of the most classical targets in liver fibrosis, which is closely related to hepatic stellate cells (HSCs) activated. Previously, we established and applied a PDGFRβ affinity chromatography model, and found that Sal B binds well to PDGFRβ. Therefore, this study aimed to investigate the direct targets of Sal B against liver fibrosis. We confirmed the binding ability of Sal B to PDGFRβ by molecular docking and a surface plasmon resonance biosensor. Our findings indicated that Sal B targeted PDGFRβ to inhibit the activation, migration and proliferation of HSCs and suppressed the PDGF-BB-induced PDGFRβ signaling pathway. Annexin V-FITC/PI assay showed that Sal B reversed the PDGF-BB-induced decrease in HSC apoptosis rate. In the mouse liver fibrosis model, Sal B inhibited the PDGFRβ signaling pathway, HSC activation and reduced inflammatory response, ultimately improved CCl4-induced liver fibrosis. In summary, the direct anti-fibrotic targets of Sal B may be PDGFRβ, and this study clarified the anti-liver fibrosis effects and mechanism of Sal B.

Salvianolic acid B suppresses hepatic stellate cell activation and liver fibrosis by inhibiting the NF-κB signaling pathway via miR-6499-3p/LncRNA-ROR

BACKGROUND

Long non-coding RNA (LncRNAs) have been reported to play an important role in liver fibrosis and are closely associated with hepatic stellate cell (HSC) activation. We previously found that salvianolic acid B (Sal B) improves liver fibrosis by regulating the NF-κB signaling pathway. However, whether the LncRNA, regulator of reprogramming (LncRNA-ROR) plays a role in Sal B-mediated anti-fibrosis effects via the NF-κB signaling pathway remain unclear.

PURPOSE

This study aimed to evaluate the effects of Sal B on HSC activation and liver fibrosis and investigate its mechanism from the perspective of LncRNA-ROR-mediated NF-κB signaling pathways.

METHODS

LX-2 and T6 cell lines were cultured. Animal models of liver fibrosis were established using CCl4 in male BALB/c mice. Primary HSCs were isolated from mice and cultured. Serum biochemical and liver histological analyses were performed to evaluate the effects of Sal B on liver fibrosis. The index of HSC activation and the expression of LncRNA-ROR, microRNAs (miRNAs), and inflammatory factors were determined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) or immunofluorescence staining. Cell proliferation was measured by a Cell Counting Kit-8 (CCK-8). NF-κB signaling-associated protein levels were assessed using western blotting or immunofluorescence staining. A luciferase reporter assay was used to detect transcription activity.

RESULTS

In this study, a lower level of LncRNA-ROR was found during Sal B attenuating HSC activation in HSCs. Mechanistically, Sal B impeded the NF-κB signaling pathway to inhibit HSC proliferation and activation by downregulating LncRNA-ROR. Additionally, Sal B upregulated miR-6499-3p to target LncRNA-ROR for degradation. Functionally, Sal B treatment ameliorated CCl4-induced liver fibrosis in mice by inhibiting HSC activation.

CONCLUSION

Sal B suppresses HSC activation and liver fibrosis via regulation of miR-6499-3p/LncRNA-ROR-mediated NF-κB signaling pathway. These results reveal a new molecular mechanism of Sal B on liver fibrosis from the insight of LncRNAs.

Salvia miltiorrhiza in cancer: Potential role in regulating MicroRNAs and epigenetic enzymes

MicroRNAs are small non-coding RNAs that play important roles in gene regulation by influencing the translation and longevity of various target mRNAs and the expression of various target genes as well as by modifying histones and DNA methylation of promoter sites. Consequently, when dysregulated, microRNAs are involved in the development and progression of a variety of diseases, including cancer, by affecting cell growth, proliferation, differentiation, migration, and apoptosis. Preparations from the dried root and rhizome of Salvia miltiorrhiza Bge (Lamiaceae), also known as red sage or danshen, are widely used for treating cardiovascular diseases. Accumulating data suggest that certain bioactive constituents of this plant, particularly tanshinones, have broad antitumor effects by interfering with microRNAs and epigenetic enzymes. This paper reviews the evidence for the antineoplastic activities of S. miltiorrhiza constituents by causing or promoting cell cycle arrest, apoptosis, autophagy, epithelial-mesenchymal transition, angiogenesis, and epigenetic changes to provide an outlook on their future roles in the treatment of cancer, both alone and in combination with other modalities.

Progress in the treatment of drug-induced liver injury with natural products

There are numerous prescription drugs and non-prescription drugs that cause drug-induced liver injury (DILI), which is the main cause of liver disease in humans around the globe. Its mechanism becomes clearer as the disease is studied further. For an instance, when acetaminophen (APAP) is taken in excess, it produces N-acetyl-p-benzoquinone imine (NAPQI) that binds to biomacromolecules in the liver causing liver injury. Treatment of DILI with traditional Chinese medicine (TCM) has shown to be effective. For example, activation of the Nrf2 signaling pathway as well as regulation of glutathione (GSH) synthesis, coupling, and excretion are the mechanisms by which ginsenoside Rg1 (Rg1) treats APAP-induced acute liver injury. Nevertheless, reducing the toxicity of TCM in treating DILI is still a problem to be overcome at present and in the future. Accumulated evidences show that hydrogel-based nanocomposite may be an excellent carrier for TCM. Therefore, we reviewed TCM with potential anti-DILI, focusing on the signaling pathway of these drugs' anti-DILI effect, as well as the possibility and prospect of treating DILI by TCM based on hydrogel materials in the future. In conclusion, this review provides new insights to further explore TCM in the treatment of DILI.

Nano-delivery of salvianolic acid B induces the quiescence of tumor-associated fibroblasts via interfering with TGF-β1/Smad signaling to facilitate chemo- and immunotherapy in desmoplastic tumor

As the key stromal cells that mediate the desmoplastic reaction, tumor-associated fibroblasts (TAFs) play a critical role in the limited nanoparticle penetration and suppressive immune tumor microenvironment. Herein, we found that salvianolic acid B-loaded PEGylated liposomes (PEG-SAB-Lip) can interfere with the activation of TAFs by inhibiting the secretion of TGF-β1. After inhibiting the activation of TAFs, collagen deposition in tumors was reduced, and the penetration of nanoparticles in tumors was enhanced. The results of RT-qPCR and immunofluorescence staining showed the high expression of Th1 cytokines and chemokines (CXCL9 and CXCL10) and the recruitment of CD4⁺, CD8⁺ T cells, and M1 macrophages in the tumor area. At the same time, the low expression of Th2 cytokine and chemokine CXCL13, as well as the decrease of MDSCs, Tregs, and M2 macrophages were also observed in the tumor area. These results were related to the inactivation of TAFs. The combined treatment of PEG-SAB-Lip and docetaxel-loaded PEG-modified liposomes (PEG-DTX-Lip) can significantly inhibit tumor growth. Moreover, PEG-SAB-Lip further inhibited tumor metastasis to the lung. Therefore, our results showed that PEG-SAB-Lip can remodel the tumor microenvironment and improve the efficacy of nanoparticles.

Limonin relieves TGF-β-induced hepatocyte EMT and hepatic stellate cell activation in vitro and CCl4-induced liver fibrosis in mice via upregulating Smad7 and subsequent suppression of TGF-β/Smad cascade

Liver fibrosis is a pathological process as a result of intrahepatic deposition of excessive extracellular matrix. Epithelial-mesenchymal transition (EMT) of hepatocytes and activation of hepatic stellate cells (HSCs) both play important roles in the etiology of liver fibrosis. Here, we found that limonin repressed transforming growth factor-β1 (TGF-β)-induced EMT in AML-12 hepatocytes and activation of LX-2 HSCs. In both kinds of cells, limonin suppressed TGF-β-provoked Smad2/3 C-terminal phosphorylation and subsequent nuclear translocation. Transcription of Smad2/3-downstream genes was in turn reduced. However, limonin exerted few effects on Smad2/3 phosphorylation at linker region. Mechanistically, limonin increased Smad7 at mRNA level in both AML-12 and LX-2 cells. Knockdown of Smad7 abrogated inhibitory effects of limonin on TGF-β-induced EMT in AML-12 cells and activation of LX-2 cells. Further studies revealed that limonin alleviated mouse liver fibrosis induced by CCl₄. In livers of model mice, limonin upregulated Smad7 and declined C-terminal phosphorylation and nuclear translocation of Smad2/3. Transcription of Smad2/3-responsive genes was also attenuated. Our findings indicated that limonin inhibits TGF-β-induced EMT of hepatocytes and activation of HSCs in vitro and CCl₄-induced liver fibrosis in mice. Upregulated Smad7 which suppresses Smad2/3-dependent gene transcription is implicated in the hepatoprotective activity of limonin.

Epithelial-mesenchymal transition in organ fibrosis development: current understanding and treatment strategies

Organ fibrosis is a process in which cellular homeostasis is disrupted and extracellular matrix is excessively deposited. Fibrosis can lead to vital organ failure and there are no effective treatments yet. Although epithelial–mesenchymal transition (EMT) may be one of the key cellular mechanisms, the underlying mechanisms of fibrosis remain largely unknown. EMT is a cell phenotypic process in which epithelial cells lose their cell-to-cell adhesion and polarization, after which they acquire mesenchymal features such as infiltration and migration ability. Upon injurious stimulation in different organs, EMT can be triggered by multiple signaling pathways and is also regulated by epigenetic mechanisms. This narrative review summarizes the current understanding of the underlying mechanisms of EMT in fibrogenesis and discusses potential strategies for attenuating EMT to prevent and/or inhibit fibrosis. Despite better understanding the role of EMT in fibrosis development, targeting EMT and beyond in developing therapeutics to tackle fibrosis is challenging but likely feasible.

Salvianolic acid B inhibits the progression of liver fibrosis in rats via modulation of the Hedgehog signaling pathway

Salvianolic acid B (Sal B) has previously reported anti-hepatic fibrosis effects, though it is not clear if it can inhibit hepatic fibrosis by regulating the hedgehog (Hh) signaling pathway. The aim of the present study was to explore the roles and mechanism of Sal B in preventing and treating liver fibrosis in rats. The study also aimed to determine the role of the Hh signaling pathway in this process. A rat model of liver fibrosis was induced through the subcutaneous injection of 50% carbon tetrachloride, followed by treatment with Sal B. After gavage, blood was collected to detect serum markers of liver injury. The degree of liver fibrosis and tissue damage was assessed using histopathological analysis. Western blotting and reverse transcription-quantitative PCR were used to detect the expression levels of TGF-β1 and Hh signaling pathway-related genes, including Sonic hedgehog (Shh) protein, membrane protein receptor protein patched homolog 1 (Ptch1), membrane protein receptor Smoothened (Smo) and transcription factor glioma-associated oncogene homolog 1 (Gli1). Serum alanine aminotransferase, aspartate aminotransferase and total bilirubin levels were decreased, whilst levels of albumin were increased in rats with liver fibrosis that were treated with Sal B (P<0.05). Additionally, significant increases in TGF-β1, Shh, Ptch1, Smo, Gli1 and α-smooth muscle actin expression levels were observed in the liver tissues of rats with hepatic fibrosis (P<0.05). However, Sal B treatment significantly reduced the expression levels of these proteins (P<0.05). In conclusion, the results of the present study suggested that the Hh signaling pathway may be activated during the process of rat liver fibrosis. Thus, Sal B may exert its anti-hepatic fibrosis effects, at least in part, by inhibiting the activation of the Hh signaling pathway.

DNMT1-Induced miR-152-3p Suppression Facilitates Cardiac Fibroblast Activation in Cardiac Fibrosis

Novel insights into epigenetic control of cardiac fibrosis are now emerging. Cardiac fibroblasts (CFs) activation into myofibroblasts and the production of extracellular matrix (ECM) is the key to cardiac fibrosis development, but the specific mechanism is not fully understood. In the present study, we found that DNMT1 hypermethylation reduces the expression of microRNA-152-3p (miR-152-3p) and promotes Wnt1/β-catenin signaling pathway leading to CFs proliferation and activation. Cardiac fibrosis was produced by ISO, and the ISO was carried out according to the method described. CFs were harvested and cultured from SD neonatal rats and stimulated with TGF-β1. Importantly, DNMT1 resulted in the inhibition of miR-152-3p in activated CFs and both DNMT1 and miR-152-3p altered Wnt/β-catenin downstream protein levels. Over expression of DNMT1 and miR-152-3p inhibitors promotes proliferation of activating CFs. In addition, decreased methylation levels and over expression of miR-152-3p inhibited CFs proliferation. We determined that DNMT1 can methylate to miR-152-3p and demonstrated that expression of miR-152-3p inhibits CFs proliferation by inhibiting the Wnt1/β-catenin pathway. Our results stand out together DNMT1 methylation regulates miR-152-3p to slow the progression of cardiac fibrosis by inhibiting the Wnt1/β-catenin pathway.

Noncoding RNAs Interactions in Hepatic Stellate Cells during Hepatic Fibrosis

Hepatic fibrosis is a reversible wound healing process following liver injury. Although this process is necessary for maintaining liver integrity, severe excessive extracellular matrix accumulation (ECM) could lead to permanent scar formation and destroy the liver structure. The activation of hepatic stellate cells (HSCs) is a key event in hepatic fibrosis. Previous studies show that most antifibrotic therapies focus on the apoptosis of HSCs and the prevention of HSC activation. Noncoding RNAs (ncRNAs) play a substantial role in HSC activation and are likely to be biomarkers or therapeutic targets for the treatment of hepatic fibrosis. This review summarizes and discusses the previously reported ncRNAs, including the microRNAs, long noncoding RNAs, and circular RNAs, highlighting their regulatory roles and interactions in the signaling pathways that regulate HSC activation in hepatic fibrosis.

Long non-coding RNAs in metabolic disorders: pathogenetic relevance and potential biomarkers and therapeutic targets

BACKGROUND

It has been suggested that dysregulation of long non-coding RNAs (lncRNAs) could be associated with the incidence and development of metabolic disorders.

AIM

Accordingly, this narrative review described the molecular mechanisms of lncRNAs in the development of metabolic diseases including insulin resistance, diabetes, obesity, non-alcoholic fatty liver disease (NAFLD), cirrhosis, and coronary artery diseases (CAD). Furthermore, we investigated the up-to-date findings on the association of deregulated lncRNAs in the metabolic disorders, and potential use of lncRNAs as biomarkers and therapeutic targets.

CONCLUSION

LncRNAs/miRNA/regulatory proteins axis plays a crucial role in progression of metabolic disorders and may be used in development of therapeutic and diagnostic approaches.

JUN promotes hypertrophic skin scarring via CD36 in preclinical in vitro and in vivo models

[Figure: see text].

miR-511-3p promotes hepatic sinusoidal obstruction syndrome by activating hedgehog pathway via targeting Ptch1

As a major complication of hematopoietic stem cell transplantation, the incidence of hepatic sinusoidal obstruction syndrome (HSOS) is as high as 70%. Previous evidence has demonstrated that miR-511-3p was involved in HSOS, but the mechanism remains unclear. This study aims to examine the mechanism underlying miR-511-3p regulating HSOS. Monocrotaline (MCT) was used to create an HSOS rat model and to treat liver sinusoidal endothelial cells (LSECs). Hematoxylin & eosin (H&E) and Masson staining were used to detect pathological changes in liver tissue. The expression of miR-511-3p and Hedgehog pathway-related proteins was assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The effect of miR-511-3p in regulating HSOS was investigated by 3-(4,5)-dimethylthiahiazo-2)-3,5-diphenytetrazoliumromide (MTT), enzyme-linked immunosorbent assay (ELISA) assay, and flow cytometry. Finally, the interaction between miR-511-3p and patched1 (Ptch1) was determined by luciferase reporter assay. The rats showed a typical HSOS phenotype, including LSEC damage, liver injury, and fibrosis after MCT administration. miR-511-3p was upregulated in hepatic tissue of rat HSOS model and MCT-induced LSECs. miR-511-3p directly targeted Ptch1 and suppressed Ptch1 expression to activate the Hedgehog signaling pathway. Depletion of miR-511-3p showed a protective effect against MCT-induced HSOS, as evidenced by decreased HSOS pathogenesis factors, matrix metalloproteinases-2 (MMP-2), matrix metalloproteinases-9 (MMP-9), tumor necrosis factor-α (TNF-α), and interleukin 1 β (IL-1β), and decreased LSEC apoptosis rates. Nevertheless, knockdown of Ptch1 reversed the protective effect of miR-511-3p depletion against MCT-induced LSEC injury and apoptosis. miR-511-3p aggravates HSOS by activating the Hedgehog signaling pathway through targeting Ptch1, and miR-511-3p may develop as the potential therapy for the treatment of HSOS.NEW & NOTEWORTHY miR-511-3p is upregulated in HSOS in vivo and in vitro models. miR-511-3p activates the Hedgehog pathway by directly targeting Ptch1. Knockdown of miR-511-3p shows a protective effect against LSEC injury and apoptosis via Hedgehog signaling pathway. Inhibition of Ptch1 reserves the effect of miR-511-3p knockdown on LSEC damage and apoptosis.

MicroRNAs in organ fibrosis: From molecular mechanisms to potential therapeutic targets

Fibrosis is caused by chronic tissue injury and characterized by the excessive deposition of extracellular matrix (ECM) that ultimately results in organ failure and death. Owing to lacking of effective treatment against tissue fibrosis, it causes a high morbidity and mortality worldwide. Thus, it is of great importance to find an effective therapy strategy for the treatment of fibrosis. MicroRNAs (miRNAs) play vital roles in many biological processes by targeting downstream genes. Numerous studies demonstrated that miRNAs served as biomarkers of various diseases, suggesting the potential therapeutic targets for diseases. It was recently reported that miRNAs played an important role in the development of organ fibrosis, which showed a promising prospect against fibrosis by targeting intervention. Here, we summarize the roles of miRNAs in the process of organ fibrosis, including liver, lung, heart and kidney, and highlight miRNAs being novel therapeutic targets for organ fibrosis.

Regulatory long non-coding RNAs of hepatic stellate cells in liver fibrosis (Review)

Liver fibrosis (LF) is a continuous wound healing process caused by numerous chronic hepatic diseases and poses a major threat to human health. Activation of hepatic stellate cells (HSCs) is a critical event in the development of hepatic fibrosis. Long non-coding RNAs (lncRNAs) that are involved in HSC activation, participate in the development of LF and are likely to be therapeutic targets for LF. In the present review, the cellular signaling pathways of LF with respect to HSCs were discussed. In particular, this present review highlighted the current knowledge on the role of lncRNAs in activating or inhibiting LF, revealing lncRNAs that are likely to be biomarkers or therapeutic targets for LF. Additional studies should be performed to elucidate the potential of lncRNAs in the diagnosis and prognosis of LF and to provide novel therapeutic approaches for the reversion of LF.

miR‑375 affects the hedgehog signaling pathway by downregulating RAC1 to inhibit hepatic stellate cell viability and epithelial‑mesenchymal transition

MicroRNAs (miRNAs/miRs) are a class of non-coding RNAs that serve crucial roles in liver cancer and other liver injury diseases. However, the expression profile and mechanisms underlying miRNAs in liver fibrosis are not completely understood. The present study identified the novel miR-375/Rac family small GTPase 1 (RAC1) regulatory axis in liver fibrosis. Reverse transcription-quantitative PCR was performed to detect miR-375 expression levels. MTT, flow cytometry and western blotting were performed to explore the in vitro roles of miR-375. The dual-luciferase reporter gene assay was performed to determine the potential mechanism underlying miR-375 in liver fibrosis. miR-375 expression was significantly downregulated in liver fibrosis tissues and cells compared with healthy control tissues and hepatocytes, respectively. Compared with the pre-negative control group, miR-375 overexpression inhibited mouse hepatic stellate cell (HSC) viability and epithelial-mesenchymal transition, and alleviated liver fibrosis. The dual-luciferase reporter assay results demonstrated that miR-375 bound to RAC1. Moreover, the results indicated that miR-375 regulated the hedgehog signaling pathway via RAC1 to restrain HSC viability and EMT, thus exerting its anti-liver fibrosis function. The present study identified the miR-375/RAC1 axis as a novel regulatory axis associated with the development of liver fibrosis.

The antimicrobial peptide YD attenuates inflammation via miR-155 targeting CASP12 during liver fibrosis

The antimicrobial peptide APKGVQGPNG (named YD), a natural peptide originating from Bacillus amyloliquefaciens CBSYD1, exhibited excellent antibacterial and antioxidant properties in vitro. These characteristics are closely related to inflammatory responses which is the central trigger for liver fibrosis. However, the therapeutic effects of YD against hepatic fibrosis and the underlying mechanisms are rarely studied. In this study, we show that YD improved liver function and inhibited the progression of liver fibrosis by measuring the serum transaminase activity and the expression of α-smooth muscle actin and collagen I in carbon tetrachloride-induced mice. Then we found that YD inhibited the level of miR-155, which plays an important role in inflammation and liver fibrosis. Bioinformatics analysis and luciferase reporter assay indicate that Casp12 is a new target of miR-155. We demonstrate that YD significantly decreases the contents of inflammatory cytokines and suppresses the NF-κB signaling pathway. Further studies show that transfection of the miR-155 mimic in RAW264.7 cells partially reversed the YD-mediated CASP12 upregulation, the downregulated levels of inflammatory cytokines, and the inactivation of the NF-κB pathways. Collectively, our study indicates that YD reduces inflammation through the miR-155–Casp12–NF-κB axis during liver fibrosis and provides a promising therapeutic candidate for hepatic fibrosis.

Danhong Injection Alleviates Cardiac Fibrosis via Preventing the Hypermethylation of Rasal1 and Rassf1 in TAC Mice

BACKGROUND/AIM

Danhong injection (DHI) is a Chinese patent drug used for relieving cardiovascular diseases. Recent studies have suggested that DNA methylation plays a pivotal role in the maintenance of cardiac fibrosis (CF) in cardiovascular diseases. This study was aimed at identifying the effect and the underlying mechanism of DHI on CF, especially the DNA methylation.

METHODS

A CF murine model was established by thoracic aortic constriction (TAC). A 28-day daily treatment with or without DHI via intraperitoneal injection was carried out immediately following TAC surgery. The changes in cardiac function, pathology, and fibrosis following TAC were measured by echocardiography and immunostaining. We used methyl-seq analysis to assess the DNA methylation changes in whole genes and identified the methylation changes of two Ras signaling-related genes in TAC mice, including Ras protein activator like-1 (Rasal1) and Ras-association domain family 1 (Rassf1). Next, the methylation status and expression levels of Rasal1 and Rassf1 genes were consolidated by bisulfite sequencing, quantitative reverse transcription polymerase chain reaction (RT-qPCR), and Western blotting, respectively. To determine the underlying molecular mechanism, the expressions of DNA methyltransferases (DNMTs), Tet methylcytosine dioxygenase 3 (TET3), fibrosis-related genes, and the activity of Ras/ERK were measured by RT-qPCR and Western blotting.

RESULTS

DHI treatment alleviated CF and significantly improved cardiac function on day 28 of TAC. The methyl-seq analysis identified 42,606 differential methylated sites (DMSs), including 19,618 hypermethylated DMSs and 22,988 hypomethylated DMSs between TAC and sham-operated mice. The enrichment analysis of these DMSs suggested that the methylated regulation of Ras signal transduction and focal adhesion-related genes would be involved in the TAC-induced CF development. The results of bisulfite sequencing revealed that the TAC-induced methylation affected the CpG site in both of Rasal1 and Rassf1 genes, and DHI treatment remarkably downregulated the promoter methylation of Rasal1 and Rassf1 in CF hearts. Furthermore, DHI treatment upregulated the expressions of Rasal1 and Rassf1, inhibited the hyperactivity of Ras/ERK, and decreased the expressions of fibrosis-related genes. Notably, we found that DHI treatment markedly downregulated the expression of DNMT3B in CF hearts, while it did not affect the expressions of DNMT1, DNMT3A, and TET3.

CONCLUSION

Aberrant DNA methylation of Rasal1 and Rassf1 genes was involved in the CF development. DHI treatment alleviated CF, prevented the hypermethylation of Rasal1 and Rassf1, and downregulated DNMT3B expression in CF hearts.

Pinostilbene hydrate suppresses hepatic stellate cell activation via inhibition of miR-17-5p-mediated Wnt/β-catenin pathway

BACKGROUND

In the development of liver fibrosis, activated hepatic stellate cells (HSCs) contribute to the synthesis and deposition of extracellular matrix (ECM) proteins. HSC activation is considered as a central driver of liver fibrosis. Recently, microRNAs (miRNAs) have been reported to act as key regulators in HSC activation.

PURPOSE

Pinostilbene hydrate (PSH), a methylated derivative of resveratrol, has demonstrated anti-inflammatory, antioxidant and anti-tumour activities. However, the effects of PSH on HSC activation remain unclear.

METHODS

The effects of PSH on HSC activation were examined. Moreover, the roles of WNT inhibitory factor 1 (WIF1) and miR-17-5p in the effects of PSH on HSC activation were examined.

RESULTS

PSH induced a significant reduction in HSC proliferation. PSH also effectively inhibited HSC activation, with reduced α-SMA and collagen expression. Notably, it was found that Wnt/β-catenin signalling was involved in the effects of PSH on HSC activation. PSH resulted in Wnt/β-catenin signalling inactivation, with a reduction in TCF activity as well as β-catenin nuclear translocation. Further studies showed that PSH inhibited Wnt/β-catenin signalling via regulation of WIF1 and miR-17-5p. Reduced HSC activation caused by PSH could be restored by loss of WIF1 or miR-17-5p mimics. Luciferase reporter assays further confirmed that WIF1 was a target of miR-17-5p.

CONCLUSION

PSH has a significant protective effect against HSC activation. In addition, we demonstrate that PSH enhances WIF1 expression and inhibits Wnt/β-catenin signalling via miR-17-5p, contributing to the suppression of HSC activation.

Pharmacological Effects of Salvianolic Acid B Against Oxidative Damage

Salvianolic acid B (Sal B) is one of the main active ingredients of Salvia miltiorrhiza, with strong antioxidant effects. Recent findings have shown that Sal B has anti-inflammatory, anti-apoptotic, anti-fibrotic effects and can promote stem cell proliferation and differentiation, and has a beneficial effect on cardiovascular and cerebrovascular diseases, aging, and liver fibrosis. Reactive oxygen species (ROS) include oxygen free radicals and oxygen-containing non-free radicals. ROS can regulate cell proliferation, survival, death and differentiation to regulate inflammation, and immunity, while Sal B can scavenge oxygen free radicals by providing hydrogen atoms and reduce the production of oxygen free radicals and oxygen-containing non-radicals by regulating the expression of antioxidant enzymes. The many pharmacological effects of Sal B may be closely related to its elimination and inhibition of ROS generation, and Nuclear factor E2-related factor 2/Kelch-like ECH-related protein 1 may be the core link in its regulation of the expression of antioxidant enzyme to exert its antioxidant effect. What is confusing and interesting is that Sal B exhibits the opposite mechanisms in tumors. To clarify the specific target of Sal B and the correlation between its regulation of oxidative stress and energy metabolism homeostasis will help to further understand its role in different pathological conditions, and provide a scientific basis for its further clinical application and new drug development. Although Sal B has broad prospects in clinical application due to its extensive pharmacological effects, the low bioavailability is a serious obstacle to further improving its efficacy in vivo and promoting clinical application. Therefore, how to improve the availability of Sal B in vivo requires the joint efforts of many interdisciplinary subjects.

A Comprehensive Review of Natural Products against Liver Fibrosis: Flavonoids, Quinones, Lignans, Phenols, and Acids

Liver fibrosis resulting from continuous long-term hepatic damage represents a heavy burden worldwide. Liver fibrosis is recognized as a complicated pathogenic mechanism with extracellular matrix (ECM) accumulation and hepatic stellate cell (HSC) activation. A series of drugs demonstrate significant antifibrotic activity in vitro and in vivo. No specific agents with ideally clinical efficacy for liver fibrosis treatment have been developed. In this review, we summarized the antifibrotic effects and molecular mechanisms of 29 kinds of common natural products. The mechanism of these compounds is correlated with anti-inflammatory, antiapoptotic, and antifibrotic activities. Moreover, parenchymal hepatic cell survival, HSC deactivation, and ECM degradation by interfering with multiple targets and signaling pathways are also involved in the antifibrotic effects of these compounds. However, there remain two bottlenecks for clinical breakthroughs. The low bioavailability of natural products should be improved, and the combined application of two or more compounds should be investigated for more prominent pharmacological effects. In summary, exploration on natural products against liver fibrosis is becoming increasingly extensive. Therefore, natural products are potential resources for the development of agents to treat liver fibrosis.

Evidence that miR-152-3p is a positive regulator of SETDB1-mediated H3K9 histone methylation and serves as a toggle between histone and DNA methylation

SETDB1 is a histone methyltransferase that converts H3K9me2 to H3K9me3. SETDB1 activity and H3K9me3 are crucial for the formation of obligately silenced heterochromatin such as that of centromeres. Here we show that a microRNA, miR-152-3p, is involved in the regulation of SETDB1 protein levels, but surprisingly, miR-152-3p plays a positive regulatory role for SETDB1 expression. Inhibition of miR-152-3p by anti-miR treatment resulted in a robust reduction in SETDB1 protein levels, though SETDB1 mRNA levels were unaffected. This was also accompanied by a blockade of the biochemical pathway proceeding from H3K9me2 to H3K9me3 as evidenced by quantitative nucleosome ELISA assays that showed that H3K9me2 accumulates in cells treated with an anti-miR that targets miR-152-3p. In addition, the action of a miR-152-3p mimic increased flux of the reaction leading to H3K9me3. We also performed site-directed mutagenesis of three predicted miR-152-3p target recognition sequences to yield three precise deletions. Deletion of one of the three sites recapitulated the positive regulatory aspect of the action of miR-152-3p upon SETDB1 expression in a luciferase reporter assay. Previous studies have shown that miR-152-3p negatively regulates DNMT1, the sole maintenance DNA methyltransferase which is required for levels of 5-methylcytosine levels within DNA. Our results shown that miR-152-3p positively regulates the production of H3K9me3 by regulating the production of SETDB1. Therefore, our findings provide strong evidence that miR-152-3p can serve as a toggle switch that regulates the balance between DNA methylation and H3K9 histone methylation in constitutive heterochromatin.

Thymoquinone alleviates liver fibrosis via miR-30a-mediated epithelial-mesenchymal transition

Thymoquinone (TQ), the main active constituent of Nigella sativa seeds, has been shown to play a role in antioxidation, anti-inflammation, and antitumor. Recent studies have demonstrated that TQ contributes to the suppression of liver fibrosis. Abnormal activated epithelial-mesenchymal transition (EMT) promotes the activation of hepatic stellate cells (HSCs). However, whether the antifibrotic effects of TQ occur through inhibiting EMT is largely unknown. In this study, it was found that TQ ameliorated liver fibrosis and collagen accumulation in carbon tetrachloride (CCl4) mice. In vitro, TQ inhibited HSC activation including reduced proliferation, α-smooth muscle actin, and collagen. In addition, TQ markedly suppressed the EMT process, with enhanced E-cadherin and reduced desmin. Notably, snail family transcriptional repressor 1 (Snai1), the EMT master transcription factor, was obviously inhibited by TQ in vivo and in vitro. Further studies demonstrated that Snai1 was a target of microRNA-30a (miR-30a), which was upregulated by TQ. Interestingly, the effects of TQ on HSC activation and EMT were almost inhibited by miR-30a inhibitor. Collectively, we demonstrate that TQ inhibits HSC activation, at least in part, via regulation of miR-30a and Snai1. TQ upregulates miR-30a expression, resulting in a reduced Snai1 level as well as EMT process inactivation, which contributes to the inhibition of HSC activation. TQ may be a potential therapeutic agent for liver fibrosis.

MicroRNA expression profiling reveals potential roles for microRNA in the liver during pigeon (Columba livia) development

The liver is the central organ for metabolism and influence the growth and development of the animals. To date, little is known about the microRNA (miRNA) in pigeon livers, particularly in different developmental stages. A comprehensive investigation into miRNA transcriptomes in livers across 3 pigeon developmental stages (1, 14, 28 d old) and an adult stage (2 y old) was performed by small RNA sequencing. We identified 312 known miRNA, 433 conserved miRNA, and 192 novel miRNA in pigeon livers. A set of differentially expressed (DE) miRNA in livers were screened out during pigeon development. This set of miRNA might be involved in hepatospecific phenotype and liver development. A Short Time-series Expression Miner analysis indicated significant expression variations in DE miRNA during liver development of pigeons. These DE miRNA with different expression patterns might play essential roles in response to growth factor, cell morphogenesis, and gland development, etc. Protein-protein interaction network and Molecular Complex Detection analysis identified several vital target genes (e.g., TNRC6B, FRS2, PTCH1, etc.) of DE miRNA, which is closely linked in liver development and enriched in PI3K cascade and regulation of growth. Our results expanded the repertoire of pigeon miRNA and may be of help in better understanding the mechanism of squab's rapid development from the perspective of liver development.

Sennoside A prevents liver fibrosis by binding DNMT1 and suppressing DNMT1-mediated PTEN hypermethylation in HSC activation and proliferation

Hepatic stellate cell (HSC) activation is an essential event during liver fibrogenesis. Phosphatase and tension homolog deleted on chromosome 10 (PTEN) is a negative regulator of this process. DNA methyltransferase 1 (DNMT1), which catalyzes DNA methylation and subsequently leads to the transcriptional repression of PTEN, is selectively induced in myofibroblasts from diseased livers. Sennoside A (SA), a major purgative constituent of senna and the Chinese herb rhubarb, is widely used in China and other Asian countries as an irritant laxative. SA is reported to improve hepatic steatosis. However, the effect and mechanism of SA on liver fibrosis remain largely unknown. We recently identified a novel strategy for protecting liver fibrosis via epigenetic modification by targeting DNMT1. A Surface Plasmon Resonance (SPR) assay first reported that SA could directly bind DNMT1 and inhibit its activity. Administration of SA significantly prevented liver fibrosis, as evidenced by the dramatic downregulation of α-smooth muscle actin (α-SMA) and type I collagen alpha-1 (Col1α1) protein levels in a CCl₄ -induced mouse hepatic fibrosis model and in TGF-β1-activated HSC-T6 cells, in vivo and in vitro. SA decreased the expression of Cyclin D1, CDK, and C-myc, indicating that SA may inhibit the activation and proliferation of TGF-β1-induced HSC-T6. Moreover, SA significantly promoted the expression of PTEN and remarkably inhibited the expression of p-AKT and p-ERK in vitro. Blocking PTEN or overexpressing DNMT1 could reduce the effect of SA on liver fibrosis. These data suggest that SA directly binds and inhibits the activity and that attenuated DNMT1-mediated PTEN hypermethylation caused the loss of PTEN expression, followed by the inhibition of the AKT and ERK pathways and prevented the development of liver fibrosis. Hence, SA might be employed as a promising natural supplement for liver fibrosis drug therapy.

The role of WNT/β-catenin signaling pathway and glutamine metabolism in the pathogenesis of CCl4-induced liver fibrosis: Repositioning of niclosamide and concerns about lithium

BACKGROUND

Liver fibrosis is a serious health problem which may lead to advanced liver cirrhosis and hepatocellular carcinoma.

OBJECTIVE

The present study aimed to investigate the role of Wnt/β-catenin signaling pathway and glutamine aminohydrolase enzyme (l-glutaminase) in the pathogenesis of liver fibrosis and the potential benefits of niclosamide in treating liver fibrosis.

METHODS

Ninety male Albino rats were divided into 6 equal groups (n = 15) as follows: a normal control group (NC), CCl₄-only treated group (Fib.) which received 1 mg/kg CCl₄ two times weekly, niclosamide-treated group (Niclo.) which received 5 mg/kg of niclosamide one time daily, lithium chloride-treated group (LiCl) which received 100 mg/kg of LiCl one time daily, niclosamide-and-CCl₄-treated group (Niclo. + Fib.) which received same doses of niclosamide and CCl₄ given to other groups, and finally lithium chloride-and-CCl₄-treated rat group (LiCl + Fib.) which received same doses of LiCl and CCl₄ given to other groups. All treatments were administered orally for 8 weeks. Liver tissue was assessed for l-hydroxyproline, beta-catenin (β-catenin), l-glutaminase activity, as well as the gene expression of transforming growth factor beta-1 (TGF-β1) and Dishevelled-2 (Dvl2). Histopathological and immunohistochemical analyses of alpha smooth muscle actin α-SMA were performed. Serum alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin were measured.

RESULTS

The group of niclosamide-and-CCl₄-treated rats showed a significant decrease in total bilirubin, ALT and AST, β-catenin, l-hydroxyproline, l-glutaminase activity, and gene expression of TGF-β1 and Dvl2. Moreover, the liver tissue in this group of rats showed mild α-SMA reactivity compared with the rats treated with CCl₄ only (fibrosis group). On the other hand, lithium chloride-and-CCl₄-treated rats showed a significant increase in liver indices, TGF-β1 expression, β-catenin, l-hydroxyproline, and l-glutaminase activity with severe α-SMA reactivity and apoptosis in the liver tissue.

CONCLUSIONS

Niclosamide protected rats against liver fibrosis by inhibiting the Wnt/β-catenin pathway and glutaminolysis.

Possible applications of salvianolic acid B against different cancers

Cancer is the second death causing disease worldwide after cardiovascular abnormalities. The difficulty in treating tumor cells with more precise targeted interventions and recurrence of cancer after treatment may pose great difficulty in developing sustainable therapeutic regimens. These limitations have prompted the need to explore several compounds with ability to cease tumor growth while at the same time induce apoptosis of tumor cells. Several studies have emphasized the use of natural compounds as antitumor agents due to their high efficacy against cancer cells and low toxicity in normal cells. Salvianolic acid B (SAB), a naturally occurring phenolic compound extracted from the radix of Chinese herb Salvia miltiorrhiza can induce apoptosis in different types of tumor cells. It can be used to treat cardiovascular and neurodegenerative disorders, hepatic fibrosis, and cancers. Several studies have shown that SAB can mitigate tumorigenesis by modulating MAPK, PI3K/AKT, and NF-ĸB signaling pathways. It also sensitizes the tumor cells to different anti-cancer agents by reversing the multi-drug resistance mechanisms found in tumor cells. This review summarizes the studies showing antitumor potential of SAB in different types of cancer cell lines, animal models and highlights the possible mechanisms through which SAB can induce apoptosis, inhibit growth and metastasis in tumor cells. Moreover, the possible role of nano-technological approaches to induce targeted delivery of SAB to eradicate tumor cells has been also discussed.

Study on the relationship between hepatic fibrosis and epithelial-mesenchymal transition in intrahepatic cells

Hepatic fibrosis is a pathophysiological process, which causes excessive extracellular matrix (ECM) deposition resulting from persistent liver damage. Myofibroblasts are the core cells that produce ECM. It is known that epithelial-mesenchymal transition (EMT) is not a simple transition of cells from the epithelial to mesenchymal state. Instead, it is a process, in which epithelial cells temporarily lose cell polarity, transform into interstitial cell-like morphology, and acquire migration ability. Hepatocytes, hepatic stellate cells, and bile duct cells are the types of intrahepatic cells found in the liver. They can be transformed into myofibroblasts via EMT and play important roles in the development of hepatic fibrosis through a maze of regulations involving various pathways. The aim of the present study is to explore the relationship between the relevant regulatory factors and the EMT signaling pathways in the various intrahepatic cells.

Chemical and pharmacological research on the polyphenol acids isolated from Danshen: A review of salvianolic acids

Danshen, the dried root of Salvia miltiorrhiza Bge, is a common medicinal herb in Traditional Chinese Medicine, which has been used for the treatment of a number of diseases for thousands of years. More than 2000 years ago, the Chinese early pharmacy monograph "Shennong Materia Medica" recorded that Danshen could be used for the treatment of gastrointestinal diseases, cardiovascular diseases, certain gynecological diseases, etc. Since then, Danshen has been widely used clinically in many different prescriptions for many different diseases, especially for the treatment of cardiovascular diseases. Nowadays, many pharmacological studies about the water-soluble components from Danshen have been reported, especially salvianolic acids. It turned out that salvianolic acids showed strong anti-lipid peroxidation and anti-thrombic activities, and among them, SalAA and SalAB were the most potent. This review focused on the achievements in research of salvianolic acids regarding their bioactivities and pharmacological effects. These studies not only shed light on the water-soluble active components of Danshen and their mechanisms at the molecular level, but also provided theoretical information for the development of new medicines from Danshen for the treatment of cardiovascular and cerebrovascular diseases, inflammatory diseases, metabolic diseases, etc.

Liquiritigenin suppresses the activation of hepatic stellate cells via targeting miR-181b/PTEN axis

BACKGROUND

Liquiritigenin (LQ), an aglycone of liquiritin in licorice, has demonstrated antioxidant, anti-inflammatory and anti-tumor activities. Previously, LQ was found to inhibit liver fibrosis progression.

PURPOSE

Phosphatase and tensin homolog (PTEN) has been reported to act as a negative regulator of hepatic stellate cell (HSC) activation. However, the roles of PTEN in the effects of LQ on liver fibrosis have not been identified to date.

METHODS

The effects of LQ on liver fibrosis in carbon tetrachloride (CCl₄) mice as well as primary HSCs were examined. Moreover, the roles of PTEN and microRNA-181b (miR-181b) in the effects of LQ on liver fibrosis were examined.

RESULTS

LQ markedly ameliorated CCl₄-induced liver fibrosis, with a reduction in collagen deposition as well as α-SMA level. Moreover, LQ induced an increase in PTEN and effectively inhibited HSC activation including cell proliferation, α-SMA and collagen expression, which was similar with curcumin (a positive control). Notably, loss of PTEN blocked down the effects of LQ on HSC activation. PTEN was confirmed as a target of miR-181b and miR-181b-mediated PTEN was involved in the effects of LQ on liver fibrosis. LQ led to a significant reduction in miR-181b expression. LQ-inhibited HSC activation could be restored by over-expression of miR-181b. Further studies demonstrated that LQ down-regulated miR-181b level via Sp1. Collectively, we demonstrate that LQ inhibits liver fibrosis, at least in part, via regulation of miR-181b and PTEN.

CONCLUSION

LQ down-regulates miR-181b level, leading to the restoration of PTEN expression, which contributes to the suppression of HSC activation. LQ may be a potential candidate drug against liver fibrosis.

miR-130a-3p inhibition protects against renal fibrosis in vitro via the TGF-β1/Smad pathway by targeting SnoN

BACKGROUND

Renal fibrosis, a common pathological outcome of chronic kidney disease (CKD), is characterized by extracellular matrix (ECM) accumulation, damage to the tubular epithelium, and the proliferation and activation of fibroblasts. SnoN, a TGF-β1/Smad transcriptional co-suppressor, is downregulated in obstructive nephropathy. However, the relationship between miR-130a-3p and SnoN expression in the regulation of renal fibrosis is still unknown.

METHODS

We used human renal proximal tubular epithelial cells (HRPTEpiCs, HK-2 and primary HRPTEpiCs) treated with TGF-β1 to establish an in vitro renal fibrosis model. The expression of miR-130a-3p, SnoN and other proteins related to epithelial mesenchymal transition (EMT) and TGF-β1/Smad signalling was investigated by western blotting or qRT-PCR. A luciferase reporter assay was conducted to confirm the interaction of SnoN mRNA and miR-130a-3p. The translocation of p-Smad 2/3 and Smad 7 was determined using immunofluorescence staining.

RESULTS

After TGF-β1 treatment, miR-130a-3p was highly expressed in renal tubular epithelial cells, while SnoN was poorly expressed. The cell morphology changed to fibroblast-like, indicating evidence of EMT. The levels of EMT and fibrosis-related proteins were decreased through miR-130a-3p inhibition. Additionally, miR-130a-3p acted upon the 3'-UTR of SnoN directly to suppress SnoN expression. Furthermore, miR-130a-3p/SnoN promoted the activation of TGF-β1/Smad signalling, as revealed by p-Smad 2/3 and Smad 7 expression levels and distribution patterns.

CONCLUSION

Our study verified that miR-130a-3p facilitates the TGF-β1/Smad pathway in renal tubular epithelial cells and may participate in renal fibrosis by targeting SnoN, which could be a possible strategy for renal fibrosis treatment.

Research progress on the anti-hepatic fibrosis action and mechanism of natural products

Hepatic fibrosis is the most common pathological feature of most chronic liver diseases, and its continuous deterioration gradually develops into liver cirrhosis and eventually leads to liver cancer. At present, there are many kinds of drugs used to treat liver fibrosis. However, Western drugs tend to only target single genes/proteins and induce many adverse reactions. Most of the mechanisms and active ingredients of traditional Chinese medicine (TCM) are not clear, and there is a lack of unified diagnosis and treatment standards. Natural products, which are characterized by structural diversity, low toxicity, and origination from a wide range of sources, have unique advantages and great potential in anti-liver fibrosis. This article summarizes the work done over the previous decade, on the active ingredients in natural products that are reported to have anti-hepatic fibrosis effects. The effective anti-hepatic fibrosis ingredients identified can be generally divided into flavonoids, saponins, polysaccharides and alkaloids. Mechanisms of anti-liver fibrosis include inhibition of liver inflammation, anti-lipid peroxidation injury, inhibition of the activation and proliferation of hepatic stellate cells (HSCs), modulation of the synthesis and secretion of pro-fibrosis factors, and regulation of the synthesis and degradation of the extracellular matrix (ECM). This review provides suggestions for the development of anti-hepatic fibrosis drugs.

The interaction between microRNA-152 and DNA methyltransferase-1 as an epigenetic prognostic biomarker in HCV-induced liver cirrhosis and HCC patients

The necessity for early detection and hence improving the outcome of treatment of hepatocellular carcinoma (HCC) is critical especially in Hepatitis C virus (HCV)-Genotype 4 induced cases. In our current work, we examined the miRNA-152 and DNMT-1 expression in chronic liver disease (CLD) due to HCV genotype 4 infection with/without cirrhosis and HCC patients as an attempt to evaluate the potential benefits of these new circulating, noninvasive, prognostic, epigenetic markers for liver cirrhosis and carcinogenesis of Egyptian patients. Eighty subjects were included in this study, divided into two groups; group I (40 patients) were classified into subgroup Ia (CLD without cirrhosis, n = 18) and subgroup Ib (CLD with cirrhosis, n = 22), group II (CLD patients with HCC, n = 20), and control (Healthy volunteer, n = 20). The expression of miRNA-152 and DNMT-1 genes were analyzed using Real-Time PCR. MiRNA-152 showed a persistent and significant downregulation in all diseased groups, which was in consistence with the progression of the disease toward the HCC stage. DNMT-1 showed upregulation in all diseased groups when compared to control and subgroup Ia. The miRNA-152 was shown to correlate inversely with DNMT-1 in subgroup Ia, Ib and group II (r = -0.557, p < 0.01), (r = -0.850, p < 0.001) and (r = -0.544, p < 0.02) respectively. In addition, miRNA-152 and DNMT-1 showed a diagnostic ability to discriminate between cases of cirrhosis and HCC against CLD without cirrhosis (p < 0.01), while DNMT-1 did not, except between HCC and cirrhotic cases. Furthermore, both genes can be considered as predictor and prognostic parameters for cirrhosis (OR = 1.041, p = 0.043) and (OR = 1.039, p = 0.04) respectively, while miRNA-152 alone is proved as a prognostic marker for HCC (OR = 1.003, p = 0.044). Finally, the persistent reverse correlation between miRNA-152 with DNMT-1 prompts their use as noninvasive prognostic biomarkers for HCV induced liver cirrhosis and HCC in HCV Genotype 4 patients.

Downregulation of miR-152 contributes to the progression of liver fibrosis via targeting Gli3 in vivo and in vitro

The Gli family is known to be required for the activation of hedgehog signalling, which participates in the pathogenesis of liver fibrosis. The aim of the present study was to identify the association between microRNA (miR)-152 and GLI family zinc finger 3 (Gli3) and their roles in liver fibrosis. In a carbon tetrachloride (CCl₄)-treated rat model, fibrogenesis-associated indexes, including hydroxyproline content, collagen deposition, and α-smooth muscle actin (α-SMA) and albumin expression, were examined in in vivo and in vitro models. The expression of miR-152 and Gli3 in cells and tissues was determined by reverse transcription quantitative polymerase chain reaction and western blot analysis. The interaction of Gli3 and miR-152 was evaluated by bioinformatical analysis and a dual-luciferase reporter assay. The results demonstrated that miR-152 was significantly downregulated in serum samples from clinical patients, liver tissues from CCl₄-treated rats and activated LX2 cells. Furthermore, at the cellular level, the mRNA and protein expression levels of α-SMA and albumin were increased and decreased, respectively, in LX2 cells. Nevertheless, following transfection with an miR-152 mimic, the expression levels of α-SMA and albumin were reversed, and Gli3 expression was notably decreased in LX2 cells. Additionally, the target interaction between miR-152 and Gli3 was demonstrated. Finally, an miR-152 mimic was introduced into the rat model and additionally demonstrated that the changes in α-SMA, albumin and Gli3 expression levels were similar to the expression pattern in LX2 cells following miR-152 mimic transfection. These data provided insight into the potential function of miR-152 as an anti-fibrotic therapy through the modulation of Gli3.

Salvianolic acid B protects against ANIT-induced cholestatic liver injury through regulating bile acid transporters and enzymes, and NF-κB/IκB and MAPK pathways

The purpose of this study was to investigate the pharmacological effects of salvianolic acid B (SA-B) on α-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury with the focus on bile acid homeostasis and anti-inflammatory pathways. Rats were randomly assigned into four groups. The control group was given normal saline (i.p.) for 7 consecutive days and on the 5th day was given the vehicle (i.g.). Model group was treated with normal saline (i.p.) for 7 days and administrated with ANIT (75 mg/kg, i.g.) on the 5th day. The SA-B groups were treated with SA-B (15 mg/kg and 30 mg/kg, i.p.) for 7 consecutive days as well as ANIT (75 mg/kg, i.g.) on the 5th day. We found that the serum levels of ALT, γ-GT, TBA, and other liver function indexes were found to be lower in the SA-B treatment groups than in the model group. SA-B also upregulated the transporters and enzymes involved in bile acid homeostasis such as Bsep, Oatp2, and Cyp3a2 in rats and BSEP, CYP3A4, and OATP2 in human cell lines. Moreover, SA-B suppressed NF-κB translocation into the nucleus, inhibited phosphorylation of p38 and JNK, and inhibited inflammation markers including IL-1β, IL-6, TGF-β, TNF-α, and COX-2 to extenuate cholestatic liver injury both in vivo and vitro. Taken together, our findings suggest that anti-cholestatic effects of SA-B may be associated with its ability to regulate NF-κB/IκB and MAPK inflammatory signaling pathways to inhibit inflammation and regulate transporters and enzymes to maintain bile acid homeostasis.

Emerging Role of Chinese Herbal Medicines in the Treatment of Pancreatic Fibrosis

Pancreatic fibrosis is the main pathologic characteristic in chronic pancreatitis (CP), a common disease that arises from surgery. Pancreatitis is caused by various etiologies, but the mechanism of fibrosis is not completely understood. Existing clinical approaches mainly focus on mitigating the symptoms and therefore do not cure the phenomena. In recent years, there has been a heightened interest in the use of Chinese herbal medicine (CHMs) in the prevention and cure of CP as expressed by increasing numbers of clinical and experimental research. Despite early cell culture and animal models, CHMs are able to interact with plenty of molecular targets involved in the pathogenesis of pancreatic fibrosis mostly via the TGF- β /Smads pathway; however, integrated and up-to-date communication in this domain is unavailable. This review focuses on the research progress of CHMs against pancreatic fibrosis due to CP in vitro and in vivo and summarizes the potential mechanisms. We also outlined the toxicology of some CHMs for fibrosis treatment in order to provide a fuller understanding of drug safety. This review may provide reference for further innovative drug research and the future development of treatments for CP with pancreatic fibrosis.

Effects of Chinese herbal medicine therapy on survival and hepatic outcomes in patients with hepatitis C virus infection in Taiwan

BACKGROUND

Chinese herbal medicine (CHM) is a complementary natural medicine that is used widely for the treatment of hepatic diseases. The aim of this study was to investigate the effects of the long-term use of CHM for the treatment of liver diseases, as prescribed by TCM doctors, on overall mortality and hepatic outcomes in patients with HCV.

PATIENTS AND METHODS

We identified 98788 patients with HCV. Of these, 829 and 829 patients who were users and non-users of CHM, respectively, were matched for age, gender, CCI, and comorbidities prior to CHM treatment. The chi-squared test, Cox proportional hazard model, Kaplan--Meier method, and log-rank test were used for comparisons.

RESULTS

CHM users had a lower risk of overall mortality than non-users after adjustment for comorbidities by using a multivariate Cox proportional hazard model (p-value < 0.001; HR: 0.12, 95% CI: 0.06-0.26). In addition,the CHM users had a lower risk of liver cirrhosis than non-users after adjustment for comorbidities (p-value = 0.028; HR: 0.29, 95% CI: 0.09-0.88). The 12-year cumulative incidences of overall mortality and liver cirrhosis were lower in the CHM group (p-value < 0.05 for both, log rank test). The CHM co-prescription for Dan-Shen, Bie-Jia, Jia-Wei-Xiao-Yao-San => E-Shu was found to occur most often associated for the specific treatment of HCV infection.

CONCLUSION

CHM as adjunctive therapy may reduce the overall mortality and the risk of liver cirrhosis in patients with HCV. The comprehensive list of the herbal medicines that may be used for the treatment of patients with HCV may be useful in future scientific investigations or for future therapeutic interventions to prevent negative hepatic outcomes in patients with HCV.

Sal B targets TAZ to facilitate osteogenesis and reduce adipogenesis through MEK-ERK pathway

Salvianolic acid B (Sal B), a major bioactive component of Chinese herb, was identified as a mediator for bone metabolism recently. The aim of this study is to investigate the underlying mechanisms by which Sal B regulates osteogenesis and adipogenesis. We used MC3T3-E1 and 3T3-L1 as the study model to explore the changes of cell differentiation induced by Sal B. The results indicated that Sal B at different concentrations had no obvious toxicity effects on cell proliferation during differentiation. Furthermore, Sal B facilitated osteogenesis but inhibited adipogenesis by increasing the expression of transcriptional co-activator with PDZ-binding motif (TAZ). Accordingly, TAZ knock-down offset the effects of Sal B on cell differentiation into osteoblasts or adipocytes. Notably, the Sal B induced up-expression of TAZ was blocked by U0126 (the MEK-ERK inhibitor), rather than LY294002 (the PI3K-Akt inhibitor). Moreover, Sal B increased the p-ERK/ERK ratio to regulate the TAZ expression as well as the cell differentiation. In summary, this study suggests for the first time that Sal B targets TAZ to facilitate osteogenesis and reduce adipogenesis by activating MEK-ERK signalling pathway, which provides evidence for Sal B to be used as a potential therapeutic agent for the management of bone diseases.