Reversibility and heritability of liver fibrosis: Implications for research and therapy

Association of CXCR4 gene expression and promoter methylation with chronic hepatitis B-related fibrosis/cirrhosis

OBJECTIVE

Chronic hepatitis B (CHB) virus infection remains a major public health concern. In this study, the diagnostic capability of C-X-C chemokine receptor type 4 promoter methylation in patients with CHB-associated liver fibrosis/cirrhosis was evaluated.

METHODS

Two hundred participants were recruited, including 25 healthy controls (HCs), 60 patients with CHB and 115 patients with hepatitis B virus (HBV)-related liver fibrosis/LC. Researchers monitored the methylation and messenger ribonucleic acid (mRNA) levels of C-X-C chemokine receptor type 4 (CXCR4) in peripheral blood mononuclear cells (PBMCs). In addition, we utilized single cell sequencing to analyze the cell types highly expressing CXCR4 in HBV-related liver fibrosis/LC.

RESULTS

HBV-related fibrosis/cirrhosis patients exhibited a significant elevation in the expression level of CXCR4 mRNA in PBMCs compared to CHB ones. The CXCR4 promoter showed a significantly lower methylation level in patients with CHB-related fibrosis/cirrhosis than in patients with CHB. Additionally, the diagnostic area under the area under the curve (AUC) of methylation of the CXCR4 promoter for CHB -related liver fibrosis/LC exceeded liver stiffness measurement (LSM), aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 score (FIB-4). Furthermore, single-cell analysis demonstrated that CXCR4 expression is closely associated with Natural Killer cells(NK cells), T lymphocytes (T cells), and monocytes.

CONCLUSION

The low methylation of the CXCR4 promoter holds promise as a non-invasive biomarker for detecting CHB-associated liver fibrosis/LC.

Exploring Fibrosis Pathophysiology in Lean and Obese Metabolic-Associated Fatty Liver Disease: An In-Depth Comparison

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-β, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.

LncRNA NEAT1 in the pathogenesis of liver-related diseases

Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long noncoding RNA (lncRNA) that is widely expressed in a variety of mammalian cell types. Altered expression levels of the lncRNA NEAT1 have been reported in liver-related disorders including cancer, fatty liver disease, liver fibrosis, viral hepatitis, and hepatic ischemia. lncRNA NEAT1 mostly acts as a competing endogenous RNA (ceRNA) to sponge various miRNAs (miRs) to regulate different functions. In regard to hepatic cancers, the elevated expression of NEAT1 has been reported to have a relation with the proliferation, migration, angiogenesis, apoptosis, as well as epithelial-mesenchymal transition (EMT) of cancer cells. Furthermore, NEAT1 upregulation has contributed to the pathogenesis of other liver diseases such as fibrosis. In this review, we summarize and discuss the molecular mechanisms by which NEAT1 contributes to liver-related disorders including acute liver failure, nonalcoholic fatty liver disease (NAFLD), liver fibrosis, and liver carcinoma, providing novel insights and introducing NEAT1 as a potential therapeutic target in these diseases.

The role of PI3k/AKT signaling pathway in attenuating liver fibrosis: a comprehensive review

Excessive accumulation of extracellular matrix (ECM) components within the liver leads to a pathological condition known as liver fibrosis. Alcohol abuse, non-alcoholic fatty liver disease (NAFLD), autoimmune issues, and viral hepatitis cause chronic liver injury. Exploring potential therapeutic targets and understanding the molecular mechanisms involved in liver fibrosis are essential for the development of effective interventions. The goal of this comprehensive review is to explain how the PI3K/AKT signaling pathway contributes to the reduction of liver fibrosis. The potential of this pathway as a therapeutic target is investigated through a summary of results from in vivo and in vitro studies. Studies focusing on PI3K/AKT activation have shown a significant decrease in fibrosis markers and a significant improvement in liver function. The review emphasizes how this pathway may prevent ECM synthesis and hepatic stellate cell (HSC) activation, ultimately reducing the fibrotic response. The specific mechanisms and downstream effectors of the PI3K/AKT pathway in liver fibrosis constitute a rapidly developing field of study. In conclusion, the PI3K/AKT signaling pathway plays a significant role in attenuating liver fibrosis. Its complex role in regulating HSC activation and ECM production, demonstrated both in vitro and in vivo, underscores its potential as a effective therapeutic approach for managing liver fibrosis and slowing disease progression. A comprehensive review of this field provides valuable insights into its future developments and implications for clinical applications.

Identification of functional genes in liver fibrosis based on bioinformatics analysis of a lncRNA-mediated ceRNA network

BACKGROUND

Liver fibrosis is a major global healths problem; nevertheless, its molecular mechanism are not completely clear. This study aimed to build a lncRNA-miRNA-mRNA network, identify potentially related lncRNAs, and explore the pathogenesis of liver fibrosis.

MATERIALS AND METHODS

We used the Gene Expression Omnibus databases and bioinformatics analysis to identify differentially expressed genes (DEGs) between liver fibrosis and normal tissues. The ceRNA network was constructed according to the interactions between DElncRNA, miRNA, and DEmRNA. Then, these DEGs were identified using functional enrichment analysis, and a protein-protein interaction (PPI) network was established. The critical lncRNAs were verified using the quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The ceRNA network was composed of three lncRNAs, five miRNAs, and 93 mRNAs. Gene Ontology functional enrichment analysis revealed significant enhancement in cell components, molecular function, and biological process. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed pathways associated with transcriptional misregulation in cancer, including the Rap1 signaling pathway, proteoglycans in cancer, mineral absorption, HTLV-l infection, and central carbon metabolism in cancer. According to the PPI network and the GSE84044 database, seven hub genes associated with liver fibrosis were identified. In addition, qRT-PCR revealed that lncRNA AC100861 (lncRNA TNFRSF10A-DT) was explicitly decreased in liver fibrosis tissues and activated hepatic stellate cells.

CONCLUSIONS

In summary, this study preliminarily found that lncRNA TNFRSF10A-DT may be a biomarker for the diagnosis and outcome of liver fibrosis. We uncovered a novel lncRNA-mediated ceRNA regulatory mechanism in the pathogenesis of liver fibrosis.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

TUG1 protects against ferroptosis of hepatic stellate cells by upregulating PDK4-mediated glycolysis

The induction of ferroptosis in hepatic stellate cells (HSCs) has shown promise in reversing liver fibrosis. And ferroptosis has been confirmed to be associated with glycolysis. The objective of this study is to determine whether ferroptosis inhibition in HSCs, induced by elevation of recombinant pyruvate dehydrogenase kinase isozyme 4 (PDK4)-mediated glycolysis, could mediate the pathogenesis of liver fibrosis. Liver fibrosis was induced using CCl4, the level of which was assessed through histochemical staining. Lentivirus was used to modulate the expression of specific genes. And underlying mechanisms were explored using primary HSCs extracted from normal mice. The results confirmed that Taurine up-regulated gene 1 (TUG1) expression was upregulated in liver fibrotic tissues and HSCs, showing a positive correlation with fibrosis. In addition, TUG1 attenuated ferroptosis in HSCs by promoting PDK4-mediated glycolysis, thereby promoting the progression of liver fibrosis. Moreover, TUG1 was observed to impact HSCs activation, exacerbating liver fibrosis to some extent. In conclusion, our study revealed that TUG1 expression was elevated in mouse models of liver fibrosis and activated HSCs, which inhibited ferroptosis in HSCs through PDK4-mediated glycolysis. This finding may open up a new therapeutic strategy for liver fibrosis.

Correlation between SDF-1α, CD34 positive hematopoietic stem cells and CXCR4 expression with liver fibrosis in CCl4 rat model

BACKGROUND

One of the most frequent disorders is liver fibrosis. An improved understanding of the different events during the process of liver fibrosis & its reversibility could be helpful in its staging and in finding potential therapeutic agents.

AIM

The goal of this research was to evaluate the relationship among CD34 + HPSCs, SDF-1α, and CXCR4 receptor expression with the percentage of the area of hepatic fibrosis.

MATERIALS AND METHODS

Thirty-six male Sprague-Dawley rats were separated into the control group, liver injury group & spontaneous reversion group. The liver injury was induced by using 2 ml/kg CCl4 twice a week. Flow cytometric examination of CD34 + cells in the blood & liver was performed. Bone marrow & liver samples were taken for evaluation of the SDF-1α mRNA by PCR. Liver specimens were stained for histopathological and CXCR4 immuno-expression evaluation.

RESULTS

In the liver injury group, the hepatic enzymes, fibrosis area percentage, CXCR4 receptor expression in the liver, CD34 + cells in the blood and bone marrow & the level SDF-1α in the liver and its concentration gradient were statistically significantly elevated with the progression of the liver fibrosis. On the contrary, SDF-1α in the bone marrow was statistically significantly reduced with the development of liver fibrosis. During the spontaneous reversion group, all the studied parameters apart from SDF-1α in the bone marrow were statistically substantially decreased compared with the liver injury group. We found a statistically substantial positive correlation between fibrosis area and all of the following: liver enzymes, CXCR4 receptor expression in the liver, CD34 + cells in the blood and liver, and SDF- 1α in the liver and its concentration gradient. In conclusion, in CCl4 rat model, the fibrosis area is significantly correlated with many parameters in the blood, bone marrow, and liver, which can be used during the process of follow-up during the therapeutic interventions.

Anti-Fibrotic Efficacy of Apigenin in a Mice Model of Carbon Tetrachloride-Induced Hepatic Fibrosis by Modulation of Oxidative Stress, Inflammation, and Fibrogenesis: A Preclinical Study

BACKGROUND

Hepatic fibrosis is a major health problem all over the world, and there is no effective treatment to cure it. Hence, the current study sought to assess the anti-fibrotic efficacy of apigenin against CCl₄-induced hepatic fibrosis in mice.

METHODS

Forty-eight mice were put into six groups. G1: Normal Control, G2: CCl₄ Control, G3: Silymarin (100 mg/kg), G4 and G5: Apigenin (2 &20 mg/Kg), G6: Apigenin alone (20 mg/Kg). Groups 2, 3, 4, and 5 were given CCl₄ (0.5 mL/kg. i.p.) twice/week for six weeks. The level of AST, ALT, TC, TG, and TB in serum and IL-1β, IL-6, and TNF-α in tissue homogenates were assessed. Histological studies by H&E staining and Immunostaining of liver tissues were also performed.

RESULTS

The CCl₄-challenged group showed increased serum AST (4-fold), ALT (6-fold), and TB (5-fold). Both silymarin and apigenin treatments significantly improved these hepatic biomarkers. The CCl₄-challenged group showed reduced levels of CAT (89%), GSH (53%), and increased MDA (3-fold). Both silymarin and apigenin treatments significantly altered these oxidative markers in tissue homogenates. The CCl₄-treated group showed a two-fold increase in IL-1β, IL-6, and TNF-α levels. Silymarin and apigenin treatment considerably decreased the IL-1β, IL-6, and TNF-α levels. Apigenin treatment inhibited angiogenic activity, as evidenced by a decrease in VEGF (vascular endothelial growth factor) expression in liver tissues, and a decline in vascular endothelial cell antigen expression (CD34).

CONCLUSIONS

Finally, these data collectively imply that apigenin may have antifibrotic properties, which may be explained by its anti-inflammatory, antioxidant, and antiangiogenic activities.

An optimized herbal combination for the treatment of liver fibrosis: Hub genes, bioactive ingredients, and molecular mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis is a chronic liver disease that can lead to cirrhosis, liver failure, and hepatocellular carcinoma, and it is associated with long-term adverse outcomes and mortality. As a primary resource for complementary and alternative medicine, traditional Chinese medicine (TCM) has accumulated a large number of effective formulas for the treatment of liver fibrosis in clinical practice. However, studies on how to systematically optimize TCM formulas are still lacking.

AIM OF THE REVIEW

To provide a methodological reference for the systematic optimization of TCM formulae against liver fibrosis and explored the underlying molecular mechanisms; To provide an efficient method for searching for lead compounds from natural sources and developing from herbal medicines; To enable clinicians and patients to make more reasonable choices and promote the effective treatment toward those patients with liver fibrosis.

MATERIALS AND METHODS

TCM formulas related to treating liver fibrosis were collected from the Web of Science, PubMed, the China National Knowledge Infrastructure (CNKI), Wan Fang, and the Chinese Scientific Journals Database (VIP). Furthermore, the TCM compatibility patterns were mined using association analysis. The core TCM combinations were found by designing an optimized formulas algorithm. Finally, the hub target proteins, potential molecular mechanisms, and active compounds were explored through integrative pharmacology and docking-based inverse virtual screening (IVS) approaches.

RESULTS

We found that the herbs for reinforcing deficiency, activating blood, removing blood stasis, and clearing heat were the basis of TCM formulae patterns. Furthermore, the combination of Salviae Miltiorrhizae (Salvia miltiorrhiza Bunge; Chinese salvia/Danshen), Astragali Radix (Astragalus membranaceus (Fisch.) Bunge; Astragalus/Huangqi), and Radix Bupleuri (Bupleurum chinense DC.; Bupleurum/Chaihu) was identified as core groups. A total of six targets (TNF, STAT3, EGFR, IL2, ICAM1, PTGS2) play a pivotal role in TCM-mediated liver fibrosis inhibition. (-)-Cryptotanshinone, Tanshinaldehyde, Ononin, Thymol, Daidzein, and Formononetin were identified as active compounds in TCM. And mechanistically, TCM could affect the development of liver fibrosis by regulating inflammation, immunity, angiogenesis, antioxidants, and involvement in TNF, MicroRNAs, Jak-STAT, NF-kappa B, and C-type lectin receptors (CLRs) signaling pathways. Molecular docking results showed that key components had good potential to bind to the target genes.

CONCLUSION

In summary, this study provides a methodological reference for the systematic optimization of TCM formulae and exploration of underlying molecular mechanisms.

The Mouse Anxa6/miR-9-5p/Anxa2 Axis Modulates TGF-β1-induced Mouse Hepatic Stellate Cell (mHSC) Activation and CCl4-caused Liver Fibrosis

Chronic liver disease such as hepatic fibrosis is a major cause of morbidity and mortality and has been related to high individual risk of hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs) activation is a central event of hepatic fibrosis progression. In this study, the up-regulation of lncRNA ANXA2P2 (mouse Anxa6) was found in liver fibrosis. Within CCl₄-caused liver fibrosis murine model, Anxa6 knockdown partially ameliorated CCl₄-induced hepatic fibrosis and blocked the PI3K/Akt signaling activation. In TGF-β1-stimulated HSCs, Anxa6 knockdown partially inhibited TGF-β1-induced HSC activation and blocked the PI3K/Akt signaling activation. Mouse Anxa6 downstream mmu-miR-9-5p directly targeted Anxa2; Anxa6 negatively regulated mmu-miR-9-5p, and mmu-miR-9-5p negatively regulated mouse Anxa2. In TGF-β1-stimulated HSCs, miR-9-5p inhibitor promoted TGF-β1-induced HSC activation and PI3K/Akt signaling activation, whereas Anxa2 knockdown exerted opposite effects; Anxa2 knockdown significantly attenuated miR-9-5p inhibitor effects upon TGF-β1-stimulated HSCs. In conclusion, lncRNA ANXA2P2 (mouse Anxa6) expression is up-regulated in hepatic fibrosis and exerts pro-fibrotic effects on CCl₄-caused liver fibrosis model mice and TGF-β1-stimulated HSCs. The mouse Anxa6/miR-9-5p/Anxa2 axis and the PI3K/Akt pathway might participate in the functions of lncRNA ANXA2P2 (mouse Anxa6) on hepatic fibrosis.

Kinsenoside Protects Against Radiation-Induced Liver Fibrosis via Downregulating Connective Tissue Growth Factor Through TGF-β1 Signaling

Radiation-induced liver fibrosis (RILF) is a serious complication of the radiotherapy of liver cancer, which lacks effective prevention and treatment measures. Kinsenoside (KD) is a monomeric glycoside isolated from Anoectochilus roxburghii, which has been reported to show protective effect on the early progression of liver fibrosis. However, the role of KD in affecting RILF remains unknown. Here, we found that KD alleviated RILF via downregulating connective tissue growth factor (CTGF) through TGF-β1 signaling. Sprague-Dawley rats were administered with 20 mg/kg KD per day for 8 weeks after a single 30Gy irradiation on the right part of liver, and tumor-bearing nude mice were administered with 30 mg/kg KD per day after a single fraction of 10Gy on the tumor inoculation site. Twenty-four weeks postirradiation, we found that the administration of KD after irradiation resulted in decreased expression of α-SMA and fibronectin in the liver tissue while had no adverse effect on the tumor radiotherapy. Besides, KD inhibited the activation of hepatic stellate cells (HSCs) postirradiation via targeting CTGF as indicated by the transcriptome sequencing. Results of the pathway enrichment and immunohistochemistry suggested that KD reduced the expression of TGF-β1 protein after radiotherapy, and exogenous TGF-β1 induced HSCs to produce α-SMA and other fibrosis-related proteins. The content of activated TGF-β1 in the supernatant decreased after treatment with KD. In addition, KD inhibited the expression of the fibrosis-related proteins by regulating the TGF-β1/Smad/CTGF pathway, resulting in the intervention of liver fibrosis. In conclusion, this study revealed that KD alleviated RILF through the regulation of TGFβ1/Smad/CTGF pathway with no side effects on the tumor therapy. KD, in combination with blocking the TGF-β1 pathway and CTGF molecule or not, may become the innovative and effective treatment for RILF.

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.

Transcriptome analysis reveals the molecular mechanism of Yiqi Rougan decoction in reducing CCl4-induced liver fibrosis in rats

Background

Liver fibrosis develops from various chronic liver diseases, and there is currently a lack of specific treatment strategies. Yiqi Rougan decoction (YQRG) is a traditional Chinese medicine that has shown durative effects in the treatment of liver fibrosis; however, the mechanism associated with YQRG-related improvements in liver fibrosis remains to be experimentally determined. This study evaluated the therapeutic effect of YQRG on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats and its molecular mechanism.

Methods

We used low-, medium-, and high-dose YQRG to treat CCl₄-induced liver fibrosis in rats, followed by assessment of liver injury and fibrosis according to liver appearance, body weight, liver mass index, histopathologic examination, and serum testing. Additionally, we performed transcriptome analysis using RNA-sequencing (RNA-seq) technology, including cluster, Gene Ontology (GO), and pathway analyses, to identify differentially expressed genes (DEGs), and protein and gene expression were detected by immunofluorescence (IFC), western blot and real-time quantitative PCR.

Results

The results showed that YQRG effectively alleviated CCl₄-induced liver injury and fibrosis in rats, including observations of improved liver function, decreased activity of hepatic stellate cells (HSCs), and decreased extracellular matrix (ECM) deposition. Moreover, we identified downregulated and upregulated DEGs in the model group relative to the control and YQRG-treated groups, with GO analysis revealing their enrichment in biological processes, such as endoplasmic reticulum stress (ERS), apoptosis, and autophagy. Furthermore, pathway analysis showed that YQRG treatment downregulated the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/Akt (PI3K/AKT) signalling pathways and upregulated other signalling pathways, including those related to peroxisome proliferator-activated receptors(PPAR) and AMP-activated protein kinase(AMPK), with these findings subsequently verified experimentally.

Conclusion

These findings showed that YQRG improved CCl₄-induced liver fibrosis through multiple mechanisms and pathways, offering critical insight into the YQRG-related therapeutic mechanism and promoting further research into its potential application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00552-w.

Pterostilbene ameliorates the disrupted Adars expression and improves liver fibrosis in DEN-induced liver injury in Wistar rats: A novel potential effect

The knowledge of RNA editing modifications and its subsequent proteomic diversity in is still limited and represents only the tip of the iceberg. Adenosine to inosine (A-to-I) RNA editing is the most prevalent in RNA editome with a rising role for ADARgene family as a major regulator of the dynamic landscape of RNA editing. This study aimed at evaluating the potential chemopreventive effects of the epigenetic regulator "pterostilbene" in diethylnitrosamine (DEN)-exposedrat model. Consequently, the hepatic Adars expression was investigated as a possible mechanism for mediation of the putative pterostilbene-induced chemopreventive effect. The effects of administration of pterostilbene were investigated on the structural changes, immunohistochemical staining, liver function test, serum alpha feto-protein (AFP), IL-6, and hepatic Adar1 and Adar2 relative gene expression at the beginning and at the 6th week of the study. Pterostilbene attenuated DEN-induced liver injury, improves hepatocyte parrafin-1 (Hep Par-1), decreases heat shock protein 70 (HSP70), improved AFP, serum albumin, transaminases, IL-6 with alleviation of disturbed hepatic Adar1 and Adar2 expression. This study spotlights the role of pterostilbene in attenuation of DEN-induced liver injury which could be mediated, at least partially, through the alleviation of the aberrant expression of Adar enzymes. Yet, more in-depth studies are needed to further elucidate the molecular mechanisms underlying the effects of pterostilbene on RNA editing enzymes.

Study on the effect of Mongolian medicine Qiwei Qinggan Powder on hepatic fibrosis through JAK2/STAT3 pathway

This research aimed to evaluate the antihepatic fibrosis effect and explore the mechanism of Qiwei Qinggan Powder (QGS-7) in vivo and in vitro. Carbon tetrachloride (CCl4)-treated rats and hepatic stellate cells (HSCs) were used. QGS-7 treatment significantly improved the liver function of rats as indicated by decreased serum enzymatic activities of alanine aminotransferase, aspartate transaminase, and alkaline phosphatase. Meanwhile, the hydroxyproline of liver was significantly decreased. Histopathological results indicated that QGS-7 alleviated liver damage and reduced the formation of fibrosis septa. Moreover, QGS-7 significantly attenuated expressions of Alpha smooth muscle actin, Collagen I, Janus kinase 2 (JAK2), phosphorylation-JAK2, signal transducer and activator of transcription 3 (STAT3), phosphorylation-STAT3 in the rat hepatic fibrosis model. QGS-7 inhibited HSC proliferation and promoted it apoptosis. QGS-7 may affect hepatic fibrosis through JAK2/STAT3 signaling pathway so as to play an antihepatic fibrosis role.

RNF2 Mediates Hepatic Stellate Cells Activation by Regulating ERK/p38 Signaling Pathway in LX-2 Cells

The therapeutic approach of liver fibrosis is still an unsolved clinical problem worldwide. Notably, the accumulation of extracellular matrix (ECM) in the liver is mediated by the production of cytokines and growth factors, such as transforming growth factor-β1 (TGF-β1) in hepatic stellate cells (HSCs). Ring finger protein 2 (RNF2) was identified as the catalytic subunit of polycomb repressive complex 1 (PRC1), mediating the monoubiquitination of histone H2A. In recent years, a growing amount of evidence suggests that RNF2 may play an important role in multiple pathological processes involved in cancer. Here, we explored the role of RNF2 in liver fibrogenesis and its potential mechanisms. The results showed that RNF2 was up-regulated in human fibrotic liver tissue. Knockdown of RNF2 led to a decreasing expression of collagen1 and α-smooth muscle actin (α-SMA) in LX-2 cells, which was upregulated by RNF2 overexpression. Moreover, RNF2 overexpression significantly promoted TGF-β1-induced LX-2 cell proliferation but decreased apoptosis. Furthermore, knockdown of RNF2 inhibited the activation of ERK/p38 signaling pathways induced by TGF-β1. These data suggested that RNF2 is an effective pro-fibrogenic factor for HSC activation via ERK/p38 signaling pathway. RNF2 inhibition might be a promising therapeutic target for liver fibrosis.

Epigenetic Biomarkers for the Diagnosis and Treatment of Liver Disease

Research in the last decades has demonstrated the relevance of epigenetics in controlling gene expression to maintain cell homeostasis, and the important role played by epigenome alterations in disease development. Moreover, the reversibility of epigenetic marks can be harnessed as a therapeutic strategy, and epigenetic marks can be used as diagnosis biomarkers. Epigenetic alterations in DNA methylation, histone post-translational modifications (PTMs), and non-coding RNA (ncRNA) expression have been associated with the process of hepatocarcinogenesis. Here, we summarize epigenetic alterations involved in the pathogenesis of chronic liver disease (CLD), particularly focusing on DNA methylation. We also discuss their utility as epigenetic biomarkers in liquid biopsy for the diagnosis and prognosis of hepatocellular carcinoma (HCC). Finally, we discuss the potential of epigenetic therapeutic strategies for HCC treatment.

Molecular factors associated with regression of liver fibrosis of alcoholic etiology

Liver fibrosis develops as a result of chronic liver damage of various etiologies, is characterized by excessive synthesis of connective tissue by activated stellate liver cells. The toxic effect of alcohol is one of the most significant and common etiological factors worldwide. Stellate cell activation results from the interaction of multiple molecular fibrogenic pathways triggered by intracellular and extracellular, hepatic and extrahepatic stimuli. Data analysis showed that knowledge about these abnormal pathways and biomolecular processes may further contribute to the improvement of approaches to assessment of disease prognosis and treatment of alcoholic liver disease.

Quantitative evaluation of liver fibrosis based on ultrasound radio frequency signals: An animal experimental study

BACKGROUND

Chronic liver disease is an important cause of liver failure and death worldwide, and liver fibrosis is a common pathological process of most chronic liver diseases. There still lacks a useful tool for evaluating liver fibrosis progression precisely and non-invasively. The purpose of this study was to explore the use of ultrasound radio frequency (RF) signals combined with deep learning approach to evaluate the degree of liver fibrosis quantitatively.

METHODS

In this study, by extracting the output of deep learning models as a prediction value, a quantitative liver fibrosis prediction method was achieved based on the bidirectional long short-term memory (Bi-LSTM) network to analyze radio frequency (RF) signals. The dataset consisted of 160 sets of ultrasound RF signals of rat livers, including five fibrosis stages 0-4, upon pathological diagnosis. In total, 150 sets of RF signals were used to train four deep learning classification models, the output of which contained quantitative information. In each training stage of the four models, a large number of signal segments were extracted from the 150 sets and divided randomly into training and validation sets in a ratio of 80:20. Ten sets of RF data using the gold standard of quantitative fibrosis parameter (q-FP) of liver tissues were left for independent testing. To validate the proposed method, correlation analysis was carried out between q-FP and the quantitative prediction results based on the independent test data.

RESULTS

The accuracy of the four deep learning networks using the training and validation data was above 0.83 and 0.80, and the corresponding areas under the receiver operating characteristic curves were higher than 0.95 and 0.93, respectively. For the quantitative analysis in the independent test set, the determination coefficient, R², of the linear regression analysis between the quantitative prediction results and q-FP was above 0.93. liver fibrosis is a common pathological process of most chronic liver diseases.

CONCLUSIONS

This study indicates that a prediction system based on ultrasound RF signals and a deep learning approach is promising for realizing quantitative and visualized diagnosis of liver fibrosis, which would be of great value in monitoring liver fibrosis non-invasively.

Role of long non‑coding RNAs and related epigenetic mechanisms in liver fibrosis (Review)

Liver fibrosis is one of the major liver pathologies affecting patients worldwide. It results from an improper tissue repair process following liver injury or inflammation. If left untreated, it ultimately leads to liver cirrhosis and liver failure. Long non‑coding RNAs (lncRNAs) have been implicated in a wide variety of diseases. They can regulate gene expression and modulate signaling. Some of the lncRNAs promote, while others inhibit liver fibrosis. Similarly, other epigenetic processes, such as methylation and acetylation regulate gene transcription and can modulate gene expression. Notably, there are several regulatory associations of lncRNAs with other epigenetic processes. A major mechanism of action of long non‑coding RNAs is to competitively bind to their target microRNAs (miRNAs or miRs), which in turn affects miRNA availability and bioactivity. In the present review, the role of lncRNAs and related epigenetic processes contributing to liver fibrosis is discussed. Finally, various potential therapeutic approaches targeting lncRNAs and related epigenetic processes, which are being considered as possible future treatment targets for liver fibrosis are identified.

MiR-34c promotes hepatic stellate cell activation and Liver Fibrogenesis by suppressing ACSL1 expression

Normally, there are multiple microRNAs involved in the pathogenesis of liver fibrosis. In our work, we aimed at identifying the role of miR-34c in the hepatic stellate cell (HSC) activation and liver fibrosis and its potential mechanism. Our results have shown that during natural activation of HSC, the level of miR-34c was increased significantly whereas acyl-CoA synthetase long-chain family member-1(ACSL1), which is a key enzyme can affect fatty acid(FA) synthesis, was decreased. A double fluorescence reporter assay further confirmed that ACSL1 is a direct target gene of miR-34c. Moreover, the inhibition of miR-34C can attenuate the synthesis of collagen in HSC-T6. In our rescue assay, ACSL1 expression was 1.49-fold higher compared to normal control cells which were transfected with the miR-34c inhibitor in a stable low expression ACSL1 cell line. While at the same time, α-SMA and Col1α expression decreased by 18.22% and 2.58%, respectively. Moreover, we performed an in vivo model using dimethylnitrosamine (DMN) in conjunction with the miR-34c agomir, combined with the treatment of DMN and the miR-34c agomir can increase liver fibrosis. Meanwhile, the degree of hepatic fibrosis was increased and lipid droplets reduced dramatically in rats and HSC-T6 cell treated with miR-34c mimics alone compared to untreated groups. Our results indicate that miR-34c plays an essential role in liver fibrosis by targeting ACSL1 closely associated with lipid droplets, and it might be used as a potential therapeutic target.

Dynamic analysis of m6A methylation spectroscopy during progression and reversal of hepatic fibrosis

Aim: To dynamically analyze the differential m6A methylation during the progression and reversal of hepatic fibrosis. Materials & methods: We induced hepatic fibrosis in C57/BL6 mice by intraperitoneal injection of CCl4. The reversal model of hepatic fibrosis was established by stopping drug after continuous injection of CCl4. Dynamic m6A methylation was evaluated using MeRIP-Seq in the progression and reversal of hepatic fibrosis at different stages. Result: During the hepatic fibrosis, differential m6A methylation was mainly enriched in processes associated with oxidative stress and cytochrome metabolism, while differential m6A methylation was mainly enriched in processes associated with immune response and apoptosis in the hepatic fibrosis reversal. Conclusion: m6A methylation plays an important role in the progression and reversal of hepatic fibrosis.

Diffusion tensor imaging quantifying the severity of chronic hepatitis in rats

BACKGROUND

Diffusion tensor imaging (DTI) is mainly used for detecting white matter fiber in the brain. DTI was applied to assess fiber in liver disorders in previous studies. However, the data obtained have been insufficient in determining if DTI can be used to exactly stage chronic hepatitis. This study assessed the value of DTI for staging of liver fibrosis (F), necroinflammatory activity (A) and steatosis (S) with chronic hepatitis in rats.

METHODS

Seventy male Sprague-Dawley rats were divided into a control group(n = 10) and an experimental group(n = 60). The rat models of chronic hepatitis were established by abdominal subcutaneous injections of 40% CCl₄. All of the rats underwent 3.0 T MRI. Regions of interest (ROIs) were subjected to DTI to estimate the MR parameters (rADC value and FA value). Histopathology was used as the reference standard. Multiple linear regression was used to analyze the associations between the MR parameters and pathology. The differences in the MR parameters among the pathological stages were evaluated by MANOVA or ANOVA. The LSD test was used to test for differences between each pair of groups. ROC analysis was also performed.

RESULTS

The count of each pathology was as follows: F0(n = 15), F1(n = 11), F2(n = 6), F3(n = 9), F4(n = 6); A0(n = 8), A1(n = 16), A2(n = 16), A3(n = 7); S0(n = 10), S1(n = 7), S2(n = 3), S3(n = 11), S4(n = 16). The rADC value had a negative correlation with liver fibrosis (r = - 0.392, P = 0.008) and inflammation (r = - 0.359, P = 0.015). The FA value had a positive correlation with fibrosis (r = 0.409, P = 0.005). Significant differences were found in the FA values between F4 and F0 ~ F3 (P = 0.03), while no significant differences among F0 ~ F3 were found (P > 0.05). The AUC of the FA value differentiating F4 from F0 ~ F3 was 0.909 (p < 0.001) with an 83.3% sensitivity and an 85.4% specificity when the FA value was at the cut-off of 588.089 (× 10^- 6 mm²/s).

CONCLUSION

The FA value for DTI can distinguish early cirrhosis from normal, mild and moderate liver fibrosis, but the rADC value lacked the ability to differentiate among the fibrotic grades. Both the FA and rADC values were unable to discriminate the stages of necroinflammatory activity and steatosis.

Isochlorogenic Acid A Attenuates the Progression of Liver Fibrosis Through Regulating HMGB1/TLR4/NF-κB Signaling Pathway

Liver fibrosis, a chronic damage process related to further progression of hepatic cirrhosis, has yet no truly effective treatment. Isochlorogenic acid A (ICQA), isolated from a traditional Chinese herbal medicine named Laggera alata (DC.) Sch.Bip. ex Oliv. (Asteraceae), is proved to exhibit anti-inflammatory, hepatoprotective and antiviral properties. However, the actions of ICQA on liver fibrosis are poorly understood. The purpose of this study was to evaluate the actions of ICQA on liver fibrosis and clarify the underlying mechanism. It was found that ICQA had significant protective actions on liver injury, inflammation as we as fibrosis in rats. Meanwhile, ICQA prevented hepatic stellate cells (HSC) activation, indicated by its inhibitory effect on the overexpression of α-smooth muscle actin (α-SMA). In addition, the reduced fibrosis was found to be associated with the decreased protein expression of high-mobility group box 1 (HMGB1) as well as toll like receptor (TLR) 4. Simultaneously, ICQA can suppress the cytoplasmic translocation of HMGB1 in rat liver. Further investigations indicated that ICQA treatment dramatically attenuated the nuclear translocation of the nuclear factor-kB (NF-κB) p65 and suppressed the hepatic expression of p−IκBα in rats with liver fibrosis. Taken together, our study indicated that ICQA could protect against CCl₄-induced liver fibrosis probably through suppressing the HMGB1/TLR4/NF-κB signaling pathways.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Many studies have revealed that circulating long noncoding RNAs (lncRNAs) regulate gene and protein expression in the process of hepatic fibrosis. Liver fibrosis is a reversible wound healing response followed by excessive extracellular matrix accumulation. In the development of liver fibrosis, some lncRNAs regulate diverse cellular processes by acting as competing endogenous RNAs (ceRNAs) and binding proteins. Previous investigations demonstrated that overexpression of lncRNAs such as H19, maternally expressed gene 3 (MEG3), growth arrest-specific transcript 5 (GAS5), Gm5091, NR_002155.1, and HIF 1alpha-antisense RNA 1 (HIF1A-AS1) can inhibit the progression of liver fibrosis. Furthermore, the upregulation of several lncRNAs [e.g., nuclear paraspeckle assembly transcript 1 (NEAT1), hox transcript antisense RNA (Hotair), and liver-enriched fibrosis-associated lncRNA1 (lnc-LFAR1)] has been reported to promote liver fibrosis. This review will focus on the functions and mechanisms of lncRNAs, the lncRNA transcriptome profile of liver fibrosis, and the main lncRNAs involved in the signalling pathways that regulate hepatic fibrosis. This review provides insight into the screening of therapeutic and diagnostic markers of liver fibrosis.

Antifibrotic effects of specific siRNA targeting connective tissue growth factor delivered by polyethyleneimine‑functionalized magnetic iron oxide nanoparticles on LX‑2 cells

Connective tissue growth factor (CTGF) is a possible key determinant of progressive fibrosis. Nanotechnology has been considered as a potential tool for developing novel drug delivery systems for various diseases, including liver fibrosis. The present study aimed to investigate the potential antifibrotic activity of CTGF small interfering RNA (siRNA) mediated by polyethyleneimine (PEI)-functionalized magnetic iron oxide (Fe₃O₄) nanoparticles (NPs) in LX-2 cells. PEI-Fe₃O₄/siRNA complexes were synthesized to facilitate siRNA delivery and were transfected into LX-2 cells. Laser confocal microscopy was employed to investigate the cell uptake of PEI-Fe₃O₄/siRNA complexes. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting were used to verify the effect of gene silencing. The results showed that siRNA-loaded PEI-Fe₃O₄ exhibited low cytotoxicity. The transfection efficiency of PEI-Fe₃O₄/siRNA reached 73.8%, and RT-qPCR and western blotting demonstrated effective gene silencing. These results indicated that CTGF siRNA delivered by PEI-Fe₃O₄ NPs significantly reduces CTGF expression and collagen production in activated LX-2 cells, providing a basis for future in vivo studies.

Whole-Liver Apparent Diffusion Coefficient Histogram Analysis for the Diagnosis and Staging of Liver Fibrosis

BACKGROUND

Conventional diffusion-weighted imaging is limited in the quantitative evaluation of liver fibrosis, and whole-liver apparent diffusion coefficient (ADC) histogram analysis might contribute to the diagnosis and staging of liver fibrosis.

PURPOSE

To explore the value of whole-liver ADC histogram parameters in the diagnosis and staging of liver fibrosis.

STUDY TYPE

Retrospective.

POPULATION

Twenty individuals with no liver disease and 86 patients with liver fibrosis, including 30 with chronic viral hepatitis, 29 with autoimmune hepatitis, and 27 with unexplained liver fibrosis patients.

FIELD STRENGTH/SEQUENCE

3.0T/T₁ -weighted, T₂ -weighted, and diffusion-weighted images.

ASSESSMENT

A region of interest (ROI) was drawn in each slice of the diffusion-weighted images. Whole-liver histogram parameters were obtained with dedicated software by accumulating all ROIs. The effectiveness of the parameters in differentiating stage 1 or greater (≥F1), stage 2 or greater (≥F2), and stage 3 or greater (≥F3) liver fibrosis was assessed.

STATISTICAL TESTS

Mann-Whitney U-test and receiver operating characteristic curve analysis.

RESULTS

Kurtosis, entropy, skewness, mode, and 90^th and 75^th percentiles exhibited significant differences among the pathological fibrosis stages (P < 0.05). Kurtosis was found to be the most meaningful parameter in differentiating fibrosis stages of the viral hepatitis, autoimmune hepatitis, and unexplained liver fibrosis group (area under the curve) (AUC = 0.793, 0.771, 0.798, respectively). In the combined liver fibrosis group, kurtosis achieved the highest AUC (0.801; 95% confidence interval [CI]: 0.702-0.900; sensitivity: 0.750; specificity: 0.850; positive likelihood ratio: 4.953; negative likelihood ratio: 0.302; positive predictive value: 0.946; negative predictive value: 0.486), with a cutoff value of 1.817, in differentiating fibrosis stage ≥F1.

DATA CONCLUSION

Kurtosis, entropy, skewness, mode, and 90^th and 75^th percentiles may contribute to the diagnosis and staging of liver fibrosis, especially kurtosis.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:1745-1754.

In vivo preclinical PET/CT imaging of carbon-11-labeled aminoglycerol probe for the diagnosis of liver fibrosis

OBJECTIVE

As an important membrane protein, aquaglyceroporin involves liver glycerol metabolism, which can be used to stage liver fibrosis. In this study, we synthesized a novel molecular probe carbon-11-labeled AR ([¹¹C]AR) with aminoglycerol (AR), and evaluated its preclinical performance for liver fibrosis diagnosis by positron emission tomography/computed tomography (PET/CT) imaging in vivo.

METHODS

We developed a fully automatic synthesis procedure for the preparation of [¹¹C]AR by radiolabeling glycerol analogue precursor AR with carbon-11. The liver uptake kinetics of [¹¹C]AR was investigated using a rat model by the PET/CT scanner. The dynamic PET/CT scans were performed between the control group (n = 5) and experimental group (n = 25), which was divided into three subgroups (S1, S2 + S3, S4) based on the stages of liver fibrosis. The regions of interest (ROIs) of 20 pixels were drawn in the liver area on the reconstructed images. One-way analysis of variance and independent sample t test were used to analyze the statistical difference of the maximum standardized uptake value (SUVmax) among the groups at series of scanning time points (20 s, 60 s, 90 s, 150 s, 5 min, 10 min, 20 min and 25 min).

RESULTS

The fully automatic synthesis of [¹¹C]AR was successfully achieved with high synthesis efficiency (above 50%). The uptake of [¹¹C]AR in progressive liver fibrosis tissues was significantly lower than that in healthy livers at all the imaging time points (P < 0.05), especially at early time points (before 10 min p.i.). A cut-off SUVmax value (1.1) at 150 s p.i. was set for discrimination progressive fibrosis from healthy liver. More experimental and healthy rats were tested with this new threshold to evaluate fibrosis situation. The sensitivity of detecting progressive fibrosis with [¹¹C]AR was 100% in the second cohort.

CONCLUSION

We demonstrated a new carbon-11-radiolabeled aminoglycerol PET/CT imaging probe [¹¹C]AR for liver fibrosis diagnosis and staging, which may allow potential assessment of liver fibrosis stages in a rapid and noninvasive method.

Silencing of EPCAM suppresses hepatic fibrosis and hepatic stellate cell proliferation in mice with alcoholic hepatitis via the PI3K/Akt/mTOR signaling pathway

Alcoholic hepatitis (AH) is a severe condition developed in patients with underlying alcoholic liver disease. Epithelial cell adhesion molecule (EPCAM) plays a role in hepatitis. Therefore, the current study aimed to explore the effect of EPCAM and its potential mechanism in AH. Bioinformatic analysis was performed to screen differentially expressed genes associated with AH. AH mouse models were established through a Lieber-DeCarli liquid diet containing 4% ethanol, which were co-treated with siRNA against EPCAM or the PI3K/Akt/mTOR signaling pathway inhibitor in order to investigate the effects of EPCAM and the PI3K/Akt/mTOR signaling pathway on hepatic fibrosis, hepatic stellate cell (HSC) proliferation and apoptosis. The relationship between EPCAM and the PI3K/Akt/mTOR signaling pathway was investigated for the purposes of elucidating the potential mechanism of EPCAM in AH. EPCAM was predicted to regulate AH progression through the PI3K/Akt/mTOR signaling pathway. Silencing EPCAM or inhibition of the PI3K/Akt/mTOR signaling pathway inhibited the hepatic fibrosis and HSC proliferation yet induced HSC apoptosis. Moreover, silencing EPCAM was found to repress the PI3K/Akt/mTOR signaling pathway as evidenced by decreased levels of Bcl2 yet increased levels of caspase-3. Collectively, silencing EPCAM could hinder AH progression by inhibiting the PI3K/Akt/mTOR signaling pathway, which might serve as a potential therapeutic target for AH treatment.

Network Pharmacology-Based Prediction of the Active Compounds, Potential Targets, and Signaling Pathways Involved in Danshiliuhao Granule for Treatment of Liver Fibrosis

This study aims to predict the active ingredients, potential targets, signaling pathways and investigate the “ingredient-target-pathway” mechanisms involved in the pharmacological action of Danshiliuhao Granule (DSLHG) on liver fibrosis. Pharmacodynamics studies on rats with liver fibrosis showed that DSLHG generated an obvious anti-liver fibrosis action. On this basis, we explored the possible mechanisms underlying its antifibrosis effect using network pharmacology approach. Information about compounds of herbs in DSLHG was collected from TCMSP public database and literature. Furthermore, the oral bioavailability (OB) and drug-likeness (DL) were screened according to ADME features. Compounds with OB≥30% and DL≥0.18 were selected as active ingredients. Then, the potential targets of the active compounds were predicted by pharmacophore mapping approach and mapped with the target genes of the specific disease. The compound-target network and Protein-Protein Interaction (PPI) network were built by Cytoscape software. The core targets were selected by degree values. Furthermore, GO biological process analysis and KEGG pathway enrichment analysis were carried out to investigate the possible mechanisms involved in the anti-hepatic fibrosis effect of DSLHG. The predicted results showed that there were 108 main active components in the DSLHG formula. Moreover, there were 192 potential targets regulated by DSLHG, of which 86 were related to liver fibrosis, including AKT1, EGFR, and IGF1R. Mechanistically, the anti-liver fibrosis effect of DSLHG was exerted by interfering with 47 signaling pathways, such as PI3K-Akt, FoxO signaling pathway, and Ras signaling pathway. Network analysis showed that DSLHG could generate the antifibrosis action by affecting multiple targets and multiple pathways, which reflects the multicomponent, multitarget, and multichannel characteristics of traditional Chinese medicine and provides novel basis to clarify the mechanisms of anti-liver fibrosis of DSLHG.

Circular RNAs as novel regulators, biomarkers and potential therapies in fibrosis

Fibrosis is the excess deposition of extracellular matrix components which ultimately leads to the disruption of organ architecture and loss of function. Circular RNAs (circRNAs) are a newly discovered type of long noncoding RNAs with single-stranded covalently closed loops. It is known that circRNAs are novel regulators of gene expression via various ways, including miRNA sponge, protein sponge, regulation of transcription and post transcription. Recently, a growing body of evidence suggests that circular RNAs are also involved in tissue fibrosis in several organs. In this review, we summarized current studies of circular RNAs in fibrosis and hopefully aid in better understanding the molecular mechanism of fibrosis and provide a basis to explore new therapeutic targets of fibrosis.

Salvianolic acid A attenuates CCl4-induced liver fibrosis by regulating the PI3K/AKT/mTOR, Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways

Background: Liver fibrosis occurs due to chronic liver disease due to multiple pathophysiological causes. The main causes for this condition are chronic alcohol abuse, nonalcoholic steatohepatitis, and infection due to hepatitis C virus. Currently, there is more and more information available about the molecular as well as cellular mechanisms, which play a role in the advancement of liver fibrosis. However, there is still no effective therapy against it.

Purpose: In order to find an effective treatment against liver fibrosis, our study explored whether salvianolic acid A (SA-A), a traditional Chinese medicine extracted from the plant Danshen, could effectively inhibit the liver fibrosis, which is induced by CCl₄ in vivo.

Methods: The effects of SA-A were evaluated by assessing the parameters related to liver fibrosis such as body weight, histological changes, and biochemical parameters. Thereafter, the related protein or gene levels of P13K/AKT/mTOR, Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways were determined by western blotting, real-time PCR or immunohistochemistry staining.

Results: According to the results of our study, SA-A could reduce liver fibrosis by inhibiting liver function, liver fibrosis index, collagen deposition, and improving the degree of liver fibrosis in rats. Mechanistically, the PI3K/AKT/mTOR signaling cascade was inhibited by SA-A to prevent the stimulation of hepatic stellate cell, as well as the synthesis of extracellular matrix, and regulated Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways to prevent hepatocyte apoptosis.

Conclusion: The novel findings of this study suggested that SA-A could reduce liver fibrosis and the molecular mechanisms behind it are closely associated with the regulation of PI3K/AKT/mTOR, Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways.

Lowering the upper limit of serum alanine aminotransferase levels may reveal significant liver disease in the elderly

This study sought to determine the prevalence of significant liver disease in those subjects with serum alanine aminotransferase levels in the range between the current and the newly suggested upper limit of normal (termed the delta range). The files of the previous study subjects (who underwent at least one alanine aminotransferase measurement in 2002 and followed to 2012) were reviewed for a diagnosis of chronic liver disease; aspartate aminotransferase/platelet ratio index, FIB-4 and alanine aminotransferase/aspartate aminotransferase ratio were used to evaluate liver fibrosis. The prevalence of significant liver disease, by diagnoses and fibrosis scores was compared between subjects with alanine aminotransferase levels in the delta range (men, 42-45 IU/L; women, 26-34 IU/L) and in the newly suggested normal range (men, 15-42 IU/L; women, 10-26 IU/L). The cohort included 49,634 subjects (41% male, mean age 83±6 years) of whom 2022 were diagnosed with chronic liver disease including 366 with cirrhosis. Compared to subjects with alanine aminotransferase levels in the newly suggested normal range, subjects with alanine aminotransferase levels in the delta range had a significantly higher rate of chronic liver disease (men, 15.3% vs. 4.9%; women, 7.8% vs. 3.3%) and of cirrhosis specifically (men, 4.2% vs. 0.9%; women, 1.5% vs. 0.4%) and also had higher mean fibrosis scores (P <0.001 for all). Lowering the current upper limit of normal of serum alanine aminotransferase may help to identify elderly patients at risk of significant liver disease.

Stem Cell Therapy for Cirrhosis of Liver in Bangladesh: Specific Design Compatible for Developing Country

Aims and objectives

To assess the safety and efficacy of stem cell therapy in patients with cirrhosis of the liver (LC) in the context of developing country with limited facilities for cell-based therapy and advanced technologies.

Materials and methods

A total of 34 patients received granulocyte colony-stimulating factor at a dose of 30 IU, daily for 2 to 11 days to upregulate the numbers of white blood cells and stem cells. Subsequently, stem cells were isolated from the peripheral blood of LC patients in a closed chamber using a harvesting machine. Variable amounts of autologous stem cells were injected to LC patients for once. The patients were followed for 3 months and various factors related to safety and parameters of efficacy were analyzed in this interim report.

Results

Out of 34 patients available for final analysis, 3 months after the start of stem therapy, 4 patients died within this period. There was no significant alteration in biochemical parameters due to stem cell therapy, and patients also did not develop any features of acute liver failure indicating that short-term safety parameters of stem cell therapy may be acceptable. Stem cell therapy had a dominant effect on ascites of in this cohort. Although 24 of 34 patients had ascites at the start of therapy,ascites were found in 11 patients after one month and only 4 patients had ascites after 3 months. The positive role of stem cell therapy on ascites in LC patients may be attributed, even in part, to increased serum levels of albumin after therapy compared to basal levels (p <0.001).

Conclusion

This first study about stem cell therapy in Bangladesh indicates that cell therapy may be accomplished in general hospitals of developing countries if the proper design and mild to moderate types of invasive approach is utilized. The apparent safety of administered stem cells in LC patients and the observed effect on ascites of LC patients inspire optimism about the installation of new and innovative therapy in Bangladesh. Future studies with phase I/II may with stem cell and others cell may be planned at Bangladesh in patients with LC and other intractable diseases with suitable control arms.How to cite this article: Mahtab MA, Akbar SMF, Begum M, Islam MA, Rahim MA, Noor-E-Alam SM, Alam MA, Khondaker FA, Moben AL, Mohsena M, Khan SI, Huq MZ, Munshi S, Hoque A, Haque SA. Stem Cell Therapy for Cirrhosis of Liver in Bangladesh: Specific Design Compatible for Developing Country. Euroasian J Hepatogastroenterol, 2018;8(2):121-125.

Using IVIM-MRI and R2⁎ Mapping to Differentiate Early Stage Liver Fibrosis in a Rat Model of Radiation-Induced Liver Fibrosis

Rationale and Objectives

To investigate the utility of intravoxel incoherent motion MRI (IVIM-MRI) and R2⁎ mapping in diagnosing early stage liver fibrosis in a radiation-induced rat model.

Materials and Methods

Thirty rats were randomly divided into three groups with 10 rats in each group. Liver fibrosis was induced by exposure of right lobe of liver in each animal to 20 Gy of radiation. MRI examination was conducted at baseline, one month, two months, and three months after radiation using T1WI, T2WI, IVIM-DWI, and R2⁎ sequences. The pathological examination included hematoxylin eosin, masson trichrome, and prussian blue staining. D, D⁎, f, and R2⁎ values were measured in both left and right lobes for quantitative analysis.

Results

Regarding the surviving 23 rats, eight rats were diagnosed with stage F0, ten with stage F1, and five with stage F2 liver fibrosis using METAVIR Scores. The D values of right lobes decreased (P<0.05), and R2⁎ values increased (P<0.01) significantly as fibrosis levels increased. But there was no statistical difference in D⁎ (P=0.970) and f values (P=0.079). R2⁎ value showed a strong positive correlation (r=0.819, P<0.001), while D value showed a negative correlation with fibrosis stages (r=-0.424, P<0.001). D⁎ (r=0.029, P=0.744) and f values (r=-0.055, P=0.536) were poorly correlated with fibrosis levels.

Conclusion

IVIM-MRI and R2⁎ mapping are useful techniques for evaluating the severity of liver fibrosis in a radiation-induced rat model, and R2⁎ value is the most sensitive parameter in detecting early stage fibrosis.

Liver fibrosis

Liver fibrosis is a wound-healing response generated against an insult to the liver that causes liver injury. It has the potential to progress into cirrhosis, and if not prevented, it may lead to liver cancer and liver failure. The activation of hepatic stellate cells (HSCs) is the central event underlying liver fibrosis. In addition to HSCs, numerous studies have supported the potential contribution of bone marrow-derived cells and myofibroblasts to liver fibrosis. The liver is a heterogeneous organ; thus, molecular and cellular events that underlie liver fibrogenesis are complex. This review aims to focus on major events that occur during liver fibrogenesis. In addition, important antifibrotic therapeutic approaches and experimental liver fibrosis models will be discussed.

Tanshinol ameliorates CCl4-induced liver fibrosis in rats through the regulation of Nrf2/HO-1 and NF-κB/IκBα signaling pathway

Tanshinol, a water-soluble component isolated from Salvia miltiorrhiza Bunge, has a variety of biological activities involving anti-fibrotic effect. However, the exact role and the underlying mechanisms remain largely unclear. This study mainly focused on the anti-hepatic fibrotic activities and mechanisms of tanshinol on carbon tetrachloride (CCl4)-induced liver fibrosis in rats via anti-oxidative and anti-inflammation pathways. The rats were divided into 4 groups as follows: control, model, tanshinol 20 mg/kg, and tanshinol 40 mg/kg. Except for the control group, CCl4 was used to induce liver fibrosis processing for 8 weeks, meanwhile rats in tanshinol groups were intraperitoneally injected with additional tanshinol. Control group simultaneously received the same volumes of olive oil and saline. The potentially protective effect and mechanisms of tanshinol on liver fibrosis in rats were evaluated. The serum levels of alanine aminotransferase, aspartate aminotransferase, and total bilirubin were obviously lower in the tanshinol treatment groups related to model group. Compared with the model group, the levels of hyaluronic acid, type IV collagen, Laminin (LN), and procollagen III peptide (PIIIP) in serum were significantly decreased after tanshinol treatment. Furthermore, tanshinol could regulate Nrf2/HO-1 signaling pathway and increase the level of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and also decrease the level of malondialdehyde (MDA) to against damage induced by oxidative stress. Simultaneously tanshinol could regulate nuclear factor kappa B signaling pathway to inhibit expression of inflammation factors, including transforming growth factor-β, tumor necrosis factor-α, Cox-2, interleukin-1β, and interleukin-6. In summary, our research demonstrated that tanshinol has protective effect on CCl4-induced liver fibrosis via inhibiting oxidative stress and inflammation, which may be associated with the regulation of nuclear factor erythroid2-related factor 2/hemeoxygenase-a and nuclear factor kappa B/inhibitor of kappa B alpha signaling pathways.

Evaluation of liver fibrosis with a monoexponential model of intravoxel incoherent motion magnetic resonance imaging

To evaluate hepatic fibrosis with a monoexponential model of intravoxel incoherent motion magnetic resonance imaging, and assess the potential application value of intravoxel incoherent motion (IVIM) in diffusion-weighted imaging (IVIM-DWI) in determining staging of liver fibrosis. 28 patients with hepatic fibrosis and 25 volunteers with healthy livers had IVIM examination and conventional MRI. All standard apparent diffusion coefficient (ADC) values of IVIM raw data were post-processed off-line after completion of data collection. All regions of interest (ROIs) were manually positioned by two experienced radiologists. All values of the different fibrosis stages in the study group were compared using independent sample t tests. Using ROC analysis, both AUC values of ADC_total and ADC_{0-400-600-800} from study and control group were found to be between 0.8 and 1 for staging fibrosis. The mean ADC_total and ADC_{0-400-600-800} values of the liver in the study group were significantly lower than the values in the control group (P < 0.05). Spearman rho correlation analysis was used to determine the relationship among fibrosis stages and the ADC_total and ADC_{0-400-600-800} in the study group. As the stage of the fibrosis increased, the values decreased. Significant differences between the two subgroups of liver fibrosis stages were found (P < 0.05). The monoexponential model of IVIM-DWI adopted multiple b values for quantitative analysis of the water molecules diffused in the tissue. It could be used as a noninvasive and valuable method for assessment of liver fibrosis.

CD147 Promotes CXCL1 Expression and Modulates Liver Fibrogenesis

Activated hepatic stellate cells (HSCs) release pro-inflammatory and pro-fibrogenic factors. CXC chemokine-ligand-1 (CXCL1) is expressed on HSCs. We previously found that the CD147 is overexpressed in activated HSCs. In this study, we showed an important role of CD147 in promoting liver fibrosis by activating HSCs and upregulating expression of chemokines. Specifically, we found that CD147 specific deletion in HSCs mice alleviated CCl₄-induced liver fibrosis and inhibited HSCs activation. Overexpression of CD147 upregulated the secretion of CXCL1. Meanwhile, CXCL1 promoted HSCs activation through autocrine. Treating with PI3K/AKT inhibitor could effectively suppress CD147-induced CXCL1 expression. Taken together, these findings suggest that CD147 regulates CXCL1 release in HSCs by PI3K/AKT signaling. Inhibition of CD147 attenuates CCl₄-induced liver fibrosis and inflammation. Therefore, administration of targeting CD147 could be a promising therapeutic strategy in liver fibrosis.

pPB Peptide-Mediated siRNA-Loaded Stable Nucleic Acid Lipid Nanoparticles on Targeting Therapy of Hepatic Fibrosis

Hepatic fibrosis is a necessary process in the development of liver diseases such as hepatic cirrhosis and its complications, which has become a serious threat to human health. Currently, antifibrotic drug treatment is ineffective, and one reason should be the lack of liver targeting ability. In this report, polypeptide pPB-modified stable nucleic acid lipid nanoparticles (pPB-SNALPs) were prepared to selectively deliver siRNAs against heat shock protein 47 to the liver for targeted therapy of hepatic fibrosis. First, siRNA sequences with high silencing efficiency were screened based on siRNA transfection efficacy. Then, pPB-SNALPs were prepared, which showed a narrow size distribution with a diameter in the range of 110-130 nm and a neutral z-potential of 0 mV. As evidenced by the in vitro and in vivo targeting study, compared with unmodified SNALP, pPB-SNALP showed increased uptake by LX-2 cells and primary hepatic stellate cells (HSC) of mice in vitro and showed increased liver distribution and HSC uptake in vivo. In addition, pPB-SNALP also exhibited an enhanced inhibitory effect on TAA-induced hepatic fibrosis mice with high gp46 mRNA expression in vivo. In summary, our results demonstrated that pPB-SNALP is an effective liver-targeted delivery system. This study could lay a good foundation for the targeted gene therapy of hepatic fibrosis.

Presence of atrial fibrillation is associated with liver stiffness in an elderly Finnish population

Background

Chronic liver injury from different etiologies drives liver fibrosis. However, little is known about the associated factors, systemic factors in particular. Recently, non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation have been shown to be associated with each other. Thereby, we aimed to study the association between atrial fibrillation and liver stiffness.

Study

Extensive clinical measurements including echocardiography of the heart, transient elastography (TE) of the liver and the presence of atrial fibrillation were determined in elderly Finnish study subjects (n = 76, mean age 73 years) from OPERA (Oulu Project Elucidating the Risk of Atherosclerosis) study cohort. Half of the study subjects had non-alcoholic fatty liver disease, whereas others did not have any known hepatic morbidity. The present study was cross-sectional by nature.

Results

The subjects with atrial fibrillation had higher TE values (with atrial fibrillation TE = 9.3kPa, without atrial fibrillation TE = 6.3kPa, p = 0.018). When the cohort was divided to four subgroups (those without NAFLD or atrial fibrillation, with NAFLD but without atrial fibrillation, with both conditions, and with atrial fibrillation but without NAFLD), the TE value was the highest in the subjects with both conditions (5.3kPa, 7.4kPa, 10.8kPa and 7.8kPa, respectively, p = 0.019). Moreover, the higher the TE value, the more prevalent atrial fibrillation was (the atrial fibrillation prevalence by tertiles of TE 27% / 36% / 77%, p = 0.001). Likewise, the greater the TE value, the greater the left atrial diameter, a collateral of atrial fibrillation (left atrial diameters by tertiles of TE 39mm / 45mm / 48mm, p<0.001) was. All these p-values for continuous variables remained statistically significant even after adjustment for common clinically relevant risk factors.

Conclusions

There is an association between atrial fibrillation and liver stiffness. This novel association may have multiple explanations and mechanistic links, which are discussed here and need further studies, prospective studies in particular.

Modulation of hepatic stellate cells and reversibility of hepatic fibrosis

Hepatic fibrosis (HF) is the pathological component of a variety of chronic liver diseases. Hepatic stellate cells (HSC) are the main collagen-producing cells in the liver and their activation promotes HF. If HSC activation and proliferation can be inhibited, HF occurrence and development can theoretically be reduced and even reversed. Over the past ten years, a number of studies have addressed this process, and here we present a review of HSC modulation and HF reversal.

Non-invasive evaluation of liver stiffness after splenectomy in rabbits with CCl4-induced liver fibrosis

AIM

To investigate the diagnostic performance of liver stiffness measurement (LSM) by elastography point quantification (ElastPQ) in animal models and determine the longitudinal changes in liver stiffness by ElastPQ after splenectomy at different stages of fibrosis.

METHODS

Liver stiffness was measured in sixty-eight rabbits with CCl₄-induced liver fibrosis at different stages and eight healthy control rabbits by ElastPQ. Liver biopsies and blood samples were obtained at scheduled time points to assess liver function and degree of fibrosis. Thirty-one rabbits with complete data that underwent splenectomy at different stages of liver fibrosis were then included for dynamic monitoring of changes in liver stiffness by ElastPQ and liver function according to blood tests.

RESULTS

LSM by ElastPQ was significantly correlated with histologic fibrosis stage (r = 0.85, P < 0.001). The optimal cutoff values by ElastPQ were 11.27, 14.89, and 18.21 kPa for predicting minimal fibrosis, moderate fibrosis, and cirrhosis, respectively. Longitudinal monitoring of the changes in liver stiffness by ElastPQ showed that early splenectomy (especially F1) may delay liver fibrosis progression.

CONCLUSION

ElastPQ is an available, convenient, objective and non-invasive technique for assessing liver stiffness in rabbits with CCl₄-induced liver fibrosis. In addition, liver stiffness measurements using ElastPQ can dynamically monitor the changes in liver stiffness in rabbit models, and in patients, after splenectomy.

Evolving Insights on Metabolism, Autophagy, and Epigenetics in Liver Myofibroblasts

Liver myofibroblasts (MFB) are crucial mediators of extracellular matrix (ECM) deposition in liver fibrosis. They arise mainly from hepatic stellate cells (HSCs) upon a process termed “activation.” To a lesser extent, and depending on the cause of liver damage, portal fibroblasts, mesothelial cells, and fibrocytes may also contribute to the MFB population. Targeting MFB to reduce liver fibrosis is currently an area of intense research. Unfortunately, a clog in the wheel of antifibrotic therapies is the fact that although MFB are known to mediate scar formation, and participate in liver inflammatory response, many of their molecular portraits are currently unknown. In this review, we discuss recent understanding of MFB in health and diseases, focusing specifically on three evolving research fields: metabolism, autophagy, and epigenetics. We have emphasized on therapeutic prospects where applicable and mentioned techniques for use in MFB studies. Subsequently, we highlighted uncharted territories in MFB research to help direct future efforts aimed at bridging gaps in current knowledge.