Targeting Follistatin like 1 ameliorates liver fibrosis induced by carbon tetrachloride through TGF-β1-miR29a in mice

Plasma FSTL-1 as a noninvasive diagnostic biomarker for patients with advanced liver fibrosis

BACKGROUND AND AIMS

Reliable novel noninvasive biomarkers for the diagnosis of advanced liver fibrosis are urgently needed in clinical practice. We aimed to investigate the accuracy of plasma Follistatin-like protein 1 (FSTL-1) in the diagnosis of advanced liver fibrosis in chronic liver diseases.

APPROACH AND RESULTS

We collected cross-sectional clinical data for a derivation cohort (n = 86) and a validation cohort (n = 431), totaling 517 subjects with liver biopsy. Advanced liver fibrosis was defined by the METAVIR pathological score (F ≥3). Dual cutoff values for diagnosis were explored. In the derivation cohort, plasma FSTL-1 levels were significantly elevated in patients with advanced liver fibrosis, with an AUROC of 0.85 (95% CI, 0.75-0.96). In the validation cohort, plasma FSTL-1 maintained good diagnostic performance, with an AUROC of 0.88 (95% CI, 0.83-0.92). Plasma FSTL-1 levels were significantly associated with individual histological features of the METAVIR scoring system, including interface hepatitis, lobular necrosis, and hepatocellular ballooning (p < 0.0001). A cutoff value ≤ 0.43 ng/mL was the optimal rule-out threshold, with a sensitivity of 84.62% (95% CI, 76.46%-90.30%) and a specificity of 79.51% (95% CI, 74.81%-83.53%), while ≥0.50 ng/mL was the best rule-in threshold, with a specificity of 86.41% (95% CI, 81.06%-90.43%) and a sensitivity of 70.67% (95% CI, 64.41%-76.23%).

CONCLUSIONS

Plasma FSTL-1 has high diagnostic accuracy and could potentially reduce the need for liver biopsy in identifying patients with advanced liver fibrosis.

Serum follistatin like 1 in children with obesity and metabolic-associated fatty liver disease

BACKGROUND

Follistatin-like protein 1 (FSTL1) has been identified as a secreted glycoprotein that plays an important role in obesity. However, its role in children with metabolic-associated fatty liver disease (MAFLD) has not been investigated. This study aimed at characterizing the relationship between serum FSTL1 concentration and MAFLD in children with obesity.

METHODS

A total of 121 subjects were recruited from the Second Affiliated Hospital of Xi'an Jiaotong University, including 45 obese children with MAFLD, 31 obese children without MAFLD, and 45 healthy controls. Anthropometric parameters, biochemical data were measured and circulating FSTL1 levels were detected by ELISA.

RESULTS

The levels of FSTL1 in obese children with MAFLD were higher than that in obese children without MAFLD: 1.31 (0.35-2.29) ng/mL vs. 0.55 (0.36-1.38) ng/mL. Correlation analysis illustrated that FSTL1 was associated with nonesterified free fatty acid and leptin (r = 0.278, P < 0.05 and r = 0.572, P < 0.05, respectively). Binary logistic regression suggested that increased FSTL1 was a risk factor for MAFLD in children (OR = 1.105, 95% CI: 1.066-1.269, P < 0.05).

CONCLUSIONS

Serum FSTL1 concentrations increase in obese children with MAFLD and may have the potential to be a risk factor for MAFLD in children with obesity.

Noncoding RNA-Mediated Epigenetic Regulation in Hepatic Stellate Cells of Liver Fibrosis

Liver fibrosis is a significant contributor to liver-related disease mortality on a global scale. Despite this, there remains a dearth of effective therapeutic interventions capable of reversing this condition. Consequently, it is imperative that we gain a comprehensive understanding of the underlying mechanisms driving liver fibrosis. In this regard, the activation of hepatic stellate cells (HSCs) is recognized as a pivotal factor in the development and progression of liver fibrosis. The role of noncoding RNAs (ncRNAs) in epigenetic regulation of HSCs transdifferentiation into myofibroblasts has been established, providing new insights into gene expression changes during HSCs activation. NcRNAs play a crucial role in mediating the epigenetics of HSCs, serving as novel regulators in the pathogenesis of liver fibrosis. As research on epigenetics expands, the connection between ncRNAs involved in HSCs activation and epigenetic mechanisms becomes more evident. These changes in gene regulation have attracted considerable attention from researchers in the field. Furthermore, epigenetics has contributed valuable insights to drug discovery and the identification of therapeutic targets for individuals suffering from liver fibrosis and cirrhosis. As such, this review offers a thorough discussion on the role of ncRNAs in the HSCs activation of liver fibrosis.

Down-regulation of DPP4 by TGFβ1/miR29a-3p inhibited proliferation and promoted migration of ovarian cancer cells

OBJECTIVE

To explore the DPP4 expression changes and functions in ovarian cancer (OV), as well as the regulation mechanism for DDP4.

METHODS

GEPIA2, GSE18520, GSE26712 and UALCAN were used to analyze differences in DPP4 expression between OV tumors and control tissues. Serum DPP4 levels were measured by ELISA. The prognostic values of DPP4 were evaluated using a Kaplan-Meier (KM) plotter. Small interfering RNA was used for DPP4 knockdown in OVCAR-3 and SKOV-3 cells. CCK-8 and scratch healing assays were used to determine the cells' proliferation and migration abilities. Flow cytometry (FCM) was used to detect the cell cycle and apoptosis. A dual-luciferase assay was designed to confirm the regulatory effect of miR-29a-3p on DPP4.

RESULTS

The expressions of DPP4 mRNA and protein were decreased in OV tumor tissues. Serum DPP4 levels decreased in OV patients. KM plotter analysis showed correlation between high DPP4 expression and a poor prognosis in OV patients. By targeting knockdown of DPP4, we found that OVCAR-3 and SKOV-3 cells' proliferation was inhibited, while cell's migration ability was significantly promoted. FCM analysis showed that DPP4 knockdown induced a decrease in the S phase. Furthermore, DPP4 was shown to be downregulated by miR-29a-3p and TGFβ1 in OVCAR-3 cells, and miR-29a-3p expression was upregulated by TGFβ1. The effects of miR-29a-3p and TGFβ1 on OVCAR-3 cells' biological behaviors were consistent with DPP4 knockdown.

CONCLUSION

DPP4 was downregulated in OV patients. DPP4 knockdown significantly inhibited OVCAR-3 and SKOV-3 cell proliferation and promoted cell migration. DDP4 can be downregulated by TGFβ1 through the upregulation of miR-29a-3p in OV cells.

Dynamic Alterations to Hepatic MicroRNA-29a in Response to Long-Term High-Fat Diet and EtOH Feeding

MicroRNA-29a (miR-29a) is a well characterized fibro-inflammatory molecule and its aberrant expression is linked to a variety of pathological liver conditions. The long-term effects of a high-fat diet (HFD) in combination with different levels of EtOH consumption on miR-29a expression and liver pathobiology are unknown. Mice at 8 weeks of age were divided into five groups (calorie-matched diet plus water (CMD) as a control group, HFD plus water (HFD) as a liver disease group, HFD plus 2% EtOH (HFD + 2% E), HFD + 10% E, and HFD + 20% E as intervention groups) and fed for 4, 13, 26, or 39 weeks. At each time point, analyses were performed for liver weight/body weight (BW) ratio, AST/ALT ratio, as well as liver histology assessments, which included inflammation, estimated fat deposition, lipid area, and fibrosis. Hepatic miR-29a was measured and correlations with phenotypic traits were determined. Four-week feeding produced no differences between the groups on all collected phenotypic traits or miR-29a expression, while significant effects were observed after 13 weeks, with EtOH concentration-specific induction of miR-29a. A turning point for most of the collected traits was apparent at 26 weeks, and miR-29a was significantly down-regulated with increasing liver injury. Overall, miR-29a up-regulation was associated with a lower liver/BW ratio, fat deposition, inflammation, and fibrosis, suggesting a protective role of miR-29a against liver disease progression. A HFD plus increasing concentrations of EtOH produces progressive adverse effects on the liver, with no evidence of beneficial effects of low-dose EtOH consumption. Moreover, miR-29a up-regulation is associated with less severe liver injury.

Cardiac RGS7 and RGS11 drive TGFβ1-dependent liver damage following chemotherapy exposure

Off target damage to vital organ systems is an unfortunate side effect of cancer chemotherapy and remains a major limitation to the use of these essential drugs in the clinic. Despite decades of research, the mechanisms conferring susceptibility to chemotherapy driven cardiotoxicity and hepatotoxicity remain unclear. In the livers of patients with a history of chemotherapy, we observed a twofold increase in expression of G protein regulator RGS7 and a corresponding decrease in fellow R7 family member RGS11. Knockdown of RGS7 via introduction of RGS7 shRNA via tail vein injection decreased doxorubicin-induced hepatic collagen and lipid deposition, glycogen accumulation, and elevations in ALT, AST, and triglycerides by approximately 50%. Surprisingly, a similar result could be achieved via introduction of RGS7 shRNA directly to the myocardium without impacting RGS7 levels in the liver directly. Indeed, doxorubicin-treated cardiomyocytes secrete the endocrine factors transforming growth factor β1 (TGFβ1) and TGFβ superfamily binding protein follistatin-related protein 1 (FSTL1). Importantly, RGS7 overexpression in the heart was sufficient to recapitulate the impacts of doxorubicin on the liver and inhibition of TGFβ1 signaling with the receptor blocker GW788388 ameliorated the effect of cardiac RGS7 overexpression on hepatic fibrosis, steatosis, oxidative stress, and cell death as well as the resultant elevation in liver enzymes. Together these data demonstrate that RGS7 controls both the release of TGFβ1 from the heart and the profibrotic and pro-oxidant actions of TGFβ1 in the liver and emphasize the functional significance of endocrine cardiokine signaling in the pathogenesis of chemotherapy drive multiorgan damage.

From Phenomenon to Essence: A Newly Involved lncRNA Kcnq1ot1 Protective Mechanism of Bone Marrow Mesenchymal Stromal Cells in Liver Cirrhosis

Bone marrow mesenchymal stromal cells (BMSCs) have a protective effect against liver cirrhosis. Long noncoding RNAs (lncRNAs) play crucial roles in the progression of liver cirrhosis. Therefore, it is aimed to clarify the lncRNA Kcnq1ot1 involved protective mechanism of BMSCs in liver cirrhosis. This study found that BMSCs treatment attenuates CCl4 -induced liver cirrhosis in mice. Additionally, the expression of lncRNA Kcnq1ot1 is upregulated in human and mouse liver cirrhosis tissues, in addition to TGF-β1-treated LX2 cells and JS1 cells. The expression of Kcnq1ot1 in liver cirrhosis is reversed with BMSCs treatment. The knockdown of Kcnq1ot1 alleviated liver cirrhosis both in vivo and in vitro. Fluorescence in situ hybridization (FISH) confirms that Kcnq1ot1 is mainly distributed in the cytoplasm of JS1 cells. It is predicted that miR-374-3p can directly bind with lncRNA Kcnq1ot1 and Fstl1, which is verified via luciferase activity assay. The inhibition of miR-374-3p or the overexpression of Fstl1 can attenuate the effect of Kcnq1ot1 knockdown. In addition, the transcription factor Creb3l1 is upregulated during JS1 cells activation. Moreover, Creb3l1 can directly bind to the Kcnq1ot1 promoter and positively regulate its transcription. In conclusion, BMSCs alleviate liver cirrhosis by modulating the Creb3l1/lncRNA Kcnq1ot1/miR-374-3p/Fstl1 signaling pathway.

Role of noncoding RNAs in liver fibrosis

Liver fibrosis is a wound-healing response following chronic liver injury caused by hepatitis virus infection, obesity, or excessive alcohol. It is a dynamic and reversible process characterized by the activation of hepatic stellate cells and excess accumulation of extracellular matrix. Advanced fibrosis could lead to cirrhosis and even liver cancer, which has become a significant health burden worldwide. Many studies have revealed that noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs and circular RNAs, are involved in the pathogenesis and development of liver fibrosis by regulating signaling pathways including transforming growth factor-β pathway, phosphatidylinositol 3-kinase/protein kinase B pathway, and Wnt/β-catenin pathway. NcRNAs in serum or exosomes have been reported to tentatively applied in the diagnosis and staging of liver fibrosis and combined with elastography to improve the accuracy of diagnosis. NcRNAs mimics, ncRNAs in mesenchymal stem cell-derived exosomes, and lipid nanoparticles-encapsulated ncRNAs have become promising therapeutic approaches for the treatment of liver fibrosis. In this review, we update the latest knowledge on ncRNAs in the pathogenesis and progression of liver fibrosis, and discuss the potentials and challenges to use these ncRNAs for diagnosis, staging and treatment of liver fibrosis. All these will help us to develop a comprehensive understanding of the role of ncRNAs in liver fibrosis.

Role of follistatin-like protein 1 in liver diseases

Liver diseases, including viral hepatitis, fatty liver, metabolic-associated fatty liver disease, liver cirrhosis, alcoholic liver disease, and liver neoplasms, are major global health challenges. Despite the continued development of new drugs and technologies, the prognosis of end-stage liver diseases, including advanced liver cirrhosis and liver neoplasms, remains poor. Follistatin-like protein 1 (FSTL1), an extracellular glycoprotein, is secreted by various cell types. It is a glycoprotein that belongs to the family of secreted proteins acidic and rich in cysteine (SPARC). It is also known as transforming growth factor-beta inducible TSC-36 and follistatin-related protein (FRP). FSTL1 plays a key role in cell survival, proliferation, differentiation, and migration, as well as the regulation of inflammation and immunity. Studies have demonstrated that FSTL1 significantly affects the occurrence and development of liver diseases. This article reviews the role and mechanism of FSLT1 in liver diseases.

The role of microRNAs on the pathogenesis, diagnosis and management of portal hypertension in patients with chronic liver disease

INTRODUCTION

Portal hypertension (PH) is the elevated pressure in the portal vein, which results in poor functioning of the liver and is influenced by various factors like liver cirrhosis, nonalcoholic fatty liver disease, schistosomiasis, thrombosis, and angiogenesis. Though the diagnosis and treatment have been advanced, early diagnosis of the disease remains a challenge, and the diagnosis methods are often invasive. Hence, the clear understanding of the molecular mechanisms of PH can give rise to the development of novel biomarkers which can pave way for early diagnosis in noninvasive methods, and also the identification of target genes can elucidate an efficient therapeutic target.

AREAS COVERED

PubMed and Embase database was used to search articles with search terms 'Portal Hypertension' or 'pathophysiology' and 'diagnosis' and 'treatment' or "role of miRNAs in portal hypertension.

EXPERT OPINION

Interestingly, biomarkers like microRNAs (miRNAs) have been studied for their potential role in various diseases including hypertension. In recent years, miRNAs have been proved to be an efficient biomarker and therapeutic target and few studies have assessed the roles of miRNAs in PH. The present paper highlights the potential roles of miRNAs in PH.

Regulatory network and interplay of hepatokines, stellakines, myokines and adipokines in nonalcoholic fatty liver diseases and nonalcoholic steatohepatitis

Fatty liver disease is a spectrum of liver pathologies ranging from simple hepatic steatosis to non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and culminating with the development of cirrhosis or hepatocellular carcinoma (HCC). The pathogenesis of NAFLD is complex and diverse, and there is a lack of effective treatment measures. In this review, we address hepatokines identified in the pathogenesis of NAFLD and NASH, including the signaling of FXR/RXR, PPARα/RXRα, adipogenesis, hepatic stellate cell activation/liver fibrosis, AMPK/NF-κB, and type 2 diabetes. We also highlight the interaction between hepatokines, and cytokines or peptides secreted from muscle (myokines), adipose tissue (adipokines), and hepatic stellate cells (stellakines) in response to certain nutritional and physical activity. Cytokines exert autocrine, paracrine, or endocrine effects on the pathogenesis of NAFLD and NASH. Characterizing signaling pathways and crosstalk amongst muscle, adipose tissue, hepatic stellate cells and other liver cells will enhance our understanding of interorgan communication and potentially serve to accelerate the development of treatments for NAFLD and NASH.

Proteomics and phosphoproteomics analysis of vitreous in idiopathic epiretinal membrane patients

PURPOSE

The purpose of the present study was to characterize the idiopathic epiretinal membrane (iERM) through proteomics and phosphoproteomics analysis to facilitate the diagnosis and treatment of iERM.

EXPERIMENTAL DESIGN

The vitreous of 25 patients with an iERM and 15 patients with an idiopathic macular hole were analyzed by proteomic and phosphoproteomic analysis based on tandem mass tag. PRM was used to verify the differential proteins.

RESULTS

Proteomic analysis identified a total of 878 proteins, including 50 differential proteins. Tenascin-C, galectin-3-binding protein, glucose-6-phosphate isomerase, neuroserpin, collagen alpha-1(XI) chain, and collagen alpha-1(II) chain were verified to be upregulated in iERM by PRM. Phosphoproteomic analysis identified a total of 401 phosphorylation sites on 213 proteins, including 27 differential phosphorylation sites on 24 proteins. Mitogen-activated protein kinase-activated protein kinase (MAPKAPK)3 and MAPKAPK5 were predicted as the major kinases in the vitreous of iERM. Twenty-six of the differential proteins and phosphorylated proteins may be closely related to fibrosis in iERM.

CONCLUSION AND CLINICAL RELEVANCE

Our results indicated the potential biomarkers or therapeutic targets for iERM, provided key kinases that may be involved in iERM. Fibrosis plays an essential role in iERM, and further exploration of related differential proteins has important clinical significance.

Mechanism and Therapeutic Targets of c-Jun-N-Terminal Kinases Activation in Nonalcoholic Fatty Liver Disease

Non-alcoholic fatty liver (NAFL) is the most common chronic liver disease. Activation of mitogen-activated kinases (MAPK) cascade, which leads to c-Jun N-terminal kinase (JNK) activation occurs in the liver in response to the nutritional and metabolic stress. The aberrant activation of MAPKs, especially c-Jun-N-terminal kinases (JNKs), leads to unwanted genetic and epi-genetic modifications in addition to the metabolic stress adaptation in hepatocytes. A mechanism of sustained P-JNK activation was identified in acute and chronic liver diseases, suggesting an important role of aberrant JNK activation in NASH. Therefore, modulation of JNK activation, rather than targeting JNK protein levels, is a plausible therapeutic application for the treatment of chronic liver disease.

Endogenous Follistatin-like 1 guarantees the immunomodulatory properties of mesenchymal stem cells during liver fibrotic therapy

Background

Mesenchymal stem cell (MSC) therapy has been shown to be a promising option for liver fibrosis treatment. However, critical factors affecting the efficacy of MSC therapy for liver fibrosis remain unknown. Follistatin-like 1 (FSTL1), a TGF-β-induced matricellular protein, is documented as an intrinsic regulator of proliferation and differentiation in MSCs. In the present study, we characterized the potential role of FSTL1 in MSC-based anti-fibrotic therapy and further elucidated the mechanisms underlying its action.

Methods

Human umbilical cord-derived MSCs were characterized by flow cytometry. FSTL1^low MSCs were achieved by FSTL1 siRNA. Migration capacity was evaluated by wound-healing and transwell assay. A murine liver fibrotic model was created by carbon tetrachloride (CCl₄) injection, while control MSCs or FSTL1^low MSC were transplanted via intravenous injection 12 weeks post CCl₄ injection. Histopathology, liver function, fibrosis degree, and inflammation were analysed thereafter. Inflammatory cell infiltration was evaluated by flow cytometry after hepatic nonparenchymal cell isolation. An MSC-macrophage co-culture system was constructed to further confirm the role of FSTL1 in the immunosuppressive capacity of MSCs. RNA sequencing was used to screen target genes of FSTL1.

Results

FSTL1^low MSCs had comparable gene expression for surface markers to wildtype but limited differentiation and migration capacity. FSTL1^low MSCs failed to alleviate CCl₄-induced hepatic fibrosis in a mouse model. Our data indicated that FSTL1 is essential for the immunosuppressive action of MSCs on inflammatory macrophages during liver fibrotic therapy. FSTL1 silencing attenuated this capacity by inhibiting the downstream JAK/STAT1/IDO pathway.

Conclusions

Our data suggest that FSTL1 facilitates the immunosuppression of MSCs on macrophages and that guarantee the anti-fibrotic effect of MSCs in liver fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03042-4.

Anti-CD20 Therapy Alters the Protein Signature in Experimental Murine AIH, but Not Exclusively towards Regeneration

Background: Autoimmune hepatitis (AIH) is a chronic autoimmune inflammatory disease that usually requires lifelong immunosuppression. Frequent recurrences after the discontinuation of therapy indicate that intrahepatic immune regulation is not restored by current treatments. Studies of other autoimmune diseases suggest that temporary depletion of B cells can improve disease progression in the long term. Methods: We tested a single administration of anti-CD20 antibodies to reduce B cells and the amount of IgG to induce intrahepatic immune tolerance. We used our experimental murine AIH (emAIH) model and treated the mice with anti-CD20 during the late stage of the disease. Results: After treatment, the mice showed the expected reductions in B cells and serum IgGs, but no improvements in pathology. However, all treated animals showed a highly altered serum protein expression pattern, which was a balance between inflammation and regeneration. Conclusions: In conclusion, anti-CD20 therapy did not produce clinically measurable results because it triggered inflammation, as well as regeneration, at the proteomic level. This finding suggests that anti-CD20 is ineffective as a sole treatment for AIH or emAIH.

Stress kinases in the development of liver steatosis and hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD) is an important component of metabolic syndrome and one of the most prevalent liver diseases worldwide. This disorder is closely linked to hepatic insulin resistance, lipotoxicity, and inflammation. Although the mechanisms that cause steatosis and chronic liver injury in NAFLD remain unclear, a key component of this process is the activation of stress-activated kinases (SAPKs), including p38 and JNK in the liver and immune system. This review summarizes findings which indicate that the dysregulation of stress kinases plays a fundamental role in the development of steatosis and are important players in inducing liver fibrosis. To avoid the development of steatohepatitis and liver cancer, SAPK activity must be tightly regulated not only in the hepatocytes but also in other tissues, including cells of the immune system. Possible cellular mechanisms of SAPK actions are discussed.

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Hepatic JNK triggers steatosis and insulin resistance, decreasing lipid oxidation and ketogenesis in HFD-fed mice.

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Decreased liver expression of p38α/β in HFD increases lipogenesis.

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Hepatic p38γ/δ drive insulin resistance and inhibit autophagy, which may lead to steatosis.

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Macrophage p38α/β promote cytokine production and M1 polarization, leading to lipid accumulation in hepatocytes.

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Myeloid p38γ/δ contribute to cytokine production and neutrophil migration, protecting against steatosis, diabetes and NAFLD.

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JNK1 and p38γ induce HCC while p38α blocks it. However, deletion of hepatic JNK1/2 induces cholangiocarcinoma.

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SAPK are potential therapeutic target for metabolic disorders, steatohepatitis and liver cancer.