IFN-gamma abrogates profibrogenic TGF-beta signaling in liver by targeting expression of inhibitory and receptor Smads

Extracellular vesicles secreted by equine adipose mesenchymal stem cells preconditioned with transforming growth factor β-1 are enriched in anti-fibrotic miRNAs and inhibit the expression of fibrotic genes in an in vitro system of endometrial stromal cells fibrosis

Mare endometrosis is a major reproductive problem associated with low fertility and is characterized by persistent inflammation, TGFβ-1 signaling, and consequently, extracellular matrix deposition, which compromises endometrial glands. Mesenchymal stem cell-based products (MSCs), such as extracellular vesicles (EVs), have gained attention due to the regulatory effects exerted by their miRNA cargo. Here, we evaluated the impact of preconditioning equine adipose mesenchymal stem cells with TGFβ-1 for short or long periods on the anti-fibrotic properties of secreted extracellular vesicles. MSCs were isolated from six healthy horses and exposed to TGFβ-1 for 4, 24, and 0 h. The expression of anti-fibrotic and pro-fibrotic miRNAs and mRNAs in treated cells and miRNAs in the cargo of secreted extracellular vesicles was measured. The resulting EVs were added for 48 h to endometrial stromal cells previously induced to a fibrotic status. The expression of anti-fibrotic and pro-fibrotic genes and miRNAs was evaluated in said cells using qPCR and next-generation sequencing. Preconditioning MSCs with TGFβ-1 for 4 h enriched the anti-fibrotic miRNAs (mir29c, mir145, and mir200) in cells and EVs. Conversely, preconditioning the cells for 24 h leads to a pro-fibrotic phenotype overexpressing mir192 and mir433. This finding might have implications for developing an EV-based protocol to treat endometrial fibrosis in mares.

Hepatitis C virus NS5A and core protein induce fibrosis-related genes regulation on Huh7 cells through activation of LX2 cells

INTRODUCTION AND OBJECTIVES

Liver fibrosis remains a complication derived from a chronic Hepatitis C Virus (HCV) infection even when it is resolved, and no liver antifibrotic drug has been approved. Molecular mechanisms on hepatocytes and activation of hepatic stellate cells (HSCs) play a central role in liver fibrogenesis. To elucidate molecular mechanisms, it is important to analyze pathway regulation during HSC activation and HCV infection.

MATERIALS AND METHODS

We evaluate the fibrosis-associated molecular mechanisms during a co-culture of human HSCs (LX2), with human hepatocytes (Huh7) that express HCV NS5A or Core protein. We evaluated LX2 activation induced by HCV NS5A or Core expression in Huh7 cells during co-culture. We determined a fibrosis-associated gene expression profile in Huh7 that expresses NS5A or Core proteins during the co-culture with LX2.

RESULTS

We observed that NS5A induced 8.3-, 6.7- and 4-fold changes and that Core induced 6.5-, 1.8-, and 6.2-fold changes in the collagen1, TGFβ1, and timp1 gene expression, respectively, in LX2 co-cultured with transfected Huh7. In addition, NS5A induced the expression of 30 genes while Core induced 41 genes and reduced the expression of 30 genes related to fibrosis in Huh7 cells during the co-culture with LX2, compared to control. The molecular pathways enriched from the gene expression profile were involved in TGFB signaling and the organization of extracellular matrix.

CONCLUSIONS

We demonstrated that HCV NS5A and Core protein expression regulate LX2 activation. NS5A and Core-induced LX2 activation, in turn, regulates diverse fibrosis-related gene expression at different levels in Huh7, which can be further analyzed as potential antifibrotic targets during HCV infection.

Combination treatment with interferon-γ may be a potential strategy to improve the efficacy of cytotherapy for rheumatoid arthritis: A network meta-analysis

Background

Mesenchymal stem cells (MSCs) are considered a promising therapeutic strategy for rheumatoid arthritis (RA), but the current clinical results are varied. This study is to analyze the therapeutic effect of cell-based strategies on RA.

Materials and Methods

The searches were performed with public databases from inception to June 17, 2021. Randomized controlled trials researching cell-based therapies in RA patients were included.

Results

Eight studies, including 480 patients, were included in the analysis. The results showed that compared to the control, MSC treatment significantly reduced the disease activity score (DAS) at the second standardized mean difference (SMD): -0.70; 95% confidence interval (CI): -1.25, -0.15; P = 0.01) and 3rd month (SMD: -1.47; 95% CI: -2.77, -0.18; P < 0.01) and significantly reduced the rheumatoid factor (RF) level at the first (SMD: -0.38; 95% CI: -0.72, -0.05; P = 0.03) and 6th months (SMD: -0.81; 95% CI: -1.32, -0.31; P < 0.01). In the network meta-analysis, MSCs combined with interferon-γ (MSC_IFN) had a significant effect on increasing the American college of rheumatology criteria (ACR) 20, ACR50, and DAS <3.2 populations, had a significant effect on reducing the DAS, and decreased the RF level for a long period.

Conclusion

MSCs could relieve the DAS of RA patients in the short term and reduce the level of RF. MSC_IFN showed a more obvious effect, which could significantly improve the results of ACR20, ACR50, and DAS <3.2 and reduce the DAS and RF levels.

The "Domino effect" in MASLD: The inflammatory cascade of steatohepatitis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly common complication of obesity, affecting over a quarter of the global adult population. A key event in the pathophysiology of MASLD is the development of metabolic-associated steatohepatitis (MASH), which greatly increases the chances of developing cirrhosis and hepatocellular carcinoma. The underlying cause of MASH is multifactorial, but accumulating evidence indicates that the inflammatory process in the hepatic microenvironment typically follows a pattern that can be roughly divided into three stages: (1) Detection of hepatocyte stress by tissue-resident immune cells including γδ T cells and CD4-CD8- double-negative T cells, followed by their secretion of pro-inflammatory mediators, most notably IL-17A. (2) Recruitment of pro-inflammatory cells, mostly of the myeloid lineage, and initiation of inflammation through secretion of effector-type cytokines such as TNF, TGF-β, and IL-1β. (3) Escalation of the inflammatory response by recruitment of lymphocytes including Th17, CD8 T, and B cells leading to chronic inflammation, hepatic stellate cell activation, and fibrosis. Here we will discuss these three stages and how they are consecutively linked like falling domino tiles to the pathophysiology of MASH. Moreover, we will highlight the clinical potential of inflammation as a biomarker and therapeutic target for the treatment of MASLD.

Neutrophil-Based Bionic Delivery System Breaks Through the Capillary Barrier of Liver Sinusoidal Endothelial Cells and Inhibits the Activation of Hepatic Stellate Cells

The capillarization of hepatic sinusoids resulting from the activation of hepatic stellate cells poses a significant challenge, impeding the effective delivery of therapeutic agents to the Disse space for liver fibrosis treatment. Therefore, overcoming these barriers and achieving efficient drug delivery to activated hepatic stellate cells (aHSCs) are pressing challenge. In this study, we developed a synergistic sequential drug delivery approach utilizing neutrophil membrane hybrid liposome@atorvastatin/amlisentan (NCM@AtAm) and vitamin A-neutrophil membrane hybrid liposome @albumin (VNCM@Bai) nanoparticles (NPs) to breach the capillary barrier for targeted HSC cell delivery. Initially, NCM@AtAm NPs were successfully directed to the site of hepatic fibrosis through neutrophil-mediated inflammatory targeting, resulting in the normalization of liver sinusoidal endothelial cells (LSECs) and restoration of fenestrations under the combined influence of At and Am. Elevated tissue levels of the p-Akt protein and endothelial nitric oxide synthase (eNOS) indicated the normalization of LSECs following treatment with At and Am. Subsequently, VNCM@Bai NPs traversed the restored LSEC fenestrations to access the Disse space, facilitating the delivery of Bai into aHSCs under vitamin A guidance. Lastly, both in vitro and in vivo results demonstrated the efficacy of Bai in inhibiting HSC cell activation by modulating the PPAR γ/TGF-β1 and STAT1/Smad7 signaling pathways, thereby effectively treating liver fibrosis. Overall, our designed synergistic sequential delivery system effectively overcomes the barrier imposed by LSECs, offering a promising therapeutic strategy for liver fibrosis treatment in clinical settings.

Antifibrotic activity of carbon quantum dots in a human in vitro model of non-alcoholic steatohepatitis using hepatic stellate cells

Around 33% of the global population suffers from non-alcoholic fatty liver disease (NAFLD). From these patients, 30% of them progress into non-alcoholic steatohepatitis (NASH), the critical point where lack of treatment leads to cirrhosis and hepatic failure. Moreover, to date, there are no approved therapeutic options available for NASH. It is known that hepatic stellate cell (HSC) activation contributes the most to hepatic disfunction, leading to reactive oxygen species (ROS) accumulation and chronic inflammation, and that the use of nanomaterials to deliver antioxidants may have potential to reduce the activity of activated HSCs. Therefore, we implemented a human in vitro co-culture model in which we take into consideration two factors related to NASH and fibrosis: human hepatic stellate cells from a NASH diagnosed donor (HHSC-N) and peripheral blood mononuclear cells (PBMCs), particularly lymphocytes. The co-cultures were treated with: (1) carbon quantum dots (CD) or (2) lactoferrin conjugated CD (CD-LF) for 24 h or 72 h. CD and CD-LF treatments significantly downregulated profibrotic genes' expression levels of ACTA2, COL1A1, and TIMP1 in co-cultured HHSC-N at 72 h. Also, we assayed the inflammatory response by quantifying the concentrations of cytokines IL-22, IL-10, IFN-γ and IL-4 present in the co-culture's conditioned media whose concentrations may suggest a resolution-associated response in progress. Our findings may serve as a starting point for the development of a NASH treatment using bio-nanotechnology.

Development of a Chimeric Protein BiPPB-mIFNγ-tTβRII for Improving the Anti-Fibrotic Activity in Vivo by Targeting Fibrotic Liver and Dual Inhibiting the TGF-β1/Smad Signaling Pathway

Excessive production of transforming growth factor β1 (TGF-β1) in activated hepatic stellate cells (aHSCs) promotes liver fibrosis by activating the TGF-β1/Smad signaling pathway. Thus, specifically inhibiting the pro-fibrotic activity of TGF-β1 in aHSCs is an ideal strategy for treating liver fibrosis. Overexpression of platelet-derived growth factor β receptor (PDGFβR) has been demonstrated on the surface of aHSCs relative to normal cells in liver fibrosis. Interferon-gamma peptidomimetic (mIFNγ) and truncated TGF-β receptor type II (tTβRII) inhibit the TGF-β1/Smad signaling pathway by different mechanisms. In this study, we designed a chimeric protein by the conjugation of (1) mIFNγ and tTβRII coupled via plasma protease-cleavable linker sequences (FNPKTP) to (2) PDGFβR-recognizing peptide (BiPPB), namely BiPPB-mIFNγ-tTβRII. This novel protein BiPPB-mIFNγ-tTβRII was effectively prepared using Escherichia coli expression system. The active components BiPPB-mIFNγ and tTβRII were slowly released from BiPPB-mIFNγ-tTβRII by hydrolysis using the plasma protease thrombin in vitro. Moreover, BiPPB-mIFNγ-tTβRII highly targeted to fibrotic liver tissues, markedly ameliorated liver morphology and fibrotic responses in chronic liver fibrosis mice by both inhibiting the phosphorylation of Smad2/3 and inducing the expression of Smad7. Meanwhile, BiPPB-mIFNγ-tTβRII markedly reduced the deposition of collagen fibrils and expression of fibrosis-related proteins in acute liver fibrosis mice. Furthermore, BiPPB-mIFNγ-tTβRII showed a good safety performance in both liver fibrosis mice. Taken together, BiPPB-mIFNγ-tTβRII improved the in vivo anti-liver fibrotic activity due to its high fibrotic liver-targeting potential and the dual inhibition of the TGF-β1/Smad signaling pathway, which may be a potential candidate for targeting therapy on liver fibrosis.

Chronic liver diseases: From development to novel pharmacological therapies: IUPHAR Review 37

Chronic liver diseases comprise a broad spectrum of burdensome diseases that still lack effective pharmacological therapies. Our research group focuses on fibrosis, which is a major precursor of liver cirrhosis. Fibrosis consists in a progressive disturbance of liver sinusoidal architecture characterised by connective tissue deposition as a reparative response to tissue injury. Multifactorial events and several types of cells participate in fibrosis initiation and progression, and the process still needs to be completely understood. The development of experimental models of liver fibrosis alongside the identification of critical factors progressing fibrosis to cirrhosis will facilitate the development of more effective therapeutic approaches for such condition. This review provides an overlook of the main process leading to hepatic fibrosis and therapeutic approaches that have emerged from a deep knowledge of the molecular regulation of fibrogenesis in the liver. LINKED ARTICLES: This article is part of a themed issue on Translational Advances in Fibrosis as a Therapeutic Target. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.22/issuetoc.

Tissue fibrosis induced by radiotherapy: current understanding of the molecular mechanisms, diagnosis and therapeutic advances

Cancer remains the leading cause of death around the world. In cancer treatment, over 50% of cancer patients receive radiotherapy alone or in multimodal combinations with other therapies. One of the adverse consequences after radiation exposure is the occurrence of radiation-induced tissue fibrosis (RIF), which is characterized by the abnormal activation of myofibroblasts and the excessive accumulation of extracellular matrix. This phenotype can manifest in multiple organs, such as lung, skin, liver and kidney. In-depth studies on the mechanisms of radiation-induced fibrosis have shown that a variety of extracellular signals such as immune cells and abnormal release of cytokines, and intracellular signals such as cGAS/STING, oxidative stress response, metabolic reprogramming and proteasome pathway activation are involved in the activation of myofibroblasts. Tissue fibrosis is extremely harmful to patients' health and requires early diagnosis. In addition to traditional serum markers, histologic and imaging tests, the diagnostic potential of nuclear medicine techniques is emerging. Anti-inflammatory and antioxidant therapies are the traditional treatments for radiation-induced fibrosis. Recently, some promising therapeutic strategies have emerged, such as stem cell therapy and targeted therapies. However, incomplete knowledge of the mechanisms hinders the treatment of this disease. Here, we also highlight the potential mechanistic, diagnostic and therapeutic directions of radiation-induced fibrosis.

Interferon-Gamma Increases the Immune Modulation of Umbilical Cord-Derived Mesenchymal Stem Cells but Decreases Their Chondrogenic Potential

INTRODUCTION

The pro-inflammatory cytokine interferon-gamma (IFN-γ) is reported to be an agent that boosts the immune modulation of mesenchymal stem cells (MSCs). However, the effects of IFN-γ on the chondrogenic potential of treated MSCs have not been evaluated in depth. This study aimed to evaluate the effects of IFN-γ on the immune modulation and chondrogenic potential of human umbilical cord-derived MSCs (hUC-MSCs).

METHODS

UC-MSCs were isolated and expanded following published protocols. They were characterized as MSCs before their use in further experiments. The UC-MSCs were treated with IFN-γ at 10 ng/mL for 48 h. Changes in phenotype were investigated based on changes in MSC markers, immunomodulatory genes (TGF-β, IL-4, and IDO) for immune modulation, and cartilage-related genes during the induction of differentiation (Col1a2, Col2a1, Sox9, Runx2, and Acan) for chondrogenic potential.

RESULTS

IFN-γ-treated UC-MSCs maintained MSC markers and exhibited decreased expression of transcriptional regulatory factors in chondrogenesis (Sox9 and Runx2) and the extracellular matrix-specific genes Col1a2 and Acan but not Col2a1 compared to non-treated cells (p < 0.05). Furthermore, the immunomodulatory capability of IFN-γ-treated UC-MSCs was clearly revealed through their increased expression of IDO and IL-4 and decreased expression of TGF-β compared to non-treated cells (p < 0.05).

CONCLUSION

This study demonstrated that UC-MSCs treated with IFN-γ at 10 ng/mL had reduced expression of chondrocyte-specific genes; however, they maintained multi-lineage differentiation and exhibited immunomodulatory properties.

Human Wharton's jelly mesenchymal stem cells derived-exosomes enriched by miR-124 promote an anti-fibrotic response in an experimental model of liver fibrosis

BACKGROUND

Liver fibrosis is a significant challenge to global health that results in organ failure through inflammation and the release of fibrotic biomarkers. Due to the lack of effective treatments for liver fibrosis, anti-fibrotic and anti-inflammatory therapies are being developed. Since there has been an association between aberrant expression of miR-124 and liver disease progression, we investigated whether delivery of miR-124 through human Wharton's jelly mesenchymal stem cells derived-exosomes (hWJMSC-Exo) can improve liver fibrosis.

METHODS

We established a 6-week carbon tetrachloride (CCl4)-induced mouse model of liver fibrosis, then we administered hWJMSC-Exo and miR-124-3p-enriched exosomes (ExomiR-124) for three weeks. The extent of fibrosis and inflammation was assessed by histology, biochemistry, Real-time PCR, immunohistochemistry, and Enzyme-linked immunoassays (ELISA). The inflammatory status of the spleen was also investigated using flow cytometry.

RESULTS

Based on the gene and protein expression measurement of IL-6, IL-17, TGF-β, STAT3, α-SMA, and COL1, In vivo administration of Exo and ExomiR-124 effectively reduce collagen accumulation and inhibition of inflammation. Regarding histopathology findings, the therapeutic effect of ExomiR-124 against liver fibrosis was significantly greater than hWJMSC-Exo. In addition, we found that Exo and ExomiR-124 was capable of phenotype switching of splenic monocytes from inflammatory Ly6C^hi to restorative Ly6C^lo.

CONCLUSIONS

MSC-derived exosomes demonstrated anti-inflammatory effect via different aspects. Aside from the therapeutic approach, enrichment of exosomes as a nanocarrier by miR-124 revealed the down-regulation of STAT3, which plays a crucial role in liver fibrosis. The anti-inflammatory and anti-fibrotic properties of ExomiR-124 could be a promising option in liver fibrosis combination therapies.

Immune cells and immune cell-targeted therapy in chronic pancreatitis

In recent years, studies have attempted to understand the immune cells and mechanisms underlying the pathogenesis of chronic pancreatitis (CP) by constructing a model of CP. Based on these studies, the innate immune response is a key factor in disease pathogenesis and inflammation severity. Novel mechanisms of crosstalk between immune and non-immune pancreatic cells, such as pancreatic stellate cells (PSC), have also been explored. Immune cells, immune responses, and signaling pathways in CP are important factors in the development and progression of pancreatitis. Based on these mechanisms, targeted therapy may provide a feasible scheme to stop or reverse the progression of the disease in the future and provide a new direction for the treatment of CP. This review summarizes the recent advances in research on immune mechanisms in CP and the new advances in treatment based on these mechanisms.

MAIT cells ameliorate liver fibrosis by enhancing the cytotoxicity of NK cells in cholestatic murine models

BACKGROUND AND AIMS

Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that display a critical role in various liver diseases. However, the role of MAIT cells in cholestatic liver fibrogenesis remains obscure. Our study aims to assess the contribution of MAIT cells and underlying mechanisms during this process.

METHODS

Cholestatic murine models using MAIT cell-deficient (MR1^- /^- ) and wild-type (WT) mice were established by feeding a 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-enriched diet or bile duct ligation (BDL). Liver samples were collected to determine the severity of fibrosis. Lymphocytes of the liver were isolated for analysing the phenotype and function of MAIT cells. Cell co-culture experiments were performed to investigate the cross-talk between MAIT and NK cells.

RESULTS

Liver MAIT cells were more activated with increased cytokines in cholestatic mice models than in control mice, although their frequency was decreased. MAIT cell deficiency led to severe liver inflammation and fibrosis with more activated HSCs in cholestatic mice. In addition, MR1^- /^- mice had an increased frequency of NK cells with higher expression of stimulatory receptors relative to WT mice. Paradoxically, activated MAIT cells significantly promoted the anti-fibrotic ability of NK cells by enhancing their cytotoxicity against HSCs in co-culture experiments. Importantly, this effect depended on direct cell-cell contact and TNF-α produced by MAIT cells.

CONCLUSION

Our findings indicate that MAIT cells ameliorate cholestatic liver fibrosis by enhancing the cytotoxicity of NK cells against HSCs. An in-depth understanding of the MAIT cell-mediated regulatory effect will provide more valuable immunotherapy strategies to treat liver fibrosis.

ChemPert: mapping between chemical perturbation and transcriptional response for non-cancer cells

Prior knowledge of perturbation data can significantly assist in inferring the relationship between chemical perturbations and their specific transcriptional response. However, current databases mostly contain cancer cell lines, which are unsuitable for the aforementioned inference in non-cancer cells, such as cells related to non-cancer disease, immunology and aging. Here, we present ChemPert (https://chempert.uni.lu/), a database consisting of 82 270 transcriptional signatures in response to 2566 unique perturbagens (drugs, small molecules and protein ligands) across 167 non-cancer cell types, as well as the protein targets of 57 818 perturbagens. In addition, we develop a computational tool that leverages the non-cancer cell datasets, which enables more accurate predictions of perturbation responses and drugs in non-cancer cells compared to those based onto cancer databases. In particular, ChemPert correctly predicted drug effects for treating hepatitis and novel drugs for osteoarthritis. The ChemPert web interface is user-friendly and allows easy access of the entire datasets and the computational tool, providing valuable resources for both experimental researchers who wish to find datasets relevant to their research and computational researchers who need comprehensive non-cancer perturbation transcriptomics datasets for developing novel algorithms. Overall, ChemPert will facilitate future in silico compound screening for non-cancer cells.

The role of immune response in the pathogenesis of idiopathic pulmonary fibrosis: far beyond the Th1/Th2 imbalance

INTRODUCTION

. Idiopathic pulmonary fibrosis (IPF) is a chronic disease of unknown origin characterized by progressive scarring of the lung leading to irreversible loss of function. Despite the availability of two drugs that are able to slow down disease progression, IPF remains a deadly disease. The pathogenesis of IPF is poorly understood, but a dysregulated wound healing response following recurrent alveolar epithelial injury is thought to be crucial. Areas covered. In the last few years, the role of the immune system in IPF pathobiology has been reconsidered; indeed, recent data suggest that a dysfunctional immune system may promote and unfavorable interplay with pro-fibrotic pathways thus acting as a cofactor in disease development and progression. In this article, we review and critically discuss the role of T cells in the pathogenesis and progression of IPF in the attempt to highlight ways in which further research in this area may enable the development of targeted immunomodulatory therapies for this dreadful disease.

EXPERT OPINION

A better understanding of T cells interactions has the potential to facilitate the development of immune modulators targeting multiple T cell-mediated pathways thus halting disease initiation and progression.

Familial hemophagocytic lymphohistiocytosis hepatitis is mediated by IFN-γ in a predominantly hepatic-intrinsic manner

Interferon gamma (IFN-γ) is the main cytokine driving organ dysfunction in Familial Hemophagocytic Lymphohistiocytosis (FHL). Blockade of IFN-γ pathway ameliorates FHL hepatitis, both in animal models and in humans with FHL. Hepatocytes are known to express IFN-γ receptor (IFN-γ-R). However, whether IFN-γ induced hepatitis in FHL is a lymphocyte or liver intrinsic response to the cytokine has yet to be elucidated. Using a IFNgR-/- bone marrow chimeric model, this study showed that non-hematopoietic IFN-γ response is critical for development of FHL hepatitis in LCMV-infected Prf1-/- mice. Lack of hepatic IFN-γ responsiveness results in reduced hepatitis as measured by hepatomegaly, alanine aminotransferase (ALT) levels and abrogated histologic endothelial inflammation. In addition, IFN-γ non-hematopoietic response was critical in activation of lymphocytes by soluble interleukin 2 receptor (sIL-2r) and recruitment of CD8+ effector T lymphocytes (CD8+ CD44hi CD62Llo) (Teff) and inflammatory monocytes. Lastly, non-hematopoietic IFN-γ response results in increased hepatic transcription of type 1 immune response and oxidative stress response pathways, while decreasing transcription of genes involved in extracellular matrix (ECM) production. In summary, these findings demonstrate that there is a hepatic transcriptional response to IFN-γ, likely critical in the pathogenesis of FHL hepatitis and hepatic specific responses could be a therapeutic target in this disorder.

Diagnostic Value of FibroTouch and Non-invasive Fibrosis Indexes in Hepatic Fibrosis with Different Aetiologies

BACKGROUND

Liver biopsy is the gold standard for staging liver fibrosis, but it has numerous drawbacks, mainly associated with bleeding and bile fistula risks. A number of non-invasive techniques have been investigated, but they all have their own disadvantages. To avoid the risks mentioned above and to improve the diagnostic value, we still need to search for a more accurate non-invasive method to evaluate the degree of liver fibrosis.

AIM

This study aimed to evaluate the diagnostic performance of FibroTouch versus other non-invasive fibrosis indexes in hepatic fibrosis of different aetiologies.

METHODS

This study retrospectively enrolled 227 patients with chronic hepatic liver disease admitted to the first hospital of Lanzhou University from 2017 to 2020. Liver biopsy was performed in all of the patients, and their biochemical indicators were all tested. Non-invasive indexes including the fibrosis index based on four factors (FIB-4), the aminotransferase-to-platelet ratio index (APRI), and the gamma-glutamyl transpeptidase-to-platelet ratio index (GPRI) were all calculated. Transient elastography was performed using FibroTouch.

RESULTS

The correlation between FibroTouch and the pathology of liver fibrosis was significantly higher than that between the non-invasive fibrosis indexes and the biopsy results (r = 0.771, p < 0.05). The area under the receiver operating curve (AUC) of FibroTouch was significantly higher than that of FIB-4, APRI, and GPRI for the diagnosis of significant fibrosis (≥ S2 fibrosis stage), advanced fibrosis (≥ S3 fibrosis stage), and cirrhosis (= S4 fibrosis stage) (p < 0.05). The patients were grouped according to different aetiologies. The diagnostic value of FibroTouch had much higher credibility in different fibrosis stages for different causes compared with other non-invasive indexes. The AUC of FibroTouch showed both higher specificity and higher sensitivity than FIB-4, APRI, and GPRI for different liver fibrosis stages with different aetiologies.

CONCLUSIONS

FibroTouch demonstrates the highest diagnostic value for liver fibrosis and cirrhosis among non-invasive methods, showing better results than FIB-4, APRI, and GPRI, and surpassed only by liver biopsy. FibroTouch is reliable in assessing liver fibrosis with different aetiologies.

Inflammasomes and Pyroptosis of Liver Cells in Liver Fibrosis

Inflammasomes are multiprotein complexes that can sense danger signals and activate caspase-1 to mediate pro-inflammatory cytokines release and pyroptotic cell death. There are two main canonical and non-canonical signaling pathways that trigger inflammasome activation. Inflammasomes are expressed and assembled in parenchymal and nonparenchymal cells in response to liver injury in the liver. Additionally, the hepatocytes, biliary epithelial cells (cholangiocytes), hepatic stellate cells (HSCs), hepatic macrophages, and liver sinusoidal endothelial cells (LSECs) contribute to liver fibrosis via different mechanisms. However, the underlying mechanism of the inflammasome and pyroptosis in these liver cells in liver fibrosis remains elusive. This review summarizes the activation and function of inflammasome complexes and then discusses the association between inflammasomes, pyroptosis, and liver fibrosis. Unlike other similar reviewers, we will focus on the effect of inflammasome activation and pyroptosis in the various liver cells during the development of liver fibrosis. We will also highlight the latest progress of pharmacological intervention in inflammasome-mediated liver fibrosis.

Guizhi Fuling pill attenuates liver fibrosis in vitro and in vivo via inhibiting TGF-β1/Smad2/3 and activating IFN-γ/Smad7 signaling pathways

Liver fibrosis resulting from chronic liver injuries (CLI) is a common health problem globally. Guizhi Fuling pill (GZFL), a modern preparation from traditional Chinese medicine, exhibited anti-dysmenorrhea, anti-inflammatory, and immune-regulative effects. However, the effect of GZFL on liver fibrosis remains unknown. In this research, LX-2 cells were stimulated with acetaldehyde for mimicking liver fibrosis progression in vitro. In addition, carbon tetrachloride (CCl₄)-induced mouse model of liver fibrosis was established as well. The data revealed GZFL obviously suppressed the proliferation and triggered the apoptosis of acetaldehyde-stimulated LX-2 cells. In addition, GZFL prevented acetaldehyde-induced activation of LX-2 cells via downregulation of TGF-β1, p-Smad2, p-Smad3, CUGBP1, and upregulation of p-STAT1 and Smad7. Meanwhile, GZFL significantly alleviated CCl₄‑induced liver fibrosis, as evidenced by the decrease of ALT and AST levels. Moreover, GZFL downregulated the expressions of TGF-β1, p-Smad2, p-Smad3, and CUGBP1 in CCl₄-treated mice. Furthermore, GZFL remarkably elevated the levels of IFN-γ, p-STAT1, and Smad7 in CCl₄-treated mice. To sum up, GZFL was able to inhibit liver fibrosis in vitro and in vivo through suppressing TGF-β1/Smad2/3-CUGBP1 signaling and activating IFN-γ/STAT1/Smad7 signaling. Thus, GZFL might have a potential to act as a therapeutic agent for anti-fibrotic therapy.

IL-1β-activated mTORC2 promotes accumulation of IFN-γ+ γδ T cells by upregulating CXCR3 to restrict hepatic fibrosis

Liver fibrosis represents a severe stage of liver damage, with hallmarks of inflammation, hepatic stellate cell activation, and extracellular matrix accumulation. Although previous studies demonstrated γδ T cells are involved in liver fibrosis, the precise role and mechanisms of γδ T cells migrating to fibrotic liver have not been elucidated. Here, we aim to investigate the functional subsets of γδ T cells in hepatic fibrosis and to further explore the underlying causes and drivers of migration. In this study, we observed that γδ T cells accumulate in fibrotic liver. Adoptive transfer of γδ T, especially Vγ4 γδ T subset, can significantly alleviate liver fibrosis. In addition, CCl4 treatment also leads to activation of mTOR signaling in γδ T cells. Genetic deletion of the Rictor gene, but not Raptor, in γδ T cells markedly exacerbated liver fibrosis. Mechanistically, CCl4-induced liver injury causes macrophage accumulation in the liver, and IL-1β produced by macrophages promotes mTORC2 signaling activation in γδ T cells, which upregulates T-bet expression and eventually promotes CXCR3 transcription to drive γδ T cell migration. Moreover, hepatic γδ T cells ameliorated liver fibrosis by cytotoxicity against activated hepatic stellate cells in FasL-dependent manner, and secrete IFN-γ to inhibit the differentiation of pro-fibrotic Th17 cells. Thus, IL-1β-activated mTORC2 signaling in γδ T cells upregulates CXCR3 expression, which is critical for IFN-γ+ γδ T cells migration into the liver and amelioration of liver fibrosis. Our findings indicate that targeting the mTORC2 or CXCR3 in γδ T cells could be considered as a promising approach for γδ T cell immunotherapy against liver fibrosis.

Hepatic Stellate Cell-Immune Interactions in NASH

Nonalcoholic fatty liver disease (NAFLD) is the dominant cause of liver disease worldwide. Nonalcoholic steatohepatitis (NASH), a more aggressive presentation of NAFLD, is characterized by severe hepatocellular injury, inflammation, and fibrosis. Chronic inflammation and heightened immune cell activity have emerged as hallmark features of NASH and key drivers of fibrosis through the activation of hepatic stellate cells (HSCs). Recent advances in our understanding of the molecular and cellular pathways in NASH have highlighted extensive crosstalk between HSCs and hepatic immune populations that strongly influences disease activity. Here, we review these findings, emphasizing the roles of HSCs in liver immunity and inflammation, key cell-cell interactions, and exciting areas for future investigation.

Cross-talk between hepatic stellate cells and T lymphocytes in liver fibrosis

BACKGROUND

Fibrosis results from inflammation and healing following injury. The imbalance between extracellular matrix (ECM) secretion and degradation leads to the ECM accumulation and liver fibrosis. This process is regulated by immune cells. T lymphocytes, including alpha beta (αβ) T cells, which have adaptive immune functions, and gamma delta (γδ) T cells, which have innate immune functions, are considered regulators of liver fibrosis. This review aimed to present the current understanding of the cross-talk between T lymphocytes and hepatic stellate cells (HSCs), which are the key cells in liver fibrosis.

DATA SOURCES

The keywords "liver fibrosis", "immune", and "T cells" were used to retrieve articles published in PubMed database before January 31, 2020.

RESULTS

The ratio of CD8+ (suppressor) T cells to CD4+ (helper) T cells is significantly higher in the liver than in the peripheral blood. T cells secrete a series of cytokines and chemokines to regulate the inflammation in the liver and the activation of HSCs to influence the course of liver fibrosis. In addition, HSCs also regulate the differentiation and proliferation of T cells.

CONCLUSIONS

The cross-talk between T cells and HSCs regulates liver fibrosis progression. The elucidation of this communication process will help us to understand the pathological process of liver fibrosis.

Glycyrrhetinic acid remodels the tumor microenvironment and synergizes with doxorubicin for breast cancer treatment in a murine model

We aimed to combine glycyrrhetinic acid with doxorubicin to prepare, characterize and evaluate a drug delivery nano-system with REDOX sensitivity for the treatment of breast cancer. M-DOX-GA NPs prepared by nano sedimentation were spherical, with a particle size of 181 nm. And the maximum encapsulation efficiency and drug loading in M-DOX-GA NPs were 89.28% and 18.22%, respectively. Cytotoxicity and cellular uptake experiments of nanoparticles to KC cells, Cal-27 cells and 4T1 cells were studied by the CCK-8 method. The result indicated that M-DOX-GA NPs could accurately release the drug into the tumor cells, thus achieving the targeted release of the drug. Comparing the survival rate of the above three cells, it was found that M-DOX-GA NPs had a good tumor selectivity and had a more significant therapeutic effect on breast cancer. A 4T1-bearing mouse model was established, and the tumor inhibition rate was 77.37% after injection of nanoparticle solution for 14 d. Normal tissue H&E stained sections and TUNEL assay were verified M-DOX-GA NPs have excellent tumor suppressive effect, and can efficiently reduce the toxic side effects on normal organisms, and effectively avoided 4T1 cells metastasis. Immunofluorescence detection and Western-blot analysis figured a decline in both CUGBP1 and α-SMA, which verifying the TME remodeling induced by glycyrrhetinic acid. Collectively, the combination of doxorubicin and glycyrrhetinic acid is an effective and safe strategy for remodeling fibrotic TME by improving the therapeutic outcome for breast cancer.

Comparative Analysis of Tenogenic Gene Expression in Tenocyte-Derived Induced Pluripotent Stem Cells and Bone Marrow-Derived Mesenchymal Stem Cells in Response to Biochemical and Biomechanical Stimuli

The tendon is highly prone to injury, overuse, or age-related degeneration in both humans and horses. Natural healing of injured tendon is poor, and cell-based therapeutic treatment is still a significant clinical challenge. In this study, we extensively investigated the expression of tenogenic genes in equine bone marrow mesenchymal stem cells (BMSCs) and tenocyte-derived induced pluripotent stem cells (teno-iPSCs) stimulated by growth factors (TGF-β3 and BMP12) combined with ectopic expression of tenogenic transcription factor MKX or cyclic uniaxial mechanical stretch. Western blotting revealed that TGF-β3 and BMP12 increased the expression of transcription factors SCX and MKX in both cells, but the tenocyte marker tenomodulin (TNMD) was detected only in BMSCs and upregulated by either inducer. On the other hand, quantitative real-time PCR showed that TGF-β3 increased the expression of EGR1, COL1A2, FMOD, and TNC in BMSCs and SCX, COL1A2, DCN, FMOD, and TNC in teno-iPSCs. BMP12 treatment elevated SCX, MKX, DCN, FMOD, and TNC in teno-iPSCs. Overexpression of MKX increased SCX, DCN, FMOD, and TNC in BMSCs and EGR1, COL1A2, DCN, FMOD, and TNC in teno-iPSCs; TGF-β3 further enhanced TNC in BMSCs. Moreover, mechanical stretch increased SCX, EGR1, DCN, ELN, and TNC in BMSCs and SCX, MKX, EGR1, COL1A2, DCN, FMOD, and TNC in teno-iPSCs; TGF-β3 tended to further elevate SCX, ELN, and TNC in BMSCs and SCX, MKX, COL1A2, DCN, and TNC in teno-iPSCs, while BMP12 further uptrended the expression of SCX and DCN in BMSCs and DCN in teno-iPSCs. Additionally, the aforementioned tenogenic inducers also affected the expression of signaling regulators SMAD7, ETV4, and SIRT1 in BMSCs and teno-iPSCs. Taken together, our data demonstrate that, in respect to the tenocyte-lineage-specific gene expression, BMSCs and teno-iPSCs respond differently to the tenogenic stimuli, which may affect the outcome of their application in tendon repair or regeneration.

Immunopathobiology and therapeutic targets related to cytokines in liver diseases

Chronic liver injury with any etiology can progress to fibrosis and the end-stage diseases cirrhosis and hepatocellular carcinoma. The progression of liver disease is controlled by a variety of factors, including liver injury, inflammatory cells, inflammatory mediators, cytokines, and the gut microbiome. In the current review, we discuss recent data on a large number of cytokines that play important roles in regulating liver injury, inflammation, fibrosis, and regeneration, with a focus on interferons and T helper (Th) 1, Th2, Th9, Th17, interleukin (IL)-1 family, IL-6 family, and IL-20 family cytokines. Hepatocytes can also produce certain cytokines (such as IL-7, IL-11, and IL-33), and the functions of these cytokines in the liver are briefly summarized. Several cytokines have great therapeutic potential, and some are currently being tested as therapeutic targets in clinical trials for the treatment of liver diseases, which are also described.

Overexpression of Smad7 in hypothalamic POMC neurons disrupts glucose balance by attenuating central insulin signaling

OBJECTIVE

Although the hypothalamus is crucial for peripheral metabolism control, the signals in specific neurons involved remain poorly understood. The aim of our current study was to explore the role of the hypothalamic gene mothers against decapentaplegic homolog 7 (Smad7) in peripheral glucose disorders.

METHODS

We studied glucose metabolism in high-fat diet (HFD)-fed mice and middle-aged mice with Cre-mediated recombination causing 1) overexpression of Smad7 in hypothalamic proopiomelanocortin (POMC) neurons, 2) deletion of Smad7 in POMC neurons, and 3) overexpression of protein kinase B (AKT) in arcuate nucleus (ARC) in Smad7 overexpressed mice. Intracerebroventricular (ICV) cannulation of insulin was used to test the hypothalamic insulin sensitivity in the mice. Hypothalamic primary neurons were used to investigate the mechanism of Smad7 regulating hypothalamic insulin signaling.

RESULTS

We found that Smad7 expression was increased in POMC neurons in the hypothalamic ARC of HFD-fed or middle-aged mice. Furthermore, overexpression of Smad7 in POMC neurons disrupted the glucose balance, and deletion of Smad7 in POMC neurons prevented diet- or age-induced glucose disorders, which was likely to be independent of changes in body weight or food intake. Moreover, the effect of Smad7 was reversed by overexpression of AKT in the ARC. Finally, Smad7 decreased AKT phosphorylation by activating protein phosphatase 1c in hypothalamic primary neurons.

CONCLUSIONS

Our results demonstrated that an excess of central Smad7 in POMC neurons disrupts glucose balance by attenuating hypothalamic insulin signaling. In addition, we found that this regulation was mediated by the activity of protein phosphatase 1c.

The Roles of Immune Cells in the Pathogenesis of Fibrosis

Tissue injury and inflammatory response trigger the development of fibrosis in various diseases. It has been recognized that both innate and adaptive immune cells are important players with multifaceted functions in fibrogenesis. The activated immune cells produce various cytokines, modulate the differentiation and functions of myofibroblasts via diverse molecular mechanisms, and regulate fibrotic development. The immune cells exhibit differential functions during different stages of fibrotic diseases. In this review, we summarized recent advances in understanding the roles of immune cells in regulating fibrotic development and immune-based therapies in different disorders and discuss the underlying molecular mechanisms with a focus on mTOR and JAK-STAT signaling pathways.

Immunopathology in schistosomiasis is regulated by TLR2,4- and IFN-γ-activated MSC through modulating Th1/Th2 responses

Background and aims

A marked egg-induced CD4⁺ T cell programmed inflammation and subsequent hepatic fibrosis characterize the pathogenesis of schistosomiasis. Mesenchymal stem cell (MSC) has been extensively studied for the treatment of schistosomiasis. However, the mechanism by which MSCs modulate the pathogenesis of schistosomiasis has not been clarified. Furthermore, the local inflammatory milieu may greatly influence the immunoregulatory properties of MSCs, and our early experiments demonstrated that Toll-like receptor (TLR)2/TLR4 agonist effected immune modulation of MSC. Here, we further investigated their modulation on the pathogenesis of schistosomiasis.

Methods

Adult BALB/c male mice were percutaneously infected with 16 ± 2 pairs S. japonicum cercariae and received intravenously pretreated MSC at 1 week and 3 weeks post-infection, respectively. At 8 weeks post-infection, effects of MSC on liver histology were shown by hematoxylin and eosin (H&E) staining and Masson staining and quantitatively compared by the hepatic hydroxyproline content; α-smooth muscle actin (α-SMA), collagen type I(Col-1), transforming growth factor β (TGF-β), and tumor necrosis factor-α (TNF-α) gene expression in the liver were assessed by semi-quantitative polymerase chain reaction (PCR); the Th1/Th2 dominance among different groups was compared by analyzing CD4⁺ interferon-γ (IFN-γ)+ and CD4+interleukin-4 (IL-4)+T cells in the liver by flow cytometry and serum level of IFN-γ and IL-5 using enzyme-linked immunosorbent assay (ELISA). Effects of different kinds of MSC were further evaluated in vitro by the coculture system.

Results

Results showed TLR4- and IFN-γ-activated MSC alleviated liver fibrosis in infected mice, without a significant increase of mortality, and unpretreated MSC showed no clear improvement; however, TLR2- and IFN-γ-activated MSC displayed aggravated immunopathology. In accord with the pathological results, TLR4- and IFN-γ-activated MSC groups showed moderate enhancement of Th1 response in vitro and clear Th1 dominance in vivo without leading to extreme inflammation, whereas TLR2- and IFN-γ-activated MSC not only induced Th1 response, but also triggered excessive inflammation as evidenced by atrophy of the thymus and higher TNF level in the coculture system.

Conclusions

This study demonstrates that TLR4 combined with IFN-γ can activate the MSC group with positive effects on the pathology of schistosomiasis by modulating Th subsets at some degree. This result suggests that when MSC is being used to treat different immuno-disturbance complications, subtle pretreatment methods should be seriously considered.

The Female Response to Seminal Fluid

Seminal fluid is often assumed to have just one function in mammalian reproduction, delivering sperm to fertilize oocytes. But seminal fluid also transmits signaling agents that interact with female reproductive tissues to facilitate conception and .pregnancy. Upon seminal fluid contact, female tissues initiate a controlled inflammatory response that affects several aspects of reproductive function to ultimately maximize the chances of a male producing healthy offspring. This effect is best characterized in mice, where the female response involves several steps. Initially, seminal fluid factors cause leukocytes to infiltrate the female reproductive tract, and to selectively target and eliminate excess sperm. Other signals stimulate ovulation, induce an altered transcriptional program in female tract tissues that modulates embryo developmental programming, and initiate immune adaptations to promote receptivity to implantation and placental development. A key result is expansion of the pool of regulatory T cells that assist implantation by suppressing inflammation, mediating tolerance to male transplantation antigens, and promoting uterine vascular adaptation and placental development. Principal signaling agents in seminal fluid include prostaglandins and transforming growth factor-β. The balance of male signals affects the nature of the female response, providing a mechanism of ‟cryptic female choiceˮ that influences female reproductive investment. Male-female seminal fluid signaling is evident in all mammalian species investigated including human, and effects of seminal fluid in invertebrates indicate evolutionarily conserved mechanisms. Understanding the female response to seminal fluid will shed new light on infertility and pregnancy disorders and is critical to defining how events at conception influence offspring health.

Interferon-γ-dependent immune responses contribute to the pathogenesis of sclerosing cholangitis in mice

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is an idiopathic, chronic cholestatic liver disorder characterized by biliary inflammation and fibrosis. Increased numbers of intrahepatic interferon-γ- (IFNγ) producing lymphocytes have been documented in patients with PSC, yet their functional role remains to be determined.

METHODS

Liver tissue samples were collected from patients with PSC. The contribution of lymphocytes to liver pathology was assessed in Mdr2-/- x Rag1-/- mice, which lack T and B cells, and following depletion of CD90.2+ or natural killer (NK)p46+ cells in Mdr2-/- mice. Liver pathology was also determined in Mdr2-/- x Ifng-/- mice and following anti-IFNγ antibody treatment of Mdr2-/- mice. Immune cell composition was analysed by multi-colour flow cytometry. Liver injury and fibrosis were determined by standard assays.

RESULTS

Patients with PSC showed increased IFNγ serum levels and elevated numbers of hepatic CD56bright NK cells. In Mdr2-/- mice, hepatic CD8+ T cells and NK cells were the primary source of IFNγ. Depletion of CD90.2+ cells reduced hepatic Ifng expression, NK cell cytotoxicity and liver injury similar to Mdr2-/- x Rag1-/- mice. Depletion of NK cells resulted in reduced CD8+ T cell cytotoxicity and liver fibrosis. The complete absence of IFNγ in Mdr2-/-x Ifng-/- mice reduced NK cell and CD8+ T cell frequencies expressing the cytotoxic effector molecules granzyme B and TRAIL and prevented liver fibrosis. The antifibrotic effect of IFNγ was also observed upon antibody-dependent neutralisation in Mdr2-/- mice.

CONCLUSION

IFNγ changed the phenotype of hepatic CD8+ T cells and NK cells towards increased cytotoxicity and its absence attenuated liver fibrosis in chronic sclerosing cholangitis. Therefore, unravelling the immunopathogenesis of PSC with a particular focus on IFNγ might help to develop novel treatment options.

LAY SUMMARY

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by biliary inflammation and fibrosis, whose current medical treatment is hardly effective. We observed an increased interferon (IFN)-γ response in patients with PSC and in a mouse model of sclerosing cholangitis. IFNγ changed the phenotype of hepatic CD8+ T lymphocytes and NK cells towards increased cytotoxicity, and its absence decreased liver cell death, reduced frequencies of inflammatory macrophages in the liver and attenuated liver fibrosis. Therefore, IFNγ-dependent immune responses may disclose checkpoints for future therapeutic intervention strategies in sclerosing cholangitis.

Interferon-gamma inhibits seminal plasma induction of colony-stimulating factor 2 in mouse and human reproductive tract epithelial cells

Seminal fluid interacts with the female reproductive tract to initiate a permissive immune response that facilitates embryo implantation and pregnancy success. The immune-regulatory cytokine interferon-γ (IFNG), which can be elevated in seminal plasma, is associated with reduced fertility. Here, we investigated how IFNG influences the female immune response to seminal fluid. In human Ect1 cervical epithelial cells, IFNG added at physiologically relevant concentrations substantially impaired seminal plasma-induced synthesis of key cytokines colony-stimulating factor 2 (CSF2) and interleukin-6 (IL6). Seminal fluid-induced CSF2 synthesis was also suppressed in the uterus of mice in vivo, when IFNG was delivered transcervically 12 h after mating. Transforming growth factor B1 (TGFB1) is the major seminal fluid signaling factor which elicits CSF2 induction, and IFNG exhibited potent dose-dependent suppression of CSF2 synthesis induced by TGFB1 in murine uterine epithelial cells in vitro. Similarly, IFNG suppressed TGFB1-mediated CSF2 induction in Ect1 cells and human primary cervical epithelial cells; however, IL6 regulation by IFNG was independent of TGFB1. Quantitative PCR confirmed that CSF2 regulation by IFNG in Ect1 cells occurs at the gene transcription level, secondary to IFNG suppression of TGFBR2 encoding TGFB receptor 2. Conversely, TGFB1 suppressed IFNG receptor 1 and 2 genes IFNGR1 and IFNGR2. These data identify IFNG as a potent inhibitor of the TGFB-mediated seminal fluid interaction with relevant reproductive tract epithelia in mice and human. These findings raise the prospect that IFNG in the male partner's seminal fluid impairs immune adaptation for pregnancy following coitus in women.

Immune suppression in chronic hepatitis B infection associated liver disease: A review

Hepatitis B virus (HBV) infection is one the leading risk factors for chronic hepatitis, liver fibrosis, cirrhosis and hepatocellular cancer (HCC), which are a major global health problem. A large number of clinical studies have shown that chronic HBV persistent infection causes the dysfunction of innate and adaptive immune response involving monocytes/macrophages, dendritic cells, natural killer (NK) cells, T cells. Among these immune cells, cell subsets with suppressive features have been recognized such as myeloid derived suppressive cells(MDSC), NK-reg, T-reg, which represent a critical regulatory system during liver fibrogenesis or tumourigenesis. However, the mechanisms that link HBV-induced immune dysfunction and HBV-related liver diseases are not understood. In this review we summarize the recent studies on innate and adaptive immune cell dysfunction in chronic HBV infection, liver fibrosis, cirrhosis, and HCC, and further discuss the potential mechanism of HBV-induced immunosuppressive cascade in HBV infection and consequences. It is hoped that this article will help ongoing research about the pathogenesis of HBV-related hepatic fibrosis and HBV-related HCC.

The opposing effects of interferon-beta and oncostatin-M as regulators of cancer stem cell plasticity in triple-negative breast cancer

Background

Highly aggressive, metastatic and therapeutically resistant triple-negative breast cancers (TNBCs) are often enriched for cancer stem cells (CSC). Cytokines within the breast tumor microenvironment (TME) influence the CSC state by regulating tumor cell differentiation programs. Two prevalent breast TME cytokines are oncostatin-M (OSM) and interferon-β (IFN-β). OSM is a member of the IL-6 family of cytokines and can drive the de-differentiation of TNBC cells to a highly aggressive CSC state. Conversely, IFN-β induces the differentiation of TNBC, resulting in the repression of CSC properties. Here, we assess how these breast TME cytokines influence CSC plasticity and clinical outcome.

Methods

Using transformed human mammary epithelial cell (HMEC) and TNBC cell models, we assessed the CSC markers and properties following exposure to OSM and/or IFN-β. CSC markers included CD24, CD44, and SNAIL; CSC properties included tumor sphere formation, migratory capacity, and tumor initiation.

Results

There are three major findings from our study. First, exposure of purified, non-CSC to IFN-β prevents OSM-mediated CD44 and SNAIL expression and represses tumor sphere formation and migratory capacity. Second, during OSM-induced de-differentiation, OSM represses endogenous IFN-β mRNA expression and autocrine/paracrine IFN-β signaling. Restoring IFN-β signaling to OSM-driven CSC re-engages IFN-β-mediated differentiation by repressing OSM/STAT3/SMAD3-mediated SNAIL expression, tumor initiation, and growth. Finally, the therapeutic use of IFN-β to treat OSM-driven tumors significantly suppresses tumor growth.

Conclusions

Our findings suggest that the levels of IFN-β and OSM in TNBC dictate the abundance of cells with a CSC phenotype. Indeed, TNBCs with elevated IFN-β signaling have repressed CSC properties and a better clinical outcome. Conversely, TNBCs with elevated OSM signaling have a worse clinical outcome. Likewise, since OSM suppresses IFN-β expression and signaling, our studies suggest that strategies to limit OSM signaling or activate IFN-β signaling will disengage the de-differentiation programs responsible for the aggressiveness of TNBCs.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1136-x) contains supplementary material, which is available to authorized users.

Co-treatment with interferon-γ and 1-methyl tryptophan ameliorates cardiac fibrosis through cardiac myofibroblasts apoptosis

Cardiac remodeling characterized by cardiac fibrosis is a pathologic process occurring after acute myocardial infarction. Fibrosis can be ameliorated by interferon-gamma (IFN-γ), which is a soluble cytokine showing various effects such as anti-fibrosis, apoptosis, anti-proliferation, immunomodulation, and anti-viral activities. However, the role of IFN-γ in cardiac myofibroblasts is not well established. Therefore, we investigated the anti-fibrotic effects of IFN-γ in human cardiac myofibroblasts (hCMs) in vitro and whether indoleamine 2,3-dioxygenase (IDO), induced by IFN-γ and resulting in cell cycle arrest, plays an important role in regulating the biological activity of hCMs. After IFN-γ treatment, cell signaling pathways and DNA contents were analyzed to assess the biological activity of IFN-γ in hCMs. In addition, an IDO inhibitor (1-methyl tryptophan; 1-MT) was used to assess whether IDO plays a key role in regulating hCMs. IFN-γ significantly inhibited hCM proliferation, and IFN-γ-induced IDO expression caused cell cycle arrest in G0/G1 through tryptophan depletion. Moreover, IFN-γ treatment gradually suppressed the expression of α-smooth muscle actin. When IDO activity was inhibited by 1-MT, marked apoptosis was observed in hCMs through the induction of interferon regulatory factor, Fas, and Fas ligand. Our results suggest that IFN-γ plays key roles in anti-proliferative and anti-fibrotic activities in hCMs and further induces apoptosis via IDO inhibition. In conclusion, co-treatment with IFN-γ and 1-MT can ameliorate fibrosis in cardiac myofibroblasts through apoptosis.

Anti-renal fibrosis effect of asperulosidic acid via TGF-β1/smad2/smad3 and NF-κB signaling pathways in a rat model of unilateral ureteral obstruction

BACKGROUND

Renal fibrosis is the most common pathway leading to end-stage renal disease. It is characterized by excess extracellular matrix (ECM) accumulation and renal tissue damage, subsequently leading to kidney failure. Asperulosidic acid (ASPA), a bioactive iridoid glycoside, exerts anti-tumor, anti-oxidant, and anti-inflammatory activities, but its effects on renal fibrosis induced by unilateral ureteral obstruction (UUO) have not yet been investigated.

PURPOSE

This study aimed to investigate the protective effect of ASPA on renal fibrosis induced by UUO, and to explore its pharmacological mechanism.

METHODS

Thirty-six Sprague-Dawley (SD) rats were randomly divided into six groups: sham group, UUO model group, three ASPA treatment groups (10, 20, and 40 mg/kg), and captopril group (20 mg/kg). Rats were administered vehicle, ASPA or captopril intraperitoneally once a day for 14 consecutive days. Urea nitrogen (BUN), uric acid (UA) and inflammatory factors in serum samples were evaluated on the 7th, 10th, and 14th day after renal fibrosis induction. In addition, the 12 h urine was collected to test the content of urinary protein (upro) on the 14th day. The obstructive renal tissues were collected for pathological analysis (hematoxylin and eosion (H&E) staining and Masson's Trichrome staining) and immunohistochemical analysis on the 14th day after renal fibrosis induction. The mRNA expression of related factors and the protein levels of smad2, smad3, and smad4 were measured in UUO-induced rats by real time PCR and Western blot, respectively.

RESULTS

The levels of BUN, UA, and upro were elevated in UUO-induced rats, but ASPA treatment improved renal function by reducing the levels of BUN, UA, and upro. The protein levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6, as well as the mRNA levels of TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1) and interferon-γ (IFN-γ), were decreased after ASPA administration (10, 20 and 40 mg/kg) in a dose-dependent manner. The ASPA exerted an alleviation effect on the inflammatory response through inhibition of nuclear factor-kappa B (NF-κB) pathway. In addition, reductions in α-smooth muscle actin (α-SMA), collagen III, and fibronectin expression were observed after ASPA administration at doses of 20 and 40 mg/kg. Furthermore, the renal expression of transforming growth factor-β1 (TGF-β1), smad2, smad3, and smad4 was down-regulated by ASPA treatment at doses of 20 and 40 mg/kg.

CONCLUSION

ASPA possessed protective effects on renal interstitial fibrosis in UUO-induced rats. These effects may be through inhibition of the activation of NF-κB and TGF-β1/smad2/smad3 signaling pathways.

Hepatoprotective immune response during Trichinella spiralis infection in mice

Infections with gastrointestinal nematodes provoke immune and inflammatory responses mediated by cytokines released from T-helper type-2 (Th2) cells. Infections with Trichinella species have been reported to differ by the host species. Previously, in rats, we observed acute liver inflammation in response to infection with Trichinella spiralis, and the rat hosts showed a series of biochemical changes characterized by a decrease in serum paraoxonase (PON) 1 activity associated with the down-regulation of hepatic PON1 synthesis. In the present study, we investigated the effect(s) of species differences on the immune response against T. spiralis infection by analyzing serum PON1 activity and the associated inflammatory/anti-inflammatory mediators in mice. There were inconsistent changes in the serum PON1 activity of mice infected with T. spiralis, and these changes were associated with significant increases in the serum levels of interleukin (IL)-2, IL-4, IL-10, IL-12 (p70), granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor α during the enteric phase of the infection, while the levels of IL-5 and interferon γ were significantly increased throughout the entire experimental period. Moreover, T. spiralis infection in mice was associated with little inflammatory cell infiltration in hepatic tissues. Given the zoonotic prevalence of T. spiralis, further mechanistic research in this area is warranted.

Interplay between interferon-stimulated gene 15/ISGylation and interferon gamma signaling in breast cancer cells

Interferon-stimulated gene 15 (ISG15) is a ubiquitin-like protein that conjugates to its target proteins to modify them through ISGylation, but the relevance of ISG15 expression and its effects have been not completely defined. Herein, we examined the interplay between ISG15/ISGylation and the interferon-gamma (IFN-γ) signaling pathway in mammary tumors and compared it with that in normal mammary tissues. Our results indicated that mammary tumors had higher levels of ISG15 mRNA and ISG15 protein than the adjacent normal mammary tissue. Furthermore, the expression of IFN-γ signaling components was altered in breast cancer. Interestingly, IFN-γ treatment induced morphological changes in MCF-7 and MDA-MB-231 breast cancer cell lines due to cytoskeletal reorganization. This cellular process seems to be related to the increase in ISGylation of cytoplasmic IQ Motif Containing GTPase Activating Protein 1 (IQGAP1). Interactome analysis also indicated that IFN-γ signaling and the ISGylation system are associated with several proteins implicated in cytoskeletal remodeling, including IQGAP1. Thus, ISG15 may present a potential biomarker for breast cancer, and IFN-γ signaling and protein ISGylation may participate in the regulation of the cytoskeleton in breast cancer cells.

Mutual regulation between miR-21 and the TGFβ/Smad signaling pathway in human bronchial fibroblasts promotes airway remodeling

OBJECTIVE

Airway remodeling is an important pathological feature of asthma. Excessive deposition of extracellular matrix (e.g., collagen) secreted from fibroblasts is a major factor contributing to airway remodeling. Currently, the mechanism by which collagen continues to be oversynthesized in the airway remains unclear. In this study, we investigated the role of the microRNA-21 (miR-21) and TGFβ/Smad signaling pathway in human bronchial fibroblasts (HBFs), and explored the regulatory mechanism of airway remodeling.

METHODS

HBFs were cultured in vitro and treated with the transforming growth factor β (TGFβ), receptor inhibitor (SB431542), and TGFβ1. miR-21 and Smad7 overexpressing lentiviruses, as well as an miR-21 interfering lentivirus were constructed and transfected into HBFs. Western blotting was used to determine the expression of airway remodeling-related proteins and proteins in the TGFβ/Smad signaling pathway. miR-21 expression was measured by quantitative real-time PCR.

RESULTS

The high expression of miR-21 induced by TGFβ1 was reduced following the treatment with the SB431542 in HBFs. Smad7 overexpression inhibited the elevated expression of the COL I protein induced by miR-21 overexpression in HBFs. Inhibiting miR-21 expression upregulated the level of Smad7 protein, thus reducing the expression of airway remodeling-related proteins induced by TGFβ1 stimulation in HBFs.

CONCLUSIONS

TGFβ1 can induce miR-21 expression in HBFs through the TGFβ/Smad signaling pathway to promote airway remodeling. miR-21 downregulates Smad7, activates the TGFβ/Smad signaling pathway, and promotes airway remodeling. Mutual regulation between miR-21 and the TGFβ/Smad signaling pathway in HBFs promotes airway remodeling.

Are we any closer to treating liver fibrosis (and if no, why not)?

This review provides a personal view on anti-fibrosis therapy in the liver. The worst clinical consequence of liver fibrosis is the development of liver cirrhosis and portal hypertension. Etiology is a decisive factor which determines patterns of fibrous septa and subsequent vascular remodeling, which is essential for the development of portal hypertension. Removing or controlling the disease-causing agent, i.e. anti-viral treatment for hepatitis, is the essential first step for treating chronic liver diseases and can reverse fibrosis in some settings. However, removing etiology is not always sufficient to prevent fibrosis from progressing towards cirrhosis and portal hypertension. In liver diseases such as severe alcoholic hepatitis and massive parenchymal loss, the formation of vascular anastomoses between portal to central veins based on bridging fibrosis results in cirrhosis and portal hypertension. For these patients, anti-fibrotic treatment is crucial and urgent. Unfortunately, a lack of understanding how fibrosis contributes to vascular remodeling caused by and combined with a lack of suitable experimental models that recapitulate human liver diseases, has hampered the development of successful anti-fibrotic drugs for clinical use to date.

MicroRNA-351 promotes schistosomiasis-induced hepatic fibrosis by targeting the vitamin D receptor

Aberrant expression of microRNAs (miRNAs) underlies a spectrum of human diseases including organ fibrosis, and hepatic stellate cells (HSCs) are the main effectors of hepatic fibrosis. Here, we showed that the expression of host miR-351 in HSCs was markedly reduced during the early stage of Schistosoma infection. However, this expression was significantly increased during the later stage of infection (after 52 d of infection). The elevated levels of miR-351 promoted hepatic fibrosis by targeting the vitamin D receptor (VDR), which is an antagonist of SMAD signaling. Importantly, efficient and sustained inhibition of miR-351 in liver tissues using the highly hepatotropic recombinant adeno-associated virus serotype 8 (rAAV8), alleviated the hepatic fibrosis, partially protecting the host from lethal schistosomiasis. In addition, we found that miR-351 is negatively regulated by IFN-γ in HSCs during infection. At the early stage of infection, the elevated levels of IFN-γ inhibited the expression of miR-351 in HSCs through activation of signal transducer and activator of transcription 1 and induction of IFN regulatory factor 2, which binds the promotor of pre-miR-351 Our study provides insights into the mechanisms by which miR-351 regulates schistosomiasis hepatic fibrosis and highlights the potential of rAAV8-mediated miR-351 inhibition as a therapeutic intervention for fibrotic diseases.

Angiotensin II induces connective tissue growth factor expression in human hepatic stellate cells by a transforming growth factor β-independent mechanism

Angiotensin II (Ang II) promotes hepatic fibrosis by increasing extracellular matrix (ECM) synthesis. Connective tissue growth factor (CTGF) plays a crucial role in the pathogenesis of hepatic fibrosis and emerges as downstream of the profibrogenic cytokine transforming growth factor-β (TGF-β). We aimed to investigate the molecular events that lead from the Ang II receptor to CTGF upregulation in human hepatic stellate cells, a principal fibrogenic cell type. Ang II produced an early, AT₁ receptor-dependent stimulation of CTGF expression and induced a rapid activation of PKC and its downstream p38 MAPK, thereby activating a nuclear factor-κB (NF-κB) and Smad2/3 cross-talk pathway. Chemical blockade of NF-κB and Smad2/3 signaling synergistically diminished Ang II-mediated CTGF induction and exhibited an additive effect in abrogating the ECM accumulation caused by Ang II. Furthermore, we demonstrated that CTGF expression was essential for Ang II-mediated ECM synthesis. Interestingly, the ability of dephosphorylated, but not phosphorylated JNK to activate Smad2/3 signaling revealed a novel role of JNK in Ang II-mediated CTGF overexpression. These results suggest that Ang II induces CTGF expression and ECM accumulation through a special TGF-β-independent interaction between the NF-κB and Smad2/3 signals elicited by the AT₁/PKCα/p38 MAPK pathway.

MHC II-, but not MHC II+, hepatic Stellate cells contribute to liver fibrosis of mice in infection with Schistosoma japonicum

Hepatic stellate cells (HSCs) are considered as the main effector cells in vitamin A metabolism and liver fibrosis, as well as in hepatic immune regulation. Recently, researches have revealed that HSCs have plasticity and heterogeneity, which depend on their lobular location and whether liver is normal or injured. This research aimed to explore the biological characteristics and heterogeneity of HSCs in mice with Schistosoma japonicum (S. japonicum) infection, and determine the subpopulation of HSCs in pathogenesis of hepatic fibrosis caused by S. japonicum infection. Results revealed that HSCs significantly increased the expressions of MHC II and fibrogenic genes after S. japonicum infection, and could be classified into MHC II⁺ HSCs and MHC II^- HSCs subsets. Both two HSCs populations suppressed the proliferation of activated CD4⁺T cells, whereas only MHC II^- HSCs displayed a myofibroblast-like phenotype. In response to IFN-γ, HSCs up-regulated the expressions of MHC II and CIITA, while down-regulated the expression of fibrogenic gene Col1. In addition, praziquantel treatment decreased the expressions of fibrogenic genes in MHC II^- HSCs. These results confirmed that HSCs from S. japonicum-infected mice have heterogeneity. The MHC II^- α-SMA⁺ HSCs were major subsets of HSCs contributing to liver fibrosis and could be considered as a potential target of praziquantel anti-fibrosis treatment.

Reversal of liver cirrhosis: current evidence and expectations

In the past, liver cirrhosis was considered an irreversible phenomenon. However, many experimental data have provided evidence of the reversibility of liver fibrosis. Moreover, multiple clinical studies have also shown regression of fibrosis and reversal of cirrhosis on repeated biopsy samples. As various etiologies are associated with liver fibrosis via integrated signaling pathways, a comprehensive understanding of the pathobiology of hepatic fibrogenesis is critical for improving clinical outcomes. Hepatic stellate cells play a central role in hepatic fibrogenesis upon their activation from a quiescent state. Collagen and other extracellular material components from activated hepatic stellate cells are deposited on, and damage, the liver parenchyma and vascular structures. Hence, inactivation of hepatic stellate cells can lead to enhancement of fibrolytic activity and could be a potential target of antifibrotic therapy. In this regard, continued efforts have been made to develop better treatments for underlying liver diseases and antifibrotic agents in multiple clinical and therapeutic trials; the best results may be expected with the integration of such evidence. In this article, we present the underlying mechanisms of fibrosis, current experimental and clinical evidence of the reversibility of liver fibrosis/cirrhosis, and new agents with therapeutic potential for liver fibrosis.

Unraveling biophysical interactions of radiation pneumonitis in non-small-cell lung cancer via Bayesian network analysis

BACKGROUND

In non-small-cell lung cancer radiotherapy, radiation pneumonitis≥grade 2 (RP2) depends on patients' dosimetric, clinical, biological and genomic characteristics.

METHODS

We developed a Bayesian network (BN) approach to explore its potential for interpreting biophysical signaling pathways influencing RP2 from a heterogeneous dataset including single nucleotide polymorphisms, micro RNAs, cytokines, clinical data, and radiation treatment plans before and during the course of radiotherapy. Model building utilized 79 patients (21 with RP2) with complete data, and model testing used 50 additional patients with incomplete data. A developed large-scale Markov blanket approach selected relevant predictors. Resampling by k-fold cross-validation determined the optimal BN structure. Area under the receiver-operating characteristics curve (AUC) measured performance.

RESULTS

Pre- and during-treatment BNs identified biophysical signaling pathways from the patients' relevant variables to RP2 risk. Internal cross-validation for the pre-BN yielded an AUC=0.82 which improved to 0.87 by incorporating during treatment changes. In the testing dataset, the pre- and during AUCs were 0.78 and 0.82, respectively.

CONCLUSIONS

Our developed BN approach successfully handled a high number of heterogeneous variables in a small dataset, demonstrating potential for unraveling relevant biophysical features that could enhance prediction of RP2, although the current observations would require further independent validation.

CUG-binding protein 1 regulates HSC activation and liver fibrogenesis

Excessive activation of hepatic stellate cells (HSCs) is a key step in liver fibrogenesis. Here we report that CUG-binding protein 1 (CUGBP1) expression is elevated in HSCs and positively correlates with liver fibrosis severity in human liver biopsies. Transforming growth factor-beta (TGF-β) selectively increases CUGBP1 expression in cultured HSCs in a p38 mitogen-activated protein kinase (MAPK)-dependent manner. Knockdown of CUGBP1 inhibits alpha smooth muscle actin (α-SMA) expression and promotes interferon gamma (IFN-γ) production in HSCs in vitro. We further show that CUGBP1 specifically binds to the 3′ untranslated region (UTR) of human IFN-γ mRNA and promotes its decay. In mice, knockdown of CUGBP1 alleviates, whereas its overexpression exacerbates, bile duct ligation (BDL)-induced hepatic fibrosis. Therefore, CUGBP1-mediated IFN-γ mRNA decay is a key event for profibrotic TGF-β-dependent activation of HSCs, and inhibiting CUGBP1 to promote IFN-γ signalling in activated HSCs could be a novel strategy to treat liver fibrosis.

Activation of hepatic stellate cells is a critical event in the development of fibrosis, which is driven by TGF-beta and inhibited by IFN-gamma. Here Wu et al. show that the RNA binding protein CUGBP1 is increased by TGF-beta signalling and promotes IFN-gamma mRNA degradation.