Notch signaling mediated by TGF-β/Smad pathway in concanavalin A-induced liver fibrosis in rats

Paclitaxel causes de novo induction of invasive breast cancer cells by repolarizing tumor-associated macrophages

Background

Metastasis is the leading cause of breast cancer (BC) death, and tumor cells must migrate and invade to metastasize. BC cells that express the pro-metastatic actin regulatory protein MenaINV have an enhanced ability to migrate and intravasate within the primary tumor and extravasate at secondary sites. Though chemotherapy improves patient survival, treatment with paclitaxel leads to upregulation of MenaINV and an increase in metastasis in mice. MenaINV expression can be induced in BC cells through cooperative NF-κB/ Notch1 signaling with macrophages, which are often increased in tumors in response to chemotherapy. MenaINV-expressing cells are also resistant to paclitaxel, begging the question of whether paclitaxel increases MenaINV by de novo induction or by selectively killing non-MenaINV-expressing cells. We hypothesized that paclitaxel causes de novo MenaINV induction by increasing macrophage-tumor cell NF-κB/ Notch1 signaling. Understanding this pro-metastatic effect of chemotherapy is crucial to refining treatment strategies.

Findings

Paclitaxel-treated tumors expressed significantly more MenaINV than vehicle-treated tumors. This effect was dependent upon both macrophages and NF-κB/ Notch signaling. This indicates that chemotherapy increases MenaINV expression by induction. Mechanistically, paclitaxel causes macrophages to take on a pro-inflammatory phenotype and increase NF-κB/ Notch1 signaling with tumor cells.

Conclusion

Paclitaxel causes de novo MenaINV induction. Mechanistically, paclitaxel repolarizes tumor-associated macrophages towards a pro-inflammatory phenotype. These pro-inflammatory macrophages then participate in enhanced NF-κB/ Notch1 signaling with tumor cells, which leads to MenaINV induction in the tumor cells. These results lay the groundwork for novel microenvironment-based therapies to alleviate the pro-metastatic effects of chemotherapy in BC.

YAP/TAZ as master regulators in liver regeneration and disease: insights into mechanisms and therapeutic targets

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are key downstream effectors of the Hippo pathway that regulate organ size, tissue homeostasis, and cancer development. YAP/TAZ play crucial regulatory roles in organ growth, cell proliferation, cell renewal, and regeneration. Mechanistically, YAP/TAZ influence the occurrence and progression of liver regeneration (LR) through various signaling pathways, including Notch, Wnt/β-catenin, TGF-β/Smad. While the activation of YAP/TAZ can promote the regeneration of damaged liver tissue, their mechanisms of action may differ under various LR conditions. Furthermore, excessive activation of YAP/TAZ may also lead to severe liver damage, manifesting as alcoholic hepatitis, liver fibrosis, and even liver cancer. Here, we review the role and mechanisms of YAP/TAZ in LR and liver disease, highlighting the potential for advancements in clinical diagnosis and treatment targeting YAP/TAZ in these contexts.

The Complex Interplay of TGF-β and Notch Signaling in the Pathogenesis of Fibrosis

Fibrosis is a major medical challenge, as it leads to irreversible tissue remodeling and organ dysfunction. Its progression contributes significantly to morbidity and mortality worldwide, with limited therapeutic options available. Extensive research on the molecular mechanisms of fibrosis has revealed numerous factors and signaling pathways involved. However, the interactions between these pathways remain unclear. A comprehensive understanding of the entire signaling network that drives fibrosis is still missing. The TGF-β and Notch signaling pathways play a key role in fibrogenesis, and this review focuses on their functional interplay and molecular mechanisms. Studies have shown synergy between TGF-β and Notch cascades in fibrosis, but antagonistic interactions can also occur, especially in cardiac fibrosis. The molecular mechanisms of these interactions vary depending on the cell context. Understanding these complex and context-dependent interactions is crucial for developing effective strategies for treating fibrosis.

A Review of Pathophysiology and Therapeutic Strategies Targeting TGF-β in Graves' Ophthalmopathy

TGF-β plays a pivotal role in the pathogenesis of GO by promoting orbital tissue remodeling and fibrosis. This process involves the stimulation of orbital fibroblasts, leading to myofibroblast differentiation, increased production of inflammatory mediators, and hyaluronan accumulation. Studies have elucidated TGF-β's role in driving fibrosis and scarring processes through both canonical and non-canonical pathways, particularly resulting in the activation of orbital myofibroblasts and the excessive accumulation of extracellular matrix. Additionally, recent in vitro and in vivo studies have been summarized, highlighting the therapeutic potential of targeting TGF-β signaling pathways, which may offer promising treatment interventions for GO. This review aims to consolidate the current understanding of the multifaceted role of TGF-β in the molecular and cellular pathophysiology in Graves' ophthalmopathy (GO) by exploring its contributions to fibrosis, inflammation, and immune dysregulation. Additionally, the review investigates the therapeutic potential of inhibiting TGF-β signaling pathways as a strategy for treating GO.

Dynamics of Endothelial Cell Diversity and Plasticity in Health and Disease

Endothelial cells (ECs) are vital structural units of the cardiovascular system possessing two principal distinctive properties: heterogeneity and plasticity. Endothelial heterogeneity is defined by differences in tissue-specific endothelial phenotypes and their high predisposition to modification along the length of the vascular bed. This aspect of heterogeneity is closely associated with plasticity, the ability of ECs to adapt to environmental cues through the mobilization of genetic, molecular, and structural alterations. The specific endothelial cytoarchitectonics facilitate a quick structural cell reorganization and, furthermore, easy adaptation to the extrinsic and intrinsic environmental stimuli, known as the epigenetic landscape. ECs, as universally distributed and ubiquitous cells of the human body, play a role that extends far beyond their structural function in the cardiovascular system. They play a crucial role in terms of barrier function, cell-to-cell communication, and a myriad of physiological and pathologic processes. These include development, ontogenesis, disease initiation, and progression, as well as growth, regeneration, and repair. Despite substantial progress in the understanding of endothelial cell biology, the role of ECs in healthy conditions and pathologies remains a fascinating area of exploration. This review aims to summarize knowledge and concepts in endothelial biology. It focuses on the development and functional characteristics of endothelial cells in health and pathological conditions, with a particular emphasis on endothelial phenotypic and functional heterogeneity.

Gadolinium retention effect on macrophages - a potential cause of MRI contrast agent Dotarem toxicity

Gadolinium is a component of the MRI contrast agent Dotarem. Although Dotarem is the least toxic among MRI contrasts used, gadolinium present in Dotarem accumulates for many years in various organs and tissues exerting toxic effects. We showed previously that gadolinium remains in macrophages for at least 7 days after exposure to Dotarem. However, very little is known about the effect of gadolinium retention on the immune cells such as macrophages. We studied the effect of 1-day and 7-day retention of gadolinium on various functions and molecular pathways of macrophages. Gadolinium retention for 7 days decreased macrophage adhesion and motility and dysregulated the expression of adhesion and fibrotic pathway-related proteins such as Notch1 and its ligand Jagged1, adhesion/migration-related proteins PAK1 and Shp1, immune response-related transcription factors Smad3 and TCF19, and chemokines CXCL10 and CXCL13, and dysregulated the mRNA expression of fibrosis-related genes involved in extracellular matrix (ECM) synthesis, such as Col6a1, Fibronectin, MMP9, and MMP12. It also completely (below a level of detection) shut down the transcription of anti-inflammatory M2 macrophage polarization marker the Arg-1. Such changes, if they occur in MRI patients, can be potentially detrimental to the patient's immune system and immune response-related processes.

Guizhi Fuling Formulation: A review on chemical constituents, quality control, pharmacokinetic studies, pharmacological properties, adverse reactions and clinical applications

ETHNOPHARMACOLOGICAL RELEVANCE

Guizhi Fuling Formulation (GF), composed of Cinnamomi Ramulus, Poria, Paeoniae Radix, Moutan Cortex, and Persicae Semen, was first recorded as a pill in the Traditional Chinese Medicine (TCM) classical book Synopsis of Prescriptions of the Golden Chamber written by Zhang Zhongjing in the Eastern Han Dynasty (25-220 CE). As a TCM prescription, it functions to improve blood circulation, reduce blood stasis and eliminate abdominal lumps. Originally used to treat the restlessness of pregnancy due to a mass, it is now also effective in treating gynecological illnesses and various tumors such as cervical cancer, ovarian cancer, and others. With the expansion of clinical applications, GF was developed into different dosage forms, including Guizhi Fuling Pill (GFP), Guizhi Fuling Capsule (GFC), Guizhi Fuling Tablet (GFT), Guizhi Fuling Granule (GFG), and Guizhi Fuling Decoction (GFD). Different dosage forms of GF play an important role in clinical treatment.

AIM OF THE REVIEW

To systematically analyze and summarize the research findings concerning the chemical constituents, quality control, pharmacokinetic studies, pharmacological properties, adverse reactions, and clinical applications of GF, so as to point out the problems existing in the current research and provides opinions for future study.

MATERIALS AND METHODS

The relevant literatures were collected from classical TCM books and a variety of databases, including China National Knowledge Infrastructure, WanFang Data, PubMed, SpringerLink, Web of Science, and Google Scholar. All eligible studies are analyzed and summarized in this review.

RESULTS

There are some problems for GF: the quality control system is not perfect, the study of pharmacokinetics is not comprehensive, the explanation of pharmacological mechanism is insufficient, and the clinical safety has not been fully verified. A few of research directions for future research are proposed: (i) to establish the method of characteristic components combined with bioassay and multi-index content determination to improve the quality evaluation; (ii) to elucidate pharmacokinetic studies based on human pharmacokinetic characteristics and interaction with intestinal microbiota; (iii) to carry out pharmacological mechanism studies at whole, organ, cellular and molecular levels; (iv) to reconfirm safety of various dosage forms of GF based on large-scale clinical studies.

CONCLUSIONS

GF is extremely valuable in drug research and in clinical treatment especially for gynecological diseases. However, there are also some issues. Future efforts should focus on strengthening quality control, clarifying pharmacological and pharmacokinetic processes, and reconfirming clinical safety.

Characterization of human stem cell-derived hepatic stellate cells and liver sinusoidal endothelial cells during extended in vitro culture

Background: There is a significant need for predictive and stable in vitro human liver representations for disease modeling and drug testing. Hepatic stellate cells (HSCs) and liver sinusoidal endothelial cells (LSECs) are important non-parenchymal cell components of the liver and are hence of relevance in a variety of disease models, including hepatic fibrosis. Pluripotent stem cell- (PSC-) derived HSCs (scHSCs) and LSECs (scLSECs) offer an attractive alternative to primary human material; yet, the suitability of scHSCs and scLSECs for extended in vitro modeling has not been characterized. Methods: In this study, we describe the phenotypic and functional development of scHSCs and scLSECs during 14 days of 2D in vitro culture. Cell-specific phenotypes were evaluated by cell morphology, immunofluorescence, and gene- and protein expression. Functionality was assessed in scHSCs by their capacity for intracellular storage of vitamin A and response to pro-fibrotic stimuli induced by TGF-β. scLSECs were evaluated by nitric oxide- and factor VIII secretion as well as endocytic uptake of bioparticles and acetylated low-density lipoprotein. Notch pathway inhibition and co-culturing scHSCs and scLSECs were separately tested as options for enhancing long-term stability and maturation of the cells. Results and Conclusion: Both scHSCs and scLSECs exhibited a post-differentiation cell type-specific phenotype and functionality but deteriorated during extended culture with PSC line-dependent variability. Therefore, the choice of PSC line and experimental timeframe is crucial when designing in vitro platforms involving scHSCs and scLSECs. Notch inhibition modestly improved long-term monoculture in a cell line-dependent manner, while co-culturing scHSCs and scLSECs provides a strategy to enhance phenotypic and functional stability.

Asiaticoside conveys an antifibrotic effect by inhibiting activation of hepatic stellate cells via the Jagged-1/Notch-1 pathway

The aim of this study was to investigate the underlying protective mechanisms of asiaticoside (AS) against liver fibrosis (LF) both in vivo and in vitro. A rat model with carbon tetrachloride (CCl₄)-induced liver fibrosis is employed to verify the effect and mechanism of AS on the process of liver fibrosis in vivo experiment. Hematoxylin/eosin and sirius red staining was conducted to assess the severity of liver injury and fibrosis. Further, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), glutamyl transferase (GGT), and total bilirubin (TBil) were measured. In addition, LX2 cells were cultured for vitro experiment to investigate the influence of AS on hepatic stellate cells (HSCs). Overproduction of α-smooth muscle actin and type I collagen is characteristic of LF and HSCs, as determined by immunohistochemical and Western blot analyses. The expression levels of molecules associated with the Notch signaling pathway (i.e., Notch-1, Jagged-1, and Delta-like-4) were assessed by Western blot analysis. The results revealed that AS attenuated LF, as defined by reduced deposition of collagen, expression of α-smooth muscle actin and collagen type 1, and expression of biochemical parameters (alanine aminotransferase, aspartate aminotransferase, and hydroxyproline). Notably, AS suppressed the expression levels of Notch-1, Jagged-1, and Delta-like-4 in activated HSCs and LF. Collectively, these results demonstrate that AS prevented the progression of LF by modulating the Notch signaling pathway, indicating that AS has potential therapeutic effects against LF.

Suppressive effect of pseudolaric acid B on Echinococcus multilocularis involving regulation of TGF-β1 signaling in vitro and in vivo

Echinococcus multilocularis, the causative agent of alveolar echinococcosis (AE), severely threats human health and livestock farming. The first line of chemotherapeutic drug for AE is albendazole, which limits rapid extension of E. multilocularis metacestodes, but is rarely curative for AE, with severe side effects in long-term use, thus development of new anti-echinococcal drugs is mandated. Pseudolaric acid B (PAB) has long been used to treat fungal-infected dermatosis, and exerted anti-tumor, -fertility, -angiogenesis, -tubulin and antiparasitic activity. However, the effect of PAB against Echinococcus spp. remains unclear. The present study is to understand the effect of PAB against E. multilocularis in vitro and in vivo, and identify potential anti-echinococcal mechanism, as well as its toxicity. After exposure to PAB at 20 μg/ml, significant reduction of the survival rate and substantial ultrastructural destructions in E. multilocularis protoscoleces were observed in vitro. Furthermore, the wet weight of E. multilocularis cysts in the infected mice was significantly decreased after treatment with PAB (40, 20 or 10 mg/kg) for 12 weeks. Meanwhile, significant increase of both protein and mRNA expression of transforming growth factor beta 1 (TGF-β1) was detected in the serum and liver of the infected mice, whereas PAB administration lowered its expression significantly. The toxicity tests demonstrated that PAB displayed lower cytotoxicity to human liver and kidney cells (HL-7702 and HK-2 cell) with IC₅₀ = 25.29 and 42.94 μg/ml than albendazole with IC₅₀ = 3.71 and 21.22 μg/ml in vitro, and caused lower hepatoxicity and nephrotoxicity in mice than ABZ. Our findings indicated that PAB possesses potent anti-echinococcal effect, with lower toxicity than albendazole, implying a potential chemotherapeutic agent for AE. Additionally, the present study demonstrated that the suppressive effect of PAB on the parasite may involve down-regulation of TGF-β1 signaling.

Jagged-1/Notch Pathway and Key Transient Markers Involved in Biliary Fibrosis during Opisthorchis felineus Infection

Chronic opisthorchiasis associated with Opisthorchis felineus infection is accompanied by severe fibrotic complications. It is of high practical significance to elucidate the mechanisms of hepatic fibrosis in chronic infection dynamics. The goal of the study is to investigate the temporal profile of key markers and the Jagged1/Notch signaling pathway in the implementation of fibrosis in a chronic O. felineus infection. For the first time, using histological methods and real-time PCR analysis, we demonstrated the activation of the Jagged1/Notch pathway in liver fibrogenesis, including the activation of the Hes1 and Hey1 target genes during experimental opisthorchiasis in Mesocricetus auratus. Cluster analysis followed by regression analysis of key markers during the infection showed that Jagged1 and Mmp9have the greatest contribution to the development of cholangiofibrosis and periductal fibrosis. Moreover, we detected a significant increase in the number of Jagged1-positive cells in the liver of chronic opisthorchiasis patients compared to that of the control group without infection. The results of the study are extremely informative both in terms of investigation both diverse fibrosis mechanisms as well as potential targets in complex antihelmintic therapy.

The novel anti-colitic effect of β-adrenergic receptors via modulation of PS1/BACE-1/Aβ axis and NOTCH signaling in an ulcerative colitis model

Although dysautonomia was documented in inflammatory bowel disease, with activation of the stress-related sympathetic system, the role of agonists/antagonists of the adrenergic receptors is not conclusive. Moreover, ulcerative colitis was recently linked to dementia, but the potential role of the presenilin 1(PS1)/BACE-1/beta-amyloid (Aβ) axis has not been evaluated. Hence, we investigated the impact of mirabegron (β3-agonist) and/or carvedilol (β1/β2 antagonist) on iodoacetamide-induced ulcerative colitis with emphasis on the novel pathomechanism of the PS1/BACE-1/Aβ axis in ulcerative colitis, and its relation to the inflammatory cascade, fibrotic processes, and the gut barrier dysfunction. Ulcerated rats were either left untreated or treated for 8 days with mirabegron and/or carvedilol. Besides minimizing colon edema and weight loss, and improving colon structure, mirabegron and/or carvedilol abated colonic PS1/BACE-1/Aβ axis and the NOTCH1/NICD/HES1 hub besides the inflammatory cascade GSK3-β/NF-κΒ/TNF-α, and the oxidative stress marker malondialdehyde. The anti-fibrotic effect was verified by boosting SMAD-7 and inhibiting TGF-β1, α-SMA immunoexpression, and MTC staining. Moreover, the drugs improved the gut barrier function, attested by the increased goblet cells and expression of E-cadherin, and the inhibited expression of p (Y654)-β-catenin to preserve the E-cadherin/β-catenin adherens junction (AJ). These signaling pathways may be orchestrated by the replenished PPAR-γ, a transcription factor known for its anti-colitic effect. Conclusion: Besides maintaining the gut barrier, mirabegron and/or carvedilol mediated their anti-colitic effect by their anti-oxidant, anti-inflammatory, and anti-fibrotic capacities. The therapeutic effect of these drugs depends partly on suppressing the harmful signaling pathways PS1/BACE-1/Aβ, NOTCH1/NICD/HES1, GSK3-β/NF-κΒ/TNF-α, and TGF-1β/α-SMA while enhancing PPAR-γ, SMAD-7, mucus, and AJ.

Oxidative stress mediated by the TLR4/NOX2 signalling axis is involved in polystyrene microplastic-induced uterine fibrosis in mice

Microplastics (MPs), as a new environmental pollutant, have received widespread attention worldwide. Uterine fibrosis is one of the main factors of female reproductive disorders. However, it is unclear whether the female reproductive disorders caused by MPs are related to uterine fibrosis. Therefore, in this study, we constructed female mouse models exposed to polystyrene microplastics (PS-MPs). We found that PS-MP exposure resulted in endometrial thinning and severe collagen fibre deposition in female mice. Further mechanistic studies found that PS-MP exposure increased the expression of high mobility group Box 1 (HMGB1) and acetyl-HMGB1, further activating the Toll-like receptor 4/NADPH oxidase 2 (TLR4/NOX2) signalling axis and eventually causing oxidative stress. Afterwards, oxidative stress elicited the activation of Notch and the transforming growth factor β (TGF-β) signalling pathway, leading to increased levels of fibrotic proteins and collagen. Correspondingly, PS-MP treatment upregulated the expression of TLR4 and NOX2 and the level of reactive oxygen species (ROS) and increased the levels of fibrotic protein and collagen in mouse endometrial epithelial cells cultured in vitro. Conversely, inhibition of the TLR4/NOX2 signalling pathway effectively reduced the level of ROS in cells, weakened the upregulation of Notch and TGF-β signalling by PS-MPs, and efficiently reduced the expression of fibrotic and collagen genes. In summary, we demonstrated a new mechanism by which MPs induce uterine fibrosis in mice, that is, by inducing oxidative stress to activate the Notch and TGF-β signalling pathways by triggering the TLR4/NOX2 signalling axis. Targeting TLR4/NOX2 signalling may consequently prove to be an innovative therapeutic option that is effective in alleviating the reproductive toxicity of PS-MPs. Our study sheds new light on the reproductive toxicity of MPs and provides suggestions and references for comparative medicine and clinical medicine.

RO4929097, a Selective γ-Secretase Inhibitor, Inhibits Subretinal Fibrosis Via Suppressing Notch and ERK1/2 Signaling in Laser-Induced Mouse Model

Purpose

This study aimed to explore whether RO4929097 (RO), a specific γ-secretase inhibitor, could inhibit the subretinal fibrosis in laser-induced mouse model and the relevant molecular mechanisms.

Methods

Male C57BL/6J mice were used to produce choroidal neovascularization (CNV) and subretinal fibrosis by laser photocoagulation, and RO was administered intravitreally 1 day after laser induction. The sizes of CNV and subretinal fibrosis were measured and quantified in both 2D and 3D constructions. The ARPE-19 cell line and primary human RPE (phRPE) cells were treated with TGFβ1, in combination with or without RO, to examine Notch related molecules, epithelial mesenchymal transition (EMT), cell viability, migration, and contractile function, as well as the crosstalk between Notch and other EMT relevant signaling pathways.

Results

Intravitreal injection of RO reduced the sizes of both CNV and subretinal fibrosis in laser-induced young and old mice at day 7 and day 14 after laser induction. Moreover, EMT and Notch activation in RPE-choroid complexes from laser-induced mice were significantly attenuated by RO. In vitro, TGFβ1 activated Notch signaling and induced EMT in ARPE-19 cells, accompanied by enhanced EMT-related function, which were inhibited by RO. The inhibition of RO on EMT was further confirmed in TGFβ1-treated phRPE cells. Blockage of Notch signaling by RO could inhibit ERK1/2 signaling; whereas ERK1/2 inhibition had no effect on Notch. The action of RO was independent of Smad2/3 or p38, and co-inhibition of Notch and Smad2/3 showed synergistic effect on EMT inhibition.

Conclusions

RO exerts its antifibrotic effect by directly inhibiting Notch signaling and indirectly suppressing ERK1/2 signaling. Targeting Notch signaling might provide a therapeutic strategy in prevention and treatment of subretinal fibrosis in neovascular age-related macular degeneration (nAMD).

Shugan Huoxue Huayu Fang attenuates carbon tetrachloride-induced hepatic fibrosis in rats by inhibiting transforming growth factor-β1/Smad signaling

OBJECTIVE

To investigate the potential mechanism by which Shugan Huoxue Huayu Fang (SGHXHYF) ameliorates liver fibrosis.

METHODS

Liver fibrosis was induced in rats by intraperitoneal injection of carbon tetrachloride (CCl4) in peanut oil solution (40%, 3 mL/kg body weight) twice a week for 8 weeks. A normal control group received the same volume of peanut oil alone. During weeks 5-8, the CCl4-injected rat groups were administered saline (vehicle control), colchicine (0.1 mg/mL, 1 mg/kg, positive control), or SGHXHYF (0.1 mg/mL; 0.3, 0.6 and 1.2 mg/kg) once daily by oral gavage. Rats were sacrificed 24 h after the last treatment. Blood samples were collected for measurement of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), albumin (ALB), collagen Ⅰ and collagen Ⅲ levels. Liver samples were analyzed by histopathological staining, Masson's staining of extracellular matrix proteins, and immune-ohistochemical staining of αsmooth muscle actin (α-SMA). TGF-β1/Smad protein and mRNA levels were analyzed by Western blot and quantitative reverse transcription-polymerase chain reaction analysis, respectively. In vitro experiments were also performed using rat hepatic stellate cells (HSCs).

RESULTS

Compared with the control animals, CCl4-exposed rats exhibited elevated serum levels of ALT, AST, ALP, collagen I, and collagen III; reduced serum levels of ALB; and increased collagen deposition and αSMA expression in liver sections, reflecting liver fibrosis. CCl4 also increased expression of TGF-β1 and the activated (phosphorylated) forms of Smad2 and Smad3 but reduced expression of the negative regulator Smad7 in the liver. Notably, concomitant administration of SGHXHYF to CCl4-exposed rats was found to significantly reverse or abolish the pro-fibrotic effects of CCl4 in the liver and reduced serum transferase levels. Analysis of HSCs in vitro confirmed that, mechanistically, SGHXHYF inhibited activation of the TGF-β1/Smad signaling pathway by downregulating phosphorylated Smad2 and Smad3 and upregulating Smad7 levels.

CONCLUSION

SGHXHYF ameliorated CCl4-induced liver fibrosis by inhibiting the TGF-β1/Smad signaling pathway. These findings suggest that SGHXHYF may have clinical utility for the treatment or prevention of liver fibrosis.

Shugan Huoxue Huayu Fang attenuates carbon tetrachloride-induced hepatic fibrosis in rats by inhibiting transforming growth factor-β1/Smad signaling

OBJECTIVE

To investigate the potential mechanism by which Shugan Huoxue Huayu Fang (SGHXHYF) ameliorates liver fibrosis.

METHODS

Liver fibrosis was induced in rats by intraperitoneal injection of carbon tetrachloride (CCl4) in peanut oil solution (40%, 3 mL/kg body weight) twice a week for 8 weeks. A normal control group received the same volume of peanut oil alone. During weeks 5-8, the CCl4-injected rat groups were administered saline (vehicle control), colchicine (0.1 mg/mL, 1 mg/kg, positive control), or SGHXHYF (0.1 mg/mL; 0.3, 0.6 and 1.2 mg/kg) once daily by oral gavage. Rats were sacrificed 24 h after the last treatment. Blood samples were collected for measurement of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), albumin (ALB), collagen Ⅰ and collagen Ⅲ levels. Liver samples were analyzed by histopathological staining, Masson's staining of extracellular matrix proteins, and immune-ohistochemical staining of αsmooth muscle actin (α-SMA). TGF-β1/Smad protein and mRNA levels were analyzed by Western blot and quantitative reverse transcription-polymerase chain reaction analysis, respectively. In vitro experiments were also performed using rat hepatic stellate cells (HSCs).

RESULTS

Compared with the control animals, CCl4-exposed rats exhibited elevated serum levels of ALT, AST, ALP, collagen I, and collagen III; reduced serum levels of ALB; and increased collagen deposition and αSMA expression in liver sections, reflecting liver fibrosis. CCl4 also increased expression of TGF-β1 and the activated (phosphorylated) forms of Smad2 and Smad3 but reduced expression of the negative regulator Smad7 in the liver. Notably, concomitant administration of SGHXHYF to CCl4-exposed rats was found to significantly reverse or abolish the pro-fibrotic effects of CCl4 in the liver and reduced serum transferase levels. Analysis of HSCs in vitro confirmed that, mechanistically, SGHXHYF inhibited activation of the TGF-β1/Smad signaling pathway by downregulating phosphorylated Smad2 and Smad3 and upregulating Smad7 levels.

CONCLUSION

SGHXHYF ameliorated CCl4-induced liver fibrosis by inhibiting the TGF-β1/Smad signaling pathway. These findings suggest that SGHXHYF may have clinical utility for the treatment or prevention of liver fibrosis.

Novel Therapeutic Targets in Liver Fibrosis

Liver fibrosis is end-stage liver disease that can be rescued. If irritation continues due to viral infection, schistosomiasis and alcoholism, liver fibrosis can progress to liver cirrhosis and even cancer. The US Food and Drug Administration has not approved any drugs that act directly against liver fibrosis. The only treatments currently available are drugs that eliminate pathogenic factors, which show poor efficacy; and liver transplantation, which is expensive. This highlights the importance of clarifying the mechanism of liver fibrosis and searching for new treatments against it. This review summarizes how parenchymal, nonparenchymal cells, inflammatory cells and various processes (liver fibrosis, hepatic stellate cell activation, cell death and proliferation, deposition of extracellular matrix, cell metabolism, inflammation and epigenetics) contribute to liver fibrosis. We highlight discoveries of novel therapeutic targets, which may provide new insights into potential treatments for liver fibrosis.

Extra- and Intra-Cellular Mechanisms of Hepatic Stellate Cell Activation

Hepatic fibrosis is characterized by the pathological accumulation of extracellular matrix (ECM) in the liver resulting from the persistent liver injury and wound-healing reaction induced by various insults. Although hepatic fibrosis is considered reversible after eliminating the cause of injury, chronic injury left unchecked can progress to cirrhosis and liver cancer. A better understanding of the cellular and molecular mechanisms controlling the fibrotic response is needed to develop novel clinical strategies. It is well documented that activated hepatic stellate cells (HSCs) is the most principal cellular players promoting synthesis and deposition of ECM components. In the current review, we discuss pathways of HSC activation, emphasizing emerging extra- and intra-cellular signals that drive this important cellular response to hepatic fibrosis. A number of cell types and external stimuli converge upon HSCs to promote their activation, including hepatocytes, liver sinusoidal endothelial cells, macrophages, cytokines, altered ECM, hepatitis viral infection, enteric dysbiosis, lipid metabolism disorder, exosomes, microRNAs, alcohol, drugs and parasites. We also discuss the emerging signaling pathways and intracellular events that individually or synergistically drive HSC activation, including TGFβ/Smad, Notch, Wnt/β-catenin, Hedgehog and Hippo signaling pathways. These findings will provide novel potential therapeutic targets to arrest or reverse fibrosis and cirrhosis.

Signaling Pathways Involved in Diabetic Renal Fibrosis

Diabetic kidney disease (DKD), as the most common complication of diabetes mellitus (DM), is the major cause of end-stage renal disease (ESRD). Renal interstitial fibrosis is a crucial metabolic change in the late stage of DKD, which is always considered to be complex and irreversible. In this review, we discuss the pathological mechanisms of diabetic renal fibrosis and discussed some signaling pathways that are closely related to it, such as the TGF-β, MAPK, Wnt/β-catenin, PI3K/Akt, JAK/STAT, and Notch pathways. The cross-talks among these pathways were then discussed to elucidate the complicated cascade behind the tubulointerstitial fibrosis. Finally, we summarized the new drugs with potential therapeutic effects on renal fibrosis and listed related clinical trials. The purpose of this review is to elucidate the mechanisms and related pathways of renal fibrosis in DKD and to provide novel therapeutic intervention insights for clinical research to delay the progression of renal fibrosis.

Repression of FBXW7 by HES5 contributes to inactivation of the TGF-β signaling pathway and alleviation of endometriosis

Endometriosis (EMS) is a gynecologic disorder associated with infertility and characterized by the endometrial-type mucosa outside the uterine cavity. Currently available treatment modalities are limited to undesirable effects. Thus, in the present study, we sought to study the pathogenesis mechanism of EMS. For this purpose, the ectopic and eutopic endometrial tissues were resected from 86 patients with EMS and 54 infertile patients without EMS, respectively. The regulatory mechanism among HES family bHLH transcription factor 5 (HES5), transforming growth factor-beta (TGF-β)-induced factor 1 (TGIF1), F-box, and WD repeat domain containing 7 (FBXW7) was studied by performing co-immunoprecipitation, dual-luciferase reporter gene assay, and chromatin immunoprecipitation, respectively. A mouse model of EMS was established to verify the aforementioned regulatory mechanism in vivo. Upregulation of HES5 and TGIF1, as well as downregulation of FBXW7, was observed in EMS endometrial tissues and human endometrial stromal cells (hESCs), respectively. The overexpression of HES5 was found to suppress the FBXW7 transcription and TGIF1 degradation, resulting in the inactivation of the TGF-β signaling pathway, as well as inhibition of hESC proliferation and invasion, thereby enhancing apoptosis. Results from a mouse model of EMS showed that the presence of HES5 contributed to the alleviation of EMS. Collectively, we attempted to provide a mechanistic insight into the unrecognized roles of the HES5/FBXW7 in EMS progression.

Notch-ing up knowledge on molecular mechanisms of skin fibrosis: focus on the multifaceted Notch signalling pathway

Fibrosis can be defined as an excessive and deregulated deposition of extracellular matrix proteins, causing loss of physiological architecture and dysfunction of different tissues and organs. In the skin, fibrosis represents the hallmark of several acquired (e.g. systemic sclerosis and hypertrophic scars) and inherited (i.e. dystrophic epidermolysis bullosa) diseases. A complex series of interactions among a variety of cellular types and a wide range of molecular players drive the fibrogenic process, often in a context-dependent manner. However, the pathogenetic mechanisms leading to skin fibrosis are not completely elucidated. In this scenario, an increasing body of evidence has recently disclosed the involvement of Notch signalling cascade in fibrosis of the skin and other organs. Despite its apparent simplicity, Notch represents one of the most multifaceted, strictly regulated and intricate pathways with still unknown features both in health and disease conditions. Starting from the most recent advances in Notch activation and regulation, this review focuses on the pro-fibrotic function of Notch pathway in fibroproliferative skin disorders describing molecular networks, interplay with other pro-fibrotic molecules and pathways, including the transforming growth factor-β1, and therapeutic strategies under development.

Depletion of serotonin relieves concanavalin A-induced liver fibrosis in mice by inhibiting inflammation, oxidative stress, and TGF-β1/Smads signaling pathway

Serotonin exerts important functions in several liver pathophysiological processes. In this study, we investigated the role of serotonin in concanavalin A (Con A)-induced liver fibrosis (LF) in mice and the underlying mechanisms. To establish the mouse model of LF, mice of wild-type (WT) and tryptophan hydroxylase 1 (Tph1) knockout (serotonin depletion) received Con A for 8 successive weeks. Degree of fibrosis was assessed by Sirius red staining, as well as the measurements of alpha smooth muscle actin (α- SMA), hydroxyproline (Hyp) and type I collagen in liver tissues. To elucidate the potential mechanisms, we assessed the effect of serotonin depletion on inflammatory, oxidative stress as well as TGF-β1/Smads signaling pathway. We found that serotonin depletion significantly inhibited collagen deposition as evaluated by less collagenous fiber in Sirus Red staining and reduced contents of Hyp and type I collagen. In addition, the absence of serotonin significantly inhibited the release of several inflammatory cytokines, including interleukin-6 (IL-6), interferon-gamma (IFN-γ), tumor necrosis-alpha (TNF-α), and transforming growth factor β1 (TGF-β1). Oxidative stress was also largely mitigated in LF mice with serotonin deficiency as manifested by the decreases of oxidative stress markers (malonaldehyde (MDA) and myeloperoxidase (MPO)), as well as the increases of antioxidant stress indicators (glutathione (GSH), and GSH-px, catalase (CAT), superoxide dismutase (SOD)) in liver tissues. Moreover, the lack of serotonin may provide an antifibrotic role by inhibiting the intrahepatic expressions of TGF-β1, phosphorylated-smad2 (p-smad2), and phosphorylated-smad3 (p-smad3). These results indicated that, serotonin depletion attenuates Con A-induced LF through the regulation of inflammatory response, oxidative stress injury, and TGF-β1/Smads signaling pathway.

miR-199b-5p promoted chondrogenic differentiation of C3H10T1/2 cells by regulating JAG1

Mesenchymal stem cells (MSCs) are considered a promising candidate for use in cell-based therapy for cartilage repair. To promote understanding of the molecular control of chondrogenesis differentiation in MSCs, we compared the changes in microRNAs during in vitro chondrogenesis process of human bone-marrow mesenchymal stem cells (hBMSCs). MiR-199b-5p was up-regulated significantly during this process. The aim of the study was to investigate the effects of miR-199b-5p on chondrogenic differentiation of C3H10T1/2 MSC cells and explore the underlying mechanisms. MiR-199b-5p mimics or inhibitor were transfected into C3H10T1/2 cells, respectively, and then, the effects of miR-199b-5p on chondrogenic differentiation of C3H10T1/2 cells were detected. The results indicated that miR-199b-5p overexpression inhibited the growth of C3H10T1/2 cells but promoted transforming growth factor-β3 (TGF-β3)-induced C3H10T1/2 cells of chondrogenic differentiation, as supported by enhancing the gene and protein expression of chondrocyte specific markers of SOX9, aggrecan, and collagen type II (Col2a1). In contrast, inhibiting miR-199b-5p notably promoted the proliferation of C3H10T1/2 cells but decreased chondrogenic differentiation. Furthermore, mechanism studies revealed that JAG1 was a direct target of miR-199b-5p by dual luciferase reporter assays. While silencing of JAG1 by isRNA resulted an increase of chondrogenic differentiation. Further, JAG1 knockdown was demonstrated to block the effect of miR-199b-5p inhibition. In conclusion, the present study revealed for the first time that miR-199b-5p was the positive regulators to modulate chondrogenic differentiation of C3H10T1/2 cells by targeting JAG1. These findings may provide a novel insight on miRNA-mediated MSC therapy for cartilage related disorders.

Targeting the Notch and TGF-β signaling pathways to prevent retinal fibrosis in vitro and in vivo

Rationale: The Notch and transforming growth factor-β (TGFβ) signaling pathways are two intracellular mechanisms that control fibrosis in general but whether they play a major role in retinal fibrosis is less clear. Here we study how these two signaling pathways regulate Müller cell-dominated retinal fibrosis in vitro and in vivo.

Methods: Human MIO-M1 Müller cells were treated with Notch ligands and TGFβ1, either alone or in combination. Western blots were performed to study changes in γ-secretase proteases, Notch downstream effectors, endogenous TGFβ1, phosphorylated Smad3 (p-Smad3) and extracellular matrix (ECM) proteins. We also studied the effects of RO4929097, a selective γ-secretase inhibitor, on expression of ECM proteins after ligand stimulation. Müller cell viability was studied by AlamarBlue and cytotoxicity by lactate cytotoxicity assays. Finally, we studied changes in Notch and TGFβ signaling and tested the effect of intravitreal injections of the Notch pathway inhibitor RO4929097 on retinal fibrosis resulted from Sodium iodate (NaIO₃)-induced retinal injury in mice. We also studied the safety of intravitreal injections of RO4929097 in normal mice.

Results: Treatment of Müller cells with Notch ligands upregulated γ-secretase proteases and Notch downstream effectors, with increased expression of endogenous TGFβ1, TGFβ receptors and p-Smad3. TGFβ1 upregulated the expression of proteins associated with both signaling pathways in a similar manner. Notch ligands and TGFβ1 had additive effects on overexpression of ECM proteins in Müller cells which were inhibited by RO4929097. Notch and TGFβ ligands stimulated Müller cell proliferation which was inhibited by RO4929097 without damaging the cells. NaIO₃-induced retinal injury activated both Notch and TGFβ signaling pathways in vivo. Intravitreal injection of RO4929097 prevented Müller cell gliosis and inhibited overexpression of ECM proteins in this murine model. We found no safety concerns for up to 17 days after an intravitreal injection of RO4929097.

Conclusions: Inhibiting Notch signaling might be an effective way to prevent retinal fibrosis. This study is of clinical significance in developing a treatment for preventing fibrosis in proliferative vitreoretinopathy, proliferative diabetic retinopathy and wet age-related macular degeneration.

Top Notch Targeting Strategies in Cancer: A Detailed Overview of Recent Insights and Current Perspectives

Evolutionarily conserved Notch plays a critical role in embryonic development and cellular self-renewal. It has both tumour suppressor and oncogenic activity, the latter of which is widely described. Notch-activating mutations are associated with haematological malignancies and several solid tumours including breast, lung and adenoid cystic carcinoma. Moreover, upregulation of Notch receptors and ligands and aberrant Notch signalling is frequently observed in cancer. It is involved in cancer hallmarks including proliferation, survival, migration, angiogenesis, cancer stem cell renewal, metastasis and drug resistance. It is a key component of cell-to-cell interactions between cancer cells and cells of the tumour microenvironment, such as endothelial cells, immune cells and fibroblasts. Notch displays diverse crosstalk with many other oncogenic signalling pathways, and may drive acquired resistance to targeted therapies as well as resistance to standard chemo/radiation therapy. The past 10 years have seen the emergence of different classes of drugs therapeutically targeting Notch including receptor/ligand antibodies, gamma secretase inhibitors (GSI) and most recently, the development of Notch transcription complex inhibitors. It is an exciting time for Notch research with over 70 cancer clinical trials registered and the first-ever Phase III trial of a Notch GSI, nirogacestat, currently at the recruitment stage.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

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

Epidermal Stem Cells in Wound Healing and Regeneration

Skin stem cells distributed in the basal layer of the epidermis and hair follicles are important cell sources for skin development, metabolism, and injury repair. At present, great progress has been made in the study of epidermal stem cells at the cellular and molecular levels. Stem cell transplantation is reported to promote skin healing, endothelial cell transformation, and vascular formation. Local stem cells can also be transformed into keratinocytes, sebaceous gland, and other skin-associated tissues. However, the mechanism of action of epidermal stem cells on wound healing and regeneration is not completely clear. This review is aimed at briefly summarizing the biological characteristics of epidermal stem cells and their clinical application in wound healing and tissue regeneration. It further discussed the mechanism of action and the development direction in the future.

Class C1 decoy oligodeoxynucleotide inhibits profibrotic genes expression in rat hepatic stellate cells

The aim of the present study was to investigate whether class C1 decoy oligodeoxynucleotides (ODNs) can inhibit the expression of pro‑fibrotic genes associated with rat hepatic stellate cell (HSC) activation and hepatic fibrosis. Luciferase reporter assays were performed to test the promoter activities of transforming growth factor (TGF)‑β and its downstream target genes following transfection of decoy ODNs and plasmids into HSC‑T6 cells, and western blot assays were performed to measure the protein expression of those genes following decoy ODN transfection. Class C1 decoy ODNs were confirmed to inhibit the promoter activity of TGF‑β and its downstream target genes, such as type 1 collagen (COLI)α1, tissue inhibitor of metalloproteinases (TIMP)1 and α‑smooth muscle actin by Gaussia luciferase reporter assay, and to further downregulate the expression of TGF‑β, SMAD3, COLIα1 and TIMP1 by western blotting in activated HSC‑T6 cells. In conclusion, class C1 decoy ODNs inhibited pro‑fibrotic gene expression in rat HSCS by downregulating TGF‑β signaling.

TGF-β in Hepatic Stellate Cell Activation and Liver Fibrogenesis-Updated 2019

Liver fibrosis is an advanced liver disease condition, which could progress to cirrhosis and hepatocellular carcinoma. To date, there is no direct approved antifibrotic therapy, and current treatment is mainly the removal of the causative factor. Transforming growth factor (TGF)-β is a master profibrogenic cytokine and a promising target to treat fibrosis. However, TGF-β has broad biological functions and its inhibition induces non-desirable side effects, which override therapeutic benefits. Therefore, understanding the pleiotropic effects of TGF-β and its upstream and downstream regulatory mechanisms will help to design better TGF-β based therapeutics. Here, we summarize recent discoveries and milestones on the TGF-β signaling pathway related to liver fibrosis and hepatic stellate cell (HSC) activation, emphasizing research of the last five years. This comprises impact of TGF-β on liver fibrogenesis related biological processes, such as senescence, metabolism, reactive oxygen species generation, epigenetics, circadian rhythm, epithelial mesenchymal transition, and endothelial-mesenchymal transition. We also describe the influence of the microenvironment on the response of HSC to TGF-β. Finally, we discuss new approaches to target the TGF-β pathway, name current clinical trials, and explain promises and drawbacks that deserve to be adequately addressed.

Widespread cis-regulatory convergence between the extinct Tasmanian tiger and gray wolf

The extinct marsupial Tasmanian tiger, or thylacine, and the eutherian gray wolf are among the most widely recognized examples of convergent evolution in mammals. Despite being distantly related, these large predators independently evolved extremely similar craniofacial morphologies, and evidence suggests that they filled similar ecological niches. Previous analyses revealed little evidence of adaptive convergence between their protein-coding genes. Thus, the genetic basis of their convergence is still unclear. Here, we identified candidate craniofacial cis-regulatory elements across vertebrates and compared their evolutionary rates in the thylacine and wolf, revealing abundant signatures of convergent positive selection. Craniofacial thylacine-wolf accelerated regions were enriched near genes involved in TGF beta (TGFB) and BMP signaling, both of which are key morphological signaling pathways with critical roles in establishing the identities and boundaries between craniofacial tissues. Similarly, enhancers of genes involved in craniofacial nerve development showed convergent selection and involvement in these pathways. Taken together, these results suggest that adaptation in cis-regulators of TGF beta and BMP signaling may provide a mechanism to explain the coevolution of developmentally and functionally integrated craniofacial structures in these species. We also found that despite major structural differences in marsupial and eutherian brains, accelerated regions in both species were common near genes with roles in brain development. Our findings support the hypothesis that, relative to protein-coding genes, positive selection on cis-regulatory elements is likely to be an essential driver of adaptive convergent evolution and may underpin thylacine-wolf phenotypic similarities.

Human umbilical cord mesenchymal stem cells ameliorate liver fibrosis in vitro and in vivo: From biological characteristics to therapeutic mechanisms

Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver; in addition, its formation is associated with multiple cytokines as well as several cell types and a variety of signaling pathways. When liver fibrosis is not well controlled, it can progress to liver cirrhosis, but it is reversible in principle. Thus far, no efficient therapy is available for treatment of liver fibrosis. Although liver transplantation is the preferred strategy, there are many challenges remaining in this approach, such as shortage of donor organs, immunological rejection, and surgical complications. Hence, there is a great need for an alternative therapeutic strategy. Currently, mesenchymal stem cell (MSC) therapy is considered a promising therapeutic strategy for the treatment of liver fibrosis; advantageously, the characteristics of MSCs are continuous self-renewal, proliferation, multipotent differentiation, and immunomodulatory activities. The human umbilical cord-derived (hUC)-MSCs possess not only the common attributes of MSCs but also more stable biological characteristics, relatively easy accessibility, abundant source, and no ethical issues (e.g., bone marrow being the adult source), making hUC-MSCs a good choice for treatment of liver fibrosis. In this review, we summarize the biological characteristics of hUC-MSCs and their paracrine effects, exerted by secretion of various cytokines, which ultimately promote liver repair through several signaling pathways. Additionally, we discuss the capacity of hUC-MSCs to differentiate into hepatocyte-like cells for compensating the function of existing hepatocytes, which may aid in amelioration of liver fibrosis. Finally, we discuss the current status of the research field and its future prospects.

Investigation of circular RNAs and related genes in pulmonary fibrosis based on bioinformatics analysis

Pulmonary fibrosis is a lethal inflammatory disease. In this study, we aimed to explore the potential-related circular RNAs (circRNAs) and genes that are associated with pulmonary fibrosis. Pulmonary fibrosis rat models were constructed and the fibrosis deposition was detected using hematoxylin and eosin and Masson staining. The differentially expressed circRNAs were obtained through RNA sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were further performed to uncover the key function and pathways in pulmonary fibrosis. The interaction networks between circRNAs and their downstream micro RNAs (miRNAs) and genes were constructed by Cytoscape Software. The quantitative polymerase chain reaction was performed to validate the expression of 10 candidate circRNAs and five of them were performed ringwise sequencing in pulmonary fibrosis rats. We further selected five candidate circRNAs target miRNAs and messenger RNAs and validated by real-time polymerase chain reaction. The pulmonary fibrosis models were successfully constructed according to the pathological examination. circRNAs were differentially expressed between the pulmonary fibrosis and normal pulmonary tissues. GO analysis verified that the differentially expressed circRNAs were significantly clustered in the cellular component, molecular function, and biological process. In the KEGG analysis, circRNAs were enriched in the following pathways: antigen processing and presentation, phagosome, PI3K-AKt signaling pathway, HTLV-I infection, and Herpes simplex infection. After validation in pulmonary fibrosis rat models, it was found that five of those circRNAs (chr9:113534327|113546234 [down], chr1:200648164|200672411 [down], chr5:150850432|150865550 [up], chr20:14319170|14326640 [down], and chr10:57634023|57634588 [down]) showed a relatively consistent trend with predictions. Validation of these circRNAs target miRNAs and genes showed that chr9:113534327|113546234, chr20:14319170|14326640, and chr10:57634023|57634588 were implicated in Notch1 activated transforming growth factor-β (TGF-β) signaling pathway. The study demonstrated that a series of circRNAs are differentially expressed in pulmonary fibrosis rats. These circRNAs, especially TGF-β- and Notch1-related circRNAs might play an important role in regulating pulmonary fibrogenesis.

Overexpression of miRNA-25-3p inhibits Notch1 signaling and TGF-β-induced collagen expression in hepatic stellate cells

During chronic liver injury hepatic stellate cells (HSCs), the principal source of extracellular matrix in the fibrotic liver, transdifferentiate into pro-fibrotic myofibroblast-like cells - a process potentially regulated by microRNAs (miRNAs). Recently, we found serum miRNA-25-3p (miR-25) levels were upregulated in children with Cystic Fibrosis (CF) without liver disease, compared to children with CF-associated liver disease and healthy individuals. Here we examine the role of miR-25 in HSC biology. MiR-25 was detected in the human HSC cell line LX-2 and in primary murine HSCs, and increased with culture-induced activation. Transient overexpression of miR-25 inhibited TGF-β and its type 1 receptor (TGFBR1) mRNA expression, TGF-β-induced Smad2 phosphorylation and subsequent collagen1α1 induction in LX-2 cells. Pull-down experiments with biotinylated miR-25 revealed Notch signaling (co-)activators ADAM-17 and FKBP14 as miR-25 targets in HSCs. NanoString analysis confirmed miR-25 regulation of Notch- and Wnt-signaling pathways. Expression of Notch signaling pathway components and endogenous Notch1 signaling was downregulated in miR-25 overexpressing LX-2 cells, as were components of Wnt signaling such as Wnt5a. We propose that miR-25 acts as a negative feedback anti-fibrotic control during HSC activation by reducing the reactivity of HSCs to TGF-β-induced collagen expression and modulating the cross-talk between Notch, Wnt and TGF-β signaling.

TGF-β induces liver fibrosis via miRNA-181a-mediated down regulation of augmenter of liver regeneration in hepatic stellate cells

OBJECTIVE

To study the role of miRNA-181a and augmenter of liver regeneration in TGF-β-induced fibrosis in hepatic stellate cells.

METHODS

LX2 cells were treated with 20 ng/ml TGF-β for 24 h. miRNA-181a, ALR plasmid and empty vectors were transfected using siPORT NeoFx reagent. Cells were harvested after 48 h or 72 h of transfection for protein or RNA analysis. Western blotting was performed for ALR, TGF-β receptor II (TGFβ-RII), collagen 1A1 (COLL1A1), alpha-smooth muscle cell actin (α-SMA), rac1, E-cadherin and β-actin. Quantitative RT-PCR was performed for ALR, GAPDH, miRNA-181a or 5S rRNA.

RESULTS

TGF-β induced the expression of miRNA-181a, which in turn down-regulated ALR thereby induced the fibrosis markers, such as COLL1A1, α-SMA and rac1 in hepatic stellate cells. Over-expression of miRNA-181a down-regulated expression of ALR and up-regulated expression of fibrosis markers. On the other hand, ALR over-expression resulted in a decrease in miRNA-181a expression and fibrosis markers. Over-expression of ALR also inhibited the expression of TGFβ-RII and increased expression E-cadherin.

CONCLUSION

TGF-β induced miRNA-181a, which in turn induced fibrosis, at least in part, by inhibiting ALR. ALR inhibited TGF-β action by decreasing the expression of TGFβ-RII, thereby inhibiting miRNA-181a expression and fibrosis markers. ALR could serve as a potential molecule to inhibit liver fibrosis.

Iron and liver fibrosis: Mechanistic and clinical aspects

Liver fibrosis is characterised by excessive deposition of extracellular matrix that interrupts normal liver functionality. It is a pathological stage in several untreated chronic liver diseases such as the iron overload syndrome hereditary haemochromatosis, viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis and diabetes. Interestingly, regardless of the aetiology, iron-loading is frequently observed in chronic liver diseases. Excess iron can feed the Fenton reaction to generate unquenchable amounts of free radicals that cause grave cellular and tissue damage and thereby contribute to fibrosis. Moreover, excess iron can induce fibrosis-promoting signals in the parenchymal and non-parenchymal cells, which accelerate disease progression and exacerbate liver pathology. Fibrosis regression is achievable following treatment, but if untreated or unsuccessful, it can progress to the irreversible cirrhotic stage leading to organ failure and hepatocellular carcinoma, where resection or transplantation remain the only curative options. Therefore, understanding the role of iron in liver fibrosis is extremely essential as it can help in formulating iron-related diagnostic, prognostic and treatment strategies. These can be implemented in isolation or in combination with the current approaches to prepone detection, and halt or decelerate fibrosis progression before it reaches the irreparable stage. Thus, this review narrates the role of iron in liver fibrosis. It examines the underlying mechanisms by which excess iron can facilitate fibrotic responses. It describes the role of iron in various clinical pathologies and lastly, highlights the significance and potential of iron-related proteins in the diagnosis and therapeutics of liver fibrosis.

Interleukin 10 Gene-Modified Bone Marrow-Derived Dendritic Cells Attenuate Liver Fibrosis in Mice by Inducing Regulatory T Cells and Inhibiting the TGF-β/Smad Signaling Pathway

Aim

To explore the therapeutic effects and mechanisms of interleukin 10 gene-modified bone marrow-derived dendritic cells (DC-IL10) on liver fibrosis.

Methods

In vitro, BMDCs were transfected with lentiviral-interleukin 10-GFP (LV-IL10-GFP) at the MOI of 1 : 40. Then, the phenotype (MHCII, CD80, and CD86) and allo-stimulatory ability of DC-IL10 were identified by flow cytometry, and the levels of IL-10 and IL-12 (p70) secreted into the culture supernatants were quantified by ELISA. In vivo, DC-IL10 was injected into mice with CCl4-induced liver fibrosis through the tail vein. Lymphocytes were isolated to investigate the differentiation of T cells, and serum and liver tissue were collected for biochemical, cytokine, histopathologic, immune-histochemical, and Western blot analyzes.

Results

In vitro, the expressions of MHCII, CD80, and CD86 in DC-IL10 were significantly suppressed, allogeneic CD4⁺T cells incubated with DC-IL10 showed a lower proliferative response, and the levels of IL-10 and IL-12 (p70) secreted into the DC-IL10 culture supernatants were significantly increased and decreased, respectively. In vivo, regulatory T cells (Tregs) were significantly increased, while ALT, AST, and inflammatory cytokines were significantly reduced in the DC-IL10 treatment group, and the degree of hepatic fibrosis was obviously reversed. The TGF-β/smad pathway was inhibited following DC-IL10 treatment compared to the liver fibrosis group.

Conclusion

IL-10 genetic modification of BMDCs may maintain DC in the state of tolerance and allow DC to induce T cell hyporesponsiveness or tolerance. DC-IL10 suppressed liver fibrosis by inducing Treg production and inhibiting the TGF-β/smad signaling pathway.

Therapeutic Effect of Glycyrrhizin Arginine Salt on Rat Cholestatic Cirrhosis and its Mechanism

To investigate the therapeutic effect of glycyrrhizin arginine salt on rat cholestatic cirrhosis, we subjected male Sprague Dawley rats to common bile duct ligation for 14 days and treated them with distilled water (model group), arginine, or a low or high dose of glycyrrhizin arginine salt by gavage. A sham-operated group was used as a control group. Treatment with glycyrrhizin arginine salt substantially improved animal growth rates, reduced the ratio of liver weight to body weight and decreased total bilirubin, aspartate aminotransferase, 8-isoprostane and malondialdehyde compared with the values measured in the model group. The progress of liver fibrosis, as detected by hematoxylin and eosin and Masson’s trichrome staining, was slower in the glycyrrhizin arginine salt groups than in the model group or the arginine group. Reductions of bile salt pool size, hepatic hydroxyproline content and fibrosis score were also seen in the glycyrrhizin arginine salt groups compared with the model group. Furthermore, glycyrrhizin arginine salt significantly reduced the expression of transforming growth factor [Formula: see text]1 (TGF-[Formula: see text]1), [Formula: see text]-smooth muscle actin, tumor necrosis factor-[Formula: see text] and matrix metalloproteinases 2 and 9. Glycyrrhizin arginine salt also inhibited the expression of [Formula: see text]-SMA and matrix metalloproteinases 2 and 9 in response to TGF-[Formula: see text]1 in LX-2 cells and primary rat hepatic stellate cells and mitigated the cytotoxicity induced by rat bile in HepG2 cells and primary rat hepatocytes.

Emodin alleviates CCl4‑induced liver fibrosis by suppressing epithelial‑mesenchymal transition and transforming growth factor‑β1 in rats

Liver fibrosis is a chronic disease that exhibits a complicated pathophysiology. It is characterized by the deposition of the extracellular matrix. Emodin, an active constituent isolated from rhubarb, has antibacterial, immunosuppressive and anti-inflammatory effects. In the present study, the mechanism through which emodin alleviates liver fibrosis in rats was investigated. A rat model of liver fibrosis was generated by administering CCl₄ via subcutaneous injection twice a week for 12 weeks. Emodin or sodium carboxymethylcellulose (CMC), as the vehicle, were intragastrically administered daily. After 12 weeks, the liver function index was examined by blood analysis, histopathological scores of fibrosis was determined by hematoxylin and eosin staining and level of collagen deposition was examined by Masson staining. In addition, protein and RNA samples were collected for further analysis. The results of the present study revealed that emodin significantly reduced the liver function index and level of collagen deposition in a dose-dependent manner. Furthermore, emodin reduced the expression of transforming growth factor-β1 (TGF-β1) and the phosphorylation levels of mothers against decapentaplegic homolog 2/3, and inhibited the CCl₄-induced downregulation of E-cadherin and upregulation of the mesenchymal markers, fibronectin and vimentin. The expression levels of TGF-β1, Snail family transcriptional repressor (Snail) 2, Snail, twist-related protein 1 and zinc finger E-box-binding homeobox (ZEB)1 and 2 mRNA were significantly decreased in emodin-treated groups compared with the untreated control. Collectively, the results of the present study suggested that emodin may exert antifibrotic effects via the suppression of TGF-β1 signaling and epithelial-mesenchymal transition.

FOXP3 expression is modulated by TGF‑β1/NOTCH1 pathway in human melanoma

Forkhead box protein 3 (FOXP3) transcription factor is expressed by immune cells and several human cancers and is associated with tumor aggressiveness and unfavorable clinical outcomes. NOTCH and transforming growth factor-β (TGF-β) protumorigenic effects are mediated by FOXP3 expression in several cancer models; however, their interaction and role in melanoma is unknown. We investigated TGF-β-induced FOXP3 gene expression during NOTCH1 signaling inactivation. Primary (WM35) and metastatic melanoma (A375 and A2058) cell lines and normal melanocytes (NHEM) were used. FOXP3 subcellular distribution was evaluated by immuno cytochemical analysis. Gene expression levels were assessed by reverse transcription-quantitative polymerase chain reaction. Protein levels were assessed by western blot analysis. The γ-secretase inhibitor (GSI) was used for NOTCH1 inhibition and recombinant human (rh)TGF-β was used for melanoma cell stimulation. Cell proliferation and viability were respectively assessed by MTT and Trypan blue dye assays. FOXP3 mRNA and protein levels were progressively higher in WM35, A375 and A2058 cell lines compared to NHEM and their levels were further increased after stimulation with rh-TGF-β. TGF-β-mediated FOXP3 expression was mediated by NOTCH1 signaling. Inhibition of NOTCH1 with concomitant rh-TGF-β stimulation determined the reduction in gene expression and protein level of FOXP3. Finally, melanoma cell line proliferation and viability were reduced by NOTCH1 inhibition. The results show that nn increase in FOXP3 expression in metastatic melanoma cell lines is a potential marker of tumor aggressiveness and metastasis. NOTCH1 is a central mediator of TGF-β-mediated FOXP3 expression and NOTCH1 inhibition produces a significant reduction of melanoma cell proliferation and viability.

Novel Insights on Notch signaling pathways in liver fibrosis

Liver fibrosis is characterized by an increased and altered deposition of extracellular matrix (ECM) proteins that make up excessive tissue scarring and promote chronic liver injury. Activation of hepatic stellate cells (HSCs) is a pivotal cellular event in the progression of liver fibrosis. However, the mechanisms involved in the development of liver fibrosis are only now beginning to be unveiled. The Notch pathway is a fundamental and highly conserved pathway able to control cell-fate, including cell proliferation, differentiation, apoptosis, regeneration and other cellular activities. Recently, the deregulation of Notch cascade has been found involved in many pathological processes, including liver fibrosis. These data give evidence for a role for Notch signaling in liver fibrosis. In addition，more and more date are available on the role of Notch pathways in the process. Therefore, this review focuses on the current knowledge about the Notch signaling pathway, which dramatically takes part in HSC activation and liver fibrosis, and look ahead on new perspectives of Notch signaling pathway research. Furthermore, we will summarize this new evidence on the different interactions in Notch signaling pathway-regulated liver fibrosis, and support the potentiality of putative biomarkers and unique therapeutic targets.

Scar management in burn injuries using drug delivery and molecular signaling: Current treatments and future directions

In recent decades, there have been tremendous improvements in burn care that have allowed patients to survive severe burn injuries that were once fatal. However, a major limitation of burn care currently is the development of hypertrophic scars in approximately 70% of patients. This significantly decreases the quality of life for patients due to the physical and psychosocial symptoms associated with scarring. Current approaches to manage scarring include surgical techniques and non-surgical methods such as laser therapy, steroid injections, and compression therapy. These treatments are limited in their effectiveness and regularly fail to manage symptoms. As a result, the development of novel treatments that aim to improve outcomes and quality of life is imperative. Drug delivery that targets the molecular cascades of wound healing to attenuate or prevent hypertrophic scarring is a promising approach that has therapeutic potential. In this review, we discuss current treatments for scar management after burn injury, and how drug delivery targeting molecular signaling can lead to new therapeutic strategies.