scholarly journals Perilipin 5 Ameliorates Hepatic Stellate Cell Activation via SMAD2/3 and SNAIL Signaling Pathways and Suppresses STAT3 Activation

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2184
Author(s):  
Rafael Cierpka ◽  
Ralf Weiskirchen ◽  
Anastasia Asimakopoulos

Comprehending the molecular mechanisms underlying hepatic fibrogenesis is essential to the development of treatment. The hallmark of hepatic fibrosis is the development and deposition of excess fibrous connective tissue forcing tissue remodeling. Hepatic stellate cells (HSC) play a major role in the pathogenesis of liver fibrosis. Their activation via the transforming growth factor-β1 (TGF-β1) as a key mediator is considered the crucial event in the pathophysiology of hepatic fibrogenesis. It has been shown that Perilipin 5 (PLIN5), known as a lipid droplet structural protein that is highly expressed in oxidative tissue, can inhibit such activation through various mechanisms associated with lipid metabolism. This study aimed to investigate the possible influence of PLIN5 on TGF-β1 signaling. Our findings confirm the importance of PLIN5 in maintaining HSC quiescence in vivo and in vitro. PLIN5 overexpression suppresses the TGF-β1-SMAD2/3 and SNAIL signaling pathways as well as the activation of the signal transducers and activators of transcription 3 (STAT3). These findings derived from experiments in hepatic cell lines LX-2 and Col-GFP, in which overexpression of PLIN5 was able to downregulate the signaling pathways SMAD2/3 and SNAIL activated previously by TGF-β1 treatment. Furthermore, TGF-β1-mediatedinduction of extracellular matrix proteins, such as collagen type I (COL1), Fibronectin, and α-smooth muscle actin (α-SMA), was suppressed by PLIN5. Moreover, STAT3, which is interrelated with TGF-β1 was already basally activated in the cell lines and inhibited by PLIN5 overexpression, leading to a further reduction in HSC activity shown by lowered α-SMA expression. This extension of the intervening mechanisms presents PLIN5 as a potent and pleiotropic target in HSC activation.

2021 ◽  
Vol 14 (1) ◽  
pp. 123-131
Author(s):  
Doha M. Beltagy ◽  
Khloud Gamal Abdelsalam ◽  
Tarek M Mohamed ◽  
Mai M. El-Keey

Liver cirrhosis is currently the 11th most common cause of death which includes inflammatory, oxidative damage, and immune response. Harmaline has antioxidant and anti-inflammatory mechanisms which can defeat against hepatic cirrhosis pathways. The present work aimed to evaluate the ameliorating effect of harmaline against liver cirrhosis induced by thioacetamide in mice. The study was carried out on sixty male mice divided into three main groups. Control and harmaline groups (GIa and GIb), thioacetamide-group (GII) and harmaline co-treated and treated groups (GIIIa and GIIIb). By the end of the experiment, adiponectin concentrations were measured in serum and liver tissue. Gene expression of adiponectin, transforming growth factor beta-1 (TGF-β1), tissue inhibitor metalloprotease-1(TIMP-1) and peroxisome proliferator activated receptor-gamma (PPAR-γ) were assessed. Some oxidative stress biomarkers as malondialdehyde, reduced glutathione, catalase, superoxide dismutase and nitric oxide were determined. The results indicated that harmaline administration cause significant suppression of oxidative stress and inflammatory response.Inhibition of hepatic stellate cell activation and extracellular matrix deposition were also noticed with a significant decrease in the expression of the profibrotic markers(TGF-β1 and TIMP-1) which have direct effects on adiponectin activation. These results were confirmed by the histological studies in liver tissue. In Conclusion,Harmaline has excellent protective role against liver cirrhosis induced by thioacetamide in mice via its antioxidant and anti-inflammatory properties.It can be therapeutically used as a safe liver support by a dose of 10 mg/kg after furtherin vivo studies.


Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 323 ◽  
Author(s):  
Hyun Jung ◽  
Dae-Sung Lee ◽  
Seong Park ◽  
Jung Choi ◽  
Won-Kyo Jung ◽  
...  

Nasal polyps (NPs) are a multifactorial disorder associated with a chronic inflammatory state of the nasal mucosa. Fucoxanthin (Fx) is a characteristic orange carotenoid obtained from brown algae and has diverse immunological properties. The present study investigated whether Fx inhibits fibrosis-related effects in nasal polyp-derived fibroblasts (NPDFs) and elucidated the molecular signaling pathways involved. The production of collagen type I (Col-1) was investigated in NP tissue via immunohistochemistry and western blot analysis. NPDFs were treated with transforming growth factor (TGF)-β1 (1 ng/mL) in the presence or absence of Fx (5–30 µM). The levels of α-smooth muscle actin (α-SMA), Col-1, and phosphorylated (p)-Smad 2/3, signal protein-1 (SP-1), MAPKs (mitogen-activated protein kinases), and Akt were measured by western blot analysis. The expression of Col-1 was detected in NP tissues. TGF-β1 stimulated the production of α-SMA and Col-1, and stimulated the contraction of collagen gel. However, pretreatment with Fx attenuated these effects. Furthermore, these inhibitory effects were mediated through modulation of both Smad 2/3 and Akt/SP-1 signaling pathways in TGF-β1-induced NPDFs. The results from the present study suggest that Fx may be a novel anti-fibrotic agent for the treatment of NP formation.


2014 ◽  
Vol 306 (6) ◽  
pp. H789-H796 ◽  
Author(s):  
Tieqiang Zhao ◽  
Wenyuan Zhao ◽  
Weixin Meng ◽  
Chang Liu ◽  
Yuanjian Chen ◽  
...  

Vascular endothelial growth factor (VEGF)-C is a key mediator of lymphangiogenesis. Our recent study shows that VEGF-C/VEGF receptors (VEGFR)-3 are significantly increased in the infarcted rat myocardium, where VEGFR-3 is expressed not only in lymph ducts but also in myofibroblasts, indicating that VEGF-C has an unrevealed role in fibrogenesis during cardiac repair. The current study is to explore the regulation and molecular mechanisms of VEGF-C in fibrogenesis. The potential regulation of VEGF-C on myofibroblast differentiation/growth/migration, collagen degradation/synthesis, and transforming growth factor (TGF)-β and ERK pathways was detected in cultured cardiac myofibroblasts. Our results showed that VEGF-C significantly increased myofibroblast proliferation, migration, and type I/III collagen production. Matrix metalloproteinase (MMP)-2 and -9 were significantly elevated in the medium of VEGF-C-treated cells, coincident with increased tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. Furthermore, VEGF-C activated the TGF-β1 pathway and ERK phosphorylation, which was significantly suppressed by TGF-β or ERK blockade. This is the first study indicating that in addition to lymphangiogenesis, VEGF-C is also involved in fibrogenesis through stimulation of myofibroblast proliferation, migration, and collagen synthesis, via activation of the TGF-β1 and ERK pathways.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1014
Author(s):  
Yufei Yan ◽  
Jiefei Zeng ◽  
Linhao Xing ◽  
Changyong Li

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.


2020 ◽  
Vol 318 (5) ◽  
pp. E710-E722 ◽  
Author(s):  
Fuxin Wang ◽  
Hsun-Ming Chang ◽  
Yuyin Yi ◽  
Yung-Ming Lin ◽  
Hong Li ◽  
...  

There is increasing evidence showing the importance of vitamin D (Vit D) and its nuclear receptor, the Vit D receptor (VDR), in female reproductive health. Transforming growth factor-β1 (TGF-β1) and its functional receptors are expressed in human oocytes and granulosa cells that participate in follicular development and ovulation. Recently, Sma- and Mad-related protein 3 (SMAD3; a downstream effector of TGF-β1) has been proposed to mediate crosstalk between the Vit D and TGF-β1 signaling pathways, but this relationship has not been fully explored and has yet to be tested in human granulosa-lutein (hGL) cells. In this study, we showed that TGF-β1 significantly promoted the expression of VDR, and this stimulatory effect occurred through the activin receptor-like kinase 5 type I receptor-mediated SMAD3 and ERK1/2 signaling pathways in hGL cells. Additionally, we showed that Vit D increased the expression of cyclooxygenase 2 (COX-2) and the synthesis of prostaglandin E2 (PGE2) in a time- and dose-dependent manner. Furthermore, we demonstrated a synergistic effect of TGF-β1 and Vit D on the expression of COX-2 and synthesis of PGE2, and this effect could be attenuated by silencing the expression of VDR. Our findings indicate that TGF-β1 upregulates the expression of VDR, which promotes Vit D-induced COX-2 expression and subsequent PGE2 production by activating the SMAD3 and ERK1/2 signaling pathways in hGL cells.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xin-Yi Xu ◽  
Yan Du ◽  
Xue Liu ◽  
Yilin Ren ◽  
Yingying Dong ◽  
...  

Abstract Background Hepatic fibrosis is a pathological response of the liver to a variety of chronic stimuli. Hepatic stellate cells (HSCs) are the major source of myofibroblasts in the liver. Follistatin like 1 (Fstl1) is a secreted glycoprotein induced by transforming growth factor-β1 (TGF-β1). However, the precise functions and regulation mechanisms of Fstl1 in liver fibrogenesis remains unclear. Methods Hepatic stellate cell (HSC) line LX-2 stimulated by TGF-β1, primary culture of mouse HSCs and a model of liver fibrosis induced by CCl4 in mice was used to assess the effect of Fstl1 in vitro and in vivo. Results Here, we found that Fstl1 was significantly up regulated in human and mouse fibrotic livers, as well as activated HSCs. Haplodeficiency of Fstl1 or blockage of Fstl1 with a neutralizing antibody 22B6 attenuated CCl4-induced liver fibrosis in vivo. Fstl1 modulates TGF-β1 classic Samd2 and non-classic JNK signaling pathways. Knockdown of Fstl1 in HSCs significantly ameliorated cell activation, cell migration, chemokines C-C Motif Chemokine Ligand 2 (CCL2) and C-X-C Motif Chemokine Ligand 8 (CXCL8) secretion and extracellular matrix (ECM) production, and also modulated microRNA-29a (miR29a) expression. Furthermore, we identified that Fstl1 was a target gene of miR29a. And TGF-β1 induction of Fstl1 expression was partially through down regulation of miR29a in HSCs. Conclusions Our data suggests TGF-β1-miR29a-Fstl1 regulatory circuit plays a key role in regulation the HSC activation and ECM production, and targeting Fstl1 may be a strategy for the treatment of liver fibrosis. Graphical abstract


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Min Liu ◽  
Youwei Xu ◽  
Xu Han ◽  
Lianhong Yin ◽  
Lina Xu ◽  
...  

Abstract The present work aimed to investigate the activities and underlying mechanisms of dioscin against alcoholic liver fibrosis (ALF). In vivo liver fibrosis in mice was induced by an alcoholic liquid diet and in vitro studies were performed on activated HSC-T6 and LX2 cells treated with lipopolysaccharide. Our results showed that dioscin significantly attenuated hepatic stellate cells (HSCs) activation, improved collagen accumulation and attenuated inflammation through down-regulating the levels of myeloid differentiation factor 88 (MyD88), nuclear factor κB (NF-κB), interleukin (IL)-1, IL-6 and tumour necrosis factor-α by decreasing Toll-like receptor (TLR)4 expression both in vivo and in vitro. TLR4 overexpression was also decreased by dioscin, leading to the markedly down-regulated levels of MyD88, NF-κB, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) in cultured HSCs. Suppression of cellular MyD88 by ST2825 or abrogation of NF-κB by pyrrolidine dithiocarbamate eliminated the inhibitory effects of dioscin on the levels of TGF-β1, α-SMA and COL1A1. In a word, dioscin exhibited potent effects against ALF via altering TLR4/MyD88/NF-κB signaling pathway, which provided novel insights into the mechanisms of this compound as an antifibrogenic candidate for the treatment of ALF in the future.


2021 ◽  
Author(s):  
Jack Carson ◽  
Mark Robinson ◽  
Grant Ramm ◽  
Geoffrey Gobert

Abstract BackgroundHepatic stellate cells (HSCs) are liver-resident myofibroblast precursors responsible for the production of collagen and maintenance of the hepatic extracellular matrix (ECM). As such, they are generally associated with fibrotic liver diseases. HSCs become "activated" in response to tissue damage or pathogen invasion, a process most commonly driven by transforming growth factor-β1 (TGF-β1). Despite this, the full extent of TGF-β1 signalling in these cells is poorly understood. Clarifying the range and diversity of this signalling will further improve our understanding of the process of HSC activation.Methods and ResultsRNA sequencing was used to quantitate the transcriptomic changes induced in LX-2 cells, an activated human HSC line, following TGF-b1 treatment. In total, 5,258 genes were found to be significantly differentially expressed with a false discovery rate cut-off of < 0.1. The topmost deregulated of these genes included those with no currently characterised role in either HSC activation or fibrotic processes, including CIITA and SERPINB2. In silico analysis revealed the prominent signalling pathways downstream of TGF-β1 in LX-2 cells.ConclusionsIn this study, we describe the genes and signalling pathways significantly deregulated in LX-2 cells following TGF-β1 treatment. We identified several highly deregulated genes with no currently characterised role in HSC activation, which may represent novel mediators of fibrotic responses in HSCs or the liver macroenvironment. This work may be of use in the identification of new markers of liver fibrosis and could provide insight into prospective genes or pathways that might be targeted for the amelioration of fibrotic liver disease in the future.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yingchun Zhao ◽  
Xinglong Liu ◽  
Chuanbo Ding ◽  
Yan Gu ◽  
Wencong Liu

As a natural active substance, dihydromyricetin (DHM) has been proven to have good hepatoprotective activity. However, the therapeutic effect of DHM on liver fibrosis, which has become a liver disease threatening the health of people around the world, has not been studied to date. The purpose of this study was to investigate the effect of DHM as a new nutritional supplement on thioacetamide (TAA)-induced liver fibrosis. The liver fibrosis model was established by intraperitoneal injection of TAA (200 mg/kg, every 3 days) for 8 weeks, and oral administration of DHM (20 mg/kg and 40 mg/kg, daily) after 4 weeks of TAA-induced liver fibrosis. The results showed that DHM treatment significantly inhibited the activities of alanine aminotransferase (ALT) (37.81 ± 7.62 U/L) and aspartate aminotransferase (AST) (55.18 ± 10.94 U/L) in serum of liver fibrosis mice, and increased the levels of superoxide dismutase (SOD) and glutathione (GSH) while reversed the level of malondialdehyde (MDA). In addition, histopathological examination illustrated that TAA induced the inflammatory infiltration, apoptosis and fibroatherosclerotic deposition in liver, which was further confirmed by western-blot and immunofluorescence staining. Moreover, DHM inhibited hepatocyte apoptosis by regulating the phosphorylation level of phosphatidylinositol 3-kinase (PI3K), protein kinase-B (AKT) and its downstream apoptotic protein family. Interestingly, immunofluorescence staining showed that DHM treatment significantly inhibited alpha smooth muscle actin (α-SMA), which was a marker of hepatic stellate cell activation, and regulated the expression of transforming growth factor (TGF-β1). Importantly, supplementation with DHM significantly inhibited the release of nuclear factor kappa-B (NF-κB) signaling pathway and pro-inflammatory factors in liver tissue induced by TAA, and improved liver fiber diseases, such as tumor necrosis factor alpha (TNF-α) and recombinant rat IL-1β (IL-1β). In conclusion, the evidence of this study revealed that DHM is a potential hepatoprotective and health factor, and which also provides the possibility for the treatment of liver fibrosis.


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