Wnt antagonism inhibits hepatic stellate cell activation and liver fibrosis

2008 ◽  
Vol 294 (1) ◽  
pp. G39-G49 ◽  
Author(s):  
Jason H. Cheng ◽  
Hongyun She ◽  
Yuan-Ping Han ◽  
Jiaohong Wang ◽  
Shigang Xiong ◽  
...  

Activation of hepatic stellate cells (HSC), a key event in liver fibrosis, is caused by diminished adipogenic transcription. This study investigated whether Wnt signaling contributes to “antiadipogenic” activation of HSC and liver fibrogenesis. Culture-activated HSC from normal rats and HSC from cholestatic rat livers were examined for expression of Wnt, Frizzled (Fz) receptors, and coreceptors by quantitative PCR. Wnt signaling was assessed by nuclear β-catenin and T cell factor (TCF) promoter activity. Dickkopf-1 (Dkk-1), a Wnt coreceptor antagonist, was transduced by an adenoviral vector to assess the effects of Wnt antagonism on culture activation of HSC and cholestatic liver fibrosis in mice. Messenger RNA for canonical (Wnt3a and 10b) and noncanonical (Wnt4 and 5a) Wnt genes, Fz-1 and 2, and coreceptors [low-density lipoprotein-receptor-related protein (LRP)6 and Ryk] are increased ∼3–12-fold in culture-activated HSC compared with quiescent HSC. The nuclear β-catenin level and TCF DNA binding are markedly increased in activated HSC. TCF promoter activity is stimulated with Wnt1 but inhibited by Chibby, a protein that blocks β-catenin interaction with TCF, and by Dkk-1. Dkk-1 enhances peroxisome proliferator-activated receptor-γ (PPARγ)-driven PPAR response element (PPRE) promoter activity, a key adipogenic transcriptional parameter, abrogates agonist-stimulated contraction, and restores HSC quiescence in culture. High expression of Dkk-1 increases apoptosis of cultured HSC. Expression of Wnt and Fz genes is also induced in HSC isolated from experimental cholestatic liver fibrosis, and Dkk-1 expression ameliorates this form of liver fibrosis in mice. These results demonstrate antiadipogenic Wnt signaling in HSC activation and therapeutic potential of Wnt antagonism for liver fibrosis.

PPAR Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Lei Xu ◽  
Gang Zhao ◽  
Hong Zhu ◽  
Shijun Wang ◽  
Aijun Sun ◽  
...  

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is one of the major receptors expressed on the endothelium of arterial wall with a key role in endothelial dysfunction and the development of atherosclerosis. Recent evidence suggested that LOX-1 is upregulated under the condition of insulin resistance and could be suppressed by the antidiabetic drugs. We previously also confirmed that Thiazolidinedione (TZD) has the inhibitory effect on LOX-1 in ox-LDL-induced endothelial cells. However, the underlying mechanism is unclear. Here we showed that Rosiglitazone treatment significantly attenuated the expressions of LOX-1, ICAM-1, VCAM-1, p47phox, and the atherosclerotic lesions in ApoE-/- mice with high-fat diet. In vitro, we revealed that Rosiglitazone inhibited LOX-1 by regulating miR-590-5p. Ox-LDL-mediated ICAM-1, VCAM-1, and p47phox were significantly reduced by Rosiglitazone, but all reversed after pretreating the cells with antagomiR-590-5p. Induction with Rosiglitazone activated PPAR-γ and promoted its nuclear translocation in cultured human umbilical vein endothelial cells (HUVECs). The nuclear PPAR-γ upregulated the miR-590-5p level through binding to its transcriptional promoter region. Retaining PPAR-γ in cytoplasm by transfecting with PPAR-γ⊿NLS plasmid in HUVECs failed to activate miR-590-5p. Mutation of the promoter region of PPAR-γ also reduced the miR-590-5p promoter luciferase activity. Collectively, these data indicated that PPAR-γ may have the therapeutic potential in atherosclerosis via the transcriptional regulation of miR-590-5p in endothelial cells.


2021 ◽  
Author(s):  
Ning Wang ◽  
Xiajing Li ◽  
Zhiyong Zhong ◽  
Yaqi Qiu ◽  
Shoupei Liu ◽  
...  

Abstract BackgroundExosomes secreted from stem cells exerted salutary effects on the fibrotic liver. Herein, the roles of exosomes derived from human embryonic stem cell (hESC) in anti-fibrosis were extensively investigated. Compared with two-dimensional (2D) culture, the clinical and biological relevance of three-dimensional (3D) cell spheroids were greater because of their higher regeneration potential since they behave more like cells in vivo. In our study, exosomes derived from 3D human embryonic stem cells (hESC) spheroids and the monolayer (2D) hESCs were collected and compared the therapeutic potential for fibrotic liver in vitro and in vivo. ResultsIn vitro, PKH26 labled-hESC-Exosomes were shown to be internalized and integrated into TGFβ-activated-LX2 cells, and reduced the expression of profibrogenic markers, thereby regulating cellular phenotypes. TPEF imaging indicated that PKH26-labled-3D-hESC-Exsomes possessed an enhanced capacity to accumulate in the livers and exhibited more dramatic therapeutic potential in the injured livers of fibrosis mouse model. 3D-hESC-Exosomes decreased profibrogenic markers and liver injury markers, and improved the level of liver functioning proteins, eventually restoring liver function of fibrosis mice. miRNA array revealed a significant enrichment of miR-6766-3p in 3D-hESC-Exosomes, moreover, bioinformatics and dual luciferase reporter assay identified and confirmed the TGFβRII gene as the target of miR-6766-3p. Furthermore, the delivery of miR-6766-3p into activated-LX2 cells decreased cell proliferation, chemotaxis and profibrotic effects, and further investigation demonstrated that the expression of target gene TGFβRII and its downstream SMADs proteins, especially phosphorylated protein p-SMAD2/3 was also notably down-regulated by miR-6766-3p. These findings unveiled that miR-6766-3p in 3D-hESC-Exosomes inactivated SMADs signaling by inhibiting TGFβRII expression, consequently attenuating stellate cell activation and suppressing liver fibrosis. ConclusionsOur results showed that miR-6766-3p in the 3D-hESC-Exosomes inactivates smads signaling by restraining TGFβRII expression, attenuated LX2 cell activation and suppressed liver fibrosis, suggesting that 3D-hESC-Exosome enriched-miR6766-3p is a novel anti-fibrotic therapeutics for treating chronic liver disease. These results also proposed a significant strategy that 3D-Exo could be used as natural nanoparticles to rescue liver injury via delivering antifibrotic miR-6766-3p.


Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3509
Author(s):  
Ratika Sehgal ◽  
Mariana Ilha ◽  
Maija Vaittinen ◽  
Dorota Kaminska ◽  
Ville Männistö ◽  
...  

Background and Aims: Gut microbiota-derived metabolites play a vital role in maintenance of human health and progression of disorders, including obesity and type 2 diabetes (T2D). Indole-3-propionic acid (IPA), a gut-derived tryptophan metabolite, has been recently shown to be lower in individuals with obesity and T2D. IPA’s beneficial effect on liver health has been also explored in rodent and cell models. In this study, we investigated the association of IPA with human liver histology and transcriptomics, and the potential of IPA to reduce hepatic stellate cell activation in vitro. Methods: A total of 233 subjects (72% women; age 48.3 ± 9.3 years; BMI 43.1 ± 5.4 kg/m2) undergoing bariatric surgery with detailed liver histology were included. Circulating IPA levels were measured using LC-MS and liver transcriptomics with total RNA-sequencing. LX-2 cells were used to study hepatoprotective effect of IPA in cells activated by TGF-β1. Results: Circulating IPA levels were found to be lower in individuals with liver fibrosis compared to those without fibrosis (p = 0.039 for all participants; p = 0.013 for 153 individuals without T2D). Accordingly, levels of circulating IPA associated with expression of 278 liver transcripts (p < 0.01) that were enriched for the genes regulating hepatic stellate cells (HSCs) activation and hepatic fibrosis signaling. Our results suggest that IPA may have hepatoprotective potential because it is able to reduce cell adhesion, cell migration and mRNA gene expression of classical markers of HSCs activation in LX-2 cells (all p < 0.05). Conclusion: The association of circulating IPA with liver fibrosis and the ability of IPA to reduce activation of LX-2 cells suggests that IPA may have a therapeutic potential. Further molecular studies are needed to investigate the mechanisms how IPA can ameliorate hepatic fibrosis.


2017 ◽  
Vol 95 (3) ◽  
pp. 400-414 ◽  
Author(s):  
Hesham Farouk Hasan ◽  
Mohamed Khairy Abdel-Rafei ◽  
Shereen Mohamed Galal

Background: Liver fibrosis is one of the major complications from upper right quadrant radiotherapy. MicroRNA-17-5p (miR-17-5p) is hypothesized to act as a regulator of hepatic stellate cell (HSCs) activation by activation of the canonical Wnt–β-catenin pathway. Diosmin (Dios), a citrus bioflavonoid, is known to possess potent antioxidant, anti-inflammatory, and anti-apoptotic properties. Purpose: To explore the molecular mechanisms that underlie radiation-induced liver fibrosis, and to evaluate the possible influence of Dios on the miR-17-5p–Wnt–β-catenin signaling axis during fibrogenesis provoked by irradiation (IRR) in rats. Also, the effect of Dios on hepatic peroxisome proliferator activated receptor-γ (PPAR-γ) expression as a regulator for HSC activation was considered. Methods: We administered 100 mg·(kg body mass)–1·day–1(per oral) of Dios were administered to IRR-exposed rats (overall dose of 12 Gy on 6 fractions of 2 Gy each) for 6 successive weeks. Results: Data analysis revealed that Dios treatment mitigated oxidative stress, enhanced antioxidant defenses, alleviated hepatic inflammatory responses, abrogated pro-fibrogenic cytokines, and stimulated PPAR-γ expression. Dios treatment repressed the miR-17-5p activated Wnt–β-catenin signaling induced by IRR. Moreover, Dios treatment restored the normal hepatic architecture and reversed pathological alterations induced by IRR. Conclusion: We hypothesize that the stimulation of PPAR-γ expression and interference with miR-17-5p activated Wnt–β-catenin signaling mediates the antifibrotic properties of Dios.


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