Caveolin-1 Alleviates Crohn’s Disease–induced Intestinal Fibrosis by Inhibiting Fibroblasts Autophagy Through Modulating Sequestosome 1

Author(s):  
Mengli Yu ◽  
Wei Zhu ◽  
Jinhai Wang ◽  
Xueyang Chen ◽  
Xinjue He ◽  
...  

Abstract Background Intestinal fibrosis is a common complication of Crohn’s disease (CD) and is characterized by the excessive accumulation of extracellular matrix produced by activated myofibroblasts. Caveolin-1 (CAV1) inhibits fibrosis. However, limited data show that CAV1 affects intestinal fibrosis. Methods Human CD tissue samples were gained from patients with CD who underwent surgical resection of the intestine and were defined as stenotic or nonstenotic areas. A dextran sodium sulfate–induced mouse model of intestinal fibrosis was established. For in vitro experiments, we purchased CCD-18Co intestinal fibrosis cells and isolated and cultured human primary colonic fibroblasts. These fibroblasts were activated by transforming growth factor β administration for 48 hours. In the functional experiments, a specific small interfering RNA or overexpression plasmid was transfected into fibroblasts. The messenger RNA levels of fibrosis markers, such as α-smooth muscle actin, fibronectin, connective tissue growth factor, and collagen I1α, were determined using quantitative polymerase chain reaction. Western blot analysis was applied to detect the expression of CAV1, SQSTM1/p62 (sequestosome 1), and other fibrosis markers. Results In human CD samples and the dextran sodium sulfate–induced mouse model of intestinal fibrosis, we observed a downregulation of CAV1 in fibrosis-activated areas. Mechanistically, CAV1 knockdown in both human primary colonic fibroblasts and CCD-18Co cells promoted fibroblast activation, while CAV1 overexpression inhibited fibroblast activation in vitro. We found that SQSTM1/p62 positively correlated with CAV1 expression levels in patients with CD and that it was indirectly modulated by CAV1 expression. Rescue experiments showed that CAV1 decreased primary human intestinal fibroblast activation by inhibiting fibroblast autophagy through the modulation of SQSTM1/p62. Conclusions Our data demonstrate that CAV1 deficiency induces fibroblast activation by indirectly regulating SQSTM1/p62 to promote fibroblast autophagy. CAV1 or SQSTM1/p62 may be potential therapeutic targets for intestinal fibrosis.

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Shufen Liu ◽  
Yuhao Cheng ◽  
Yuqi Tan ◽  
Jingcheng Dong ◽  
Qin Bian

Objectives. Aberrant transforming growth factor β (TGFβ) activation is detrimental to both nucleus pulposus (NP) cells and cartilage endplates (CEPs), which can lead to intervertebral disc degeneration (IDD). Ligustrazine (LIG) reduces the expression of inflammatory factors and TGFβ1 in hypertrophic CEP to prevent IDD. In this study, we investigate the effects of LIG on NP cells and the TGFβ signaling. Design. LIG was injected to the lumbar spinal instability (LSI) mouse model. The effect of LIG was evaluated by intervertebral disc (IVD) score in the LSI mouse model. The expression of activated TGFβ was examined using immunostaining with pSmad2/3 antibody. The upright posture (UP) rat model was also treated and evaluated in the same manner to assess the effect of LIG. In ex vivo study, IVDs from four-week old mice were isolated and treated with 10−5, 10−6, and 10−7 M of LIG. We used western blot to detect activated TGFβ expression. TGFβ-treated human nucleus pulposus cells (HNPCs) were cotreated with optimized dose of LIG in vitro. Immunofluorescence staining was performed to determine pSmad2/3, connective tissue growth factor (CCN2), and aggrecan (ACAN) expression levels. Results. IVD score and the percentage of pSmad2/3+ NP cells were low in LIG-treated LSI mice in comparison with LSI mice, but close to the levels in the Sham group. Similarly, LIG reduced the overexpression of TGFβ1 in NP cells. The inhibitory effect of LIG was dose dependent. A dose of 10−5 M LIG not only strongly attenuated Smad2/3 phosphorylation in TGFβ-treated IVD ex vivo but also suppressed pSmad2/3, CCN2, and ACAN expression in TGFβ-treated NP cells in vitro. Conclusions. LIG prevents IDD via suppression of TGFβ overactivation in NP cells.


2018 ◽  
Vol 104 (3) ◽  
pp. 557-572 ◽  
Author(s):  
Mahdis Monajemi ◽  
Yvonne C. F. Pang ◽  
Saelin Bjornson ◽  
Susan C. Menzies ◽  
Nico van Rooijen ◽  
...  

2014 ◽  
Vol 26 (1) ◽  
pp. 177
Author(s):  
H.-R. Lee ◽  
R.-E. Go ◽  
K.-C. Choi

Activated oestrogen receptor (ER) signaling pathway by 17β-estadiol (E2) appeared to suppress transforming growth factor β (TGF-β) signaling pathway by cross-talk with TGF-β components in ER-positive cancer cells. In this study, we further examined the inhibitory effects of alkylphenols, including 4-nonylphenol (NP), 4-otylphenol (OP), bisphenol A (BPA), and benzophenon-1 (BP-1), in TGF-β signaling pathway. The transcriptional and translational levels of TGF-β-related genes were examined by reverse-transcription PCR (RT-PCR), Western blotting analysis in xenografted mouse models of ovarian cancer BG-1 cells. The NP, OP, and BPA induced the expression of snoN, a TGF-β pathway inhibitor. Treatment with NP, BPA, and BP-1 resulted in decreased phosphorylation of Smad3, a downstream target of TGF-β. With these 2 effects, NP and BPA stimulated the proliferation of BG-1 cells via inhibition of the TGF-β signaling pathway. In a xenograft mouse model, transplanted BG-1 ovarian cancer cells showed significantly decreased phosphorylation of Smad3 and increased expression of snoN in the ovarian tumour masses following treatment with E2, NP, or BPA. In parallel with an in vitro model, the expressions of TGF-β signaling pathway were similarly regulated by NP or BPA in a xenograft mouse model, revealing consistent results. Taken together, these results support that NP and BPA may cause the disruption of the TGF-β signaling pathway and increase the risk of oestrogen-dependent cancers such as ovarian cancer. This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ009599), Rural Development Administration, Republic of Korea.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Mei Jing ◽  
Yuqiang Wang ◽  
Lipeng Xu

Trinitrobenzenesulfonic acid (TNBS) and dextran sodium sulfate (DSS) are commonly used to induce experimental murine ulcerative colitis (UC). Our recent study has demonstrated that a novel andrographolide derivative, AL-1, ameliorated TNBS-induced colitis in mice. However, the effect of AL-1 on DSS-induced murine colitis and the underlying mechanisms are yet unknown. In the present study, we aimed to investigate the therapeutic potential of AL-1 against DSS-induced UC in mice and to define its mechanisms of action. Oral administration of AL-1 attenuated body weight loss, reduced colon length shortening, lowered the disease activity index score, and alleviated colon histological damage. AL-1 significantly inhibited myeloperoxidase activity and suppressed immune inflammatory responses in colonic tissues. Moreover, AL-1 reversed DSS-altered expression of inflammatory cytokines in DSS-induced colitis mice. Importantly, the efficacy of 45 mg/kg of AL-1 was higher than that of 100 mg/kg of the positive control drugs 5-aminosalicylic acid and mesalazine. AL-1 decreased lipopolysaccharide-induced generation of reactive oxygen species and nitric oxide in cultured macrophages in vitro; it also reversed the altered expression of inflammatory cytokines. In both in vivo and in vitro studies, Western blot analysis revealed that AL-1 reduced the expression of phosphorylated NF-κB p65 and IκBα, downregulated the expression of iNOS and COX-2, and attenuated the expression of phosphorylated p38 mitogen-activated protein kinase (MAPK), ERK, and JNK. In conclusion, AL-1 alleviated DSS-induced murine colitis by inhibiting activation of the NF-κB and MAPK signaling pathways. Our data suggest that AL-1 could be a potential new treatment for UC.


2014 ◽  
Vol 30 (12) ◽  
pp. 1199-1206 ◽  
Author(s):  
Yuhki Koike ◽  
Keiichi Uchida ◽  
Koji Tanaka ◽  
Shozo Ide ◽  
Kohei Otake ◽  
...  

2010 ◽  
Vol 90 (4) ◽  
pp. 566-576 ◽  
Author(s):  
Pieter Hindryckx ◽  
Anouk Waeytens ◽  
Debby Laukens ◽  
Harald Peeters ◽  
Jacques Van Huysse ◽  
...  

2014 ◽  
Vol 92 (5) ◽  
pp. 370-378 ◽  
Author(s):  
Stefan W. Ryter ◽  
Augustine M.K. Choi ◽  
Hong Pyo Kim

Fibrosis underlies the pathogenesis of several human diseases, which can lead to severe injury of vital organs. We previously demonstrated that caveolin-1 expression is reduced in experimental fibrosis and that caveolin-1 exerts antiproliferative and antifibrotic effects in lung fibrosis models. The signal transducers and activators of transcription (STAT) proteins, STAT1 and STAT3, can be activated simultaneously. STAT1 can inhibit cell growth and promote apoptosis while STAT3 inhibits apoptosis. Here, we show that caveolin-1-deficient (cav-1−/−) lung fibroblasts display dramatically upregulated STAT3 activation in response to platelet-derived growth factor-BB and transforming growth factor-β stimuli, whereas STAT1 activation is undetectable. Downregulation of protein tyrosine phosphatase-1B played a role in the preferential activation of STAT3 in cav-1−/− fibroblasts. Genetic deletion of STAT3 by siRNA modulated the expression of genes involved in cell proliferation and fibrogenesis. Basal expression of α-smooth muscle actin was prominent in cav-1−/− liver and kidney, consistent with deposition of collagen in these organs. Collectively, we demonstrate that the antiproliferative and antifibrogenic properties of caveolin-1 in vitro are mediated by the balance between STAT1 and STAT3 activation. Deregulated STAT signaling associated with caveolin-1 deficiency may be relevant to proliferative disorders such as tissue fibrosis.


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