scholarly journals Brusatol-enriched Brucea Javanica Oil Ameliorated Dextran Sulfate Sodium-induced Colitis in Mice: Involvement of NF-κB and RhoA/ROCK Signaling Pathways

Author(s):  
xing han zheng ◽  
li ting mai ◽  
tong tong wang ◽  
ying xu ◽  
zi ren su ◽  
...  

Abstract Background: Our previous study indicates that Brucea javanica oil (BJO) is beneficial for treatment of ulcerative colitis (UC), and that quassinoids in particular brusatol are bioactive components. However, it is still uncertain whether or not other components in BJO, such as oleic acid and fatty acids, have anti-UC effect.Purpose: The present study aimed to compare the anti-UC effects between brusatol-enriched BJO (BE-BJO) and brusatol-free BJO (BF-BJO), and to explore the effects and mechanisms of BE-BJO on colon inflammation and intestinal epithelial barrier function.Methods: Balb/C mice received 3% (wt/vol) DSS for one weeks to establish the UC model. Different doses of BE-BJO, BF-BJO or BJO were treated. Body weight and colon length were measured. Disease activity index (DAI) and histological analysis were evaluated. The levels of pro-inflammatory cytokines in the colon tissues were measured by enzyme linked immunosorbent assay (ELISA). The expressions of tight junction proteins were tested to investigate the intestinal epithelial barrier function. The effects of BE-BJO on NF-κB and RhoA/ROCK pathways were studied.Results: BE-BJO alleviated DSS-induced loss of body weight, increase of DAI and shortening of colon, whereas BF-BJO did not have these protective effects. BE-BJO treatment improved the morphology of colon tissue, inhibited the production and release of pro-inflammatory cytokines including TNF-α、 IFN-γ、 IL-6 and IL-1β in the colon tissue, as well as reversed the decreased expressions of ZO-1, Occludin, Claudin-1and E-cadherin induced by DSS, but augmented Claudin-2 expression. Mechanistically, BE-BJO repressed phosphorylation of NF-κB subunit p65, suppressed RhoA activation, downregulated ROCK, and prevented phosphorylation of myosin light chain (MLC) in DSS-treated mice.Conclusions: This work demonstrated that BE-BJO could ameliorate DSS-induced UC by preventing colon inflammation and enhancing intestinal epithelial barrier function, probably via suppression of NF-κB and RhoA/ROCK signaling pathways. These findings confirm that quassinoids are active compounds from BJO and suggest the therapeutic potential of quassinoids and BE-BJO in the treatment of UC.

2015 ◽  
Vol 114 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Jie Zhao ◽  
Peiliang Shi ◽  
Ye Sun ◽  
Jing Sun ◽  
Jian-Ning Dong ◽  
...  

A defect in the intestinal barrier is one of the characteristics of Crohn's disease (CD). The tight junction (TJ) changes and death of epithelial cells caused by intestinal inflammation play an important role in the development of CD. DHA, a long-chain PUFA, has been shown to be helpful in treating inflammatory bowel disease in experimental models by inhibiting the NF-κB pathway. The present study aimed at investigating the specific effect of DHA on the intestinal barrier function in IL-10-deficient mice. IL-10-deficient mice (IL-10− / −) at 16 weeks of age with established colitis were treated with DHA (i.g. 35·5 mg/kg per d) for 2 weeks. The severity of their colitis, levels of pro-inflammatory cytokines, epithelial gene expression, the distributions of TJ proteins (occludin and zona occludens (ZO)-1), and epithelial apoptosis in the proximal colon were measured at the end of the experiment. DHA treatment attenuated the established colitis and was associated with reduced infiltration of inflammatory cells in the colonic mucosa, lower mean histological scores and decreased levels of pro-inflammatory cytokines (IL-17, TNF-α and interferon-γ). Moreover, enhanced barrier function was observed in the DHA-treated mice that resulted from attenuated colonic permeability, rescued expression and corrected distributions of occludin and ZO-1. The results of the present study indicate that DHA therapy may ameliorate experimental colitis in IL-10− / − mice by improving the intestinal epithelial barrier function.


2010 ◽  
Vol 4 (5) ◽  
pp. 637-651 ◽  
Author(s):  
Susanne A Snoek ◽  
Marleen I Verstege ◽  
Guy E Boeckxstaens ◽  
René M van den Wijngaard ◽  
Wouter J de Jonge

2008 ◽  
Vol 19 (9) ◽  
pp. 3701-3712 ◽  
Author(s):  
Jie Chen ◽  
Lan Xiao ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
...  

The AP-1 transcription factor JunD is highly expressed in intestinal epithelial cells, but its exact role in maintaining the integrity of intestinal epithelial barrier remains unknown. The tight junction (TJ) protein zonula occludens (ZO)-1 links the intracellular domain of TJ-transmembrane proteins occludin, claudins, and junctional adhesion molecules to many cytoplasmic proteins and the actin cytoskeleton and is crucial for assembly of the TJ complex. Here, we show that JunD negatively regulates expression of ZO-1 and is implicated in the regulation of intestinal epithelial barrier function. Increased JunD levels by ectopic overexpression of the junD gene or by depleting cellular polyamines repressed ZO-1 expression and increased epithelial paracellular permeability. JunD regulated ZO-1 expression at the levels of transcription and translation. Transcriptional repression of ZO-1 by JunD was mediated through cAMP response element-binding protein-binding site within its proximal region of the ZO-1-promoter, whereas induced JunD inhibited ZO-1 mRNA translation by enhancing the interaction of the ZO-1 3′-untranslated region with RNA-binding protein T cell-restricted intracellular antigen 1-related protein. These results indicate that JunD is a biological suppressor of ZO-1 expression in intestinal epithelial cells and plays a critical role in maintaining epithelial barrier function.


2013 ◽  
Vol 33 (10) ◽  
pp. 1457-1469 ◽  
Author(s):  
Kirsten E. Pijls ◽  
Daisy M. A. E. Jonkers ◽  
Elhaseen E. Elamin ◽  
Ad A. M. Masclee ◽  
Ger H. Koek

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xinghan Zheng ◽  
Liting Mai ◽  
Tongtong Wang ◽  
Ying Xu ◽  
Zireng Su ◽  
...  

Brucea javanica oil (BJO) is beneficial for the treatment of ulcerative colitis (UC), and that quassinoids in particular brusatol are bioactive components. However, it is still uncertain whether or not other components in BJO, such as oleic acid and fatty acids, have an anti-UC effect. The present study is aimed at comparing the anti-UC effects between brusatol-enriched BJO (BE-BJO) and brusatol-free BJO (BF-BJO) and at exploring the effects and mechanisms of BE-BJO on colon inflammation and intestinal epithelial barrier function. Balb/C mice received 3% (wt/vol) DSS for one week to establish the UC model. Different doses of BE-BJO, BF-BJO, or BJO were treated. The result illustrated that BE-BJO alleviated DSS-induced loss of body weight, an increase of disease activity index (DAI), and a shortening of colon, whereas BF-BJO did not have these protective effects. BE-BJO treatment improved the morphology of colon tissue, inhibited the production and release of TNF-α, IFN-γ, IL-6, and IL-1β in the colon tissue, and reversed the decreased expressions of ZO-1, occludin, claudin-1, and E-cadherin induced by DSS but augmented claudin-2 expression. Mechanistically, BE-BJO repressed phosphorylation of NF-κB subunit p65, suppressed RhoA activation, downregulated ROCK, and prevented phosphorylation of myosin light chain (MLC) in DSS-treated mice, indicating that the protective effect of BE-BJO is attributed to suppression of NF-κB and RhoA/ROCK signaling pathways. These findings confirm that brusatol is an active component from BJO in the treatment of UC.


2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Alexander Shea Dowdell ◽  
Ian Cartwright ◽  
Rachael Kostelecky ◽  
Tyler Ross ◽  
Nichole Welch ◽  
...  

Epigenomics ◽  
2021 ◽  
Author(s):  
Bing Li ◽  
Yan Li ◽  
Lixiang Li ◽  
Yu Yu ◽  
Xiang Gu ◽  
...  

Aims: Few circRNAs have been thoroughly explored in ulcerative colitis (UC). Materials & methods: Microarrays and qualitative real-time PCR were used to detect and confirm dysregulated circRNAs associated with UC. Functional analysis was performed to explore the roles. Results: A total of 580 circRNAs and 87 miRNAs were simultaneously dysregulated in both inflamed and noninflamed UC colonic mucosa compared with healthy controls. Accordingly, hsa_circ_0001021 was significantly downregulated in patients with UC and was related to Mayo scores. Clinical samples and cell experiments revealed that hsa_circ_0001021 was expressed in epithelial cells and correlated with ZO-1, occludin and CLDN-2. Moreover, hsa_circ_0001021 sponged miR-224-5p to upregulate smad4 and increased ZO-1 and occludin. Conclusion: Hsa_circ_0001021 is related to UC severity and regulates epithelial barrier function via sponging miR-224-5p.


2013 ◽  
Vol 304 (5) ◽  
pp. G479-G489 ◽  
Author(s):  
Katherine R. Groschwitz ◽  
David Wu ◽  
Heather Osterfeld ◽  
Richard Ahrens ◽  
Simon P. Hogan

Mast cells regulate intestinal barrier function during disease and homeostasis. Secretion of the mast cell-specific serine protease chymase regulates homeostasis. In the present study, we employ in vitro model systems to delineate the molecular pathways involved in chymase-mediated intestinal epithelial barrier dysfunction. Chymase stimulation of intestinal epithelial (Caco-2 BBe) cell monolayers induced a significant reduction in transepithelial resistance, indicating decreased intestinal epithelial barrier function. The chymase-induced intestinal epithelial barrier dysfunction was characterized by chymase-induced protease-activated receptor (PAR)-2 activation and matrix metalloproteinase (MMP)-2 expression and activation. Consistent with this observation, in vitro analysis revealed chymase-induced PAR-2 activation and increased MAPK activity and MMP-2 expression. Pharmacological and small interfering RNA-mediated antagonism of PAR-2 and MMP-2 significantly attenuated chymase-stimulated barrier dysfunction. Additionally, the chymase/MMP-2-mediated intestinal epithelial dysfunction was associated with a significant reduction in the tight junction protein claudin-5, which was partially restored by MMP-2 inhibition. Finally, incubation of Caco-2 BBe cells with chymase-sufficient, but not chymase-deficient, bone marrow-derived mast cells decreased barrier function, which was attenuated by the chymase inhibitor chymostatin. Collectively, these results suggest that mast cell/chymase-mediated intestinal epithelial barrier function is mediated by PAR-2/MMP-2-dependent pathways.


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