scholarly journals Meprin A impairs epithelial barrier function, enhances monocyte migration, and cleaves the tight junction protein occludin

2013 ◽  
Vol 305 (5) ◽  
pp. F714-F726 ◽  
Author(s):  
Jialing Bao ◽  
Renee E. Yura ◽  
Gail L. Matters ◽  
S. Gaylen Bradley ◽  
Pan Shi ◽  
...  

Meprin metalloproteases are highly expressed at the luminal interface of the intestine and kidney and in certain leukocytes. Meprins cleave a variety of substrates in vitro, including extracellular matrix proteins, adherens junction proteins, and cytokines, and have been implicated in a number of inflammatory diseases. The linkage between results in vitro and pathogenesis, however, has not been elucidated. The present study aimed to determine whether meprins are determinative factors in disrupting the barrier function of the epithelium. Active meprin A or meprin B applied to Madin-Darby canine kidney (MDCK) cell monolayers increased permeability to fluorescein isothiocyanate-dextran and disrupted immunostaining of the tight junction protein occludin but not claudin-4. Meprin A, but not meprin B, cleaved occludin in MDCK monolayers. Experiments with recombinant occludin demonstrated that meprin A cleaves the protein between Gly100 and Ser101 on the first extracellular loop. In vivo experiments demonstrated that meprin A infused into the mouse bladder increased the epithelium permeability to sodium fluorescein. Furthermore, monocytes from meprin knockout mice on a C57BL/6 background were less able to migrate through an MDCK monolayer than monocytes from their wild-type counterparts. These results demonstrate the capability of meprin A to disrupt epithelial barriers and implicate occludin as one of the important targets of meprin A that may modulate inflammation.

2018 ◽  
Vol 66 ◽  
pp. 93-109 ◽  
Author(s):  
Yeojung Kim ◽  
Gail A. West ◽  
Greeshma Ray ◽  
Sean P. Kessler ◽  
Aaron C. Petrey ◽  
...  

2020 ◽  
Author(s):  
Guangmang Liu ◽  
Xiaomei Xu ◽  
Caimei Wu ◽  
Gang Jia ◽  
Hua Zhao ◽  
...  

Abstract Background: Weaning stress can lead to the disruption of tight junctions and increased intestinal permeabilty, which contributes to the initiation and development of many disease, such as Crohn’s disease and ulcerative colitis. Pigs are more ideal models for human studies than other animals. However, no information is found about the relationship of intestinal integrity and spermine supplementation in pigs. The objective of this study is to investigate whether spermine protects intestinal barrier integrity via Rac1/PLC-γ1 signalling pathway in piglets. Methods: In vivo, the piglets were categorised into the control group and the spermine group, which was fed with spermine at 0.4 mmol kg−1 body weight for 7 hours and 3, 6 and 9 days. In vitro, we examined whether spermine protects the intestinal barrier after TNF-α challenge through Ras-related C3 botulinum toxin substrate 1 (Rac1)/Phospho-lipase C-γ1 (PLC-γ1) signalling pathway. Results: In vivo study revealed that the spermine treatment upregulated tight junction protein mRNA levels and Rac1/PLC-γ1 signalling pathway gene expression in the jejunum of piglets. The serum D-lactate content was significantly reduced after spermine treatment (P < 0.05). In vitro study revealed that 0.1 μM spermine significantly increased the levels of tight junction protein expression, Rac1/PLC-γ1 signalling pathway and transepithelial electrical resistance, and decreased paracellular permeability (P < 0.05). Further experiments showed that spermine treatment increased the levels of tight junction protein expression, Rac1/PLC-γ1 signalling pathway and transepithelial electrical resistance, and decreased paracellular permeability compared with the NSC-23766 and U73122 treatment with spermine after TNF-α challenge (P < 0.05). Conclusion: spermine protects intestinal integrity through the Rac1/PLC-γ1 signalling pathway.


2016 ◽  
Vol 84 (1) ◽  
pp. 99-101 ◽  
Author(s):  
Seon-Pil Jin ◽  
Sang Bum Han ◽  
Yeon Kyung Kim ◽  
Elizabeth Eunkyung Park ◽  
Eun Jin Doh ◽  
...  

2017 ◽  
Vol 62 ◽  
pp. 28-39 ◽  
Author(s):  
Yeojung Kim ◽  
Sean P. Kessler ◽  
Dana R. Obery ◽  
Craig R. Homer ◽  
Christine McDonald ◽  
...  

Reproduction ◽  
2008 ◽  
Vol 135 (6) ◽  
pp. 867-877 ◽  
Author(s):  
Gerard A Tarulli ◽  
Sarah J Meachem ◽  
Stefan Schlatt ◽  
Peter G Stanton

This study aimed to assess the effect of gonadotrophin suppression and FSH replacement on testicular tight junction dynamics and blood–testis barrier (BTB) organisation in vivo, utilising the seasonal breeding Djungarian hamster. Confocal immunohistology was used to assess the cellular organisation of tight junction proteins and real-time PCR to quantify tight junction mRNA. The effect of tight junction protein organisation on the BTB permeability was also investigated using a biotin-linked tracer. Tight junction protein (claudin-3, junctional adhesion molecule (JAM)-A and occludin) localisation was present but disorganised after gonadotrophin suppression, while mRNA levels (claudin-11, claudin-3 and occludin) were significantly (two- to threefold) increased. By contrast, both protein localisation and mRNA levels for the adaptor protein zona occludens-1 decreased after gonadotrophin suppression. FSH replacement induced a rapid reorganisation of tight junction protein localisation. The functionality of the BTB (as inferred by biotin tracer permeation) was found to be strongly associated with the organisation and localisation of claudin-11. Surprisingly, JAM-A was also recognised on spermatogonia, suggesting an additional novel role for this protein in trans-epithelial migration of germ cells across the BTB. It is concluded that gonadotrophin regulation of tight junction proteins forming the BTB occurs primarily at the level of protein organisation and not gene transcription in this species, and that immunolocalisation of the organised tight junction protein claudin-11 correlates with BTB functionality.


2011 ◽  
Vol 140 (5) ◽  
pp. S-619-S-620
Author(s):  
Xin Chen ◽  
Tadayuki Oshima ◽  
Toshihiko Tomita ◽  
Hirokazu Fukui ◽  
Jiro Watari ◽  
...  

2018 ◽  
Vol 46 (1) ◽  
pp. 253-268 ◽  
Author(s):  
Ying Xu ◽  
Weixing Wu ◽  
Yunxia Fan ◽  
Shuyi Jiang ◽  
Xiaoyu Jia ◽  
...  

Background/Aims: Transforming growth factor-β3 (TGF-β3) has been proved to perturb the blood-testis barrier (BTB) by accelerating junction protein endocytosis in Sertoli cells (SCs) to accommodate the traversing of preleptotene spermatocytes across the BTB around stage VIII in rat. Yet the molecular network underlying the impairment of TGF-β3 on BTB integrity is not fully elucidated. Our study herein was designed to investigate the participation of microRNA-142-3p (miR-142-3p), which has been reported to affect TGF-β3 signaling via different pathways, during BTB dynamics and the corresponding mechanisms. Methods: MiRNA mimic or agomiRNA was co-administered with or without TGF-β3 in the cultured SCs or in the rat testis. The SC permeability barrier function was reflected by measuring the transepithelial resistance (TER) and the permeability of the sodium fluorescein (Na-F). The BTB integrity was detected by the permeation of biotin. A luciferase reporter assay was used to testify the potential target of miR-142-3p, lethal giant larvae 2 (Lgl2). Laser capture microdissection (LCM) was applied to acquire cell components of different stages of seminiferious tubules, followed by detection of the expression levels of miR-142-3p, TGF-β3, and Lgl2 by qPCR. The SC barrier function was also detected as above in the presence of TGF-β3 after Lgl2 knockdown. Results: We revealed a reversion of TGF-β3-induced BTB impairment after miR-142-3p treatment both in vitro and in vivo. Meanwhile, the activation of Cdc42 and reduction in occludin aroused by TGF-β3 were also reversed by miR-142-3p. The predicted binding of miR-142-3p with 3’-untranslated region (3’-UTR) of Lgl2, was verified by the luciferase assay. Moreover, an increased Lgl2 level in TGF-β3-treated SCs was found and correlated stage-specific expressions of TGF-β3, miR-142-3p, and Lgl2 were revealed. Knockdown of Lgl2 in SCs was shown to partially antagonize the BTB disruption mediated by TGF-β3. Conclusions: Collectively, our results suggest a resistance of miR-142-3p on the BTB impairment caused by TGF-β3 during the seminiferous epithelial cycle by targeting Lgl2.


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