Gene silencing of porcine MUC13 and ITGB5: candidate genes towards Escherichia coli F4ac adhesion.
BACKGROUND
Integrin beta-5 (ITGB5) and mucin 13 (MUC13) genes are highly expressed on the apical surface of intestinal epithelia and are thought to be candidate genes for controlling the expression of the receptor for enterotoxigenic Escherichia coli (ETEC) F4ac. Human MUC13 protein has an expected role in protecting intestinal mucosal surfaces and porcine ITGB5 is a newly identified potential receptor for ETEC F4ac.


RESULTS
To test the hypothesis that ITGB5 and MUC13 both play key roles in protection of the intestinal mucosa against pathogenic bacterium, porcine intestinal epithelial cells (IPEC-J2) were transfected with ITGB5-targeting, MUC13-targeting or negative control small interfering RNA (siRNA), respectively. Firstly, we measured mRNA expression levels of mucin genes (MUC4, MUC20), pro-inflammatory genes (IL8, IL1A, IL6, CXCL2), anti-inflammatory mediator SLPI, and PLAU after RNAi treatments with and without ETEC infection. Secondly, we compared the adhesions of ETEC to the pre- and post-knockdown IPEC-J2 cells of ITGB5 and MUC13, respectively. We found that ITGB5 and MUC13 knockdown both had small but significant effects in attenuating the inflammation induced by ETEC infection, and both increased bacterial adhesion in response to F4ac ETEC exposure.


CONCLUSIONS
Our current study first reported that ITGB5 and MUC13 are important adhesion molecules of mucosal epithelial signaling in response to Escherichia coli in pigs. These data suggest that both ITGB5 and MUC13 play key roles in defending the attachment and adhesion of ETEC to porcine jejunal cells and in maintaining epithelial barrier and immunity function.
Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P.R. China.
Chuanli
C
Zhou
Zhengzhu
Z
Liu
Yang
Y
Liu
Weixuan
W
Fu
Xiangdong
X
Ding
Jianfeng
J
Liu
Ying
Y
Yu
Qin
Q
Zhang
D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D002462:Cell Membrane; D054307:Enterotoxigenic Escherichia coli / Q000235:genetics; D015870:Gene Expression; D020868:Gene Silencing; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D039641:Integrin beta Chains / Q000235:genetics* / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D009077:Mucins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D013552:Swine
D039641:Integrin beta Chains; D009077:Mucins; D012333:RNA, Messenger