scholarly journals Human β-defensin-3 reduces excessive autophagy in intestinal epithelial cells and in experimental necrotizing enterocolitis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Liping Chen ◽  
Zhibao Lv ◽  
Zhimei Gao ◽  
Guijie Ge ◽  
Xueli Wang ◽  
...  

AbstractNecrotizing enterocolitis (NEC) is a leading cause of mortality in preterm newborns. Intestinal barrier dysfunction is one key event in NEC pathogenesis. Human β-defensin-3 (hBD3), one member of cationic host defence peptides, was reported to reduce the development of necrotizing enterocolitis in a neonatal rat model. And autophagy was induced in the intestine of human and animals with NEC. We hypothesized that regulation of autophagy might play a critical role in hBD3-mediated protection against NEC injury. Autophagy activity was evaluated both in intestinal epithelial cells and in NEC models. Newborn Sprague-Dawley rats were divided randomly into four groups: Control + NS, Control + rapamycin, NEC + NS, and NEC + hBD3. Body weight, histological score, survival time, enterocyte migration and mucosal barrier were recorded. Our results showed that hBD3 pretreatment could effectively inhibit autophagy activity in cultured IEC-6 and Caco2 enterocytes, and CXCR4 might be involved in hBD3-mediated autophagy suppression. Moreover, hBD3-induced inhibition of autophagy significantly promoted the intestinal epithelial cell migration by wound healing assay and transwell migration assay. In the rat model of NEC, hBD3 could noticeably reduce the expression of autophagy-activated proteins, down-regulate the expression of inflammatory mediators, and promote the mucosal integrity. Our data suggest an additional role of hBD3-mediated protection against intestinal mucosal injury: inhibition of over-activated autophagy in enterocytes.

2017 ◽  
Vol 152 (5) ◽  
pp. S967 ◽  
Author(s):  
Elisabeth M. Davis ◽  
Yihong Kaufmann ◽  
Hannah Goyne ◽  
Yuxiu Wang ◽  
Tsungyen Chen ◽  
...  

2018 ◽  
Author(s):  
Hongying Fan ◽  
Ruqin Lin ◽  
Zhenhui Chen ◽  
Xingyu Leng ◽  
Xianbo Wu ◽  
...  

AbstractCronobacter sakazakii (CS), an important pathogen, is associated with the development of necrotizing enterocolitis (NEC), infant sepsis, and meningitis. Several randomized prospective clinical trials demonstrated that oral probiotics could decrease the incidence of NEC. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. However, it remains unclear how ZY-312 protects the host from the effects of CS infection. To understand the underlying mechanisms triggering the probiotic effects, we tested the hypothesis that there was a cross-talk between probiotics/probiotics-modulated microbiota and the local immune system, governed by the permeability of the intestinal mucosa using in vitro and in vivo models for the intestinal permeability. The probiotic effects of ZY-312 on intestinal epithelial cells were first examined, which revealed that ZY-312 inhibited CS invasion, CS-induced dual cell death (pyroptosis and apoptosis), and epithelial barrier dysfunction in vitro and in vivo. ZY-312 also decreased the expression of an inflammasome (NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3), caspase-3, and serine protease caspase-1 in a neonatal rat model. Furthermore, ZY-312 significantly modulated the compositions of the intestinal bacterial communities, and decreased the relative abundances of Proteobacteria, Gamma proteobacteria, but increased the relative abundance of Bacteroides and Bacillus in neonatal rats. In conclusion, our findings have shown for the first time that the probiotic, B. fragilis ZY-312, suppresses CS-induced NEC by modulating the pro-inflammatory response and dual cell death (apoptosis and pyroptosis).Author summaryCronobacter sakazakii, a major necrotizing enterocolitis pathogen, is used as a model microorganism for the study of opportunistic bacteria in the pathogenesis of necrotizing enterocolitis. Here, we have now unequivocally demonstrated that both apoptotic and pyroptotic stimuli contribute to the pathogenesis of Cronobacter sakazakii -induced necrotizing enterocolitis. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. We found that the ZY-312 defense against Cronobacter sakazakii-induced necrotizing enterocolitis by inhibiting Cronobacter sakazakii invasion, epithelial barrier dysfunction, the expression of inflammatory cytokines and dual cell death (pyroptosis and apoptosis). This study demonstrates the utility of ZY-312 as a promising probiotic agent for the prevention and treatment of various intestinal diseases, including NEC.


2005 ◽  
Vol 29 (12) ◽  
pp. 2116-2122 ◽  
Author(s):  
Hiroshi Kishikawa ◽  
Soichiro Miura ◽  
Jiro Nishida ◽  
Masaru Nakano ◽  
Erika Hirano ◽  
...  

2006 ◽  
Vol 290 (4) ◽  
pp. G782-G792 ◽  
Author(s):  
Jaladanki N. Rao ◽  
Oleksandr Platoshyn ◽  
Vera A. Golovina ◽  
Lan Liu ◽  
Tongtong Zou ◽  
...  

An increase in cytosolic free Ca2+ concentration ([Ca2+]cyt) results from Ca2+ release from intracellular stores and extracellular Ca2+ influx through Ca2+-permeable ion channels and is crucial for initiating intestinal epithelial restitution to reseal superficial wounds after mucosal injury. Capacitative Ca2+ entry (CCE) induced by Ca2+ store depletion represents a major Ca2+ influx mechanism, but the exact molecular components constituting this process remain elusive. This study determined whether canonical transient receptor potential (TRPC)1 served as a candidate protein for Ca2+-permeable channels mediating CCE in intestinal epithelial cells and played an important role in early epithelial restitution. Normal intestinal epithelial cells (the IEC-6 cell line) expressed TRPC1 and TPRC5 and displayed typical records of whole cell store-operated Ca2+ currents and CCE generated by Ca2+ influx after depletion of intracellular stores. Induced TRPC1 expression by stable transfection with the TRPC1 gene increased CCE and enhanced cell migration during restitution. Differentiated IEC-Cdx2L1 cells induced by forced expression of the Cdx2 gene highly expressed endogenous TRPC1 and TRPC5 and exhibited increased CCE and cell migration. Inhibition of TRPC1 expression by small interfering RNA specially targeting TRPC1 not only reduced CCE but also inhibited cell migration after wounding. These findings strongly suggest that TRPC1 functions as store-operated Ca2+ channels and plays a critical role in intestinal epithelial restitution by regulating CCE and intracellular [Ca2+]cyt.


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