title: The protective effect of enteric glial cells on intestinal epithelial barrier function is enhanced by inhibiting inducible nitric oxide synthase activity under lipopolysaccharide stimulation.
abstract: Enteric glial cells (EGC) play an essential role in maintaining the integrity of intestinal epithelial barrier (IEB). However, the mechanism of EGCs in the regulation of IEB functions under lipopolysaccharide (LPS) stimulation is unknown. To investigate the barrier-related role of EGCs in response to the LPS challenge, the coculture model of EGCs and intestinal epithelial cells (IEC) IEC-6 was established in vitro. Transepithelial resistance (TER) measurements showed that, LPS treatment significantly increased barrier permeability of IEC monolayer from the basolateral side (35.4±6.3 Ω/cm(2), p<0.05) but not the apical side (69.7±6.3 Ω/cm(2)) when compared with the control group (81.8±10.9 Ω/cm(2)). The assessment of intestinal epithelial integrity by TER reading and by measuring expression of tight junction protein revealed that, incubation with EGCs or EGC conditioned media significantly increased the TER of IEC monolayers under normal condition as well as the LPS stimulation, accompanied with upregulating zonula occludens-1 and occludin expression at mRNA and protein levels. Real-time quantitative polymerase chain reaction and nitric production assay demonstrated that LPS exposure elicited a maximally 13-fold increase of inducible nitric oxide synthase (iNOS) mRNA expression and 10-fold increase of nitric oxide production of EGCs. After being pretreated with the selective iNOS inhibitor 1400 W, EGCs significantly increased the TER of IEC monolayers against the disruption effect of LPS (p<0.05). These findings suggest that EGCs play an important role in maintaining the IEB function in response to the LPS stimulation. The protective effect of EGCs on IEB functions could be enhanced by inhibiting the increase of iNOS activity induced by LPS.
authors.affiliation: Department of General Surgery, Xinqiao Hospital, The Third Military Medical University, Shapingba District, Chongqing, PR China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Xiao
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Sun
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Wang
authors.forename: Shi-Wen
authors.initials: SW
authors.lastname: Zhou
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D018920:Coculture Techniques; D017615:Enteric Nervous System / Q000166:cytology; D005455:Fluorescent Antibody Technique; D007413:Intestinal Mucosa / Q000166:cytology* / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000633:toxicity; D009457:Neuroglia / Q000166:cytology* / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D010539:Permeability; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019108:Tight Junctions / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D052247:Nitric Oxide Synthase Type II