Brain‐derived neurotrophic factor preserves intestinal mucosal barrier function and alters gut microbiota in mice

Abstract

The intestinal mucosal barrier (IMB) enables the intestine to provide adequate containment of luminal microorganisms and molecules while preserving the ability to absorb nutrients. In this study, we explored the effect of brain-derived neurotrophic factor (BDNF) on IMB function and gut microbiota in mice. BDNF gene knock-out mice (the BDNF group) and wild-type mice (the BDNF group) were selected. The gut microbiota of these mice was analyzed by denaturing gradient gel electrophoresis (DGGE) assay. The ultrastructure of the ileum and the colonic epithelium obtained from decapitated mice were observed by transmission electron microscopy. The protein expression of epithelial tight junction proteins, zonula occludens-1 (ZO-1) and occludin was detected by immunohistochemistry staining. The protein expression of claudin-1 and claudin-2 was determined by Western blotting. The DGGE band patterns of gut microbiota in the BDNF group were significantly different from that in the BDNF group, which indicated that the BDNF expression alters the gut microbiota in mice. Compared with the BDNF group, the BDNF group presented no significant difference in the ultrastructure of ileal epithelium; however, a significant difference was observed in the colonic epithelial barrier, manifested by decreased microvilli, widening intercellular space and bacterial invasion. Compared with the BDNF group, the expression of ZO-1 and occludin in the BDNF group was significantly decreased. The expression of claudin-1 in the BDNF group was significantly reduced, while the expression of claudin-2 was elevated. These findings indicate that BDNF preserves IMB function and modulates gut microbiota in mice.

Musca domestica Cecropin (Mdc) Alleviates Salmonella typhimurium-Induced Colonic Mucosal Barrier Impairment: Associating With Inflammatory and Oxidative Stress Response, Tight Junction as Well as Intestinal Flora

“…These proteins play pivotal roles in maintaining the integrity of tight junction between cells and the normal function of epithelial cell barriers. Abnormal expression of these protein cause barrier dysfunction, leading to dysfunction of tight junction and increased tissue permeability, which is one of the characteristics of inflammatory bowel disease (Walsh-Reitz et al, 2005; Förster, 2008; Mir et al, 2016; Li et al, 2018; Lucke et al, 2018). In the present study, the results of immunofluorescence analysis, Real-time quantitative PCR detection and western blot analysis demonstrated that Mdc could improve diseased intestinal tight junction by up-regulating the level of tight junction proteins ZO-1, Occludin and Claudin-1.…”

Chitosan Ameliorates DSS-Induced Ulcerative Colitis Mice by Enhancing Intestinal Barrier Function and Improving Microflora

“…The pathogenesis of UC is not clearly understood, and it is generally considered to be caused by multiple factors [3]. Among these, intestinal mucosal barrier function and microflora play major roles in which UC occurs and develops [4]. The intestinal mucosal barrier is the first barrier against a hostile environment, mainly formed by the tight junctions (TJs) of epithelial cells.…”

Effect of Xiaoyaosan on Colon Morphology and Intestinal Permeability in Rats With Chronic Unpredictable Mild Stress

“…Hormones released during the stress response, such as cortisol, can modulate the composition and function of the intestinal mucosal barrier to affect intestinal permeability (Maqsood and Stone, 2016). The tight junctions of epithelial cells (ECs) are the main structures of the intestinal mucosal barrier (Li et al, 2018). Tight junctions consist of two proteins: occludin and claudin, both of which are transmembrane proteins.…”