SP385
Effect of Hypoxia-inducible factor-1α stabilizers on the destruction of tight junctions in uremic intestinal epithelial cells Free

INTRODUCTION: Intestinal barrier dysfunction in uremic patients is an important factor leading to intestinal microflora translocation-microinflammatory state, and its mechanism involves impaired tight connection of intestinal epithelial cells. Hypoxia-inducible factor-1α (HIF-1α) plays an important role in the maintenance of intestinal mucosal barrier structure and function, and is involved in the regulation of the expression of tight junction proteins in intestinal epithelial cells. In this study, based on the previous findings of decreased expression of intestinal tight junction protein in uremia, the role of HIF-1α in intestinal barrier dysfunction caused by ureima toxins and the effect of intervention of HIF-1α stabilizer (FG-4592) on the above effects were explored.

METHODS: Caco2 cells was cultured and divided into 3 groups, the normal control group, the uremic serum stimulation group, and the uremic serum + HIF-1α stabilizer (FG-4592) intervention group. RT-PCR and Western blotting method was used to detect the expression of HIF-1α, intestinal tight junction protein ZO-1, claudin-1, Occludin, and NLRP3 inflammasome, and mir-223 in each group.

RESULTS: The application of uremia serum to stimulate Caco2 cells can reduce the expression of HIF-1α, ZO-1, claudin-1, occluding mRNA, while the HIF-1α stabilizer (FG-4592) can increase these mRNA expression (P<0.05) (Fig 1). Stimulation of Caco2 cells by Uremia serum can increase the expression of caspase-1, IL-1β and NLRP3, while FG-4592 can reduce the expression of NLRP3 inflammasome (P<0.05) (Fig 2). Stimulation of Caco2 cells with Uremia serum increased NLRP3 expression, while mir-223 -mimic and siNLRP3 decreased NLRP3 expression (P<0.05) (Fig 2).

CONCLUSIONS: This study suggests that HIF-1α may be involved in the regulation of uremic intestinal mucosal barrier function, and its mechanism of action involves the effect on intestinal epithelial tight junction protein, which can improve the claudin-1, Occludin, ZO-1. HIF-1α stabilizer (FG-4592) increases the decrease of HIF-1α expression under the stimulation of uremic serum, and its improvement of the expression mechanism of tight junction protein may play a role in the down-regulation of NLRP3 inflammasome caused by the up-regulation of mir-223 expression, thus improving the intestinal barrier function, which needs further experimental verification.