Aquaporin-3 May Have A Protective Effect On Intestinal Barrier Damage In Septic Mice

Objective:To explore the protective effect of aquaporin-3(AQP3)on intestinal mucosal barrier function.Methods:128 male Balb/c mice were used in this study.Forty-eight mice were randomly assigned to four groups:sham operation(n=6);sham operation with oral glycerol(n=6);sepsis(n=30,of which 24 mice were executed at 0h,6h,12h and 24h after cecal ligation and puncture,6 mice at each time point);and sepsis with oral glycerol(n=6).Another 80 mice were divided into four groups on average to observe the mortality rate.In addition to the time-dependent group,four groups of mice were executed 24h after modeling,and blood and intestinal mucosal tissue samples were collected.A mouse sepsis model was established using cecal ligation and puncture(CLP).Hematoxylin-eosin staining(HE staining)was used to detect morphological changes in the ileal mucosal.The plasma diamine oxidase(DAO)concentration and intestinal-type fatty acid-binding protein(FABP2)concentration were measured by enzyme-linked immunosorbent assay(ELISA)to detect intestinal mucosal injury.Immunohistochemistry,real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)and Western blot(WB)were used to detect the expression of AQP3 and occludin in intestinal mucosa.Results:Sepsis induced intestinal injury,as demonstrated by the disordered destruction of the morphology of the intestinal mucosa,time-dependent increases in Chiu's score(P<0.05),significantly increased(P<0.05)plasma concentrations of DAO and intestinal FABP2,and time-dependent downregulation of the expression of AQP3(P<0.05).The administration of oral glycerol partially which can replace some functions of AQP3 ameliorated the sepsis-induced injury of the intestinal mucosa,as shown by the partial recovery of the morphological structure,with decreased Chiu's score,decreased plasma concentrations of DAO and FABP2,increased occludin expression and decreased mortality(P<0.05).Conclusion:The results showed that the expression levels of AQP3 and occludin were downregulated after septic intestinal injury,while treatment with glycerol,which acts as a substitute for AQP3,partly ameliorated intestinal injury.This preliminary experiment suggests that AQP3 may protect the intestinal tract against the effects of sepsis.