The Effect And Significance Of Intestional Trefoil Factor On Neonatal Rat Model PI3K/AKT Signal Pathway For Necrotizing Enterocolitis

Objectives:To study the effects of ITF on PI3K/AKT and caspases-3/9 (cysteinyl aspartate-specific protea-ses) and BAD,p-BAD density in neonatal rat NEC model, with wortmannin (specific inhibitor of PI3K), to investigate if the PI3K/Akt/Caspase-3 /9/BAD signaling pathway activated in the protective effect of ITF on neonatal rat intestinal tissues with NEC.Methods:NEC model of neonatal rats was established as followed.Asphyxia stress was accomplished by exposure to 100% nitrogen for 60 s, followed by exposure to cold (4℃) for 10 min twice daily. Neonatal rats were fed formula (200 kcal/kg/day) every 3 h via an orogastric feeding catheter. The feeding volume began at 0.1 cc per 3 h and was increased incrementally to account for somatic growth. This procedure was done once everyday and continued 3 days. On the 4th day, all the subjects were put to death. Fifty neonatal rats were divided randomly into five groups:A) NEC + NS 0.2 ml, (B) NEC + ITF 0.2 mg, (C) NEC+Wortmannin (0.1mg/kg) (D) NEC +ITF 0.2 mg + Wortmannin (0.1mg/kg), (E) control. The intestinal tissue located at the boundary of ileum and cecum was obtained to observe histological changes. Other intestinal tissue was homogenated. After the homogenate was centrifuged, supernates were used to test the density of PI3K and Caspase-3 and caspase-9.,Other intestinal tissue were used to test the density of p-AKT and BAD,p-BAD by westernblot.Results:The pathological lesions indicated that intestinal tissue necrosis was severe in group A,C and D, which was graded as 3 points, but obviously lessen in group B, which was graded 1 point. The density of PI3K(pg/ml)was increased in Group A than that in group E (p<0.05), which had no difference with those in group D (P>0.05). The density of PI3K (pg/ml) was the strongest in group B and was weakest in group C. The activity of Caspase-3 and Caspase-9 was significantly increased in group A than those in group B and E (p<0.01), while dramatic increased in Group C(p<0.01). Caspase-3 and Caspase-9 content between group A and D, group B and E was not dramatically different (P>0.05). The density of p-AKT and p-BADwas increased in Group A than those in group E (p<0.05), there was not difference with those in group D (P>0.05). The density of p-AKT was the strongest in group B and were weakest in group C (P<0.01) and p-BAD had no difference in group C and E (P>0.05). The activity of BAD was significantly increased in group A than those in group B and E (p<0.01), while dramatic increased in Group C(p<0.01). BAD content between group A and D, group B and E is not dramatically different (P>0.05)Conclusions:Intestinal inflammation is ameliorated after ITF was injected intraperitoneally. ITF may provide a brand-new way for the therapy of NEC in neonatal rats; PI3K/Akt signal pathways might play important roles in the mechanism and signal transduction of NEC; ITF may protect the intestinal injury of neonatal wistar rat from NEC model by activation of PI3K/Akt signal transduction paths way, and down regulation of caspase-3/9 and BAD.