Effect And Mechanism Of ?-carotene Intervention On Aquaporin In Intestinal Inflammation In Rats

Aquaporin(AQPs)is the main protein responsible for the transport of water molecules across the cell membrane,and also participates in the secretion of intestinal mucus and the homeostasis of the intestinal cell environment.The intestine is a complex dynamic equilibrium ecosystem.Inflammation is a basic physiological and pathological process.When foreign substances stimulate the intestine,it will trigger a series of immune responses and release inflammatory cytokines,causing inflammatory damage.Early weaning and inflammatory bowel disease can cause animal intestinal inflammatory damage,impaired immune barrier,and ultimately lead to changes in intestinal mucosal permeability and diarrhea.It will activate changes in the structure or activity of related AQPs when inflammatory damage occurs in the intestine.AQPs structure changes will lead to disturbances in the absorption and metabolism of water in the intestine,which in turn causes water to accumulate in the intestinal lumen and cause diarrhea.Therefore,the role of AQPs in diarrhea is clear.And the mechanism is particularly important.As a natural pigment,?-carotene has strong antioxidant properties and participates in the body's natural immunity and cellular immunity.However,the biological mechanism of ?-carotene in regulating the changes of AQPs in intestinal inflammation is still unclear.In this study,?-carotene nutrition intervention was used to explore its effect on aquaporin in the inflammatory injury caused by early weaning stress and ulcerative colitis in rats and its mechanism of action.SD rats with the same birthday and age were selected and randomly divided into control group(CON);weaning group(WS);?-carotene low-dose group(BLWS);?-carotene high-dose group(BHWS).Serum,small intestine and colon tissues were collected on the 3rd,5th,and 7th day after weaning.H&E staining,ELISA,QPCR,immunohistochemistry,Western blot and PAS staining were used to detect the effect of ?-carotene intervention on AQPs in intestinal inflammation in rats caused by early weaning stress.The results showed that early weaning stress can change the permeability of the intestinal mucosa,cause inflammatory reactions,and significantly down-regulate the expression of AQPs protein.?-carotene intervention can increase the ratio of small intestine to villi,improve the surface morphology of the colonic mucosa,bring the immunoglobulin to a normal level,significantly down-regulate the secretion of inflammatory cytokines and the relative expression of mRNA,and significantly down-regulate phosphorylated p38 and Erk And NF-?B protein level,significantly up-regulate the expression level of MUC2 protein,significantly increase the number of goblet cells,and make the intestinal mucosal repair factor tend to be normal;?-carotene intervention significantly up-regulates the relative expression of AQPs mRNA;significantly up-regulates cAMP,PKA,p-CREB protein expression level.?-carotene intervention can alleviate the inflammatory injury caused by early weaning and improve the abnormal expression of AQPs.Six-week-old SPF male SD rats were randomly divided into control group(Con);low,medium,and high dose ?-carotene groups(BL,BM,BH);ulcerative colitis group(DSS);low,Medium and high dose ?-carotene + DSS group(DBL,DBM,DBH).During the seven-day test period,serum,colon tissue and feces were collected to detect the effect of ?-carotene intervention on AQPs in intestinal inflammation in rats caused by Ulcerative colitis(UC).The results show that: UC can cause inflammatory diarrhea in rats,and the expression of AQPs protein is significantly down-regulated.?-carotene intervention significantly increased the average daily gain of rats,increased colon length,decreased DAI score,improved mucosal damage,significantly down-regulated the secretion of inflammatory cytokines and the relative expression of mRNA,and significantly down-regulated phosphorylated p38,Erk,JNK and NF-?B protein level significantly up-regulates the expression level of MUC2 protein,significantly increases the number of goblet cells,and makes the intestinal mucosal repair factor tend to be at a normal level;?-carotene intervention significantly up-regulates the relative expression of AQPs mRNA,and significantly up-regulates cAMP,PKA,and p-CREB protein expression level;16S highthroughput sequencing was used to detect that ?-carotene intervention can reduce the abundance of the flora that is positively correlated with inflammatory cytokines,and significantly increase the relative abundance of Faecalibacterium genus.?-carotene intervention can alleviate the inflammatory injury of ulcerative colitis rats and improve the abnormal expression of AQPs.Establish a TNF-?-induced in vitro inflammation model of rat colonic epithelial cells to verify the mechanism of ?-carotene intervention on aquaporin in rat intestinal inflammation.TNF-? activates the MAPKs signaling pathway,?-carotene intervention significantly down-regulates the relative expression of inflammatory cytokines mRNA,changes the relative expression of intestinal mucosal repair factor mRNA,up-regulates the relative expression of AQPs mRNA,and down-regulates p38,Erk,and NF-The expression level of ?B phosphorylated protein can alleviate cell inflammatory damage.After inhibiting p38 and Erk,the intervention effect of ?-carotene is significantly reduced;TNF-? also activates the AC/cAMP/PKA signaling pathway.?-carotene intervention significantly increased the relative expression of AQPs mRNA,up-regulated the protein expression levels of cAMP,PKA,and p-CREB.After inhibiting AC and PKA,the intervention effect of ?-carotene decreased significantly.?-carotene can alleviate the abnormal expression of AQPs caused by inflammation through the AC/cAMP/PKA and MAPKs signaling pathways.In summary,both early weaning and ulcerative colitis can cause intestinal inflammation in rats.Inflammation can lead to abnormal expression of AQPs.?-carotene intervention can regulate protein expression levels in AC/cAMP/PKA and MAPKs signaling pathways.Relieve inflammatory damage,repair the integrity of the intestinal mucosa,and improve the abnormal expression of AQPs.This study provides a new entry point and theoretical basis for further revealing that ?-carotene relieves inflammation,and lays a foundation for the study of nutrient targeted regulation of weaning stress in production.