YAP1/β-catenin/HIF-1α相关因子在牦牛和黄牛小肠组织中的表达分析OA

The intestine is the largest barrier organ of the body,and its structural and functional homeostasis serve as a critical foundation for yaks(Bos grunniens)to tolerate hypoxic stress.To investigate the role of YAP1/β-catenin/HIF-1α signaling pathway-related factors in the hypoxic adaptation of the yak small intestine,this study used 5 juvenile yaks and 5 juvenile cattle(Bos taurus)as experimental subjects.qRT-PCR,Western blot,immunohistochemistry(IHC),and immunofluorescence(IF)were employed to detect the expression and distribution of Yes1-associated transcriptional regulator(YAP1),β-catenin,hypoxia-inducible factor-1α(HIF-1α),and the tight junction proteins claudin-1 and occludin in the duodenal,jejunal,and ileal tissues.The qRT-PCR and Western blot results demonstrated that the expression levels of all 5 factors were extremely significantly higher in the duodenum,jejunum,and ileum of yaks compared with cattle(P＜0.01),suggesting that yaks may possess a stronger adaptive capacity to hypoxia in the small intestine.Additionally,in both yaks and cattle,the mRNA and protein expression levels of YAP1,β-catenin,HIF-1α,claudin-1,and occludin in the ileum were extremely significantly higher than those in the duodenum and jejunum(P＜0.01).IHC and IF results revealed that YAP1,β-catenin,and HIF-1α were predominantly localized in the nuclei of crypt stem cells within the small intestinal mucosal epithelium,with scattered distribution also observed in the nuclei of fibroblasts and lymphocytes in the lamina propria.Claudin-1 and occludin were mainly distributed in the cytoplasm of absorptive cells and goblet cells in the small intestinal mucosal epithelium,as well as in fibroblasts,lymphocytes,and glandular goblet cells in the lamina propria.Furthermore,YAP1,β-catenin and HIF-1α were co-localized in the nuclei of stem cells at the base of small intestinal crypts together with the intestinal stem cell marker—leucine-rich repeat-containing G-protein coupled receptor 5(Lgr5),suggesting that factors related to the YAP1/β-catenin/HIF-1α signaling pathway might play a protective role in the mucosal epithelium and crypt stem cells of yak small intestinal tissues.This study provides basic data for further exploration of the molecular mechanisms underlying hypoxic adaptation in the yak digestive tract.