牦牛小脑不同区域神经营养素-4及其受体的表达特征与定位研究OA北大核心CSTPCD

Neurotrophin-4(NT-4)and its neurotrophic receptor,Tyrosine Kinase Receptor 2(NTRK2),play significant roles in the survival,growth and functionality of cerebellar neurons.To investigate the roles of NT-4 and NTRK2 in the adaptation to high-altitude hypoxia in yaks(Bos grunniens),this study examined the expression levels and localization patterns of NT-4 and NTRK2 in different regions of the cerebellum of yaks and plain cattle(Bos taurus)using quantitative real-time PCR(qRT-PCR),Western blot(WB),Hematoxylin-Eosin(HE)staining and immunohistochemistry(IHC).qRT-PCR and WB results revealed that the expression of NT-4 gene and protein was the highest in the cerebellar hemisphere cortex of yaks,significantly higher than those in other tissues(P<0.05).NTRK2 gene and protein has the highest expression in the cerebellar vermis cortex of yaks,significantly higher than in other tissues(P<0.05).Compared to plain cattle,the expression of NT-4 protein in all areas of the yak cerebellum was higher(P<0.05).Yak NTRK2 protein in the vermis medulla was lower than in cattle,but significantly higher in all other areas(P<0.05).IHC results indicated that the positive expression of NT-4 and NTRK2 proteins was consistent,primarily distributed in Purkinje cell layer and granule cell layer in the cortex regions,while sparsely distributed in glial cells and nerve fibers in the medullary substance.These results suggest that the differential expression of NT-4 and NTRK2 in various cerebellar regions may be related to their involvement in the normal physiological functions of brain tissue and adaptation to high-altitude hypoxia.Under hypoxia conditions,NT-4 and NTRK2 likely activate relevant pathways to exert an endogenous neuroprotective effect,thereby safeguard brain tissue from hypoxia damage.This study provides a basis for exploring the mechanisms of hypoxia adaptation in yak brain tissue.