Expression And Distribution Of Nerve Gowth Factor And Its Receptor Tyrosine Protein Kina In Different Regions Of Yak And Cattle Brain

The aim of this study was to investigate the expression differences and partitioning characteristics of nerve growth factor and its high-affinity receptor tyrosine protein kinase A in different regions of yak(Bos grunniens)and cattle brain tissues,and to investigate the interaction between nerve growth factor and its receptor tyrosine protein kinase A,so as to provide a theoretical reference to further explore the adaptation mechanism of yak brain tissues to the plateau hypoxic environment.In this study,brain tissues were collected from the telencephalon,cerebellum,diencephalon and brainstem of adult yaks and cattles at different altitudes,including frontal cortex,temporal cortex,parietal cortex,occipital cortex,cerebral white matter,hippocampus and corpus callosum.The cerebellar tissues included corpus medullane,cerebellar cortex,vermis medulla,vermis cortical;the diencephalon and brainstem tissues included thalamus,hypothalamus,pons and medulla oblongata.The histological structures of different regions of adult yak and cattle brain tissues were observed and analyzed by HE;the distribution and the expression levels of nerve growth factor and its receptor tyrosine protein kinase A different regions of adult yak and cattle brain tissues were examined by immunohistochemistry,qRT-PCR and Western blot techniques,and their expression differences were analyzed.The results showed that:1.Nerve growth factor and its receptor tyrosine protein kinase A mRNA and protein were expressed in different regions of the telencephalon of yaks and cattles,and the trend of their protein content was basically consistent with the trend of mRNA expression.The expression of both factors in most tissues of the telencephalon was significantly higher in yaks than in cattles,while the expression of NGF and TrkA in the frontal cortex and cerebral white matter appeared to be lower in yaks than in cattles or not significantly different from cattles,and the highest expression of nerve growth factor and tyrosine protein kinase A was found in the cerebral cortex and hippocampus,respectively.The immunohistochemical results showed that nerve growth factor and its receptor tyrosine protein kinase A were similarly distributed in different regions of the telencephalon of yaks and cattles,mainly localized in the cytoplasm of neurons,glial cells and blood vessels in various regions of the telencephalon,with no positive expression in negative controls.2.Nerve growth factor and its receptor tyrosine protein kinase A mRNA and protein were expressed in different regions of the cerebellum of yaks and cattles,and the trend of their protein content was basically consistent with the trend of mRNA expression.The expression of nerve growth factor mRNA and protein in the cerebellar cortex was lower in yaks than in cattles,while the expression of mRNA in other regions was not significantly different between yaks and cattles,and the expression of protein was significantly higher in yaks than in cattles;in the vermis medulla,the expression of tyrosine protein kinakinase A mRNA was not significantly different between yaks and cattles,and the expression of protein was lower in yaks than in cattles,while the expression of protein in other regions was higher in yaks than in cattles.The immunohistochemical results showed that nerve growth factor and its receptor tyrosine protein kinase A were similarly distributed in different regions of the cerebellum in yaks and cattles,mainly localised in neuronal cytoplasm,glial cells and blood vessels in all regions of the cerebellum,with no positive expression in negative controls.3.Nerve growth factor and its receptor tyrosine protein kinase A mRNA and protein were expressed in different regions of the diencephalon and brainstem of yaks and cattles,and the trend of their protein content was basically consistent with the trend of mRNA expression.In the hypothalamus and pons,the expression of nerve growth factor mRNA was not significantly different between yaks and cattles,and its protein expression was lower in yaks than in cattles,while in the thalamus and medulla,the expression of both gene and protein was significantly higher in yaks than in cattles.Immunohistochemical results showed that nerve growth factor and its receptor tyrosine protein kinase A were similarly distributed in different regions of the mesencephalon and brainstem of yaks and cattles,and were also localised in the cytoplasm of neurons,glial cells and blood vessels in all regions,with no positive expression in negative controls.The findings suggest that nerve growth factor and tyrosine protein kinase A were not only involved in regulating the physiological activities of various neurons and glial cells in brain tissues,but also can exert endogenous protective mechanisms through upregulation of expression under hypoxic conditions,thereby increasing brain tissue tolerance to hypoxia.