自然衰老大鼠海马神经干细胞增殖和分化及其调节变化与补肾方作用机理研究

Proliferation and differentiation and giving rise to all CNS phenotypes are the Characterization of neural stem cells(NSCs) .These make them can supplement or replace the injured neurons or function.These has been proven that there are NSCs in central nervous system in mammalian animals in all life,and proliferation and differentiation of NSCs are degenerating with aging.But the mechanism of them is still not clear.Our group proved that the cortcostrone(CORT) was increasing in blood in natural aging rats,and CORT can influence the function of hippocampus with feedback..Based on the theory of traditional chinese medicine"Kidney stores semen and produces marrow ","Brain is sea of marrow"and "Difficiency of kidney results in aging ",We combine feature of the change of proliferation and differentiation of NCSs and glucocorticoid(GCs) concentration in blood in aged organism.Natural aging rats are used as aged model.From observing CORT,GCs receptor in hippocampus and different fields of hippocampus,related neurotransmitter and cytokines and key molecules of signal transduction,and the change of proliferation and differentiation of NSCs in natural aged rats(24months).The aging rats are interfered with Zuogui pill and Yougui pill.Our aim is mainly in search for the relation between change of proliferation and differentiation of NSCs and GCs and the regulative mechanism of them in aged rats and probing what is difficiency of kidney and providing new target and provement for antiaging and treating neurodegenerative diseases with kidney strengthen method.

神经干细胞（NSCs）具有增殖和分化为各类神经细胞的特点，可补充、替代受损的神经细胞或功能。研究发现，成体哺乳动物中枢系统终生存在NSCs，其增殖和分化能力随机体衰老而减退，但机制仍不明确。课题组研究证明自然衰老大鼠血中皮质酮（CORT）浓度增高，而CORT可通过反馈作用影响海马功能。.本项目根据肾"藏精、生髓"、"脑为髓之海"及"肾虚致衰"等中医理论，结合衰老时血中糖皮质激素（GCs）浓度与NSCs增殖和分化能力的变化特点，以自然衰老大鼠为模型，观察自然衰老大鼠（24月龄）血中CORT、海马及其分区糖皮质激素受体、相关神经递质、细胞因子、信号通路关键分子及海马NSCs增殖和分化能力的变化，并以经典补肾方-左归丸和右归丸进行干预，探索衰老时海马神经干细胞增殖和分化能力的变化与GCs的关系及其调节机理，进一步阐释"肾虚"的本质，为补肾延衰和治疗相关神经退行性疾病提供新的靶点和实验依据。

根据中医“肾藏精，生髓”、“脑为髓之海”及“肾虚致衰”的理论，结合衰老时血清糖皮质激素（GCs）浓度与NSCs增殖和分化能力的变化特点，项目以自然衰老大鼠为模型，观察自然衰老大鼠（24月龄）血清皮质酮（CORT）、海马及其分区糖皮质激素受体、相关神经递质、细胞因子、信号通路关键分子及海马NSCs增殖和分化能力的变化，并以经典补肾方-左归丸和右归丸进行干预。. 项目研究发现，与青年对照组比较，自然衰老大鼠：血清CORT含量显著增高；海马组织Nestin和Ki-67的蛋白表达水平显著降低；海马组织神经递质Glu含量显著增高、GABA含量显著降低、5-HT和ACh的含量显著降低；海马组织GDNF、 NGF及FGF等的含量均显著降低；海马组织Wnt和Notch-1蛋白表达水平显著上调；海马齿状回海FGF、NGF、Erk1/2、Notch-1和EGF蛋白表达明显降低；海马神经细胞的线粒体减少，突触小泡明显减少，突触小泡内的线粒体明显减少。与老年对照组比较，左归丸和右归丸组大鼠：海马组织Nestin和Ki-67的蛋白表达水平显著上调；海马组织Glu含量显著降低，GABA、5-HT和ACh的含量显著升高；海马组织GDNF、 NGF及FGF等蛋白表达均显著升高；海马组织Wnt蛋白的表达水平显著下调；大鼠海马齿状回FGF、NGF蛋白表达均显著升高；大鼠海马齿状回Erk1/2的蛋白表达显著升高；海马神经细胞中的线粒体明显增加，突触小泡明显增大且数量明显增加，突触内的线粒体明显增加。左归丸组大鼠：血清CORT含量显著降低；海马齿状回EGF蛋白表达显著升高。. 自然衰老大鼠海马NSCs的增殖和分化能力降低，补肾方左归丸和右归丸均可显著增强自然衰老大鼠海马NSCs的增殖和分化能力；自然衰老大鼠NSCs增殖和分化能力的降低与衰老时下丘脑-垂体-肾上腺（HPA）轴功能亢进、海马组织相关神经递质和神经营养因子的含量变化等有密切关系，补肾方可改善自然衰老大鼠HPA轴功能及海马组织相关神经递质和神经营养因子的含量变化；海马NSCs含量的减少是机体衰老的一个重要因素，而通过增强海马NSCs的增殖和分化的能力是补肾方延缓机体衰老的重要机制之一。.