Resveratrol联合MSCs移植对阿尔茨海默鼠的干预效果及Sirt1分子信号的介导作用

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory and cognitive impairment and changes in behavior. There has been no effective therapy till now. stem cell transplantation is promising for AD treatment. We previously showed that transplantation of umbilical cord derived mesenchymal stem cells (MSCs) to AD mice could ameliorate clinical systom ,improve the ability of learning and memory and reduce β-amyloid deposition. However, the rates of cell survival and neuronal differentiation were pretty low. It is critical to promote the cell fate of stem cells and efficacy. Sirt1 gene, which plays an important role in regulating the lifespan and aging of cells, can be actived by Resveratrol. Although Resveratrol possesses diverse biochemical and physiological properties, its neuroprotective benefits in animal models of AD were still controversial. Considering the inconsistent results, It is necessary to determine the exact role of Resveratrol on AD. In this study, we will examine the effect of Resveratrol with different doses on cell survival，proliferation, differentiation and senencense by isolating umbilical cord derived MSCs and neural stem cells (NSCs) from different ages of AD trangenic mice. The expression of Sirt1 and related molecules p16、p53、p21、pCNA will be detected by real time PCR and Western blot. Different ages of AD mice were divided into groups to investigate Aβ deposition, learning and memory ability,stem cell survival, proliferation and differentiation, Sirt1 signaling molecules in the brain. Also,MRI in vivo monitoring after stem cell transplantation will be compared with neural behavior tests. This study present a theoretical hypotheis about Resveratrol combining MSCs transplant to improve cell fate and efficacy, which will contribute to clarify the intervention effect of Resveratrol on AD, also illuminate the mechanism of Sirt1 signaling pathway mediating the process, which will provide scientific bases and strategy for AD therapy.

阿尔茨海默病(AD) 是中枢神经系统退行性变，目前无有效疗法。课题组前期发现，脐带源性MSCs移植能改善AD鼠症状，但干细胞在脑内存活和定向分化为神经元的效率低，细胞转归和疗效提高是亟需解决的关键问题。Sirt1基因能调控细胞寿命，Resveratrol可激活Sirt1，然而对AD的干预效果报道不一。本研究拟通过体外实验观察Resveratrol对脐带MSCs和不同月龄AD鼠神经干细胞增殖、分化、衰老影响的量效关系，Sirt1及相关分子p16、p53、p21、pCNA表达；体内研究Resveratrol联合MSCs移植对不同月龄AD鼠脑内Aβ沉积、学习记忆能力、干细胞存活、增殖、分化， MRI活体示踪及Sirt1分子信号作用。该研究提出Resveratrol联合MSCs移植调控干细胞微环境，重塑细胞命运的理论假设，并有助于明确干预效果和Sirt1分子的作用机制，为AD防治提供科学依据。

阿尔茨海默病(AD) 是中枢神经系统退行性变，目前无有效疗法。干细胞具有自我更新和多向分化的潜能，为AD的治疗带来希望。但干细胞在脑内存活和定向分化为神经元的效率低，细胞转归和疗效提高是亟需解决的关键问题。白藜芦醇（RES）可调控SIRT1的活性发挥抗衰老、抗氧化等生物学功能。然而，RES是否能够通过SIRT1分子信号调控MSCs的命运，提高MSCs治疗AD的效果还有待探讨。我们发现白藜芦醇对脐带源性MSCs（hUC-MSC）的自我更新和神经分化具有浓度依赖性作用。低浓度（0.1、1、2.5 μmol/L）RES可通过促进细胞增殖、抑制细胞衰老、上调SIRT1和PCNA并下调p53和p16表达，对细胞自我更新产生促进作用；而高浓度（5、10 μmol/L）白藜芦醇则抑制细胞自我更新。0.1-10 μmol/LRES对hUC-MSCs神经样分化具有浓度依赖性的促进作用。体内研究显示RES促进hUC-MSCs在AD小鼠脑内的迁移与存活；RES联合hUC-MSCs能更有效地降低APP表达、Tau磷酸化水平、神经细胞凋亡、氧化应激损伤，改善AD病理状态；此外，RES和hUC-MSCs协同调节脑内神经炎症、促进神经再生、提高AD小鼠的学习记忆能力。白藜芦醇联合hUC-MSCs对有望成为更有效的治疗AD的手段，其分子机制与SIRT1分子信号中SIRT1、PCNA、ac-p53、p53、p21、p16表达的改变相关。因此，我们研究显示RES联合MSCs移植可以调控Sirt1分子途径，改善干细胞微环境，促进干细胞转归和重塑干细胞命运，提高干细胞治疗效果，为AD防治提供科学依据。