花青素在由辐射引起的大脑海马神经元凋亡中的防护作用及其分子机理研究

Neuronal apoptosis induced by ionizing radiation is one of the most urgent problems to be resoved in radiotherapy. Therefore,to study radiation-protectively natural compounds with function has become a recent research topic. Anthocyanins, a class of natural flavonoids, have been demonstrated to have strong antioxidant activities and free radicals scavenging capacities. Studies have shown that grapes, blueberries, mulberries and other berries that are abundant in anthocyanins exhibit antioxidant activity of oxidative stress induced by radiation, and have preventive effects against several neuropathic diseases. On the basis of our previous research, we propose to investigate the neuroprotective effects of anthocyanins on neuronal apoptosis induced by 137 Cs γ-ray irradiation in Sprague-Dawley rats. The levels of oxidative stress markers, antioxidant capacity, free radical scavenging enzyme activities of anchocyanins and their effects on neuronal apoptosis in rats hippocampal will be studied. The molecular mechanism of anthocyanins will be further investigated by the combination of traditional molecular biology methods and gene chip analysis, as well as weighted gene co-expression network analysis (WGCNA), with a particular focus on apoptosis mitochondrial pathway. Our research will provide a theoretical basis for the development and application of anthocyanins as a natural radioprotective agent, as well as provide new information on the development of anti-radiation drugs for clinical use.

由电离辐射引起的神经元凋亡是目前放射防护领域中亟待解决的问题之一，发现并研究具有放射防护作用的天然化合物是目前的研究热点。花青素是自然界中广泛的一种黄酮类化合物，具有强有力的抗氧功效，能够保护人体免受自由基的侵害。已有研究表明，葡萄、蓝莓、黑枸杞等富含花青素的浆果具有对由活性氧引起的氧化应激的防辐射功效，并且对神经病变性疾病具有较好的防治作用。因此，本课题提出研究花青素在由铯-137γ射线仪器辐射诱导的Sprague-Dawley大鼠脑海马神经元凋亡的放射防护功效。通过检测氧化应激标志物水平、抗氧化能力、自由基清除酶活性变化和对神经元凋亡的作用等方面进行花青素发挥放射防护作用的药效学研究；并采用结合传统分子生物学研究手段和和微阵列技术、加权基因共表达网络分析（WGCNA）等方法，系统、深入地探讨花青素发挥放射防护功效的分子作用机理。

由电离辐射引起的神经元凋亡是目前放射防护领域中亟待解决的问题之一，发现并研究具有放射防护作用的天然化合物是目前的研究热点。本项目检测了花青素对由铯-137γ射线辐照的实验大鼠体重的影响；测量了花青素对大脑海马中氧化应激的标志物；测量了花青素对大脑海马自由基清除酶系统活性的影响；使用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定法检测了花青素对大脑海马细胞凋亡的影响；通过免疫组织化学研究大脑海马中凋亡标志物Caspase-3的表达；通过蛋白质印记分析和实时荧光定量PCR等传统分子生物学方法检测细胞凋亡线粒体途径中Bax，Bcl-2，Caspase-3、-8、-9等蛋白质及其相关基因的表达水平；采用基高通量测序技术检测大脑海马中与氧化应激有关的细胞信号系统中的基因表达变化；通过对辐射对照组和实验组（花青素高剂量组）进行加权基因共表达网络分析（WGCNA）进一步探讨花青素发挥放射防护功能的治疗靶标。明确了花青素在由辐射引起的大脑海马神经元凋亡中的神经防护作用；探讨了花青素在大脑海马神经元中神经防护作用的分子作用机制，为花青素作为天然放射防护剂的开发进一步提供理论研究支持。