β-淀粉样蛋白对原代培养大鼠海马神经细胞Sorcin、RyR2mRNA基因表达的影响

Effect of β-amyloid on Sordn and RyR2mRNA expression in the hippocampal neurons of the SD rats

目的研究β-淀粉样蛋白（Aβ）对原代培养的大鼠脑海马神经细胞内钙稳态相关蛋白Sorcin、RyR2mRNA的影响。方法新生1-3天的Wistar大鼠，取其海马组织，原代培养8d后，用已老化过的Aβ25-35对海马神经细胞进行1μmol／L，10μmol／L和20μmol／L剂量的染毒，培养24和48h后分别观察海马神经细胞形态、和海马神经细胞内钙调节相关蛋白Sorcin、RyR2mRNA的基因表达水平。结果随着Aβ25-35剂量的增加和染毒时间的延长，可发现随着Aβ25-35剂量的增加和染毒时间的延长，海马细胞出现细胞凋亡的比例增加，其中Aβ25-35 20μmol／L染毒48h培养海马细胞中出现了大量早期凋亡细胞和少量中期凋亡细胞。实时定量PCR结果显示，10μLmol／LAβ25-35在对原代细胞染毒24和48h后SorcinmRNA的相对表达量为（1．42±0．03）和（1．63±0．02），与对照组相比，表达增加（P〈0．05）；20μmol／L Aβ25-35在对原代细胞染毒24h和48h后SorcinmRNA的相对表达量（2．11±0．05）和（2．23±0．05），与对照组相比，表达增加（P〈0．05）；20μmol／L Aβ25-35在对原代细胞染毒24和48h后RyR2mRNA的相对表达量为（1．64±0．03）和（1．95±0．03），表达显著高于对照组相（P〈0．05）。结论Aβ具有神经毒性，可抑制海马神经细胞的生长，可通过作用于钙调节相关蛋白的表达，诱发阿尔茨海默氏病（AD）的发生。

To study the effects of β-amyloid （Aβ25-35） on calcium homeostasis related genes such as Sor- cin and RyR2mRNA in primary cultured rats hippocampal neurons. Methods After 8 days of primary cultured, hippocampal neurons were exposure with different doses （ 1 μmol/L, 10 μmol/L, and 20 μmol/L, respectively） of Aβ25-35 ,and 0μmol/L dose as control group. After cultured 24h and 48h ,observed hippocampal neuronal morphol- ogy by transmission electron microscope, detected the Sorcin and RyR2 gene relative expressions of the cultured hippocampal neurons by real-time PCR. Results With the increase of Aβ25-35 dose and exposure time,morpholog- ical changes of primary cultured hippocampal neurons were observed, showing the percentage of apoptosis neurons increased in the Aβ25-35 exposure groups. There were more apoptosis neurons in the Aβ20μmol/L group than other groups. The results of Real-time PCR showed Aβraised the expression of Sorcin mRNA and Ryr2 mRNA. The Sor-cin mRNA relative expression were （1.42 ±0.03）and （1.63 ±0.02）when cultured 24h and 48h respectively in 10μmol/L Aβ25-35 group;the Sorcin mRNA relative expression were （2.11 ±0.05）and （2.23 ±0.05） when cul- tured 24h and 48h respectively in 20μmol/L Aβ25-35 group;these results had statistically difference （P 〈 0.05 ） compared with control group. The RyR2 mRNA relative expression were （ 1.64 ± 0.03 ） and （ 1.95 ± 0.03 ） when cultured 24h and 48h respectively in 20μmol/L Aβ25-35 group;These results also showed statistically difference compared with control group. Conclusion Aβ25-35 exhibits a neurotoxicity effect by inducing the apoptosis in pri- mary cultured hippocampal neurons and inhibiting the growth of hippocampal neurons. It can induce AD by regula- ting the expression of calcium related proteins such as Sorcin and RyR.