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医学论文范文:CpG甲基化调节神经黏附分子多聚唾液酸的合成
【摘要】 目的 探讨DNA甲基化是否能够用来作为多聚唾液酸(PSA)表达的基因外调控。方法 用甲基化PCR分析成年小鼠和18d的胚胎鼠(E18)大脑不同区域合成多聚唾液酸的酶的基因- mST8SiaIV(PST)和mST8SiaII(STX)启动子甲基化水平;用dot-blotting分析不同浓度的甲硫胺酸和丙戊酸对PSA表达的影响;用CBRA(Combined bisulfite restriction analysis)进一步确认基因- ST8SiaIV和mST8SiaII启动子甲基化水平，神经细胞和神经胶质的原代培养。结果 (1)胎儿鼠与小鼠的大脑、小脑、基底核和海马，甲基化特异性的PCR结果显示：STX基因转录起始区没有甲基化，PST基因转录起始区在18d的胎儿鼠的所有4个区域和成年鼠的2个区域-大脑和小脑都有甲基化。(2)甲基化特异性的PCR分析原代培养的神经细胞和神经胶质细胞STX基因未发生甲基化，但是在PST基因在神经胶质细胞发现轻微的甲基化。(3)小鼠神经纤维母细胞瘤细胞株-Neuron2A细胞的PST基因启动子几乎完全被甲基化。(4)不同浓度甲硫氨酸处理Neuron2A细胞，PSA表达下降;相反丙戊酸增强了PSA的表达。结论 甲基化能够用来作为多聚唾液酸表达的基因外调控，多聚唾液酸表达的基因外调控可能与突触的形成和记忆的形成有关。
【关键词】 多聚唾液酸;DNA甲基化;基因外调控;突触
Polysialylation of neural cell adhesion molecule can be regulated by CpG methylation
GAO Yong-ying, CAI Hai-yan WANG Wei.(Ningxia People's Hospital, Yinchuan 750021, China)医.学全.在.线网站www.med126.com
[Abstract] Objective To explore the methylation could be used for epigenetic regulation of PSA expression or not. Methods Methylation-specific PCR was used to analyze the promoter methylation level of mST8SiaIV (PST) and mST8SiaII (STX) which were known as enzymes to synthesize polysialic acid (PSA). Using dot-blotting to assay expression of PSA on the surface of Neuron2A treated by methionine and valproic acid at different concentration. CBRA (Combined bisulfite restriction analysis) was used to confirm the promoter methylation level of PST and STX, and primary culture of neuronal and glial cells. Results STX promoter was not methylated, but PST promoter was methylated in all four region of E18 and in two region of adult mouse brain; In primary cultured neuronal and glial cells, no methylation could be detected in STX gene, but slight methylation in PST gene in glial cells; In mouse neuroblastoma cell line, Neuro2A cells, most of the promoters of PST gene were methylated; Neuro2A cells treated by methionine or valproic acid, methionine slightly decreased the PSA expression, whereas valproic acid significantly increased. Conclusion Methylation can be utilized for epigenetic regulation of PSA expression. Epigenetic regulation of PSA may be associated with synaptic plasticity, or memory formation.
