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他汀类药物可上调内皮一氧化氮合酶(ENOS)的表达,并由甲羟戊酸(MVA)途径介导,但具体机制未完全阐明.本研究旨在探索洛伐他汀(LVT)上调ENOS表达的分子信号机制并明确同ENOS表达相关的顺式作用元件的定位.洛伐他汀通过减少细胞内固醇,如MVA和geranylgeranylpyrophosphate(GGPP),从而增加ENOS mRNA的稳定性.因GGPP是细胞内信号蛋白如Ras、RhoGTPase进行翻译后修饰和膜定位所必需的,因此很可能洛伐他汀的作用与细胞内信号途径有关.进一步的实验结果显示Rho激酶抑制剂hydroxyfasudil和细胞松弛素D均可在转录后水平上调ENOS mRNA表达,表明Rho途径介导的细胞骨架状态在ENOS mRNA降解率的调控中起一定作用.细胞转染实验证明调控ENOS mRNA降解的顺式作用元件位于其mRNA序列上的3’未翻译区(3’UTR)和相邻的编码区.其中调控GGPP介导ENOS mRNA稳定性的顺式作用元件位于序列的3 751～4 606位点间;而hydroxyfasudil通过位于3 751～4 468位点间的顺式作用元件稳定ENOSmRNA;细胞松弛素D通过位于3 904～4 188位点间的元件稳定ENOS mRNA.洛伐他汀可能通过抑制Rho激酶途径稳定ENOS mRNA,此过程由位于mRNA序列上3’UTR及相邻编码区的多样顺式作用元件介导.另外,细胞骨架的空间构造也可影响ENOS mRNA的稳定性,此过程由位于其mRNA序列编码区的顺式作用元件介导.本研究为转录子稳定性调控机制的进一步研究提供了有力根据,或许可为心血管疾病的治疗提供新的分子靶点.
Statins can up-regulate the expression of endothelial nitric oxide synthase (ENOS) and is mediated by the mevalonate (MVA) pathway, but the exact mechanism has not been fully elucidated.This study aimed to investigate the effects of lovastatin (LVT) on ENOS Expression of the molecular signaling mechanism and clarify the location of cis-acting elements associated with ENOS expression Lovastatin increases the stability of ENOS mRNA by reducing cellular sterols such as MVA and geranylgeranylpyrophosphate (GGPP) Since GGPP is intracellular Signaling proteins such as Ras and RhoGTPase are necessary for post-translational modification and membrane localization, it is likely that the effect of lovastatin is related to the intracellular signaling pathway.Further experimental results show that both Rho kinase inhibitors, hydroxyfasudil and cytochalasin D, The post-transcriptional level up-regulated the expression of ENOS mRNA, which indicated that the Rho pathway-mediated cytoskeleton played a role in the regulation of ENOS mRNA degradation.Transfection experiments demonstrated that the cis-acting element that regulates the ENOS mRNA degradation is located at 3 ’Untranslated region (3’UTR) and the adjacent coding region. Among them, the cis-acting element that regulates the stability of GGPP-mediated ENOS mRNA is located between 3 751 ~ 4 606 of the sequence; and hy droxyfasudil stabilizes ENOS mRNA through a cis-acting element located between 3 751 ~ 4 468; cytochalasin D stabilizes ENOS mRNA through an element located between 3 904 and 4 188 sites Lovastatin may stabilize ENOS by inhibiting the Rho kinase pathway mRNA by a variety of cis-acting elements located in the 3 ’UTR of the mRNA sequence and adjacent coding regions.In addition, the spatial structure of the cytoskeleton can also affect the stability of ENOS mRNA, Region of cis-acting elements mediated by the study of the stability of transcriptional regulatory mechanisms provide a strong basis for further research, may provide a new molecular target for the treatment of cardiovascular disease.