Dong Yue, Han Li-Li, Xu Zhong-Xin
Department of Neurology , China-Japan Union Hospital, Jilin University, No. 126, Xiantai Street, Erdao District, Changchun, 130012, Jilin Province, People's Republic of China.
Department of Neurology, Cangzhou Central Hospital, Cangzhou, 061000, People's Republic of China.
Mol Med. 2018 Nov 28;24(1):61. doi: 10.1186/s10020-018-0059-9.
There have been a number of reports implicating the association of microRNAs (miRs) and the MAPK signaling pathway with the dopaminergic neuron, which is involved in the development of Parkinson's disease (PD). The present study was conducted with aims of exploring the role of miR-96 in the activation of iNOS and apoptosis of dopaminergic neuron through the MAPK signaling pathway in mice with PD.
The miR and the differentially expressed gene in PD were screened out and the relationship between them was verified. A mouse model of PD induced by MPTP and was then constructed and treated with miR-96 mimic/inhibitor and CACNG5 overexpression plasmid to extract nigral dopaminergic neuron for the purpose of detecting the effect of miR-96 on PD. The TH and iNOS positive neuronal cells, the apoptotic neuronal cells by TUNEL staining, and expression of miR-96, CACNG5, iNOS, p38MAPK, p-p38MAPK, c-Fos, Bax, and Bcl-2 in substantia nigra dopaminergic neuronal tissues were evaluated.
The results obtained from the aforementioned procedure were then verified by cell culture of the SH-SY5Y cells, followed by treatment with miR-96 mimic/inhibitor, CACNG5 overexpression plasmid and the inhibitor of the MAPK signaling pathway. CACNG5 was confirmed as a target gene of miR-96. The inhibition of miR-96 resulted in a substantial increase in nigral cells, TH positive cells and expression of CACNG5 and Bcl-2 in nigral dopaminergic neuronal tissues, and a decrease in iNOS positive cells, apoptotic neuronal cells, and expression of iNOS, p38MAPK, p-p38MAPK, c-Fos, and Bax.
The above results implicated that the downregulation of miR-96 inhibits the activation of iNOS and apoptosis of dopaminergic neuron through the blockade of the MAPK signaling pathway by promoting CACNG5 in mice with PD.
已有多项报道表明，微小RNA（miR）和丝裂原活化蛋白激酶（MAPK）信号通路与多巴胺能神经元相关，而多巴胺能神经元参与帕金森病（PD）的发病过程。本研究旨在探讨miR-96在PD小鼠中通过MAPK信号通路激活诱导型一氧化氮合酶（iNOS）及导致多巴胺能神经元凋亡中的作用。
筛选出PD中差异表达的miR和基因，并验证它们之间的关系。构建MPTP诱导的PD小鼠模型，用miR-96模拟物/抑制剂和钙通道γ5亚基（CACNG5）过表达质粒处理，提取黑质多巴胺能神经元，以检测miR-96对PD的影响。评估黑质多巴胺能神经元组织中酪氨酸羟化酶（TH）和iNOS阳性神经元细胞、TUNEL染色的凋亡神经元细胞，以及miR-96、CACNG5、iNOS、p38丝裂原活化蛋白激酶（p38MAPK）、磷酸化p38丝裂原活化蛋白激酶（p-p38MAPK）、c-Fos、Bax和Bcl-2的表达。
上述实验所得结果随后通过SH-SY5Y细胞培养，并用miR-96模拟物/抑制剂、CACNG5过表达质粒和MAPK信号通路抑制剂处理进行验证。证实CACNG5是miR-96的靶基因。抑制miR-96可使黑质细胞、TH阳性细胞以及黑质多巴胺能神经元组织中CACNG5和Bcl-2的表达显著增加，使iNOS阳性细胞、凋亡神经元细胞以及iNOS、p38MAPK、p-p38MAPK、c-Fos和Bax的表达减少。
上述结果表明，在PD小鼠中，miR-96的下调通过促进CACNG5阻断MAPK信号通路，抑制iNOS的激活和多巴胺能神经元的凋亡。
