MiR-133b在甲基苯丙胺诱导神经元损伤中的表达变化及调控作用

Objective To investigate the expression of miR-133b and their regulation mechanism in methamphetamine (MA)-induced neurotoxicity. Methods PC12 cells were treated with MA of different concentrations, and the morphological changes were observed using inverted microscope. MTT assay was used to observe the cell viability and determine the optimal MA concentration for cellular damage. The changes of DNA and RNA expressions in PC12 were observed with acridine orange staining method and real time fluorescent quantitative PCR (qRT-PCR) was performed for miR-133b. To further analyze the miR-133b molecular pathway, miR-133b mimic and inhibitor were added to interfere the expression of miR-133b. Results PC12 cells were damaged under the MA treatments of all concentrations and cell activity was decreased gradually. However, when exposed to 800μM MA, the morphological changes to the cells were optical, resulting in rounded cell bodies with dendrite disruptions. Also, cell viability decreased significantly as was shown by MTT, with shorten lengths of nervous process. and decreased expression of miR-133b. Applying miR-133b mimic and inhibitor before inducing cell damage with MA interfere the expression of miR-133b .Adding mimics resulted in cells with increased cell viability and longer neurites. Applying miR-133b inhibitor, on the contrary, led to reversed results. Conclusion MA can induce cytotoxicity in the PC12 cells by down-regulating miR-133b expression. Therefore, it is possible that the high expression of miR-133b can weaken MA-induced neurotoxicity.