14-3-3γ过表达通过抑制促凋亡分子Bax转位保护多巴胺能细胞对抗MPP^+的毒性作用

Overexpression of 14-3-3γ protects dopaminergic cells against neurotoxicity of MMP^+ through inhibiting translocation of the apoptotic factor Bax

目的:探讨14-3-3γ蛋白过表达能否抑制促凋亡分子Bax对抗MPP+对多巴胺能细胞的毒性作用。方法:用腺病毒载体携带人14-3-3γ基因感染PC12细胞,使14-3-3蛋白在细胞中过表达,通过Western Blot检测14-3-3γ、Bax、细胞色素c、caspase 3蛋白质的表达、DAPI染色法检测细胞凋亡、MTT法和自动生化检测法测定细胞活力及LDH酶的活性。结果:14-3-3γ蛋白的过表达能抑制Bax转位到线粒体,抑制LDH的活性(MPP+组41.18±2.71,m14-3-3γ组39.45±3.16,14-3-3γ组13.54±1.82),提高细胞活力(MPP+组49.86±6.27%,m14-3-3γ组52.35±5.59%,14-3-3γ组81.02±5.83%),从而抑制了MPP+诱导的PC12细胞的凋亡(MPP+组49.38±7.31%,m14-3-3γ组46.54±5.49%,14-3-3γ组8.76±3.59%)。结论:14-3-3γ蛋白可以通过对促凋亡分子Bax转位的抑制对抗MPP+对PC12细胞的毒性作用,最终达到细胞保护作用。

Objective： To explore whether the overexpression of 14-3-3γ, protein protects dopaminergic cells against neurotoxicity of MPP ＋ through inhibition of the apoptotic factor Bax. Methods： Adenovirus vector carrying the gene of 14-3-3γwas used to infect PC12 cells for overexpression of 14-3-3 protein. The protein expression of 14-3-3γ, Bax, eyto- chrome c and caspase 3 were measured by Western Blot; the cellular apoptosis was detected by DAPI staining; and MTT assay, automatic biochemistry analyzer were utilized to determine the cell viability and LDH activity respectively. Results： The overexpression of 14-3-3γ, inhibited translocation of Bax from the cytosol to the mitochondria, inhibited LDH activity （ MPP＋ group 41.18 ± 2.71, m14-3-3γ, group 39.45 ± 3.16, and 14-3-3γ, group 13.54 ± 1.82）, and increase cell viability （ MPP＋ group 49.86 ±6.27%, m14-3-3γ, group 52.35 ±5.59% , and 14-3-3γ组81.02 ±5.83% ）, and thus inhibited the apoptosis of PC12 cells induced by MPP＋ （ MPP＋ group 49.38 ± 7.31% , 14-3-3γ, group 46.54 ± 5.49% ,and 14-3-3γ, group 8.76 ± 3.59% ）. Conclution： The overexpression of 14-3-3γ, could protect PC12 cells against the neurotoxicity of MPP ＋ through inhibition of the apoptotic factor Bax.