Churchill M J, Pflibsen L, Sconce M D, Moore C, Kim K, Meshul C K
VA Medical Center/Portland, Mail Code: RD-29, Research Services, 3710 SW Veterans Hospital Road, Portland, OR 97239, United States.
VA Medical Center/Portland, Mail Code: RD-29, Research Services, 3710 SW Veterans Hospital Road, Portland, OR 97239, United States.
Neuroscience. 2017 Sep 17;359:224-247. doi: 10.1016/j.neuroscience.2017.07.031. Epub 2017 Jul 25.
Many clinical studies have reported on the benefits of exercise therapy in patients with Parkinson's disease (PD). Exercise cannot stop the progression of PD or facilitate the recovery of dopamine (DA) neurons in the substantia nigra pars compacta (SNpc) (Bega et al., 2014). To tease apart this paradox, we utilized a progressive MPTP (1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine) mouse model in which we initiated 4weeks of treadmill exercise after the completion of toxin administration (i.e., restoration). We found in our MPTP/exercise (MPTP+EX) group several measures of gait function that recovered compared to the MPTP only group. Although there was a small recovery of tyrosine hydroxylase (TH) positive DA neurons in the SNpc and terminals in the striatum, this increase was not statistically significant. These small changes in TH could not explain the improvement of motor function. The MPTP group had a significant 170% increase in the glycosylated/non-glycosylated dopamine transporter (DAT) and a 200% increase in microglial marker, IBA-1, in the striatum. The MPTP+EX group showed a nearly full recovery of these markers back to the vehicle levels. There was an increase in GLT-1 levels in the striatum due to exercise, with no change in striatal BDNF protein expression. Our data suggest that motor recovery was not prompted by any significant restoration of DA neurons or terminals, but rather the recovery of DAT and dampening the inflammatory response. Although exercise does not promote recovery of nigrostriatal DA, it should be used in conjunction with pharmaceutical methods for controlling PD symptoms.
许多临床研究都报道了运动疗法对帕金森病(PD)患者的益处。运动并不能阻止PD的进展,也不能促进黑质致密部(SNpc)中多巴胺(DA)神经元的恢复(贝加等人,2014年)。为了厘清这一矛盾,我们使用了一种渐进性1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)小鼠模型,在毒素给药完成后(即恢复阶段)开始进行为期4周的跑步机运动。我们发现,与仅接受MPTP处理的组相比,我们的MPTP/运动(MPTP+EX)组的多项步态功能指标有所恢复。虽然SNpc中酪氨酸羟化酶(TH)阳性DA神经元及纹状体终末有少量恢复,但这种增加在统计学上并不显著。TH的这些微小变化无法解释运动功能的改善。MPTP组纹状体中糖基化/非糖基化多巴胺转运体(DAT)显著增加了170%,小胶质细胞标志物离子钙结合衔接分子1(IBA-1)增加了200%。MPTP+EX组这些标志物几乎完全恢复到了溶剂对照组水平。运动使纹状体中谷氨酸转运体1(GLT-1)水平升高,纹状体脑源性神经营养因子(BDNF)蛋白表达无变化。我们的数据表明,运动恢复并非由DA神经元或终末的任何显著恢复所引发,而是DAT的恢复以及炎症反应的减弱所致。虽然运动并不能促进黑质纹状体DA的恢复,但它应与控制PD症状的药物方法联合使用。