Gu Naibing, Rao Chunguang, Tian Ye, Di Zhengli, Liu Zhiqin, Chang Mingze, Lei Hui
Department of Neurology, The Central Hospital of Xi'an, Xi'an, China.
Department of Neurology, The Central Hospital of Xi'an, Xi'an, China.
J Stroke Cerebrovasc Dis. 2014 Nov-Dec;23(10):2598-2606. doi: 10.1016/j.jstrokecerebrovasdis.2014.05.032. Epub 2014 Oct 3.
Excessive inflammation and apoptosis contribute to the pathogenesis of ischemic brain damage. Nuclear factor-kappa B (NF-κB) is considered to be a key protein complex involved in this cascade of events. The aim of the present study was to clarify the protection mechanism of the mesenchymal stem cells (MSCs).
Lewis rats (N = 90) were randomly assigned to three groups: (1) the sham-operated group; (2) the saline group, in which the animals underwent rat transient middle cerebral artery occlusion (tMCAO, for 2 hours) and were treated with saline through the tail vein; and (3) the MSCs group, in which the animals underwent tMCAO (for 2 hours) and were infused with cultured human MSCs (4 × 10(6)/0.4 ml PBS) through the tail vein. At days 1 and 3 post-MSCs infusion, real-time PCR, and Western blot, immunohistochemical analyses were applied for tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and P-IKKβ, p53, and B-cell lymphoma 2 (Bcl-2) expression levels.
TNF-α, IL-1β messenger RNA (mRNA) and P-IκB-α, P-IKKβ, p53 protein expression levels were significantly increased in the saline group compared with the sham group. However, IκB-α and Bcl-2 protein expression levels were markedly decreased in the saline group. After injection of BrdU(+) MSCs, the expression levels of TNF-α, IL-1β mRNA and P-IκB-α, P-IKKβ, p53 protein were significantly decreased. Contrary to these findings, IκB-α, Bcl-2 protein expression levels were markedly increased. In addition, we found that infarct area was significantly reduced in MSCs group.
These results suggest that MSCs' neuroprotection is attributable to its anti-inflammatory and antiapoptotic effect through inhibition of NF-κB.
过度的炎症反应和细胞凋亡参与了缺血性脑损伤的发病机制。核因子-κB（NF-κB）被认为是参与这一系列事件的关键蛋白复合物。本研究旨在阐明间充质干细胞（MSCs）的保护机制。
将90只Lewis大鼠随机分为三组：（1）假手术组；（2）生理盐水组，该组动物接受大鼠短暂性大脑中动脉闭塞（tMCAO，持续2小时），并通过尾静脉注射生理盐水；（3）间充质干细胞组，该组动物接受tMCAO（持续2小时），并通过尾静脉注入培养的人MSCs（4×10⁶/0.4 ml PBS）。在注入MSCs后的第1天和第3天，应用实时PCR、蛋白质免疫印迹和免疫组织化学分析检测肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）以及磷酸化IκB激酶β（P-IKKβ）、p53和B细胞淋巴瘤2（Bcl-2）的表达水平。
与假手术组相比，生理盐水组中TNF-α、IL-1β信使核糖核酸（mRNA）以及磷酸化IκB-α（P-IκB-α）、P-IKKβ、p53蛋白的表达水平显著升高。然而，生理盐水组中IκB-α和Bcl-2蛋白的表达水平明显降低。注射BrdU（+）MSCs后，TNF-α、IL-1β mRNA以及P-IκB-α、P-IKKβ、p53蛋白的表达水平显著降低。与这些结果相反，IκB-α、Bcl-2蛋白的表达水平明显升高。此外，我们发现间充质干细胞组的梗死面积显著减小。
这些结果表明，间充质干细胞的神经保护作用归因于其通过抑制NF-κB产生的抗炎和抗凋亡作用。
