Zhang Jing, Li Yi, Zhang Zheng Gang, Lu Mei, Borneman Jade, Buller Ben, Savant-Bhonsale Smita, Elias Stanton B, Chopp Michael
Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA.
J Cereb Blood Flow Metab. 2009 Jun;29(6):1166-74. doi: 10.1038/jcbfm.2009.41. Epub 2009 Apr 22.
Oligodendrocytes are sensitive to ischemic damage. The Sonic hedgehog (Shh) pathway is critical in oligodendrogenesis; Gli1 is the principal effector of Shh signaling. We investigated oligodendrogenesis and Shh/Gli1 pathway activation after bone marrow stromal cell (BMSC) treatment of stroke in rats. Rats were subjected to the middle cerebral artery occlusion (MCAo). BMSCs have been shown to promote functional recovery post stroke. A therapeutic dose of BMSC (3 x 10(6) cells) treatment was initiated 1 day after MCAo. Immunohistochemistry was carried out to measure the oligodendrocyte progenitor cells, oligodendrocytes, myelin, and expressions of Shh and Gli1 at 14 days after MCAo. Gene expression of Shh and Gli1 was tested at 2 days after MCAo. An in vitro study was used to investigate the effects of BMSC on a premature oligodendrocyte cell line (N20.1 cells). BMSC treatment significantly increased O4(+) oligodendrocytes, MBP(+) area, and bromodeoxyuridine (BrdU)(+), NG2(+), BrdU(+)-NG2(+) cells, and mRNA and protein expressions of Shh and Gli1 in the ipsilateral brain of the MCAo rats than that in phosphate buffered saline (PBS)-treated rats. BMSCs promoted N20.1 cell proliferation and Gli1 mRNA expression, and these effects were abolished by the Shh pathway inhibitor cyclopamine. These data indicate that the BMSC treatment stimulates oligodendrogenesis by activation of the Shh/Gli1 pathway post stroke.
少突胶质细胞对缺血性损伤敏感。音猬因子（Shh）信号通路在少突胶质细胞生成中起关键作用；Gli1是Shh信号的主要效应器。我们研究了骨髓基质细胞（BMSC）治疗大鼠中风后少突胶质细胞生成及Shh/Gli1信号通路的激活情况。大鼠接受大脑中动脉闭塞（MCAo）手术。已有研究表明BMSC可促进中风后的功能恢复。在MCAo术后1天开始给予治疗剂量的BMSC（3×10⁶个细胞）。在MCAo术后14天进行免疫组织化学检测，以测量少突胶质前体细胞、少突胶质细胞、髓鞘以及Shh和Gli1的表达。在MCAo术后2天检测Shh和Gli1的基因表达。采用体外研究来探究BMSC对少突胶质前体细胞系（N20.1细胞）的影响。与磷酸盐缓冲盐水（PBS）处理的大鼠相比，BMSC治疗显著增加了MCAo大鼠同侧脑内O4⁺少突胶质细胞、髓鞘碱性蛋白（MBP）⁺面积以及溴脱氧尿苷（BrdU）⁺、神经胶质抗原2（NG2）⁺、BrdU⁺-NG2⁺细胞，以及Shh和Gli1的mRNA和蛋白表达。BMSC促进了N20.1细胞增殖和Gli1 mRNA表达，而这些作用被Shh信号通路抑制剂环杷明所消除。这些数据表明，BMSC治疗通过激活中风后的Shh/Gli1信号通路刺激少突胶质细胞生成。
