NG2 proteoglycan-expressing cells of the adult rat brain: Possible involvement in the formation of glial scar astrocytes following stab wound
NG2 proteoglycan-expressing cells of the adult rat brain: Possible involvement in the formation of glial scar astrocytes following stab wound
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作者：
Alonso, G
成人中枢神经系统的刺伤损伤引起强烈的增殖反应，随后形成致密的星形胶质瘢痕。为了确定构成胶质瘢痕的星形胶质细胞的来源，在损伤后3 h或6 d分别给予细胞增殖标志物溴脱氧尿苷（BrdU）。在BrdU给药后3小时，标记核通常与NG2（+）细胞或小胶质细胞/巨噬细胞相关，但很少与表达胶质纤维酸性蛋白（GFAP）的星形胶质细胞相关。相比之下，6天后，许多brdu标记的细胞核与位于病变边缘的星形胶质细胞相关。将绿色荧光蛋白（GFP）的病毒载体注射到病变腔内后，分别在注射后1天和6天固定病变动物时，在NG2或GFP标记的细胞内优先检测到GFP。结合检测病变区域细胞内的胶质标记物发现，成熟星形胶质细胞的标记物NG2（+）位于病变边缘，虽然它们很少表达GFAP，但它们经常表达nestin和vimentin，即未成熟星形胶质细胞的两种标记物。最后，用地塞米松对损伤大鼠进行慢性治疗，发现可以抑制损伤区域内NG2（+）细胞的增殖，并随后改变致密星形胶质瘢痕的形成。综上所述，这些数据强烈表明，在手术损伤后，构成胶质瘢痕的星形胶质细胞至少有一部分来自于原有的NG2（+）细胞。(C) 2004 Wiley-Liss, Inc。
Stab wound lesion to the adult central nervous system induces strong proliferative response that is followed by the formation of a dense astroglial scar. In order to determine the origin of those astrocytes composing the glial scar, the cell proliferation marker bromodeoxyuridine (BrdU) was administered to lesioned rats that were fixed 3 h or 6 days later. At 3 h after the BrdU administration, labeled nuclei were frequently associated with either NG2(+) cells or microglia/macrophages, but rarely with astrocytes expressing glial fibrillary acidic protein (GFAP). Six days later, by contrast, numerous BrdU-labeled nuclei were associated with astrocytes located along the lesion borders. After the injection of a viral vector of the green fluorescent protein (GFP) into the lesional cavity, GFP was preferentially detected within NG2- or GFAP-labeled cells when lesioned animals were fixed 1 or 6 days after the injections, respectively. The combined detection of glial markers within cells present in the lesioned area indicated that, although they rarely express GFAP, the marker of mature astrocytes, NG2(+) cells located along the lesion borders frequently express nestin and vimentin, i.e., two markers of immature astrocytes. Lastly, chronic treatment of lesioned rats with dexamethasone was found to inhibit the proliferation of NG2(+) cells present within the lesioned area and to subsequently alter the formation of a dense astroglial scar. Taken together, these data strongly suggest that following a surgical lesion, at least a portion of the astrocytes that constitute the glial scar are issued from resident NG2(+) cells. (C) 2004 Wiley-Liss, Inc.