Department of Orthopedic Surgery, Cleveland Clinic, Cleveland, OH, USA.
Spine (Phila Pa 1976). 2009 Jul 15;34(16):1631-7. doi: 10.1097/BRS.0b013e3181ab1f68.
After undergoing L5 hemilaminectomy, chromic gut suture was placed onto the DRG and the animals were sacrificed at various time-points.
The purpose of this study was to identify the effects of inflammation on satellite cells (SCs) of the dorsal root ganglion (DRG) by analyzing glial fibrillary acidic protein (GFAP) expression in of the DRG at various time points.
SCs are neuroglial cells that closely interact with nerve cells of the DRG. The role of SC remains unknown GFAP expression increases in response to CNS injury. Loss of GFAP has impaired Schwann cell proliferation and delayed nerve regeneration after injury.
Sixty rats underwent a left L5 hemilaminectomy. In Group I, a chromic-gut suture was place topically on the DRG (n = 30), Group II was the sham surgery group (n = 30). DRGs were harvested at 6, 24, 48, 72 hours, and 7 days after surgery. In Group III, 6 control rats were killed and their bilateral L5 DRG harvested. The harvested DRG were analyzed using light microscopy for SC immunoreactivity, using GFAP, HIS-36, TNF-alpha, IL-1alpha, IL-1beta, IL-6 monoclonal antibodies.
One hundred thirty-two DRGs were harvested for analysis. Naïve controls and neurons did not express GFAP. The SC sheath expressed GFAP as early as 6 hours postchromic gut application. In Group I, GFAP expression steadily increased after chromic-gut application with 100% of SC soma and SC sheaths being GFAP positive at 7 days. The contralateral DRG demonstrated delayed GFAP expression, with 83% of SC soma and SC sheaths were GFAP positive at 7 days. In Group II, 89% of sacs expressed GFAP by 7 compared to 79% in the contralateral undisturbed DRG.
Under physiologic conditions, the expression of GFAP by SCs is undetectable. As the inflammatory process develops, GFAP expression steadily increases with 100% of SCs being GFAP immunoreactive 7 days after chromic gut application. These data suggest that SCs are the primary source of GFAP in the DRG. We hypothesize that SC play an important role in the response to early inflammatory injury.
在进行 L5 半椎板切除术之后，铬制肠线被放置到背根神经节（DRG）上，并且在不同时间点对动物进行了安乐死。
本研究的目的是通过分析 DRG 中神经胶质纤维酸性蛋白（GFAP）的表达，来确定炎症对 DRG 卫星细胞（SCs）的影响。
SCs 是与 DRG 神经细胞密切相互作用的神经胶质细胞。SCs 的作用仍然未知，GFAP 的表达会对中枢神经系统损伤做出反应而增加。GFAP 的缺失会损害施万细胞的增殖，并延迟损伤后的神经再生。
60 只大鼠接受了左侧 L5 半椎板切除术。在 I 组中，铬制肠线被局部放置在 DRG 上（n = 30），II 组为假手术组（n = 30）。手术后 6、24、48、72 小时和 7 天采集 DRG。在 III 组中，6 只对照大鼠被处死，双侧 L5 DRG 被采集。使用针对 SC 免疫反应性的 GFAP、HIS-36、TNF-alpha、IL-1alpha、IL-1beta、IL-6 单克隆抗体，通过光镜对采集的 DRG 进行分析。
共采集了 132 个 DRG 进行分析。未成熟的对照神经元不表达 GFAP。SCs 鞘在铬制肠线应用后 6 小时就开始表达 GFAP。在 I 组中，GFAP 的表达在铬制肠线应用后稳步增加，7 天时 100%的 SC 体和 SC 鞘呈 GFAP 阳性。对侧 DRG 表现出延迟的 GFAP 表达，7 天时 83%的 SC 体和 SC 鞘呈 GFAP 阳性。在 II 组中，7 天时 89%的囊表达 GFAP，而对侧未受干扰的 DRG 中 79%表达 GFAP。
在生理条件下，SCs 中 GFAP 的表达无法检测到。随着炎症过程的发展，GFAP 的表达稳步增加，7 天后 100%的 SC 呈 GFAP 免疫反应性。这些数据表明，SCs 是 DRG 中 GFAP 的主要来源。我们假设 SC 在对早期炎症损伤的反应中起重要作用。
