Axon-glia interactions regulate ECM patterning in the postnatal rat olfactory bulb
Axon-glia interactions regulate ECM patterning in the postnatal rat olfactory bulb
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DOI：
10.1523/jneurosci.14-10-06121.1994
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发表时间：
1994-10
期刊：
影响因子：
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通讯作者：
Ml Gonzalez;J. Silver
中科院分区：
文献类型：
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作者：
Ml Gonzalez;J. Silver
有人提出，含有 6-硫酸软骨素蛋白聚糖 (C-6S-PG) 和腱蛋白 (TN) 的抑制性 ECM 在传入纤维到达后均匀地出现在 OB 的核心中，有助于将向内生长的嗅轴突定位在预期肾小球层 (GL) 中（Gonzalez 和 Silver，1992；Gonzalez 等人，1993）。后来，与星形胶质细胞相关的类似 ECM 将轴突肾小球包裹在环中，这表明轴突可能控制精确的 ECM 模式。问题仍然是每个轴突肾小球周围的基质环模式的形成是基质生成细胞的固有特性还是对轴突发育的反应。为了确定 OB 中神经胶质相关基质的组织是否依赖于轴突的存在，我们研究了向出生后大鼠的嗅上皮单侧注射神经毒素的效果。使用嗅觉标记蛋白 (OMP)、β-微管蛋白 (TUJ1) 抗体和尼氏染色，我们发现在神经毒素给药后 5 和 10 天，注射侧肾小球数量平均减少 77.0%。同时，我们观察到 TN/C-6S-PG 环和肾小球周围细胞仅存在于剩余的少量肾小球周围。在其他地方，GL 中的 ECM 表达和肾小球周围细胞结构更加混乱。胶质纤维酸性蛋白（GFAP）的模式没有显着变化。我们发现，随着嗅轴突在 20 天时重新形成，OMP 染色、β-微管蛋白免疫反应性和肾小球周围细胞以肾小球样模式重新形成。当轴突末端的肾小球状集合重新出现时，TN/C-6S-PG 免疫反应性也在新轴突束周围的环中重新出现。同样，在这个后期阶段，两侧的 GFAP 表达相似。在我们之前的研究中（Gonzalez et al., 1993），我们认为肾小球的初始总体定位可能由TN/C-6S-PG的整体定位控制。在本研究中，我们认为肾小球周围精确环形图案中 TN/C-6S-PG 的形成似乎取决于成束嗅觉轴突的存在。讨论了可以解释神经毒素治疗后肾小球内部发生的 ECM 表达动态变化的各种机制。
It has been suggested that an inhibitory ECM containing chondroitin-6- sulfate proteoglycan (C-6S-PG) and tenascin (TN), which appears homogeneously in the core of the OB following afferent fiber arrival, helps position ingrowing olfactory axons in the prospective glomerular layer (GL) (Gonzalez and Silver, 1992; Gonzalez et al., 1993). Later, a similar ECM associated with astrocytes envelopes axonal glomeruli in rings, suggesting that axons may control the precise ECM patterning. The question remains whether formation of the matrix ring pattern around each axonal glomerulus is an intrinsic property of the matrix- producing cells or a response to developing axons. To determine if the organization of glial associated matrix in the OB was dependent on the presence of axons, we studied the effect of unilateral injection of a neurotoxin into the olfactory epithelium of postnatal rats. Using olfactory marker protein (OMP), beta-tubulin (TUJ1) antibodies, and Nissl staining, we found that at 5 and 10 d following neurotoxin administration the number of glomeruli decreased by an average of 77.0% in the injected side. At the same time, we observed that the TN/C-6S-PG rings and periglomerular cells were present only around the remaining small number of glomeruli. Elsewhere, ECM expression and the periglomerular cell configuration were more disorganized in the GL. The pattern of glial fibrillary acidic protein (GFAP) did not change significantly. We found that OMP staining, beta-tubulin immunoreactivity, and periglomerular cells reformed in a glomerular- like pattern as the olfactory axons reformed by 20 d. As the glomeruli- shaped collection of axon terminals reappeared, TN/C-6S-PG immunoreactivity also reoccurred in rings around the new axon bundles. Again, at this later stage, the expression of GFAP was similar in both sides. In our previous study (Gonzalez et al., 1993), we suggested that the initial gross positioning of glomeruli may be controlled by the overall positioning of TN/C-6S-PG. In the present study, we suggest that the formation of TN/C-6S-PG in the precise ring pattern around glomeruli appears to be dependent upon the presence of bundled olfactory axons. Various mechanisms are discussed that may explain the dynamic change in ECM expression that occurs inside the glomerulus after the neurotoxin treatment.