BIOSYNTHESIS OF TYPE-IV COLLAGEN BY CULTURED RAT SCHWANN-CELLS
BIOSYNTHESIS OF TYPE-IV COLLAGEN BY CULTURED RAT SCHWANN-CELLS
复制标题
DOI：
10.1083/jcb.97.2.473
复制
发表时间：
1983-01-01
影响因子：
7.8
通讯作者：
BUNGE, RP
中科院分区：
文献类型：
--
作者：
CAREY, DJ;ELDRIDGE, CF;BUNGE, RP
有证据表明大鼠雪旺细胞合成并分泌IV型前胶原。对雪旺细胞和神经元的原代培养物进行代谢标记，并通过 SDS PAGE [十二烷基硫酸钠聚丙烯酰胺凝胶电泳] 进行分析，揭示了这些培养物的培养基中存在一对紧密间隔的多肽，这些多肽易于被纯化的细菌胶原酶消化，与大鼠壁内胚层细胞分泌的 IV 型前胶原共迁移，并被针对小鼠 IV 型胶原的抗体特异性免疫沉淀。代谢标记的培养基或细胞层的有限胃蛋白酶消化产生了pro-α1(IV)链的胃蛋白酶抗性片段特征。在标记前立即从培养物中去除神经元细胞体并不会减少培养基中检测到的 IV 型前胶原的量。这表明雪旺细胞而不是神经元负责合成 IV 型前胶原。显然，IV 型原胶原是雪旺细胞胞外基质的主要成分，基于其存在于去污剂不溶性基质制剂中，其存在于培养物的细胞层中，其可以通过用细菌胶原酶或胰蛋白酶短暂处理而去除，以及通过抗 IV 型胶原抗体对雪旺细胞-神经元培养物进行阳性免疫荧光。当雪旺细胞在没有神经元的情况下维持时，IV 型前胶原的分泌显着减少。这一观察结果可能解释了先前报道的发现，即雪旺细胞仅在与神经元共培养时才组装基底层。
Evidence was obtained that rat Schwann cells synthesize and secrete type IV procollagen. Metabolic labeling of primary cultures of Schwann cells plus neurons and analysis by SDS PAGE [sodium dodecyl sulfate polyacrylamide gel electrophoresis] revealed the presence of a closely spaced pair of polypeptides in the medium of these cultures that were susceptible to digestion by purified bacterial collagenase, that co-migrated with type IV procollagen secreted by rat parietal endoderm cells, and were specifically immunoprecipitated by antibodies against mouse type IV collagen. Limited pepsin digestion of metabolically labeled medium or cell layers produced a pepsin-resistant fragment characteristic of pro-.alpha.1(IV) chains. Removal of neuronal cell bodies from the cultures immediately before labeling did not reduce the amount of type IV procollagen detected in the medium. This indicated that Schwann cells, not neurons, were responsible for synthesis of type IV procollagen. Apparently, type IV procollagen is a major constituent of the Schwann-cell extracellular matrix based upon its presence in a detergent-insoluble matrix preparation, its presence in the cell layer of the cultures in a state in which it can be removed by brief treatment with bacterial collagenase or tryspin, and by positive immunofluorescence of Schwann cell-neuron cultures with anti-type-IV collagen antibodies. Secretion of type IV procollagen was substantially reduced when Schwann cells were maintained in the absence of neurons. This observation may account for the previously reported finding that Schwann cells assemble a basal lamina only when co-cultured with neurons.