MITOGENICITY OF BRAIN AXOLEMMA MEMBRANES AND SOLUBLE FACTORS FOR DORSAL-ROOT GANGLION SCHWANN-CELLS
MITOGENICITY OF BRAIN AXOLEMMA MEMBRANES AND SOLUBLE FACTORS FOR DORSAL-ROOT GANGLION SCHWANN-CELLS
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DOI：
10.1002/jcb.1982.240180405
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发表时间：
1982-01-01
影响因子：
4
通讯作者：
GLASER, L
中科院分区：
文献类型：
--
作者：
CASSEL, D;WOOD, PM;GLASER, L
描述了用于制备源自背根神经节 [DRG] 的雪旺细胞的改进程序，该细胞对各种有丝分裂原高度敏感。在这些条件下，细胞不仅对神经突有丝分裂原作出反应，而且对垂体提取物、二丁酰cAMP和霍乱毒素作出反应，这些物质被证明是来自坐骨神经的雪旺细胞的良好有丝分裂原。因此，这些不同的雪旺细胞制剂对有丝分裂原的反应差异得到了协调。牛脑轴膜对雪旺细胞具有高度促有丝分裂作用。在与[3H]胸苷一起孵育24小时期间，添加轴膜使雪旺细胞的有丝分裂指数从0.5-2%增加到30-50%。半最大效应在.apprx处获得。每微孔含有 0.4 μg 轴膜蛋白，含有 2-4 倍。 103个细胞。轴膜丝裂原似乎是一种完整的膜蛋白，在各种离子条件下仍与膜结合，但可以用脱氧胆酸盐以部分活性形式提取。与 DRG 神经突有丝分裂原一样，轴突的有丝分裂活性被胰蛋白酶处理消除。然而，与神经突制备物不同，轴突的有丝分裂活性仅通过热处理部分失活（60-70%失活）。轴膜和神经突膜的促有丝分裂活性之间的显着差异在于，轴膜膜在确定的无血清培养基（N-2）中不能刺激雪旺细胞增殖，而神经突在该培养基中表现出显着的促有丝分裂活性。指出了 DRG 神经突和脑轴突之间可能存在的差异，无论是在有丝分裂原本身还是在负责膜和细胞之间识别的表面成分上。
Improved procedures are described for preparing Schwann cells derived from dorsal root ganglia [DRG] that are highly responsive to various mitogens. Under these conditions, the cells respond not only to the neurite mitogen but also to pituitary extracts, dibutyryl cAMP and cholera toxin, shown to be good mitogens for Schwann cells derived from sciatic nerve. Discrepancies in the response of these different Schwann cell preparations to mitogens are thus reconciled. Bovine brain axolemma was highly mitogenic for Schwann cells. The mitotic index of Schwann cells was increased by the addition of axolemma from 0.5-2% to 30-50% during 24-h incubation with [3H]thymidine. Half maximal effect was obtained at .apprx. 0.4 .mu.g axolemma protein per microwell containing 2-4 .times. 103 cells. The axolemma mitogen appears to be an integral membrane protein that remains bound to the membrane under various ionic conditions but can be extracted in a partially active form with deoxycholate. Like the DRG neurite mitogen, the mitogenic activity of axolemma was abolished by trypsin treatment. Unlike the neurite preparation, however, the mitogenic activity of axolemma was only partially inactivated by heat treatment (60-70% inactivation). A significant difference between the mitogenic activity of axolemma membranes and neurite membranes is the fact that axolemma membranes fail to stimulate Schwann cell proliferation in a defined, serum-free medium (N-2), whereas neurites show significant mitogenic activity in this medium. A possible difference between DRG neurites and brain axolemma either in the mitogen itself or surface components responsible for recognition between the membranes and the cells is indicated.