Azzarelli B, Woodburn R, Olivelle S, Kimbro S, Siakotos A, Taylor M, Lee C H, Yen M, Paulsrud J
Department of Pathology, Indiana University Medical Center, Indianapolis 46202.
J Comp Neurol. 1993 Nov 15;337(3):353-65. doi: 10.1002/cne.903370302.
Expression of the Schwann cell phenotype is regulated by signals from the adjoining axon. After axotomy, the Schwann cell ceases the production and maintenance of the myelin sheath and assumes phagocytic properties necessary to digest its own myelin. The molecular mechanisms responsible for this behavior remain unclear. A monoclonal antibody termed BIKS was produced after the immunization of mice with guinea pig lymphoid tissue. This antibody recognizes a cytoplasmic vesicle-associated molecule (A-1 antigen) which is abundant in all tissue macrophages but is also expressed in small amounts in normal Schwann cells. Following axotomy, the A-1 antigen appears to be translocated from a perinuclear site to accumulate in large quantities around myelin ovoids in Schwann cells, as well at the nodes of Ranvier-sites where Wallerian degeneration is known to commence. The level of the antigen remains high when axons are prevented from regeneration. During repair of crush injury, however, the level of antigen drops concomitant with the ingrowth of regenerating axons, suggesting axonal control of A-1 antigen expression.
雪旺细胞表型的表达受相邻轴突发出的信号调控。轴突切断后，雪旺细胞停止髓鞘的产生和维持，并呈现出消化自身髓鞘所需的吞噬特性。导致这种行为的分子机制仍不清楚。在用豚鼠淋巴组织免疫小鼠后，产生了一种名为BIKS的单克隆抗体。这种抗体识别一种与细胞质囊泡相关的分子（A - 1抗原），该分子在所有组织巨噬细胞中都很丰富，但在正常雪旺细胞中也有少量表达。轴突切断后，A - 1抗原似乎从核周部位移位，大量积聚在雪旺细胞的髓鞘卵圆体周围，以及郎飞结部位（已知华勒变性开始的部位）。当轴突再生受阻时，抗原水平仍然很高。然而，在挤压伤修复过程中，随着再生轴突的长入，抗原水平下降，提示轴突对A - 1抗原表达的控制。
