Schluesener H, Meyermann R
Institute of Brain Research, University of Tübingen, Germany.
J Neurosci Res. 1995 Dec;42(5):718-23. doi: 10.1002/jnr.490420515.
Defensins are small, cationic, cyclic peptides that are abundantly stored in granules of neutrophils. Defensins non-specifically interact with membranes by forming weakly ion-selective pores. Here we demonstrate immunolocalization of defensin-secreting cells in human brain. Defensins, secreted by activated granulocytes, apparently are not prevented by the blood-brain barrier (BBB) from diffusing across cerebral endothelium to penetrate the neuropil for a considerable distance from the granulocyte. This is in contrast to other neutrophil proteins like the granule-associated enzyme elastase or the cytosolic protein MRP-14, which are strictly localized to the cytoplasm or granules of neutrophils. Thus, defensins, known chemokinetic and chemotactic molecules, display a unique distribution at BBB sites.
防御素是一种小的阳离子环肽，大量储存在中性粒细胞的颗粒中。防御素通过形成弱离子选择性孔与膜进行非特异性相互作用。在此我们展示了人类大脑中分泌防御素的细胞的免疫定位。活化粒细胞分泌的防御素显然不会被血脑屏障（BBB）阻止穿过脑内皮扩散，从而从粒细胞向神经毡穿透相当长的距离。这与其他中性粒细胞蛋白如颗粒相关酶弹性蛋白酶或胞质蛋白MRP - 14形成对比，后者严格定位于中性粒细胞的细胞质或颗粒中。因此，已知具有趋化活性和趋化作用的防御素在血脑屏障部位呈现独特的分布。
