Jumblatt M M, Matkin E D, Neufeld A H
Ophthalmic Pharmacology Unit, Eye Research Institute, Boston, MA 02114.
Invest Ophthalmol Vis Sci. 1988 Apr;29(4):586-93.
Cultured rabbit corneal endothelial cells elongate when grown in the presence of epidermal growth factor (EGF) and indomethacin (INDO); whereas maintenance of the differentiated polygonal cell shape is apparently dependent upon endogenous synthesis of prostaglandin E2 (PGE2). In the current study, the authors demonstrate morphological changes in phenotypically altered cells and identify two intracellular pathways which interdependently regulate endothelial cells. Morphometric and mitotic analyses of cultures treated with a variety of pharmacological agents indicate that both protein kinases A- and C-dependent pathways regulate cell shape and cell division in corneal endothelial cells. Marked intracellular reorganization is associated with the morphological changes in the endothelial cells. When stained with rhodamine conjugated phallicidin, polygonal endothelial cells have circumferential bands of f-actin at their borders. EGF and/or INDO induce elongation and redistribution of f-actin into a diffuse cytoplasmic reticulum. Transmission electron microscopy demonstrates loss of several characteristic morphological markers for endothelial cells in response to pharmacologically induced elongation. The elongated cells lose intracellular junctions, apical/basal polarity and rough endoplasmic reticulum. These ultrastructural markers and circumferential f-actin bands are restored in cultures supplemented with exogenous PGE2. Modulation of these pathways in vivo may regulate cellular migration and mitosis during wound closure, stress, trauma and with age.
培养的兔角膜内皮细胞在表皮生长因子（EGF）和吲哚美辛（INDO）存在的情况下生长时会伸长；而维持分化的多边形细胞形状显然依赖于前列腺素E2（PGE2）的内源性合成。在当前的研究中，作者展示了表型改变的细胞中的形态变化，并确定了两条相互依赖地调节内皮细胞的细胞内途径。对用多种药理剂处理的培养物进行的形态计量学和有丝分裂分析表明，蛋白激酶A和C依赖性途径均调节角膜内皮细胞的细胞形状和细胞分裂。明显的细胞内重组与内皮细胞的形态变化相关。当用罗丹明偶联的鬼笔环肽染色时，多边形内皮细胞在其边界处有f-肌动蛋白的圆周带。EGF和/或INDO诱导f-肌动蛋白伸长并重新分布到弥漫性细胞质网中。透射电子显微镜显示，响应于药理诱导的伸长，内皮细胞的几种特征性形态学标志物消失。伸长的细胞失去细胞内连接、顶端/基底极性和粗面内质网。在补充有外源性PGE2的培养物中，这些超微结构标志物和圆周f-肌动蛋白带得以恢复。体内这些途径的调节可能在伤口愈合、应激、创伤和衰老过程中调节细胞迁移和有丝分裂。
