The relationship between protein kinase C and the phagocytic fuction of human pigment epithelium cells

• 1、Department of Ophthalmology，the First Clinical College of China Medical University

Abstract：Objective To investigate the role of protein kinase C (PKC) in the phagocytic process of human retinal pigment epithelium (HRPE) cells by measuring this two indexes in the specific and nonspecific phagocytic process. Method The cultured HRPE cells were incubated with 1×107 ml-1rod outer segments (ROS) or leatex beads(LB) at 37℃,then were rinsed the at different incubation time (5min-48h) to terminate the phagocysis.The kinetics of phagocytosis was measured by double- fluorescent vital assay.The binding and ingestion of ROS or LB were proved by scanning and transmission electron microscope. PKC activity was measured by counting γ-32P radio-activity with liquid scintillation. Result In specific phagocytosis of HRPE cells ，the binding of ROS happened at 15 min of incubation；the activity of PKC （both in cytoplasm and on membrane）decreased at 5 min，but both indexes reach their minimum level at 24h. In nonspecific phagocytosis of HRPE cells ，the binding of LB by HRPE cells happened at 90 min；on the other hand, when HRPE cells were incubated with LB, the activity of PKC（both in cytoplasm and on membrane） was stable during all incubation periods(p＞0.05). Conclusion PKC are very important for sustaining the ingestion process in specific phagocytosis of HRPE cells, but has no direct realationship with nonspecific phagocytosis .Furthermore, PKC activity in HRPE cells decreases during specific phagocytosis.

Keywords： retinal pigment epithelium cell； phagocytosis； protein kinase C.