Najam A Sharif1, Terry K Wiernas. 1. Pharmaceutical Products Research, Alcon Research, Ltd, Fort Worth, Texas 76134, USA. naj.sharif@alconlabs.com
Abstract
PURPOSE AND METHODS: Immortalized human corneal epithelial (CEPI-17-CL4) cells were exposed to different concentrations of platelet-activating factor (PAF) and the mobilization of intracellular calcium ([Ca(2+)](i)) was studied using fluorometrics. Additionally, the production of the cytokines [interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha)], and matrix metalloproteinase-1 (MMP-1) and prostaglandin E(2) (PGE(2)) from PAF-stimulated cells was also determined using ELISA assays. RESULTS: While PAF, histamine, and bradykinin stimulated the mobilization of [Ca(2+)](i) in these cells, PAF was the least efficacious. [Ca(2+)](i) mobilization induced by PAF was inhibited by 2 PAF receptor antagonists, PCA-42481 and CV-6209 (both 10 microM), and by a phospholipase C inhibitor, U73122 (60% at 4 microM). PAF increased the production of PGE(2) (with maximum effect at 30 and 100 nM) and GM-CSF (maximum effect at 1 microM) in CEPI-17-CL4 cells. However, PAF did not stimulate the generation of IL-6, IL-8, TNF-alpha, and MMP-1 to any significant level and in a consistent manner. PAF increased the incorporation of [(3)H]-thymidine into CEPI-17-CL4 cells with a maximal effect at 30 nM. CONCLUSIONS: These data indicate that functional PAF receptors are present on CEPI-17-CL4 cells that can activate mobilization of [Ca(2+)](i). Other consequences of PAF receptor activation in CEPI-17-CL4 cells are the generation of PGE(2) and certain proinflammatory cytokines such as GM-CSF, and increasing cell proliferation.
PURPOSE AND METHODS: Immortalized human corneal epithelial (CEPI-17-CL4) cells were exposed to different concentrations of platelet-activating factor (PAF) and the mobilization of intracellular calcium ([Ca(2+)](i)) was studied using fluorometrics. Additionally, the production of the cytokines [interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha)], and matrix metalloproteinase-1 (MMP-1) and prostaglandin E(2) (PGE(2)) from PAF-stimulated cells was also determined using ELISA assays. RESULTS: While PAF, histamine, and bradykinin stimulated the mobilization of [Ca(2+)](i) in these cells, PAF was the least efficacious. [Ca(2+)](i) mobilization induced by PAF was inhibited by 2 PAF receptor antagonists, PCA-42481 and CV-6209 (both 10 microM), and by a phospholipase C inhibitor, U73122 (60% at 4 microM). PAF increased the production of PGE(2) (with maximum effect at 30 and 100 nM) and GM-CSF (maximum effect at 1 microM) in CEPI-17-CL4 cells. However, PAF did not stimulate the generation of IL-6, IL-8, TNF-alpha, and MMP-1 to any significant level and in a consistent manner. PAF increased the incorporation of [(3)H]-thymidine into CEPI-17-CL4 cells with a maximal effect at 30 nM. CONCLUSIONS: These data indicate that functional PAF receptors are present on CEPI-17-CL4 cells that can activate mobilization of [Ca(2+)](i). Other consequences of PAF receptor activation in CEPI-17-CL4 cells are the generation of PGE(2) and certain proinflammatory cytokines such as GM-CSF, and increasing cell proliferation.
Authors: Matheus Correa-Costa; Vinicius Andrade-Oliveira; Tarcio T Braga; Angela Castoldi; Cristhiane F Aguiar; Clarice S T Origassa; Andrea C D Rodas; Meire I Hiyane; Denise M A C Malheiros; Francisco J O Rios; Sonia Jancar; Niels O S Câmara Journal: Lab Invest Date: 2014-02-03 Impact factor: 5.662