cyclin-d1 and Retinal-Detachment

The roles of the extracellular signal-regulated kinase (ERK) pathway in the expression of cyclin D1 and p27(KIP1), the phosphorylation of p27(KIP1), and proliferation activity were examined after retinal detachment.. Normal eyes and eyes at 15 min, 2 and 4 days after retinal detachment in C57Bl6 mice were examined by immunohistochemistry using anti-phosphorylated (p) ERK1/2, anti-cyclin D1, anti-p27(KIP1), anti-p27(KIP1) phosphorylated at serine 10 (S10-phospho-p27), and anti-proliferating cell nuclear antigen (PCNA) antibodies with or without treatment with a specific ERK inhibitor, PD98059. Mouse Müller cells were isolated and examined for alteration of p27(KIP1) and cyclin D1 after exposure of basic fibroblast growth factor (bFGF) with and without treatment of PD98059 using Western blotting.. In the normal retina, nuclear immunoreactivity for p27(KIP1), but not S10-phospho-p27 or pERK1/2, was observed in the middle sublayer of the inner nuclear layer (INL), where Müller glial cells are situated. At 15 min after the retinal detachment, p27(KIP1), S10-phospho-p27 and pERK1/2-positive nuclei were noted in the INL, whereas immunoreactivity for pERK1/2 or S10-phospho-p27 was not observed after treatment with PD98095. Cyclin D1 was induced in the INL 2 days after the retinal detachment, and the induction was inhibited by PD98059. At 4 days after the detachment, p27(KIP1) immunoreactivity was not observed, and cyclin D1 and PCNA were expressed. The disappearance of p27(KIP1) was suppressed, whereas expression of cyclin D1 and PCNA was not observed in mice treated with PD98059. Exposure of bFGF relatively decreased the expression level of p27(KIP1) and increased the level of cyclin D1 in mouse Müller cells, compared with control level. Induction of cyclin D1 and decrease in p27(KIP1) were inhibited with treatment of PD98059.. Phosphorylation of ERK and expression of p27(KIP1) and cyclin D1 are involved in the proliferation of Müller cells after retinal detachment.

Topics: Animals; Blotting, Western; Calcium-Calmodulin-Dependent Protein Kinases; Cell Culture Techniques; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Disease Models, Animal; Flavonoids; Fluorescent Antibody Technique, Indirect; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neuroglia; Phosphorylation; Proliferating Cell Nuclear Antigen; Retinal Detachment; Serine

To examine the expression of the p27(KIP1), cyclin D1, and proliferating cell nuclear antigen (PCNA) in the retina and retinal pigment epithelium (RPE) after retinal detachment.. Normal eyes and eyes at 2 or 4 days after retinal detachment with the C57B16 mouse were analyzed by immunocytochemistry using anti-p27(KIP1), anti-cyclin D1, and anti-proliferating cell nuclear antigen (PCNA) antibodies as well as anti-glutamate synthetase (GS) antibody.. The p27(KIP1) positive nuclei were distributed in the inner nuclear layer (INL) and the RPE of the normal mice eye. In the INL, p27(KIP1) was detected in the middle sublayer, where the nuclei of glutamate synthetase positive Müller cells were situated. In contrast, cyclin D1 was not detected either in the retina or in the RPE. At 2 and 4 days after the retinal detachment, RPE cells under the detached retina were negative for p27(KIP1) and positive for cyclin D1 and PCNA. In the INL of the detached retina, p27(KIP1) was detected after 2 days, but was not detected after 4 days. In contrast, PCNA was not detected in the INL after 2 days, but was detected after 4 days. Cyclin D1 was detected in the middle sublayer of the INL at both 2 and 4 days after the retinal detachment.. These results suggested that degradation of p27(KIP1) and expression of cyclin D1 was involved in the proliferation of the Müller cells as well as RPE cells after retinal detachment.

Topics: Animals; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Fluorescent Antibody Technique, Indirect; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence; Pigment Epithelium of Eye; Proliferating Cell Nuclear Antigen; Retina; Retinal Detachment; Tumor Suppressor Proteins