Mitogen-Activated Protein Kinase-Signaling Stimulates Muller Glia to Proliferate in Acutely Damaged Chicken Retina

作者：Fischer Andy J^*; Scott Melissa A; Tuten William

来源：GLIA, 2009, 57(2): 166-181.

DOI：10.1002/glia.20743

• retina
• insulin
• FGF2
• Egr1
• cFos
• pCREB
• progenitor

Muller glia in the mature retina have the capacity to become progenitor-like cells in a many different vertebrate classes. The cell-signaling pathways that control the ability of mature Muller glia to become progenitor-like cells remain uncertain. The purpose of this study was to investigate the roles of the Mitogen-Activated Protein Kinase (MAPK) pathway in regulating the activity of Muller glia in the chicken retina. In response to acute retinal damage, we found that Muller glia accumulated phosphorylated ERK1/2 and phospho-CyclicAMP Response Element Binding-protein (pCREB), and transiently expressed immediate early genes, cFos and Egr1, that are known to be downstream of MAPK-signaling. Egr1 and pCREB were normally expressed by retinal progenitors in the circumferential marginal zone (CMZ), whereas cFos and pERK1/2 were not. In addition, small molecule inhibitors of MEK (UO126) and the FGF-receptor (SU5402) suppressed the proliferation of Muller glia-derived progenitor-like cells. These inhibitors suppressed the accumulation of Egr1 and pCREB, whereas levels of cFos were unaffected in the glial cells. These findings suggest that Egr1 and pCREB are downstream of the signaling cascade activated by FGF-receptors and ERK1/2. Further, our findings suggest that Egr1 and pCREB may promote glial proliferation. We propose that activation of both the FGF-receptor and ERK1/2-pathway is required for the proliferation and transdifferentiation of Muller glia into progenitor-like cells.

• 出版日期2009-1-15