Osteopontin inhibits osmotic swelling of retinal glial (Müller) cells by inducing release of VEGF

Identification of a Novel Neurotrophic Factor from Primary Retinal Müller Cells Using Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC)

“…In that study, Del Rio et al induced SPP1 se- cretion by stimulating RMGs with glial-cell-derived neurotrophic factor, and its neurotrophic activity was demonstrated on primary porcine PRs and Pde6b rd1 mouse mutant retinal explants (10). Wahl et al later demonstrated that RMGderived SPP1 might exert its neuroprotective effect by preventing cytotoxic RMG swelling (42). The identification of SPP1 in our samples demonstrates the reliability of our proteomic approach.…”

Interactions between osteopontin and vascular endothelial growth factor: Implications for cancer

“…OPN activates a cell-volume regulatory signaling cascade that acts via VEGF production. Upon activation, VEGF stimulates the release of glutamate, ATP and adenosine, which are responsible for the efflux of potassium and chloride ions from these cells, thus stabilizing the transmembrane osmotic gradient [13]. After subarachnoid hemorrhage in the brain, OPN mediates its protective effects on the blood/brain barrier via upregulation of MAP kinase phosphatase 1 (MKP-1) and suppression of MAP kinase.…”

“…Past studies have found that under specific conditions these proteins may be coexpressed [1][2][3][4][5][6][7][8][9][10], OPN can induce VEGF [11][12][13][14][15][16][17][18][19][20][21], or VEGF can induce OPN [22][23][24][25][26][27][28][29][30][31][32], and both molecules can function in synergy. In other cases, OPN and VEGF act mutually independently [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51].…”

Proteins involved in focal adhesion signaling pathways are differentially regulated in experimental branch retinal vein occlusion

“…Extracellular intergrin ligands involved in focal adhesion also included the multifunctional protein osteopontin. Studies based on models of experimental retinal ischemia-reperfusion by Wahl et al (2013) and Chidlow et al (2008) suggest that osteopontin is involved in the inflammatory response that follows after retinal vascular disease. Wahl et al (2013) demonstrated that osteopontin inhibits osmotic swelling of retinal glial Müller cells by inducing release of VEGF.…”

“…Studies based on models of experimental retinal ischemia-reperfusion by Wahl et al (2013) and Chidlow et al (2008) suggest that osteopontin is involved in the inflammatory response that follows after retinal vascular disease. Wahl et al (2013) demonstrated that osteopontin inhibits osmotic swelling of retinal glial Müller cells by inducing release of VEGF. Chidlow et al (2008) identified an increased expression of osteopontin in retinal microglia following retinal ischemia and suggested that retinal injury with an inflammatory component leads to an upregulation of osteopontin in microglia and hypothesized that osteopontin regulates or is regulated by proinflammatory mediators.…”