Hosoki Akiko, Oku Hidehiro, Horie Taeko, Kida Teruyo, Sugiyama Tetsuya, Nakamura Kimitoshi, Ikeda Tsunehiko
1 Department of Ophthalmology, Osaka Medical College , Takatsuki, Osaka, Japan .
2 Nakamura Eye Clinic , Nagano, Japan .
J Ocul Pharmacol Ther. 2015 Oct;31(8):476-81. doi: 10.1089/jop.2014.0117. Epub 2015 Jun 19.
Müller cells are dedifferentiated after retinal injuries and are transformed into nestin-positive progenitor cells that play crucial roles in remodeling. The purpose of this study was to determine the changes in the expression of nestin, CD44 (a receptor of hyaluronan), vascular endothelial growth factor (VEGF), and glutamine sythetase in cultured Müller cells after dedifferentiation by basic fibroblast growth factor (bFGF) and insulin.
Cells from a rat retinal Müller cell line (TR-MUL5) and from primary rat retinal Müller cells were grown in culture. The cells were incubated in various concentrations of bFGF (1.0, 10, 100 ng/mL) with or without insulin (5 μM) for 48 h. Changes in the expression of nestin, CD44, VEGF, and glutamine synthetase were determined by immunoblot and immunohistochemistry.
Exposure of TR-MUL5 cells to 10 ng/mL of bFGF led to the maximum increase in nestin by 1.5-fold, whereas the exposure had no effects on the expression of CD44. Addition of insulin (5 μM) to the bFGF significantly increased the CD44 level in TR-MUL5 cells by 1.4-fold. Immunohistochemistry showed that the combined treatments also upregulated the expression of nestin and CD44 in primary retinal Müller cells. Immunoblot analyses showed that exposure to bFGF and insulin caused significant increases of nestin (4.9-fold), CD44 (3.4-fold), and VEGF (1.44-fold) and decreases in glutamine synthetase (0.7-fold).
The inflammation and angiogenesis that develop after retinal injuries may be due to an upregulation of CD44 and VEGF by the dedifferentiated Müller cells.
视网膜损伤后，穆勒细胞去分化并转化为巢蛋白阳性的祖细胞，这些祖细胞在重塑过程中发挥关键作用。本研究的目的是确定碱性成纤维细胞生长因子（bFGF）和胰岛素诱导培养的穆勒细胞去分化后，巢蛋白、CD44（透明质酸受体）、血管内皮生长因子（VEGF）和谷氨酰胺合成酶表达的变化。
培养大鼠视网膜穆勒细胞系（TR-MUL5）和原代大鼠视网膜穆勒细胞。将细胞在不同浓度的bFGF（1.0、10、100 ng/mL）中，添加或不添加胰岛素（5 μM）孵育48小时。通过免疫印迹和免疫组织化学法测定巢蛋白、CD44、VEGF和谷氨酰胺合成酶表达的变化。
TR-MUL5细胞暴露于10 ng/mL的bFGF导致巢蛋白最大增加1.5倍，而该暴露对CD44的表达无影响。向bFGF中添加胰岛素（5 μM）可使TR-MUL5细胞中的CD44水平显著增加1.4倍。免疫组织化学显示，联合处理也上调了原代视网膜穆勒细胞中巢蛋白和CD44的表达。免疫印迹分析表明，暴露于bFGF和胰岛素会导致巢蛋白（4.9倍）、CD44（3.4倍）和VEGF（1.44倍）显著增加，而谷氨酰胺合成酶减少（0.7倍）。
视网膜损伤后发生的炎症和血管生成可能是由于去分化的穆勒细胞上调了CD44和VEGF。
