Lewis Geoffrey P, Chapin Ethan A, Byun Jiyun, Luna Gabriel, Sherris David, Fisher Steven K
Neuroscience Research Institute, University of California, Santa Barbara, California 93106-5060, USA.
Invest Ophthalmol Vis Sci. 2009 Sep;50(9):4429-35. doi: 10.1167/iovs.09-3445. Epub 2009 Apr 15.
To test the effect of Palomid 529, an inhibitor of the Akt/mTOR pathway, on Müller cell proliferation, subretinal glial scar formation, and photoreceptor survival after experimental retinal detachment (RD).
Palomid 529 (600 microg) in balanced salt solution or balanced salt solution alone was injected intravitreally immediately after RD into the right eyes of 12 rabbits. Ten micrograms of BrdU was injected intravitreally on day 3. Animals were killed on day 3 or 7, at which time retinal sections were labeled with anti-BrdU to detect dividing cells, with anti-vimentin to identify Müller cells, and with the isolectin B4 to identify microglia and macrophages. Outer nuclear layer (ONL) thickness was measured from fluorescence-labeled nuclear-stained sections. Labeling was imaged using confocal microscopy. Six additional animals received either drug or balanced salt solution injections into normal eyes, and paraffin sections were stained with hematoxylin and eosin.
In the drug-treated eyes there was a significant decrease in the number of anti-BrdU-labeled Müller cells, the number and size of subretinal scars, and the number of isolectin B4-labeled cells. The ONL was also significantly thicker, and there was no evidence of toxic effects.
Palomid 529 is an effective suppressor of Müller cell proliferation, glial scar formation, and photoreceptor cell death in a rabbit model of RD. This suggests that inhibiting the Akt/mTOR signal transduction pathway may be an effective strategy to decrease proliferation and photoreceptor cell death induced by detachment and perhaps represents a novel therapy for related human diseases such as proliferative vitreoretinopathy.
检测Akt/mTOR信号通路抑制剂Palomid 529对实验性视网膜脱离（RD）后Müller细胞增殖、视网膜下胶质瘢痕形成及光感受器存活的影响。
12只家兔右眼在视网膜脱离后立即玻璃体内注射含Palomid 529（600微克）的平衡盐溶液或单纯平衡盐溶液。第3天玻璃体内注射10微克溴脱氧尿苷（BrdU）。在第3天或第7天处死动物，此时视网膜切片用抗BrdU抗体标记以检测分裂细胞，用抗波形蛋白抗体鉴定Müller细胞，用异凝集素B4鉴定小胶质细胞和巨噬细胞。从荧光标记的核染色切片测量外核层（ONL）厚度。使用共聚焦显微镜对标记物进行成像。另外6只动物正常眼接受药物或平衡盐溶液注射，石蜡切片进行苏木精和伊红染色。
药物治疗组眼中，抗BrdU标记的Müller细胞数量、视网膜下瘢痕的数量和大小以及异凝集素B4标记的细胞数量显著减少。ONL也显著增厚，且无毒性作用证据。
在兔视网膜脱离模型中，Palomid 529是Müller细胞增殖、胶质瘢痕形成和光感受器细胞死亡的有效抑制剂。这表明抑制Akt/mTOR信号转导通路可能是减少脱离诱导的增殖和光感受器细胞死亡的有效策略，也许代表了一种针对增殖性玻璃体视网膜病变等相关人类疾病的新疗法。
