Selective culture of rat retinal microvascular pericytes / 中华实验眼科杂志

ABSTRACT

Background Retinal microvascular pericytes (RMPs) have been played increasing attention as an emerging key in pathogenesis of various retinal angiogenic diseases including diabetic retinopathy,and RMPs are thought to be a potential target for treatment.Yet the study has been hindered by the difficulty of obtaining source of tissue and isolating pure population.Objective This study was to establish a simple method of isolation,purification and cultivation of primary RMPs for rat.Methods Eyeballs were extracted from clean male Sprague Dawley rats and immersed by 75％ alcohol for 1 minute.The retinas were isolated and mechanical morcel.Trypsin (2.5 g/L) was firstly used and followed by type Ⅰ collagenase (2 g/L) for the digestion of the retina for 15 minutes,respectively.Retinal microvascular fragments were screened by 100 μm and 55 μm filter screen.DMEM containing 20％ fetal bovine serum was added for the cultivation and passaged of the cells.The cells were purified by exchanging medium and partial enzymatic digestion.The morphology and growth status were monitored under the phase contrast microscope,and α-smooth muscle actin (α-SMA),platelet-derived growth factor receptor-β (PDGFR-β),yon Willebrand factor (vWF),glial fibrillary acidic protein (GFAP) antibodies were used for the identification of RMPs.Results RMPs migrated out of fragments after 24-48 hours of plating.On day 7,RMPs appeared in primary cultures as loose colonies.The cells reached confluence to about 80％-90％ on day 14-16.The subcultures grew faster than the primary and reached confluence on day 12-14.The culture showed typical morphology of pericyte with large irregular triangular cell body and multiple long processes,and they could be repeatedly passaged 9 times without obvious loss of characteristic phenotype.Fluorescence assay exhibited that 96％ of the cells showed positive immunofluorescence for α-SMA and PDGFR-β,confirming the purity of RMPs in culture.However,only a few of them were positive for GFAP and the cells response for vWF was absent.Conclusions High purity of rat RMPs can be obtained easily by our method without high cost-consuming.Hcrc wc cstablished a simple mcthod for the primary culture of rat RMPs.