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.

DNA copy number variation is an important pathogenic factor of human diseases and might be involved in the pathogenesis and pathological process of inflammatory bowel disease (IBD).Aims: To investigate the copy number variation of CNTNAP3 gene and its significance in Crohn''s disease (CD).Methods: A total of 101 active CD patients admitted from Jul.2009 to Dec.2010 at Renji Hospital, School of Medicine, Shanghai Jiao Tong University were enrolled.Eighty healthy subjects were served as controls.Peripheral blood or intestinal mucosa samples of CD patients were collected, and the copy number variation of CNTNAP3 gene was screened and validated by array-based comparative genomic hybridization (aCGH, n=8) and real-time PCR (n=93);expression of CNTNAP3 encoding protein was determined by ELISA (n=55).Results: A large fragment copy number amplification was revealed by aCGH at chromosome 9p13 region (including CNTNAP3 gene) in untreated CD patients.Real-time PCR confirmed that the copy number of CNTNAP3 gene was amplified in peripheral blood of CD patients, especially steroid-naive patients as compared with the normal controls (208 616.4±126 984.7 and 233 453.3±113 520.8 vs.161 750.2 ±53 940.3, P<0.05 and P<0.01).In the clinical parameters analyzed in this study, only smoking was significantly correlated with CNTNAP3 copy number amplification (P<0.05).However, there was no significant difference in plasma CNTNAP3 level between CD patients with amplified copy number and normal controls (P>0.05).Furthermore, the plasma CNTNAP3 level in CD patients with amplified copy number was not correlated with the simplified endoscopic score for CD (P>0.05).Conclusions: Copy number amplification of CNTNAP3 gene might be involved in the pathogenesis of CD in Chinese population.Glucocorticoid treatment and smoking might affect the copy number variation of CNTNAP3 gene.Plasma CNTNAP3 level cannot discriminate CD patients from healthy subjects.Conclusions of this study needs to be further demonstrated and discussed.