Objective To investigate the viability and the characters of proliferation and differentiation of retinal stem cells (RSCs) after cryopreservation and anabiosis. Methods The RSCs of a Long Evans rat with the embryonic age of 17 days were separated and cultured in vitro. The third-passage RSCs in the cryopreservation liquid consisted of 80% Dulbecco modified Eagle medium (DMEM)/F12，10% bovine serum albumin (BSA)，10% dimethylsulfoxide (DMSO)，and basic fibroblast growth factor (bFGF) (20 ng/ml), were stored in liquid nitrogen. After 1, 2, 4, 8, 12, and 16 weeks of freezing period, these cells were thawed. The livability of the cells was counted and the differentiation was induced while the proliferation and characters of differentiation were detected by immunofluorescence. Results The effects of different durations of cryopreservation on the livability of RSCs did not differs much (Pgt;0.05). These cells were reculturd well and presented specific marker of RSCs. In addition, they also could be induced and differentiated into several types of retinal cells. Conclusion Cryopreservation and anabiosis of RSCs does not affect the cellular intrinsic characters of proliferation and differentiation. (Chin J Ocul Fundus Dis, 2007, 23: 94-97)
Objective To isolate and purify the melanoma stem cells (MSC) in choroidal melanoma OCM-1 cells. Methods OCM-1 cells were resuscitated, and after cultured in standard Dubecco's modifided Eagle's medium (DMEM)/F12, they were cultured in serum-free medium (SFM). The cultured MSC were isolated and purified, and the positive rate of CD133, the specific markers of neurostem cells, was observed by flow cytometry (FCM). The 6th generation of the cells were stained by musashi-1 immunocytochemistry, and the rate of the positive cells was observed under the microscope. Results After the Adherent OCM-1 cells cultured in SFM, the number of the adherent number decreased obviously. The cells at the 6th generation grew as the suspended gobbets, which represented the typical grow manner of the stem cells. Positive CD133 could be found in the cells of different generations, which was 2.5％, 21.7％, and 57.8％ in the non-isolated OCM-1 cells, the 1st generation of isolated cells, and the 2nd generation cells, respectively. The positive rate of CD133 in the cells at the sixth generation was 79.8% with b positive expression of musashi-1. Conclusion MSC is in the human choroidal melanoma OCM-1 cells. The suspended stem cells may be purified by limited differentiation and serial passage in SFM. (Chin J Ocul Fundus Dis, 2007, 23: 87-90)
Stem cells belong to a subgroup of undifferentiated cells in organisms, which has the features of proliferation, self maintaining, and self renewal, and may produce plentiful filial generation with functions. According to the researches on embryonic stem cells, retinal stem cells in adults, and intraocular tumor stem cells, stems cells exist in human embryo, adult retina, and also intraocular tumors like retinoblastoma and choroidal melanoma. Different stem cells transplanted into subretinal interspace or vitreous cavity may differentiate into structure of neurone or retina. Stem cells may become a newest target of the researches on pathogenesis and treatment of diseases. (Chin J Ocul Fundus Dis, 2007, 23: 83-86)
Objective To establish a culture method for human fetal retinal progenitor cells (RPC) in vitro. Methods Retinal neuroepithelium of 8-12-week human fetal were isolated and cultured in suspension and adherent methods. The passage cells were cultured and differentiated for 14 days with 5% fetal bovine serum without basic fibroblast growth factor (bFGF). The expressions of RPC and retinal final cells markers before and after the differentiation were detected by immunohistochemical analysis. Results The isolated cells cultured in suspension method congregated as the neurospheres and expressed the neuroectodermal marker nestin, but failed in passage and expansion; while the expression of nestin and serial passage were found in the cells cultured in adherent way. The differentiated passage cells expressed retinal final cells markers including glial fibrillary acid protein, beta;-tubulin and recoverin. Conclusions RPC derived from human fetal neural retina at the 8th12th week of gestation are capable of expansion and multipotentiality. (Chin J Ocul Fundus Dis, 2007, 23: 98-100)
Objective To observe whether transforming growth factor-beta;2（TGF-beta;2）could promote the differentiation of retinal stem cells in rats cultured in vitro. Methods The retinal stem cells were separated from the embryonic ratsprime; eyes under the dissecting microscope, cultured, and subcultured. The cells were identified by nestin and Chx-10 immunofluorescence. The sixth generation of cells were induced and differentiated, immunofluorescent stained with anti-glial fibrillary acidic protein，anti-opsin, anti-b-tubulin, and anti-protein kinase C, and identified the final cells. Results The cultured cells after induced by TGF-beta;2 differentiated to the mature cells. The results of immunofluorescence showed that the differentiated cells induced by TGF-beta;2 were more than which induced by the embryonic bovine blood serum. Conclusion TGF-beta;2 may induce the retinal stem cell differentiating into retinal cells. The inductive and differentiating effect of TGF-beta;2 is ber than which of the blood serum. (Chin J Ocul Fundus Dis, 2007, 23: 104-107)