Objective To observe the differentiation effect of rabbit amnion-derived stem cells (ADSC) induced into neural cells.Methods ADSC of New Zealand female rabbits were isolated and cultured. Its mRNA level of Fibronectin, Nestin and Vimentin were detected by real-time quantitative polymerase chain reaction. The selfreplication ability of ADSC was confirmed by monoclonal formation experiments. These ADSC were further induced into neural cells in vitro. Five days after induced differentiation, the expression of -tubulin and glial fibrillary acidic protein (GFAP) were detected by immunofluorescent staining. Results ADSC were separated from amnion tissue gradually after 24 hours. There were polygonal cells gathered around the amnion tissue at 72 hours, and were distributed compactly around the amnion at 120 hours. The morphology of cleavage daughter cells was basically the same as parent cells. ADSC has the ability of self-replication. The Nestin, Vimentin, Fibronectin mRNA expressions in ADSC were 15.79, 1.91, 7.65 times those in spleen cells. The differences were statistically significant(Z=-5.243, -3.972, -2.524; P＜0.05). The beta;-tubulin expression was found in cytoplasm of most cells. The GFAP expression was found in cytoplasm in some cells. Conclusions ADSC has self-replication ability. It can be induced into neurons and neuroglial cells under the right conditions.
Objective To observe the survival of human umbilical cord derived mesenchymal stem cells (hUC-MSCs) after injection into the vitreous of rabbits,and the animal safety under those procedures.Methods Twentyseven pigmented rabbits were randomly divided into 3 groups (intravitreal injection 1 week group，2 weeks group and 4 weeks group)， each with 9 rabbits.For each animal the right eye was the experimental eye receiving hUCMSCs injection,while the left eye was the control eye receiving culture medium. The rabbit eyes were examined by slitlamp microscope, indirect ophthalmoscopy, fundus photography, fundus fluorescence angiography（FFA）and Tonopen tonometer before and after injection. hUCMSCs were labeled by CMDil in vitro, and their survival status was measured by confocal fluorescence microscopy, light microscope and transmission electron microscope at 4 weeks after injection. Results Four weeks after injection, a large number of the hUCMSCs were still alive in the vitreous cavity. The overall condition of those rabbits was good. The anterior segment and retina of experimental eyes were normal, without hyperfluorescence, hypofluorescence and leakage in the retina at 1,2 and 4 weeks after injection. There was no significant difference on IOP before and after injection at different time points (P＞0.05), and no obvious changes at cornea, anterior chamber angle,lens,retinal structure by.light microscope and transmission electron microscope examination.Conclusion hUC-MSCs can survive in the rabbit vitreous for four weeks；intravitreal injection of hUCMSCs was safe and feasible.
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)
Objective To study the effect of different types of supernatants fluid of retinal cells on the physiological function of neuron cells derived from embryonic stem cells. Methods Embryonic bodies were sub-induced by retinoic acid (group A), retinoic acid with the supernatant fluid of retinal glia cells and neurons of mouse (group B), retinoic acid with the supernatant fluid of fetal retinal glia cells (group C), respectively. The Sodium ion channels on the cytomembrane in the 3 groups were analyzed 5-21 days after the inducement. Results The sodium current in each group didn't change much 5-21 days after the inducement. The sodium channels presented burst-opening discharge in group A, brief-opening discharge in group B, and long-opening discharge in group C. The percentage of the cells without current in group A, B and C was 25%, 11.4%, and 23.8%, respectively, but the difference was not significant among the 3 groups(Pgt;0.05). The number of cells with sodium current increased at first and decreased later in group A, continuously increased in group B, and decreased at first and kept stable later in group C. The open time of sodium channels was the longest in group A, and the shortest in group B. The distribution of open time in the three groups could be managed with two-step exponential fit. Conclusion The supernatant fluid of retinal cells has apparent influence on the physiological function of the neuron cells derived from embryonic stem cells. (Chin J Ocul Fundus Dis, 2007, 23: 91-93)
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)
Objective To investigate the feasibility of differentiation of invitro induced rat bone marrowderived mesenchymal stem cells（rMSCs） into retinal pigment epithelial （RPE） cells.Methods The rMSCs from BrwonNorway (BN) rats were isolated and cultured by adherent screening method. RPE cells lysate made by repeated freezethawing was put into the rMSCs culture system to identify whether the induced cells could express characteristic label cytokeratin（CK）and S-100 simultaneously or not.Results The growth rate of rMSCs induced by RPE cells lysate was slower and protuberant burr surrounded the fusiform cells. The results of immunoblotting and double immunofluorescence showed that partial induced cells expressed CK and S-100 simultaneously. The result of flow cytometry indicated that 14.1% induced cells expressed CK and S-100 simultaneously.Conclusion Induced by RPE cells lysate, rMSCs can differentiate into RPE cells.
Objective To observe the effects of subretinal transplantation of rat mesenchymal stem cells (rMSCs) on Sodium Iodate (SI)induced retinal degeneration. Methods One hundred and twenty BrownNorway (BN) rats were divided into three groups including SI injection group,rMSCs transplantation group and normal control group, each with 40 rats. The retinal degeneration was induced by caudal vein injection of SI. The retinal pigment epithelium（RPE）and neural retinal were evaluated by ocular fundus photograph, fluorescein fundus angiography (FFA)，electroretinogram (ERG) and histological approach, and TUNEL（terminal deoxynucleotidyl transferasemediated dUTP nick end labeling ）. CMDiIprelabeled primary rMSCs were transplanted into the subretinal space of SIinduced rats. The survival, integration, and differentiation of rMSCs were observed between 14 day to 60 day after the transplantation.Results The rat retinal function was gradually reduced after14 days of SI injection, with a timedependent manner. After the RPE cells were damaged，the outer segments of photoreceptors became disrupted and shortened until karyopyknosis. The nuclear morphology and positive TUNEL labeling indicated that the death of photoreceptor cells was apoptosis. After rMSCs transplantation, CMDiI labeled donor cells were observed to be scattered in the subretinal space and expressed RPE cell markers. Average amplitude of b wave and Ops (oscillation potential) in ERG improved 27.80%,59.38% respectively after rMSCs transplantation.Conclusions Transplanted rMSCs can survive in subretinal space and differentiate into RPE.
Replacement therapy of stem cells transplantation represents a potential treatment for neural retinal diseases. Despite the encouraging results in laboratory, the clinical application of cells replacement therapy is still difficult because the limitation of seed cells, immunologic rejection, oncogenicity and ethical problems, etc. Recent breakthrough in somatic reprogramming provides a promising solution overcoming these obstacles. Further researches on virus free reprogramming will make the clinical application of stem cell replacement therapy possible.
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)