Objective To probe the relationship of differentiation degree with spread or survival prognosis in retinoblastoma (RB). Methods Clinical data, follow up status and eyeball specimens in 156 RB cases were investigated retrospectively. The tumors were divided into differentiated and undifferentiated groups. Conditions of the tumor invasion of ocular or surrounding tissues were reviewed. The fatality rate was obtained from the follow-up materials of 82 cases of RB. The fatality rate and the invasion rate between the two types were compared statistically by Chi-square test. In addition, the relation between the tumor invasion and death ,and the average survival time for dead people after surgery were explored. Results Local invasion of tumor cell was found in 8 eyes among 17 eyes with differentiated RB (47.06%),and in 66 eyes among 139 eyes with undifferentiated RB (47.48%).There was no significant difference with regards to the local invasion between the two types ( The fatality rate of cases of differentiated RB was 27.27%,and 22.54% in undifferent iated RB, and there was no statistical difference between the two types .The fat ality rate for patients with orbital and scleral extension was 100%, optic nerve invasion (grade Ⅳ) was 62.50%,and uveal invasion was 22.22%.The survival time for the dead victims were from 5 months to 41 months and averaged to 21.92 months. Conclusion There was no significant differ ence both in survival prognosis and local invasion between the two types. The survival prognosis of metastatic RB was dependent on the degree of spread and the efforts of treatment and regardless of the types of differentiation of RB cells. (Chin J Ocul Fundus Dis, 2001,17:18-20)
Objective To investigate the division, prol iferation and differentiation abil ities of nestin+/GFAP+cell after spinal cord injury and to identify whether it has the characteristic of neural stem cells (NSCs). Methods Twelvemale SD rats, aged 8 weeks and weighing 200-250 g, were randomized into 2 groups (n=6 per group): model group inwhich the spinal cord injury model was establ ished by aneurysm cl ip compression method, and control group in which no processing was conducted. At 5 days after model ing, T8 spinal cord segment of rats in each group were obtained and the gray and the white substance of spinal cord outside the ependymal region around central tube were isolated to prepare single cellsuspension. Serum-free NSCs culture medium was adopted to culture and serum NSCs culture medium was appl ied to induce differentiation. Immunohistochemistry detection and flow cytometry were appl ied to observe and analyze the type of cells and their capabil ity of division, prol iferation and differentiation. Results At 3-7 days after injury, the model group witnessed a plenty of nestin+/GFAP+ cells in the single cell suspension, while the control group witnessed few. Cell count of the model and the control group was 5.15 ± 0.71 and 1.12 ± 0.38, respectively, indicating there was a significant difference between two groups (P lt; 0.01). Concerning cell cycle, the proportion of S-phase cell and prol iferation index of the model group (15.49% ± 3.04%, 15.88% ± 2.56%) were obviously higher than those of the control group (5.84% ± 0.28%, 6.47% ± 0.61%), indicating there were significant differences between two groups (P lt; 0.01). In the model group, primary cells gradually formed threedimensional cell clone spheres, which were small in size, smooth in margin, protruding in center and positive for nestin immunofluorescence staining, and large amounts of cell clone spheres were harvested after multi ple passages. While in the control group, no obvious cell clone spheres was observed in the primary and passage culture of single cell suspension. At 5 days after induced differentiation of cloned spheres in the model group, immunofluorescence staining showed there were a number of galactocerebroside (GaLC) -nestin+ cells; at 5-7 days, there were abundance of β-tubul in III-nestin+ and GFAP-nestin+ cells; and at 5-14 days, GaLC+ ol igodendrocyte, β-tubul in II+ neuron and GalC+ cell body and protruding were observed. Conclusion Nestin+/GFAP+ cells obtained by isolating the gray and the white substance of spinal cord outside the ependymal region around central tube after compressive spinal cord injury in adult rat has the abil ity of self-renewal and the potential of multi-polarization and may be a renewable source of NSCs in the central nervous system.
ObjectiveTo investigate the effect of serum on the differentiation of neural stem cells.MethodsThe neural stem cells were isolated from the embryonic hippocampus tissues of Sprague Dawley rats at 14 day of pregnancy. After culturing and passaging, the 3rd generation cells were identified by immunocytochemical staining. Then, the cells were divided into 3 groups according to the concentrations of fetal bovine serum (FBS) used in the differentiation cell culture medium: 5% (group A), 1% (group B), 0 (group C), respectively. The other components of the culture media in 3 groups were the same. Cell viability was determined by using the Live/Dead cell staining at 8 days; the expressions of glial cell marker [glial fibrillary acidic protein (GFAP)] and neuronal marker (β-Ⅲ Tubulin) were determined and analyzed by immunocytochemical staining and real-time fluorescent PCR at 4 and 8 days of culture.ResultsBased on cell morphology and immunocytochemical staining, neural stem cells were identified. Cells were growing well with no death in all groups. With decreasing FBS concentration, the expression of GFAP was significantly decreased on both protein and mRNA level, whereas the expression of β-Ⅲ Tubulin was evidently increased. The staining of each group at 8 days was more obvious than that at 4 days. There were significant differences in mRNA expressions of GFAP and β-Ⅲ Tubulin at 4 and 8 days between groups (P<0.05).ConclusionSerum can promote the differentiation of neural stem cells into glial cells. At the same time, it inhibits the differentiation of neural stem cells into neurons, the lower the serum concentration, the smaller the effect.
Objective To isolate neural stem cells (NSCs) from rabbit retina and brain, and induce differentiation of those NSCs using different culture media. Methods Single-cell suspensions of retina and cerebral cortex were prepared from rabbit embryo, cultured in 5 types of different media to isolate the NSCs by continual passages. After 3 passages, NSCs were induced to differentiation in 2 types of different media for 8 to 10 days. NSCs and inducedretinal cells were examined by immunofluorescence and flow cytometry for the expression pattern of some specific antigens.Results Immunofluorescence showed that NSCs from retina and brain, cultured in serumfree media, both expressed Nestin partially. Flow cytometry showed that Nestin positive cells were significantly decreased while the Rhodopsin and Thy1.1 positive cells were increased after induction. Compared with the combined induction of alltrans retinoid acid (ATRA) and serum, 5%FBS (fetal bovine serum) led to higher expression of Rhodopsin（P＜0.01），but lower expression of Thy1.1（P=0.01）.Conclusion Serumfree media with N2, EGF, bFGF, LIF is the best for NSCs purification. Both induciton media can induce NSCs to differentiate.Retina NSCs have higher potentials to differentiate into retinal neuroepithelial cells than brain NSCs.
ObjectiveTo investigate the impact of L-Phenylalanine on the efficiency of retinal pigment epithelial (RPE) cell derivation from human embryonic stem cells (hESCs) and explore the underlying mechanisms. MethodsH1 hESCs were routinely cultured with mTeSR medium and divided into control and experimental groups. When cells reached over-confluence, spontaneous differentiation was triggered using 10% KSR differentiation medium without bFGF. L-Phenylalanine (0.2 mmol/L) was supplemented in the experimental group from the 3rd week. The expression of RPE markers and Wnt signaling components in the two groups was detected by Real time-RCR, Western blot and Flow cytometry analyses. Purified hESC-RPE cells and PBS were injected into the subretinal space of sodium iodine-induced retinal degeneration rats separately. Retinal function was assessed by ERG 6 weeks after the transplantation. ResultsOn the 7th week, much more pigment cell clumps appeared in the experimental group compared to the control group. Within these areas there were monolayer hexagonal RPE cells full of pigment granules. The experimental group showed significantly higher expression of Pax6, MITF, Tyrosinase, RPE65, Wnt3a, Lef1 and Tcf7 genes than the control group (P < 0.01). Higher expression level of MITF and RPE65 proteins and higher percentage of RPE65 (+) cells (P < 0.01) were detected in the experimental group. 6 weeks after sub-retinal transplantation of hESC-RPE cells, the amplitudes of a-b wave in the transplanted eyes were significantly higher than those in the control eyes (P < 0.01) at the stimulus intensity of 3.0 cd·s/m2. ConclusionsL-Phenylalanine effectively promoted the differentiation of embryonic stem cells into retinal pigment epithelial cells, and its impacts on the Wnt/β-catenin signaling pathway may partially explain the underlying mechanisms. Subretinal transplantation of hESC-RPE remarkably improved the retinal functions of retinal degenerative animal models.
Previous studies have shown that growth arrest, dedifferentiation, and loss of original function occur in cells after multiple generations of culture, which are attributed to the lack of stress stimulation. To investigate the effects of multi-modal biomimetic stress (MMBS) on the biological function of human bladder smooth muscle cells (HBSMCs), a MMBS culture system was established to simulate the stress environment suffered by the bladder, and HBSMCs were loaded with different biomimetic stress for 24 h. Then, cell growth, proliferation and functional differentiation were detected. The results showed that MMBS promoted the growth and proliferation of HBSMCs, and 80 cm H2O pressure with 4% stretch stress were the most effective in promoting the growth and proliferation of HBSMCs and the expression level of α-smooth muscle actin and smooth muscle protein 22-α. These results suggest that the MMBS culture system will be beneficial in regulating the growth and functional differentiation of HBSMCs in the construction of tissue engineered bladder.
【Abstract】 Objective To explore the interventional effect of platelet lysate (PL) on osteogenic differentiation ofBMSCs by induction in rats in vitro. Methods Twenty-four clean-grade adult Wistar rats, weighing from 250 g to 300 g, maleor female, were included in this study. PL was obtained through three times of centrifugation and repeated freeze-thaw for the blood aspirated from cardiac cavities in 16 Wistar rats. ELISA assay was conducted to detect the concentration of growth factors PDGF, TGF-β1, IGF-1 and VEGF in PL. The BMSCs harvested by flushing femurs of 8 adult Wistar rats were isolated, cultivated and expanded in vitro. The cells at the 4 passage were performed for osteogenic differentiation by induction in three groups of A (5% PL of final concentration in basic induction medium), B (1% PL of final concentration in basic induction medium), and C (no presence of PL in basic induction medium as a control). The morphological changes of the cells were dynamically observed with inverted phase contrast microscope during the whole period. At different time-points, ALP staining (7 days) and ALP/TP (2, 8, 12 days) of the cells were detected to evaluate ALP activity, and the mineral formation in extracellular martrix was examined with Al izarin red staining which provided quantitative analysis of mineral deposits. Results ELISA assay showed that the content of PDGF, TGF-β1, IGF-1 and VEGF in PL reached (300 ± 30), (140 ± 25), (80 ± 35), (70 ± 20) pg/mL, respectively. Morphological observation displayed BMSCs in group A or B gradually turned from spindle-shape to square- or polygon-shape as the morphorlogical type of osteoblast-l ike cells at 7 days. The cells in group A showed slower shape changesbut higher prol iferation than that in group B or C. Moreover, at the 20 days, the cells in group A still displayed dense gro wth and produced obviously decreased amount of mineral deposits in ECM when compared with group B or C. At the 7 days, the cells ofgroup A showed smaller amount of granules positive for ALP staining in cytoplasm when compared with groups B and C, and displayed marked reduction in ALP activity assay at the 2, 8, and 10 days compared with that of groups B and C (P lt; 0.05). At the 20 days, Al izarin red staining showed the number of mineral deposits in groups A, B and C were 7.67 ± 1.10, 12.87 ± 0.81 and 15.59 ± 0.25, respectively, while the area of mineral deposits were (161 778.70 ± 44 550.80), (337 349.70 ± 56 083.24), and (415 921.70 ± 71 725.39) pixels, respectively. The number of mineral deposits and the area of mineral deposits in group A were smaller than those in groups B and C (P lt;0.05). But there was no statistically significant difference between groups B and C (P gt; 0.05). Conclusion PL is a kind of system carrying various growth factors. Exposure of PL inhibits both ALP activity and mineral formation of BMCs in a dose-dependent way under the osteogenic induction environment.
ObjectiveTo investigate the differentiation potential of human umbilical cord mesenchymal stem cells (HUCMSCs) into hepatocytes induced by rat fibrotic liver tissue extracts. MethodsLiver fibrosis was induced in the Sprague Dawley rats (weighting, 180-220 g) by repeated intraperitoneal injections of 3% thioacetamide-saline at a dose of 200 mg/kg twice a week for 4 weeks;fibrotic liver tissues were used to prepare liver homogenate supernatants. The HUCMSCs at passage 3 were cultured in DMEM/F12 with 10% fetal bovine serum (FBS) (control group) and in DMEM/F12 with 10%FBS and 50 g/L liver homogenate supernatants (experimental group) for 7 days. The morphological changes of the cells were recorded;the protein levels of cytokeratin 18 (CK18), alpha fetoprotein (AFP), and CYP3A4 were measured using Western blot. The glycogen storing ability of the cells was detected by periodic acid-schiff (PAS) staining. Furthermore, the synthesis of albumin (ALB) and blood urea nitrogen (BUN) was measured. ResultsIn experimental group, after 1 day of induction, the stem cells of fusiform shape began to lose sharp edges and progressively shrunk, and then they changed into hepatocyte-like cells with round and irregular shape at 7 days. Positive expressions of AFP, CK18, and CYP3A4 were observed in the experimental group, but negative expression in the control group. The concentrations of BUN and ALB were (0.43±0.07) mmol/L and (8.08±0.41) μg/mL in the control group and were (2.52±0.20) mmol/L and (41.48±4.11) μg/mL in the experimental group, showing significant differences (t=24.160, P=0.000;t=19.810, P=0.000). PAS staining results showed navy blue nucleus and lavender cytoplasm in the control group, but dark purple cell body and visible nucleus in the experimental group. ConclusionHUCMSCs could differentiate into hepatocyte-like cells induced by rat fibrotic liver tissue extracts, which have hepatocyte biomarkers (AFP, CK18, and CYP3A4) and hepatocyte-specific functions of glycogen storage, urea production and ALB secretion, so they could partially replace the function of hepatocytes, that may be one of the therapeutic mechanisms of stem cell transplantation.
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.