ObjectiveTo investigate the feasibility of adipose-derived mesenchymal stem cells (ADMSCs) differentiating into corneal epithelium-like cells after transfection with Pax6 gene. MethodsThe adipose tissue from bilateral inguinal of healthy C57BL/6 mice (5-6 weeks old) was used to isolate and culture ADMSCs.The 3rd passage ADMSCs were subjected to treatments of non-transfection (group A),pcDNA3.1 empty vector transfection (group B),and recombinant plasmid of pcDNA3.1-Pax6 transfection (group C),respectively.At 48 hours after transfection,the cells in groups B and C were selected with G418.The cell morphology changes were observed under the inverted microscope.Pax6 protein and level of corneal epithelial cells specific molecular-cytokeratin 12 (CK-12) were measured by Western blot.Real-time fluorescence quantitative PCR was applied to measure the mRNA expression of CK-12. ResultsNo morphology change was observed in groups A and B.Two different cell clones were found in group C.No.1 selected clone showed a flagstone-like appearance that was similar to that of corneal epithelial cells;No.2 selected clone showed a net-like appearance,with 3-7 cell processes.The Western blot results showed the Pax6 protein expression in 2 clones of group C,but no expression in groups A and B; and CK-12 protein expression was only observed in No.1 selected clone of group C,and no expression in the others.The real-time fluorescence quantitative PCR results showed that the CK-12 mRNA expression level of No.1 selected clone of group C was 8.64±0.73,which was significantly higher than that of No.2 selected clone of group C (0.55±0.42),group B (1.36±0.40),and group A (1.00±0.00) (P<0.05),and there was no significant difference among groups A,B and No.2 selected clone of group C (P>0.05). ConclusionPax6 gene transfection could induce differentiation of ADMSCs into corneal epithelium-like cells which express CK-12 at both the mRNA and protein levels.This result provides a promising strategy of generating corneal epithelilcm-like cells for construction of tissue engineered cornea.
This study aims to investigate the effect ofγ-Secretase Inhibitor DAPT, (N-[N-(3, 5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester), on the differentiation of neural precursor cells and the production of neurons in the neural precursor cell line GE6. GE6 was cultured in medium with 4μmol/L DAPT added as the experimental group and the untreated medium separately as the control group. After 4 days of differentiation, we carried out the following experiments. We used immuno-fluorescent staining to observe the ratio of Tuj1, GFAP and O4 positive cells. We also used qRT-PCR to detect the effect of the DAPT on Tuj1 and GFAP mRNA transcription in the GE6. The results of immuno-fluorescent staining indicated that the Tuj1 ratio of experimental group was higher compared to that of the control group, but the GFAP and O4 ratio of experimental group was lower than that of the control group. The differences were statistically significant (P < 0.05). The result of qRT-PCR was in accordance with immunofluorescent staining results. It was well concluded that DAPT could promote the neurogenic differentiation of neural precursor cell line rather than leading to gliogenic differentiation. More neurons could be obtained for transplantation with the addition of DAPT.
Objective To investigate the possibility of ectomesenchymal stem cell of human embryo facial process in differentiating into osteoblasts.Methods Ectomesenchymal stem cells of human embryo facial process were isolated and cultured in mineralized promoting solution containing 10 mmol/L β-glycerophosphate, 100 μg/ml ascorbic acid and 10 nmol/L dexamethasone supplemented with 15% FBS. The morphological change was observed by phase contrast microscopy. The characteristics of cells was identified by immunohistochemistry assay. Alkaline phosphatase activity was tested and the form of mineralized nodules was tested with Von Kossa staining. The expression of osteocalcin was identified by RT-PCR.Results There were significant changes in the shape of the cells after 3 days cultured in mineralized promoting solution. The cells became larger and the shape changed from fibroblast-like to multilateral. The result for anticollogen typeⅠstaining was positive. The alkaline phosphatase activity increased. Mineralized nodules were formed aftercultured 25 days by Von Kossa staining. RT-PCR assay showed induced cells expressed osteocalcin.Conclusion Ectomesenchymal stem cells of humanembryo facial process can be induced to differentiate into osteoblasts by mineralized promoting solution.
ObjectiveTo evaluate the influence of pathological differentiation in the effect of preoperative chemo-therapy for patients with locally advanced gastric cancer (LAGC). MethodsThirty-two patients with LAGA received preoperative chemotherapy with oxaliplatin and capecitabine (XELOX regimen).According to the pathological examina-tion, patients were classified into better (well and moderate, 16 cases) and poorly (16 cases) differentiated groups, and the clinical response rate, type of gastrectomy, and negative tumor residual rate were compared between the two groups.Morphological changes and toxic reactions were monitored after chemotherapy. ResultsThe results showed that the clinical response rate in the better differentiated group was significantly higher than that in the poorly differentiated group (100% vs.6.4%, P=0.000).The partial gastrectomy rate in the better differentiated group was significantly higher than that in the poorly differentiated group (87.5% vs.25.0%, P=0.000).A significant shrinking of tumor size and necrosis of tumor tissues caused by chemotherapy could be observed. ConclusionThe better differentiated group with locally advanced gastric cancer is suitable for preoperative chemotherapy with XELOX regimen, and as a result of effective preoperative chemotherapy, much more gastric tissue can be preserved for better differentiated group.
Dental pulp stem cells(DPSCs) are adult stem cells with strong proliferative ability, self-renewal ability and multidirectional differentiation potential. DPSCs have abundant source are easy to obtain, and do not have ethical problems. As seed cells, they played an important role and showed great potential in tissue engineering and regenerative medicine, making them potential ideal seed cells for repairation and regeneration of tissue and organ. Clinical application of DPSCs in bone regeneration has already been achieved, and studies on differentiation of DPSCs into other tissues are still at different levels of basic stage. In this paper, the research and application of directional differentiation potential such as tooth formation, osteogenesis, and nerve formation are reviewed in order to provide clues and ideas for further study on DPSCs in the field of tissue engineering and regenerative medicine.
ObjectiveTo investigate the effect of small interfering RNA (siRNA) lentivirus-mediated silencing of P75 neurotrophin receptor (P75NTR) gene on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in rats.MethodsThree lentivirus-mediated P75NTR gene siRNA sequences (P75NTR-siRNA-1, 2, 3) and negative control (NC)-siRNA were designed and transfected into the 3rd generation Sprague Dawley (SD) rat BMSCs. The cells morphological changes were observed under an inverted microscope, and the expressions of P75NTR gene and protein in cells were detected by real-time fluorescence quantitative PCR and Western blot. Then the best silencing P75NTR-siRNA for subsequent osteogenic differentiation experiments was screened out. The 3rd generation SD rat BMSCs were randomly divided into experimental group, negative control group, and blank control group (normal BMSCs). The BMSCs of negative control group and experimental group were transfected with NC-siRNA and the selected P75NTR-siRNA lentiviral vector, respectively. The cells of each group were cultured by osteogenic induction. The expressions of osteogenic related proteins [osteocalcin (OCN) and Runx related transcription factor 2 (Runx2)] were detected by Western blot; the collagen type Ⅰ expression was observed by immunohistochemical staining; the osteogenesis of BMSCs was observed by alkaline phosphatase (ALP) detection and alizarin red staining.ResultsAfter lentivirus-mediated P75NTR transfected into BMSCs, the expressions of P75NTR mRNA and protein significantly reduced (P<0.05), and the best silencing P75NTR-siRNA was P75NTR-siRNA-3. After P75NTR gene was silenced, MTT test showed that the cell proliferation in the experimental group was significantly faster than those in the two control groups (P<0.05). After osteogenic induction, the relative expressions of OCN and Runx2 proteins, collagen type Ⅰ expression, and ALP activity were significantly higher in the experimental group than in the two control groups, the differences were significant (P<0.05). With the prolongation of osteogenic induction, the mineralized nodules in the experimental group gradually increased.ConclusionSilencing the P75NTR gene with siRNA lentivirus can promote the osteogenic differentiation of rat BMSCs and provide a new idea for the treatment of bone defects.
ObjectiveTo investigate the regulatory effect of simvastatin on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) at middle/late stages by p38MAPK pathway under condition of osteoinductive environment. MethodsThe bone marrow of bilateral femur and tibia were harvested from 20 4-week-old female Sprague Dawley rats. BMSCs were isolated and cultured with whole bone marrow culture method; the second generation of cells were randomly divided into 5 groups: control group (complete medium, CM), simvastatin group (simvastatin medium, SIM), osteogenic induction group (osteogenic induction medium, OM), simvastatin and osteogenic induction group (simvastatin+osteogenic induction medium, OM+SIM), and blocker group (SB203580+simvastatin+osteogenic induction medium, OM+SIM+SB). MTT assay was used to detect the cell activity in CM group and SIM group at 2, 3, 4, 5, and 6 days, ELISA method to measure the content of alkaline phosphatase (ALP) in OM group and OM+SIM group at 7 and 14 days. The mRNA and protein expressions of osteocalcin (OCN) were detected by real-time quatitative PCR and Western blot after 1, 12, and 24 hours of osteogenic induction at 21 and 28 days. The protein expressions of phospho-p38 (p-p38) and p38 in OM group, OM+SIM group, and OM+SIM+SB group were detected by Western blot at the best induction time of simvastatin. ResultsMTT assay showed that no significant difference was found in absorbance (A) value between CM group and SIM group at each time point (P > 0.05), indicating no effect of 1×10-7 mol/L simvastatin on cell viability. ELISA results showed that ALP content significantly increased in OM+SIM group when compared with OM group at 7 and 14 days; the ALP content was significantly higher at 7 days than 14 days in OM group and OM+SIM group (P < 0.05). OCN mRNA and protein expressions at 12 hours were significantly higher than those at other time points in each group (P < 0.05), and the expressions of OM+SIM group was significantly higher than those of OM group (P < 0.05). The best induction time of simvastatin was 12 hours. At 12 hours after blocking intervention, the p-p38/p38 in OM+SIM+SB group was significantly lower than that in OM group and OM+SIM group (P < 0.05), and the p-p38/p38 in OM+SIM group was significantly higher than that in OM group (P < 0.05). ConclusionSimvastatin can increase the mRNA and protein expression levels of OCN and the protein of p-p38 in osteogenic differentiation of BMSCs at middle/ late stages, and its best induction time is 12 hours.
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 explore the in vitrodifferentiation of the rat mesenchymal stem cells (MSCs ) into the skeletal muscle cells induced by the myoblast differentiation factor (MyoD) and 5-azacytidine. Methods The MSCs were taken from the rat bone marrow and the suspension of MSCs was made and cultured in the homeothermia incubator which contained 5% CO2at 37℃. The cells were observed under the inverted phase contrast microscope daily. The cells spreading all the bottom of the culture bottle were defined as onepassage. The differentiation of the 3rd passage of MSCs was induced by the combination of 5-azacytidine, MyoD, transforming growth factor β1, and the insulin like growth factor 1. Nine days after the induction, the induced MSCs were collected, which were analyzed with the MTT chromatometry, theflow cytometry, and the immunohistochemistry. Results The primarily cultured MSCs grew as a colony on the walls of the culture bottle; after the culture for 5-7 days, the cells were shaped like the fibroblasts, the big flat polygonal cells, the medium sized polygonal cells, and the small triangle cells; after the culture for 12 days, the cells were found to be fused, spreadingall over the bottle bottom, but MSCs were unchanged too much in shape. After the induction by 5-azacytidine, some of the cells died, and the cells grew slowly. However, after the culture for 7 days, the cells grew remarkably, the cell volume increased gradually in a form of ellipse, fusiform or irregularity. After theculture for 14 days, the proliferated fusiform cells began to increase in a great amount. After the culture for 18-22 days, the myotubes increased in number and volume, with the nucleus increased in number, and the newly formed myotubes and the fusiform myoblst grew parallelly and separately. The immunohistochemistry for MSCs revealed that CD44 was positive in reaction, with the cytoplasm ina form of brown granules. And the nucleus had an obvious border，and CD34 was negative. The induced MSCs were found to be positive for desmin and specific myoglobulin of the skeletal muscle. The flow cytometry showed that most of the MSCs and the induced MSCs were in the stages of G0/G1，accounting for 79.4％ and 62.9％，respectively; however, the cells in the stages of G2/S accounted for 20.6％ and 36.1％. The growth curve was drawn based on MTT，which showed that MSCs weregreater in the growth speed than the induced MSCs. The two kinds of cells did not reach the platform stage，having a tendency to continuously proliferate.ConclusionIn vitro,the rat MSCs can be differentiated into the skeletal muscle cells with an induction by MyoD and 5-azacytidine, with a positive reaction for the desmin and the myoglobulin of the skeletal muscle. After the induction, the proliferation stage of MSCs can be increased, with a higher degree of the differentiation into the skeletal muscle.
ObjectiveTo summarize the mechanism of long non-coding RNA (lncRNA) in signal pathways related to osteogenic differentiation. Methods Relevant domestic and foreign researches in recent years were consulted. The characteristics and biological functions of lncRNA were introduced, and the specific mechanism of lncRNA regulating related signal pathways in osteogenic differentiation was elaborated. Results The exertion and maintenance of normal function of bone requires the closed coordination of transcription networks and signal pathways. However, most of these signal pathways or networks are dysregulated under pathological conditions that affect bone homeostasis. lncRNA can regulate the differentiation of various bone cells by activating or inhibiting signal pathways to achieve the balance of bone homeostasis, thereby reversing the pathological state of bones and achieving the purpose of treating bone metabolic diseases. Conclusion At present, the research on the mechanism of lncRNA regulating various osteogenic differentiation pathways is still in the early stage. Its in-depth regulator mechanism, especially the cross-talk of complex signal pathways needs to be further studied. And how to apply these molecular targets to clinical treatment is also a big challenge.