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BACKGROUND:The research of dental stem cells in the fields of regenerative medicine and tissue engineering has been deepening,bringing hope for the repair of tooth-related tissues and the treatment of systemic diseases.However,there is a lack of systematic research and analysis on the biological characteristics of dental stem cells in different age groups. OBJECTIVE:To explore the biological characteristics of the human deciduous tooth and permanent tooth pulp stem cells cultured in umbilical cord blood platelet lysate to provide a reliable basis for human platelet lysates to replace fetal bovine serum. METHODS:The pulp tissues of deciduous teeth,juvenile permanent teeth and adult permanent teeth were taken out and cultured in DMEM/F-12 medium supplemented with 10%fetal bovine serum or different concentrations(5%,10%and 15%)of human platelet lysates.Cell proliferation in the four groups was detected by cytometry.The optimal concentration of human platelet lysates was selected for subsequent experiments.Under the optimal concentration of human platelet lysates,human deciduous tooth and juvenile and adult permanent tooth pulp stem cells were cultured in vitro.The cell growth status was observed under the microscope.The specific antigen on the cell surface was detected by flow cytometry.The cell proliferation ability was tested by the cell counting method and CCK-8 assay.The cell differentiation ability in vitro was observed by a three-line differentiation assay. RESULTS AND CONCLUSION:(1)The cell proliferation rate of the 10%human platelet lysate group was the highest.(2)In all three groups,fusiform fibrous cells grew and expanded from around the tissue block.There was no significant difference between deciduous teeth and juvenile permanent tooth cells,but the adult permanent tooth cells were larger than the deciduous and juvenile permanent tooth cells of the same generation.(3)The results of flow cytometry showed that deciduous teeth,juvenile permanent teeth and adult permanent teeth conformed to the phenotypic characteristics of mesenchymal stem cells.(4)The proliferative capacity of adult permanent dental pulp stem cells was significantly lower than those of deciduous teeth and juvenile permanent dental pulp stem cells(P<0.01).(5)mRNA expressions of osteoblast-related genes alkaline phosphatase and bone morphogenetic protein 2,lipoprotein lipase and peroxisome proliferator-activated receptor γ2,mRNA expressions of chondroblast related gene type II collagen α1 and cartilage oligomeric matrix protein in adult pulp stem cells of permanent teeth were significantly lower than those of deciduous teeth and juvenile permanent teeth pulp stem cells(P<0.01).(6)Compared with adult dental pulp stem cells,human deciduous teeth and juvenile permanent teeth dental pulp stem cells have the stronger proliferative capacity and multidirectional differentiation potential,and are more suitable for clinical research and disease treatment.
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【Objective】 To investigate the level of glycosylated hemoglobin (HbA1c) in apheresis platelet donors, so as to further ensure the safety of apheresis platelet donors and provide guidance for the recruitment strategy. 【Methods】 Apheresis platelet donors from July 2018 to December 2020 were selected and venous blood was drawn. The glycosylated hemoglobin detection was conducted for donors who had never did this before or did this 3 months ago, and glycosylated hemoglobin >6.0% was regarded as abnormal. 【Results】 A total of 986 blood donors were detected, among which 32 donors with abnormal glycosylated hemoglobin were found, rated at 3.25%. With the increase of age and BMI(height and body mass index), the proportion of abnormal glycosylated hemoglobin increased, but the 51~60 age group and BMI > 28.0 group were not the highest, which may be related to the source of samples.The rate of abnormal glycosylated hemoglobin was highest in 40~50 years old group (5.43%, 15 / 276) and BMI ranged of 24.0~27.9 (4.04%, 9 / 223), and lowest (0.85%, 1 / 118) in 18~25 years old group and BMI >28.0(none). 【Conclusion】 The abnormal glycosylated hemoglobin is closely related to age and BMI. Therefore, we should give priority to young and underweight donors when recruiting blood donors, which can improve efficiency and maximize the safety of blood donors.
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Objective To explore the effect and potential mechanism of suppressors of cytokine signaling 3 (SOCS3) knockout on cell viability and apoptosis of retinal ganglion cells (RGCs) after optic nerve injury.Methods The optic nerve transection was used to construct optic nerve injury model of rats,and RGCs were isolated after optic nerve injury.The experimental animals were divided into optic nerve transection injury (ONT) group and sham-operation (Sham) group.The expression of SOCS3 in RGCs was detected by Western blot and RT-PCR in each group.Subsequently,SOCS3 siRNA was transfected into RGCs of Sham group and ONT group,and the experimental were further subdivided into blank control group,negative control group and SOCS3 silence groups.Cell viability was measured by CCK8 and MTr methods.Apoptosis was detected by Hoechst 33342 staining and flow cytometry.Furthermore,the mTOR siRNA and SOCS3 siRNA were co-transfected into RGCs,and cell viability and apoptosis were detected.Results The expression of SOCS3 was dramatically increased at 3 days after injury in the ONT group when compared with Sham group (P =0.049),and it showed an increased tendency gradually along with the extension of injury time.Compared with the blank control in the ONT group,SOCS3 silence markedly promoted cell viability [(49.47 ± 7.35) % vs.(73.24 ± 8.70) %],reduced cell growth inhibition [(27.25 ±0.75)% vs.(10.96 ± 1.07)%] and apoptosis [(23.06 ± 1.43)% vs.(10.65 ± 1.77)%].The result of Hoechst 33342 staining indicated that SOCS3 silence ameliorated the cell apoptosis induced by ONT.In addition,SOCS3 silence significantly improved pS6 expression at 2 weeks after injury,and mTOR and SOCS3 co-silence reduced cell viability,increased cell growth inhibition and apoptosis compared with SOCS3 silence group after injury.Conclusion SOCS3 silence promotes injury-induced cell viability of RGCs and suppresses injury-induced apoptosis of RGCs via up-regulating mTOR activity in the later period of injury.
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Background Studies showed that microRNA (miR)-375 suppresses the growth,apoptosis,migration and adhesion of tumor cells,and it plays a regulation to the changes of vascular endothelial growth factor (VEGF) in tumor tissue to arrest neovascularization.However,whether miR-375 intervenes the formation of new blood vessel in eyes is unelucidated.Objective This study was to explore the effects of miR-375 on human retinal capillary endothelial cells (HRCECs) function induced by hypoxia.Methods HRCECs were cultured using IMDM and divided into normal control group,CoCl2 model group,CoCl2 +miR-375 mimic group,CoCl2 +miR-375 mimic control group,CoCl2+miR-375 inhibitor group and CoCl2 +miR-375 inhibitor control group,and hypoxia cell models were created by adding 200 μmol/L CoCl2.MiR-375 and frizzled 4 (FZD4) small interfering RNA (siRNA) were transfected into the cells by 50 nmol/L miRNA lipidosome for 48 hours.The proliferation of the cells was detected by MTT assay;migrated number of the cells was examined by Transwell chamber assay;ELISA was employed to detect the concentrations of VEGF and VE-cadherin in the medium;the expression of β-catenin,cyclinD1,matrix metalloproteinase-2 (MMP2) and VEGF proteins were analyzed by Western blot;tube length of vessel formation was evaluated by Matrigel assay.Cultured cells were divided into normal control group,CoCl2 model group,CoCl2 +mock group and CoCl2 + FZD4 siRNA group,the relative expression of FZD4,a miR-375 targeted gene,was detected by luciferase reporter.Results The relative expression of miR-375 mRNA was significantly increased in the CoCl2 +miR-375 mimic group compared with the CoCl2 + miR-375 mimic control group and reduced in the CoCo2 + miR-375 inhibitor group compared with the CoCo2 + miR-375 inhibitor control group (t =-19.237,8.764,both at P<0.01),with a higher transfected efficacy for miR-375.The cell proliferative fold,migrated cell number,VEGF and VE-Cadherin contents in the medium and the tube length were significantly different among the CoCl2 model group,CoCl2 +miR-375 mimic group,CoCl2 +miR-375 mimic control group,CoCl2 +miR-375 inhibitor group and CoCl2 +miR-375 inhibitor control group (F =24.324,26.776,14.113,19.225,15.040,all at P<0.001),and those in the CoCl2 +miR-375 mimic group were evidently reduced in the CoCl2 +miR-375 mimic group compared with the CoCl2 +miR-375 mimic control group,while those in the CoCl2 +miR-375 inhibitor group were considerably elevated in comparison with the CoCl2 +miR-375 inhibitor control group (all at P<0.01).The expressions of β3-catenin,cyclinD1,MMP2 and VEGF protein were significantly different among the normal control group,CoCl2 model group,CoCl2 +miR-375 mimic group,CoCl2+miR-375 mimic control group,CoCl2 +miR-375 inhibitor group and CoCl2 +miR-375 inhibitor control group (F=11.753,13.283,16.770,10.334,all at P<0.001).In addition,the cell proliferative fold,migrated cell number and the tube length were significantly increased in the CoCl2 model group and CoCl2+mock group,and those in the CoCl2+FZD4 siRNA group were decreased in comparison with the CoCl2 +mock group (all at P<0.05).Conclusions MiR-375 inhibits the growth,migration and tube formation ability of HRCECs in hypoxic status probably by regulating the activation of Wnt pathway via directly targeting FZD4.
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Objective:Immunoregulation study of umbilical mesenchymal stem cell (UCMSCs) on allogeneic umbilical cord blood(UCB) CD4+T lymphocytes,which proliferation,apoptosis and the differentiation to CD4+CD25+ regulatory T cell (Treg) in vitro. Methods:Establishing on direct contact or transwell co-culture system,adopt in different proportion of UCMCs with phytohaemag-glutinin (PHA)-activated UCB CD4+T lymphocytes were co-cultured. The proliferation of lymphocyte,percent of CD4+CD25+/CD4+and Foxp3 expression, regulatory T cell marker gene were measured. Apoptosis of CD4+T lymphocytes were observed in the direct contact or transwell coculture system of UCMSCs with desamethason( DXM)-stimulated UCB CD4+T lymphocytes. Results: The UCB CD4+T lymphocytes cocultured with UCMSCs with PHA-activating for 3 days,compared with the UCMSCs free control group,the amount of cells was reduced noticeably(P<0. 05) and the percent of CD4+CD25+in CD4+T lymphocytes and Foxp3 expression significantly in-creased(P<0. 01) in a dose dependent way(P<0. 05). The UCB CD4+T lymphocytes cocultured with UCMSCs with DXM-inducing for 7 days,the apoptosis rate was significantly lower than that of the control group without UCMSCs (P<0. 01). These effects were partially attenuated in transwell coculture but could not be eliminated. Conclusion: UCMSCs are negative effect on UCB CD4+T lymphocytes-mediated immunity effects,and mainly manifested in the regulation on cell proliferate ability and differentiation rather than promoting apoptosis.
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BACKGROUND:As current studies on isolation, culture andcryopreservation of human amniotic epithelial cells (hAECs) are relatively scattered, it is difficult to form a comprehensive and effective solution to meet the clinical needs of stem cells for transplantation in future.OBJECTIVE:To establish the technology of isolation, culture and cryopreservation of hAECs, and to study the biological characteristics of hAECs.METHODS:Orthogonal method was used to study the effects of different factors on the separation, culture and cryopreservation, and range method was adopted to analyze the data to optimize the separation, culture and cryopreservation. We performed cell primary and passage cultures, morphology observed by microscope, drawn cell growth curve and flow cytometry assay, immunofluorescence staining, hepatocyte like cell differentiation to study the biological characteristics of hAECs.RESULTS AND CONCLUSION:(1) The optimal hAECs separation conditions were as follows:trypsin digestions were conducted at a concentration of 0.25%, four times, once for 20 minutes digestion; optimal conditions of culture were 4×108/L cell seeding density, 10 μg/L epidermal growth factor, 5% serum; optimal conditions of cryopreservation were 1×1010/L cell cryopreservation density, 10% dimethyl sulfoxide, 80% serum. (2) The primary cells were adhered to the wall in 2-3 days, exhibiting irregular polygon, paving stone-like growth. Cell adherence and growth rate were accelerated after subculture, and the growth and proliferation ability of passage 2 cells were not significantly decreased after cryopreservation and resuscitation. (3) Immunofluorescence staining showed that the primary cells strongly expressed SSEA-4 and CK19, but did not express Vimentin, CD45 and HLA-DR. The immunophenotype statistics of the primary and passage 4 cells showed the epithelial mesenchymal transition of hAECs in culture process. (4) Immunofluorescence staining showed that the liver cell marker expression of ALB, CK18 was significantly increased after hAECs were induced to differentiate into hepatocyte-like cells. Glycogen staining revealed glycogen synthesis in hAECs after 3 weeks of induction. To conclude, hAECs are easy to obtain and have strong proliferation ability in vitro, and express surface markers for undifferentiated embryonic stem cells.
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Objective To evaluate the effects and underlying mechanisms of crocin on glutamate-induced apoptosis of retinal ganglion cells (RGCs) by affecting extracellular calcium influx.Methods Primary rat retinal ganglion cells were isolated and stimulated with glutamate at concentrations of 0.1 mmol/L and 1 mmol/L for 24 h or 48 h,respectively,to establish apoptosis model of RGCs.Afterwards,crocin of different doses (0.1,1.0 and 3.0 μmol/L) was used to treat the glutamate-induced RGCs for 12 h;then cell apoptosis was detected by Annexin V-FITC/PI staining.The intracellular calcium concentration was determined by FIuo-3/AM fluorescent labeling.Western blot was used to examine the effect of crocin on Ca2+-mediated apoptotic signal molecules calpain and CaMKII.The mitochondrial membrane potential was detected by JC-1 staining and mitochondrial apoptosis-related signaling molecules Caspase-3,Caspase-9 and Bcl-2/Bax were evaluated by Western blot,respectively.Results In comparison with the untreated controls,the cell apoptosis of RGCs exposed to 0.1 mmol/L of glutamate for 24 h did not significantly change (P> 0.05).However,apoptosis rate of the cells reached (43.050 ± 2.616) % when the stimulation time lasted for 48 h and showed a significant increase (P<0.01).Treatment with higher-dose glutamate (1 mmol/L) significantly increased apoptosis of RGCs at 24 h (46.450±1.061)% and 48 h (45.500±3.253)% compared with the controls (P<0.01).RGCs were induced by 1 mmol/L of glutamate for 12 h,followed by the treatment with crocin at concentrations of 0.1,1.0 and 3.0 μmol/L,respectively.Each dose of crocin could significantly inhibit cell apoptosis in the dose-dependent manner (P<0.01).In addition,crocin at 1.0 μmol/L blocked glutamate-induced extracellular calcium influx,inhibited the expression of calcium-dependent proteins Calpainl and CaMK Ⅱ.Moreover,crocin at the dose of 1.0 μmol/L also increased mitochondrial membrane potential,suppressed the expressions of Caspase-3 and Caspase-9,and elevated Bcl-2/Bax ratio.Cornclusion Crocin inhibits glutamate-induced apoptosis of retinal ganglion cells through suppressing extracellular calcium influx,thereby blocking calcium-dependent and mitochondria-dependent apoptosis signaling pathways.