BACKGROUND:Previous experiments have shown that improved platelet-rich plasma can promote the proliferation of human dental pulp cells in a concentration-dependent manner, particularly when the concentration is 10%.
OBJECTIVE:To investigate the effect of platelet-rich plasma at different concentrations on the proliferation and immunogenicity of human bone marrow mesenchymal stem cells.
METHODS:Human bone marrow mesenchymal stem cells from healthy donors were cultured and passaged for 3-4 passages, identified by flow cytometry and differentiation inductions. Platelet-rich plasma samples which were manufactured from the venous blood of the same donor were used for culturing human bone marrow mesenchymal stem cells. The proliferation of human bone marrow mesenchymal stem cells was measured by cellcounting kit-8 method and the growth curves were drawn. The most suitable concentration of platelet-rich plasma was selected to culture human bone marrow mesenchymal stem cells for three generations and the Stro-1 expression rate on the surface of human bone marrow mesenchymal stem cells was determined through flow cytometry.
RESULTS AND CONCLUSION:Platelet-rich plasma at the concentration of 5%-10%evidently promoted the proliferation of human bone marrow mesenchymal stem cells on the 6th and 8th days. The most effective concentration to promote the proliferation was 10%. Platelet-rich plasma at the concentration of 10%stil promoted the proliferation of human bone marrow mesenchymal stem cells on the 10th day, and maintained a better immunogenicity of human bone marrow mesenchymal stem cells compared to the control group. These findings indicate that platelet-rich plasma can promote the proliferation of human bone marrow mesenchymal stem cells in a concentration-dependent manner, and 10%platelet-rich plasma is better to maintain the immunogenicity of human bone marrow mesenchymal stem cells.

Objective:To investigate the effect of modified plateletrich plasma(mPRP)on the osteogenic differentiation of stemcells from human exfoliated deciduous teeth(SHED).Methods:mPRP at 1%,2%,5%,10% and FBS at 10% were added to thecultured SHED of passage 4,respectively.The influence of mPRP on alkaline phosphatase(ALP)activity was evaluated using ALPkit.RUNX2 and osteocalcin mRNA expression in the treated cells were examined by realtime PCR.Results:mPRP enhanced ALPactivity in the SHED,and the effect of mPRP was more obvious at 2%.Treatment of the cells with 2% mPRP upregulated the mRNAexpressions of RUNX2 and osteocalcin.Conclusion:mPRP can promote the osteogenic differentiation of SHED.

BACKGROUND:Previous experiments have shown that modified platelet-rich plasma activated by liquid nitrogen freezing and thawing can promote the proliferation of human bone marrow mesenchymal stem cells and dental pulp stem cells in a concentration-dependent manner. OBJECTIVE:To investigate the effect of modified platelet-rich plasma at different concentrations on the proliferation of dental pulp stem cells from human exfoliated deciduous teeth. METHODS:Platelets were selected and harvested by automatic blood cellanalyzer, and then activated by liquid nitrogen freezing and thawing.α-MEM served as basal medium. Different concentrations of modified platelet-rich plasma (2%, 5%, 10%, 20%) or 10%fetal bovine serum were added, respectively. The difference in cellproliferation was observed. RESULTS AND CONCLUSION:Modified platelet-rich plasma at different concentrations could promote the proliferation of dental pulp stem cells from deciduous teeth. The effects of 2%modified platelet-rich plasma and 10%fetal bovine serum on promoting the proliferation of dental pulp stem cells from deciduous teeth were similar. These results indicated that 2%modified platelet-rich plasma could promote the proliferation of dental pulp stem cells from deciduous teeth, and substitute for fetal bovine serum in the amplification of dental pulp stem cells from deciduous teeth in vitro.

Biochemical indicators of bone metabolism may change at the initial stage of type 2 diabetes, and the risk of osteoporosis and fracture in patients is significantly increased compared with normal people. Osteoporosis is a systemic bone disease characterized by low bone mass and degeneration of bone tissue microstructure, leading to increased bone fragility and susceptibility to fractures. The main mechanism of type 2 diabetes is insulin resistance (IR). A large number of clinical studies have shown that there is a relationship between insulin resistance and osteoporosis. There is a close association between miR-155 in microRNAs (miRNAs) and IR. At present, studies have found that the increased expression of miR-155 can improve insulin sensitivity, and IR is a potential mechanism leading to diabetes induced osteoporosis. However, although the risk of osteoporosis or fracture in type 2 diabetes patients increases, their bone mineral density (BMD) values are still normal or even slightly increased. Therefore, at present, the relevant mechanism of osteoporosis fracture in type 2 diabetes cannot be fully explained by BMD alone. This article mainly reviews the progress of the relationship between miR-155 and osteoporosis in type 2 diabetes patients.

OBJECTIVE To observe whether mitochondria can be transferred from mesenchymal stem cells(MSCs)to irradiated cells by establishing a mitochondrial fluorescent reporting system.METHODS The lentiviral vector pSIN-EF1α-COX8A-DsRed2(named COX8A-DsRed2)that might guide the expres-sion of red fluorescence protein in the membrane of mitochondria was constructed.A lentivirus(named Lv-COX8A-DsRed2)was prepared in 293T cell line.Dental pulp stem cells(DPSCs)(named DPSC-COX8A-DsRed2)was infected with Lv-COX8A-DsRed2.The intracellular expression of the red fluores-cence protein in DPSC was observed under fluorescence microcopy.The mitochondrial localization of the expressed red fluorescent probe in DPSC-COX8A-DsRed2 was confirmed according to TOMM20 immunostaining and MitoTracker Green staining results,which could specifically label mitochondria.The IEC-6 cells that received 10 Gy X-ray radiation were used as an injured cell model.The co-culture system was established by supplementing DPSC-COX8A-DsRed2 into the culture plate with the irradi-ated IEC-6 labelled by CFSE for 24 h.RESULTS The imaging results of fluorescent microcopy obser-vation showed that DPSC-COX8A-DsRed2 expressed the mitochondrial fluorescent reporting system,which was co-located with TOMM20 protein and Mito Tracker Green.The imaging results of confocal fluorescence microcopy showed that the mitochondria with red fluorescent protein were transferred from DPSC-COX8A-DsRed2 to the irradiated IEC-6 cells,suggesting that the established mitochondrial fluorescent reporting system could indicate mitochondrial transfer from donor cells to injured ones.CONCLUSION DPSC-COX8A-DsRed2 stably expressing the mitochondrial fluorescent reporting system is established,which can be used to track mitochondrial transfer.