BACKGROUND:The biological behavior of mesenchymal stem cells is influenced by the survival microenvironment.Pre-treatment of the microenvironment is an important means of regulating the function of mesenchymal stem cells. OBJECTIVE:To compare the differences in paracrine function of umbilical cord mesenchymal stem cells and adipose mesenchymal stem cells under oxidative stress and hypoxia,and to provide a theoretical basis for selecting appropriate pretreatment of mesenchymal stem cells to treat different diseases. METHODS:Umbilical cord mesenchymal stem cells and adipose mesenchymal stem cells were cultured by H2O2 or O2 oxygen,respectively,and cell morphology,proliferation,viability and paracrine factor expression were examined. RESULTS AND CONCLUSION:(1)The expression levels of brain-derived neurotrophic factor and transforming growth factor-β were higher in umbilical cord mesenchymal stem cells than in adipose mesenchymal stem cells under a normal culture environment,while the expressions of stromal cell-derived factor-1α and tumor necrosis factor stimulating factor-6 in the adipose mesenchymal stem cells were significantly higher than those in the umbilical cord mesenchymal stem cells.(2)There was no significant difference in the effect of low and moderate levels(≤100 μmol/L)of H2O2 on the viability of the two mesenchymal stem cells.However,increasing the H2O2 concentration from 50 μmol/L to 100 μmol/L resulted in a distinct increase in vascular endothelial growth factor expression in umbilical cord mesenchymal stem cells.The expression of basic fibroblast growth factor,vascular endothelial growth factor,stromal cell-derived factor-1α and interleukin-10 in adipose mesenchymal stem cells was greatly increased by increasing H2O2 concentration in this range.(3)1%O2 hypoxia promoted mesenchymal stem cell proliferation.After 24 hours of culture in 1%O2,gene expression levels were elevated in both mesenchymal stem cells,but the expression levels of vascular endothelial growth factor,interleukin-10 and tumor necrosis factor stimulating factor-6 were significantly higher in adipose mesenchymal stem cells than in umbilical cord mesenchymal stem cells.(4)It is concluded that hypoxia and oxidative stress preconditioning enhances the paracrine function of mesenchymal stem cells.However,mesenchymal stem cells respond differently to hypoxia and oxidative stress.Treating diseases can choose suitable mesenchymal stem cells for appropriate pretreatment to further enhance their therapeutic potential.

Objective:To systematically compare the cell damage characteristics of stretch injury model, oxygen-glucose deprivation (OGD) model and hydrogen peroxide (H2O2)-treated oxidative stress model, and to provide a reference for the selection of cell models in TBI research.Methods:After resuscitation of frozen HT-22 cells, HT-22 cells were seeded in Six-well plates, which were divided into experimental group and control group. The experimental group prepared cell stretch injury models, OGD models, and oxidative stress injury models respectively. The control group was cultured normally without any special treatment. The changes of cell morphology were observed by microscope, and cell viability was tested by CCK-8 analysis; cell proteins were extracted, and changes of apoptosis markers (Bcl-2, Bax), necroptosis markers (RIPK3, RIPK1), ferroptosis markers (ACSL4, GPX4, SLC7A11) were detected by Western blot.Results:Compared with the control group, all three injury models led to abnormal morphological changes in different degrees, restricted proliferation or cell shedding in HT-22 cells, indicating cell damage. CCK-8 analysis showed that the cell viability in different model treatment groups was significantly reduced (P<0.05). The results of Western blot demonstrated that the expression of GPX4, SLC7A11, Bax, RIPK3 and RIPK1 proteins in cells treated with 3.0 PSI tensile strength was significantly increased, with statistical significance (P<0.05). After OGD treatment for 12 h, the expression of SLC7A11 and Bax was significantly up-regulated, with statistical significance (P<0.05). After 800 μmol/L hydrogen peroxide treatment, the expression of Bcl-2 and RIPK1 proteins was significantly up-regulated, with statistical significance (P<0.05).Conclusion:The stretch model can better reflect the complex injury characteristics after TBI, and the OGD and H2O2 treatment models are more suitable for studying specific injury pathways.