Résumé
Objective @# To investigate the effect of erythropoietin producing hepatocyte kinase receptor ligand B2-erythropoietin producing hepatocyte kinase receptor B4 (EphrinB2/EphB4) on the osteogenic differentiation of MC3T3-E1 cells in a hypoxic environment to provide experimental evidence for hypoxia regulation of osteoblast differentiation.@*Methods @# Control groups and cobalt chloride (CoCl2)-induced hypoxia groups were set up first. qRT-PCR was used to detect the mRNA expression of the osteogenic markers alkaline phosphatase (ALP), collogen1 (COL I), runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN). ALP staining was used to detect the activity of cell alkaline phosphatase after osteogenic induction. The mRNA and protein expression levels of hypoxia inducible factor-1α (HIF-1α), EphrinB2 and EphB4 in the two groups were detected via qRT-PCR and Western blot. Then, the CoCl2 + inhibitor group was established. NVP-BHG712, an EphB4 phosphorylation inhibitor, was added to this group to prevent EphrinB2 from binding to EphB4 and producing signals. qRT-PCR and Western blot were used to detect the mRNA and protein expression of osteogenic markers, including ALP, RUNX2, COL I, and OCN. ALP staining and Alizarin red S staining were used to measure osteoblast differentiation and mineralization. @*Results @# Compared with the control group, the mRNA expression of the osteogenic differentiation markers ALP, RUNX2, COL-1, and OCN in MC3T3-E1 cells increased, and ALP activity and mineralization were enhanced under CoCl2-induced hypoxia in vitro (P<0.05). Additionally, the expression of HIF-1α, EphrinB2 and EphB4 was upregulated at the mRNA and protein levels under hypoxia (P<0.05). When NVP-BHG712 was used to block the connection between EphrinB2 and EphB4, the expression of osteogenic markers and ALP activity and mineralization were decreased (P<0.05).@*Conclusion@#EphrinB2/EphB4 can promote osteogenic differentiation of MC3T3-E1 cells and increase the expression of osteogenic markers and tissue mineralization in a hypoxic environment.
Résumé
Objective@#Explore the feasibility of POL intervention based on life skills in young students at high-risk of AIDS, and to provide reference for POL intervention.@*Methods@#Nine potential POLs were recruited from young students at high risk of AIDS in Xi’an, and received life-skill-based interventions from May to October in 2017. A unified approach was adopted before the intervention. The effect of intervention was evaluated at 1 month and 3 months after the intervention.@*Results@#The difference in POLs peer status and psychosocial ability scores was not significant after the intervention. The scores of persistence efficacy dimension of condom use efficacy before, 1-month and 3-month after the intervention were (10.56±1.88)(11.11±2.21)(12.89±2.09)(F=6.84, P<0.05) respectively. No significant changes were found in AIDS-related knowledge and behavior before and after the intervention. POL has increased from 108 students before intervention to 216 publicity coverage after three months intervention, however, the difference was not statistically significant. Feasibility analysis of the POL intervention showed that 8 of the POLs considered to be "very useful".@*Conclusion@#Life skill-based POL intervention for young students at high-risk of AIDS has a wide coverage and reasonable acceptance, as well as condom use adherence. The long-term effectiveness still needs to be verified.