ObjectiveTo compare the effects on the osteogenesis of bone marrow mesenchymal stem cells (BMSCs) between hypoxia and hypoxia mimetic agents dimethyloxalylglycine (DMOG) under normal oxygen condition. MethodsBMSCs were isolated and cultured from healthy 3-4 weeks old Kunming mouse. Cell phenotype of CD29, CD44, CD90, and CD34 was assayed with flow cytometry; after osteogenic, adipogenic, and chondrogenic induction, alizarin red staining, oil red O staining, and toluidine blue staining were performed. The passage 3 BMSCs were cultured under normal oxygen in control group (group A), under 1%O2 in hypoxia group (group B), and under normal oxygen and 0.5 mmol/L DMOG in DMOG intervention group (group C). BMSCs proliferation was estimated by methyl thiazolyl tetrazolium assay at 1, 2, 3, and 4 days. Alkaline phophatase (ALP) expression was determined at 7 and 14 days after osteogenic induction. Western blot was employed for detecting hypoxia inducible factor-1α(HIF-1α) at 24 hours. Real time fluorescence quantitative PCR was employed for detecting the mRNA expression of runt-related transcription factor 2 (RUNX2) and Osterix at 3 and 7 days. Alizarin red staining was applied to assess the deposition of calcium tubercle at 21 days. ResultsThe BMSCs presented CD29(+), CD44(+), CD90(+), and CD34(-); and results of the alizarin red staining, oil red O staining, and toluidine blue staining were positive after osteogenic, adipogenic, and chondrogenic induction. No significant difference in BMSCs proliferation was observed among 3 groups at 1 day (P>0.05); compared with group A, BMSCs proliferation was inhibited in group C at 2, 3, and 4 days, but no significant difference was observed (P>0.05); compared with group A, BMSCs proliferation was significantly promoted in group B (P < 0.05). At each time point, compared with group A, the ALP expression, HIF-1αprotein relative expression, and mRNA relative expressions of RUNX2 and Osterix were significantly up-regulated in groups B and C (P < 0.05); compared with group B, the ALP expression, the RUNX2 and Osterix mRNA relative expression were significantly up-regulated in group C (P < 0.05); compared with group C, the HIF-1αprotein relative expression was significantly up-regulated in group B (P < 0.05). The alizarin red staining showed little red staining materials in group A, some red staining materials in group B, and a large number of red staining materials in group C. ConclusionHypoxia can promote BMSCs proliferation, DMOG can not influence the BMSCs proliferation; both hypoxia and DMOG can improve osteogenic differentiation of BMSCs, and DMOG is better than hypoxia in improving the BMSCs osteogenesis.
ObjectiveTo understand the initiation, maturing, and resolution of thrombus by comparing the length and weight of thrombus at different time in the rat inferior vena cava (IVC) stenosis model. MethodsForty-eight female Sprague Dawley rats, weighing 180-230 g, were selected to prepare the IVC stenosis model by blocking the most of the IVC blood flow. The length and weight of IVC thrombus were measured at different time points, the histological features were observed via HE staining. ResultsBlood clots formed after 2 hours of modeling, the thrombus length and weight showed no significant difference between at 2 hours and 4 hours after modeling (P>0.05). The thrombus length and weight increased significantly at 6 hours, showing significant differences between at 2 and 4 hours and at 6, 8, 12, 24, and 48 hours (P<0.05); and from 6 to 48 hours, there was no significant difference in the thrombus length and weight (P>0.05), indicating that thrombus was stable, or maturing. Blood clots began to become smaller after 3 days when compared with ones at 48 hours (P<0.05), indicating the start of resolution at 3 days. At 7 days, the thrombus length and weight became further smaller when compared with ones at 3 days (P<0.05). The thrombus completely subsided at 21 days, the IVC recanalized. HE staining showed that thrombus formed after 2 hours of modeling; from 6 to 48 hours, the lumen became hyperemia, and the inflammatory cells, especially neutrophils, could be found. The organization of thrombus could be observed at 3 days and 7 days; thrombus gradually vanished at 21 days. ConclusionThe time of thrombus initiation, maturing stage, and resolution stage is 6 hours, 6 to 48 hours, and 3 to 21 days after modeling, respectively.