Effects Of Bone Marrow Transplantations On Radiation Induced Bone Marrow Adipogenesis In Mice

Objectives:1. To argue the relationship of hematopoietic cells'injury and adipogenesis through observing the injury effects of different doses of 60Coy-ray on hematopoietic cells and adipogenesis in mouse bone marrow, to establish mouse models of bone marrow adipogenesis, and to provide the experimental basis for researching diseases with bone marrow adipogenesis.2. To argue the regulating role of hematopoietic stem/progenitor cells to the differentiation of mesenchymal stem cells by observing effects of bone marrow transplantation on mouse bone marrow adipogenesis inducing by 60Coy-rays,.Methods:PartⅠThe study of bone marrow adipogenesis induced by 60Coy-ray 1.8 week old female Babl/c mice 128 were randomly divided into normal group,2Gy group,4Gy group and 6Gy group, respectively used 2Gy,4Gy,6Gy 60Coy-ray irradiation for radiation treatment, after radiation 6,12,24,48 days, each group take 8 mice made femur bone marrow biopsy, observed and compared injury of bone marrow and bone marrow adipogenesis at different time points under different radiation.2. Optional 10 view of bone marrow cavity in 200-fold higher magnification, application PAS-8000 image analysis system pathology measured the area of intramedullary fat cells size percentage of each view of each sectionPartⅡEffects of bone marrow transplantations on 60Coy-ray induced bone marrow adipogenesis in mice 1.8 weeks old female Babl/c mice 120 were randomly divided into normal, transplant group and irradiation group, the latter two groups were using 6Gy 60Coy-ray irradiation, then the transplant group infusion the same gene male bone marrow cells 5×106 cell/mouse, after radiation 6,12,24,48 days, each group take 8 mice made femur bone marrow biopsy.At 48 days, remaining mice of each group received 6Gy 60Coy- ray again. At 54 days, each group of mice were made bone marrow biopsy. Observed and compared injury of bone marrow and bone marrow adipogenesis of transplantation group, irradiation group and control group at different time points.2. Optional 10 view of bone marrow cavity in 200-fold higher magnification, application PAS-8000 image analysis system pathology measured the area of intramedullary fat cells size percentage of each view of each section.3. With Fluorescence in situ hybridization detection the implantion of transplanted mice.Results:PartⅠ6 days after irradiation,6.0Gy group bone marrow biopsy could observe obvious adipose tissue, percentage of fat vacuoles area was (26.9±5.22%), as time goes by, could see more and more adipose tissue, to 24 days reached the highest level,was (69.61±6.39%), nearly occupied the entire bone marrow cavity, could form a typical model of bone marrow adipogenesis, but at 48 days was (6.02±1.15%); At 6 and 12 days the WBC and HB of peripheral decreased significantly. From 6 to 48 days the adipose tissue of normal group had non-changes in the percentage of fat vacuoles area,was (1.90±0.52%); The WBC and HB of peripheral had no changed.2.0Gy group on the 6th day the percentage of fat vacuoles area was (5.71±1.54%), at 12 days was (8.74±1.82%), over time, adipose tissue less and less,at 48 days was (2.32±0.65%);At 6 and12 days the WBC and HB of peripheral decreased a litte.4.0Gy group on the 6th day the percentage of fat vacuoles area was (12.08±5.22)%, as time goes by, more and more adipose tissue appeared, to 24 was (22.08±5.64%), but at 48 days was (4.15±1.05%);The WBC and HB of peripheral decreased more than 2.0Gy group but less than 6.0Gy group. The results shew that with the doses of 60Coy-ray irradiation increasing, bone marrow hematopoietic tissue injury is more serious, more and more severe bone marrow adipogenesis.PartⅡ6 days after irradiation, compared the bone marrow biopsy of transplanted group and irradiation group,there was no significant changes in adipose tissue, the percentage of fat void area was (25.8±4.98%,24.9±5.45%). Over time, the adipose tissue of transplanted group was less and less, while radiation group was more and more.At 24 days,the percentage of fat vacuoles area of the two groups were (15.9±4.76%,70.54±6.21%). At 48 days, the percentages of fat vacuoles area of the two groups were (4.5±1.23%,6.13±1.05%), but after 6 days of the second time irradiation, the adipose tissue occupied the entire bone marrow cavity of transplanted group and irradiation group, the percentage of fat vacuoles area was (73.62±6.20%, 69.17±6.13%); and normal group from 6 days to 48 days the adipose tissue was rare, after 6 days in received 6.0Gy 60Coy-ray irradiation, could observe obvious adipose tissue, the percentage of fat vacuoles area was (25.62±1.80%). But the WBC and HB of peripheral of transplanted group decreased less then radiation group at 6 and 12 days.Conclusions:1.60Coy-ray induced adipogenesis in bone marrow, which was relevanted to the activity of hematopoietic stem/progenitor cells.2. Hematopoietic stem/progenitor cells in bone marrow had the role of regulating mesenchymal stem cell differentiation, which inhibit its differentiation to adipocytes.