| There are two results, that can be developed by tissues and organs repair regeneration, pancreas injury, acute and chronic pancreas inflammations. One is damaged cell replaced by the new same kind of cells, and function and construction can be recovered completely. The other is damaged cell cannot be regenerated, the tissue injury is replaced by fiber scar and lead to fibrosis, function and construction cannot be recovered completely as the situation before the damage. Division and proliferation of adult pancreas cells are difficult. For getting the ideal repair of function and construction after pancreas damage, it should have adult multifunctional stem cells or the other similar cells. And that is the ultimate way to solve the regeneration problem. Recently, it has not have break.Stem cell can be classified as embryo stem cell and adult stem cell. The main function of adult stem cells which founded in tissues at the present is the preparation for repairing damaged tissues. In bone marrow, not only have haemopoietic stem cells had the generation function and differentiation ability but mesenchymal stem cells (MSCs) have. In some situation, MSCs can beinduced to special tissue cells for replacing damaged tissue. MSCs have multi-directional differentiation potentiality and plasticity obviously. MSCs can migrate to some haematopoiesis tissues and differentiate to corresponding tissue cells in vivo, and have the ability to differentiate mesoderm and neuroectoderm tissue cells (such as osteoblast, chondroblast, adipocyte, fibroblast, endotheliocyte, myocyte, neurocyte and stroma-cell which can support hematopoiesis) in different induction condition (dexamethasone, TGF-β, FGF, insulin, for instance) in vitro.For knowing the immunity after MSCs being transplanted, some scholar used fluorescent labeling to label histoleucocyte which was non-passage and isolated directly from bone marrow and MSCs which was purified, and transplanted the labeling cells to rats'bodies. The result was no detection of non-passage histoleucocyte which labeled. It is considered that histoleucocyte could be rejected by immune system of host rat. Purified MSCs could survive, ecesis, and had no rejection in host rats; that proves that MSCs have unique immunogenicity and antigenicity is low even not have. It is possible to transplanting stem cells and ecesising successfully in vivo by the feature.The research is based on the feature mentioned. It discussed the repair function and mechanism by using pancreas injury animal models which used rats'MSCs cell cultured in vitro and injected after purifying.1. The cell culture of rats'MSCs in vitroCell adherence culture and tissue culture, which the research used, can get a large number of MSCs with high cell purity. G0-G1 cells are account 85.87% on the total cellular score determined by flow cytometer. It shows MSCs have infinite generation ability.2. The induction and regeneration of MSCs in vitroThe purified MSCs were added in osteoblast induction liquid and lipoblast induction liquid. After two weeks inducted, the cells were tested the production of cell induction by alkaline phosphatase and oil red staining. The result showed that MSCs have been inducted to osteoblast and lipoblast after inducted cell culture, and the specificity staining was positive. It proves the ability of MSCs'multi-differentiation.3. The survival rate of animal which injected MSCsTwo groups of animal model were set up, one was injected the MSCs (MSCs group), the other was injected the isotonic sodium chloride (group). The result showed the MSCs group was better than the NaCl2 group in aspects of mental status, activity, eating and drinking. To be observed 6 weeks continuously, the mortal rate of MSCs group is 10%, by contrast, that of the NaCl2 group is 80%. The differences between two groups were significant by statistics analysis.4. The observation of the position where MSCs settled down in vivoThe MSCs with Ad-EGFP labeled were transplanted into animal models. The animals were executed by luxation after transplantation 1 day, 3 day and 7 day. The pancreas tissues would be taken out, and be made into frozen section which would be observed with confocal microscopy. To observe the frozen section in the first 24 hours after injection of MSCs, the back ground was clean; there has only little non-specificity fluorescence; only one circular fluorescent image was showed in tissue frozen section and no fluorescent labeling was found. The circle is micro-circulatory system lumina tissue, and it was strong considered as venule by pathology specialist. Therefore, afterMSCs entered the damaged tissue, circulatory system was the first place where MSCs have been, and angei-endothelial tissue was the first repaired tissue. Duo to MSCs entered the angei-endothelial of damaged tissue's circulatory system, small vessels got repaired, and it improved blood supply and ventilation of tissue. Damaged cell's nutrition state improved, and got repaired. That leaded to tissue repaired. It might be one of the mechanisms of repairing damaged cells by MSCs.Some experiments showed that bone mesenchymal stem cells (BMSCs) can differentiate to pancreas cell by using inducing factor in vitro. It can find out in the research that BMSCs can differentiate to pancreas cells and substituted damaged or necrosis cells even though BMSCs was not induced to pancreas cells in vitro, so that the damaged tissue could recover quickly. The procedure happened at the proper circumstance with various kinds of biological factor in proper proportion if it was the emergency request of body. |
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