| Objective:Adipose derived stem cells(ADSCs)are self-renewing and multi-directional mesenchymal stem cells isolated from adipose tissue.They can differentiate into a variety of cell phenotypes,promote osteogenesis,and then promote bone repair.HIF-1?is an upstream gene of vascular endothelial growth factor(VEGF).Overexpression of HIF-1? can enhance the secretion of VEGF in adipose stem cells and induce the formation of new blood vessels.Core decompression combined with tissue engineering bone transplantation for the treatment of femoral head necrosis is a relatively mature and effective method for the treatment of early ANFH lesions.This experiment by HIF-1 alpha transfection ADSCs composite HA/beta TCP,artificial bone transplantation of rabbit osteonecrosis in improved or cured early ischemic change or necrosis of the femoral head,for clinical provides the experimental basis for early repair osteonecrosis?Methods:In the first part,female New Zealand white rabbits were used as the research object to simulate the treatment path of core decompression for early femoral head necrosis.Kirschner was used to drill the femoral head,and then liquid nitrogen was used to freeze the femoral head.Bone morphological changes were observed one month after the operation,and X-ray,micro-ct and MRI were performed on the femoral head.Combined with the pathological section results,the model of femoral head necrosis in rabbits constructed by liquid nitrogen freezing was identified.The second part of the study mainly analyzed the effect of hif-1 on the proliferation,survival,osteogenic and lipogenic differentiation of adipose stem cells by isolating fat stem cells from rabbits in vitro,so as to further study the pathogenesis of femoral head necrosis and provide a new direction and theoretical basis for clinical prevention and treatment of femoral head necrosis.In the third part of the study,ADSCs transfected with hif-1 transfection and HA/-tcp artificial bone transplantation was used to treat frozen femoral head necrosis with liquid nitrogen in rabbits,aiming atearly improvement or cure of ischemic changes or necrosis of the femoral head,providing experimental basis for clinical repair of early femoral head necrosis,and opening up a new way for clinical treatment of early femoral head necrosis.The fourth part studies mainly through RNA-seq and bioinformatics analysis and statistical HIF-1 alpha transfection adipose stem cells composite HA/beta TCP in the process of the treatment of femoral head necrosis,femoral head before and after transplantation of gene expression in fat cells,and the gene expression differences apparent by qPCR,western blot and immunofluorescence for further confirmation,to prove the reliability of the chip sequencing results.Based on bioinformatics analysis method,we can preliminary understanding in the process of the femoral head necrosis affected fat/osteogenetic differentiation of stem cells into fat key regulatory gene,in order to further explore the pathogenesis of femoral head necrosis provides new train of thought,in order to realize new markers for the early diagnosis of femoral head necrosis,provide new targets for clinical treatment of femoral head necrosis and theoretical basis.Results:(1)Postoperative X-ray and micro-ct confirmed that the holes were put into appropriate positions.International is believed to femoral head inside the empty pit rate,bone marrow fat tissue hyperplasia,and BMD is central to the success of femoral head necrosis model logo,combined with femoral head morphology,we believe that the liquid nitrogen freezing method to construct the model of rabbit femoral head necrosis build is successful,can be simulated femoral head necrosis,can be used for subsequent experiments.In this part,the model of femoral head necrosis in rabbits was successfully constructed by liquid nitrogen freezing.(2)HIF-1 can promote the proliferation and survival of fat stem cells,promote the osteogenic differentiation of fat stem cells,and inhibit the lipogenic differenti-ation of fat stem cells,which has potential application value in the treatment of femoral head necrosis and bone repair.(3)The femoral head necrosis induced by liquid nitrogen refrigeration can lead to femoral head shape is irregular,and the trabecular bone thinning,fatty tissue in the bone,bone empty bone pit rate increased,but the transplant HIF-1 alpha transfectionadipose stem cells and implanted HA/beta TCP artificial bone can to a certain extent,the breakage of the trabecular bone and empty pit production,while the combination can significantly alleviate the symptoms of the necrosis of the femoral head,have very good effect for the treatment of femoral head necrosis.Hif-1 transfected fat stem cells combined with HA/-tcp artificial bone can significantly improve the treatment of femoral head necrosis.In the future clinical treatment of femoral head necrosis,hif-1 transfected fat stem cells combined with HA/ t-tcp artificial bone implantation may be an effective treatment.(4)In the treatment of femoral head necrosis by hif-1 transfection of fat stem cells with HA/ rt-tcp,CGRP may promote osteogenic differentiation of fat stem cells by activating the BMP signaling pathway,thus playing a role in the treatment of femoral head necrosis.Conclusion:In this study,the model of femoral head necrosis was successfully constructed by liquid nitrogen freezing method.In vitro experiments showed that hif-1 could promote the osteogenic differentiation of fat stem cells and inhibit the adipogenic differentiation of fat stem cells.The model of osteonecrosis of the femoral head in rabbits demonstrated that hif-1 transfected fat stem cells combined with HA/down-tcp could significantly inhibit the occurrence of osteonecrosis of the femoral head,and further second-generation sequencing and bioinformatics analysis suggested that this process might rely on CGRP to activate the BMP signaling pathway. |
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