Study On The Subgroup Of Bone Mesenchymal Stem Cells In Elderly Hip Fracture Patients By Single Cell Transcriptome Sequencing

BackgroundHip fracture is one of the most common injuries in the elderly,and its prognosis is poor.The rate of disability within one year after fracture is over 50% and the mortality rate is up to 36%.Although the current treatment program emphasizes early operation fixation and functional rehabilitation exercise,the mortality rate and disability rate still remain high.In recent years,the high rate of disability and high mortality after the hip fracture in the elderly have a close relationship with the immunity and inflammatory disorder after the fracture of the body.Therefore,at the same time of surgical treatment,we should correct the disorder of immune function in elderly patients with hip fracture,which will be the key to solve this problem.Bone marrow mesenchymal stem cells have a strong ability of tissue repair and immunomodulatory function,and have achieved great success in many immunological and inflammatory related diseases.However,there is no report about the regulation of immune function in elderly patients after trauma.Bone marrow mesenchymal stem cells(MSCs)are highly heterogeneous cell populations.In the past,our understanding of heterogeneous cell populations is limited at the level of group level.Therefore,it is very necessary to have a more systematic and comprehensive understanding and exploration of the composition of subgroup and find the subgroup/subgroup ratio that is truly meaningful(which is related to immunomodulation).In recent years,the development of single cell transcriptome sequencing technology has laid an important foundation for the study of the single cell level of heterogeneous cell populations.ObjectiveTo analyze the heterogeneity of bone marrow mesenchymal stem cells in elderly patients with hip fractures by single cell transcriptome sequencing technology,identify different subgroups,and analyze the function of each group.for each cell subgroup,compare the subgroup with the others.All the subgroups were analyzed and compared for differences.The genes with high expression in each subgroup were obtained as the characteristic genes of the subgroups.The genes specifically expressed in each group were used to analyze through the database to find out the specific expression of genes associated with what disease.Find out a relevant subgroup or subgroup ratio which is related to immunomodulation and lay asolid foundation to reduce the complications of elderly patients after hip fracture surgery through stem cell therapy.Method1.One patients with intertrochanteric fracture need to be treated surgically.During the reaming process,about 10 ml bone marrow was extracted by syringe and sent to the laboratory immediately in sterile bag.2.The mixture of bone marrow mesenchymal stem cells was isolated and cultured,and then the cells were fused when the cells grew to 80%.Then the cells were cultured to obtain the second generation of MSCs.3.The second generation of MSCs was identified by flow cytometry,and was differentiated into osteoblasts,chondrocytes and adipocytes.It was identified as bone marrow mesenchymal stem cells.4.Cell digestion of the second generation of MSCs,when the cell volume reached 1000 /ul,total volume 100 ul,dissolved in PBS and put in a sterile bag and sent to the Beijing Capitalbio Technology Co.Ltd.ResultsBone marrow mesenchymal stem cells can be cultivated in the bone marrow of the elderly patients during the reaming process according to a certain method.The cultured bone marrow mesenchymal stem cells have the best cell morphology and adherence in the second generation;when the third generation occurs,the proliferation is not obvious and the adherence is not good;the cells no longer proliferate at the fourth generation;the cultured bone marrow mesenchymal stem cell suspension can be divided into 10 subgroups,and 10 subgroups have good correlations,each group has different proportions and functions are also different.ConclusionSingle cell sequencing technology is feasible for subgroup analysis of bone marrow mesenchymal stem cells in elderly patients with hip fractures;different cell subgroups determine cell properties;differential expression of top20 genes in each group is not identical in function,differentially expression of the top20 genes is associated with many diseases in the body.