Multi-omics Analysis Of Differentiation Differences Of Bone Marrow Mesenchymal Stem Cells In Osteoporosis

ObjectiveTo study the functional differences of adipogenic and osteogenic differentiation of bone marrow mesenchymal stem cells in ovariectomized rats in osteoporosis,so as to provide a new idea for further exploring the pathogenesis and clinical treatment of osteoporosis.BackgroundOsteoporosis is a systemic bone disease characterized by low bone mass and degradation of bone microstructure,resulting in increased bone fragility and increased risk of fracture.However,the pathogenesis of osteoporosis is not clear,and ovariectomized mice are the most commonly used model to simulate the occurrence of human postmenopausal osteoporosis.At the same time,bone marrow mesenchymal stem cells play a pivotal role in the occurrence of osteoporosis.Bone marrow mesenchymal stem cells can differentiate into osteoblasts and osteoblasts in the bone marrow microenvironment,and also participate in the regulation of the production of osteoclasts.However,in the process of osteoporosis,we found that there were significant differences in adipogenic and osteogenic differentiation between bone marrow mesenchymal stem cells from ovariectomized rats and normal rats,but the mechanism of this difference is unknown.Methods1.Forty female SD rats were randomly divided into two groups（n = 20 / group）:blank control group（control group）and model group（OVX group）.After that,bilateral ovariectomy was performed in the model group to establish an animal model of osteoporosis.2.8 weeks after operation,bilateral femurs of rats were extracted and mirco CT was used to scan the femoral growth plate of rats to identify the osteoporosis model.3.After the establishment of osteoporosis model,the bone marrow mesenchymal stem cells were extracted,and the extracted bone marrow mesenchymal stem cells were identified and cultured by flow cytometry.4.Mesenchymal stem cells were induced by osteogenic and adipogenic induction solution.After osteogenic induction,they were identified by alkaline phosphatase staining（ALP）,and after adipogenic induction,they were identified by oil red O staining.5.The osteogenic markers bsp2 and Runx2 and the adipogenic markers PPARy and C / EBPα were detected by Western blot Expression quantity.Results1.Ovx-derived bone marrow mesenchymal stem cells were higher than Control-derived bone marrow mesenchymal stem cells in osteogenesis as well as in lipogenic differentiation during osteoporosis.2.We used proteomics to identify the number of proteins in both groups 5523,the number of peptides identified 26141,208 differentially expressed proteins,of which 86 were upregulated and 119 were decreased in expression,of which differentially expressed proteins were enriched in 135 different pathways,with screening conditions of Ratio >1.5 or <0.667 and Pvalue <0.05.3.In the analysis of reverse transcriptomics we used DESeq for differential analysis of gene expression in two groups of bone marrow MSCs,and the screening differentially expressed genes condition was: expression differential fold|log2Fold Change| > 1,significant P-value < 0.05,and found that the differential m RNA expression in two groups of bone marrow MSCs was more significant,in which 1308 genes were upregulated kinds of genes and 986 kinds of genes were down-regulated,of which 109 pathways were analyzed for gene enrichment of expression differences,with screening condition of P-value<0.05.4.By comparing the enrichment results of both proteomics and transcriptomics,we found that both differential proteins and genes were mainly enriched in ECM-receptor interaction pathway,so we inferred that ECM-receptor interaction pathway is the main cause of differential differentiation of bone marrow MSCs pathway and a key pathway in the pathogenesis of osteoporosis.Conclusionswe found for the first time that OVX has significant differences in the differentiation ability of bone marrow mesenchymal stem cells in the environment of estrogen deficiency when simulating postmenopausal osteoporosis.Proteomic and reverse transcriptomic analysis provides a new direction for us to further study the mechanism of osteoporosis,to provide new ideas for clinical diagnosis and early intervention in the occurrence and development of osteoporosis.