Project description:Pathological processes like osteoporosis or steroid-induced osteonecrosis of the hip are accompanied by increased bone marrow adipogenesis. Such disorder of adipogenic/osteogenic differentiation, which affects also bone marrow derived mesenchymal stem cells (BMSCs) contributes to bone loss during aging. Therefore, we investigated the effects of extracellular vesicles (EVs) isolated from human (h)BMSCs during different stages of osteogenic differentiation on osteogenic and adipogenic differentiation capacity of naïve hBMSCs.
Project description:Extracellular nucleotides are potent signaling molecules mediating cell-specific biological functions. We previously demonstrated that adenosine 5'-triphosphate (ATP) inhibits the proliferation while stimulating the migration, in vitro and in vivo, of human bone marrow-derived mesenchymal stem cells (BM-hMSC). Here, we investigated the effects of ATP on BM-hMSC differentiation capacity. Molecular analysis showed that ATP treatment modulated the expression of several genes (e.g. wnt-pathway-related genes) governing osteoblastic and adipogenic differentiation of MSCs. Functional studies demonstrated that ATP, under specific culture conditions, stimulated adipogenic and osteogenic differentiation by significantly increasing the lipid accumulation and the expression levels of the adipogenic master gene PPARγ (peroxisome proliferator activated receptor-gamma) and by promoting the mineralization and the expression of the osteoblast-related gene RUNX2 (Runt-related transcription factor 2), respectively. BM-hMSCs cells were transiently exposed to ATP 1mM for 24 hours (ATP pre-treatment) before starting differentiation induction. Then, BM-hMSCs were cultured under adipogenic/osteogenic conditions. Gene Expression Profile was performed on differentiate cells after 3 weeks of induction culture.
Project description:LncRNA transcriptional profiling of human mesenchymal stem cells comparing control undifferentiated HMSC with Day3 and Day6 adipogenic differentiation stages
Project description:Extracellular nucleotides are potent signaling molecules mediating cell-specific biological functions. We previously demonstrated that adenosine 5'-triphosphate (ATP) inhibits the proliferation while stimulating the migration, in vitro and in vivo, of human bone marrow-derived mesenchymal stem cells (BM-hMSC). Here, we investigated the effects of ATP on BM-hMSC differentiation capacity. Molecular analysis showed that ATP treatment modulated the expression of several genes (e.g. wnt-pathway-related genes) governing osteoblastic and adipogenic differentiation of MSCs. Functional studies demonstrated that ATP, under specific culture conditions, stimulated adipogenic and osteogenic differentiation by significantly increasing the lipid accumulation and the expression levels of the adipogenic master gene PPARγ (peroxisome proliferator activated receptor-gamma) and by promoting the mineralization and the expression of the osteoblast-related gene RUNX2 (Runt-related transcription factor 2), respectively.
Project description:LncRNA transcriptional profiling of human mesenchymal stem cells comparing control undifferentiated HMSC with Day3 and Day6 adipogenic differentiation stages Three-condition experiment, Day0 vs. Day3 vs Day6 cells. Day0: 4 replicates, Day3: 3 replicates and Day6: 3 replicates.
Project description:Long non-coding RNAs (lncRNAs) are master regulators of gene expression and have recently emerged as potential innovative therapeutic targets. The deregulation of lncRNA expression patterns has been associated with age-related and noncommunicable diseases, including osteoporosis and bone tumors. However, the specific role of lncRNAs in physiological or pathological conditions in the bone tissue still needs to be further clarified, for their exploitation as therapeutic tools. In the present study, we evaluate the potential of the lncRNA CASC2 as a regulator of osteogenic differentiation and mineralization. Results show that CASC2 expression is decreased during osteogenic differentiation of human bone marrow-derived Mesenchymal Stem/Stromal cells (MSCs). CASC2 knockdown using small interfering RNA (siCASC2) increases the expression of the late osteogenic marker Bone Sialoprotein (BSP), but does not impact ALP staining levels, or the expression of early osteogenic transcripts including RUNX2 and OPG. Although siCASC2 does not impact hMSC proliferation nor apoptosis, it promotes the mineralization of hMSC cultured under osteogenic-inducing conditions, as shown by the increase of calcium deposits. Mass spectrometry-based proteomic analysis revealed that 89 proteins are regulated by CASC2 at late osteogenic stages, including proteins associated with bone diseases or anthropometric and musculoskeletal traits. Specifically, the Cartilage Oligomeric Matrix Protein (COMP) is highly enhanced by CASC2 knockdown at late stages of osteogenic differentiation, at either transcriptional and protein level. Inhibition of COMP impairs osteoblasts mineralization as well as the expression of BSP levels. The results indicate that lncRNA CASC2 regulates late osteogenesis and mineralization in hMSC via COMP and BSP. In conclusion, this study suggests lncRNA CASC2 as a potential new therapeutic target in bone mineralization.
Project description:Gene Expression analysis of a differentiation timeseries of human Mesenchymal Stem Cells (hMSCs) in the presence of adipogenic/osteogenic factors. hMSCs differentiate into fat cells when treated with dexamethasone (10^-6 M), insulin (10 ug/ml), rosiglitazone (10^-7 M) and IBMX (250 uM). TGFbeta (5 ng/ml) inhibits this process and redirects these cells to differentiate into bone cells. Introduction: Patients suffering from osteoporosis show an increased number of adipocytes in their bone marrow, concomitant with a reduction in the pool of human mesenchymal stem cells (hMSCs) that are able to differentiate into osteoblasts, thus leading to suppressed osteogenesis. Methods: In order be able to interfere with this process, we have investigated in vitro culture conditions whereby adipogenic differentiation of hMSCs is impaired and osteogenic differentiation is promoted. By means of gene expression microarray analysis, we have investigated genes which are potential targets for prevention of fat cell differentiation. Results: Our data show that BMP2 promotes both adipogenic and osteogenic differentiation of hMSCs, while TGFβ inhibits differentiation into both lineages. However, when cells are cultured under adipogenic differentiation conditions, which contains cAMP-enhancing agents such as IBMX of PGE2, TGFβ promotes osteogenic differentiation, while at the same time inhibiting adipogenic differentiation. Gene expression and immunoblot analysis indicated that cAMP-induced suppression of HDAC5 levels plays an important role in the inhibitory effect of TGFβ on osteogenic differentiation. By means of gene expression microarray analysis, we have investigated genes which are downregulated by TGFβ under adipogenic differentiation conditions and may therefore be potential targets for prevention of fat cell differentiation. We thus identified 9 genes for which FDA-approved drugs are available. Our results show that drugs directed against the nuclear hormone receptor PPARG, the metalloproteinase ADAMTS5 and the aldo-keto reductase AKR1B10 inhibit adipogenic differentiation in a dose-dependent manner, although in contrast to TGFβ they do not appear to promote osteogenic differentiation. Conclusions: The approach chosen in this study has resulted in the identification of new targets for inhibition of fat cell differentiation, which may not only be relevant for prevention of osteoporosis, but also of obesity. hMSCs were induced to differentiate in the presence dexamethasone, insulin and rosiglitazone, to which was added either 50 ng/ml BMP2; BMP2 + TGFbeta; BMP2 + IBMX; BMP2 + TGFbeta + IBMX.