Project description:GDF5 is a potent tenogenic differentiation inducer. We previously demonstrated that GDF5 induced in vitro tenogenesis of human bone marrow-derived stromal cells (hMSC). We used microarrays to detail the global gene expression profiles underlying tenogenesis and identified distinct classes of up-regulated genes during this process.
Project description:Human bone marrow mesenchymal stromal cells are capable of limited self-renewal and multi-lineage differentiation in vitro. Several studies have demonstrated that microRNAs, post-transcriptional modifiers of protein expression, play crucial roles in the regulation of these complex processes. To gain knowledge regarding the role of microRNAs in human adipocyte regulation, we examined the microRNA expression profile of the immortalized human bone marrow-derived stromal cell line hMSC-Tert20. We identified 12 microRNAs that were differentially expressed during adipogenesis, of which several have previously been shown to play important roles in adipocyte biology. The expression of miR-155, miR-221 and miR-222 decreased during the adipogenic program, suggesting that they act as negative regulators of differentiation. Interestingly, adenovirus-mediated expression of either miR-155 alone or miR-221 plus miR-222 significantly inhibited adipogenesis and repressed induction of the master regulators C/EBP? and PPAR?. Our study provides the first experimental evidence that miR-155, miR-221 and miR-222 function in human adipocyte differentiation. The telomerase immortalized human bone marrow-derived stromal cell line hMSC-Tert20 was differentiated towards adipocytes, and total RNA was harvested at various time points (0, 8, 24, 32, 48 and 72 hours, and 7, 14 and 21 days). All hybridizations, except for 0h, 8h and 32h, were performed twice. The expression of each miRNA at a given time point was calculated as a ratio relative to its level on day 0. No dye swaps.
Project description:The aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip® Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis. Experiment Overall Design: hMSC were derived from mononuclear cells (MNC) of bone marrow aspirates of four patients. MNC cultures were maintained in differentiation medium containing ascorbic acid-2 phosphate and dexamethasone, and hMSC were collected at different time points. The experimental protocol was specifically devised to mark five steps of hMSC differentiation (MD). The reference sample consisted in MNCs before the addition of differentiation medium (MD1).
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:We performed small RNA sequencing on telomerized human bone marrow skeletal (stromal or mesenchymal) stem cells (hMSC-TERT) at various timepoints during differentiated into osteoblasts
Project description:Recent studies have provided links between glutamine metabolism and bone remodeling, but little is known about its role in primary osteoporosis progression. We aimed to determine the effects of inhibiting glutaminase (GLS) on two types of primary osteoporosis and elucidate the related metabolism. To address this issue, age-related and ovariectomy (OVX)-induced bone loss mouse models were used to study the in vivo effects of CB-839, a potent and selective GLS inhibitor, on bone mass and bone turnover. We also studied the metabolic profile changes related with aging and GLS inhibition in primary bone marrow stromal cells (BMSC) and that related with OVX and GLS inhibition in primary bone marrow-derived monocytes (BMM). Besides, we studied the possible metabolic processes mediating GLS blockade effects during aging-impaired osteogenic differentiation and RANKL-induced osteoclast differentiation respectively via in vitro rescue experiments. We found that inhibiting GLS via CB-839 prevented OVX-induced bone loss while aggravated age-related bone loss. Further investigations showed that effects of CB-839 treatment on bone mass were associated with alterations of bone turnover. Moreover, CB-839 treatment altered metabolic profile in different orientations between BMSC of aged mice and BMM of ovariectomized mice. In addition, rescue experiments revealed that different metabolic processes mediated glutaminase blockade effects between aging-impaired osteogenic differentiation and RANKL-induced osteoclast differentiation. Taken together, our data demonstrated the different outcomes caused by CB-839 treatment between two types of osteoporosis in mice, which were tightly connected to the suppressive effects on both aging-impaired osteoblastogenesis and OVX-enhanced osteoclastogenesis mediated by different metabolic processes downstream of glutaminolysis.
Project description:The aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip® Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis. Experiment Overall Design: hMSC were obtained from bone marrow aspirates of four patients. hMSC cultures were maintained in mineralization medium containing β-glycerophosphate, and collected at different time points. The experimental protocol was specifically devised to mark three steps of hMSC mineralization (MM). The reference sample consisted in confluent hMSCs before the addition of mineralization medium (MD4).
Project description:In the present study we analyzed the effect of primary osteoporosis on the transcriptome of human mesenchymal stem cells (hMSC; alternatively named mesenchymal stromal cells) from human bone marrow. Human MSC of elderly patients suffering from osteoporosis were isolated from femoral heads after low-energy fracture of the femoral neck. Bone marrow of age-matched, non-osteoporotic donors was obtained of femoral heads after total hip arthroplasty.
Project description:In the present study we analyzed the effect of cellular senescence on the transcriptome of human mesenchymal stem cells (hMSC; alternatively named mesenchymal stromal cells) from bone marrow. Human MSC were isolated from femoral heads of non-osteoporotic donors after total hip arthroplasty.
Project description:In the present study we analyzed the effect of primary osteoporosis and advanced donor age on the transcriptome of human mesenchymal stem cells (hMSC; alternatively named mesenchymal stromal cells) from bone marrow. Human MSC of elderly patients suffering from osteoporosis were isolated from femoral heads after low-energy fracture of the femoral neck. Control cells were obtained from bone marrow of femoral heads of middle-aged, non-osteoporotic donors after total hip arthroplasty.