Dataset Information

Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells.

ABSTRACT: : The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still not fully understood. Herein, we performed an epigenetic library functional screen and identified several novel compounds, including abexinostat, which promoted adipocytic and osteoblastic differentiation of hMSCs. Using gene expression microarrays, chromatin immunoprecipitation for H3K9Ac combined with high-throughput DNA sequencing (ChIP-seq), and bioinformatics, we identified several key genes involved in regulating stem cell proliferation and differentiation that were targeted by abexinostat. Concordantly, ChIP-quantitative polymerase chain reaction revealed marked increase in H3K9Ac epigenetic mark on the promoter region of AdipoQ, FABP4, PPAR?, KLF15, CEBPA, SP7, and ALPL in abexinostat-treated hMSCs. Pharmacological inhibition of focal adhesion kinase (PF-573228) or insulin-like growth factor-1R/insulin receptor (NVP-AEW51) signaling exhibited significant inhibition of abexinostat-mediated adipocytic differentiation, whereas inhibition of WNT (XAV939) or transforming growth factor-? (SB505124) signaling abrogated abexinostat-mediated osteogenic differentiation of hMSCs. Our findings provide insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways governing adipocyte and osteoblast differentiation. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies and tissue engineering.This unbiased epigenetic library functional screen identified several novel compounds, including abexinostat, that promoted adipocytic and osteoblastic differentiation of human skeletal (mesenchymal or stromal) stem cells (hMSCs). These data provide new insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways controlling adipocyte and osteoblast differentiation of hMSCs. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies for tissue engineering, bone disease, obesity, and metabolic-disorders.

SUBMITTER: Ali D

PROVIDER: S-EPMC4954455 | biostudies-other | 2016 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells.

Ali Dalia D Hamam Rimi R Alfayez Musaed M Kassem Moustapha M Aldahmash Abdullah A Alajez Nehad M NM

Stem cells translational medicine 20160518 8

<h4>Unlabelled</h4>: The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still not fully understood. Herein, we performed an epigenetic library functional screen and identified several novel compounds, including abexinostat, which promoted adipocytic and osteoblastic differentiation of hMSCs. Using gene expression microarrays, chromatin immunoprecipitation for H3K9Ac combined with high-th ...[more]

PMID: 27194745

Similar Datasets

Project description:BACKGROUND:Better understanding of the signaling pathways that regulate human bone marrow stromal stem cell (hBMSC) differentiation into bone-forming osteoblasts is crucial for their clinical use in regenerative medicine. Chemical biology approaches using small molecules targeting specific signaling pathways are increasingly employed to manipulate stem cell differentiation fate. METHODS:We employed alkaline phosphatase activity and staining assays to assess osteoblast differentiation and Alizarin R staining to assess mineralized matrix formation of cultured hBMSCs. Changes in gene expression were assessed using an Agilent microarray platform, and data normalization and bioinformatics were performed using GeneSpring software. For in vivo ectopic bone formation experiments, hMSCs were mixed with hydroxyapatite-tricalcium phosphate granules and implanted subcutaneously into the dorsal surface of 8-week-old female nude mice. Hematoxylin and eosin staining and Sirius Red staining were used to detect bone formation in vivo. RESULTS:We identified several compounds which inhibited osteoblastic differentiation of hMSCs. In particular, we identified ruxolitinib (INCB018424) (3 ?M), an inhibitor of JAK-STAT signaling that inhibited osteoblastic differentiation and matrix mineralization of hMSCs in vitro and reduced ectopic bone formation in vivo. Global gene expression profiling of ruxolitinib-treated cells identified 847 upregulated and 822 downregulated mRNA transcripts, compared to vehicle-treated control cells. Bioinformatic analysis revealed differential regulation of multiple genetic pathways, including TGF? and insulin signaling, endochondral ossification, and focal adhesion. CONCLUSIONS:We identified ruxolitinib as an important regulator of osteoblast differentiation of hMSCs. It is plausible that inhibition of osteoblast differentiation by ruxolitinib may represent a novel therapeutic strategy for the treatment of pathological conditions caused by accelerated osteoblast differentiation and mineralization.

Project description:BackgroundDifferentiation of mesenchymal stem cells to osteoblasts is widely performed in research laboratories. Classical tests to prove this differentiation employ procedures such as cell fixation, cell lysis or cell scraping. Very few studies report gentle dissociation of mesenchymal stem cells undergoing an osteodifferentiation process. Here we used this technique to reveal the presence of several cell layers during osteogenesis and to study their different properties.MethodsThrough the sequential enzymatic detachment of the cells, we confirm the presence of several layers of differentiated cells and we compare them in terms of enzymatic sensitivity for dissociation, expression of cluster of differentiation, cytosolic calcium oscillations and osteogenic potential. Adipogenic and neurogenic differentiations were also performed in order to compare the cell layers.ResultsThe cells undergoing differentiation formed one layer in the neurogenic differentiation, two layers in the adipogenic differentiation and at least four layers in the osteogenic differentiation. In the latter, the upper layers, maintained by a collagen I extracellular matrix, can be dissociated using collagenase I, while the remaining lowest layer, attached to the bottom of the dish, is sensitive only to trypsin-versene. The action of collagenase I is more efficient before the mineralization of the extracellular matrix. The collagenase-sensitive and trypsin-sensitive layers differ in their cluster of differentiation expression. The dissociation of the cells on day 15 reveals that cells could resume their growth (increase in cell number) and rapidly differentiate again in osteoblasts, in 2 weeks (instead of 4 weeks). Cells from the upper layers displayed a higher mineralization.ConclusionsMSCs undergoing osteogenic differentiation form several layers with distinct osteogenic properties. This could allow the investigators to use upper layers to rapidly produce differentiated osteoblasts and the lowest layer to continue growth and differentiation until an ulterior dissociation.

Project description:Glioblastoma multiforme is the most common and most aggressive type of primary brain tumor. The brain-infiltrative character of glioblastoma makes complete surgical removal of the tumor impossible and neither radiation nor current chemotherapy provide cure. Recent evidence shows that glioblastoma multiforme consists of heterogeneous cell populations which differ in tumor-forming potential. Enriched tumor-initiating capacity has been linked to poorly differentiated glioblastoma cells sharing features with neural stem cells. Thus, these cells are important targets for new therapeutic strategies. We aim to identify novel targets controlling maintenance and differentiation in glioblastoma-initiating cells through high throughput screening. To this end, we utilized libraries of small chemical compounds and small interference RNAs in combination with automated imaging and data analysis. Patient-derived glioblastoma cells were expanded and characterized using neural stem cell conditions. In culture, the cells showed low differentiation but expression of neural stem cell markers such as Nestin and Sox2. Upon intracranial injection into SCID mice these cells gave rise to tumors displaying the hallmarks of the human disease. Differentiation of glioblastoma-initiating cells (for example elicited through bone morphogenetic protein, BMP) was associated with strong morphological changes. Hence, cellular morphology, as well as markers specific for differentiation or death were used as screen readout. Lentiviral RNA interference-based screening yielded several gene knockdowns leading to ‘forced’ differentiation of glioblastoma-initiating cells. For example, knockdown of TRRAP (transformation/transcription domain associated protein) led to strongly increased differentiation and loss of proliferative and self-renewing capacity in these cells. TRRAP is an adapter protein implicated in oncogenic transformation through c-MYC transcription activation, also participating in chromatin remodeling and DNA repair. Glioblastoma-initiating cells with reduced TRRAP displayed increased apoptosis upon treatment with the genotoxic agent temozolomide. In vivo, Trapp knockdown cells were not able to give rise to glioblastoma upon transplantation into the brain of SCID mice. Together, these findings support a crucial role for TRRAP in maintenance and tumorigenicity of glioblastoma-initiating cells and might offer future therapeutic options. Two treatments compared to control: two different shRNA sequences for TRRAP were compared to a control shRNA sequence in their effects on global transcription in brain tumor initiating cells

Dataset Information

Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells.

Publications

Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets