Effect of fibronectin, FGF-2, and BMP4 in the stemness maintenance of BMSCs and the metabolic and proteomic cues involved

Abstract Background Growing evidence suggests that the pluripotent state of mesenchymal stem cells (MSCs) relies on specific local microenvironmental cues such as adhesion molecules and growth factors. Fibronectin (FN), fibroblast growth factor 2 (FGF2), and bone morphogenetic protein 4 (BMP4) are the key players in the regulation of stemness and lineage commitment of MSCs. Therefore, this study was designed to investigate the pluripotency and multilineage differentiation of bone marrow-derived MSCs (BMSCs) with the introduction of FN, FGF-2, and BMP4 and to identify the metabolic and proteomic cues involved in stemness maintenance. Methods To elucidate the stemness of BMSCs when treated with FN, FGF-2, and BMP4, the pluripotency markers of OCT4, SOX2, and c-MYC in BMSCs were monitored by real-time PCR and/or western blot. The nuclear translocation of OCT4, SOX2, and c-MYC was investigated by immunofluorescence staining. Multilineage differentiation of the treated BMSCs was determined by relevant differentiation markers. To identify the molecular signatures of BMSC stemness, gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and bioinformatics analysis were utilized to determine the metabolite and protein profiles associated with stem cell maintenance. Results Our results demonstrated that the expression of stemness markers decreased with BMSC passaging, and the manipulation of the microenvironment with fibronectin and growth factors (FGF2 and BMP4) can significantly improve BMSC stemness. Of note, we revealed 7 differentially expressed metabolites, the target genes of these metabolites may have important implications in the maintenance of BMSCs through their effects on metabolic activity, energy production, and potentially protein production. We also identified 21 differentially abundant proteins, which involved in multiple pathways, including metabolic, autophagy-related, and signaling pathways regulating the pluripotency of stem cells. Additionally, bioinformatics analysis comfirned the correlation between metabolic and proteomic profiling, suggesting that the importance of metabolism and proteome networks and their reciprocal communication in the preservation of stemness. Conclusions These results indicate that the culture environment supplemented with the culture cocktail (FN, FGF2, and BMP4) plays an essential role in shaping the pluripotent state of BMSCs. Both the metabolism and proteome networks are involved in this process and the modulation of cell-fate decision making. All these findings may contribute to the application of MSCs for regenerative medicine.

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Regulation and Directing Stem Cell Fate by Tissue Engineering Functional Microenvironments: Scaffold Physical and Chemical Cues

Stem Cells International ◽

10.1155/2019/2180925 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 8

Author(s):

Fei Xing ◽

Lang Li ◽

Changchun Zhou ◽

Cheng Long ◽

Lina Wu ◽

...

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Stem Cell ◽

Growth Factors ◽

Cell Fate ◽

Chemical Cues ◽

Physical Factors ◽

Stem Cell Fate ◽

Physical And Chemical

It is well known that stem cells reside within tissue engineering functional microenvironments that physically localize them and direct their stem cell fate. Recent efforts in the development of more complex and engineered scaffold technologies, together with new understanding of stem cell behavior in vitro, have provided a new impetus to study regulation and directing stem cell fate. A variety of tissue engineering technologies have been developed to regulate the fate of stem cells. Traditional methods to change the fate of stem cells are adding growth factors or some signaling pathways. In recent years, many studies have revealed that the geometrical microenvironment played an essential role in regulating the fate of stem cells, and the physical factors of scaffolds including mechanical properties, pore sizes, porosity, surface stiffness, three-dimensional structures, and mechanical stimulation may affect the fate of stem cells. Chemical factors such as cell-adhesive ligands and exogenous growth factors would also regulate the fate of stem cells. Understanding how these physical and chemical cues affect the fate of stem cells is essential for building more complex and controlled scaffolds for directing stem cell fate.

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Ezh2 Plays a Critical Role in the Progression of MLL-AF9-Induced Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v118.21.57.57 ◽

2011 ◽

Vol 118 (21) ◽

pp. 57-57

Author(s):

Satomi Tanaka ◽

Goro Sashida ◽

Satoru Miyagi ◽

Koutaro Yokote ◽

Chiaki Nakaseko ◽

...

Keyword(s):

Stem Cells ◽

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Target Genes ◽

Nuclear Translocation ◽

Conflicts Of Interest ◽

Critical Role ◽

Histone H3 ◽

Chip Sequencing ◽

Acute Myeloid

Abstract Abstract 57 The polycomb group proteins function in gene silencing through histone modifications. They have been characterized as a general regulator of stem cells, but also play a critical role in cancer. EZH2 is a catalytic component of the polycomb repressive complex 2 (PRC2) and tri-methylates histone H3 at lysine 27 to transcriptionally repress the target genes. Although EZH2 is over-expressed in various cancers including hematological malignancies, it remains unknown how EZH2 contributes to the initiation and/or progression of acute myeloid leukemia (AML). To understand the role of EZH2 in AML, we transformed granulocyte macrophage progenitors (GMPs) from Cre-ERT;Ezh2+/+ and Cre-ERT;Ezh2flox/flox mice with the MLL-AF9 fusion gene. Then, Ezh2 was deleted by inducing nuclear translocation of Cre by adding tamoxifen to culture. We found that proliferation of Ezh2δ/δ transformed cells was severely compromised upon deletion of Ezh2 (Ezh2δ/δ) in liquid culture. They gave rise to a significantly reduced number of colonies in replating assays. Of note, while Ezh2+/+ cells formed compact colonies composed of immature myeloblasts, Ezh2δ/δ cells formed dispersed colonies composed of differentiated myeloid cells. We next transplanted Cre-ERT;Ezh2+/+ and Cre-ERT;Ezh2flox/flox GMPs transformed by MLL-AF9 into recipient mice. All the recipient mice developed AML by 3 weeks after transplantation. At 3 weeks after transplantation, we depleted Ezh2 by intraperitoneal injection of tamoxifen. Deletion of Ezh2 significantly prolonged the survival of the recipient mice (60 days vs. 76 days, p<0.0001), although all the mice eventually died of leukemia. Nonetheless, as was detected in vitro, Ezh2δ/δ AML cells in BM were apparently differentiated in morphology compared with the control. Ezh2δ/δ AML cells in BM gave rise to 10-fold fewer colonies in methylcellulose medium compared with Ezh2+/+ AML cells, and again showed an obvious tendency of differentiation. These observations imply that Ezh2 is critical for the progression of MLL-AF9 AML and maintains the immature state of AML cells. To elucidate the mechanism how Ezh2 promotes the progression of MLL-AF9-induced AML, we examined the genome-wide distribution of tri-methylation of histone H3 at lysine 27 (H3K27me3) by ChIP-sequencing and microarray-based expression analysis. ChIP-sequencing using Ezh2+/+ and Ezh2δ/δ BM AML cells identified 3525 and 89 genes exhibiting a ≧ 10-fold enrichment in H3K27me3 levels in Ezh2+/+ and Ezh2δ/δ AML cells, respectively, confirming a drastic reduction in the levels of global H3K27me3 in the absence of Ezh2. Microarray analysis using lineage marker (except for Mac1)−Sca-1−c-Kit+FcγRII/IIIhi BM AML cells revealed 252 upregulated and 154 downregulated genes (≧ 2-fold) in Ezh2δ/δ AML cells compared with Ezh2+/+ AML cells. Of interest, the absence of Ezh2 did not affect the transcriptional activation of the major target genes of MLL-AF9, including HoxA9 and Meis1. Because Ezh2 functions as transcriptional repressor, de-repressed genes could be direct targets of Ezh2. Based on these data, we are now engaged in further comprehensive analysis to narrow down the direct target genes of Ezh2 responsible for the progression of AML. Collectively, our findings suggest that Ezh2 is the major enzyme for H3K27me3 in AML and contributes to the progression of AML by regulating transcription a cohort of genes that are supposedly relevant to the self-renewal capacity and perturbed differentiation of AML stem cells. Disclosures: No relevant conflicts of interest to declare.

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Characterization of Human Mesenchymal Stem Cells from Different Tissues and Their Membrane Encasement for Prospective Transplantation Therapies

BioMed Research International ◽

10.1155/2019/6376271 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 17

Author(s):

Eva Schmelzer ◽

Daniel T. McKeel ◽

Jörg C. Gerlach

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Growth Factors ◽

Cell Fusion ◽

Human Mesenchymal Stem Cells ◽

Surface Markers ◽

Multilineage Differentiation ◽

Differentiation Potential ◽

Donor Cells ◽

Different Tissues

Human mesenchymal stem cells can be isolated from various organs and are in studies on therapeutic cell transplantation. Positive clinical outcomes of transplantations have been attributed to both the secretion of cytokines and growth factors as well as the fusion of donor cells with that of the host. We compared human mesenchymal stem cells from six different tissues for their transplantation-relevant potential. Furthermore, for prospective allogenic transplantation we developed a semipermeable hollow-fiber membrane enclosure, which would prevent cell fusion, would provide an immune barrier, and would allow for easy removal of donor cells from patients after recovery. We investigated human mesenchymal stem cells from adipose tissue, amniotic tissue, bone marrow, chorionic tissue, liver, and umbilical cord. We compared their multilineage differentiation potential, secretion of growth factors, and the expression of genes and surface markers. We found that although the expression of typical mesenchymal stem cell-associated gene THY1 and surface markers CD90 and CD73 were mostly similar between mesenchymal stem cells from different donor sites, their expression of lineage-specific genes, secretion of growth factors, multilineage differentiation potential, and other surface markers were considerably different. The encasement of mesenchymal stem cells in fibers affected the various mesenchymal stem cells differently depending on their donor site. Conclusively, mesenchymal stem cells isolated from different tissues were not equal, which should be taken into consideration when deciding for optimal sourcing for therapeutic transplantation. The encasement of mesenchymal stem cells into semipermeable membranes could provide a physical immune barrier, preventing cell fusion.

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Identification of the Regulatory Elements and Target Genes of Megakaryopoietic Transcription Factor MEF2C

Thrombosis and Haemostasis ◽

10.1055/s-0039-1678694 ◽

2019 ◽

Vol 119 (05) ◽

pp. 716-725 ◽

Cited By ~ 2

Author(s):

Xianguo Kong ◽

Lin Ma ◽

Edward Chen ◽

Chad Shaw ◽

Leonard Edelstein

Keyword(s):

Gene Expression ◽

Stem Cells ◽

Genetic Variation ◽

Transcription Factors ◽

Cell Fate ◽

Target Genes ◽

Regulatory Elements ◽

Haematopoietic Stem Cells ◽

Platelet Production ◽

Induced Pluripotent

AbstractMegakaryopoiesis produces specialized haematopoietic stem cells in the bone marrow that give rise to megakaryocytes which ultimately produce platelets. Defects in megakaryopoiesis can result in altered platelet counts and physiology, leading to dysfunctional haemostasis and thrombosis. Additionally, dysregulated megakaryopoiesis is also associated with myeloid pathologies. Transcription factors play critical roles in cell differentiation by regulating the temporal and spatial patterns of gene expression which ultimately decide cell fate. Several transcription factors have been described as regulating megakaryopoiesis including myocyte enhancer factor 2C (MEF2C); however, the genes regulated by MEF2C that influence megakaryopoiesis have not been reported. Using chromatin immunoprecipitation-sequencing and Gene Ontology data we identified five candidate genes that are bound by MEF2C and regulate megakaryopoiesis: MOV10, AGO3, HDAC1, RBBP5 and WASF2. To study expression of these genes, we silenced MEF2C gene expression in the Meg01 megakaryocytic cell line and in induced pluripotent stem cells by CRISPR/Cas9 editing. We also knocked down MEF2C expression in cord blood-derived haematopoietic stem cells by siRNA. We found that absent or reduced MEF2C expression resulted in defects in megakaryocytic differentiation and reduced levels of the candidate target genes. Luciferase assays confirmed that genomic sequences within the target genes are regulated by MEF2C levels. Finally, we demonstrate that small deletions linked to a platelet count-associated single nucleotide polymorphism alter transcriptional activity, suggesting a mechanism by which genetic variation in MEF2C alters platelet production. These data help elucidate the mechanism behind MEF2C regulation of megakaryopoiesis and genetic variation driving platelet production.

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Investigation of the Effect of Secreted Factors from Mesenchymal Stem Cells on Disc Cells from Degenerated Discs

Cells Tissues Organs ◽

10.1159/000506350 ◽

2019 ◽

Vol 208 (1-2) ◽

pp. 76-88 ◽

Cited By ~ 2

Author(s):

Daphne Hingert ◽

Phonphan Nawilaijaroen ◽

Jonathan Aldridge ◽

Adad Baranto ◽

Helena Brisby

Keyword(s):

Mass Spectrometry ◽

Stem Cells ◽

Mesenchymal Stem Cells ◽

Low Back Pain ◽

Back Pain ◽

Growth Factors ◽

Disc Degeneration ◽

Mass Spectrometry Analysis ◽

Low Back ◽

Disc Cells

Low back pain is experienced by a large number of people in western countries and may be caused and influenced by many different pathologies and psychosocial factors including disc degeneration. Disc degeneration involves the increased expression of proinflammatory cytokines and matrix metalloproteinases (MMPs) in the disc environment, which leads to the loss of extracellular matrix (ECM) and the viability of the native disc cells (DCs). Treatment approaches using growth factors and cell therapy have been proposed due to the compelling results that growth factors and mesenchymal stem cells (MSCs) can influence the degenerated discs. The aim of this study was to investigate the effects of conditioned media (CM) from human MSCs (hMSCs) and connective tissue growth factor (CTGF) and TGF-β on disc cells, and hMSCs isolated from patients with degenerative discs and severe low back pain. The aim was also to examine the constituents of CM in order to study the peptides that could bring about intervertebral disc (IVD) regeneration. DCs and hMSC pellets (approx.. 200,000 cells) were cultured and stimulated with hMSC-derived CM or CTGF and TGF-β over 28 days. The effects of CM and CTGF on DCs and hMSCs were assessed via cell viability, proteoglycan production, the expression of ECM proteins, and chondrogenesis in 3D pellet culture. To identify the constituents of CM, CM was analyzed with tandem mass spectrometry. The findings indicate that CM enhanced the cellular viability and ECM production of DCs while CTGF and the control exhibited nonsignificant differences. The same was observed in the hMSC group. Mass spectrometry analysis of CM identified >700 peptides, 129 of which showed a relative abundance of ≥2 (CTGF among them). The results suggest that CM holds potential to counter the progression of disc degeneration, likely resulting from the combination of all the substances released by the hMSCs. The soluble factors released belong to different peptide families. The precise mechanism underlying the regenerative effect needs to be investigated further, prior to incorporating peptides in the development of new treatment strategies for low back pain that is potentially caused by IVD degeneration.

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BASP1 labels neural stem cells in the neurogenic niches of mammalian brain

Scientific Reports ◽

10.1038/s41598-021-85129-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Louis N. Manganas ◽

Irene Durá ◽

Sivan Osenberg ◽

Faith Semerci ◽

Mehmet Tosun ◽

...

Keyword(s):

Mass Spectrometry ◽

Stem Cells ◽

Stem Cell ◽

Western Blot ◽

Human Brain ◽

Cell Fate ◽

Neural Stem Cell ◽

Developmental Stages ◽

Mammalian Brain ◽

Stem Cell Fate

AbstractThe mechanisms responsible for determining neural stem cell fate are numerous and complex. To begin to identify the specific components involved in these processes, we generated several mouse neural stem cell (NSC) antibodies against cultured mouse embryonic neurospheres. Our immunohistochemical data showed that the NSC-6 antibody recognized NSCs in the developing and postnatal murine brains as well as in human brain organoids. Mass spectrometry revealed the identity of the NSC-6 epitope as brain abundant, membrane-attached signal protein 1 (BASP1), a signaling protein that plays a key role in neurite outgrowth and plasticity. Western blot analysis using the NSC-6 antibody demonstrated multiple BASP1 isoforms with varying degrees of expression and correlating with distinct developmental stages. Herein, we describe the expression of BASP1 in NSCs in the developing and postnatal mammalian brains and human brain organoids, and demonstrate that the NSC-6 antibody may be a useful marker of these cells.

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At a Crossroads to Cancer: How p53-induced Cell Fate Decisions Secure Genome Integrity

10.20944/preprints202109.0063.v1 ◽

2021 ◽

Author(s):

Dario Rizzotto ◽

Lukas Englmaier ◽

Andreas Villunger

Keyword(s):

Cell Death ◽

Cell Fate ◽

Target Genes ◽

Nuclear Translocation ◽

Current Knowledge ◽

Cellular Transformation ◽

Model Systems ◽

Specific Cell ◽

Cell Type ◽

Cell Fate Decisions

P53 is known as the most critical tumor suppressor and is often referred to as the guardian of our genome. More than 40 years after its discovery, we are still struggling to understand all molecular details on how this transcription factor prevents oncogenesis or how to leverage current knowledge about its function to improve cancer treatment. Multiple cues, including DNA-damage or mitotic errors, can lead to the stabilization and nuclear translocation of p53, initiating the expression of multiple target genes. These transcriptional programs may well be cell type and stimulus-specific, as is their outcome that ultimately imposes a barrier to cellular transformation. Cell cycle arrest and cell death are two well-studied consequences of p53 activation, but, while being considered as critical, they do not fully explain the consequences of p53 loss-of-function phenotypes in cancer. Here, we discuss how mitotic errors alert the p53 network and give an overview on multiple ways how p53 can trigger cell death. We argue that a comparative analysis of different types of p53 responses, elicited by different triggers in a time-resolved manner in well-defined model systems is critical to understand cell type specific cell fate induced by p53 upon its activation, in order to resolve the remaining mystery of its tumor suppressive function.

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At a Crossroads to Cancer: How p53-Induced Cell Fate Decisions Secure Genome Integrity

International Journal of Molecular Sciences ◽

10.3390/ijms221910883 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10883

Author(s):

Dario Rizzotto ◽

Lukas Englmaier ◽

Andreas Villunger

Keyword(s):

Cell Death ◽

Cell Fate ◽

Target Genes ◽

Nuclear Translocation ◽

Current Knowledge ◽

Cellular Transformation ◽

Model Systems ◽

Specific Cell ◽

Cell Type ◽

Cell Fate Decisions

P53 is known as the most critical tumor suppressor and is often referred to as the guardian of our genome. More than 40 years after its discovery, we are still struggling to understand all molecular details on how this transcription factor prevents oncogenesis or how to leverage current knowledge about its function to improve cancer treatment. Multiple cues, including DNA-damage or mitotic errors, can lead to the stabilization and nuclear translocation of p53, initiating the expression of multiple target genes. These transcriptional programs may be cell-type- and stimulus-specific, as is their outcome that ultimately imposes a barrier to cellular transformation. Cell cycle arrest and cell death are two well-studied consequences of p53 activation, but, while being considered critical, they do not fully explain the consequences of p53 loss-of-function phenotypes in cancer. Here, we discuss how mitotic errors alert the p53 network and give an overview of multiple ways that p53 can trigger cell death. We argue that a comparative analysis of different types of p53 responses, elicited by different triggers in a time-resolved manner in well-defined model systems, is critical to understand the cell-type-specific cell fate induced by p53 upon its activation in order to resolve the remaining mystery of its tumor-suppressive function.

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Transcriptomics-Based Repositioning of Natural Compound, Eudesmin, as a PRC2 Modulator

Molecules ◽

10.3390/molecules26185665 ◽

2021 ◽

Vol 26 (18) ◽

pp. 5665

Author(s):

Sang Ah Yi ◽

Ki Hong Nam ◽

Min Gyu Lee ◽

Hwamok Oh ◽

Jae Sung Noh ◽

...

Keyword(s):

Stem Cells ◽

Wnt Signaling ◽

Cell Fate ◽

Target Genes ◽

Transcriptome Profiling ◽

Opposite Pattern ◽

H3k27me3 Level ◽

Epigenetic Remodeling ◽

Dependent Potential

Extensive epigenetic remodeling occurs during the cell fate determination of stem cells. Previously, we discovered that eudesmin regulates lineage commitment of mesenchymal stem cells through the inhibition of signaling molecules. However, the epigenetic modulations upon eudesmin treatment in genomewide level have not been analyzed. Here, we present a transcriptome profiling data showing the enrichment in PRC2 target genes by eudesmin treatment. Furthermore, gene ontology analysis showed that PRC2 target genes downregulated by eudesmin are closely related to Wnt signaling and pluripotency. We selected DKK1 as an eudesmin-dependent potential top hub gene in the Wnt signaling and pluripotency. Through the ChIP-qPCR and RT-qPCR, we found that eudesmin treatment increased the occupancy of PRC2 components, EZH2 and SUZ12, and H3K27me3 level on the promoter region of DKK1, downregulating its transcription level. According to the analysis of GEO profiles, DEGs by depletion of Oct4 showed an opposite pattern to DEGs by eudesmin treatment. Indeed, the expression of pluripotency markers, Oct4, Sox2, and Nanog, was upregulated upon eudesmin treatment. This finding demonstrates that pharmacological modulation of PRC2 dynamics by eudesmin might control Wnt signaling and maintain pluripotency of stem cells.

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Distinct SoxB1 networks are required for naïve and primed pluripotency

10.1101/229716 ◽

2017 ◽

Author(s):

Andrea Corsinotti ◽

Frederick C. K. Wong ◽

Tülin Tatar ◽

Iwona Szczerbinska ◽

Florian Halbritter ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Embryonic Stem Cells ◽

Cell Fate ◽

Neural Differentiation ◽

Embryonic Stem ◽

Functional Redundancy ◽

Self Renewal ◽

Cell Fate Decisions ◽

Pluripotent State

AbstractDeletion of Sox2 from embryonic stem cells (ESCs) causes trophectodermal differentiation. While this can be prevented by enforced expression of the related SOXB1 proteins, SOX1 or SOX3, the roles of SOXB1 proteins in epiblast stem cell (EpiSC) pluripotency are unknown. Here we show that Sox2 can be deleted from EpiSCs with impunity. This is due to a shift in the balance of SoxB1 expression in EpiSCs, which have decreased Sox2 and increased Sox3 compared to ESCs. Consistent with functional redundancy, Sox3 can also be deleted from EpiSCs without eliminating self-renewal. However, deletion of both Sox2 and Sox3 prevents self-renewal. The overall SOXB1 levels in ESCs affect differentiation choices: neural differentiation of Sox2 heterozygous ESCs is compromised, while increased SOXB1 levels divert the ESC to EpiSC transition towards neural differentiation. Therefore, optimal SOXB1 levels are critical for each pluripotent state and for cell fate decisions during exit from naïve pluripotency.

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