- Extracellular vesicles from Wharton's jelly mesenchymal stem cells suppress CD4 expressing T cells through transforming growth factor beta and adenosine signaling in a canine model. [Journal Article]
- SCStem Cells Dev 2018 Nov 09
- Mesenchymal stem cells (MSC) are widely investigated as potential therapeutic agents due to their potent immunomodulatory capacity. Although specific mechanisms by which MSC act on immune cells are e...
Mesenchymal stem cells (MSC) are widely investigated as potential therapeutic agents due to their potent immunomodulatory capacity. Although specific mechanisms by which MSC act on immune cells are emerging, many questions remain including the potential of extracellular vesicles (EV) to mediate biological activities. Canine MSCs are of interest for both veterinary and comparative models of disease and have been shown to suppress CD4pos T cell (T helper cell) proliferation. The aim of this study was to determine whether EV isolated from canine Wharton's jelly-derived MSC (WJ-MSC EV) suppress CD4pos T cell proliferation using biochemical mechanisms previously ascribed to soluble mediators (TGF-β and adenosine). WJ-MSC EV exhibited mode of 125 nm diameter, low buoyant density (1.1 g/mL), and expression of EV proteins Alix and TSG101. Functionally, EV inhibited CD4pos T cell proliferation in a dose-dependent fashion, which was absent in EV-depleted samples and EV from non-MSC fibroblasts. EV suppression of CD4pos T cell proliferation was inhibited by a TGF-βRI antagonist, neutralizing antibodies to TGF-β, or A2A adenosine receptor blockade. TGF-β was present on EV as latent complexes most likely tethered to EV membrane by betaglycan. These data demonstrate that canine WJ-MSC EV utilize TGF-β and adenosine signaling to suppress proliferation of CD4pos T cell, and will enable further investigation into mechanisms of immune cell modulation, as well as refinement of WJ-MSC and their EV for therapeutic application.
- Enhancing Retention of Mesenchymal Stem Cells with Pro-survival Factors Promotes Angiogenesis in a Mouse Model of Limb Ischemia. [Journal Article]
- SCStem Cells Dev 2018 Nov 06
- Mesenchymal stem/stromal cells (MSCs) offer great promise in the treatment of ischemic injuries including stroke, heart infarction and limb ischemia. However, poor cell survival after transplantation...
Mesenchymal stem/stromal cells (MSCs) offer great promise in the treatment of ischemic injuries including stroke, heart infarction and limb ischemia. However, poor cell survival after transplantation remains a major obstacle to achieve effective MSC therapies. To improve cell survival and retention, we transplanted human bone marrow MSCs with or without a specific pro-survival factor (PSF) cocktail consisting of IGF1, Bcl-XL, a caspase inhibitor, a mitochondrial pathway inhibitor and matrigel into the limbs of immune deficient mice, after induction of hindlimb ischemia. The PSF markedly prolonged the retention of the MSCs in the ischemic limb muscles as demonstrated by bioluminescence imaging. Using micro-computed tomography (micro-CT) to image the limb muscle vasculature in the mice nine weeks after the transplantation, we found that the mice transplanted with MSCs without PSF did not show a significant increase in the blood vessels in the ischemic limb compared to the non-transplanted control mice. In contrast, the mice transplanted with MSCs plus PSF showed a significant increase in the blood vessels, especially the larger and branching vessels, in the ischemic limb as compared to the control mice that did not receive MSCs. Thus, we demonstrated that prolonged retention of MSCs using PSF effectively promoted angiogenesis in ischemic animal limbs. This study highlights the importance of enhancing cell survival in the development of effective MSC therapies to treat vascular diseases.
- Enhancement of Graft-versus-Host Disease Control Efficacy by Adoptive Transfer of Type 1-Regulatory T Cells in Bone Marrow Transplant Model. [Journal Article]
- SCStem Cells Dev 2018 Nov 01
- Interleukin (IL)-10-producing type 1 regulatory T (Tr1) cells, which are Foxp3<sup>-</sup> memory T lymphocytes, play important roles in peripheral immune tolerance. We investigated whether Tr1 cells...
Interleukin (IL)-10-producing type 1 regulatory T (Tr1) cells, which are Foxp3<sup>-</sup> memory T lymphocytes, play important roles in peripheral immune tolerance. We investigated whether Tr1 cells exert immunoregulatory effects in a mouse model of acute graft-versus-host disease (GVHD). Mouse CD4<sup>+</sup> T cells were induced to differentiate in vitro into Tr1 cells using vitamin D3 and dexamethasone, and these donor-derived Tr1 cells were infused on the day of bone marrow transplantation. The Tr1 cell-transferred group showed less weight-loss and a twofold higher survival rate than the GVHD group, together with markedly decreased histopathologic grades. It was associated with the expansion of CD4<sup>+</sup>IL-4<sup>+</sup> type 2 T-helper (Th2) cells and CD4<sup>+</sup>CD25<sup>+</sup>Foxp3<sup>+</sup> regulatory T (Treg) cells. Furthermore, Tr1 cells decreased the numbers of CD4<sup>+</sup>interferon (IFN)-γ<sup>+</sup> Th1 and CD4<sup>+</sup>IL-17<sup>+</sup> Th17 cells. Recipient mice harboured some Foxp3<sup>+</sup> Tregs due to adoptive transfer of Tr1 cells, together with the upregulated expression of costimulatory molecules, including cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and inducible T-cell co stimulator (ICOS); however, the Treg cells did not show plasticity. Therefore, adoptive Tr1 cell therapy may be effective against manifestations of GVHD, exert immunomodulatory effects in a manner dependent on CTLA-4 and ICOS, and induce differentiation of the transferred Tr1 cells into Foxp3<sup>+</sup> Treg cells.
- A novel human pluripotent stem cell-derived neural crest model of Treacher Collins Syndrome shows defects in cell death and migration. [Journal Article]
- SCStem Cells Dev 2018 Oct 30
- The neural crest (NC) is a transient, multipotent cell population present during embryonic development. The NC can give rise to multiple cell types and is involved in a number of different diseases. ...
The neural crest (NC) is a transient, multipotent cell population present during embryonic development. The NC can give rise to multiple cell types and is involved in a number of different diseases. Therefore, the development of new strategies to model NC in vitro enables investigations into the mechanisms involved in NC development and disease. Here we report a simple and efficient protocol to differentiate human pluripotent stem cells (HPSC) into NC using a chemically defined media, with basic fibroblast growth factor (FGF2) and the transforming growth factor-β inhibitor SB-431542. The cell population generated expresses a range of NC markers including P75, TWIST1, SOX10 and TFAP2A. NC purification was achieved in vitro through serial passaging of the population, recreating the developmental stages of NC differentiation. The generated NC cells are highly proliferative, capable of differentiating to their derivatives in vitro and engraft in vivo to NC specific locations. In addition, these cells could be frozen for storage and thawed with no loss of NC properties, nor the ability to generate cellular derivatives. We assessed the potential of the derived NC population to model the neurocristopathy, Treacher Collins Syndrome (TCS), by using siRNA knockdown of TCOF1 and by creating different TCOF1+/- HPSC lines via CRISPR/Cas9 technology. The NC cells derived from TCOF1+/- HPSCs recapitulate the phenotype of the reported Treacher Collins Syndrome murine model. We also report for the first time an impairment of migration in TCOF1+/- NC and mesenchymal stem cells. In conclusion, the developed protocol permits the generation of the large number of NC cells required for developmental studies, disease modeling, and for drug discovery platforms in vitro.
- Discovery of natural compounds promoting cardiomyocyte differentiation. [Journal Article]
- SCStem Cells Dev 2018 Oct 25
- The commitment of pluripotent stem cells to the cardiac lineage has enormous potential in regenerative medicine interventions for several cardiac diseases. Thus, it is necessary to understand and reg...
The commitment of pluripotent stem cells to the cardiac lineage has enormous potential in regenerative medicine interventions for several cardiac diseases. Thus, it is necessary to understand and regulate this differentiation process for potential clinical application. In this study, we developed defined conditions with chemical inducers for effective cardiac lineage commitment and elucidated the mechanism for high-efficiency differentiation. First, we designed a robust reporter-based platform to screen chemical inducers of cardiac differentiation in the mouse P19 teratocarcinoma cell line. Using this system, we identified two natural alkaloids, lupinine and ursinoic acid, that enhanced cardiomyocyte differentiation of P19 cells in terms of beating colony numbers with respect to oxytocin, and confirmed their activity in mouse ES cells. By analyzing the expression of key markers, we found that this enhancement can be attributed to the early and rapid induction of the Wnt signaling pathway. We also found that these natural compounds could not only supersede the action of the Wnt3a ligand but they also had a very quick response time, allowing them to act as efficient cardiac mesoderm inducers that subsequently promoted cardiomyocyte differentiation. Thus, this study offers a way to develop chemical-based differentiation strategy for high-efficiency cardiac lineage commitment, which has an advantage over currently available methods with complex media composition and parameters. Furthermore, it also provides an opportunity to pinpoint the key molecular mechanisms pivotal to the cardiac differentiation process, which are necessary to design an efficient strategy for cardiomyocyte differentiation.
- Telomerase reverse transcriptase expression in mouse endometrium during re-epithelialization and regeneration in a menses-like model. [Journal Article]
- SCStem Cells Dev 2018 Oct 25
- The regenerative capacity of the endometrium has been attributed to resident stem/progenitor cells. A number of stem/progenitor markers have been reported for human endometrial stem/progenitor cells,...
The regenerative capacity of the endometrium has been attributed to resident stem/progenitor cells. A number of stem/progenitor markers have been reported for human endometrial stem/progenitor cells, however the lack of convenient markers in the mouse has made experimental investigation into endometrial regeneration difficult. We recently identified endometrial epithelial, endothelial and immune cells which express a reporter for the stem/progenitor marker, mouse telomerase reverse transcriptase (mTert). Here we investigate the expression pattern of a GFP reporter for mTert promoter activity (mTert-GFP) in endometrial regeneration following a menses-like event. mTert-GFP expression marks sub-epithelial populations of T cells and mature macrophages and may play a role in immune cell regulated repair. Clusters of mTert-GFP positive epithelial cells were identified close to areas of re-epithelialization and possibly highlight a role for mTert in the repair and regeneration of the endometrial epithelium.
- Transient Cell-to-Cell Signaling before Mitosis in Cultures of human Bone Marrow-Derived Mesenchymal Stem/Stromal Cells. [Journal Article]
- SCStem Cells Dev 2018 Oct 25
- Some types of cells, if not all, that undergo signal exchanges in culture need to contact other cells for various reasons, such as cell-to-cell contact for growth inhibition. However, signal exchange...
Some types of cells, if not all, that undergo signal exchanges in culture need to contact other cells for various reasons, such as cell-to-cell contact for growth inhibition. However, signal exchanges by cell-to-cell contact before proliferation has never been reported. Using time-lapse recording, we discovered the emergence of several astonishing cell-to-cell contact modes in bone marrow-derived mesenchymal stem/stromal cells (MSCs) before the cells divided. When the cells contacted with another, a huge temporary synapse-like structure formed for molecules exchanges; a cell-tissue particle was taken in by a recipient cell; two cells membranes formed infusion-like structure for a short time; even a 20-micron long and 5-micron wide cell tail was grafted to another cell. A total of 87% of cells underwent cell-to-cell contact before dividing. After epidermal growth factor-green fluorescent protein (EGF-GFP) vectors were transfected into MSCs and the cells were cocultured with unmanipulated MSCs, the unmanipulated MSCs took in EGF-GFP particles from EGF-GFPexpressed MSC cells, immediately increased in mitogen genes, and then divided. These results suggest that cells which may lack signal molecules may need to obtain these molecules from other cells through various types of cell-to-cell contact, as mentioned above. Our study provided valuable information to better understand the behaviors of cell-to-cell contact and communication before mitosis.
- Author Accountability in Biomedical Research. [Journal Article]
- SCStem Cells Dev 2018 Oct 23
- Human Cortical Neuron Generation using Cell Reprogramming: A Review of Recent Advances. [Journal Article]
- SCStem Cells Dev 2018 Oct 20
- The study and treatment of neurological disorders have been hampered by a lack of access to live, healthy or disease-affected human neurons. The recent advances in the field of cell reprogramming off...
The study and treatment of neurological disorders have been hampered by a lack of access to live, healthy or disease-affected human neurons. The recent advances in the field of cell reprogramming offer exciting new possibilities for disease modelling, drug development, and cell-based therapies. Since the derivation of human embryonic stem cells (hESC) and their differentiation into neurons, cell reprogramming technologies have built on these protocols to generate mature human neurons of disease-associated phenotypes from somatic cells. Mechanistic knowledge of neural patterning and neurogenesis has been essential for the establishment of reprogramming strategies that employ a combination of transcription factors and small molecules selected due to their critical role in brain development. The generation of reprogrammed human neurons has the potential to further enhance our knowledge of pathways underlying the developmental process of the human brain, the current knowledge of which has predominantly come from animal studies, post-mortem tissue and most recently hESCs. Somatic cell reprogramming began in 2006 with the first report of induced pluripotent stem cell (iPSC) derivation from mouse fibroblasts. This has now expanded to direct-to-induced neuron and direct-to-induced neural stem or precursor reprogramming using a variety of viral and non-viral delivery methods. Most recently, iPSC technology has been extended to the development of 3D brain structures referred to as brain spheroids or organoids. This review will discuss the reprogramming strategies that have been formulated to generate cortical neurons which are associated with many diseases including autism spectrum disorders and schizophrenia.
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- Therapeutic Effects of Human Umbilical Cord Mesenchymal Stromal Cells in Sprague Dawley Rats with Percutaneous Exposure to Sulfur Mustard. [Journal Article]
- SCStem Cells Dev 2018 Oct 20
- Sulfur mustard (SM) exposure, whose symptoms are similar to radiation exposure, can lead to acute injury. Because mesenchymal stromal cells (MSCs) have been used to experimentally and clinically trea...
Sulfur mustard (SM) exposure, whose symptoms are similar to radiation exposure, can lead to acute injury. Because mesenchymal stromal cells (MSCs) have been used to experimentally and clinically treat acute radiation syndrome, in this study, MSCs were intravenously injected into rats after percutaneous SM exposure. Then, we examined sternum and spleen samples by histopathological and immunohistochemical methods to observe pathological changes. Furthermore, blood samples were taken to test the white blood cell count (W.B.C.), blood platelet count (B.P.C.) and red blood cell count (R.B.C.) and the levels of cytokines in the serum. The number of bone marrow karyocytes and the W.B.C. in the MSC + SM group were higher than those in the SM group, and the levels of G-CSF, GM-CSF, MCP-1, IL-1α, IL-5 and IFN-γ in the MSC + SM group remained high at different time points after SM exposure. In addition, the B.P.C., the level of EPO and the relative weight of the spleen in the MSC + SM group were significantly higher than those in the SM group. Meanwhile, spleens in the MSC + SM group were more hyperplastic and hematopoietic, and had fewer apoptotic cells than in the SM group. Furthermore, rat body weight and locomotion ability in the MSC + SM group were higher than in the SM group. This evidence supports the potential ability of MSCs in immunoregulation and functional improvements to the hemopoietic microenvironment. Intravenous injection of MSCs exerted significant therapeutic effects in rats with percutaneous exposure to SM.