Self-renewing Multipotent Progenitors Research Articles

A Microfluidic Chip for Growth and Characterization of Adult Rat Hippocampal Progenitor Cell Neurospheroids

Adult hippocampal neural stem/progenitor cells (AHPCs), which are self-renewing multipotent progenitors that can differentiate into neurons, astrocytes, and oligodendrocytes, are suitable as a central nervous system (CNS) molecular model, and the formation of 3D AHPC neurospheroids are potentially suitable as an in vitro brain model. In this paper we report a new microfluidic chip to culture AHPC neurospheroids (NSs-AHPC) inside culture-chambers on chip. After cell fixation and immunostaining were conducted, the fluorescence images of NSs-AHPC were analyzed. It has been found that the AHPCs comprising neurospheroids remained highly viable. Cell proliferation and neuronal differentiation have also been observed, indicating the feasibility of NSs-AHPC as the in vitro brain model on chip. Given its simple-to-use, low-cost, and orderly arranged culture-chambers, this type of chip is particularly suitable for culturing and analyzing multiple in vitro brain models in an efficient manner. [2021-0199]

The CD11a and Endothelial Protein C Receptor Marker Combination Simplifies and Improves the Purification of Mouse Hematopoietic Stem Cells

Hematopoietic stem cells (HSCs) are the self‐renewing multipotent progenitors to all blood cell types. Identification and isolation of HSCs for study has depended on the expression of combinations of surface markers on HSCs that reliably distinguish them from other cell types. However, the increasing number of markers required to isolate HSCs has made it tedious, expensive, and difficult for newcomers, suggesting the need for a simpler panel of HSC markers. We previously showed that phenotypic HSCs could be separated based on expression of CD11a and that only the CD11a negative fraction contained true HSCs. Here, we show that CD11a and another HSC marker, endothelial protein C receptor (EPCR), can be used to effectively identify and purify HSCs. We introduce a new two‐color HSC sorting method that can highly enrich for HSCs with efficiencies comparable to the gold standard combination of CD150 and CD48. Our results demonstrate that adding CD11a and EPCR to the HSC biologist's toolkit improves the purity of and simplifies isolation of HSCs. stem cells translational medicine 2018;7:468–476

Orphan nuclear receptor TLX regulates astrogenesis by modulating BMP signaling.

Neural stem cells (NSCs) are self-renewing multipotent progenitors that generate both neurons and glia. The precise control of NSC behavior is fundamental to the architecture and function of the central nervous system. We previously demonstrated that the orphan nuclear receptor TLX is required for postnatal NSC activation and neurogenesis in the neurogenic niche. Here, we show that TLX modulates bone morphogenetic protein (BMP)-SMAD signaling to control the timing of postnatal astrogenesis. Genes involved in the BMP signaling pathway, such as Bmp4, Hes1, and Id3, are upregulated in postnatal brains lacking Tlx. Chromatin immunoprecipitation and electrophoretic mobility shift assays reveal that TLX can directly bind the enhancer region of Bmp4. In accordance with elevated BMP signaling, the downstream effectors SMAD1/5/8 are activated by phosphorylation in Tlx mutant mice. Consequently, Tlx mutant brains exhibit an early appearance and increased number of astrocytes with marker expression of glial fibrillary acidic protein (GFAP) and S100B. Taken together, these results suggest that TLX tightly controls postnatal astrogenesis through the modulation of BMP-SMAD signaling pathway activity.

Umbilical cord blood-derived mesenchymal stem cells consist of a unique population of progenitors co-expressing mesenchymal stem cell and neuronal markers capable of instantaneous neuronal differentiation

IntroductionUmbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) are self-renewing multipotent progenitors with the potential to differentiate into multiple lineages of mesoderm, in addition to generating ectodermal and endodermal lineages by crossing the germline barrier. In the present study we have investigated the ability of UCB-MSCs to generate neurons, since we were able to observe varying degrees of neuronal differentiation from a few batches of UCB-MSCs with very simple neuronal induction protocols whereas other batches required extensive exposure to combination of growth factors in a stepwise protocol. Our hypothesis was therefore that the human UCB-MSCs would contain multiple types of progenitors with varying neurogenic potential and that the ratio of the progenitors with high and low neurogenic potentials varies in different batches of UCB.MethodsIn total we collected 45 UCB samples, nine of which generated MSCs that were further expanded and characterized using immunofluorescence, fluorescence-activated cell sorting and RT-PCR analysis. The neuronal differentiation potential of the UCB-MSCs was analyzed with exposure to combination of growth factors.ResultsWe could identify two different populations of progenitors within the UCB-MSCs. One population represented progenitors with innate neurogenic potential that initially express pluripotent stem cell markers such as Oct4, Nanog, Sox2, ABCG2 and neuro-ectodermal marker nestin and are capable of expanding and differentiating into neurons with exposure to simple neuronal induction conditions. The remaining population of cells, typically expressing MSC markers, requires extensive exposure to a combination of growth factors to transdifferentiate into neurons. Interesting to note was that both of these cell populations were positive for CD29 and CD105, indicating their MSC lineage, but showed prominent difference in their neurogenic potential.ConclusionOur results suggest that the expanded UCB-derived MSCs harbor a small unique population of cells that express pluripotent stem cell markers along with MSC markers and possess an inherent neurogenic potential. These pluripotent progenitors later generate cells expressing neural progenitor markers and are responsible for the instantaneous neuronal differentiation; the ratio of these pluripotent marker expressing cells in a batch determines the innate neurogenic potential.

Bone marrow vascular niche and the control of tumor growth in hematological malignancies

Bone marrow contains hematopoietic stem cells (HSCs) and nonhematopoietic cells. HSCs are self-renewing multipotent progenitors that give rise to all types of mature blood cells, whereas the nonhematopoietic component is composed of osteoblasts/osteoclasts, endothelial cells, endothelial progenitor cells, T lymphocytes, macrophages, mast cells, fibroblasts and mesenchymal stem cells. All of these cells contribute to the formation of specialized ‘niches’, which are close to the marrow vasculature (‘vascular niche’) or to the endosteum (‘osteoblast niche’).1 Depletion of either osteoblasts or endothelial cells is negatively associated with HSC survival, suggesting that both niches are important for maintaining HSC.2, 3

Immunohistochemical Expression of Stem Cell Markers during the Wound Healing Process of Cutaneous Burn

Purpose: A cutaneous wound healing requires a well-orchestrated integration of the complex biological and molecular events of cell migration and proliferation, extracellular matrix deposition, angiogenesis and remodeling. Finally, skin regeneration is the main goal. Stem cells are self-renewing multipotent progenitors with the broadest developmental potential in a given tissue at a given time. The aim of this study was to examine the role of stem cells during the wound healing process of cutaneous burn in hairless mice by using immunohistochemical stainings (nestin, cytokeratin 15 and CD31). Methods: Each mouse received 2 burns at the dorsal area by applying a metal stick heated in boiling water. Burn wound sites were dressed with duoderm. The mice were sacrificed at 0, 2, 7, 14 and 21 days after burn. Histological findings and immunohistochemical expression for stem cell markers were observed. Results: Nestin was expressed in the stromal cells beneath the epidermis, hair follices, dermal cysts and endothelial cells. Cytokeratin 15 was expressed in the epidermis except in basal cells. On 7 and 14 days after burn, the regenerated epidermis didn't express cytokeratin 15. CD31 was expressed in the endothelial cells on 7 and 14 days after burn. The amount of nestin expression was the highest. Conclusion: Our results showed that nestin may have various effects on burn wound healing. Cytokeratin 15 was expressed before burn and after burn. It is likely that other cytokeratin may stimulate epithelial regeneration. CD31 may act in vascular regeneration during burn healing. (J Korean Surg Soc 2010;79:1-7)

High-resolution gene expression analysis of the developing mouse kidney defines novel cellular compartments within the nephron progenitor population.

The functional unit of the kidney is the nephron. During its organogenesis, the mammalian metanephric kidney generates thousands of nephrons over a protracted period of fetal life. All nephrons are derived from a population of self-renewing multi-potent progenitor cells, termed the cap mesenchyme. However, our understanding of the molecular and cellular mechanisms underlying nephron development is at an early stage. In order to identify factors involved in nephrogenesis, we performed a high-resolution, spatial profiling of a number of transcriptional regulators expressed within the cap mesenchyme and early developing nephron. Our results demonstrate novel, stereotypic, spatially defined cellular sub-domains within the cap mesenchyme, which may, in part, reflect induction of nephron precursors. These results suggest a hitherto unappreciated complexity of cell states that accompany the assembly of the metanephric kidney, likely reflecting diverse regulatory actions such as the maintenance and induction of nephron progenitors.

Adult stem cells and their trans-differentiation potential--perspectives and therapeutic applications.

Stem cells are self-renewing multipotent progenitors with the broadest developmental potential in a given tissue at a given time. Normal stem cells in the adult organism are responsible for renewal and repair of aged or damaged tissue. Adult stem cells are present in virtually all tissues and during most stages of development. In this review, we introduce the reader to the basic information about the field. We describe selected stem cell isolation techniques and stem cell markers for various stem cell populations. These include makers for endothelial progenitor cells (CD146/MCAM/MUC18/S-endo-1, CD34, CD133/prominin, Tie-2, Flk1/KD/VEGFR2), hematopoietic stem cells (CD34, CD117/c-Kit, Sca1), mesenchymal stem cells (CD146/MCAM/MUC18/S-endo-1, STRO-1, Thy-1), neural stem cells (CD133/prominin, nestin, NCAM), mammary stem cells (CD24, CD29, Sca1), and intestinal stem cells (NCAM, CD34, Thy-1, CD117/c-Kit, Flt-3). Separate section provides a concise summary of recent clinical trials involving stem cells directed towards improvement of a damaged myocardium. In the last part of the review, we reflect on the field and on future developments.