CALCIUM-DRIVEN TRANSCRIPTION OF CARDIAC SPECIFYING GENE PROGRAM IN LIVER STEM CELLS

EPA Science Inventory

We have previously shown that a cloned liver stem cell line (WB F344) acquires a cardiac phenotype when seeded in a cardiac microenvironment in vivo and ex vivo. Here we investigated the mechanisms of this transdifferentiation in early (<72 hr) WB F344 cell, rat neonatal ventricu...

Stem cells in nephrology: present status and future.

PubMed

Watorek, Ewa; Klinger, Marian

2006-01-01

Stem cell biology is currently developing rapidly because of the potential therapeutic utility of stem cells. The ability to acquire any desired phenotype raises hope for regenerative therapies. Manipulation of these cells is a potentially valuable tool; however, the mechanisms of stem cell differentiation and plasticity are currently beyond our control. In the field of nephrology, the presence of adult kidney stem cells has been debated. Renal adult stem cells may be descendants of some early kidney progenitors, or may be derived from bone marrow. Evidence of a hematopoietic stem-cell contribution to renal repair encourages the possibility of bone marrow or stem cell transplantation as a means of treating autoimmune glomerulopathies. The transplantation of fetal kidney tissue containing renal progenitors, which then develop into functional nephrons, is a step towards renal regeneration. According to recent reports, the development of functional nephrons from human mesenchymal stem cells in rodent whole-embryo culture is possible. Establishing in vitro self organs from autologous stem cells would be a promising therapeutic solution in light of the shortage of allogenic organs and the unresolved problem of chronic allograft rejection.

Investigating the Regulation and Potential Role of Nonhypoxic Hypoxia Inducible Factor 1 (HIF 1) in Aromatase Inhibitor Resistant Breast Cancer

DTIC Science & Technology

2015-12-01

resistance include: 1) cancer stem cell maintenance markers (Oct-4, kit ligand, JARID1B); 2) epithelial- mesenchymal -transition (EMT) markers (Snail...target proteins, such as BCRP andvimentin. BCRP and vimentin contribute to letrozole resistance through their effects on maintaining cacer stem cell ...treatment of acquired AI resistance. 15. SUBJECT TERMS Breast cancer, aromatase inhibitors (ex. letrozole), drug resistance, cancer stem cells ,nonhypoxic

Recent Progress in Stem Cell Modification for Cardiac Regeneration

PubMed Central

Voronina, Natalia; Steinhoff, Gustav

2018-01-01

During the past decades, stem cell-based therapy has acquired a promising role in regenerative medicine. The application of novel cell therapeutics for the treatment of cardiovascular diseases could potentially achieve the ambitious aim of effective cardiac regeneration. Despite the highly positive results from preclinical studies, data from phase I/II clinical trials are inconsistent and the improvement of cardiac remodeling and heart performance was found to be quite limited. The major issues which cardiac stem cell therapy is facing include inefficient cell delivery to the site of injury, accompanied by low cell retention and weak effectiveness of remaining stem cells in tissue regeneration. According to preclinical and clinical studies, various stem cells (adult stem cells, embryonic stem cells, and induced pluripotent stem cells) represent the most promising cell types so far. Beside the selection of the appropriate cell type, researchers have developed several strategies to produce “second-generation” stem cell products with improved regenerative capacity. Genetic and nongenetic modifications, chemical and physical preconditioning, and the application of biomaterials were found to significantly enhance the regenerative capacity of transplanted stem cells. In this review, we will give an overview of the recent developments in stem cell engineering with the goal to facilitate stem cell delivery and to promote their cardiac regenerative activity. PMID:29535769

Integration of immunological aspects in the European Human Embryonic Stem Cell Registry.

PubMed

Borstlap, Joeri; Kurtz, Andreas

2008-05-01

The immunological properties of stem cells are of increasing importance in regenerative medicine. Immunomodulatory mechanisms seem to play an important role not only with respect to the understanding of underlying mechanisms of autologous versus allogenic therapeutic approaches, but also for endogeneous tissue regeneration. The newly established European human embryonic stem cell registry (hESCreg) offers an international database for the registration, documentation and characterisation of human embryonic stem cells (hESC) and their use. By doing so, hESCreg aims to develop a model procedure for further standardisation efforts in the field of stem cell research and regenerative medicine, and eventually the registry may lead to a repository of therapy-related information. Currently the stem cell characterisation data acquired by the registry are divided into several categories such as cell derivation, culture conditions, genetic constitution, stem cell marker expression and degree of modification. This article describes immunological aspects of stem cell characterisation and explores the layout and relevance of a possible additional section to the hESCreg repository to include immunological characteristics of human embryonic stem cells.

Induced pluripotent stem cells: advances to applications

PubMed Central

Nelson, Timothy J; Martinez-Fernandez, Almudena; Yamada, Satsuki; Ikeda, Yasuhiro; Perez-Terzic, Carmen; Terzic, Andre

2010-01-01

Induced pluripotent stem cell (iPS) technology has enriched the armamentarium of regenerative medicine by introducing autologous pluripotent progenitor pools bioengineered from ordinary somatic tissue. Through nuclear reprogramming, patient-specific iPS cells have been derived and validated. Optimizing iPS-based methodology will ensure robust applications across discovery science, offering opportunities for the development of personalized diagnostics and targeted therapeutics. Here, we highlight the process of nuclear reprogramming of somatic tissues that, when forced to ectopically express stemness factors, are converted into bona fide pluripotent stem cells. Bioengineered stem cells acquire the genuine ability to generate replacement tissues for a wide-spectrum of diseased conditions, and have so far demonstrated therapeutic benefit upon transplantation in model systems of sickle cell anemia, Parkinson’s disease, hemophilia A, and ischemic heart disease. The field of regenerative medicine is therefore primed to adopt and incorporate iPS cell-based advancements as a next generation stem cell platforms. PMID:21165156

Acquired von Willebrand Syndrome Associated to Secondary IgM MGUS Emerging after Autologous Stem Cell Transplantation for AL Amyloidosis

PubMed Central

Qamar, Hina; Lee, Adrienne; Valentine, Karen; Skeith, Leslie; Jimenez-Zepeda, Victor H

2017-01-01

Acquired von Willebrand syndrome (AVWS) is a rare hemorrhagic disorder that occurs in patients with no prior personal or family history of bleeding. Here, we describe a case of AVWS occurring after autologous stem cell transplantation (ASCT). Interestingly, AVWS developed after bortezomib-based induction and conditioning regimens. Recent evidence suggests that the proximity of the bortezomib therapy to the collection of stem cells with consequent depletion of regulatory T cells after the conditioning regimen could explain some of the unusual autoimmune complications reported in patients receiving bortezomib prior to ASCT. In addition, this patient developed a secondary MGUS post-ASCT, which may have also contributed to the AVWS. To the best of our knowledge, this is the first case of post-ASCT AVWS reported. Prospective data is needed to better elucidate the mechanisms by which these unusual complications occur in patients receiving bortezomib prior to ASCT. PMID:28512563

Acquired von Willebrand Syndrome Associated to Secondary IgM MGUS Emerging after Autologous Stem Cell Transplantation for AL Amyloidosis.

PubMed

Qamar, Hina; Lee, Adrienne; Valentine, Karen; Skeith, Leslie; Jimenez-Zepeda, Victor H

2017-01-01

Acquired von Willebrand syndrome (AVWS) is a rare hemorrhagic disorder that occurs in patients with no prior personal or family history of bleeding. Here, we describe a case of AVWS occurring after autologous stem cell transplantation (ASCT). Interestingly, AVWS developed after bortezomib-based induction and conditioning regimens. Recent evidence suggests that the proximity of the bortezomib therapy to the collection of stem cells with consequent depletion of regulatory T cells after the conditioning regimen could explain some of the unusual autoimmune complications reported in patients receiving bortezomib prior to ASCT. In addition, this patient developed a secondary MGUS post-ASCT, which may have also contributed to the AVWS. To the best of our knowledge, this is the first case of post-ASCT AVWS reported. Prospective data is needed to better elucidate the mechanisms by which these unusual complications occur in patients receiving bortezomib prior to ASCT.

Hematopoietic stem cell engineering at a crossroads.

PubMed

Rivière, Isabelle; Dunbar, Cynthia E; Sadelain, Michel

2012-02-02

The genetic engineering of hematopoietic stem cells is the basis for potentially treating a large array of hereditary and acquired diseases, and stands as the paradigm for stem cell engineering in general. Recent clinical reports support the formidable promise of this approach but also highlight the limitations of the technologies used to date, which have on occasion resulted in clonal expansion, myelodysplasia, or leukemogenesis. New research directions, predicated on improved vector designs, targeted gene delivery or the therapeutic use of pluripotent stem cells, herald the advent of safer and more effective hematopoietic stem cell therapies that may transform medical practice. In this review, we place these recent advances in perspective, emphasizing the solutions emerging from a wave of new technologies and highlighting the challenges that lie ahead.

Cancer stem cells, cancer cell plasticity and radiation therapy.

PubMed

Vlashi, Erina; Pajonk, Frank

2015-04-01

Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alternative generation of CNS neural stem cells and PNS derivatives from neural crest-derived peripheral stem cells.

PubMed

Weber, Marlen; Apostolova, Galina; Widera, Darius; Mittelbronn, Michel; Dechant, Georg; Kaltschmidt, Barbara; Rohrer, Hermann

2015-02-01

Neural crest-derived stem cells (NCSCs) from the embryonic peripheral nervous system (PNS) can be reprogrammed in neurosphere (NS) culture to rNCSCs that produce central nervous system (CNS) progeny, including myelinating oligodendrocytes. Using global gene expression analysis we now demonstrate that rNCSCs completely lose their previous PNS characteristics and acquire the identity of neural stem cells derived from embryonic spinal cord. Reprogramming proceeds rapidly and results in a homogenous population of Olig2-, Sox3-, and Lex-positive CNS stem cells. Low-level expression of pluripotency inducing genes Oct4, Nanog, and Klf4 argues against a transient pluripotent state during reprogramming. The acquisition of CNS properties is prevented in the presence of BMP4 (BMP NCSCs) as shown by marker gene expression and the potential to produce PNS neurons and glia. In addition, genes characteristic for mesenchymal and perivascular progenitors are expressed, which suggests that BMP NCSCs are directed toward a pericyte progenitor/mesenchymal stem cell (MSC) fate. Adult NCSCs from mouse palate, an easily accessible source of adult NCSCs, display strikingly similar properties. They do not generate cells with CNS characteristics but lose the neural crest markers Sox10 and p75 and produce MSC-like cells. These findings show that embryonic NCSCs acquire a full CNS identity in NS culture. In contrast, MSC-like cells are generated from BMP NCSCs and pNCSCs, which reveals that postmigratory NCSCs are a source for MSC-like cells up to the adult stage. © 2014 AlphaMed Press.

Constitutive Proteasomal Degradation of TWIST-1 in Epithelial Ovarian Cancer Stem Cells Impacts Differentiation and Metastatic Potential

PubMed Central

Yin, Gang; Alvero, Ayesha B.; Craveiro, Vinicius; Holmberg, Jennie C.; Fu, Han-Hsuan; Montagna, Michele K.; Yang, Yang; Chefetz-Menaker, Ilana; Nuti, Sudhakar; Rossi, Michael; Silasi, Dan-Arin; Rutherford, Thomas; Mor, Gil

2013-01-01

Epithelial-mesenchymal transition (EMT) is a critical process for embryogenesis but is abnormally activated during cancer metastasis and recurrence. This process enables epithelial cancer cells to acquire mobility and traits associated with stemness. It is unknown whether epithelial stem cells or epithelial cancer stem cells are able to undergo EMT, and what molecular mechanism regulates this process in these specific cell types. We found that Epithelial Ovarian Cancer Stem cells (EOC stem cells) are the source of metastatic progenitor cells through a differentiation process involving EMT and Mesenchymal-Epithelial Transition (MET). We demonstrate both in vivo and in vitro the differentiation of EOC stem cells into mesenchymal spheroid-forming cells (MSFCs) and their capacity to initiate an active carcinomatosis. Furthermore, we demonstrate that human EOC stem cells injected i.p in mice are able to form ovarian tumors, suggesting that the EOC stem cells have the ability to “home” to the ovaries and establish tumors. Most interestingly, we found that TWIST1 is constitutively degraded in EOC stem cells, and that the acquisition of TWIST1 requires additional signals that will trigger the differentiation process. These findings are relevant for understanding the differentiation and metastasis process in EOC stem cells. PMID:22349827

Concise review: managing genotoxicity in the therapeutic modification of stem cells.

PubMed

Baum, Christopher; Modlich, Ute; Göhring, Gudrun; Schlegelberger, Brigitte

2011-10-01

The therapeutic use of procedures for genetic stem cell modification is limited by potential adverse events related to uncontrolled mutagenesis. Prominent findings have been made in hematopoietic gene therapy, demonstrating the risk of clonal, potentially malignant outgrowth on the basis of mutations acquired during or after therapeutic genome modification. The incidence and the growth rate of insertional mutants have been linked to the "stemness" of the target cells and vector-related features such as the integration pattern, the architecture, and the exact content of transgene cassettes. Milieu factors supporting the survival and expansion of mutants may eventually allow oncogenic progression. Similar concerns apply for medicinal products based on pluripotent stem cells. Focusing on the genetic stress induced by insertional mutagenesis and culture adaptation, we propose four conclusions. (a) Mutations occurring in the production of stem cell-based medicines may be unavoidable and need to be classified according to their risk to trigger the formation of clones that are sufficiently long-lived and mitotically active to acquire secondary transforming mutations. (b) The development of rational prevention strategies depends upon the identification of the specific mutations forming such "dominant clones" (which can also be addressed as cancer stem cell precursors) and a better knowledge of the mechanisms underlying their creation, expansion, and homeostatic control. (c) Quantitative assay systems are required to assess the practical value of preventive actions. (d) Improved approaches for the genetic modification of stem cells can address all critical steps in the origin and growth control of mutants. Copyright © 2011 AlphaMed Press.

Pluripotency of embryo-derived stem cells from rodents, lagomorphs, and primates: Slippery slope, terrace and cliff.

PubMed

Savatier, Pierre; Osteil, Pierre; Tam, Patrick P L

2017-03-01

The diverse cell states and in vitro conditions for the derivation and maintenance of the mammalian embryo-derived pluripotent stem cells raise the questions of whether there are multiple states of pluripotency of the stem cells of each species, and if there are innate species-specific variations in the pluripotency state. We will address these questions by taking a snapshot of our knowledge of the properties of the pluripotent stem cells, focusing on the maintenance of pluripotency and inter-conversion of the different types of pluripotent stem cells from rodents, lagomorphs and primates. We conceptualize pluripotent stem cells acquiring a series of cellular states represented as terraces on a slope of descending gradient of pluripotency. We propose that reprogramming pluripotent stem cells from a primed to a naive state is akin to moving upstream over a steep cliff to a higher terrace. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Parsing Stem Cell Lineage Development Using High Content Image Analysis of Epigenetic Spatial Markers.

PubMed

Kim, Joseph J; Moghe, Prabhas V

2018-06-14

This unit describes a protocol for acquiring and analyzing high-content super-resolution images of human stem cell nuclei for the characterization and classification of the cell differentiation paths based on distinct patterns of epigenetic mark organization. Here, we describe the cell culture, immunocytochemical labeling, super-resolution imaging parameters, and MATLAB-based quantitative image analysis approaches for monitoring human mesenchymal stem cells (hMSCs) and human induced pluripotent stem cells (hiPSCs) as the cells differentiate towards various lineages. Although this protocol uses specific cell types as examples, this approach could be easily extended to a variety of cell types and nuclear epigenetic and mechanosensitive biomarkers that are relevant to specific cell developmental scenarios. © 2018 by John Wiley & Sons, Inc. Copyright © 2018 John Wiley & Sons, Inc.

Cutaneous acquired toxoplasmosis in a child: a case report and review of the literature.

PubMed

Rand, Andrew J; Buck, Andrew B; Love, Porcia B; Prose, Neil S; Selim, M Angelica

2015-04-01

Cutaneous toxoplasmosis is a rare and diagnostically challenging entity. Today, the acquired form occurs predominantly in immunocompromised patients with human immunodeficiency virus or after hematopoietic stem cell transplantation. We report a case of cutaneous toxoplasmosis in a 6-year-old girl after allogeneic stem cell transplantation for immune-mediated encephalopathy, first manifesting at 16 months of age. In the post-transplant setting, she developed a rash consisting of approximately 8 scattered 3–4-mm round, erythematous macules and papules on her back, abdomen, and right shoulder. Sections from a biopsy of a lesion on the back revealed numerous spherules tightly packed within small cystic structures in the epidermis. The diagnosis of cutaneous toxoplasmosis was confirmed by an immunohistochemical stain for Toxoplasma gondii and polymerase chain reaction on the peripheral blood for the T. gondii genome. This case should raise awareness that acquired toxoplasmosis with cutaneous involvement can occur in the pediatric population, particularly in immunocompromised patients after stem cell transplantation. Early diagnosis and treatment of this life-threatening opportunistic infection may improve patient outcomes.

The potential role of adult stem cells in the management of the rheumatic diseases

PubMed Central

Franceschetti, Tiziana; De Bari, Cosimo

2017-01-01

Adult stem cells are considered as appealing therapeutic candidates for inflammatory and degenerative musculoskeletal diseases. A large body of preclinical research has contributed to describing their immune-modulating properties and regenerative potential. Additionally, increasing evidence suggests that stem cell differentiation and function are disrupted in the pathogenesis of rheumatic diseases. Clinical studies have been limited, for the most part, to the application of adult stem cell-based treatments on small numbers of patients or as a ‘salvage’ therapy in life-threatening disease cases. Nevertheless, these preliminary studies indicate that adult stem cells are promising tools for the long-term treatment of rheumatic diseases. This review highlights recent knowledge acquired in the fields of hematopoietic and mesenchymal stem cell therapy for the management of systemic sclerosis (SSc), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and osteoarthritis (OA) and the potential mechanisms mediating their function. PMID:28717403

Dedifferentiation of Glioma Cells to Glioma Stem-like Cells By Therapeutic Stress-induced HIF Signaling in the Recurrent GBM Model.

PubMed

Lee, Gina; Auffinger, Brenda; Guo, Donna; Hasan, Tanwir; Deheeger, Marc; Tobias, Alex L; Kim, Jeong Yeon; Atashi, Fatemeh; Zhang, Lingjiao; Lesniak, Maciej S; James, C David; Ahmed, Atique U

2016-12-01

Increasing evidence exposes a subpopulation of cancer cells, known as cancer stem cells (CSCs), to be critical for the progression of several human malignancies, including glioblastoma multiforme. CSCs are highly tumorigenic, capable of self-renewal, and resistant to conventional therapies, and thus considered to be one of the key contributors to disease recurrence. To elucidate the poorly understood evolutionary path of tumor recurrence and the role of CSCs in this process, we developed patient-derived xenograft glioblastoma recurrent models induced by anti-glioma chemotherapy, temozolomide. In this model, we observed a significant phenotypic shift towards an undifferentiated population. We confirmed these findings in vitro as sorted CD133-negative populations cultured in differentiation-forcing media were found to acquire CD133 expression following chemotherapy treatment. To investigate this phenotypic switch at the single-cell level, glioma stem cell (GSC)-specific promoter-based reporter systems were engineered to track changes in the GSC population in real time. We observed the active phenotypic and functional switch of single non-stem glioma cells to a stem-like state and that temozolomide therapy significantly increased the rate of single-cell conversions. Importantly, we showed the therapy-induced hypoxia-inducible factors (HIF) 1α and HIF2α play key roles in allowing non-stem glioma cells to acquire stem-like traits, as the expression of both HIFs increase upon temozolomide therapy and knockdown of HIFs expression inhibits the interconversion between non-stem glioma cells and GSCs post-therapy. On the basis of our results, we propose that anti-glioma chemotherapy promotes the accumulation of HIFs in the glioblastoma multiforme cells that induces the formation of therapy-resistant GSCs responsible for recurrence. Mol Cancer Ther; 15(12); 3064-76. ©2016 AACR. ©2016 American Association for Cancer Research.

Hematopoietic stem cell engineering at a crossroads

PubMed Central

Rivière, Isabelle; Dunbar, Cynthia E.

2012-01-01

The genetic engineering of hematopoietic stem cells is the basis for potentially treating a large array of hereditary and acquired diseases, and stands as the paradigm for stem cell engineering in general. Recent clinical reports support the formidable promise of this approach but also highlight the limitations of the technologies used to date, which have on occasion resulted in clonal expansion, myelodysplasia, or leukemogenesis. New research directions, predicated on improved vector designs, targeted gene delivery or the therapeutic use of pluripotent stem cells, herald the advent of safer and more effective hematopoietic stem cell therapies that may transform medical practice. In this review, we place these recent advances in perspective, emphasizing the solutions emerging from a wave of new technologies and highlighting the challenges that lie ahead. PMID:22096239

An Overview of Direct Somatic Reprogramming: The Ins and Outs of iPSCs

PubMed Central

Menon, Siddharth; Shailendra, Siny; Renda, Andrea; Longaker, Michael; Quarto, Natalina

2016-01-01

Stem cells are classified into embryonic stem cells and adult stem cells. An evolving alternative to conventional stem cell therapies is induced pluripotent stem cells (iPSCs), which have a multi-lineage potential comparable to conventionally acquired embryonic stem cells with the additional benefits of being less immunoreactive and avoiding many of the ethical concerns raised with the use of embryonic material. The ability to generate iPSCs from somatic cells provides tremendous promise for regenerative medicine. The breakthrough of iPSCs has raised the possibility that patient-specific iPSCs can provide autologous cells for cell therapy without the concern for immune rejection. iPSCs are also relevant tools for modeling human diseases and drugs screening. However, there are still several hurdles to overcome before iPSCs can be used for translational purposes. Here, we review the recent advances in somatic reprogramming and the challenges that must be overcome to move this strategy closer to clinical application. PMID:26805822

Chemotherapy curable malignancies and cancer stem cells: a biological review and hypothesis.

PubMed

Savage, Philip

2016-11-21

Cytotoxic chemotherapy brings routine cures to only a small select group of metastatic malignancies comprising gestational trophoblast tumours, germ cell tumours, acute leukemia, Hodgkin's disease, high grade lymphomas and some of the rare childhood malignancies. We have previously postulated that the extreme sensitivity to chemotherapy for these malignancies is linked to the on-going high levels of apoptotic sensitivity that is naturally linked with the unique genetic events of nuclear fusion, meiosis, VDJ recombination, somatic hypermutation, and gastrulation that have occurred within the cells of origin of these malignancies. In this review we will examine the cancer stem cell/cancer cell relationship of each of the chemotherapy curable malignancies and how this relationship impacts on the resultant biology and pro-apoptotic sensitivity of the varying cancer cell types. In contrast to the common epithelial cancers, in each of the chemotherapy curable malignancies there are no conventional hierarchical cancer stem cells. However cells with cancer stem like qualities can arise stochastically from within the general tumour cell population. These stochastic stem cells acquire a degree of resistance to DNA damaging agents but also retain much of the key characteristics of the cancer cells from which they develop. We would argue that the balance between the acquired resistance of the stochastic cancer stem cell and the inherent chemotherapy sensitivity of parent tumour cell determines the overall chemotherapy curability of each diagnosis. The cancer stem cells in the chemotherapy curable malignancies appear to have two key biological differences from those of the more common chemotherapy incurable malignancies. The first difference is that the conventional hierarchical pattern of cancer stem cells is absent in each of the chemotherapy curable malignancies. The other key difference, we suggest, is that the stochastic stem cells in the chemotherapy curable malignancies take on a significant aspect of the biological characteristics of their parent cancer cells. This action includes for the chemotherapy curable malignancies the heightened pro-apoptotic sensitivity linked to their respective associated unique genetic events. For the chemotherapy curable malignancies the combination of the relationship of their cancer stem cells combined with the extreme inherent sensitivity to induction of apoptosis from DNA damaging agents plays a key role in determining their overall curability with chemotherapy.

Embryonic attenuated Wnt/β-catenin signaling defines niche location and long-term stem cell fate in hair follicle

PubMed Central

Xu, Zijian; Wang, Wenjie; Jiang, Kaiju; Yu, Zhou; Huang, Huanwei; Wang, Fengchao; Zhou, Bin; Chen, Ting

2015-01-01

Long-term adult stem cells sustain tissue regeneration throughout the lifetime of an organism. They were hypothesized to originate from embryonic progenitor cells that acquire long-term self-renewal ability and multipotency at the end of organogenesis. The process through which this is achieved often remains unclear. Here, we discovered that long-term hair follicle stem cells arise from embryonic progenitor cells occupying a niche location that is defined by attenuated Wnt/β-catenin signaling. Hair follicle initiation is marked by placode formation, which depends on the activation of Wnt/β-catenin signaling. Soon afterwards, a region with attenuated Wnt/β-catenin signaling emerges in the upper follicle. Embryonic progenitor cells residing in this region gain expression of adult stem cell markers and become definitive long-term hair follicle stem cells at the end of organogenesis. Attenuation of Wnt/β-catenin signaling is a prerequisite for hair follicle stem cell specification because it suppresses Sox9, which is required for stem cell formation. DOI: http://dx.doi.org/10.7554/eLife.10567.001 PMID:26653852

Stem-Cell-Based Tumorigenesis in Adult Drosophila.

PubMed

Hou, S X; Singh, S R

2017-01-01

Recent studies suggest that a small subset of cells within a tumor, the so-called cancer stem cells (CSCs), are responsible for tumor propagation, relapse, and the eventual death of most cancer patients. CSCs may derive from a few tumor-initiating cells, which are either transformed normal stem cells or reprogrammed differentiated cells after acquiring initial cancer-causing mutations. CSCs and normal stem cells share some properties, but CSCs differ from normal stem cells in their tumorigenic ability. Notably, CSCs are usually resistant to chemo- and radiation therapies. Despite the apparent roles of CSCs in human cancers, the biology underlying their behaviors remains poorly understood. Over the past few years, studies in Drosophila have significantly contributed to this new frontier of cancer research. Here, we first review how stem-cell tumors are initiated and propagated in Drosophila, through niche appropriation in the posterior midgut and through stem-cell competition for niche occupancy in the testis. We then discuss the differences between normal and tumorigenic stem cells, revealed by studying Ras V12 -transformed stem-cell tumors in the Drosophila kidney. Finally, we review the biology behind therapy resistance, which has been elucidated through studies of stem-cell resistance and sensitivity to death inducers using female germline stem cells and intestinal stem cells of the posterior midgut. We expect that screens using adult Drosophila neoplastic stem-cell tumor models will be valuable for identifying novel and effective compounds for treating human cancers. © 2017 Elsevier Inc. All rights reserved.

Single-Cell Transcriptomics and Fate Mapping of Ependymal Cells Reveals an Absence of Neural Stem Cell Function.

PubMed

Shah, Prajay T; Stratton, Jo A; Stykel, Morgan Gail; Abbasi, Sepideh; Sharma, Sandeep; Mayr, Kyle A; Koblinger, Kathrin; Whelan, Patrick J; Biernaskie, Jeff

2018-05-03

Ependymal cells are multi-ciliated cells that form the brain's ventricular epithelium and a niche for neural stem cells (NSCs) in the ventricular-subventricular zone (V-SVZ). In addition, ependymal cells are suggested to be latent NSCs with a capacity to acquire neurogenic function. This remains highly controversial due to a lack of prospective in vivo labeling techniques that can effectively distinguish ependymal cells from neighboring V-SVZ NSCs. We describe a transgenic system that allows for targeted labeling of ependymal cells within the V-SVZ. Single-cell RNA-seq revealed that ependymal cells are enriched for cilia-related genes and share several stem-cell-associated genes with neural stem or progenitors. Under in vivo and in vitro neural-stem- or progenitor-stimulating environments, ependymal cells failed to demonstrate any suggestion of latent neural-stem-cell function. These findings suggest remarkable stability of ependymal cell function and provide fundamental insights into the molecular signature of the V-SVZ niche. Copyright © 2018 Elsevier Inc. All rights reserved.

Multiple mutant clones in blood rarely coexist

NASA Astrophysics Data System (ADS)

Dingli, David; Pacheco, Jorge M.; Traulsen, Arne

2008-02-01

Leukemias arise due to mutations in the genome of hematopoietic (blood) cells. Hematopoiesis has a multicompartment architecture, with cells exhibiting different rates of replication and differentiation. At the root of this process, one finds a small number of stem cells, and hence the description of the mutation-selection dynamics of blood cells calls for a stochastic approach. We use stochastic dynamics to investigate to which extent acquired hematopoietic disorders are associated with mutations of single or multiple genes within developing blood cells. Our analysis considers the appearance of mutations both in the stem cell compartment as well as in more committed compartments. We conclude that in the absence of genomic instability, acquired hematopoietic disorders due to mutations in multiple genes are most likely very rare events, as multiple mutations typically require much longer development times compared to those associated with a single mutation.

Chromatin in embryonic stem cell neuronal differentiation.

PubMed

Meshorer, E

2007-03-01

Chromatin, the basic regulatory unit of the eukaryotic genetic material, is controlled by epigenetic mechanisms including histone modifications, histone variants, DNA methylation and chromatin remodeling. Cellular differentiation involves large changes in gene expression concomitant with alterations in genome organization and chromatin structure. Such changes are particularly evident in self-renewing pluripotent embryonic stem cells, which begin, in terms of cell fate, as a tabula rasa, and through the process of differentiation, acquire distinct identities. Here I describe the changes in chromatin that accompany neuronal differentiation, particularly of embryonic stem cells, and discuss how chromatin serves as the master regulator of cellular destiny.

Assessment of the Tumorigenic Potential of Spontaneously Immortalized and hTERT-Immortalized Cultured Dental Pulp Stem Cells.

PubMed

Wilson, Ryan; Urraca, Nora; Skobowiat, Cezary; Hope, Kevin A; Miravalle, Leticia; Chamberlin, Reed; Donaldson, Martin; Seagroves, Tiffany N; Reiter, Lawrence T

2015-08-01

Dental pulp stem cells (DPSCs) provide an exciting new avenue to study neurogenetic disorders. DPSCs are neural crest-derived cells with the ability to differentiate into numerous tissues including neurons. The therapeutic potential of stem cell-derived lines exposed to culturing ex vivo before reintroduction into patients could be limited if the cultured cells acquired tumorigenic potential. We tested whether DPSCs that spontaneously immortalized in culture acquired features of transformed cells. We analyzed immortalized DPSCs for anchorage-independent growth, genomic instability, and ability to differentiate into neurons. Finally, we tested both spontaneously immortalized and human telomerase reverse transcriptase (hTERT)-immortalized DPSC lines for the ability to form tumors in immunocompromised animals. Although we observed increased colony-forming potential in soft agar for the spontaneously immortalized and hTERT-immortalized DPSC lines relative to low-passage DPSC, no tumors were detected from any of the DPSC lines tested. We noticed some genomic instability in hTERT-immortalized DPSCs but not in the spontaneously immortalized lines tested. We determined that immortalized DPSC lines generated in our laboratory, whether spontaneously or induced, have not acquired the potential to form tumors in mice. These data suggest cultured DPSC lines that can be differentiated into neurons may be safe for future in vivo therapy for neurobiological diseases. ©AlphaMed Press.

Assessment of the Tumorigenic Potential of Spontaneously Immortalized and hTERT-Immortalized Cultured Dental Pulp Stem Cells

PubMed Central

Wilson, Ryan; Urraca, Nora; Skobowiat, Cezary; Hope, Kevin A.; Miravalle, Leticia; Chamberlin, Reed; Donaldson, Martin; Seagroves, Tiffany N.

2015-01-01

Dental pulp stem cells (DPSCs) provide an exciting new avenue to study neurogenetic disorders. DPSCs are neural crest-derived cells with the ability to differentiate into numerous tissues including neurons. The therapeutic potential of stem cell-derived lines exposed to culturing ex vivo before reintroduction into patients could be limited if the cultured cells acquired tumorigenic potential. We tested whether DPSCs that spontaneously immortalized in culture acquired features of transformed cells. We analyzed immortalized DPSCs for anchorage-independent growth, genomic instability, and ability to differentiate into neurons. Finally, we tested both spontaneously immortalized and human telomerase reverse transcriptase (hTERT)-immortalized DPSC lines for the ability to form tumors in immunocompromised animals. Although we observed increased colony-forming potential in soft agar for the spontaneously immortalized and hTERT-immortalized DPSC lines relative to low-passage DPSC, no tumors were detected from any of the DPSC lines tested. We noticed some genomic instability in hTERT-immortalized DPSCs but not in the spontaneously immortalized lines tested. We determined that immortalized DPSC lines generated in our laboratory, whether spontaneously or induced, have not acquired the potential to form tumors in mice. These data suggest cultured DPSC lines that can be differentiated into neurons may be safe for future in vivo therapy for neurobiological diseases. Significance This study demonstrated that immortalized dental pulp stem cells (DPSCs) do not form tumors in animals and that immortalized DPSCs can be differentiated into neurons in culture. These results lend support to the use of primary and immortalized DPSCs for future therapeutic approaches to treatment of neurobiological diseases. PMID:26032749

Stem-cell-activated organ following ultrasound exposure: better transplant option for organ transplantation.

PubMed

Wang, Sen; Li, Yu; Ji, Ying-Chang; Lin, Chang-Min; Man, Cheng; Zheng, Xiao-Xuan

2010-01-01

Although doctors try their best to protect transplants during surgery, there remain great challenges for the higher survival rate and less rejection of transplants after organ transplantation. Growing evidence indicates that the stem cells could function after injury rather than aging, implying that suitable injury may activate the stem cells of damaged organs. Furthermore, it has been revealed that stem cells can be used to induce tolerance in transplantation and the ultrasound has great biological effects on organs. Basing on these facts, we hypothesize that the stem cells within the transplants can be activated by ultrasound with high-frequency and medium-intensity. Therefore, the stem-cell-activated organs (SCAO) can be derived, and the SCAO will be better transplant option for organ transplantation. We postulate the ultrasound can change the molecular activity and/or quantity of the stem cells, the membrane permeability, the cell-cell junctions, and their surrounding microenvironments. As a result, the stem cells are activated, and the SCAO will acquire more regenerative capacity and less rejection. In the paper, we also discuss the process, methods and models for verifying the theory, and the consequences. We believe the theory may provide a practical method for the clinical application of the ultrasound and stem cells in organ transplantation.

Cancer Stem Cells: Dynamic Entities in an Ever-Evolving Paradigm.

PubMed

Lopez-Bertoni, Hernando; Li, Yunqing; Laterra, John

2015-11-01

The cancer stem cell (CSC) hypothesis postulates that there is a hierarchy of cellular differentiation within cancers and that the bulk population of tumor cells is derived from a relatively small population of multi-potent neoplastic stem-like cells (CSCs). This tumor-initiating cell population plays an important role in maintaining tumor growth through their unlimited self-renewal, therapeutic resistance, and capacity to propagate tumors through asymmetric cell division. Recent findings from multiple laboratories show that cancer progenitor cells have the capacity to de-differentiate and acquire a stem-like phenotype in response to either genetic manipulation or environmental cues. These findings suggest that CSCs and relatively differentiated progenitors coexist in dynamic equilibrium and are subject to bidirectional conversion. In this review, we discuss emerging concepts regarding the stem-like phenotype, its acquisition by cancer progenitor cells, and the molecular mechanisms involved. Understanding the dynamic equilibrium between CSCs and cancer progenitor cells is critical for the development of novel therapeutic strategies that focus on depleting tumors of their tumor-propagating cell population.

Adipogenic placenta-derived mesenchymal stem cells are not lineage restricted by withdrawing extrinsic factors: developing a novel visual angle in stem cell biology.

PubMed

Hu, C; Cao, H; Pan, X; Li, J; He, J; Pan, Q; Xin, J; Yu, X; Li, J; Wang, Y; Zhu, D; Li, L

2016-03-17

Current evidence implies that differentiated bone marrow mesenchymal stem cells (BMMSCs) can act as progenitor cells and transdifferentiate across lineage boundaries. However, whether this unrestricted lineage has specificities depending on the stem cell type is unknown. Placental-derived mesenchymal stem cells (PDMSCs), an easily accessible and less invasive source, are extremely useful materials in current stem cell therapies. No studies have comprehensively analyzed the transition in morphology, surface antigens, metabolism and multilineage potency of differentiated PDMSCs after their dedifferentiation. In this study, we showed that after withdrawing extrinsic factors, adipogenic PDMSCs reverted to a primitive cell population and retained stem cell characteristics. The mitochondrial network during differentiation and dedifferentiation may serve as a marker of absent or acquired pluripotency in various stem cell models. The new population proliferated faster than unmanipulated PDMSCs and could be differentiated into adipocytes, osteocytes and hepatocytes. The cell adhesion molecules (CAMs) signaling pathway and extracellular matrix (ECM) components modulate cell behavior and enable the cells to proliferate or differentiate during the differentiation, dedifferentiation and redifferentiation processes in our study. These observations indicate that the dedifferentiated PDMSCs are distinguishable from the original PDMSCs and may serve as a novel source in stem cell biology and cell-based therapeutic strategies. Furthermore, whether PDMSCs differentiated into other lineages can be dedifferentiated to a primitive cell population needs to be investigated.

Combining targeted drugs to overcome and prevent resistance of solid cancers with some stem-like cell features

PubMed Central

Koivunen, Peppi; Koivunen, Jussi P.

2014-01-01

Treatment resistance significantly inhibits the efficiency of targeted cancer therapies in drug-sensitive genotypes. In the current work, we studied mechanisms for rapidly occurring, adaptive resistance in targeted therapy-sensitive lung, breast, and melanoma cancer cell lines. The results show that in ALK translocated lung cancer lines H3122 and H2228, cells with cancer stem-like cell features characterized by high expression of cancer stem cell markers and/or in vivo tumorigenesis can mediate adaptive resistance to oncogene ablative therapy. When pharmacological ablation of ALK oncogene was accompanied with PI3K inhibitor or salinomycin therapy, cancer stem-like cell features were reversed which was accompanied with decreased colony formation. Furthermore, co-targeting was able to block the formation of acquired resistance in H3122 line. The results suggest that cells with cancer stem-like cell features can mediate adaptive resistance to targeted therapies. Since these cells follow the stochastic model, concurrent therapy with an oncogene ablating agent and a stem-like cell-targeting drug is needed for maximal therapeutic efficiency. PMID:25238228

Genome stability of programmed stem cell products.

PubMed

Martin, Ulrich

2017-10-01

Inherited and acquired genomic abnormalities are known to cause genetic diseases and contribute to cancer formation. Recent studies demonstrated a substantial mutational load in mouse and human embryonic and induced pluripotent stem cells (ESCs and iPSCs). Single nucleotide variants, copy number variations, and larger chromosomal abnormalities may influence the differentiation capacity of pluripotent stem cells and the functionality of their derivatives in disease modeling and drug screening, and are considered a serious risk for cellular therapies based on ESC or iPSC derivatives. This review discusses the types and origins of different genetic abnormalities in pluripotent stem cells, methods for their detection, and the mechanisms of development and enrichment during reprogramming and culture expansion. Copyright © 2017 Elsevier B.V. All rights reserved.

Reactive astrocytes as neural stem or progenitor cells: In vivo lineage, In vitro potential, and Genome‐wide expression analysis

PubMed Central

Sirko, Swetlana; Beckers, Johannes; Irmler, Martin

2015-01-01

Here, we review the stem cell hallmarks of endogenous neural stem cells (NSCs) during development and in some niches of the adult mammalian brain to then compare these with reactive astrocytes acquiring stem cell hallmarks after traumatic and ischemic brain injury. Notably, even endogenous NSCs including the earliest NSCs, the neuroepithelial cells, generate in most cases only a single type of progeny and self‐renew only for a rather short time in vivo. In vitro, however, especially cells cultured under neurosphere conditions reveal a larger potential and long‐term self‐renewal under the influence of growth factors. This is rather well comparable to reactive astrocytes in the traumatic or ischemic brain some of which acquire neurosphere‐forming capacity including multipotency and long‐term self‐renewal in vitro, while they remain within their astrocyte lineage in vivo. Both reactive astrocytes and endogenous NSCs exhibit stem cell hallmarks largely in vitro, but their lineage differs in vivo. Both populations generate largely a single cell type in vivo, but endogenous NSCs generate neurons and reactive astrocytes remain in the astrocyte lineage. However, at some early postnatal stages or in some brain regions reactive astrocytes can be released from this fate restriction, demonstrating that they can also enact neurogenesis. Thus, reactive astrocytes and NSCs share many characteristic hallmarks, but also exhibit key differences. This conclusion is further substantiated by genome‐wide expression analysis comparing NSCs at different stages with astrocytes from the intact and injured brain parenchyma. GLIA 2015;63:1452–1468 PMID:25965557

Effect of Mutation Order on Myeloproliferative Neoplasms

PubMed Central

Nangalia, Jyoti; Silber, Yvonne; Wedge, David C.; Grinfeld, Jacob; Baxter, E. Joanna; Massie, Charles E.; Papaemmanuil, Elli; Menon, Suraj; Godfrey, Anna L.; Dimitropoulou, Danai; Guglielmelli, Paola; Bellosillo, Beatriz; Besses, Carles; Döhner, Konstanze; Harrison, Claire N.; Vassiliou, George S.; Vannucchi, Alessandro; Campbell, Peter J.; Green, Anthony R.

2015-01-01

BACKGROUND Cancers result from the accumulation of somatic mutations, and their properties are thought to reflect the sum of these mutations. However, little is known about the effect of the order in which mutations are acquired. METHODS We determined mutation order in patients with myeloproliferative neoplasms by genotyping hematopoietic colonies or by means of next-generation sequencing. Stem cells and progenitor cells were isolated to study the effect of mutation order on mature and immature hematopoietic cells. RESULTS The age at which a patient presented with a myeloproliferative neoplasm, acquisition of JAK2 V617F homozygosity, and the balance of immature progenitors were all influenced by mutation order. As compared with patients in whom the TET2 mutation was acquired first (hereafter referred to as “TET2-first patients”), patients in whom the Janus kinase 2 (JAK2) mutation was acquired first (“JAK2-first patients”) had a greater likelihood of presenting with polycythemia vera than with essential thrombocythemia, an increased risk of thrombosis, and an increased sensitivity of JAK2-mutant progenitors to ruxolitinib in vitro. Mutation order influenced the proliferative response to JAK2 V617F and the capacity of double-mutant hematopoietic cells and progenitor cells to generate colony-forming cells. Moreover, the hematopoietic stem-and-progenitor-cell compartment was dominated by TET2 single-mutant cells in TET2-first patients but by JAK2–TET2 double-mutant cells in JAK2-first patients. Prior mutation of TET2 altered the transcriptional consequences of JAK2 V617F in a cell-intrinsic manner and prevented JAK2 V617F from up-regulating genes associated with proliferation. CONCLUSIONS The order in which JAK2 and TET2 mutations were acquired influenced clinical features, the response to targeted therapy, the biology of stem and progenitor cells, and clonal evolution in patients with myeloproliferative neoplasms. (Funded by Leukemia and Lymphoma Research and others.) PMID:25671252

Stem cell transplantation of matched sibling donors compared with immunosuppressive therapy for acquired severe aplastic anaemia: a Cochrane systematic review.

PubMed

Peinemann, Frank; Labeit, Alexander Michael

2014-07-15

Acquired severe aplastic anaemia is a rare and potentially fatal disease. The aim of this Cochrane review was to evaluate the effectiveness and adverse events of first-line allogeneic haematopoietic stem cell transplantation of human leucocyte antigen (HLA)-matched sibling donors compared with first-line immunosuppressive therapy. Specialised stem cell transplantations units in primary care hospitals. We included 302 participants with newly diagnosed acquired severe aplastic anaemia. The age ranged from early childhood to young adulthood. We excluded studies on participants with secondary aplastic anaemia. We included allogeneic haematopoietic stem cell transplantation as the test intervention harvested from any source of matched sibling donor and serving as a first-line therapy. We included immunosuppressive therapy as comparator with either antithymocyte/antilymphocyte globulin or ciclosporin or a combination of the two. PRIMARY AND SECONDARY OUTCOME MEASURES PLANNED AND FINALLY MEASURED: The primary outcome was overall mortality. Secondary outcomes were treatment-related mortality, graft failure, graft-versus-host disease, no response to immunosuppressive therapy, relapse after initial successful treatment, secondary clonal disease or malignancies, health-related quality of life and performance scores. We identified three prospective non-randomised controlled trials with a study design that was consistent with the principle of 'Mendelian randomisation' in allocating patients to treatment groups. All studies had a high risk of bias due to the study design and were conducted more than 15 years. The pooled HR for overall mortality for the donor group versus the no donor group was 0.95 (95% CI 0.43 to 2.12, p=0.90). There are insufficient and biased data that do not allow any firm conclusions to be made about the comparative effectiveness of first-line allogeneic haematopoietic stem cell transplantation of HLA-matched sibling donors and first-line immunosuppressive therapy of patients with acquired severe aplastic anaemia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

HPV-Induced Field Cancerisation: Transformation of Adult Tissue Stem Cell Into Cancer Stem Cell.

PubMed

Olivero, Carlotta; Lanfredini, Simone; Borgogna, Cinzia; Gariglio, Marisa; Patel, Girish K

2018-01-01

Field cancerisation was originally described as a basis for multiple head and neck squamous cell carcinoma (HNSCC) and is a pre-malignant phenomenon that is frequently attributable to oncogenic human papillomavirus (HPV) infection. Our work on β-HPV-induced cutaneous squamous cell carcinomas identified a novel Lrig1+ hair follicle junctional zone keratinocyte stem cell population as the basis for field cancerisation. Herein, we describe the ability for HPV to infect adult tissue stem cells in order to establish persistent infection and induce their proliferation and displacement resulting in field cancerisation. By review of the HPV literature, we reveal how this mechanism is conserved as the basis of field cancerisation across many tissues. New insights have identified the capacity for HPV early region genes to dysregulate adult tissue stem cell self-renewal pathways ensuring that the expanded population preserve its stem cell characteristics beyond the stem cell niche. HPV-infected cells acquire additional transforming mutations that can give rise to intraepithelial neoplasia (IEN), from environmental factors such as sunlight or tobacco induced mutations in skin and oral cavity, respectively. With establishment of IEN, HPV viral replication is sacrificed with loss of the episome, and the tissue is predisposed to multiple cancer stem cell-driven carcinomas.

Vessel-associated stem cells from skeletal muscle: From biology to future uses in cell therapy.

PubMed

Sancricca, Cristina; Mirabella, Massimiliano; Gliubizzi, Carla; Broccolini, Aldobrando; Gidaro, Teresa; Morosetti, Roberta

2010-06-26

Over the last years, the existence of different stem cells with myogenic potential has been widely investigated. Besides the classical skeletal muscle progenitors represented by satellite cells, numerous multipotent and embryologically unrelated progenitors with a potential role in muscle differentiation and repair have been identified. In order to conceive a therapeutic approach for degenerative muscle disorders, it is of primary importance to identify an ideal stem cell endowed with all the features for a possible use in vivo. Among all emerging populations, vessel-associated stem cells are a novel and promising class of multipotent progenitors of mesodermal origin and with high myogenic potential which seem to best fit all the requirements for a possible cell therapy. In vitro and in vivostudies have already tested the effectiveness and safety of vessel-associated stem cells in animal models. This leads to the concrete possibility in the future to start pilot human clinical trials, hopefully opening the way to a turning point in the treatment of genetic and acquired muscle disorders.

Regenerating new heart with stem cells

PubMed Central

Anversa, Piero; Kajstura, Jan; Rota, Marcello; Leri, Annarosa

2013-01-01

This article discusses current understanding of myocardial biology, emphasizing the regeneration potential of the adult human heart and the mechanisms involved. In the last decade, a novel conceptual view has emerged. The heart is no longer considered a postmitotic organ, but is viewed as a self-renewing organ characterized by a resident stem cell compartment responsible for tissue homeostasis and cardiac repair following injury. Additionally, HSCs possess the ability to transdifferentiate and acquire the cardiomyocyte, vascular endothelial, and smooth muscle cell lineages. Both cardiac and hematopoietic stem cells may be used therapeutically in an attempt to reverse the devastating consequences of chronic heart failure of ischemic and nonischemic origin. PMID:23281411

Presentation, diagnosis and management of limbal stem cell deficiency.

PubMed

Sejpal, Kunjal; Bakhtiari, Pejman; Deng, Sophie X

2013-01-01

The human corneal surface epithelium is continuously repopulated by the limbal stem cells (LSCs). Limbal Stem Cell Deficiency (LSCD) can lead to corneal opacity and vascularization, with consequent visual impairment or blindness. Many acquired and congenital diseases can lead to LCSD by direct injury to the LSCs, destruction of LSC niche, or both. Based on the severity of the disease, LSCD can present with various symptoms and signs. Although LSCD can be detected clinically, laboratory tests are necessary to confirm the diagnosis and monitor the disease progression. This article concisely reviews the clinical presentation, techniques for diagnosis and management of LSCD.

Which has more stem-cell characteristics: Müller cells or Müller cells derived from in vivo culture in neurospheres?

PubMed

Ji, Hong-Pei; Xiong, Yu; Zhang, En-Dong; Song, Wei-Tao; Gao, Zhao-Lin; Yao, Fei; Sun, Hong; Zhou, Rong-Rong; Xia, Xiao-Bo

2017-01-01

Müller cells can be acquired from in vitro culture or a neurosphere culture system. Both culture methods yield cells with progenitor-cell characteristics that can differentiate into mature nervous cells. We compared the progenitor-cell traits of Müller cells acquired from each method. Primary murine Müller cells were isolated in serum culture media and used to generate Müller cells derived from neurospheres in serum-free culture conditions. Gene expression of neural progenitor cell markers was examined by Q-PCR in the two groups. Expression of rhodopsin and the cone-rod homeobox protein CRX were assessed after induction with 1 μM all-trans retinoic acid (RA) for 7 days. After more than four passages, many cells were large, flattened, and difficult to passage. A spontaneously immortalized Müller cell line was not established. Three-passage neurospheres yielded few new spheres. Genes coding for Nestin, Sox2, Chx10, and Vimentin were downregulated in cells derived from neurospheres compared to the cells from standard culture, while Pax6 was upregulated. Müller cells from both culture methods were induced into rod photoreceptors, but expression of rhodopsin and CRX was greater in the Müller cells from the standard culture. Both culture methods yielded cells with stem-cell characteristics that can be induced into rod photoreceptor neurons by RA. Serum had no influence on the "stemness" of the cells. Cells from standard culture had greater "stemness" than cells derived from neurospheres. The standard Müller cells would seem to be the best choice for transplantation in cell replacement therapy for photoreceptor degeneration.

Kidney specific protein-positive cells derived from embryonic stem cells reproduce tubular structures in vitro and differentiate into renal tubular cells.

PubMed

Morizane, Ryuji; Monkawa, Toshiaki; Fujii, Shizuka; Yamaguchi, Shintaro; Homma, Koichiro; Matsuzaki, Yumi; Okano, Hideyuki; Itoh, Hiroshi

2014-01-01

Embryonic stem cells and induced pluripotent stem cells have the ability to differentiate into various organs and tissues, and are regarded as new tools for the elucidation of disease mechanisms as well as sources for regenerative therapies. However, a method of inducing organ-specific cells from pluripotent stem cells is urgently needed. Although many scientists have been developing methods to induce various organ-specific cells from pluripotent stem cells, renal lineage cells have yet to be induced in vitro because of the complexity of kidney structures and the diversity of kidney-component cells. Here, we describe a method of inducing renal tubular cells from mouse embryonic stem cells via the cell purification of kidney specific protein (KSP)-positive cells using an anti-KSP antibody. The global gene expression profiles of KSP-positive cells derived from ES cells exhibited characteristics similar to those of cells in the developing kidney, and KSP-positive cells had the capacity to form tubular structures resembling renal tubular cells when grown in a 3D culture in Matrigel. Moreover, our results indicated that KSP-positive cells acquired the characteristics of each segment of renal tubular cells through tubular formation when stimulated with Wnt4. This method is an important step toward kidney disease research using pluripotent stem cells, and the development of kidney regeneration therapies.

Eight types of stem cells in the life cycle of the moss Physcomitrella patens.

PubMed

Kofuji, Rumiko; Hasebe, Mitsuyasu

2014-02-01

Stem cells self-renew and produce cells that differentiate to become the source of the plant body. The moss Physcomitrella patens forms eight types of stem cells during its life cycle and serves as a useful model in which to explore the evolution of such cells. The common ancestor of land plants is inferred to have been haplontic and to have formed stem cells only in the gametophyte generation. A single stem cell would have been maintained in the ancestral gametophyte meristem, as occurs in extant basal land plants. During land plant evolution, stem cells diverged in the gametophyte generation to form different types of body parts, including the protonema and rhizoid filaments, leafy-shoot and thalloid gametophores, and gametangia formed in moss. A simplex meristem with a single stem cell was acquired in the sporophyte generation early in land plant evolution. Subsequently, sporophyte stem cells became multiple in the meristem and were elaborated further in seed plant lineages, although the evolutionary origin of niche cells, which maintain stem cells is unknown. Comparisons of gene regulatory networks are expected to give insights into the general mechanisms of stem cell formation and maintenance in land plants and provide information about their evolution. P. patens develops at least seven types of simplex meristem in the gametophyte and at least one type in the sporophyte generation and is a good material for regulatory network comparisons. In this review, we summarize recently revealed molecular mechanisms of stem cell initiation and maintenance in the moss. Copyright © 2013 Elsevier Ltd. All rights reserved.

The complex pathophysiology of acquired aplastic anaemia

PubMed Central

Zeng, Y; Katsanis, E

2015-01-01

Immune-mediated destruction of haematopoietic stem/progenitor cells (HSPCs) plays a central role in the pathophysiology of acquired aplastic anaemia (aAA). Dysregulated CD8+ cytotoxic T cells, CD4+ T cells including T helper type 1 (Th1), Th2, regulatory T cells and Th17 cells, natural killer (NK) cells and NK T cells, along with the abnormal production of cytokines including interferon (IFN)-γ, tumour necrosis factor (TNF)-α and transforming growth factor (TGF)-β, induce apoptosis of HSPCs, constituting a consistent and defining feature of severe aAA. Alterations in the polymorphisms of TGF-β, IFN-γ and TNF-α genes, as well as certain human leucocyte antigen (HLA) alleles, may account for the propensity to immune-mediated killing of HSPCs and/or ineffective haematopoiesis. Although the inciting autoantigens remain elusive, autoantibodies are often detected in the serum. In addition, recent studies provide genetic and molecular evidence that intrinsic and/or secondary deficits in HSPCs and bone marrow mesenchymal stem cells may underlie the development of bone marrow failure. PMID:25683099

Stereotypical architecture of the stem cell niche is spatiotemporally established by miR-125-dependent coordination of Notch and steroid signaling.

PubMed

Yatsenko, Andriy S; Shcherbata, Halyna R

2018-02-08

Stem cell niches act as signaling platforms that regulate stem cell self-renewal and sustain stem cells throughout life; however, the specific developmental events controlling their assembly are not well understood. Here, we show that during Drosophila ovarian germline stem cell niche formation, the status of Notch signaling in the cell can be reprogrammed. This is controlled via steroid-induced miR-125 , which targets a negative regulator of Notch signaling, Tom. Thus, miR-125 acts as a spatiotemporal coordinator between paracrine Notch and endocrine steroid signaling. Moreover, a dual security mechanism for Notch signaling activation exists to ensure the robustness of niche assembly. Particularly, stem cell niche cells can be specified either via lateral inhibition, in which a niche cell precursor acquires Notch signal-sending status randomly, or via peripheral induction, whereby Delta is produced by a specific cell. When one mechanism is perturbed due to mutations, developmental defects or environmental stress, the remaining mechanism ensures that the niche is formed, perhaps abnormally, but still functional. This guarantees that the germline stem cells will have their residence, thereby securing progressive oogenesis and, thus, organism reproduction. © 2018. Published by The Company of Biologists Ltd.

Steady advance of stem cell therapies: report from the 2011 World Stem Cell Summit, Pasadena, California, October 3-5.

PubMed

Swan, Melanie

2011-12-01

Stem cell research and related therapies (including regenerative medicine and cellular therapies) could have a significant near-term impact on worldwide public health and aging. One reason is the industry's strong linkage between policy, science, industry, and patient advocacy, as was clear in the attendance and programming at the 7(th) annual World Stem Cell Summit held in Pasadena, California, October 3-5, 2011. A special conference session sponsored by the SENS Foundation discussed how stem cell therapies are being used to extend healthy life span. Stem cells are useful not only in cell-replacement therapies, but also in disease modeling, drug discovery, and drug toxicity screening. Stem cell therapies are currently being applied to over 50 diseases, including heart, lung, neurodegenerative, and eye disease, cancer, and human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Dozens of companies are developing therapeutic solutions that are in different stages of clinical use and clinical trials. Some high-profile therapies include Dendreon's Provenge for prostate cancer, Geron's first-ever embryonic stem cell trials for spinal cord injury, Fibrocell's laViv cellular therapy for wrinkles, and well-established commercial skin substitutes (Organogenesis' Apligraf and Advanced BioHealing's Dermagraft). Stem cell policy issues under consideration include medical tourism, standards for large-scale stem cell manufacturing, and lingering ethical debates over the use of embryonic stem cells. Contemporary stem cell science advances include a focus on techniques for the direct reprogramming of cells from one lineage to another without returning to pluripotency as an intermediary step, improved means of generating and characterizing induced pluripotent cells, and progress in approaches to neurodegenerative disease.

PGE2 /EP4 Signaling Controls the Transfer of the Mammary Stem Cell State by Lipid Rafts in Extracellular Vesicles.

PubMed

Lin, Meng-Chieh; Chen, Shih-Yin; Tsai, Ho-Min; He, Pei-Lin; Lin, Yen-Chun; Herschman, Harvey; Li, Hua-Jung

2017-02-01

Prostaglandin E 2 (PGE 2 )-initiated signaling contributes to stem cell homeostasis and regeneration. However, it is unclear how PGE 2 signaling controls cell stemness. This study identifies a previously unknown mechanism by which PGE 2 /prostaglandin E receptor 4 (EP 4 ) signaling regulates multiple signaling pathways (e.g., PI3K/Akt signaling, TGFβ signaling, Wnt signaling, EGFR signaling) which maintain the basal mammary stem cell phenotype. A shift of basal mammary epithelial stem cells (MaSCs) from a mesenchymal/stem cell state to a non-basal-MaSC state occurs in response to prostaglandin E receptor 4 (EP 4 ) antagonism. EP 4 antagonists elicit release of signaling components, by controlling their trafficking into extracellular vesicles/exosomes in a lipid raft/caveolae-dependent manner. Consequently, EP 4 antagonism indirectly inactivates, through induced extracellular vesicle/exosome release, pathways required for mammary epithelial stem cell homeostasis, e.g. canonical/noncanonical Wnt, TGFβ and PI3K/Akt pathways. EP 4 antagonism causes signaling receptors and signaling components to shift from non-lipid raft fractions to lipid raft fractions, and to then be released in EP 4 antagonist-induced extracellular vesicles/exosomes, resulting in the loss of the stem cell state by mammary epithelial stem cells. In contrast, luminal mammary epithelial cells can acquire basal stem cell properties following ingestion of EP 4 antagonist-induced stem cell extracellular vesicles/exosomes, and can then form mammary glands. These findings demonstrate that PGE 2 /EP 4 signaling controls homeostasis of mammary epithelial stem cells through regulating extracellular vesicle/exosome release. Reprogramming of mammary epithelial cells can result from EP 4 -mediated stem cell property transfer by extracellular vesicles/exosomes containing caveolae-associated proteins, between mammary basal and luminal epithelial cells. Stem Cells 2017;35:425-444. © 2016 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

The gene expression profile of non-cultured, highly purified human adipose tissue pericytes: Transcriptomic evidence that pericytes are stem cells in human adipose tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva Meirelles, Lindolfo da, E-mail: lindolfomeirelles@gmail.com; Laboratory for Stem Cells and Tissue Engineering, PPGBioSaúde, Lutheran University of Brazil, Av. Farroupilha 8001, 92425-900 Canoas, RS; Deus Wagatsuma, Virgínia Mara de

Pericytes (PCs) are a subset of perivascular cells that can give rise to mesenchymal stromal cells (MSCs) when culture-expanded, and are postulated to give rise to MSC-like cells during tissue repair in vivo. PCs have been suggested to behave as stem cells (SCs) in situ in animal models, although evidence for this role in humans is lacking. Here, we analyzed the transcriptomes of highly purified, non-cultured adipose tissue (AT)-derived PCs (ATPCs) to detect gene expression changes that occur as they acquire MSC characteristics in vitro, and evaluated the hypothesis that human ATPCs exhibit a gene expression profile compatible with anmore » AT SC phenotype. The results showed ATPCs are non-proliferative and express genes characteristic not only of PCs, but also of AT stem/progenitor cells. Additional analyses defined a gene expression signature for ATPCs, and revealed putative novel ATPC markers. Almost all AT stem/progenitor cell genes differentially expressed by ATPCs were not expressed by ATMSCs or culture-expanded ATPCs. Genes expressed by ATMSCs but not by ATPCs were also identified. These findings strengthen the hypothesis that PCs are SCs in vascularized tissues, highlight gene expression changes they undergo as they assume an MSC phenotype, and provide new insights into PC biology. - Highlights: • Non-cultured adipose tissue-derived human pericytes (ncATPCs) exhibit a distinctive gene expression signature. • ncATPCs express key adipose tissue stem cell genes previously described in vivo in mice. • ncATPCs express message for anti-proliferative and antiangiogenic molecules. • Most ncATPC-specific transcripts are absent in culture-expanded pericytes or ATMSCs • Gene expression changes ncATPCs undergo as they acquire a cultured ATMSC phenotype are pointed out.« less

Concise review: carbon nanotechnology: perspectives in stem cell research.

PubMed

Pryzhkova, Marina V

2013-05-01

Carbon nanotechnology has developed rapidly during the last decade, and carbon allotropes, especially graphene and carbon nanotubes, have already found a wide variety of applications in industry, high-tech fields, biomedicine, and basic science. Electroconductive nanomaterials have attracted great attention from tissue engineers in the design of remotely controlled cell-substrate interfaces. Carbon nanoconstructs are also under extensive investigation by clinical scientists as potential agents in anticancer therapies. Despite the recent progress in human pluripotent stem cell research, only a few attempts to use carbon nanotechnology in the stem cell field have been reported. However, acquired experience with and knowledge of carbon nanomaterials may be efficiently used in the development of future personalized medicine and in tissue engineering.

X Chromosome of female cells shows dynamic changes in status during human somatic cell reprogramming.

PubMed

Kim, Kun-Yong; Hysolli, Eriona; Tanaka, Yoshiaki; Wang, Brandon; Jung, Yong-Wook; Pan, Xinghua; Weissman, Sherman Morton; Park, In-Hyun

2014-06-03

Induced pluripotent stem cells (iPSCs) acquire embryonic stem cell (ESC)-like epigenetic states, including the X chromosome. Previous studies reported that human iPSCs retain the inactive X chromosome of parental cells, or acquire two active X chromosomes through reprogramming. Most studies investigated the X chromosome states in established human iPSC clones after completion of reprogramming. Thus, it is still not fully understood when and how the X chromosome reactivation occurs during reprogramming. Here, we report a dynamic change in the X chromosome state throughout reprogramming, with an initial robust reactivation of the inactive X chromosome followed by an inactivation upon generation of nascent iPSC clones. iPSCs with two active X chromosomes or an eroded X chromosome arise in passaging iPSCs. These data provide important insights into the plasticity of the X chromosome of human female iPSCs and will be crucial for the future application of such cells in cell therapy and X-linked disease modeling.

Stem cells in reproductive medicine: ready for the patient?

PubMed

Vassena, R; Eguizabal, C; Heindryckx, B; Sermon, K; Simon, C; van Pelt, A M M; Veiga, A; Zambelli, F

2015-09-01

Are there effective and clinically validated stem cell-based therapies for reproductive diseases? At the moment, clinically validated stem cell treatments for reproductive diseases and alterations are not available. Research in stem cells and regenerative medicine is growing in scope, and its translation to the clinic is heralded by the recent initiation of controlled clinical trials with pluripotent derived cells. Unfortunately, stem cell 'treatments' are currently offered to patients outside of the controlled framework of scientifically sound research and regulated clinical trials. Both physicians and patients in reproductive medicine are often unsure about stem cells therapeutic options. An international working group was assembled to review critically the available scientific literature in both the human species and animal models. This review includes work published in English until December 2014, and available through Pubmed. A few areas of research in stem cell and reproductive medicine were identified: in vitro gamete production, endometrial regeneration, erectile dysfunction amelioration, vaginal reconstruction. The stem cells studied range from pluripotent (embryonic stem cells and induced pluripotent stem cells) to monopotent stem cells, such as spermatogonial stem cells or mesenchymal stem cells. The vast majority of studies have been carried out in animal models, with data that are preliminary at best. This review was not conducted in a systematic fashion, and reports in publications not indexed in Pubmed were not analyzed. A much broader clinical knowledge will have to be acquired before translation to the clinic of stem cell therapies in reproductive medicine; patients and physicians should be wary of unfounded claims of improvement of existing medical conditions; at the moment, effective stem cell treatment for reproductive diseases and alterations is not available. None. NA. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Somatic cell reprogramming informed by the oocyte.

PubMed

Gonzalez-Munoz, Elena; Cibelli, Jose B

2018-05-08

The successful production of animals and embryonic stem cells (ESCs) using somatic cell nuclear transfer (SCNT) has demonstrated the unmatched nuclear reprogramming capacity of the oocyte and helped prove the degree of plasticity of differentiated cells. The introduction of transcription factors to generate induced pluripotent stem cells (iPSCs) displaced SCNT and, due to its ease of implementation, became the method of choice for cell reprogramming. Nonetheless, iPSC derivation remains inefficient and stochastic. This review article focuses on using the oocyte as a source of reprogramming factors, comparing the SCNT and iPSC mechanisms for remodeling chromatin and acquiring pluripotency.

Metastable Pluripotent States in NOD Mouse Derived ES Cells

PubMed Central

Hanna, Jacob; Markoulaki, Styliani; Mitalipova, Maisam; Cheng, Albert W.; Cassady, John P.; Staerk, Judith; Carey, Bryce W.; Lengner, Christopher J.; Foreman, Ruth; Love, Jennifer; Gao, Qing; Kim, Jongpil; Jaenisch, Rudolf

2009-01-01

Embryonic stem (ES) cells are isolated from the inner cell mass (ICM) of blastocysts, whereas epiblast stem cells (EpiSCs) are derived from the post-implantation epiblast and display a restricted developmental potential. Here we characterize pluripotent states in the non-obese diabetic (NOD) mouse strain, which prior to this study was considered “non-permissive” for ES cell derivation. We find that NOD stem cells can be stabilized by providing constitutive expression of Klf4 or c-Myc or small molecules that can replace these factors during in vitro reprogramming. The NOD ES and iPS cells appear “metastable”, as they acquire an alternative EpiSC-like identity after removal of the exogenous factors, while their reintroduction converts the cells back to ICM-like pluripotency. Our findings suggest that stem cells from different genetic backgrounds can assume distinct states of pluripotency in vitro, the stability of which is regulated by endogenous genetic determinants and can be modified by exogenous factors. PMID:19427283

Vessel-associated stem cells from skeletal muscle: From biology to future uses in cell therapy

PubMed Central

Sancricca, Cristina; Mirabella, Massimiliano; Gliubizzi, Carla; Broccolini, Aldobrando; Gidaro, Teresa; Morosetti, Roberta

2010-01-01

Over the last years, the existence of different stem cells with myogenic potential has been widely investigated. Besides the classical skeletal muscle progenitors represented by satellite cells, numerous multipotent and embryologically unrelated progenitors with a potential role in muscle differentiation and repair have been identified. In order to conceive a therapeutic approach for degenerative muscle disorders, it is of primary importance to identify an ideal stem cell endowed with all the features for a possible use in vivo. Among all emerging populations, vessel-associated stem cells are a novel and promising class of multipotent progenitors of mesodermal origin and with high myogenic potential which seem to best fit all the requirements for a possible cell therapy. In vitro and in vivo studies have already tested the effectiveness and safety of vessel-associated stem cells in animal models. This leads to the concrete possibility in the future to start pilot human clinical trials, hopefully opening the way to a turning point in the treatment of genetic and acquired muscle disorders. PMID:21607121

Plasticity of male germline stem cells and their applications in reproductive and regenerative medicine.

PubMed

Chen, Zheng; Li, Zheng; He, Zuping

2015-01-01

Spermatogonial stem cells (SSCs), also known as male germline stem cells, are a small subpopulation of type A spermatogonia with the potential of self-renewal to maintain stem cell pool and differentiation into spermatids in mammalian testis. SSCs are previously regarded as the unipotent stem cells since they can only give rise to sperm within the seminiferous tubules. However, this concept has recently been challenged because numerous studies have demonstrated that SSCs cultured with growth factors can acquire pluripotency to become embryonic stem-like cells. The in vivo and in vitro studies from peers and us have clearly revealed that SSCs can directly transdifferentiate into morphologic, phenotypic, and functional cells of other lineages. Direct conversion to the cells of other tissues has important significance for regenerative medicine. SSCs from azoospermia patients could be induced to differentiate into spermatids with fertilization and developmental potentials. As such, SSCs could have significant applications in both reproductive and regenerative medicine due to their unique and great potentials. In this review, we address the important plasticity of SSCs, with focuses on their self-renewal, differentiation, dedifferentiation, transdifferentiation, and translational medicine studies.

The role of CD133 in normal human prostate stem cells and malignant cancer-initiating cells.

PubMed

Vander Griend, Donald J; Karthaus, Wouter L; Dalrymple, Susan; Meeker, Alan; DeMarzo, Angelo M; Isaacs, John T

2008-12-01

Resolving the specific cell of origin for prostate cancer is critical to define rational targets for therapeutic intervention and requires the isolation and characterization of both normal human prostate stem cells and prostate cancer-initiating cells (CIC). Single epithelial cells from fresh normal human prostate tissue and prostate epithelial cell (PrEC) cultures derived from them were evaluated for the presence of subpopulations expressing stem cell markers and exhibiting stem-like growth characteristics. When epithelial cell suspensions containing cells expressing the stem cell marker CD133+ are inoculated in vivo, regeneration of stratified human prostate glands requires inductive prostate stromal cells. PrEC cultures contain a small subpopulation of CD133+ cells, and fluorescence-activated cell sorting-purified CD133+ PrECs self-renew and regenerate cell populations expressing markers of transit-amplifying cells (DeltaNp63), intermediate cells (prostate stem cell antigen), and neuroendocrine cells (CD56). Using a series of CD133 monoclonal antibodies, attachment and growth of CD133+ PrECs requires surface expression of full-length glycosylated CD133 protein. Within a series of androgen receptor-positive (AR+) human prostate cancer cell lines, CD133+ cells are present at a low frequency, self-renew, express AR, generate phenotypically heterogeneous progeny negative for CD133, and possess an unlimited proliferative capacity, consistent with CD133+ cells being CICs. Unlike normal adult prostate stem cells, prostate CICs are AR+ and do not require functional CD133. This suggests that (a) AR-expressing prostate CICs are derived from a malignantly transformed intermediate cell that acquires "stem-like activity" and not from a malignantly transformed normal stem cell and (b) AR signaling pathways are a therapeutic target for prostate CICs.

Cancer stemness and metastatic potential of the novel tumor cell line K3: an inner mutated cell of bone marrow-derived mesenchymal stem cells.

PubMed

Qian, Hui; Ding, Xiaoqing; Zhang, Jiao; Mao, Fei; Sun, Zixuan; Jia, Haoyuan; Yin, Lei; Wang, Mei; Zhang, Xu; Zhang, Bin; Yan, Yongmin; Zhu, Wei; Xu, Wenrong

2017-06-13

Mesenchymal stem cells (MSCs) transplantation has been used for therapeutic applications in various diseases. Here we report MSCs can malignantly transform in vivo. The novel neoplasm was found on the tail of female rat after injection with male rat bone marrow-derived MSCs (rBM-MSCs) and the new tumor cell line, K3, was isolated from the neoplasm. The K3 cells expressed surface antigens and pluripotent genes similar to those of rBM-MSCs and presented tumor cell features. Moreover, the K3 cells contained side population cells (SP) like cancer stem cells (CSCs), which might contribute to K3 heterogeneity and tumorigenic capacity. To investigate the metastatic potential of K3 cells, we established the nude mouse models of liver and lung metastases and isolated the corresponding metastatic cell lines K3-F4 and K3-B6. Both K3-F4 and K3-B6 cell lines with higher metastatic potential acquired more mesenchymal and stemness-related features. Epithelial-mesenchymal transition is a potential mechanism of K3-F4 and K3-B6 formation.

Klotho, stem cells, and aging.

PubMed

Bian, Ao; Neyra, Javier A; Zhan, Ming; Hu, Ming Chang

2015-01-01

Aging is an inevitable and progressive biological process involving dysfunction and eventually destruction of every tissue and organ. This process is driven by a tightly regulated and complex interplay between genetic and acquired factors. Klotho is an antiaging gene encoding a single-pass transmembrane protein, klotho, which serves as an aging suppressor through a wide variety of mechanisms, such as antioxidation, antisenescence, antiautophagy, and modulation of many signaling pathways, including insulin-like growth factor and Wnt. Klotho deficiency activates Wnt expression and activity contributing to senescence and depletion of stem cells, which consequently triggers tissue atrophy and fibrosis. In contrast, the klotho protein was shown to suppress Wnt-signaling transduction, and inhibit cell senescence and preserve stem cells. A better understanding of the potential effects of klotho on stem cells could offer novel insights into the cellular and molecular mechanisms of klotho deficiency-related aging and disease. The klotho protein may be a promising therapeutic agent for aging and aging-related disorders.

Induced pluripotent stem cells as custom therapeutics for retinal repair: progress and rationale.

PubMed

Wright, Lynda S; Phillips, M Joseph; Pinilla, Isabel; Hei, Derek; Gamm, David M

2014-06-01

Human pluripotent stem cells have made a remarkable impact on science, technology and medicine by providing a potentially unlimited source of human cells for basic research and clinical applications. In recent years, knowledge gained from the study of human embryonic stem cells and mammalian somatic cell reprogramming has led to the routine production of human induced pluripotent stem cells (hiPSCs) in laboratories worldwide. hiPSCs show promise for use in transplantation, high throughput drug screening, "disease-in-a-dish" modeling, disease gene discovery, and gene therapy testing. This review will focus on the first application, beginning with a discussion of methods for producing retinal lineage cells that are lost in inherited and acquired forms of retinal degenerative disease. The selection of appropriate hiPSC-derived donor cell type(s) for transplantation will be discussed, as will the caveats and prerequisite steps to formulating a clinical Good Manufacturing Practice (cGMP) product for clinical trials. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Induced pluripotent stem cells as custom therapeutics for retinal repair: Progress and rationale

PubMed Central

Wright, Lynda S.; Phillips, M. Joseph; Pinilla, Isabel; Hei, Derek; Gamm, David M.

2014-01-01

Human pluripotent stem cells have made a remarkable impact on science, technology and medicine by providing a potentially unlimited source of human cells for basic research and clinical applications. In recent years, knowledge gained from the study of human embryonic stem cells and mammalian somatic cell reprogramming has led to the routine production of human induced pluripotent stem cells (hiPSCs) in laboratories worldwide. hiPSCs show promise for use in transplantation, high throughput drug screening, “disease-in-a-dish” modeling, disease gene discovery, and gene therapy testing. This review will focus on the first application, beginning with a discussion of methods for producing retinal lineage cells that are lost in inherited and acquired forms of retinal degenerative disease. The selection of appropriate hiPSC-derived donor cell type(s) for transplantation will be discussed, as will the caveats and prerequisite steps to formulating a clinical Good Manufacturing Practice (cGMP) product for clinical trials. PMID:24534198

Concise Review: Carbon Nanotechnology: Perspectives in Stem Cell Research

PubMed Central

2013-01-01

Carbon nanotechnology has developed rapidly during the last decade, and carbon allotropes, especially graphene and carbon nanotubes, have already found a wide variety of applications in industry, high-tech fields, biomedicine, and basic science. Electroconductive nanomaterials have attracted great attention from tissue engineers in the design of remotely controlled cell-substrate interfaces. Carbon nanoconstructs are also under extensive investigation by clinical scientists as potential agents in anticancer therapies. Despite the recent progress in human pluripotent stem cell research, only a few attempts to use carbon nanotechnology in the stem cell field have been reported. However, acquired experience with and knowledge of carbon nanomaterials may be efficiently used in the development of future personalized medicine and in tissue engineering. PMID:23572053

A lineage CLOUD for neoblasts.

PubMed

Tran, Thao Anh; Gentile, Luca

2018-05-10

In planarians, pluripotency can be studied in vivo in the adult animal, making these animals a unique model system where pluripotency-based regeneration (PBR)-and its therapeutic potential-can be investigated. This review focuses on recent findings to build a cloud model of fate restriction likelihood for planarian stem and progenitor cells. Recently, a computational approach based on functional and molecular profiling at the single cell level was proposed for human hematopoietic stem cells. Based on data generated both in vivo and ex vivo, we hypothesized that planarian stem cells could acquire multiple direction lineage biases, following a "badlands" landscape. Instead of a discrete tree-like hierarchy, where the potency of stem/progenitor cells reduces stepwise, we propose a Continuum of LOw-primed UnDifferentiated Planarian Stem/Progenitor Cells (CLOUD-PSPCs). Every subclass of neoblast/progenitor cells is a cloud of likelihood, as the single cell transcriptomics data indicate. The CLOUD-HSPCs concept was substantiated by in vitro data from cell culture; therefore, to confirm the CLOUD-PSPCs model, the planarian community needs to develop new tools, like live cell tracking. Future studies will allow a deeper understanding of PBR in planarian, and the possible implications for regenerative therapies in human. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stem cell fusion as an ultimate line of defense against xenobiotics.

PubMed

Padron Velazquez, Julio Lazaro

2006-01-01

There are several indications that the potential of stem cells to fuse with somatic cells is extremely high and, what's more exciting, in some instances goes as far as reprogramming and/or rescuing altered cells. It remains unclear, however, how frequent this mechanism is and what patho-physiological role it might play in nature. A plausible hypothesis, discussed in this paper, suggests that stem cell niches might provide a safeguard for the intact genome and epigenome. By fusing with somatic de-differentiated cells, stem cells might consent epigenetic reprogramming and/or genetic recovery of genes which otherwise could drive altered cells to malignancy. If the many sophisticated mechanisms of metabolism, cell repair, programmed cell death and tissue regeneration should fail, stem cells might represent a final attempt to recover dedifferentiated cells to avoid inflowing in cancer. In the current reappraisal of the different mechanisms of defense against xenobiotics, even the incidence of cancer itself is considered an evolving mechanism which, through a kind of programmed death of individuals exhibiting defective mutations, favors advancement of the phenotypes which adapt best. Additionally, with regard to the mechanisms of transmitting somatic mutations, based on stem cells' capacity to migrate and to fuse, here it is speculated that stem cells might be capable of carrying acquired somatic mutations from peripheral tissues to the gonads, and transmit that information into the germinal line. If appropriately demonstrated, these mechanisms might delineate a novel therapeutic area to be explored. The use of stem cells to reprogram/recover irreversibly damaged cells or to transmit beneficial mutations might be a valuable therapeutic approach in the future.

The complex pathophysiology of acquired aplastic anaemia.

PubMed

Zeng, Y; Katsanis, E

2015-06-01

Immune-mediated destruction of haematopoietic stem/progenitor cells (HSPCs) plays a central role in the pathophysiology of acquired aplastic anaemia (aAA). Dysregulated CD8(+) cytotoxic T cells, CD4(+) T cells including T helper type 1 (Th1), Th2, regulatory T cells and Th17 cells, natural killer (NK) cells and NK T cells, along with the abnormal production of cytokines including interferon (IFN)-γ, tumour necrosis factor (TNF)-α and transforming growth factor (TGF)-β, induce apoptosis of HSPCs, constituting a consistent and defining feature of severe aAA. Alterations in the polymorphisms of TGF-β, IFN-γ and TNF-α genes, as well as certain human leucocyte antigen (HLA) alleles, may account for the propensity to immune-mediated killing of HSPCs and/or ineffective haematopoiesis. Although the inciting autoantigens remain elusive, autoantibodies are often detected in the serum. In addition, recent studies provide genetic and molecular evidence that intrinsic and/or secondary deficits in HSPCs and bone marrow mesenchymal stem cells may underlie the development of bone marrow failure. © 2015 British Society for Immunology.

Targeting stemness is an effective strategy to control EML4-ALK+ non-small cell lung cancer cells

PubMed Central

Oh, Se Jin; Noh, Kyung Hee; Lee, Young-Ho; Hong, Soon-Oh; Song, Kwon-Ho; Lee, Hyo-Jung; Kim, Soyeon; Kim, Tae Min; Jeon, Ju-Hong; Seo, Jae Hong; Kim, Dong-Wan; Kim, Tae Woo

2015-01-01

The fusion between anaplastic lymphoma kinase (ALK) and echinoderm microtubule-associated protein-like 4 (EML4) is a causative factor in a unique subset of patients with non-small cell lung carcinoma (NSCLC). Although the inhibitor crizotinib, as it blocks the kinase activity of the resulting EML4-ALK fusion protein, displays remarkable initial responses, a fraction of NSCLC cases eventually become resistant to crizotinib by acquiring mutations in the ALK domain or activating bypass pathways via EGFR, KIT, or KRAS. Cancer stem cell (CSC) theory provides a plausible explanation for acquisition of tumorigenesis and resistance. However, the question as to whether EML4-ALK-driven tumorigenesis is linked with the stem-like property and whether the stemness is an effective target in controlling EML4-ALK+ NSCLC including crizotinib-resistant NSCLC cells has not been addressed. Here, we report that stem-like properties stem from ALK activity in EML4-ALK+ NSCLC cells. Notably, treatment with rapamycin, a CSC targeting agent, attenuates stem-like phenotypes of the EML4-ALK+ cells, which increased capability of tumor formation and higher expression of stemness-associated molecules such as ALDH, NANOG, and OCT4. Importantly, combinational treatment with rapamycin and crizotinib leads to synergistic anti-tumor effects on EML4-ALK+ NSCLC cells as well as on those resistant to crizotinib. Thus, we provide a proof of principle that targeting stemness would be a novel strategy to control intractable EML4-ALK+ NSCLC. PMID:26517679

Targeting stemness is an effective strategy to control EML4-ALK+ non-small cell lung cancer cells.

PubMed

Oh, Se Jin; Noh, Kyung Hee; Lee, Young-Ho; Hong, Soon-Oh; Song, Kwon-Ho; Lee, Hyo-Jung; Kim, Soyeon; Kim, Tae Min; Jeon, Ju-Hong; Seo, Jae Hong; Kim, Dong-Wan; Kim, Tae Woo

2015-11-24

The fusion between anaplastic lymphoma kinase (ALK) and echinoderm microtubule-associated protein-like 4 (EML4) is a causative factor in a unique subset of patients with non-small cell lung carcinoma (NSCLC). Although the inhibitor crizotinib, as it blocks the kinase activity of the resulting EML4-ALK fusion protein, displays remarkable initial responses, a fraction of NSCLC cases eventually become resistant to crizotinib by acquiring mutations in the ALK domain or activating bypass pathways via EGFR, KIT, or KRAS. Cancer stem cell (CSC) theory provides a plausible explanation for acquisition of tumorigenesis and resistance. However, the question as to whether EML4-ALK-driven tumorigenesis is linked with the stem-like property and whether the stemness is an effective target in controlling EML4-ALK+ NSCLC including crizotinib-resistant NSCLC cells has not been addressed. Here, we report that stem-like properties stem from ALK activity in EML4-ALK+ NSCLC cells. Notably, treatment with rapamycin, a CSC targeting agent, attenuates stem-like phenotypes of the EML4-ALK+ cells, which increased capability of tumor formation and higher expression of stemness-associated molecules such as ALDH, NANOG, and OCT4. Importantly, combinational treatment with rapamycin and crizotinib leads to synergistic anti-tumor effects on EML4-ALK+ NSCLC cells as well as on those resistant to crizotinib. Thus, we provide a proof of principle that targeting stemness would be a novel strategy to control intractable EML4-ALK+ NSCLC.

Generation of eggs from mouse embryonic stem cells and induced pluripotent stem cells.

PubMed

Hayashi, Katsuhiko; Saitou, Mitinori

2013-08-01

Oogenesis is an integrated process through which an egg acquires the potential for totipotency, a fundamental condition for creating new individuals. Reconstitution of oogenesis in a culture that generates eggs with proper function from pluripotent stem cells (PSCs) is therefore one of the key goals in basic biology as well as in reproductive medicine. Here we describe a stepwise protocol for the generation of eggs from mouse PSCs, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs and iPSCs are first induced into primordial germ cell-like cells (PGCLCs) that are in turn aggregated with somatic cells of female embryonic gonads, the precursors for adult ovaries. Induction of PGCLCs followed by aggregation with the somatic cells takes up to 8 d. The aggregations are then transplanted under the ovarian bursa, in which PGCLCs grow into germinal vesicle (GV) oocytes in ∼1 month. The PGCLC-derived GV oocytes can be matured into eggs in 1 d by in vitro maturation (IVM), and they can be fertilized with spermatozoa by in vitro fertilization (IVF) to obtain healthy and fertile offspring. This method provides an initial step toward reconstitution of the entire process of oogenesis in vitro.

Stem cell therapy and its potential role in pituitary disorders.

PubMed

Lara-Velazquez, Montserrat; Akinduro, Oluwaseun O; Reimer, Ronald; Woodmansee, Whitney W; Quinones-Hinojosa, Alfredo

2017-08-01

The pituitary gland is one of the key components of the endocrine system. Congenital or acquired alterations can mediate destruction of cells in the gland leading to hormonal dysfunction. Even though pharmacological treatment for pituitary disorders is available, exogenous hormone replacement is neither curative nor sustainable. Thus, alternative therapies to optimize management and improve quality of life are desired. An alternative modality to re-establish pituitary function is to promote endocrine cell regeneration through stem cells that can be obtained from the pituitary parenchyma or pluripotent cells. Stem cell therapy has been successfully applied to a plethora of other disorders, and is a promising alternative to hormonal supplementation for resumption of normal hormone homeostasis. In this review, we describe the common causes for pituitary deficiencies and the advances in cellular therapy to restore the physiological pituitary function.

Generation of Cardiomyocytes from Pluripotent Stem Cells.

PubMed

Nakahama, Hiroko; Di Pasquale, Elisa

2016-01-01

The advent of pluripotent stem cells (PSCs) enabled a multitude of studies for modeling the development of diseases and testing pharmaceutical therapeutic potential in vitro. These PSCs have been differentiated to multiple cell types to demonstrate its pluripotent potential, including cardiomyocytes (CMs). However, the efficiency and efficacy of differentiation vary greatly between different cell lines and methods. Here, we describe two different methods for acquiring CMs from human pluripotent lines. One method involves the generation of embryoid bodies, which emulates the natural developmental process, while the other method chemically activates the canonical Wnt signaling pathway to induce a monolayer of cardiac differentiation.

Human embryonic stem cell-derived NK cells acquire functional receptors and cytolytic activity.

PubMed

Woll, Petter S; Martin, Colin H; Miller, Jeffrey S; Kaufman, Dan S

2005-10-15

Human embryonic stem cells (hESCs) provide a unique resource to analyze early stages of human hematopoiesis. However, little is known about the ability to use hESCs to evaluate lymphocyte development. In the present study, we use a two-step culture method to demonstrate efficient generation of functional NK cells from hESCs. The CD56(+)CD45(+) hESC-derived lymphocytes express inhibitory and activating receptors typical of mature NK cells, including killer cell Ig-like receptors, natural cytotoxicity receptors, and CD16. Limiting dilution analysis suggests that these cells can be produced from hESC-derived hemopoietic progenitors at a clonal frequency similar to CD34(+) cells isolated from cord blood. The hESC-derived NK cells acquire the ability to lyse human tumor cells by both direct cell-mediated cytotoxicity and Ab-dependent cellular cytotoxicity. Additionally, activated hESC-derived NK cells up-regulate cytokine production. hESC-derived lymphoid progenitors provide a novel means to characterize specific cellular and molecular mechanisms that lead to development of specific human lymphocyte populations. These cells may also provide a source for innovative cellular immune therapies.

Cellular reprogramming in skin cancer.

PubMed

Song, Ihn Young; Balmain, Allan

2015-06-01

Early primitive stem cells have long been viewed as the cancer cells of origin (tumor initiating target cells) due to their intrinsic features of self-renewal and longevity. However, emerging evidence suggests a surprising capacity for normal committed cells to function as reserve stem cells upon reprogramming as a consequence of tissue damage resulting in inflammation and wound healing. This results in an alternative concept positing that tumors may originate from differentiated cells that can re-acquire stem cell properties due to genetic or epigenetic reprogramming. It is likely that both models are correct, and that a continuum of potential cells of origin exists, ranging from early primitive stem cells to committed progenitor or even terminally differentiated cells. A combination of the nature of the target cell and the specific types of gene mutations introduced determine tumor cell lineage, as well as potential for malignant conversion. Evidence from mouse skin models of carcinogenesis suggests that initiated cells at different stages within a stem cell hierarchy have varying degrees of requirement for reprogramming (e.g. inflammation stimuli), depending on their degree of differentiation. This article will present evidence in favor of these concepts that has been developed from studies of several mouse models of skin carcinogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fully reduced HMGB1 accelerates the regeneration of multiple tissues by transitioning stem cells to GAlert.

PubMed

Lee, Geoffrey; Espirito Santo, Ana Isabel; Zwingenberger, Stefan; Cai, Lawrence; Vogl, Thomas; Feldmann, Marc; Horwood, Nicole J; Chan, James K; Nanchahal, Jagdeep

2018-05-08

A major discovery of recent decades has been the existence of stem cells and their potential to repair many, if not most, tissues. With the aging population, many attempts have been made to use exogenous stem cells to promote tissue repair, so far with limited success. An alternative approach, which may be more effective and far less costly, is to promote tissue regeneration by targeting endogenous stem cells. However, ways of enhancing endogenous stem cell function remain poorly defined. Injury leads to the release of danger signals which are known to modulate the immune response, but their role in stem cell-mediated repair in vivo remains to be clarified. Here we show that high mobility group box 1 (HMGB1) is released following fracture in both humans and mice, forms a heterocomplex with CXCL12, and acts via CXCR4 to accelerate skeletal, hematopoietic, and muscle regeneration in vivo. Pretreatment with HMGB1 2 wk before injury also accelerated tissue regeneration, indicating an acquired proregenerative signature. HMGB1 led to sustained increase in cell cycling in vivo, and using Hmgb1 -/- mice we identified the underlying mechanism as the transition of multiple quiescent stem cells from G 0 to G Alert HMGB1 also transitions human stem and progenitor cells to G Alert Therefore, exogenous HMGB1 may benefit patients in many clinical scenarios, including trauma, chemotherapy, and elective surgery. Copyright © 2018 the Author(s). Published by PNAS.

Brain vascular pericytes following ischemia have multipotential stem cell activity to differentiate into neural and vascular lineage cells.

PubMed

Nakagomi, Takayuki; Kubo, Shuji; Nakano-Doi, Akiko; Sakuma, Rika; Lu, Shan; Narita, Aya; Kawahara, Maiko; Taguchi, Akihiko; Matsuyama, Tomohiro

2015-06-01

Brain vascular pericytes (PCs) are a key component of the blood-brain barrier (BBB)/neurovascular unit, along with neural and endothelial cells. Besides their crucial role in maintaining the BBB, increasing evidence shows that PCs have multipotential stem cell activity. However, their multipotency has not been considered in the pathological brain, such as after an ischemic stroke. Here, we examined whether brain vascular PCs following ischemia (iPCs) have multipotential stem cell activity and differentiate into neural and vascular lineage cells to reconstruct the BBB/neurovascular unit. Using PCs extracted from ischemic regions (iPCs) from mouse brains and human brain PCs cultured under oxygen/glucose deprivation, we show that PCs developed stemness presumably through reprogramming. The iPCs revealed a complex phenotype of angioblasts, in addition to their original mesenchymal properties, and multidifferentiated into cells from both a neural and vascular lineage. These data indicate that under ischemic/hypoxic conditions, PCs can acquire multipotential stem cell activity and can differentiate into major components of the BBB/neurovascular unit. Thus, these findings support the novel concept that iPCs can contribute to both neurogenesis and vasculogenesis at the site of brain injuries. © 2015 AlphaMed Press.

TRA-1–60+, SSEA-4+, POU5F1+, SOX2+, NANOG+ Clones of Pluripotent Stem Cells in the Embryonal Carcinomas of the Testes

PubMed Central

Malecki, Marek; Tombokan, Xenia; Anderson, Mark; Malecki, Raf; Beauchaine, Michael

2013-01-01

Introduction Cancer of the testes is currently the most frequent neoplasm and a leading cause of morbidity in men 15–35 years of age. Its incidence is increasing. Embryonal carcinoma is its most malignant form, which either may be resistant or may develop resistance to therapies, which results in relapses. Cancer stem cells are hypothesized to be drivers of these phenomena. Specific aim The specific aim of this work was identification and isolation of spectra of single, living cancer stem cells, which were acquired directly from the patients’ biopsies, followed by testing of their pluripotency. Patients. Methods Biopsies were obtained from the patients with the clinical and histological diagnoses of the primary, pure embryonal carcinomas of the testes. The magnetic and fluorescent antibodies were genetically engineered. The SSEA-4 and TRA-1–60 cell surface display was analyzed by multiphoton fluorescence spectroscopy (MPFS), flow cytometry (FCM), immunoblotting (IB), nuclear magnetic resonance spectroscopy (NMRS), energy dispersive x-ray spectroscopy (EDXS), and total reflection x-ray spectroscopy (TRXFS). The single, living cells were isolated by magnetic or fluorescent sorting followed by their clonal expansion. The OCT4A, SOX2, and NANOG genes’ transcripts were analyzed by qRTPCR and the products by IB and MPFS. Results The clones of cells, with the strong surface display of TRA-1–60 and SSEA-4, were identified and isolated directly from the biopsies acquired from the patients diagnosed with the pure embryonal carcinomas of the testes. These cells demonstrated high levels of transcription and translation of the pluripotency genes: OCT4A, SOX2, and NANOG. They formed embryoid bodies, which differentiated into ectoderm, mesoderm, and endoderm. Conclusion In the pure embryonal carcinomas of the testes, acquired directly from the patients, we identified, isolated with high viability and selectivity, and profiled the clones of the pluripotent stem cells. These results may help in explaining therapy-resistance and relapses of these neoplasms, as well as, in designing targeted, personalized therapy. PMID:23772337

Transforming growth factor-beta1 promotes the migration and invasion of sphere-forming stem-like cell subpopulations in esophageal cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Dongli; Zhang, Zhen; Li, Jieyao

Esophageal cancer is one of the most lethal solid malignancies. Mounting evidence demonstrates that cancer stem cells (CSCs) are able to cause tumor initiation, metastasis and responsible for chemotherapy and radiotherapy failures. As CSCs are thought to be the main reason of therapeutic failure, these cells must be effectively targeted to elicit long-lasting therapeutic responses. We aimed to enrich and identify the esophageal cancer cell subpopulation with stem-like properties and help to develop new target therapy strategies for CSCs. Here, we found esophageal cancer cells KYSE70 and TE1 could form spheres in ultra low attachment surface culture and be seriallymore » passaged. Sphere-forming cells could redifferentiate and acquire morphology comparable to parental cells, when return to adherent culture. The sphere-forming cells possessed the key criteria that define CSCs: persistent self-renewal, overexpression of stemness genes (SOX2, ALDH1A1 and KLF4), reduced expression of differentiation marker CK4, chemoresistance, strong invasion and enhanced tumorigenic potential. SB525334, transforming growth factor-beta 1(TGF-β1) inhibitor, significantly inhibited migration and invasion of sphere-forming stem-like cells and had no effect on sphere-forming ability. In conclusion, esophageal cancer sphere-forming cells from KYSE70 and TE1 cultured in ultra low attachment surface possess cancer stem cell properties, providing a model for CSCs targeted therapy. TGF-β1 promotes the migration and invasion of sphere-forming stem-like cells, which may guide future studies on therapeutic strategies targeting these cells. - Highlights: • Esophageal cancer sphere-forming cells possess cancer stem cell properties. • Sphere-forming cells enhance TGF-β1 pathway activity. • TGF-β 1 inhibitor suppresses the migration and invasion of sphere-forming cells.« less

What determines neurogenic competence in glia?

PubMed

Costa, Marcos Romualdo; Götz, Magdalena; Berninger, Benedikt

2010-05-01

One of the most intriguing discoveries during the last decade of developmental neurobiology is the fact that both in the developing and adult nervous system neural stem cells often turn out to have a glial identity: Radial glia generates neurons in the developing telencephalon of fish, birds and mammals and astro/radial glial stem cells in specialized neurogenic zones give rise to new neurons throughout life. What are the extrinsic signals acting on and the intrinsic signals acting within these glial populations endowing these with a neurogenic potential, whilst most other glia seemingly lack it? Studies on postnatal astroglia shed interesting light on this question as they are the intermediate between neurogenic radial glia and mature parenchymal astrocytes. At least in vitro their decision to acquire a glial fate is not yet irrevocable as forced expression of a single neurogenic transcription factor enables them to transgress their lineage and to give rise to fully functional neurons acquiring specific subtype characteristics. But even bona fide non-neurogenic glia in the adult nervous system can regain some of their radial glial heritage following injury as exemplified by reactive astroglia in the cerebral cortex and Müller glia in the retina. In this review first we will follow the direction of the physiological times' arrow, along which radial glia become transformed on one side into mature astrocytes gradually losing their neurogenic potential, while some of them seem to escape this dire destiny to settle in the few neurogenic oases of the adult brain where they generate neurons and glia throughout life. But we will also see how pathophysiological conditions partially can reverse the arrow of time reactivating the parenchymal astroglia to re-acquire some of the hallmarks of neural stem cells or progenitors. We will close this review with some thoughts on the surprising compatibility of the co-existence of a neural stem cell and glial identity within the very same cell from the perspective of the concept of transcriptional core networks. Copyright 2010 Elsevier B.V. All rights reserved.

Pluripotency of adult stem cells derived from human and rat pancreas

NASA Astrophysics Data System (ADS)

Kruse, C.; Birth, M.; Rohwedel, J.; Assmuth, K.; Goepel, A.; Wedel, T.

Adult stem cells are undifferentiated cells found within fully developed tissues or organs of an adult individuum. Until recently, these cells have been considered to bear less self-renewal ability and differentiation potency compared to embryonic stem cells. In recent studies an undifferentiated cell type was found in primary cultures of isolated acini from exocrine pancreas termed pancreatic stellate cells. Here we show that pancreatic stellate-like cells have the capacity of extended self-renewal and are able to differentiate spontaneously into cell types of all three germ layers expressing markers for smooth muscle cells, neurons, glial cells, epithelial cells, chondrocytes and secretory cells (insulin, amylase). Differentiation and subsequent formation of three-dimensional cellular aggregates (organoid bodies) were induced by merely culturing pancreatic stellate-like cells in hanging drops. These cells were developed into stable, long-term, in vitro cultures of both primary undifferentiated cell lines as well as organoid cultures. Thus, evidence is given that cell lineages of endodermal, mesodermal, and ectodermal origin arise spontaneously from a single adult undifferentiated cell type. Based on the present findings it is assumed that pancreatic stellate-like cells are a new class of lineage uncommitted pluripotent adult stem cells with a remarkable self-renewal ability and differentiation potency. The data emphasize the versatility of adult stem cells and may lead to a reappraisal of their use for the treatment of inherited disorders or acquired degenerative diseases.

Reprogramming triggers endogenous L1 and Alu retrotransposition in human induced pluripotent stem cells.

PubMed

Klawitter, Sabine; Fuchs, Nina V; Upton, Kyle R; Muñoz-Lopez, Martin; Shukla, Ruchi; Wang, Jichang; Garcia-Cañadas, Marta; Lopez-Ruiz, Cesar; Gerhardt, Daniel J; Sebe, Attila; Grabundzija, Ivana; Merkert, Sylvia; Gerdes, Patricia; Pulgarin, J Andres; Bock, Anja; Held, Ulrike; Witthuhn, Anett; Haase, Alexandra; Sarkadi, Balázs; Löwer, Johannes; Wolvetang, Ernst J; Martin, Ulrich; Ivics, Zoltán; Izsvák, Zsuzsanna; Garcia-Perez, Jose L; Faulkner, Geoffrey J; Schumann, Gerald G

2016-01-08

Human induced pluripotent stem cells (hiPSCs) are capable of unlimited proliferation and can differentiate in vitro to generate derivatives of the three primary germ layers. Genetic and epigenetic abnormalities have been reported by Wissing and colleagues to occur during hiPSC derivation, including mobilization of engineered LINE-1 (L1) retrotransposons. However, incidence and functional impact of endogenous retrotransposition in hiPSCs are yet to be established. Here we apply retrotransposon capture sequencing to eight hiPSC lines and three human embryonic stem cell (hESC) lines, revealing endogenous L1, Alu and SINE-VNTR-Alu (SVA) mobilization during reprogramming and pluripotent stem cell cultivation. Surprisingly, 4/7 de novo L1 insertions are full length and 6/11 retrotransposition events occurred in protein-coding genes expressed in pluripotent stem cells. We further demonstrate that an intronic L1 insertion in the CADPS2 gene is acquired during hiPSC cultivation and disrupts CADPS2 expression. These experiments elucidate endogenous retrotransposition, and its potential consequences, in hiPSCs and hESCs.

Reprogramming triggers endogenous L1 and Alu retrotransposition in human induced pluripotent stem cells

PubMed Central

Klawitter, Sabine; Fuchs, Nina V.; Upton, Kyle R.; Muñoz-Lopez, Martin; Shukla, Ruchi; Wang, Jichang; Garcia-Cañadas, Marta; Lopez-Ruiz, Cesar; Gerhardt, Daniel J.; Sebe, Attila; Grabundzija, Ivana; Merkert, Sylvia; Gerdes, Patricia; Pulgarin, J. Andres; Bock, Anja; Held, Ulrike; Witthuhn, Anett; Haase, Alexandra; Sarkadi, Balázs; Löwer, Johannes; Wolvetang, Ernst J.; Martin, Ulrich; Ivics, Zoltán; Izsvák, Zsuzsanna; Garcia-Perez, Jose L.; Faulkner, Geoffrey J.; Schumann, Gerald G.

2016-01-01

Human induced pluripotent stem cells (hiPSCs) are capable of unlimited proliferation and can differentiate in vitro to generate derivatives of the three primary germ layers. Genetic and epigenetic abnormalities have been reported by Wissing and colleagues to occur during hiPSC derivation, including mobilization of engineered LINE-1 (L1) retrotransposons. However, incidence and functional impact of endogenous retrotransposition in hiPSCs are yet to be established. Here we apply retrotransposon capture sequencing to eight hiPSC lines and three human embryonic stem cell (hESC) lines, revealing endogenous L1, Alu and SINE-VNTR-Alu (SVA) mobilization during reprogramming and pluripotent stem cell cultivation. Surprisingly, 4/7 de novo L1 insertions are full length and 6/11 retrotransposition events occurred in protein-coding genes expressed in pluripotent stem cells. We further demonstrate that an intronic L1 insertion in the CADPS2 gene is acquired during hiPSC cultivation and disrupts CADPS2 expression. These experiments elucidate endogenous retrotransposition, and its potential consequences, in hiPSCs and hESCs. PMID:26743714

Approaches for targeting self-renewal pathways in cancer stem cells: implications for hematological treatments.

PubMed

Horne, Gillian A; Copland, Mhairi

2017-05-01

Self-renewal is considered a defining property of stem cells. Self-renewal is essential in embryogenesis and normal tissue repair and homeostasis. However, in cancer, self-renewal pathways, e.g. WNT, NOTCH, Hedgehog and BMP, frequently become de-regulated in stem cells, or more mature progenitor cells acquire self-renewal properties, resulting in abnormal tissue growth and tumorigenesis. Areas covered: This review considers the conserved embryonic self-renewal pathways, including WNT, NOTCH, Hedgehog and BMP. The article describes recent advances in our understanding of these pathways in leukemia and, more specifically, leukemia stem cells (LSC), how these pathways cross-talk and interact with the LSC microenvironment, and discusses the clinical implications and potential therapeutic strategies, both in preclinical and in clinical trials for hematological malignancies. Expert opinion: The conserved embryonic self-renewal pathways are frequently de-regulated in cancer stem cells (CSC), including LSCs. There is significant cross-talk between self-renewal pathways, and their downstream targets, and the microenvironment. Effective targeting of these pathways is challenging due to cross-talk, and importantly, because these pathways are important for normal stem cells as well as CSC, adverse effects on normal tissues may mean a therapeutic window cannot be identified. Nonetheless, several agents targeting these pathways are currently in clinical trials in hematological malignancies.

ATG3-dependent autophagy mediates mitochondrial homeostasis in pluripotency acquirement and maintenance

PubMed Central

Liu, Kun; Zhao, Qian; Liu, Pinglei; Cao, Jiani; Gong, Jiaqi; Wang, Chaoqun; Wang, Weixu; Li, Xiaoyan; Sun, Hongyan; Zhang, Chao; Li, Yufei; Jiang, Minggui; Zhu, Shaohua; Sun, Qingyuan; Jiao, Jianwei; Hu, Baoyang; Zhao, Xiaoyang; Li, Wei; Chen, Quan; Zhou, Qi; Zhao, Tongbiao

2016-01-01

ABSTRACT Pluripotent stem cells, including induced pluripotent and embryonic stem cells (ESCs), have less developed mitochondria than somatic cells and, therefore, rely more heavily on glycolysis for energy production.1-3 However, how mitochondrial homeostasis matches the demands of nuclear reprogramming and regulates pluripotency in ESCs is largely unknown. Here, we identified ATG3-dependent autophagy as an executor for both mitochondrial remodeling during somatic cell reprogramming and mitochondrial homeostasis regulation in ESCs. Dysfunctional autophagy by Atg3 deletion inhibited mitochondrial removal during pluripotency induction, resulting in decreased reprogramming efficiency and accumulation of abnormal mitochondria in established iPSCs. In Atg3 null mouse ESCs, accumulation of aberrant mitochondria was accompanied by enhanced ROS generation, defective ATP production and attenuated pluripotency gene expression, leading to abnormal self-renewal and differentiation. These defects were rescued by reacquisition of wild-type but not lipidation-deficient Atg3 expression. Taken together, our findings highlight a critical role of ATG3-dependent autophagy for mitochondrial homeostasis regulation in both pluripotency acquirement and maintenance. PMID:27575019

ATG3-dependent autophagy mediates mitochondrial homeostasis in pluripotency acquirement and maintenance.

PubMed

Liu, Kun; Zhao, Qian; Liu, Pinglei; Cao, Jiani; Gong, Jiaqi; Wang, Chaoqun; Wang, Weixu; Li, Xiaoyan; Sun, Hongyan; Zhang, Chao; Li, Yufei; Jiang, Minggui; Zhu, Shaohua; Sun, Qingyuan; Jiao, Jianwei; Hu, Baoyang; Zhao, Xiaoyang; Li, Wei; Chen, Quan; Zhou, Qi; Zhao, Tongbiao

2016-11-01

Pluripotent stem cells, including induced pluripotent and embryonic stem cells (ESCs), have less developed mitochondria than somatic cells and, therefore, rely more heavily on glycolysis for energy production. 1-3 However, how mitochondrial homeostasis matches the demands of nuclear reprogramming and regulates pluripotency in ESCs is largely unknown. Here, we identified ATG3-dependent autophagy as an executor for both mitochondrial remodeling during somatic cell reprogramming and mitochondrial homeostasis regulation in ESCs. Dysfunctional autophagy by Atg3 deletion inhibited mitochondrial removal during pluripotency induction, resulting in decreased reprogramming efficiency and accumulation of abnormal mitochondria in established iPSCs. In Atg3 null mouse ESCs, accumulation of aberrant mitochondria was accompanied by enhanced ROS generation, defective ATP production and attenuated pluripotency gene expression, leading to abnormal self-renewal and differentiation. These defects were rescued by reacquisition of wild-type but not lipidation-deficient Atg3 expression. Taken together, our findings highlight a critical role of ATG3-dependent autophagy for mitochondrial homeostasis regulation in both pluripotency acquirement and maintenance.

Reprogramming Enhancers to Drive Metastasis.

PubMed

Mostoslavsky, Raul; Bardeesy, Nabeel

2017-08-24

Acquired molecular changes can promote the spreading of primary tumor cells to distant tissues. In this issue of Cell, Roe et al. show that metastatic progression of pancreatic cancer involves large-scale enhancer reprogramming by Foxa1, which activates transcriptional program specifying early endodermal stem cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of Melatonin Effect on Human Breast Cancer Stem Cells Using a Threedimensional Growth Method of Mammospheres.

PubMed

Lopes, Juliana Ramos; da Silva Kavagutti, Mayume; de Medeiros, Felipe Arthur Faustino; de Campos Zuccari, Debora Aparecida Pires

2017-01-01

The high rates of women&#039;s death from breast cancer occur due to acquired resistance by patients to certain treatments, enabling the recurrence and/or tumor growth, invasion and metastasis. It has been demonstrated that the presence of cancer stem cells in human tumors, as responsible for recurrence and resistance to therapy. Studies have identified OCT4 as responsible for self-renewal and maintenance of pluripotency of stem cells. Thus, it is interesting to study potential drugs that target this specific population in breast cancer. Melatonin, appears to have oncostatic effects on cancer cells, however, little is known about its therapeutic effect on cancer stem cells. Evaluate the viability and the expression of OCT4 in breast cancer stem cells, MCF-7 and MDA-MB- 231, after melatonin treatment. The cells were grown in a 3-dimensional model of mammospheres, representing the breast cancer stem cell population and treated or not with melatonin. The cell viability of mammospheres were evaluated by MTT assay and the OCT4 expression, a cancer stem cells marker, was verified by immunocitochemistry. Our results demonstrated that the melatonin treatment decreased the cell viability of MCF-7 and MDAMB- 231 mammospheres. Furthermore, it was observed that in both cell lines, the expression of OCT4 was decreased in melatonin-treated cells compared to the control group. This fact suggests that melatonin is effective against breast cancer stem cells inhibiting the cell viability via OCT 4. Based on that, we believe that melatonin has a high potential to be used as an alternative treatment for breast cancer. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Cell-Imprinted Substrates Modulate Differentiation, Redifferentiation, and Transdifferentiation.

PubMed

Bonakdar, Shahin; Mahmoudi, Morteza; Montazeri, Leila; Taghipoor, Mojtaba; Bertsch, Arnaud; Shokrgozar, Mohammad Ali; Sharifi, Shahriar; Majidi, Mohammad; Mashinchian, Omid; Hamrang Sekachaei, Mohammad; Zolfaghari, Pegah; Renaud, Philippe

2016-06-08

Differentiation of stem cells into mature cells through the use of physical approaches is of great interest. Here, we prepared smart nanoenvironments by cell-imprinted substrates based on chondrocytes, tenocytes, and semifibroblasts as templates and demonstrated their potential for differentiation, redifferentiation, and transdifferentiation. Analysis of shape and upregulation/downregulation of specific genes of stem cells, which were seeded on these cell-imprinted substrates, confirmed that imprinted substrates have the capability to induce specific shapes and molecular characteristics of the cell types that were used as templates for cell-imprinting. Interestingly, immunofluorescent staining of a specific protein in chondrocytes (i.e., collagen type II) confirmed that adipose-derived stem cells, semifibroblasts, and tenocytes can acquire the chondrocyte phenotype after a 14 day culture on chondrocyte-imprinted substrates. In summary, we propose that common polystyrene tissue culture plates can be replaced by this imprinting technique as an effective and promising way to regulate any cell phenotype in vitro with significant potential applications in regenerative medicine and cell-based therapies.

Links between DNA Replication, Stem Cells and Cancer

PubMed Central

Vassilev, Alex; DePamphilis, Melvin L.

2017-01-01

Cancers can be categorized into two groups: those whose frequency increases with age, and those resulting from errors during mammalian development. The first group is linked to DNA replication through the accumulation of genetic mutations that occur during proliferation of developmentally acquired stem cells that give rise to and maintain tissues and organs. These mutations, which result from DNA replication errors as well as environmental insults, fall into two categories; cancer driver mutations that initiate carcinogenesis and genome destabilizing mutations that promote aneuploidy through excess genome duplication and chromatid missegregation. Increased genome instability results in accelerated clonal evolution leading to the appearance of more aggressive clones with increased drug resistance. The second group of cancers, termed germ cell neoplasia, results from the mislocation of pluripotent stem cells during early development. During normal development, pluripotent stem cells that originate in early embryos give rise to all of the cell lineages in the embryo and adult, but when they mislocate to ectopic sites, they produce tumors. Remarkably, pluripotent stem cells, like many cancer cells, depend on the Geminin protein to prevent excess DNA replication from triggering DNA damage-dependent apoptosis. This link between the control of DNA replication during early development and germ cell neoplasia reveals Geminin as a potential chemotherapeutic target in the eradication of cancer progenitor cells. PMID:28125050

Overexpression of Trophoblast Stem Cell-Enriched MicroRNAs Promotes Trophoblast Fate in Embryonic Stem Cells.

PubMed

Nosi, Ursula; Lanner, Fredrik; Huang, Tsu; Cox, Brian

2017-05-09

The first cell fate choice of the preimplantation embryo generates the extraembryonic trophoblast and embryonic epiblast lineages. Embryonic stem cells (ESCs) and trophoblast stem cells (TSCs) can be utilized to investigate molecular mechanisms of this first cell fate decision. It has been established that ESCs can be induced to acquire trophoblast lineage characteristics upon manipulation of lineage-determining transcription factors. Here, we have interrogated the potential of microRNAs (miRNAs) to drive trans-differentiation of ESCs into the trophoblast lineage. Analysis of gene expression data identified a network of TSC-enriched miRNAs that were predicted to target mRNAs enriched in ESCs. Ectopic expression of these miRNAs in ESCs resulted in a stable trophoblast phenotype, supported by gene expression changes and in vivo contribution potential. This process is highly miRNA-specific and dependent on Hdac2 inhibition. Our experimental evidence suggests that these miRNAs promote a mural trophectoderm (TE)-like cell fate with physiological properties that differentiate them from the polar TE. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Dynamic Interactions Between Cancer Stem Cells And Their Stromal Partners.

PubMed

Park, Tea Soon; Donnenberg, Vera S; Donnenberg, Albert D; Zambidis, Elias T; Zimmerlin, Ludovic

2014-03-01

The cancer stem cell (CSC) paradigm presumes the existence of self-renewing cancer cells capable of regenerating all tumor compartments and exhibiting stem cell-associated phenotypes. Recent interpretations of the CSC hypothesis envision stemness as a dynamic trait of tumor-initiating cells rather than a defined and unique cell type. Bidirectional crosstalk between the tumor microenvironment and the cancer bulk is well described in the literature and the tumor-associated stroma, vasculature and immune infiltrate have all been implicated as direct contributors to tumor development. These non-neoplastic cell types have also been shown to organize specific niches within the tumor bulk where they can control the intra-tumor CSC content and alter the fate of CSCs and tumor progenitors during tumorigenesis to acquire phenotypic features for invasion, metastasis and dormancy. Despite the complexity of the tumor-stroma interactome, novel therapeutic approaches envision combining tumor-ablative treatment with manipulation of the tumor microenvironment. We will review the currently available literature that provides clues about the complex cellular network that regulate the CSC phenotype and its niches during tumor progression.

Acquired aplastic anemia.

PubMed

Keohane, Elaine M

2004-01-01

Acquired aplastic anemia (AA) is a disorder characterized by a profound deficit of hematopoietic stem and progenitor cells, bone marrow hypocellularity, and peripheral blood pancytopenia. It primarily affects children, young adults, and those over 60 years of age. The majority of cases are idiopathic; however, idiosyncratic reactions to some drugs, chemicals, and viruses have been implicated in its etiology. An autoimmune T-cell reaction likely causes the stem cell depletion, but the precise mechanism, as well as the eliciting and target antigens, is unknown. Symptoms vary from severe life-threatening cytopenias to moderate or non-severe disease that does not require transfusion support. The peripheral blood typically exhibits pancytopenia, reticulocytopenia, and normocytic or macrocytic erythrocytes. The bone marrow is hypocellular and may exhibit dysplasia of the erythrocyte precursors. First line treatment for severe AA consists of hematopoietic stem cell transplantation in young patients with HLA identical siblings, while immunosuppression therapy is used for older patients and for those of any age who lack a HLA matched donor. Patients with AA have an increased risk of developing paroxysmal nocturnal hemoglobinuria (PNH), myelodysplastic syndrome (MDS), or acute leukemia. Further elucidation of the pathophysiology of this disease will result in a better understanding of the interrelationship among AA, PNH, and MDS, and may lead to novel targeted therapies.

Adult Lung Spheroid Cells Contain Progenitor Cells and Mediate Regeneration in Rodents With Bleomycin-Induced Pulmonary Fibrosis.

PubMed

Henry, Eric; Cores, Jhon; Hensley, M Taylor; Anthony, Shirena; Vandergriff, Adam; de Andrade, James B M; Allen, Tyler; Caranasos, Thomas G; Lobo, Leonard J; Cheng, Ke

2015-11-01

Lung diseases are devastating conditions and ranked as one of the top five causes of mortality worldwide according to the World Health Organization. Stem cell therapy is a promising strategy for lung regeneration. Previous animal and clinical studies have focused on the use of mesenchymal stem cells (from other parts of the body) for lung regenerative therapies. We report a rapid and robust method to generate therapeutic resident lung progenitors from adult lung tissues. Outgrowth cells from healthy lung tissue explants are self-aggregated into three-dimensional lung spheroids in a suspension culture. Without antigenic sorting, the lung spheroids recapitulate the stem cell niche and contain a natural mixture of lung stem cells and supporting cells. In vitro, lung spheroid cells can be expanded to a large quantity and can form alveoli-like structures and acquire mature lung epithelial phenotypes. In severe combined immunodeficiency mice with bleomycin-induced pulmonary fibrosis, intravenous injection of human lung spheroid cells inhibited apoptosis, fibrosis, and infiltration but promoted angiogenesis. In a syngeneic rat model of pulmonary fibrosis, lung spheroid cells outperformed adipose-derived mesenchymal stem cells in reducing fibrotic thickening and infiltration. Previously, lung spheroid cells (the spheroid model) had only been used to study lung cancer cells. Our data suggest that lung spheroids and lung spheroid cells from healthy lung tissues are excellent sources of regenerative lung cells for therapeutic lung regeneration. The results from the present study will lead to future human clinical trials using lung stem cell therapies to treat various incurable lung diseases, including pulmonary fibrosis. The data presented here also provide fundamental knowledge regarding how injected stem cells mediate lung repair in pulmonary fibrosis. ©AlphaMed Press.

Mesenchymal and embryonic characteristics of stem cells obtained from mouse dental pulp.

PubMed

Guimarães, Elisalva Teixeira; Cruz, Gabriela Silva; de Jesus, Alan Araújo; Lacerda de Carvalho, Acácia Fernandes; Rogatto, Silvia Regina; Pereira, Lygia da Veiga; Ribeiro-dos-Santos, Ricardo; Soares, Milena Botelho Pereira

2011-11-01

Several studies have demonstrated that human dental pulp is a source of mesenchymal stem cells. To better understand the biological properties of these cells we isolated and characterized stem cells from the dental pulp of EGFP transgenic mice. The pulp tissue was gently separated from the roots of teeth extracted from C57BL/6 mice, and cultured under appropriate conditions. Flow cytometry, RT-PCR, light microscopy (staining for alkaline phosphatase) and immunofluorescence were used to investigate the expression of stem cell markers. The presence of chromosomal abnormalities was evaluated by G banding. The mouse dental pulp stem cells (mDPSC) were highly proliferative, plastic-adherent, and exhibited a polymorphic morphology predominantly with stellate or fusiform shapes. The presence of cell clusters was observed in cultures of mDPSC. Some cells were positive for alkaline phosphatase. The karyotype was normal until the 5th passage. The Pou5f1/Oct-4 and ZFP42/Rex-1, but not Nanog transcripts were detected in mDPSC. Flow cytometry and fluorescence analyses revealed the presence of a heterogeneous population positive for embryonic and mesenchymal cell markers. Adipogenic, chondrogenic and osteogenic differentiation was achieved after two weeks of cell culture under chemically defined in vitro conditions. In addition, some elongated cells spontaneously acquired a contraction capacity. Our results reinforce that the dental pulp is an important source of adult stem cells and encourage studies on therapeutic potential of mDPSC in experimental disease models. Copyright © 2011 Elsevier Ltd. All rights reserved.

Myelodysplastic syndromes are propagated by rare and distinct human cancer stem cells in vivo.

PubMed

Woll, Petter S; Kjällquist, Una; Chowdhury, Onima; Doolittle, Helen; Wedge, David C; Thongjuea, Supat; Erlandsson, Rikard; Ngara, Mtakai; Anderson, Kristina; Deng, Qiaolin; Mead, Adam J; Stenson, Laura; Giustacchini, Alice; Duarte, Sara; Giannoulatou, Eleni; Taylor, Stephen; Karimi, Mohsen; Scharenberg, Christian; Mortera-Blanco, Teresa; Macaulay, Iain C; Clark, Sally-Ann; Dybedal, Ingunn; Josefsen, Dag; Fenaux, Pierre; Hokland, Peter; Holm, Mette S; Cazzola, Mario; Malcovati, Luca; Tauro, Sudhir; Bowen, David; Boultwood, Jacqueline; Pellagatti, Andrea; Pimanda, John E; Unnikrishnan, Ashwin; Vyas, Paresh; Göhring, Gudrun; Schlegelberger, Brigitte; Tobiasson, Magnus; Kvalheim, Gunnar; Constantinescu, Stefan N; Nerlov, Claus; Nilsson, Lars; Campbell, Peter J; Sandberg, Rickard; Papaemmanuil, Elli; Hellström-Lindberg, Eva; Linnarsson, Sten; Jacobsen, Sten Eirik W

2014-06-16

Evidence for distinct human cancer stem cells (CSCs) remains contentious and the degree to which different cancer cells contribute to propagating malignancies in patients remains unexplored. In low- to intermediate-risk myelodysplastic syndromes (MDS), we establish the existence of rare multipotent MDS stem cells (MDS-SCs), and their hierarchical relationship to lineage-restricted MDS progenitors. All identified somatically acquired genetic lesions were backtracked to distinct MDS-SCs, establishing their distinct MDS-propagating function in vivo. In isolated del(5q)-MDS, acquisition of del(5q) preceded diverse recurrent driver mutations. Sequential analysis in del(5q)-MDS revealed genetic evolution in MDS-SCs and MDS-progenitors prior to leukemic transformation. These findings provide definitive evidence for rare human MDS-SCs in vivo, with extensive implications for the targeting of the cells required and sufficient for MDS-propagation. Copyright © 2014 Elsevier Inc. All rights reserved.

Stem cells from foetal adnexa and fluid in domestic animals: an update on their features and clinical application.

PubMed

Iacono, E; Rossi, B; Merlo, B

2015-06-01

Over the past decade, stem cell research has emerged as an area of major interest for its potential in regenerative medicine applications. This is in constant need of new cell sources to conceive regenerative medicine approaches for diseases that are still without therapy. Scientists drew the attention towards alternative sources such as foetal adnexa and fluid, as these sources possess many advantages: first of all, cells can be extracted from discarded foetal material and it is non-invasive and inexpensive for the patient; secondly, abundant stem cells can be obtained; and finally, these stem cell sources are free from ethical considerations. Cells derived from foetal adnexa and fluid preserve some of the characteristics of the primitive embryonic layers from which they originate. Many studies have demonstrated the differentiation potential in vitro and in vivo towards mesenchymal and non-mesenchymal cell types; in addition, the immune-modulatory properties make these cells a good candidate for allo- and xenotransplantation. Naturally occurring diseases in domestic animals can be more ideal as disease model of human genetic and acquired diseases and could help to define the potential therapeutic use efficiency and safety of stem cells therapies. This review offers an update on the state of the art of characterization of domestic animals' MSCs derived from foetal adnexa and fluid and on the latest findings in pre-clinical or clinical setting of the stem cell populations isolated from these sources. © 2015 Blackwell Verlag GmbH.

Telomerase gene therapy rescues telomere length, bone marrow aplasia, and survival in mice with aplastic anemia.

PubMed

Bär, Christian; Povedano, Juan Manuel; Serrano, Rosa; Benitez-Buelga, Carlos; Popkes, Miriam; Formentini, Ivan; Bobadilla, Maria; Bosch, Fatima; Blasco, Maria A

2016-04-07

Aplastic anemia is a fatal bone marrow disorder characterized by peripheral pancytopenia and marrow hypoplasia. The disease can be hereditary or acquired and develops at any stage of life. A subgroup of the inherited form is caused by replicative impairment of hematopoietic stem and progenitor cells due to very short telomeres as a result of mutations in telomerase and other telomere components. Abnormal telomere shortening is also described in cases of acquired aplastic anemia, most likely secondary to increased turnover of bone marrow stem and progenitor cells. Here, we test the therapeutic efficacy of telomerase activation by using adeno-associated virus (AAV)9 gene therapy vectors carrying the telomerase Tert gene in 2 independent mouse models of aplastic anemia due to short telomeres (Trf1- and Tert-deficient mice). We find that a high dose of AAV9-Tert targets the bone marrow compartment, including hematopoietic stem cells. AAV9-Tert treatment after telomere attrition in bone marrow cells rescues aplastic anemia and mouse survival compared with mice treated with the empty vector. Improved survival is associated with a significant increase in telomere length in peripheral blood and bone marrow cells, as well as improved blood counts. These findings indicate that telomerase gene therapy represents a novel therapeutic strategy to treat aplastic anemia provoked or associated with short telomeres. © 2016 by The American Society of Hematology.

40 projects in stem cell research, tissue engineering, tolerance induction and more (NRP46 "Implants and Transplants" 1999-2006).

PubMed

Thiel, Gilbert T

2007-03-02

Forty projects on stem cell research, tissue and matrix engineering, tolerance induction and other topics were supported by the Swiss National Research Program NRP46 (Implants, Transplants) from 1999-2006. The last project is devoted to developing stem cell lines from frozen surplus human embryos in Switzerland, which would otherwise have to be destroyed at the end of 2008. It is entitled JESP (Joint Embryonic Stem Cell Project) since it involves two Swiss universities, in vitro fertilisation centres and experts from the humanities (ethics and law) to handle this difficult problem. Over the years, stem cell transplantation and tissue/matrix engineering have drawn closer to each other and even developed synergies. Progress in stem cell research has been slower than anticipated, but a multitude of technical skills (phenotyping, isolation, transfection, induction of differentiation, labelling, expanding cells in culture, etc) were acquired. Understanding of stem cell biology has grown. The 7 projects on tissue and matrix engineering progressed closer to clinical applicability than the stem cell projects. Of 3 projects to implant encapsulated cells for the production of hormones (insulin, erythropoietin), one is close to clinical pilot studies with an advanced encapsulated device. Five projects were devoted to mechanisms of tolerance or the role of metzincins in chronic allograft nephropathy. Four studies in psychology and communication in transplantation were funded, as were 5 projects in ethics, law and the history of transplantation in Switzerland. The goal of NRP46 was to provide an impulse for research in these new fields and bring together experts from the humanities, biology and medicine to cope more effectively with the problems of regenerative medicine in the future. The majority of goals were attained, mainly in the basics.

Cancer stem cell mediated acquired chemoresistance in head and neck cancer can be abrogated by aldehyde dehydrogenase 1 A1 inhibition.

PubMed

Kulsum, Safeena; Sudheendra, Holalugunda Vittalamurthy; Pandian, Ramanan; Ravindra, Doddathimmasandra Ramanjanappa; Siddappa, Gangotri; R, Nisheena; Chevour, Priyanka; Ramachandran, Balaji; Sagar, Milind; Jayaprakash, Aravindakshan; Mehta, Alka; Kekatpure, Vikram; Hedne, Naveen; Kuriakose, Moni A; Suresh, Amritha

2017-02-01

Chemoresistance leading to disease relapse is one of the major challenges to improve outcome in head and neck cancers. Cancer Stem Cells (CSCs) are increasingly being implicated in chemotherapy resistance, this study investigates the correlation between CSC behavior and acquired drug resistance in in vitro cell line models. Cell lines resistant to Cisplatin (Cal-27 CisR, Hep-2 CisR) and 5FU (Cal-27 5FUR) with high Resistance Indices (RI) were generated (RI ≥ 3) by short-term treatment of head and neck squamous cell carcinoma (HNSCC) cell lines with chemotherapeutic drugs (Cisplatin, Docetaxel, 5FU), using a dose-incremental strategy. The cell lines (Cal-27 DoxR, Hep-2 DoxR, Hep-2 5FUR) that showed low RI, nevertheless had a high cross resistance to Cisplatin/5FU (P < 0.05). Cal-27 CisR and DoxR showed 12-14% enrichment of CD44+ cells, while CisR/5FUR showed 4-6% increase in ALDH1A1+ cells as compared to parental cells (P < 0.05). Increased expression of stem cell markers (CD44, CD133, NOTCH1, ALDH1A1, OCT4, SOX2) in these cell lines, correlated with enhanced spheroid/colony formation, migratory potential, and increased in vivo tumor burden (P < 0.05). Inhibition of ALDH1A1 in Cal-27 CisR led to down regulation of the CSC markers, reduction in migratory, self-renewal and tumorigenic potential (P < 0.05) accompanied by an induction of sensitivity to Cisplatin (P < 0.05). Further, ex vivo treatment of explants (n = 4) from HNSCC patients with the inhibitor (NCT-501) in combination with Cisplatin showed a significant decrease in proliferating cells as compared to individual treatment (P = 0.001). This study hence suggests an ALDH1A1-driven, CSC-mediated mechanism in acquired drug resistance of HNSCC, which may have therapeutic implications. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Generation of H1 PAX6WT/EGFP reporter cells to purify PAX6 positive neural stem/progenitor cells.

PubMed

Wu, Wei; Liu, Juli; Su, Zhenghui; Li, Zhonghao; Ma, Ning; Huang, Ke; Zhou, Tiancheng; Wang, Linli

2018-08-25

Neural conversion from human pluripotent cells (hPSCs) is a potential therapy to neurological disease in the future. However, this is still limited by efficiency and stability of existed protocols used for neural induction from hPSCs. To overcome this obstacle, we developed a reporter system to screen PAX6 + neural progenitor/stem cells using transcription activator like effector nuclease (TALEN). We found that knock-in 2 A-EGFP cassette into PAX6 exon of human embryonic stem cells H1 with TALEN-based homology recombination could establish PAX6 WT/EGFP H1 reporter cell line fast and efficiently. This reporter cell line could differentiate into PAX6 and EGFP double positive neural progenitor/stem cells (NPCs/NSCs) after neural induction. Those PAX6 WT/EGFP NPCs could be purified, expanded and specified to post-mitotic neurons in vitro efficiently. With this reporter cell line, we also screened out 1 NPC-specific microRNA, hsa-miR-99a-5p, and 3 ESCs-enriched miRNAs, hsa-miR-302c-5p, hsa-miR-512-3p and hsa-miR-518 b. In conclusion, the TALEN-based neural stem cell screening system is safe and efficient and could help researcher to acquire adequate and pure neural progenitor cells for further application. Copyright © 2018 Elsevier Inc. All rights reserved.

Epigenome regulation during germ cell specification and development from pluripotent stem cells.

PubMed

Kurimoto, Kazuki; Saitou, Mitinori

2018-06-13

Germ cells undergo epigenome reprogramming for proper development of the next generation. The realization of germ cell derivation from human and mouse pluripotent stem cells offers unprecedented opportunity for investigation of germline development. Primordial germ cells reconstituted in vitro (PGC-like cells [PGCLCs]) show progressive dilution of genomic DNA methylation, tightly linked with chromatin remodeling, during their specification. PGCLCs can be further expanded by plane culture, allowing maintenance of the gene-expression profiles of early PGCs and continuance of the DNA methylation erasure, thereby establishing an epigenetic `blank slate'. PGCLCs undergo further epigenome regulation to acquire the male or female fates. These findings will provide a foundation for basic germ cell biology and for in-depth evaluations of in vitro gametogenesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Human blood and marrow side population stem cell and Stro-1 positive bone marrow stromal cell numbers decline with age, with an increase in quality of surviving stem cells: Correlation with cytokines

PubMed Central

Brusnahan, S.K.; McGuire, T.R.; Jackson, J.D.; Lane, J.T.; Garvin, K.L.; O’Kane, B.J.; Berger, A.M.; Tuljapurkar, S.R.; Kessinger, M.A.; Sharp, J.G.

2010-01-01

Hematological deficiencies increase with aging leading to anemias, reduced hematopoietic stress responses and myelodysplasias. This study tested the hypothesis that side population hematopoietic stem cells (SP-HSC) would decrease with aging, correlating with IGF-1 and IL-6 levels and increases in bone marrow fat. Marrow was obtained from the femoral head and trochanteric region of the femur at surgery for total hip replacement (N = 100). Whole trabecular marrow samples were ground in a sterile mortar and pestle and cellularity and fat content determined. Marrow and blood mononuclear cells were stained with Hoechst dye and the SP-HSC profiles acquired. Marrow stromal cells (MSC) were enumerated flow cytometrically employing the Stro-1 antibody, and clonally in the colony forming unit fibroblast (CFU-F) assay. Plasma levels of IGF-1 (ng/ml) and IL-6 (pg/ml) were measured by ELISA. SP-HSC in blood and bone marrow decreased with age but the quality of the surviving stem cells increased. MSC decreased non-significantly. IGF-1 levels (mean = 30.7, SEM = 2) decreased and IL-6 levels (mean = 4.4, SEM = 1) increased with age as did marrow fat (mean = 1.2 mm fat/g, SEM = 0.04). There were no significant correlations between cytokine levels or fat and SP-HSC numbers. Stem cells appear to be progressively lost with aging and only the highest quality stem cells survive. PMID:21035480

Improved targeting and enhanced retention of the human, autologous, fibroblast-derived, induced, pluripotent stem cells to the sarcomeres of the infarcted myocardium with the aid of the bioengineered, heterospecific, tetravalent antibodies**

PubMed Central

Malecki, Marek

2013-01-01

Clinical trials, to regenerate the human heart injured by myocardial infarction, involve the delivery of stem cells to the site of the injury. However, only a small fraction of the introduced stem cells are detected at the site of the injury, merely two weeks after this therapeutic intervention. This significantly hampers the effectiveness of the stem cell therapy. To resolve the aforementioned problem, we genetically and molecularly bioengineered heterospecific, tetravalent antibodies (htAbs), which have both exquisite specificity and high affinity towards human, pluripotent, stem cells through the htAbs’ domains binding SSEA-4, SSEA-3, TRA-1-60, and TRA-1-81, as well as towards the injured cardiac muscle through the htAbs’ domains binding human cardiac myosin, α-actinin, actin, and titin. The cardiac tissue was acquired from the patients, who were receiving heart transplants. The autologous, human, induced, pluripotent stem cells (hiPSCs) were generated from the patients’ fibroblasts by non-viral delivery and transient expression of the DNA constructs for: Oct4, Nanog, Sox2, Lin28, Klf4, c-Myc. In the trials involving the htAbs, the human, induced, pluripotent stem cells anchored to the myocardial sarcomeres with the efficiency, statistically, significantly higher, than in the trials with non-specific or without antibodies (p < 0.0003). Moreover, application of the htAbs resulted in cross-linking of the sarcomeric proteins to create the stable scaffolds for anchoring of the stem cells. Thereafter, these human, induced pluripotent stem cells differentiated into cardiomyocytes at their anchorage sites. By bioengineering of these novel heterospecific, tetravalent antibodies and using them to guide and to anchor the stem cells specifically to the stabilized sarcomeric scaffolds, we demonstrated the proof of concept in vitro for improving effectiveness of regenerative therapy of myocardial infarction and created the foundations for the trials in vivo. PMID:23956947

Isolated acquired factor VII deficiency: review of the literature.

PubMed

Mulliez, Sylvie M N; Devreese, Katrien M J

2016-04-01

Isolated acquired factor VII (FVII) deficiency is a rare haemorrhagic disorder. We report what is currently known about the pathogenesis, clinical features, diagnosis, treatment and prognosis of acquired FVII deficiency. We performed a literature search and included all articles published between 1980 and August 2015. Acquired FVII deficiency has been reported in 42 patients. There are well-established clinical diseases associated with acquired FVII deficiency, most notably infections, malignancy and haematological stem cell transplantation. The exact pathogenesis of the diseases is still unknown, but different pathophysiological hypotheses have been suggested. The clinical manifestation of acquired FVII deficiency varies greatly in severity; asymptomatic course as well as severe life-threatening bleeding diathesis and fatal bleedings have been described.

Genome-wide RNA profiling of long-lasting stem cell-like memory CD8 T cells induced by Yellow Fever vaccination in humans.

PubMed

Fuertes Marraco, Silvia A; Soneson, Charlotte; Delorenzi, Mauro; Speiser, Daniel E

2015-09-01

The live-attenuated Yellow Fever (YF) vaccine YF-17D induces a broad and polyfunctional CD8 T cell response in humans. Recently, we identified a population of stem cell-like memory CD8 T cells induced by YF-17D that persists at stable frequency for at least 25 years after vaccination. The YF-17D is thus a model system of human CD8 T cell biology that furthermore allows to track and study long-lasting and antigen-specific human memory CD8 T cells. Here, we describe in detail the sample characteristics and preparation of a microarray dataset acquired for genome-wide gene expression profiling of long-lasting YF-specific stem cell-like memory CD8 T cells, compared to the reference CD8 T cell differentiation subsets from total CD8 T cells. We also describe the quality controls, annotations and exploratory analyses of the dataset. The microarray data is available from the Gene Expression Omnibus (GEO) public repository with accession number GSE65804.

Adipose tissue-deprived stem cells acquire cementoblast features treated with dental follicle cell conditioned medium containing dentin non-collagenous proteins in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wen, Xiujie; Nie, Xin; Zhang, Li

Highlights: {yields} In this study we examine the effects of dental follicle cell conditioned medium (DFCCM) containing dentin non-collagenous proteins (dNCPs) on differentiation of ADSCs. {yields} We examined that ADSCs treated with dNCPs/DFCCM underwent morphological changes and significantly lost their proliferative capacity. {yields} dNCPs/DFCCM enhanced the mineralization behaviour and mineralization-related marker expression of ADSCs. {yields} ADSCs acquired cementoblast features in vitro with dNCPs/DFCCM treatment. -- Abstract: Adipose tissue-derived stem cells (ADSCs), which are easily harvested and show excellent pluripotency potential, have generated considerable interest in regenerative medicine. In this study, the differentiation of ADSCs was assessed after treatment with dentalmore » follicle cell conditioned medium (DFCCM) containing dentin non-collagenous proteins (dNCPs). ADSCs exhibited a fibroblast-like morphology and high proliferative capacity. However, after treatment with dNCPs/DFCCM, ADSCs changed from a fibroblast-like to cementoblast-like morphology and significantly lost their proliferative capacity. Alkaline phosphatase activity and in vitro mineralization behaviour of ADSCs were significantly enhanced. Mineralization-related markers including cementum attachment protein, bone sialoprotein, osteocalcin, osteopontin and osteonectin were detected at mRNA or protein levels, whereas dentin sialophosphoprotein and dentin sialoprotein were not detected, implying a cementoblast-like phenotype. These results demonstrate that ADSCs acquired cementoblast features in vitro with dNCPs/DFCCM treatment and could be a potential source of cementogenic cells for periodontal regeneration.« less

Cancer stem cells in head and neck squamous cell carcinoma: a review.

PubMed

Satpute, Pranali Shirish; Hazarey, Vinay; Ahmed, Riyaz; Yadav, Lalita

2013-01-01

Research indicates that a small population of cancer cells is highly tumorigenic, endowed with the capacity for self-renewal, and has the ability to differentiate into cells that constitute the bulk of tumors. These cells are considered the "drivers" of the tumorigenic process in some tumor types, and have been named cancer stem cells (CSC). Epithelial-mesenchymal transition (EMT) appears to be involved in the process leading to the acquisition of stemness by epithelial tumor cells. Through this process, cells acquire an invasive phenotype that may contribute to tumor recurrence and metastasis. CSC have been identified in human head and neck squamous cell carcinomas (HNSCC) using markers such as CD133 and CD44 expression, and aldehyde dehydrogenase (ALDH) activity. Head and neck cancer stem cells reside primarily in perivascular niches in the invasive fronts where endothelial-cell initiated events contribute to their survival and function. Clinically, CSC enrichment has been shown to be enhanced in recurrent disease, treatment failure and metastasis. CSC represent a novel target of study given their slow growth and innate mechanisms conferring treatment resistance. Further understanding of their unique phenotype may reveal potential molecular targets to improve therapeutic and survival outcomes in patients with HNSCC. Here, we discuss the state-of-the-knowledge on the pathobiology of cancer stem cells, with a focus on the impact of these cells on head and neck tumor progression, metastasis and recurrence due to treatment failure.

Functional properties of cells obtained from human cord blood CD34+ stem cells and mouse cardiac myocytes in coculture.

PubMed

Orlandi, Alessia; Pagani, Francesca; Avitabile, Daniele; Bonanno, Giuseppina; Scambia, Giovanni; Vigna, Elisa; Grassi, Francesca; Eusebi, Fabrizio; Fucile, Sergio; Pesce, Maurizio; Capogrossi, Maurizio C

2008-04-01

Prior in vitro studies suggested that different types of hematopoietic stem cells may differentiate into cardiomyocytes. The present work examined whether human CD34(+) cells from the human umbilical cord blood (hUCB), cocultured with neonatal mouse cardiomyocytes, acquire the functional properties of myocardial cells and express human cardiac genes. hUCB CD34(+) cells were cocultured onto cardiomyocytes following an infection with a lentivirus-encoding enhanced green fluorescent protein (EGFP). After 7 days, mononucleated EGFP(+) cells were tested for their electrophysiological features by patch clamp and for cytosolic [Ca(2+)] ([Ca(2+)](i)) homeostasis by [Ca(2+)](i) imaging of X-rhod1-loaded cells. Human Nkx2.5 and GATA-4 expression was examined in cocultured cell populations by real-time RT-PCR. EGFP(+) cells were connected to surrounding cells by gap junctions, acquired electrophysiological properties similar to those of cardiomyocytes, and showed action potential-associated [Ca(2+)](i) transients. These cells also exhibited spontaneous sarcoplasmic reticulum [Ca(2+)](i) oscillations and the associated membrane potential depolarization. However, RT-PCR of both cell populations showed no upregulation of human-specific cardiac genes. In conclusion, under our experimental conditions, hUCB CD34(+) cells cocultured with murine cardiomyocytes formed cells that exhibited excitation-contraction coupling features similar to those of cardiomyocytes. However, the expression of human-specific cardiac genes was undetectable by RT-PCR.

Targeting Notch, Hedgehog, and Wnt pathways in cancer stem cells: clinical update

PubMed Central

Miele, Lucio; Harris, Pamela Jo; Jeong, Woondong; Bando, Hideaki; Kahn, Michael; Yang, Sherry X.

2015-01-01

During the past decade, cancer stem cells (CSCs) have been increasingly identified in many malignancies. Although the origin and plasticity of these cells remain controversial, tumour heterogeneity and the presence of small populations of cells with stem-like characteristics is established in most malignancies. CSCs display many features of embryonic or tissue stem cells, and typically demonstrate persistent activation of one or more highly conserved signal transduction pathways involved in development and tissue homeostasis, including the Notch, Hedgehog (HH), and Wnt pathways. CSCs generally have slow growth rates and are resistant to chemotherapy and/or radiotherapy. Thus, new treatment strategies targeting these pathways to control stem-cell replication, survival and differentiation are under development. Herein, we provide an update on the latest advances in the clinical development of such approaches, and discuss strategies for overcoming CSC-associated primary or acquired resistance to cancer treatment. Given the crosstalk between the different embryonic developmental signalling pathways, as well as other pathways, designing clinical trials that target CSCs with rational combinations of agents to inhibit possible compensatory escape mechanisms could be of particular importance. We also share our views on the future directions for targeting CSCs to advance the clinical development of these classes of agents. PMID:25850553

Concise Review: One Stone for Multiple Birds: Generating Universally Compatible Human Embryonic Stem Cells.

PubMed

Zheng, Dejin; Wang, Xiaofang; Xu, Ren-He

2016-09-01

With ongoing clinical trials, human embryonic stem cells (hESCs) have shown substantial potential for regenerative medicine. However, due to the mismatch of human leukocyte antigens (HLAs) between hESC-derived allografts and recipients, immunosuppressant regimens must be used to prevent immune rejection of the grafts. Considerable efforts have been devoted to overcoming this hurdle via the derivation and banking of human nuclear transfer ESCs, parthenogenetic ESCs, and induced pluripotent stem cells. However, ethical and safety concerns remain, hindering the application of these types of pluripotent cells. Other approaches have recently been explored to generate universally compatible hESCs through the silencing or deletion of HLAs or genes essential for HLA expression, including β-2-microglobulin and class-II MHC transactivator, as well as the induction of immunosuppression via the ectopic expression of non-classical HLAs (e.g., HLA-E and -G), cytotoxic T lymphocyte antigen 4 fused with immunoglobulin, and programmed death ligand-1. In this review, we introduce developments in this line of research and discuss strategies to reduce the tumorigenic concerns regarding hESCs, especially after they acquire the capability to escape immune surveillance. Stem Cells 2016;34:2269-2275. © 2016 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Laterally confined growth of cells induces nuclear reprogramming in the absence of exogenous biochemical factors.

PubMed

Roy, Bibhas; Venkatachalapathy, Saradha; Ratna, Prasuna; Wang, Yejun; Jokhun, Doorgesh Sharma; Nagarajan, Mallika; Shivashankar, G V

2018-05-22

Cells in tissues undergo transdifferentiation programs when stimulated by specific mechanical and biochemical signals. While seminal studies have demonstrated that exogenous biochemical factors can reprogram somatic cells into pluripotent stem cells, the critical roles played by mechanical signals in such reprogramming process have not been well documented. In this paper, we show that laterally confined growth of fibroblasts on micropatterned substrates induces nuclear reprogramming with high efficiency in the absence of any exogenous reprogramming factors. We provide compelling evidence on the induction of stem cell-like properties using alkaline phosphatase assays and expression of pluripotent markers. Early onset of reprogramming was accompanied with enhanced nuclear dynamics and changes in chromosome intermingling degrees, potentially facilitating rewiring of the genome. Time-lapse analysis of promoter occupancy by immunoprecipitation of H3K9Ac chromatin fragments revealed that epithelial, proliferative, and reprogramming gene promoters were progressively acetylated, while mesenchymal promoters were deacetylated by 10 days. Consistently, RNA sequencing analysis showed a systematic progression from mesenchymal to stem cell transcriptome, highlighting pathways involving mechanisms underlying nuclear reprogramming. We then demonstrated that these mechanically reprogrammed cells could be maintained as stem cells and can be redifferentiated into multiple lineages with high efficiency. Importantly, we also demonstrate the induction of cancer stemness properties in MCF7 cells grown in such laterally confined conditions. Collectively, our results highlight an important generic property of somatic cells that, when grown in laterally confined conditions, acquire stemness. Such mechanical reprogramming of somatic cells demonstrated here has important implications in tissue regeneration and disease models. Copyright © 2018 the Author(s). Published by PNAS.

New insights into the biology and origin of mature aggressive B-cell lymphomas by combined epigenomic, genomic, and transcriptional profiling.

PubMed

Martín-Subero, José I; Kreuz, Markus; Bibikova, Marina; Bentink, Stefan; Ammerpohl, Ole; Wickham-Garcia, Eliza; Rosolowski, Maciej; Richter, Julia; Lopez-Serra, Lidia; Ballestar, Esteban; Berger, Hilmar; Agirre, Xabier; Bernd, Heinz-Wolfram; Calvanese, Vincenzo; Cogliatti, Sergio B; Drexler, Hans G; Fan, Jian-Bing; Fraga, Mario F; Hansmann, Martin L; Hummel, Michael; Klapper, Wolfram; Korn, Bernhard; Küppers, Ralf; Macleod, Roderick A F; Möller, Peter; Ott, German; Pott, Christiane; Prosper, Felipe; Rosenwald, Andreas; Schwaenen, Carsten; Schübeler, Dirk; Seifert, Marc; Stürzenhofecker, Benjamin; Weber, Michael; Wessendorf, Swen; Loeffler, Markus; Trümper, Lorenz; Stein, Harald; Spang, Rainer; Esteller, Manel; Barker, David; Hasenclever, Dirk; Siebert, Reiner

2009-03-12

Lymphomas are assumed to originate at different stages of lymphocyte development through chromosomal aberrations. Thus, different lymphomas resemble lymphocytes at distinct differentiation stages and show characteristic morphologic, genetic, and transcriptional features. Here, we have performed a microarray-based DNA methylation profiling of 83 mature aggressive B-cell non-Hodgkin lymphomas (maB-NHLs) characterized for their morphologic, genetic, and transcriptional features, including molecular Burkitt lymphomas and diffuse large B-cell lymphomas. Hierarchic clustering indicated that methylation patterns in maB-NHLs were not strictly associated with morphologic, genetic, or transcriptional features. By supervised analyses, we identified 56 genes de novo methylated in all lymphoma subtypes studied and 22 methylated in a lymphoma subtype-specific manner. Remarkably, the group of genes de novo methylated in all lymphoma subtypes was significantly enriched for polycomb targets in embryonic stem cells. De novo methylated genes in all maB-NHLs studied were expressed at low levels in lymphomas and normal hematopoietic tissues but not in nonhematopoietic tissues. These findings, especially the enrichment for polycomb targets in stem cells, indicate that maB-NHLs with different morphologic, genetic, and transcriptional background share a similar stem cell-like epigenetic pattern. This suggests that maB-NHLs originate from cells with stem cell features or that stemness was acquired during lymphomagenesis by epigenetic remodeling.

The Abbreviated Pluripotent Cell Cycle

PubMed Central

Kapinas, Kristina; Grandy, Rodrigo; Ghule, Prachi; Medina, Ricardo; Becker, Klaus; Pardee, Arthur; Zaidi, Sayyed K.; Lian, Jane; Stein, Janet; van Wijnen, Andre; Stein, Gary

2013-01-01

Human embryonic stem cells and induced pluripotent stem cells proliferate rapidly and divide symmetrically producing equivalent progeny cells. In contrast, lineage committed cells acquire an extended symmetrical cell cycle. Self-renewal of tissue-specific stem cells is sustained by asymmetric cell division where one progeny cell remains a progenitor while the partner progeny cell exits the cell cycle and differentiates. There are three principal contexts for considering the operation and regulation of the pluripotent cell cycle: temporal, regulatory andstructural. The primary temporal context that the pluripotent self-renewal cell cycle of human embryonic stem cells (hESCs) is a short G1 period without reducing periods of time allocated to S phase, G2, and mitosis. The rules that govern proliferation in hESCs remain to be comprehensively established. However, several lines of evidence suggest a key role for the naïve transcriptome of hESCs, which is competent to stringently regulate the ESC cell cycle. This supports the requirements of pluripotent cells to self propagate while suppressing expression of genes that confer lineage commitment and/or tissue specificity. However, for the first time, we consider unique dimensions to the architectural organization and assembly of regulatory machinery for gene expression in nuclear microenviornments that define parameters of pluripotency. From both fundamental biological and clinical perspectives, understanding control of the abbreviated embryonic stem cell cycle can provide options to coordinate control of proliferation versus differentiation. Wound healing, tissue engineering, and cell-based therapy to mitigate developmental aberrations illustrate applications that benefit from knowledge of the biology of the pluripotent cell cycle. PMID:22552993

Therapy targets in glioblastoma and cancer stem cells: lessons from haematopoietic neoplasms

PubMed Central

Cruceru, Maria Linda; Neagu, Monica; Demoulin, Jean-Baptiste; Constantinescu, Stefan N

2013-01-01

Despite intense efforts to identify cancer-initiating cells in malignant brain tumours, markers linked to the function of these cells have only very recently begun to be uncovered. The notion of cancer stem cell gained prominence, several molecules and signalling pathways becoming relevant for diagnosis and treatment. Whether a substantial fraction or only a tiny minority of cells in a tumor can initiate and perpetuate cancer, is still debated. The paradigm of cancer-initiating stem cells has initially been developed with respect to blood cancers where chronic conditions such as myeloproliferative neoplasms are due to mutations acquired in a haematopoietic stem cell (HSC), which maintains the normal hierarchy to neoplastic haematopoiesis. In contrast, acute leukaemia transformation of such blood neoplasms appears to derive not only from HSCs but also from committed progenitors that cannot differentiate. This review will focus on putative novel therapy targets represented by markers described to define cancer stem/initiating cells in malignant gliomas, which have been called ‘leukaemia of the brain’, given their rapid migration and evolution. Parallels are drawn with other cancers, especially haematopoietic, given the similar rampant proliferation and treatment resistance of glioblastoma multiforme and secondary acute leukaemias. Genes associated with the malignant conditions and especially expressed in glioma cancer stem cells are intensively searched. Although many such molecules might only coincidentally be expressed in cancer-initiating cells, some may function in the oncogenic process, and those would be the prime candidates for diagnostic and targeted therapy. For the latter, combination therapies are likely to be envisaged, given the robust and plastic signalling networks supporting malignant proliferation. PMID:23998913

Liquid scanning transmission electron microscopy: imaging protein complexes in their native environment in whole eukaryotic cells.

PubMed

Peckys, Diana B; de Jonge, Niels

2014-04-01

Scanning transmission electron microscopy (STEM) of specimens in liquid, so-called Liquid STEM, is capable of imaging the individual subunits of macromolecular complexes in whole eukaryotic cells in liquid. This paper discusses this new microscopy modality within the context of state-of-the-art microscopy of cells. The principle of operation and equations for the resolution are described. The obtained images are different from those acquired with standard transmission electron microscopy showing the cellular ultrastructure. Instead, contrast is obtained on specific labels. Images can be recorded in two ways, either via STEM at 200 keV electron beam energy using a microfluidic chamber enclosing the cells, or via environmental scanning electron microscopy at 30 keV of cells in a wet environment. The first series of experiments involved the epidermal growth factor receptor labeled with gold nanoparticles. The labels were imaged in whole fixed cells with nanometer resolution. Since the cells can be kept alive in the microfluidic chamber, it is also feasible to detect the labels in unfixed, live cells. The rapid sample preparation and imaging allows studies of multiple whole cells.

Multipotent progenitor cells are present in human peripheral blood.

PubMed

Cesselli, Daniela; Beltrami, Antonio Paolo; Rigo, Silvia; Bergamin, Natascha; D'Aurizio, Federica; Verardo, Roberto; Piazza, Silvano; Klaric, Enio; Fanin, Renato; Toffoletto, Barbara; Marzinotto, Stefania; Mariuzzi, Laura; Finato, Nicoletta; Pandolfi, Maura; Leri, Annarosa; Schneider, Claudio; Beltrami, Carlo Alberto; Anversa, Piero

2009-05-22

To determine whether the peripheral blood in humans contains a population of multipotent progenitor cells (MPCs), products of leukapheresis were obtained from healthy donor volunteers following the administration of granulocyte colony-stimulating factor. Small clusters of adherent proliferating cells were collected, and these cells continued to divide up to 40 population doublings without reaching replicative senescence and growth arrest. MPCs were positive for the transcription factors Nanog, Oct3/4, Sox2, c-Myc, and Klf4 and expressed several antigens characteristic of mesenchymal stem cells. However, they were negative for markers of hematopoietic stem/progenitor cells and bone marrow cell lineages. MPCs had a cloning efficiency of approximately 3%, and following their expansion, retained a highly immature phenotype. Under permissive culture conditions, MPCs differentiated into neurons, glial cells, hepatocytes, cardiomyocytes, endothelial cells, and osteoblasts. Moreover, the gene expression profile of MPCs partially overlapped with that of neural and embryonic stem cells, further demonstrating their primitive, uncommitted phenotype. Following subcutaneous transplantation in nonimmunosuppressed mice, MPCs migrated to distant organs and integrated structurally and functionally within the new tissue, acquiring the identity of resident parenchymal cells. In conclusion, undifferentiated cells with properties of embryonic stem cells can be isolated and expanded from human peripheral blood after granulocyte colony-stimulating factor administration. This cell pool may constitute a unique source of autologous cells with critical clinical import.

Colorectal cancer: genetic abnormalities, tumor progression, tumor heterogeneity, clonal evolution and tumor-initiating cells.

PubMed

Testa, Ugo; Pelosi, Elvira; Castelli, Germana

2018-04-13

Colon cancer is the third most common cancer worldwide. Most colorectal cancer occurrences are sporadic, not related to genetic predisposition or family history; however, 20-30% of patients with colorectal cancer have a family history of colorectal cancer and 5% of these tumors arise in the setting of a Mendelian inheritance syndrome. In many patients, the development of a colorectal cancer is preceded by a benign neoplastic lesion: either an adenomatous polyp or a serrated polyp. Studies carried out in the last years have characterized the main molecular alterations occurring in colorectal cancers, showing that the tumor of each patient displays from two to eight driver mutations. The ensemble of molecular studies, including gene expression studies, has led to two proposed classifications of colorectal cancers, with the identification of four/five non-overlapping groups. The homeostasis of the rapidly renewing intestinal epithelium is ensured by few stem cells present at the level of the base of intestinal crypts. Various experimental evidence suggests that colorectal cancers may derive from the malignant transformation of intestinal stem cells or of intestinal cells that acquire stem cell properties following malignant transformation. Colon cancer stem cells seem to be involved in tumor chemoresistance, radioresistance and relapse.

Human blood and marrow side population stem cell and Stro-1 positive bone marrow stromal cell numbers decline with age, with an increase in quality of surviving stem cells: correlation with cytokines.

PubMed

Brusnahan, S K; McGuire, T R; Jackson, J D; Lane, J T; Garvin, K L; O'Kane, B J; Berger, A M; Tuljapurkar, S R; Kessinger, M A; Sharp, J G

2010-01-01

Hematological deficiencies increase with aging leading to anemias, reduced hematopoietic stress responses and myelodysplasias. This study tested the hypothesis that side population hematopoietic stem cells (SP-HSC) would decrease with aging, correlating with IGF-1 and IL-6 levels and increases in bone marrow fat. Marrow was obtained from the femoral head and trochanteric region of the femur at surgery for total hip replacement (N=100). Whole trabecular marrow samples were ground in a sterile mortar and pestle and cellularity and fat content determined. Marrow and blood mononuclear cells were stained with Hoechst dye and the SP-HSC profiles acquired. Marrow stromal cells (MSC) were enumerated flow cytometrically employing the Stro-1 antibody, and clonally in the colony forming unit fibroblast (CFU-F) assay. Plasma levels of IGF-1 (ng/ml) and IL-6 (pg/ml) were measured by ELISA. SP-HSC in blood and bone marrow decreased with age but the quality of the surviving stem cells increased. MSC decreased non-significantly. IGF-1 levels (mean=30.7, SEM=2) decreased and IL-6 levels (mean=4.4, SEM=1) increased with age as did marrow fat (mean=1.2mmfat/g, SEM=0.04). There were no significant correlations between cytokine levels or fat and SP-HSC numbers. Stem cells appear to be progressively lost with aging and only the highest quality stem cells survive. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Stem cell industry update: 2012 to 2016 reveals accelerated investment, but market capitalization and earnings lag.

PubMed

Ng, Mitchell; Song, Simon; Piuzzi, Nicolas S; Ng, Kenneth; Gwam, Chukwuweike; Mont, Michael A; Muschler, George F

2017-10-01

Treatments based on stem cells have long been heralded for their potential to drive the future of regenerative medicine and have inspired increasing medical and business interest. The stem cell therapy market has been expanding since 2012, but earnings and profitability still lag the broader health care sector (compounded annual growth rate in annual financing of 31.5% versus 13.4%, respectively). On the basis of historical financial data, approximately $23 billion has been invested in stem cell companies since 1994, with more than 80% of this raised from 2011 through 2016. This reflects a marked acceleration in capital investment, as companies began late-stage clinical trials, initiate partnerships or are acquired by large pharmaceutical companies. All of these data reflect a field that is emerging from infancy, which will demand more time and capital to mature. This update is relevant to researchers, clinicians and investors who wish to quantify the potential in this field. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Application of stem cells for cardiovascular grafts tissue engineering.

PubMed

Wu, Kaihong; Liu, Ying Long; Cui, Bin; Han, Zhongchao

2006-06-01

Congenital and acquired heart diseases are leading causes of morbidity and mortality world-wide. Currently, the synthetic materials or bioprosthetic replacement devices for cardiovascular surgery are imperfect and subject patients to one or more ongoing risks including thrombosis, limited durability and need for reoperations due to lack of growth in children and young adults. Suitable replacement grafts should have appropriate characteristics, including resistance to infection, low immunogenicity, good biocompatability and thromboresistance, with appropriate mechanical and physiological properties. Tissue engineering is a new scientific field aiming at fabrication of living, autologous grafts having structure or function properties that can be used to restore, maintain or improve tissue function. The use of autologous stem cells in cardiovascular tissue engineering is quite promising due to their capacity of self-renewal, high proliferation, and differentiation into specialized progeny. Progress has been made in engineering the various components of the cardiovascular system, including myocardial constructs, heart valves, and vascular patches or conduits with autologous stem cells. This paper will review the current achievements in stem cell-based cardiovascular grafts tissue engineering, with an emphasis on its clinical or possible clinical use in cardiovascular surgery.

Characterization of hepatic markers in human Wharton's Jelly-derived mesenchymal stem cells.

PubMed

Buyl, Karolien; De Kock, Joery; Najar, Mehdi; Lagneaux, Laurence; Branson, Steven; Rogiers, Vera; Vanhaecke, Tamara

2014-02-01

Stem cell technology could offer a unique tool to develop human-based in vitro liver models that are applicable for testing of potential liver toxicity early during drug development. In this context, recent research has indicated that human Wharton's Jelly-derived mesenchymal stem cells (hWJs) represent an interesting stem cell population to develop human hepatocyte-like cells. Here, an in-depth analysis of the expression of liver-specific transcription factors and other key hepatic markers in hWJs is evaluated at both the mRNA and protein level. Our results reveal that transcription factors that are mandatory to acquire and maintain an adult hepatic phenotype (HNF4A and HNF1A), as well as adult hepatic markers (ALB, CX32, CYP1A1, CYP1A2, CYP2B6 and CYP3A4) are not expressed in hWJs with the exception of K18. On the contrary, transcription factors involved in liver development (GATA4, GATA6, SOX9 and SOX17) and liver progenitor markers (DKK1, DPP4, DSG2, CX43 and K19) were found to be highly expressed in hWJs. These findings provide additional indication that hWJs could be a promising stem cell source to generate hepatocyte-like cells necessary for the development of a functional human-based in vitro liver model. Copyright © 2013 Elsevier Ltd. All rights reserved.

Epigenetic regulation of open chromatin in pluripotent stem cells

PubMed Central

Kobayashi, Hiroshi; Kikyo, Nobuaki

2014-01-01

The recent progress in pluripotent stem cell research has opened new avenues of disease modeling, drug screening, and transplantation of patient-specific tissues that had been unimaginable until a decade ago. The central mechanism underlying pluripotency is epigenetic gene regulation; the majority of cell signaling pathways, both extracellular and cytoplasmic, eventually alter the epigenetic status of their target genes during the process of activating or suppressing the genes to acquire or maintain pluripotency. It has long been thought that the chromatin of pluripotent stem cells is globally open to enable the timely activation of essentially all genes in the genome during differentiation into multiple lineages. The current article reviews descriptive observations and the epigenetic machinery relevant to what is supposed to be globally open chromatin in pluripotent stem cells. This includes microscopic appearance, permissive gene transcription, chromatin remodeling complexes, histone modifications, DNA methylation, noncoding RNAs, dynamic movement of chromatin proteins, nucleosome accessibility and positioning, and long-range chromosomal interactions. Detailed analyses of each element, however, have revealed that the globally open chromatin hypothesis is not necessarily supported by some of the critical experimental evidence, such as genome-wide nucleosome accessibility and nucleosome positioning. Further understanding of the epigenetic gene regulation is expected to determine the true nature of the so-called globally open chromatin in pluripotent stem. PMID:24695097

Bone Marrow Transplantation Results in Human Donor Blood Cells Acquiring and Displaying Mouse Recipient Class I MHC and CD45 Antigens on Their Surface

PubMed Central

Yamanaka, Nobuko; Wong, Christine J.; Gertsenstein, Marina; Casper, Robert F.; Nagy, Andras; Rogers, Ian M.

2009-01-01

Background Mouse models of human disease are invaluable for determining the differentiation ability and functional capacity of stem cells. The best example is bone marrow transplants for studies of hematopoietic stem cells. For organ studies, the interpretation of the data can be difficult as transdifferentiation, cell fusion or surface antigen transfer (trogocytosis) can be misinterpreted as differentiation. These events have not been investigated in hematopoietic stem cell transplant models. Methodology/Principal Findings In this study we investigated fusion and trogocytosis involving blood cells during bone marrow transplantation using a xenograft model. We report that using a standard SCID repopulating assay almost 100% of the human donor cells appear as hybrid blood cells containing both mouse and human surface antigens. Conclusion/Significance Hybrid cells are not the result of cell-cell fusion events but appear to be due to efficient surface antigen transfer, a process referred to as trogocytosis. Antigen transfer appears to be non-random and includes all donor cells regardless of sub-type. We also demonstrate that irradiation preconditioning enhances the frequency of hybrid cells and that trogocytosis is evident in non-blood cells in chimera mice. PMID:20046883

A Model of Cancer Stem Cells Derived from Mouse Induced Pluripotent Stem Cells

PubMed Central

Chen, Ling; Kasai, Tomonari; Li, Yueguang; Sugii, Yuh; Jin, Guoliang; Okada, Masashi; Vaidyanath, Arun; Mizutani, Akifumi; Satoh, Ayano; Kudoh, Takayuki; Hendrix, Mary J. C.; Salomon, David S.; Fu, Li; Seno, Masaharu

2012-01-01

Cancer stem cells (CSCs) are capable of continuous proliferation and self-renewal and are proposed to play significant roles in oncogenesis, tumor growth, metastasis and cancer recurrence. CSCs are considered derived from normal stem cells affected by the tumor microenvironment although the mechanism of development is not clear yet. In 2007, Yamanaka's group succeeded in generating Nanog mouse induced pluripotent stem (miPS) cells, in which green fluorescent protein (GFP) has been inserted into the 5′-untranslated region of the Nanog gene. Usually, iPS cells, just like embryonic stem cells, are considered to be induced into progenitor cells, which differentiate into various normal phenotypes depending on the normal niche. We hypothesized that CSCs could be derived from Nanog miPS cells in the conditioned culture medium of cancer cell lines, which is a mimic of carcinoma microenvironment. As a result, the Nanog miPS cells treated with the conditioned medium of mouse Lewis lung carcinoma acquired characteristics of CSCs, in that they formed spheroids expressing GFP in suspension culture, and had a high tumorigenicity in Balb/c nude mice exhibiting angiogenesis in vivo. In addition, these iPS-derived CSCs had a capacity of self-renewal and expressed the marker genes, Nanog, Rex1, Eras, Esg1 and Cripto, associated with stem cell properties and an undifferentiated state. Thus we concluded that a model of CSCs was originally developed from miPS cells and proposed the conditioned culture medium of cancer cell lines might perform as niche for producing CSCs. The model of CSCs and the procedure of their establishment will help study the genetic alterations and the secreted factors in the tumor microenvironment which convert miPS cells to CSCs. Furthermore, the identification of potentially bona fide markers of CSCs, which will help the development of novel anti-cancer therapies, might be possible though the CSC model. PMID:22511923

Tumor-Like Stem Cells Derived from Human Keloid Are Governed by the Inflammatory Niche Driven by IL-17/IL-6 Axis

PubMed Central

Zhang, Qunzhou; Yamaza, Takayoshi; Kelly, A. Paul; Shi, Shihong; Wang, Songlin; Brown, Jimmy; Wang, Lina; French, Samuel W.; Shi, Songtao; Le, Anh D.

2009-01-01

Background Alterations in the stem cell niche are likely to contribute to tumorigenesis; however, the concept of niche promoted benign tumor growth remains to be explored. Here we use keloid, an exuberant fibroproliferative dermal growth unique to human skin, as a model to characterize benign tumor-like stem cells and delineate the role of their “pathological” niche in the development of the benign tumor. Methods and Findings Subclonal assay, flow cytometric and multipotent differentiation analyses demonstrate that keloid contains a new population of stem cells, named keloid derived precursor cells (KPCs), which exhibit clonogenicity, self-renewal, distinct embryonic and mesenchymal stem cell surface markers, and multipotent differentiation. KPCs display elevated telomerase activity and an inherently upregulated proliferation capability as compared to their peripheral normal skin counterparts. A robust elevation of IL-6 and IL-17 expression in keloid is confirmed by cytokine array, western blot and ELISA analyses. The altered biological functions are tightly regulated by the inflammatory niche mediated by an autocrine/paracrine cytokine IL-17/IL-6 axis. Utilizing KPCs transplanted subcutaneously in immunocompromised mice we generate for the first time a human keloid-like tumor model that is driven by the in vivo inflammatory niche and allows testing of the anti-tumor therapeutic effect of antibodies targeting distinct niche components, specifically IL-6 and IL-17. Conclusions/Significance These findings support our hypothesis that the altered niche in keloids, predominantly inflammatory, contributes to the acquirement of a benign tumor-like stem cell phenotype of KPCs characterized by the uncontrolled self-renewal and increased proliferation, supporting the rationale for in vivo modification of the “pathological” stem cell niche as a novel therapy for keloid and other mesenchymal benign tumors. PMID:19907660

In vitro differentiation of human umbilical cord blood-derived mesenchymal stem cells into hepatocyte-like cells.

PubMed

Hong, Seung Hyun; Gang, Eun Ji; Jeong, Ju Ah; Ahn, Chiyoung; Hwang, Soo Han; Yang, Il Ho; Park, Hwon Kyum; Han, Hoon; Kim, Hoeon

2005-05-20

In addition to long-term self-renewal capability, human mesenchymal stem cells (MSCs) possess versatile differentiation potential ranging from mesenchyme-related multipotency to neuroectodermal and endodermal competency. Of particular concern is hepatogenic potential that can be used for liver-directed stem cell therapy and transplantation. In this study, we have investigated whether human umbilical cord blood (UCB)-derived MSCs are also able to differentiate into hepatocyte-like cells. MSCs isolated from UCB were cultured under the pro-hepatogenic condition similar to that for bone marrow (BM)-derived MSCs. Expression of a variety of hepatic lineage markers was analyzed by flow cytometry, RT-PCR, Western blot, and immunofluorescence. The functionality of differentiated cells was assessed by their ability to incorporate DiI-acetylated low-density lipoprotein (DiI-Ac-LDL). As the cells were morphologically transformed into hepatocyte-like cells, they expressed Thy-1, c-Kit, and Flt-3 at the cell surface, as well as albumin, alpha-fetoprotein, and cytokeratin-18 and 19 in the interior. Moreover, about a half of the cells were found to acquire the capability to transport DiI-Ac-LDL. Based on these observations, and taking into account immense advantages of UCB over other stem cell sources, we conclude that UCB-derived MSCs retain hepatogenic potential suitable for cell therapy and transplantation against intractable liver diseases.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doi, Nobutaka; New Products Research & Development, Gene Engineering Division, NIPPON GENE Co., Ltd.; Ogawa, Ryohei, E-mail: ogawa@med.u-toyama.ac.jp

The cancer cells residing in the hypoxic layer are resistant to radiation and these are ones responsible for cancer recurrence after radiation therapy. One of the reasons why hypoxic cancer cells acquire radioresistance may be attributable to changes in the gene expression profile by the activation of hypoxia inducible factors (HIFs). However, the details underlying this process remain unknown. In this study, we investigated the effects of knockdown of HIF subunit genes to elucidate how HIF subunit genes may be involved in the radioresistance acquired by HeLa cells following exposure to a hypoxia mimic. Interestingly, HIF-1α and HIF-2α seemed mutuallymore » complementary for each other when either of them was suppressed. We thus suppressed the expression of both genes simultaneously. To do this, we developed a short hairpin RNA (shRNA) targeting a high homology region between HIF-1α and HIF-2α. It was shown that the expression of the shRNA effectively suppressed the acquisition of radioresistance following the hypoxia mimic. Moreover, it was confirmed that suppression of both subunits resulted in the downregulation of stem cell markers and the suppression of spheroid formation during the hypoxia mimicking-conditions. This shRNA-mediated knockdown method targeting a common region shared by a family of genes may offer a new candidate cancer treatment. - Highlights: • Incubation with CoCl{sub 2} confers radioresistance to HeLa cells. • Both HIF-1α and HIF-2α are involved in the acquisition of radioresistance. • An shRNA to a homology region of HIF-1α and HIF-2α suppressed the radioresistance. • The shRNA decreased cells with stem cell markers and a stem cell phenotype.« less

Progressive Enrichment of Stemness Features and Tumor Stromal Alterations in Multistep Hepatocarcinogenesis.

PubMed

Yoo, Jeong Eun; Kim, Young-Joo; Rhee, Hyungjin; Kim, Haeryoung; Ahn, Ei Yong; Choi, Jin Sub; Roncalli, Massimo; Park, Young Nyun

2017-01-01

Cancer stem cells (CSCs), a subset of tumor cells, contribute to an aggressive biological behavior, which is also affected by the tumor stroma. Despite the role of CSCs and the tumor stroma in hepatocellular carcinoma (HCC), features of stemness have not yet been studied in relation to tumor stromal alterations in multistep hepatocarcinogenesis. We investigated the expression status of stemness markers and tumor stromal changes in B viral carcinogenesis, which is the main etiology of HCC in Asia. Stemness features of tumoral hepatocytes (EpCAM, K19, Oct3/4, c-KIT, c-MET, and CD133), and tumor stromal cells expressing α-smooth muscle actin (α-SMA), CD68, CD163, and IL-6 were analyzed in 36 low grade dysplastic nodules (DNs), 48 high grade DNs, 30 early HCCs (eHCCs), and 51 progressed HCCs (pHCCs) by immunohistochemistry or real-time PCR. Stemness features (EpCAM and K19 in particular) were progressively acquired during hepatocarcinogenesis in combination with enrichment of stromal cells (CAFs, TAMs, IL-6+ cells). Stemness features were seen sporadically in DNs, more consistent in eHCCs, and peaked in pHCCs. Likewise, stromal cells were discernable in DNs, showed up as consistent cell densities in eHCCs and peaked in pHCCs. The stemness features and tumor stromal alterations also peaked in less differentiated or larger HCCs. In conclusion, progression of B viral multistep hepatocarcinogenesis is characterized by an enrichment of stemness features of neoplastic hepatocytes and a parallel alteration of the tumor stroma. The modulation of neoplastic hepatocytes and stromal cells was at low levels in precancerous lesions (DNs), consistently increased in incipient cancer (eHCCs) and peaked in pHCCs. Thus, in B viral hepatocarcinogenesis, interactions between CSCs and the tumor stroma, although starting early, seem to play a major role in tumor progression.

MiRNA-20 and mirna-106a regulate spermatogonial stem cell renewal at the post-transcriptional level via targeting STAT3 and Ccnd1.

PubMed

He, Zuping; Jiang, Jiji; Kokkinaki, Maria; Tang, Lin; Zeng, Wenxian; Gallicano, Ian; Dobrinski, Ina; Dym, Martin

2013-10-01

Studies on spermatogonial stem cells (SSCs) are of unusual significance because they are the unique stem cells that transmit genetic information to subsequent generations and they can acquire pluripotency to become embryonic stem-like cells that have therapeutic applications in human diseases. MicroRNAs (miRNAs) have recently emerged as critical endogenous regulators in mammalian cells. However, the function and mechanisms of individual miRNAs in regulating SSC fate remain unknown. Here, we report for the first time that miRNA-20 and miRNA-106a are preferentially expressed in mouse SSCs. Functional assays in vitro and in vivo using miRNA mimics and inhibitors reveal that miRNA-20 and miRNA-106a are essential for renewal of SSCs. We further demonstrate that these two miRNAs promote renewal at the post-transcriptional level via targeting STAT3 and Ccnd1 and that knockdown of STAT3, Fos, and Ccnd1 results in renewal of SSCs. This study thus provides novel insights into molecular mechanisms regulating renewal and differentiation of SSCs and may have important implications for regulating male reproduction. © AlphaMed Press.

Yin and Yang of mesenchymal stem cells and aplastic anemia

PubMed Central

Broglie, Larisa; Margolis, David; Medin, Jeffrey A

2017-01-01

Acquired aplastic anemia (AA) is a bone marrow failure syndrome characterized by peripheral cytopenias and bone marrow hypoplasia. It is ultimately fatal without treatment, most commonly from infection or hemorrhage. Current treatments focus on suppressing immune-mediated destruction of bone marrow stem cells or replacing hematopoietic stem cells (HSCs) by transplantation. Our incomplete understanding of the pathogenesis of AA has limited development of targeted treatment options. Mesenchymal stem cells (MSCs) play a vital role in HSC proliferation; they also modulate immune responses and maintain an environment supportive of hematopoiesis. Some of the observed clinical manifestations of AA can be explained by mesenchymal dysfunction. MSC infusions have been shown to be safe and may offer new approaches for the treatment of this disorder. Indeed, infusions of MSCs may help suppress auto-reactive, T-cell mediated HSC destruction and help restore an environment that supports hematopoiesis. Small pilot studies using MSCs as monotherapy or as adjuncts to HSC transplantation have been attempted as treatments for AA. Here we review the current understanding of the pathogenesis of AA and the function of MSCs, and suggest that MSCs should be a target for further research and clinical trials in this disorder. PMID:29321823

Downregulation of 26S proteasome catalytic activity promotes epithelial-mesenchymal transition

PubMed Central

van Baarsel, Eric D.; Metz, Patrick J.; Fisch, Kathleen; Widjaja, Christella E.; Kim, Stephanie H.; Lopez, Justine; Chang, Aaron N.; Geurink, Paul P.; Florea, Bogdan I.; Overkleeft, Hermen S.; Ovaa, Huib; Bui, Jack D.; Yang, Jing; Chang, John T.

2016-01-01

The epithelial-mesenchymal transition (EMT) endows carcinoma cells with phenotypic plasticity that can facilitate the formation of cancer stem cells (CSCs) and contribute to the metastatic cascade. While there is substantial support for the role of EMT in driving cancer cell dissemination, less is known about the intracellular molecular mechanisms that govern formation of CSCs via EMT. Here we show that β2 and β5 proteasome subunit activity is downregulated during EMT in immortalized human mammary epithelial cells. Moreover, selective proteasome inhibition enabled mammary epithelial cells to acquire certain morphologic and functional characteristics reminiscent of cancer stem cells, including CD44 expression, self-renewal, and tumor formation. Transcriptomic analyses suggested that proteasome-inhibited cells share gene expression signatures with cells that have undergone EMT, in part, through modulation of the TGF-β signaling pathway. These findings suggest that selective downregulation of proteasome activity in mammary epithelial cells can initiate the EMT program and acquisition of a cancer stem cell-like phenotype. As proteasome inhibitors become increasingly used in cancer treatment, our findings highlight a potential risk of these therapeutic strategies and suggest a possible mechanism by which carcinoma cells may escape from proteasome inhibitor-based therapy. PMID:26930717

HIF-2α mediates a marked increase in migration and stemness characteristics in a subset of glioma cells under hypoxia by activating an Oct-4/Sox-2-Mena (INV) axis.

PubMed

Bhagat, Mohita; Palanichamy, Jayanth Kumar; Ramalingam, Pradeep; Mudassir, Madeeha; Irshad, Khushboo; Chosdol, Kunzang; Sarkar, Chitra; Seth, Pankaj; Goswami, Sumanta; Sinha, Subrata; Chattopadhyay, Parthaprasad

2016-05-01

Hypoxia is a salient feature of most solid tumors and plays a central role in tumor progression owing to its multiple contributions to therapeutic resistance, metastasis, angiogenesis and stemness properties. Reports exist in literature about hypoxia increasing stemness characteristics and invasiveness potential of malignant cells. In order to delineate molecular crosstalk among factors driving glioma progression, we used knockdown and overexpression strategies. We have demonstrated that U87MG and A172 glioma cells inherently have a subset of cells with high migratory potential due to migration-inducing Mena transcripts. These cells also have elevated stemness markers (Sox-2 and Oct-4). There was a significant increase of number in this subset of migratory cells on exposure to hypoxia with corresponding elevation (over 1000 fold) in migration-inducing Mena transcripts. We were able to demonstrate that a HIF-2α-Sox-2/Oct-4-Mena (INV) axis that is strongly activated in hypoxia and markedly increases the migratory potential of the cells. Such cells also formed tumor spheres with greater efficiency. We have correlated our in-vitro results with human glioblastoma samples and found that hypoxia, invasiveness and stemness markers correlated well in native tumor samples. This study identifies a novel signaling mechanism mediated by HIF-2α in regulating invasiveness and stemness characteristics, suggesting that under hypoxic conditions, some tumor cells acquire more migratory potential by increased Pan Mena and Mena INV expression as a consequence of this HIF-2α mediated increase in Oct-4 and Sox-2. These properties would help the cells to form a new nidus after local invasion or metastasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Therapy targets in glioblastoma and cancer stem cells: lessons from haematopoietic neoplasms.

PubMed

Cruceru, Maria Linda; Neagu, Monica; Demoulin, Jean-Baptiste; Constantinescu, Stefan N

2013-10-01

Despite intense efforts to identify cancer-initiating cells in malignant brain tumours, markers linked to the function of these cells have only very recently begun to be uncovered. The notion of cancer stem cell gained prominence, several molecules and signalling pathways becoming relevant for diagnosis and treatment. Whether a substantial fraction or only a tiny minority of cells in a tumor can initiate and perpetuate cancer, is still debated. The paradigm of cancer-initiating stem cells has initially been developed with respect to blood cancers where chronic conditions such as myeloproliferative neoplasms are due to mutations acquired in a haematopoietic stem cell (HSC), which maintains the normal hierarchy to neoplastic haematopoiesis. In contrast, acute leukaemia transformation of such blood neoplasms appears to derive not only from HSCs but also from committed progenitors that cannot differentiate. This review will focus on putative novel therapy targets represented by markers described to define cancer stem/initiating cells in malignant gliomas, which have been called 'leukaemia of the brain', given their rapid migration and evolution. Parallels are drawn with other cancers, especially haematopoietic, given the similar rampant proliferation and treatment resistance of glioblastoma multiforme and secondary acute leukaemias. Genes associated with the malignant conditions and especially expressed in glioma cancer stem cells are intensively searched. Although many such molecules might only coincidentally be expressed in cancer-initiating cells, some may function in the oncogenic process, and those would be the prime candidates for diagnostic and targeted therapy. For the latter, combination therapies are likely to be envisaged, given the robust and plastic signalling networks supporting malignant proliferation. © 2013 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Direct transdifferentiation of spermatogonial stem cells to morphological, phenotypic and functional hepatocyte-like cells via the ERK1/2 and Smad2/3 signaling pathways and the inactivation of cyclin A, cyclin B and cyclin E

PubMed Central

2013-01-01

Background Severe shortage of liver donors and hepatocytes highlights urgent requirement of extra-liver and stem cell source of hepatocytes for treating liver-related diseases. Here we hypothesized that spermatogonial stem cells (SSCs) can directly transdifferentiate to hepatic stem-like cells capable of differentiating into mature hepatocyte-like cells in vitro without an intervening pluripotent state. Results SSCs first changed into hepatic stem-like cells since they resembled hepatic oval cells in morphology and expressed Ck8, Ck18, Ck7, Ck19, OV6, and albumin. Importantly, they co-expressed CK8 and CK19 but not ES cell markers. Hepatic stem-like cells derived from SSCs could differentiate into small hepatocytes based upon their morphological features and expression of numerous hepatic cell markers but lacking of bile epithelial cell hallmarks. Small hepatocytes were further coaxed to differentiate into mature hepatocyte-like cells, as identified by their morphological traits and strong expression of Ck8, Ck18, Cyp7a1, Hnf3b, Alb, Tat, Ttr, albumin, and CYP1A2 but not Ck7 or CK19. Notably, these differentiated cells acquired functional attributes of hepatocyte-like cells because they secreted albumin, synthesized urea, and uptake and released indocyanine green. Moreover, phosphorylation of ERK1/2 and Smad2/3 rather than Akt was activated in hepatic stem cells and mature hepatocytes. Additionally, cyclin A, cyclin B and cyclin E transcripts and proteins but not cyclin D1 or CDK1 and CDK2 transcripts or proteins were reduced in mature hepatocyte-like cells or hepatic stem-like cells derived from SSCs compared to SSCs. Conclusions SSCs can transdifferentiate to hepatic stem-like cells capable of differentiating into cells with morphological, phenotypic and functional characteristics of mature hepatocytes via the activation of ERK1/2 and Smad2/3 signaling pathways and the inactivation of cyclin A, cyclin B and cyclin E. This study thus provides an invaluable source of mature hepatocytes for treating liver-related diseases and drug toxicity screening and offers novel insights into mechanisms of liver development and cell reprogramming. PMID:24047406

Derivation of therapeutic lung spheroid cells from minimally invasive transbronchial pulmonary biopsies.

PubMed

Dinh, Phuong-Uyen C; Cores, Jhon; Hensley, M Taylor; Vandergriff, Adam C; Tang, Junnan; Allen, Tyler A; Caranasos, Thomas G; Adler, Kenneth B; Lobo, Leonard J; Cheng, Ke

2017-06-30

Resident stem and progenitor cells have been identified in the lung over the last decade, but isolation and culture of these cells remains a challenge. Thus, although these lung stem and progenitor cells provide an ideal source for stem-cell based therapy, mesenchymal stem cells (MSCs) remain the most popular cell therapy product for the treatment of lung diseases. Surgical lung biopsies can be the tissue source but such procedures carry a high risk of mortality. In this study we demonstrate that therapeutic lung cells, termed "lung spheroid cells" (LSCs) can be generated from minimally invasive transbronchial lung biopsies using a three-dimensional culture technique. The cells were then characterized by flow cytometry and immunohistochemistry. Angiogenic potential was tested by in-vitro HUVEC tube formation assay. In-vivo bio- distribution of LSCs was examined in athymic nude mice after intravenous delivery. From one lung biopsy, we are able to derive >50 million LSC cells at Passage 2. These cells were characterized by flow cytometry and immunohistochemistry and were shown to represent a mixture of lung stem cells and supporting cells. When introduced systemically into nude mice, LSCs were retained primarily in the lungs for up to 21 days. Here, for the first time, we demonstrated that direct culture and expansion of human lung progenitor cells from pulmonary tissues, acquired through a minimally invasive biopsy, is possible and straightforward with a three-dimensional culture technique. These cells could be utilized in long-term expansion of lung progenitor cells and as part of the development of cell-based therapies for the treatment of lung diseases such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).

Reversine-treated fibroblasts acquire myogenic competence in vitro and in regenerating skeletal muscle.

PubMed

Anastasia, Luigi; Sampaolesi, Maurilio; Papini, Nadia; Oleari, Diego; Lamorte, Giuseppe; Tringali, Cristina; Monti, Eugenio; Galli, Daniela; Tettamanti, Guido; Cossu, Giulio; Venerando, Bruno

2006-12-01

Stem cells hold a great potential for the regeneration of damaged tissues in cardiovascular or musculoskeletal diseases. Unfortunately, problems such as limited availability, control of cell fate, and allograft rejection need to be addressed before therapeutic applications may become feasible. Generation of multipotent progenitors from adult differentiated cells could be a very attractive alternative to the limited in vitro self-renewal of several types of stem cells. In this direction, a recently synthesized unnatural purine, named reversine, has been proposed to induce reversion of adult cells to a multipotent state, which could be then converted into other cell types under appropriate stimuli. Our study suggests that reversine treatment transforms primary murine and human dermal fibroblasts into myogenic-competent cells both in vitro and in vivo. Moreover, this is the first study to demonstrate that plasticity changes arise in primary mouse and human cells following reversine exposure.

Rapid fusion between mesenchymal stem cells and cardiomyocytes yields electrically active, non-contractile hybrid cells.

PubMed

Shadrin, Ilya Y; Yoon, Woohyun; Li, Liqing; Shepherd, Neal; Bursac, Nenad

2015-07-10

Cardiac cell therapies involving bone marrow-derived human mesenchymal stem cells (hMSCs) have shown promising results, although their mechanisms of action are still poorly understood. Here, we investigated direct interactions between hMSCs and cardiomyocytes in vitro. Using a genetic Ca(2+) indicator gCaMP3 to efficiently label hMSCs in co-cultures with neonatal rat ventricular myocytes (NRVMs), we determined that 25-40% of hMSCs (from 4 independent donors) acquired periodic Ca(2+) transients and cardiac markers through spontaneous fusion with NRVMs. Sharp electrode and voltage-clamp recordings in fused cells showed action potential properties and Ca(2+) current amplitudes in between those of non-fused hMSCs and NRVMs. Time-lapse video-microscopy revealed the first direct evidence of active fusion between hMSCs and NRVMs within several hours of co-culture. Application of blebbistatin, nifedipine or verapamil caused complete and reversible inhibition of fusion, suggesting potential roles for actomyosin bridging and Ca(2+) channels in the fusion process. Immunostaining for Cx43, Ki67, and sarcomeric α-actinin showed that fused cells remain strongly coupled to surrounding NRVMs, but downregulate sarcomeric structures over time, acquiring a non-proliferative and non-contractile phenotype. Overall, these results describe the phenotype and mechanisms of hybrid cell formation via fusion of hMSCs and cardiomyocytes with potential implications for cardiac cell therapy.

Treatment Analysis in a Cancer Stem Cell Context Using a Tumor Growth Model Based on Cellular Automata.

PubMed

Monteagudo, Ángel; Santos, José

2015-01-01

Cancer can be viewed as an emergent behavior in terms of complex system theory and artificial life, Cellular Automata (CA) being the tool most used for studying and characterizing the emergent behavior. Different approaches with CA models were used to model cancer growth. The use of the abstract model of acquired cancer hallmarks permits the direct modeling at cellular level, where a cellular automaton defines the mitotic and apoptotic behavior of cells, and allows for an analysis of different dynamics of the cellular system depending on the presence of the different hallmarks. A CA model based on the presence of hallmarks in the cells, which includes a simulation of the behavior of Cancer Stem Cells (CSC) and their implications for the resultant growth behavior of the multicellular system, was employed. This modeling of cancer growth, in the avascular phase, was employed to analyze the effect of cancer treatments in a cancer stem cell context. The model clearly explains why, after treatment against non-stem cancer cells, the regrowth capability of CSCs generates a faster regrowth of tumor behavior, and also shows that a continuous low-intensity treatment does not favor CSC proliferation and differentiation, thereby allowing an unproblematic control of future tumor regrowth. The analysis performed indicates that, contrary to the current attempts at CSC control, trying to make CSC proliferation more difficult is an important point to consider, especially in the immediate period after a standard treatment for controlling non-stem cancer cell proliferation.

Changes in human bone marrow fat content associated with changes in hematopoietic stem cell numbers and cytokine levels with aging

PubMed Central

Tuljapurkar, Sonal R; McGuire, Timothy R; Brusnahan, Susan K; Jackson, John D; Garvin, Kevin L; Kessinger, Margaret A; Lane, Judy T; O' Kane, Barbara J; Sharp, John G

2011-01-01

Hematological deficiencies increase with aging, including anemias, reduced responses to hematopoietic stress and myelodysplasias. This investigation tested the hypothesis that increased bone marrow (BM) fat content in humans with age was associated with decreased numbers of side population (SP) hematopoietic stem cells, and this decrease correlated with changes in cytokine levels. BM was obtained from the femoral head and trochanteric region of the femur removed at surgery for total hip replacement (N = 100 subjects). In addition, BM from cadavers (N = 36), with no evidence of hip disease, was evaluated for fat content. Whole trabecular marrow samples were ground in a sterile mortar and pestle, and cellularity and lipid content determined. Marrow cells were stained with Hoechst dye and SP profiles were acquired. Plasma levels of insulin-like growth factor (IGF)-1, stromal-derived factor (SDF)-1 and interleukin (IL)-6 were measured using ELISA. Fat content in the BM of human subjects and cadavers increased with age. The numbers of SP stem cells in BM as well as plasma IGF-1 and SDF-1 levels decreased in correlation with increased BM fat. IL-6 had no relationship to changes in marrow fat. These data suggest that increased BM fat may be associated with a decreased number of SP stem cells and IGF-1 and SDF-1 levels with aging. These data further raise a more general question as to the role of adipose cells in the regulation of tissue stem cells. PMID:21923862

Stem Cell Niche is Partially Lost during Follicular Plucking: A Preliminary Pilot Study

PubMed Central

Kumar, Anil; Gupta, Somesh; Mohanty, Sujata; Bhargava, Balram; Airan, Balram

2013-01-01

Background: Clinical hair transplant studies have revealed that follicular unit extraction (FUE) is superior in terms of stable hair growth in comparison to follicular plucking (FP). Various reasons have been cited for this clinical outcome. FUE and FP are employed to obtain the hair follicle units for hair transplant and recently for cell based therapies in vitiligo. However, there is no scientific data available on the comparison of stem cell fraction in the cell suspension obtained by FUE and FP. Therefore, we undertook this study to compare the percentage of stem cells in the hair follicle obtained by FUE and FP. Objective: The purpose of the following study is to evaluate the quantitative stem cell pool in the hair follicle obtained by FUE and FP. Materials and Methods: A total of 3 human subjects were enrolled with age groups of 17-25 years. Both methods of tissue harvest: FUE and FP; were employed on each subject. There was no vitiligo lesion on the scalp in any of the patients. Hair follicles were incubated with trypsin-EDTA solution at 37°C for 90 min to separate outer root sheath cells. The cell suspension was passed through a 70 μm cell strainer; filtrate was centrifuged to obtain the cell pellet. Cells were labeled with cluster of differentiation (CD200) antibody and acquired with flowcytometry. Results: The mean percentage of CD200 positive cells in FUE and FP method come out to be 8.43 and 1.63 respectively (P = 0.0152). Conclusion: FUE is a better method of the hair follicle harvesting for cell based applications as the stem cell fraction is significantly higher in comparison to FP. PMID:24403776

Subsequent vitiligo after hematopoietic stem cell transplantation: A nationwide population-based cohort study from Korea.

PubMed

Bae, Jung Min; Choi, Kwang Hyun; Jung, Han Mi; Kim, Sook Young; Kim, Miri; Kim, Gyung Moon; Yu, Dong Soo; Lee, Young Bok

2017-03-01

Subsequent vitiligo after hematopoietic stem cell transplantation (HSCT) has been described sporadically in case series. To investigate the incidence and risk factors of subsequent vitiligo after HSCT. A nationwide, population-based cohort study was performed using the Korean National Health Insurance Claims Database from 2009 to 2013. All HSCT recipients who had undergone HSCT between 2010 and 2011 and not treatment for vitiligo in 2009 (to exclude preexisting active vitiligo) were included in the HSCT recipient group, and an age- and sex-matched control group without HSCT was also established. A total of 2747 HSCT recipients and 8241 controls were enrolled. Newly acquired vitiligo occurred in 1.06% of HSCT recipients between 2010 and 2013, and there was a significant increase (OR 3.130, 95% CI 1.859-5.271) in cases of vitiligo in HSCT recipients compared with controls (0.34%). Allogeneic HSCT (OR 5.593, 95% CI 1.628-19.213) and bone marrow-sourced stem cells (as compared with peripheral blood-sourced stem cells; OR 2.492, 95% CI 1.114-5.576) were independently associated with the development of vitiligo after HSCT. Medical record review was not available. Vitiligo developed at a significantly increased rate after HSCT compared with controls. Allogeneic HSCT and bone marrow-sourced stem cells were independent risk factors. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Infusion of cytotoxic T lymphocytes for the treatment of viral infections in hematopoetic stem cell transplant patients.

PubMed

Baugh, Katherine A; Tzannou, Ifigeneia; Leen, Ann M

2018-05-09

Allogeneic hematopoietic stem cell transplantation has proven curative for a range of malignant and nonmalignant disorders. However, the clinical success of this therapy is marred by the morbidity associated with viral infections, which are frequent (cytomegalovirus 15.6-28%, adenovirus 3-21%, BK virus 18.5-20.7%) post-transplant. These infections occur as a consequence of transplant conditioning regimens designed to eliminate not only malignant cells but also host immune cells that might interfere with stem cell engraftment. The result is a transient period of immune compromise when hematopoietic stem cell transplant recipients are at risk of infectious complications associated with both latent (cytomegalovirus, Epstein-Barr virus, BK virus, human herpes virus 6, herpes simplex virus, varicella-zoster virus) and community-acquired viruses including adenovirus, respiratory syncytial virus, and parainfluenza virus. Current standard of care for many of these infections involves pharmacologic agents, which are often ineffective and associated with side effects including nephrotoxicity and hepatotoxicity. Ultimately, because these agents do not address the underlying immune compromise, viral rebound often occurs. Thus, a number of groups have explored the clinical potential of adoptively transferred virus-specific T cells (VSTs) as an approach to prevent/treat virus-associated complications. The current review will highlight recent publications showcasing VST manufacturing technologies and clinical experience with such cells.

Mutations in the estrogen receptor alpha hormone binding domain promote stem cell phenotype through notch activation in breast cancer cell lines.

PubMed

Gelsomino, L; Panza, S; Giordano, C; Barone, I; Gu, G; Spina, E; Catalano, S; Fuqua, S; Andò, S

2018-04-24

The detection of recurrent mutations affecting the hormone binding domain (HBD) of estrogen receptor alpha (ERα/ESR1) in endocrine therapy-resistant and metastatic breast cancers has prompted interest in functional characterization of these genetic alterations. Here, we explored the role of HBD-ESR1 mutations in influencing the behavior of breast cancer stem cells (BCSCs), using various BC cell lines stably expressing wild-type or mutant (Y537 N, Y537S, D538G) ERα. Compared to WT-ERα clones, mutant cells showed increased CD44 + /CD24 - ratio, mRNA levels of stemness genes, Mammosphere Forming Efficiency (MFE), Self-Renewal and migratory capabilities. Mutant clones exhibited high expression of NOTCH receptors/ligands/target genes and blockade of NOTCH signaling reduced MFE and migratory potential. Mutant BCSC activity was dependent on ERα phosphorylation at serine 118, since its inhibition decreased MFE and NOTCH4 activation only in mutant cells. Collectively, we demonstrate that the expression of HBD-ESR1 mutations may drive BC cells to acquire stem cell traits through ER/NOTCH4 interplay. We propose the early detection of HBD-ESR1 mutations as a challenge in precision medicine strategy, suggesting the development of tailored-approaches (i.e. NOTCH inhibitors) to prevent disease development and metastatic spread in BC mutant-positive patients. Copyright © 2018 Elsevier B.V. All rights reserved.

Reprogramming to developmental plasticity in cancer stem cells.

PubMed

O'Brien-Ball, Caitlin; Biddle, Adrian

2017-10-15

During development and throughout adult life, sub-populations of cells exist that exhibit phenotypic plasticity - the ability to differentiate into multiple lineages. This behaviour is important in embryogenesis, is exhibited in a more limited context by adult stem cells, and can be re-activated in cancer cells to drive important processes underlying tumour progression. A well-studied mechanism of phenotypic plasticity is the epithelial-to-mesenchymal transition (EMT), a process which has been observed in both normal and cancerous cells. The epigenetic and metabolic modifications necessary to facilitate phenotypic plasticity are first seen in development and can be re-activated both in normal regeneration and in cancer. In cancer, the re-activation of these mechanisms enables tumour cells to acquire a cancer stem cell (CSC) phenotype with enhanced ability to survive in hostile environments, resist therapeutic interventions, and undergo metastasis. However, recent research has suggested that plasticity may also expose weaknesses in cancer cells that could be exploited for future therapeutic development. More research is needed to identify developmental mechanisms that are active in cancer, so that these may be targeted to reduce tumour growth and metastasis and overcome therapeutic resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

Insulin-independent role of adiponectin receptor signaling in Drosophila germline stem cell maintenance.

PubMed

Laws, Kaitlin M; Sampson, Leesa L; Drummond-Barbosa, Daniela

2015-03-15

Adipocytes have key endocrine roles, mediated in large part by secreted protein hormones termed adipokines. The adipokine adiponectin is well known for its role in sensitizing peripheral tissues to insulin, and several lines of evidence suggest that adiponectin might also modulate stem cells/precursors. It remains unclear, however, how adiponectin signaling controls stem cells and whether this role is secondary to its insulin-sensitizing effects or distinct. Drosophila adipocytes also function as an endocrine organ and, although no obvious adiponectin homolog has been identified, Drosophila AdipoR encodes a well-conserved homolog of mammalian adiponectin receptors. Here, we generate a null AdipoR allele and use clonal analysis to demonstrate an intrinsic requirement for AdipoR in germline stem cell (GSC) maintenance in the Drosophila ovary. AdipoR null GSCs are not fully responsive to bone morphogenetic protein ligands from the niche and have a slight reduction in E-cadherin levels at the GSC-niche junction. Conversely, germline-specific overexpression of AdipoR inhibits natural GSC loss, suggesting that reduction in adiponectin signaling might contribute to the normal decline in GSC numbers observed over time in wild-type females. Surprisingly, AdipoR is not required for insulin sensitization of the germline, leading us to speculate that insulin sensitization is a more recently acquired function than stem cell regulation in the evolutionary history of adiponectin signaling. Our findings establish Drosophila female GSCs as a new system for future studies addressing the molecular mechanisms whereby adiponectin receptor signaling modulates stem cell fate. Copyright © 2015 Elsevier Inc. All rights reserved.

Generation of an expandable intermediate mesoderm restricted progenitor cell line from human pluripotent stem cells

PubMed Central

Kumar, Nathan; Richter, Jenna; Cutts, Josh; Bush, Kevin T; Trujillo, Cleber; Nigam, Sanjay K; Gaasterland, Terry; Brafman, David; Willert, Karl

2015-01-01

The field of tissue engineering entered a new era with the development of human pluripotent stem cells (hPSCs), which are capable of unlimited expansion whilst retaining the potential to differentiate into all mature cell populations. However, these cells harbor significant risks, including tumor formation upon transplantation. One way to mitigate this risk is to develop expandable progenitor cell populations with restricted differentiation potential. Here, we used a cellular microarray technology to identify a defined and optimized culture condition that supports the derivation and propagation of a cell population with mesodermal properties. This cell population, referred to as intermediate mesodermal progenitor (IMP) cells, is capable of unlimited expansion, lacks tumor formation potential, and, upon appropriate stimulation, readily acquires properties of a sub-population of kidney cells. Interestingly, IMP cells fail to differentiate into other mesodermally-derived tissues, including blood and heart, suggesting that these cells are restricted to an intermediate mesodermal fate. DOI: http://dx.doi.org/10.7554/eLife.08413.001 PMID:26554899

Enabling Interactive Measurements from Large Coverage Microscopy

PubMed Central

Bajcsy, Peter; Vandecreme, Antoine; Amelot, Julien; Chalfoun, Joe; Majurski, Michael; Brady, Mary

2017-01-01

Microscopy could be an important tool for characterizing stem cell products if quantitative measurements could be collected over multiple spatial and temporal scales. With the cells changing states over time and being several orders of magnitude smaller than cell products, modern microscopes are already capable of imaging large spatial areas, repeat imaging over time, and acquiring images over several spectra. However, characterizing stem cell products from such large image collections is challenging because of data size, required computations, and lack of interactive quantitative measurements needed to determine release criteria. We present a measurement web system consisting of available algorithms, extensions to a client-server framework using Deep Zoom, and the configuration know-how to provide the information needed for inspecting the quality of a cell product. The cell and other data sets are accessible via the prototype web-based system at http://isg.nist.gov/deepzoomweb. PMID:28663600

Pancreatic differentiation of Pdx1-GFP reporter mouse induced pluripotent stem cells.

PubMed

Porciuncula, Angelo; Kumar, Anujith; Rodriguez, Saray; Atari, Maher; Araña, Miriam; Martin, Franz; Soria, Bernat; Prosper, Felipe; Verfaillie, Catherine; Barajas, Miguel

2016-12-01

Efficient induction of defined lineages in pluripotent stem cells constitutes the determinant step for the generation of therapeutically relevant replacement cells to potentially treat a wide range of diseases, including diabetes. Pancreatic differentiation has remained an important challenge in large part because of the need to differentiate uncommitted pluripotent stem cells into highly specialized hormone-secreting cells, which has been shown to require a developmentally informed step-by-step induction procedure. Here, in the framework of using induced pluripotent stem cells (iPSCs) to generate pancreatic cells for pancreatic diseases, we have generated and characterized iPSCs from Pdx1-GFP transgenic mice. The use of a GFP reporter knocked into the endogenous Pdx1 promoter allowed us to monitor pancreatic induction based on the expression of Pdx1, a pancreatic master transcription factor, and to isolate a pure Pdx1-GFP + population for downstream applications. Differentiated cultures timely expressed markers specific to each stage and end-stage progenies acquired a rather immature beta-cell phenotype, characterized by polyhormonal expression even among cells highly expressing the Pdx1-GFP reporter. Our findings highlight the utility of employing a fluorescent protein reporter under the control of a master developmental gene in order to devise novel differentiation protocols for relevant cell types for degenerative diseases such as pancreatic beta cells for diabetes. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Biodistribution of Liver-Derived Mesenchymal Stem Cells After Peripheral Injection in a Hemophilia A Patient.

PubMed

Sokal, Etienne M; Lombard, Catherine Anne; Roelants, Véronique; Najimi, Mustapha; Varma, Sharat; Sargiacomo, Camillo; Ravau, Joachim; Mazza, Giuseppe; Jamar, François; Versavau, Julia; Jacobs, Vanessa; Jacquemin, Marc; Eeckhoudt, Stéphane; Lambert, Catherine; Stéphenne, Xavier; Smets, Françoise; Hermans, Cédric

2017-08-01

With the exception of liver transplantation, there is no cure for hemophilia, which is currently managed by preemptive replacement therapy. Liver-derived stem cells are in clinical development for inborn and acquired liver diseases and could represent a curative treatment for hemophilia A. The liver is a major factor VIII (FVIII) synthesis site, and mesenchymal stem cells have been shown to control joint bleeding in animal models of hemophilia. Adult-derived human liver stem cells (ADHLSCs) have mesenchymal characteristics and have been shown able to engraft in and repopulate both animal and human livers. Thus, the objectives were to evaluate the potency of ADHLSCs to control bleeding in a hemophilia A patient and assess the biodistribution of the cells after intravenous injection. A patient suffering from hemophilia A was injected with repeated doses of ADHLSCs via a peripheral vein (35 million In-oxine-labeled cells, followed by 125 million cells the next day, and 3 infusions of 250 million cells every 2 weeks thereafter; total infusion period, 50 days). After cell therapy, we found a temporary (15 weeks) decrease in the patient's FVIII requirements and severe bleeding complications, despite a lack of increase in circulating FVIII. The cells were safely administered to the patient via a peripheral vein. Biodistribution analysis revealed an initial temporary entrapment of the cells in the lungs, followed by homing to the liver and to a joint afflicted with hemarthrosis. These results suggest the potential use of ADHLSCs in the treatment of hemophilia A.

Coregistration of Magnetic Resonance and Single Photon Emission Computed Tomography Images for Noninvasive Localization of Stem Cells Grafted in the Infarcted Rat Myocardium

PubMed Central

Shen, Dinggang; Liu, Dengfeng; Cao, Zixiong; Acton, Paul D.; Zhou, Rong

2008-01-01

This paper demonstrates the application of mutual information based coregistration of radionuclide and magnetic resonance imaging (MRI) in an effort to use multimodality imaging for noninvasive localization of stem cells grafted in the infarcted myocardium in rats. Radionuclide imaging such as single photon emission computed tomography (SPECT) or positron emission tomography (PET) inherently has high sensitivity and is suitable for tracking of labeled stem cells, while high-resolution MRI is able to provide detailed anatomical and functional information of myocardium. Thus, coregistration of PET or SPECT images with MRI will map the location and distribution of stem cells on detailed myocardium structures. To validate this coregistration method, SPECT data were simulated by using a Monte Carlo-based projector that modeled the pinhole-imaging physics assuming nonzero diameter and photon penetration at the edge. Translational and rotational errors of the coregistration were examined with respect to various SPECT activities, and they are on average about 0.50 mm and 0.82°, respectively. Only the rotational error is dependent on activity of SPECT data. Stem cells were labeled with 111 Indium oxyquinoline and grafted in the ischemic myocardium of a rat model. Dual-tracer small-animal SPECT images were acquired, which allowed simultaneous detection of 111In-labeled stem cells and of [99mTc]sestamibi to assess myocardial perfusion deficit. The same animals were subjected to cardiac MRI. A mutual-information-based coregistration method was then applied to the SPECT and MRIs. By coregistration, the 111 In signal from labeled cells was mapped into the akinetic region identified on cine MRIs; the regional perfusion deficit on the SPECT images also coincided with the akinetic region on the MR image. PMID:17053860

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Chen; Paudel, Naba R.; Yan, Yanfa

Atom probe tomography (APT) data acquired from a CAMECA LEAP 4000 XHR for the CdS/CdTe interface for a non-CdCl 2 treated CdTe solar cell as well as the mass spectrum of an APT data set including a GB in a CdCl 2-treated CdTe solar cell are presented. Scanning electron microscopy (SEM) data showing the evolution of sample preparation for APT and scanning transmission electron microscopy (STEM) electron beam induced current (EBIC) are also presented. As a result, these data show mass spectrometry peak decomposition of Cu and Te within an APT dataset, the CdS/CdTe interface of an untreated CdTe solarmore » cell, preparation of APT needles from the CdS/CdTe interface in superstrate grown CdTe solar cells, and the preparation of a cross-sectional STEM EBIC sample.« less

APT mass spectrometry and SEM data for CdTe solar cells

DOE PAGES

Li, Chen; Paudel, Naba R.; Yan, Yanfa; ...

2016-03-16

Atom probe tomography (APT) data acquired from a CAMECA LEAP 4000 XHR for the CdS/CdTe interface for a non-CdCl 2 treated CdTe solar cell as well as the mass spectrum of an APT data set including a GB in a CdCl 2-treated CdTe solar cell are presented. Scanning electron microscopy (SEM) data showing the evolution of sample preparation for APT and scanning transmission electron microscopy (STEM) electron beam induced current (EBIC) are also presented. As a result, these data show mass spectrometry peak decomposition of Cu and Te within an APT dataset, the CdS/CdTe interface of an untreated CdTe solarmore » cell, preparation of APT needles from the CdS/CdTe interface in superstrate grown CdTe solar cells, and the preparation of a cross-sectional STEM EBIC sample.« less

5-Fluorouracil may enrich cancer stem cells in canine mammary tumor cells in vitro.

PubMed

Zhou, Bin; Jin, Yipeng; Zhang, Di; Lin, Degui

2018-05-01

Mammary gland carcinomas are the most common neoplasms in women and unsterilized female dogs. Owing to the existence of cancer stem cells (CSCs), chemotherapy is not able to cure these types of diseases completely. A number of studies have demonstrated that CSCs are resistant to chemotherapeutic drugs, but whether canine mammary tumor cells that have acquired resistance to 5-fluorouracil (5-FU) exhibited properties of CSCs remains unknown. The aim of the present study was to investigate whether 5-fluorouracil-resistant canine mammary tumor cells exhibited properties of CSCs. CSCs were analyzed using western blot assays, ultra-low attachment sphere cultures, flow cytometry and migration (wound healing and Transwell) assays. The results indicated that, compared with parental cells, proteins associated with the Wnt/β-catenin signaling pathway and aldehyde dehydrogenase 1 were overexpressed, the number and size of spheres in the 5-FU-resistant cells were increased, the ratio of CD44 + /CD24 -/low cells was increased and the migratory ability was improved in vitro compared with the 5-FU-susceptible cells. In conclusion, stimulation with chemotherapeutic drugs including 5-FU is a good method for increasing the proportion of canine mammary tumor stem cells in vitro , which may provide further understanding of chemotherapeutic methods and CSCs.

Derivation and characterization of hepatic progenitor cells from human embryonic stem cells.

PubMed

Zhao, Dongxin; Chen, Song; Cai, Jun; Guo, Yushan; Song, Zhihua; Che, Jie; Liu, Chun; Wu, Chen; Ding, Mingxiao; Deng, Hongkui

2009-07-31

The derivation of hepatic progenitor cells from human embryonic stem (hES) cells is of value both in the study of early human liver organogenesis and in the creation of an unlimited source of donor cells for hepatocyte transplantation therapy. Here, we report for the first time the generation of hepatic progenitor cells derived from hES cells. Hepatic endoderm cells were generated by activating FGF and BMP pathways and were then purified by fluorescence activated cell sorting using a newly identified surface marker, N-cadherin. After co-culture with STO feeder cells, these purified hepatic endoderm cells yielded hepatic progenitor colonies, which possessed the proliferation potential to be cultured for an extended period of more than 100 days. With extensive expansion, they co-expressed the hepatic marker AFP and the biliary lineage marker KRT7 and maintained bipotential differentiation capacity. They were able to differentiate into hepatocyte-like cells, which expressed ALB and AAT, and into cholangiocyte-like cells, which formed duct-like cyst structures, expressed KRT19 and KRT7, and acquired epithelial polarity. In conclusion, this is the first report of the generation of proliferative and bipotential hepatic progenitor cells from hES cells. These hES cell-derived hepatic progenitor cells could be effectively used as an in vitro model for studying the mechanisms of hepatic stem/progenitor cell origin, self-renewal and differentiation.

The transcriptional landscape of hematopoietic stem cell ontogeny

PubMed Central

McKinney-Freeman, Shannon; Cahan, Patrick; Li, Hu; Lacadie, Scott A.; Huang, Hsuan-Ting; Curran, Matthew; Loewer, Sabine; Naveiras, Olaia; Kathrein, Katie L.; Konantz, Martina; Langdon, Erin M.; Lengerke, Claudia; Zon, Leonard I.; Collins, James J.; Daley, George Q.

2012-01-01

Transcriptome analysis of adult hematopoietic stem cells (HSC) and their progeny has revealed mechanisms of blood differentiation and leukemogenesis, but a similar analysis of HSC development is lacking. Here, we acquired the transcriptomes of developing HSC purified from >2500 murine embryos and adult mice. We found that embryonic hematopoietic elements clustered into three distinct transcriptional states characteristic of the definitive yolk sac, HSCs undergoing specification, and definitive HSCs. We applied a network biology-based analysis to reconstruct the gene regulatory networks of sequential stages of HSC development and functionally validated candidate transcriptional regulators of HSC ontogeny by morpholino-mediated knock-down in zebrafish embryos. Moreover, we found that HSCs from in vitro differentiated embryonic stem cells closely resemble definitive HSC, yet lack a Notch-signaling signature, likely accounting for their defective lymphopoiesis. Our analysis and web resource (http://hsc.hms.harvard.edu) will enhance efforts to identify regulators of HSC ontogeny and facilitate the engineering of hematopoietic specification. PMID:23122293

In vitro study of stem cell communication via gap junctions for fibrocartilage regeneration at entheses.

PubMed

Nayak, Bibhukalyan Prasad; Goh, James Cho Hong; Toh, Siew Lok; Satpathy, Gyan Ranjan

2010-03-01

Entheses are fibrocartilaginous organs that bridge ligament with bone at their interface and add significant insertional strength. To replace a severely damaged ligament, a tissue-engineered graft preinstalled with interfacial fibrocartilage, which is being regenerated from stem cells, appears to be more promising than ligament-alone graft. Such a concept can be realized by a biomimetic approach of establishing a dynamic communication of stem cells with bone cells and/or ligament fibroblasts in vitro. The current study has two objectives. The first objective is to demonstrate functional coculture of bone marrow-derived stem cells (BMSCs) with mature bone cells/ligament fibroblasts as evidenced by gap-junctional communication in vitro. The second objective is to investigate the role of BMSCs in the regeneration of fibrocartilage within the coculture. Rabbit bone/ligament fibroblasts were dual-stained with DiI-Red and calcein (gap-junction permeable dye), and cocultured with unlabeled BMSCs at fixed ratio (1:10). The functional gap junction was demonstrated by the transfer of calcein from donor to recipient cells that was confirmed and quantified by flow cytometry. Type 2 collagen (cartilage extracellular matrix-specific protein) expressed by the mixed cell lines in the cocultures were estimated by real-time reverse transcription PCR and compared with that of the ligament-bone coculture (control). Significant transfer of calcein into BMSCs was observed and flow cytometry analyses showed a gradual increase in the percentage of BMSCs acquiring calcein with time. Cocultures that included BMSCs expressed significantly more type 2 collagen compared with the control. The current study, for the first time, reported the expression of gap-junctional communication of BMSCs with two adherent cell lines of musculoskeletal system in vitro and also confirmed that incorporation of stem cells augments fibrocartilage regeneration. The results open up a path to envisage a composite graft preinstalled with enthesial fibrocartilage using a stem cell-based coculture system.

Human pluripotent stem cells recurrently acquire and expand dominant negative P53 mutations

PubMed Central

Kamitaki, Nolan; Mitchell, Jana; Avior, Yishai; Mello, Curtis; Kashin, Seva; Mekhoubad, Shila; Ilic, Dusko; Charlton, Maura; Saphier, Genevieve; Handsaker, Robert E.; Genovese, Giulio; Bar, Shiran; Benvenisty, Nissim; McCarroll, Steven A.; Eggan, Kevin

2017-01-01

Human pluripotent stem cells (hPSCs) can self-renew indefinitely, making them an attractive source for regenerative therapies. This expansion potential has been linked with acquisition of large copy number variants (CNVs) that provide mutant cells with a growth advantage in culture1–3. However, the nature, extent, and functional impact of other acquired genome sequence mutations in cultured hPSCs is not known. Here, we sequenced the protein-coding genes (exomes) of 140 independent human embryonic stem cell (hESC) lines, including 26 lines prepared for potential clinical use4. We then applied computational strategies for identifying mutations present in a subset of cells5. Though such mosaic mutations were generally rare, we identified five unrelated hESC lines that carried six mutations in the TP53 gene that encodes the tumor suppressor P53. Notably, the TP53 mutations we observed are dominant negative and are the mutations most commonly seen in human cancers. We used droplet digital PCR to demonstrate that the TP53 mutant allelic fraction increased with passage number under standard culture conditions, suggesting that P53 mutation confers selective advantage. When we then mined published RNA sequencing data from 117 hPSC lines, we observed another nine TP53 mutations, all resulting in coding changes in the DNA binding domain of P53. Strikingly, in three lines, the allelic fraction exceeded 50%, suggesting additional selective advantage resulting from loss of heterozygosity at the TP53 locus. As the acquisition and favored expansion of cancer-associated mutations in hPSCs may go unnoticed during most applications, we suggest that careful genetic characterization of hPSCs and their differentiated derivatives should be carried out prior to clinical use. PMID:28445466

Changes in human bone marrow fat content associated with changes in hematopoietic stem cell numbers and cytokine levels with aging.

PubMed

Tuljapurkar, Sonal R; McGuire, Timothy R; Brusnahan, Susan K; Jackson, John D; Garvin, Kevin L; Kessinger, Margaret A; Lane, Judy T; O' Kane, Barbara J; Sharp, John G

2011-11-01

Hematological deficiencies increase with aging, including anemias, reduced responses to hematopoietic stress and myelodysplasias. This investigation tested the hypothesis that increased bone marrow (BM) fat content in humans with age was associated with decreased numbers of side population (SP) hematopoietic stem cells, and this decrease correlated with changes in cytokine levels. BM was obtained from the femoral head and trochanteric region of the femur removed at surgery for total hip replacement (N = 100 subjects). In addition, BM from cadavers (N = 36), with no evidence of hip disease, was evaluated for fat content. Whole trabecular marrow samples were ground in a sterile mortar and pestle, and cellularity and lipid content determined. Marrow cells were stained with Hoechst dye and SP profiles were acquired. Plasma levels of insulin-like growth factor (IGF)-1, stromal-derived factor (SDF)-1 and interleukin (IL)-6 were measured using ELISA. Fat content in the BM of human subjects and cadavers increased with age. The numbers of SP stem cells in BM as well as plasma IGF-1 and SDF-1 levels decreased in correlation with increased BM fat. IL-6 had no relationship to changes in marrow fat. These data suggest that increased BM fat may be associated with a decreased number of SP stem cells and IGF-1 and SDF-1 levels with aging. These data further raise a more general question as to the role of adipose cells in the regulation of tissue stem cells. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.

Embryological origin of the endocardium and derived valve progenitor cells: from developmental biology to stem cell-based valve repair.

PubMed

Pucéat, Michel

2013-04-01

The cardiac valves are targets of both congenital and acquired diseases. The formation of valves during embryogenesis (i.e., valvulogenesis) originates from endocardial cells lining the myocardium. These cells undergo an endothelial-mesenchymal transition, proliferate and migrate within an extracellular matrix. This leads to the formation of bilateral cardiac cushions in both the atrioventricular canal and the outflow tract. The embryonic origin of both the endocardium and prospective valve cells is still elusive. Endocardial and myocardial lineages are segregated early during embryogenesis and such a cell fate decision can be recapitulated in vitro by embryonic stem cells (ESC). Besides genetically modified mice and ex vivo heart explants, ESCs provide a cellular model to study the early steps of valve development and might constitute a human therapeutic cell source for decellularized tissue-engineered valves. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction. Copyright © 2012 Elsevier B.V. All rights reserved.

In vitro and in vivo antiproliferative activity of metformin on stem-like cells isolated from spontaneous canine mammary carcinomas: translational implications for human tumors.

PubMed

Barbieri, Federica; Thellung, Stefano; Ratto, Alessandra; Carra, Elisa; Marini, Valeria; Fucile, Carmen; Bajetto, Adriana; Pattarozzi, Alessandra; Würth, Roberto; Gatti, Monica; Campanella, Chiara; Vito, Guendalina; Mattioli, Francesca; Pagano, Aldo; Daga, Antonio; Ferrari, Angelo; Florio, Tullio

2015-04-07

Cancer stem cells (CSCs) are considered the cell subpopulation responsible for breast cancer (BC) initiation, growth, and relapse. CSCs are identified as self-renewing and tumor-initiating cells, conferring resistance to chemo- and radio-therapy to several neoplasias. Nowadays, th (about 10mM)e pharmacological targeting of CSCs is considered an ineludible therapeutic goal. The antidiabetic drug metformin was reported to suppress in vitro and in vivo CSC survival in different tumors and, in particular, in BC preclinical models. However, few studies are available on primary CSC cultures derived from human postsurgical BC samples, likely because of the limited amount of tissue available after surgery. In this context, comparative oncology is acquiring a relevant role in cancer research, allowing the analysis of larger samples from spontaneous pet tumors that represent optimal models for human cancer. Isolation of primary canine mammary carcinoma (CMC) cells and enrichment in stem-like cell was carried out from fresh tumor specimens by culturing cells in stem-permissive conditions. Phenotypic and functional characterization of CMC-derived stem cells was performed in vitro, by assessment of self-renewal, long-lasting proliferation, marker expression, and drug sensitivity, and in vivo, by tumorigenicity experiments. Corresponding cultures of differentiated CMC cells were used as internal reference. Metformin efficacy on CMC stem cell viability was analyzed both in vitro and in vivo. We identified a subpopulation of CMC cells showing human breast CSC features, including expression of specific markers (i.e. CD44, CXCR4), growth as mammospheres, and tumor-initiation in mice. These cells show resistance to doxorubicin but were highly sensitive to metformin in vitro. Finally, in vivo metformin administration significantly impaired CMC growth in NOD-SCID mice, associated with a significant depletion of CSCs. Similarly to the human counterpart, CMCs contain stem-like subpopulations representing, in a comparative oncology context, a valuable translational model for human BC, and, in particular, to predict the efficacy of antitumor drugs. Moreover, metformin represents a potential CSC-selective drug for BC, as effective (neo-)adjuvant therapy to eradicate CSC in mammary carcinomas of humans and animals.

Naïve Induced Pluripotent Stem Cells Generated From β-Thalassemia Fibroblasts Allow Efficient Gene Correction With CRISPR/Cas9.

PubMed

Yang, Yuanyuan; Zhang, Xiaobai; Yi, Li; Hou, Zhenzhen; Chen, Jiayu; Kou, Xiaochen; Zhao, Yanhong; Wang, Hong; Sun, Xiao-Fang; Jiang, Cizhong; Wang, Yixuan; Gao, Shaorong

2016-01-01

Conventional primed human embryonic stem cells and induced pluripotent stem cells (iPSCs) exhibit molecular and biological characteristics distinct from pluripotent stem cells in the naïve state. Although naïve pluripotent stem cells show much higher levels of self-renewal ability and multidifferentiation capacity, it is unknown whether naïve iPSCs can be generated directly from patient somatic cells and will be superior to primed iPSCs. In the present study, we used an established 5i/L/FA system to directly reprogram fibroblasts of a patient with β-thalassemia into transgene-free naïve iPSCs with molecular signatures of ground-state pluripotency. Furthermore, these naïve iPSCs can efficiently produce cross-species chimeras. Importantly, using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 nuclease genome editing system, these naïve iPSCs exhibit significantly improved gene-correction efficiencies compared with the corresponding primed iPSCs. Furthermore, human naïve iPSCs could be directly generated from noninvasively collected urinary cells, which are easily acquired and thus represent an excellent cell resource for further clinical trials. Therefore, our findings demonstrate the feasibility and superiority of using patient-specific iPSCs in the naïve state for disease modeling, gene editing, and future clinical therapy. In the present study, transgene-free naïve induced pluripotent stem cells (iPSCs) directly converted from the fibroblasts of a patient with β-thalassemia in a defined culture system were generated. These naïve iPSCs, which show ground-state pluripotency, exhibited significantly improved single-cell cloning ability, recovery capacity, and gene-targeting efficiency compared with conventional primed iPSCs. These results provide an improved strategy for personalized treatment of genetic diseases such as β-thalassemia. ©AlphaMed Press.

Naïve Induced Pluripotent Stem Cells Generated From β-Thalassemia Fibroblasts Allow Efficient Gene Correction With CRISPR/Cas9

PubMed Central

Yang, Yuanyuan; Zhang, Xiaobai; Yi, Li; Hou, Zhenzhen; Chen, Jiayu; Kou, Xiaochen; Zhao, Yanhong; Wang, Hong; Sun, Xiao-Fang; Jiang, Cizhong

2016-01-01

Conventional primed human embryonic stem cells and induced pluripotent stem cells (iPSCs) exhibit molecular and biological characteristics distinct from pluripotent stem cells in the naïve state. Although naïve pluripotent stem cells show much higher levels of self-renewal ability and multidifferentiation capacity, it is unknown whether naïve iPSCs can be generated directly from patient somatic cells and will be superior to primed iPSCs. In the present study, we used an established 5i/L/FA system to directly reprogram fibroblasts of a patient with β-thalassemia into transgene-free naïve iPSCs with molecular signatures of ground-state pluripotency. Furthermore, these naïve iPSCs can efficiently produce cross-species chimeras. Importantly, using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 nuclease genome editing system, these naïve iPSCs exhibit significantly improved gene-correction efficiencies compared with the corresponding primed iPSCs. Furthermore, human naïve iPSCs could be directly generated from noninvasively collected urinary cells, which are easily acquired and thus represent an excellent cell resource for further clinical trials. Therefore, our findings demonstrate the feasibility and superiority of using patient-specific iPSCs in the naïve state for disease modeling, gene editing, and future clinical therapy. Significance In the present study, transgene-free naïve induced pluripotent stem cells (iPSCs) directly converted from the fibroblasts of a patient with β-thalassemia in a defined culture system were generated. These naïve iPSCs, which show ground-state pluripotency, exhibited significantly improved single-cell cloning ability, recovery capacity, and gene-targeting efficiency compared with conventional primed iPSCs. These results provide an improved strategy for personalized treatment of genetic diseases such as β-thalassemia. PMID:26676643

Generation of induced pluripotent stem cells as a potential source of hematopoietic stem cells for transplant in PNH patients.

PubMed

Phondeechareon, Tanapol; Wattanapanitch, Methichit; U-Pratya, Yaowalak; Damkham, Chanapa; Klincumhom, Nuttha; Lorthongpanich, Chanchao; Kheolamai, Pakpoom; Laowtammathron, Chuti; Issaragrisil, Surapol

2016-10-01

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia caused by lack of CD55 and CD59 on blood cell membrane leading to increased sensitivity of blood cells to complement. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for PNH, however, lack of HLA-matched donors and post-transplant complications are major concerns. Induced pluripotent stem cells (iPSCs) derived from patients are an attractive source for generating autologous HSCs to avoid adverse effects resulting from allogeneic HSCT. The disease involves only HSCs and their progeny; therefore, other tissues are not affected by the mutation and may be used to produce disease-free autologous HSCs. This study aimed to derive PNH patient-specific iPSCs from human dermal fibroblasts (HDFs), characterize and differentiate to hematopoietic cells using a feeder-free protocol. Analysis of CD55 and CD59 expression was performed before and after reprogramming, and hematopoietic differentiation. Patients' dermal fibroblasts expressed CD55 and CD59 at normal levels and the normal expression remained after reprogramming. The iPSCs derived from PNH patients had typical pluripotent properties and differentiation capacities with normal karyotype. After hematopoietic differentiation, the differentiated cells expressed early hematopoietic markers (CD34 and CD43) with normal CD59 expression. The iPSCs derived from HDFs of PNH patients have normal levels of CD55 and CD59 expression and hold promise as a potential source of HSCs for autologous transplantation to cure PNH patients.

Parthenogenesis and somatic cell nuclear transfer in sheep oocytes using Polscope.

PubMed

Nandedkar, Pandit; Chohan, Parul; Patwardhan, Archana; Gaikwad, Santosh; Bhartiya, Deepa

2009-07-01

Parthenogenesis and Somatic cell nuclear transfer (SCNT) techniques, offer a unique approach to manipulate the genetic composition of derived human embryonic stem cells - an essential step if the full opportunities for disease modeling, drug discovery or individualized stem cell therapy are to be realized. The present study describes the use of sheep oocytes to acquire expertise and establish methods to reconstruct embryos for obtaining blastocysts before venturing into human SCNT where the oocytes are a very precious starting material. Maturation of sheep eggs in vitro for 20-24 hr resulted in 65% metaphase II (MII) eggs which were either parthenogenetically activated using calcium ionomycin or ethanol or subjected to SCNT using cumulus cell as somatic cell. Sixteen blastocysts were produced by parthenogenetic activation of 350 eggs whereas reconstructed embryos, after SCNT carried out in 139 eggs, progressed only up to morula stage. The procedure of parthenogenesis and SCNT will be useful to generate autologous ES cells using human eggs.

Primate Primordial Germ Cells Acquire Transplantation Potential by Carnegie Stage 23.

PubMed

Clark, Amander T; Gkountela, Sofia; Chen, Di; Liu, Wanlu; Sosa, Enrique; Sukhwani, Meena; Hennebold, Jon D; Orwig, Kyle E

2017-07-11

Primordial germ cells (PGCs) are the earliest embryonic progenitors in the germline. Correct formation of PGCs is critical to reproductive health as an adult. Recent work has shown that primate PGCs can be differentiated from pluripotent stem cells; however, a bioassay that supports their identity as transplantable germ cells has not been reported. Here, we adopted a xenotransplantation assay by transplanting single-cell suspensions of human and nonhuman primate embryonic Macaca mulatta (rhesus macaque) testes containing PGCs into the seminiferous tubules of adult busulfan-treated nude mice. We discovered that both human and nonhuman primate embryonic testis are xenotransplantable, generating colonies while not generating tumors. Taken together, this work provides two critical references (molecular and functional) for defining transplantable primate PGCs. These results provide a blueprint for differentiating pluripotent stem cells to transplantable PGC-like cells in a species that is amenable to transplantation and fertility studies. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Potent and reversible lentiviral vector restriction in murine induced pluripotent stem cells.

PubMed

Geis, Franziska K; Galla, Melanie; Hoffmann, Dirk; Kuehle, Johannes; Zychlinski, Daniela; Maetzig, Tobias; Schott, Juliane W; Schwarzer, Adrian; Goffinet, Christine; Goff, Stephen P; Schambach, Axel

2017-05-31

Retroviral vectors are derived from wild-type retroviruses, can be used to study retrovirus-host interactions and are effective tools in gene and cell therapy. However, numerous cell types are resistant or less permissive to retrovirus infection due to the presence of active defense mechanisms, or the absence of important cellular host co-factors. In contrast to multipotent stem cells, pluripotent stem cells (PSC) have potential to differentiate into all three germ layers. Much remains to be elucidated in the field of anti-viral immunity in stem cells, especially in PSC. In this study, we report that transduction with HIV-1-based, lentiviral vectors (LV) is impaired in murine PSC. Analyses of early retroviral events in induced pluripotent stem cells (iPSC) revealed that the restriction is independent of envelope choice and does not affect reverse transcription, but perturbs nuclear entry and proviral integration. Proteasomal inhibition by MG132 could not circumvent the restriction. However, prevention of cyclophilin A (CypA) binding to the HIV-1 capsid via use of either a CypA inhibitor (cyclosporine A) or CypA-independent capsid mutants improved transduction. In addition, application of higher vector doses also increased transduction. Our data revealed a CypA mediated restriction in iPSC, which was acquired during reprogramming, associated with pluripotency and relieved upon subsequent differentiation. We showed that murine PSC and iPSC are less susceptible to LV. The block observed in iPSC was CypA-dependent and resulted in reduced nuclear entry of viral DNA and proviral integration. Our study helps to improve transduction of murine pluripotent cells with HIV-1-based vectors and contributes to our understanding of retrovirus-host interactions in PSC.

Finding the rhythm of sudden cardiac death: new opportunities using induced pluripotent stem cell-derived cardiomyocytes.

PubMed

Sallam, Karim; Li, Yingxin; Sager, Philip T; Houser, Steven R; Wu, Joseph C

2015-06-05

Sudden cardiac death is a common cause of death in patients with structural heart disease, genetic mutations, or acquired disorders affecting cardiac ion channels. A wide range of platforms exist to model and study disorders associated with sudden cardiac death. Human clinical studies are cumbersome and are thwarted by the extent of investigation that can be performed on human subjects. Animal models are limited by their degree of homology to human cardiac electrophysiology, including ion channel expression. Most commonly used cellular models are cellular transfection models, which are able to mimic the expression of a single-ion channel offering incomplete insight into changes of the action potential profile. Induced pluripotent stem cell-derived cardiomyocytes resemble, but are not identical, adult human cardiomyocytes and provide a new platform for studying arrhythmic disorders leading to sudden cardiac death. A variety of platforms exist to phenotype cellular models, including conventional and automated patch clamp, multielectrode array, and computational modeling. Induced pluripotent stem cell-derived cardiomyocytes have been used to study long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and other hereditary cardiac disorders. Although induced pluripotent stem cell-derived cardiomyocytes are distinct from adult cardiomyocytes, they provide a robust platform to advance the science and clinical care of sudden cardiac death. © 2015 American Heart Association, Inc.

Blockade of Notch3 inhibits the stem-like property and is associated with ALDH1A1 and CD44 via autophagy in non-small lung cancer.

PubMed

Ma, Yuanyuan; Li, Mingzhen; Si, Jiahui; Xiong, Ying; Lu, Fangliang; Zhang, Jianzhi; Zhang, Liyi; Zhang, Panpan; Yang, Yue

2016-06-01

Acquired resistance to standard chemotherapy causes treatment failure in patients with local advanced and advanced non-small lung cancer (NSCLC). Cancer stem cells (CSCs) are a small subpopulation within cancer that is thought to be resistant to conventional chemotherapy. The Notch pathway is one of the most intensively studied for putative therapeutic targets of CSCs in solid tumors. In our study, suppression of Notch3 decreased colony and sphere formation of stem-like property in lung cancer cells. In addition, Notch3 expression was demonstrated to be upregulated in the patients with chemoresistance and related to poor prognosis of NSCLC patients. Our results also showed that CSC markers ALDH1A1 and CD44 were highly expressed in NSCLC patients with chemoresistance and these two markers were positively correlated with Notch3 expression in lung cancer specimens from TCGA database. Furthermore, the lung cancer cells with drug resistance were shown to be associated with activation of autophagy. All the data support a crucial role of Notch3 in the increase of stem-like property in NSCLC cells that might be associated with upregulation of ALDH1A1 and CD44 and activation of autophagy.

The Paramyxea Levine 1979: An original example of evolution towards multicellularity

NASA Astrophysics Data System (ADS)

Desportes, Isabelle

1984-03-01

The Paramyxea are parasitic in marine invertebrates. Their development is a sporulation involving the differentiation within a stem cell of several sporonts which produce spores made of cells enclosed inside each other. Three genera are recognized according to the number of spores and sporal cells, and the taxonomic position of the host (Polychaeta, Mollusca, Crustacea). The Paramyxea exhibit both protistan and metazoan characters. Their nine singlets centrioles are observed in different Protoctists whereas the fact that their sporal cells acquire distinctive cytological features may be interpreted as an evolution towards multicellularity.

Dynamics of embryonic stem cell differentiation inferred from single-cell transcriptomics show a series of transitions through discrete cell states

PubMed Central

Jang, Sumin; Choubey, Sandeep; Furchtgott, Leon; Zou, Ling-Nan; Doyle, Adele; Menon, Vilas; Loew, Ethan B; Krostag, Anne-Rachel; Martinez, Refugio A; Madisen, Linda; Levi, Boaz P; Ramanathan, Sharad

2017-01-01

The complexity of gene regulatory networks that lead multipotent cells to acquire different cell fates makes a quantitative understanding of differentiation challenging. Using a statistical framework to analyze single-cell transcriptomics data, we infer the gene expression dynamics of early mouse embryonic stem (mES) cell differentiation, uncovering discrete transitions across nine cell states. We validate the predicted transitions across discrete states using flow cytometry. Moreover, using live-cell microscopy, we show that individual cells undergo abrupt transitions from a naïve to primed pluripotent state. Using the inferred discrete cell states to build a probabilistic model for the underlying gene regulatory network, we further predict and experimentally verify that these states have unique response to perturbations, thus defining them functionally. Our study provides a framework to infer the dynamics of differentiation from single cell transcriptomics data and to build predictive models of the gene regulatory networks that drive the sequence of cell fate decisions during development. DOI: http://dx.doi.org/10.7554/eLife.20487.001 PMID:28296635

G-CSF and GM-CSF in Neutropenia

PubMed Central

Mehta, Hrishikesh M.; Malandra, Michael; Corey, Seth J.

2015-01-01

Granulocyte Colony Stimulating Factor (G-CSF) and Granulocyte/Macrophage Colony Stimulating Factor (GM-CSF) are used widely to promote the production of granulocytes or antigen presenting cells (APC). The Food and Drug Administration approved G-CSF (filgrastim) for the treatment of congenital and acquired neutropenias and for mobilization of peripheral hematopoietic progenitor cells for stem cell transplantation. A polyethylene glycol modified (PEGylated) form of G-CSF is approved for the treatment of neutropenias. Clinically significant neutropenia, rendering an individual immunocompromised, occurs when their number is less than 1500/µl. Current guidelines recommend their use when the risk of febrile neutropenia is greater than 20%. GM-CSF (sargramostim) is approved for neutropenia associated with stem cell transplantation. Because of its promotion of APC function, GM-CSF is being evaluated as an immunostimulatory adjuvant in a number of clinical trials. More than 20 million persons have benefited worldwide, and more than $5 billion sales occur annually in the United States. PMID:26254266

The emerging roles of Notch signaling in leukemia and stem cells

PubMed Central

2013-01-01

The Notch signaling pathway plays a critical role in maintaining the balance between cell proliferation, differentiation and apoptosis, and is a highly conserved signaling pathway that regulates normal development in a context- and dose-dependent manner. Dysregulation of Notch signaling has been suggested to be key events in a variety of hematological malignancies. Notch1 signaling appears to be the central oncogenic trigger in T cell acute lymphoblastic leukemia (T-ALL), in which the majority of human malignancies have acquired mutations that lead to constitutive activation of Notch1 signaling. However, emerging evidence unexpectedly demonstrates that Notch signaling can function as a potent tumor suppressor in other forms of leukemia. This minireview will summarize recent advances related to the roles of activated Notch signaling in human lymphocytic leukemia, myeloid leukemia, stem cells and stromal microenvironment, and we will discuss the perspectives of Notch signaling as a potential therapeutic target as well. PMID:24252593

A novel Fizzy/Cdc20-dependent mechanism suppresses necrosis in neural stem cells

PubMed Central

Kuang, Chaoyuan; Golden, Krista L.; Simon, Claudio R.; Damrath, John; Buttitta, Laura; Gamble, Caitlin E.; Lee, Cheng-Yu

2014-01-01

Cancer stem cells likely survive chemotherapy or radiotherapy by acquiring mutations that inactivate the endogenous apoptotic machinery or by cycling slowly. Thus, knowledge about the mechanisms linking the activation of an alternative cell death modality and the cell cycle machinery could have a transformative impact on the development of new cancer therapies, but the mechanisms remain completely unknown. We investigated the regulation of alternative cell death in Drosophila larval brain neural stem cells (neuroblasts) in which apoptosis is normally repressed. From a screen, we identified two novel loss-of-function alleles of the Cdc20/fizzy (fzy) gene that lead to premature brain neuroblast loss without perturbing cell proliferation in other diploid cell types. Fzy is an evolutionarily conserved regulator of anaphase promoting complex/cyclosome (APC/C). Neuroblasts carrying the novel fzy allele or exhibiting reduced APC/C function display hallmarks of necrosis. By contrast, neuroblasts overexpressing the non-degradable form of canonical APC/C substrates required for cell cycle progression undergo mitotic catastrophe. These data strongly suggest that Fzy can elicit a novel pro-survival function of APC/C by suppressing necrosis. Neuroblasts experiencing catastrophic cellular stress, or overexpressing p53, lose Fzy expression and undergo necrosis. Co-expression of fzy suppresses the death of these neuroblasts. Consequently, attenuation of the Fzy-dependent survival mechanism functions downstream of catastrophic cellular stress and p53 to eliminate neuroblasts by necrosis. Strategies that target the Fzy-dependent survival mechanism might lead to the discovery of new treatments or complement the pre-existing therapies to eliminate apoptosis-resistant cancer stem cells by necrosis. PMID:24598157

Inhibition of Bone Marrow-Derived Mesenchymal Stem Cells Homing Towards Triple-Negative Breast Cancer Microenvironment Using an Anti-PDGFRβ Aptamer

PubMed Central

Camorani, Simona; Hill, Billy Samuel; Fontanella, Raffaela; Greco, Adelaide; Gramanzini, Matteo; Auletta, Luigi; Gargiulo, Sara; Albanese, Sandra; Lucarelli, Enrico; Cerchia, Laura; Zannetti, Antonella

2017-01-01

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are shown to participate in tumor progression by establishing a favorable tumor microenvironment (TME) that promote metastasis through a cytokine networks. However, the mechanism of homing and recruitment of BM-MSCs into tumors and their potential role in malignant tissue progression is poorly understood and controversial. Here we show that BM-MSCs increase aggressiveness of triple-negative breast cancer (TNBC) cell lines evaluated as capability to migrate, invade and acquire stemness markers. Importantly, we demonstrate that the treatment of BM-MSCs with a nuclease-resistant RNA aptamer against platelet-derived growth factor receptor β (PDGFRβ) causes the inhibition of receptor-dependent signaling pathways thus drastically hampering BM-MSC recruitment towards TNBC cell lines and BM-MSCs trans-differentiation into carcinoma-associated fibroblast (CAF)-like cells. Moreover, in vivo molecular imaging analysis demonstrated the aptamer ability to prevent BM-MSCs homing to TNBC xenografts. Collectively, our results indicate the anti-PDGFRβ aptamer as a novel therapeutic tool to interfere with BM-MSCs attraction to TNBC providing the rationale to further explore the aptamer in more complex pre-clinical settings. PMID:28912898

Breast cancer stem cell-like cells generated during TGFβ-induced EMT are radioresistant.

PubMed

Konge, Julie; Leteurtre, François; Goislard, Maud; Biard, Denis; Morel-Altmeyer, Sandrine; Vaurijoux, Aurélie; Gruel, Gaetan; Chevillard, Sylvie; Lebeau, Jérôme

2018-05-04

Failure of conventional antitumor therapy is commonly associated with cancer stem cells (CSCs), which are often defined as inherently resistant to radiation and chemotherapeutic agents. However, controversy about the mechanisms involved in the radiation response remains and the inherent intrinsic radioresistance of CSCs has also been questioned. These discrepancies observed in the literature are strongly associated with the cell models used. In order to clarify these contradictory observations, we studied the radiosensitivity of breast CSCs using purified CD24 -/low /CD44 + CSCs and their corresponding CD24 + /CD44 low non-stem cells. These cells were generated after induction of the epithelial-mesenchymal transition (EMT) by transforming growth factor β (TGFβ) in immortalized human mammary epithelial cells (HMLE). Consequently, these 2 cellular subpopulations have an identical genetic background, their differences being related exclusively to TGFβ-induced cell reprogramming. We showed that mesenchymal CD24 -/low /CD44 + CSCs are more resistant to radiation compared with CD24 + /CD44 low parental cells. Cell cycle distribution and free radical scavengers, but not DNA repair efficiency, appeared to be intrinsic determinants of cellular radiosensitivity. Finally, for the first time, we showed that reduced radiation-induced activation of the death receptor pathways (FasL, TRAIL and TNF-α) at the transcriptional level was a key causal event in the radioresistance of CD24 -/low / CD44+ cells acquired during EMT.

EML4-ALK induces epithelial–mesenchymal transition consistent with cancer stem cell properties in H1299 non-small cell lung cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Fuchun; Liu, Xiaoke, E-mail: liuxk57@163.com; Qing, Qin, E-mail: qinqingscu@126.com

2015-04-10

The echinoderm microtubule-associated protein-like 4(EML4) – anaplastic lymphoma kinase (ALK) fusion gene has been identified as a driver mutation in non-small-cell lung cancer (NSCLC). However, the role of EML4-ALK in malignant transformation is not entirely clear. Here, for the first time, we showed that H1299 NSCLC cells stably expressing EML4-ALK acquire EMT phenotype, associated with enhanced invasive migration and increased expression of EMT-inducing transcription factors. H1299-EML4-ALK cells also displayed cancer stem cell-like properties with a concomitant up-regulation of CD133 and enhanced ability of mammospheres formation. Moreover, we found that inhibition of ERK1/2 reversed EMT induced by EML4-ALK in H1299 cells.more » Taken together, these results suggested that EML4-ALK induced ERK activation is mechanistically associated with EMT phenotype. Thus, inhibition of ERK signaling pathway could be a potential strategy in treatment of NSCLC patients with EML4-ALK translocation. - Highlights: • EML4-ALK induced epithelial–mesenchymal transition in H1299 cells. • Expression of EML4-ALK promotes invasion and migration in vitro. • EML4-ALK enhanced sphere formation and stem cell-like properties in H1299 cells. • Blockage of ERK1/2 reverse Epithelial–Mesenchymal transition induced by EML4-ALK.« less

Lentiviral Vectors Bearing the Cardiac Promoter of the Na+-Ca2+ Exchanger Report Cardiogenic Differentiation in Stem Cells

PubMed Central

Barth, Andreas S; Kizana, Eddy; Smith, Rachel R; Terrovitis, John; Dong, Peihong; Leppo, Michelle K; Zhang, Yiqiang; Miake, Junichiro; Olson, Eric N; Schneider, Jay W; Abraham, M Roselle; Marbán, Eduardo

2009-01-01

Cardiosphere-derived resident cardiac stem cells (CDCs) are readily isolated from adult hearts and confer functional benefit in animal models of heart failure. To study cardiogenic differentiation in CDCs, we developed a method to genetically label and selectively enrich for cells that have acquired a cardiac phenotype. Lentiviral vectors achieved significantly higher transduction efficiencies in CDCs than any of the nine adeno-associated viral (AAV) serotypes tested. To define the most suitable vector system for reporting cardiogenic differentiation, we compared the cell specificity of five commonly-used cardiac-specific promoters in the context of lentiviral vectors. The promoter of the cardiac sodium-calcium exchanger (NCX1) conveyed the highest degree of cardiac specificity, as assessed by transducing seven cell types with each vector and measuring fluorescence intensity by flow cytometry. NCX1-GFP-positive CDC subpopulations, demonstrating prolonged expression of a variety of cardiac markers, could be isolated and expanded in vitro. Finally, we used chemical biology to validate that lentiviral vectors bearing the cardiac NCX1-promoter can serve as a highly accurate biosensor of cardiogenic small molecules in stem cells. The ability to accurately report cardiac fate and selectively enrich for cardiomyocytes and their precursors has important implications for drug discovery and the development of cell-based therapies. PMID:18388932

Cellular and molecular interactions of mesenchymal stem cells in innate immunity.

PubMed

Spaggiari, Grazia Maria; Moretta, Lorenzo

2013-01-01

In recent years, human mesenchymal stem/stromal cells (MSC) have attracted major attention for their possible clinical applications. In addition to their tissue regenerative capacity, they display immune-modulatory properties for which they have been used in the treatment of acute graft-versus-host disease and autoimmune diseases. Various studies have analyzed the inhibitory effect exerted by MSC on cells belonging to acquired or to innate immunity. In this context, MSC have been shown to inhibit proliferation and function of natural killer (NK) cells and to hinder the generation of dendritic cells and macrophages, thus interfering with inflammatory processes and with the generation of type I immune responses. In addition, MSC promote the differentiation of regulatory cells and participate in the regeneration of tissues damaged as a consequence of the inflammatory process. Different molecular mechanisms are involved in the immunosuppressive effect. Further investigation on the biology of MSC and on the regulatory events involved in their functional activities can help to optimize their use in clinical practice.

Engineering kidney cells: reprogramming and directed differentiation to renal tissues.

PubMed

Kaminski, Michael M; Tosic, Jelena; Pichler, Roman; Arnold, Sebastian J; Lienkamp, Soeren S

2017-07-01

Growing knowledge of how cell identity is determined at the molecular level has enabled the generation of diverse tissue types, including renal cells from pluripotent or somatic cells. Recently, several in vitro protocols involving either directed differentiation or transcription-factor-based reprogramming to kidney cells have been established. Embryonic stem cells or induced pluripotent stem cells can be guided towards a kidney fate by exposing them to combinations of growth factors or small molecules. Here, renal development is recapitulated in vitro resulting in kidney cells or organoids that show striking similarities to mammalian embryonic nephrons. In addition, culture conditions are also defined that allow the expansion of renal progenitor cells in vitro. Another route towards the generation of kidney cells is direct reprogramming. Key transcription factors are used to directly impose renal cell identity on somatic cells, thus circumventing the pluripotent stage. This complementary approach to stem-cell-based differentiation has been demonstrated to generate renal tubule cells and nephron progenitors. In-vitro-generated renal cells offer new opportunities for modelling inherited and acquired renal diseases on a patient-specific genetic background. These cells represent a potential source for developing novel models for kidney diseases, drug screening and nephrotoxicity testing and might represent the first steps towards kidney cell replacement therapies. In this review, we summarize current approaches for the generation of renal cells in vitro and discuss the advantages of each approach and their potential applications.

Azimuthal phase retardation microscope for visualizing actin filaments of biological cells

NASA Astrophysics Data System (ADS)

Shin, In Hee; Shin, Sang-Mo

2011-09-01

We developed a new theory-based azimuthal phase retardation microscope to visualize distributions of actin filaments in biological cells without having them with exogenous dyes, fluorescence labels, or stains. The azimuthal phase retardation microscope visualizes distributions of actin filaments by measuring the intensity variations of each pixel of a charge coupled device camera while rotating a single linear polarizer. Azimuthal phase retardation δ between two fixed principal axes was obtained by calculating the rotation angles of the polarizer at the intensity minima from the acquired intensity data. We have acquired azimuthal phase retardation distributions of human breast cancer cell, MDA MB 231 by our microscope and compared the azimuthal phase retardation distributions with the fluorescence image of actin filaments by the commercial fluorescence microscope. Also, we have observed movement of human umbilical cord blood derived mesenchymal stem cells by measuring azimuthal phase retardation distributions.

Notch3 signaling-mediated melanoma-endothelial crosstalk regulates melanoma stem-like cell homeostasis and niche morphogenesis.

PubMed

Hsu, Mei-Yu; Yang, Moon Hee; Schnegg, Caroline I; Hwang, Soonyean; Ryu, Byungwoo; Alani, Rhoda M

2017-06-01

Melanoma is among the most virulent cancers, owing to its propensity to metastasize and its resistance to current therapies. The treatment failure is largely attributed to tumor heterogeneity, particularly subpopulations possessing stem cell-like properties, ie, melanoma stem-like cells (MSLCs). Evidence indicates that the MSLC phenotype is malleable and may be acquired by non-MSLCs through phenotypic switching upon appropriate stimuli, the so-called 'dynamic stemness'. Since the phenotypic characteristics and functional integrity of MSLCs depend on their vascular niche, using a two-dimensional (2D) melanoma-endothelium co-culture model, where the MSLC niche is recapitulated in vitro, we identified Notch3 signaling pathway as a micro-environmental cue governing MSLC phenotypic plasticity via pathway-specific gene expression arrays. Accordingly, lentiviral shRNA-mediated Notch3 knockdown (KD) in melanoma cell lines exhibiting high levels of endogenous Notch3 led to retarded/abolished tumorigenicity in vivo through both depleting MSLC fractions, evinced by MSLC marker downregulation (eg, CD133 and CD271); and impeding the MSLC niche, corroborated by the attenuated tumor angiogenesis as well as vasculogenic mimicry. In contrast, Notch3 KD affected neither tumor growth nor MSLC subsets in a melanoma cell line with relatively low endogenous Notch3 expression. Thus, Notch3 signaling may facilitate MSLC plasticity and niche morphogenesis in a cell context-dependent manner. Our findings illustrate Notch3 as a molecular switch driving melanoma heterogeneity, and provide the biological rationale for Notch inhibition as a promising therapeutic option.

c-MYC independent nuclear reprogramming favors cardiogenic potential of induced pluripotent stem cells

PubMed Central

Martinez-Fernandez, Almudena; Nelson, Timothy J.; Ikeda, Yasuhiro; Terzic, Andre

2010-01-01

Induced pluripotent stem cell (iPS) technology has launched a new platform in regenerative medicine aimed at deriving unlimited replacement tissue from autologous sources through somatic cell reprogramming using stemness factor sets. In this way, authentic cardiomyocytes have been obtained from iPS and recently demonstrated in proof-of-principle studies to repair infarcted heart. Optimizing the cardiogenic potential of iPS progeny would ensure a maximized yield of bioengineered cardiac tissue. Here, we reprogrammed fibroblasts in the presence or absence of c-MYC to determine if the acquired cardiogenicity is sensitive to the method of nuclear reprogramming. Using lentiviral constructs that expressed stemness factors SOX2, OCT4, and KLF4 with or without c-MYC, iPS clones generated through fibroblast reprogramming demonstrated indistinguishable characteristics for 5 days of differentiation with similar cell morphology, growth rates, and chimeric embryo integration. However, 4-factor c-MYC dependent nuclear reprogramming produced iPS progeny that consistently prolonged the expression of pluripotent Oct-4 and Fgf4 genes and repressed cardiac differentiation. In contrast, 3-factor c-MYC-less iPS clones efficiently up-regulated pre-cardiac (CXCR4, Flk-1, and Mesp1/2) and cardiac (Nkx2.5, Mef2c, and Myocardin) gene expression patterns. In fact, 3-factor iPS progeny demonstrated early and robust cardiogenesis during in vitro differentiation with consistent beating activity, sarcomere maturation, and rhythmical intracellular calcium dynamics. Thus, nuclear reprogramming independent of c-MYC enhances production of pluripotent stem cells with innate cardiogenic potential. PMID:20221419

Dynamics of genomic H3K27me3 domains and role of EZH2 during pancreatic endocrine specification

PubMed Central

Xu, Cheng-Ran; Li, Lin-Chen; Donahue, Greg; Ying, Lei; Zhang, Yu-Wei; Gadue, Paul; Zaret, Kenneth S

2014-01-01

Endoderm cells undergo sequential fate choices to generate insulin-secreting beta cells. Ezh2 of the PRC2 complex, which generates H3K27me3, modulates the transition from endoderm to pancreas progenitors, but the role of Ezh2 and H3K27me3 in the next transition to endocrine progenitors is unknown. We isolated endoderm cells, pancreas progenitors, and endocrine progenitors from different staged mouse embryos and analyzed H3K27me3 genome-wide. Unlike the decline in H3K27me3 domains reported during embryonic stem cell differentiation in vitro, we find that H3K27me3 domains increase in number during endocrine progenitor development in vivo. Genes that lose the H3K27me3 mark typically encode transcriptional regulators, including those for pro-endocrine fates, whereas genes that acquire the mark typically are involved in cell biology and morphogenesis. Deletion of Ezh2 at the pancreas progenitor stage enhanced the production of endocrine progenitors and beta cells. Inhibition of EZH2 in embryonic pancreas explants and in human embryonic stem cell cultures increased endocrine progenitors in vitro. Our studies reveal distinct dynamics in H3K27me3 targets in vivo and a means to modulate beta cell development from stem cells. PMID:25107471

X-inactivation and X-reactivation: epigenetic hallmarks of mammalian reproduction and pluripotent stem cells.

PubMed

Payer, Bernhard; Lee, Jeannie T; Namekawa, Satoshi H

2011-08-01

X-chromosome inactivation is an epigenetic hallmark of mammalian development. Chromosome-wide regulation of the X-chromosome is essential in embryonic and germ cell development. In the male germline, the X-chromosome goes through meiotic sex chromosome inactivation, and the chromosome-wide silencing is maintained from meiosis into spermatids before the transmission to female embryos. In early female mouse embryos, X-inactivation is imprinted to occur on the paternal X-chromosome, representing the epigenetic programs acquired in both parental germlines. Recent advances revealed that the inactive X-chromosome in both females and males can be dissected into two elements: repeat elements versus unique coding genes. The inactive paternal X in female preimplantation embryos is reactivated in the inner cell mass of blastocysts in order to subsequently allow the random form of X-inactivation in the female embryo, by which both Xs have an equal chance of being inactivated. X-chromosome reactivation is regulated by pluripotency factors and also occurs in early female germ cells and in pluripotent stem cells, where X-reactivation is a stringent marker of naive ground state pluripotency. Here we summarize recent progress in the study of X-inactivation and X-reactivation during mammalian reproduction and development as well as in pluripotent stem cells.

The meaning of PIWI proteins in cancer development.

PubMed

Litwin, Monika; Szczepańska-Buda, Anna; Piotrowska, Aleksandra; Dzięgiel, Piotr; Witkiewicz, Wojciech

2017-05-01

Cancer is a histologically and genetically heterogeneous population of tumor cells that exhibits distinct molecular profiles determined by epigenetic alterations. P-element-induced wimpy testis (PIWI) proteins in complex with PIWI-interacting RNA (piRNA) have been previously demonstrated to be involved in epigenetic regulation in germline cells. Recently, reactivation of PIWI expression, primarily PIWI-like protein 1 and 2, through aberrant DNA methylation resulting in genomic silencing has been identified in various types of tumors. It has been suggested that the PIWI-piRNA complex contributes to cancer development and progression by promoting a stem-like state of cancer cells, or cancer stem cells (CSCs). It has been identified that CSCs represent the cells that have undergone epithelial-mesenchymal transition (EMT) and acquired metastatic capacities. However, the molecular association between the EMT process and the stem-cell state remains unclear. Further extensive characterization of CSCs in individual types of tumors is required to identify specific markers for the heterogeneous population of CSCs and therefore selectively target CSCs. Previous studies indicate a reciprocal regulation between PIWI proteins and a complex signaling network linking markers characterized for CSCs and transcription factors involved in EMT. In the present review, studies of PIWI function are summarized, and the potential involvement of PIWI proteins in cancer development and progression is discussed.

The meaning of PIWI proteins in cancer development

PubMed Central

Litwin, Monika; Szczepańska-Buda, Anna; Piotrowska, Aleksandra; Dzięgiel, Piotr; Witkiewicz, Wojciech

2017-01-01

Cancer is a histologically and genetically heterogeneous population of tumor cells that exhibits distinct molecular profiles determined by epigenetic alterations. P-element-induced wimpy testis (PIWI) proteins in complex with PIWI-interacting RNA (piRNA) have been previously demonstrated to be involved in epigenetic regulation in germline cells. Recently, reactivation of PIWI expression, primarily PIWI-like protein 1 and 2, through aberrant DNA methylation resulting in genomic silencing has been identified in various types of tumors. It has been suggested that the PIWI-piRNA complex contributes to cancer development and progression by promoting a stem-like state of cancer cells, or cancer stem cells (CSCs). It has been identified that CSCs represent the cells that have undergone epithelial-mesenchymal transition (EMT) and acquired metastatic capacities. However, the molecular association between the EMT process and the stem-cell state remains unclear. Further extensive characterization of CSCs in individual types of tumors is required to identify specific markers for the heterogeneous population of CSCs and therefore selectively target CSCs. Previous studies indicate a reciprocal regulation between PIWI proteins and a complex signaling network linking markers characterized for CSCs and transcription factors involved in EMT. In the present review, studies of PIWI function are summarized, and the potential involvement of PIWI proteins in cancer development and progression is discussed. PMID:28529570

Neurogenic differentiation of dental pulp stem cells to neuron-like cells in dopaminergic and motor neuronal inductive media.

PubMed

Chang, Chia-Chieh; Chang, Kai-Chun; Tsai, Shang-Jye; Chang, Hao-Hueng; Lin, Chun-Pin

2014-12-01

Dental pulp stem cells (DPSCs) have been proposed as a promising source of stem cells in nerve regeneration due to their close embryonic origin and ease of harvest. The aim of this study was to evaluate the efficacy of dopaminergic and motor neuronal inductive media on transdifferentiation of human DPSCs (hDPSCs) into neuron-like cells. Isolation, cultivation, and identification of hDPSCs were performed with morphological analyses and flow cytometry. The proliferation potential of DPSCs was evaluated with an XTT [(2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide)] assay. Media for the induction of dopaminergic and spinal motor neuronal differentiation were prepared. The efficacy of neural induction was evaluated by detecting the expression of neuron cell-specific cell markers in DPSCs by immunocytochemistry and quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). In the XTT assay, there was a 2.6- or 2-fold decrease in DPSCs cultured in dopaminergic or motor neuronal inductive media, respectively. The proportions of βIII-tubulin (βIII-tub), glial fibrillary acidic protein (GFAP), and oligodendrocyte (O1)-positive cells were significantly higher in DPSCs cultured in both neuronal inductive media compared with those cultured in control media. Furthermore, hDPSC-derived dopaminergic and spinal motor neuron cells after induction expressed a higher density of neuron cell markers than those before induction. These findings suggest that in response to the neuronal inductive stimuli, a greater proportion of DPSCs stop proliferation and acquire a phenotype resembling mature neurons. Such neural crest-derived adult DPSCs may provide an alternative stem cell source for therapy-based treatments of neuronal disorders and injury. Copyright © 2014. Published by Elsevier B.V.

HOXB7 overexpression in lung cancer is a hallmark of acquired stem-like phenotype.

PubMed

Monterisi, Simona; Lo Riso, Pietro; Russo, Karin; Bertalot, Giovanni; Vecchi, Manuela; Testa, Giuseppe; Di Fiore, Pier Paolo; Bianchi, Fabrizio

2018-03-26

HOXB7 is a homeodomain (HOX) transcription factor involved in regional body patterning of invertebrates and vertebrates. We previously identified HOXB7 within a ten-gene prognostic signature for lung adenocarcinoma, where increased expression of HOXB7 was associated with poor prognosis. This raises the question of how HOXB7 overexpression can influence the metastatic behavior of lung adenocarcinoma. Here, we analyzed publicly available microarray and RNA-seq lung cancer expression datasets and found that HOXB7-overexpressing tumors are enriched in gene signatures characterizing adult and embryonic stem cells (SC), and induced pluripotent stem cells (iPSC). Experimentally, we found that HOXB7 upregulates several canonical SC/iPSC markers and sustains the expansion of a subpopulation of cells with SC characteristics, through modulation of LIN28B, an emerging cancer gene and pluripotency factor, which we discovered to be a direct target of HOXB7. We validated this new circuit by showing that HOXB7 enhances reprogramming to iPSC with comparable efficiency to LIN28B or its target c-MYC, which is a canonical reprogramming factor.

Genomic Instability in Human Pluripotent Stem Cells Arises from Replicative Stress and Chromosome Condensation Defects.

PubMed

Lamm, Noa; Ben-David, Uri; Golan-Lev, Tamar; Storchová, Zuzana; Benvenisty, Nissim; Kerem, Batsheva

2016-02-04

Human pluripotent stem cells (hPSCs) frequently acquire chromosomal aberrations such as aneuploidy in culture. These aberrations progressively increase over time and may compromise the properties and clinical utility of the cells. The underlying mechanisms that drive initial genomic instability and its continued progression are largely unknown. Here, we show that aneuploid hPSCs undergo DNA replication stress, resulting in defective chromosome condensation and segregation. Aneuploid hPSCs show altered levels of actin cytoskeletal genes controlled by the transcription factor SRF, and overexpression of SRF rescues impaired chromosome condensation and segregation defects in aneuploid hPSCs. Furthermore, SRF downregulation in diploid hPSCs induces replication stress and perturbed condensation similar to that seen in aneuploid cells. Together, these results suggest that decreased SRF expression induces replicative stress and chromosomal condensation defects that underlie the ongoing chromosomal instability seen in aneuploid hPSCs. A similar mechanism may also operate during initiation of instability in diploid cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Self-Renewal of Single Mouse Hematopoietic Stem Cells Is Reduced by JAK2V617F Without Compromising Progenitor Cell Expansion

PubMed Central

Kent, David G.; Li, Juan; Tanna, Hinal; Fink, Juergen; Kirschner, Kristina; Pask, Dean C.; Silber, Yvonne; Hamilton, Tina L.; Sneade, Rachel; Simons, Benjamin D.; Green, Anthony R.

2013-01-01

Recent descriptions of significant heterogeneity in normal stem cells and cancers have altered our understanding of tumorigenesis, emphasizing the need to understand how single stem cells are subverted to cause tumors. Human myeloproliferative neoplasms (MPNs) are thought to reflect transformation of a hematopoietic stem cell (HSC) and the majority harbor an acquired V617F mutation in the JAK2 tyrosine kinase, making them a paradigm for studying the early stages of tumor establishment and progression. The consequences of activating tyrosine kinase mutations for stem and progenitor cell behavior are unclear. In this article, we identify a distinct cellular mechanism operative in stem cells. By using conditional knock-in mice, we show that the HSC defect resulting from expression of heterozygous human JAK2V617F is both quantitative (reduced HSC numbers) and qualitative (lineage biases and reduced self-renewal per HSC). The defect is intrinsic to individual HSCs and their progeny are skewed toward proliferation and differentiation as evidenced by single cell and transplantation assays. Aged JAK2V617F show a more pronounced defect as assessed by transplantation, but mice that transform reacquire competitive self-renewal ability. Quantitative analysis of HSC-derived clones was used to model the fate choices of normal and JAK2-mutant HSCs and indicates that JAK2V617F reduces self-renewal of individual HSCs but leaves progenitor expansion intact. This conclusion is supported by paired daughter cell analyses, which indicate that JAK2-mutant HSCs more often give rise to two differentiated daughter cells. Together these data suggest that acquisition of JAK2V617F alone is insufficient for clonal expansion and disease progression and causes eventual HSC exhaustion. Moreover, our results show that clonal expansion of progenitor cells provides a window in which collaborating mutations can accumulate to drive disease progression. Characterizing the mechanism(s) of JAK2V617F subclinical clonal expansions and the transition to overt MPNs will illuminate the earliest stages of tumor establishment and subclone competition, fundamentally shifting the way we treat and manage cancers. PMID:23750118

Two-Step Functional Innovation of the Stem-Cell Factors WUS/WOX5 during Plant Evolution

PubMed Central

Zhang, Yuzhou; Jiao, Yue; Jiao, Hengwu

2017-01-01

WUS and WOX5, which are expressed, respectively, in the organizing center (OC) and the quiescent center (QC), are essential for shoot/root apical stem-cell maintenance in flowering plants. However, little is known about how these stem-cell factors evolved their functions in flowering plants. Here, we show that the WUS/WOX5 proteins acquired two distinct capabilities by a two-step functional innovation process in the course of plant evolution. The first-step is the apical stem-cell maintenance activity of WUS/WOX5, which originated in the common ancestor of ferns and seed plants, as evidenced by the interspecies complementation experiments, showing that ectopic expression of fern Ceratopteris richardii WUS-like (CrWUL) surrounding OC/QC, or exclusive OC-/QC-expressed gymnosperms/angiosperms WUS/WOX5 in Arabidopsis wus-1 and wox5-1 mutants, could rescue their phenotypes. The second-step is the intercellular mobility that emerged in the common ancestor of seed plants after divergence from the ferns. Evidence for this includes confocal imaging of GFP fusion proteins, showing that WUS/WOX5 from seed plants, rather than from the fern CrWUL, can migrate into cells adjacent to the OC/QC. Evolutionary analysis showed that the WUS-like gene was duplicated into two copies prior to the divergence of gymnosperms/angiosperms. Then the two gene copies (WUS and WOX5) have undergone similar levels of purifying selection, which is consistent with their conserved functions in angiosperm shoot/root stem-cell maintenance and floral organ formation. Our results highlight the critical roles and the essential prerequisites that the two-step functional innovation of these genes performs and represents in the origin of flowering plants. PMID:28053005

EML4-ALK induces epithelial-mesenchymal transition consistent with cancer stem cell properties in H1299 non-small cell lung cancer cells.

PubMed

Guo, Fuchun; Liu, Xiaoke; Qing, Qin; Sang, Yaxiong; Feng, Chengjun; Li, Xiaoyu; Jiang, Li; Su, Pei; Wang, Yongsheng

2015-04-10

The echinoderm microtubule-associated protein-like 4(EML4)--anaplastic lymphoma kinase (ALK) fusion gene has been identified as a driver mutation in non-small-cell lung cancer (NSCLC). However, the role of EML4-ALK in malignant transformation is not entirely clear. Here, for the first time, we showed that H1299 NSCLC cells stably expressing EML4-ALK acquire EMT phenotype, associated with enhanced invasive migration and increased expression of EMT-inducing transcription factors. H1299-EML4-ALK cells also displayed cancer stem cell-like properties with a concomitant up-regulation of CD133 and enhanced ability of mammospheres formation. Moreover, we found that inhibition of ERK1/2 reversed EMT induced by EML4-ALK in H1299 cells. Taken together, these results suggested that EML4-ALK induced ERK activation is mechanistically associated with EMT phenotype. Thus, inhibition of ERK signaling pathway could be a potential strategy in treatment of NSCLC patients with EML4-ALK translocation. Copyright © 2015 Elsevier Inc. All rights reserved.

Fabrication of a co-culture micro-bioreactor device for efficient hepatic differentiation of human induced pluripotent stem cells (hiPSCs).

PubMed

Kehtari, Mousa; Zeynali, Bahman; Soleimani, Masoud; Kabiri, Mahboubeh; Seyedjafari, Ehsan

2018-04-27

Primary hepatocytes, as the gold standard cell type for in vitro models, lose their characteristic morphology and functions after few days. There is an urgent need to develop physiologically relevant models that recapitulate liver microenvironment to obtain mature hepatocyte from stem cells. We designed and fabricated a micro-bioreactor device mimicking the physiological shear stress and cell-cell interaction in liver sinusoid microenvironment. Induced pluripotent stem cells (iPSCs) were co-cultured with human umbilical vein endothelial cells (HUVECs) in the micro-bioreactor device with continuous perfusion of hepatic differentiation medium (100 μL/h). Simulation results showed that flow field inside our perfusion device was uniform and shear stress was adjusted to physiological condition (<2 dyne/cm 2 ). IPSCs-derived hepatocytes (iPSCs-Heps) that were cultured in micro-bioreactor device showed a higher level of hepatic markers compared to those in static condition. Flow cytometry and immunocytochemistry analysis revealed iPSCs cultured in the device sequentially acquired characteristics of definitive endodermal cells (SOX17 positive), hepatoblasts (AFP positive) and mature hepatocyte (ALB positive). Moreover, the albumin and urea secretion were significantly higher in micro-bioreactor device than those cultured in culture dishes during experiment. Thus, based on our results, we propose our micro-bioreactor as a beneficial device to generate mature hepatocytes for drug screening and basic research.

Cancer stem cell-related gene expression as a potential biomarker of response for first-in-class imipridone ONC201 in solid tumors.

PubMed

Prabhu, Varun V; Lulla, Amriti R; Madhukar, Neel S; Ralff, Marie D; Zhao, Dan; Kline, Christina Leah B; Van den Heuvel, A Pieter J; Lev, Avital; Garnett, Mathew J; McDermott, Ultan; Benes, Cyril H; Batchelor, Tracy T; Chi, Andrew S; Elemento, Olivier; Allen, Joshua E; El-Deiry, Wafik S

2017-01-01

Cancer stem cells (CSCs) correlate with recurrence, metastasis and poor survival in clinical studies. Encouraging results from clinical trials of CSC inhibitors have further validated CSCs as therapeutic targets. ONC201 is a first-in-class small molecule imipridone in Phase I/II clinical trials for advanced cancer. We have previously shown that ONC201 targets self-renewing, chemotherapy-resistant colorectal CSCs via Akt/ERK inhibition and DR5/TRAIL induction. In this study, we demonstrate that the anti-CSC effects of ONC201 involve early changes in stem cell-related gene expression prior to tumor cell death induction. A targeted network analysis of gene expression profiles in colorectal cancer cells revealed that ONC201 downregulates stem cell pathways such as Wnt signaling and modulates genes (ID1, ID2, ID3 and ALDH7A1) known to regulate self-renewal in colorectal, prostate cancer and glioblastoma. ONC201-mediated changes in CSC-related gene expression were validated at the RNA and protein level for each tumor type. Accordingly, we observed inhibition of self-renewal and CSC markers in prostate cancer cell lines and patient-derived glioblastoma cells upon ONC201 treatment. Interestingly, ONC201-mediated CSC depletion does not occur in colorectal cancer cells with acquired resistance to ONC201. Finally, we observed that basal expression of CSC-related genes (ID1, CD44, HES7 and TCF3) significantly correlate with ONC201 efficacy in >1000 cancer cell lines and combining the expression of multiple genes leads to a stronger overall prediction. These proof-of-concept studies provide a rationale for testing CSC expression at the RNA and protein level as a predictive and pharmacodynamic biomarker of ONC201 response in ongoing clinical studies.

Cancer stem cell-related gene expression as a potential biomarker of response for first-in-class imipridone ONC201 in solid tumors

PubMed Central

Zhao, Dan; Kline, Christina Leah B.; Van den Heuvel, A. Pieter J.; Lev, Avital; Garnett, Mathew J.; McDermott, Ultan; Benes, Cyril H.; Batchelor, Tracy T.; Chi, Andrew S.; Elemento, Olivier; Allen, Joshua E.

2017-01-01

Cancer stem cells (CSCs) correlate with recurrence, metastasis and poor survival in clinical studies. Encouraging results from clinical trials of CSC inhibitors have further validated CSCs as therapeutic targets. ONC201 is a first-in-class small molecule imipridone in Phase I/II clinical trials for advanced cancer. We have previously shown that ONC201 targets self-renewing, chemotherapy-resistant colorectal CSCs via Akt/ERK inhibition and DR5/TRAIL induction. In this study, we demonstrate that the anti-CSC effects of ONC201 involve early changes in stem cell-related gene expression prior to tumor cell death induction. A targeted network analysis of gene expression profiles in colorectal cancer cells revealed that ONC201 downregulates stem cell pathways such as Wnt signaling and modulates genes (ID1, ID2, ID3 and ALDH7A1) known to regulate self-renewal in colorectal, prostate cancer and glioblastoma. ONC201-mediated changes in CSC-related gene expression were validated at the RNA and protein level for each tumor type. Accordingly, we observed inhibition of self-renewal and CSC markers in prostate cancer cell lines and patient-derived glioblastoma cells upon ONC201 treatment. Interestingly, ONC201-mediated CSC depletion does not occur in colorectal cancer cells with acquired resistance to ONC201. Finally, we observed that basal expression of CSC-related genes (ID1, CD44, HES7 and TCF3) significantly correlate with ONC201 efficacy in >1000 cancer cell lines and combining the expression of multiple genes leads to a stronger overall prediction. These proof-of-concept studies provide a rationale for testing CSC expression at the RNA and protein level as a predictive and pharmacodynamic biomarker of ONC201 response in ongoing clinical studies. PMID:28767654

Zeb2 Regulates Cell Fate at the Exit from Epiblast State in Mouse Embryonic Stem Cells.

PubMed

Stryjewska, Agata; Dries, Ruben; Pieters, Tim; Verstappen, Griet; Conidi, Andrea; Coddens, Kathleen; Francis, Annick; Umans, Lieve; van IJcken, Wilfred F J; Berx, Geert; van Grunsven, Leo A; Grosveld, Frank G; Goossens, Steven; Haigh, Jody J; Huylebroeck, Danny

2017-03-01

In human embryonic stem cells (ESCs) the transcription factor Zeb2 regulates neuroectoderm versus mesendoderm formation, but it is unclear how Zeb2 affects the global transcriptional regulatory network in these cell-fate decisions. We generated Zeb2 knockout (KO) mouse ESCs, subjected them as embryoid bodies (EBs) to neural and general differentiation and carried out temporal RNA-sequencing (RNA-seq) and reduced representation bisulfite sequencing (RRBS) analysis in neural differentiation. This shows that Zeb2 acts preferentially as a transcriptional repressor associated with developmental progression and that Zeb2 KO ESCs can exit from their naïve state. However, most cells in these EBs stall in an early epiblast-like state and are impaired in both neural and mesendodermal differentiation. Genes involved in pluripotency, epithelial-to-mesenchymal transition (EMT), and DNA-(de)methylation, including Tet1, are deregulated in the absence of Zeb2. The observed elevated Tet1 levels in the mutant cells and the knowledge of previously mapped Tet1-binding sites correlate with loss-of-methylation in neural-stimulating conditions, however, after the cells initially acquired the correct DNA-methyl marks. Interestingly, cells from such Zeb2 KO EBs maintain the ability to re-adapt to 2i + LIF conditions even after prolonged differentiation, while knockdown of Tet1 partially rescues their impaired differentiation. Hence, in addition to its role in EMT, Zeb2 is critical in ESCs for exit from the epiblast state, and links the pluripotency network and DNA-methylation with irreversible commitment to differentiation. Stem Cells 2017;35:611-625. © 2016 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Generation and Characterisation of Cisplatin-Resistant Non-Small Cell Lung Cancer Cell Lines Displaying a Stem-Like Signature

PubMed Central

Barr, Martin P.; Gray, Steven G.; Hoffmann, Andreas C.; Hilger, Ralf A.; Thomale, Juergen; O’Flaherty, John D.; Fennell, Dean A.; Richard, Derek; O’Leary, John J.; O’Byrne, Kenneth J.

2013-01-01

Introduction Inherent and acquired cisplatin resistance reduces the effectiveness of this agent in the management of non-small cell lung cancer (NSCLC). Understanding the molecular mechanisms underlying this process may result in the development of novel agents to enhance the sensitivity of cisplatin. Methods An isogenic model of cisplatin resistance was generated in a panel of NSCLC cell lines (A549, SKMES-1, MOR, H460). Over a period of twelve months, cisplatin resistant (CisR) cell lines were derived from original, age-matched parent cells (PT) and subsequently characterized. Proliferation (MTT) and clonogenic survival assays (crystal violet) were carried out between PT and CisR cells. Cellular response to cisplatin-induced apoptosis and cell cycle distribution were examined by FACS analysis. A panel of cancer stem cell and pluripotent markers was examined in addition to the EMT proteins, c-Met and β-catenin. Cisplatin-DNA adduct formation, DNA damage (γH2AX) and cellular platinum uptake (ICP-MS) was also assessed. Results Characterisation studies demonstrated a decreased proliferative capacity of lung tumour cells in response to cisplatin, increased resistance to cisplatin-induced cell death, accumulation of resistant cells in the G0/G1 phase of the cell cycle and enhanced clonogenic survival ability. Moreover, resistant cells displayed a putative stem-like signature with increased expression of CD133+/CD44+cells and increased ALDH activity relative to their corresponding parental cells. The stem cell markers, Nanog, Oct-4 and SOX-2, were significantly upregulated as were the EMT markers, c-Met and β-catenin. While resistant sublines demonstrated decreased uptake of cisplatin in response to treatment, reduced cisplatin-GpG DNA adduct formation and significantly decreased γH2AX foci were observed compared to parental cell lines. Conclusion Our results identified cisplatin resistant subpopulations of NSCLC cells with a putative stem-like signature, providing a further understanding of the cellular events associated with the cisplatin resistance phenotype in lung cancer. PMID:23349823

Viral infections in transplant recipients.

PubMed

Razonable, R R; Eid, A J

2009-12-01

Solid organ and hematopoietic stem cell transplant recipients are uniquely predisposed to develop clinical illness, often with increased severity, due to a variety of common and opportunistic viruses. Patients may acquire viral infections from the donor (donor-derived infections), from reactivation of endogenous latent virus, or from the community. Herpes viruses, most notably cytomegalovirus and Epstein Barr virus, are the most common among opportunistic viral pathogens that cause infection after solid organ and hematopoietic stem cell transplantation. The polyoma BK virus causes opportunistic clinical syndromes predominantly in kidney and allogeneic hematopoietic stem cell transplant recipients. The agents of viral hepatitis B and C present unique challenges particularly among liver transplant recipients. Respiratory viral illnesses due to influenza, respiratory syncytial virus, and parainfluenza virus may affect all types of transplant recipients, although severe clinical disease is observed more commonly among lung and allogeneic hematopoietic stem cell transplant recipients. Less common viral infections affecting transplant recipients include those caused by adenoviruses, parvovirus B19, and West Nile virus. Treatment for viruses with proven effective antiviral drug therapies should be complemented by reduction in the degree of immunosuppression. For others with no proven antiviral drugs for therapy, reduction in the degree of immunosuppression remains as the sole effective strategy for management. Prevention of viral infections is therefore of utmost importance, and this may be accomplished through vaccination, antiviral strategies, and aggressive infection control measures.

Cancer stem cells and drug resistance: the potential of nanomedicine

PubMed Central

Vinogradov, Serguei; Wei, Xin

2012-01-01

Properties of the small group of cancer cells called tumor-initiating or cancer stem cells (CSCs) involved in drug resistance, metastasis and relapse of cancers can significantly affect tumor therapy. Importantly, tumor drug resistance seems to be closely related to many intrinsic or acquired properties of CSCs, such as quiescence, specific morphology, DNA repair ability and overexpression of antiapoptotic proteins, drug efflux transporters and detoxifying enzymes. The specific microenvironment (niche) and hypoxic stability provide additional protection against anticancer therapy for CSCs. Thus, CSC-focused therapy is destined to form the core of any effective anticancer strategy. Nanomedicine has great potential in the development of CSC-targeting drugs, controlled drug delivery and release, and the design of novel gene-specific drugs and diagnostic modalities. This review is focused on tumor drug resistance-related properties of CSCs and describes current nanomedicine approaches, which could form the basis of novel combination therapies for eliminating metastatic and CSCs. PMID:22471722

Assessing the risks of genotoxicity in the therapeutic development of induced pluripotent stem cells.

PubMed

Hong, So Gun; Dunbar, Cynthia E; Winkler, Thomas

2013-02-01

Induced pluripotent stem cells (iPSCs) have great potential for regenerative medicine as well as for basic and translational research. However, following the initial excitement over the enormous prospects of this technology, several reports uncovered serious concerns regarding its safety for clinical applications and reproducibility for laboratory applications such as disease modeling or drug screening. In particular, the genomic integrity of iPSCs is the focus of extensive research. Epigenetic remodeling, aberrant expression of reprogramming factors, clonal selection, and prolonged in vitro culture are potential pathways for acquiring genomic alterations. In this review, we will critically discuss current reprogramming technologies particularly in the context of genotoxicity, and the consequences of these alternations for the potential applications of reprogrammed cells. In addition, current strategies of genetic modification of iPSCs, as well as applicable suicide strategies to control the risk of iPSC-based therapies will be introduced.

Cytokine Immunopathogenesis of Enterovirus 71 Brain Stem Encephalitis

PubMed Central

Wang, Shih-Min; Lei, Huan-Yao; Liu, Ching-Chuan

2012-01-01

Enterovirus 71 (EV71) is one of the most important causes of herpangina and hand, foot, and mouth disease. It can also cause severe complications of the central nervous system (CNS). Brain stem encephalitis with pulmonary edema is the severe complication that can lead to death. EV71 replicates in leukocytes, endothelial cells, and dendritic cells resulting in the production of immune and inflammatory mediators that shape innate and acquired immune responses and the complications of disease. Cytokines, as a part of innate immunity, favor the development of antiviral and Th1 immune responses. Cytokines and chemokines play an important role in the pathogenesis EV71 brain stem encephalitis. Both the CNS and the systemic inflammatory responses to infection play important, but distinctly different, roles in the pathogenesis of EV71 pulmonary edema. Administration of intravenous immunoglobulin and milrinone, a phosphodiesterase inhibitor, has been shown to modulate inflammation, to reduce sympathetic overactivity, and to improve survival in patients with EV71 autonomic nervous system dysregulation and pulmonary edema. PMID:22956971

Mesenchymal stem cell-derived inflammatory fibroblasts mediate interstitial fibrosis in the aging heart.

PubMed

Trial, JoAnn; Entman, Mark L; Cieslik, Katarzyna A

2016-02-01

Pathologic fibrosis in the aging mouse heart is associated with dysregulated resident mesenchymal stem cells (MSC) arising from reduced stemness and aberrant differentiation into dysfunctional inflammatory fibroblasts. Fibroblasts derived from aging MSC secrete higher levels of 1) collagen type 1 (Col1) that directly contributes to fibrosis, 2) monocyte chemoattractant protein-1 (MCP-1) that attracts leukocytes from the blood and 3) interleukin-6 (IL-6) that facilitates transition of monocytes into myeloid fibroblasts. The transcriptional activation of these proteins is controlled via the farnesyltransferase (FTase)-Ras-Erk pathway. The intrinsic change in the MSC phenotype acquired by advanced age is specific for the heart since MSC originating from bone wall (BW-MSC) or fibroblasts derived from them were free of these defects. The potential therapeutic interventions other than clinically approved strategies based on findings presented in this review are discussed as well. This article is a part of a Special Issue entitled "Fibrosis and Myocardial Remodeling". Copyright © 2015 Elsevier Ltd. All rights reserved.

A novel autologous stem cell procedure for the treatment of aplastic anaemia using reprogrammed mature adult cells: a pilot study

PubMed Central

Abuljadayel, Ilham Saleh; Mohanty, Dipika; Suri, Rajendar K.

2012-01-01

Background & objectives: Aplastic anaemia is a life threatening rare bone marrow failure disorder. The underlying haematopoietic cellular deficit leads to haemorrhage, infection and severe anaemia. The treatment of choice for this haematological condition is allogeneic bone marrow transplantation from fully matched HLA sibling. Though this procedure is curative in the majority of young patients with aplastic anaemia, extending this benefit to older patients or those lacking a family donor remains a major challenge. Herein, the safety and efficacy of infusing autologous retrodifferentiated haematopoietic stem cells (RHSC) into four patients with aplastic anaemia without the use of any pre- or post-conditioning regimen including immunosuppression is described. Methods: Un-mobilized, mononuclear cells were harvested from four patients with acquired aplastic anaemia by aphaeresis. Mononuclear cells of patients were cultured with purified monoclonal antibody against the monomorphic regions of the beta chain of MHC class II antigens (Clone CR3/43) for 3 h, to obtain autologous RHSC. Autologous RHSC were washed and infused into the four patients without the use of any pre- or post-conditioning regimen. Thereafter, the efficacy (engraftment) of autologous RHSC was assessed in these patients. Results: Following single infusion of the autologous RHSC, two of the four patients with aplastic anaemia become transfusion independent for more than seven years. Karyotyping and G-banding analysis prior and post-procedure in all patients remained the same. Interpretation & conclusions: The findings of this pilot study demonstrated the functional utility of reprogrammed fully differentiated adult cells into pluripotent stem cells with extensive repopulation potentials in a human setting and without any pre- or post-conditioning regimen, including immunosuppression. This autologous approach of stem cell creation may broaden the curative potentials of stem cell therapy to a wider population of patients with aplastic anaemia, including many patients suffering from other haematological and non-haematological disorders. PMID:22825605

A novel autologous stem cell procedure for the treatment of aplastic anaemia using reprogrammed mature adult cells: a pilot study.

PubMed

Abuljadayel, Ilham Saleh; Mohanty, Dipika; Suri, Rajendar K

2012-06-01

Aplastic anaemia is a life threatening rare bone marrow failure disorder. The underlying haematopoietic cellular deficit leads to haemorrhage, infection and severe anaemia. The treatment of choice for this haematological condition is allogeneic bone marrow transplantation from fully matched HLA sibling. Though this procedure is curative in the majority of young patients with aplastic anaemia, extending this benefit to older patients or those lacking a family donor remains a major challenge. Herein, the safety and efficacy of infusing autologous retrodifferentiated haematopoietic stem cells (RHSC) into four patients with aplastic anaemia without the use of any pre- or post-conditioning regimen including immunosuppression is described. Un-mobilized, mononuclear cells were harvested from four patients with acquired aplastic anaemia by aphaeresis. Mononuclear cells of patients were cultured with purified monoclonal antibody against the monomorphic regions of the beta chain of MHC class II antigens (Clone CR3/43) for 3 h, to obtain autologous RHSC. Autologous RHSC were washed and infused into the four patients without the use of any pre- or post-conditioning regimen. Thereafter, the efficacy (engraftment) of autologous RHSC was assessed in these patients. Following single infusion of the autologous RHSC, two of the four patients with aplastic anaemia become transfusion independent for more than seven years. Karyotyping and G-banding analysis prior and post-procedure in all patients remained the same. The findings of this pilot study demonstrated the functional utility of reprogrammed fully differentiated adult cells into pluripotent stem cells with extensive repopulation potentials in a human setting and without any pre- or post-conditioning regimen, including immunosuppression. This autologous approach of stem cell creation may broaden the curative potentials of stem cell therapy to a wider population of patients with aplastic anaemia, including many patients suffering from other haematological and non-haematological disorders.

The impact of trisomy 21 on foetal haematopoiesis

PubMed Central

Roberts, Irene; O'Connor, David; Roy, Anindita; Cowan, Gillian; Vyas, Paresh

2015-01-01

The high frequency of a unique neonatal preleukaemic syndrome, Transient Abnormal Myelopoiesis (TAM), and subsequent acute myeloid leukaemia in early childhood in patients with trisomy 21 (Down syndrome) points to a specific role for trisomy 21 in transforming foetal haematopoietic cells. N-terminal truncating mutations in the key haematopoietic transcription factor GATA1 are acquired during foetal life in virtually every case. These mutations are not leukaemogenic in the absence of trisomy 21. In mouse models, deregulated expression of chromosome 21-encoded genes is implicated in leukaemic transformation, but does not recapitulate the effects of trisomy 21 in a human context. Recent work using primary human foetal liver and bone marrow cells, human embryonic stem cells and iPS cells cells shows that prior to acquistion of GATA1 mutations, trisomy 21 itself alters human foetal haematopoietic stem cell and progenitor cell biology causing multiple abnormalities in myelopoiesis and B-lymphopoiesis. The molecular basis by which trisomy 21 exerts these effects is likely to be extremely complex, to be tissue- and lineage-specific and to be dependent on ontogeny-related characteristics of the foetal microenvironment. PMID:23932236

Epigenetic regulation leading to induced pluripotency drives cancer development in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohnishi, Kotaro; Department of Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194; Semi, Katsunori

Highlights: • Epigenetic regulation of failed reprogramming-associated cancer cells is discussed. • Similarity between pediatric cancer and reprogramming-associated cancer is discussed. • Concept for epigenetic cancer is discussed. - Abstract: Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSCs) by the transient expression of reprogramming factors. During the reprogramming process, somatic cells acquire the ability to undergo unlimited proliferation, which is also an important characteristic of cancer cells, while their underlying DNA sequence remains unchanged. Based on the characteristics shared between pluripotent stem cells and cancer cells, the potential involvement of the factors leading to reprogramming toward pluripotencymore » in cancer development has been discussed. Recent in vivo reprogramming studies provided some clues to understanding the role of reprogramming-related epigenetic regulation in cancer development. It was shown that premature termination of the in vivo reprogramming result in the development of tumors that resemble pediatric cancers. Given that epigenetic modifications play a central role during reprogramming, failed reprogramming-associated cancer development may have provided a proof of concept for epigenetics-driven cancer development in vivo.« less

Human Adipose‐Derived Stem Cells Expanded Under Ambient Oxygen Concentration Accumulate Oxidative DNA Lesions and Experience Procarcinogenic DNA Replication Stress

PubMed Central

Renoud, Marie‐Laure; Hoede, Claire; Gonzalez, Ignacio; Jones, Natalie; Longy, Michel; Sensebé, Luc; Cazaux, Christophe

2016-01-01

Abstract Adipose‐derived stem cells (ADSCs) have led to growing interest in cell‐based therapy because they can be easily harvested from an abundant tissue. ADSCs must be expanded in vitro before transplantation. This essential step causes concerns about the safety of adult stem cells in terms of potential transformation. Tumorigenesis is driven in its earliest step by DNA replication stress, which is characterized by the accumulation of stalled DNA replication forks and activation of the DNA damage response. Thus, to evaluate the safety of ADSCs during ex vivo expansion, we monitored DNA replication under atmospheric (21%) or physiologic (1%) oxygen concentration. Here, by combining immunofluorescence and DNA combing, we show that ADSCs cultured under 21% oxygen accumulate endogenous oxidative DNA lesions, which interfere with DNA replication by increasing fork stalling events, thereby leading to incomplete DNA replication and fork collapse. Moreover, we found by RNA sequencing (RNA‐seq) that culture of ADSCs under atmospheric oxygen concentration leads to misexpression of cell cycle and DNA replication genes, which could contribute to DNA replication stress. Finally, analysis of acquired small nucleotide polymorphism shows that expansion of ADSCs under 21% oxygen induces a mutational bias toward deleterious transversions. Overall, our results suggest that expanding ADSCs at a low oxygen concentration could reduce the risk for DNA replication stress‐associated transformation, as occurs in neoplastic tissues. Stem Cells Translational Medicine 2017;6:68–76 PMID:28170194

18F-FDG labeling of mesenchymal stem cells and multipotent adult progenitor cells for PET imaging: effects on ultrastructure and differentiation capacity.

PubMed

Wolfs, Esther; Struys, Tom; Notelaers, Tineke; Roberts, Scott J; Sohni, Abhishek; Bormans, Guy; Van Laere, Koen; Luyten, Frank P; Gheysens, Olivier; Lambrichts, Ivo; Verfaillie, Catherine M; Deroose, Christophe M

2013-03-01

Because of their extended differentiation capacity, stem cells have gained great interest in the field of regenerative medicine. For the development of therapeutic strategies, more knowledge on the in vivo fate of these cells has to be acquired. Therefore, stem cells can be labeled with radioactive tracer molecules such as (18)F-FDG, a positron-emitting glucose analog that is taken up and metabolically trapped by the cells. The aim of this study was to optimize the radioactive labeling of mesenchymal stem cells (MSCs) and multipotent adult progenitor cells (MAPCs) in vitro with (18)F-FDG and to investigate the potential radiotoxic effects of this labeling procedure with a range of techniques, including transmission electron microscopy (TEM). Mouse MSCs and rat MAPCs were used for (18)F-FDG uptake kinetics and tracer retention studies. Cell metabolic activity, proliferation, differentiation and ultrastructural changes after labeling were evaluated using an Alamar Blue reagent, doubling time calculations and quantitative TEM, respectively. Additionally, mice were injected with MSCs and MAPCs prelabeled with (18)F-FDG, and stem cell biodistribution was investigated using small-animal PET. The optimal incubation period for (18)F-FDG uptake was 60 min. Significant early tracer washout was observed, with approximately 30%-40% of the tracer being retained inside the cells 3 h after labeling. Cell viability, proliferation, and differentiation capacity were not severely affected by (18)F-FDG labeling. No major changes at the ultrastructural level, considering mitochondrial length, lysosome size, the number of lysosomes, the number of vacuoles, and the average rough endoplasmic reticulum width, were observed with TEM. Small-animal PET experiments with radiolabeled MAPCs and MSCs injected intravenously in mice showed a predominant accumulation in the lungs and a substantial elution of (18)F-FDG from the cells. MSCs and MAPCs can be successfully labeled with (18)F-FDG for molecular imaging purposes. The main cellular properties are not rigorously affected. TEM confirmed that the cells' ultrastructural properties are not influenced by (18)F-FDG labeling. Small-animal PET studies confirmed the intracellular location of the tracer and the possibility of imaging injected prelabeled stem cell types in vivo. Therefore, direct labeling of MSCs and MAPCs with (18)F-FDG is a suitable technique to noninvasively assess cell delivery and early retention with PET.

Diagnosis and management of acquired aplastic anemia in childhood. Guidelines from the Marrow Failure Study Group of the Pediatric Haemato-Oncology Italian Association (AIEOP).

PubMed

Barone, Angelica; Lucarelli, Annunziata; Onofrillo, Daniela; Verzegnassi, Federico; Bonanomi, Sonia; Cesaro, Simone; Fioredda, Francesca; Iori, Anna Paola; Ladogana, Saverio; Locasciulli, Anna; Longoni, Daniela; Lanciotti, Marina; Macaluso, Alessandra; Mandaglio, Rosalba; Marra, Nicoletta; Martire, Baldo; Maruzzi, Matteo; Menna, Giuseppe; Notarangelo, Lucia Dora; Palazzi, Giovanni; Pillon, Marta; Ramenghi, Ugo; Russo, Giovanna; Svahn, Johanna; Timeus, Fabio; Tucci, Fabio; Cugno, Chiara; Zecca, Marco; Farruggia, Piero; Dufour, Carlo; Saracco, Paola

2015-06-01

Acquired aplastic anemia (AA) is a rare heterogeneous disease characterized by pancytopenia and hypoplastic bone marrow. The incidence is 2-3/million inhabitants/year, in Europe, but higher in East Asia. Survival in severe aplastic anemia (SAA) has markedly improved in the past 2 decades because of advances in hematopoietic stem cell transplantation, immunosuppressive and biologic drugs, and supportive care. In SAA hematopoietic stem cell transplant (HSCT) from a matched sibling donor (MSD) is the treatment of choice. If a MSD is not available, the options include immunosuppressive therapy (IST) or unrelated donor HSCT. The objective of this guideline is to provide healthcare professionals with clear guidance on the diagnosis and management of pediatric patients with AA. A preliminary, evidence-based document issued by a group of pediatric hematologists was discussed, modified and approved during a series of "Consensus Conferences" according to procedures previously validated by the AIEOP Board. The guidelines highlight the importance of referring pediatric patients with AA to pediatric centers with long experience in diagnosis, differential diagnosis, management, supportive care and follow-up of AA. Copyright © 2015. Published by Elsevier Inc.

High Dose Cyclophosphamide without Stem Cell Rescue in 207 Patients with Aplastic anemia and other Autoimmune Diseases

PubMed Central

DeZern, Amy E.; Petri, Michelle; Drachman, Daniel B.; Kerr, Doug; Hammond, Edward R.; Kowalski, Jeanne; Tsai, Hua-Ling; Loeb, David M.; Anhalt, Grant; Wigley, Fredrick; Jones, Richard J.; Brodsky, Robert A.

2011-01-01

High-dose cyclophosphamide has long been used an anticancer agent, a conditioning regimen for hematopoietic stem cell transplantation and as potent immunosuppressive agent in autoimmune diseases including aplastic anemia. High-dose cyclophosphamide is highly toxic to lymphocytes but spares hematopoietic stem cells because of their abundant levels of aldehyde dehydrogenase, the major mechanism of cyclophosphamide inactivation. High dose cyclophosphamide therapy induces durable remissions in most patients with acquired aplastic anemia. Moreover, high-dose cyclophosphamide without hematopoietic stem cell rescue has shown activity in a variety of other severe autoimmune diseases. Here we review the history of cyclophosphamide as is applies to aplastic anemia (AA) and other autoimmune diseases. Included here are the historical data from early patients treated for AA as well as an observational retrospective study in a single tertiary care hospital. This latter component was designed to assess the safety and efficacy of high-dose cyclophosphamide therapy without stem cell rescue in patients with refractory autoimmune diseases. We analyzed fully the 140 patients with severe, progressive autoimmune diseases treated. All patients discussed here received cyclophosphamide, 50 mg/kg per day for 4 consecutive days. Response, relapse and overall survival were measured. Response was defined as a decrease in disease activity in conjunction with a decrease or elimination of immune modulating drugs. Relapse was defined as worsening disease activity and/or a requirement of an increase in dose of, or administration of new, immunosuppressive medications. Hematologic recovery occurred in all patients. The overall response rate of the was 95%, and 44% of those patients remain progression-free with a median follow up time of 36 (range 1–120) months for the 140 patients analyzed together. The overall actuarial and event free survival across all diseases at 60 months is 90.7% and 20.6%, respectively. High- dose cyclophosphamide without stem cell rescue is well-tolerated and induces a high rate of remissions in severe autoimmune diseases. PMID:21358440

Modeling Human Bone Marrow Failure Syndromes Using Pluripotent Stem Cells and Genome Engineering.

PubMed

Jung, Moonjung; Dunbar, Cynthia E; Winkler, Thomas

2015-12-01

The combination of epigenetic reprogramming with advanced genome editing technologies opened a new avenue to study disease mechanisms, particularly of disorders with depleted target tissue. Bone marrow failure syndromes (BMFS) typically present with a marked reduction of peripheral blood cells due to a destroyed or dysfunctional bone marrow compartment. Somatic and germline mutations have been etiologically linked to many cases of BMFS. However, without the ability to study primary patient material, the exact pathogenesis for many entities remained fragmentary. Capturing the pathological genotype in induced pluripotent stem cells (iPSCs) allows studying potential developmental defects leading to a particular phenotype. The lack of hematopoietic stem and progenitor cells in these patients can also be overcome by differentiating patient-derived iPSCs into hematopoietic lineages. With fast growing genome editing techniques, such as CRISPR/Cas9, correction of disease-causing mutations in iPSCs or introduction of mutations in cells from healthy individuals enable comparative studies that may identify other genetic or epigenetic events contributing to a specific disease phenotype. In this review, we present recent progresses in disease modeling of inherited and acquired BMFS using reprogramming and genome editing techniques. We also discuss the challenges and potential shortcomings of iPSC-based models for hematological diseases.

Order Matters: The Order of Somatic Mutations Influences Cancer Evolution.

PubMed

Kent, David G; Green, Anthony R

2017-04-03

Cancers evolve as a consequence of multiple somatic lesions, with competition between subclones and sequential subclonal evolution. Some driver mutations arise either early or late in the evolution of different individual tumors, suggesting that the final malignant properties of a subclone reflect the sum of mutations acquired rather than the order in which they arose. However, very little is known about the cellular consequences of altering the order in which mutations are acquired. Recent studies of human myeloproliferative neoplasms show that the order in which individual mutations are acquired has a dramatic impact on the cell biological and molecular properties of tumor-initiating cells. Differences in clinical presentation, complications, and response to targeted therapy were all observed and implicate mutation order as an important player in cancer biology. These observations represent the first demonstration that the order of mutation acquisition influences stem and progenitor cell behavior and clonal evolution in any cancer. Thus far, the impact of different mutation orders has only been studied in hematological malignancies, and analogous studies of solid cancers are now required. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Cisplatin-induced mesenchymal stromal cells-mediated mechanism contributing to decreased antitumor effect in breast cancer cells.

PubMed

Skolekova, Svetlana; Matuskova, Miroslava; Bohac, Martin; Toro, Lenka; Durinikova, Erika; Tyciakova, Silvia; Demkova, Lucia; Gursky, Jan; Kucerova, Lucia

2016-01-12

Cells of the tumor microenvironment are recognized as important determinants of the tumor biology. The adjacent non-malignant cells can regulate drug responses of the cancer cells by secreted paracrine factors and direct interactions with tumor cells. Human mesenchymal stromal cells (MSC) actively contribute to tumor microenvironment. Here we focused on their response to chemotherapy as during the treatment these cells become affected. We have shown that the secretory phenotype and behavior of mesenchymal stromal cells influenced by cisplatin differs from the naïve MSC. MSC were more resistant to the concentrations of cisplatin, which was cytotoxic for tumor cells. They did not undergo apoptosis, but a part of MSC population underwent senescence. However, MSC pretreatment with cisplatin led to changes in phosphorylation profiles of many kinases and also increased secretion of IL-6 and IL-8 cytokines. These changes in cytokine and phosphorylation profile of MSC led to increased chemoresistance and stemness of breast cancer cells. Taken together here we suggest that the exposure of the chemoresistant cells in the tumor microenvironment leads to substantial alterations and might lead to promotion of acquired microenvironment-mediated chemoresistance and stemness.

p53 inhibits CRISPR-Cas9 engineering in human pluripotent stem cells.

PubMed

Ihry, Robert J; Worringer, Kathleen A; Salick, Max R; Frias, Elizabeth; Ho, Daniel; Theriault, Kraig; Kommineni, Sravya; Chen, Julie; Sondey, Marie; Ye, Chaoyang; Randhawa, Ranjit; Kulkarni, Tripti; Yang, Zinger; McAllister, Gregory; Russ, Carsten; Reece-Hoyes, John; Forrester, William; Hoffman, Gregory R; Dolmetsch, Ricardo; Kaykas, Ajamete

2018-06-11

CRISPR/Cas9 has revolutionized our ability to engineer genomes and conduct genome-wide screens in human cells 1-3 . Whereas some cell types are amenable to genome engineering, genomes of human pluripotent stem cells (hPSCs) have been difficult to engineer, with reduced efficiencies relative to tumour cell lines or mouse embryonic stem cells 3-13 . Here, using hPSC lines with stable integration of Cas9 or transient delivery of Cas9-ribonucleoproteins (RNPs), we achieved an average insertion or deletion (indel) efficiency greater than 80%. This high efficiency of indel generation revealed that double-strand breaks (DSBs) induced by Cas9 are toxic and kill most hPSCs. In previous studies, the toxicity of Cas9 in hPSCs was less apparent because of low transfection efficiency and subsequently low DSB induction 3 . The toxic response to DSBs was P53/TP53-dependent, such that the efficiency of precise genome engineering in hPSCs with a wild-type P53 gene was severely reduced. Our results indicate that Cas9 toxicity creates an obstacle to the high-throughput use of CRISPR/Cas9 for genome engineering and screening in hPSCs. Moreover, as hPSCs can acquire P53 mutations 14 , cell replacement therapies using CRISPR/Cas9-enginereed hPSCs should proceed with caution, and such engineered hPSCs should be monitored for P53 function.

Layer-by-layer buildup of polysaccharide-containing films: Physico-chemical properties and mesenchymal stem cells adhesion.

PubMed

Kulikouskaya, Viktoryia I; Pinchuk, Sergei V; Hileuskaya, Kseniya S; Kraskouski, Aliaksandr N; Vasilevich, Irina B; Matievski, Kirill A; Agabekov, Vladimir E; Volotovski, Igor D

2018-03-22

Layer-by-Layer assembled polyelectrolyte films offer the opportunity to control cell attachment and behavior on solid surfaces. In the present study, multilayer films based on negatively charged biopolymers (pectin, dextran sulfate, carboxymethylcellulose) and positively charged polysaccharide chitosan or synthetic polyelectrolyte polyethyleneimine has been prepared and evaluated. Physico-chemical properties of the formed multilayer films, including their growth, morphology, wettability, stability, and mechanical properties, have been studied. We demonstrated that chitosan-containing films are characterized by the linear growth, the defect-free surface, and predominantly viscoelastic properties. When chitosan is substituted for the polyethyleneimine in the multilayer system, the properties of the formed films are significantly altered: the rigidity and surface roughness increases, the film growth acquires the exponential character. The multilayer films were subsequently used for culturing mesenchymal stem cells. It has been determined that stem cells effectively adhered to chitosan-containing films and formed on them the monolayer culture of fibroblast-like cells with high viability. Our results show that cell attachment is a complex process which is not only governed by the surface functionality because one of the key parameter effects on cell adhesion is the stiffness of polyelectrolyte multilayer films. We therefore propose our Layer-by-Layer films for applications in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018. © 2018 Wiley Periodicals, Inc.

Making neurons from mature glia: a far-fetched dream?

PubMed

Berninger, Benedikt

2010-05-01

The fact that cells with glial characteristics such as forebrain radial glia during development and astroglial stem cells in the adult neurogenic zones serve as neuronal precursors provokes the question why glia in most other areas of the adult central nervous system are apparently incapable of generating new neurons. Besides being of pivotal biological interest answers to this question may also open new avenues for cell-based therapies of neurodegenerative diseases that involve a permanent loss of neurons which are not replaced naturally. For if one could indeed instruct glia to generate neurons, such a strategy would carry the enormous advantage of making use of a large pool of endogenous, and hence autologous cells, thereby circumventing many of the problems associated with therapeutic strategies based on transplantation. Accordingly, the recent years have seen increasing effort in assessing the plasticity of astroglia and other types of resident non-neuronal cells as a potential source for new neurons in the injured brain or eye. For instance, following injury astroglia in the cerebral cortex and Müller glia in the retina can de-differentiate and acquire stem or precursor cell like properties. Moreover, it has been shown that astroglia can be reprogrammed in vitro by forced expression of neurogenic transcription factors to transgress their lineage restriction and stably acquire a neuronal identity. In this review I will discuss the status quo of these early attempts, the limitations currently encountered and the future challenges before the full potential of this approach can be weighed. Copyright 2009 Elsevier Ltd. All rights reserved.

Bone marrow mesenchymal stem cells could acquire the phenotypes of epithelial cells and accelerate vaginal reconstruction combined with small intestinal submucosa.

PubMed

Li, Yanan; Liu, Fangfang; Zhang, Zhiqiang; Zhang, Mingle; Cao, Shanjin; Li, Yachai; Zhang, Lin; Huang, Xianghua; Xu, Yanfang

2015-11-01

Grafting material for vaginal reconstruction commonly includes the bowel, peritoneum, skin, and amniotic membrane. Bone marrow mesenchymal stem cells (MSCs) have the potential of multilineage differentiation into a variety of cells and have been widely explored in tissue engineering. In the current study, we examined whether MSCs could be differentiated to vaginal epithelial cells (VECs) upon co-culturing with VECs. We also examined whether Wnt/β-catenin signaling pathway is implicated in such differentiation. Co-culture of MSCs with VECs using a transwell insert system (with no direct contact) induced the expression of VECs marker AE1/AE3 in MSCs. MSCs combined with small intestinal submucosa (SIS) scaffold were implanted in place of the native vagina in rats to observe the implications for vaginal reconstruction in vivo. Anatomic repair of neovagina was assessed by histological staining for H/E and Masson's Trichrome. GSK-3β and β-catenin, main members of Wnt/β-catenin signaling pathway, in MSCs were increased upon co-culturing with VECs. Exposure of co-cultured MSCs to a Wnt/β-catenin signaling activator, lithium chloride (LiCl, 20 µM) increased phosphorylated GSK-3β and β-catenin and enhanced expression of AE1/AE3. In vivo-grafted cells displayed significant matrix infiltration and expressed epithelial markers in neovagina. These findings suggest that MSCs could acquire the phenotype of VECs when co-cultured with VECs, possibly via activation of Wnt/β-catenin signaling. MSCs provide an alternative cell source for potential use in vaginal tissue engineering. © 2015 International Federation for Cell Biology.

Impact of the International Prognostic Scoring System cytogenetic risk groups on the outcome of patients with primary myelodysplastic syndromes undergoing allogeneic stem cell transplantation from human leukocyte antigen-identical siblings: a retrospective analysis of the European Society for Blood and Marrow Transplantation-Chronic Malignancies Working Party.

PubMed

Onida, Francesco; Brand, Ronald; van Biezen, Anja; Schaap, Michel; von dem Borne, Peter A; Maertens, Johan; Beelen, Dietrich W; Carreras, Enric; Alessandrino, Emilio P; Volin, Liisa; Kuball, Jürgen H E; Figuera, Angela; Sierra, Jorge; Finke, Jürgen; Kröger, Nicolaus; de Witte, Theo

2014-10-01

Acquired chromosomal abnormalities are important prognostic factors in patients with myelodysplastic syndromes treated with supportive care and with disease-modifying therapeutic interventions, including allogeneic hematopoietic stem cell transplantation. To assess the prognostic impact of cytogenetic characteristics after hematopoietic stem cell transplantation accurately, we investigated a homogeneous group of 523 patients with primary myelodysplastic syndromes who have received stem cells from human leukocyte antigen-identical siblings. Overall survival at five years from transplantation in good, intermediate, and poor cytogenetic risk groups according to the International Prognostic Scoring System was 48%, 45% and 30%, respectively (P<0.01). Both the disease status (complete remission vs. not in complete remission) and the morphological classification at transplant in the untreated patients were significantly associated with probability of overall survival and relapse-free survival (P<0.01). The cytogenetic risk groups have no prognostic impact in untreated patients with refractory anemia ± ringed sideroblasts (P=0.90). However, combining the good and intermediate cytogenetic risk groups and comparing them to the poor-risk group showed within the other three disease-status-at-transplant groups a hazard ratio of 1.86 (95%CI: 1.41-2.45). In conclusion, this study shows that, in a large series of patients with primary myelodysplastic syndromes, poor-risk cytogenetics as defined by the standard International Prognostic Scoring System is associated with a relatively poor survival after allogeneic stem cell transplantation from human leukocyte antigen-identical siblings except in patients who are transplanted in refractory anemia/refractory anemia with ringed sideroblasts stage before progression to higher myelodysplastic syndrome stages. Copyright© Ferrata Storti Foundation.

Reprogramming of Somatic Cells Towards Pluripotency by Cell Fusion.

PubMed

Malinowski, Andrzej R; Fisher, Amanda G

2016-01-01

Pluripotent reprogramming can be dominantly induced in a somatic nucleus upon fusion with a pluripotent cell such as embryonic stem (ES) cell. Cell fusion between ES cells and somatic cells results in the formation of heterokaryons, in which the somatic nuclei begin to acquire features of the pluripotent partner. The generation of interspecies heterokaryons between mouse ES- and human somatic cells allows an experimenter to distinguish the nuclear events occurring specifically within the reprogrammed nucleus. Therefore, cell fusion provides a simple and rapid approach to look at the early nuclear events underlying pluripotent reprogramming. Here, we describe a polyethylene glycol (PEG)-mediated cell fusion protocol to generate interspecies heterokaryons and intraspecies hybrids between ES cells and B lymphocytes or fibroblasts.

Clonal dynamics of native haematopoiesis

PubMed Central

Sun, Jianlong; Ramos, Azucena; Chapman, Brad; Johnnidis, Jonathan B.; Le, Linda; Ho, Yu-Jui; Klein, Allon; Hofmann, Oliver; Camargo, Fernando D.

2015-01-01

It is currently thought that life-long blood cell production is driven by the action of a small number of multipotent haematopoietic stem cells. Evidence supporting this view has been largely acquired through the use of functional assays involving transplantation. However, whether these mechanisms also govern native non-transplant haematopoiesis is entirely unclear. Here we have established a novel experimental model in mice where cells can be uniquely and genetically labelled in situ to address this question. Using this approach, we have performed longitudinal analyses of clonal dynamics in adult mice that reveal unprecedented features of native haematopoiesis. In contrast to what occurs following transplantation, steady-state blood production is maintained by the successive recruitment of thousands of clones, each with a minimal contribution to mature progeny. Our results demonstrate that a large number of long-lived progenitors, rather than classically defined haematopoietic stem cells, are the main drivers of steady-state haematopoiesis during most of adulthood. Our results also have implications for understanding the cellular origin of haematopoietic disease. PMID:25296256

Clonal dynamics of native haematopoiesis.

PubMed

Sun, Jianlong; Ramos, Azucena; Chapman, Brad; Johnnidis, Jonathan B; Le, Linda; Ho, Yu-Jui; Klein, Allon; Hofmann, Oliver; Camargo, Fernando D

2014-10-16

It is currently thought that life-long blood cell production is driven by the action of a small number of multipotent haematopoietic stem cells. Evidence supporting this view has been largely acquired through the use of functional assays involving transplantation. However, whether these mechanisms also govern native non-transplant haematopoiesis is entirely unclear. Here we have established a novel experimental model in mice where cells can be uniquely and genetically labelled in situ to address this question. Using this approach, we have performed longitudinal analyses of clonal dynamics in adult mice that reveal unprecedented features of native haematopoiesis. In contrast to what occurs following transplantation, steady-state blood production is maintained by the successive recruitment of thousands of clones, each with a minimal contribution to mature progeny. Our results demonstrate that a large number of long-lived progenitors, rather than classically defined haematopoietic stem cells, are the main drivers of steady-state haematopoiesis during most of adulthood. Our results also have implications for understanding the cellular origin of haematopoietic disease.

Mathematical modelling as a proof of concept for MPNs as a human inflammation model for cancer development.

PubMed

Andersen, Morten; Sajid, Zamra; Pedersen, Rasmus K; Gudmand-Hoeyer, Johanne; Ellervik, Christina; Skov, Vibe; Kjær, Lasse; Pallisgaard, Niels; Kruse, Torben A; Thomassen, Mads; Troelsen, Jesper; Hasselbalch, Hans Carl; Ottesen, Johnny T

2017-01-01

The chronic Philadelphia-negative myeloproliferative neoplasms (MPNs) are acquired stem cell neoplasms which ultimately may transform to acute myelogenous leukemia. Most recently, chronic inflammation has been described as an important factor for the development and progression of MPNs in the biological continuum from early cancer stage to the advanced myelofibrosis stage, the MPNs being described as "A Human Inflammation Model for Cancer Development". This novel concept has been built upon clinical, experimental, genomic, immunological and not least epidemiological studies. Only a few studies have described the development of MPNs by mathematical models, and none have addressed the role of inflammation for clonal evolution and disease progression. Herein, we aim at using mathematical modelling to substantiate the concept of chronic inflammation as an important trigger and driver of MPNs.The basics of the model describe the proliferation from stem cells to mature cells including mutations of healthy stem cells to become malignant stem cells. We include a simple inflammatory coupling coping with cell death and affecting the basic model beneath. First, we describe the system without feedbacks or regulatory interactions. Next, we introduce inflammatory feedback into the system. Finally, we include other feedbacks and regulatory interactions forming the inflammatory-MPN model. Using mathematical modeling, we add further proof to the concept that chronic inflammation may be both a trigger of clonal evolution and an important driving force for MPN disease progression. Our findings support intervention at the earliest stage of cancer development to target the malignant clone and dampen concomitant inflammation.

Matched sibling versus matched unrelated allogeneic hematopoietic stem cell transplantation in children with severe acquired aplastic anemia: experience of the polish pediatric group for hematopoietic stem cell transplantation.

PubMed

Szpecht, Dawid; Gorczyńska, Ewa; Kałwak, Krzysztof; Owoc-Lempach, Joanna; Choma, Marta; Styczyński, Jan; Goździk, Jolanta; Dłużniewska, Agnieszka; Wysocki, Mariusz; Kowalczyk, Jerzy R; Chybicka, Alicja; Pieczonka, Anna; Wachowiak, Jacek

2012-06-01

In the study, 48 children with severe acquired aplastic anemia (SAA) transplanted from matched sibling donor (MSD) between 1991 and 2009, and 38 children with SAA transplanted from matched unrelated donor (MUD) between 2000 and 2009 were evaluated. Engraftment was achieved in 45 (93.75 %) patients after MSD-hematopoietic stem cell transplantation (HSCT) and in 33 (86.8 %) after MUD-HSCT. Transplant-related mortality rate after MSD-HSCT was 8 %, while 37 % after MUD-HSCT. After MSD-HSCT 44 (91.7 %) patients are alive for 1-216 months (median: 85 months), while after MUD-HSCT 24 (63.2 %) patients for 1-84 months (median: 16 months). The 5-year probability of event-free survival after MSD-HSCT and MUD-HSCT was 87 and 53 %, respectively, while 5 years of overall survival was 91 and 64 %, respectively. It was concluded that MSD-HSCT as the first line treatment for children with SAA is a safe therapeutic approach with a low rate of treatment failures and excellent outcome. Results of MUD-HSCT in pediatric patients with SAA who failed to respond to immunosuppressive therapy are still inferior than those of MSD-HSCT. Treatment failures of MUD-HSCT are mainly related to infectious complications and graft failure. It seems, however, that HLA-matching of unrelated donors at allelic level along with early MUD-HSCT after FCA (FLUDA, low-dose cyclophosphamide, and anti-thymocyte globulin) conditioning, perhaps using lower Thymoglobulin dose could enable further improvement of long-term results in children with SAA who lack MSD.

The impact of trisomy 21 on foetal haematopoiesis.

PubMed

Roberts, Irene; O'Connor, David; Roy, Anindita; Cowan, Gillian; Vyas, Paresh

2013-12-01

The high frequency of a unique neonatal preleukaemic syndrome, transient abnormal myelopoiesis (TAM), and subsequent acute myeloid leukaemia in early childhood in patients with trisomy 21 (Down syndrome) points to a specific role for trisomy 21 in transforming foetal haematopoietic cells. N-terminal truncating mutations in the key haematopoietic transcription factor GATA1 are acquired during foetal life in virtually every case. These mutations are not leukaemogenic in the absence of trisomy 21. In mouse models, deregulated expression of chromosome 21-encoded genes is implicated in leukaemic transformation, but does not recapitulate the effects of trisomy 21 in a human context. Recent work using primary human foetal liver and bone marrow cells, human embryonic stem cells and iPS cells shows that prior to acquisition of GATA1 mutations, trisomy 21 itself alters human foetal haematopoietic stem cell and progenitor cell biology causing multiple abnormalities in myelopoiesis and B-lymphopoiesis. The molecular basis by which trisomy 21 exerts these effects is likely to be extremely complex, to be tissue-specific and lineage-specific and to be dependent on ontogeny-related characteristics of the foetal microenvironment. © 2013.

Establishment and Characterization of a Highly Tumourigenic and Cancer Stem Cell Enriched Pancreatic Cancer Cell Line as a Well Defined Model System

PubMed Central

Fredebohm, Johannes; Boettcher, Michael; Eisen, Christian; Gaida, Matthias M.; Heller, Anette; Keleg, Shereen; Tost, Jörg; Greulich-Bode, Karin M.; Hotz-Wagenblatt, Agnes; Lathrop, Mark; Giese, Nathalia A.; Hoheisel, Jörg D.

2012-01-01

Standard cancer cell lines do not model the intratumoural heterogeneity situation sufficiently. Clonal selection leads to a homogeneous population of cells by genetic drift. Heterogeneity of tumour cells, however, is particularly critical for therapeutically relevant studies, since it is a prerequisite for acquiring drug resistance and reoccurrence of tumours. Here, we report the isolation of a highly tumourigenic primary pancreatic cancer cell line, called JoPaca-1 and its detailed characterization at multiple levels. Implantation of as few as 100 JoPaca-1 cells into immunodeficient mice gave rise to tumours that were histologically very similar to the primary tumour. The high heterogeneity of JoPaca-1 was reflected by diverse cell morphology and a substantial number of chromosomal aberrations. Comparative whole-genome sequencing of JoPaca-1 and BxPC-3 revealed mutations in genes frequently altered in pancreatic cancer. Exceptionally high expression of cancer stem cell markers and a high clonogenic potential in vitro and in vivo was observed. All of these attributes make this cell line an extremely valuable model to study the biology of and pharmaceutical effects on pancreatic cancer. PMID:23152778

Development of a Monitoring Method for Nonlabeled Human Pluripotent Stem Cell Growth by Time-Lapse Image Analysis.

PubMed

Suga, Mika; Kii, Hiroaki; Niikura, Keiichi; Kiyota, Yasujiro; Furue, Miho K

2015-07-01

: Cell growth is an important criterion for determining healthy cell conditions. When somatic cells or cancer cells are dissociated into single cells for passaging, the cell numbers can be counted at each passage, providing information on cell growth as an indicator of the health conditions of these cells. In the case of human pluripotent stem cells (hPSCs), because the cells are usually dissociated into cell clumps of ∼50-100 cells for passaging, cell counting is time-consuming. In the present study, using a time-lapse imaging system, we developed a method to determine the growth of hPSCs from nonlabeled live cell phase-contrast images without damaging these cells. Next, the hPSC colony areas and number of nuclei were determined and used to derive equations to calculate the cell number in hPSC colonies, which were assessed on time-lapse images acquired using a culture observation system. The relationships between the colony areas and nuclei numbers were linear, although the equation coefficients were dependent on the cell line used, colony size, colony morphology, and culture conditions. When the culture conditions became improper, the change in cell growth conditions could be detected by analysis of the phase-contrast images. This method provided real-time information on colony growth and cell growth rates without using treatments that can damage cells and could be useful for basic research on hPSCs and cell processing for hPSC-based therapy. This is the first study to use a noninvasive method using images to systemically determine the growth of human pluripotent stem cells (hPSCs) without damaging or wasting cells. This method would be useful for quality control during cell culture of clinical hPSCs. ©AlphaMed Press.

False homozygous HLA genotyping results due to copy number neutral loss of heterozygosity in acquired aplastic anaemia.

PubMed

Heyrman, Bert; De Becker, Ann; Verheyden, Sonja; Demanet, Christian

2017-03-02

The aim of this case report is to draw attention on possible false human leucocyte antigen (HLA) genotyping in acquired aplastic anaemia prior to allogeneic haematopoietic stem cell transplantation. In acquired aplastic anaemia loss of heterozygosity (LOH) of chromosome 6p is known to occur in around 12%. We report false HLA genotyping results due to LOH and a coinciding steep rise in neutrophils following filgrastim stimulation in a patient with very severe aplastic anaemia. At diagnosis we obtained heterozygous results on peripheral blood. Failing to reach a partial response at 6 months with immune-suppressive therapy we repeated HLA genotyping, obtaining homozygous results. Repeated testing confirmed loss of HLA genotype heterozygosity. HLA genotyping on cells obtained by a buccal swab confirmed the previous HLA heterozygosity. A second course of filgrastim at the time of homozygous HLA genotyping resulted in a steep rise in neutrophils. Stopping filgrastim resulted in an equally steep drop. 2017 BMJ Publishing Group Ltd.

In Vitro Expanded Stem Cells from the Developing Retina Fail to Generate Photoreceptors but Differentiate into Myelinating Oligodendrocytes

PubMed Central

Czekaj, Magdalena; Haas, Jochen; Gebhardt, Marlen; Müller-Reichert, Thomas; Humphries, Peter; Farrar, Jane; Bartsch, Udo; Ader, Marius

2012-01-01

Cell transplantation to treat retinal degenerative diseases represents an option for the replacement of lost photoreceptor cells. In vitro expandable cells isolated from the developing mammalian retina have been suggested as a potential source for the generation of high numbers of donor photoreceptors. In this study we used standardized culture conditions based on the presence of the mitogens FGF-2 and EGF to generate high numbers of cells in vitro from the developing mouse retina. These presumptive ‘retinal stem cells’ (‘RSCs’) can be propagated as monolayer cultures over multiple passages, express markers of undifferentiated neural cells, and generate neuronal and glial cell types upon withdrawal of mitogens in vitro or following transplantation into the adult mouse retina. The proportion of neuronal differentiation can be significantly increased by stepwise removal of mitogens and inhibition of the notch signaling pathway. However, ‘RSCs’, by contrast to their primary counterparts in vivo, i.e. retinal progenitor cells, loose the expression of retina-specific progenitor markers like Rax and Chx10 after passaging and fail to differentiate into photoreceptors both in vitro or after intraretinal transplantation. Notably, ‘RSCs’ can be induced to differentiate into myelinating oligodendrocytes, a cell type not generated by primary retinal progenitor cells. Based on these findings we conclude that ‘RSCs’ expanded in high concentrations of FGF-2 and EGF loose their retinal identity and acquire features of in vitro expandable neural stem-like cells making them an inappropriate cell source for strategies aimed at replacing photoreceptor cells in the degenerated retina. PMID:22848612

Human memory CD8 T cell effector potential is epigenetically preserved during in vivo homeostasis.

PubMed

Abdelsamed, Hossam A; Moustaki, Ardiana; Fan, Yiping; Dogra, Pranay; Ghoneim, Hazem E; Zebley, Caitlin C; Triplett, Brandon M; Sekaly, Rafick-Pierre; Youngblood, Ben

2017-06-05

Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell-mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (T EM ), and longer-lived central memory (T CM ) and stem cell memory (T SCM ) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7- and IL-15-mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of T CM and T SCM memory cells resulted in phenotypic conversion into T EM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired T EM -associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells. © 2017 Abdelsamed et al.

Differential gene expression profiling of human adipose stem cells differentiating into smooth muscle-like cells by TGFβ1/BMP4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elçin, Ayşe Eser; Parmaksiz, Mahmut; Dogan, Arin

Regenerative repair of the vascular system is challenging from the perspectives of translational medicine and tissue engineering. There are fundamental hurdles in front of creating bioartificial arteries, which involve recaputilation of the three-layered structure under laboratory settings. Obtaining and maintaining smooth muscle characteristics is an important limitation, as the transdifferentiated cells fail to display mature phenotype. This study aims to shed light on the smooth muscle differentiation of human adipose stem cells (hASCs). To this end, we first acquired hASCs from lipoaspirate samples. Upon characterization, the cells were induced to differentiate into smooth muscle (SM)-like cells using a variety ofmore » inducer combinations. Among all, TGFβ1/BMP4 combination had the highest differentiation efficiency, based on immunohistochemical analyses. hSM-like cell samples were compared to hASCs and to the positive control, human coronary artery-smooth muscle cells (hCA-SMCs) through gene transcription profiling. Microarray findings revealed the activation of gene groups that function in smooth muscle differentiation, signaling pathways, extracellular modeling and cell proliferation. Our results underline the effectiveness of the growth factors and suggest some potential variables for detecting the SM-like cell characteristics. Evidence in transcriptome level was used to evaluate the TGFβ1/BMP4 combination as a previously unexplored effector for the smooth muscle differentiation of adipose stem cells. - Highlights: • Human adipose stem cells (hASCs) were isolated, characterized and cultured. • Growth factor combinations were evaluated for their effectiveness in differentiation using IHC. • hASCs were differentiated into smooth muscle (SM)-like cells using TGF-β1 and BMP4 combination. • Microarray analysis was performed for hASCs, SM-like cells and coronary artery-SMCs. • Microarray data was used to perform hierarchical clustering and interpretation of activated pathways.« less

Glycome Diagnosis of Human Induced Pluripotent Stem Cells Using Lectin Microarray*

PubMed Central

Tateno, Hiroaki; Toyota, Masashi; Saito, Shigeru; Onuma, Yasuko; Ito, Yuzuru; Hiemori, Keiko; Fukumura, Mihoko; Matsushima, Asako; Nakanishi, Mio; Ohnuma, Kiyoshi; Akutsu, Hidenori; Umezawa, Akihiro; Horimoto, Katsuhisa; Hirabayashi, Jun; Asashima, Makoto

2011-01-01

Induced pluripotent stem cells (iPSCs) can now be produced from various somatic cell (SC) lines by ectopic expression of the four transcription factors. Although the procedure has been demonstrated to induce global change in gene and microRNA expressions and even epigenetic modification, it remains largely unknown how this transcription factor-induced reprogramming affects the total glycan repertoire expressed on the cells. Here we performed a comprehensive glycan analysis using 114 types of human iPSCs generated from five different SCs and compared their glycomes with those of human embryonic stem cells (ESCs; nine cell types) using a high density lectin microarray. In unsupervised cluster analysis of the results obtained by lectin microarray, both undifferentiated iPSCs and ESCs were clustered as one large group. However, they were clearly separated from the group of differentiated SCs, whereas all of the four SCs had apparently distinct glycome profiles from one another, demonstrating that SCs with originally distinct glycan profiles have acquired those similar to ESCs upon induction of pluripotency. Thirty-eight lectins discriminating between SCs and iPSCs/ESCs were statistically selected, and characteristic features of the pluripotent state were then obtained at the level of the cellular glycome. The expression profiles of relevant glycosyltransferase genes agreed well with the results obtained by lectin microarray. Among the 38 lectins, rBC2LCN was found to detect only undifferentiated iPSCs/ESCs and not differentiated SCs. Hence, the high density lectin microarray has proved to be valid for not only comprehensive analysis of glycans but also diagnosis of stem cells under the concept of the cellular glycome. PMID:21471226

Variations in Glycogen Synthesis in Human Pluripotent Stem Cells with Altered Pluripotent States

PubMed Central

Chen, Richard J.; Zhang, Guofeng; Garfield, Susan H.; Shi, Yi-Jun; Chen, Kevin G.; Robey, Pamela G.; Leapman, Richard D.

2015-01-01

Human pluripotent stem cells (hPSCs) represent very promising resources for cell-based regenerative medicine. It is essential to determine the biological implications of some fundamental physiological processes (such as glycogen metabolism) in these stem cells. In this report, we employ electron, immunofluorescence microscopy, and biochemical methods to study glycogen synthesis in hPSCs. Our results indicate that there is a high level of glycogen synthesis (0.28 to 0.62 μg/μg proteins) in undifferentiated human embryonic stem cells (hESCs) compared with the glycogen levels (0 to 0.25 μg/μg proteins) reported in human cancer cell lines. Moreover, we found that glycogen synthesis was regulated by bone morphogenetic protein 4 (BMP-4) and the glycogen synthase kinase 3 (GSK-3) pathway. Our observation of glycogen bodies and sustained expression of the pluripotent factor Oct-4 mediated by the potent GSK-3 inhibitor CHIR-99021 reveals an altered pluripotent state in hPSC culture. We further confirmed glycogen variations under different naïve pluripotent cell growth conditions based on the addition of the GSK-3 inhibitor BIO. Our data suggest that primed hPSCs treated with naïve growth conditions acquire altered pluripotent states, similar to those naïve-like hPSCs, with increased glycogen synthesis. Furthermore, we found that suppression of phosphorylated glycogen synthase was an underlying mechanism responsible for altered glycogen synthesis. Thus, our novel findings regarding the dynamic changes in glycogen metabolism provide new markers to assess the energetic and various pluripotent states in hPSCs. The components of glycogen metabolic pathways offer new assays to delineate previously unrecognized properties of hPSCs under different growth conditions. PMID:26565809

3-dimensional examination of the adult mouse subventricular zone reveals lineage-specific microdomains.

PubMed

Azim, Kasum; Fiorelli, Roberto; Zweifel, Stefan; Hurtado-Chong, Anahi; Yoshikawa, Kazuaki; Slomianka, Lutz; Raineteau, Olivier

2012-01-01

Recent studies suggest that the subventricular zone (SVZ) of the lateral ventricle is populated by heterogeneous populations of stem and progenitor cells that, depending on their exact location, are biased to acquire specific neuronal fates. This newly described heterogeneity of SVZ stem and progenitor cells underlines the necessity to develop methods for the accurate quantification of SVZ stem and progenitor subpopulations. In this study, we provide 3-dimensional topographical maps of slow cycling "stem" cells and progenitors based on their unique cell cycle properties. These maps revealed that both cell populations are present throughout the lateral ventricle wall as well as in discrete regions of the dorsal wall. Immunodetection of transcription factors expressed in defined progenitor populations further reveals that divergent lineages have clear regional enrichments in the rostro-caudal as well as in the dorso-ventral span of the lateral ventricle. Thus, progenitors expressing Tbr2 and Dlx2 were confined to dorsal and dorso-lateral regions of the lateral ventricle, respectively, while Mash1+ progenitors were more homogeneously distributed. All cell populations were enriched in the rostral-most region of the lateral ventricle. This diversity and uneven distribution greatly impede the accurate quantification of SVZ progenitor populations. This is illustrated by measuring the coefficient of error of estimates obtained by using increasing section sampling interval. Based on our empirical data, we provide such estimates for all progenitor populations investigated in this study. These can be used in future studies as guidelines to judge if the precision obtained with a sampling scheme is sufficient to detect statistically significant differences between experimental groups if a biological effect is present. Altogether, our study underlines the need to consider the SVZ of the lateral ventricle as a complex 3D structure and define methods to accurately assess neural stem cells or progenitor diversity and population sizes in physiological or experimental paradigms.

Role of Pharmacogenetics in Hematopoietic Stem Cell Transplantation Outcome in Children

PubMed Central

Franca, Raffaella; Stocco, Gabriele; Favretto, Diego; Giurici, Nagua; Decorti, Giuliana; Rabusin, Marco

2015-01-01

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic procedure for several congenital and acquired disorders, both malignant and nonmalignant. Despite the great improvements in HSCT clinical practices over the last few decades, complications, such as graft vs. host disease (GVHD) and sinusoidal obstructive syndrome (SOS), are still largely unpredictable and remain the major causes of morbidity and mortality. Both donor and patient genetic background might influence the success of bone marrow transplantation and could at least partially explain the inter-individual variability in HSCT outcome. This review summarizes some of the recent studies on candidate gene polymorphisms in HSCT, with particular reference to pediatric cohorts. The interest is especially focused on pharmacogenetic variants affecting myeloablative and immunosuppressive drugs, although genetic traits involved in SOS susceptibility and transplant-related mortality are also reviewed. PMID:26266406

The Cosmopolitanization of Science: Experience from Chinese Stem Cell Scientists.

PubMed

Zhang, Joy Yueyue

2010-09-01

It is commonly perceived that the 'globalization of science' may result in a 'Westernization of science'. In this paper, however, I use the case of stem cell science in China to demonstrate that developing countries are sometimes able to effectively shape the norms of global/local scientific exchange. Based on interviews with 38 stem cell scientists in six Chinese cities in early 2008, this paper elucidates Chinese scientists' outlook towards cross-border collaborations and the effects that the internationalization of science has had on everyday laboratory operations. Findings suggest that although there still exists an asymmetry of scientific influence, and in many aspects China is still 'catching-up' to the West, there is also a changing nature of communication beyond borders. One key aspect of recent international scientific development is the growing necessity for local stakeholders to acquire a global mindset and to compare, reflect and accommodate diverse interests. This is what I define as the 'cosmopolitanization of science'. The study empirically examines the sociological and methodological implications of the cosmopolitanization process and further develops Ulrich Beck's cosmopolitan theory by delineating four main features of the 'cosmopolitanization of science': shared future benefits, passive ethicization, reflexive negotiation, and continuous performance.

Instruction of haematopoietic lineage choices, evolution of transcriptional landscapes and cancer stem cell hierarchies derived from an AML1-ETO mouse model

PubMed Central

Cabezas-Wallscheid, Nina; Eichwald, Victoria; de Graaf, Jos; Löwer, Martin; Lehr, Hans-Anton; Kreft, Andreas; Eshkind, Leonid; Hildebrandt, Andreas; Abassi, Yasmin; Heck, Rosario; Dehof, Anna Katharina; Ohngemach, Svetlana; Sprengel, Rolf; Wörtge, Simone; Schmitt, Steffen; Lotz, Johannes; Meyer, Claudius; Kindler, Thomas; Zhang, Dong-Er; Kaina, Bernd; Castle, John C; Trumpp, Andreas; Sahin, Ugur; Bockamp, Ernesto

2013-01-01

The t(8;21) chromosomal translocation activates aberrant expression of the AML1-ETO (AE) fusion protein and is commonly associated with core binding factor acute myeloid leukaemia (CBF AML). Combining a conditional mouse model that closely resembles the slow evolution and the mosaic AE expression pattern of human t(8;21) CBF AML with global transcriptome sequencing, we find that disease progression was characterized by two principal pathogenic mechanisms. Initially, AE expression modified the lineage potential of haematopoietic stem cells (HSCs), resulting in the selective expansion of the myeloid compartment at the expense of normal erythro- and lymphopoiesis. This lineage skewing was followed by a second substantial rewiring of transcriptional networks occurring in the trajectory to manifest leukaemia. We also find that both HSC and lineage-restricted granulocyte macrophage progenitors (GMPs) acquired leukaemic stem cell (LSC) potential being capable of initiating and maintaining the disease. Finally, our data demonstrate that long-term expression of AE induces an indolent myeloproliferative disease (MPD)-like myeloid leukaemia phenotype with complete penetrance and that acute inactivation of AE function is a potential novel therapeutic option. PMID:24124051

Aging, clonal hematopoiesis and preleukemia: not just bad luck?

PubMed

Shlush, Liran I; Zandi, Sasan; Itzkovitz, Shalev; Schuh, Andre C

2015-11-01

Chronological human aging is associated with a number of changes in the hematopoietic system, occurring at many levels from stem to mature cells, and the marrow microenvironment as well. This review will focus mainly on the aging of hematopoietic stem and progenitor cells (HSPCs), and on the associated increases in the incidence of hematological malignancies. HSPCs manifest reduced function and acquire molecular changes with chronological aging. Furthermore, while for many years it has been known that the human hematopoietic system becomes increasingly clonal with chronological aging (clonal hematopoiesis), only in the last few years has it become clear that clonal hematopoiesis may result from the accumulation of preleukemic mutations in HSPCs. Such mutations confer a selective advantage that leads to clonal hematopoiesis, and that may occasionally result in the development of leukemia, and define the existence of both preleukemic stem cells, and of 'preleukemia' as a clinical entity. While it is well appreciated that clonal hematopoiesis is very common in the elderly, several questions remain unanswered: why and how does clonal hematopoiesis develop? How is clonal hematopoiesis related to the age-related changes observed in the hematopoietic system? And why do only some individuals with clonal hematopoiesis develop leukemia?

Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia

PubMed Central

Will, Britta; Vogler, Thomas O.; Narayanagari, Swathi; Bartholdy, Boris; Todorova, Tihomira I.; da Silva Ferreira, Mariana; Chen, Jiahao; Yu, Yiting; Mayer, Jillian; Barreyro, Laura; Carvajal, Luis; Ben Neriah, Daniela; Roth, Michael; van Oers, Johanna; Schaetzlein, Sonja; McMahon, Christine; Edelmann, Winfried; Verma, Amit; Steidl, Ulrich

2016-01-01

Modest transcriptional changes caused by genetic or epigenetic mechanisms are frequent in human cancer. Although loss or near-complete loss of the hematopoietic transcription factor PU.1 induces acute myeloid leukemia (AML) in mice, a similar degree of PU.1 impairment is exceedingly rare in human AML; yet moderate PU.1 inhibition is common in AML patients. We assessed functional consequences of modest reduction of PU.1 expression on leukemia development in mice harboring DNA lesions resembling those acquired during human stem cell aging. Heterozygous deletion of an enhancer of PU.1, which resulted in 35% reduction of PU.1 expression, was sufficient to induce myeloid biased preleukemic stem cells and subsequent transformation to AML in a DNA mismatch repair-deficient background. AML progression was mediated by inhibition of expression of a PU.1 cooperating transcription factor, Irf8. Strikingly, we found significant molecular similarities with human myelodysplastic syndrome and AML. This study demonstrates that minimal reduction of a key lineage-specific transcription factor that commonly occurs in human disease is sufficient to initiate cancer development and provides mechanistic insight into the formation and progression of preleukemic stem cells in AML. PMID:26343801

MMR Deficiency Does Not Sensitize or Compromise the Function of Hematopoietic Stem Cells to Low and High LET Radiation.

PubMed

Patel, Rutulkumar; Qing, Yulan; Kennedy, Lucy; Yan, Yan; Pink, John; Aguila, Brittany; Desai, Amar; Gerson, Stanton L; Welford, Scott M

2018-04-14

One of the major health concerns on long-duration space missions will be radiation exposure to the astronauts. Outside the earth's magnetosphere, astronauts will be exposed to galactic cosmic rays (GCR) and solar particle events that are principally composed of protons and He, Ca, O, Ne, Si, Ca, and Fe nuclei. Protons are by far the most common species, but the higher atomic number particles are thought to be more damaging to biological systems. Evaluation and amelioration of risks from GCR exposure will be important for deep space travel. The hematopoietic system is one of the most radiation-sensitive organ systems, and is highly dependent on functional DNA repair pathways for survival. Recent results from our group have demonstrated an acquired deficiency in mismatch repair (MMR) in human hematopoietic stem cells (HSCs) with age due to functional loss of the MLH1 protein, suggesting an additional risk to astronauts who may have significant numbers of MMR deficient HSCs at the time of space travel. In the present study, we investigated the effects gamma radiation, proton radiation, and 56 Fe radiation on HSC function in Mlh1 +/+ and Mlh1 -/- marrow from mice in a variety of assays and have determined that while cosmic radiation is a major risk to the hematopoietic system, there is no dependence on MMR capacity. Stem Cells Translational Medicine 2018. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

REGULATION OF LUNG CANCER METASTASIS BY Klf4-Numb-like SIGNALING

PubMed Central

Vaira, Valentina; Faversani, Alice; Martin, Nina M.; Garlick, David S.; Ferrero, Stefano; Nosotti, Mario; Kissil, Joseph L.; Bosari, Silvano; Altieri, Dario C.

2013-01-01

Metastatic traits appear to be acquired by transformed cells with progenitor-like cancer-initiating properties, but there remains little mechanistic insight into this linkage. In this report, we show that the polarity protein Numbl, which is expressed normally in neuronal progenitors, becomes overexpressed and mislocalized in cancer cells from a variety of human tumors. Numbl overexpression relies on loss of the tumor suppressor microRNA-296-5p (miR-296), which actively represses translation of Numbl in normal cells. In turn, deregulated expression of Numbl mediates random tumor cell migration and invasion, blocking anoikis and promoting metastatic dissemination. In clinical specimens of non-small cell lung cancer, we found that Numbl overexpression correlated with a reduction in overall patient survival. Mechanistically, Numbl-mediated tumorigenesis involved suppression of a "stemness" transcriptional program driven by the stem cell programming transcription factor Klf4, thereby preserving a pool of progenitor-like cells in lung cancer. Our results reveal that Numbl-Klf4 signaling is critical to maintain multiple nodes of metastatic progression, including persistence of cancer-initiating cells, rationalizing its therapeutic exploitation to improve the treatment of advanced lung cancer PMID:23440423

The role of lin-22, a hairy/enhancer of split homolog, in patterning the peripheral nervous system of C. elegans.

PubMed

Wrischnik, L A; Kenyon, C J

1997-08-01

In C. elegans, six lateral epidermal stem cells, the seam cells V1-V6, are located in a row along the anterior-posterior (A/P) body axis. Anterior seam cells (V1-V4) undergo a fairly simple sequence of stem cell divisions and generate only epidermal cells. Posterior seam cells (V5 and V6) undergo a more complicated sequence of cell divisions that include additional rounds of stem cell proliferation and the production of neural as well as epidermal cells. In the wild type, activity of the gene lin-22 allows V1-V4 to generate their normal epidermal lineages rather than V5-like lineages. lin-22 activity is also required to prevent additional neurons from being produced by one branch of the V5 lineage. We find that the lin-22 gene exhibits homology to the Drosophila gene hairy, and that lin-22 activity represses neural development within the V5 lineage by blocking expression of the posterior-specific Hox gene mab-5 in specific cells. In addition, in order to prevent anterior V cells from generating V5-like lineages, wild-type lin-22 gene activity must inhibit (directly or indirectly) at least five downstream regulatory gene activities. In anterior body regions, lin-22(+) inhibits expression of the Hox gene mab-5. It also inhibits the activity of the achaete-scute homolog lin-32 and an unidentified gene that we postulate regulates stem cell division. Each of these three genes is required for the expression of a different piece of the ectopic V5-like lineages generated in lin-22 mutants. In addition, lin-22 activity prevents two other Hox genes, lin-39 and egl-5, from acquiring new activities within their normal domains of function along the A/P body axis. Some, but not all, of the patterning activities of lin-22 in C. elegans resemble those of hairy in Drosophila.

Recruited brain tumor-derived mesenchymal stem cells contribute to brain tumor progression.

PubMed

Behnan, Jinan; Isakson, Pauline; Joel, Mrinal; Cilio, Corrado; Langmoen, Iver A; Vik-Mo, Einar O; Badn, Wiaam

2014-05-01

The identity of the cells that contribute to brain tumor structure and progression remains unclear. Mesenchymal stem cells (MSCs) have recently been isolated from normal mouse brain. Here, we report the infiltration of MSC-like cells into the GL261 murine glioma model. These brain tumor-derived mesenchymal stem cells (BT-MSCs) are defined with the phenotype (Lin-Sca-1+CD9+CD44+CD166+/-) and have multipotent differentiation capacity. We show that the infiltration of BT-MSCs correlates to tumor progression; furthermore, BT-MSCs increased the proliferation rate of GL261 cells in vitro. For the first time, we report that the majority of GL261 cells expressed mesenchymal phenotype under both adherent and sphere culture conditions in vitro and that the non-MSC population is nontumorigenic in vivo. Although the GL261 cell line expressed mesenchymal phenotype markers in vitro, most BT-MSCs are recruited cells from host origin in both wild-type GL261 inoculated into green fluorescent protein (GFP)-transgenic mice and GL261-GFP cells inoculated into wild-type mice. We show the expression of chemokine receptors CXCR4 and CXCR6 on different recruited cell populations. In vivo, the GL261 cells change marker profile and acquire a phenotype that is more similar to cells growing in sphere culture conditions. Finally, we identify a BT-MSC population in human glioblastoma that is CD44+CD9+CD166+ both in freshly isolated and culture-expanded cells. Our data indicate that cells with MSC-like phenotype infiltrate into the tumor stroma and play an important role in tumor cell growth in vitro and in vivo. Thus, we suggest that targeting BT-MSCs could be a possible strategy for treating glioblastoma patients. © 2013 AlphaMed Press.

Cell Therapy in Dermatology

PubMed Central

Petrof, Gabriela; Abdul-Wahab, Alya; McGrath, John A.

2014-01-01

Harnessing the regenerative capacity of keratinocytes and fibroblasts from human skin has created new opportunities to develop cell-based therapies for patients. Cultured cells and bioengineered skin products are being used to treat patients with inherited and acquired skin disorders associated with defective skin, and further clinical trials of new products are in progress. The capacity of extracutaneous sources of cells such as bone marrow is also being investigated for its plasticity in regenerating skin, and new strategies, such as the derivation of inducible pluripotent stem cells, also hold great promise for future cell therapies in dermatology. This article reviews some of the preclinical and clinical studies and future directions relating to cell therapy in dermatology, particularly for inherited skin diseases associated with fragile skin and poor wound healing. PMID:24890834

TRAF6 regulates satellite stem cell self-renewal and function during regenerative myogenesis

PubMed Central

Hindi, Sajedah M.; Kumar, Ashok

2015-01-01

Satellite cells are a stem cell population within adult muscle and are responsible for myofiber regeneration upon injury. Satellite cell dysfunction has been shown to underlie the loss of skeletal muscle mass in many acquired and genetic muscle disorders. The transcription factor paired box-protein-7 (PAX7) is indispensable for supplementing the reservoir of satellite cells and driving regeneration in normal and diseased muscle. TNF receptor–associated factor 6 (TRAF6) is an adaptor protein and an E3 ubiquitin ligase that mediates the activation of multiple cell signaling pathways in a context-dependent manner. Here, we demonstrated that TRAF6-mediated signaling is critical for homeostasis of satellite cells and their function during regenerative myogenesis. Selective deletion of Traf6 in satellite cells of adult mice led to profound muscle regeneration defects and dramatically reduced levels of PAX7 and late myogenesis markers. TRAF6 was required for the activation of MAPKs ERK1/2 and JNK1/2, which in turn activated the transcription factor c-JUN, which binds the Pax7 promoter and augments Pax7 expression. Moreover, TRAF6/c-JUN signaling repressed the levels of the microRNAs miR-1 and miR-206, which promote differentiation, to maintain PAX7 levels in satellite cells. We also determined that satellite cell–specific deletion of Traf6 exaggerates the dystrophic phenotype in the mdx (a mouse model of Duchenne muscular dystrophy) mouse by blunting the regeneration of injured myofibers. Collectively, our study reveals an essential role for TRAF6 in satellite stem cell function. PMID:26619121

Epigenetic Loss of MLH1 Expression in Normal Human Hematopoietic Stem Cell Clones is Defined by the Promoter CpG Methylation Pattern Observed by High-Throughput Methylation Specific Sequencing

PubMed Central

Kenyon, Jonathan; Nickel-Meester, Gabrielle; Qing, Yulan; Santos-Guasch, Gabriela; Drake, Ellen; PingfuFu; Sun, Shuying; Bai, Xiaodong; Wald, David; Arts, Eric; Gerson, Stanton L.

2016-01-01

Normal human hematopoietic stem and progenitor cells (HPC) lose expression of MLH1, an important mismatch repair (MMR) pathway gene, with age. Loss of MMR leads to replication dependent mutational events and microsatellite instability observed in secondary acute myelogenous leukemia and other hematologic malignancies. Epigenetic CpG methylation upstream of the MLH1 promoter is a contributing factor to acquired loss of MLH1 expression in tumors of the epithelia and proximal mucosa. Using single molecule high-throughput bisulfite sequencing we have characterized the CpG methylation landscape from −938 to −337 bp upstream of the MLH1 transcriptional start site (position +0), from 30 hematopoietic colony forming cell clones (CFC) either expressing or not expressing MLH1. We identify a correlation between MLH1 promoter methylation and loss of MLH1 expression. Additionally, using the CpG site methylation frequencies obtained in this study we were able to generate a classification algorithm capable of sorting the expressing and non-expressing CFC. Thus, as has been previously described for many tumor cell types, we report for the first time a correlation between the loss of MLH1 expression and increased MLH1 promoter methylation in CFC derived from CD34+ selected hematopoietic stem and progenitor cells. PMID:27570841

Epigenetic Loss of MLH1 Expression in Normal Human Hematopoietic Stem Cell Clones is Defined by the Promoter CpG Methylation Pattern Observed by High-Throughput Methylation Specific Sequencing.

PubMed

Kenyon, Jonathan; Nickel-Meester, Gabrielle; Qing, Yulan; Santos-Guasch, Gabriela; Drake, Ellen; PingfuFu; Sun, Shuying; Bai, Xiaodong; Wald, David; Arts, Eric; Gerson, Stanton L

Normal human hematopoietic stem and progenitor cells (HPC) lose expression of MLH1 , an important mismatch repair (MMR) pathway gene, with age. Loss of MMR leads to replication dependent mutational events and microsatellite instability observed in secondary acute myelogenous leukemia and other hematologic malignancies. Epigenetic CpG methylation upstream of the MLH1 promoter is a contributing factor to acquired loss of MLH1 expression in tumors of the epithelia and proximal mucosa. Using single molecule high-throughput bisulfite sequencing we have characterized the CpG methylation landscape from -938 to -337 bp upstream of the MLH1 transcriptional start site (position +0), from 30 hematopoietic colony forming cell clones (CFC) either expressing or not expressing MLH1 . We identify a correlation between MLH1 promoter methylation and loss of MLH1 expression. Additionally, using the CpG site methylation frequencies obtained in this study we were able to generate a classification algorithm capable of sorting the expressing and non-expressing CFC. Thus, as has been previously described for many tumor cell types, we report for the first time a correlation between the loss of MLH1 expression and increased MLH1 promoter methylation in CFC derived from CD34 + selected hematopoietic stem and progenitor cells.

Epigenetic Mechanisms Regulate MHC and Antigen Processing Molecules in Human Embryonic and Induced Pluripotent Stem Cells

PubMed Central

Suárez-Álvarez, Beatriz; Rodriguez, Ramón M.; Calvanese, Vincenzo; Blanco-Gelaz, Miguel A.; Suhr, Steve T.; Ortega, Francisco; Otero, Jesus; Cibelli, Jose B.; Moore, Harry; Fraga, Mario F.; López-Larrea, Carlos

2010-01-01

Background Human embryonic stem cells (hESCs) are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC) class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored. Methodology/Principal Findings We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM) components and NKG2D ligands (NKG2D-L) in hESCs, induced pluripotent stem cells (iPSCs) and NTera2 (NT2) teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP) assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1) and tapasin (TPN) components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of β2-microglobulin (β2m) light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB) were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and β2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs). Absence of HLA-DR and HLA-G expression was regulated by DNA methylation. Conclusions/Significance Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell allograft acceptance. PMID:20419139

Development of suspension cell culture model to mimic circulating tumor cells

PubMed Central

Park, Ji Young; Jeong, Ae Lee; Joo, Hyun Jeong; Han, Sora; Kim, So-Hyun; Kim, Hye-Youn; Lim, Jong-Seok; Lee, Myeong-Sok; Choi, Hyung-Kyoon; Yang, Young

2018-01-01

Circulating tumor cells (CTCs) are essential for the establishment of distant metastasis. Numerous studies have characterized CTCs as metastatic precursors; however, the molecular nature of CTCs has not been completely revealed yet due to the low number of CTCs in the blood stream. As an alternative approach, we developed a long-term suspension cell culture model using human breast cancer cell lines to mimic CTCs. We found that more than 40 passaged suspension cells acquired the ability to enhance metastasis like cancer stem cells. To identify molecular changes acquired during the suspension cell culture, we analyzed metabolic and lipidomic profiles as well as transcriptome in MDA-MB-468 suspension cells. Glutamate and leucine levels increased in suspension cells, and cholesterol synthesis pathway was altered. The inhibition of glutamate metabolic pathway decreased the proliferation of suspension cells compared to that of adherent cells. In the lipidomic profile, PC species containing long chain and polyunsaturated fatty acids increased in suspension cells and these species could be authentic and specific biomarkers for highly metastatic cancers. As this CTC-mimicking suspension cell culture model may easily apply to various types of cancer, we suggest this model as a great tool to develop therapeutic targets and drugs to eradicate metastatic cancer cells. PMID:29416640

IL-7 signaling imparts polyfunctionality and stemness potential to CD4+ T cells

PubMed Central

Ding, Zhi-Chun; Liu, Chufeng; Cao, Yang; Habtetsion, Tsadik; Kuczma, Michal; Pi, Wenhu; Kong, Heng; Cacan, Ercan; Greer, Susanna F.; Cui, Yan; Blazar, Bruce R.; Munn, David H.; Zhou, Gang

2016-01-01

ABSTRACT The functional status of CD4+ T cells is a critical determinant of antitumor immunity. Polyfunctional CD4+ T cells possess the ability to concomitantly produce multiple Th1-type cytokines, exhibiting a functional attribute desirable for cancer immunotherapy. However, the mechanisms by which these cells are induced are neither defined nor it is clear if these cells can be used therapeutically to treat cancer. Here, we report that CD4+ T cells exposed to exogenous IL-7 during antigenic stimulation can acquire a polyfunctional phenotype, characterized by their ability to simultaneously express IFNγ, IL-2, TNFα and granzyme B. This IL-7-driven polyfunctional phenotype was associated with increased histone acetylation in the promoters of the effector genes, indicative of increased chromatin accessibility. Moreover, forced expression of a constitutively active (CA) form of STAT5 recapitulated IL-7 in inducing CD4+ T-cell polyfunctionality. Conversely, the expression of a dominant negative (DN) form of STAT5 abolished the ability of IL-7 to induce polyfunctional CD4+ T cells. These in-vitro-generated polyfunctional CD4+ T cells can traffic to tumor and expand intratumorally in response to immunization. Importantly, adoptive transfer of polyfunctional CD4+ T cells following lymphodepletive chemotherapy was able to eradicate large established tumors. This beneficial outcome was associated with the occurrence of antigen epitope spreading, activation of the endogenous CD8+ T cells and persistence of donor CD4+ T cells exhibiting memory stem cell attributes. These findings indicate that IL-7 signaling can impart polyfunctionality and stemness potential to CD4+ T cells, revealing a previously unknown property of IL-7 that can be exploited in adoptive T-cell immunotherapy. PMID:27471650

Induction of mast cell proliferation, maturation, and heparin synthesis by the rat c-kit ligand, stem cell factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, M.; Takeishi, Takashi; Geissler, E.N.

1991-07-15

The authors investigated the effects of a newly recognized multifunctional growth factor, the c-kit ligand stem cell factor (SCF), on mouse mast cell proliferation and phenotype. Recombinant rat SCF{sup 164} (rrSCF{sup 164}) induced the development of large numbers of dermal mast cells in normal mice in vivo. Many of these mast cells had features of connective tissue-type mast cells (CTMC), in that they were reactive both with the heparin-binding fluorescent dye berberine sulfate and with safranin. In vitro, rrSCF{sup 164} induced the proliferation of cloned interleukin 3 (IL-3)-dependent mouse mast cells and primary populations of IL-3-dependent, bone marrow-derived cultured mastmore » cells (BMCMC), which represent immature mast cells, and purified peritoneal mast cells, which represent a type of mature CTMC> BMCMC maintained in rrSCF{sup 164} not only proliferated but also matured. These findings identify SCF as a single cytokine that can induce immature, IL-3-dependent mast cells to mature and to acquire multiple characteristics of CTMC. These findings also directly demonstrate that SCF can regulate the development of a cellular lineage expressing c-kit through effects on both proliferation and maturation.« less

Disease-causing mitochondrial heteroplasmy segregated within induced pluripotent stem cell clones derived from a patient with MELAS.

PubMed

Folmes, Clifford D L; Martinez-Fernandez, Almudena; Perales-Clemente, Ester; Li, Xing; McDonald, Amber; Oglesbee, Devin; Hrstka, Sybil C; Perez-Terzic, Carmen; Terzic, Andre; Nelson, Timothy J

2013-07-01

Mitochondrial diseases display pathological phenotypes according to the mixture of mutant versus wild-type mitochondrial DNA (mtDNA), known as heteroplasmy. We herein examined the impact of nuclear reprogramming and clonal isolation of induced pluripotent stem cells (iPSC) on mitochondrial heteroplasmy. Patient-derived dermal fibroblasts with a prototypical mitochondrial deficiency diagnosed as mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) demonstrated mitochondrial dysfunction with reduced oxidative reserve due to heteroplasmy at position G13513A in the ND5 subunit of complex I. Bioengineered iPSC clones acquired pluripotency with multilineage differentiation capacity and demonstrated reduction in mitochondrial density and oxygen consumption distinguishing them from the somatic source. Consistent with the cellular mosaicism of the original patient-derived fibroblasts, the MELAS-iPSC clones contained a similar range of mtDNA heteroplasmy of the disease-causing mutation with identical profiles in the remaining mtDNA. High-heteroplasmy iPSC clones were used to demonstrate that extended stem cell passaging was sufficient to purge mutant mtDNA, resulting in isogenic iPSC subclones with various degrees of disease-causing genotypes. On comparative differentiation of iPSC clones, improved cardiogenic yield was associated with iPSC clones containing lower heteroplasmy compared with isogenic clones with high heteroplasmy. Thus, mtDNA heteroplasmic segregation within patient-derived stem cell lines enables direct comparison of genotype/phenotype relationships in progenitor cells and lineage-restricted progeny, and indicates that cell fate decisions are regulated as a function of mtDNA mutation load. The novel nuclear reprogramming-based model system introduces a disease-in-a-dish tool to examine the impact of mutant genotypes for MELAS patients in bioengineered tissues and a cellular probe for molecular features of individual mitochondrial diseases. Copyright © 2013 AlphaMed Press.

Two-Step Functional Innovation of the Stem-Cell Factors WUS/WOX5 during Plant Evolution.

PubMed

Zhang, Yuzhou; Jiao, Yue; Jiao, Hengwu; Zhao, Huabin; Zhu, Yu-Xian

2017-03-01

WUS and WOX5, which are expressed, respectively, in the organizing center (OC) and the quiescent center (QC), are essential for shoot/root apical stem-cell maintenance in flowering plants. However, little is known about how these stem-cell factors evolved their functions in flowering plants. Here, we show that the WUS/WOX5 proteins acquired two distinct capabilities by a two-step functional innovation process in the course of plant evolution. The first-step is the apical stem-cell maintenance activity of WUS/WOX5, which originated in the common ancestor of ferns and seed plants, as evidenced by the interspecies complementation experiments, showing that ectopic expression of fern Ceratopteris richardii WUS-like (CrWUL) surrounding OC/QC, or exclusive OC-/QC-expressed gymnosperms/angiosperms WUS/WOX5 in Arabidopsis wus-1 and wox5-1 mutants, could rescue their phenotypes. The second-step is the intercellular mobility that emerged in the common ancestor of seed plants after divergence from the ferns. Evidence for this includes confocal imaging of GFP fusion proteins, showing that WUS/WOX5 from seed plants, rather than from the fern CrWUL, can migrate into cells adjacent to the OC/QC. Evolutionary analysis showed that the WUS-like gene was duplicated into two copies prior to the divergence of gymnosperms/angiosperms. Then the two gene copies (WUS and WOX5) have undergone similar levels of purifying selection, which is consistent with their conserved functions in angiosperm shoot/root stem-cell maintenance and floral organ formation. Our results highlight the critical roles and the essential prerequisites that the two-step functional innovation of these genes performs and represents in the origin of flowering plants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The cancer paradigms of mammalian regeneration: can mammals regenerate as amphibians?

PubMed

Sarig, Rachel; Tzahor, Eldad

2017-04-01

Regeneration in mammals is restricted to distinct tissues and occurs mainly by expansion and maturation of resident stem cells. During regeneration, even subtle mutations in the proliferating cells may cause a detrimental effect by eliciting abnormal differentiation or malignant transformation. Indeed, cancer in mammals has been shown to arise through deregulation of stem cells maturation, which often leads to a differentiation block and cell transformation. In contrast, lower organisms such as amphibians retain a remarkable regenerative capacity in various organs, which occurs via de- and re-differentiation of mature cells. Interestingly, regenerating amphibian cells are highly resistant to oncogenic transformation. Therapeutic approaches to improve mammalian regeneration mainly include stem-cell transplantations; but, these have proved unsuccessful in non-regenerating organs such as the heart. A recently developed approach is to induce de-differentiation of mature cardiomyocytes using factors that trigger their re-entry into the cell cycle. This novel approach raises numerous questions regarding the balance between transformation and regeneration induced by de-differentiation of mature mammalian somatic cells. Can this balance be controlled artificially? Do de-differentiated cells acquire the protection mechanisms seen in regenerating cells of lower organisms? Is this model unique to the cardiac tissue, which rarely develops tumors? This review describes regeneration processes in both mammals and lower organisms and, particularly, the ability of regenerating cells to avoid transformation. By comparing the characteristics of mammalian embryonic and somatic cells, we discuss therapeutic strategies of using various cell populations for regeneration. Finally, we describe a novel cardiac regeneration approach and its implications for regenerative medicine. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Differentiation potential of human CD133 positive hematopoietic stem cells into motor neuron- like cells, in vitro.

PubMed

Moghaddam, Sepideh Alavi; Yousefi, Behnam; Sanooghi, Davood; Faghihi, Faezeh; Hayati Roodbari, Nasim; Bana, Nikoo; Joghataei, Mohammad Taghi; Pooyan, Paria; Arjmand, Babak

2017-12-01

Spinal cord injuries and motor neuron-related disorders impact on life of many patients around the world. Since pharmacotherapy and surgical approaches were not efficient to regenerate these types of defects; stem cell therapy as a good strategy to restore the lost cells has become the focus of interest among the scientists. Umbilical cord blood CD133 + hematopoietic stem cells (UCB- CD133 + HSCs) with self- renewal property and neural lineage differentiation capacity are ethically approved cell candidate for use in regenerative medicine. In this regard the aim of this study was to quantitatively evaluate the capability of these cells to differentiate into motor neuron-like cells (MNL), in vitro. CD133 + HSCs were isolated from human UCB using MACS system. After cell characterization using flow cytometry, the cells were treated with a combination of Retinoic acid, Sonic hedgehog, Brain derived neurotrophic factor, and B27 through a 2- step procedure for two weeks. The expression of MN-specific markers was examined using qRT- PCR, flow cytometry and immunocytochemistry. By the end of the two-week differentiation protocol, CD133 + cells acquired unipolar MNL morphology with thin and long neurites. The expression of Isl-1(62.15%), AChE (41.83%), SMI-32 (21.55%) and Nestin (17.46%) was detected using flow cytometry and immunocytochemistry. The analysis of the expression of PAX6, ISL-1, ACHE, CHAT and SMI-32 revealed that MNLs present these neural markers at levels comparable with undifferentiated cells. In Conclusion Human UCB- CD133 + HSCs are remarkably potent cell candidates to transdifferentiate into motor neuron-like cells, in vitro. Copyright © 2017. Published by Elsevier B.V.

Thidiazuron Triggers Morphogenesis in Rosa canina L. Protocorm-Like Bodies by Changing Incipient Cell Fate.

PubMed

Kou, Yaping; Yuan, Cunquan; Zhao, Qingcui; Liu, Guoqin; Nie, Jing; Ma, Zhimin; Cheng, Chenxia; Teixeira da Silva, Jaime A; Zhao, Liangjun

2016-01-01

Thidiazuron (N-phenyl-N'-1,2,3-thiadiazol-5-ylurea; TDZ) is an artificial plant growth regulator that is widely used in plant tissue culture. Protocorm-like bodies (PLBs) induced by TDZ serve as an efficient and rapid in vitro regeneration system in Rosa species. Despite this, the mechanism of PLB induction remains relatively unclear. TDZ, which can affect the level of endogenous auxins and cytokinins, converts the cell fate of rhizoid tips and triggers PLB formation and plantlet regeneration in Rosa canina L. In callus-rhizoids, which are rhizoids that co-develop from callus, auxin and a Z-type cytokinin accumulated after applying TDZ, and transcription of the auxin transporter gene RcPIN1 was repressed. The expression of RcARF4, RcRR1, RcCKX2, RcCKX3, and RcLOG1 increased in callus-rhizoids and rhizoid tips while the transcription of an auxin response factor (RcARF1) and auxin transport proteins (RcPIN2, RcPIN3) decreased in callus-rhizoids but increased in rhizoid tips. In situ hybridization of rhizoids showed that RcWUS and RcSERK1 were highly expressed in columella cells and root stem cells resulting in the conversion of cell fate into shoot apical meristems or embryogenic callus. In addition, transgenic XVE::RcWUS lines showed repressed RcWUS overexpression while RcWUS had no effect on PLB morphogenesis. Furthermore, higher expression of the root stem cell marker RcWOX5 and root stem cell maintenance regulator genes RcPLT1 and RcPLT2 indicated the presence of a dedifferentiation developmental pathway in the stem cell niche of rhizoids. Viewed together, our results indicate that different cells in rhizoid tips acquired regeneration competence after induction by TDZ. A novel developmental pathway containing different cell types during PLB formation was identified by analyzing the endogenous auxin and cytokinin content. This study also provides a deeper understanding of the mechanisms underlying in vitro regeneration in Rosa.

New insights into transfusion-related iron toxicity: Implications for the oncologist.

PubMed

Porter, John B; de Witte, Theo; Cappellini, M Domenica; Gattermann, Norbert

2016-03-01

Iron overload is a potentially life-threatening consequence of multiple red-blood-cell transfusions. Here, we review factors affecting excess iron distribution and its damage to specific tissues, as well as mechanisms of oncogenesis by iron. Although consequences of transfusional iron overload are best described in thalassemia major and related inherited anemias, they are increasingly recognized in acquired conditions, such as myelodysplastic syndromes (MDS). Iron overload in MDS not only impacts on certain tissues, but may affect the clonal evolution of MDS through generation of reactive oxygen species. Iron overload may also influence hematopoietic-stem-cell-transplantation outcomes. Novel MRI methods for assessing body iron have impacted significantly on outcome in inherited anemias by allowing monitoring of iron burden and iron chelation therapy. This approach is increasingly being used in MDS and stem-cell-transplant procedures. Knowledge gained from managing transfusional iron overload in inherited anemias may be translated to general oncology, with potential for improved patient outcomes. Copyright © 2016. Published by Elsevier Ireland Ltd.

Reconstitution of adaptive and innate immunity following allogeneic hematopoietic stem cell transplantation in humans.

PubMed

Peggs, K S

2006-01-01

Allogeneic hematopoietic stem cell transplantation is a potentially curative treatment modality for a number of hematologic malignancies, as well as inherited immunodeficiencies and hemoglobinopathies, and may also have a role in selected acquired autoimmune disorders. The complete or near-complete ablation of host immunity and subsequent establishment of donor-derived immunity that is required for successful engraftment and long-term outcomes provide a major obstacle to such transplantation approaches. A delicate balance exists between the need for the reconstituted donor-derived immunity to provide both protection against pathogenic challenges and graft-versus-malignancy activity, and the potentially harmful expansion of alloreactive T-cell clones mediating GvHD. The search for interventions that would allow more rapid and selective reconstitution of beneficial immune specificities continues to be informed by the development of new tools enabling a more precise dissection of the kinetics of reconstituting populations. This review summarizes more recent data on immune reconstitution following allogeneic transplantation in humans.

Induction of hair follicle dermal papilla cell properties in human induced pluripotent stem cell-derived multipotent LNGFR(+)THY-1(+) mesenchymal cells

PubMed Central

Veraitch, Ophelia; Mabuchi, Yo; Matsuzaki, Yumi; Sasaki, Takashi; Okuno, Hironobu; Tsukashima, Aki; Amagai, Masayuki; Okano, Hideyuki; Ohyama, Manabu

2017-01-01

The dermal papilla (DP) is a specialised mesenchymal component of the hair follicle (HF) that plays key roles in HF morphogenesis and regeneration. Current technical difficulties in preparing trichogenic human DP cells could be overcome by the use of highly proliferative and plastic human induced pluripotent stem cells (hiPSCs). In this study, hiPSCs were differentiated into induced mesenchymal cells (iMCs) with a bone marrow stromal cell phenotype. A highly proliferative and plastic LNGFR(+)THY-1(+) subset of iMCs was subsequently programmed using retinoic acid and DP cell activating culture medium to acquire DP properties. The resultant cells (induced DP-substituting cells [iDPSCs]) exhibited up-regulated DP markers, interacted with human keratinocytes to up-regulate HF related genes, and when co-grafted with human keratinocytes in vivo gave rise to fibre structures with a hair cuticle-like coat resembling the hair shaft, as confirmed by scanning electron microscope analysis. Furthermore, iDPSCs responded to the clinically used hair growth reagent, minoxidil sulfate, to up-regulate DP genes, further supporting that they were capable of, at least in part, reproducing DP properties. Thus, LNGFR(+)THY-1(+) iMCs may provide material for HF bioengineering and drug screening for hair diseases. PMID:28220862

Naturally acquired microchimerism

PubMed Central

Eikmans, Michael; van Halteren, Astrid GS; van Besien, Koen; van Rood, Jon J; Drabbels, Jos JM; Claas, Frans HJ

2014-01-01

Microchimerism represents a condition where one individual harbors genetically distinct cell populations, and the chimeric population constitutes <1% of the total number of cells. The most common natural source of microchimerism is pregnancy. The reciprocal cell exchange between a mother and her child often leads to the stable engraftment of hematopoietic and non-hematopoietic stem cells in both parties. Interaction between cells from the mother and those from the child may result in maternal immune cells becoming sensitized to inherited paternal alloantigens of the child, which are not expressed by the mother herself. Vice versa, immune cells of the child may become sensitized toward the non-inherited maternal alloantigens of the mother. The extent of microchimerism, its anatomical location, and the sensitivity of the techniques used for detecting its presence collectively determine whether microchimerism can be detected in an individual. In this review, we focus on the clinical consequences of microchimerism in solid organ and hematopoietic stem cell transplantation, and propose concepts derived from data of epidemiologic studies. Next, we elaborate on the latest molecular methodology, including digital PCR, for determining in a reliable and sensitive way the extent of microchimerism. For the first time, tools have become available to isolate viable chimeric cells from a host background, so that the challenges of establishing the biologic mechanisms and function of these cells may finally be tackled. PMID:24762743

Immunohistochemical analysis of the role and relationship between Notch-1 and Oct-4 expression in urinary bladder carcinoma.

PubMed

Abdou, Asmaa Gaber; El-Wahed, Moshira Mohammed Abd; Kandil, Mona Abd-Elhalim; Samaka, Rehab Monir; Elkady, Noha

2013-10-01

Most tumors contain a minor population of cancer stem cells that are responsible for tumor heterogeneity, resistance to therapy and recurrence. Oct-4 is a transcription factor responsible for self-renewal of stem cells, whereas the Notch family of receptors and ligands may play a pivotal role in the regulation of stem cell maintenance and differentiation. This study aimed at an evaluation of Oct-4 and Notch-1 expression in both carcinoma and stromal cells of 83 cases of primary bladder carcinoma and to study the relationship between them. Notch-1 was expressed in carcinoma and stromal cells of all malignant cases, where expression in both cell types was correlated with parameters indicating differentiation, such as low grade (p < 0.05) and less proliferation (p < 0.05). However, Notch-1 expression in stromal cells was associated with nodal metastasis (p = 0.016) and advanced stage (p = 0.030). 56.6 and 75.9% of carcinoma and stromal cells of malignant cases showed Oct-4 expression, respectively. Oct-4 expression in carcinoma cells or stromal cells was associated with aggressive features of bladder carcinoma, such as poor differentiation (p = 0.001), high proliferation (p < 0.001, 0.030), and liability for recurrence (p = 0.010, p < 0.001). There was an inverse relationship between Notch-1 and Oct-4 expression in carcinoma cells (p = 0.002), but stromal expression of Notch-1 was found to be associated with a nuclear pattern of Oct-4 expression in carcinoma cells (p = 0.030). Oct-4 as a stem cell marker is expressed in carcinoma cells and in stromal cells of bladder carcinoma, where they may cooperate in the progression of bladder carcinoma by acquiring aggressive features, such as a liability for recurrence and dissemination. Notch-1 is also expressed in both carcinoma cells and stromal cells of bladder carcinoma. Although they could share in enhancing differentiation, stromal expression of Notch-1 may have a bad impact, possibly through up-regulation of the active nuclear form of Oct-4 in carcinoma cells. © 2013 APMIS Published by Blackwell Publishing Ltd.

Subretinal transplantation of rat MSCs and erythropoietin gene modified rat MSCs for protecting and rescuing degenerative retina in rats.

PubMed

Guan, Y; Cui, L; Qu, Z; Lu, L; Wang, F; Wu, Y; Zhang, J; Gao, F; Tian, H; Xu, L; Xu, G; Li, W; Jin, Y; Xu, G-T

2013-11-01

For degenerative retinal diseases, like the acquired form exemplified by age-related macular degeneration (AMD), there is currently no cure. This study was to explore a stem cell therapy and a stem cell based gene therapy for sodium iodate (SI)-induced retinal degeneration in rats. Three cell types, i.e., rat mesenchymal stem cells (rMSCs) alone, erythropoietin (EPO) gene modified rMSCs (EPO-rMSCs) or doxycycline (DOX) inducible EPO expression rMSCs (Tet-on EPO-rMSCs), were transplanted into the subretinal spaces of SI-treated rats. The rMSCs were prepared for transplantation after 3 to 5 passages or modified with EPO gene. During the 8 weeks after the transplantation, the rats treated with rMSCs alone or with two types of EPO-rMSCs were all monitored with fundus examination, fundus fluorescein angiography (FFA) and electroretinogram. The transplantation efficiency of donor cells was examined for their survival, integration and differentiation. Following the transplantation, labeled donor cells were observed in subretinal space and adopted RPE morphology. EPO concentration in vitreous and retina of SI-treated rats which were transplanted with EPO-rMSCs or Tet-on EPO-rMSCs was markedly increased, in parallel with the improvement of retinal morphology and function. These findings suggest that rMSCs transplantation could be a new therapy for degenerative retinal diseases since it can protect and rescue RPE and retinal neurons, while EPO gene modification to rMSCs could be an even better option.

Daily chlorhexidine bathing does not increase skin toxicity after remission induction or stem cell transplantation.

PubMed

Deeren, Dries; Dewulf, Evelyne; Verfaillie, Lydie

2016-12-01

A recent multicenter study demonstrated that bathing with chlorhexidine reduces the transmission of resistant organisms and the risk of hospital-acquired bloodstream infections in ICUs. We wanted to confirm the feasibility of this strategy in a cohort of patients in a typical intensive haematology unit. Patients treated with remission induction chemotherapy, autologous or allogeneic stem cell transplantation received daily chlorhexidine bathing. To avoid deshydratation of skin, we used prophylactic application of hydrating lotion, replaced by corticosteroid cream in case of skin toxicity of chemotherapy or conditioning. We studied 15 consecutive admissions of 12 patients. Daily chlorhexidine bathing never needed to be interrupted, even though 53% of patients were treated with intravenous cytarabine. Patients were satisfied with the skin treatment and reported few unwanted effects. Daily chlorhexidine bathing was feasible in our intensive haematology unit in all patients and did not increase skin toxicity, even when treated with IV cytarabine.

Siblings with fucosidosis

PubMed Central

Muthusamy, Karthik; Thomas, Maya Mary; George, Renu Elizabeth; Alexander, Mathew; Mani, Sunithi; Benjamin, Rohit N

2014-01-01

Fucosidosis is a rare lysosomal storage disorder due to deficiency of fucosidase enzyme, with around 100 cases reported worldwide. Here, we describe the clinical and imaging features in two siblings with fucosidosis. An 8-year-old girl presented with global developmental delay, followed by regression of acquired milestones from 3 years of age with bipyramidal, extrapyramidal involvement, coarse facies, telangiectatic lesions, dysostosis multiplex, characteristic magnetic resonance imaging finding along with undetectable levels of the fucosidase activity, which confirmed the diagnosis. Younger sibling has mild developmental delay with autistic traits with no neuroregression until now. He also has undetectable level of fucosidase enzyme activity and is being considered for stem cell transplantation. New case reports would expand the clinical spectrum, early diagnosis and help formulating appropriate therapy. Early diagnosis is crucial and hence sibling screening can be done, and those in the presymptomatic stage can undergo hematopoietic stem cell transplantation, which is potentially curable. PMID:25250075

Reactivation of NCAM1 defines a subpopulation of human adult kidney epithelial cells with clonogenic and stem/progenitor properties.

PubMed

Buzhor, Ella; Omer, Dorit; Harari-Steinberg, Orit; Dotan, Zohar; Vax, Einav; Pri-Chen, Sara; Metsuyanim, Sally; Pleniceanu, Oren; Goldstein, Ronald S; Dekel, Benjamin

2013-11-01

The nephron is composed of a monolayer of epithelial cells that make up its various compartments. In development, these cells begin as mesenchyme. NCAM1, abundant in the mesenchyme and early nephron lineage, ceases to express in mature kidney epithelia. We show that, once placed in culture and released from quiescence, adult human kidney epithelial cells (hKEpCs), uniformly positive for CD24/CD133, re-express NCAM1 in a specific cell subset that attains a stem/progenitor state. Immunosorted NCAM1(+) cells overexpressed early nephron progenitor markers (PAX2, SALL1, SIX2, WT1) and acquired a mesenchymal fate, indicated by high vimentim and reduced E-cadherin levels. Gene expression and microarray analysis disclosed both a proximal tubular origin of these cells and molecules regulating epithelial-mesenchymal transition. NCAM1(+) cells generated clonal progeny when cultured in the presence of fetal kidney conditioned medium, differentiated along mesenchymal lineages but retained the unique propensity to generate epithelial kidney spheres and produce epithelial renal tissue on single-cell grafting in chick CAM and mouse. Depletion of NCAM1(+) cells from hKEpCs abrogated stemness traits in vitro. Eliminating these cells during the regenerative response that follows glycerol-induced acute tubular necrosis worsened peak renal injury in vivo. Thus, higher clone-forming and developmental capacities characterize a distinct subset of adult kidney-derived cells. The ability to influence an endogenous regenerative response via NCAM1 targeting may lead to novel therapeutics for renal diseases. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Tracking and Functional Characterization of Epithelial-Mesenchymal Transition and Mesenchymal Tumor Cells During Prostate Cancer Metastasis

PubMed Central

Ruscetti, Marcus; Quach, Bill; Dadashian, Eman L.; Mulholland, David J.; Wu, Hong

2015-01-01

The epithelial-mesenchymal transition (EMT) has been postulated as a mechanism by which cancer cells acquire the invasive and stem-like traits necessary for distant metastasis. However, direct in vivo evidence for the role of EMT in the formation of cancer stem-like cells (CSC) and the metastatic cascade remains lacking. Here we report the first isolation and characterization of mesenchymal and EMT tumor cells, which harbor both epithelial and mesenchymal characteristics, in an autochthonous murine model of prostate cancer. By crossing the established Pb-Cre+/−;PtenL/L;KrasG12D/+ prostate cancer model with a vimentin-GFP reporter strain, generating CPKV mice, we were able to isolate epithelial, EMT and mesenchymal cancer cells based on expression of vimentin and EpCAM. CPKV mice (but not mice with Pten deletion alone) exhibited expansion of cells with EMT (EpCAM+/Vim-GFP+) and mesenchymal (EpCAM−/Vim-GFP+) characteristics at the primary tumor site and in circulation. These EMT and mesenchymal tumor cells displayed enhanced stemness and invasive character compared to epithelial tumor cells. Moreover, they displayed an enriched tumor-initiating capacity and could regenerate epithelial glandular structures in vivo, indicative of epithelia-mesenchyme plasticity. Interestingly, while mesenchymal tumor cells could persist in circulation and survive in the lung following intravenous injection, only epithelial and EMT tumor cells could form macrometastases. Our work extends the evidence that mesenchymal and epithelial states in cancer cells contribute differentially to their capacities for tumor initiation and metastatic seeding, respectively, and that EMT tumor cells exist with plasticity that can contribute to multiple stages of the metastatic cascade. PMID:25948589

Efficient stage-specific differentiation of human pluripotent stem cells toward retinal photoreceptor cells.

PubMed

Mellough, Carla B; Sernagor, Evelyne; Moreno-Gimeno, Inmaculada; Steel, David H W; Lako, Majlinda

2012-04-01

Recent successes in the stem cell field have identified some of the key chemical and biological cues which drive photoreceptor derivation from human embryonic stem cells (hESC) and human induced pluripotent stem cells (hiPSC); however, the efficiency of this process is variable. We have designed a three-step photoreceptor differentiation protocol combining previously published methods that direct the differentiation of hESC and hiPSC toward a retinal lineage, which we further modified with additional supplements selected on the basis of reports from the eye field and retinal development. We report that hESC and hiPSC differentiating under our regimen over a 60 day period sequentially acquire markers associated with neural, retinal field, retinal pigmented epithelium and photoreceptor cells, including mature photoreceptor markers OPN1SW and RHODOPSIN with a higher efficiency than previously reported. In addition, we report the ability of hESC and hiPSC cultures to generate neural and retinal phenotypes under minimal culture conditions, which may be linked to their ability to endogenously upregulate the expression of a range of factors important for retinal cell type specification. However, cultures that were differentiated with full supplementation under our photoreceptor-induction regimen achieve this within a significantly shorter time frame and show a substantial increase in the expression of photoreceptor-specific markers in comparison to cultures differentiated under minimal conditions. Interestingly, cultures supplemented only with B27 and/or N2 displayed comparable differentiation efficiency to those under full supplementation, indicating a key role for B27 and N2 during the differentiation process. Furthermore, our data highlight an important role for Dkk1 and Noggin in enhancing the differentiation of hESC and hiPSC toward retinal progenitor cells and photoreceptor precursors during the early stages of differentiation, while suggesting that further maturation of these cells into photoreceptors may not require additional factors and can ensue under minimal culture conditions. Copyright © 2012 AlphaMed Press.

Epithelial-mesenchymal transition: a hallmark in metastasis formation linking circulating tumor cells and cancer stem cells.

PubMed

Książkiewicz, Magdalena; Markiewicz, Aleksandra; Zaczek, Anna J

2012-01-01

The occurrence of either regional or distant metastases is an indicator of poor prognosis for cancer patients. The mechanism of their formation has not yet been fully uncovered, which limits the possibility of developing new therapeutic strategies. Nevertheless, the discovery of circulating tumor cells (CTCs), which are responsible for tumor dissemination, and cancer stem cells (CSCs), required for tumor growth maintenance, shed light on the metastatic cascade. It seems that CTCs and CSCs are not necessarily separate populations of cancer cells, as CTCs generated in the process of epithelial-mesenchymal transition (EMT) can bear features characteristic of CSCs. This article describes the mechanisms of CTC and CSC formation and characterizes their molecular hallmarks. Moreover, we present different types of EMT occurring in physiological and pathological conditions, and we demonstrate its crucial role in providing CTCs with a CSC phenotype. The article delineates molecular changes acquired by cancer cells undergoing EMT that facilitate metastasis formation. Deeper understanding of those processes is of fundamental importance for the development of new strategies of early cancer detection and effective cancer treatment approaches that will be translated into clinical practice. Copyright © 2012 S. Karger AG, Basel.

[Integration of Internal and Clinical Laboratory Medicine].

PubMed

Hirokawa, Makoto

2015-03-01

The mission of our department is to contribute to diagnostic improvement in medicine in order to promote better outcomes. We have clinical expertise in internal medicine including primary care medicine, hematology, allergy, rheumatology, and nephrology. We also have expertise in clinical laboratory medicine and hospital infection control. Specific areas of academic interest include immune-mediated hematological diseases, allergic diseases, autoimmune diseases, and chronic kidney disease. Immune recovery following hematopoietic stem cell transplantation and the immunopathophysiology of bone marrow failure syndrome have been our main topics of interest, and we have been applying our knowledge of T-cell receptor diversity to these areas in order to explore the mechanisms of immunodeficiency and autoimmunity in hematological disorders. We have found that the peripheral expansion of mature T cells in grafts plays an important role in immune reconstitution after stem cell transplantation in humans, and have also found altered T-cell repertoires in immune-mediated chronic acquired pure red cell aplasia. Thus, quantitative and qualitative analyses of immune receptors could be a promising method for assessing immunocompetence and exploring the pathophysiology of autoimmune diseases. Research and development of novel approaches in this field should be intensively conducted.

Quantifying intrinsic and extrinsic control of single-cell fates in cancer and stem/progenitor cell pedigrees with competing risks analysis

PubMed Central

Cornwell, J. A.; Hallett, R. M.; der Mauer, S. Auf; Motazedian, A.; Schroeder, T.; Draper, J. S.; Harvey, R. P.; Nordon, R. E.

2016-01-01

The molecular control of cell fate and behaviour is a central theme in biology. Inherent heterogeneity within cell populations requires that control of cell fate is studied at the single-cell level. Time-lapse imaging and single-cell tracking are powerful technologies for acquiring cell lifetime data, allowing quantification of how cell-intrinsic and extrinsic factors control single-cell fates over time. However, cell lifetime data contain complex features. Competing cell fates, censoring, and the possible inter-dependence of competing fates, currently present challenges to modelling cell lifetime data. Thus far such features are largely ignored, resulting in loss of data and introducing a source of bias. Here we show that competing risks and concordance statistics, previously applied to clinical data and the study of genetic influences on life events in twins, respectively, can be used to quantify intrinsic and extrinsic control of single-cell fates. Using these statistics we demonstrate that 1) breast cancer cell fate after chemotherapy is dependent on p53 genotype; 2) granulocyte macrophage progenitors and their differentiated progeny have concordant fates; and 3) cytokines promote self-renewal of cardiac mesenchymal stem cells by symmetric divisions. Therefore, competing risks and concordance statistics provide a robust and unbiased approach for evaluating hypotheses at the single-cell level. PMID:27250534

Sex Differences in Maturation of Human Embryonic Stem Cell-Derived β Cells in Mice.

PubMed

Saber, Nelly; Bruin, Jennifer E; O'Dwyer, Shannon; Schuster, Hellen; Rezania, Alireza; Kieffer, Timothy J

2018-04-01

Pancreatic progenitors derived from human embryonic stem cells (hESCs) are now in clinical trials for insulin replacement in patients with type 1 diabetes. Animal studies indicate that pancreatic progenitor cells can mature into a mixed population of endocrine cells, including glucose-responsive β cells several months after implantion. However, it remains unclear how conditions in the recipient may influence the maturation and ultimately the function of these hESC-derived cells. Here, we investigated the effects of (1) pregnancy on the maturation of human stage 4 (S4) pancreatic progenitor cells and (2) the impact of host sex on both S4 cells and more mature stage 7 (S7) pancreatic endocrine cells implanted under the kidney capsule of immunodeficient SCID-beige mice. Pregnancy led to increased proliferation of endogenous pancreatic β cells, but did not appear to affect proliferation or maturation of S4 cells at midgestation. Interestingly, S4 and S7 cells both acquired glucose-stimulated C-peptide secretion in females before males. Moreover, S4 cells lowered fasting blood glucose levels in females sooner than in males, whereas the responses with S7 cells were similar. These data indicate that the host sex may impact the maturation of hESC-derived cells in vivo and that this effect can be minimized by more advanced differentiation of the cells before implantation.

Neurogenic and cardiomyogenic differentiation of mesenchymal stem cells isolated from minipig bone marrow.

PubMed

Kumar, B Mohana; Maeng, Geun-Ho; Lee, Yeon-Mi; Kim, Tae-Ho; Lee, Jeong-Hyeon; Jeon, Byeong-Gyun; Ock, Sun-A; Yoo, Jae-Gyu; Rho, Gyu-Jin

2012-10-01

The present study investigated the potential of minipig bone marrow-mesenchymal stem cells (BM-MSCs) to differentiate in vitro into neuron- and cardiomyocyte-like cells. Isolated BM-MSCs exhibited a fibroblast-like morphology, expressed CD29, CD44 and CD90, and differentiated into osteocytes, adipocytes and chondrocytes. Upon induction in two different neuronal specific media, most of BM-MSCs acquired the distinctive morphological features and positively stained for nestin, neurofilament-M (NF-M), neuronal nuclei (NeuN), β-tubulin, galactocerebroside (Gal-C) and glial fibrillary acidic protein (GFAP). Expression of nestin, GFAP and NF-M was further demonstrated by RT-PCR and RT-qPCR. Following cardiomyogenic induction, MSCs exhibited a stick-like morphology with extended cytoplasmic processes, and formed cluster-like structures. The expression of cardiac specific markers α-smooth muscle actin, cardiac troponin T, desmin and α-cardiac actin was positive for immunofluorescence staining, and further confirmed by RT-PCR and RT-qPCR. In conclusion, our results showed the in vitro differentiation ability of porcine BM-MSCs into neuron-like and cardiomyocyte-like cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

The role of the thymus in allogeneic hematopoietic stem cell transplantation.

PubMed

Krenger, Werner; Holländer, Georg A

2010-07-19

Allogeneic haematopoietic stem cell transplantation (HSCT) is used to treat an increasing number of congenital and acquired disorders of the haematopoietic system. Even though cytoreductive conditioning regimens vary in intensity, all clinically used protocols invariably cause side effects that compromise transiently or long-term the response of the natural and the adaptive immune systems. However, in the context of the reconstruction of immunity, the generation of naïve T cells constitutes a slow process, and requires a functionally competent thymus. Unfortunately, regular thymic function is frequently suppressed by transplant-related toxicities. Most notably, graft-versus-host disease (GVHD) causes a state of posttransplantation immune deficiency. Here we discuss preclinical allogeneic HSCT models and clinical observations that have contributed to a detailed understanding of the cellular and molecular mechanisms responsible for the thymic dysfunction caused by acute GVHD. An in-depth knowledge of the mechanisms that control regular thymopoiesis and, conversely, affect thymus function is expected to provide the factual basis for the design of innovative therapies to recover T-cell numbers and function following allogeneic HSCT.

Towards in vivo amplification: Overcoming hurdles in the use of hematopoietic stem cells in transplantation and gene therapy

PubMed Central

Nagree, Murtaza S; López-Vásquez, Lucía; Medin, Jeffrey A

2015-01-01

With the advent of safer and more efficient gene transfer methods, gene therapy has become a viable solution for many inherited and acquired disorders. Hematopoietic stem cells (HSCs) are a prime cell compartment for gene therapy aimed at correcting blood-based disorders, as well as those amenable to metabolic outcomes that can effect cross-correction. While some resounding clinical successes have recently been demonstrated, ample room remains to increase the therapeutic output from HSC-directed gene therapy. In vivo amplification of therapeutic cells is one avenue to achieve enhanced gene product delivery. To date, attempts have been made to provide HSCs with resistance to cytotoxic drugs, to include drug-inducible growth modules specific to HSCs, and to increase the engraftment potential of transduced HSCs. This review aims to summarize amplification strategies that have been developed and tested and to discuss their advantages along with barriers faced towards their clinical adaptation. In addition, next-generation strategies to circumvent current limitations of specific amplification schemas are discussed. PMID:26730268

[JACIE: from guidelines to clinical practice and continuous quality improvement, the Léon-Bérard cancer center experience].

PubMed

Donot, Pierre Emmanuel

2009-01-01

JACIE, a European certification program for stem cell transplantation, has now been recognized by the French Health Authorities. It can be considered as an evaluation of professional practice, an activity that can be promoted by health centres. The present article has two aims: firstly, it describes the structure of the certification standard based on the relative structure of each of its components; secondly, it reports on the experience acquired by the Léon-Bérard cancer centre (Lyon-France) during the certification of its own stem cell transplantation program. The JACIE manual written in English is divided into three parts corresponding to the three processes identified. Part B describes the clinical haematopoietic stem cell transplantation program. Part C is dedicated to the collection of haematopoietic stem cells from blood and marrow. Finally, part D applies to the cell therapy laboratory in charge of cell preservation and the preparation of grafts for re-infusion. After the application has been submitted to the JACIE board, a date is set for an inspection visit. The cell therapy laboratory at Léon-Bérard cancer centre has already participated to a certified transplantation project of the Edouard-Herriot Hospital (Lyon public hospitals) [parts C and D of the certification]. The executive board proposed that the clinical haematology unit of the cancer centre also applied for JACIE certification. A multidisciplinary work group-combining document writing skills and a real capacity to convince and motivate clinical staff was formed. Secondly, a comprehensive collection of existing documents was issued and the clinical pathway of the patients was formalized so that no step of the graft process would be omitted. A physician from another hospital also tested the evaluation process with the organisation of a mock visit. He confirmed that everything was in good way and provided recommendations to improve the program. This huge preparation provided invaluable learning opportunities to the participants. After the final visit by JACIE inspectors, the cancer centre received four-year certification. The challenge is now to maintain this momentum for the next certifications and to better take into account the ethical and juridical constraints of haematopoietic stem cell transplantation.

Optical Coherence Tomography Imaging of the Palisades of Vogt to Assist Clinical Evaluation and Surgical Planning in a Case of Limbal Stem-Cell Deficiency.

PubMed

Espandar, Ladan; Steele, Jessica F; Lathrop, Kira L

2017-09-01

To describe the use of volumetric optical coherence tomography (OCT) imaging to assist evaluation of a patient referred for autologous limbal stem-cell transplant. This is a case report of a 50-year-old patient presenting with unilateral limbal stem-cell deficiency who was referred for autologous limbal stem-cell transplant. The presence of Salzmann nodules in the donor eye raised questions about the efficacy of transplantation, prompting examination of both eyes using volumetric OCT imaging to determine whether there were palisades of Vogt (POV) present. Image volumes were acquired in all clock hours and were compared against those of an age-matched normal subject. Palisades were found in both eyes, although in both eyes there were fewer palisade ridges, and those that were present were not as distinct as those of the normal subject. The OCT volumes also showed that stromal scarring was present only in the anterior stroma of the intended transplant eye. These findings suggested that the patient may be able to sustain a deep anterior lamellar keratoplasty without an autologous transplant, which would spare any insult to the opposing eye and require less surgery to restore vision in the affected eye. Nine months postsurgical follow-up revealed significant improvement in visual acuity and no scar tissue development. The OCT evaluation of the POV provides detailed information to the clinician that may assist in diagnosis and evaluation of patients before transplantation. Further development of this technique is necessary to make it clinically available.

Endometrial stem cells repair injured endometrium and induce angiogenesis via AKT and ERK pathways.

PubMed

Zhang, Yanling; Lin, Xiaona; Dai, Yongdong; Hu, Xiaoxiao; Zhu, Haiyan; Jiang, Yinshen; Zhang, Songying

2016-11-01

Intrauterine adhesions are common acquired endometrial syndromes secondary to endometrial injury, with limited effective therapies. Recently, several studies have reported that bone marrow stem cells (BMSCs) could repair injured endometrium in animal experiments. However, the role of stem cells in endometrial injury repair and its therapeutic mechanisms remain unclear. Here, we established mouse endometrial injury model and examined the benefit of human endometrial mesenchymal stem cells derived from menstrual blood (MenSCs) in restoration of injured endometrium. Injured endometrium exhibited significantly accelerated restoration at Day 7 after MenSCs transplantation, with increased endometrial thickness and microvessel density. Moreover, the fertility of mice with injured endometrium was improved, with higher conception rate (53.57% vs 14.29%, P = 0.014) and larger embryo number (3.1 ± 0.6 vs 0.9 ± 0.7, P = 0.030) in MenSCs group than control group, while no difference was found in undamaged horns between two groups. Conditioned medium from MenSCs (MenSCs-CM) could decrease H2O2-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and promote proliferation, migration and angiogenesis. Angiogenesis effect of MenSCs-CM was also confirmed in Matrigel plug assay in mice. Furthermore, we discovered that MenSCs-CM could activate AKT and ERK pathways and induce the overexpression of eNOS, VEGFA, VEGFR1, VEGFR2 and TIE2 in HUVECs, which are critical in MenSCs-CM-induced angiogenesis. Angiogenesis induced by MenSCs-CM could be reversed by inhibitors of AKT and/or ERK. Taken together, we concluded that MenSCs could restore injured endometrium and improve the fertility of the endometrial injury mice, which was partially attributed to angiogenesis induced by MenSCs. © 2016 Society for Reproduction and Fertility.

Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells.

PubMed

Farace, Cristiano; Oliver, Jaime Antonio; Melguizo, Consolacion; Alvarez, Pablo; Bandiera, Pasquale; Rama, Ana Rosa; Malaguarnera, Giulia; Ortiz, Raul; Madeddu, Roberto; Prados, Jose

2015-01-01

The presence of cancer stem cells (CSCs) or tumor-initiating cells can lead to cancer recurrence in a permissive cell-microenvironment interplay, promoting invasion in glioblastoma (GBM) and neuroblastoma (NB). Extracellular matrix (ECM) small leucine-rich proteoglycans (SLRPs) play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM) components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs), SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN) and lumican (LUM) are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM) to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+) CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like) showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ) at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge quantities of SLRP in response to CSC enrichment, simultaneously acquiring TMZ resistance, cellular heterogeneity, and a quiescent phenotype, suggesting a novel pivotal role for SLRP in drug resistance and cell plasticity of CSC-like, allowing cell survival and ECM/niche modulation potential.

Combined scanning transmission electron microscopy tilt- and focal series.

PubMed

Dahmen, Tim; Baudoin, Jean-Pierre; Lupini, Andrew R; Kübel, Christian; Slusallek, Philipp; de Jonge, Niels

2014-04-01

In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt-focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller "missing wedge" artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.

Generation of highly purified neural stem cells from human adipose-derived mesenchymal stem cells by Sox1 activation.

PubMed

Feng, Nianhua; Han, Qin; Li, Jing; Wang, Shihua; Li, Hongling; Yao, Xinglei; Zhao, Robert Chunhua

2014-03-01

Neural stem cells (NSCs) are ideal candidates in stem cell-based therapy for neurodegenerative diseases. However, it is unfeasible to get enough quantity of NSCs for clinical application. Generation of NSCs from human adipose-derived mesenchymal stem cells (hAD-MSCs) will provide a solution to this problem. Currently, the differentiation of hAD-MSCs into highly purified NSCs with biological functions is rarely reported. In our study, we established a three-step NSC-inducing protocol, in which hAD-MSCs were induced to generate NSCs with high purity after sequentially cultured in the pre-inducing medium (Step1), the N2B27 medium (Step2), and the N2B27 medium supplement with basic fibroblast growth factor and epidermal growth factor (Step3). These hAD-MSC-derived NSCs (adNSCs) can form neurospheres and highly express Sox1, Pax6, Nestin, and Vimentin; the proportion was 96.1% ± 1.3%, 96.8% ± 1.7%, 96.2% ± 1.3%, and 97.2% ± 2.5%, respectively, as detected by flow cytometry. These adNSCs can further differentiate into astrocytes, oligodendrocytes, and functional neurons, which were able to generate tetrodotoxin-sensitive sodium current. Additionally, we found that the neural differentiation of hAD-MSCs were significantly suppressed by Sox1 interference, and what's more, Step1 was a key step for the following induction, probably because it was associated with the initiation and nuclear translocation of Sox1, an important transcriptional factor for neural development. Finally, we observed that bone morphogenetic protein signal was inhibited, and Wnt/β-catenin signal was activated during inducing process, and both signals were related with Sox1 expression. In conclusion, we successfully established a three-step inducing protocol to derive NSCs from hAD-MSCs with high purity by Sox1 activation. These findings might enable to acquire enough autologous transplantable NSCs for the therapy of neurodegenerative diseases in clinic.

Microbial-derived lithocholic acid and vitamin K2 drive the metabolic maturation of pluripotent stem cells-derived and fetal hepatocytes.

PubMed

Avior, Yishai; Levy, Gahl; Zimerman, Michal; Kitsberg, Daniel; Schwartz, Robert; Sadeh, Ronen; Moussaieff, Arieh; Cohen, Merav; Itskovitz-Eldor, Joseph; Nahmias, Yaakov

2015-07-01

The liver is the main organ responsible for the modification, clearance, and transformational toxicity of most xenobiotics owing to its abundance in cytochrome P450 (CYP450) enzymes. However, the scarcity and variability of primary hepatocytes currently limits their utility. Human pluripotent stem cells (hPSCs) represent an excellent source of differentiated hepatocytes; however, current protocols still produce fetal-like hepatocytes with limited mature function. Interestingly, fetal hepatocytes acquire mature CYP450 expression only postpartum, suggesting that nutritional cues may drive hepatic maturation. We show that vitamin K2 and lithocholic acid, a by-product of intestinal flora, activate pregnane X receptor (PXR) and subsequent CYP3A4 and CYP2C9 expression in hPSC-derived and isolated fetal hepatocytes. Differentiated cells produce albumin and apolipoprotein B100 at levels equivalent to primary human hepatocytes, while demonstrating an 8-fold induction of CYP450 activity in response to aryl hydrocarbon receptor (AhR) agonist omeprazole and a 10-fold induction in response to PXR agonist rifampicin. Flow cytometry showed that over 83% of cells were albumin and hepatocyte nuclear factor 4 alpha (HNF4α) positive, permitting high-content screening in a 96-well plate format. Analysis of 12 compounds showed an R(2) correlation of 0.94 between TC50 values obtained in stem cell-derived hepatocytes and primary cells, compared to 0.62 for HepG2 cells. Finally, stem cell-derived hepatocytes demonstrate all toxicological endpoints examined, including steatosis, apoptosis, and cholestasis, when exposed to nine known hepatotoxins. Our work provides fresh insights into liver development, suggesting that microbial-derived cues may drive the maturation of CYP450 enzymes postpartum. Addition of these cues results in the first functional, inducible, hPSC-derived hepatocyte for predictive toxicology. © 2015 by the American Association for the Study of Liver Diseases.

Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells

PubMed Central

Melguizo, Consolacion; Alvarez, Pablo; Bandiera, Pasquale; Rama, Ana Rosa; Malaguarnera, Giulia; Ortiz, Raul; Madeddu, Roberto; Prados, Jose

2015-01-01

The presence of cancer stem cells (CSCs) or tumor-initiating cells can lead to cancer recurrence in a permissive cell–microenvironment interplay, promoting invasion in glioblastoma (GBM) and neuroblastoma (NB). Extracellular matrix (ECM) small leucine-rich proteoglycans (SLRPs) play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM) components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs), SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN) and lumican (LUM) are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM) to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+) CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like) showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ) at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge quantities of SLRP in response to CSC enrichment, simultaneously acquiring TMZ resistance, cellular heterogeneity, and a quiescent phenotype, suggesting a novel pivotal role for SLRP in drug resistance and cell plasticity of CSC-like, allowing cell survival and ECM/niche modulation potential. PMID:26230845

Proteomic Analysis of Human Adipose Derived Stem Cells during Small Molecule Chemical Stimulated Pre-neuronal Differentiation

PubMed Central

Santos, Jerran; Milthorpe, Bruce K; Herbert, Benjamin R; Padula, Matthew P

2017-01-01

Background Adipose derived stem cells (ADSCs) are acquired from abdominal liposuction yielding a thousand fold more stem cells per millilitre than those from bone marrow. A large research void exists as to whether ADSCs are capable of transdermal differentiation toward neuronal phenotypes. Previous studies have investigated the use of chemical cocktails with varying inconclusive results. Methods Human ADSCs were treated with a chemical stimulant, beta-mercaptoethanol, to direct them toward a neuronal-like lineage within 24 hours. Quantitative proteomics using iTRAQ was then performed to ascertain protein abundance differences between ADSCs, beta-mercaptoethanol treated ADSCs and a glioblastoma cell line. Results The soluble proteome of ADSCs differentiated for 12 hours and 24 hours was significantly different from basal ADSCs and control cells, expressing a number of remodeling, neuroprotective and neuroproliferative proteins. However toward the later time point presented stress and shock related proteins were observed to be up regulated with a large down regulation of structural proteins. Cytokine profiles support a large cellular remodeling shift as well indicating cellular distress. Conclusion The earlier time point indicates an initiation of differentiation. At the latter time point there is a vast loss of cell population during treatment. At 24 hours drastically decreased cytokine profiles and overexpression of stress proteins reveal that exposure to beta-mercaptoethanol beyond 24 hours may not be suitable for clinical application as our results indicate that the cells are in trauma whilst producing neuronal-like morphologies. The shorter treatment time is promising, indicating a reducing agent has fast acting potential to initiate neuronal differentiation of ADSCs. PMID:28844130

Proteomic Analysis of Human Adipose Derived Stem Cells during Small Molecule Chemical Stimulated Pre-neuronal Differentiation.

PubMed

Santos, Jerran; Milthorpe, Bruce K; Herbert, Benjamin R; Padula, Matthew P

2017-11-30

Adipose derived stem cells (ADSCs) are acquired from abdominal liposuction yielding a thousand fold more stem cells per millilitre than those from bone marrow. A large research void exists as to whether ADSCs are capable of transdermal differentiation toward neuronal phenotypes. Previous studies have investigated the use of chemical cocktails with varying inconclusive results. Human ADSCs were treated with a chemical stimulant, beta-mercaptoethanol, to direct them toward a neuronal-like lineage within 24 hours. Quantitative proteomics using iTRAQ was then performed to ascertain protein abundance differences between ADSCs, beta-mercaptoethanol treated ADSCs and a glioblastoma cell line. The soluble proteome of ADSCs differentiated for 12 hours and 24 hours was significantly different from basal ADSCs and control cells, expressing a number of remodeling, neuroprotective and neuroproliferative proteins. However toward the later time point presented stress and shock related proteins were observed to be up regulated with a large down regulation of structural proteins. Cytokine profiles support a large cellular remodeling shift as well indicating cellular distress. The earlier time point indicates an initiation of differentiation. At the latter time point there is a vast loss of cell population during treatment. At 24 hours drastically decreased cytokine profiles and overexpression of stress proteins reveal that exposure to beta-mercaptoethanol beyond 24 hours may not be suitable for clinical application as our results indicate that the cells are in trauma whilst producing neuronal-like morphologies. The shorter treatment time is promising, indicating a reducing agent has fast acting potential to initiate neuronal differentiation of ADSCs.

Ovine induced pluripotent stem cells are resistant to reprogramming after nuclear transfer.

PubMed

German, Sergio D; Campbell, Keith H S; Thornton, Elisabeth; McLachlan, Gerry; Sweetman, Dylan; Alberio, Ramiro

2015-02-01

Induced pluripotent stem cells (iPSCs) share similar characteristics of indefinite in vitro growth with embryonic stem cells (ESCs) and may therefore serve as a useful tool for the targeted genetic modification of farm animals via nuclear transfer (NT). Derivation of stable ESC lines from farm animals has not been possible, therefore, it is important to determine whether iPSCs can be used as substitutes for ESCs in generating genetically modified cloned farm animals. We generated ovine iPSCs by conventional retroviral transduction using the four Yamanaka factors. These cells were basic fibroblast growth factor (bFGF)- and activin A-dependent, showed persistent expression of the transgenes, acquired chromosomal abnormalities, and failed to activate endogenous NANOG. Nonetheless, iPSCs could differentiate into the three somatic germ layers in vitro. Because cloning of farm animals is best achieved with diploid cells (G1/G0), we synchronized the iPSCs in G1 prior to NT. Despite the cell cycle synchronization, preimplantation development of iPSC-NT embryos was lower than with somatic cells (2% vs. 10% blastocysts, p<0.01). Furthermore, analysis of the blastocysts produced demonstrated persistent expression of the transgenes, aberrant expression of endogenous SOX2, and a failure to activate NANOG consistently. In contrast, gene expression in blastocysts produced with the parental fetal fibroblasts was similar to those generated by in vitro fertilization. Taken together, our data suggest that the persistent expression of the exogenous factors and the acquisition of chromosomal abnormalities are incompatible with normal development of NT embryos produced with iPSCs.

Xenografted human amniotic membrane-derived mesenchymal stem cells are immunologically tolerated and transdifferentiated into cardiomyocytes.

PubMed

Tsuji, Hiroko; Miyoshi, Shunichiro; Ikegami, Yukinori; Hida, Naoko; Asada, Hironori; Togashi, Ikuko; Suzuki, Junshi; Satake, Masaki; Nakamizo, Hikaru; Tanaka, Mamoru; Mori, Taisuke; Segawa, Kaoru; Nishiyama, Nobuhiro; Inoue, Junko; Makino, Hatsune; Miyado, Kenji; Ogawa, Satoshi; Yoshimura, Yasunori; Umezawa, Akihiro

2010-05-28

Amniotic membrane is known to have the ability to transdifferentiate into multiple organs and is expected to stimulate a reduced immunologic reaction. Determine whether human amniotic membrane-derived mesenchymal cells (hAMCs) can be an ideal allograftable stem cell source for cardiac regenerative medicine. We established hAMCs. After cardiomyogenic induction in vitro, hAMCs beat spontaneously, and the calculated cardiomyogenic transdifferentiation efficiency was 33%. Transplantation of hAMCs 2 weeks after myocardial infarction improved impaired left ventricular fractional shortening measured by echocardiogram (34+/-2% [n=8] to 39+/-2% [n=11]; P<0.05) and decreased myocardial fibrosis area (18+/-1% [n=9] to 13+/-1% [n=10]; P<0.05), significantly. Furthermore hAMCs transplanted into the infarcted myocardium of Wistar rats were transdifferentiated into cardiomyocytes in situ and survived for more than 4 weeks after the transplantation without using any immunosuppressant. Immunologic tolerance was caused by the hAMC-derived HLA-G expression, lack of MHC expression of hAMCs, and activation of FOXP3-positive regulatory T cells. Administration of IL-10 or progesterone, which is known to play an important role in feto-maternal tolerance during pregnancy, markedly increased HLA-G expression in hAMCs in vitro and, surprisingly, also increased cardiomyogenic transdifferentiation efficiency in vitro and in vivo. Because hAMCs have a high ability to transdifferentiate into cardiomyocytes and to acquire immunologic tolerance in vivo, they can be a promising cellular source for allograftable stem cells for cardiac regenerative medicine.

Bone marrow-derived SP cells can contribute to the respiratory tract of mice in vivo.

PubMed

Macpherson, Heather; Keir, Pamela; Webb, Sheila; Samuel, Kay; Boyle, Shelagh; Bickmore, Wendy; Forrester, Lesley; Dorin, Julia

2005-06-01

Recent work has indicated that adult bone marrow-derived cells have the ability to contribute to both the haematopoietic system and other organs. Haematopoietic reconstitution by whole bone marrow and selected but not fully characterised cell populations have resulted in reports indicating high-level repopulation of lung epithelia. The well-characterised cells from the side population have a robust ability for haematopoietic reconstitution. We have used freshly isolated side population cells derived from ROSA26 adult bone marrow and demonstrate that despite being unable to contribute to embryos following blastocyst injection, or air liquid interface cultures or denuded tracheal xenografts, they could contribute to the tracheal epithelium in vivo. Epithelial damage is reported to be important in encouraging the recruitment of marrow-derived stem cells into non-haematopoietic organs. Here we demonstrate that mice engrafted with side population cells have donor-derived cells present in the epithelial lining of the trachea following damage and repair. Donor-derived cells were found at a frequency of 0.83%. Widefield and confocal microscopy revealed donor cells that expressed cytokeratins, indicative of cells of an epithelial nature. These results imply that SP haematopoietic stem cells from the bone marrow do not have the ability to contribute to airway epithelia themselves but require factors present in vivo to allow them to acquire characteristics of this tissue.

Adult cardiac stem cells are multipotent and robustly myogenic: c-kit expression is necessary but not sufficient for their identification.

PubMed

Vicinanza, Carla; Aquila, Iolanda; Scalise, Mariangela; Cristiano, Francesca; Marino, Fabiola; Cianflone, Eleonora; Mancuso, Teresa; Marotta, Pina; Sacco, Walter; Lewis, Fiona C; Couch, Liam; Shone, Victoria; Gritti, Giulia; Torella, Annalaura; Smith, Andrew J; Terracciano, Cesare Mn; Britti, Domenico; Veltri, Pierangelo; Indolfi, Ciro; Nadal-Ginard, Bernardo; Ellison-Hughes, Georgina M; Torella, Daniele

2017-12-01

Multipotent adult resident cardiac stem cells (CSCs) were first identified by the expression of c-kit, the stem cell factor receptor. However, in the adult myocardium c-kit alone cannot distinguish CSCs from other c-kit-expressing (c-kit pos ) cells. The adult heart indeed contains a heterogeneous mixture of c-kit pos cells, mainly composed of mast and endothelial/progenitor cells. This heterogeneity of cardiac c-kit pos cells has generated confusion and controversy about the existence and role of CSCs in the adult heart. Here, to unravel CSC identity within the heterogeneous c-kit-expressing cardiac cell population, c-kit pos cardiac cells were separated through CD45-positive or -negative sorting followed by c-kit pos sorting. The blood/endothelial lineage-committed (Lineage pos ) CD45 pos c-kit pos cardiac cells were compared to CD45 neg (Lineage neg /Lin neg ) c-kit pos cardiac cells for stemness and myogenic properties in vitro and in vivo. The majority (~90%) of the resident c-kit pos cardiac cells are blood/endothelial lineage-committed CD45 pos CD31 pos c-kit pos cells. In contrast, the Lin neg CD45 neg c-kit pos cardiac cell cohort, which represents ⩽10% of the total c-kit pos cells, contain all the cardiac cells with the properties of adult multipotent CSCs. These characteristics are absent from the c-kit neg and the blood/endothelial lineage-committed c-kit pos cardiac cells. Single Lin neg c-kit pos cell-derived clones, which represent only 1-2% of total c-kit pos myocardial cells, when stimulated with TGF-β/Wnt molecules, acquire full transcriptome and protein expression, sarcomere organisation, spontaneous contraction and electrophysiological properties of differentiated cardiomyocytes (CMs). Genetically tagged cloned progeny of one Lin neg c-kit pos cell when injected into the infarcted myocardium, results in significant regeneration of new CMs, arterioles and capillaries, derived from the injected cells. The CSC's myogenic regenerative capacity is dependent on commitment to the CM lineage through activation of the SMAD2 pathway. Such regeneration was not apparent when blood/endothelial lineage-committed c-kit pos cardiac cells were injected. Thus, among the cardiac c-kit pos cell cohort only a very small fraction has the phenotype and the differentiation/regenerative potential characteristics of true multipotent CSCs.

Mechanisms of zolpidem-induced long QT syndrome: acute inhibition of recombinant hERG K+ channels and action potential prolongation in human cardiomyocytes derived from induced pluripotent stem cells

PubMed Central

Jehle, J; Ficker, E; Wan, X; Deschenes, I; Kisselbach, J; Wiedmann, F; Staudacher, I; Schmidt, C; Schweizer, PA; Becker, R; Katus, HA; Thomas, D

2013-01-01

Background and Purpose Zolpidem, a short-acting hypnotic drug prescribed to treat insomnia, has been clinically associated with acquired long QT syndrome (LQTS) and torsade de pointes (TdP) tachyarrhythmia. LQTS is primarily attributed to reduction of cardiac human ether-a-go-go-related gene (hERG)/IKr currents. We hypothesized that zolpidem prolongs the cardiac action potential through inhibition of hERG K+ channels. Experimental Approach Two-electrode voltage clamp and whole-cell patch clamp electrophysiology was used to record hERG currents from Xenopus oocytes and from HEK 293 cells. In addition, hERG protein trafficking was evaluated in HEK 293 cells by Western blot analysis, and action potential duration (APD) was assessed in human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes. Key Results Zolpidem caused acute hERG channel blockade in oocytes (IC50 = 61.5 μM) and in HEK 293 cells (IC50 = 65.5 μM). Mutation of residues Y652 and F656 attenuated hERG inhibition, suggesting drug binding to a receptor site inside the channel pore. Channels were blocked in open and inactivated states in a voltage- and frequency-independent manner. Zolpidem accelerated hERG channel inactivation but did not affect I–V relationships of steady-state activation and inactivation. In contrast to the majority of hERG inhibitors, hERG cell surface trafficking was not impaired by zolpidem. Finally, acute zolpidem exposure resulted in APD prolongation in hiPSC-derived cardiomyocytes. Conclusions and Implications Zolpidem inhibits cardiac hERG K+ channels. Despite a relatively low affinity of zolpidem to hERG channels, APD prolongation may lead to acquired LQTS and TdP in cases of reduced repolarization reserve or zolpidem overdose. PMID:23061993

An outline of main factors of drug resistance influencing cancer therapy.

PubMed

Frączek, Natalia; Bronisz, Iwona; Pietryka, Magdalena; Kępińska, Dorota; Strzała, Patrycja; Mielnicka, Kamila; Korga, Agnieszka; Dudka, Jaroslaw

2016-12-01

Drug resistance in cancer therapy is a multifactorial phenomenon that determines remission or progression. It is known that resistance to used anticancer drugs may be the consequence of drug transport to the cell or intracellular distribution. It may also be the result of its molecular target structural change, apoptosis inhibition or increase in some enzymes activity, e.g. pentose phosphate pathway enzymes. Intrinsic (pre-existed) drug resistance is related to the phenotype of cancer as well as normal cells. Acquired, after partial administration of chemotherapy, type of drug resistance in addition to the starting phenotype is closely linked to the development of new more aggressive clones and adaptive processes. In both, the intrinsic and acquired resistance, role play also mutations. These may be partially spontaneous, but in terms of acquired resistance, they are mostly induced by the exposure to the drugs. The article mentions some traditional mechanisms related to the acquisition of resistance by cancer cells during therapy, through the protein transporters, apoptosis deregulation, angiogenesis and the impact of the tumour microenvironment. We focused however on some more alternative ways of therapy resistance, such as, hypoxia and tumour acidification, cancer stem cells (CSCs), exosomes and radiotherapy resistance. A concise summary of the drug resistance presented in the paper may be an important aspect in studies to increase the effectiveness of cancer therapies.

Bacterial meningitis in hematopoietic stem cell transplant recipients: a population-based prospective study.

PubMed

van Veen, K E B; Brouwer, M C; van der Ende, A; van de Beek, D

2016-11-01

We performed a nationwide prospective cohort study on the epidemiology and clinical features of community-acquired bacterial meningitis. Patients with a medical history of autologous or allogeneic hematopoietic stem cell transplantation (HSCT) were identified from the cohort performed from March 2006 to October 2014. Fourteen of 1449 episodes (1.0%) of bacterial meningitis occurred in patients with a history of HSCT. The incidence of bacterial meningitis in HSCT recipients was 40.4 per 100 000 patients per year (95% confidence interval (CI) 23.9-62.2), which is 30-fold (95% CI 18-51; P<0.001) higher compared with persons without HSCT. Incidence was higher in allogeneic HSCT compared with autologous HSCT (70.0 vs 15.8 per 100 000 patients per year). Causative organisms were Streptococcus pneumoniae in 11 patients, Neisseria meningitidis in two and Streptococcus mitis in one patient. Mortality was 3 of 14 (21%) and 6 of 11 (55%) survivors had sequelae. Nine of 11 patients (82%) with pneumococcal meningitis were infected with a serotype included in the 23-valent pneumococcal polysaccharide vaccine, of whom four developed meningitis despite vaccination. In conclusion, HSCT recipients have a substantially increased risk compared with the general population of acquiring bacterial meningitis, which is mostly due to S. pneumoniae, and disease is associated with high mortality and morbidity. Vaccination is important to prevent disease although vaccine failures did occur.

Clonal heterogeneity as a driver of disease variability in the evolution of myeloproliferative neoplasms.

PubMed

Prick, Janine; de Haan, Gerald; Green, Anthony R; Kent, David G

2014-10-01

Myeloproliferative neoplasms (MPNs) are clonal hematological diseases in which cells of the myelo-erythroid lineage are overproduced and patients are predisposed to leukemic transformation. Hematopoietic stem cells are the suspected disease-initiating cells, and these cells must acquire a clonal advantage relative to nonmutant hematopoietic stem cells to perpetuate disease. In 2005, several groups identified a single gain-of-function point mutation in JAK2 that associated with the majority of MPNs, and subsequent studies have led to a comprehensive understanding of the mutational landscape in MPNs. However, confusion still exists as to how a single genetic aberration can be associated with multiple distinct disease entities. Many explanations have been proposed, including JAK2V617F homozygosity, individual patient heterogeneity, and the differential regulation of downstream JAK2 signaling pathways. Several groups have made knock-in mouse models expressing JAK2V617F and have observed divergent phenotypes, each recapitulating some aspects of disease. Intriguingly, most of these models do not observe a strong hematopoietic stem cell self-renewal advantage compared with wild-type littermate controls, raising the question of how a clonal advantage is established in patients with MPNs. This review summarizes the current molecular understanding of MPNs and the diversity of disease phenotypes and proposes that the increased proliferation induced by JAK2V617F applies a selection pressure on the mutant clone that results in highly diverse clonal evolution in individuals. Copyright © 2014 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Notch3 Signaling-Mediated Melanoma-Endothelial Crosstalk Regulates Melanoma Stem-Like Cell Homeostasis and Niche Morphogenesis

PubMed Central

Hsu, Mei-Yu; Yang, Moon Hee; Schnegg, Caroline I.; Hwang, Soonyean; Ryu, Byungwoo; Alani, Rhoda M.

2016-01-01

Melanoma is among the most virulent cancers, owing to its propensity to metastasize and its resistance to current therapies. The treatment failure is largely attributed to tumor heterogeneity, particularly subpopulations possessing stem cell-like properties, i.e., melanoma stem-like cells (MSLCs). Evidence indicates that the MSLC phenotype is malleable and may be acquired by non-MSLCs through phenotypic switching upon appropriate stimuli, the so–called “dynamic stemness”. Since the phenotypic characteristics and functional integrity of MSLCs depend on their vascular niche, using a two dimensional (2D) melanoma-endothelium co-culture model, where the MSLC niche is recapitulated in vitro, we identified Notch3 signaling pathway as a micro-environmental cue governing MSLC phenotypic plasticity via pathway-specific gene expression arrays. Accordingly, lentiviral shRNA-mediated Notch3 knockdown (KD) in melanoma cell lines exhibiting high levels of endogenous Notch3 led to retarded/abolished tumorigenicity in vivo through both depleting MSLC fractions, evinced by MSLC marker down-regulation (e.g., CD133 and CD271); and impeding the MSLC niche, corroborated by the attenuated tumor angiogenesis as well as vasculogenic mimicry. In contrast, Notch3 KD affected neither tumor growth nor MSLC subsets in a melanoma cell line with relatively low endogenous Notch3 expression. Thus, Notch3 signaling may facilitate MSLC plasticity and niche morphogenesis in a cell context-dependent fashion. Our findings illustrate Notch3 as a molecular switch driving melanoma heterogeneity, and provide the biological rationale for Notch inhibition as a promising therapeutic option. PMID:28165469

Zeb2 Regulates Cell Fate at the Exit from Epiblast State in Mouse Embryonic Stem Cells

PubMed Central

Stryjewska, Agata; Dries, Ruben; Pieters, Tim; Verstappen, Griet; Conidi, Andrea; Coddens, Kathleen; Francis, Annick; Umans, Lieve; van IJcken, Wilfred F. J.; Berx, Geert; van Grunsven, Leo A.; Grosveld, Frank G.; Goossens, Steven; Haigh, Jody J.

2016-01-01

Abstract In human embryonic stem cells (ESCs) the transcription factor Zeb2 regulates neuroectoderm versus mesendoderm formation, but it is unclear how Zeb2 affects the global transcriptional regulatory network in these cell‐fate decisions. We generated Zeb2 knockout (KO) mouse ESCs, subjected them as embryoid bodies (EBs) to neural and general differentiation and carried out temporal RNA‐sequencing (RNA‐seq) and reduced representation bisulfite sequencing (RRBS) analysis in neural differentiation. This shows that Zeb2 acts preferentially as a transcriptional repressor associated with developmental progression and that Zeb2 KO ESCs can exit from their naïve state. However, most cells in these EBs stall in an early epiblast‐like state and are impaired in both neural and mesendodermal differentiation. Genes involved in pluripotency, epithelial‐to‐mesenchymal transition (EMT), and DNA‐(de)methylation, including Tet1, are deregulated in the absence of Zeb2. The observed elevated Tet1 levels in the mutant cells and the knowledge of previously mapped Tet1‐binding sites correlate with loss‐of‐methylation in neural‐stimulating conditions, however, after the cells initially acquired the correct DNA‐methyl marks. Interestingly, cells from such Zeb2 KO EBs maintain the ability to re‐adapt to 2i + LIF conditions even after prolonged differentiation, while knockdown of Tet1 partially rescues their impaired differentiation. Hence, in addition to its role in EMT, Zeb2 is critical in ESCs for exit from the epiblast state, and links the pluripotency network and DNA‐methylation with irreversible commitment to differentiation. Stem Cells 2017;35:611–625 PMID:27739137

Niclosamide inhibits epithelial-mesenchymal transition and tumor growth in lapatinib-resistant human epidermal growth factor receptor 2-positive breast cancer.

PubMed

Liu, Junjun; Chen, Xiaosong; Ward, Toby; Mao, Yan; Bockhorn, Jessica; Liu, Xiaofei; Wang, Gen; Pegram, Mark; Shen, Kunwei

2016-02-01

Acquired resistance to lapatinib, a human epidermal growth factor receptor 2 kinase inhibitor, remains a clinical problem for women with human epidermal growth factor receptor 2-positive advanced breast cancer, as metastasis is commonly observed in these patients. Niclosamide, an anti-helminthic agent, has recently been shown to exhibit cytotoxicity to tumor cells with stem-like characteristics. This study was designed to identify the mechanisms underlying lapatinib resistance and to determine whether niclosamide inhibits lapatinib resistance by reversing epithelial-mesenchymal transition. Here, two human epidermal growth factor receptor 2-positive breast cancer cell lines, SKBR3 and BT474, were exposed to increasing concentrations of lapatinib to establish lapatinib-resistant cultures. Lapatinib-resistant SKBR3 and BT474 cells exhibited up-regulation of the phenotypic epithelial-mesenchymal transition markers Snail, vimentin and α-smooth muscle actin, accompanied by activation of nuclear factor-кB and Src and a concomitant increase in stem cell marker expression (CD44(high)/CD24(low)), compared to naive lapatinib-sensitive SKBR3 and BT474 cells, respectively. Interestingly, niclosamide reversed epithelial-mesenchymal transition, induced apoptosis and inhibited cell growth by perturbing aberrant signaling pathway activation in lapatinib-resistant human epidermal growth factor receptor 2-positive cells. The ability of niclosamide to alleviate stem-like phenotype development and invasion was confirmed. Collectively, our results demonstrate that lapatinib resistance correlates with epithelial-mesenchymal transition and that niclosamide inhibits lapatinib-resistant cell viability and epithelial-mesenchymal transition. These findings suggest a role of niclosamide or derivatives optimized for more favorable bioavailability not only in reversing lapatinib resistance but also in reducing metastatic potential during the treatment of human epidermal growth factor receptor 2-positive breast cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Paracrine Maturation and Migration of SH-SY5Y Cells by Dental Pulp Stem Cells.

PubMed

Gervois, P; Wolfs, E; Dillen, Y; Hilkens, P; Ratajczak, J; Driesen, R B; Vangansewinkel, T; Bronckaers, A; Brône, B; Struys, T; Lambrichts, I

2017-06-01

Neurological disorders are characterized by neurodegeneration and/or loss of neuronal function, which cannot be adequately repaired by the host. Therefore, there is need for novel treatment options such as cell-based therapies that aim to salvage or reconstitute the lost tissue or that stimulate host repair. The present study aimed to evaluate the paracrine effects of human dental pulp stem cells (hDPSCs) on the migration and neural maturation of human SH-SY5Y neuroblastoma cells. The hDPSC secretome had a significant chemoattractive effect on SH-SY5Y cells as shown by a transwell assay. To evaluate neural maturation, SH-SY5Y cells were first induced toward neuronal cells, after which they were exposed to the hDPSC secretome. In addition, SH-SY5Y cells subjected to the hDPSC secretome showed increased neuritogenesis compared with nonexposed cells. Maturated cells were shown to increase immune reactivity for neuronal markers compared with controls. Ultrastructurally, retinoic acid (RA) signaling and subsequent exposure to the hDPSC secretome induced a gradual rise in metabolic activity and neuronal features such as multivesicular bodies and cytoskeletal elements associated with cellular communication. In addition, electrophysiological recordings of differentiating cells demonstrated a transition toward a neuronal electrophysiological profile based on the maximum tetrodotoxin (TTX)-sensitive, Na + current. Moreover, conditioned medium (CM)-hDPSC-maturated SH-SY5Y cells developed distinct features including, Cd 2+ -sensitive currents, which suggests that CM-hDPSC-maturated SH-SY5Y acquired voltage-gated Ca 2+ channels. The results reported in this study demonstrate the potential of hDPSCs to support differentiation and recruitment of cells with neuronal precursor characteristics in a paracrine manner. Moreover, this in vitro experimental design showed that the widely used SH-SY5Y cell line can improve and simplify the preclinical in vitro research on the molecular mechanisms of stem cell-mediated neuronal regeneration.

Characterization of Neurons from Immortalized Dental Pulp Stem Cells for the Study of Neurogenetic Disorders

PubMed Central

Urraca, Nora; Memon, Rawaha; El-Iyachi, Ikbale; Goorha, Sarita; Valdez, Colleen; Tran, Quynh T.; Scroggs, Reese; Miranda-Carboni, Gustavo A.; Donaldson, Martin; Bridges, Dave; Reiter, Lawrence T.

2015-01-01

A major challenge to the study and treatment of neurogenetic syndromes is accessing live neurons for study from affected individuals. Although several sources of stem cells are currently available, acquiring these involve invasive procedures, may be difficult or expensive to generate and are limited in number. Dental pulp stem cells (DPSC) are multipotent stem cells that reside deep the pulp of shed teeth. To investigate the characteristics of DPSC that make them a valuable resource for translational research, we performed a set of viability, senescence, immortalization and gene expression studies on control DPSC and derived neurons. We investigated the basic transport conditions and maximum passage number for primary DPSC. We immortalized control DPSC using human telomerase reverse transcriptase (hTERT) and evaluated neuronal differentiation potential and global gene expression changes by RNA-seq. We show that neurons from immortalized DPSC share morphological and electrophysiological properties with non-immortalized DPSC. We also show that differentiation of DPSC into neurons significantly alters gene expression for 1305 transcripts. Here we show that these changes in gene expression are concurrent with changes in protein levels of the transcriptional repressor REST/NSRF, which is known to be involved in neuronal differentiation. Immortalization significantly altered the expression of 183 genes after neuronal differentiation, 94 of which also changed during differentiation. Our studies indicate that viable DPSC can be obtained from teeth stored for ≥72hrs, these can then be immortalized and still produce functional neurons for in vitro studies, but that constitutive hTERT immortalization is not be the best approach for long term use of patient derived DPSC for the study of disease. PMID:26599327

Characterization of neurons from immortalized dental pulp stem cells for the study of neurogenetic disorders.

PubMed

Urraca, Nora; Memon, Rawaha; El-Iyachi, Ikbale; Goorha, Sarita; Valdez, Colleen; Tran, Quynh T; Scroggs, Reese; Miranda-Carboni, Gustavo A; Donaldson, Martin; Bridges, Dave; Reiter, Lawrence T

2015-11-01

A major challenge to the study and treatment of neurogenetic syndromes is accessing live neurons for study from affected individuals. Although several sources of stem cells are currently available, acquiring these involve invasive procedures, may be difficult or expensive to generate and are limited in number. Dental pulp stem cells (DPSCs) are multipotent stem cells that reside deep the pulp of shed teeth. To investigate the characteristics of DPSCs that make them a valuable resource for translational research, we performed a set of viability, senescence, immortalization and gene expression studies on control DPSC and derived neurons. We investigated the basic transport conditions and maximum passage number for primary DPSCs. We immortalized control DPSCs using human telomerase reverse transcriptase (hTERT) and evaluated neuronal differentiation potential and global gene expression changes by RNA-seq. We show that neurons from immortalized DPSCs share morphological and electrophysiological properties with non-immortalized DPSCs. We also show that differentiation of DPSCs into neurons significantly alters gene expression for 1305 transcripts. Here we show that these changes in gene expression are concurrent with changes in protein levels of the transcriptional repressor REST/NRSF, which is known to be involved in neuronal differentiation. Immortalization significantly altered the expression of 183 genes after neuronal differentiation, 94 of which also changed during differentiation. Our studies indicate that viable DPSCs can be obtained from teeth stored for ≥72 h, these can then be immortalized and still produce functional neurons for in vitro studies, but that constitutive hTERT immortalization is not be the best approach for long term use of patient derived DPSCs for the study of disease. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Adult hippocampus derived soluble factors induce a neuronal-like phenotype in mesenchymal stem cells.

PubMed

Rivera, Francisco J; Sierralta, Walter D; Minguell, Jose J; Aigner, Ludwig

2006-10-02

Bone marrow-derived mesenchymal stem cells (MSCs) are not restricted in their differentiation fate to cells of the mesenchymal lineage. They acquire a neural phenotype in vitro and in vivo after transplantation in the central nervous system. Here we investigated whether soluble factors derived from different brain regions are sufficient to induce a neuronal phenotype in MSCs. We incubated bone marrow-derived MSCs in conditioned medium (CM) derived from adult hippocampus (HCM), cortex (CoCM) or cerebellum (CeCM) and analyzed the cellular morphology and the expression of neuronal and glial markers. In contrast to muscle derived conditioned medium, which served as control, conditioned medium derived from the different brain regions induced a neuronal morphology and the expression of the neuronal markers GAP-43 and neurofilaments in MSCs. Hippocampus derived conditioned medium had the strongest activity. It was independent of NGF or BDNF; and it was restricted to the neuronal differentiation fate, since no induction of the astroglial marker GFAP was observed. The work indicates that soluble factors present in the brain are sufficient to induce a neuronal phenotype in MSCs.

On the dynamics of neutral mutations in a mathematical model for a homogeneous stem cell population.

PubMed

Traulsen, Arne; Lenaerts, Tom; Pacheco, Jorge M; Dingli, David

2013-02-01

The theory of the clonal origin of cancer states that a tumour arises from one cell that acquires mutation(s) leading to the malignant phenotype. It is the current belief that many of these mutations give a fitness advantage to the mutant population allowing it to expand, eventually leading to disease. However, mutations that lead to such a clonal expansion need not give a fitness advantage and may in fact be neutral--or almost neutral--with respect to fitness. Such mutant clones can be eliminated or expand stochastically, leading to a malignant phenotype (disease). Mutations in haematopoietic stem cells give rise to diseases such as chronic myeloid leukaemia (CML) and paroxysmal nocturnal haemoglobinuria (PNH). Although neutral drift often leads to clonal extinction, disease is still possible, and in this case, it has important implications both for the incidence of disease and for therapy, as it may be more difficult to eliminate neutral mutations with therapy. We illustrate the consequences of such dynamics, using CML and PNH as examples. These considerations have implications for many other tumours as well.

A new centrifuge microscope reveals that mobile plastids trigger gravity sensing in Arabidopsis inflorescence stems

NASA Astrophysics Data System (ADS)

Toyota, Masatsugu; Tasaka, Masao; Morita, Miyo T.; Gilroy, Simon

2012-07-01

The starch-statolith hypothesis is the most widely accepted model for plant gravity sensing and proposes that the sedimentation of high-density starch-filled plastids (amyloplasts) in shoot endodermal cells and root columella cells is important for gravity sensing of each organ. However, starch-deficient phosphoglucomutase (pgm-1) mutants sense gravity and show gravitropism in inflorescence stems, even though most starchless amyloplasts in this mutant fail to sediment toward the gravity vector. These results raise the questions about the role of starch in gravity sensing and the features of statolith/statocyte essential for shoot gravity sensing. To address these questions, we developed a new centrifuge microscope and analyzed two gravitropic mutants, i.e., pgm-1 and endodermal-amyloplast less 1 (eal1). All optical devices (e.g., objective lens, light source and CCD camera) and specimens were rotated on a direct-drive motor, and acquired images were wirelessly transmitted during centrifugation. Live-cell imaging during centrifugation revealed that the starchless amyloplasts sedimented to the hypergravity vector (10 and 30 g) in endodermal cells of pgm-1 stems, indicating that the density of the starchless amyloplasts is higher than that of cytoplasm. Electron micrographs of shoot endodermal cells in pgm-1 mutants suggested that the starchless amyloplast contains an organized thylakoid membrane but not starch granules, which morphologically resembles chloroplasts in the adjacent cortical cells. Therefore, the shoot amyloplasts without starch are possibly as dense as chloroplasts. We examined eal1 mutants, an allele of shoot gravitropism (sgr) 7/short-root (shr), which also have starchless amyloplasts due to abnormal differentiation of amyloplasts and show no gravitropic response at 1 g. Hypergravity up to 30 g induced little gravitropism in eal1 stems and the starchless amyloplasts failed to sediment under 30 g conditions. However, the eal1 mutants treated with latrunculin B, an actin disrupting drug, showed gravitropism under 30 g conditions, during which amyloplasts were artificially sedimented by hypergravity. These results suggest that shoot amyloplasts are intrinsically dense enough to trigger gravity sensing without starch and, rather, intracellular environments that render amyloplasts sedimentable/mobile, such as actin organization, are essential for gravity sensing in Arabidopsis inflorescence stems.

Thidiazuron Triggers Morphogenesis in Rosa canina L. Protocorm-Like Bodies by Changing Incipient Cell Fate

PubMed Central

Kou, Yaping; Yuan, Cunquan; Zhao, Qingcui; Liu, Guoqin; Nie, Jing; Ma, Zhimin; Cheng, Chenxia; Teixeira da Silva, Jaime A.; Zhao, Liangjun

2016-01-01

Thidiazuron (N-phenyl-N′-1,2,3-thiadiazol-5-ylurea; TDZ) is an artificial plant growth regulator that is widely used in plant tissue culture. Protocorm-like bodies (PLBs) induced by TDZ serve as an efficient and rapid in vitro regeneration system in Rosa species. Despite this, the mechanism of PLB induction remains relatively unclear. TDZ, which can affect the level of endogenous auxins and cytokinins, converts the cell fate of rhizoid tips and triggers PLB formation and plantlet regeneration in Rosa canina L. In callus-rhizoids, which are rhizoids that co-develop from callus, auxin and a Z-type cytokinin accumulated after applying TDZ, and transcription of the auxin transporter gene RcPIN1 was repressed. The expression of RcARF4, RcRR1, RcCKX2, RcCKX3, and RcLOG1 increased in callus-rhizoids and rhizoid tips while the transcription of an auxin response factor (RcARF1) and auxin transport proteins (RcPIN2, RcPIN3) decreased in callus-rhizoids but increased in rhizoid tips. In situ hybridization of rhizoids showed that RcWUS and RcSERK1 were highly expressed in columella cells and root stem cells resulting in the conversion of cell fate into shoot apical meristems or embryogenic callus. In addition, transgenic XVE::RcWUS lines showed repressed RcWUS overexpression while RcWUS had no effect on PLB morphogenesis. Furthermore, higher expression of the root stem cell marker RcWOX5 and root stem cell maintenance regulator genes RcPLT1 and RcPLT2 indicated the presence of a dedifferentiation developmental pathway in the stem cell niche of rhizoids. Viewed together, our results indicate that different cells in rhizoid tips acquired regeneration competence after induction by TDZ. A novel developmental pathway containing different cell types during PLB formation was identified by analyzing the endogenous auxin and cytokinin content. This study also provides a deeper understanding of the mechanisms underlying in vitro regeneration in Rosa. PMID:27200031

Overcoming adaptive resistance in mucoepidermoid carcinoma through inhibition of the IKK-β/IκBα/NFκB axis

PubMed Central

Wagner, Vivian P.; Martins, Marco A.T.; Martins, Manoela D.; Warner, Kristy A.; Webber, Liana P.; Squarize, Cristiane H.; Nör, Jacques E.; Castilho, Rogerio M.

2016-01-01

Patients with mucoepidermoid carcinoma (MEC) experience low survival rates and high morbidity following treatment, yet the intrinsic resistance of MEC cells to ionizing radiation (IR) and the mechanisms underlying acquired resistance remain unexplored. Herein, we demonstrated that low doses of IR intrinsically activated NFκB in resistant MEC cell lines. Moreover, resistance was significantly enhanced in IR-sensitive cell lines when NFκB pathway was stimulated. Pharmacological inhibition of the IKK-β/IκBα/NFκB axis, using a single dose of FDA-approved Emetine, led to a striking sensitization of MEC cells to IR and a reduction in cancer stem cells. We achieved a major step towards better understanding the basic mechanisms involved in IR-adaptive resistance in MEC cell lines and how to efficiently overcome this critical problem. PMID:27682876

Types of Stem Cells

MedlinePlus

... Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

Impact of Environmental Power Monitoring Activities on Middle School Student Perceptions of STEM

ERIC Educational Resources Information Center

Knezek, Gerald; Christensen, Rhonda; Tyler-Wood, Tandra; Periathiruvadi, Sita

2013-01-01

Middle school is a crucial stage in student development as students prepare for a fast changing future. The science, technology, engineering and mathematics (STEM) skills that students acquire in middle school lay the foundation for a successful career in STEM. Moreover, most STEM occupations require competencies in science, math and logical…

Comparative expression analysis reveals lineage relationships between human and murine gliomas and a dominance of glial signatures during tumor propagation in vitro.

PubMed

Henriquez, Nico V; Forshew, Tim; Tatevossian, Ruth; Ellis, Matthew; Richard-Loendt, Angela; Rogers, Hazel; Jacques, Thomas S; Reitboeck, Pablo Garcia; Pearce, Kerra; Sheer, Denise; Grundy, Richard G; Brandner, Sebastian

2013-09-15

Brain tumors are thought to originate from stem/progenitor cell populations that acquire specific genetic mutations. Although current preclinical models have relevance to human pathogenesis, most do not recapitulate the histogenesis of the human disease. Recently, a large series of human gliomas and medulloblastomas were analyzed for genetic signatures of prognosis and therapeutic response. Using a mouse model system that generates three distinct types of intrinsic brain tumors, we correlated RNA and protein expression levels with human brain tumors. A combination of genetic mutations and cellular environment during tumor propagation defined the incidence and phenotype of intrinsic murine tumors. Importantly, in vitro passage of cancer stem cells uniformly promoted a glial expression profile in culture and in brain tumors. Gene expression profiling revealed that experimental gliomas corresponded to distinct subclasses of human glioblastoma, whereas experimental supratentorial primitive neuroectodermal tumors (sPNET) correspond to atypical teratoid/rhabdoid tumor (AT/RT), a rare childhood tumor. ©2013 AACR.

[Hematopoietic stem cell transplantation. Indications, foundations and perspective].

PubMed

Buchholz, S; Ganser, A

2009-05-01

The hematopoietic stem cell transplantation (HSCT) has become a standard therapy for many inherited and acquired disorders of the bone marrow and immune system. Autologous HSCT is mainly done as part of the primary therapy in multiple myeloma and as part of relapse therapy in malignant lymphoma. In contrast, allogeneic HSCT is predominantly performed in patients with acute leukemias. The selection process for allogeneic HSCT takes disease-specific as well as patient-specific factors into account. Risk factors which can predict for poor response to chemotherapy can now be identified in acute myeloid as well as lymphoid leukemia, based on phenotype, cytogenetics, molecular genetics and response to therapy. In these patients allogeneic HSCT can improve overall survival from 0-20% to 30-60%. New conditioning protocols have now raised the upper age limit for transplantation to 70 years. In elderly patients the selection of patients based on absence of comorbidities becomes especially important. The increasing number of long-term survivors requires knowledge of organ-specific late toxicities including secondary malignancies.

Reconstructive Surgery of Auricular Defects: An Overview.

PubMed

Ebrahimi, Ali; Kazemi, Alireza; Rasouli, Hamid Reza; Kazemi, Maryam; Kalantar Motamedi, Mohammad Hosein

2015-11-01

Despite the ongoing advances in surgical procedures and promising progress in bioengineering techniques, auricular reconstruction remains a significant challenge in plastic surgery. There are different causes for acquired auricular defects, including trauma, tumor ablation and burns. The management options for upper, middle and lower third auricular defects are briefly reviewed in the current paper. Original research papers investigating the plastic surgeons, otolaryngologists and maxillofacial surgeons in approaching the complicated issue of auricular reconstruction published from January 1995 to December 2014 were aggregated and used in the current study. Utilizing autologous stem cell populations to treat craniofacial defects is a promising field of ongoing investigations. Studies show that cartilage stem/progenitor cells (CSPCs) are highly chondrogenic and can produce elastic reconstructive material with long-term tissue restoration. Auricular reconstruction surgery is a challenging plastic procedure that requires great expertise and expert knowledge of the various techniques available. Novel techniques in the fields of reconstructive bioengineering and regenerative medicine are promising but further research is required before widespread clinical application.

Diagnosis and treatment of viral diseases in recipients of allogeneic hematopoietic stem cell transplantation

PubMed Central

2013-01-01

Viral infections are important causes of morbidity and mortality after allogeneic stem cell hematopoietic transplantation (allo-HSCT). Although most viral infections present with asymptomatic or subclinical manifestations, viruses may result in fatal complications in severe immunocompromised recipients. Reactivation of latent viruses, such as herpesviruses, is frequent during the immunosuppression that occurs with allo-HSCT. Viruses acquired from community, such as the respiratory and gastrointestinal viruses, are also important pathogens of post-transplant viral diseases. Currently, molecular diagnostic methods have replaced or supplemented traditional methods, such as viral culture and antigen detection, in diagnosis of viral infections. The utilization of polymerase chain reaction facilitates the early diagnosis. In view of lacking efficacious agents for treatment of viral diseases, prevention of viral infections is extremely valuable. Application of prophylactic strategies including preemptive therapy reduces viral infections and diseases. Adoptive cellular therapy for restoring virus-specific immunity is a promising method in the treatment of viral diseases. PMID:24341630

Homeostasis or channelopathy? Acquired cell type-specific ion channel changes in temporal lobe epilepsy and their antiepileptic potential

PubMed Central

Wolfart, Jakob; Laker, Debora

2015-01-01

Neurons continuously adapt the expression and functionality of their ion channels. For example, exposed to chronic excitotoxicity, neurons homeostatically downscale their intrinsic excitability. In contrast, the “acquired channelopathy” hypothesis suggests that proepileptic channel characteristics develop during epilepsy. We review cell type-specific channel alterations under different epileptic conditions and discuss the potential of channels that undergo homeostatic adaptations, as targets for antiepileptic drugs (AEDs). Most of the relevant studies have been performed on temporal lobe epilepsy (TLE), a widespread AED-refractory, focal epilepsy. The TLE patients, who undergo epilepsy surgery, frequently display hippocampal sclerosis (HS), which is associated with degeneration of cornu ammonis subfield 1 pyramidal cells (CA1 PCs). Although the resected human tissue offers insights, controlled data largely stem from animal models simulating different aspects of TLE and other epilepsies. Most of the cell type-specific information is available for CA1 PCs and dentate gyrus granule cells (DG GCs). Between these two cell types, a dichotomy can be observed: while DG GCs acquire properties decreasing the intrinsic excitability (in TLE models and patients with HS), CA1 PCs develop channel characteristics increasing intrinsic excitability (in TLE models without HS only). However, thorough examination of data on these and other cell types reveals the coexistence of protective and permissive intrinsic plasticity within neurons. These mechanisms appear differentially regulated, depending on the cell type and seizure condition. Interestingly, the same channel molecules that are upregulated in DG GCs during HS-related TLE, appear as promising targets for future AEDs and gene therapies. Hence, GCs provide an example of homeostatic ion channel adaptation which can serve as a primer when designing novel anti-epileptic strategies. PMID:26124723

Mast cells and mastocytosis

PubMed Central

2008-01-01

Mast cells have been recognized for well over 100 years. With time, human mast cells have been documented to originate from CD34+ cells, and have been implicated in host responses in both innate and acquired immunity. In clinical immunology, they are recognized for their central role in IgE-mediated degranulation and allergic inflammation by virtue of their expression of the high-affinity receptor for IgE and release of potent proinflammatory mediators. In hematology, the clinical disease of mastocytosis is characterized by a pathologic increase of mast cells in tissues, often associated with mutations in KIT, the receptor for stem cell factor. More recently, and with increased understanding of how human mast cells are activated through receptors including the high-affinity receptor for IgE and KIT, specific tyrosine kinase inhibitors have been identified with the potential to interrupt signaling pathways and thus limit the proliferation of mast cells as well as their activation through immunoglobulin receptors. PMID:18684881

[High-dose chemotherapy as a strategy to overcome drug resistance in solid tumors].

PubMed

Selle, Frédéric; Gligorov, Joseph; Soares, Daniele G; Lotz, Jean-Pierre

2016-10-01

The concept of high-doses chemotherapy was developed in the 1980s based on in vitro scientific observations. Exposure of tumor cells to increasing concentrations of alkylating agents resulted in increased cell death in a strong dose-response manner. Moreover, the acquired resistance of tumor cells could be overcome by dose intensification. In clinic, dose intensification of alkylating agents resulted in increased therapeutic responses, however associated with significant hematological toxicity. Following the development of autologous stem cells transplantation harvesting from peripheral blood, the high-doses of chemotherapy, initially associated with marked toxic effects, could be more easily tolerated. As a result, the approach was evaluated in different types of solid tumors, including breast, ovarian and germ cell tumors, small cell lung carcinoma, soft tissue sarcomas and Ewing sarcoma. To date, high-doses chemotherapy with hematopoietic stem cells support is only used as a salvage therapy to treat poor prognosis germ cell tumors patients with chemo-sensitive disease. Regarding breast and ovarian cancer, high-doses chemotherapy should be considered only in the context of clinical trials. However, intensive therapy as an approach to overcome resistance to standard treatments is still relevant. Numerous efforts are still ongoing to identify novel therapeutic combinations and active treatments to improve patients' responses. Copyright © 2016 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

Phenotypic high-throughput screening elucidates target pathway in breast cancer stem cell-like cells.

PubMed

Carmody, Leigh C; Germain, Andrew R; VerPlank, Lynn; Nag, Partha P; Muñoz, Benito; Perez, Jose R; Palmer, Michelle A J

2012-10-01

Cancer stem cells (CSCs) are resistant to standard cancer treatments and are likely responsible for cancer recurrence, but few therapies target this subpopulation. Due to the difficulty in propagating CSCs outside of the tumor environment, previous work identified CSC-like cells by inducing human breast epithelial cells into an epithelial-to-mesenchymal transdifferentiated state (HMLE_sh_ECad). A phenotypic screen was conducted against HMLE_sh_ECad with 300 718 compounds from the Molecular Libraries Small Molecule Repository to identify selective inhibitors of CSC growth. The screen yielded 2244 hits that were evaluated for toxicity and selectivity toward an isogenic control cell line. An acyl hydrazone scaffold emerged as a potent and selective scaffold targeting HMLE_sh_ECad. Fifty-three analogues were acquired and tested; compounds ranged in potency from 790 nM to inactive against HMLE_sh_ECad. Of the analogues, ML239 was best-in-class with an IC(50)= 1.18 µM against HMLE_sh_ECad, demonstrated a >23-fold selectivity over the control line, and was toxic to another CSC-like line, HMLE_shTwist, and a breast carcinoma cell line, MDA-MB-231. Gene expression studies conducted with ML239-treated cells showed altered gene expression in the NF-κB pathway in the HMLE_sh_ECad line but not in the isogenic control line. Future studies will be directed toward the identification of ML239 target(s).

Epidemiologic Profile of Patients Transplanted With Hematopoietic Stem Cells in a Reference Service in the State of Rio Grande do Norte, Brazil.

PubMed

Campos de Azevedo, I; Ferreira Júnior, M A; Pereira de Aquino, L A; de Oliveira, A A; Cruz, G K P; de Queiroz Cardoso, A I; Ivo, M L; Santos, V E P

2018-04-01

Hematopoietic stem cell transplantation (HSCT) consists of the intravenous infusion of healthy hematopoietic stem cells to restore the medullary and immunologic function of patients affected by a series of hematologic, oncologic, immunologic, malignant and nonmalignant inherited or acquired diseases, with the possibility of cure or increase of disease-free survival. To characterize the epidemiologic profile and the cases of death of patients who underwent HSCT. This is a cohort quantitative study, nested with a retrospective, descriptive, and analytical study of a hospital-based cohort that included the patients who underwent HSCT at a referral service in the state of Rio Grande do Norte, a region of northeastern Brazil. There was a slight male prevalence (52.94%), the age of the patients ranged from 2 to 73 years old, 18.38% were brown, 47.06% were married, 15.07% were students, 78.31% had a diagnosis of multiple myeloma, 93.38% developed gastrointestinal toxicities, all patients received chemotherapeutic treatment, 54.78% had allogeneic HSCT, and the cause of the most recorded deaths was septic shock (48.19%). This study showed relevant scientific evidence on the clinical and epidemiologic profile of patients who underwent HSCT. In general, sociodemographic data are similar to national and international research results. Copyright © 2018 Elsevier Inc. All rights reserved.

Exploring of bioactive compounds in essential oil acquired from the stem and root derivatives of Hypericum triquetrifolium callus cultures.

PubMed

Tahir, Nawroz Abdul-Razzak; Azeez, Hoshyar Abdullah; Muhammad, Kadhm Abdullah; Faqe, Shewa Anwer; Omer, Dlshad Ali

2017-12-25

The chemical profile of the essential oil of callus and cell suspension cultures derivatives from stem and root of Hypericum triquetrifolium were explored by ITEX/GC-MS. The major constituents for stem derivatives were undecane (78.44%) and 2,4,6-trimethyl-octane (9.74%) for fresh calli, 2,4-dimethyl-benzaldehyde (46.94%), 2,3-dimethyl-undecane (28.39%), 2,4-dimethyl-1-hexene (10.17%), 1,2-oxolinalool (3.64%) and limonene (3.55%) for dry calli and undecane (61.24%), octane, 2,4,6-trimethyl- (16.73%), nonane, 3-methyl-(3.74%), 2,5-diphenyl-benzoquinone (3.70%) and limonene (3.60%) for cell suspension. However, for root derivatives, the dominated components were: undecane (49.94%), eucalyptol (12.07%), limonene (9.98%), toluene (9.03%) and 3-methyl-nonane (4.29%) for fresh calli, 2,4-dimethyl-benzaldehyde (29.80%), 1,1-dimethylethyl-cyclohexane (14.99%), 3-methyl-pentanal (14.99%), undecane (10.04%), beta-terpinyl acetate (8.60%), 1,2-oxolinalool (6.27%) and 2-pentyl-furan (4.09%) for dry calli, undecane (52.38%), 2,4,6-trimethyl-octane (13.81%), 3-methyl-nonane (5.73%), toluene (4.82%) and limonene (4.57%) for cell suspension derivative in root. The attained outcomes indicated that the alkane, aldehyde and monoterpene fractions dominated the chemical composition of essential oils.

miRNA-regulated cancer stem cells: understanding the property and the role of miRNA in carcinogenesis.

PubMed

Chakraborty, Chiranjib; Chin, Kok-Yong; Das, Srijit

2016-10-01

Over the last few years, microRNAs (miRNA)-controlled cancer stem cells have drawn enormous attention. Cancer stem cells are a small population of tumor cells that possess the stem cell property of self-renewal. Recent data shows that miRNA regulates this small population of stem cells. In the present review, we explained different characteristics of cancer stem cells as well as miRNA regulation of self-renewal and differentiation in cancer stem cells. We also described the migration and tumor formation. Finally, we described the different miRNAs that regulate various types of cancer stem cells, such as prostate cancer stem cells, head and neck cancer stem cells, breast cancer stem cells, colorectal cancer stem cells, lung cancer stem cells, gastric cancer stem cells, pancreatic cancer stem cells, etc. Extensive research is needed in order to employ miRNA-based therapeutics to control cancer stem cell population in various cancers in the future.

Evolution of acute myelogenous leukemia stem cell properties after treatment and progression.

PubMed

Ho, Tzu-Chieh; LaMere, Mark; Stevens, Brett M; Ashton, John M; Myers, Jason R; O'Dwyer, Kristen M; Liesveld, Jane L; Mendler, Jason H; Guzman, Monica; Morrissette, Jennifer D; Zhao, Jianhua; Wang, Eunice S; Wetzler, Meir; Jordan, Craig T; Becker, Michael W

2016-09-29

Most cancers evolve over time as patients initially responsive to therapy acquire resistance to the same drugs at relapse. Cancer stem cells have been postulated to represent a therapy-refractory reservoir for relapse, but formal proof of this model is lacking. We prospectively characterized leukemia stem cell populations (LSCs) from a well-defined cohort of patients with acute myelogenous leukemia (AML) at diagnosis and relapse to assess the effect of the disease course on these critical populations. Leukemic samples were collected from patients with newly diagnosed AML before therapy and after relapse, and LSC frequency was assessed by limiting dilution analyses. LSC populations were identified using fluorescent-labeled cell sorting and transplantation into immunodeficient NOD/SCID/interleukin 2 receptor γ chain null mice. The surface antigen expression profiles of pretherapy and postrelapse LSCs were determined for published LSC markers. We demonstrate a 9- to 90-fold increase in LSC frequency between diagnosis and relapse. LSC activity at relapse was identified in populations of leukemic blasts that did not demonstrate this activity before treatment and relapse. In addition, we describe genetic instability and exceptional phenotypic changes that accompany the evolution of these new LSC populations. This study is the first to characterize the evolution of LSCs in vivo after chemotherapy, identifying a dramatic change in the physiology of primitive AML cells when the disease progresses. Taken together, these findings provide a new frame of reference by which to evaluate candidate AML therapies in which both disease control and the induction of more advanced forms of disease should be considered. © 2016 by The American Society of Hematology.

Evolution of acute myelogenous leukemia stem cell properties after treatment and progression

PubMed Central

Ho, Tzu-Chieh; LaMere, Mark; Stevens, Brett M.; Ashton, John M.; Myers, Jason R.; O’Dwyer, Kristen M.; Liesveld, Jane L.; Mendler, Jason H.; Guzman, Monica; Morrissette, Jennifer D.; Zhao, Jianhua; Wang, Eunice S.; Wetzler, Meir; Jordan, Craig T.

2016-01-01

Most cancers evolve over time as patients initially responsive to therapy acquire resistance to the same drugs at relapse. Cancer stem cells have been postulated to represent a therapy-refractory reservoir for relapse, but formal proof of this model is lacking. We prospectively characterized leukemia stem cell populations (LSCs) from a well-defined cohort of patients with acute myelogenous leukemia (AML) at diagnosis and relapse to assess the effect of the disease course on these critical populations. Leukemic samples were collected from patients with newly diagnosed AML before therapy and after relapse, and LSC frequency was assessed by limiting dilution analyses. LSC populations were identified using fluorescent-labeled cell sorting and transplantation into immunodeficient NOD/SCID/interleukin 2 receptor γ chain null mice. The surface antigen expression profiles of pretherapy and postrelapse LSCs were determined for published LSC markers. We demonstrate a 9- to 90-fold increase in LSC frequency between diagnosis and relapse. LSC activity at relapse was identified in populations of leukemic blasts that did not demonstrate this activity before treatment and relapse. In addition, we describe genetic instability and exceptional phenotypic changes that accompany the evolution of these new LSC populations. This study is the first to characterize the evolution of LSCs in vivo after chemotherapy, identifying a dramatic change in the physiology of primitive AML cells when the disease progresses. Taken together, these findings provide a new frame of reference by which to evaluate candidate AML therapies in which both disease control and the induction of more advanced forms of disease should be considered. PMID:27421961

What is a stem cell?

PubMed

Slack, Jonathan M W

2018-05-15

The historical roots of the stem cell concept are traced with respect to its usage in embryology and in hematology. The modern consensus definition of stem cells, comprising both pluripotent stem cells in culture and tissue-specific stem cells in vivo, is explained and explored. Methods for identifying stem cells are discussed with respect to cell surface markers, telomerase, label retention and transplantability, and properties of the stem cell niche are explored. The CreER method for identifying stem cells in vivo is explained, as is evidence in favor of a stochastic rather than an obligate asymmetric form of cell division. In conclusion, it is found that stem cells do not possess any unique and specific molecular markers; and stem cell behavior depends on the environment of the cell as well as the stem cell's intrinsic qualities. Furthermore, the stochastic mode of division implies that stem cell behavior is a property of a cell population not of an individual cell. In this sense, stem cells do not exist in isolation but only as a part of multicellular system. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells. © 2018 Wiley Periodicals, Inc.

Breaking tolerance to self, circulating natural killer cells expressing inhibitory KIR for non-self HLA exhibit effector function after T cell-depleted allogeneic hematopoietic cell transplantation.

PubMed

Yu, Junli; Venstrom, Jeffrey M; Liu, Xiao-Rong; Pring, James; Hasan, Reenat S; O'Reilly, Richard J; Hsu, Katharine C

2009-04-16

Alloreactive natural killer (NK) cells are an important influence on hematopoietic stem cell transplantation (HSCT) outcome. In HLA-mismatched HSCT, alloreactivity occurs when licensed donor NK cells expressing inhibitory killer Ig-like receptors (KIR) for donor MHC class I ligands recognize the lack of the class I ligands in the mismatched recipient ("missing self"). Studies in HLA-matched HSCT, however, have also demonstrated improved outcome in patients lacking class I ligands for donor inhibitory KIR ("missing ligand"), indicating that classically nonlicensed donor NK cells expressing KIR for non-self MHC class I ligands may exhibit functional competence in HSCT. We examined NK function in 16 recipients of T cell-depleted allografts from HLA-identical or KIR-ligand matched donors after myeloablative therapy. After HSCT, nonlicensed NK cells expressing inhibitory KIR for non-self class I exhibit robust intracellular IFN-gamma and cytotoxic response to target cells lacking cognate ligand, gradually becoming tolerized to self by day 100. These findings could not be correlated with cytokine environment or phenotypic markers of NK development, nor could they be attributed to non-KIR receptors such as CD94/NKG2A. These findings confirm that NK alloreactivity can occur in HLA-matched HSCT, where tolerance to self is either acquired by the stem cell-derived NK cell after exiting the bone marrow or where tolerance to self can be temporarily overcome.

Elevated expression of CX3C chemokine receptor 1 mediates recruitment of T cells into bone marrow of patients with acquired aplastic anaemia.

PubMed

Ren, J; Hou, X Y; Ma, S H; Zhang, F K; Zhen, J H; Sun, L; Sun, Y X; Hao, Y L; Cheng, Y F; Hou, M; Xu, C G; Zhang, M H; Peng, J

2014-11-01

Acquired aplastic anaemia (AA) is a T-cell-mediated, organ-specific autoimmune disease characterized by haematopoietic stem cell destruction in the bone marrow. The exact molecular mechanism of T-cell trafficking into the bone marrow is unclear in AA. Very late activation antigen-4 (VLA-4) and CX3C chemokine receptor 1 (CX3CR1) play active roles in many autoimmune diseases. Therefore, we investigated whether VLA-4 and CX3CR1 also contribute to T-cell migration into the bone marrow in acquired AA. Expression levels of CX3CR1 and VLA-4 and their ligands [fractalkine (CX3CL1) and vascular cell adhesion molecule-1 (VCAM-1)] were examined in 63 patients with AA and 21 healthy control subjects. T-cell chemotaxis and adhesion were analysed in 17 patients with severe AA. We also prospectively evaluated the expression pattern of CX3CR1 during treatment with antithymocyte globulin plus cyclosporine in 11 patients with severe AA. The proportion of peripheral and bone marrow CD4(+) and CD8(+) T cells expressing CX3CR1 and the level of CX3CL1 was increased in patients with AA. However, there was no significant difference in VLA-4 expression or VCAM-1 levels. Functional studies demonstrated that chemotaxis towards autologous bone marrow plasma or soluble CX3CL1 was significantly higher in T cells from AA patients and could be blocked by CX3CR1 inhibitors. CX3CR1-mediated T-cell adhesion was also upregulated in these patients. The expression of CX3CR1 was associated with the efficacy of immunosuppressive therapy. The present findings demonstrate that CX3CR1 plays a pivotal role in recruitment of T cells into the bone marrow in acquired AA and is a potential therapeutic target for treatment of this disorder. © 2014 The Association for the Publication of the Journal of Internal Medicine.

Bridging innate NK cell functions with adaptive immunity.

PubMed

Marcenaro, Emanuela; Carlomagno, Simona; Pesce, Silvia; Moretta, Alessandro; Sivori, Simona

2011-01-01

Killer Ig-like receptors (KIRs) are major human NK receptors displaying either inhibitory or activating functions which recognize allotypic determinants of HLA-class I molecules. Surprisingly, NK cell treatment with CpG-ODN (TLR9 ligands) results in selective down-modulation of KIR3DL2, its co-internalization with CpG-ODN and its translocation to TLR9-rich early endosomes. This novel KIR-associated function may offer clues to better understand the possible role of certain KIRs and also emphasizes the involvement of NK cells in the course of microbial infections. NK cells are involved not only in innate immune responses against viruses and tumors but also participate in the complex network of cell-to cell interaction that leads to the development of adaptive immune responses. In this context the interaction of NK cells with DC appears to play a crucial role in the acquisition of CCR7, a chemokine receptor that enables NK cells to migrate towards lymph nodes in response to CCL19 and/or CCL21. Analysis of NK cell clones revealed that KIR-mismatched but not KIR-matched NK cells acquire CCR7. These data have important implications in haploidentical haematopoietic stem cell transplantation (HSCT), in which KIR-mismatched NK cells may acquire the ability to migrate to secondary lymphoid compartments (SLCs), where they can kill recipient's antigen presenting cells (APCs) and T cells thus preventing graft versus host (and host vs. graft) reactions.

The many faces of REST oversee epigenetic programming of neuronal genes.

PubMed

Ballas, Nurit; Mandel, Gail

2005-10-01

Nervous system development relies on a complex signaling network to engineer the orderly transitions that lead to the acquisition of a neural cell fate. Progression from the non-neuronal pluripotent stem cell to a restricted neural lineage is characterized by distinct patterns of gene expression, particularly the restriction of neuronal gene expression to neurons. Concurrently, cells outside the nervous system acquire and maintain a non-neuronal fate that permanently excludes expression of neuronal genes. Studies of the transcriptional repressor REST, which regulates a large network of neuronal genes, provide a paradigm for elucidating the link between epigenetic mechanisms and neurogenesis. REST orchestrates a set of epigenetic modifications that are distinct between non-neuronal cells that give rise to neurons and those that are destined to remain as nervous system outsiders.

Overexpression of Polysialylated Neural Cell Adhesion Molecule Improves the Migration Capacity of Induced Pluripotent Stem Cell-Derived Oligodendrocyte Precursors

PubMed Central

Czepiel, Marcin; Leicher, Lasse; Becker, Katja; Boddeke, Erik

2014-01-01

Cell replacement therapy aiming at the compensation of lost oligodendrocytes and restoration of myelination in acquired or congenital demyelination disorders has gained considerable interest since the discovery of induced pluripotent stem cells (iPSCs). Patient-derived iPSCs provide an inexhaustible source for transplantable autologous oligodendrocyte precursors (OPCs). The first transplantation studies in animal models for demyelination with iPSC-derived OPCs demonstrated their survival and remyelinating capacity, but also revealed their limited migration capacity. In the present study, we induced overexpression of the polysialylating enzyme sialyltransferase X (STX) in iPSC-derived OPCs to stimulate the production of polysialic acid-neuronal cell adhesion molecules (PSA-NCAMs), known to promote and facilitate the migration of OPCs. The STX-overexpressing iPSC-derived OPCs showed a normal differentiation and maturation pattern and were able to downregulate PSA-NCAMs when they became myelin-forming oligodendrocytes. After implantation in the demyelinated corpus callosum of cuprizone-fed mice, STX-expressing iPSC-derived OPCs demonstrated a significant increase in migration along the axons. Our findings suggest that the reach and efficacy of iPSC-derived OPC transplantation can be improved by stimulating the OPC migration potential via specific gene modulation. PMID:25069776

Recellularization of Rat Liver Scaffolds by Human Liver Stem Cells

PubMed Central

Navarro-Tableros, Victor; Herrera Sanchez, Maria Beatriz; Figliolini, Federico; Romagnoli, Renato; Tetta, Ciro

2015-01-01

In the present study, rat liver acellular scaffolds were used as biological support to guide the differentiation of human liver stem-like cells (HLSC) to hepatocytes. Once recellularized, the scaffolds were maintained for 21 days in different culture conditions to evaluate hepatocyte differentiation. HLSC lost the embryonic markers (alpha-fetoprotein, nestin, nanog, sox2, Musashi1, Oct 3/4, and pax2), increased the expression of albumin, and acquired the expression of lactate dehydrogenase and three subtypes of cytochrome P450. The presence of urea nitrogen in the culture medium confirmed their metabolic activity. In addition, cells attached to tubular remnant matrix structures expressed cytokeratin 19, CD31, and vimentin. The rat extracellular matrix (ECM) provides not only a favorable environment for differentiation of HLSC in functional hepatocytes (hepatocyte like) but also promoted the generation of some epithelial-like and endothelial-like cells. When fibroblast growth factor–epidermal growth factor or HLSC-derived conditioned medium was added to the perfusate, an improvement of survival rate was observed. The conditioned medium from HLSC potentiated also the metabolic activity of hepatocyte-like cells repopulating the acellular liver. In conclusion, HLSC have the potential, in association with the natural ECM, to generate in vitro a functional “humanized liver-like tissue.” PMID:25794768

Effect on Multipotency and Phenotypic Transition of Unrestricted Somatic Stem Cells from Human Umbilical Cord Blood after Treatment with Epigenetic Agents

PubMed Central

2016-01-01

The epigenetic mechanism of DNA methylation is of central importance for cellular differentiation processes. Unrestricted somatic stem cells (USSCs) from human umbilical cord blood, which have a broad differentiation spectrum, reside in an uncommitted epigenetic state with partial methylation of the regulatory region of the gene coding for the pluripotency master regulator OCT4. Thus we hypothesized that further opening of this “poised” epigenetic state could broaden the differentiation potential of USSCs. Here we document that USSCs drastically change their phenotype after treatment by a new elaborated cultivation protocol which utilizes the DNA hypomethylating compound 5′-aza-2-deoxycytidine (5-Aza-CdR) and the histone deacetylase inhibitor trichostatin A (TSA). This treatment leads to a new stable, spheroid-forming cell type which we have named SpheUSSC. These cells can be stably propagated over at least 150 cell divisions, express OCT4, retain the potential to undergo osteogenic differentiation, and have additionally acquired the ability to uniformly differentiate into adipocytes, unlike the source USSC population. Here we describe our treatment protocol and provide evidence that it induces a dedifferentiation step and concomitantly the acquisition of an extended differentiation capability of the new SpheUSSC type. PMID:26788071

Emerging role of brain metastases in the prognosis of breast cancer patients.

PubMed

Hambrecht, Amanda; Jandial, Rahul; Neman, Josh

2011-08-10

Cancer starts with one rogue cell. Through mutations and genomic alterations, the cell acquires specific and stem cell-like characteristics necessary for invasion of a distant organ and ultimately metastasis. Metastatic brain cancer is a particularly formidable disease because of its poor prognosis and the highly resistant nature of the tumor to chemotherapy. Although several types of primary tumors have a tendency to metastasize to the brain, the incidence of brain metastases has increased dramatically in some subsets of breast cancer patients. Several conventional treatments are available, but success is limited and often short-lived. Given that no standard treatment options exist, there is a significant need to investigate the biology of these clinically recalcitrant tumors.

Emerging role of brain metastases in the prognosis of breast cancer patients

PubMed Central

Hambrecht, Amanda; Jandial, Rahul; Neman, Josh

2011-01-01

Cancer starts with one rogue cell. Through mutations and genomic alterations, the cell acquires specific and stem cell-like characteristics necessary for invasion of a distant organ and ultimately metastasis. Metastatic brain cancer is a particularly formidable disease because of its poor prognosis and the highly resistant nature of the tumor to chemotherapy. Although several types of primary tumors have a tendency to metastasize to the brain, the incidence of brain metastases has increased dramatically in some subsets of breast cancer patients. Several conventional treatments are available, but success is limited and often short-lived. Given that no standard treatment options exist, there is a significant need to investigate the biology of these clinically recalcitrant tumors. PMID:24367178

Cannabidiol stimulates Aml-1a-dependent glial differentiation and inhibits glioma stem-like cells proliferation by inducing autophagy in a TRPV2-dependent manner.

PubMed

Nabissi, Massimo; Morelli, Maria Beatrice; Amantini, Consuelo; Liberati, Sonia; Santoni, Matteo; Ricci-Vitiani, Lucia; Pallini, Roberto; Santoni, Giorgio

2015-10-15

Glioma stem-like cells (GSCs) correspond to a tumor cell subpopulation, involved in glioblastoma multiforme (GBM) tumor initiation and acquired chemoresistance. Currently, drug-induced differentiation is considered as a promising approach to eradicate this tumor-driving cell population. Recently, the effect of cannabinoids (CBs) in promoting glial differentiation and inhibiting gliomagenesis has been evidenced. Herein, we demonstrated that cannabidiol (CBD) by activating transient receptor potential vanilloid-2 (TRPV2) triggers GSCs differentiation activating the autophagic process and inhibits GSCs proliferation and clonogenic capability. Above all, CBD and carmustine (BCNU) in combination overcome the high resistance of GSCs to BCNU treatment, by inducing apoptotic cell death. Acute myeloid leukemia (Aml-1) transcription factors play a pivotal role in GBM proliferation and differentiation and it is known that Aml-1 control the expression of several nociceptive receptors. So, we evaluated the expression levels of Aml-1 spliced variants (Aml-1a, b and c) in GSCs and during their differentiation. We found that Aml-1a is upregulated during GSCs differentiation, and its downregulation restores a stem cell phenotype in differentiated GSCs. Since it was demonstrated that CBD induces also TRPV2 expression and that TRPV2 is involved in GSCs differentiation, we evaluated if Aml-1a interacted directly with TRPV2 promoters. Herein, we found that Aml-1a binds TRPV2 promoters and that Aml-1a expression is upregulated by CBD treatment, in a TRPV2 and PI3K/AKT dependent manner. Altogether, these results support a novel mechanism by which CBD inducing TRPV2-dependent autophagic process stimulates Aml-1a-dependent GSCs differentiation, abrogating the BCNU chemoresistance in GSCs. © 2015 UICC.

Senescence-associated ultrastructural features of long-term cultures of induced pluripotent stem cells (iPSCs)

PubMed Central

Colasuonno, Fiorella; Borghi, Rossella; Niceforo, Alessia; Muzzi, Maurizio; Bertini, Enrico; Di Giulio, Andrea

2017-01-01

Induced pluripotent stem cells (iPSCs) hold great promise for developing personalized regenerative medicine, however characterization of their biological features is still incomplete. Moreover, changes occurring in long-term cultured iPSCs have been reported, suggesting these as a model of cellular aging. For this reason, we addressed the ultrastructural characterization of iPSCs, with a focus on possible time-dependent changes, involving specific cell compartments. To this aim, we comparatively analysed cultures at different timepoints, by an innovative electron microscopic technology (FIB/SEM). We observed progressive loss of cell-to-cell contacts, associated with increased occurrence of exosomes. Mitochondria gradually increased, while acquiring an elongated shape, with well-developed cristae. Such mitochondrial maturation was accompanied by their turnover, as assessed by the presence of autophagomes (undetectable in young iPSCs), some containing recognizable mitochondria. This finding was especially frequent in middle-aged iPSCs, while being occasional in aged cells, suggesting early autophagic activation followed by a decreased efficiency of the process with culturing time. Accordingly, confocal microscopy showed age-dependent alterations to the expression and distribution of autophagic markers. Interestingly, responsivity to rapamycin, highest in young iPSCs, was almost lost in aged cells. Overall, our results strongly support long-term cultured iPSCs as a model for studying relevant aspects of cellular senescence, involving intercellular communication, energy metabolism, and autophagy. PMID:29064821

Differential marker expression by cultures rich in mesenchymal stem cells

PubMed Central

2013-01-01

Background Mesenchymal stem cells have properties that make them amenable to therapeutic use. However, the acceptance of mesenchymal stem cells in clinical practice requires standardized techniques for their specific isolation. To date, there are no conclusive marker (s) for the exclusive isolation of mesenchymal stem cells. Our aim was to identify markers differentially expressed between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. We compared and contrasted the phenotype of tissue cultures in which mesenchymal stem cells are rich and rare. By initially assessing mesenchymal stem cell differentiation, we established that bone marrow and breast adipose cultures are rich in mesenchymal stem cells while, in our hands, foreskin fibroblast and olfactory tissue cultures contain rare mesenchymal stem cells. In particular, olfactory tissue cells represent non-stem cell mesenchymal cells. Subsequently, the phenotype of the tissue cultures were thoroughly assessed using immuno-fluorescence, flow-cytometry, proteomics, antibody arrays and qPCR. Results Our analysis revealed that all tissue cultures, regardless of differentiation potential, demonstrated remarkably similar phenotypes. Importantly, it was also observed that common mesenchymal stem cell markers, and fibroblast-associated markers, do not discriminate between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. Examination and comparison of the phenotypes of mesenchymal stem cell and non-stem cell mesenchymal cell cultures revealed three differentially expressed markers – CD24, CD108 and CD40. Conclusion We indicate the importance of establishing differential marker expression between mesenchymal stem cells and non-stem cell mesenchymal cells in order to determine stem cell specific markers. PMID:24304471

Innate signals overcome acquired TCR signaling pathway regulation and govern the fate of human CD161(hi) CD8α⁺ semi-invariant T cells.

PubMed

Turtle, Cameron J; Delrow, Jeff; Joslyn, Rochelle C; Swanson, Hillary M; Basom, Ryan; Tabellini, Laura; Delaney, Colleen; Heimfeld, Shelly; Hansen, John A; Riddell, Stanley R

2011-09-08

Type 17 programmed CD161(hi)CD8α(+) T cells contribute to mucosal immunity to bacteria and yeast. In early life, microbial colonization induces proliferation of CD161(hi) cells that is dependent on their expression of a semi-invariant Vα7.2(+) TCR. Although prevalent in adults, CD161(hi)CD8α(+) cells exhibit weak proliferative and cytokine responses to TCR ligation. The mechanisms responsible for the dichotomous response of neonatal and adult CD161(hi) cells, and the signals that enable their effector function, have not been established. We describe acquired regulation of TCR signaling in adult memory CD161(hi)CD8α(+) T cells that is absent in cord CD161(hi) cells and adult CD161(lo) cells. Regulated TCR signaling in CD161(hi) cells was due to profound alterations in TCR signaling pathway gene expression and could be overcome by costimulation through CD28 or innate cytokine receptors, which dictated the fate of their progeny. Costimulation with IL-1β during TCR ligation markedly increased proinflammatory IL-17 production, while IL-12-induced Tc1-like function and restored the response to TCR ligation without costimulation. CD161(hi) cells from umbilical cord blood and granulocyte colony stimulating factor-mobilized leukaphereses differed in frequency and function, suggesting future evaluation of the contribution of CD161(hi) cells in hematopoietic stem cell grafts to transplant outcomes is warranted.

KCTD2, an adaptor of Cullin3 E3 ubiquitin ligase, suppresses gliomagenesis by destabilizing c-Myc

PubMed Central

Kim, Eun-Jung; Kim, Sung-Hak; Jin, Xiong; Jin, Xun; Kim, Hyunggee

2017-01-01

Cullin3 E3 ubiquitin ligase ubiquitinates a wide range of substrates through substrate-specific adaptors Bric-a-brac, Tramtrack, and Broad complex (BTB) domain proteins. These E3 ubiquitin ligase complexes are involved in diverse cellular functions. Our recent study demonstrated that decreased Cullin3 expression induces glioma initiation and correlates with poor prognosis of patients with malignant glioma. However, the substrate recognition mechanism associated with tumorigenesis is not completely understood. Through yeast two-hybrid screening, we identified potassium channel tetramerization domain-containing 2 (KCTD2) as a BTB domain protein that binds to Cullin3. The interaction of Cullin3 and KCTD2 was verified using immunoprecipitation and immunofluorescence. Of interest, KCTD2 expression was markedly decreased in patient-derived glioma stem cells (GSCs) compared with non-stem glioma cells. Depletion of KCTD2 using a KCTD2-specific short-hairpin RNA in U87MG glioma cells and primary Ink4a/Arf-deficient murine astrocytes markedly increased self-renewal activity in addition with an increased expression of stem cell markers, and mouse in vivo intracranial tumor growth. As an underlying mechanism for these KCTD2-mediated phenotypic changes, we demonstrated that KCTD2 interacts with c-Myc, which is a key stem cell factor, and causes c-Myc protein degradation by ubiquitination. As a result, KCTD2 depletion acquires GSC features and affects aerobic glycolysis via expression changes in glycolysis-associated genes through c-Myc protein regulation. Of clinical significance was our finding that patients having a profile of KCTD2 mRNA-low and c-Myc gene signature-high, but not KCTD2 mRNA-low and c-Myc mRNA-high, are strongly associated with poor prognosis. This study describes a novel regulatory mode of c-Myc protein in malignant gliomas and provides a potential framework for glioma therapy by targeting c-Myc function. PMID:28060381

Learn About Stem Cells

MedlinePlus

... Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... Home > Learn About Stem Cells > Stem Cell Basics Cells in the human body The human body comprises ...

Erythroid differentiation of human induced pluripotent stem cells is independent of donor cell type of origin.

PubMed

Dorn, Isabel; Klich, Katharina; Arauzo-Bravo, Marcos J; Radstaak, Martina; Santourlidis, Simeon; Ghanjati, Foued; Radke, Teja F; Psathaki, Olympia E; Hargus, Gunnar; Kramer, Jan; Einhaus, Martin; Kim, Jeong Beom; Kögler, Gesine; Wernet, Peter; Schöler, Hans R; Schlenke, Peter; Zaehres, Holm

2015-01-01

Epigenetic memory in induced pluripotent stem cells, which is related to the somatic cell type of origin of the stem cells, might lead to variations in the differentiation capacities of the pluripotent stem cells. In this context, induced pluripotent stem cells from human CD34(+) hematopoietic stem cells might be more suitable for hematopoietic differentiation than the commonly used fibroblast-derived induced pluripotent stem cells. To investigate the influence of an epigenetic memory on the ex vivo expansion of induced pluripotent stem cells into erythroid cells, we compared induced pluripotent stem cells from human neural stem cells and human cord blood-derived CD34(+) hematopoietic stem cells and evaluated their potential for differentiation into hematopoietic progenitor and mature red blood cells. Although genome-wide DNA methylation profiling at all promoter regions demonstrates that the epigenetic memory of induced pluripotent stem cells is influenced by the somatic cell type of origin of the stem cells, we found a similar hematopoietic induction potential and erythroid differentiation pattern of induced pluripotent stem cells of different somatic cell origin. All human induced pluripotent stem cell lines showed terminal maturation into normoblasts and enucleated reticulocytes, producing predominantly fetal hemoglobin. Differences were only observed in the growth rate of erythroid cells, which was slightly higher in the induced pluripotent stem cells derived from CD34(+) hematopoietic stem cells. More detailed methylation analysis of the hematopoietic and erythroid promoters identified similar CpG methylation levels in the induced pluripotent stem cell lines derived from CD34(+) cells and those derived from neural stem cells, which confirms their comparable erythroid differentiation potential. Copyright© Ferrata Storti Foundation.

[Progress in stem cells and regenerative medicine].

PubMed

Wang, Libin; Zhu, He; Hao, Jie; Zhou, Qi

2015-06-01

Stem cells have the ability to differentiate into all types of cells in the body and therefore have great application potential in regenerative medicine, in vitro disease modelling and drug screening. In recent years, stem cell technology has made great progress, and induced pluripotent stem cell technology revolutionizes the whole stem cell field. At the same time, stem cell research in our country has also achieved great progress and becomes an indispensable power in the worldwide stem cell research field. This review mainly focuses on the research progress in stem cells and regenerative medicine in our country since the advent of induced pluripotent stem cell technology, including induced pluripotent stem cells, transdifferentiation, haploid stem cells, and new gene editing tools.

Application of Graphene Based Nanotechnology in Stem Cells Research.

PubMed

Hu, Shanshan; Zeng, Yongxiang; Yang, Shuying; Qin, Han; Cai, He; Wang, Jian

2015-09-01

The past several years have witnessed significant advances in stem cell therapy, tissue engineering and regenerative medicine. Graphene, with its unique properties such as high electrical conductivity, elasticity and good molecule absorption, have potential for creating the next generation of biomaterials. This review summarizes the interrelationship between graphene and stem cells. The analysis of graphene when applied on mesenchymal stem cells, neural stem cells, induced pluripotent stem cells, embryonic stem cells, periodontal ligament stem cells, human adipose-derived stem cells and cancer stem cells, and how graphene influences cell behavior and differentiation are discussed in details.

A revisionist history of adult marrow stem cell biology or 'they forgot about the discard'.

PubMed

Quesenberry, P; Goldberg, L

2017-08-01

The adult marrow hematopoietic stem cell biology has largely been based on studies of highly purified stem cells. This is unfortunate because during the stem cell purification the great bulk of stem cells are discarded. These cells are actively proliferating. The final purified stem cell is dormant and not representative of the whole stem cell compartment. Thus, a large number of studies on the cellular characteristics, regulators and molecular details of stem cells have been carried on out of non-represented cells. Niche studies have largely pursued using these purified stem cells and these are largely un-interpretable. Other considerations include the distinction between baseline and transplant stem cells and the modulation of stem cell phenotype by extracellular vesicles, to cite a non-inclusive list. Work needs to proceed on characterizing the true stem cell population.

Human beta-cell precursors mature into functional insulin-producing cells in an immunoisolation device: implications for diabetes cell therapies.

PubMed

Lee, Seung-Hee; Hao, Ergeng; Savinov, Alexei Y; Geron, Ifat; Strongin, Alex Y; Itkin-Ansari, Pamela

2009-04-15

Islet transplantation is limited by the need for chronic immunosuppression and the paucity of donor tissue. As new sources of human beta-cells are developed (e.g., stem cell-derived tissue), transplanting them in a durable device could obviate the need for immunosuppression, while also protecting the patient from any risk of tumorigenicity. Here, we studied (1) the survival and function of encapsulated human beta-cells and their progenitors and (2) the engraftment of encapsulated murine beta-cells in allo- and autoimmune settings. Human islets and human fetal pancreatic islet-like cell clusters were encapsulated in polytetrafluorethylene devices (TheraCyte) and transplanted into immunodeficient mice. Graft survival and function was measured by immunohistochemistry, circulating human C-peptide levels, and blood glucose levels. Bioluminescent imaging was used to monitor encapsulated neonatal murine islets. Encapsulated human islet-like cell clusters survived, replicated, and acquired a level of glucose responsive insulin secretion sufficient to ameliorate hyperglycemia in diabetic mice. Bioluminescent imaging of encapsulated murine neonatal islets revealed a dynamic process of cell death followed by regrowth, resulting in robust long-term allograft survival. Further, in the non-obese diabetic (NOD) mouse model of type I diabetes, encapsulated primary beta-cells ameliorated diabetes without stimulating a detectable T-cell response. We demonstrate for the first time that human beta-cells function is compatible with encapsulation in a durable, immunoprotective device. Moreover, our study suggests that encapsulation of beta-cells before terminal differentiation will be a successful approach for new cell-based therapies for diabetes, such as those derived from stem cells.

Depletion of Mediator Kinase Module Subunits Represses Superenhancer-Associated Genes in Colon Cancer Cells.

PubMed

Kuuluvainen, Emilia; Domènech-Moreno, Eva; Niemelä, Elina H; Mäkelä, Tomi P

2018-06-01

In cancer, oncogene activation is partly mediated by acquired superenhancers, which therefore represent potential targets for inhibition. Superenhancers are enriched for BRD4 and Mediator, and both BRD4 and the Mediator MED12 subunit are disproportionally required for expression of superenhancer-associated genes in stem cells. Here we show that depletion of Mediator kinase module subunit MED12 or MED13 together with MED13L can be used to reduce expression of cancer-acquired superenhancer genes, such as the MYC gene, in colon cancer cells, with a concomitant decrease in proliferation. Whereas depletion of MED12 or MED13/MED13L caused a disproportional decrease of superenhancer gene expression, this was not seen with depletion of the kinases cyclin-dependent kinase 9 (CDK8) and CDK19. MED12-MED13/MED13L-dependent superenhancer genes were coregulated by β-catenin, which has previously been shown to associate with MED12. Importantly, β-catenin depletion caused reduced binding of MED12 at the MYC superenhancer. The effect of MED12 or MED13/MED13L depletion on cancer-acquired superenhancer gene expression was more specific than and partially distinct from that of BRD4 depletion, with the most efficient inhibition seen with combined targeting. These results identify a requirement of MED12 and MED13/MED13L for expression of acquired superenhancer genes in colon cancer, implicating these Mediator subunits as potential therapeutic targets for colon cancer, alone or together with BRD4. Copyright © 2018 American Society for Microbiology.

Perspectives on stem cell therapy for cardiac regeneration. Advances and challenges.

PubMed

Choi, Sung Hyun; Jung, Seok Yun; Kwon, Sang-Mo; Baek, Sang Hong

2012-01-01

Ischemic heart disease (IHD) accelerates cardiomyocyte loss, but the developing stem cell research could be useful for regenerating a variety of tissue cells, including cardiomyocytes. Diverse sources of stem cells for IHD have been reported, including embryonic stem cells, induced pluripotent stem cells, skeletal myoblasts, bone marrow-derived stem cells, mesenchymal stem cells, and cardiac stem cells. However, stem cells have unique advantages and disadvantages for cardiac tissue regeneration, which are important considerations in determining the specific cells for improving cell survival and long-term engraftment after transplantation. Additionally, the dosage and administration method of stem cells need to be standardized to increase stability and efficacy for clinical applications. Accordingly, this review presents a summary of the stem cell therapies that have been studied for cardiac regeneration thus far, and discusses the direction of future cardiac regeneration research for stem cells.

Histological transformation after acquired resistance to epidermal growth factor tyrosine kinase inhibitors.

PubMed

Shao, Yi; Zhong, Dian-Sheng

2018-04-01

Non-small-cell lung cancer patients with sensitive epidermal growth factor receptor mutations generally respond well to tyrosine kinase inhibitors (TKIs). However, acquired resistance will eventually develop place after 8-16 months. Several mechanisms contribute to the resistance including T790M mutation, c-Met amplification, epithelial mesenchymal transformation and PIK3CA mutation; however, histological transformation is a rare mechanism. The patterns and mechanisms underlying histological transformation need to be explored. We searched PubMed, EMBASE and search engines Google Scholar, Medical Matrix for literature related to histological transformation. Case reports, cases series, and clinical and basic medical research articles were reviewed. Sixty-one articles were included in this review. Cases of transformation to small-cell lung cancer, squamous cell carcinoma, large-cell neuroendocrine carcinoma and sarcoma after TKI resistance have all been reported. As the clinical course differed dramatically between cases, a new treatment scheme needs to be recruited. The mechanisms underlying histological transformation have not been fully elucidated and probably relate to cancer stem cells, driver genetic alterations under selective pressure or the heterogeneity of the tumor. When TKI resistance develops, we recommend that patients undergo a second biopsy to determine the reason, guide the next treatment and predict the prognosis.

Stem Cells

MedlinePlus

Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair ... body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

The Role of Integrin α6 (CD49f) in Stem Cells: More than a Conserved Biomarker.

PubMed

Krebsbach, Paul H; Villa-Diaz, Luis G

2017-08-01

Stem cells have the capacity for self-renewal and differentiation into specialized cells that form and repopulated all tissues and organs, from conception to adult life. Depending on their capacity for differentiation, stem cells are classified as totipotent (ie, zygote), pluripotent (ie, embryonic stem cells), multipotent (ie, neuronal stem cells, hematopoietic stem cells, epithelial stem cells, etc.), and unipotent (ie, spermatogonial stem cells). Adult or tissue-specific stem cells reside in specific niches located in, or nearby, their organ or tissue of origin. There, they have microenvironmental support to remain quiescent, to proliferate as undifferentiated cells (self-renewal), and to differentiate into progenitors or terminally differentiated cells that migrate from the niche to perform specialized functions. The presence of proteins at the cell surface is often used to identify, classify, and isolate stem cells. Among the diverse groups of cell surface proteins used for these purposes, integrin α6, also known as CD49f, may be the only biomarker commonly found in more than 30 different populations of stem cells, including some cancer stem cells. This broad expression among stem cell populations indicates that integrin α6 may play an important and conserved role in stem cell biology, which is reaffirmed by recent demonstrations of its role maintaining self-renewal of pluripotent stem cells and breast and glioblastoma cancer stem cells. Therefore, this review intends to highlight and synthesize new findings on the importance of integrin α6 in stem cell biology.

Removing the cells from adult bone marrow derived stem cell therapy does not eliminate cardioprotection.

PubMed

Yasin, Mohammed

2013-04-01

The debate as to whether adult stem cell therapy is regenerative or not continues. The non-regenerative benefits of adult bone marrow-derived stem cell therapy were investigated by testing whether the supernatant derived from unfractionated bone marrow mononuclear cells might be cardioprotective in an animal model of myocardial ischaemia-reperfusion injury. Regional myocardial reperfusion injury was acquired by 25 min reversible left anterior descending coronary artery (LAD) occlusion followed by 2 h reperfusion, in anaesthetized Wistar male rats. Unfractionated bone marrow mononuclear cells (BMMNC) isolated from sibling Wistar male rat whole bone marrow were phenotyped by fluorescence activated cell sorting flowcytometry for the haematopoietic stem cell surface markers c-kit, CD34, CD45 and CD133. Animals subjected to regional myocardial reperfusion injury received either 10 million BMMNC or BMMNC supernatant (BMS); both were collected in 0.5 ml phosphate-buffered saline and delivered by intravenous bolus at the onset of reperfusion. The left ventricular region distal to the LAD occlusion point was excised for measurement of myocardial infarct size and proteomic analysis, which was used to identify whether there were any differences in myocardial proteins associated with intravenous injection of either BMMNC or BMS. BMMNC were phenotyped to be c-kit(+) (7 ± 1%), CD34(+) (7 ± 1%), CD45(+) (54 ± 6%), CD133(+) (15 ± 1%). The supernatant reduced myocardial infarct size (BMS 34 ± 2%, n = 15 vs control 57 ± 2%, n = 7, P < 0.0001), which was comparable to the reduction in infarct size afforded by the injection of cells (BMMNC 33 ± 3% vs control 57 ± 2%, n = 10, P < 0.0001). Proteomics of hearts treated with either BMS or BMMNC demonstrated higher expression of (i) anti-apoptotic signal transduction protein: 14-3-3-epsilon (1.5-fold); (ii) anti-oxidants: peroxiredoxin-6 (2.1-fold); (iii) heat shock proteins: alpha B-crystallin (1.7-fold), heat shock protein 72 (2.8-fold), tumour necrosis factor receptor-1 associated protein (2.3-fold), ischaemia responsive protein-94 (1.6-fold); (iv) glycolytic protein: glyceraldehyde-3-phosphate dehydrogenase (2.3-fold); (v) mitochondrial respiratory proteins: mitochondrial aconitase (4.7-fold), voltage-dependent anion-selective channel protein-1 (VDAC-1) (2.7-fold). Regional myocardial reperfusion injury can be attenuated by intravenous administration of either BMMNC or BMS at the onset of reperfusion, which suggests adult stem cells mediate non-regenerative cardioprotection.

Bovine apolipoprotein B-100 is a dominant immunogen in therapeutic cell populations cultured in fetal calf serum in mice and humans

PubMed Central

Sakamoto, Norihisa; Tsuji, Kazuhide; Muul, Linda M.; Lawler, Ann M.; Petricoin, Emanuel F.; Candotti, Fabio; Metcalf, Julia A.; Tavel, Jorge A.; Lane, H. Clifford; Urba, Walter J.; Fox, Bernard A.; Varki, Ajit; Lunney, Joan K.

2007-01-01

Recent studies have demonstrated that cell populations intended for therapeutic purposes that are cultured in heterologous animal products can acquire xenoantigens, potentially limiting their utility. In investigations of the immune response to murine embryonic stem cells, we found that a strong antibody response was generated after the second infusion. Both polyclonal and monoclonal antibody responses, derived from immunized mice, were found to be specific for bovine apolipoprotein B-100, which binds to abundant low-density lipoprotein receptors on the cell surface and is internalized. Here we show that in the majority of patients administered 3 different types of cell-based therapies using cells grown in fetal calf serum-containing media, an antibody response to bovine apolipoprotein B-100 develops after the second infusion and is the dominant specificity. The known and potential clinical effects of such antibodies are discussed. PMID:17395779

Drosophila's contribution to stem cell research.

PubMed

Singh, Gyanesh

2015-01-01

The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs) are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub). Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd) proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila.

Drosophila's contribution to stem cell research

PubMed Central

Singh, Gyanesh

2016-01-01

The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs) are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub). Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd) proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila. PMID:26180635

Current overview on dental stem cells applications in regenerative dentistry.

PubMed

Bansal, Ramta; Jain, Aditya

2015-01-01

Teeth are the most natural, noninvasive source of stem cells. Dental stem cells, which are easy, convenient, and affordable to collect, hold promise for a range of very potential therapeutic applications. We have reviewed the ever-growing literature on dental stem cells archived in Medline using the following key words: Regenerative dentistry, dental stem cells, dental stem cells banking, and stem cells from human exfoliated deciduous teeth. Relevant articles covering topics related to dental stem cells were shortlisted and the facts are compiled. The objective of this review article is to discuss the history of stem cells, different stem cells relevant for dentistry, their isolation approaches, collection, and preservation of dental stem cells along with the current status of dental and medical applications.

First-Line Matched Related Donor Hematopoietic Stem Cell Transplantation Compared to Immunosuppressive Therapy in Acquired Severe Aplastic Anemia

PubMed Central

Peinemann, Frank; Grouven, Ulrich; Kröger, Nicolaus; Bartel, Carmen; Pittler, Max H.; Lange, Stefan

2011-01-01

Introduction Acquired severe aplastic anemia (SAA) is a rare and progressive disease characterized by an immune-mediated functional impairment of hematopoietic stem cells. Transplantation of these cells is a first-line treatment option if HLA-matched related donors are available. First-line immunosuppressive therapy may be offered as alternative. The aim was to compare the outcome of these patients in controlled trials. Methods A systematic search was performed in the bibliographic databases MEDLINE, EMBASE, and The Cochrane Library. To show an overview of various outcomes by treatment group we conducted a meta-analysis on overall survival. We evaluated whether studies reported statistically significant factors for improved survival. Results 26 non-randomized controlled trials (7,955 patients enrolled from 1970 to 2001) were identified. We did not identify any RCTs. Risk of bias was high except in 4 studies. Young age and recent year of treatment were identified as factors for improved survival in the HSCT group. Advanced age, SAA without very severe aplastic anemia, and combination of anti-lymphocyte globulin with cyclosporine A were factors for improved survival in the IST group. In 19 studies (4,855 patients), summary statistics were sufficient to be included in meta-analysis. Considerable heterogeneity did not justify a pooled estimate. Adverse events were inconsistently reported and varied significantly across studies. Conclusions Young age and recent year of treatment were identified as factors for improved survival in the transplant group. Advanced age, SAA without very severe aplastic anemia, and combination of anti-lymphocyte globulin with cyclosporine A were factors for improved survival in the immunosuppressive group. Considerable heterogeneity of non-randomized controlled studies did not justify a pooled estimate. Adverse events were inconsistently reported and varied significantly across studies. PMID:21541024

Bringing prosocial values to translational, disease-specific stem cell research.

PubMed

Sass, Reuben G

2014-02-27

Disease-specific stem cell therapies, created from induced pluripotent stem cell lines containing the genetic defects responsible for a particular disease, have the potential to revolutionize the treatment of refractory chronic diseases. Given their capacity to differentiate into any human cell type, these cell lines might be reprogrammed to correct a disease-causing genetic defect in any tissue or organ, in addition to offering a more clinically realistic model for testing new drugs and studying disease mechanisms. Clinical translation of these therapies provides an opportunity to design a more systematic, accessible and patient-influenced model for the delivery of medically innovative treatments to chronically ill patients. I focus on disease-specific cell therapies because the types of patients who would benefit from them have congenital, severe, high-maintenance chronic conditions. They accordingly have a very strong claim for medical need and therapeutic intervention, must interact regularly with health providers, and so have the greatest stake in influencing, at a systemic level, the way their care is delivered. Given such patients' shared, aggregate needs for societal support and access to medical innovation, they constitute "patient communities". To reify the relevance of patient communities within a clinical context, I propose competitive grants or "prizes" to spur innovation in delivery of care, promoting "prosocial" values of transparency, equity, patient empowerment, and patient-provider and inter-institutional collaboration. As facilitators of participant-driven advocacy for health and quality of life-improving measures, patient communities may be synergistic with the broad-based, geo-culturally embedded public health networks typically referred to as "communities" in the public health literature. Prosocial values acquire a strong ethical justification based on shared need, and can be clearly defined as grant criteria, when applied to patients such as those who will benefit from disease-specific stem cell treatments. Within this context, prosociality aims not just to expand patients' treatment choices, but also their opportunities to take a more active role in the management of their own care and contribute towards shared goals through better-informed advocacy. Accordingly, prosociality promotes relational autonomy as well as other basic bioethical principles, including beneficence and a holistic, relational conception of human dignity.

The longest telomeres: a general signature of adult stem cell compartments

PubMed Central

Flores, Ignacio; Canela, Andres; Vera, Elsa; Tejera, Agueda; Cotsarelis, George; Blasco, María A.

2008-01-01

Identification of adult stem cells and their location (niches) is of great relevance for regenerative medicine. However, stem cell niches are still poorly defined in most adult tissues. Here, we show that the longest telomeres are a general feature of adult stem cell compartments. Using confocal telomere quantitative fluorescence in situ hybridization (telomapping), we find gradients of telomere length within tissues, with the longest telomeres mapping to the known stem cell compartments. In mouse hair follicles, we show that cells with the longest telomeres map to the known stem cell compartments, colocalize with stem cell markers, and behave as stem cells upon treatment with mitogenic stimuli. Using K15-EGFP reporter mice, which mark hair follicle stem cells, we show that GFP-positive cells have the longest telomeres. The stem cell compartments in small intestine, testis, cornea, and brain of the mouse are also enriched in cells with the longest telomeres. This constitutes the description of a novel general property of adult stem cell compartments. Finally, we make the novel finding that telomeres shorten with age in different mouse stem cell compartments, which parallels a decline in stem cell functionality, suggesting that telomere loss may contribute to stem cell dysfunction with age. PMID:18283121

Development and Application of STEM for the Biological Sciences

PubMed Central

Sousa, Alioscka A.; Leapman, Richard D.

2012-01-01

The design of the scanning transmission electron microscope (STEM), as conceived originally by Crewe and coworkers, enables the highly efficient and flexible collection of different elastic and inelastic signals resulting from the interaction of a focused probe of incident electrons with a specimen. In the present paper we provide a brief review for how the STEM today can be applied towards a range of different problems in the biological sciences, emphasizing four main areas of application. (1) For three decades, the most widely used STEM technique has been the mass determination of proteins and other macromolecular assemblies. Such measurements can be performed at low electron dose by collecting the high-angle dark-field signal using an annular detector. STEM mass mapping has proven valuable for characterizing large protein assemblies such as filamentous proteins with a well-defined mass per length. (2) The annular dark-field signal can also be used to image ultrasmall, functionalized nanoparticles of heavy atoms for labeling specific aminoacid sequences in protein assemblies. (3) By acquiring electron energy loss spectra (EELS) at each pixel in a hyperspectral image, it is possible to map the distributions of specific bound elements like phosphorus, calcium and iron in isolated macromolecular assemblies or in compartments within sectioned cells. Near single atom sensitivity is feasible provided that the specimen can tolerate a very high incident electron dose. (4) Electron tomography is a new application of STEM that enables three-dimensional reconstruction of micrometer-thick sections of cells. In this technique a probe of small convergence angle gives a large depth of field throughout the thickness of the specimen while maintaining a probe diameter of < 2 nm; and the use of an on-axis bright-field detector reduces the effects of beam broadening and thus improves the spatial resolution compared to that attainable by STEM dark-field tomography. PMID:22749213

Vegetation water content of crops and woodlands for improving soil moisture retrievals from Coriolis WindSat

USDA-ARS?s Scientific Manuscript database

Estimation of vegetation water content (VWC) by shortwave infrared remote sensing improves soil moisture retrievals. The largest unknown for predicting VWC is stem water content; for woodlands, stem water content is expected to be proportional to stem height. Airborne imagery were acquired and photo...

Context clues: the importance of stem cell-material interactions

PubMed Central

Murphy, William L.

2014-01-01

Understanding the processes by which stem cells give rise to de novo tissues is an active focus of stem cell biology and bioengineering disciplines. Instructive morphogenic cues surrounding the stem cell during morphogenesis create what is referred to as the stem cell microenvironment. An emerging paradigm in stem cell bioengineering involves “biologically driven assembly,” in which stem cells are encouraged to largely define their own morphogenesis processes. However, even in the case of biologically driven assembly, stem cells do not act alone. The properties of the surrounding microenvironment can be critical regulators of cell fate. Stem cell-material interactions are among the most well-characterized microenvironmental effectors of stem cell fate, and they establish a signaling “context” that can define the mode of influence for morphogenic cues. Here we describe illustrative examples of cell-material interactions that occur during in vitro stem cell studies, with an emphasis on how cell-material interactions create instructive contexts for stem cell differentiation and morphogenesis. PMID:24369691

Cancer stem cells and differentiation therapy.

PubMed

Jin, Xiong; Jin, Xun; Kim, Hyunggee

2017-10-01

Cancer stem cells can generate tumors from only a small number of cells, whereas differentiated cancer cells cannot. The prominent feature of cancer stem cells is its ability to self-renew and differentiate into multiple types of cancer cells. Cancer stem cells have several distinct tumorigenic abilities, including stem cell signal transduction, tumorigenicity, metastasis, and resistance to anticancer drugs, which are regulated by genetic or epigenetic changes. Like normal adult stem cells involved in various developmental processes and tissue homeostasis, cancer stem cells maintain their self-renewal capacity by activating multiple stem cell signaling pathways and inhibiting differentiation signaling pathways during cancer initiation and progression. Recently, many studies have focused on targeting cancer stem cells to eradicate malignancies by regulating stem cell signaling pathways, and products of some of these strategies are in preclinical and clinical trials. In this review, we describe the crucial features of cancer stem cells related to tumor relapse and drug resistance, as well as the new therapeutic strategy to target cancer stem cells named "differentiation therapy."

Clinical trials for stem cell transplantation: when are they needed?

PubMed

Van Pham, Phuc

2016-04-27

In recent years, both stem cell research and the clinical application of these promising cells have increased rapidly. About 1000 clinical trials using stem cells have to date been performed globally. More importantly, more than 10 stem cell-based products have been approved in some countries. With the rapid growth of stem cell applications, some countries have used clinical trials as a tool to diminish the rate of clinical stem cell applications. However, the point at which stem cell clinical trials are essential remains unclear. This commentary discusses when stem cell clinical trials are essential for stem cell transplantation therapies.

Stem cells - biological update and cell therapy progress

PubMed Central

GIRLOVANU, MIHAI; SUSMAN, SERGIU; SORITAU, OLGA; RUS-CIUCA, DAN; MELINCOVICI, CARMEN; CONSTANTIN, ANNE-MARIE; MIHU, CARMEN MIHAELA

2015-01-01

In recent years, the advances in stem cell research have suggested that the human body may have a higher plasticity than it was originally expected. Until now, four categories of stem cells were isolated and cultured in vivo: embryonic stem cells, fetal stem cells, adult stem cells and induced pluripotent stem cells (hiPSCs). Although multiple studies were published, several issues concerning the stem cells are still debated, such as: the molecular mechanisms of differentiation, the methods to prevent teratoma formation or the ethical and religious issues regarding especially the embryonic stem cell research. The direct differentiation of stem cells into specialized cells: cardiac myocytes, neural cells, pancreatic islets cells, may represent an option in treating incurable diseases such as: neurodegenerative diseases, type I diabetes, hematologic or cardiac diseases. Nevertheless, stem cell-based therapies, based on stem cell transplantation, remain mainly at the experimental stages and their major limitation is the development of teratoma and cancer after transplantation. The induced pluripotent stem cells (hiPSCs) represent a prime candidate for future cell therapy research because of their significant self-renewal and differentiation potential and the lack of ethical issues. This article presents an overview of the biological advances in the study of stem cells and the current progress made in the field of regenerative medicine. PMID:26609255

Live Bacterial Physiology Visualized with 5 nm Resolution Using Scanning Transmission Electron Microscopy.

PubMed

Kennedy, Eamonn; Nelson, Edward M; Tanaka, Tetsuya; Damiano, John; Timp, Gregory

2016-02-23

It is now possible to visualize at nanometer resolution the infection of a living biological cell with virus without compromising cell viability using scanning transmission electron microscopy (STEM). To provide contrast while preserving viability, Escherichia coli and P1 bacteriophages were first positively stained with a very low concentration of uranyl acetate in minimal phosphate medium and then imaged with low-dose STEM in a microfluidic liquid flow cell. Under these conditions, it was established that the median lethal dose of electrons required to kill half the tested population was LD50 = 30 e(-)/nm(2), which coincides with the disruption of a wet biological membrane, according to prior reports. Consistent with the lateral resolution and high-contrast signal-to-noise ratio (SNR) inferred from Monte Carlo simulations, images of the E. coli membrane, flagella, and the bacteriophages were acquired with 5 nm resolution, but the cumulative dose exceeded LD50. On the other hand, with a cumulative dose below LD50 (and lower SNR), it was still possible to visualize the infection of E. coli by P1, showing the insertion of viral DNA within 3 s, with 5 nm resolution.

Establishment of mouse expanded potential stem cells

PubMed Central

Gao, Xuefei; Antunes, Liliana; Yu, Yong; Zhu, Zhexin; Wang, Juexuan; Kolodziejczyk, Aleksandra A.; Campos, Lia S.; Wang, Cui; Yang, Fengtang; Zhong, Zhen; Fu, Beiyuan; Eckersley-Maslin, Melanie A.; Woods, Michael; Tanaka, Yosuke; Chen, Xi; Wilkinson, Adam C.; Bussell, James; White, Jacqui; Ramirez-Solis, Ramiro; Reik, Wolf; Göttgens, Berthold; Teichmann, Sarah A.; Tam, Patrick P. L.; Nakauchi, Hiromitsu; Zou, Xiangang; Lu, Liming; Liu, Pentao

2018-01-01

Mouse embryonic stem cells derived from the epiblast1 contribute to the somatic lineages and the germline but are excluded from the extra-embryonic tissues that are derived from the trophectoderm and the primitive endoderm2 upon reintroduction to the blastocyst. Here we report that cultures of expanded potential stem cells can be established from individual eight-cell blastomeres, and by direct conversion of mouse embryonic stem cells and induced pluripotent stem cells. Remarkably, a single expanded potential stem cell can contribute both to the embryo proper and to the trophectoderm lineages in a chimaera assay. Bona fide trophoblast stem cell lines and extra-embryonic endoderm stem cells can be directly derived from expanded potential stem cells in vitro. Molecular analyses of the epigenome and single-cell transcriptome reveal enrichment for blastomere-specific signature and a dynamic DNA methylome in expanded potential stem cells. The generation of mouse expanded potential stem cells highlights the feasibility of establishing expanded potential stem cells for other mammalian species. PMID:29019987

Muscle Satellite Cell Protein Teneurin‐4 Regulates Differentiation During Muscle Regeneration

PubMed Central

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So‐ichiro; Okano, Hideyuki; Takeda, Shin'ichi

2015-01-01

Abstract Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin‐4 (Ten‐4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten‐4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten‐4‐deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten‐4‐deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten‐4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten‐4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. Stem Cells 2015;33:3017–3027 PMID:26013034

The epithelial-mesenchymal transition in cancer: a potential critical topic for translational proteomic research.

PubMed

Bottoni, Patrizia; Isgrò, Maria Antonietta; Scatena, Roberto

2016-01-01

The epithelial-mesenchymal transition (EMT) is a morphogenetic process that results in a loss of epithelial characteristics and the acquisition of a mesenchymal phenotype. First described in embryogenesis, the EMT has been recently implicated in carcinogenesis and tumor progression. In addition, recent evidence has shown that stem-like cancer cells present the hallmarks of the EMT. Some of the molecular mechanisms related to the interrelationships between cancer pathophysiology and the EMT are well-defined. Nevertheless, the precise molecular mechanism by which epithelial cancer cells acquire the mesenchymal phenotype remains largely unknown. This review focuses on various proteomic strategies with the goal of better understanding the physiological and pathological mechanisms of the EMT process.

Adult Stem Cell Therapy for Stroke: Challenges and Progress

PubMed Central

Bang, Oh Young; Kim, Eun Hee; Cha, Jae Min; Moon, Gyeong Joon

2016-01-01

Stroke is one of the leading causes of death and physical disability among adults. It has been 15 years since clinical trials of stem cell therapy in patients with stroke have been conducted using adult stem cells like mesenchymal stem cells and bone marrow mononuclear cells. Results of randomized controlled trials showed that adult stem cell therapy was safe but its efficacy was modest, underscoring the need for new stem cell therapy strategies. The primary limitations of current stem cell therapies include (a) the limited source of engraftable stem cells, (b) the presence of optimal time window for stem cell therapies, (c) inherited limitation of stem cells in terms of growth, trophic support, and differentiation potential, and (d) possible transplanted cell-mediated adverse effects, such as tumor formation. Here, we discuss recent advances that overcome these hurdles in adult stem cell therapy for stroke. PMID:27733032

Two sides of the same coin? Unraveling subtle differences between human embryonic and induced pluripotent stem cells by Raman spectroscopy.

PubMed

Parrotta, Elvira; De Angelis, Maria Teresa; Scalise, Stefania; Candeloro, Patrizio; Santamaria, Gianluca; Paonessa, Mariagrazia; Coluccio, Maria Laura; Perozziello, Gerardo; De Vitis, Stefania; Sgura, Antonella; Coluzzi, Elisa; Mollace, Vincenzo; Di Fabrizio, Enzo Mario; Cuda, Giovanni

2017-11-28

Human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells, hold enormous promise for many biomedical applications, such as regenerative medicine, drug testing, and disease modeling. Although induced pluripotent stem cells resemble embryonic stem cells both morphologically and functionally, the extent to which these cell lines are truly equivalent, from a molecular point of view, remains controversial. Principal component analysis and K-means cluster analysis of collected Raman spectroscopy data were used for a comparative study of the biochemical fingerprint of human induced pluripotent stem cells and human embryonic stem cells. The Raman spectra analysis results were further validated by conventional biological assays. Raman spectra analysis revealed that the major difference between human embryonic stem cells and induced pluripotent stem cells is due to the nucleic acid content, as shown by the strong positive peaks at 785, 1098, 1334, 1371, 1484, and 1575 cm -1 , which is enriched in human induced pluripotent stem cells. Here, we report a nonbiological approach to discriminate human induced pluripotent stem cells from their native embryonic stem cell counterparts.

Pancreatic ductal cells acquire mesenchymal characteristics through cell fusion with bone marrow-derived mesenchymal stem cells and SIRT1 attenuates the apoptosis of hybrid cells.

PubMed

Gou, Shanmiao; Liu, Tao; Li, Xiangsheng; Cui, Jing; Wan, Chidan; Wang, Chunyou

2012-01-01

Bone marrow-derived mesenchymal stem cells (bMSCs) contribute to tissue repair and regeneration. Cell fusion between somatic cells and bMSCs to form hybrid cells may have an important role in tissue repair through the subsequent reprogramming of the somatic cell nucleus. Few studies have assessed the mesenchymal characteristics of fusion-induced hybrid cells and their survival mechanisms. In this study, we investigated the effect of cell fusion on the biological characteristics of pancreatic ductal cells (PDCs) and on the survival mechanism of hybrid cells. To this end, we generated mouse-mouse hybrid cells in vitro by polyethylene glycol-mediated fusion of primary mouse bMSCs with primary mouse PDCs. Hybrid cells showed an enhanced capacity for proliferation and self-renewal compared with PDCs. No PDC had the capacity for anchorage-independent growth or invasion into Matrigel, but some hybrid cells were able to form colonies in soft agar and invade Matrigel. Expression of the tumor suppressor protein p53, which initiates apoptosis, was detected in hybrid cells but not in PDCs or bMSCs. However, the p53 deacetylase, sirtuin 1 (SIRT1), was also detected in hybrid cells, and the level of acetylated p53, the active form, was low. The addition of nicotinamide (Nam) inhibited the deacetylation activity of SIRT1 on p53 and induced cell apoptosis in hybrid cells. This study demonstrated that PDCs could obtain high proliferation rates, self-renewal capabilities, and mesenchymal characteristics by fusion with bMSCs. SIRT1 expression in the hybrid cells attenuated their apoptosis. Copyright © 2012 S. Karger AG, Basel.

Natural gene therapy in monozygotic twins with Fanconi anemia.

PubMed

Mankad, Anuj; Taniguchi, Toshiyasu; Cox, Barbara; Akkari, Yassmine; Rathbun, R Keaney; Lucas, Lora; Bagby, Grover; Olson, Susan; D'Andrea, Alan; Grompe, Markus

2006-04-15

Monozygotic twin sisters, with nonhematologic symptoms of Fanconi anemia (FA), were discovered to be somatic mosaics for mutations in the FANCA gene. Skin fibroblasts, but not lymphocytes or committed hematopoietic progenitors, were sensitive to DNA cross-linking agents. Molecular analysis revealed, in skin cells of both twins, a frameshift causing deletion in exon 27 (2555deltaT) and an exon 28 missense mutation (2670G>A/R880Q). The latter resulted in primarily cytoplasmic expression and reduced function of the mutant FANCA (R880Q) protein. Surprisingly, the same acquired exon 30 missense change (2927G>A/E966K) was detected in the hematopoietic cells of both sisters, but not in their fibroblasts, nor in either parent. This compensatory mutation existed in cis with the maternal exon 28 mutation, and it restored function and nuclear localization of the resulting protein. Both sisters have been free of hematologic symptoms for more than 2 decades, suggesting that this de novo mutation occurred prenatally in a single hematopoietic stem cell (HSC) in one twin and that descendants of this functionally corrected HSC, via intra-uterine circulation, repopulated the blood lineages of both sisters. This finding suggests that treating FA patients with gene therapy might require transduction of only a few hematopoietic stem cells.

Insights into molecular therapy of glioma: current challenges and next generation blueprint

PubMed Central

Rajesh, Y; Pal, Ipsita; Banik, Payel; Chakraborty, Sandipan; Borkar, Sachin A; Dey, Goutam; Mukherjee, Ahona; Mandal, Mahitosh

2017-01-01

Glioma accounts for the majority of human brain tumors. With prevailing treatment regimens, the patients have poor survival rates. In spite of current development in mainstream glioma therapy, a cure for glioma appears to be out of reach. The infiltrative nature of glioma and acquired resistance substancially restrict the therapeutic options. Better elucidation of the complicated pathobiology of glioma and proteogenomic characterization might eventually open novel avenues for the design of more sophisticated and effective combination regimens. This could be accomplished by individually tailoring progressive neuroimaging techniques, terminating DNA synthesis with prodrug-activating genes, silencing gliomagenesis genes (gene therapy), targeting miRNA oncogenic activity (miRNA-mRNA interaction), combining Hedgehog-Gli/Akt inhibitors with stem cell therapy, employing tumor lysates as antigen sources for efficient depletion of tumor-specific cancer stem cells by cytotoxic T lymphocytes (dendritic cell vaccination), adoptive transfer of chimeric antigen receptor-modified T cells, and combining immune checkpoint inhibitors with conventional therapeutic modalities. Thus, the present review captures the latest trends associated with the molecular mechanisms involved in glial tumorigenesis as well as the limitations of surgery, radiation and chemotherapy. In this article we also critically discuss the next generation molecular therapeutic strategies and their mechanisms for the successful treatment of glioma. PMID:28317871

Phytochemicals as Innovative Therapeutic Tools against Cancer Stem Cells.

PubMed

Scarpa, Emanuele-Salvatore; Ninfali, Paolino

2015-07-10

The theory that several carcinogenetic processes are initiated and sustained by cancer stem cells (CSCs) has been validated, and specific methods to identify the CSCs in the entire population of cancer cells have also proven to be effective. This review aims to provide an overview of recently acquired scientific knowledge regarding phytochemicals and herbal extracts, which have been shown to be able to target and kill CSCs. Many genes and proteins that sustain the CSCs' self-renewal capacity and drug resistance have been described and applications of phytochemicals able to interfere with these signaling systems have been shown to be operatively efficient both in vitro and in vivo. Identification of specific surface antigens, mammosphere formation assays, serial colony-forming unit assays, xenograft transplantation and label-retention assays coupled with Aldehyde dehydrogenase 1 (ALDH1) activity evaluation are the most frequently used techniques for measuring phytochemical efficiency in killing CSCs. Moreover, it has been demonstrated that EGCG, curcumin, piperine, sulforaphane, β-carotene, genistein and the whole extract of some plants are able to kill CSCs. Most of these phytochemicals act by interfering with the canonical Wnt (β-catenin/T cell factor-lymphoid enhancer factor (TCF-LEF)) pathway implicated in the pathogenesis of several cancers. Therefore, the use of phytochemicals may be a true therapeutic strategy for eradicating cancer through the elimination of CSCs.

Cancer cells enter dormancy after cannibalizing mesenchymal stem/stromal cells (MSCs)

PubMed Central

Bartosh, Thomas J.; Ullah, Mujib; Zeitouni, Suzanne; Beaver, Joshua; Prockop, Darwin J.

2016-01-01

Patients with breast cancer often develop malignant regrowth of residual drug-resistant dormant tumor cells years after primary treatment, a process defined as cancer relapse. Deciphering the causal basis of tumor dormancy therefore has obvious therapeutic significance. Because cancer cell behavior is strongly influenced by stromal cells, particularly the mesenchymal stem/stromal cells (MSCs) that are actively recruited into tumor-associated stroma, we assessed the impact of MSCs on breast cancer cell (BCC) dormancy. Using 3D cocultures to mimic the cellular interactions of an emerging tumor niche, we observed that MSCs sequentially surrounded the BCCs, promoted formation of cancer spheroids, and then were internalized/degraded through a process resembling the well-documented yet ill-defined clinical phenomenon of cancer cell cannibalism. This suspected feeding behavior was less appreciable in the presence of a rho kinase inhibitor and in 2D monolayer cocultures. Notably, cannibalism of MSCs enhanced survival of BCCs deprived of nutrients but suppressed their tumorigenicity, together suggesting the cancer cells entered dormancy. Transcriptome profiles revealed that the resulting BCCs acquired a unique molecular signature enriched in prosurvival factors and tumor suppressors, as well as inflammatory mediators that demarcate the secretome of senescent cells, also referred to as the senescence-associated secretory phenotype. Overall, our results provide intriguing evidence that cancer cells under duress enter dormancy after cannibalizing MSCs. Importantly, our practical 3D coculture model could provide a valuable tool to understand the antitumor activity of MSCs and cell cannibalism further, and therefore open new therapeutic avenues for the prevention of cancer recurrence. PMID:27698134

Cancer cells enter dormancy after cannibalizing mesenchymal stem/stromal cells (MSCs).

PubMed

Bartosh, Thomas J; Ullah, Mujib; Zeitouni, Suzanne; Beaver, Joshua; Prockop, Darwin J

2016-10-18

Patients with breast cancer often develop malignant regrowth of residual drug-resistant dormant tumor cells years after primary treatment, a process defined as cancer relapse. Deciphering the causal basis of tumor dormancy therefore has obvious therapeutic significance. Because cancer cell behavior is strongly influenced by stromal cells, particularly the mesenchymal stem/stromal cells (MSCs) that are actively recruited into tumor-associated stroma, we assessed the impact of MSCs on breast cancer cell (BCC) dormancy. Using 3D cocultures to mimic the cellular interactions of an emerging tumor niche, we observed that MSCs sequentially surrounded the BCCs, promoted formation of cancer spheroids, and then were internalized/degraded through a process resembling the well-documented yet ill-defined clinical phenomenon of cancer cell cannibalism. This suspected feeding behavior was less appreciable in the presence of a rho kinase inhibitor and in 2D monolayer cocultures. Notably, cannibalism of MSCs enhanced survival of BCCs deprived of nutrients but suppressed their tumorigenicity, together suggesting the cancer cells entered dormancy. Transcriptome profiles revealed that the resulting BCCs acquired a unique molecular signature enriched in prosurvival factors and tumor suppressors, as well as inflammatory mediators that demarcate the secretome of senescent cells, also referred to as the senescence-associated secretory phenotype. Overall, our results provide intriguing evidence that cancer cells under duress enter dormancy after cannibalizing MSCs. Importantly, our practical 3D coculture model could provide a valuable tool to understand the antitumor activity of MSCs and cell cannibalism further, and therefore open new therapeutic avenues for the prevention of cancer recurrence.

A family business: stem cell progeny join the niche to regulate homeostasis.

PubMed

Hsu, Ya-Chieh; Fuchs, Elaine

2012-01-23

Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems.

A family business: stem cell progeny join the niche to regulate homeostasis

PubMed Central

Hsu, Ya-Chieh; Fuchs, Elaine

2012-01-01

Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems. PMID:22266760

Systemic T Cells Immunosuppression of Glioma Stem Cell-Derived Exosomes Is Mediated by Monocytic Myeloid-Derived Suppressor Cells

PubMed Central

Domenis, Rossana; Cesselli, Daniela; Toffoletto, Barbara; Bourkoula, Evgenia; Caponnetto, Federica; Manini, Ivana; Beltrami, Antonio Paolo; Ius, Tamara; Skrap, Miran; Di Loreto, Carla

2017-01-01

A major contributing factor to glioma development and progression is its ability to evade the immune system. Nano-meter sized vesicles, exosomes, secreted by glioma-stem cells (GSC) can act as mediators of intercellular communication to promote tumor immune escape. Here, we investigated the immunomodulatory properties of GCS-derived exosomes on different peripheral immune cell populations. Healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3, anti-CD28 and IL-2, were treated with GSC-derived exosomes. Phenotypic characterization, cell proliferation, Th1/Th2 cytokine secretion and intracellular cytokine production were analysed by distinguishing among effector T cells, regulatory T cells and monocytes. In unfractionated PBMCs, GSC-derived exosomes inhibited T cell activation (CD25 and CD69 expression), proliferation and Th1 cytokine production, and did not affect cell viability or regulatory T-cell suppression ability. Furthermore, exosomes were able to enhance proliferation of purified CD4+ T cells. In PBMCs culture, glioma-derived exosomes directly promoted IL-10 and arginase-1 production and downregulation of HLA-DR by unstimulated CD14+ monocytic cells, that displayed an immunophenotype resembling that of monocytic myeloid-derived suppressor cells (Mo-MDSCs). Importantly, the removal of CD14+ monocytic cell fraction from PBMCs restored T-cell proliferation. The same results were observed with exosomes purified from plasma of glioblastoma patients. Our results indicate that glioma-derived exosomes suppress T-cell immune response by acting on monocyte maturation rather than on direct interaction with T cells. Selective targeting of Mo-MDSC to treat glioma should be considered with regard to how immune cells allow the acquirement of effector functions and therefore counteracting tumor progression. PMID:28107450

Systemic T Cells Immunosuppression of Glioma Stem Cell-Derived Exosomes Is Mediated by Monocytic Myeloid-Derived Suppressor Cells.

PubMed

Domenis, Rossana; Cesselli, Daniela; Toffoletto, Barbara; Bourkoula, Evgenia; Caponnetto, Federica; Manini, Ivana; Beltrami, Antonio Paolo; Ius, Tamara; Skrap, Miran; Di Loreto, Carla; Gri, Giorgia

2017-01-01

A major contributing factor to glioma development and progression is its ability to evade the immune system. Nano-meter sized vesicles, exosomes, secreted by glioma-stem cells (GSC) can act as mediators of intercellular communication to promote tumor immune escape. Here, we investigated the immunomodulatory properties of GCS-derived exosomes on different peripheral immune cell populations. Healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3, anti-CD28 and IL-2, were treated with GSC-derived exosomes. Phenotypic characterization, cell proliferation, Th1/Th2 cytokine secretion and intracellular cytokine production were analysed by distinguishing among effector T cells, regulatory T cells and monocytes. In unfractionated PBMCs, GSC-derived exosomes inhibited T cell activation (CD25 and CD69 expression), proliferation and Th1 cytokine production, and did not affect cell viability or regulatory T-cell suppression ability. Furthermore, exosomes were able to enhance proliferation of purified CD4+ T cells. In PBMCs culture, glioma-derived exosomes directly promoted IL-10 and arginase-1 production and downregulation of HLA-DR by unstimulated CD14+ monocytic cells, that displayed an immunophenotype resembling that of monocytic myeloid-derived suppressor cells (Mo-MDSCs). Importantly, the removal of CD14+ monocytic cell fraction from PBMCs restored T-cell proliferation. The same results were observed with exosomes purified from plasma of glioblastoma patients. Our results indicate that glioma-derived exosomes suppress T-cell immune response by acting on monocyte maturation rather than on direct interaction with T cells. Selective targeting of Mo-MDSC to treat glioma should be considered with regard to how immune cells allow the acquirement of effector functions and therefore counteracting tumor progression.

The thrombopoietin receptor, MPL, is critical for development of a JAK2V617F-induced myeloproliferative neoplasm

PubMed Central

Sangkhae, Veena; Etheridge, S. Leah; Kaushansky, Kenneth

2014-01-01

The most frequent contributing factor in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) is the acquisition of a V617F mutation in Janus kinase 2 (JAK2) in hematopoietic stem cells (HSCs). Recent evidence has demonstrated that to drive MPN transformation, JAK2V617F needs to directly associate with a functional homodimeric type I cytokine receptor, suggesting that, although acquiring JAK2V617F may promote disease, there are additional cellular components necessary for MPN development. Here we show that loss of the thrombopoietin (TPO) receptor (MPL) significantly ameliorates MPN development in JAK2V617F+ transgenic mice, whereas loss of TPO only mildly affects the disease phenotype. Specifically, compared with JAK2V617F+ mice, JAK2V617F+Mpl−/− mice exhibited reduced thrombocythemia, neutrophilia, splenomegaly, and neoplastic stem cell pool. The importance of MPL is highlighted as JAK2V617FMpl+/− mice displayed a significantly reduced MPN phenotype, indicating that Mpl level may have a substantial effect on MPN development and severity. Splenomegaly and the increased neoplastic stem cell pool were retained in JAK2V617F+Tpo−/− mice, although thrombocytosis was reduced compared with JAK2V617F+ mice. These results demonstrate that Mpl expression, but not Tpo, is fundamental in the development of JAK2V617F+ MPNs, highlighting an entirely novel target for therapeutic intervention. PMID:25339357

The thrombopoietin receptor, MPL, is critical for development of a JAK2V617F-induced myeloproliferative neoplasm.

PubMed

Sangkhae, Veena; Etheridge, S Leah; Kaushansky, Kenneth; Hitchcock, Ian S

2014-12-18

The most frequent contributing factor in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) is the acquisition of a V617F mutation in Janus kinase 2 (JAK2) in hematopoietic stem cells (HSCs). Recent evidence has demonstrated that to drive MPN transformation, JAK2V617F needs to directly associate with a functional homodimeric type I cytokine receptor, suggesting that, although acquiring JAK2V617F may promote disease, there are additional cellular components necessary for MPN development. Here we show that loss of the thrombopoietin (TPO) receptor (MPL) significantly ameliorates MPN development in JAK2V617F(+) transgenic mice, whereas loss of TPO only mildly affects the disease phenotype. Specifically, compared with JAK2V617F(+) mice, JAK2V617F(+)Mpl(-/-) mice exhibited reduced thrombocythemia, neutrophilia, splenomegaly, and neoplastic stem cell pool. The importance of MPL is highlighted as JAK2V617FMpl(+/-) mice displayed a significantly reduced MPN phenotype, indicating that Mpl level may have a substantial effect on MPN development and severity. Splenomegaly and the increased neoplastic stem cell pool were retained in JAK2V617F(+)Tpo(-/-) mice, although thrombocytosis was reduced compared with JAK2V617F(+) mice. These results demonstrate that Mpl expression, but not Tpo, is fundamental in the development of JAK2V617F(+) MPNs, highlighting an entirely novel target for therapeutic intervention. © 2014 by The American Society of Hematology.

Stem Cell Therapy for Erectile Dysfunction.

PubMed

Matz, Ethan L; Terlecki, Ryan; Zhang, Yuanyuan; Jackson, John; Atala, Anthony

2018-04-06

The prevalence of erectile dysfunction (ED) is substantial and continues to rise. Current therapeutics for ED consist of oral medications, intracavernosal injections, vacuum erection devices, and penile implants. While such options may manage the disease state, none of these modalities, however, restore function. Stem cell therapy has been evaluated for erectile restoration in animal models. These cells have been derived from multiple tissues, have varied potential, and may function via local engraftment or paracrine signaling. Bone marrow-derived stem cells (BMSC) and adipose-derived stem cells (ASC) have both been used in these models with noteworthy effects. Herein, we will review the pathophysiology of ED, animal models, current and novel stem-cell based therapeutics, clinical trials and areas for future research. The relevant literature and contemporary data using keywords, "stem cells and erectile dysfunction" was reviewed. Examination of evidence supporting the association between erectile dysfunction and adipose derived stem cells, bone marrow derived stem cells, placental stem cells, urine stem cells and stem cell therapy respectively. Placental-derived stem cells and urine-derived stem cells possess many similar properties as BMSC and ASC, but the methods of acquisition are favorable. Human clinical trials have already demonstrated successful use of stem cells for improvement of erectile function. The future of stem cell research is constantly being evaluated, although, the evidence suggests a place for stem cells in erectile dysfunction therapeutics. Matz EL, Terlecki R, Zhang Y, et al. Stem Cell Therapy for Erectile Dysfunction. Sex Med Rev 2018;XX:XXX-XXX. Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

A new prospect in cancer therapy: targeting cancer stem cells to eradicate cancer.

PubMed

Chen, Li-Sha; Wang, An-Xin; Dong, Bing; Pu, Ke-Feng; Yuan, Li-Hua; Zhu, Yi-Min

2012-12-01

According to the cancer stem cell theory, cancers can be initiated by cancer stem cells. This makes cancer stem cells prime targets for therapeutic intervention. Eradicating cancer stem cells by efficient targeting agents may have the potential to cure cancer. In this review, we summarize recent breakthroughs that have improved our understanding of cancer stem cells, and we discuss the therapeutic strategy of targeting cancer stem cells, a promising future direction for cancer stem cell research.

Adult bone marrow-derived stem cells for organ regeneration and repair.

PubMed

Tögel, Florian; Westenfelder, Christof

2007-12-01

Stem cells have been recognized as a potential tool for the development of innovative therapeutic strategies. There are in general two types of stem cells, embryonic and adult stem cells. While embryonic stem cell therapy has been riddled with problems of allogeneic rejection and ethical concerns, adult stem cells have long been used in the treatment of hematological malignancies. With the recognition of additional, potentially therapeutic characteristics, bone marrow-derived stem cells have become a tool in regenerative medicine. The bone marrow is an ideal source of stem cells because it is easily accessible and harbors two types of stem cells. Hematopoietic stem cells give rise to all blood cell types and have been shown to exhibit plasticity, while multipotent marrow stromal cells are the source of osteocytes, chondrocytes, and fat cells and have been shown to support and generate a large number of different cell types. This review describes the general characteristics of these stem cell populations and their current and potential future applications in regenerative medicine. 2007 Wiley-Liss, Inc

Stem cells.

PubMed

Behr, Björn; Ko, Sae Hee; Wong, Victor W; Gurtner, Geoffrey C; Longaker, Michael T

2010-10-01

Stem cells are self-renewing cells capable of differentiating into multiple cell lines and are classified according to their origin and their ability to differentiate. Enormous potential exists in use of stem cells for regenerative medicine. To produce effective stem cell-based treatments for a range of diseases, an improved understanding of stem cell biology and better control over stem cell fate are necessary. In addition, the barriers to clinical translation, such as potential oncologic properties of stem cells, need to be addressed. With renewed government support and continued refinement of current stem cell methodologies, the future of stem cell research is exciting and promises to provide novel reconstructive options for patients and surgeons limited by traditional paradigms.

Some Ethical Concerns About Human Induced Pluripotent Stem Cells.

PubMed

Zheng, Yue Liang

2016-10-01

Human induced pluripotent stem cells can be obtained from somatic cells, and their derivation does not require destruction of embryos, thus avoiding ethical problems arising from the destruction of human embryos. This type of stem cell may provide an important tool for stem cell therapy, but it also results in some ethical concerns. It is likely that abnormal reprogramming occurs in the induction of human induced pluripotent stem cells, and that the stem cells generate tumors in the process of stem cell therapy. Human induced pluripotent stem cells should not be used to clone human beings, to produce human germ cells, nor to make human embryos. Informed consent should be obtained from patients in stem cell therapy.

Laser biomodulation on stem cells

NASA Astrophysics Data System (ADS)

Liu, Timon C.; Duan, Rui; Li, Yan; Li, Xue-Feng; Tan, Li-Ling; Liu, Songhao

2001-08-01

Stem cells are views from the perspectives of their function, evolution, development, and cause. Counterintuitively, most stem cells may arise late in development, to act principally in tissue renewal, thus ensuring an organisms long-term survival. Surprisingly, recent reports suggest that tissue-specific adult stem cells have the potential to contribute to replenishment of multiple adult tissues. Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. The spotlight on stem cells has revealed gaps in our knowledge that must be filled if we are to take advantage of their full potential for treating devastating degenerative diseases such as Parkinsons's disease and muscular dystrophy. We need to know more about the intrinsic controls that keep stem cells as stem cells or direct them along particular differentiation pathways. Such intrinsic regulators are, in turn, sensitive to the influences of the microenvironment, or niche, where stem cells normally reside. Both intrinsic and extrinsic signals regular stem cell fate and some of these signals have now been identified. Vacek et al and Wang et al have studied the effect of low intensity laser on the haemopoietic stem cells in vitro. There experiments show there is indeed the effect of low intensity laser on the haemopoietic stem cells in vitro, and the present effect is the promotion of haemopoietic stem cells proliferation. In other words, low intensity laser irradiation can act as an extrinsic signal regulating stem cell fate. In this paper, we study how low intensity laser can be used to regulate stem cell fate from the viewpoint of collective phototransduction.

Embryos aggregation improves development and imprinting gene expression in mouse parthenogenesis.

PubMed

Bai, Guang-Yu; Song, Si-Hang; Wang, Zhen-Dong; Shan, Zhi-Yan; Sun, Rui-Zhen; Liu, Chun-Jia; Wu, Yan-Shuang; Li, Tong; Lei, Lei

2016-04-01

Mouse parthenogenetic embryonic stem cells (PgESCs) could be applied to study imprinting genes and are used in cell therapy. Our previous study found that stem cells established by aggregation of two parthenogenetic embryos at 8-cell stage (named as a2 PgESCs) had a higher efficiency than that of PgESCs, and the paternal expressed imprinting genes were observably upregulated. Therefore, we propose that increasing the number of parthenogenetic embryos in aggregation may improve the development of parthenogenetic mouse and imprinting gene expression of PgESCs. To verify this hypothesis, we aggregated four embryos together at the 4-cell stage and cultured to the blastocyst stage (named as 4aPgB). qPCR detection showed that the expression of imprinting genes Igf2, Mest, Snrpn, Igf2r, H19, Gtl2 in 4aPgB were more similar to that of fertilized blastocyst (named as fB) compared to 2aPgB (derived from two 4-cell stage parthenogenetic embryos aggregation) or PgB (single parthenogenetic blastocyst). Post-implantation development of 4aPgB extended to 11 days of gestation. The establishment efficiency of GFP-a4 PgESCs which derived from GFP-4aPgB is 62.5%. Moreover, expression of imprinting genes Igf2, Mest, Snrpn, notably downregulated and approached the level of that in fertilized embryonic stem cells (fESCs). In addition, we acquired a 13.5-day fetus totally derived from GFP-a4 PgESCs with germline contribution by 8-cell under zona pellucida (ZP) injection. In conclusion, four embryos aggregation improves parthenogenetic development, and compensates imprinting genes expression in PgESCs. It implied that a4 PgESCs could serve as a better scientific model applied in translational medicine and imprinting gene study. © 2016 Japanese Society of Developmental Biologists.

The natural flavonoid apigenin sensitizes human CD44+ prostate cancer stem cells to cisplatin therapy.

PubMed

Erdogan, Suat; Turkekul, Kader; Serttas, Rıza; Erdogan, Zeynep

2017-04-01

Prostate cancer (PCa) is the second most common type of cancer and the fifth leading cause of cancer-related death among men. Development of chemoresistance, tumor relapse and metastasis remain major barriers to effective treatment and all been identified to be associated with cancer stem cells (CSCs). Natural flavonoids such as apigenin have been shown to have the ability to improve the therapeutic efficacy of common chemotherapy agents through CSCs sensitization. Thus, the aim of this study was to evaluate the combination of apigenin with cisplatin on CD44 + PCa stem cell growth and migration. Platinum-based anti-neoplastic drugs have been used to treat a number of malignancies including PCa. However, acquired resistance and side effects unfortunately have limited cisplatin's use. A CD44 + subpopulation was isolated from human androgen-independent PC3 PCa cells by using human CD44-PE antibody. IC 50 values were determined by MTT test. RT-qPCR, Western blot analyses and image-based cytometer were used to investigate apoptosis, cell cycle and their underlying molecular mechanisms. Cell migration was evaluated by wound healing test. The combination of the IC 50 doses of apigenin (15μM) and cisplatin (7.5μM) for 48h significantly enhanced cisplatin's cytotoxic and apoptotic effects through downregulation of Bcl-2, sharpin and survivin; and upregulation of caspase-8, Apaf-1 and p53 mRNA expression. The combined therapy suppressed the phosphorylation of p-PI3K and p-Akt, inhibited the protein expression of NF-κB, and downregulated the cell cycle by upregulating p21, as well as cyclin dependent kinases CDK-2, -4, and -6. Apigenin significantly increased the inhibitory effects of cisplatin on cell migration via downregulation of Snail expression. In conclusion, our study showed the possible therapeutic approach of using apigenin to potentially increase the effects of cisplatin by targeting CSCs subset in prostate cancer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Potential antitumor therapeutic strategies of human amniotic membrane and amniotic fluid-derived stem cells.

PubMed

Kang, N-H; Hwang, K-A; Kim, S U; Kim, Y-B; Hyun, S-H; Jeung, E-B; Choi, K-C

2012-08-01

As stem cells are capable of self-renewal and can generate differentiated progenies for organ development, they are considered as potential source for regenerative medicine and tissue replacement after injury or disease. Along with this capacity, stem cells have the therapeutic potential for treating human diseases including cancers. According to the origins, stem cells are broadly classified into two types: embryonic stem cells (ESCs) and adult stem cells. In terms of differentiation potential, ESCs are pluripotent and adult stem cells are multipotent. Amnion, which is a membranous sac that contains the fetus and amniotic fluid and functions in protecting the developing embryo during gestation, is another stem cell source. Amnion-derived stem cells are classified as human amniotic membrane-derived epithelial stem cells, human amniotic membrane-derived mesenchymal stem cells and human amniotic fluid-derived stem cells. They are in an intermediate stage between pluripotent ESCs and lineage-restricted adult stem cells, non-tumorigenic, and contribute to low immunogenicity and anti-inflammation. Furthermore, they are easily available and do not cause any controversial issues in their recovery and applications. Not only are amnion-derived stem cells applicable in regenerative medicine, they have anticancer capacity. In non-engineered stem cells transplantation strategies, amnion-derived stem cells effectively target the tumor and suppressed the tumor growth by expressing cytotoxic cytokines. Additionally, they also have a potential as novel delivery vehicles transferring therapeutic genes to the cancer formation sites in gene-directed enzyme/prodrug combination therapy. Owing to their own advantageous properties, amnion-derived stem cells are emerging as a new candidate in anticancer therapy.

In vitro differentiation of primordial germ cells and oocyte-like cells from stem cells.

PubMed

Costa, José J N; Souza, Glaucinete B; Soares, Maria A A; Ribeiro, Regislane P; van den Hurk, Robert; Silva, José R V

2018-02-01

Infertility is the result of failure due to an organic disorder of the reproductive organs, especially their gametes. Recently, much progress has been made on generating germ cells, including oocytes, from various types of stem cells. This review focuses on advances in female germ cell differentiation from different kinds of stem cells, with emphasis on embryonic stem cells, adult stem cells, and induced pluripotent stem cells. The advantages and disadvantages of the derivation of female germ cells from several types of stem cells are also highlighted, as well as the ability of stem cells to generate mature and functional female gametes. This review shows that stem cell therapies have opened new frontiers in medicine, especially in the reproductive area, with the possibility of regenerating fertility.

Reduced hematopoietic stem cell frequency predicts outcome in acute myeloid leukemia.

PubMed

Wang, Wenwen; Stiehl, Thomas; Raffel, Simon; Hoang, Van T; Hoffmann, Isabel; Poisa-Beiro, Laura; Saeed, Borhan R; Blume, Rachel; Manta, Linda; Eckstein, Volker; Bochtler, Tilmann; Wuchter, Patrick; Essers, Marieke; Jauch, Anna; Trumpp, Andreas; Marciniak-Czochra, Anna; Ho, Anthony D; Lutz, Christoph

2017-09-01

In patients with acute myeloid leukemia and low percentages of aldehyde-dehydrogenase-positive cells, non-leukemic hematopoietic stem cells can be separated from leukemic cells. By relating hematopoietic stem cell frequencies to outcome we detected poor overall- and disease-free survival of patients with low hematopoietic stem cell frequencies. Serial analysis of matched diagnostic and follow-up samples further demonstrated that hematopoietic stem cells increased after chemotherapy in patients who achieved durable remissions. However, in patients who eventually relapsed, hematopoietic stem cell numbers decreased dramatically at the time of molecular relapse demonstrating that hematopoietic stem cell levels represent an indirect marker of minimal residual disease, which heralds leukemic relapse. Upon transplantation in immune-deficient mice cases with low percentages of hematopoietic stem cells of our cohort gave rise to leukemic or no engraftment, whereas cases with normal hematopoietic stem cell levels mostly resulted in multi-lineage engraftment. Based on our experimental data, we propose that leukemic stem cells have increased niche affinity in cases with low percentages of hematopoietic stem cells. To validate this hypothesis, we developed new mathematical models describing the dynamics of healthy and leukemic cells under different regulatory scenarios. These models suggest that the mechanism leading to decreases in hematopoietic stem cell frequencies before leukemic relapse must be based on expansion of leukemic stem cells with high niche affinity and the ability to dislodge hematopoietic stem cells. Thus, our data suggest that decreasing numbers of hematopoietic stem cells indicate leukemic stem cell persistence and the emergence of leukemic relapse. Copyright© 2017 Ferrata Storti Foundation.

Evaluation of the secretion and release of vascular endothelial growth factor from two-dimensional culture and three-dimensional cell spheroids formed with stem cells and osteoprecursor cells.

PubMed

Lee, Hyunjin; Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2018-05-18

Co-culture has been applied in cell therapy, including stem cells, and has been reported to give enhanced functionality. In this study, stem-cell spheroids were formed in concave micromolds at different ratios of stem cells to osteoprecursor cells, and the amount of secretion of vascular endothelial growth factor (VEGF) was evaluated. Gingiva-derived stem cells and osteoprecursor cells in the amount of 6 × 105 were seeded on a 24-well culture plate or concave micromolds. The ratios of stem cells to osteoprecursor cells included: 0:4 (group 1), 1:3 (group 2), 2:2 (group 3), 3:1 (group 4), and 4:0 (group 5). The morphology of cells in a 2-dimensional culture (groups 1-5) showed a fibroblast-like appearance. The secretion of VEGF increased with the increase in stem cells, and a statistically significant increase was noted in groups 3, 4 and 5 when compared with the media-only group (p < 0.05). Osteoprecursor cells formed spheroids in concave microwells, and no noticeable change in the morphology was noted with the increase in stem cells. Spheroids containing stem cells were positive for the stem-cell markers SSEA-4. The secretion of VEGF from cell spheroids increased with the increase in stem cells. This study showed that cell spheroids formed with stem cells and osteoprecursor cells with different ratios, using microwells, had paracrine effects on the stem cells. The secretion of VEGF increased with the increase in stem cells. This stem-cell spheroid may be applied for tissue-engineering purposes.

The Role of Stem Cells in Aesthetic Surgery: Fact or Fiction?

PubMed Central

McArdle, Adrian; Senarath-Yapa, Kshemendra; Walmsley, Graham G.; Hu, Michael; Atashroo, David A.; Tevlin, Ruth; Zielins, Elizabeth; Gurtner, Geoffrey C.; Wan, Derrick C.; Longaker, Michael T.

2014-01-01

Stem cells are attractive candidates for the development of novel therapies, targeting indications that involve functional restoration of defective tissue. Although most stem cell therapies are new and highly experimental, there are clinics around the world that exploit vulnerable patients with the hope of offering supposed stem cell therapies, many of which operate without credible scientific merit, oversight, or other patient protection. We review the potential, as well as drawbacks, for incorporation of stem cells in cosmetic procedures. A review of FDA-approved indications and ongoing clinical trials with adipose stem cells is provided. Furthermore, a “snapshot” analysis of websites using the search terms “stem cell therapy” or “stem cell treatment” or “stem cell facelift” was performed. Despite the protective net cast by regulatory agencies such as the FDA and professional societies such as the American Society of Plastic Surgeons, we are witnessing worrying advertisements for procedures such as stem cell facelifts, stem cell breast augmentations, and even stem cell vaginal rejuvenation. The marketing and promotion of stem cell procedures in aesthetic surgery is not adequately supported by clinical evidence in the majority of cases. Stem cells offer tremendous potential, but the marketplace is saturated with unsubstantiated and sometimes fraudulent claims that may place patients at risk. With plastic surgeons at the forefront of stem cell-based regenerative medicine, it is critically important that we provide an example of a rigorous approach to research, data collection, and advertising of stem cell therapies. PMID:24732654

A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis.

PubMed

Lee, Chunghee; Clark, Steven E

2015-01-01

The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified.

A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis

PubMed Central

Lee, Chunghee; Clark, Steven E.

2015-01-01

The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified. PMID:26011610

Generation, characterization and potential therapeutic applications of mature and functional hepatocytes from stem cells.

PubMed

Zhang, Zhenzhen; Liu, Jianfang; Liu, Yang; Li, Zheng; Gao, Wei-Qiang; He, Zuping

2013-02-01

Liver cancer is the sixth most common tumor in the world and the majority of patients with this disease usually die within 1 year. The effective treatment for end-stage liver disease (also known as liver failure), including liver cancer or cirrhosis, is liver transplantation. However, there is a severe shortage of liver donors worldwide, which is the major handicap for the treatment of patients with liver failure. Scarcity of liver donors underscores the urgent need of using stem cell therapy to the end-stage liver disease. Notably, hepatocytes have recently been generated from hepatic and extra-hepatic stem cells. We have obtained mature and functional hepatocytes from rat hepatic stem cells. Here, we review the advancements on hepatic differentiation from various stem cells, including hepatic stem cells, embryonic stem cells, the induced pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, and probably spermatogonial stem cells. The advantages, disadvantages, and concerns on differentiation of these stem cells into hepatic cells are highlighted. We further address the methodologies, phenotypes, and functional characterization on the differentiation of numerous stem cells into hepatic cells. Differentiation of stem cells into mature and functional hepatocytes, especially from an extra-hepatic stem cell source, would circumvent the scarcity of liver donors and human hepatocytes, and most importantly it would offer an ideal and promising source of hepatocytes for cell therapy and tissue engineering in treating liver disease. Copyright © 2012 Wiley Periodicals, Inc.

Characterizing PCDH19 in human induced pluripotent stem cells (iPSCs) and iPSC-derived developing neurons: emerging role of a protein involved in controlling polarity during neurogenesis

PubMed Central

Compagnucci, Claudia; Petrini, Stefania; Higuraschi, Norimichi; Trivisano, Marina; Specchio, Nicola; Hirose, Shinichi; Bertini, Enrico; Terracciano, Alessandra

2015-01-01

PCDH19 (Protocadherin 19), a member of the cadherin superfamily, is involved in the pathogenic mechanism of an X-linked model of neurological disease. The biological function of PCHD19 in human neurons and during neurogenesis is currently unknown. Therefore, we decided to use the model of the induced pluripotent stem cells (iPSCs) to characterize the location and timing of expression of PCDH19 during cortical neuronal differentiation. Our data show that PCDH19 is expressed in pluripotent cells before differentiation in a homogeneous pattern, despite its localization is often limited to one pole of the cell. During neuronal differentiation, positional information on the progenitor cells assumes an important role in acquiring polarization. The proper control of the cell orientation ensures a fine balancing between symmetric (giving rise to two progenitor sister cells) versus asymmetric (giving rise to one progenitor cell and one newborn neuron) division. This process results in the polar organization of the neural tube with a lumen indicating the basal part of the polarized neuronal progenitor cell; in the iPSC model the cells are organized in the ‘neural rosette’ and interestingly, PCDH19 is located at the center of the rosette, with other well-known markers of the lumen (N-cadherin and ZO-1). These data suggest that PCDH19 has a role in instructing the apico-basal polarity of the progenitor cells, thus regulating the development of a properly organized human brain. PMID:26450854

Dynamic epigenetic regulation of glioblastoma tumorigenicity through LSD1 modulation of MYC expression

PubMed Central

Kozono, David; Li, Jie; Nitta, Masayuki; Sampetrean, Oltea; Gonda, David; Kushwaha, Deepa S.; Merzon, Dmitry; Ramakrishnan, Valya; Zhu, Shan; Zhu, Kaya; Matsui, Hiroko; Harismendy, Olivier; Hua, Wei; Mao, Ying; Kwon, Chang-Hyuk; Saya, Hideyuki; Nakano, Ichiro; Pizzo, Donald P.; VandenBerg, Scott R.; Chen, Clark C.

2015-01-01

The available evidence suggests that the lethality of glioblastoma is driven by small subpopulations of cells that self-renew and exhibit tumorigenicity. It remains unclear whether tumorigenicity exists as a static property of a few cells or as a dynamically acquired property. We used tumor-sphere and xenograft formation as assays for tumorigenicity and examined subclones isolated from established and primary glioblastoma lines. Our results indicate that glioblastoma tumorigenicity is largely deterministic, yet the property can be acquired spontaneously at low frequencies. Further, these dynamic transitions are governed by epigenetic reprogramming through the lysine-specific demethylase 1 (LSD1). LSD depletion increases trimethylation of histone 3 lysine 4 at the avian myelocytomatosis viral oncogene homolog (MYC) locus, which elevates MYC expression. MYC, in turn, regulates oligodendrocyte lineage transcription factor 2 (OLIG2), SRY (sex determining region Y)-box 2 (SOX2), and POU class 3 homeobox 2 (POU3F2), a core set of transcription factors required for reprogramming glioblastoma cells into stem-like states. Our model suggests epigenetic regulation of key transcription factors governs transitions between tumorigenic states and provides a framework for glioblastoma therapeutic development. PMID:26159421

Stem cells in dentistry--part I: stem cell sources.

PubMed

Egusa, Hiroshi; Sonoyama, Wataru; Nishimura, Masahiro; Atsuta, Ikiru; Akiyama, Kentaro

2012-07-01

Stem cells can self-renew and produce different cell types, thus providing new strategies to regenerate missing tissues and treat diseases. In the field of dentistry, adult mesenchymal stem/stromal cells (MSCs) have been identified in several oral and maxillofacial tissues, which suggests that the oral tissues are a rich source of stem cells, and oral stem and mucosal cells are expected to provide an ideal source for genetically reprogrammed cells such as induced pluripotent stem (iPS) cells. Furthermore, oral tissues are expected to be not only a source but also a therapeutic target for stem cells, as stem cell and tissue engineering therapies in dentistry continue to attract increasing clinical interest. Part I of this review outlines various types of intra- and extra-oral tissue-derived stem cells with regard to clinical availability and applications in dentistry. Additionally, appropriate sources of stem cells for regenerative dentistry are discussed with regard to differentiation capacity, accessibility and possible immunomodulatory properties. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Plant stem cell niches.

PubMed

Stahl, Yvonne; Simon, Rüdiger

2005-01-01

Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

Stem cells in the Drosophila digestive system.

PubMed

Zeng, Xiankun; Chauhan, Chhavi; Hou, Steven X

2013-01-01

Adult stem cells maintain tissue homeostasis by continuously replenishing damaged, aged and dead cells in any organism. Five types of region and organ-specific multipotent adult stem cells have been identified in the Drosophila digestive system: intestinal stem cells (ISCs) in the posterior midgut; hindgut intestinal stem cells (HISCs) at the midgut/hindgut junction; renal and nephric stem cells (RNSCs) in the Malpighian Tubules; type I gastric stem cells (GaSCs) at foregut/midgut junction; and type II gastric stem cells (GSSCs) at the middle of the midgut. Despite the fact that each type of stem cell is unique to a particular organ, they share common molecular markers and some regulatory signaling pathways. Due to the simpler tissue structure, ease of performing genetic analysis, and availability of abundant mutants, Drosophila serves as an elegant and powerful model system to study complex stem cell biology. The recent discoveries, particularly in the Drosophila ISC system, have greatly advanced our understanding of stem cell self-renewal, differentiation, and the role of stem cells play in tissue homeostasis/regeneration and adaptive tissue growth.

Induced cancer stem cells generated by radiochemotherapy and their therapeutic implications.

PubMed

Chen, Xiewan; Liao, Rongxia; Li, Dezhi; Sun, Jianguo

2017-03-07

Local and distant recurrence of malignant tumors following radio- and/or chemotherapy correlates with poor prognosis of patients. Among the reasons for cancer recurrence, preexisting cancer stem cells (CSCs) are considered the most likely cause due to their properties of self-renewal, pluripotency, plasticity and tumorigenicity. It has been demonstrated that preexisting cancer stem cells derive from normal stem cells and differentiated somatic cells that undergo transformation and dedifferentiation respectively under certain conditions. However, recent studies have revealed that cancer stem cells can also be induced from non-stem cancer cells by radiochemotherapy, constituting the subpopulation of induced cancer stem cells (iCSCs). These findings suggest that radiochemotherapy has the side effect of directly transforming non-stem cancer cells into induced cancer stem cells, possibly contributing to tumor recurrence and metastasis. Therefore, drugs targeting cancer stem cells or preventing dedifferentiation of non-stem cancer cells can be combined with radiochemotherapy to improve its antitumor efficacy. The current review is to investigate the mechanisms by which induced cancer stem cells are generated by radiochemotherapy and hence provide new strategies for cancer treatment.

Stem cells in gastroenterology and hepatology

PubMed Central

Quante, Michael; Wang, Timothy C.

2010-01-01

Cellular and tissue regeneration in the gastrointestinal tract and liver depends on stem cells with properties of longevity, self-renewal and multipotency. Progress in stem cell research and the identification of potential esophageal, gastric, intestinal, colonic, hepatic and pancreatic stem cells provides hope for the use of stem cells in regenerative medicine and treatments for disease. Embryonic stem cells and induced pluripotent stem cells have the potential to give rise to any cell type in the human body, but their therapeutic application remains challenging. The use of adult or tissue-restricted stem cells is emerging as another possible approach for the treatment of gastrointestinal diseases. The same self-renewal properties that allow stem cells to remain immortal and generate any tissue can occasionally make their proliferation difficult to control and make them susceptible to malignant transformation. This Review provides an overview of the different types of stem cell, focusing on tissue-restricted adult stem cells in the fields of gastroenterology and hepatology and summarizing the potential benefits and risks of using stems cells to treat gastroenterological and liver disorders. PMID:19884893

Lower Oncogenic Potential of Human Mesenchymal Stem Cells Derived from Cord Blood Compared to Induced Pluripotent Stem Cells

PubMed Central

Foroutan, T.; Najmi, M.; Kazemi, N.; Hasanlou, M.; Pedram, A.

2015-01-01

Background: In regenerative medicine, use of each of the mesenchymal stem cells derived from bone marrow, cord blood, and adipose tissue, has several cons and pros. Mesenchymal stem cells derived from cord blood have been considered the best source for precursor transplantation. Direct reprogramming of a somatic cell into induced pluripotent stem cells by over-expression of 6 transcription factors Oct4, Sox2, Klf4, lin28, Nanog, and c-Myc has great potential for regenerative medicine, eliminating the ethical issues of embryonic stem cells and the rejection problems of using non-autologous cells. Objective: To compare reprogramming and pluripotent markers OCT4, Sox-2, c-Myc, Klf4, Nanog, and lin28 in mesenchymal stem cells derived from cord blood and induced pluripotent stem cells. Methods: We analyzed the expression level of OCT4, Sox-2, c-Myc, Klf4, Nanog and lin28 genes in human mesenchymal stem cells derived from cord blood and induced pluripotent stem cells by cell culture and RT-PCR. Results: The expression level of pluripotent genes OCT4 and Sox-2, Nanog and lin28 in mesenchymal stem cells derived from cord blood were significantly higher than those in induced pluripotent stem cells. In contrast to OCT-4A and Sox-2, Nanog and lin28, the expression level of oncogenic factors c-Myc and Klf4 were significantly higher in induced pluripotent stem cells than in mesenchymal stem cells derived from cord blood. Conclusion: It could be concluded that mesenchymal stem cells derived from human cord blood have lower oncogenic potential compared to induced pluripotent stem cells. PMID:26306155

Eckol suppresses maintenance of stemness and malignancies in glioma stem-like cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyun, Kyung-Hwan; Yoon, Chang-Hwan; Kim, Rae-Kwon

A subpopulation of cancer cells with stem cell properties is responsible for tumor maintenance and progression, and may contribute to resistance to anticancer treatments. Thus, compounds that target cancer stem-like cells could be usefully applied to destroy cancer. In this study, we investigated the effect of Eckol, a phlorotannin compound, on stemness and malignancies in glioma stem-like cells. To determine whether Eckol targets glioma stem-like cells, we examined whether Eckol treatment could change the expression levels of glioma stem-like cell markers and self-renewal-related proteins as well as the sphere forming ability, and the sensitivity to anticancer treatments. Alterations in themore » malignant properties of sphere-derived cells by Eckol were also investigated by soft-agar colony forming assay, by xenograft assay in nude mice, and by cell invasion assay. Treatment of sphere-forming glioma cells with Eckol effectively decreased the sphere formation as well as the CD133{sup +} cell population. Eckol treatment suppressed expression of the glioma stem-like cell markers and the self-renewal-related proteins without cell death. Moreover, treatment of glioma stem-like cells with Eckol significantly attenuated anchorage-independent growth on soft agar and tumor formation in xenograft mice. Importantly, Eckol treatment effectively reduced the resistance of glioma stem-like cells to ionizing radiation and temozolomide. Treatment of glioma stem-like cells with Eckol markedly blocked both phosphoinositide 3-kinase-Akt and Ras-Raf-1-Erk signaling pathways. These results indicate that the natural phlorotannin Eckol suppresses stemness and malignancies in glioma stem-like cells, and thereby makes glioma stem-like cells more sensitive to anticancer treatments, providing novel therapeutic strategies targeting specifically cancer stem-like cells.« less

Molecular stages of rapid and uniform neuralization of human embryonic stem cells.

PubMed

Bajpai, R; Coppola, G; Kaul, M; Talantova, M; Cimadamore, F; Nilbratt, M; Geschwind, D H; Lipton, S A; Terskikh, A V

2009-06-01

Insights into early human development are fundamental for our understanding of human biology. Efficient differentiation of human embryonic stem cells (hESCs) into neural precursor cells is critical for future cell-based therapies. Here, using defined conditions, we characterized a new method for rapid and uniform differentiation of hESCs into committed neural precursor cells (designated C-NPCs). Dynamic gene expression analysis identified several distinct stages of ESC neuralization and revealed functional modules of coregulated genes and pathways. The first wave of gene expression changes, likely corresponding to the transition through primitive ectoderm, started at day 3, preceding the formation of columnar neuroepithelial rosettes. The second wave started at day 5, coinciding with the formation of rosettes. The majority of C-NPCs were positive for both anterior and posterior markers of developing neuroepithelium. In culture, C-NPCs became electrophysiologically functional neurons; on transplantation into neonatal mouse brains, C-NPCs integrated into the cortex and olfactory bulb, acquiring appropriate neuronal morphologies and markers. Compared to rosette-NPCs,(1) C-NPCs exhibited limited in vitro expansion capacity and did not express potent oncogenes such as PLAG1 or RSPO3. Concordantly, we never detected tumors or excessive neural proliferation after transplantation of C-NPCs into mouse brains. In conclusion, our study provides a framework for future analysis of molecular signaling during ESC neuralization.

Involvement of auxin and a homeodomain-leucine zipper I gene in rhizoid development of the moss Physcomitrella patens.

PubMed

Sakakibara, Keiko; Nishiyama, Tomoaki; Sumikawa, Naomi; Kofuji, Rumiko; Murata, Takashi; Hasebe, Mitsuyasu

2003-10-01

Differentiation of epidermal cells is important for plants because they are in direct contact with the environment. Rhizoids are multicellular filaments that develop from the epidermis in a wide range of plants, including pteridophytes, bryophytes, and green algae; they have similar functions to root hairs in vascular plants in that they support the plant body and are involved in water and nutrient absorption. In this study, we examined mechanisms underlying rhizoid development in the moss, Physcomitrella patens, which is the only land plant in which high-frequency gene targeting is possible. We found that rhizoid development can be split into two processes: determination and differentiation. Two types of rhizoids with distinct developmental patterns (basal and mid-stem rhizoids) were recognized. The development of basal rhizoids from epidermal cells was induced by exogenous auxin, while that of mid-stem rhizoids required an unknown factor in addition to exogenous auxin. Once an epidermal cell had acquired a rhizoid initial cell fate, expression of the homeodomain-leucine zipper I gene Pphb7 was induced. Analysis of Pphb7 disruptant lines showed that Pphb7 affects the induction of pigmentation and the increase in the number and size of chloroplasts, but not the position or number of rhizoids. This is the first report on the involvement of a homeodomain-leucine zipper I gene in epidermal cell differentiation.

Gap Junctions Are Involved in the Rescue of CFTR-Dependent Chloride Efflux by Amniotic Mesenchymal Stem Cells in Coculture with Cystic Fibrosis CFBE41o- Cells.

PubMed

Carbone, Annalucia; Zefferino, Roberto; Beccia, Elisa; Casavola, Valeria; Castellani, Stefano; Di Gioia, Sante; Giannone, Valentina; Seia, Manuela; Angiolillo, Antonella; Colombo, Carla; Favia, Maria; Conese, Massimo

2018-01-01

We previously found that human amniotic mesenchymal stem cells (hAMSCs) in coculture with CF immortalised airway epithelial cells (CFBE41o- line, CFBE) on Transwell® filters acquired an epithelial phenotype and led to the expression of a mature and functional CFTR protein. In order to explore the role of gap junction- (GJ-) mediated intercellular communication (GJIC) in this rescue, cocultures (hAMSC : CFBE, 1 : 5 ratio) were studied for the formation of GJIC, before and after silencing connexin 43 (Cx43), a major component of GJs. Functional GJs in cocultures were inhibited when the expression of the Cx43 protein was downregulated. Transfection of cocultures with siRNA against Cx43 resulted in the absence of specific CFTR signal on the apical membrane and reduction in the mature form of CFTR (band C), and in parallel, the CFTR-dependent chloride channel activity was significantly decreased. Cx43 downregulation determined also a decrease in transepithelial resistance and an increase in paracellular permeability as compared with control cocultures, implying that GJIC may regulate CFTR expression and function that in turn modulate airway epithelium tightness. These results indicate that GJIC is involved in the correction of CFTR chloride channel activity upon the acquisition of an epithelial phenotype by hAMSCs in coculture with CF cells.

Flagellin preconditioning enhances the efficacy of mesenchymal stem cells in an irradiation-induced proctitis model.

PubMed

Linard, Christine; Strup-Perrot, Carine; Lacave-Lapalun, Jean-Victor; Benderitter, Marc

2016-09-01

The success of mesenchymal stem cell transplantation for proctitis depends not only on cell donors but also on host microenvironmental factors, which play a major role in conditioning mesenchymal stem cell immunosuppressive action and repair. This study sought to determine if flagellin, a TLR5 ligand, can enhance the mesenchymal stem cell treatment efficacy in radiation-induced proctitis. With the use of a colorectal model of 27 Gy irradiation in rats, we investigated and compared the effects on immune capacity and remodeling at 28 d after irradiation of the following: 1) systemic mesenchymal stem cell (5 × 10(6)) administration at d 7 after irradiation, 2) administration of flagellin at d 3 and systemic mesenchymal stem cell administration at d 7, and 3) in vitro preconditioning of mesenchymal stem cells with flagellin, 24 h before their administration on d 7. The mucosal CD8(+) T cell population was normalized after treatment with flagellin-preconditioned mesenchymal stem cells or flagellin plus mesenchymal stem cells, whereas mesenchymal stem cells alone did not alter the radiation-induced elevation of CD8(+) T cell frequency. Mesenchymal stem cell treatment returned the irradiation-elevated frequency of CD25(+) cells in the mucosa-to-control levels, whereas both flagellin-preconditioned mesenchymal stem cell and flagellin-plus-mesenchymal stem cell treatment each significantly increased not only CD25(+) cell frequency but also forkhead box p3 and IL-2Rα expression. Specifically, IL-10 was overexpressed after flagellin-preconditioned mesenchymal stem cell treatment. Analysis of collagen expression showed that the collagen type 1/collagen type 3 ratio, an indicator of wound-healing maturation, was low in the irradiated and mesenchymal stem cell-treated groups and returned to the normal level only after the flagellin-preconditioned mesenchymal stem cell treatment. This was associated with a reduction in myofibroblast accumulation. In a proctitis model, flagellin-preconditioned mesenchymal stem cells improved colonic immune capacity and enhanced tissue remodeling. © Society for Leukocyte Biology.

Epithelial-to-mesenchymal transition leads to loss of EpCAM and different physical properties in circulating tumor cells from metastatic breast cancer.

PubMed

Hyun, Kyung-A; Koo, Gi-Bang; Han, Hyunju; Sohn, Joohyuk; Choi, Wonshik; Kim, Seung-Il; Jung, Hyo-Il; Kim, You-Sun

2016-04-26

The dissemination of circulating tumor cells (CTCs) requires the Epithelial-to-Mesenchymal transition (EMT), in which cells lose their epithelial characteristics and acquire more mesenchymal-like phenotypes. Current isolation of CTCs relies on affinity-based approaches reliant on the expression of Epithelial Cell Adhesion Molecule (EpCAM). Here we show EMT-induced breast cancer cells maintained in prolonged mammosphere culture conditions possess increased EMT markers and cancer stem cell markers, as well as reduced cell mass and size by quantitative phase microscopy; however, EpCAM expression is dramatically decreased in these cells. Moreover, CTCs isolated from breast cancer patients using a label-free microfluidic flow fractionation device had differing expression patterns of EpCAM, indicating that affinity approaches reliant on EpCAM expression may underestimate CTC number and potentially miss critical subpopulations. Further characterization of CTCs, including low-EpCAM populations, using this technology may improve detection techniques and cancer diagnosis, ultimately improving cancer treatment.

Repositioning chloroquine and metformin to eliminate cancer stem cell traits in pre-malignant lesions.

PubMed

Vazquez-Martin, Alejandro; López-Bonetc, Eugeni; Cufí, Sílvia; Oliveras-Ferraros, Cristina; Del Barco, Sonia; Martin-Castillo, Begoña; Menendez, Javier A

2011-01-01

Ideal oncology drugs would be curative after a short treatment course if they could eliminate epithelium-originated carcinomas at their non-invasive, pre-malignant stages. Such ideal molecules, which are expected to molecularly abrogate all the instrumental mechanisms acquired by migrating cancer stem cells (CSCs) to by-pass tumour suppressor barriers, might already exist. We here illustrate how system biology strategies for repositioning existing FDA-approved drugs may accelerate our therapeutic capacity to eliminate CSC traits in pre-invasive intraepithelial neoplasias. First, we describe a signalling network signature that overrides bioenergetics stress- and oncogene-induced senescence (OIS) phenomena in CSCs residing at pre-invasive lesions. Second, we functionally map the anti-malarial chloroquine and the anti-diabetic metformin ("old drugs") to their recently recognized CSC targets ("new uses") within the network. By discussing the preclinical efficacy of chloroquine and metformin to inhibiting the genesis and self-renewal of CSCs we finally underscore the expected translational impact of the "old drugs-new uses" repurposing strategy to open a new CSC-targeted chemoprevention era. Copyright © 2011 Elsevier Ltd. All rights reserved.

Repositioning chloroquine and metformin to eliminate cancer stem cell traits in pre-malignant lesions

PubMed Central

Vazquez-Martin, Alejandro; López-Bonetc, Eugeni; Cufí, Sílvia; Oliveras-Ferraros, Cristina; Del Barco, Sonia; Martin-Castillo, Begoña; Menendez, Javier A.

2013-01-01

Ideal oncology drugs would be curative after a short treatment course if they could eliminate epithelium-originated carcinomas at their non-invasive, pre-malignant stages. Such ideal molecules, which are expected to molecularly abrogate all the instrumental mechanisms acquired by migrating cancer stem cells (CSCs) to by-pass tumour suppressor barriers, might already exist. We here illustrate how system biology strategies for repositioning existing FDA-approved drugs may accelerate our therapeutic capacity to eliminate CSC traits in pre-invasive intraepithelial neoplasias. First, we describe a signalling network signature that overrides bioenergetics stress- and oncogene-induced senescence (OIS) phenomena in CSCs residing at pre-invasive lesions. Second, we functionally map the anti-malarial chloroquine and the anti-diabetic metformin (“old drugs”) to their recently recognized CSC targets (“new uses”) within the network. By discussing the preclinical efficacy of chloroquine and metformin to inhibiting the genesis and self-renewal of CSCs we finally underscore the expected translational impact of the “old drugs–new uses” repurposing strategy to open a new CSC-targeted chemoprevention era. PMID:21600837

Epidermal stem cells: location, potential and contribution to cancer.

PubMed

Ambler, C A; Määttä, A

2009-01-01

Epidermal stem cells have been classically characterized as slow-cycling, long-lived cells that reside in discrete niches in the skin. Gene expression studies of niche-resident cells have revealed a number of stem cell markers and regulators, including the Wnt/beta-catenin, Notch, p63, c-Myc and Hedgehog pathways. A new study challenges the traditional developmental paradigm of slow-cycling stem cells and rapid-cycling transit amplifying cells in some epidermal regions, and there is mounting evidence to suggest that multi-lineage epidermal progenitors can be isolated from highly proliferative, non-niche regions. Whether there is a unique microenvironment surrounding these progenitors remains to be determined. Interestingly, cancer stem cells derived from epidermal tumours exist independent of the classic skin stem cell niche, yet also have stem cell properties, including multi-lineage differentiation. This review summarizes recent studies identifying the location and regulators of mouse and human epidermal stem cells and highlights the strategies used to identify cancer stem cells, including expression of normal epidermal stem cell markers, expression of cancer stem cell markers identified in other epidermal tumours and characterization of side-population tumour cells.

MicroRNAs: key regulators of stem cells.

PubMed

Gangaraju, Vamsi K; Lin, Haifan

2009-02-01

The hallmark of a stem cell is its ability to self-renew and to produce numerous differentiated cells. This unique property is controlled by dynamic interplays between extrinsic signalling, epigenetic, transcriptional and post-transcriptional regulations. Recent research indicates that microRNAs (miRNAs) have an important role in regulating stem cell self-renewal and differentiation by repressing the translation of selected mRNAs in stem cells and differentiating daughter cells. Such a role has been shown in embryonic stem cells, germline stem cells and various somatic tissue stem cells. These findings reveal a new dimension of gene regulation in controlling stem cell fate and behaviour.

[Progress in epidermal stem cells].

PubMed

Wang, Li-Juan; Wang, You-Liang; Yang, Xiao

2010-03-01

Mammalian skin epidermis contains different epidermal stem cell pools which contribute to the homeostasis and repair of skin epithelium. Epidermal stem cells possess two essential features common to all stem cells: self-renewal and differentiation. Disturbing the balance between self-renewal and differentiation of epidermal stem cell often causes tumors or other skin diseases. Epidermal stem cell niches provide a special microenvironment that maintains a balance of stem cell quiescence and activity. This review primarily concentrates on the following points of the epidermal stem cells: the existing evidences, the self-renewal and differentiation, the division pattern, the signal pathways regulating self-renewal and differentiation, and the microenvironment (niche) and macroenvironment maintaining the homeostasis of stem cells.

Human β-cell Precursors Mature Into Functional Insulin-producing Cells in an Immunoisolation Device: Implications for Diabetes Cell Therapies

PubMed Central

Lee, Seung-Hee; Hao, Ergeng; Savinov, Alexei Y.; Geron, Ifat; Strongin, Alex Y.; Itkin-Ansari, Pamela

2009-01-01

Background Islet transplantation is limited by the need for chronic immunosuppression and the paucity of donor tissue. As new sources of human β-cells are developed (e.g., stem cell-derived tissue), transplanting them in a durable device could obviate the need for immunosuppression, while also protecting the patient from any risk of tumorigenicity. Here, we studied (1) the survival and function of encapsulated human β-cells and their progenitors and (2) the engraftment of encapsulated murine β-cells in allo- and autoimmune settings. Methods Human islets and human fetal pancreatic islet-like cell clusters were encapsulated in polytetrafluorethylene devices (TheraCyte) and transplanted into immunodeficient mice. Graft survival and function was measured by immunohistochemistry, circulating human C-peptide levels, and blood glucose levels. Bioluminescent imaging was used to monitor encapsulated neonatal murine islets. Results Encapsulated human islet-like cell clusters survived, replicated, and acquired a level of glucose responsive insulin secretion sufficient to ameliorate hyperglycemia in diabetic mice. Bioluminescent imaging of encapsulated murine neonatal islets revealed a dynamic process of cell death followed by regrowth, resulting in robust long-term allograft survival. Further, in the non-obese diabetic (NOD) mouse model of type I diabetes, encapsulated primary β-cells ameliorated diabetes without stimulating a detectable T-cell response. Conclusions We demonstrate for the first time that human β-cells function is compatible with encapsulation in a durable, immunoprotective device. Moreover, our study suggests that encapsulation of β-cells before terminal differentiation will be a successful approach for new cell-based therapies for diabetes, such as those derived from stem cells. PMID:19352116

[Research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration].

PubMed

Liang, Hang; Deng, Xiangyu; Shao, Zengwu

2017-10-01

To summarize the research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration and deduce the therapeutic potential of endogenous repair for intervertebral disc degeneration. The original articles about intervertebral disc endogenous stem cells for intervertebral disc regeneration were extensively reviewed; the reparative potential in vivo and the extraction and identification in vitro of intervertebral disc endogenous stem cells were analyzed; the prospect of endogenous stem cells for intervertebral disc regeneration was predicted. Stem cell niche present in the intervertebral discs, from which stem cells migrate to injured tissues and contribute to tissues regeneration under certain specific microenvironment. Moreover, the migration of stem cells is regulated by chemokines system. Tissue specific progenitor cells have been identified and successfully extracted and isolated. The findings provide the basis for biological therapy of intervertebral disc endogenous stem cells. Intervertebral disc endogenous stem cells play a crucial role in intervertebral disc regeneration. Therapeutic strategy of intervertebral disc endogenous stem cells is proven to be a promising biological approach for intervertebral disc regeneration.

Amnion-derived stem cells: in quest of clinical applications

PubMed Central

2011-01-01

In the promising field of regenerative medicine, human perinatal stem cells are of great interest as potential stem cells with clinical applications. Perinatal stem cells could be isolated from normally discarded human placentae, which are an ideal cell source in terms of availability, the fewer number of ethical concerns, less DNA damage, and so on. Numerous studies have demonstrated that some of the placenta-derived cells possess stem cell characteristics like pluripotent differentiation ability, particularly in amniotic epithelial (AE) cells. Term human amniotic epithelium contains a relatively large number of stem cell marker-positive cells as an adult stem cell source. In this review, we introduce a model theory of why so many AE cells possess stem cell characteristics. We also describe previous work concerning the therapeutic applications and discuss the pluripotency of the AE cells and potential pitfalls for amnion-derived stem cell research. PMID:21596003

The role of stem cells in aesthetic surgery: fact or fiction?

PubMed

McArdle, Adrian; Senarath-Yapa, Kshemendra; Walmsley, Graham G; Hu, Michael; Atashroo, David A; Tevlin, Ruth; Zielins, Elizabeth; Gurtner, Geoffrey C; Wan, Derrick C; Longaker, Michael T

2014-08-01

Stem cells are attractive candidates for the development of novel therapies, targeting indications that involve functional restoration of defective tissue. Although most stem cell therapies are new and highly experimental, there are clinics around the world that exploit vulnerable patients with the hope of offering supposed stem cell therapies, many of which operate without credible scientific merit, oversight, or other patient protection. The authors review the potential and the drawbacks of incorporation of stem cells in cosmetic procedures. A review of U.S. Food and Drug Administration-approved indications and ongoing clinical trials with adipose stem cells is provided. Furthermore, a "snapshot" analysis of Web sites using the search terms "stem cell therapy" or "stem cell treatment" or "stem cell facelift" was performed. Despite the protective net cast by regulatory agencies such as the U.S. Food and Drug Administration and professional societies such as the American Society of Plastic Surgeons, the authors are witnessing worrying advertisements for procedures such as stem cell face lifts, stem cell breast augmentations, and even stem cell vaginal rejuvenation. The marketing and promotion of stem cell procedures in aesthetic surgery is not adequately supported by clinical evidence in the majority of cases. Stem cells offer tremendous potential, but the marketplace is saturated with unsubstantiated and sometimes fraudulent claims that may place patients at risk. With plastic surgeons at the forefront of stem cell-based regenerative medicine, it is critically important that they provide an example of a rigorous approach to research, data collection, and advertising of stem cell therapies.

Polymer microarray technology for stem cell engineering

PubMed Central

Coyle, Robert; Jia, Jia; Mei, Ying

2015-01-01

Stem cells hold remarkable promise for applications in tissue engineering and disease modeling. During the past decade, significant progress has been made in developing soluble factors (e.g., small molecules and growth factors) to direct stem cells into a desired phenotype. However, the current lack of suitable synthetic materials to regulate stem cell activity has limited the realization of the enormous potential of stem cells. This can be attributed to a large number of materials properties (e.g., chemical structures and physical properties of materials) that can affect stem cell fate. This makes it challenging to design biomaterials to direct stem cell behavior. To address this, polymer microarray technology has been developed to rapidly identify materials for a variety of stem cell applications. In this article, we summarize recent developments in polymer array technology and their applications in stem cell engineering. Statement of significance Stem cells hold remarkable promise for applications in tissue engineering and disease modeling. In the last decade, significant progress has been made in developing chemically defined media to direct stem cells into a desired phenotype. However, the current lack of the suitable synthetic materials to regulate stem cell activities has been limiting the realization of the potential of stem cells. This can be attributed to the number of variables in material properties (e.g., chemical structures and physical properties) that can affect stem cells. Polymer microarray technology has shown to be a powerful tool to rapidly identify materials for a variety of stem cell applications. Here we summarize recent developments in polymer array technology and their applications in stem cell engineering. PMID:26497624

Stem cells in kidney regeneration.

PubMed

Yokote, Shinya; Yokoo, Takashi

2012-01-01

Currently many efforts are being made to apply regenerative medicine to kidney diseases using several types of stem/progenitor cells, such as mesenchymal stem cells, renal stem/progenitor cells, embryonic stem cells and induced pluripotent stem cells. Stem cells have the ability to repair injured organs and ameliorate damaged function. The strategy for kidney tissue repair is the recruitment of stem cells and soluble reparative factors to the kidney to elicit tissue repair and the induction of dedifferentiation of resident renal cells. On the other hand, where renal structure is totally disrupted, absolute kidney organ regeneration is needed to rebuild a whole functional kidney. In this review, we describe current advances in stem cell research for kidney tissue repair and de novo organ regeneration.

Stem Cell Sciences plc.

PubMed

Daniels, Sebnem

2006-09-01

Stem Cell Sciences' core objective is to develop safe and effective stem cell-based therapies for currently incurable diseases. In order to achieve this goal, Stem Cell Sciences recognizes the need for multiple technologies and a globally integrated stem cell initiative. The key challenges for the successful application of stem cells in the clinic is the need for a reproducible supply of pure, fully characterized stem cells that have been grown in suitable conditions for use in the clinic.

Immortalization of human AE pre-leukemia cells by hTERT allows leukemic transformation

PubMed Central

Wunderlich, Mark; Chou, Fu-Sheng; Mulloy, James C.

2016-01-01

Human CD34+ hematopoietic stem and progenitor cells (HSPC) expressing fusion protein AML1-ETO (AE), generated by the t(8;21)(q22;q22) rearrangement, manifest enhanced self-renewal and dysregulated differentiation without leukemic transformation, representing a pre-leukemia stage. Enabling replicative immortalization via telomerase reactivation is a crucial step in cancer development. However, AE expression alone is not sufficient to maintain high telomerase activity to immortalize human HSPC cells, which may hamper transformation. Here, we investigated the cooperativity of telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, and AE in disease progression. Enforced expression of hTERT immortalized human AE pre-leukemia cells in a telomere-lengthening independent manner, and improved the pre-leukemia stem cell function by enhancing cell proliferation and survival. AE-hTERT cells retained cytokine dependency and multi-lineage differentiation potential similar to parental AE clones. Over the short-term, AE-hTERT cells did not show features of stepwise transformation, with no leukemogenecity evident upon initial injection into immunodeficient mice. Strikingly, after extended culture, we observed full transformation of one AE-hTERT clone, which recapitulated the disease evolution process in patients and emphasizes the importance of acquiring cooperating mutations in t(8;21) AML leukemogenesis. In summary, achieving unlimited proliferative potential via hTERT activation, and thereby allowing for acquisition of additional mutations, is a critical link for transition from pre-leukemia to overt disease in human cells. AE-hTERT cells represent a tractable model to study cooperating genetic lesions important for t(8;21) AML disease progression. PMID:27509060

Stem cell-derived vascular endothelial cells and their potential application in regenerative medicine

USDA-ARS?s Scientific Manuscript database

Although a 'vascular stem cell' population has not been identified or generated, vascular endothelial and mural cells (smooth muscle cells and pericytes) can be derived from currently known pluripotent stem cell sources, including human embryonic stem cells and induced pluripotent stem cells. We rev...

Hematopoietic cell differentiation from embryonic and induced pluripotent stem cells

PubMed Central

2013-01-01

Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells. PMID:23796405

Stem Cell Basics

MedlinePlus

... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

TOPICAL REVIEW: Stem cells engineering for cell-based therapy

NASA Astrophysics Data System (ADS)

Taupin, Philippe

2007-09-01

Stem cells carry the promise to cure a broad range of diseases and injuries, from diabetes, heart and muscular diseases, to neurological diseases, disorders and injuries. Significant progresses have been made in stem cell research over the past decade; the derivation of embryonic stem cells (ESCs) from human tissues, the development of cloning technology by somatic cell nuclear transfer (SCNT) and the confirmation that neurogenesis occurs in the adult mammalian brain and that neural stem cells (NSCs) reside in the adult central nervous system (CNS), including that of humans. Despite these advances, there may be decades before stem cell research will translate into therapy. Stem cell research is also subject to ethical and political debates, controversies and legislation, which slow its progress. Cell engineering has proven successful in bringing genetic research to therapy. In this review, I will review, in two examples, how investigators are applying cell engineering to stem cell biology to circumvent stem cells' ethical and political constraints and bolster stem cell research and therapy.

From Banking to International Governance: Fostering Innovation in Stem Cell Research

PubMed Central

Isasi, Rosario; Knoppers, Bartha M.

2011-01-01

Stem cell banks are increasingly recognized as an essential resource of biological materials for both basic and translational stem cell research. By providing transnational access to quality controlled and ethically sourced stem cell lines, stem cell banks seek to foster international collaboration and innovation. However, given that national stem cell banks operate under different policy, regulatory and commercial frameworks, the transnational sharing of stem cell materials and data can be complicating. This paper will provide an overview of the most pressing challenges regarding the governance of stem cell banks, and the difficulties in designing regulatory and commercial frameworks that foster stem cell research. Moreover, the paper will shed light on the numerous international initiatives that have arisen to help harmonize and standardize stem cell banking and research processes to overcome such challenges. PMID:21904557

Stem Cells Transplantation in the Treatment of Patients with Liver Failure.

PubMed

Tao, Ya-Chao; Wang, Meng-Lan; Chen, En-Qiang; Tang, Hong

2018-02-23

Liver failure is a life-threatening liver disease encompassing severe acute deterioration of liver function. Emergency liver transplantation is the only curative treatment for liver failure, but is restricted by the severe shortage of organ donors. Stem cell, including embroyonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, hematopoietic stem cells and hepatic progenitor cells, have capacity to proliferate and differentiate and could be used in a variety of liver diseases including hereditary liver diseases, cirrhosis and liver failure. We summarized the basic experimental and clinical advances of stem cell transplantation in liver failure treatment, and also discussed the advantages and disadvantage of different stem cells subtype in this field, aiming to provide a perspective on the stem cell-based therapy for liver failure. Stem cells, especially mesenchymal stem cells (mainly low immunogenicity and paracrine characteristics) and induced pluripotent stem cells (generation of desired cell type from somatic cell), are feasible candidates for cell therapy in the treatment of liver failure, but there are some drawbacks remaining to be resolved, such as low engraftment, cryotpreservation methods and tumorigenesis. Stem cell transplantation is a promising but challenging strategy and paves a new way for curing liver failure. But more efforts need to be made to overcome problems before this new strategy could be safely and effectively applied to humans. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Eat, breathe, ROS: controlling stem cell fate through metabolism.

PubMed

Kubli, Dieter A; Sussman, Mark A

2017-05-01

Research reveals cardiac regeneration exists at levels previously deemed unattainable. Clinical trials using stem cells demonstrate promising cardiomyogenic and regenerative potential but insufficient contractile recovery. Incomplete understanding of the biology of administered cells likely contributes to inconsistent patient outcomes. Metabolism is a core component of many well-characterized stem cell types, and metabolic changes fundamentally alter stem cell fate from self-renewal to lineage commitment, and vice versa. However, the metabolism of stem cells currently studied for cardiac regeneration remains incompletely understood. Areas covered: Key metabolic features of stem cells are reviewed and unique stem cell metabolic characteristics are discussed. Metabolic changes altering stem cell fate are considered from quiescence and self-renewal to lineage commitment. Key metabolic concepts are applied toward examining cardiac regeneration through stem cell-based approaches, and clinical implications of current cell therapies are evaluated to identify potential areas of improvement. Expert commentary: The metabolism and biology of stem cells used for cardiac therapy remain poorly characterized. A growing appreciation for the fundamental relationship between stem cell functionality and metabolic phenotype is developing. Future studies unraveling links between cardiac stem cell metabolism and regenerative potential may considerably improve treatment strategies and therapeutic outcomes.

Eat, breathe, ROS: controlling stem cell fate through metabolism

PubMed Central

Kubli, Dieter A.; Sussman, Mark A.

2017-01-01

Introduction Research reveals cardiac regeneration exists at levels previously deemed unattainable. Clinical trials using stem cells demonstrate promising cardiomyogenic and regenerative potential but insufficient contractile recovery. Incomplete understanding of the biology of administered cells likely contributes to inconsistent patient outcomes. Metabolism is a core component of many well-characterized stem cell types, and metabolic changes fundamentally alter stem cell fate from self-renewal to lineage commitment, and vice versa. However, the metabolism of stem cells currently studied for cardiac regeneration remains incompletely understood. Areas covered Key metabolic features of stem cells are reviewed and unique stem cell metabolic characteristics are discussed. Metabolic changes altering stem cell fate are considered from quiescence and self-renewal to lineage commitment. Key metabolic concepts are applied toward examining cardiac regeneration through stem cell-based approaches, and clinical implications of current cell therapies are evaluated to identify potential areas of improvement. Expert commentary The metabolism and biology of stem cells used for cardiac therapy remain poorly characterized. A growing appreciation for the fundamental relationship between stem cell functionality and metabolic phenotype is developing. Future studies unraveling links between cardiac stem cell metabolism and regenerative potential may considerably improve treatment strategies and therapeutic outcomes. PMID:28406333

Therapeutic strategies involving uterine stem cells in reproductive medicine.

PubMed

Simoni, Michael; Taylor, Hugh S

2018-06-01

The current review provides an update on recent advances in stem cell biology relevant to female reproduction. Stem cells are undifferentiated cells that often serve as a reservoir of cells to regenerate tissue in settings or injury or cell loss. The endometrium has progenitor stem cells that can replace all of the endometrium during each menstrual cycle. In addition, multipotent endometrial cells replace these progenitor cells when depleted. Recruitment of stem cells from outside of the uterus occurs in setting of increased demand such as ischemia or injury. Bone marrow-derived multipotent stem cells are recruited to the uterus by estrogen or injury-induced expression of the chemokine CXCL12. In the setting of overwhelming injury, especially in the setting of low estrogen levels, there may be insufficient stem cell recruitment to adequately repair the uterus resulting in conditions such as Asherman syndrome or other endometrial defects. In contrast, excessive recruitment of stem cells underlies endometriosis. Enhanced understanding of stem-cell mobilization, recruitment, and engraftment has created the possibility of improved therapy for endometrial defects and endometriosis through enhanced manipulation of stem-cell trafficking. Further, the normal endometrium is a rich source of multipotent stem cells that can be used for numerous applications in regenerative medicine beyond reproduction. A better understanding of reproductive stem-cell biology may allow improved treatment of endometrial disease such as Asherman syndrome and other endometrial receptivity defects. Inhibiting stem-cell mobilization may also be helpful in endometriosis therapy. Finally, endometrial derived multipotent stem cells may play a crucial role in cell therapy for regenerative medicine.

Gene screening of Wharton's jelly derived stem cells.

PubMed

Mechiche Alami, S; Velard, F; Draux, F; Siu Paredes, F; Josse, J; Lemaire, F; Gangloff, S C; Graesslin, O; Laurent-Maquin, D; Kerdjoudj, H

2014-01-01

Stem cells are the most powerful candidate for the treatment of various diseases. Suitable stem cell source should be harvested with minimal invasive procedure, found in great quantity, and transplanted with no risk of immune response and tumor formation. Fetal derived stem cells have been introduced as an excellent alternative to adult and embryonic stem cells use, but unfortunately, their degree of "stemness" and molecular characterization is still unclear. Several studies have been performed deciphering whether fetal stem cells meet the needs of regenerative medicine. We believe that a transcriptomic screening of Wharton's jelly stem cells will bring insights on cell population features.

Stem Cell Banking for Regenerative and Personalized Medicine

PubMed Central

Harris, David T.

2014-01-01

Regenerative medicine, tissue engineering and gene therapy offer the opportunity to treat and cure many of today’s intractable afflictions. These approaches to personalized medicine often utilize stem cells to accomplish these goals. However, stem cells can be negatively affected by donor variables such as age and health status at the time of collection, compromising their efficacy. Stem cell banking offers the opportunity to cryogenically preserve stem cells at their most potent state for later use in these applications. Practical stem cell sources include bone marrow, umbilical cord blood and tissue, and adipose tissue. Each of these sources contains stem cells that can be obtained from most individuals, without too much difficulty and in an economical fashion. This review will discuss the advantages and disadvantages of each stem cell source, factors to be considered when contemplating banking each stem cell source, the methodology required to bank each stem cell source, and finally, current and future clinical uses of each stem cell source. PMID:28548060

Nine Things to Know About Stem Cell Treatments

MedlinePlus

... Toggle Nav Nine Things To Know About Stem Cell Treatments Home > Stem Cells and Medicine > Nine Things ... About Stem Cell Treatments Many clinics offering stem cell treatments make claims that are not supported by ...

Sox10+ adult stem cells contribute to biomaterial encapsulation and microvascularization

PubMed Central

Wang, Dong; Wang, Aijun; Wu, Fan; Qiu, Xuefeng; Li, Ye; Chu, Julia; Huang, Wen-Chin; Xu, Kang; Gong, Xiaohua; Li, Song

2017-01-01

Implanted biomaterials and biomedical devices generally induce foreign body reaction and end up with encapsulation by a dense avascular fibrous layer enriched in extracellular matrix. Fibroblasts/myofibroblasts are thought to be the major cell type involved in encapsulation, but it is unclear whether and how stem cells contribute to this process. Here we show, for the first time, that Sox10+ adult stem cells contribute to both encapsulation and microvessel formation. Sox10+ adult stem cells were found sparsely in the stroma of subcutaneous loose connective tissues. Upon subcutaneous biomaterial implantation, Sox10+ stem cells were activated and recruited to the biomaterial scaffold, and differentiated into fibroblasts and then myofibroblasts. This differentiation process from Sox10+ stem cells to myofibroblasts could be recapitulated in vitro. On the other hand, Sox10+ stem cells could differentiate into perivascular cells to stabilize newly formed microvessels. Sox10+ stem cells and endothelial cells in three-dimensional co-culture self-assembled into microvessels, and platelet-derived growth factor had chemotactic effect on Sox10+ stem cells. Transplanted Sox10+ stem cells differentiated into smooth muscle cells to stabilize functional microvessels. These findings demonstrate the critical role of adult stem cells in tissue remodeling and unravel the complexity of stem cell fate determination. PMID:28071739

Tumor suppressors Sav/Scrib and oncogene Ras regulate stem cell transformation in adult Drosophila Malpighian Tubules

PubMed Central

Zeng, Xiankun; Singh, Shree Ram; Hou, David; Hou, Steven X.

2012-01-01

An increasing body of evidence suggests that tumors might originate from a few transformed cells that share many properties with normal stem cells. However, it remains unclear how normal stem cells are transformed into cancer stem cells. Here, we demonstrated that mutations causing the loss of tumor suppressor Sav or Scrib or activation of the oncogene Ras transform normal stem cells into cancer stem cells through a multistep process in the adult Drosophila Malpighian Tubules (MTs). In wild-type MTs, each stem cell generates one self-renewing and one differentiating daughter cell. However, in flies with loss-of-function sav or scrib or gain-of-function Ras mutations, both daughter cells grew and behaved like stem cells, leading to the formation of tumors in MTs. Ras functioned downstream of Sav and Scrib in regulating the stem cell transformation. The Ras-transformed stem cells exhibited many of the hallmarks of cancer, such as increased proliferation, reduced cell death, and failure to differentiate. We further demonstrated that several signal transduction pathways (including MEK/MAPK, RhoA, PKA, and TOR) mediate Rasṕ function in the stem cell transformation. Therefore, we have identified a molecular mechanism that regulates stem cell transformation, and this finding may lead to strategies for preventing tumor formation in certain organs. PMID:20432470

The king is dead, long live the king: entering a new era of stem cell research and clinical development.

PubMed

Ichim, Thomas; Riordan, Neil H; Stroncek, David F

2011-12-20

In mid November the biopharma industry was shocked by the announcement from Geron that they were ending work on embryonic stem cell research and therapy. For more than 10 years the public image of all stem cell research has been equated with embryonic stem cells. Unfortunately, a fundamentally important medical and financial fact was being ignored: embryonic stem cell therapy is extremely immature. In parallel to efforts in embryonic stem cell research and development, scientists and physicians in the field of adult stem cells realized that the natural role of adult stem cells in the body is to promote healing and to act like endogenous "repair cells" and, as a result, numerous companies have entered the field of adult stem cell therapy with the goal of expanding numbers of adult stem cells for administration to patients with various conditions. In contrast to embryonic stem cells, which are extremely expensive and potentially dangerous, adult cell cells are inexpensive and have an excellent safety record when used in humans. Many studies are now showing that adult stem cells are practical, patient-applicable, therapeutics that are very close to being available for incorporation into the practice of medicine. These events signal the entrance of the field of stem cells into a new era: an era where hype and misinformation no longer triumph over economic and medical realities.

Control of stem cell fate by engineering their micro and nanoenvironment

PubMed Central

Griffin, Michelle F; Butler, Peter E; Seifalian, Alexander M; Kalaskar, Deepak M

2015-01-01

Stem cells are capable of long-term self-renewal and differentiation into specialised cell types, making them an ideal candidate for a cell source for regenerative medicine. The control of stem cell fate has become a major area of interest in the field of regenerative medicine and therapeutic intervention. Conventional methods of chemically inducing stem cells into specific lineages is being challenged by the advances in biomaterial technology, with evidence highlighting that material properties are capable of driving stem cell fate. Materials are being designed to mimic the clues stem cells receive in their in vivo stem cell niche including topographical and chemical instructions. Nanotopographical clues that mimic the extracellular matrix (ECM) in vivo have shown to regulate stem cell differentiation. The delivery of ECM components on biomaterials in the form of short peptides sequences has also proved successful in directing stem cell lineage. Growth factors responsible for controlling stem cell fate in vivo have also been delivered via biomaterials to provide clues to determine stem cell differentiation. An alternative approach to guide stem cells fate is to provide genetic clues including delivering DNA plasmids and small interfering RNAs via scaffolds. This review, aims to provide an overview of the topographical, chemical and molecular clues that biomaterials can provide to guide stem cell fate. The promising features and challenges of such approaches will be highlighted, to provide directions for future advancements in this exciting area of stem cell translation for regenerative medicine. PMID:25621104

The Neurovascular Properties of Dental Stem Cells and Their Importance in Dental Tissue Engineering

PubMed Central

Ratajczak, Jessica; Bronckaers, Annelies; Dillen, Yörg; Gervois, Pascal; Vangansewinkel, Tim; Driesen, Ronald B.; Wolfs, Esther; Lambrichts, Ivo

2016-01-01

Within the field of tissue engineering, natural tissues are reconstructed by combining growth factors, stem cells, and different biomaterials to serve as a scaffold for novel tissue growth. As adequate vascularization and innervation are essential components for the viability of regenerated tissues, there is a high need for easily accessible stem cells that are capable of supporting these functions. Within the human tooth and its surrounding tissues, different stem cell populations can be distinguished, such as dental pulp stem cells, stem cells from human deciduous teeth, stem cells from the apical papilla, dental follicle stem cells, and periodontal ligament stem cells. Given their straightforward and relatively easy isolation from extracted third molars, dental stem cells (DSCs) have become an attractive source of mesenchymal-like stem cells. Over the past decade, there have been numerous studies supporting the angiogenic, neuroprotective, and neurotrophic effects of the DSC secretome. Together with their ability to differentiate into endothelial cells and neural cell types, this makes DSCs suitable candidates for dental tissue engineering and nerve injury repair. PMID:27688777

Multipotent Stem Cell and Reproduction.

PubMed

Khanlarkhani, Neda; Baazm, Maryam; Mohammadzadeh, Farzaneh; Najafi, Atefeh; Mehdinejadiani, Shayesteh; Sobhani, Aligholi

Stem cells are self-renewing and undifferentiated cell types that can be differentiate into functional cells. Stem cells can be classified into two main types based on their source of origin: Embryonic and Adult stem cells. Stem cells also classified based on the range of differentiation potentials into Totipotent, Pluripotent, Multipotent, and Unipotent. Multipotent stem cells have the ability to differentiate into all cell types within one particular lineage. There are plentiful advantages and usages for multipotent stem cells. Multipotent Stem cells act as a significant key in procedure of development, tissue repair, and protection. The accessibility and adaptability of these amazing cells create them a great therapeutic choice for different part of medical approaches, and it becomes interesting topic in the scientific researches to found obvious method for the most advantageous use of MSC-based therapies. Recent studies in the field of stem cell biology have provided new perspectives and opportunities for the treatment of infertility disorders.

Strategies to improve homing of mesenchymal stem cells for greater efficacy in stem cell therapy.

PubMed

Naderi-Meshkin, Hojjat; Bahrami, Ahmad Reza; Bidkhori, Hamid Reza; Mirahmadi, Mahdi; Ahmadiankia, Naghmeh

2015-01-01

Stem/progenitor cell-based therapeutic approach in clinical practice has been an elusive dream in medical sciences, and improvement of stem cell homing is one of major challenges in cell therapy programs. Stem/progenitor cells have a homing response to injured tissues/organs, mediated by interactions of chemokine receptors expressed on the cells and chemokines secreted by the injured tissue. For improvement of directed homing of the cells, many techniques have been developed either to engineer stem/progenitor cells with higher amount of chemokine receptors (stem cell-based strategies) or to modulate the target tissues to release higher level of the corresponding chemokines (target tissue-based strategies). This review discusses both of these strategies involved in the improvement of stem cell homing focusing on mesenchymal stem cells as most frequent studied model in cellular therapies. © 2014 International Federation for Cell Biology.

Clonal evolution and clinical significance of copy number neutral loss of heterozygosity of chromosome arm 6p in acquired aplastic anemia.

PubMed

Betensky, Marisol; Babushok, Daria; Roth, Jacquelyn J; Mason, Philip J; Biegel, Jaclyn A; Busse, Tracy M; Li, Yimei; Lind, Curt; Papazoglou, Anna; Monos, Dimitri; Podsakoff, Gregory; Bessler, Monica; Olson, Timothy S

2016-01-01

Acquired aplastic anemia (aAA) results from the T cell-mediated autoimmune destruction of hematopoietic stem cells. Factors predicting response to immune suppression therapy (IST) or development of myelodysplastic syndrome (MDS) are beginning to be elucidated. Our recent data suggest most patients with aAA treated with IST develop clonal somatic genetic alterations in hematopoietic cells. One frequent acquired abnormality is copy-number neutral loss of heterozygosity on chromosome 6p (6p CN-LOH) involving the human leukocyte antigen (HLA) locus. We hypothesized that because 6p CN-LOH clones may arise from selective pressure to escape immune surveillance through deletion of HLA alleles, the development of 6p CN-LOH may affect response to IST. We used single nucleotide polymorphism array genotyping and targeted next-generation sequencing of HLA alleles to assess frequency of 6p CN-LOH, identity of HLA alleles lost through 6p CN-LOH, and impact of 6p CN-LOH on response to IST. 6p CN-LOH clones were present in 11.3% of patients, remained stable over time, and were not associated with development of MDS-defining cytogenetic abnormalities. Notably, no patient with 6p CN-LOH treated with IST achieved a complete response. In summary, clonal 6p CN-LOH in aAA defines a unique subgroup of patients that may provide insights into hematopoietic clonal evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

Clonal Evolution and Clinical Significance of Copy Number Neutral Loss of Heterozygosity of Chromosome Arm 6p in Acquired Aplastic Anemia

PubMed Central

Betensky, Marisol; Babushok, Daria; Roth, Jacquelyn J.; Mason, Philip J; Biegel, Jaclyn A.; Busse, Tracy M; Li, Yimei; Lind, Curt; Papazoglou, Anna; Monos, Dimitri; Podsakoff, Gregory; Bessler, Monica; Olson, Timothy S.

2015-01-01

Acquired aplastic anemia (aAA) results from the T cell-mediated autoimmune destruction of hematopoietic stem cells. Factors predicting response to immune suppression therapy (IST) or development of myelodysplastic syndrome (MDS) are beginning to be elucidated. Our recent data suggest most patients with aAA treated with IST develop clonal somatic genetic alterations in hematopoietic cells. One frequent acquired abnormality is copy-number neutral loss of heterozygosity on chromosome 6p (6p CN-LOH) involving the human leukocyte antigen (HLA) locus. We hypothesized that because 6p CN-LOH clones may arise from selective pressure to escape immune surveillance through deletion of HLA alleles, the development of 6p CN-LOH may affect response to IST. We used single nucleotide polymorphism array genotyping and targeted next-generation sequencing of HLA alleles to assess frequency of 6p CN-LOH, identity of HLA alleles lost through 6p CN-LOH, and impact of 6p CN-LOH on response to IST. 6p CN-LOH clones were present in 11.3% of patients, remained stable over time, and were not associated with development of MDS-defining cytogenetic abnormalities. Notably, no patient with 6p CN-LOH treated with IST achieved a complete response. In summary, clonal 6p CN-LOH in aAA defines a unique subgroup of patients that may provide insights into hematopoietic clonal evolution. PMID:26702937

College Students' Conceptions of Stem Cells, Stem Cell Research, and Cloning

ERIC Educational Resources Information Center

Concannon, James P.; Siegel, Marcelle A.; Halverson, Kristy; Freyermuth, Sharyn

2010-01-01

In this study, we examined 96 undergraduate non-science majors' conceptions of stem cells, stem cell research, and cloning. This study was performed at a large, Midwest, research extensive university. Participants in the study were asked to answer 23 questions relating to stem cells, stem cell research, and cloning in an on-line assessment before…

Stem cell biobanks.

PubMed

Bardelli, Silvana

2010-04-01

Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

Muscle Stem Cells: A Model System for Adult Stem Cell Biology.

PubMed

Cornelison, Ddw; Perdiguero, Eusebio

2017-01-01

Skeletal muscle stem cells, originally termed satellite cells for their position adjacent to differentiated muscle fibers, are absolutely required for the process of skeletal muscle repair and regeneration. In the last decade, satellite cells have become one of the most studied adult stem cell systems and have emerged as a standard model not only in the field of stem cell-driven tissue regeneration but also in stem cell dysfunction and aging. Here, we provide background in the field and discuss recent advances in our understanding of muscle stem cell function and dysfunction, particularly in the case of aging, and the potential involvement of muscle stem cells in genetic diseases such as the muscular dystrophies.

Redox regulation of plant stem cell fate.

PubMed

Zeng, Jian; Dong, Zhicheng; Wu, Haijun; Tian, Zhaoxia; Zhao, Zhong

2017-10-02

Despite the importance of stem cells in plant and animal development, the common mechanisms of stem cell maintenance in both systems have remained elusive. Recently, the importance of hydrogen peroxide (H 2 O 2 ) signaling in priming stem cell differentiation has been extensively studied in animals. Here, we show that different forms of reactive oxygen species (ROS) have antagonistic roles in plant stem cell regulation, which were established by distinct spatiotemporal patterns of ROS-metabolizing enzymes. The superoxide anion (O2·-) is markedly enriched in stem cells to activate WUSCHEL and maintain stemness, whereas H 2 O 2 is more abundant in the differentiating peripheral zone to promote stem cell differentiation. Moreover, H 2 O 2 negatively regulates O2·- biosynthesis in stem cells, and increasing H 2 O 2 levels or scavenging O2·- leads to the termination of stem cells. Our results provide a mechanistic framework for ROS-mediated control of plant stem cell fate and demonstrate that the balance between O2·- and H 2 O 2 is key to stem cell maintenance and differentiation. © 2017 The Authors.

Ocular Stem Cell Research from Basic Science to Clinical Application: A Report from Zhongshan Ophthalmic Center Ocular Stem Cell Symposium

PubMed Central

Ouyang, Hong; Goldberg, Jeffrey L.; Chen, Shuyi; Li, Wei; Xu, Guo-Tong; Li, Wei; Zhang, Kang; Nussenblatt, Robert B.; Liu, Yizhi; Xie, Ting; Chan, Chi-Chao; Zack, Donald J.

2016-01-01

Stem cells hold promise for treating a wide variety of diseases, including degenerative disorders of the eye. The eye is an ideal organ for stem cell therapy because of its relative immunological privilege, surgical accessibility, and its being a self-contained system. The eye also has many potential target diseases amenable to stem cell-based treatment, such as corneal limbal stem cell deficiency, glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa (RP). Among them, AMD and glaucoma are the two most common diseases, affecting over 200 million people worldwide. Recent results on the clinical trial of retinal pigment epithelial (RPE) cells from human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) in treating dry AMD and Stargardt’s disease in the US, Japan, England, and China have generated great excitement and hope. This marks the beginning of the ocular stem cell therapy era. The recent Zhongshan Ophthalmic Center Ocular Stem Cell Symposium discussed the potential applications of various stem cell types in stem cell-based therapies, drug discoveries and tissue engineering for treating ocular diseases. PMID:27102165

StemTextSearch: Stem cell gene database with evidence from abstracts.

PubMed

Chen, Chou-Cheng; Ho, Chung-Liang

2017-05-01

Previous studies have used many methods to find biomarkers in stem cells, including text mining, experimental data and image storage. However, no text-mining methods have yet been developed which can identify whether a gene plays a positive or negative role in stem cells. StemTextSearch identifies the role of a gene in stem cells by using a text-mining method to find combinations of gene regulation, stem-cell regulation and cell processes in the same sentences of biomedical abstracts. The dataset includes 5797 genes, with 1534 genes having positive roles in stem cells, 1335 genes having negative roles, 1654 genes with both positive and negative roles, and 1274 with an uncertain role. The precision of gene role in StemTextSearch is 0.66, and the recall is 0.78. StemTextSearch is a web-based engine with queries that specify (i) gene, (ii) category of stem cell, (iii) gene role, (iv) gene regulation, (v) cell process, (vi) stem-cell regulation, and (vii) species. StemTextSearch is available through http://bio.yungyun.com.tw/StemTextSearch.aspx. Copyright © 2017. Published by Elsevier Inc.

Application of Stem Cell Technology in Dental Regenerative Medicine.

PubMed

Feng, Ruoxue; Lengner, Chistopher

2013-07-01

In this review, we summarize the current literature regarding the isolation and characterization of dental tissue-derived stem cells and address the potential of these cell types for use in regenerative cell transplantation therapy. Looking forward, platforms for the delivery of stem cells via scaffolds and the use of growth factors and cytokines for enhancing dental stem cell self-renewal and differentiation are discussed. We aim to understand the developmental origins of dental tissues in an effort to elucidate the molecular pathways governing the genesis of somatic dental stem cells. The advantages and disadvantages of several dental stem cells are discussed, including the developmental stage and specific locations from which these cells can be purified. In particular, stem cells from human exfoliated deciduous teeth may act as a very practical and easily accessibly reservoir for autologous stem cells and hold the most value in stem cell therapy. Dental pulp stem cells and periodontal ligament stem cells should also be considered for their triple lineage differentiation ability and relative ease of isolation. Further, we address the potentials and limitations of induced pluripotent stem cells as a cell source in dental regenerative. From an economical and a practical standpoint, dental stem cell therapy would be most easily applied in the prevention of periodontal ligament detachment and bone atrophy, as well as in the regeneration of dentin-pulp complex. In contrast, cell-based tooth replacement due to decay or other oral pathology seems, at the current time, an untenable approach.

The UK Stem Cell Bank: a UK government-funded, international resource center for stem cell research.

PubMed

Stacey, Glyn; Hunt, Charles J

2006-01-01

The UK Stem Cell Bank is a UK Research Council-funded initiative that aims to provide ethically sourced and quality controlled stocks of cells for researchers and also establish seed stocks of cell lines for clinical trials. Whilst the Bank is prohibited from carrying out basic stem cell research (to avoid conflicts of interest) it is working to improve stem cell banking procedures including cryopreservation, characterization and quality control. The Bank also supports training activities and has provided the hub for the International Stem Cell Initiative, which includes 17 expert stem cell centers aiming to characterize a large number of human embryonic stem cell lines in a standardized way to improve our understanding of the characteristics of these cells.

Methods for Stem Cell Production and Therapy

NASA Technical Reports Server (NTRS)

Valluri, Jagan V. (Inventor); Claudio, Pier Paolo (Inventor)

2015-01-01

The present invention relates to methods for rapidly expanding a stem cell population with or without culture supplements in simulated microgravity conditions. The present invention relates to methods for rapidly increasing the life span of stem cell populations without culture supplements in simulated microgravity conditions. The present invention also relates to methods for increasing the sensitivity of cancer stem cells to chemotherapeutic agents by culturing the cancer stem cells under microgravity conditions and in the presence of omega-3 fatty acids. The methods of the present invention can also be used to proliferate cancer cells by culturing them in the presence of omega-3 fatty acids. The present invention also relates to methods for testing the sensitivity of cancer cells and cancer stem cells to chemotherapeutic agents by culturing the cancer cells and cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce tissue for use in transplantation by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors to promote differentiation of cancer stem cells under microgravity conditions.

Dental pulp stem cells in regenerative dentistry.

PubMed

Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

2011-01-01

Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

Translating stem cell therapies: the role of companion animals in regenerative medicine

PubMed Central

Volk, Susan W.; Theoret, Christine

2013-01-01

Veterinarians and veterinary medicine have been integral to the development of stem cell therapies. The contributions of large animal experimental models to the development and refinement of modern hematopoietic stem cell transplantation were noted nearly five decades ago. More recent advances in adult stem cell/regenerative cell therapies continue to expand knowledge of the basic biology and clinical applications of stem cells. A relatively liberal legal and ethical regulation of stem cell research in veterinary medicine has facilitated the development and in some instances clinical translation of a variety of cell-based therapies involving hematopoietic (HSC) and mesenchymal stem cells (MSC) as well as other adult regenerative cells and recently embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC). In fact, many of the pioneering developments in these fields of stem cell research have been achieved through collaborations of veterinary and human scientists. This review aims to provide an overview of the contribution of large animal veterinary models in advancing stem cell therapies for both human and clinical veterinary applications. Moreover, in the context of the “One Health Initiative”, the role veterinary patients may play in the future evolution of stem cell therapies for both human and animal patients will be explored. PMID:23627495

Live imaging reveals the progenitors and cell dynamics of limb regeneration

PubMed Central

Alwes, Frederike; Enjolras, Camille; Averof, Michalis

2016-01-01

Regeneration is a complex and dynamic process, mobilizing diverse cell types and remodelling tissues over long time periods. Tracking cell fate and behaviour during regeneration in active adult animals is especially challenging. Here, we establish continuous live imaging of leg regeneration at single-cell resolution in the crustacean Parhyale hawaiensis. By live recordings encompassing the first 4-5 days after amputation, we capture the cellular events that contribute to wound closure and morphogenesis of regenerating legs with unprecedented resolution and temporal detail. Using these recordings we are able to track cell lineages, to generate fate maps of the blastema and to identify the progenitors of regenerated epidermis. We find that there are no specialized stem cells for the epidermis. Most epidermal cells in the distal part of the leg stump proliferate, acquire new positional values and contribute to new segments in the regenerating leg. DOI: http://dx.doi.org/10.7554/eLife.19766.001 PMID:27776632

Wnt6 maintains anterior escort cells as an integral component of the germline stem cell niche

PubMed Central

2018-01-01

ABSTRACT Stem cells reside in a niche, a local environment whose cellular and molecular complexity is still being elucidated. In Drosophila ovaries, germline stem cells depend on cap cells for self-renewing signals and physical attachment. Germline stem cells also contact the anterior escort cells, and here we report that anterior escort cells are absolutely required for germline stem cell maintenance. When escort cells die from impaired Wnt signaling or hid expression, the loss of anterior escort cells causes loss of germline stem cells. Anterior escort cells function as an integral niche component by promoting DE-cadherin anchorage and by transiently expressing the Dpp ligand to promote full-strength BMP signaling in germline stem cells. Anterior escort cells are maintained by Wnt6 ligands produced by cap cells; without Wnt6 signaling, anterior escort cells die leaving vacancies in the niche, leading to loss of germline stem cells. Our data identify anterior escort cells as constituents of the germline stem cell niche, maintained by a cap cell-produced Wnt6 survival signal. PMID:29361569

Wnt6 maintains anterior escort cells as an integral component of the germline stem cell niche.

PubMed

Wang, Xiaoxi; Page-McCaw, Andrea

2018-02-07

Stem cells reside in a niche, a local environment whose cellular and molecular complexity is still being elucidated. In Drosophila ovaries, germline stem cells depend on cap cells for self-renewing signals and physical attachment. Germline stem cells also contact the anterior escort cells, and here we report that anterior escort cells are absolutely required for germline stem cell maintenance. When escort cells die from impaired Wnt signaling or hid expression, the loss of anterior escort cells causes loss of germline stem cells. Anterior escort cells function as an integral niche component by promoting DE-cadherin anchorage and by transiently expressing the Dpp ligand to promote full-strength BMP signaling in germline stem cells. Anterior escort cells are maintained by Wnt6 ligands produced by cap cells; without Wnt6 signaling, anterior escort cells die leaving vacancies in the niche, leading to loss of germline stem cells. Our data identify anterior escort cells as constituents of the germline stem cell niche, maintained by a cap cell-produced Wnt6 survival signal. © 2018. Published by The Company of Biologists Ltd.

Hemangiosarcoma and its cancer stem cell subpopulation are effectively killed by a toxin targeted through epidermal growth factor and urokinase receptors.

PubMed

Schappa, Jill T; Frantz, Aric M; Gorden, Brandi H; Dickerson, Erin B; Vallera, Daniel A; Modiano, Jaime F

2013-10-15

Targeted toxins have the potential to overcome intrinsic or acquired resistance of cancer cells to conventional cytotoxic agents. Here, we hypothesized that EGFuPA-toxin, a bispecific ligand-targeted toxin (BLT) consisting of a deimmunized Pseudomonas exotoxin (PE) conjugated to epidermal growth factor and urokinase, would efficiently target and kill cells derived from canine hemangiosarcoma (HSA), a highly chemotherapy resistant tumor, as well as cultured hemangiospheres, used as a surrogate for cancer stem cells (CSC). EGFuPA-toxin showed cytotoxicity in four HSA cell lines (Emma, Frog, DD-1 and SB) at a concentration of ≤100 nM, and the cytotoxicity was dependent on specific ligand-receptor interactions. Monospecific targeted toxins also killed these chemoresistant cells; in this case, a "threshold" level of EGFR expression appeared to be required to make cells sensitive to the monospecific EGF-toxin, but not to the monospecific uPA-toxin. The IC₅₀ of CSCs was higher by approximately two orders of magnitude as compared to non-CSCs, but these cells were still sensitive to EGFuPA-toxin at nanomolar (i.e., pharmacologically relevant) concentrations, and when targeted by EGFuPA-toxin, resulted in death of the entire cell population. Taken together, our results support the use of these toxins to treat chemoresistant tumors such as sarcomas, including those that conform to the CSC model. Our results also support the use of companion animals with cancer for further translational development of these cytotoxic molecules. Copyright © 2013 UICC.

21st Nantes Actualités Transplantation: "When Stem Cells Meet Immunology".

PubMed

Anegon, Ignacio; Nguyen, Tuan Huy

2017-01-01

"When Stem Cells Meet Immunology" has been the topic of the 21st annual "Nantes Actualités en Transplantation" meeting (June 9-10, 2016, Nantes, France). This meeting brought together pioneers and leading experts in the fields of stem cells, biomaterials and immunoregulation. Presentations covered multipotent (mesenchymal and hematopoietic) and pluripotent stem cells (embryonic and induced) for regenerative medicine of incurable diseases, immunotherapy and blood transfusions. An additional focus had been immune rejections and responses of allogeneic or autologous stem cells. Conversely, stem cells are also able to directly modulate the immune response through the production of immunoregulatory molecules. Moreover, stem cells may also provide an unlimited source of immune cells (DCs, NK cells, B cells, and T cells) that can operate as "super" immune cells, for example, through genetic engineering with chimeric antigen receptors.This meeting report puts presentations into an overall context highlighting new potential biomarkers for potency prediction of mesenchymal stem cell-derived and pluripotent stem cell-derived multicellular organoids. Finally, we propose future directions arising from the flourishing encounter of stem cell and immune biology.

Differential sensitivity of Glioma stem cells to Aurora kinase A inhibitors: implications for stem cell mitosis and centrosome dynamics.

PubMed

Mannino, Mariella; Gomez-Roman, Natividad; Hochegger, Helfrid; Chalmers, Anthony J

2014-07-01

Glioma stem-cell-like cells are considered to be responsible for treatment resistance and tumour recurrence following chemo-radiation in glioblastoma patients, but specific targets by which to kill the cancer stem cell population remain elusive. A characteristic feature of stem cells is their ability to undergo both symmetric and asymmetric cell divisions. In this study we have analysed specific features of glioma stem cell mitosis. We found that glioma stem cells appear to be highly prone to undergo aberrant cell division and polyploidization. Moreover, we discovered a pronounced change in the dynamic of mitotic centrosome maturation in these cells. Accordingly, glioma stem cell survival appeared to be strongly dependent on Aurora A activity. Unlike differentiated cells, glioma stem cells responded to moderate Aurora A inhibition with spindle defects, polyploidization and a dramatic increase in cellular senescence, and were selectively sensitive to Aurora A and Plk1 inhibitor treatment. Our study proposes inhibition of centrosomal kinases as a novel strategy to selectively target glioma stem cells. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of aging on stem cells

PubMed Central

Ahmed, Abu Shufian Ishtiaq; Sheng, Matilda HC; Wasnik, Samiksha; Baylink, David J; Lau, Kin-Hing William

2017-01-01

Pluripotent stem cells have the remarkable self-renewal ability and are capable of differentiating into multiple diverse cells. There is increasing evidence that the aging process can have adverse effects on stem cells. As stem cells age, their renewal ability deteriorates and their ability to differentiate into the various cell types is altered. Accordingly, it is suggested aging-induced deterioration of stem cell functions may play a key role in the pathophysiology of the various aging-associated disorders. Understanding the role of the aging process in deterioration of stem cell function is crucial, not only in understanding the pathophysiology of aging-associated disorders, but also in future development of novel effective stem cell-based therapies to treat aging-associated diseases. This review article first focuses on the basis of the various aging disease-related stem cell dysfunction. It then addresses the several concepts on the potential mechanism that causes aging-related stem cell dysfunction. It also briefly discusses the current potential therapies under development for aging-associated stem cell defects. PMID:28261550

Engineering Stem Cells for Biomedical Applications

PubMed Central

Yin, Perry T.; Han, Edward

2018-01-01

Stem cells are characterized by a number of useful properties, including their ability to migrate, differentiate, and secrete a variety of therapeutic molecules such as immunomodulatory factors. As such, numerous pre-clinical and clinical studies have utilized stem cell-based therapies and demonstrated their tremendous potential for the treatment of various human diseases and disorders. Recently, efforts have focused on engineering stem cells in order to further enhance their innate abilities as well as to confer them with new functionalities, which can then be used in various biomedical applications. These engineered stem cells can take on a number of forms. For instance, engineered stem cells encompass the genetic modification of stem cells as well as the use of stem cells for gene delivery, nanoparticle loading and delivery, and even small molecule drug delivery. The present Review gives an in-depth account of the current status of engineered stem cells, including potential cell sources, the most common methods used to engineer stem cells, and the utilization of engineered stem cells in various biomedical applications, with a particular focus on tissue regeneration, the treatment of immunodeficiency diseases, and cancer. PMID:25772134

Therapeutic potential of dental stem cells

PubMed Central

Chalisserry, Elna Paul; Nam, Seung Yun; Park, Sang Hyug; Anil, Sukumaran

2017-01-01

Stem cell biology has become an important field in regenerative medicine and tissue engineering therapy since the discovery and characterization of mesenchymal stem cells. Stem cell populations have also been isolated from human dental tissues, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, stem cells from apical papilla, dental follicle progenitor cells, and periodontal ligament stem cells. Dental stem cells are relatively easily obtainable and exhibit high plasticity and multipotential capabilities. The dental stem cells represent a gold standard for neural-crest-derived bone reconstruction in humans and can be used for the repair of body defects in low-risk autologous therapeutic strategies. The bioengineering technologies developed for tooth regeneration will make substantial contributions to understand the developmental process and will encourage future organ replacement by regenerative therapies in a wide variety of organs such as the liver, kidney, and heart. The concept of developing tooth banking and preservation of dental stem cells is promising. Further research in the area has the potential to herald a new dawn in effective treatment of notoriously difficult diseases which could prove highly beneficial to mankind in the long run. PMID:28616151

Single-cell sequencing in stem cell biology.

PubMed

Wen, Lu; Tang, Fuchou

2016-04-15

Cell-to-cell variation and heterogeneity are fundamental and intrinsic characteristics of stem cell populations, but these differences are masked when bulk cells are used for omic analysis. Single-cell sequencing technologies serve as powerful tools to dissect cellular heterogeneity comprehensively and to identify distinct phenotypic cell types, even within a 'homogeneous' stem cell population. These technologies, including single-cell genome, epigenome, and transcriptome sequencing technologies, have been developing rapidly in recent years. The application of these methods to different types of stem cells, including pluripotent stem cells and tissue-specific stem cells, has led to exciting new findings in the stem cell field. In this review, we discuss the recent progress as well as future perspectives in the methodologies and applications of single-cell omic sequencing technologies.

The Implications of the Cancer Stem Cell Hypothesis for Neuro-Oncology and Neurology.

PubMed

Rich, Jeremy N

2008-05-01

The cancer stem cell hypothesis posits that cancers contain a subset of neoplastic cells that propagate and maintain tumors through sustained self-renewal and potent tumorigenecity. Recent excitement has been generated by a number of reports that have demonstrated the existence of cancer stem cells in several types of brain tumors. Brain cancer stem cells - also called tumor initiating cells or tumor propagating cells - share features with normal neural stem cells but do not necessarily originate from stem cells. Although most cancers have only a small fraction of cancer stem cells, these tumor cells have been shown in laboratory studies to contribute to therapeutic resistance, formation of new blood vessels to supply the tumor, and tumor spread. As malignant brain tumors rank among the deadliest of all neurologic diseases, the identification of new cellular targets may have profound implications in neuro-oncology. Novel drugs that target stem cell pathways active in brain tumors have been efficacious against cancer stem cells suggesting that anti-cancer stem cell therapies may advance brain tumor therapy. The cancer stem cell hypothesis may have several implications for other neurologic diseases as caution must be exercised in activating stem cell maintenance pathways in cellular therapies for neurodegenerative diseases. The ability for a small fraction of cells to determine the overall course of a disease may also inform new paradigms of disease that may translate into improved patient outcomes.

Can bone marrow differentiate into renal cells?

PubMed

Imai, Enyu; Ito, Takahito

2002-10-01

A considerable plasticity of adult stem cells has been confirmed in a wide variety of tissues. In particular, the pluripotency of bone marrow-derived stem cells may influence the regeneration of injured tissues and may provide novel avenues in regenerative medicine. Bone marrow contains at least hematopoietic and mesenchymal stem cells, and both can differentiate into a wide range of differentiated cells. Side population (SP) cells, which are originally defined in bone marrow cells by high efflux of DNA-binding dye, seem to be a new class of multipotent stem cells. Irrespective of the approach used to obtain stem cells, the fates of marrow-derived cells following bone marrow transplantation can be traced by labeling donor cells with green fluorescence protein or by identifying donor Y chromosome in female recipients. So far, bone marrow-derived cells have been reported to differentiate into renal cells, including mesangial cells, endothelial cells, podocytes, and tubular cells in the kidney, although controversy exists. Further studies are required to address this issue. Cell therapy will be promising when we learn to control stem cells such as bone marrow-derived stem cells, embryonic stem cells, and resident stem cells in the kidney. Identification of factors that support stem cells or promote their differentiation should provide a relevant step towards cell therapy.

[The emerging technology of tissue engineering : Focus on stem cell niche].

PubMed

Schlötzer-Schrehardt, U; Freudenberg, U; Kruse, F E

2017-04-01

Limbal stem cells reside in a highly specialized complex microenvironment that is known as the stem cell niche, an anatomically protected region at the bottom of the Palisades of Vogt, where the stem cells are located and where their quiescence, proliferation and differentiation are maintained in balance. Besides the epithelial stem and progenitor cell clusters, the limbal niche comprises several types of supporting niche cells and a specific extracellular matrix mediating biochemical and biophysical signals. Stem cell-based tissue engineering aims to mimic the native stem cell niche and to present appropriate microenvironmental cues in a controlled and reproducible fashion in order to maintain stem cell function within the graft. Current therapeutic approaches for ex vivo expansion of limbal stem cells only take advantage of surrogate niches. However, new insights into the molecular composition of the limbal niche and innovative biosynthetic scaffolds have stimulated novel strategies for niche-driven stem cell cultivation. Promising experimental approaches include collagen-based organotypic coculture systems of limbal epithelial stem cells with their niche cells and biomimetic hydrogel platforms prefunctionalized with appropriate biomolecular and biophysical signals. Future translation of these novel regenerative strategies into clinical application is expected to improve long-term outcomes of limbal stem cell transplantation for ocular surface reconstruction.

The innate immune system in host mice targets cells with allogenic mitochondrial DNA

PubMed Central

Ishikawa, Kaori; Nakada, Kazuto; Morimoto, Mami; Imanishi, Hirotake; Yoshizaki, Mariko; Sasawatari, Shigemi; Niikura, Mamoru; Takenaga, Keizo; Yonekawa, Hiromichi

2010-01-01

Mitochondrial DNA (mtDNA) has been proposed to be involved in respiratory function, and mtDNA mutations have been associated with aging, tumors, and various disorders, but the effects of mtDNA imported into transplants from different individuals or aged subjects have been unclear. We examined this issue by generating trans-mitochondrial tumor cells and embryonic stem cells that shared the syngenic C57BL/6 (B6) strain–derived nuclear DNA background but possessed mtDNA derived from allogenic mouse strains. We demonstrate that transplants with mtDNA from the NZB/B1NJ strain were rejected from the host B6 mice, not by the acquired immune system but by the innate immune system. This rejection was caused partly by NK cells and involved a MyD88-dependent pathway. These results introduce novel roles of mtDNA and innate immunity in tumor immunology and transplantation medicine. PMID:20937705

Combination cell therapy with mesenchymal stem cells and neural stem cells for brain stroke in rats.

PubMed

Hosseini, Seyed Mojtaba; Farahmandnia, Mohammad; Razi, Zahra; Delavari, Somayeh; Shakibajahromi, Benafsheh; Sarvestani, Fatemeh Sabet; Kazemi, Sepehr; Semsar, Maryam

2015-05-01

Brain stroke is the second most important events that lead to disability and morbidity these days. Although, stroke is important, there is no treatment for curing this problem. Nowadays, cell therapy has opened a new window for treating central nervous system disease. In some previous studies the Mesenchymal stem cells and neural stem cells. In this study, we have designed an experiment to assess the combination cell therapy (Mesenchymal and Neural stem cells) effects on brain stroke. The Mesenchymal stem cells were isolated from adult rat bone marrow and the neural stem cells were isolated from ganglion eminence of rat embryo 14 days. The Mesenchymal stem cells were injected 1 day after middle cerebral artery occlusion (MCAO) and the neural stem cells transplanted 7 day after MCAO. After 28 days, the neurological outcomes and brain lesion volumes were evaluated. Also, the activity of Caspase 3 was assessed in different groups. The group which received combination cell therapy had better neurological examination and less brain lesion. Also the combination cell therapy group had the least Caspase 3 activity among the groups. The combination cell therapy is more effective than Mesenchymal stem cell therapy and neural stem cell therapy separately in treating the brain stroke in rats.

Application of Stem Cells in Oral Disease Therapy: Progresses and Perspectives

PubMed Central

Yang, Bo; Qiu, Yi; Zhou, Niu; Ouyang, Hong; Ding, Junjun; Cheng, Bin; Sun, Jianbo

2017-01-01

Stem cells are undifferentiated and pluripotent cells that can differentiate into specialized cells with a more specific function. Stem cell therapies become preferred methods for the treatment of multiple diseases. Oral and maxillofacial defect is one kind of the diseases that could be most possibly cured by stem cell therapies. Here we discussed oral diseases, oral adult stem cells, iPS cells, and the progresses/challenges/perspectives of application of stem cells for oral disease treatment. PMID:28421002

Diploid, but not haploid, human embryonic stem cells can be derived from microsurgically repaired tripronuclear human zygotes

PubMed Central

Fan, Yong; Li, Rong; Huang, Jin; Yu, Yang; Qiao, Jie

2013-01-01

Human embryonic stem cells have shown tremendous potential in regenerative medicine, and the recent progress in haploid embryonic stem cells provides new insights for future applications of embryonic stem cells. Disruption of normal fertilized embryos remains controversial; thus, the development of a new source for human embryonic stem cells is important for their usefulness. Here, we investigated the feasibility of haploid and diploid embryo reconstruction and embryonic stem cell derivation using microsurgically repaired tripronuclear human zygotes. Diploid and haploid zygotes were successfully reconstructed, but a large proportion of them still had a tripolar spindle assembly. The reconstructed embryos developed to the blastocyst stage, although the loss of chromosomes was observed in these zygotes. Finally, triploid and diploid human embryonic stem cells were derived from tripronuclear and reconstructed zygotes (from which only one pronucleus was removed), but haploid human embryonic stem cells were not successfully derived from the reconstructed zygotes when two pronuclei were removed. Both triploid and diploid human embryonic stem cells showed the general characteristics of human embryonic stem cells. These results indicate that the lower embryo quality resulting from abnormal spindle assembly contributed to the failure of the haploid embryonic stem cell derivation. However, the successful derivation of diploid embryonic stem cells demonstrated that microsurgical tripronuclear zygotes are an alternative source of human embryonic stem cells. In the future, improving spindle assembly will facilitate the application of triploid zygotes to the field of haploid embryonic stem cells. PMID:23255130

Identification of genes differentially expressed in Mikania micrantha during Cuscuta campestris infection by suppression subtractive hybridization.

PubMed

Li, Dong-Mei; Staehelin, Christian; Zhang, Yi-Shun; Peng, Shao-Lin

2009-09-01

The influence of Cuscuta campestris on its host Mikania micrantha has been studied with respect to biomass accumulation, physiology and ecology. Molecular events of this parasitic plant-plant interaction are poorly understood, however. In this study, we identified novel genes from M. micrantha induced by C. campestris infection. Genes expressed upon parasitization by C. campestris at early post-penetration stages were investigated by construction and characterization of subtracted cDNA libraries from shoots and stems of M. micrantha. Three hundred and three presumably up-regulated expressed sequence tags (ESTs) were identified and classified in functional categories, such as "metabolism", "cell defence and stress", "transcription factor", "signal transduction", "transportation" and "photosynthesis". In shoots and stems of infected M. micrantha, genes associated with defence responses and cell wall modifications were induced, confirming similar data from other parasitic plant-plant interactions. However, gene expression profiles in infected shoots and stems were found to be different. Compared to infected shoots, more genes induced in response to biotic and abiotic stress factors were identified in infected stems. Furthermore, database comparisons revealed a notable number of M. micrantha ESTs that matched genes with unknown function. Expression analysis by quantitative real-time RT-PCR of 21 genes (from different functional categories) showed significantly increased levels for 13 transcripts in response to C. campestris infection. In conclusion, this study provides an overview of genes from parasitized M. micrantha at early post-penetration stages. The acquired data form the basis for a molecular understanding of host reactions in response to parasitic plants.

Nano scaffolds and stem cell therapy in liver tissue engineering

NASA Astrophysics Data System (ADS)

Montaser, Laila M.; Fawzy, Sherin M.

2015-08-01

Tissue engineering and regenerative medicine have been constantly developing of late due to the major progress in cell and organ transplantation, as well as advances in materials science and engineering. Although stem cells hold great potential for the treatment of many injuries and degenerative diseases, several obstacles must be overcome before their therapeutic application can be realized. These include the development of advanced techniques to understand and control functions of micro environmental signals and novel methods to track and guide transplanted stem cells. A major complication encountered with stem cell therapies has been the failure of injected cells to engraft to target tissues. The application of nanotechnology to stem cell biology would be able to address those challenges. Combinations of stem cell therapy and nanotechnology in tissue engineering and regenerative medicine have achieved significant advances. These combinations allow nanotechnology to engineer scaffolds with various features to control stem cell fate decisions. Fabrication of Nano fiber cell scaffolds onto which stem cells can adhere and spread, forming a niche-like microenvironment which can guide stem cells to proceed to heal damaged tissues. In this paper, current and emergent approach based on stem cells in the field of liver tissue engineering is presented for specific application. The combination of stem cells and tissue engineering opens new perspectives in tissue regeneration for stem cell therapy because of the potential to control stem cell behavior with the physical and chemical characteristics of the engineered scaffold environment.

Stem cells with potential to generate insulin producing cells in man.

PubMed

Zulewski, Henryk

2006-10-14

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Stem cells with potential to generate insulin-producing cells in man.

PubMed

Zulewski, Henryk

2007-03-02

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Mechanical forces direct stem cell behaviour in development and regeneration

PubMed Central

Vining, Kyle H.; Mooney, David J.

2018-01-01

Stem cells and their local microenvironment, or niche, communicate through mechanical, cues to regulate cell fate and cell behaviour, and to guide developmental processes. During embryonic development, mechanical forces are involved in patterning and organogenesis. The physical environment of pluripotent stem cells regulates their differentiation and self-renewal. Mechanical and physical cues are also important in adult tissues, where adult stem cells require physical interactions with the extracellular matrix to maintain their potency. In vitro, synthetic models of the stem cell niche can be used to precisely control and manipulate the biophysical and biochemical properties of the stem cell microenvironment and examine how the mode and magnitude of mechanical cues, such as matrix stiffness or applied forces, direct stem cell differentiation and function. Fundamental insights on the mechanobiology of stem cells also inform the design of artificial niches to support stem cells for regenerative therapies. PMID:29115301

Recent Advances towards the Clinical Application of Stem Cells for Retinal Regeneration

PubMed Central

Becker, Silke; Jayaram, Hari; Limb, G. Astrid

2012-01-01

Retinal degenerative diseases constitute a major cause of irreversible blindness in the world. Stem cell-based therapies offer hope for these patients at risk of or suffering from blindness due to the deterioration of the neural retina. Various sources of stem cells are currently being investigated, ranging from human embryonic stem cells to adult-derived induced pluripotent stem cells as well as human Müller stem cells, with the first clinical trials to investigate the safety and tolerability of human embryonic stem cell-derived retinal pigment epithelium cells having recently commenced. This review aims to summarize the latest advances in the development of stem cell strategies for the replacement of retinal neurons and their supportive cells, the retinal pigment epithelium (RPE) affected by retinal degenerative conditions. Particular emphasis will be given to the advances in stem cell transplantation and the challenges associated with their translation into clinical practice. PMID:24710533

Stem-Cell Therapy Advances in China.

PubMed

Hu, Lei; Zhao, Bin; Wang, Songlin

2018-02-01

Stem-cell therapy is a promising method for treating patients with a wide range of diseases and injuries. Increasing government funding of scientific research has promoted rapid developments in stem-cell research in China, as evidenced by the substantial increase in the number and quality of publications in the past 5 years. Multiple high-quality studies have been performed in China that concern cell reprogramming, stem-cell homeostasis, gene modifications, and immunomodulation. The number of translation studies, including basic and preclinical investigations, has also increased. Around 100 stem-cell banks have been established in China, 10 stem-cell drugs are currently in the approval process, and >400 stem cell-based clinical trials are currently registered in China. With continued state funding, advanced biotechnical support, and the development of regulatory standards for the clinical application of stem cells, further innovations are expected that will lead to a boom in stem-cell therapies. This review highlights recent achievements in stem-cell research in China and discusses future prospects.

Gene editing of stem cells for kidney disease modelling and therapeutic intervention.

PubMed

Lau, Ricky W K; Wang, Bo; Ricardo, Sharon D

2018-05-30

Recent developments in targeted gene editing have paved the way for the wide adoption of cluster regular interspaced short palindromic repeats (CRISPR)-associated protein-9 nucleases (Cas9) as a RNA guide molecular tool to modify the genome of eukaryotic cells or animals. Theoretically, the translation of CRISPR-Cas9 can be applied to the treatment of inherited or acquired kidney disease, kidney transplantation and genetic corrections of somatic cells from kidneys with inherited mutations such as polycystic kidney disease. Human pluripotent stem cells have been used to generate an unlimited source of kidney progenitor cells or when spontaneously differentiated into three-dimensional kidney organoids to model kidney organogenesis or the pathogenesis of disease. Gene editing now allows for the tagging and selection of specific kidney cell types or disease specific gene knock in/out, which enables more precise understanding of kidney organogenesis and genetic diseases. This review discusses the mechanisms of action, in addition to the advantages and disadvantages, of the major three gene editing technologies, namely CRISPR-Cas9, zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs). The implications of using gene editing to better understand kidney disease is reviewed in detail. In addition, the ethical issues of gene editing, which could be easily neglected in the modern fast paced research environment, are highlighted. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pioneer factors govern super-enhancer dynamics in stem cell plasticity and lineage choice

PubMed Central

Adam, Rene C.; Yang, Hanseul; Rockowitz, Shira; Larsen, Samantha B.; Nikolova, Maria; Oristian, Daniel S.; Polak, Lisa; Kadaja, Meelis; Asare, Amma; Zheng, Deyou; Fuchs, Elaine

2015-01-01

Adult stem cells (SCs) reside in niches which balance self-renewal with lineage selection and progression during tissue homeostasis. Following injury, culture or transplantation, SCs outside their niche often display fate flexibility1-4. Here we show that super-enhancers5 underlie the identity, lineage commitment and plasticity of adult SCs in vivo. Using hair follicle (HF) as model, we map the global chromatin domains of HFSCs and their committed progenitors in their native microenvironments. We show that super-enhancers and their dense clusters (‘epicenters’) of transcription factor (TF) binding sites change upon lineage progression. New fate is acquired by decommissioning old and establishing new super-enhancers and/or epicenters, an auto-regulatory process that abates one master regulator subset while enhancing another. We further show that when outside their niche, either in vitro or in wound-repair, HFSCs dynamically remodel super-enhancers in response to changes in their microenvironment. Intriguingly, some key super-enhancers shift epicenters, enabling them to remain active and maintain a transitional state in an ever-changing transcriptional landscape. Finally, we identify SOX9 as a crucial chromatin rheostat of HFSC super-enhancers, and provide functional evidence that super-enhancers are dynamic, dense TF-binding platforms which are acutely sensitive to pioneer master regulators whose levels define not only spatial and temporal features of lineage-status, but also stemness, plasticity in transitional states and differentiation. PMID:25799994

Selection of Phage Display Peptides Targeting Human Pluripotent Stem Cell-Derived Progenitor Cell Lines.

PubMed

Bignone, Paola A; Krupa, Rachel A; West, Michael D; Larocca, David

2016-01-01

The ability of human pluripotent stem cells (hPS) to both self-renew and differentiate into virtually any cell type makes them a promising source of cells for cell-based regenerative therapies. However, stem cell identity, purity, and scalability remain formidable challenges that need to be overcome for translation of pluripotent stem cell research into clinical applications. Directed differentiation from hPS cells is inefficient and residual contamination with pluripotent cells that have the potential to form tumors remains problematic. The derivation of scalable (self-renewing) embryonic progenitor stem cell lines offers a solution because they are well defined and clonally pure. Clonally pure progenitor stem cell lines also provide a means for identifying cell surface targeting reagents that are useful for identification, tracking, and repeated derivation of the corresponding progenitor stem cell types from additional hPS cell sources. Such stem cell targeting reagents can then be applied to the manufacture of genetically diverse banks of human embryonic progenitor cell lines for drug screening, disease modeling, and cell therapy. Here we present methods to identify human embryonic progenitor stem cell targeting peptides by selection of phage display libraries on clonal embryonic progenitor cell lines and demonstrate their use for targeting quantum dots (Qdots) for stem cell labeling.

Extinction models for cancer stem cell therapy

PubMed Central

Sehl, Mary; Zhou, Hua; Sinsheimer, Janet S.; Lange, Kenneth L.

2012-01-01

Cells with stem cell-like properties are now viewed as initiating and sustaining many cancers. This suggests that cancer can be cured by driving these cancer stem cells to extinction. The problem with this strategy is that ordinary stem cells are apt to be killed in the process. This paper sets bounds on the killing differential (difference between death rates of cancer stem cells and normal stem cells) that must exist for the survival of an adequate number of normal stem cells. Our main tools are birth–death Markov chains in continuous time. In this framework, we investigate the extinction times of cancer stem cells and normal stem cells. Application of extreme value theory from mathematical statistics yields an accurate asymptotic distribution and corresponding moments for both extinction times. We compare these distributions for the two cell populations as a function of the killing rates. Perhaps a more telling comparison involves the number of normal stem cells NH at the extinction time of the cancer stem cells. Conditioning on the asymptotic time to extinction of the cancer stem cells allows us to calculate the asymptotic mean and variance of NH. The full distribution of NH can be retrieved by the finite Fourier transform and, in some parameter regimes, by an eigenfunction expansion. Finally, we discuss the impact of quiescence (the resting state) on stem cell dynamics. Quiescence can act as a sanctuary for cancer stem cells and imperils the proposed therapy. We approach the complication of quiescence via multitype branching process models and stochastic simulation. Improvements to the τ-leaping method of stochastic simulation make it a versatile tool in this context. We conclude that the proposed therapy must target quiescent cancer stem cells as well as actively dividing cancer stem cells. The current cancer models demonstrate the virtue of attacking the same quantitative questions from a variety of modeling, mathematical, and computational perspectives. PMID:22001354

Extinction models for cancer stem cell therapy.

PubMed

Sehl, Mary; Zhou, Hua; Sinsheimer, Janet S; Lange, Kenneth L

2011-12-01

Cells with stem cell-like properties are now viewed as initiating and sustaining many cancers. This suggests that cancer can be cured by driving these cancer stem cells to extinction. The problem with this strategy is that ordinary stem cells are apt to be killed in the process. This paper sets bounds on the killing differential (difference between death rates of cancer stem cells and normal stem cells) that must exist for the survival of an adequate number of normal stem cells. Our main tools are birth-death Markov chains in continuous time. In this framework, we investigate the extinction times of cancer stem cells and normal stem cells. Application of extreme value theory from mathematical statistics yields an accurate asymptotic distribution and corresponding moments for both extinction times. We compare these distributions for the two cell populations as a function of the killing rates. Perhaps a more telling comparison involves the number of normal stem cells NH at the extinction time of the cancer stem cells. Conditioning on the asymptotic time to extinction of the cancer stem cells allows us to calculate the asymptotic mean and variance of NH. The full distribution of NH can be retrieved by the finite Fourier transform and, in some parameter regimes, by an eigenfunction expansion. Finally, we discuss the impact of quiescence (the resting state) on stem cell dynamics. Quiescence can act as a sanctuary for cancer stem cells and imperils the proposed therapy. We approach the complication of quiescence via multitype branching process models and stochastic simulation. Improvements to the τ-leaping method of stochastic simulation make it a versatile tool in this context. We conclude that the proposed therapy must target quiescent cancer stem cells as well as actively dividing cancer stem cells. The current cancer models demonstrate the virtue of attacking the same quantitative questions from a variety of modeling, mathematical, and computational perspectives. Copyright © 2011 Elsevier Inc. All rights reserved.

Aging and stem cell therapy: AMPK as an applicable pharmacological target for rejuvenation of aged stem cells and achieving higher efficacy in stem cell therapy.

PubMed

Khorraminejad-Shirazi, Mohammadhossein; Farahmandnia, Mohammad; Kardeh, Bahareh; Estedlal, Alireza; Kardeh, Sina; Monabati, Ahmad

2017-10-19

In recent years, tissue regeneration has become a promising field for developing stem cell-based transplantation therapies for human patients. Adult stem cells are affected by the same aging mechanisms that involve somatic cells. One of the mechanisms involved in cellular aging is hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) and disruption of 5' adenosine monophosphate-activated protein kinase (AMPK). Aging of stem cells results in their impaired regenerative capacity and depletion of stem cell pools in adult tissue, which results in lower efficacy of stem cell therapy. By utilizing an effective therapeutic intervention for aged stem cells, stem cell therapy can become more promising for future application. mTORC1 inhibition is a practical approach to preserve the stem cell pool. In this article, we review the dynamic interaction between sirtuin (silent mating type information regulation 2 homolog) 1, AMPK, and mTORC1. We propose that using AMPK activators such as 5-aminoimidazole-4-carboxamide ribonucleotide, A769662, metformin, and oxidized nicotinamide adenine dinucleotide (NAD + ) are practical ways to be employed for achieving better optimized results in stem cell-based transplantation therapies. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

Stemness of spermatogonial stem cells encapsulated in alginate hydrogel during cryopreservation.

PubMed

Pirnia, A; Parivar, K; Hemadi, M; Yaghmaei, P; Gholami, M

2017-06-01

This study investigated the effect of spermatogonial stem cell encapsulated in alginate hydrogel during cryopreservation, as cells were protected against damage during cryopreservation within the hydrogel. Spermatogonial stem cells were isolated from the testes of Balb/c mice pups (6 days old), purified in laminin-coated dishes and CD90.1 microbeads, encapsulated in alginate hydrogel and then cryopreserved. After thawing, cell viability and Spermatogonial stem cell (SSC) colony diameter were evaluated. After RNA was isolated and cDNA was synthesised, the expression of stemness genes was considered using RT real-time PCR. Finally, spermatogonial stem cells labelled with BrdU were transplanted to busulfan azoospermic mouse models. Lin28a and Sall4 genes were significantly upregulated after cryopreservation in alginate hydrogel. However, cell viability was significantly decreased. The diameter of colonies consisting of spermatogonial stem cells freeze-thawed in alginate microbeads showed no significant difference with fresh spermatogonial stem cells and the control group. The injection of freeze-thawed spermatogonial stem cells encapsulated in alginate hydrogel resulted in spermatogenesis recovery. Alginate mimics the extracellular matrices (ECM) for spermatogonial stem cells; therefore, it can support stemness potential during the cell cryopreservation process and restart spermatogenesis after transplantation. © 2016 Blackwell Verlag GmbH.

Normal and cancer mammary stem cells evade interferon-induced constraint through the miR-199a-LCOR Axis

PubMed Central

Celià-Terrassa, Toni; Liu, Daniel; Choudhury, Abrar; Hang, Xiang; Wei, Yong; Zamalloa, Jose; Alfaro-Aco, Raymundo; Chakrabarti, Rumela; Jiang, Yi-Zhou; Koh, Bong Ihn; Smith, Heath; DeCoste, Christina; Li, Jun-Jing; Shao, Zhi-Ming; Kang, Yibin

2017-01-01

Tumor-initiating cells (TICs), or cancer stem cells (CSC), possess stem cell-like properties observed in normal adult tissue stem cells. Normal and cancerous stem cells may therefore share regulatory mechanisms for maintaining self-renewing capacity and resisting differentiation elicited by cell-intrinsic or microenvironmental cues. Here, we show that miR-199a promotes stem cell properties in mammary stem cells (MaSCs) and breast CSCs by directly repressing nuclear receptor corepressor LCOR, which primes interferon (IFN) responses. Elevated miR-199a expression in stem cell-enriched populations protects normal and malignant stem-like cells from differentiation and senescence induced by IFNs that are produced by epithelial and immune cells in the mammary gland. Importantly, the miR-199a-LCOR-IFN axis is activated in poorly differentiated ER− breast tumors, functionally promotes tumor initiation and metastasis, and is associated with poor clinical outcome. Our study therefore reveals a common mechanism shared by normal and malignant stem cells to protect them from suppressive immune cytokine signaling. PMID:28530657

The Role of Epithelial-Mesenchymal Transition in the Formation of Normal and Neoplastic Mammary Epithelial Stem Cells

DTIC Science & Technology

2011-09-01

separating stem cell and non- stem cell populations of normal and breast cancer cells and identified EMT transcription factors most likely involved in... stem cell biology. Preliminary results directly demonstrate that transient induction of EMT increases the number of mammary epithelial stem cells...EMT and entrance into a stem - cell state. The outcome of these experiments holds important implications for the mechanisms controlling the formation of