scholarly journals The Emerging Roles of JNK Signaling in Drosophila Stem Cell Homeostasis

2021 ◽  
Vol 22 (11) ◽  
pp. 5519
Author(s):  
Salvador C. Herrera ◽  
Erika A. Bach
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Stem Cell Biology ◽  
Self Renewal ◽  
Jnk Pathway ◽  
Jnk Signaling ◽  
Kinase Cascade ◽  
Induced Apoptosis ◽  
Drosophila Models

The Jun N-terminal kinase (JNK) pathway is an evolutionary conserved kinase cascade best known for its roles during stress-induced apoptosis and tumor progression. Recent findings, however, have identified new roles for this pleiotropic pathway in stem cells during regenerative responses and in cellular plasticity. Here, we provide an overview of recent findings about the new roles of JNK signaling in stem cell biology using two well-established Drosophila models: the testis and the intestine. We highlight the pathway’s roles in processes such as proliferation, death, self-renewal and reprogramming, and discuss the known parallels between flies and mammals.

scholarly journals Advances and Applications in Stem Cell Biology

2012 ◽  
Vol 46 (2) ◽  
pp. 75-80
Author(s):  
Shamoli Bhattacharyya
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Adult Stem Cells ◽  
Great Promise ◽  
Stem Cell Biology ◽  
Self Renewal ◽  
Main Challenge ◽  
Basic Biology

ABSTRACT Mesenchymal stem cells have shown great promise as the source of adult stem cells for regenerative medicine. Present research efforts are directed at isolating these cells from various sources, growing them in vitro and maintaining their pluripotency as well as capacity for self renewal. It is crucial to identify the regulatory molecules which directly or indirectly control the proliferative status or influence the niche microenvironment. The main challenge is to understand the basic biology of the stem cells and manipulate them for further therapeutic applications. Considering their malignant potential, stem cells may be a double edged sword. While the benefits of these cells need to be harnessed judiciously, a significant amount of research is required before embarking on widespread use of this tool for the benefit of humanity. How to cite this article Bhattacharyya S. Advances and Applications in Stem Cell Biology. J Postgrad Med Edu Res 2012;46(2):75-80.

Gastrointestinal Stem Cells. III. Emergent themes of liver stem cell biology: niche, quiescence, self-renewal, and plasticity

2006 ◽  
Vol 290 (2) ◽  
pp. G189-G193 ◽  
Author(s):  
Neil D. Theise
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Cell Biology ◽  
Stem Cell Niche ◽  
Progenitor Cell ◽  
Stem Cell Biology ◽  
Cell Plasticity ◽  
Self Renewal ◽  
Cell Niche

This essay will address areas of liver stem/progenitor cell studies in which consensus has emerged and in which controversy still prevails over consensus, but it will also highlight important themes that inevitably should be a focus of liver stem/progenitor cell investigations in coming years. Thus concepts regarding cell plasticity, the existence of a physiological/anatomic stem cell niche, and whether intrahepatic liver stem/progenitor cells comprise true stem cells or progenitor cells (or both) will be approached in some detail.

scholarly journals TSH-induced gene expression involves regulation of self-renewal and differentiation-related genes in human bone marrow-derived mesenchymal stem cells

2011 ◽  
Vol 212 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Emin Umit Bagriacik ◽  
Melek Yaman ◽  
Rauf Haznedar ◽  
Gulsan Sucak ◽  
Tuncay Delibasi
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Stem Cell Biology ◽  
Self Renewal ◽  
Regulatory Pathways

Bone marrow-derived mesenchymal stem cells are pluripotent cells that are capable of differentiating into a variety of cell types including neuronal cells, osteoblasts, chondrocytes, myocytes, and adipocytes. Despite recent advances in stem cell biology, neuroendocrine relations, particularly TSH interactions remain elusive. In this study, we investigated expression and biological consequence of TSH receptor (TSHR) interactions in mesenchymal stem cells of cultured human bone marrow. To the best of our knowledge, we demonstrated for the first time that human bone marrow-derived mesenchymal stem cells expressed a functional thyrotropin receptor that was capable of transducing signals through cAMP. We extended this study to explore possible pathways that could be associated directly or indirectly with the TSHR function in mesenchymal stem cells. Expression of 80 genes was studied by real-time PCR array profiles. Our investigation indicated involvements of interactions between TSH and its receptor in novel regulatory pathways, which could be the important mediators of self-renewal, maintenance, development, and differentiation in bone marrow-derived mesenchymal stem cells. TSH enhanced differentiation to the chondrogenic cell lineage; however, further work is required to determine whether osteoblastic differentiation is also promoted. Our results presented in this study have opened an era of regulatory events associated with novel neuroendocrine interactions of hypothalamic–pituitary axis in mesenchymal stem cell biology and differentiation.

scholarly journals Autophagy in Stem Cell Biology: A Perspective on Stem Cell Self-Renewal and Differentiation

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xihang Chen ◽  
Yunfan He ◽  
Feng Lu
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Cell Biology ◽  
Viral Infections ◽  
Stem Cell Biology ◽  
Self Renewal ◽  
Cellular Homeostasis ◽  
Intracellular Degradation ◽  
Induced Pluripotent

Autophagy is a highly conserved cellular process that degrades modified, surplus, or harmful cytoplasmic components by sequestering them in autophagosomes which then fuses with the lysosome for degradation. As a major intracellular degradation and recycling pathway, autophagy is crucial for maintaining cellular homeostasis, as well as for remodeling during normal development. Impairment of this process has been implicated in various diseases, in the pathogenic response to bacterial and viral infections, and in aging. Pluripotent stem cells, with their ability to self-replicate and to give rise to any specialized cell type, are very valuable resources for cell-based medical therapies and open a number of promising avenues for studying human development and disease. It has been suggested that autophagy is vital for the maintenance of cellular homeostasis in stem cells, and subsequently more in-depth knowledge about the regulation of autophagy in stem cell biology has been acquired recently. In this review, we describe the most significant advances in the understanding of autophagy regulation in hematopoietic and mesenchymal stem cells, as well as in induced pluripotent stem cells. In particular, we highlight the roles of various autophagy activities in the regulation of self-renewal and differentiation of these stem cells.

Establishment of human OCT4 as a putative HSP90 client protein : a case for HSP90 chaperoning pluripotency

2015 ◽  
Author(s):  
◽  
Jason Neville Sterrenberg
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Stem Cell ◽  
Cell Biology ◽  
Therapeutic Potential ◽  
Stem Cell Biology ◽  
Client Protein ◽  
Hsp90 Inhibition ◽  
Regulated Gene Expression ◽  
Hsp90 Client Protein

The therapeutic potential of stem cells is already being harnessed in clinical trails. Of even greater therapeutic potential has been the discovery of mechanisms to reprogram differentiated cells into a pluripotent stem cell-like state known as induced pluripotent stem cells (iPSCs). Stem cell nature is governed and maintained by a hierarchy of transcription factors, the apex of which is OCT4. Although much research has elucidated the transcriptional regulation of OCT4, OCT4 regulated gene expression profiles and OCT4 transcriptional activation mechanisms in both stem cell biology and cellular reprogramming to iPSCs, the fundamental biochemistry surrounding the OCT4 transcription factor remains largely unknown. In order to analyze the biochemical relationship between HSP90 and human OCT4 we developed an exogenous active human OCT4 expression model with human OCT4 under transcriptional control of a constitutive promoter. We identified the direct interaction between HSP90 and human OCT4 despite the fact that the proteins predominantly display differential subcellular localizations. We show that HSP90 inhibition resulted in degradation of human OCT4 via the ubiquitin proteasome degradation pathway. As human OCT4 and HSP90 did not interact in the nucleus, we suggest that HSP90 functions in the cytoplasmic stabilization of human OCT4. Our analysis suggests HSP90 inhibition inhibits the transcriptional activity of human OCT4 dimers without affecting monomeric OCT4 activity. Additionally our data suggests that the HSP90 and human OCT4 complex is modulated by phosphorylation events either promoting or abrogating the interaction between HSP90 and human OCT4. Our data suggest that human OCT4 displays the characteristics describing HSP90 client proteins, therefore we identify human OCT4 as a putative HSP90 client protein. The regulation of the transcription factor OCT4 by HSP90 provides fundamental insights into the complex biochemistry of stem cell biology. This may also be suggestive that HSP90 not only regulates stem cell biology by maintaining routine cellular homeostasis but additionally through the direct regulation of pluripotency factors.

scholarly journals Toward Personalized Cell Therapies by Using Stem Cells: Seven Relevant Topics for Safety and Success in Stem Cell Therapy

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Fernando de Sá Silva ◽  
Paula Nascimento Almeida ◽  
João Vitor Paes Rettore ◽  
Claudinéia Pereira Maranduba ◽  
Camila Maurmann de Souza ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Therapy ◽  
Cell Biology ◽  
Stem Cell Biology ◽  
Controversial Issues ◽  
Immunosuppressive Activity ◽  
Cell Therapies ◽  
Tumorigenic Potential ◽  
Wide Range

Stem cells, both embryonic and adult, due to the potential for application in tissue regeneration have been the target of interest to the world scientific community. In fact, stem cells can be considered revolutionary in the field of medicine, especially in the treatment of a wide range of human diseases. However, caution is needed in the clinical application of such cells and this is an issue that demands more studies. This paper will discuss some controversial issues of importance for achieving cell therapy safety and success. Particularly, the following aspects of stem cell biology will be presented: methods for stem cells culture, teratogenic or tumorigenic potential, cellular dose, proliferation, senescence, karyotyping, and immunosuppressive activity.

Realistic Prospects for Stem Cell Therapeutics

Hematology ◽  
2003 ◽  
Vol 2003 (1) ◽  
pp. 398-418 ◽  
Author(s):  
George Q. Daley ◽  
Margaret A. Goodell ◽  
Evan Y. Snyder
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Regenerative Medicine ◽  
Cell Biology ◽  
Adult Stem Cells ◽  
Stem Cell Biology ◽  
Cell Therapies ◽  
The Media ◽  
New Treatment ◽  
Definition Of

Abstract Studies of the regenerating hematopoietic system have led to the definition of many of the fundamental principles of stem cell biology. Therapies based on a range of tissue stem cells have been widely touted as a new treatment modality, presaging an emerging new specialty called regenerative medicine that promises to harness stem cells from embryonic and somatic sources to provide replacement cell therapies for genetic, malignant, and degenerative conditions. Insights borne from stem cell biology also portend development of protein and small molecule therapeutics that act on endogenous stem cells to promote repair and regeneration. Much of the newfound enthusiasm for regenerative medicine stems from the hope that advances in the laboratory will be followed soon thereafter by breakthrough treatments in the clinic. But how does one sort through the hype to judge the true promise? Are stem cell biologists and the media building expectations that cannot be met? Which diseases can be treated, and when can we expect success? In this review, we outline the realms of investigation that are capturing the most attention, and consider the current state of scientific understanding and controversy regarding the properties of embryonic and somatic (adult) stem cells. Our objective is to provide a framework for appreciating the promise while at the same time understanding the challenges behind translating fundamental stem cell biology into novel clinical therapies.

scholarly journals Extracellular Vesicles: Evolving Factors in Stem Cell Biology

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Muhammad Nawaz ◽  
Farah Fatima ◽  
Krishna C. Vallabhaneni ◽  
Patrice Penfornis ◽  
Hadi Valadi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Tumor Microenvironment ◽  
Extracellular Vesicles ◽  
Cell Biology ◽  
Trophic Factors ◽  
Stem Cell Biology ◽  
Cell Fates ◽  
Bidirectional Communication

Stem cells are proposed to continuously secrete trophic factors that potentially serve as mediators of autocrine and paracrine activities, associated with reprogramming of the tumor microenvironment, tissue regeneration, and repair. Hitherto, significant efforts have been made to understand the level of underlying paracrine activities influenced by stem cell secreted trophic factors, as little is known about these interactions. Recent findings, however, elucidate this role by reporting the effects of stem cell derived extracellular vesicles (EVs) that mimic the phenotypes of the cells from which they originate. Exchange of genetic information utilizing persistent bidirectional communication mediated by stem cell-EVs could regulate stemness, self-renewal, and differentiation in stem cells and their subpopulations. This review therefore discusses stem cell-EVs as evolving communication factors in stem cell biology, focusing on how they regulate cell fates by inducing persistent and prolonged genetic reprogramming of resident cells in a paracrine fashion. In addition, we address the role of stem cell-secreted vesicles in shaping the tumor microenvironment and immunomodulation and in their ability to stimulate endogenous repair processes during tissue damage. Collectively, these functions ensure an enormous potential for future therapies.

Leukemic CD34+CD38- Cells Display Conserved Differential Expression of Many ATP Binding-Cassette Transporter Genes.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1380-1380
Author(s):  
Marc H.G.P. Raaijmakers ◽  
Elke P.L.M. de Grouw ◽  
Louis T.F. van de Locht ◽  
Bert A. van der Reijden ◽  
Theo J.M. de Witte ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Stem Cell ◽  
Abc Transporters ◽  
Cell Biology ◽  
Cell Fraction ◽  
Atp Binding ◽  
Stem Cell Biology ◽  
Hematopoietic Stem ◽  
Atp Binding Cassette

Abstract In most cases of acute myeloid leukemia (AML) CD34+CD38− cells are considered to be stem cells, responsible for the maintenance and relapse of AML. ATP binding cassette transporters function in the extrusion of xenobiotics and chemotherapeutical compounds, and may be involved in therapy resistance. Elucidation of mechanisms conferring drug resistance to CD34+CD38− cells is essential to provide novel targets for stem cell eradication in AML. We studied gene expression of all 45 transmembrane ABC transporters (the complete ABCA, B, C, D and G family) in human hematopoietic CD34+CD38− cells and more committed CD34+CD38+ progenitor cells, from healthy donors and patients with non-hematological diseases (N=11) and AML patients (N=11). Gene expression was assessed using a novel real-time RT-PCR approach with micro fluidic cards. In normal CD34+CD38− cells 36 ABC transporters were expressed, 22 of these displayed significant higher expression in the CD34+CD38− cell fraction compared to the CD34+CD38+ cell fraction. In addition to the known stem cell transporters (ABCB1, ABCC1 and ABCG2) these differential expressed genes included many members not previously associated with stem cell biology. In AML the ABC transporter expression profile was largely conserved, including expression of all 13 known drug transporters. These data suggest an important role for many ABC transporters in hematopoietic stem cell biology. In addition, the preferential expression of a high number of drug transport related transporters predicts that broad spectrum inhibition of ABC transporters is likely to be required for CD34+38− stem cell eradication in AML. This approach will, apart from affecting the leukemic stem cells, equally affect the normal stem cells.

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