scholarly journals Basic Research Advances on Pituitary Stem Cell Function and Regulation

2018 ◽  
Vol 107 (2) ◽  
pp. 196-203 ◽  
Author(s):  
John P. Russell ◽  
Emily J. Lodge ◽  
Cynthia L. Andoniadou
Keyword(s):  
Stem Cells ◽  
Pituitary Gland ◽  
Cell Fate ◽  
Cell Function ◽  
Basic Research ◽  
Cell Fate Decisions ◽  
Disease States ◽  
Differentiated Cells ◽  
Physiological Processes ◽  
Hypothalamic Influence

As a central regulator of major physiological processes, the pituitary gland is a highly dynamic organ, capable of responding to hormonal demand and hypothalamic influence, through adapting secretion as well as remodelling cell numbers among its seven populations of differentiated cells. Stem cells of the pituitary have been shown to actively generate new cells during postnatal development but remain mostly quiescent during adulthood, where they persist as a long-lived population. Despite a significant body of research characterising attributes of anterior pituitary stem cells, the regulation of this population is poorly understood. A better grasp on the signalling mechanisms influencing stem proliferation and cell fate decisions can impact on our future treatments of pituitary gland disorders such as organ failure and pituitary tumours, which can disrupt endocrine homeostasis with life-long consequences. This minireview addresses the current methodologies aiming to understand better the attributes of pituitary stem cells and the normal regulation of this population in the organ, and discusses putative future avenues to manipulate pituitary stem cells during disease states or regenerative medicine approaches.

scholarly journals Heterochromatin protein 1 promotes self-renewal and triggers regenerative proliferation in adult stem cells

2013 ◽  
Vol 201 (3) ◽  
pp. 409-425 ◽  
Author(s):  
An Zeng ◽  
Yong-Qin Li ◽  
Chen Wang ◽  
Xiao-Shuai Han ◽  
Ge Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Adult Stem Cells ◽  
Cell Function ◽  
Heterochromatin Protein 1 ◽  
Self Renewal ◽  
Blastema Formation ◽  
Cell Fate Decisions ◽  
Chromatin Regulators

Adult stem cells (ASCs) capable of self-renewal and differentiation confer the potential of tissues to regenerate damaged parts. Epigenetic regulation is essential for driving cell fate decisions by rapidly and reversibly modulating gene expression programs. However, it remains unclear how epigenetic factors elicit ASC-driven regeneration. In this paper, we report that an RNA interference screen against 205 chromatin regulators identified 12 proteins essential for ASC function and regeneration in planarians. Surprisingly, the HP1-like protein SMED–HP1-1 (HP1-1) specifically marked self-renewing, pluripotent ASCs, and HP1-1 depletion abrogated self-renewal and promoted differentiation. Upon injury, HP1-1 expression increased and elicited increased ASC expression of Mcm5 through functional association with the FACT (facilitates chromatin transcription) complex, which consequently triggered proliferation of ASCs and initiated blastema formation. Our observations uncover an epigenetic network underlying ASC regulation in planarians and reveal that an HP1 protein is a key chromatin factor controlling stem cell function. These results provide important insights into how epigenetic mechanisms orchestrate stem cell responses during tissue regeneration.

scholarly journals Epigenetic Erosion in Adult Stem Cells: Drivers and Passengers of Aging

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 237 ◽  
Author(s):  
Christian Kosan ◽  
Florian Heidel ◽  
Maren Godmann ◽  
Holger Bierhoff
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Adult Stem Cells ◽  
Healthy Aging ◽  
Cell Function ◽  
Functional Decline ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions

In complex organisms, stem cells are key for tissue maintenance and regeneration. Adult stem cells replenish continuously dividing tissues of the epithelial and connective types, whereas in non-growing muscle and nervous tissues, they are mainly activated upon injury or stress. In addition to replacing deteriorated cells, adult stem cells have to prevent their exhaustion by self-renewal. There is mounting evidence that both differentiation and self-renewal are impaired upon aging, leading to tissue degeneration and functional decline. Understanding the molecular pathways that become deregulate in old stem cells is crucial to counteract aging-associated tissue impairment. In this review, we focus on the epigenetic mechanisms governing the transition between quiescent and active states, as well as the decision between self-renewal and differentiation in three different stem cell types, i.e., spermatogonial stem cells, hematopoietic stem cells, and muscle stem cells. We discuss the epigenetic events that channel stem cell fate decisions, how this epigenetic regulation is altered with age, and how this can lead to tissue dysfunction and disease. Finally, we provide short prospects of strategies to preserve stem cell function and thus promote healthy aging.

scholarly journals Metabolic Control of m6A RNA Modification

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 80
Author(s):  
Joohwan Kim ◽  
Gina Lee
Keyword(s):  
Cell Fate ◽  
Metabolic Pathways ◽  
Epigenetic Modification ◽  
Genetic Material ◽  
Rna Modification ◽  
Cell Fate Decisions ◽  
Disease States ◽  
Evolutionarily Conserved ◽  
Regulate Cell Growth ◽  
Epigenetic Processes

Nutrients and metabolic pathways regulate cell growth and cell fate decisions via epigenetic modification of DNA and histones. Another key genetic material, RNA, also contains diverse chemical modifications. Among these, N6-methyladenosine (m6A) is the most prevalent and evolutionarily conserved RNA modification. It functions in various aspects of developmental and disease states, by controlling RNA metabolism, such as stability and translation. Similar to other epigenetic processes, m6A modification is regulated by specific enzymes, including writers (methyltransferases), erasers (demethylases), and readers (m6A-binding proteins). As this is a reversible enzymatic process, metabolites can directly influence the flux of this reaction by serving as substrates and/or allosteric regulators. In this review, we will discuss recent understanding of the regulation of m6A RNA modification by metabolites, nutrients, and cellular metabolic pathways.

scholarly journals Regulated Fluctuations in Nanog Expression Mediate Cell Fate Decisions in Embryonic Stem Cells

PLoS Biology ◽  
2009 ◽  
Vol 7 (7) ◽  
pp. e1000149 ◽  
Author(s):  
Tibor Kalmar ◽  
Chea Lim ◽  
Penelope Hayward ◽  
Silvia Muñoz-Descalzo ◽  
Jennifer Nichols ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Cell Fate ◽  
Embryonic Stem ◽  
Cell Fate Decisions ◽  
Nanog Expression ◽  
Mediate Cell

scholarly journals Control of cellular responses to mechanical cues through YAP/TAZ regulation

2019 ◽  
Vol 294 (46) ◽  
pp. 17693-17706 ◽  
Author(s):  
Ishani Dasgupta ◽  
Dannel McCollum
Keyword(s):  
Cell Fate ◽  
Wound Repair ◽  
Hippo Pathway ◽  
Three Dimensional ◽  
Focal Adhesions ◽  
Mechanical Stimuli ◽  
Cell Contractility ◽  
Cell Fate Decisions ◽  
Disease States ◽  
The Hippo Pathway

To perceive their three-dimensional environment, cells and tissues must be able to sense and interpret various physical forces like shear, tensile, and compression stress. These forces can be generated both internally and externally in response to physical properties, like substrate stiffness, cell contractility, and forces generated by adjacent cells. Mechanical cues have important roles in cell fate decisions regarding proliferation, survival, and differentiation as well as the processes of tissue regeneration and wound repair. Aberrant remodeling of the extracellular space and/or defects in properly responding to mechanical cues likely contributes to various disease states, such as fibrosis, muscle diseases, and cancer. Mechanotransduction involves the sensing and translation of mechanical forces into biochemical signals, like activation of specific genes and signaling cascades that enable cells to adapt to their physical environment. The signaling pathways involved in mechanical signaling are highly complex, but numerous studies have highlighted a central role for the Hippo pathway and other signaling networks in regulating the YAP and TAZ (YAP/TAZ) proteins to mediate the effects of mechanical stimuli on cellular behavior. How mechanical cues control YAP/TAZ has been poorly understood. However, rapid progress in the last few years is beginning to reveal a surprisingly diverse set of pathways for controlling YAP/TAZ. In this review, we will focus on how mechanical perturbations are sensed through changes in the actin cytoskeleton and mechanosensors at focal adhesions, adherens junctions, and the nuclear envelope to regulate YAP/TAZ.

scholarly journals Do Neural Stem Cells Have a Choice? Heterogenic Outcome of Cell Fate Acquisition in Different Injury Models

2019 ◽  
Vol 20 (2) ◽  
pp. 455 ◽  
Author(s):  
Felix Beyer ◽  
Iria Samper Agrelo ◽  
Patrick Küry
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Cell Fate ◽  
Ex Vivo ◽  
Meta Analysis ◽  
Cell Types ◽  
Adult Brain ◽  
Repair Capacity ◽  
Cell Fate Decisions ◽  
Limiting Parameters

The adult mammalian central nervous system (CNS) is generally considered as repair restricted organ with limited capacities to regenerate lost cells and to successfully integrate them into damaged nerve tracts. Despite the presence of endogenous immature cell types that can be activated upon injury or in disease cell replacement generally remains insufficient, undirected, or lost cell types are not properly generated. This limitation also accounts for the myelin repair capacity that still constitutes the default regenerative activity at least in inflammatory demyelinating conditions. Ever since the discovery of endogenous neural stem cells (NSCs) residing within specific niches of the adult brain, as well as the description of procedures to either isolate and propagate or artificially induce NSCs from various origins ex vivo, the field has been rejuvenated. Various sources of NSCs have been investigated and applied in current neuropathological paradigms aiming at the replacement of lost cells and the restoration of functionality based on successful integration. Whereas directing and supporting stem cells residing in brain niches constitutes one possible approach many investigations addressed their potential upon transplantation. Given the heterogeneity of these studies related to the nature of grafted cells, the local CNS environment, and applied implantation procedures we here set out to review and compare their applied protocols in order to evaluate rate-limiting parameters. Based on our compilation, we conclude that in healthy CNS tissue region specific cues dominate cell fate decisions. However, although increasing evidence points to the capacity of transplanted NSCs to reflect the regenerative need of an injury environment, a still heterogenic picture emerges when analyzing transplantation outcomes in injury or disease models. These are likely due to methodological differences despite preserved injury environments. Based on this meta-analysis, we suggest future NSC transplantation experiments to be conducted in a more comparable way to previous studies and that subsequent analyses must emphasize regional heterogeneity such as accounting for differences in gray versus white matter.

scholarly journals Runx1 downregulates stem cell and megakaryocytic transcription programs that support niche interactions

Blood ◽  
2016 ◽  
Vol 127 (26) ◽  
pp. 3369-3381 ◽  
Author(s):  
Kira Behrens ◽  
Ioanna Triviai ◽  
Maike Schwieger ◽  
Nilgün Tekin ◽  
Malik Alawi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Cell Adhesion ◽  
Cell Fate ◽  
Bone Marrow Niche ◽  
Cell Fate Decisions ◽  
Multipotent Progenitors ◽  
Key Points

Key Points Runx1 is a key determinant of megakaryocyte cell-fate decisions in multipotent progenitors. Runx1 downregulates cell-adhesion factors that promote residency of stem cells and megakaryocytes in their bone marrow niche.

Abstract 3451: Interactions between N-myc and Sox9 promote medulloblastoma and determine cell fate decisions in cerebellar neural stem cells

2011 ◽  
Author(s):  
Fredrik J. Swartling ◽  
Anders I. Persson ◽  
Jasmine Lau ◽  
Paul A. Northcott ◽  
Matthew R. Grimmer ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Cell Fate ◽  
Cell Fate Decisions

scholarly journals The Proliferation and Differentiation of Adipose-Derived Stem Cells in Neovascularization and Angiogenesis

2020 ◽  
Vol 21 (11) ◽  
pp. 3790
Author(s):  
Greg Hutchings ◽  
Krzysztof Janowicz ◽  
Lisa Moncrieff ◽  
Claudia Dompe ◽  
Ewa Strauss ◽  
...  
Keyword(s):  
Stem Cells ◽  
Adipose Tissue ◽  
Blood Vessel ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Paracrine Factors ◽  
Differentiated Cells ◽  
Heterogenous Population ◽  
Vessel Networks ◽  
Differentiation And Proliferation

Neovascularization and angiogenesis are vital processes in the repair of damaged tissue, creating new blood vessel networks and increasing oxygen and nutrient supply for regeneration. The importance of Adipose-derived Mesenchymal Stem Cells (ASCs) contained in the adipose tissue surrounding blood vessel networks to these processes remains unknown and the exact mechanisms responsible for directing adipogenic cell fate remain to be discovered. As adipose tissue contains a heterogenous population of partially differentiated cells of adipocyte lineage; tissue repair, angiogenesis and neovascularization may be closely linked to the function of ASCs in a complex relationship. This review aims to investigate the link between ASCs and angiogenesis/neovascularization, with references to current studies. The molecular mechanisms of these processes, as well as ASC differentiation and proliferation are described in detail. ASCs may differentiate into endothelial cells during neovascularization; however, recent clinical trials have suggested that ASCs may also stimulate angiogenesis and neovascularization indirectly through the release of paracrine factors.

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