scholarly journals Functional Specificity of the Members of the Sos Family of Ras-GEF Activators: Novel Role of Sos2 in Control of Epidermal Stem Cell Homeostasis

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2152
Author(s):  
Fernando C. Baltanás ◽  
Cynthia Mucientes-Valdivieso ◽  
L. Francisco Lorenzo-Martín ◽  
Natalia Fernández-Parejo ◽  
Rósula García-Navas ◽  
...  
Keyword(s):  
Stem Cell ◽  
Layer Structure ◽  
3D Culture ◽  
Hair Follicles ◽  
Specific Cell ◽  
Epidermal Stem Cell ◽  
Primary Keratinocytes ◽  
Cell Homeostasis ◽  
Primary Mouse

Prior reports showed the critical requirement of Sos1 for epithelial carcinogenesis, but the specific functionalities of the homologous Sos1 and Sos2 GEFs in skin homeostasis and tumorigenesis remain unclear. Here, we characterize specific mechanistic roles played by Sos1 or Sos2 in primary mouse keratinocytes (a prevalent skin cell lineage) under different experimental conditions. Functional analyses of actively growing primary keratinocytes of relevant genotypes—WT, Sos1-KO, Sos2-KO, and Sos1/2-DKO—revealed a prevalent role of Sos1 regarding transcriptional regulation and control of RAS activation and mechanistic overlapping of Sos1 and Sos2 regarding cell proliferation and survival, with dominant contribution of Sos1 to the RAS-ERK axis and Sos2 to the RAS-PI3K/AKT axis. Sos1/2-DKO keratinocytes could not grow under 3D culture conditions, but single Sos1-KO and Sos2-KO keratinocytes were able to form pseudoepidermis structures that showed disorganized layer structure, reduced proliferation, and increased apoptosis in comparison with WT 3D cultures. Remarkably, analysis of the skin of both newborn and adult Sos2-KO mice uncovered a significant reduction of the population of stem cells located in hair follicles. These data confirm that Sos1 and Sos2 play specific, cell-autonomous functions in primary keratinocytes and reveal a novel, essential role of Sos2 in control of epidermal stem cell homeostasis.

scholarly journals Stem/Progenitor Cells, Atherosclerosis and Cardiovascular Regeneration

2010 ◽  
Vol 4 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Olena Dotsenko
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Current Knowledge ◽  
Specific Cell ◽  
Therapeutic Effects ◽  
Cell Trafficking ◽  
Chronic Coronary Artery Disease ◽  
Atherosclerosis Progression ◽  
Cell Based Therapy

Regenerative cell based therapy has potential to become effective adjuvant treatment for patients with atherosclerotic disease. Although data from animal studies support this notion, clinical studies undertaken in patients with acute and chronic coronary artery disease do not conclusively demonstrate benefits of such therapy. There are many questions on the stem cell translational roadmap. The basic mechanisms of stem cell-dependent tissue regeneration are not well understood. There is a debate regarding characterization of specific cell types conferring therapeutic effects. In particular, the role of endothelial progenitor cells as a specific reparative cell subtype is questioned, and the role of myeloid cell linage in fostering of vasculo- and angiogenesis is being increasingly appreciated. Intense discussions surround the place of stem/progenitor cells in atherosclerosis progression, plaque destabilization and vessel remodeling. This paper summarizes the current knowledge on the regenerative stem/progenitor cell definitions, mechanisms of stem cell trafficking, homing and their involvement in atherosclerosis progression.

scholarly journals The Role of p16INK4a Pathway in Human Epidermal Stem Cell Self-Renewal, Aging and Cancer

2017 ◽  
Vol 18 (7) ◽  
pp. 1591 ◽  
Author(s):  
Daniela D’Arcangelo ◽  
Lavinia Tinaburri ◽  
Elena Dellambra
Keyword(s):  
Stem Cell ◽  
Epidermal Stem Cell ◽  
Self Renewal

scholarly journals Role of Fanconi DNA repair pathway in neural stem cell homeostasis

Cell Cycle ◽  
2008 ◽  
Vol 7 (13) ◽  
pp. 1911-1915 ◽  
Author(s):  
Karine Sii-Felice ◽  
Vilma Barroca ◽  
Olivier Etienne ◽  
Lydia Riou ◽  
Françoise Hoffschir ◽  
...  
Keyword(s):  
Dna Repair ◽  
Stem Cell ◽  
Neural Stem Cell ◽  
Repair Pathway ◽  
Cell Homeostasis

The Emerging Role of Stem Cells in Regenerative Dentistry

2020 ◽  
Vol 20 (4) ◽  
pp. 259-268 ◽  
Author(s):  
Paolo Capparè ◽  
Giulia Tetè ◽  
Maria Teresa Sberna ◽  
Paola Panina-Bordignon
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Specific Cell ◽  
Cell Plasticity ◽  
Regenerative Dentistry ◽  
Cell Sources ◽  
Induced Pluripotent

Progress of modern dentistry is accelerating at a spectacular speed in the scientific, technological and clinical areas. Practical examples are the advancement in the digital field, which has guaranteed an average level of prosthetic practices for all patients, as well as other scientific developments, including research on stem cell biology. Given their plasticity, defined as the ability to differentiate into specific cell lineages with a capacity of almost unlimited self-renewal and release of trophic/immunomodulatory factors, stem cells have gained significant scientific and commercial interest in the last 15 years. Stem cells that can be isolated from various tissues of the oral cavity have emerged as attractive sources for bone and dental regeneration, mainly due to their ease of accessibility. This review will present the current understanding of emerging conceptual and technological issues of the use of stem cells to treat bone and dental loss defects. In particular, we will focus on the clinical application of stem cells, either directly isolated from oral sources or in vitro reprogrammed from somatic cells (induced pluripotent stem cells). Research aimed at further unraveling stem cell plasticity will allow to identify optimal stem cell sources and characteristics, to develop novel regenerative tools in dentistry.

scholarly journals Microstructured hydrogels to guide self-assembly and function of lung alveolospheres

2021 ◽  
Author(s):  
Claudia Loebel ◽  
Aaron I. Weiner ◽  
Jeremy B. Katzen ◽  
Michael P. Morley ◽  
Vikram Bala ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
3D Culture ◽  
Size Composition ◽  
Mouse Tissue ◽  
Alveolar Type ◽  
Primary Mouse ◽  
Defined Culture

AbstractEpithelial cell organoids have increased opportunities to probe questions on tissue development and disease in vitro and for therapeutic cell transplantation. Despite their potential, current protocols to grow these organoids almost exclusively depend on culture within three-dimensional (3D) Matrigel, which limits defined culture conditions, introduces animal components, and results in heterogenous organoids (i.e., shape, size, composition). Here, we describe a method that relies on polymeric hydrogel substrates for the generation and expansion of lung alveolar organoids (alveolospheres). Using synthetic hydrogels with defined chemical and physical properties, human induced pluripotent stem cell (iPSC)-derived alveolar type 2 cells (iAT2s) self-assemble into alveolospheres and propagate in Matrigel-free conditions. By engineering pre-defined microcavities within these hydrogels, the heterogeneity of alveolosphere size and structure was reduced when compared to 3D culture while maintaining alveolar type 2 cell fate of human iAT2 and primary mouse tissue-derived progenitor cells. This hydrogel system is a facile and accessible culture system for the culture of primary and iPSC-derived lung progenitors and the method could be expanded to the culture of other epithelial progenitor and stem cell aggregates.

Sa1464 - Role of BETA2 Spectrin and SMAD3 in Alcohol-Induced Liver Injury and Liver Stem Cell Homeostasis

2018 ◽  
Vol 154 (6) ◽  
pp. S-1122
Author(s):  
Shoujun Gu ◽  
Shuyun Rao ◽  
Sobia Zaidi ◽  
Kazufumi Ohshiro ◽  
Jian Chen ◽  
...  
Keyword(s):  
Stem Cell ◽  
Liver Injury ◽  
Cell Homeostasis

scholarly journals Nanoscale microenvironment engineering for expanding human hair follicle stem cell and revealing their plasticity

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Peng Chen ◽  
Feifei Zhang ◽  
Zhexiang Fan ◽  
Tianding Shen ◽  
Bingcheng Liu ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hair Follicle ◽  
Tissue Regeneration ◽  
Hair Follicles ◽  
Bmp Signaling ◽  
Signal Molecules ◽  
Layer By Layer ◽  
Cell Homeostasis ◽  
Excellent Research ◽  
Essential Components

Abstract Background Periodically regenerated hair follicles provide an excellent research model for studying tissue regeneration and stem cell homeostasis. Periodic activation and differentiation of hair follicle stem cells (HFSCs) fuel cyclical bouts of hair regeneration. HFSCs represent an excellent paradigm for studying tissue regeneration and somatic stem cell homeostasis. However, these crucial studies are hampered by the lack of a culture system able to stably expand human HFSCs and regulate their fate. Results Here, we use layer-by-layer (LbL) self-assembly with gelatin/alginate to construct a nanoscale biomimetic extracellular matrix (ECM) for an HFSC population. The LbL coating provides ECM and mechanical support for individual cells, which helps to maintain the CD200+α6+ HFSC population to a certain extent. Addition of key signal molecules (FGF-7 and VEGF-A) simulates the minimum essential components of the stem cell microenvironment, thereby effectively and stably expanding HFSCs and maintaining the CD200+α6+ HFSC population. Subsequently, BMP2 loaded to the nanocoated layer, as a slow-release signal molecule, activates BMP signaling to regulate HFSCs’ fate in order to obtain a purified CD200+α6+ HFSC population. Conclusion This system can minimize the microenvironment of HFSCs; thus, stably amplifying HFSCs and revealing their plasticity. Our study thus provides a new tool for studies of hair follicle reconstruction and stem cell homeostasis.

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