scholarly journals Hydra, a model system for deciphering the mechanisms of aging and resistance to aging

2017 ◽  
Author(s):  
Quentin Schenkelaars ◽  
Szymon Tomczyk ◽  
Yvan Wenger ◽  
Kazadi Ekundayo ◽  
Victor Girard ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Adult Stem Cell ◽  
Distinct Species ◽  
Model System ◽  
Epithelial Stem Cells ◽  
Muscular System ◽  
Autophagy Flux ◽  
Self Renewal ◽  
Stem Cell Populations

ABSTRACTThe freshwater cnidarian polyp named Hydra, which can be mass-cultured in the laboratory, is characterized by a highly dynamic homeostasis with a continuous self-renewal of its three adult stem cell populations, the epithelial stem cells from the epidermis, the epithelial stem cells from the gastrodermis, and the multipotent interstitial stem cells, which provide cells of the nervous system, gland cells and germ cells. Two unusual features characterize these stem cells that cannot replace each other, they all avoid G1 to pause in G2, and the two epithelial populations are concomitantly multifunctional and stem cells. H. vulgaris that does not show any signs of aging over the years, resists to weeks of starvation and adapts to the loss of neurogenesis, providing a unique model system to study the resistance to aging. By contrast some strains of a distinct species named H. oligactis undergo a rapid aging process when undergoing gametogenesis or when placed in stress conditions. The aging phenotype is characterized by the rapid loss of somatic interstitial stem cells, the progressive reduction in epithelial stem cell self-renewal, the loss of regeneration, the disorganization of the neuro-muscular system, the loss of the feeding behavior, and the death of all animals within about three months. We review here the possible mechanisms that help H. vulgaris to sustain stem cell self-renewal and thus bypass aging processes. For this, FoxO seems to act as a pleiotropic actor, regulating stem cell proliferation, stress response and apoptosis. In H. oligactis, the regulation of the autophagy flux differs between aging-sensitive and aging-resistant animals, pointing to a key role for proteostasis in the maintenance of a large pool of active and plastic epithelial stem cells.

scholarly journals Strategic Tools in Regenerative and Translational Dentistry

2019 ◽  
Vol 20 (8) ◽  
pp. 1879 ◽  
Author(s):  
Marco Tatullo ◽  
Bruna Codispoti ◽  
Francesco Paduano ◽  
Manuel Nuzzolese ◽  
Irina Makeeva
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
State Of The Art ◽  
Adult Stem Cell ◽  
Point Of View ◽  
Local Inflammation ◽  
Differentiation Potential ◽  
Clear Point ◽  
Regenerative Ability ◽  
Stem Cell Populations

Human oral-derived stem cells can be easily obtained from several oral tissues, such as dental pulp, periodontal ligament, from gingiva, or periapical cysts. Due to their differentiation potential, oral-derived mesenchymal stem cells are promising for tissue engineering and regenerative medicine. The regenerative ability showed by some oral tissues strongly depends on their sleeping adult stem cell populations that are able to repair small defects and to manage local inflammation. To date, researchers are working on effective and efficient methods to ensure safe and predictable protocols to translate stem cell research into human models. In the last decades, the challenge has been to finally use oral-derived stem cells together with biomaterials or scaffold-free techniques, to obtain strategic tools for regenerative and translational dentistry. This paper aims to give a clear point of view on state of the art developments, with some exciting insights into future strategies.

scholarly journals Integrins control the positioning and proliferation of follicle stem cells in the Drosophila ovary

2008 ◽  
Vol 182 (4) ◽  
pp. 801-815 ◽  
Author(s):  
Alana M. O'Reilly ◽  
Hsiu-Hsiang Lee ◽  
Michael A. Simon
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Adult Stem Cells ◽  
Cell Communication ◽  
Self Renewal ◽  
Ovarian Stem Cells ◽  
Stem Cell Populations ◽  
Integrin Ligand ◽  
Follicle Stem Cells ◽  
Drosophila Ovary

Adult stem cells are maintained in specialized microenvironments called niches, which promote self-renewal and prevent differentiation. In this study, we show that follicle stem cells (FSCs) in the Drosophila melanogaster ovary rely on cues that are distinct from those of other ovarian stem cells to establish and maintain their unique niche. We demonstrate that integrins anchor FSCs to the basal lamina, enabling FSCs to maintain their characteristic morphology and position. Integrin-mediated FSC anchoring is also essential for proper development of differentiating prefollicle cells that arise from asymmetrical FSC divisions. Our results support a model in which FSCs contribute to the formation and maintenance of their own niche by producing the integrin ligand, laminin A (LanA). Together, LanA and integrins control FSC proliferation rates, a role that is separable from their function in FSC anchoring. Importantly, LanA-integrin function is not required to maintain other ovarian stem cell populations, demonstrating that distinct pathways regulate niche–stem cell communication within the same organ.

Mesenchymal stem cells from the outer ear: a novel adult stem cell model system for the study of adipogenesis

2005 ◽  
Vol 19 (9) ◽  
pp. 1205-1207 ◽  
Author(s):  
Jong‐Seop Rim ◽  
Randall L. Mynatt ◽  
Barbara Gawronska‐Kozak
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Model ◽  
Adult Stem Cell ◽  
Model System ◽  
Stem Cell Model ◽  
Cell Model System

scholarly journals Deficient autophagy drives aging in Hydra

2017 ◽  
Author(s):  
Szymon Tomczyk ◽  
Quentin Schenkelaars ◽  
Nenad Suknovic ◽  
Yvan Wenger ◽  
Kazadi Ekundayo ◽  
...  
Keyword(s):  
Stem Cell ◽  
Aging Effect ◽  
Proteasome Inhibition ◽  
Cell Loss ◽  
Cell Renewal ◽  
Epithelial Stem Cells ◽  
Autophagy Flux ◽  
Stem Cell Renewal ◽  
Negligible Senescence ◽  
Stem Cell Populations

AbstractHydra exhibits a negligible senescence as its epithelial and interstitial stem cell populations continuously divide. Here we identified two H. oligactis strains that respond differently to interstitial stem cell loss. Cold-resistant (Ho_CR) animals adapt and remain healthy while cold-sensitive (Ho_CS) ones die within three months, after their epithelial stem cells lose their selfrenewal potential. In Ho_CS but not in Ho_CR animals, the autophagy flux is deficient, characterized by a low induction upon starvation, proteasome inhibition or Rapamycin treatment, and a constitutively repressed Ulk activity. In the non-aging Hydra vulgaris, WIPI2 silencing suffices to induce aging. Rapamycin can delay aging by sustaining epithelial self-renewal and regeneration, although without enhancing the autophagy flux. Instead Rapamycin promotes engulfment in epithelial cells where p62/SQSTM1-positive phagocytic vacuoles accumulate. This study uncovers the importance of autophagy in the longevity of early-branched eumetazoans by maintaining stem cell renewal, and a novel anti-aging effect of Rapamycin via phagocytosis.

scholarly journals Stem Cell Niche Microenvironment: Review

2021 ◽  
Vol 8 (8) ◽  
pp. 108
Author(s):  
Mohamed Abdul-Al ◽  
George Kumi Kyeremeh ◽  
Morvarid Saeinasab ◽  
Saeed Heidari Keshel ◽  
Farshid Sefat
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Corneal Epithelium ◽  
Stem Cell Niche ◽  
Epithelial Stem Cells ◽  
Self Renewal ◽  
Human Corneal Epithelium ◽  
Limbal Epithelial Stem Cells ◽  
Cell Niche

The cornea comprises a pool of self-regenerating epithelial cells that are crucial to preserving clarity and visibility. Limbal epithelial stem cells (LESCs), which live in a specialized stem cell niche (SCN), are crucial for the survival of the human corneal epithelium. They live at the bottom of the limbal crypts, in a physically enclosed microenvironment with a number of neighboring niche cells. Scientists also simplified features of these diverse microenvironments for more analysis in situ by designing and recreating features of different SCNs. Recent methods for regenerating the corneal epithelium after serious trauma, including burns and allergic assaults, focus mainly on regenerating the LESCs. Mesenchymal stem cells, which can transform into self-renewing and skeletal tissues, hold immense interest for tissue engineering and innovative medicinal exploration. This review summarizes all types of LESCs, identity and location of the human epithelial stem cells (HESCs), reconstruction of LSCN and artificial stem cells for self-renewal.

scholarly journals The impact of housing conditions on porcine adult stem cell populations differ between adipose tissue and skeletal muscle

2021 ◽  
Author(s):  
Audrey QUEMENER ◽  
Frederic DESSAUGE ◽  
Marie-Helene PERRUCHOT ◽  
Nathalie LE FLOC'H ◽  
Isabelle LOUVEAU
Keyword(s):  
Skeletal Muscle ◽  
Stem Cells ◽  
Adipose Tissue ◽  
Stem Cell ◽  
Adult Stem Cells ◽  
Adult Stem Cell ◽  
Cell Populations ◽  
Housing Conditions ◽  
Stem Cell Populations ◽  
The Impact

Background: In pigs, the ratio between lean mass and fat mass determines production efficiency and is strongly influenced by the number and size of cells in tissues. During growth, the increase in the number of cells results from the recruitment of different populations of multipotent adult stem cells residing in the tissues. We hypothesized that the impact of a hygiene challenge on the proportions of adult stem cells in adipose tissue and skeletal muscle may differ between pigs with different residual feed intake (RFI), a measure of feed efficiency. Methods: At the age of 11 weeks, Large White pigs from two lines divergently selected for low and high RFI were housed in two contrasting hygiene conditions (good vs poor). After six weeks of challenge, pigs were slaughtered (n = 5-9/group). Samples of subcutaneous adipose tissue and longissimus muscle were collected, and cells from the stromal vascular fraction (FSV), which includes adult stem cell populations, were isolated from each tissue. Adipose and muscle cell populations from the FSV were phenotyped by flow cytometry using antibodies that targeted different cell surface markers (CD45 to identify hematopoietic cells; CD34, CD38, CD56 and CD140a to identify mesenchymal stem cells (MSC) with adipogenic and/or myogenic potential). Results: Adipose tissue and muscle shared some common MSC populations although MSC diversity was higher in muscle than in adipose tissue. In muscle, the CD45-CD56+CD34-CD140a+ and CD45-CD56+CD34+CD140a+ cell populations were abundant. Of these two cell populations, only the proportions of CD45-CD56+CD34+CD140a+ cells increased (P < 0.05) in pigs housed in poor hygiene compared with good hygiene conditions. For the CD45-CD56-CD34- cell population, present in low proportion, there was an interaction between hygiene condition and genetic line (P < 0.05) with a decrease in low RFI pigs housed in poor hygiene conditions. In adipose tissue, the two abundant MSC populations were CD45-CD56-CD34- and CD45-CD56+CD34-. The proportion of CD45-CD56-CD34- cells increased (P < 0.05) whereas the proportion of CD45-CD56+CD34- tended to decrease (P < 0.1) in pigs housed in poor conditions. This study shows that the proportions of some MSC populations were affected by hygiene of housing conditions in a tissue-dependent manner in pigs of both RFI lines. Therefore, these cell populations could be targeted to modulate growth and body composition in growing animals.

Integrin α6 (CD49f), The Microenvironment and Cancer Stem Cells

2019 ◽  
Vol 14 (5) ◽  
pp. 428-436 ◽  
Author(s):  
Gabriele D. Bigoni-Ordóñez ◽  
Daniel Czarnowski ◽  
Tyler Parsons ◽  
Gerard J. Madlambayan ◽  
Luis G. Villa-Diaz
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Cancer Stem Cell ◽  
The Self ◽  
Self Renewal ◽  
Terminal Disease

Cancer is a highly prevalent and potentially terminal disease that affects millions of individuals worldwide. Here, we review the literature exploring the intricacies of stem cells bearing tumorigenic characteristics and collect evidence demonstrating the importance of integrin &#945;6 (ITGA6, also known as CD49f) in cancer stem cell (CSC) activity. ITGA6 is commonly used to identify CSC populations in various tissues and plays an important role sustaining the self-renewal of CSCs by interconnecting them with the tumorigenic microenvironment.

Sign in / Sign up

Export Citation Format

Share Document