scholarly journals Automated collective motion analysis validates human keratinocyte stem cell cultures

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Koji Kinoshita ◽  
Takuya Munesue ◽  
Fujio Toki ◽  
Masaharu Isshiki ◽  
Shigeki Higashiyama ◽  
...  

AbstractIdentification and quality assurance of stem cells cultured in heterogeneous cell populations are indispensable for successful stem cell therapy. Here we present an image-processing pipeline for automated identification and quality assessment of human keratinocyte stem cells. When cultivated under appropriate conditions, human epidermal keratinocyte stem cells give rise to colonies and exhibit higher locomotive capacity as well as significant proliferative potential. Image processing and kernel density estimation were used to automatically extract the area of keratinocyte colonies from phase-contrast images of cultures containing feeder cells. The DeepFlow algorithm was then used to calculate locomotion speed of the colony area by analyzing serial images. This image-processing pipeline successfully identified keratinocyte stem cell colonies by measuring cell locomotion speed, and also assessed the effect of oligotrophic culture conditions and chemical inhibitors on keratinocyte behavior. Therefore, this study provides automated procedures for image-based quality control of stem cell cultures and high-throughput screening of small molecules targeting stem cells.

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Xuefeng Hu ◽  
Jyh-Wei Lee ◽  
Xi Zheng ◽  
Junhua Zhang ◽  
Xin Lin ◽  
...  

2021 ◽  
Vol 22 (15) ◽  
pp. 7813
Author(s):  
Lindsay Kraus ◽  
Chris Bryan ◽  
Marcus Wagner ◽  
Tabito Kino ◽  
Melissa Gunchenko ◽  
...  

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Multiple stem cell types have been safely transferred into failing human hearts, but the overall clinical cardiovascular benefits have been modest. Therefore, there is a dire need to understand the basic biology of stem cells to enhance therapeutic effects. Bmi1 is part of the polycomb repressive complex 1 (PRC1) that is involved in different processes including proliferation, survival and differentiation of stem cells. We isolated cortical bones stem cells (CBSCs) from bone stroma, and they express significantly high levels of Bmi1 compared to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs). Using lentiviral transduction, Bmi1 was knocked down in the CBSCs to determine the effect of loss of Bmi1 on proliferation and survival potential with or without Bmi1 in CBSCs. Our data show that with the loss of Bmi1, there is a decrease in CBSC ability to proliferate and survive during stress. This loss of functionality is attributed to changes in histone modification, specifically histone 3 lysine 27 (H3K27). Without the proper epigenetic regulation, due to the loss of the polycomb protein in CBSCs, there is a significant decrease in cell cycle proteins, including Cyclin B, E2F, and WEE as well as an increase in DNA damage genes, including ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). In conclusion, in the absence of Bmi1, CBSCs lose their proliferative potential, have increased DNA damage and apoptosis, and more cell cycle arrest due to changes in epigenetic modifications. Consequently, Bmi1 plays a critical role in stem cell proliferation and survival through cell cycle regulation, specifically in the CBSCs. This regulation is associated with the histone modification and regulation of Bmi1, therefore indicating a novel mechanism of Bmi1 and the epigenetic regulation of stem cells.


2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Nathan Moore ◽  
Stephen Lyle

Long-lived cancer stem cells (CSCs) with indefinite proliferative potential have been identified in multiple epithelial cancer types. These cells are likely derived from transformed adult stem cells and are thought to share many characteristics with their parental population, including a quiescent slow-cycling phenotype. Various label-retaining techniques have been used to identify normal slow cycling adult stem cell populations and offer a unique methodology to functionally identify and isolate cancer stem cells. The quiescent nature of CSCs represents an inherent mechanism that at least partially explains chemotherapy resistance and recurrence in posttherapy cancer patients. Isolating and understanding the cell cycle regulatory mechanisms of quiescent cancer cells will be a key component to creation of future therapies that better target CSCs and totally eradicate tumors. Here we review the evidence for quiescent CSC populations and explore potential cell cycle regulators that may serve as future targets for elimination of these cells.


2012 ◽  
Vol 23 (1-4) ◽  
pp. 153-165 ◽  
Author(s):  
Yusuke Ueda ◽  
Satoshi Fujita ◽  
Tatsuya Nishigaki ◽  
Yusuke Arima ◽  
Hiroo Iwata

1997 ◽  
Vol 45 (6) ◽  
pp. 867-874 ◽  
Author(s):  
Jean-Pierre Molès ◽  
Fiona M. Watt

The basal layer of the epidermis contains two types of proliferating keratinocyte: stem cells, with high proliferative potential, and transit amplifying cells, which are destined to undergo terminal differentiation after a few rounds of division. It has been shown previously that two- to three-fold differences in the average staining intensity of fluorescein-conjugated antibodies to β1 integrin subunits reflect profound differences in the proliferative potential of keratinocytes, with integrin-bright populations being enriched for stem cells. In the search for additional stem cell markers, we have stained sections of normal human epidermis with antibodies to proteins involved in intercellular adhesion and quantitated the fluorescence of individual cell-cell borders. In the basal layer, patches of brightly labeled cells were detected with antibodies to E-cadherin, β-catenin, and γ-catenin, but not with antibodies to P-cadherin, α-catenin, or with pan-desmocollin and pan-desmoglein antibodies. In the body sites examined, palm and foreskin, integrinbright regions were strongly labeled for γ-catenin and weakly labeled for E-cadherin and β-catenin. Our data suggest that there are gradients of both cell-cell and cell-extracellular matrix adhesiveness within the epidermal basal layer and that the levels of E-cadherin and of β-and γ-catenin may provide markers for the stem cell compartment, stem cells expressing relatively higher levels of γ-catenin and lower levels of E-cadherin and β-catenin than other basal keratinocytes.


2008 ◽  
Vol 396-398 ◽  
pp. 123-126
Author(s):  
Timothy Wilson ◽  
Reeta Viitala ◽  
Mervi Puska ◽  
Mika Jokinen ◽  
Risto Penttinen

The role of silica and macrophages in fibrosis is well documented, but in bone formation it is relatively unknown despite decades of research with bioactive glasses. In this study macrophages were isolated from rat peritoneal and then cultured for five days in the presence of two types of silica microparticles with different solubilities. After the fifth day the culture medium was collected, purified and used as an additive in bone marrow derived rat stem cell cultures. The stem cells were cultured for five days in α-mem containing only 0,5% of FCS, enabling cell survival but disrupting their proliferation. As controls, stem cells were also cultured in α-mem containing silica microparticles. At days one and five the amount of soluble collagen was assayed from the culture medium and the cells were counted. All stem cell cultures with macrophage medium additives were found to be proliferative, with statistically significant difference to controls. However, collagen was only produced in cultures containing medium from macrophages cultured with fast-dissolving silica microparticles. This suggests that silica can induce cell proliferation and extra cellular matrix protein secretion which is mediated by macrophages, and that the solubility of silica is also a major factor in this reaction.


2014 ◽  
Vol 63 ◽  
pp. 30-37 ◽  
Author(s):  
Jienny Lee ◽  
Jae Youl Cho ◽  
Sang Yeol Lee ◽  
Kyung-Woo Lee ◽  
Jongsung Lee ◽  
...  

2015 ◽  
Vol 209 (2) ◽  
pp. 305-315 ◽  
Author(s):  
Daisuke Nanba ◽  
Fujio Toki ◽  
Sota Tate ◽  
Matome Imai ◽  
Natsuki Matsushita ◽  
...  

Image-based identification of cultured stem cells and noninvasive evaluation of their proliferative capacity advance cell therapy and stem cell research. Here we demonstrate that human keratinocyte stem cells can be identified in situ by analyzing cell motion during their cultivation. Modeling experiments suggested that the clonal type of cultured human clonogenic keratinocytes can be efficiently determined by analysis of early cell movement. Image analysis experiments demonstrated that keratinocyte stem cells indeed display a unique rotational movement that can be identified as early as the two-cell stage colony. We also demonstrate that α6 integrin is required for both rotational and collective cell motion. Our experiments provide, for the first time, strong evidence that cell motion and epidermal stemness are linked. We conclude that early identification of human keratinocyte stem cells by image analysis of cell movement is a valid parameter for quality control of cultured keratinocytes for transplantation.


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