scholarly journals Characterization of putative stem cells in isolated human colonic crypt epithelial cells and their interactions with myofibroblasts

2009 ◽  
Vol 296 (2) ◽  
pp. C296-C305 ◽  
Author(s):  
S. Samuel ◽  
R. Walsh ◽  
J. Webb ◽  
A. Robins ◽  
C. Potten ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Epithelial Cells ◽  
Side Population ◽  
Cell Types ◽  
Population Characteristics ◽  
Colonic Crypt ◽  
Epithelial Stem Cells ◽  
Colonic Crypts ◽  
Cell Niche

Colonic epithelial stem cells are believed to be located at the crypt base where they have previously been shown to express musashi-1. The colonic stem cell niche, which includes extracellular matrix and myofibroblasts (together with other cell types), is likely to be important in maintaining the function of the progenitor cells. The aims of our studies were to characterize stem cells in isolated and disaggregated human colonic crypt epithelial cells and investigate their interactions with monolayers of primary human colonic myofibroblasts. In unfractionated preparations of disaggregated colonic crypts, musashi-1 positive cells preferentially adhered to colonic myofibroblasts, despite the presence of excess blocking anti-β1-integrin antibody. These adherent epithelial cells remained viable for a number of days and developed slender processes. Cells with side population characteristics (as demonstrated by ability to expel the dye Hoechst 33342) were consistently seen in the isolated colonic crypt epithelial cells. These side population cells expressed musashi-1, β1-integrin, BerEP4, and CD133. Sorted side population crypt epithelial cells also rapidly adhered to primary colonic myofibroblasts. In conclusion, in preparation of isolated and disaggregated human colonic crypts, cells with stem cell characteristics preferentially adhere to primary human colonic myofibroblasts in a β1-integrin-independent fashion.

scholarly journals PIWI-piRNA pathway-mediated transposable element repression in Hydra somatic stem cells

2019 ◽  
Author(s):  
Bryan B. Teefy ◽  
Stefan Siebert ◽  
Jack F. Cazet ◽  
Haifan Lin ◽  
Celina E. Juliano
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Epithelial Cells ◽  
Mammalian Cells ◽  
Cell Types ◽  
Somatic Tissue ◽  
Epithelial Stem Cells ◽  
Conserved Sequence ◽  
Rna Immunoprecipitation ◽  
Pirna Pathway

AbstractTransposable elements (TEs) can damage genomes, thus organisms employ a variety of mechanisms to repress TE expression. However, these mechanisms often fail over time leading to de-repression of TEs in aging tissues. The PIWI-piRNA pathway is a small RNA pathway that represses TE expression in the germline of animals. Here we explore the function of the pathway in the epithelial stem cells of Hydra, a long-lived freshwater cnidarian. Hydra have three stem cell populations; endodermal and ectodermal epithelial stem cells are strictly somatic, whereas the interstitial stem cells retain germline competence. In our previous study, we found that the PIWI proteins are expressed in all three Hydra stem cell types. In this study, we focus on the ectodermal and endodermal epithelial stem cells to understand the somatic function of the pathway. We isolated piRNAs from Hydra that lack the interstitial lineage and found that these somatic piRNAs map predominantly to TE transcripts and display the conserved sequence signatures typical of germline piRNAs. Three lines of evidence suggest that the PIWI-piRNA pathway represses TEs in Hydra epithelial stem cells. First, epithelial knockdown of the Hydra PIWI protein hywi resulted in upregulation of TE expression. Second, degradome sequencing revealed evidence of PIWI-mediated cleavage of TE RNAs in epithelial cells using the ping-pong mechanism. Finally, we demonstrated a direct association between Hywi protein and TE transcripts in epithelial cells using RNA immunoprecipitation. Interestingly, we found that RNAi knockdown of hywi leads to an upregulation of genes involved in innate immunity, which may be in response to TE upregulation; this is consistent with recent studies on TE expression in mammalian cells. Altogether, this study suggests a function for the PIWI-piRNA pathway in maintaining the long-lived somatic cell lineages of Hydra and may point to a broader role for this pathway in protecting somatic tissue from TE-induced damage.

scholarly journals Insulin/IGF-1 enhances intestinal epithelial crypt proliferation through PI3K/Akt, and not ERK signaling in obese humans

2018 ◽  
Vol 243 (11) ◽  
pp. 911-916 ◽  
Author(s):  
Weinan Zhou ◽  
Blair M Rowitz ◽  
Megan J Dailey
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Growth Factor ◽  
Insulin Like Growth Factor ◽  
Intestinal Epithelial ◽  
Receptor Signaling ◽  
Epithelial Stem Cells ◽  
Cell Niche ◽  
And Function ◽  
Abnormal Tissue

The intestinal epithelium is continuously regenerated through proliferation and differentiation of stem cells located in the intestinal crypts. Obesity affects this process and results in greater stem cell proliferation and altered tissue growth and function. Obesity-induced high levels of insulin and insulin-like growth factor-1 in the stem cell niche are found to impact proliferation in rodents indicating that insulin and insulin-like growth factor-1 receptors may play a role in modulating intestinal epithelial stem cell proliferation. To determine whether insulin or insulin-like growth factor-1 can induce proliferation in human intestinal epithelial stem cells, and if two downstream insulin and insulin-like growth factor-1 receptor signaling pathways, PI3K/Akt and ERK, are involved, we used primary small intestinal epithelial crypts isolated from obese humans and investigated (1) the effect of insulin or insulin-like growth factor-1 on crypt proliferation, and (2) the effect of insulin and insulin-like growth factor-1 signaling inhibitors on insulin or insulin-like growth factor-1-induced proliferation. We found that insulin and insulin-like growth factor-1 enhanced the proliferation of crypt cells, including intestinal epithelial stem cells. Inhibition of the PI3K/Akt pathway attenuated insulin and insulin-like growth factor-1-induced proliferation, but inhibition of the ERK pathway had no effect. These results suggest that the classical metabolic PI3K pathway and not the canonical proliferation ERK pathway is involved in the insulin/insulin-like growth factor-1-induced increase in crypt proliferation in obese humans, which may contribute to abnormal tissue renewal and function. Impact statement This study investigates if insulin or insulin-like growth factor-1 (IGF-1) induces intestinal epithelial proliferation in humans, and if insulin and IGF-1 receptor signaling is involved in this process in obesity. Although obesity-induced high levels of insulin and IGF-1 in the stem cell niche are found to impact the proliferation of intestinal epithelial stem cells in rodents, we are the first to investigate this effect in humans. We found that insulin and IGF-1 enhanced the proliferation of intestinal crypts (including stem cells and other crypt cells) isolated from obese humans, and PI3K/Akt, and not ERK signaling was involved in insulin or IGF-1-induced proliferation. The imbalance in signaling between PI3K/Akt and ERK pathways may point to a pathway-specific impairment in insulin/IGF-1 receptor signaling. We propose that this may contribute to reciprocal relationships between insulin/IGF-1 receptor resistance and intestinal epithelial proliferation that leads to abnormal tissue renewal and function.

scholarly journals Islet morphogenesis and stem cell markers in rat pancreas.

1996 ◽  
Vol 44 (9) ◽  
pp. 947-951 ◽  
Author(s):  
L Bouwens ◽  
E De Blay
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Epithelial Cells ◽  
Endocrine Cells ◽  
Stem Cell Marker ◽  
Intermediate Filament Protein ◽  
Stem Cell Markers ◽  
Epithelial Stem Cells ◽  
Duct Cells ◽  
Pancreatic Islets Of Langerhans

During embryonic development, and possibly also later in life, pancreatic islets of Langerhans originate from differentiating epithelial stem cells. These stem cells are situated in the pancreatic ducts but are otherwise poorly characterized. We found by immunohistochemical staining that protodifferentiated pancreatic epithelial cells from rat embryos of Day 13-Day 15 express the cytoskeletal protein keratin 20, similar to mature duct epithelium. During the period of islet morphogenesis, which occurs between Day 17 and birth, large aggregates of K20-positive duct cells were formed, which gradually differentiated into endocrine cells. This islet morphogenic mechanism has not been described thus far and we did not observe it in postnatal rats. During fetal islet formation, transient expression of vimentin was noted in the duct cells but not in endocrine cells. This intermediate filament protein is not observed in duct epithelial cells after birth. The proto-oncogene product bcl-2, a putative epithelial stem cell marker, was detected in duct cells from fetal and postnatal pancreas. We conclude that K20, vimentin, and bcl-2 are markets for the pancreatic (islet) stem cells.

scholarly journals Comparative Analysis of KnockOut™Serum with Fetal Bovine Serum for the In Vitro Long-Term Culture of Human Limbal Epithelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Shaokun Zhang ◽  
Zaoxia Liu ◽  
Guanfang Su ◽  
Hong Wu
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Bovine Serum ◽  
Fetal Bovine Serum ◽  
Epithelial Stem Cells ◽  
Fetal Bovine ◽  
Limbal Epithelial Stem Cells

The limbal epithelial cells can be maintained on 3T3 feeder layer with fetal bovine serum supplemented culture medium, and these cells have been used to successfully treat limbal stem cell deficiency. However, fetal bovine serum contains unknown components and displays quantitative and qualitative lot-to-lot variations. To improve the culture condition, the defined KnockOut serum replacement was investigated to replace fetal bovine serum for culturing human limbal epithelial cell. Human primary limbal epithelial cells were cultured in KnockOut serum and fetal bovine serum supplemented medium, respectively. The cell growth rate, gene expression, and maintenance of limbal epithelial stem cells were studied and compared between these two groups. Human primary limbal epithelial cells were isolated and successfully serially cultivated in this novel KnockOut serum supplemented medium; the cell proliferation and stem cell maintenance were similar to those of cells grown in fetal bovine serum supplemented medium. These data suggests that this KnockOut serum supplemented medium is an efficient replacement to traditional fetal bovine serum supplemented medium for limbal epithelial cell culture, and this medium has great potential for long term maintenance of limbal epithelial cells, limbal epithelial stem cells transplantation, and tissue regeneration.

scholarly journals Stem cell niche signals Wnt, Hedgehog, and Notch distinctively regulate Drosophila follicle precursor cell differentiation

2017 ◽  
Author(s):  
Wei Dai ◽  
Amy Peterson ◽  
Thomas Kenney ◽  
Denise J. Montell
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Cell Fate ◽  
Stem Cell Niche ◽  
Adult Stem Cells ◽  
Cell Types ◽  
Wnt Signalling ◽  
Main Body ◽  
Cell Niche

AbstractAdult stem cells commonly give rise to transit-amplifying progenitors, whose progeny differentiate into distinct cell types. Signals within the stem cell niche maintain the undifferentiated state. However it is unclear whether or how niche signals might also coordinate fate decisions within the progenitor pool. Here we use quantitative microscopy to elucidate distinct roles for Wnt, Hedgehog (Hh), and Notch signalling in progenitor development in the Drosophila ovary. Follicle stem cells (FSCs) self-renew and produce precursors whose progeny adopt distinct polar, stalk, and main body cell fates. We show that a steep gradient of Wnt signalling maintains a multipotent state in proximally located progenitor cells by inhibiting expression of the cell fate determinant Eyes Absent (Eya). A shallower gradient of Hh signalling controls the proliferation to differentiation transition. The combination of Notch and Wnt signalling specifies polar cells. These findings reveal a mechanism by which multiple niche signals coordinate cell fate diversification of progenitor cells.

scholarly journals The role of pulmonary mesenchymal cells in airway epithelium regeneration during injury repair

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Suyun Fang ◽  
Suhong Zhang ◽  
Haiting Dai ◽  
Xiaoxiang Hu ◽  
Changgong Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Airway Epithelium ◽  
Cell Types ◽  
Mesenchymal Cells ◽  
Ciliated Cells ◽  
Epithelial Stem Cells ◽  
Injury Repair ◽  
Club Cells

Abstract Background The airways of mammalian lung are lined with highly specialized cell types that are the target of airborne toxicants and injury. Several epithelial cell types and bone marrow-derived mesenchymal stem cells have been identified to serve as stem cells during injury repair. However, the contributions of endogenous mesenchymal cells to recruitment, expansion or differentiation of stem cells, and repair and reestablishment of the normal composition of airway epithelium following injury have not been addressed. Methods The role of mouse pulmonary mesenchymal cells was investigated by lineage tracing using Dermo1-Cre; ROSAmTmG mice. In experimental models of lung injury by lipopolysaccharide and naphthalene, GFP-labeled Dermo1+ mesenchymal cells were traced during injury repair. In vitro lung explant culture treated with or without lipopolysaccharide was also used to verify in vivo data. Results During injury repair, a subgroup of GFP-labeled Dermo1+ mesenchymal cells were found to contribute to normal repair of the airway epithelium and differentiated into Club cells, ciliated cells, and goblet cells. In Club cell-specific naphthalene injury model, the process of Dermo1+ stem cell regenerating epithelial cells was dissected. The Dermo1+ stem cells was migrated into the airway epithelium layer sooner after injury, and sequentially differentiated transitionally to epithelial stem cells, such as neuroendocrine cells, and finally to newly differentiated Club cells, ciliated cells, and goblet cells in injury repair. Conclusion In this study, a population of Dermo1+ mesenchymal stem cell was identified to serve as stem cells in airway epithelial cell regeneration during injury repair. The Dermo1+ mesenchymal stem cell differentiated into epithelial stem cells before reestablishing various epithelial cells. These findings have implications for understanding the regulation of lung repair and the potential for usage of mesenchymal stem cells in therapeutic strategies for lung diseases.

scholarly journals The Role of Limbal Epithelial Stem Cells in Regulating Corneal (Lymph)angiogenic Privilege and the Micromilieu of the Limbal Niche following UV Exposure

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
M. Notara ◽  
A. Lentzsch ◽  
M. Coroneo ◽  
C. Cursiefen
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Damage ◽  
Lymphatic Vessels ◽  
Uv Exposure ◽  
Epithelial Stem Cells ◽  
Limbal Epithelium ◽  
Limbal Epithelial Stem Cells ◽  
Cell Niche

The cornea is a clear structure, void of blood, and lymphatic vessels, functioning as our window to the world. Limbal epithelial stem cells, occupying the area between avascular cornea and vascularized conjunctiva, have been implicated in tissue border maintenance, preventing conjunctivalisation and propagation of blood and lymphatic vessels into the cornea. Defects in limbal epithelial stem cells are linked to corneal neovascularisation, including lymphangiogenesis, chronic inflammation, conjunctivalisation, epithelial abnormalities including the presence of goblet cells, breaks in Bowman’s membrane, persistent epithelial defects and ulceration, ocular surface squamous neoplasia, lipid keratopathy, pain, discomfort, and compromised vision. It has been postulated that pterygium is an example of focal limbal deficiency. Previous reports showing changes occurring in limbal epithelium during pterygium pathogenesis suggest that there is a link to stem cell damage. In this light, pterygium can serve as a model disease of UV-induced stem cell damage also characterised by corneal blood and lymphangiogenesis. This review focuses on the role of corneal and limbal epithelial cells and the stem cell niche in maintaining corneal avascularity and corneal immune privilege and how this may be deregulated following UV exposure. We present an overview of the PUBMED literature in the field as well as recent work from our laboratories.

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 Human Amniotic Epithelial Stem Cells: A Promising Seed Cell for Clinical Applications

2020 ◽  
Vol 21 (20) ◽  
pp. 7730
Author(s):  
Chen Qiu ◽  
Zhen Ge ◽  
Wenyu Cui ◽  
Luyang Yu ◽  
Jinying Li
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cellular Therapy ◽  
Therapeutic Potential ◽  
Current Knowledge ◽  
Embryonic Stem ◽  
Cell Types ◽  
Epithelial Stem Cells ◽  
Application Procedure ◽  
Cell Source

Perinatal stem cells have been regarded as an attractive and available cell source for medical research and clinical trials in recent years. Multiple stem cell types have been identified in the human placenta. Recent advances in knowledge on placental stem cells have revealed that human amniotic epithelial stem cells (hAESCs) have obvious advantages and can be used as a novel potential cell source for cellular therapy and clinical application. hAESCs are known to possess stem-cell-like plasticity, immune-privilege, and paracrine properties. In addition, non-tumorigenicity and a lack of ethical concerns are two major advantages compared with embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). All of the characteristics mentioned above and other additional advantages, including easy accessibility and a non-invasive application procedure, make hAESCs a potential ideal cell type for use in both research and regenerative medicine in the near future. This review article summarizes current knowledge on the characteristics, therapeutic potential, clinical advances and future challenges of hAESCs in detail.

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