scholarly journals Identification of putative dental epithelial stem cells in a lizard with life-long tooth replacement

Development ◽  
2010 ◽  
Vol 137 (21) ◽  
pp. 3545-3549 ◽  
Author(s):  
G. R. Handrigan ◽  
K. J. Leung ◽  
J. M. Richman
Keyword(s):  
Stem Cells ◽  
Tooth Replacement ◽  
Epithelial Stem Cells

Continuous tooth replacement: the possible involvement of epithelial stem cells

BioEssays ◽  
2004 ◽  
Vol 26 (6) ◽  
pp. 665-671 ◽  
Author(s):  
Ann Huysseune ◽  
Irma Thesleff
Keyword(s):  
Stem Cells ◽  
Tooth Replacement ◽  
Epithelial Stem Cells

scholarly journals Tooth Removal in the Leopard Gecko and the de novo Formation of Replacement Teeth

2021 ◽  
Vol 12 ◽  
Author(s):  
Kirstin S. Brink ◽  
Joaquín Ignacio Henríquez ◽  
Theresa M. Grieco ◽  
Jesus Rodolfo Martin del Campo ◽  
Katherine Fu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
De Novo ◽  
Microscopic Analysis ◽  
Tooth Replacement ◽  
Epithelial Stem Cells ◽  
Dental Lamina ◽  
Eublepharis Macularius ◽  
Post Surgery ◽  
Leopard Gecko

Many reptiles are able to continuously replace their teeth through life, an ability attributed to the existence of epithelial stem cells. Tooth replacement occurs in a spatially and temporally regulated manner, suggesting the involvement of diffusible factors, potentially over long distances. Here, we locally disrupted tooth replacement in the leopard gecko (Eublepharis macularius) and followed the recovery of the dentition. We looked at the effects on local patterning and functionally tested whether putative epithelial stem cells can give rise to multiple cell types in the enamel organs of new teeth. Second generation teeth with enamel and dentine were removed from adult geckos. The dental lamina was either left intact or disrupted in order to interfere with local patterning cues. The dentition began to reform by 1 month and was nearly recovered by 2–3 months as shown in μCT scans and eruption of teeth labeled with fluorescent markers. Microscopic analysis showed that the dental lamina was fully healed by 1 month. The deepest parts of the dental lamina retained odontogenic identity as shown by PITX2 staining. A pulse-chase was carried out to label cells that were stimulated to enter the cell cycle and then would carry BrdU forward into subsequent tooth generations. Initially we labeled 70–78% of PCNA cells with BrdU. After a 1-month chase, the percentage of BrdU + PCNA labeled cells in the dental lamina had dropped to 10%, consistent with the dilution of the label. There was also a population of single, BrdU-labeled cells present up to 2 months post surgery. These BrdU-labeled cells were almost entirely located in the dental lamina and were the likely progenitor/stem cells because they had not entered the cell cycle. In contrast fragmented BrdU was seen in the PCNA-positive, proliferating enamel organs. Homeostasis and recovery of the gecko dentition was therefore mediated by a stable population of epithelial stem cells in the dental lamina.

A common mechanism links activities of butyrate in the colon

2017 ◽  
Author(s):  
Mohit S. Verma ◽  
Michael J. Fink ◽  
Gabriel L Salmon ◽  
Nadine Fornelos ◽  
Takahiro E. Ohara ◽  
...  
Keyword(s):  
Stem Cells ◽  
Histone Deacetylases ◽  
Biological Activities ◽  
Short Chain Fatty Acids ◽  
Common Mechanism ◽  
Epithelial Stem Cells ◽  
Degree Of Unsaturation ◽  
Structure Activity ◽  
Starting Point ◽  
New Compounds

Two biological activities of butyrate in the colon (suppression of proliferation of colonic epithelial stem cells and inflammation) correlate with inhibition of histone deacetylases. Cellular and biochemical studies of molecules similar in structure to butyrate, but different in molecular details (functional groups, chain-length, deuteration, oxidation level, fluorination, or degree of unsaturation) demonstrated that these activities were sensitive to molecular structure, and were compatible with the hypothesis that butyrate acts by binding to the Zn<sup>2+</sup> in the catalytic site of histone deacetylases. Structure-activity relationships drawn from a set of 36 compounds offer a starting point for the design of new compounds targeting the inhibition of histone deacetylases. The observation that butyrate was more potent than other short-chain fatty acids is compatible with the hypothesis that crypts evolved (at least in part), to separate stem cells at the base of crypts from butyrate produced by commensal bacteria.

scholarly journals Stem Cells in the Path of Light, from Corneal to Retinal Reconstruction

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 873
Author(s):  
Ovidiu Samoila ◽  
Lacramioara Samoila
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Clinical Success ◽  
Corneal Stroma ◽  
Cell Transplant ◽  
Inclusion Criteria ◽  
Epithelial Stem Cells ◽  
Corneal Epithelial ◽  
Stem Cells Transplantation ◽  
Limbal Epithelial Stem Cells

The future of eye reconstruction invariably includes stem cells transplantation. Corneal limbus, corneal stroma, trabeculum, retinal cells, optic nerve, and all structures that are irreversibly damaged and have no means to be repaired or replaced, through conventional treatment or surgery, represent targets for stem cell reconstruction. This review tries to answer the question if there is any clinical validation for stem therapies, so far, starting from the cornea and, on the path of light, arriving to the retina. The investigation covers the last 10 years of publications. From 2385 published sources, we found 56 clinical studies matching inclusion criteria, 39 involving cornea, and 17 involving retina. So far, corneal epithelial reconstruction seems well validated clinically. Enough clinical data are collected to allow some form of standardization for the stem cell transplant procedures. Cultivated limbal epithelial stem cells (CLET), simple limbal epithelial transplant (SLET), and oral mucosa transplantation are implemented worldwide. In comparison, far less patients are investigated in retinal stem reconstructions, with lower anatomical and clinical success, so far. Intravitreal, subretinal, and suprachoroidal approach for retinal stem therapies face specific challenges.

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