Distribution and quantity of label-retaining cells in rat oral epithelia.
BACKGROUND
Label-retaining cells (LRCs), the presumptive stem cells, have been detected in the mouse and hamster oral epithelia, but the data on LRCs in rat oral epithelia have not been available yet. The aim of this study was to identify LRCs in oral squamous epithelia of rat.


METHODS
Fifty-four two-week-old Sprague-Dawley rats were injected intraperitoneally with BrdU twice daily for four consecutive days. The BrdU-labeled rats were sacrificed at 2 h, week 2, 4, 6, 8, 10, 12, 14 and 16 after the last BrdU injection. The tissues of cheek, tongue and palate were analyzed by techniques of fluorescence-activated cell sorting (FACS) and immunohistochemistry.


RESULTS
The number of BrdU-labeled cells quantified by FACS increased within 2 weeks after labeling, then, decreased gradually until week 10. After week 10, the BrdU-labeled cells were found to locate mainly in basal layer and their number kept consistent at 3-7% of total oral epithelial cells. The number of BrdU-labeled epithelial cells in palate was statistically higher than that in cheek or tongue at the same time point.


CONCLUSIONS
This study showed that the number and the distribution of BrdU-labeled epithelial cells stabilized from 10 weeks after labeling. Therefore, these BrdU-labeled cells after a 10-week chase were considered oral epithelial LRCs.
Huang
Yu-Lei
YL
Department of Oral Medicine, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong 510055, China.
Tao
Xiaoan
X
Xia
Juan
J
Li
Chun-Yang
CY
Cheng
Bin
B
D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D002452:Cell Count; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D007150:Immunohistochemistry; D008137:Longitudinal Studies; D009055:Mouth / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods; D055153:Stem Cell Niche / Q000166:cytology* / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution
D015415:Biomarkers; D001973:Bromodeoxyuridine