Naslov
Spatial and temporal distribution of Ki-67 proliferation marker, Bcl-2 and Bax proteins in the developing human tooth

Autori
Kalibović Govorko, Danijela ; Bečić, Tina ; Vukojević, Katarina ; Mardešić Brakus, Snježana ; Biočina-Lukenda, Dolores ; Saraga-Babić, Mirna

Izvornik
Archives of oral biology (0003-9969) 55 (2010), 12; 1007-1016

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
human embryo; tooth development; Ki-67; Bax; Bcl-2

Sažetak
To investigate the spatial and temporal expression of proliferation Ki-67 marker, pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins during early development of the human tooth. Histological sections of eight human conceptuses, 5-10 postovulatory weeks old, were used for immunolocalization for Ki-67, Bax and Bcl-2 markers. Quantification was performed by calculating the fraction of Ki-67 positive cells, expressed as a mean +/- SD, and analysed by Mann-Whitney test, Kruskal-Wallis and Dunn's post hoc test. In 6th-7th developmental weeks, the tooth germ and dental crest contained 37% of proliferating cells, which increased to 40% in the 8th week, and then decreased to 15% in the 10th week, whilst the proliferation in the ectomesenchyme subsequently dropped from 37% to 23%. Epithelial parts of the enamel organ displayed similar proliferation activity (31-36%), dental crest 10%, whilst enamel knot showed no proliferating activity. The tooth ectomesenchyme contained more proliferating cells (50%) than the jaw ectomesenchyme (35%), and both dropped to 28% in the 10th week. Ectomesenchyme between the tooth germs contained 23%, whilst the jaw ectomesenchyme contained 15% of proliferating cells. Bcl-2 expression had following pattern: strong in proliferating cells, moderate in tooth germs and dental crest, and weak in the ectomesenchyme. Bax co-expressed with Bcl-2 in the tooth germ and dental crest. In the reticulum and inner enamel epithelium Bcl-2 had prevalent expression, whilst Bax prevailed in the outer enamel epithelium and tooth ectomesenchyme. Proliferating cells most likely influence growth of the tooth germ, Bcl-2 affects proliferation and differentiation of specific cell lineages, whilst Bax influences process of cell death.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti, Dentalna medicina

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