Disputas: Khan Ahmed Qalb-e-Saleem
Cand.odont. Khan Ahmed Qalb-e-Saleem ved IOB vil forsvare sin avhandling for graden ph.d.: On development of mouse molar tooth - selected genes and proteins
Tid og sted for prøveforelesning
- Professor, Dr. Thimios A. Mitsiadis, University of Zürich (førsteopponent)
- Professor, PhD Michael A. Tranulis, Norges Veterinærhøgskole (andreopponent)
- Professor dr.odont. Anne Aamdal Scheie, komiteens leder
- Instituttleder Edvard Messelt, Det odontologisk fakultet, Universitetet i Oslo
- Professor Harald Osmundsen, Det odontologiske fakultet, Universitetet i Oslo
- Professor II Steinar Risnes, Det odontologiske fakultet, Universitetet i Oslo
On development of mouse molar tooth ‐selected genes and proteins
Numerous genes are likely involved during odontogenesis. Some of these have established functions during tooth development, while the functions of the majority of these genes are either not fully understood, not mapped, or are unknown. The murine tooth germ is a rapidly differentiating organ and a convenient model for studying organ development.
The overall aim in the study was to gain knowledge about selected genes based on their expression profile, and their possible functions as proteins. Microarrays combined with bioinformatic analysis and real time RT-PCRT was used for mapping gene expression of PrnP, Aplp1, Clstn1, Dlk1, Igf2 Gtl2, H19, Clu and Tgfb1 at different days of development (Paper I-III). For selected proteins, PrP, APLP1 protein, DLK1, IGF2 protein, CLU and TGFB1 protein, Western blotting and was used to determine the presence and to measure the amount of proteins (Paper I-III).
To further understand the role of these proteins in tooth development, immunohistochemistry was used to determine their location. The results suggested PrP to be present in ameloblasts, cervical loops, the dental papilla and Hertwig’s epithelial root sheath (Paper I). CLU was detected in oral epithelium, dental lamina and secretory ameloblasts (Paper III). DLK1 was detected in dentin and enamel, in matrix-producing odontoblasts and ameloblasts and in the basal lamina throughout tooth development (Paper II). The results suggest that PrP, CLU, DLK1 along with TGFB1 protein and IGF2 protein, to have a role in odontogenesis.
In vivo transfection with anti-miR-214 revealed markedly decreased expression of Clu and Tgfb1, as expression of Dlk1, Grb10, Gtl2, H19, Igf2, Ndn and Plagl1, genes associated with regulation of organ growth, were in contrast markedly stimulated (Paper III). These findings suggest that knock-down of miR-214 in the tooth germ decreased expression of genes associated with terminal odontogenesis; while expression of genes associated with alternative organogenesis was stimulated.