Søren Jepsen

Abstract

Recently we demonstrated that human dentin contained relatively high amounts of transforming growth factor beta (TGF-ß) and proposed that dentin TGF-ß originated from odontoblasts. Because of the suggested role of TGF-ß in mediating cellular interactions in dental cell development by paracrine mechanisms, we studied the expression of TGF-ß message in developing teeth by in situ hybridization. 5 µm serial sections of neonatal sheep mandibular third molars that had been fixed in glutaraldehyde and paraffin-embedded were used for in situ analysis. An [35S]-labeled cRNA probe, complementary to TGF-ß1 mRNA, was constructed from human TGF-ß1 cDNA. Northern analysis of total RNA from sheep placenta and molars demonstrated hybridization to a single 2.4 kb TGF-ß1 transcript from both tissues, showing cross-reactivity of the human probe in the sheep model. In sheep molars, hybridization signal was observed in cells of the stratum intermedium, inner enamel epithelium, mature ameloblasts and odontoblasts, but not within preodontoblasts prior to dentin matrix formation. Evidence for hybridization was also apparent in the cells of the dental papilla but scarcely so in stellate reticulum. Hybridization in stratum intermedium was observed before hybridization was evident in cells of inner enamel epithelium.

Based on this evidence and on previous reports of the stimulation of alkaline phosphatase activity in osteoblasts by TGF-ß, we conclude that TGF-ß may act in a paracrine (or autocrine) manner to stimulate the differentiation of ameloblasts or odontoblasts. Our findings suggest a potential novel regulatory role for the cells of the stratum intermedium.

LLU Discipline

Periodontics

Department

Periodontics

School

Graduate School

First Advisor

Richard D. Finkelman

Second Advisor

Ulf M.E. Wikesjö

Third Advisor

Donna D. Strong

Fourth Advisor

Patric Schiltz

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1992

Date (Title Page)

8-1992

Language

English

Library of Congress/MESH Subject Headings

Transforming Growth Factor Beta -- physiology -- dissertations; Tooth -- growth & development; In Situ Hybridization

Type

Thesis

Page Count

2 vi; 104

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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