Tooth agenesis, the congenital absence of one or more permanent teeth, is the most common inherited disorder in humans, affecting up to 10% of the population, even when third molars are excluded. The condition occurs as an isolated anomaly or as part of dozens of syndromes and imposes significant functional, emotional and financial burdens on patients and their families. Since restoring esthetics and function for patients with tooth agenesis is complex and expensive, new therapies are warranted. Thus a central challenge relates to the critical need to translate the fruits of several decades of basic and clinical research on tooth development and tooth agenesis into tangible therapies that can benefit these patients. The long-range goals of this research are to develop replacement therapies that are safe and effective in correcting non-syndromic tooth agenesis in humans. We propose translational approaches that will test the hypotheses that the timely administration of select recombinant proteins or small molecule activators/inhibitors of major developmental signaling pathways will be able to replace missing or mutated gene products needed for tooth development. Furthermore, replacement proteins do not have to be identical with the tooth agenesis-causing protein as downstream targets/effectors of the mutated gene can also achieve the desired effect, either singly or in combination with other downstream effectors. Our approaches are inspired by the recent success in using recombinant Ectodysplasin A (rEDA) protein to treat X-linked hypohidrotic ectodermal dyslpasia (ED) in mice and dogs, results that led to clinical trials that are now assessing the safety and efficacy of rEDA therapy in humans with ED.
Three aims are proposed as follows: (1) To explore the expanded use of EDA therapeutics for non-syndromic tooth agenesis. (2) To develop and evaluate novel Wnt therapeutics for non-syndromic tooth agenesis. (3) To identify new tooth agenesis genes through the use of human genetics approaches. The project addresses an important problem of high clinical relevance for which there are no cures. Data from these translational studies will provide the proof of principles needed to test whether such therapies can be used to restore tooth development in humans affected by non-syndromic tooth agenesis. In the broadest sense, this research will impact concepts and technologies that drive the field of therapies for other single gene disorders affecting the craniofacial complex and other systems.

Public Health Relevance

Tooth agenesis is defined as the congenital absence of one or more permanent teeth and is the most common inherited disorder in humans, affecting up to 10 to 20 % of the population when third molars are excluded or included, respectively. The condition imposes significant functional, emotional and financial burdens on patients and their families. Current treatment is both complex and expensive. This project aims to better understand the molecules that cause tooth agenesis and will tackle questions related to potentially novel therapeutic applications to treat the condition. Several translational approaches are proposed that will provide the framework for future therapies to treat tooth agenesis in humans.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
High Priority, Short Term Project Award (R56)
Project #
2R56DE019471-06A1
Application #
9326494
Study Section
Skeletal Biology Development and Disease Study Section (SBDD)
Program Officer
Scholnick, Steven
Project Start
2008-12-01
Project End
2017-08-31
Budget Start
2016-09-01
Budget End
2017-08-31
Support Year
6
Fiscal Year
2016
Total Cost
$335,250
Indirect Cost
$110,250
Name
University of Utah
Department
Type
Schools of Dentistry
DUNS #
009095365
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112
Jia, Shihai; Zhou, Jing; Fanelli, Christopher et al. (2017) Small-molecule Wnt agonists correct cleft palates in Pax9 mutant mice in utero. Development 144:3819-3828
Jia, S; Zhou, J; Wee, Y et al. (2017) Anti-EDAR Agonist Antibody Therapy Resolves Palate Defects in Pax9-/- Mice. J Dent Res 96:1282-1289