Antiresorptive agents, such as bisphosphonates (BPs) and denosumab (Dmab), are commonly used to treat osteoporosis and bone malignancies. While their therapeutic effects have long been documented, their side effects can be serious and devastating. One such side effect has been identified as osteonecrosis of the jaws (ONJ), exposed bone in the maxillofacial region for at least 8 weeks in the presence of antiresorptive medications. Although it has been studied extensively, its pathophysiology remains largely elusive. Osteoclast inhibition has been shown to be crucial in ONJ pathogenesis, as these cells play a central role in the maintenance of normal bone homeostasis. Osteoclasts not only are the master bone resorbing cells, but they communicate with other cells in their vicinity to coordinate bone modeling and remodeling. Despite distinct pharmacologic effects of BPs and Dmab, the incidence and appearance of ONJ is similar. BPs inhibit protein farnesylation, leading to inhibition of osteoclast function, while Dmab binds to receptor activator of NFKB ligand (RANKL), inhibiting differentiation of osteoclast precursors. Thus, these similar, but distinct effects of BPs and Dmab may affect ONJ pathophysiology. Utilizing different types of antiresorptives, we will study the effects of osteoclastic inhibition on ONJ development in Aim 1.
Aim 2 will identify differential gene expression during ONJ development utilizing diverse antiresorptives. This study will provide insight into the involvement of osteoclast function in ONJ pathophysiology. In addition, differential gene expression during ONJ development will be identified. Importantly, these studies will begin to delineate ONJ pathophysiology and identify potential therapeutic strategies. Finally, these proposed studies will prepare the fellowship applicant for a career as a clinician-scientist.

Public Health Relevance

This proposed research project will highlight the significance of osteoclastic inhibition in development of Osteonecrosis of the Jaws (ONJ) in patients on antiresorptives for osteoporosis or bone malignancies. Importantly, our analysis of differential gene expression will allow for a more targeted approach to disease prevention and therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Individual Predoctoral NRSA for M.D./Ph.D. Fellowships (ADAMHA) (F30)
Project #
5F30DE028171-02
Application #
9703692
Study Section
Special Emphasis Panel (ZDE1)
Program Officer
Frieden, Leslie A
Project Start
2018-07-01
Project End
2020-06-30
Budget Start
2019-07-01
Budget End
2020-06-30
Support Year
2
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Dentistry
Type
Schools of Dentistry/Oral Hygn
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Hadaya, Danny; Soundia, Akrivoula; Freymiller, Earl et al. (2018) Nonsurgical Management of Medication-Related Osteonecrosis of the Jaws Using Local Wound Care. J Oral Maxillofac Surg :