Bisphosphonates (BPs) are commonly used medications to treat primary and metastatic bone cancer, as well as osteoporosis. Though BPs improve bone mineral density, reduce fracture risk, and reduce hypercalcemia of malignancy, many patients develop osteonecrosis of the jaws. BP related osteonecrosis of the jaws (BRONJ) is a devastating complication, presenting as clinically exposed bone in the maxillofacial region for more than 8 weeks. BRONJ is associated with severe pain, swelling, infection, fistulae, and jaw fracture, all of which significantly impact patients'quality of life. Despite the increasing number of BRONJ cases since the first report in 2003, the pathophysiology of the disease remains largely unknown. Two major impediments in exploring BRONJ etiology exist. First, many of our assumptions concerning alveolar bone (AB) cell function and differentiation are extrapolated from experimental models using cells from other skeletal sites. Second, there is no well-established BRONJ animal model to study the in vivo parameters of disease initiation and progression. In this application, we have addressed these two gaps. We have established a method for isolating AB marrow stromal cells (MSCs) and have demonstrated differences in the osteoblastic potential of AB vs. long bone (LB) MSCs, providing a relevant in vitro model to study differences between the craniofacial and appendicular skeleton. Moreover, AB MSCs express lower RANKL mRNA levels and are more sensitive to oxidative stress than their LB counterparts. Published studies and our own preliminary data demonstrate a significant role for dental disease in the pathophysiology of BRONJ. Excitingly, we have developed a rodent model of BRONJ. Equipped both with a model to study AB MSC differentiation in culture and with a BRONJ animal model, our objective is to explore molecular and cellular mechanisms of BRONJ. Based on our preliminary data, we hypothesize that BPs robustly suppress AB resorption at the area of periodontal inflammation. The high oxidative stress environment around the inflammatory nidus strongly decreases AB healing capacity and increases cell apoptosis. The net result of these processes is AB necrosis that presents clinically as BRONJ. To achieve our objective and test our hypothesis, we propose three specific aims: (1) To explore the necessary and sufficient requirement of bisphosphonate treatment and periodontal disease for BRONJ development in the rat;(2) To investigate the ability of AB vs. LB marrow to support osteoclastogenesis in the presence or absence of bisphosphonates;and (3) To investigate the AB vs. LB MSC sensitivity to oxidative stress in the presence or absence of bisphosphonates. The proposed studies will begin uncovering the mechanisms underlying BRONJ pathophysiology and will provide evidence for BP and dental disease involvement in BRONJ incidence. Understanding the mechanisms by which the oral environment is sensitive to oxidative stress and BP inhibition of bone remodeling may lead to novel therapeutic approaches to reduce BRONJ frequency, progression, and severity.

Public Health Relevance

Bisphosphonates are drugs used to treat bone metastasis in cancer patients and osteoporosis. However, bisphosphonate use has been associated with significant oral complications including exposure of the jaw bone, abscesses and jaw fractures. No treatment for these complications exists, because we do not understand the mechanisms of their development. In this application, we explore mechanisms of bisphosphonate related jaw necrosis and establish an animal model of the disease. Results of this research can potentially lead to novel therapeutic approaches that can reduce the incidence, severity, and progression of BRONJ.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE019465-04
Application #
8272459
Study Section
Skeletal Biology Development and Disease Study Section (SBDD)
Program Officer
Wan, Jason
Project Start
2009-09-15
Project End
2014-05-31
Budget Start
2012-06-01
Budget End
2014-05-31
Support Year
4
Fiscal Year
2012
Total Cost
$418,572
Indirect Cost
$143,232
Name
University of California Los Angeles
Department
Dentistry
Type
Schools of Dentistry
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Choi, Hyewon; Srikanth, Sonal; Atti, Elisa et al. (2018) Deletion of Orai1 leads to bone loss aggravated with aging and impairs function of osteoblast lineage cells. Bone Rep 8:147-155
Soundia, A; Hadaya, D; Esfandi, N et al. (2018) Zoledronate Impairs Socket Healing after Extraction of Teeth with Experimental Periodontitis. J Dent Res 97:312-320
Soundia, Akrivoula; Hadaya, Danny; Mallya, Sanjay M et al. (2018) Radiographic predictors of bone exposure in patients with stage 0 medication-related osteonecrosis of the jaws. Oral Surg Oral Med Oral Pathol Oral Radiol 126:537-544
Shimamoto, Hiroaki; Grogan, Tristan R; Tsujimoto, Tomomi et al. (2018) Does CBCT alter the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaws? Dentomaxillofac Radiol 47:20170290
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 :
Mallya, Sanjay M; Tetradis, Sotirios (2018) Imaging of Radiation- and Medication-Related Osteonecrosis. Radiol Clin North Am 56:77-89
Aghaloo, Tara L; Tetradis, Sotirios (2017) Osteonecrosis of the Jaw in the Absence of Antiresorptive or Antiangiogenic Exposure: A Series of 6 Cases. J Oral Maxillofac Surg 75:129-142
Soundia, Akrivoula; Hadaya, Danny; Esfandi, Navid et al. (2016) Osteonecrosis of the jaws (ONJ) in mice after extraction of teeth with periradicular disease. Bone 90:133-41
de Molon, Rafael Scaf; Hsu, Chingyun; Bezouglaia, Olga et al. (2016) Rheumatoid Arthritis Exacerbates the Severity of Osteonecrosis of the Jaws (ONJ) in Mice. A Randomized, Prospective, Controlled Animal Study. J Bone Miner Res 31:1596-607
Hiyari, S; Atti, E; Camargo, P M et al. (2015) Heritability of periodontal bone loss in mice. J Periodontal Res 50:730-6

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