The majority of the US population that suffers from temporomandibular joint (TMJ) degeneration and osteoarthritis (TMJ-OA) are females between 45 and 65 years old. Prevalence of TMJ-OA in this population suggests that estrogen loss plays a role in the disease pathogenesis. Previous evidence from our lab suggests that estrogen through estrogen receptor alpha (ER?) protects the TMJ from degeneration by promoting Col2 and proteoglycan production. Further, we have preliminary evidence indicating that estrogen-ER? inhibits Wnt pathway signaling. These findings suggest that estrogen signaling promotes chondrogenesis via ER? by mediating the canonical Wnt pathway. The objective of this proposal is to investigate the role of ER? signaling on mandibular condylar cartilage matrix production and TMJ homeostasis. The proposed work comprises two aims:
AIM 1 : Evaluate the role of estrogen via ER? on collagen type II (Col2) production. We hypothesize that estrogen promotes Col2 transcription via ER? by inhibiting canonical Wnt signaling. To confirm the effects of estrogen-ER? on chondrogenesis, reporter mice will be utilized to examine upregulation of Col2 and downregulation of Wnt signaling with estrogen and an ER? agonist. Then, the ability of estrogen-ER? to promote chondrogenesis by inhibiting Wnt signaling will be determined by activating the Wnt pathway in WT and ER?KO mice in an ovariectomy-estrogen replacement model.
AIM 2 : Determine the effects of ER? deficiency on TMJ degeneration and correlate to resulting compressive properties and masticatory function. We hypothesize that ER?KO mice will exhibit accelerated age-related TMJ degeneration which will correspond to a decrease in compressive modulus, fixed charge density, and bite force compared to WT controls. Changes in matrix composition will be correlated to alterations in compressive properties and masticatory function. The results from this proposed research will provide evidence of the sex predilection of TMJ degeneration and provide therapeutic targets (e.g. ER? agonist) to delay degeneration. Through this work, we aim to enhance the understanding of estrogen?s role in TMJ condylar cartilage chondrogenesis and homeostasis. Also, the development of TMJ condylar cartilage structure/function relationships will be beneficial for the development of regenerative therapies to combat TMJ degeneration.

Public Health Relevance

This proposed research is relevant to public health because it has the potential to elucidate therapeutic targets to reduce estrogen-related temporomandibular joint degeneration. This work fulfills the NIH mission by determining both fundamental and applied understanding of the function of estrogen in TMJ degeneration.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32DE026366-02
Application #
9349337
Study Section
NIDR Special Grants Review Committee (DSR)
Program Officer
Frieden, Leslie A
Project Start
2016-09-18
Project End
2017-12-31
Budget Start
2017-09-18
Budget End
2017-12-31
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Biomedical Engineering
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
049179401
City
New York
State
NY
Country
United States
Zip Code
10027
Robinson, Jennifer L; Soria, Paola; Xu, Manshan et al. (2018) Estrogen Promotes Mandibular Condylar Fibrocartilage Chondrogenesis and Inhibits Degeneration via Estrogen Receptor Alpha in Female Mice. Sci Rep 8:8527
Robinson, J L; Gupta, V; Soria, P et al. (2017) Estrogen receptor alpha mediates mandibular condylar cartilage growth in male mice. Orthod Craniofac Res 20 Suppl 1:167-171