ACR Meeting Abstracts

ACR Meeting Abstracts

  • Meetings
    • ACR Convergence 2024
    • ACR Convergence 2023
    • 2023 ACR/ARP PRSYM
    • ACR Convergence 2022
    • ACR Convergence 2021
    • ACR Convergence 2020
    • 2020 ACR/ARP PRSYM
    • 2019 ACR/ARP Annual Meeting
    • 2018-2009 Meetings
    • Download Abstracts
  • Keyword Index
  • Advanced Search
  • Your Favorites
    • Favorites
    • Login
    • View and print all favorites
    • Clear all your favorites
  • ACR Meetings

Abstract Number: 2206

Dopamine Pathway and Bone Metabolism in Arthritis

Silvia Capellino1, Klaus W. Frommer1, Markus Rickert2, Jürgen Steinmeyer3, Stefan Rehart4, Ulf Müller-Ladner1 and Elena Neumann1, 1Internal Medicine and Rheumatology, Justus-Liebig-University of Giessen, Kerckhoff-Klinik, Bad Nauheim, Germany, 2Dept of Orthopedics and Orthopedic Surgery, University Hospital of Giessen and Marburg, Gießen, Germany, 3Dept Orthopedics and Experimental Orthopedics, University Hospital of Giessen and Marburg, Giessen, Germany, 4Orthopedics and Trauma Surgery, Markus-Hospital, Frankfurt, Germany

Meeting: 2015 ACR/ARHP Annual Meeting

Date of first publication: September 29, 2015

Keywords: bone remodeling, dopamine agonists, osteoarthritis and rheumatoid arthritis (RA)

  • Tweet
  • Email
  • Print
Session Information

Date: Tuesday, November 10, 2015

Title: Biology and Pathology of Bone and Joint: Bone Remodeling and Metabolism

Session Type: ACR Poster Session C

Session Time: 9:00AM-11:00AM

Background/Purpose: A body of studies demonstrates the influence of the nervous system on the immune response. We recently described that dopamine, a neurotransmitter of the sympathetic nervous system, is locally produced by synovial fibroblasts of rheumatoid arthritis (RA) patients and influences in vitro cytokine release and inflammation. In addition, in vivo evidence confirmed the involvement of dopamine receptors (DR) in arthritis, and a subtype of DR was described to be expressed by in vitro differentiated human osteoclasts. These studies, together with the clinical evidence of an increased risk of osteoporosis in patients affected by Parkinson’s disease, suggest an involvement of dopamine in joint destruction during RA. The aim of this study was therefore not only to investigate the role of the dopamine pathway on bone remodeling in RA patients, but also to unravel new pathways involved in joint destruction.

Methods: Bone tissue was obtained from osteoarthritis (OA, n=5) and RA (n=4) patients during knee joint replacement surgery. Osteoblasts were isolated from the bone spongiosa. Immunohistochemistry of paraffin-embedded bone samples and immunocytochemistry of isolated osteoblasts were performed using antibodies against the five subtypes of DR (D1 to D5). Isolated osteoblasts were treated with specific DR agonists for 24 h or 7 d. IL-6 and IL-8 were quantified after 24 h stimulation by ELISA, and expression of osteoblast activation markers was quantified after 7 d stimulation by real-time PCR. Mann Whitney test was used for statistical data analysis.

Results: Dopamine receptors D1, D3 and D4 could be detected by immunohistochemistry in the bone remodeling zone of RA patients while OA samples did not express these receptors in the bone remodeling zone. Dopamine receptor subtypes D1, D2, D3 and D5 were present on isolated osteoblasts, with stronger expression in RA compared to OA. Stimulation of DR with specific agonists induced a significant dose-dependent increase of IL-6 release in RA compared to the untreated control (D1-like agonist: +79 ±43%, P<0.005. D2-like agonist: +70 ±49%. n=4), but no significant effects were detectable for OA osteoblasts. IL-8 release was not significantly altered in both, RA and OA osteoblasts. DR activation inhibited mRNA expression of osteocalcin, collagen type I, alkaline phosphatase and osteoprotegerin in RA osteoblasts (up to -10% compared to untreated control, n=2). 

Conclusion: Dopamine receptors are upregulated in the bone remodeling zone of RA patients and their activation seems to have proinflammatory effects and to inhibit osteoblast activation. These data suggest an involvement of the dopamine pathway in bone remodeling and joint erosion in RA, and could open future perspectives to target joint destruction.


Disclosure: S. Capellino, None; K. W. Frommer, None; M. Rickert, None; J. Steinmeyer, None; S. Rehart, None; U. Müller-Ladner, None; E. Neumann, None.

To cite this abstract in AMA style:

Capellino S, Frommer KW, Rickert M, Steinmeyer J, Rehart S, Müller-Ladner U, Neumann E. Dopamine Pathway and Bone Metabolism in Arthritis [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/dopamine-pathway-and-bone-metabolism-in-arthritis/. Accessed .
  • Tweet
  • Email
  • Print

« Back to 2015 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/dopamine-pathway-and-bone-metabolism-in-arthritis/

Advanced Search

Your Favorites

You can save and print a list of your favorite abstracts during your browser session by clicking the “Favorite” button at the bottom of any abstract. View your favorites »

All abstracts accepted to ACR Convergence are under media embargo once the ACR has notified presenters of their abstract’s acceptance. They may be presented at other meetings or published as manuscripts after this time but should not be discussed in non-scholarly venues or outlets. The following embargo policies are strictly enforced by the ACR.

Accepted abstracts are made available to the public online in advance of the meeting and are published in a special online supplement of our scientific journal, Arthritis & Rheumatology. Information contained in those abstracts may not be released until the abstracts appear online. In an exception to the media embargo, academic institutions, private organizations, and companies with products whose value may be influenced by information contained in an abstract may issue a press release to coincide with the availability of an ACR abstract on the ACR website. However, the ACR continues to require that information that goes beyond that contained in the abstract (e.g., discussion of the abstract done as part of editorial news coverage) is under media embargo until 10:00 AM ET on November 14, 2024. Journalists with access to embargoed information cannot release articles or editorial news coverage before this time. Editorial news coverage is considered original articles/videos developed by employed journalists to report facts, commentary, and subject matter expert quotes in a narrative form using a variety of sources (e.g., research, announcements, press releases, events, etc.).

Violation of this policy may result in the abstract being withdrawn from the meeting and other measures deemed appropriate. Authors are responsible for notifying colleagues, institutions, communications firms, and all other stakeholders related to the development or promotion of the abstract about this policy. If you have questions about the ACR abstract embargo policy, please contact ACR abstracts staff at [email protected].

Wiley

  • Online Journal
  • Privacy Policy
  • Permissions Policies
  • Cookie Preferences

© Copyright 2025 American College of Rheumatology