Immunohistochemical panel of degenerated articular discs from patients with temporomandibular joint osteoarthritis

Abstract

Background Temporomandibular joint osteoarthritis (TMJOA) is a progressive degenerative disease caused by imbalance between anabolic and catabolic stimuli. Objective The aim of this study was to evaluate histopathological changes, collagen degeneration and the expression of eleven TMJOA biomarkers in articular discs. Methods Specimens were obtained from eight female patients submitted to discectomy. Discs were divided into anterior band (AB), intermediate zone (IZ) and posterior band (PB) for computerised histomorphometric analyses. Each was assigned a histopathological degeneration score (HDS). Collagen degeneration was assessed with Picrosirius‐polarisation method. Biomarkers were evaluated through immunohistochemistry, including IGF‐1, OPG, VEGF, TNF‐α, FGF‐23, IHH, MMP‐3, MMP‐9, TGF‐β1, BMP‐2 and WNT‐3. Image processing software was used to calculate average immature collagen ratios and immunostained areas. Spearman rank tests were applied to verify correlations, with significance level of 0.05. Results The HDS showed negative correlation with expression of VEGF in IZ and PB (P < .05) and positive with TNF‐α in AB (P < .01). Collagen degeneration correlated with TGF‐β1 (P < .05), BMP‐2 (P < .01) and IHH (P < .05) immunostained areas in the IZ; TGF‐β1, BMP‐2 and IHH expression correlated among each other in AB and IZ (P < .05). Conclusion Angiogenesis and tissue fragmentation may result from aberrant physiologic responses mediated by VEGF and TNF‐α, compromising TMJ discs during OA progression. The expression of TGF‐β1, BMP‐2 and IHH could be related to collagen degeneration in displaced discs and may participate in TMJOA pathogenesis.

Enriched Peripheral Blood-Derived Mononuclear Cells for Treating Knee Osteoarthritis

“…In the pilot human clinical trial, we demonstrated that MoFi-processed PBMNCs effectively ameliorated pain and stiffness in OA patients. The administration of the PBMNCs might prohibit the inflammatory response of synovial tissues by suppressing IL-1, TNF-α, and C-reactive protein (CRP) expression and decreasing bone marrow lesions or edema (BML/BME) and synovitis even at the late stage of KOA 23 , 24 . The validation of the anti-inflammatory effects of PBMNCs injection in humans requires further magnetic resonance imaging (MRI) to examine the reduced knee synovitis and BML at 1 year and 2 years post-treatment 25 , 26 .…”

Mechanical overload induces TMJ disc degeneration via TRPV4 activation

“…The temporomandibular joint (TMJ) disc cushions and redistributes the mechanical load on condyles during mandibular movements (Tanaka & van Eijden, 2003). Degenerative joint disease of the TMJ is common and affects 17.97%–77.23% of patients with TMJ disorders (Pantoja et al, 2019; Valesan et al, 2021); it is characterized by the release of inflammatory cytokines and overexpression of catabolic biomarkers, such as matrix metalloproteinases (MMPs) (Fernandes et al, 2020; Leonardi et al, 2007). Local inflammation damages the micro‐environment around TMJ disc cells and deteriorates the TMJ disc ultrastructure and its nanomechanical properties (Cui et al, 2019).…”

“…biomarkers, such as matrix metalloproteinases (MMPs) (Fernandes et al, 2020;Leonardi et al, 2007). Local inflammation damages the micro-environment around TMJ disc cells and deteriorates the TMJ disc ultrastructure and its nanomechanical properties (Cui et al, 2019).…”