Date of Award

Fall 12-15-2025

Degree Type

Dissertation

Degree Name

PhD Molecular Bioscience

Department

Biology

Advisor

Jessica Cottrell, Ph.D.

Committee Member

Jane Ko, P.hD.

Committee Member

J. Patrick O’Connor, PhD, MS

Committee Member

C.J. Urso, Ph.D.

Committee Member

Constantine Bitsaktsis, Ph.D.

Keywords

Rheumatoid Arthritis, Organoid, Bone-Cartilage Interface

Abstract

Rheumatoid Arthritis (RA) is a chronic autoimmune disease characterized by synovial inflammation, cartilage degradation, and bone erosion. Fibroblast-like synoviocytes (FLS) play a critical role in RA joint destruction. Despite advances in therapy, current treatments do not fully address the fibroblast-driven pathology, and relevant in vitro models are not capable of capturing this aspect of disease. To address this gap, we developed and validated a novel three-dimensional (3D) Fibrotic RA bone-cartilage interface (BCI) model that integrates osteoblasts, osteoclasts, chondrocytes, peripheral immune cells, and RA-FLS in a single organoid. The model was first established using mouse-derived cell lines and subsequently adapted to incorporate primary human mesenchymal stem cell-derived osteoblasts, peripheral blood mononuclear cell-derived osteoclasts and lymphocytes, immortalized human chondrocyte spheroids, and SW982 RA-FLS. RA-like conditions were induced using a cytokine cocktail of TNF-α, IL-1β, and TGF-β, resulting in upregulation of inflammatory mediators, matrix-degrading enzymes, and fibrotic gene expression, accompanied by increased calcium deposition, visible bone degradation, and immune cell and RA-FLS infiltration.

Therapeutic testing reveals that methotrexate, etanercept, and tofacitinib reduced certain pro-inflammatory mediators but had limited impact on fibrotic remodeling, consistent with clinical limitations of these agents. In contrast, antifibrotic agents nintedanib and pirfenidone significantly reduced fibrotic gene expression and FLS proliferation, highlighting their potential to complement current anti-inflammatory therapies. The Fibrotic RA BCI model provides a physiologically relevant, modular, and adaptable platform for studying disease mechanisms and evaluating candidate therapeutics that target both immune-mediated inflammation and fibroblast-induced joint damage. This system has the potential to improve translational relevance in preclinical drug discovery and may be adapted for other joint disorders, including osteoarthritis and ankylosing spondylitis, thereby broadening its utility in preclinical research.

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