Date of Award
2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Biotechnology Science and Engineering
Committee Chair
Anu Subramanian
Committee Member
Luis R. Cruz-Vera
Committee Member
Ahmed Lawan
Committee Member
Kyung-Ho Roh
Committee Member
Rosa A. Serra
Research Advisor
Anu Subramanian
Subject(s)
Inflammation--Treatment, Osteoarthritis--Treatment, Synovial fluid, Ultrasonic waves--Therapeutic use
Abstract
Post-traumatic osteoarthritis (PTOA), a subset of OA caused by direct injury or repetitive microtrauma, results in a robust release of inflammatory mediators. If inadequately controlled, this pro-inflammatory phase leads to early tissue damage. The biomedical burden of PTOA is significant and inadequately addressed due to difficulties in identifying the disease onset, slow progression, and incomplete understanding of its etiology and pathogenesis. However, PTOA's distinct initiating events allow for early intervention. This thesis investigates whether fibronectin fragments (FnFs) can induce an early inflammatory response in a triple cellular in vitro model of early PTOA and whether continuous low-intensity ultrasound (cLIUS) can provide anti-inflammatory effects in this model. The study found that FnFs levels are higher in synovial fluids of OA patients and in media containing blunt-impacted cartilage explants. FnFs, as danger-associated molecular patterns (DAMPs), activate macrophages similarly to post-trauma. Exogenously administered FnFs were used to examine early inflammatory processes in chondrocytes, synovial fibroblasts, and macrophages. The hypothesis was that cLIUS would have anti-inflammatory effects and mitigate early inflammatory cascades. cLIUS was applied for 12 days to the in vitro PTOA model, with IL4 used as a treatment control. Results showed that cLIUS downregulated key chemokines and cytokines and catabolic genes. It also upregulated the M2 macrophage marker CD163, indicating macrophage polarization. In conclusion, cLIUS demonstrated therapeutic potential in reducing early inflammatory biomarkers in an FnF-induced early PTOA model, showing promise for improving early inflammatory processes in both PTOA and OA. This thesis comprises three chapters that collectively advance the understanding and potential treatment of early PTOA. Chapter 1 introduces PTOA, detailing the cell types, models, and biomarkers involved, and sets the thesis's objectives and hypothesis. Chapter 2 develops an in-vitro model of early PTOA using Fnfs, establishing a triple cell-culture system that mimics the disease's inflammatory response. Chapter 3 explores the therapeutic potential of cLIUS, demonstrating its ability to mitigate catabolic effects and promote anti-inflammatory macrophage polarization in the in-vitro PTOA model. Chapter 4 uses a transcriptomic approach to elucidate the molecular mechanisms behind cLIUS-induced inflammation rescue, providing insights into cLIUS as a potential disease-modifying therapy for PTOA.
Recommended Citation
Khan, Shahid, "Mitigation of inflammation in early post-traumatic osteoarthritis through low-intensity ultrasound" (2024). Dissertations. 413.
https://louis.uah.edu/uah-dissertations/413