# Role of CCR2 in osteoarthritis > **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2024 · $487,422 ## Abstract PROJECT ABSTRACT Joint damage caused by trauma can proceed to post-traumatic osteoarthritis (PTOA). Published data from us and literature demonstrated the importance of the CC-chemokine receptor 2 (CCR2) and its ligand CCL2 in OA. CCL2 is the most abundant ligand in humans, and we reported that high serum CCL2 is associated with radiographic knee OA onset at 5 year followups and correlates with cartilage damage following ACL reconstruction. Animal studies showed that PTOA progression can be slowed by pharmacological CCR2 targeting or by early ccr2 gene deletion in chondrocytes or osteoblasts. We and others have reported a major role for CCR2 in chronic and acute pain. Macrophages play a role in OA onset, progression and pain and CCL2 is a powerful chemoattractant for macrophages. However, it is unknown how macrophage infiltration correlates to PTOA damage and how CCL2/CCR2 contributes to macrophage activation vs an inflammatory phenotype. Therefore, in the efforts to identify PTOA treatments that can impact multiple tissue degeneration, inflammation, and pain, targeting CCL2/CCR2 axis may represent an ideal choice. Muscles absorb the loads of articular joints and muscle dysfunction may precede and expedite cartilage deterioration. Literature and our preliminary data in PTOA showed a decreased expression of critical genes required in muscular excitation/contraction, followed by loss of muscle strength. However, how muscle changes relate to PTOA is unclear. We hypothesize that, following injury, the CCR2-mediated tissue damage (in cartilage, bone and synovium) and increased inflammation (in joints as well as systemically) can be reduced by treatment with the RS antagonist, alleviating pain and improving muscle strength. In order to develop therapeutic methods for efficient CCR2 targeting in PTOA, our proposal will establish: 1) the molecular events leading to the tissue degeneration and macrophage activation induced by CCR2 and how they correlate to pain and muscle damage; 2) the CCR2 contribution to macrophage polarization vs an inflammatory phenotype (M1) at different disease stages; 3) the interconnection among joint structure, muscle strength and pain; 4) two efficient drug delivery systems for tissue targeting, avoiding extended high- dose exposure while protecting the drug from degradation. To accomplish these objectives, we will use an inter- disciplinary combination of in-vivo studies in a rat PTOA model in the following aims: in Aim 1 we will determine the therapeutic potential of intra-articular CCR2 targeting on joint degeneration, inflammation, muscle weakness, and pain during PTOA using biodegradable microplates for sustained local release. In Aim 2 we will specifically target activated macrophages systemically and assess their contribution of to PTOA and pain; moreover, we will use activated macrophages to systemically deliver RS to inflamed tissues to determine its contribution to macrophage activation and phenotype while improving j... ## Key facts - **NIH application ID:** 10879280 - **Project number:** 2R01AR070821-06A1 - **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL - **Principal Investigator:** Lara Longobardi - **Activity code:** R01 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $487,422 - **Award type:** 2 - **Project period:** 2017-08-01 → 2029-05-31 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10879280 ## Citation > US National Institutes of Health, RePORTER application 10879280, Role of CCR2 in osteoarthritis (2R01AR070821-06A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10879280. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*