Matrix Metalloproteinase Inhibition With Doxycycline Affects the Progression of Posttraumatic Osteoarthritis After Anterior Cruciate Ligament Rupture: Evaluation in a New Nonsurgical Murine ACL Rupture Model

Abstract

Background: Doxycycline has broad-spectrum activity as a matrix metalloproteinase (MMP) inhibitor and thus could reduce the progression of posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament (ACL) rupture. Hypothesis: Doxycycline would inhibit progression of PTOA in a murine ACL rupture model. Study Design: Controlled laboratory study. Methods: For the in vitro study, cadaveric C57BL/6 male mice knees (N = 108) were used for the development of a nonsurgical ACL rupture model. For the in vivo study, 24 C57BL/6 male mice then underwent ACL rupture with our manual procedure and were divided into 4 groups: untreated control; doxycycline, 10 mg/kg/d; doxycycline, 50 mg/kg/d; and doxycycline, 100 mg/kg/d. Doxycycline was administered in drinking water beginning immediately after ACL rupture. Radiographic imaging and paw prints were evaluated at 3, 7, 14, and 28 days. The foot length and toe spread were analyzed as measures of function. Histology and MMP-13 immunohistochemistry were done at 4 weeks. Results: Radiographs demonstrated anterior tibial subluxation and meniscal extrusion after ACL rupture, confirming knee joint instability without fractures. Statistically significant differences in gait were found between the intact and experimental groups. Histologic examination demonstrated cartilage damage, meniscal tears, and mild osteoarthritis after ACL rupture, similar to what occurs in human patients. Hypertrophy of the posterior horn of the medial and lateral meniscus was found, and tears of the posterior horn of the menisci were common. All doxycycline groups had a lower score than the untreated control group, indicating less cartilage damage. The posterior tibia of the untreated group had the most cartilage damage as compared with the 3 doxycycline groups, with a significant difference between the untreated and 50-mg/kg/d doxycycline groups, suggesting that the latter dose may protect against proteoglycan loss and decrease the progression of osteoarthritis. The nondoxycycline group had the highest synovial inflammation score among all groups, indicating that doxycycline has an inhibitory effect on synovitis. There was significantly lower MMP-13 expression on the tibia in the doxycycline-treated groups, with a positive correlation between doxycycline concentration and MMP-13 inhibition. Conclusion: Modulation of MMP-13 activity by doxycycline treatment may offer a novel biological pathway to decrease the progression of PTOA after ACL rupture. Clinical Relevance: Doxycycline is an approved, readily available drug with infrequent side effects of photosensitivity and gastrointestinal symptoms. Future clinical trials could evaluate doxycycline to reduce or prevent progressive cartilage damage after ACL rupture.

A Systematic Review of Basic Science and Animal Studies on the Use of Doxycycline to Reduce the Risk of Posttraumatic Osteoarthritis After Anterior Cruciate Ligament Rupture/Transection

“…Seven studies 6,14,17,18,[20][21][22] met the inclusion criteria and were therefore included in this systematic review (Figure 1). Five studies were performed in dogs, 6,14,18,20,21 1 study in mice, 22 and 1 study in rabbits 17 (Table 1).…”

“…Adult dogs, 6,14,18,20,21 mice, 22 and rabbits 17 underwent ACL/CCL transection/rupture. In 3 studies, 14,20,21 dogs underwent CCL transection; in 1 study, 21 transection was performed 2 weeks after dorsal root ganglionectomy, and in another study, 14 transection was performed through a lateral arthrotomy.…”

“…One of these pathways is the inhibition of several matrix metalloproteinases (MMPs). 22 MMPs are responsible for degrading extracellular matrix proteins, and some MMPs, including MMP-13, have been shown to play a role in the pathogenesis of OA. 12 More specifically, there is increased MMP activity in osteoarthritic cartilage without an equivalent increase in tissue inhibitor of metalloproteinase.…”

Prevention of posttraumatic osteoarthritis at the time of injury: Where are we now, and where are we going?

“…All but one of these studies was in surgical models of PTOA, where the inflammatory and degenerative effects of sham surgery complicate the interpretation of any protective effects of treatment. Four recent studies published after the systematic PubMed search (Table 3, 2019–2020) exclusively use nonsurgical trauma models where treatment is given at the time of injury either orally (Doxycycline 23 or GKT137831 24 ) or as i.a. injection (dexamethasone, 25 2,3‐Dioxo‐6‐nitro‐1,2,3,4‐tetrahydrobenzo[f]quinoxaline‐7‐sulfonamide [NBQX] 26 ).…”

Combination of collagen scaffold with doxycycline for the treatment of cartilage and subchondral bone defects

“…The protective effect of doxycycline on cartilage precedents have been reported. [14][15][16][17] However, most of the studies focused on the ability of doxycycline to inhibit collagenases, such as MMP1, MMP9, and MMP13. 2,18 The finding in the present study indicates that the effects of doxycycline on chondrocytes could be much broader.…”