Murine Osteoarthritis Induction and Evaluation

All mice were housed on a 12-hour light/dark cycle with unrestricted access to standard mouse food and water. C57/Bl6 wild type mice were randomly designated into 2 groups: DMM and SHAM, and three termination time-points (2, 5 and 10 weeks post-surgery). DMM or sham surgery was performed when mice were 12 weeks of age. All animals were housed and used in accordance with Western University’s Animal Care and Use Guidelines. The protocol was approved by the Animal Care and Veterinary Services of Western University (protocol# 2015-031). Surgery was performed on the left knee joint of mice as previously described^{20 (link),21 (link)}. A single dose of Amoxicillin (Novopharm, Toronto, Ontario, Canada) was injected subcutaneously right after the surgery to prevent joint infection (20 mg/kg). Buprenorphine (Schering-Plough, Herfordshire, UK) was administered twice (0 and 4 hours after surgery) subcutaneously to minimized pain (0.05 mg/kg). Mice were housed in colony cage after the surgery (up to 6 mice in one cage) and running wheels were put in two days after the surgery to encourage exercise. Excluding the mice that had dislocated patella after surgery (discussed in Results and Discussion Sections), the final size of each group was as followed: DMM group (2W: 6, 5W: 8, 10W: 6), SHAM group (2W: 5, 5W: 7, 10W: 6).