title: RNA-seq from whole osteoarthritic murine knee joint induced by CiOA model and spontaneous age-related model in p21/mTERT transgenic mice and their littermate controls
design: RNA-seq from whole osteoarthritic murine knee joint induced by CiOA model and spontaneous age-related model in p21/mTERT transgenic mice and their littermate controls
library_construction_protocol: Harvested knees joint were dissected using surgical scissors, snap frozen immediately, and then stored in liquid nitrogen until the extraction step. Protocol for young mice: The induction of osteoarthritis will be performed by injecting 5 μl of type VII collagenase (1U/5μl) into the joint of one of the mouse's knees on day 0 and day 2 (the other knee being injected with physiological saline solution). The mice will be anesthetized with isoflurane, and the leg will be shaved at the knee joint. A small incision (2mm) of the skin will be made at the central part of the joint. The needle of a 10μl Hamilton syringe will be inserted at the center of the patellar tendon to reach the intra-articular space, and the collagenase solution (or the  physiological saline solution for the Sham knee joint) will be injected. The wound is sterilized with betadine. CiOA mice were euthanized at day 42 after the first collagenase injection. Protocol for old mice: Osteoarthritis in older mice is spontaneous age-related. Therefore, the mice underwent no interventions. They were simply euthanized at 18 months.  The grinding of the whole joint was performed using a pestle and mortar in liquid nitrogen. Total RNA from the resulting powder tissue was extracted using TRI Reagent (Sigma Aldrich #T94424) and RNeasy Kit (QIAGEN) according to the manufacturer's instructions. The quantity and quality of extracted RNA was evaluated using the NanoDrop ND-1000 spectrophotometer and the Agilent 2100.  Nucleic acid library construction protocol was performed according to the manufacturer's instructions by the Beijing Genomic Institute (BGI).