Experimental design
A total of 84 rats were included in the two experiments of this study.
The experimental timeline and the sample size of rats are illustrated in
Figure 1. Experiment 1 included 36 rats and were randomly divided into
the control group, OA group and OA+HIIT group (N = 12/group). Experiment
2 included 48 OA rats and were randomly divided into the OA group,
OA+HIIT group, OA+C-A1 group, and OA+C-A1+HIIT group (N= 12/group).
Jak2/Stat3 pathway activator (C-A1, 100ug/kg/d, MedChemExpress, New
Jersey, USA) was administered by intraperitoneal injection in the third
week for 28 days [24]. HIIT treatments were conducted in the fourth
week and continued for six weeks. After six weeks of exercise, the L3-L5
segments of the spinal cord tissue were harvested and analyzed by
proteomics sequencing, quantitative real-time polymerase chain reaction
(qRT-PCR), flow cytometry, Western blot (WB) and immunofluorescence
(IF). Immunohistochemistry (IHC) was used to detect the matrix
metalloproteinase 13 (MMP-13) and IL-6 in the extracellular matrix of
articular cartilage.