Fig 1: RSK-3 activates rpS6, but not autophagy, to regulate CSPCs proliferation. The proliferative ability of CSPCs from C57/BL6J mice after RSK-3 inhibitor (BI-D1870) and mTOR inhibitor (rapamycin) treatment detected by CCK-8 assay (A) and Ki67 labeling (B). (C,D) Protein expression of RSK-3, p-RSK-3, mTOR, p-mTOR, p-rpS6 and rpS6 in CSPCs from C57/BL6J mice and the corresponding quantifications. (E) p-RSK-3, p-mTOR and LC3 immunolabeling in CSPCs from C57/BL6J mice. *p < 0.05, **p < 0.01, ***p < 0.001 versus control, ##p < 0.01, ###p < 0.001 versus BI-D1870 (n = 6 per group). Scale bars = 100 µm.
Fig 2: CSPCs from MRL/MpJ mice show high expression levels of rpS6 and autophagy. (A) Protein expression of p-rpS6, rpS6, p-mTOR and mTOR in CSPCs from STR/Ort, CBA and MRL/MpJ mouse. Immunolabeling of p-RSK-3 (B) and LC3 (C) in cartilage isolated from each mouse strain. Scale bars = 50 µm. *p < 0.05, **p < 0.01, ***p < 0.001 versus STR/Ort (n = 6 per group).
Fig 3: RSK-3 promotes cell proliferation by regulating rpS6 and autophagy. Effects of downregulated RSK-3 in MRL/MpJ CSPCs (A) and overexpressed (OE) RSK-3 in STR/Ort CSPCs (B) on the protein expression of p-rpS6, rpS6, p-mTOR and mTOR. *p < 0.05, **p < 0.01, ***p < 0.001 versus STR/Ort (n = 6 per group). (C) Immunolabeling of p-mTOR and LC3 in articular cartilage after DMM injury in normal and RSK-3-/- mice. **p < 0.01, ***p < 0.001 versus sham (RSK-3+/+), #p < 0.05, ###p < 0.001 versus DMM (RSK-3+/+) (n = 6 per group). Scale bars = 100 µm.
Supplier Page from Abcam for Anti-RPS6 (phospho S235 + S236) antibody