tRNA-Derived Fragment tRF-5009A Regulates Autophagy and Degeneration of Cartilage in Osteoarthritis via Targeting mTOR

Figure 5

tRF-5009A inhibitor suppresses autophagy and promotes degeneration of OA cartilage. (a) Inhibitor efficiency of tRF-5009A by qRT-PCR. (b) qRT-PCR analysis of the expression of mTOR, COL2A1, and MMP13 after 24 h of OA cell transfection with a tRF-5009A inhibitor. (c) Western blotting results of COL2A1, MMP13, LC3, p62, Beclin1, ATG13, p-ULK1, ULK1, and mTOR. (d, e) Quantification analysis of western blotting results. (f) Expression of mTOR detected by immunofluorescence. (g) Double labelling with mRFP-GFP-LC3 adenovirus and (h) quantification of mRFP and merge dots per cell in chondrocytes. mRFP (red) represents autolysosomes (ALs); merge (yellow) represents autophagosomes (APs). (i) Transmission electron microscopy (TEM) analysis (blue arrows = APs and ALs) and (j) quantitative analysis. (k) Levels of reactive oxygen species (ROS) analyzed by DCFH-DA staining and (l) quantification analysis of mean fluorescence intensity (MFI). (m) Evaluation of cell apoptosis rate by flow cytometry. All data were expressed as the . ns: not significant, .

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