MP03-02 DEREGULATED MTOR IS RESPONSIBLE FOR AUTOPHAGY DEFECT EXACERBATING KIDNEY STONE DEVELOPMENT

INTRODUCTION AND OBJECTIVES:We found that cellular damage caused by calcium oxalate (CaOx) was repaired by the induction of autophagy using renal tubule cultured cells and CaOx crystal model mice, and the failure of the repair mechanism caused kidney stones. In this study, we focused on selective autophagy and upstream regulatory factors mTORC1 and transcription factor TFEB and tried to elucidate the mechanism of calculus formation.METHODS:In vitro: We exposed renal tubular cells to calcium oxalate monohydrate (COM) crystals at a concentration of 20 μg/cm2, and autophagy was examined by immunostaining and Western-blot. mTORC1 activity was examined by Western blotting of phosphorylated S6 kinase, and nuclear import of TFEB was examined by transfection of GFP-TFEB.In vivo:We used autophagy visualization (GFP-LC3) mice, and kidney crystal formation in mice was induced by daily intra-abdominal injection of 80 mg/kg−1 glyoxylic acid. We investigated autophagy by immunostaining and Western blotting. Finally, we...