lysosomal function, immunohistochemistry and an autophagy flux assay kit were employed.Additionally, immunofluorescence costaining for LAMP2 and LC3B was performed to evaluate autolysosome formation.Results: RBM3 knockout mice exhibited significantly aggravated renal injury compared with wild-type AKI controls.In both in vivo and in vitro models, RBM3 deficiency impaired autophagic flux, as evidenced by LC3B and LAMP2 immunofluorescence, p62 accumulation, and autophagy flux assays.Mechanistically, the loss of RBM3 diminished lysosomal degradative capacity, thereby disrupting autophagic progression.To compensate for the incomplete autophagy caused by RBM3 deficiency, excessive autophagic activity was induced, accompanied by mTORC1 suppression and activation of lysosomal factors including TFEB, LAMP2, and cathepsins B/D.This dysregulated autophagy ultimately resulted in exacerbated tubular injury, increased apoptosis, and worsened renal dysfunction in both RBM3 knockout mice and RBM3-silenced HK-2 cells.Conversely, mild hypothermiainduced RBM3 overexpression in HK-2 cells enhanced autophagic activity and preserved cellular integrity.Conclusion: These findings demonstrate that RBM3 serves a crucial protective role in maintaining renal homeostasis during AKI.RBM3 deficiency leads to impaired autophagy completion, lysosomal dysfunction, and aggravated tubular injury.Conversely, RBM3 restoration mitigates renal damage and activates autophagic flux by sustaining lysosomal degradative capacity and preventing excessive compensatory activation of autophagy.These results suggest that RBM3 may serve as a potential therapeutic target for preserving autophagic flux and attenuating renal injury in AKI.
Takahashi et al. (Wed,) studied this question.