STING mediates lysosomal quality control and recovery through its proton channel function and TFEB activation in lysosomal storage disorders

Lysosomes are essential organelles for cellular homeostasis. Defective lysosomes are associated with diseases like lysosomal storage disorders (LSDs). How lysosomal defects are detected and lysosomal function restored remain incompletely understood. Here, we show that STING mediates a neuroinflammatory gene signature in three distinct LSD mouse models, Galc^twi/twi, Ppt1^-/-, and Cln7^-/-. Transcriptomic analysis of Galc^twi/twi mouse brain tissue revealed that STING also mediates the expression of lysosomal genes that are regulated by transcriptional factor EB (TFEB). Immunohistochemical and single-nucleus RNA-sequencing (snRNA-seq) analysis show that STING regulates lysosomal gene expression in microglia. Mechanistically, we show that STING activation leads to TFEB dephosphorylation, nuclear translocation, and expression of lysosomal genes. This process requires STING's proton channel function, the V-ATPase-ATG5-ATG8 cascade, and is independent of immune signaling. Furthermore, we show that the STING-TFEB axis facilitates lysosomal repair. Together, our data identify STING-TFEB as a lysosomal quality control mechanism that responds to lysosomal dysfunction.

Krabbe disease; Niemann-Pick disease; STING; TFEB; innate immunity; lysosomal storage disorder; lysosome repair; neuroinflammation; non-canonical autophagy.