1
|
Berquez M, Chen Z, Festa BP, Krohn P, Keller SA, Parolo S, Korzinkin M, Gaponova A, Laczko E, Domenici E, Devuyst O, Luciani A. Lysosomal cystine export regulates mTORC1 signaling to guide kidney epithelial cell fate specialization. Nat Commun 2023; 14:3994. [PMID: 37452023 PMCID: PMC10349091 DOI: 10.1038/s41467-023-39261-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 06/06/2023] [Indexed: 07/18/2023] Open
Abstract
Differentiation is critical for cell fate decisions, but the signals involved remain unclear. The kidney proximal tubule (PT) cells reabsorb disulphide-rich proteins through endocytosis, generating cystine via lysosomal proteolysis. Here we report that defective cystine mobilization from lysosomes through cystinosin (CTNS), which is mutated in cystinosis, diverts PT cells towards growth and proliferation, disrupting their functions. Mechanistically, cystine storage stimulates Ragulator-Rag GTPase-dependent recruitment of mechanistic target of rapamycin complex 1 (mTORC1) and its constitutive activation. Re-introduction of CTNS restores nutrient-dependent regulation of mTORC1 in knockout cells, whereas cell-permeant analogues of L-cystine, accumulating within lysosomes, render wild-type cells resistant to nutrient withdrawal. Therapeutic mTORC1 inhibition corrects lysosome and differentiation downstream of cystine storage, and phenotypes in preclinical models of cystinosis. Thus, cystine serves as a lysosomal signal that tailors mTORC1 and metabolism to direct epithelial cell fate decisions. These results identify mechanisms and therapeutic targets for dysregulated homeostasis in cystinosis.
Collapse
Affiliation(s)
- Marine Berquez
- Institute of Physiology, University of Zurich, 8057, Zurich, Switzerland
| | - Zhiyong Chen
- Institute of Physiology, University of Zurich, 8057, Zurich, Switzerland
| | | | - Patrick Krohn
- Institute of Physiology, University of Zurich, 8057, Zurich, Switzerland
| | | | - Silvia Parolo
- Fondazione The Microsoft Research University of Trento-Centre for Computational and Systems Biology (COSBI), 38068, Rovereto, Italy
| | - Mikhail Korzinkin
- Insilico Medicine Hong Kong Ltd., Hong Kong Science and Technology Park, Hong Kong, Hong Kong SAR, China
| | - Anna Gaponova
- Insilico Medicine Hong Kong Ltd., Hong Kong Science and Technology Park, Hong Kong, Hong Kong SAR, China
| | - Endre Laczko
- Functional Genomics Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Enrico Domenici
- Fondazione The Microsoft Research University of Trento-Centre for Computational and Systems Biology (COSBI), 38068, Rovereto, Italy
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123, Trento, Italy
| | - Olivier Devuyst
- Institute of Physiology, University of Zurich, 8057, Zurich, Switzerland.
- Institute for Rare Diseases, UCLouvain Medical School, 1200, Brussels, Belgium.
| | - Alessandro Luciani
- Institute of Physiology, University of Zurich, 8057, Zurich, Switzerland.
| |
Collapse
|