Chemical modulation of SQSTM1/p62-mediated xenophagy that targets a broad range of pathogenic bacteria

Autophagy. 2022 Dec;18(12):2926-2945. doi: 10.1080/15548627.2022.2054240. Epub 2022 Apr 5.

Abstract

The N-degron pathway is a proteolytic system in which the N-terminal degrons (N-degrons) of proteins, such as arginine (Nt-Arg), induce the degradation of proteins and subcellular organelles via the ubiquitin-proteasome system (UPS) or macroautophagy/autophagy-lysosome system (hereafter autophagy). Here, we developed the chemical mimics of the N-degron Nt-Arg as a pharmaceutical means to induce targeted degradation of intracellular bacteria via autophagy, such as Salmonella enterica serovar Typhimurium (S. Typhimurium), Escherichia coli, and Streptococcus pyogenes as well as Mycobacterium tuberculosis (Mtb). Upon binding the ZZ domain of the autophagic cargo receptor SQSTM1/p62 (sequestosome 1), these chemicals induced the biogenesis and recruitment of autophagic membranes to intracellular bacteria via SQSTM1, leading to lysosomal degradation. The antimicrobial efficacy was independent of rapamycin-modulated core autophagic pathways and synergistic with the reduced production of inflammatory cytokines. In mice, these drugs exhibited antimicrobial efficacy for S. Typhimurium, Bacillus Calmette-Guérin (BCG), and Mtb as well as multidrug-resistant Mtb and inhibited the production of inflammatory cytokines. This dual mode of action in xenophagy and inflammation significantly protected mice from inflammatory lesions in the lungs and other tissues caused by all the tested bacterial strains. Our results suggest that the N-degron pathway provides a therapeutic target in host-directed therapeutics for a broad range of drug-resistant intracellular pathogens.Abbreviations: ATG: autophagy-related gene; BCG: Bacillus Calmette-Guérin; BMDMs: bone marrow-derived macrophages; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CFUs: colony-forming units; CXCL: C-X-C motif chemokine ligand; EGFP: enhanced green fluorescent protein; IL1B/IL-1β: interleukin 1 beta; IL6: interleukin 6; LIR: MAP1LC3/LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; Mtb: Mycobacterium tuberculosis; MTOR: mechanistic target of rapamycin kinase; NBR1: NBR1 autophagy cargo receptor; OPTN: optineurin; PB1: Phox and Bem1; SQSTM1/p62: sequestosome 1; S. Typhimurium: Salmonella enterica serovar Typhimurium; TAX1BP1: Tax1 binding protein 1; TNF: tumor necrosis factor; UBA: ubiquitin-associated.

Keywords: Inflammation; Mycobacterium tuberculosis; N-degron pathway; lysosomal degradation; selective autophagy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins / metabolism
  • Autophagy* / genetics
  • BCG Vaccine
  • Cytokines / metabolism
  • Macroautophagy*
  • Mice
  • Salmonella typhimurium / metabolism
  • Sequestosome-1 Protein / metabolism
  • Sirolimus / pharmacology
  • Ubiquitin / metabolism

Substances

  • Sequestosome-1 Protein
  • BCG Vaccine
  • Ubiquitin
  • Apoptosis Regulatory Proteins
  • Cytokines
  • Sirolimus
  • Sqstm1 protein, mouse

Grants and funding

This work was supported by the Basic Science Research Programs [2021R1A2B5B03002614and 2020R1A5A1019023 to Y.T.K.; 2021R1C1C1005184 and 2020M3A9H5104237 to J.Y.; 2017R1A5A2015385 to E.-K.J.] through the National Research Foundation of Korea funded by the Ministry of Science, ICT, and Future Planning (MSIP). This work was also supported by the international cooperation program managed by the NRF [2015K2A2A6002008 to E.-K.J.], the Seoul National University Hospital (to Y.T.K.), and the SNU Startup Fund (to J.Y.)