Aims: The small Heat Shock Protein B8 (HSPB8) is the core component of the chaperone-assisted selective autophagy (CASA) complex. This complex selectively targets, transports, and tags misfolded proteins for their recognition by autophagic receptors and insertion into autophagosome for clearance. CASA is essential to maintain intracellular proteostasis, especially in heart, muscle, and brain often exposed to various types of cell stresses. In neurons, HSPB8 protects against neurotoxicity caused by misfolded proteins in several models of neurodegenerative diseases; by facilitating autophagy, HSPB8 assists misfolded protein degradation also counteracting proteasome overwhelming and inhibition. Materials and Methods: To enhance HSPB8 protective activity, we screened a library of approximately 120,000 small molecules to identify compounds capable of increasing HSPB8 gene transcription, translation, or protein stability. We found 83 compounds active in preliminary dose-response assays and further classified them in 19 chemical classes by medicinal chemists' visual inspection. Of these 19 prototypes, 14 induced HSPB8 mRNA and protein levels in SH-SY5Y cells. Key findings: Out of these 14, 3 successfully reduced the aggregation propensity of a disease-associated mutant misfolded Superoxide Dismutase 1 (SOD1) protein in a flow cytometry-based “aggregation assay” [Flow cytometric analysis of Inclusions and Trafficking” (FloIT)] and induced the expression (mRNA and protein) of some autophagy receptors. Notably, the 3 hits were inactive in HSPB8-depleted cells, confirming that their protective activity is mediated by and requires HSPB8. Significance: Thus, these compounds may be highly relevant for a therapeutic approach in several human disorders, including neurodegenerative diseases, in which enhancement of CASA exerts beneficial activities.

Identification of HSPB8 modulators counteracting misfolded protein accumulation in neurodegenerative diseases / M. Chierichetti, M. Cerretani, A. Ciammaichella, V. Crippa, P. Rusmini, V. Ferrari, B. Tedesco, E. Casarotto, M. Cozzi, F. Mina, P. Pramaggiore, M. Galbiati, M. Piccolella, A. Bresciani, R. Cristofani, A. Poletti. - In: LIFE SCIENCES. - ISSN 0024-3205. - (2022). [Epub ahead of print] [10.1016/j.lfs.2022.121323]

Identification of HSPB8 modulators counteracting misfolded protein accumulation in neurodegenerative diseases

M. Chierichetti
Primo
;
V. Crippa;P. Rusmini;V. Ferrari;B. Tedesco;E. Casarotto;M. Cozzi;F. Mina;P. Pramaggiore;M. Galbiati;M. Piccolella;R. Cristofani
Penultimo
;
A. Poletti
Ultimo
2022

Abstract

Aims: The small Heat Shock Protein B8 (HSPB8) is the core component of the chaperone-assisted selective autophagy (CASA) complex. This complex selectively targets, transports, and tags misfolded proteins for their recognition by autophagic receptors and insertion into autophagosome for clearance. CASA is essential to maintain intracellular proteostasis, especially in heart, muscle, and brain often exposed to various types of cell stresses. In neurons, HSPB8 protects against neurotoxicity caused by misfolded proteins in several models of neurodegenerative diseases; by facilitating autophagy, HSPB8 assists misfolded protein degradation also counteracting proteasome overwhelming and inhibition. Materials and Methods: To enhance HSPB8 protective activity, we screened a library of approximately 120,000 small molecules to identify compounds capable of increasing HSPB8 gene transcription, translation, or protein stability. We found 83 compounds active in preliminary dose-response assays and further classified them in 19 chemical classes by medicinal chemists' visual inspection. Of these 19 prototypes, 14 induced HSPB8 mRNA and protein levels in SH-SY5Y cells. Key findings: Out of these 14, 3 successfully reduced the aggregation propensity of a disease-associated mutant misfolded Superoxide Dismutase 1 (SOD1) protein in a flow cytometry-based “aggregation assay” [Flow cytometric analysis of Inclusions and Trafficking” (FloIT)] and induced the expression (mRNA and protein) of some autophagy receptors. Notably, the 3 hits were inactive in HSPB8-depleted cells, confirming that their protective activity is mediated by and requires HSPB8. Significance: Thus, these compounds may be highly relevant for a therapeutic approach in several human disorders, including neurodegenerative diseases, in which enhancement of CASA exerts beneficial activities.
HSPB8; cancer; neurodegenerative disorders; neuromuscular disorders; chaperone-assisted selective autophagy; proteasome
Settore BIO/13 - Biologia Applicata
Settore BIO/09 - Fisiologia
INTLI19RCRIS_01 - Selective translation of androgen receptor isoform A to prevent polyQ mediated toxicity in Kennedy’s disease - CRISTOFANI, RICCARDO MARIA - INTLI - Finanziamenti internazionali - 2019
FON_NAZ19APOLE_03 - Alternative translation initiation as a novel strategy to block toxicity of the mutant Androgen Receptor in SBMA - POLETTI, ANGELO - FON_NAZ - Bandi Altre Fondazioni - 2019
INTLI21MGALB_01 - Unveiling regenerative and metabolic features of SBMA muscle cells to identify new therapeutic targets - GALBIATI, MARIARITA - INTLI - Finanziamenti internazionali - 2021
CAR_RIC22RCRIS_01 - Role of CHIP/STUB1 in the clearance of toxic proteins responsible for repeat expansion neurodegenerative diseases - CRISTOFANI, RICCARDO MARIA - CAR_RIC - Bandi Fondazione Cariplo - 2022
FON_NAZ19APOLE_02 - Membrane-less organelle pathology in ALS: identification of causes and rescuing factors (MLOMALS) - POLETTI, ANGELO - FON_NAZ - Bandi Altre Fondazioni - 2019
FON_NAZ19APOLE_01 - Targeting RAN translation in ALS (Target-RAN) - POLETTI, ANGELO - FON_NAZ - Bandi Altre Fondazioni - 2019
INTLI21APOLE_01 - The involvement of the small heat shock protein HSPB8 in amyotrophic lateral sclerosis - POLETTI, ANGELO - INTLI - Finanziamenti internazionali - 2021
PRIN201719APOLE_01 - The interplay between the “rna/protein quality control system” and “exosomes” as a spreading mechanism in amyotrophic lateral sclerosis (EX_ALS) - POLETTI, ANGELO - PRIN2017 - PRIN bando 2017 - 2019
PRIN202022VCRIP_01 - Role of TDP-43 self-assembly in health and disEase: molecular characteristics, cellular Aspects and animal Models - CRIPPA, VALERIA - PRIN2020 - PRIN bando 2020 - 2022
AL_RIC18APOLE_01 - Colchicine for Amyotrophic Lateral Sclerosis: a phase II, randomized, double blind, placebo controlled, multicenter clinical trial (Co-ALS) - POLETTI, ANGELO - AL_RIC - Bandi da altri enti di ricerca - 2018
PNRR_RS22ACASE_01 - National Center for Gene Therapy and Drugs based on RNA Technology - TORRENTE, YVAN - Progetti PNRR - per il potenziamento di strutture di ricerca e creazioni di campioni nazionali di R&S - 2022
Article (author)
File in questo prodotto:
File Dimensione Formato  
1-s2.0-S0024320522010232-main.pdf

accesso aperto

Descrizione: In Press, Journal Pre Proof
Tipologia: Publisher's version/PDF
Dimensione 10.14 MB
Formato Adobe PDF
10.14 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/949710
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact