17-AAG-induced activation of the autophagic pathway in Leishmania is associated with parasite death

Petersen, A. L. d. O. A., Cull, B., Dias, B. R. S., Palma, L. C., Luz, Y. d. S., de Menezes, J. P. B., Mottram, J. C. and Veras, P. S. T. (2021) 17-AAG-induced activation of the autophagic pathway in Leishmania is associated with parasite death. Microorganisms, 9(5), 1089. (doi: 10.3390/microorganisms9051089) (PMID:34069389) (PMCID:PMC8158731)

Abstract

The heat shock protein 90 (Hsp90) is thought to be an excellent drug target against parasitic diseases. The leishmanicidal effect of an Hsp90 inhibitor, 17-N-allylamino-17-demethoxygeldanamycin (17-AAG), was previously demonstrated in both in vitro and in vivo models of cutaneous leishmaniasis. Parasite death was shown to occur in association with severe ultrastructural alterations in Leishmania, suggestive of autophagic activation. We hypothesized that 17-AAG treatment results in the abnormal activation of the autophagic pathway, leading to parasite death. To elucidate this process, experiments were performed using transgenic parasites with GFP-ATG8-labelled autophagosomes. Mutant parasites treated with 17-AAG exhibited autophagosomes that did not entrap cargo, such as glycosomes, or fuse with lysosomes. ATG5-knockout (Δatg5) parasites, which are incapable of forming autophagosomes, demonstrated lower sensitivity to 17-AAG-induced cell death when compared to wild-type (WT) Leishmania, further supporting the role of autophagy in 17-AAG-induced cell death. In addition, Hsp90 inhibition resulted in greater accumulation of ubiquitylated proteins in both WT- and Δatg5-treated parasites compared to controls, in the absence of proteasome overload. In conjunction with previously described ultrastructural alterations, herein we present evidence that treatment with 17-AAG causes abnormal activation of the autophagic pathway, resulting in the formation of immature autophagosomes and, consequently, incidental parasite death.

• Item Type: Articles
• Keywords: Hsp90, leishmaniasis, chemotherapy, Hsp90 inhibitors, autophagy, ubiquitin.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cull, Mr Benjamin and Mottram, Professor Jeremy
• Authors: Petersen, A. L. d. O. A., Cull, B., Dias, B. R. S., Palma, L. C., Luz, Y. d. S., de Menezes, J. P. B., Mottram, J. C., and Veras, P. S. T.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Microorganisms
• Publisher: MDPI
• ISSN: 2076-2607
• ISSN (Online): 2076-2607
• Published Online: 19 May 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Microorganisms 9(5): 1089
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
168381		Proteolysis and life cycle progression in Leishmania	Jeremy Mottram	Medical Research Council (MRC)	MR/K019384/1	III - Parasitology