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Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Citation

Klionsky, DJ and Abdelmohsen, K and Abe, A and Abedin, MJ and Abeliovich, H and Eri, RD and Randall-Demllo, S, 𝘦𝘵 𝘢𝘭, Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition), Autophagy, 12, (1) pp. 1-222. ISSN 1554-8627 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 Taylor & Francis Group, LLC

DOI: doi:10.1080/15548627.2015.1100356

Abstract

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes.

For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy.

Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagyrelated protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.

Item Details

Item Type:Refereed Article
Keywords:autolysosome, autophagosome, chaperone-mediated autophagy, flux, LC3, lysosome, macroautophagy, phagophore, stress, vacuole
Research Division:Biological Sciences
Research Group:Genetics
Research Field:Genetic Immunology
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Digestive System Disorders
Author:Eri, RD (Dr Raj Eri)
Author:Randall-Demllo, S (Mr Sarron Randall-Demllo)
ID Code:107873
Year Published:2016
Web of Science® Times Cited:774
Deposited By:Health Sciences
Deposited On:2016-03-30
Last Modified:2017-12-15
Downloads:0

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