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- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)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. 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 vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most 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. 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. 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 autophagy assays, we hope to encourage technical innovation in the field.
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| 2. |
- Shirai, Takaaki, et al.
(författare)
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Longitudinal evaluation of cartilage after osteochondral autogenous transfer with delayed gadolinium-enhanced MRI of the cartilage (dGEMRIC)
- 2012
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Ingår i: Journal of Orthopaedic Research. - : Wiley. - 1554-527X .- 0736-0266. ; 30:2, s. 221-225
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to use repeat delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) to estimate glycosaminoglycan (GAG) content in reparative cartilage after osteochondral autogenous transfer (OAT). The study group comprised 7 knees of 7 patients that were examined three times by dGEMRIC, at 3, 6, and 12 months using a 1.5 Tesla MRI system in both OAT operated and nonoperated condyles at 90 min after the injection. The gadolinium diethylene triamine pentaacetic acid (Gd-DTPA)2- containing contrast medium (0.2 mmols/kg) was injected intravenously. The mean T1 values of the plug cartilage at 3, 6, and 12 months after OAT was 230 +/- 40, 213 +/- 31, and 230 +/- 23 ms (mean +/- SD), respectively. There were differences between the plug and control cartilage at 3 (p<0.01) and 12 (p<0.05) months after OAT, but not at 6 months (p=0.089). No T1 changes were detected between the plug cartilage at the different time points after OAT. The fact that the GAG content of the OAT plugs were maintained for 12-month study period suggest that no major deterioration of load-bearing properties occurs in the cartilage after the OAT. (C) 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:221225, 2012
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