Some scientists might just shrug and sweep those errors — and their previous papers — under the rug. But when it happened to Jeffery Kelly, of the Scripps Research Institute, and his colleagues, they decided to retract their earlier work.
Here’s the abstract of their new paper (we bolded a few sentences for emphasis):
The accumulation of cross-β-sheet amyloid fibrils is the hallmark of amyloid diseases. Recently, we reported the discovery of amyloid disaggregase activities in extracts from mammalian cells and C. elegans. However, we have discovered a problem with the interpretation of our previous results as Aβ disaggregation in vitro. Here, we show that Aβ fibrils adsorb to the plastic surface of multi-well plates and Eppendorf tubes. This adsorption is markedly increased in the presence of complex biological mixtures subjected to a denaturing air-water interface. The time-dependent loss of thioflavin T fluorescence that we interpreted previously as disaggregation is due to increased adsorption of Aβ amyloid to the surfaces of multi-well plates and Eppendorf tubes in the presence of biological extracts. As the proteins in biological extracts denature over time at the air-water interface due to agitation/shaking, their adsorption increases, in turn promoting adsorption of amyloid fibrils. We delineate important control experiments that quantify the extent of amyloid adsorption to the surface of plastic and quartz containers. Based on the results described in this paper, we conclude that our interpretation of the kinetic fibril disaggregation assay data previously reported in Protein Sci. 2009, 18, 2231-2241 and Protein Sci. 2010, 19, 836-846 is invalid when used as evidence for a disaggregase activity. Thus, we retract the two prior publications reporting that worm or mammalian cell extracts disaggregate Aβ amyloid fibrils in vitro at 37°C. We apologize for misinterpreting our previous data and for any confounding experimental efforts this may have caused.
The two papers to which the abstract refers are
- “A kinetic assessment of the C. elegans amyloid disaggregation activity enables uncoupling of disassembly and proteolysis,” published in 2009 and cited 12 times, according to Thomson Scientific’s Web of Knowledge, and
- “Discovery and characterization of a mammalian amyloid disaggregation activity,” published in 2010 and cited 13 times
Here’s how Kelly explained in an email to us what happened:
My laboratory, in the process of trying to isolate and identify a protein(s) exhibiting disaggregase activity, realized that too many candidates were active which led to us realize that the interpretation of our previous data was incorrect. It took us almost a year of effort to figure this out and convince my trainees who actually did the initial experiments that we misinterpreted our data.
The retractions haven’t yet run. Kelly:
My understanding is that the editor and experts at Protein Science have determined that this is a corrigendum instead of a retraction, we are agnostic about what the determination is, but clearly we misinterpreted our data which we have corrected and apologized for.
We’ve contacted the editor of the journal to learn his plans for the papers, and will update with anything we find out. Regardless of how the retractions are treated, however, Kelly and his colleagues deserve kudos for their efforts, at their own professional expense, to correct the scientific literature.
In short, we agree with the tip we received about the paper on Twitter:
I think this paper is a model retraction and should be highly praised.
Please see an update on this post.