The above-cited article has been retracted by the American Diabetes Association, the publisher of Diabetes. This article was previously the subject of an expression of concern in the March 2015 issue of the journal (Diabetes 2015;64:1068–1070. DOI: 10.2337/db15-ec03).
As noted in the March 2015 expression of concern, the American Diabetes Association asked the corresponding author’s institution, the University of Campinas, to review the following issues with the article:
There appear to be instances of duplicated bands in Fig. 3B (bands 1, 3, and 7), Fig. 3D (bands 2 and 5 and bands 3 and 6), Fig. 5E (bands 1 and 3 and bands 2 and 4), and Fig. 8E (bands 2 and 5).
Figures 3, 5, 6, 7, and 8 contain evidence of suspected splicing in the displayed immunoblot images.
The Association also asked the University of Campinas to review several discrepancies between source images previously provided by the corresponding author and the published images.
The issues described in the March 2015 expression of concern were then reviewed by an investigative commission appointed by the University of Campinas.
The university commission concluded that modifications (e.g., brightness and contrast adjustments, reordering of lanes, changes to the size of the bands) had been made to several images but that the presented data are “basically correct.” These images include Figs. 3A, 3D, 3E, 5B, 6E, 7A, and 8E. The university commission also concluded that bands 1, 3, and 7 in Fig. 3B are duplicates. According to the university commission report, the duplication in Fig. 3B is the result of an unintentional mistake. To address these issues, the university commission recommended publishing a corrigendum with replacement images to alert readers to manipulations made to Figs. 3A, 3B, 3D, 3E, 5B, 6E, 7A, and 8E.
The university commission’s report and recommendation were reviewed by the American Diabetes Association’s Panel on Ethical Scientific Programs (ESP).
Despite the university’s recommendation, the ESP does not agree with the publication of a corrigendum to report manipulations (whether deliberate or inadvertent) to several key portions of data in an individual study. The practice of doing so underscores the unreliability of the study as a whole without appropriately and responsibly updating the literature record. The ESP believes that this is especially relevant where issues of data duplication are concerned. As confirmed by the university commission, Fig. 3B contains duplicated data, and the ESP still has concerns that lanes 1 and 3 and lanes 2 and 4 in the IKKβ band of Fig. 5E and lanes 2 and 5 in the IKKβ band of Fig. 8E are duplicated.
It should be noted that the ESP was informed by readers of an additional concern involving other data presented in this article. The investigative commission appointed by the University of Campinas did not identify or address this additional concern in its investigative report:
The Akt strip in Fig. 5B (lanes 1–4) appears to be duplicated from images previously published in the following articles:
Prada et al. FEBS Lett 2006;580:4889–4894. DOI: 10.1016/j.febslet.2006.08.004. PMID: 16919274 (Fig. 4C, IB:IRS-1, with horizontal and vertical rotation)
Ropelle et al. Endocrinology 2007;148:5220–5229. DOI: 10.1210/en.2007-0381. PMID: 17717055 (Fig. 2D, total AMPK, and Fig. 2F, α-tubulin, with horizontal and vertical rotation)
These images may have been republished in other independent and unrelated experiments:
Ropelle et al. Diabetes 2008;57:594–605. DOI: 10.2337/db07-0573. PMID: 18057094 (Fig. 6L, total eIF4E, with horizontal and vertical rotation)
De Souza et al. J Physiol 2010;588(Pt. 12):2239–2253. DOI: 10.1113/jphysiol.2009.183996. PMID: 20421289 (Fig. 1C, IB:IRS2, and Fig. 1G, IB:Foxo1)
Oliveira et al. Diabetes 2011;60:784–796. DOI: 10.2337/db09-1907. PMID: 21282367 (Fig. 3A, IB:IKKβ)
Calisto et al. Crit Care 2012;16:R158. DOI: 10.1186/cc11478. PMID: 22897821 (Fig. 4B, IB:Akt, lanes 1–4)
This concern has been reviewed by the ESP and has been recently reported to the university.
On the basis of its review of the university commission’s report and the additional concern described above, the ESP believes that the study as a whole is unreliable and that the only responsible course of action for updating the status of Diabetes 2007;56:1986–1998 is to issue a full retraction. The American Diabetes Association, the publisher of Diabetes, approved the Panel’s recommendation.
Diabetes is a member journal of the Committee on Publication Ethics (COPE) (publicationethics.org). As such, the editors of the journal and the ESP refer to COPE’s guidelines and recommendations when reviewing such matters.