Resveratrol modulates response against acute inflammatory stimuli in aged mouse brain
Authors: A Camins
V Palomera-√Åvalos
C Gri√±√°n-Ferr√©
V Izquierdo
M Pall√†s
C Sanfeliu
A M Canudas
Journal: Experimental Gerontology (2018)
Discipline: CLINICAL MEDICINE
Keywords: Aging; Cytokines; Inflammation; eukaryotic Initiation Factor 2 (eIF2); iNOS
Affiliations: Department of Pharmacology, Toxicology and Therapeutic Chemistry (Pharmacology Section), Institute of Neuroscience, CIBERNED, University of Barcelona, Avda. Joan XXIII s/n, 08028 Barcelona, Spain., Institut d'Investigacions Biom√®diques de Barcelona (IIBB), CSIC, and IDIBAPS, 08036 Barcelona, Spain., Department of Pharmacology, Toxicology and Therapeutic Chemistry (Pharmacology Section), Institute of Neuroscience, CIBERNED, University of Barcelona, Avda. Joan XXIII s/n, 08028 Barcelona, Spain. Electronic address: .

Abstract:  With upcoming age, the capability to fight against harmful stimuli decreases and the organism becomes more susceptible to infections and diseases. Here, the objective was to demonstrate the effect of dietary resveratrol in aged mice in potentiating brain defenses against LipoPolySaccharide (LPS). Acute LPS injection induced a strong proinflammatory effect in 24-months-old C57/BL6 mice hippocampi, increasing InterLeukin (Il)-6, Tumor Necrosis Factor-alpha (Tnf-Œ±), Il-1Œ≤, and C-X-C motif chemokine (Cxcl10) gene expression levels. Resveratrol induced higher expression in those cytokines regarding to LPS. Oxidative Stress (OS) markers showed not significant changes after LPS or resveratrol, although for resveratrol treated groups a slight increment in most of the parameters studies was observed, reaching signification for NF-kB protein levels and iNOS expression. However, Endoplasmic Reticulum (ER) stress markers demonstrated significant changes in resveratrol-treated mice after LPS treatment, specifically in eIF2Œ±, BIP, and ATF4. Moreover, as described, resveratrol is able to inhibit the mechanistic Target of Rapamycin (mTOR) pathway and this effect could be linked to (eIF2Œ±) phosphorylation and the increase in the expression of the previously mentioned proinflammatory genes as a response to LPS treatment in aged animals. In conclusion, resveratrol treatment induced a different cellular response in aged animals when they encountered acute inflammatory stimuli. 

Retracted: No

PubPeer comments:
 The blots in Figure 4A and 4B appear to have some unexpected similarities (green). The bands marked in red seem similar as well, possibly after resizing. I did not check elsewhere. Could the authors please provide the original data? *** Close up  *** Original  , 
 Dear Sir, The WB highlighted are the same. Both correspond to total EI2fu03b1 protein levels at the different experimental conditions tested (CT, LPS, LPS+Resveratrol). In panel A, There are representative images of phospho EI2fu03b1 and total EI2fu03b1, and the bar graph is the semiquantitative values of ratio between phosphorylated protein and total levels of the same protein in order to express activation of EI2fu03b1 as a transcription factor, as is explained in the results and discussion In panel B, there are the same representative image for total EI2fu03b1 but compared with tubulin as a control charge to demonstrate that LPS treatment and LPS+resveratrol do no change the total levels of EI2fu03b1 protein, then corroborating that the results in panel A are due to an effective increase in phosphorylation rather than a changes in the levels of EI2fu03b1 protein. The only mistake in this figure was the wrong molecular weight stated in total EI2fu03b1 band in panel A, but correct in panel B (38Kda). Molecular weight 50 Kda is for tubulin. This error in not scientifically relevant for the interpretation of results and conclusion of the work discussion. The aim of experiments was to demonstrate changes in phosphorylation of eIF2u03b1 in response to an stressors (in this case LPS) (Liu et al., 2007; Woo et al., 2009; Nakayama et al., 2010). Accordingly, in our work, phopho-eIF2u03b1 levels were found increased in resveratrol-fed animals after LPS injection. And this is widely demostrated in panel A results, being panel B the validation of phospho E2F not the E2F protein levels . Lu YC, Yeh WC, Ohashi PS. LPS TLR4 signal transduction pathway. Cytokine. 2008 May;42(2):145-151. doi: 10.1016 j.cyto.2008.01.006. Nakayama Y, Endo M, Tsukano H, Mori M, Oike Y, Gotoh T. Molecular mechanisms of the LPS-induced non-apoptotic ER stress-CHOP pathway. J Biochem. 2010 Apr;147(4):471-83. doi: 10.1093 jb mvp189. Epub 2009 Nov 16. PMID: 19919955. Woo, C.W., Cui, D., Arellano, J., Dorweiler, B., Harding, H., Fitzgerald, K.A., Ron, D., Tabas, I., 2009. Adaptive suppression of the ATF4-CHOP branch of the unfolded protein response by Toll-like receptor signaling. Nat. Cell Biol. 11, 1473u20131480. Tong, L., Heim, R.A., Wu, S., 2011. Nitric oxide: a regulator of eukaryotic initiation factor 2 kinases. Free Radic Biol Med 50 (12), 1717u20131725. , 
 #2 Thank you for confirming the labeling mistake. , 
 Another reader suggested I ask you  why same loading control if the 38kD bands for A and B appear to be from two physically different gels. In addition, doesn t the error affect the quantification bar chart? Perhaps providing the original uncropped scans could address these questions. ,