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Fibroblast growth factor (FGF)-21 is a novel regulator of insulin-independent glucose transport in 3T3-L1 adipocytes and has glucose and triglyceride lowering effects in rodent models of diabetes. In this study, we found that FGF-21 can significantly attenuate ischemia-reperfusion (I/R) induced damage in H9c2 cells (rat heart). However, it is unclear which signal transduction pathway is involved in the cardioprotective effect of FGF-21. Thus, this study was designed to investigate the potential mechanism induced by FGF-21. The results showed that FGF-21 treatment prevented the oxidative stress and apoptosis associated with I/R damage by reducing the levels of superoxide anions, inhibiting glycogen synthase kinase (GSK) 3β by activating Akt phosphorylation, and recovering the levels of ATP synthase pyruvate kinase isozymes M1 and protein kinase C, thereby improving energy supply. In summary, we conclude that FGF-21 protects H9c2 cells against I/R injury mainly through the Akt-GSK-3β-caspase-3 dependent pathway, preventing oxidative stress, and recovery of the energy supply. Key words: FGF-21, myocardial ischemia-reperfusion, H9c2, proteomics, Akt, ROS, apoptosis, signaling pathway. Le facteur de croissance des fibroblastes (FGF)-21 est nouveau regulateur du transport de glucose independant de l'insuline dans les adipocytes 3T3-L1 qui diminue le glucose et les triglycerides dans des modeles de diabete chez le rongeur. Dans cette etude, nous avons trouve que le FGF-21 pouvait attenuer significativement le dommage induit par l'ischemiereperfusion (I/R) chez les cellules H9c2. Cependant, la voie de transduction impliquee dans l'effet cardioprotecteur du FGF-21 n'est pas clairement definie. Ainsi, cette etude a ete concue pour examiner le mecanisme d'action potentiel du FGF-21. Les resultats ont montre que le traitement au FGF-21 prevenait le stress oxydant et l'apoptose associes au dommage d'I/R en reduisant les anions superoxydes, inhibait la glycogene synthase kinase (GSK)-3β en activant la phosphorylation d'Akt, et restaurait l'ATP synthase, les isozymes M1 de la pyruvate kinase et la proteine kinase C afin d'ameliorer l'apport en energie. En resume, nous concluons que le FGF-21 protege les cellules H9c2 du dommage d'I/R principalement par l'intermediaire de la voie dependante d'Akt-GSK-3β-caspase-3, du stress anti-oxydant et de la restauration de l'apport energetique. [Traduit par la Redaction] Mots-cles: FGF-21, ischemie-reperfusion myocardique, H92c, proteomique, Akt, ERO, apoptose, voie de signalisation., Introduction It has been reported that ischemia-reperfusion (I/R) injury is commonly associated with oxidative stress, and that reactive oxygen species (ROS) are the major mediators contributing to acute myocardial injury [...]

A Schiff base compound derived from naphthalene has been synthesized and characterized as an Al3+-selective fluorescent probe. The chemosensor ( L) exhibits high selectively for Al3+ in aqueous solution, even in the presence of biologically relevant cations such as Na+, K+, Ca2+, Mg2+, Pb2+ and several transition metal ions. There was no observed interference from anions like Br−, Cl−, HSO3−, SO32−, S2O32−, NO2−, CO32− and AC−. The lowest detection limit for the chemosensor L was found to be 1.89 × 10−8 M with a linear response towards Al3+ over a concentration range of 5 × 10−6 to 4 × 10−5 M. Furthermore, the proposed chemosensor has been used for imaging of Al3+ in two different types of cells with satisfying results, which further demonstrates its value for practical application in biological systems. [ABSTRACT FROM AUTHOR]

As a non-covalent fluorescence probe, in this study, salicylaldehyde azine (SA) was introduced as a sensitive fluorescence-based dye for detecting proteins both in 1-D and 2-D polyacrylamide electrophoresis gels. Down to 0.2 ng of single protein band could be detected within 1 h, which similars to that of glutaraldehyde (GA)-silver stain, but approximately four times higher than that of SYPRO Ruby fluorescent stain. Furthermore, comparative analysis of the MS compatibility of SA stain with SYPRO Ruby stain indicated that SA stain is compatible with the downstream of protein identification by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, the probable mechanism of the SA stain was investigated by molecular docking. The results demonstrated that the interaction between SA and protein was mainly contributed by hydrogen bonding and hydrophobic forces., (2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A fast and matrix-assisted laser desorption/ionization mass spectrometry compatible protein staining method in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis is described. It is based on the counterion dye staining method that employs oppositely charged two dyes, zincon and ethyl violet, to form an ion-pair complex. The protocol, including fixing, staining, and quick washing steps, can be completed in 1-1.5 h, depending upon gel thickness. It has the sensitivity comparable to the colloidal Coomassie Brilliant Blue G stain using phosphoric acid as a component of staining solution (4-8 ng). The counterion dye stain does not induce protein modifications that complicate interpretation of peptide mapping data from mass spectrometry. Considering the speed, sensitivity, and compatibility with mass spectrometry, the counterion dye stain may be more practical than any other dye-based protein stains for routine proteomic researches.

Delta-catenin was first identified because of its interaction with presenilin-1, and its aberrant expression has been reported in various human tumors and in patients with Cri-du-Chat syndrome, a form of mental retardation. However, the mechanism whereby delta-catenin is regulated in cells has not been fully elucidated. We investigated the possibility that glycogen-synthase kinase-3 (GSK-3) phosphorylates delta-catenin and thus affects its stability. Initially, we found that the level of delta-catenin was greater and the half-life of delta-catenin was longer in GSK-3beta(-/-) fibroblasts than those in GSK-3beta(+/+) fibroblasts. Furthermore, four different approaches designed to specifically inhibit GSK-3 activity, i.e. GSK-3-specific chemical inhibitors, Wnt-3a conditioned media, small interfering RNAs, and GSK-3alpha and -3beta kinase dead constructs, consistently showed that the levels of endogenous delta-catenin in CWR22Rv-1 prostate carcinoma cells and primary cortical neurons were increased by inhibiting GSK-3 activity. In addition, it was found that both GSK-3alpha and -3beta interact with and phosphorylate delta-catenin. The phosphorylation of DeltaC207-delta-catenin (lacking 207 C-terminal residues) and T1078A delta-catenin by GSK-3 was noticeably reduced compared with that of wild type delta-catenin, and the data from liquid chromatography-tandem mass spectrometry analyses suggest that the Thr(1078) residue of delta-catenin is one of the GSK-3 phosphorylation sites. Treatment with MG132 or ALLN, specific inhibitors of proteosome-dependent proteolysis, increased delta-catenin levels and caused an accumulation of ubiquitinated delta-catenin. It was also found that GSK-3 triggers the ubiquitination of delta-catenin. These results suggest that GSK-3 interacts with and phosphorylates delta-catenin and thereby negatively affects its stability by enabling its ubiquitination/proteosome-mediated proteolysis.