Chimeric Agonist of Galanin Receptor GALR2 Reduces Heart Damage in Rats with Streptozotocin-Induced Diabetes.

Neuropeptide galanin and its N-terminal fragments reduce the generation of reactive oxygen species and normalize metabolic and antioxidant states of myocardium in experimental cardiomyopathy and ischemia/reperfusion injury. The aim of this study was to elucidate the effect of WTLNSAGYLLGPßAH-OH (peptide G), a pharmacological agonist of the galanin receptor GalR2, on the cardiac injury induced by administration of streptozotocin (STZ) in rats. Peptide G was prepared by solid phase peptide synthesis using the Fmoc strategy and purified by preparative HPLC; its structure was confirmed by 1H-NMR spectroscopy and MALDI-TOF mass spectrometry. Experimental animals were randomly distributed into five groups: C, control; S, STZ-treated; SG10, STZ + peptide G (10 nmol/kg/day); SG50, STZ + peptide G (50 nmol/kg/day); G, peptide G (50 nmol/kg/day). Administration of peptide G prevented hyperglycemia in SG50 rats. By the end of the experiment, the ATP content, total pool of adenine nucleotides, phosphocreatine (PCr) content, and PCr/ATP ratio in the myocardium of animals of the SG50 group were significantly higher than in rats of the S group. In the SG50 and SG10 groups, the content of lactate and lactate/pyruvate ratio in the myocardium were reduced, while the glucose content was increased vs. the S group. Both doses of peptide G reduced the activation of creatine kinase-MB and lactate dehydrogenase, as well as the concentration of thiobarbituric acid reactive products in the blood plasma of STZ-treated rats to the control values. Taken together, these results suggest that peptide G has cardioprotective properties in type 1 diabetes mellitus. Possible mechanisms of peptide G action in the STZ-induced diabetes are discussed.

Antioxidant Properties of Galanin and Its N-Terminal Fragments in in vitro and in vivo Oxidative Stress Modeling.

Antioxidant properties of rat galanin GWTLNSAGYLLGPHAIDNHRSFSDKHGLT-NH2 (Gal), N-terminal fragment of galanin (2-15 aa) WTLNSAGYLLGPHA (G1), and its modified analogue WTLNSAGYLLGPßAH (G2) were studied in vivo in the rat model of regional myocardial ischemia and reperfusion and in vitro in the process of Cu2+-induced free radical oxidation of human blood plasma low-density lipoproteins. Intravenous administration of G1, G2, and Gal to rats after ischemia induction reduced the infarction size and activities of the necrosis markers, creatine kinase-MB and lactate dehydrogenase, in blood plasma at the end of reperfusion. G1, G2, and Gal reduced formation of the spin adducts of hydroxyl radicals in the interstitium of the area at risk during reperfusion, moreover, G2 and Gal also reduced formation of the secondary products of lipid peroxidation in the reperfused myocardium. It was shown in the in vivo experiments and in the in vitro model system that the ability of galanin peptides to reduce formation of ROS and attenuate lipid peroxidation during myocardial reperfusion injury was not associated directly with their effects on activities of the antioxidant enzymes of the heart: Cu,Zn-superoxide dismutase, catalase, and glutathione peroxidase. The peptides G1, G2, and Gal at concentrations of 0.01 and 0.1 mM inhibited Cu2+-induced free radical oxidation of human low-density lipoproteins in vitro. The results of oxidative stress modeling demonstrated that the natural and synthetic agonists of galanin receptors reduced formation of the short-lived ROS in the reperfused myocardium, as well as of lipid radicals in blood plasma. Thus, galanin receptors could be a promising therapeutic target for cardiovascular diseases.

Permanent proteins in the urine of healthy humans during the Mars-500 experiment.

Urinary proteins serve as indicators of various conditions in human normal physiology and disease pathology. Using mass spectrometry proteome analysis, the permanent constituent of the urine was examined in the Mars-500 experiment (520 days isolation of healthy volunteers in a terrestrial complex with an autonomous life support system). Seven permanent proteins with predominant distribution in the liver and blood plasma as well as extracellular localization were identified. Analysis of the overrepresentation of the molecular functions and biological processes based on Gene Ontology revealed that the functional association among these proteins was low. The results showed that the identified proteins may be independent markers of the various conditions and processes in healthy humans and that they can be used as standards in determination of the concentration of other proteins in the urine.

Detection of renal tissue and urinary tract proteins in the human urine after space flight.

The urine protein composition samples of ten Russian cosmonauts (male, aged of 35 up to 51) performed long flight missions and varied from 169 up to 199 days on the International Space Station (ISS) were analyzed. As a control group, urine samples of six back-up cosmonauts were analyzed. We used proteomic techniques to obtain data and contemporary bioinformatics approaches to perform the analysis. From the total number of identified proteins (238) in our data set, 129 were associated with a known tissue origin. Preflight samples contained 92 tissue-specific proteins, samples obtained on Day 1 after landing had 90 such proteins, while Day 7 samples offered 95 tissue-specific proteins. Analysis showed that consistently present proteins in urine (under physiological conditions and after space flight) are cubilin, epidermal growth factor, kallikrein-1, kininogen-1, megalin, osteopontin, vitamin K-dependent protein Z, uromodulin. Variably present proteins consists of: Na(+)/K(+) ATPase subunit gamma, ß-defensin-1, dipeptidyl peptidase 4, maltasa-glucoamilasa, cadherin-like protein, neutral endopeptidase and vascular cell adhesion protein 1. And only three renal proteins were related to the space flight factors. They were not found in the pre-flight samples and in the back-up cosmonaut urine, but were found in the urine samples after space flight: AFAM (afamin), AMPE (aminopeptidase A) and AQP2 (aquaporin-2). This data related with physiological readaptation of water-salt balance. The proteomic analysis of urine samples in different phases of space missions with bioinformation approach to protein identification provides new data relative to biomechemical mechanism of kidney functioning after space flight.