Peroxisome proliferator-activated receptor delta agonist, HPP593, prevents renal necrosis under chronic ischemia

The Goldblatt’s 2 kidney 1 clip (2K1C) rat animal model of renovascular hypertension is characterized by ischemic nephropathy of the clipped kidney. 2K1C rats were treated with a specific peroxisome proliferator-activated receptor δ (PPARδ) agonist, HPP593. Clipped kidneys from untreated rats developed tubular and glomerular necrosis and massive interstitial, periglomerular and perivascular fibrosis. HPP593 kidneys did not exhibit any histochemical features of necrosis; fibrotic lesions were present only in perivascular areas. Necrosis in the untreated clipped kidneys was associated with an increased oxidative stress, up regulation and mitochondrial translocation of the pro-death protein BNIP3 specifically in tubules. In the kidneys of HPP593-treated rats oxidative stress was attenuated and BNIP3 protein decreased notably in the mitochondrial fraction when compared to untreated animals. In untreated clipped kidneys, mitochondria were dysfunctional as revealed by perturbations in the levels of MCAD, COXIV, TFAM, and Parkin proteins and AMPK activation, while in HPP593-treated rats these proteins remained at the physiological levels. Nuclear amounts of oxidative stress-responsive proteins, NRF1 and NRF2 were below physiological levels in treated kidneys. Mitochondrial biogenesis and autophagy were inhibited similarly in both treated and untreated 2K1C kidneys as indicated by a decrease in PGC1-α and deficiency of the autophagy-essential proteins LC3-II and ATG5. However, HPP593 treatment resulted in increased accumulation of p62 protein, an autophagic substrate and an enhancer of NRF2 activity. Therefore, inhibition of BNIP3 activation by the preservation of mitochondrial function and control of oxidative stress by PPARδ is the most likely mechanism to account for the prevention of necrotic death in the kidney under conditions of persistent ischemia

Transcriptomic changes triggered by ouabain in rat cerebellum granule cells: Role of α3- and α1-Na+,K+-ATPase-mediated signaling

It was shown previously that inhibition of the ubiquitous α1 isoform of Na+,K+-ATPase by ouabain sharply affects gene expression profile via elevation of intracellular [Na+]i/[K+]i ratio. Unlike other cells, neurons are abundant in the α3 isoform of Na+,K+-ATPase, whose affinity in rodents to ouabain is 104-fold higher compared to the α1 isoform. With these sharp differences in mind, we compared transcriptomic changes in rat cerebellum granule cells triggered by inhibition of α1- and α3-Na+,K+-ATPase isoforms. Inhibition of α1- and α3-Na+,K+-ATPase isoforms by 1 mM ouabain resulted in dissipation of transmembrane Na+ and K+ gradients and differential expression of 994 transcripts, whereas selective inhibition of α3-Na+,K+-ATPase isoform by 100 nM ouabain affected expression of 144 transcripts without any impact on the [Na+]i/[K+]i ratio. The list of genes whose expression was affected by 1 mM ouabain by more than 2-fold was abundant in intermediates of intracellular signaling and transcription regulators, including augmented content of Npas4, Fos, Junb, Atf3, and Klf4 mRNAs, whose upregulated expression was demonstrated in neurons subjected to electrical and glutamatergic stimulation. The role [Na+]i/[K+]i-mediated signaling in transcriptomic changes involved in memory formation and storage should be examined further

Circulating Ouabain Modulates Expression of Claudins in Rat Intestine and Cerebral Blood Vessels

The ability of exogenous low ouabain concentrations to affect claudin expression and therefore epithelial barrier properties was demonstrated previously in cultured cell studies. We hypothesized that chronic elevation of circulating ouabain in vivo can affect the expression of claudins and tight junction permeability in different tissues. We tested this hypothesis in rats intraperitoneally injected with ouabain (1 μg/kg) for 4 days. Rat jejunum, colon and brain frontal lobes, which are variable in the expressed claudins and tight junction permeability, were examined. Moreover, the porcine jejunum cell line IPEC-J2 was studied. In IPEC-J2-cells, ouabain (10 nM, 19 days of incubation) stimulated epithelial barrier formation, increased transepithelial resistance and the level of cSrc-kinase activation by phosphorylation, accompanied with an increased expression of claudin-1, -5 and down-regulation of claudin-12; the expression of claudin-3, -4, -8 and tricellulin was not changed. In the jejunum, chronic ouabain increased the expression of claudin-1, -3 and -5 without an effect on claudin-2 and -4 expression. In the colon, only down-regulation of claudin-3 was observed. Chronic ouabain protected the intestine transepithelial resistance against functional injury induced by lipopolysaccharide treatment or by modeled acute microgravity; this regulation was most pronounced in the jejunum. Claudin-1 was also up-regulated in cerebral blood vessels. This was associated with reduction of claudin-3 expression while the expression of claudin-5 and occludin was not affected. Altogether, our results confirm that circulating ouabain can functionally and tissue-specifically affect barrier properties of epithelial and endothelial tissues via Na,K-ATPase-mediated modulation of claudins expression

Angiotensin II and transforming growth factor β affect cardiovascular and renal disease in patients with type 2 diabetes mellitus: benefits of dpp-4 inhibitors treatment

BACKGROUND: Diabetes mellitus type 2 (T2DM) is associated with impaired glucose metabolism and peripheral insulin resistance, which is accompanied by an high risk of cardiovascular disease (CVD) and nephropathy. Metabolic syndrome and T2DM are accompanied by renin-angiotensin system (RAS) activation, which is also associated with increased risk of CVD and kidney damage. Obesity lead to a wide range of pathophysiological changes, that stimulate cardiac fibrosis, and various fibrosis processes initiation, including activation of transforming growth factor β (TGF-β). AIMS: To determine activity of angiotensin II (Ang II) and TGF-β in patients with obesity and T2DM and their association with heart and kidney damage. MATERIALS AND METHODS: Ang II and TGF-β were identified in the peripheral blood of 66 obese patients aged 48-65 years. The first group included 21 patients with coronary heart disease (CHD) and T2DM; The second group included 22 patients with T2DM and excluded CHD; The third group – 20 patients with normal glucose metabolism and excluded CHD. RESULTS: The values of TGF-β in the 1st group (patients with CHD) were statistically lower than in the group of metabolically healthy obesity (p=0.021). Patients who received DPP-4 inhibitors had a lower Ang II level compared to patients with other hypoglycemic therapy (p=0.005). TGF-β positively correlated with glomerular filtration rate (eGFR) in all patients (r=-0.414, p=0.006). TGF-β negatively correlated with the degree of internal carotid artery stenosis in patients of the 2nd group (r=-0.42, p=0.09) and LDL-cholesterol in all patients (r=-0.426, p=0.038). CONCLUSIONS: TGF-β negatively correlated with the factors that contribute to CVD progression. TGF-β correlated with pathological angiogenesis and changes in normal cardiac geometry in obesity, T2DM and CHD. DPP-4 inhibitors can improve the cardiovascular prognosis in this group of patients by affecting Ang II level. Low levels of TGF-β were associated with higher cardiovascular risk and were commonly found in patients with more severe nephropathy

The efficacy of high-dose cabergoline treatment of prolactinomas resistant to standard doses: a clinical observation

Hyperprolactinemia (HP) is one of the most common neuroendocrine disorders. In 60% of cases, pathological HP is caused by pituitary prolactin-secreting adenoma. Therapy with agonists of dopamine type 2 receptors (D2 receptor agonists) is a method of choice for the treatment of pathological HP which allows to achieve prolactin normalization and reduction of pituitary adenoma in most cases. However, 15-20% of patients are resistant to D2 receptor agonists, and the question of overcoming this resistance is highly relevant. Different approaches are considered to solve this problem, one - is to increase the dose of D2 receptor agonists up to the maximally tolerated. In this article, we present a clinical observation of a patient with a partial resistance to D2 receptor agonists who demonstrated a good response to treatment with high doses of cabergoline

Использование методологии SAR для идентификации аллелохемиков пресноводных макрофитов с высоким антицианобактериальным эффектом в отношении планктонных цианобактерий

Controlling harmful cyanobacterial “blooms” through developing a new generation of algaecides based on allelochemical substances is a challenge facing modern aquatic ecology and biotechnology. The present article is devoted to the use of the SAR (Structure-Activity-Relationship) information technology to identify allelochemicals from aquatic macrophytes (floating-leaved Nuphar lutea (L.) Sm. and several species of submerged macrophytes: Ceratophyllum demersum L., Myriophyllum spicatum L., Elodea canadensis Michx, and species of the genus Potamogeton) effective against planktonic cyanobacteria. Detection and identification of compounds were performed using gas chromatography-mass spectrometry. The PASS (Prediction of Activity Spectra for Substances) computer program has been applied to predict biological activity spectra of the major components of macrophyte metabolomes and discover their ecological potential against cyanobacteria. A study of the biological activities of major low-molecular-weight organic compounds showed that monocarboxylic acids, gallic acid, cis‑6-octadecenoic acid, cis‑9-octadecenoic acid, palmitoleic acid, linolenic acid, and 9-cis‑12-cis-linoleic acid are the most promising compounds for the experimental verification and creation of nature-like algaecides of a new generation. PASS predictions were successfully compared to the available information on the biological activity of those compounds and confirmed experimentally. The present study shows that some organic acids significantly inhibit the growth of Synechocystis aquatilis Sauvageau and Aphanizomenon flos-aquae Ralfs ex Bornet and Flahault and can be used as algaecides for suppression of cyanobacteria. The inhibitory effect of the combined mixture of these allelochemicals is stronger than the effect of each individual component, suggesting that there are various mechanisms of cyanobacterial growth inhibitionПроблема борьбы с опасными цианобактериальными «цветениями» посредством разработки нового поколения альгицидов, основанных на аллелохемиках растений, актуальна на современной стадии развития водной экологии и биотехнологии. Статья посвящена использованию информационной технологии SAR (cвязь структура – активность) для выявления эффективных аллелохемиков водных макрофитов (с плавающими листьями – Nuphar lutea (L.) Sm., и нескольких видов погруженных макрофитов: Ceratophyllum demersum L., Myriophyllum spicatum L., Elodea canadensis Michx и виды рода Potamogeton) против планктонных цианобактерий. Обнаружение и идентификацию соединений проводили с использованием метода газовой хромато-масс- спектрометрии. Компьютерная программа PASS (прогнозирование спектров активности для веществ) была применена для прогнозирования спектров биологической активности мажорных компонентов метаболома макрофитов, чтобы обнаружить их экологический потенциал против цианобактерий. Изучение биологической активности основных низкомолекулярных органических соединений показало, что монокарбоновые кислоты, галловая кислота, цис‑6-октадеценовая кислота, цис‑9-октадеценовая кислота, пальмитолеиновая кислота, линоленовая кислота и 9-цис‑12- цис-линолевая кислота являются наиболее перспективными соединениями для экспериментальной проверки и создания природоподобных альгицидов нового поколения. Прогнозные оценки PASS были успешно сопоставлены с доступной информацией о биологической активности этих соединений, а также подтверждены экспериментально. Было показано, что некоторые жирные кислоты значительно ингибировали рост Synechocystis aquatilis Sauvageau и Aphanizomenon flos-aque Ralfs ex Bornet and Flahault и могут использоваться в качестве альгицидов для подавления цианобактерий. Поскольку ингибирующий эффект комбинированной смеси аллелохемиков был сильнее, чем у отдельных компонентов, имеются основания предполагать, что существуют различные механизмы ингибирования роста цианобактери

Beringian Standstill and Spread of Native American Founders

Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the intial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic

Genomic analyses inform on migration events during the peopling of Eurasia.

High-coverage whole-genome sequence studies have so far focused on a limited number of geographically restricted populations, or been targeted at specific diseases, such as cancer. Nevertheless, the availability of high-resolution genomic data has led to the development of new methodologies for inferring population history and refuelled the debate on the mutation rate in humans. Here we present the Estonian Biocentre Human Genome Diversity Panel (EGDP), a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations, which we group into diversity and selection sets. We analyse this dataset to refine estimates of continent-wide patterns of heterozygosity, long- and short-distance gene flow, archaic admixture, and changes in effective population size through time as well as for signals of positive or balancing selection. We find a genetic signature in present-day Papuans that suggests that at least 2% of their genome originates from an early and largely extinct expansion of anatomically modern humans (AMHs) out of Africa. Together with evidence from the western Asian fossil record, and admixture between AMHs and Neanderthals predating the main Eurasian expansion, our results contribute to the mounting evidence for the presence of AMHs out of Africa earlier than 75,000 years ago.Support was provided by: Estonian Research Infrastructure Roadmap grant no 3.2.0304.11-0312; Australian Research Council Discovery grants (DP110102635 and DP140101405) (D.M.L., M.W. and E.W.); Danish National Research Foundation; the Lundbeck Foundation and KU2016 (E.W.); ERC Starting Investigator grant (FP7 - 261213) (T.K.); Estonian Research Council grant PUT766 (G.C. and M.K.); EU European Regional Development Fund through the Centre of Excellence in Genomics to Estonian Biocentre (R.V.; M.Me. and A.Me.), and Centre of Excellence for Genomics and Translational Medicine Project No. 2014-2020.4.01.15-0012 to EGC of UT (A.Me.) and EBC (M.Me.); Estonian Institutional Research grant IUT24-1 (L.S., M.J., A.K., B.Y., K.T., C.B.M., Le.S., H.Sa., S.L., D.M.B., E.M., R.V., G.H., M.K., G.C., T.K. and M.Me.) and IUT20-60 (A.Me.); French Ministry of Foreign and European Affairs and French ANR grant number ANR-14-CE31-0013-01 (F.-X.R.); Gates Cambridge Trust Funding (E.J.); ICG SB RAS (No. VI.58.1.1) (D.V.L.); Leverhulme Programme grant no. RP2011-R-045 (A.B.M., P.G. and M.G.T.); Ministry of Education and Science of Russia; Project 6.656.2014/K (S.A.F.); NEFREX grant funded by the European Union (People Marie Curie Actions; International Research Staff Exchange Scheme; call FP7-PEOPLE-2012-IRSES-number 318979) (M.Me., G.H. and M.K.); NIH grants 5DP1ES022577 05, 1R01DK104339-01, and 1R01GM113657-01 (S.Tis.); Russian Foundation for Basic Research (grant N 14-06-00180a) (M.G.); Russian Foundation for Basic Research; grant 16-04-00890 (O.B. and E.B); Russian Science Foundation grant 14-14-00827 (O.B.); The Russian Foundation for Basic Research (14-04-00725-a), The Russian Humanitarian Scientific Foundation (13-11-02014) and the Program of the Basic Research of the RAS Presidium “Biological diversity” (E.K.K.); Wellcome Trust and Royal Society grant WT104125AIA & the Bristol Advanced Computing Research Centre (http://www.bris.ac.uk/acrc/) (D.J.L.); Wellcome Trust grant 098051 (Q.A.; C.T.-S. and Y.X.); Wellcome Trust Senior Research Fellowship grant 100719/Z/12/Z (M.G.T.); Young Explorers Grant from the National Geographic Society (8900-11) (C.A.E.); ERC Consolidator Grant 647787 ‘LocalAdaptatio’ (A.Ma.); Program of the RAS Presidium “Basic research for the development of the Russian Arctic” (B.M.); Russian Foundation for Basic Research grant 16-06-00303 (E.B.); a Rutherford Fellowship (RDF-10-MAU-001) from the Royal Society of New Zealand (M.P.C.)

The Structure of the Potato Virus A Particles Elucidated by Small Angle X-Ray Scattering and Complementary Techniques

Potato virus A (PVA) protein coat contains on its surface partially unstructured N-terminal domain of the viral coat protein (CP), whose structural and functional characteristics are important for understanding the mechanism of plant infection with this virus. In this work, we investigated the properties and the structure of intact PVA and partially trypsinized PVAΔ32 virions using small-angle X-ray scattering (SAXS) and complimentary methods. It was shown that after the removal of 32 N-terminal amino acids of the CP, the virion did not disintegrate and remained compact, but the helical pitch of the CP packing changed. To determine the nature of these changes, we performed ab initio modeling, including the multiphase procedure, with the geometric bodies (helices) and restoration of the PVA structure in solution using available high-resolution structures of the homologous CP from the PVY potyvirus, based on the SAXS data. As a result, for the first time, a low-resolution structure of the filamentous PVA virus, both intact and partially degraded, was elucidated under conditions close to natural. The far-UV circular dichroism spectra of the PVA and PVAΔ32 samples differed significantly in the amplitude and position of the main negative maximum. The extent of thermal denaturation of these samples in the temperature range of 20-55°C was also different. The data of transmission electron microscopy showed that the PVAΔ32 virions were mostly rod-shaped, in contrast to the flexible filamentous particles typical of the intact virus, which correlated well with the SAXS results. In general, structural analysis indicates an importance of the CP N-terminal domain for the vital functions of PVA, which can be used to develop a strategy for combating this plant pathogen