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This study examines the relative impact of canonical hypoxia-inducible factor-1alpha- (HIF-1α and Na+i/K+i-mediated signaling on transcriptomic changes evoked by hypoxia and glucose deprivation. Incubation of RASMC in ischemic conditions resulted in ∼3-fold elevation of [Na+]i and 2-fold reduction of [K+]i. Using global gene expression profiling we found that Na+,K+-ATPase inhibition by ouabain or K+-free medium in rat aortic vascular smooth muscle cells (RASMC) led to the differential expression of dozens of genes whose altered expression was previously detected in cells subjected to hypoxia and ischemia/reperfusion. For further investigations, we selected Cyp1a1, Fos, Atf3, Klf10, Ptgs2, Nr4a1, Per2 and Hes1, i.e. genes possessing the highest increments of expression under sustained Na+,K+-ATPase inhibition and whose implication in the pathogenesis of hypoxia was proved in previous studies. In ouabain-treated RASMC, low-Na+, high-K+ medium abolished amplification of the [Na+]i/[K+]i ratio as well as the increased expression of all tested genes. In cells subjected to hypoxia and glucose deprivation, dissipation of the transmembrane gradient of Na+ and K+ completely eliminated increment of Fos, Atf3, Ptgs2 and Per2 mRNAs and sharply diminished augmentation expression of Klf10, Edn1, Nr4a1 and Hes1. In contrast to low-Na+, high-K+ medium, RASMC transfection with Hif-1a siRNA attenuated increments of Vegfa, Edn1, Klf10 and Nr4a1 mRNAs triggered by hypoxia but did not impact Fos, Atf3, Ptgs2 and Per2 expression. Thus, our investigation demonstrates, for the first time, that Na+i/K+i-mediated, Hif-1α- -independent excitation-transcription coupling contributes to transcriptomic changes evoked in RASMC by hypoxia and glucose deprivation. [ABSTRACT FROM AUTHOR]

Stimulus-dependent elevation of intracellular Ca2+ ([Ca2+]i) affects the expression of numerous genes - a phenomenon known as excitation-transcription coupling. Recently, we found that increases in [Na+]i trigger c-Fos expression via a novel Ca2+i-independent pathway. In the present study, we identified ubiquitous and tissue-specific [Na+]i/[K+]i-sensitive transcriptomes by comparative analysis of differentially expressed genes in vascular smooth muscle cells from rat aorta (RVSMC), the human adenocarcinoma cell line HeLa, and human umbilical vein endothelial cells (HUVEC). To augment [Na+]i and reduce [K+]i, cells were treated for 3 hrs with the Na+,K+-ATPase inhibitor ouabain or placed for the same time in the K+- free medium. Employing Affymetrix-based technology, we detected changes in expression levels of 684, 737 and 1839 transcripts in HeLa, HUVEC and RVSMC, respectively, that were highly correlated between two treatments (p<0.0001; R2.0.62). Among these Na+ i/K+ i-sensitive genes, 80 transcripts were common for all three types of cells. To establish if changes in gene expression are dependent on increases in [Ca2+]i, we performed identical experiments in Ca2+-free media supplemented with extracellular and intracellular Ca2+ chelators. Surprisingly, this procedure elevated rather than decreased the number of ubiquitous and cell-type specific Na+i/K+i-sensitive genes. Among the ubiquitous Na+i/K+i-sensitive genes whose expression was regulated independently of the presence of Ca2+ chelators by more than 3-fold, we discovered several transcription factors (Fos, Jun, Hes1, Nfkbia), interleukin-6, protein phosphatase 1 regulatory subunit, dual specificity phosphatase (Dusp8), prostaglandin-endoperoxide synthase 2, cyclin L1, whereas expression of metallopeptidase Adamts1, adrenomedulin, Dups1, Dusp10 and Dusp16 was detected exclusively in Ca2+-depleted cells. Overall, our findings indicate that Ca2+i-independent mechanisms of excitation-transcription coupling are involved in transcriptomic alterations triggered by elevation of the [Na+]i/[K+]i ratio. There results likely have profound implications for normal and pathological regulation of mammalian cells, including sustained excitation of neuronal cells, intensive exercise and ischemia-triggered disorders. [ABSTRACT FROM AUTHOR]

In the present work, we compared the outcome of hyperosmotic and isosmotic shrinkage on ion transport and protein phosphorylation in C11-MDCK cells resembling intercalated cells from collecting ducts and in vascular smooth muscle cells (VSMC) from the rat aorta. Hyperosmotic shrinkage was triggered by cell exposure to hypertonic medium, whereas isosmotic shrinkage was evoked by cell transfer from an hypoosmotic to an isosmotic environment. Despite a similar cell volume decrease of 40%-50%, the consequences of hyperosmotic and isosmotic shrinkage on cellular functions were sharply different. In C11-MDCK and VSMC, hyperosmotic shrinkage completely inhibited Na+,K+-ATPase and Na+,Pi cotransport. In contrast, in both types of cells isosmotic shrinkage slightly increased rather than suppressed Na+,K+-ATPase and did not change Na+,Pi cotransport. In C11-MDCK cells, phosphorylation of JNK1/2 and Erk1/2 mitogen-activated protein kinases was augmented in hyperosmotically shrunken cells by ~7- and 2-fold, respectively, but was not affected in cells subjected to isosmotic shrinkage. These results demonstrate that the data obtained in cells subjected to hyperosmotic shrinkage cannot be considered as sufficient proof implicating cell volume perturbations in the regulation of cellular functions under isosmotic conditions. [ABSTRACT FROM AUTHOR]

Purinergic receptors activate diverse signaling cascades and regulate the activity of cell volume-sensitive ion transporters. However, the effects of ATP and other agonists of P2 receptors on cell volume dynamics are only scarcely studied. In the present work, we used the recently developed dual-image surface reconstruction technique to explore the influence of purinergic agonists on cell volume in the C11-Madin-Darby canine kidney cell line resembling intercalated cells from kidney collecting ducts. Unexpectedly, we found that ATP and UTP triggered very robust (55-60%) cell shrinkage that lasted up to 2 h after agonist washout. Purinergic regulation of cell volume required increases in intracellular Ca2+ and could be partially mimicked by the Ca2+-ionophore ionomycin or activation of protein kinase C by 4β-phorbol 12-myristate 13-acetate. Cell shrinkage was accompanied by strong reductions in intracellular K+ and Cl- content measured using steady-state 86Rb+ and 36Cl- distribution. Both shrinkage and ion efflux in ATP-treated cells were prevented by the anion channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and by the BKCa channel inhibitors charybdotoxin, iberiotoxin, and paxilline. To evaluate the significance of cell-volume changes in purinergic signaling, we measured the impact of ATP on the expression of the immediate-early gene c-Fos. Thirty-minute treatment with ATP increased c-Fos immunoreactivity by approximately fivefold, an effect that was strongly inhibited by charybdotoxin and completely prevented by NPPB. Overall, our findings suggest that ATP-induced cell-volume changes are partially responsible for the physiological actions of purinergic agonists. [ABSTRACT FROM AUTHOR]

Abstract: Numerous studies have demonstrated heightened Na+/Li+ countertransport (NLCT) activity in erythrocytes of patients with essential hypertension or diabetic nephropathy. The same carrier also contributes to the therapeutic action of lithium salt, widely used in the treatment of psychiatric disorders. However, the molecular origin of NLCT remains unknown. This study examined the role of major ion transporters in NLCT by comparative analysis of its activity and that of ion transporters providing inwardly directed 86Rb, 22Na and 32P fluxes. NLCT was below the detection limit in rat erythrocytes and ∼50-fold higher in rabbits compared to humans. Unlike NLCT, the activities of Na+,K+-ATPase, Na+,K+,2Cl− cotransporter and anion exchanger were somewhat similar in the erythrocytes of these species, whereas Na+,Pi cotransport was in 1:2:6 proportion in rats, humans and rabbits, respectively. Loading of erythrocytes with Li+ for NLCT measurement did not affect the activity of Na+,Pi cotransporter. Keeping in mind that NLCT is much higher in rabbits vs humans and rats, we compared the set of membrane proteins in these species using 2-dimensional gel electrophoresis. This approach revealed 174 common spots, whereas 132 proteins were detected only in human and rabbit erythrocyte membranes. Among these proteins, we found 17 spots whose expression was higher by more than 5-fold in rabbit compared to human erythrocytes. Thus, our results argue against the involvement of major ion transporters in NLCT. They also show that comparative proteomics is a potent tool to identify the molecular origin of this carrier. [Copyright &y& Elsevier]

Abstract: Bumetanide and other high-ceiling diuretics (HCD) attenuate myogenic tone and contractions of vascular smooth muscle cells (VSMC) triggered by diverse stimuli. HCD outcome may be mediated by their interaction with NKCC1, the only isoform of Na+, K+, 2Cl− cotransporter expressed in VSMC as well as with targets distinct from this carrier. To examine these hypotheses, we compared the effect of bumetanide on contractions of mesenteric arteries from wild-type and NKCC1 knockout mice. In mesenteric arteries from wild-type controls, 100μM bumetanide evoked a decrease of up to 4-fold in myogenic tone and contractions triggered by modest [K+]o-induced depolarization, phenylephrine and UTP. These actions of bumetanide were preserved after inhibition of nitric oxide synthase with NG-nitro-l-arginine methyl ester, but were absent in mesenteric arteries from NKCC1-/- mice. The data show that bumetanide inhibits VSMC contractile responses via its interaction with NKCC1 and independently of nitric oxide production by endothelial cells. [Copyright &y& Elsevier]

In smooth muscles, inhibition of Na+,K+,2Cl- cotransport (NKCC) by bumetanide decreased intracellular Cl- content ([Cl-]i) and suppressed the contractions triggered by diverse stimuli. This study examines whether or not bicarbonate, a regulator of several Cl- transporters, affects the impact of NKCC in excitation-contraction coupling. Addition of 25 mM NaHCO3 attenuated the inhibitory action of bumetanide on mesenteric artery contractions evoked by 30 mM KCl and phenylephrine (PE) by 5 and 3-fold, respectively. In cultured vascular smooth muscle cells, NaHCO3 almost completely abolished inhibitory actions of bumetanide on transient depolarization and [Ca2+]i elevation triggered by PE. In bicarbonate-free medium, bumetanide decreased [Cl-]i by ∼15%; this effect was almost totally abrogated by NaHCO3. The addition of NaHCO3 resulted in 2-fold inhibition of NKCC activity and 3-fold attenuation of [Cl-]i. These data strongly suggest that extracellular HCO3- diminishes the NKCC-sensitive component of excitation-contraction coupling via suppression of this carrier. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Previously, we reported that hyposmotic swelling evoked transient vascular smooth muscle cell (SMC) contraction that was completely abolished by L-type Ca2+ channel blockers. In contrast, sustained contraction revealed in hyper- and isoosmotically-shrunken SMCs was insensitive to L-type channel blockers and was diminished in Ca2+-free medium by only 30-50%. Several research groups reported cell volume-dependent cytoskeleton network rearrangements. This study examines the role of cytoskeleton proteins in cell volume-dependent contraction of endothelium-denuded vascular smooth muscle rings (VSMR) from the rat thoracic aorta. Hyperosmotic shrinkage and hyposmotic swelling were triggered by modulation of medium osmolality; isosmotic shrinkage was induced by VSMR transfer from hypo- to isosmotic medium. The relative content of globular (G) and fibrillar (F) actin was estimated by fluorescence microscopy. Hyperosmotic shrinkage and hyposmotic swelling led to elevation of the F-actin/G-actin ratio by 2.5- and 1.8-fold respectively. Contraction of shrunken and swollen VSMR was insensitive to modulators of microtubules such as vinblastine, colchicine and docetaxel. Microfilament disassembly by cytochalasin B resulted in dramatic attenuation of the maximal amplitude of contraction of hyperosmotically-shrunken and hyposmotically-swollen VSMR, and almost completely abolished the contraction triggered by isosmotic shrinkage. These data suggest that both L-type Ca2+ channel-mediated contraction of swollen vascular SMC and Ca2+o-insensitive contractions of shrunken cells are triggered by reorganization of the microfilament network caused by elevation of the F-actin/G-actin ratio. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

An overview of the last works concerning the Recent environment and bottom sediments in the White Sea is presented. Special attention is devoted to the existing schemes of the modern facies structure. Up-to-date factual material allowed the authors to offer a new version of the facies structure. According to this version, the White Sea can be divided into two areas (scale 1 : 5 000 000): Northeastern and Southwestern. The Northeastern facies area includes two facies zones: Western and Eastern. The Southwestern facies area includes three facies zones: Central, Transitional, and Peripheral. In turn, the Peripheral facies zone is divided into the following facies subzones: (1) shallow-water Kandalaksha Bay; (2) Onega Bay, and (3) Severnaya Dvina prodelta and the Letnii Coast. Typical peculiarities of the Recent depositional environment and accumulated marine sediments are presented for all facies areas, zones and subzones. [ABSTRACT FROM AUTHOR]

In the geochemical review based on records from cruises of the International Deep Marine Drilling Project (DSDP, ODP, and IODP phases) and other literature data on the main types of Pleistocene sediments in the Atlantic, tables of average arithmetic chemical composition, mean weighted chemical composition, accumulation rates, and mass accumulation rates of chemical components are presented. These tables can be used for the comparative analysis with sediments of the same or other stratons in different oceanic basins, as well as with paleoceanic sediments on the continents. The terrigenous matrix dominates within the lithogenic matter. Using methods of mathematical statistics, we revealed the main geochemical associations and major factors determining the chemical composition of studied sediments. Masses of oxides of petrogenic elements and several trace elements have been calculated for Pleistocene sediments. Average chemical composition of Pleistocene sediments is proposed for the Atlantic. [ABSTRACT FROM AUTHOR]

Abstract—Lithological–facies zonality of Neo– and Eopleistocene sediments from the Fiji Sea is described for the first time. Processing of corresponding maps and isopachite schemes using A.B. Ronov's volumetric method gave us an opportunity to calculate the quantitative parameters of sedimentation for distinguished types of Pleistocene sediments. Carbonate sediments dominate over other groups of sediments. Carbonate planktonic sediments have been more intensively accumulated in the Neopleistocene than in the Eopleistocene. The highest volcanotectonic activity is typical of Eopleistocene. [ABSTRACT FROM AUTHOR]

A geochemical review of Pleistocene sediments in the Indian Ocean has been accomplished based on the deep-sea drilling cruise reports and other literature references. We compiled the database including more than 2000 chemical analyses of sediment samples and tables showing the mean arithmetic composition of lithogenic and biogenic sediments. All data were PAAS-normalized. The dominant role of terrigenous clastics is revealed in the formation of the chemical composition of noncarbonate sediments and noncarbonate matter in planktonic carbonates. The results made it possible to establish the main geochemical associations together with three main (terrigenous, carbonate, and hydrogenous) factors determinating the sediment composition. We calculated the weighted mean chemical composition, as well as the element accumulation rate in the sediments and their mass accumulation rates. All these parameters of the chemical composition can be used for the comparative analysis, with analogous parameters in other ocean sediments within Pleistocene straton in the World Ocean. [ABSTRACT FROM AUTHOR]

Abstract—Lithological and facies zonality of Neopleistocene and Eopleistocene sediments of the Australian seas is described for the first time. Processing of these maps and isopach schemes by A.B. Ronov volumetric method gave us an opportunity to calculate the quantitative parameters of sedimentation for different types of the Pleistocene sediments. It was revealed that carbonate sediments predominate over other sediment groups. The Neopleistocene was characterized by more intense accumulation of carbonate planktic sediments and lithogenic sediments than Eopleistocene. [ABSTRACT FROM AUTHOR]

We performed a comparative analysis of quantitative parameters for Pleistocene sediments from the pelagic zone and submarine parts of continental margins of the Atlantic Ocean in seven key areas. In the Neopleistocene compared to the Eopleistocene, the lithogenic fluxes increased both in the pelagic zone and on the continental margins. The residual absolute masses of СаСО3 and biogenic opal decreased in both megafacies zones. The biogenic sedimentation was more important for facies structure of the pelagic zone than for continental margins. [ABSTRACT FROM AUTHOR]

We have done a comparative analysis of quantitative parameters for Pleistocene sediments from pelagic zone of the Indian Ocean and submarine parts of its continental margins (for five key areas). The distribution areas, thicknesses, and volumes of main lithological types and groups have been analyzed. Dry sediment masses and their accumulation rates have been calculated. In the Neopleistocene compared to Eopleistocene, the fluxes (absolute masses) of all components of bottom sediments have been increased both in the pelagic zone and on the continental margins. Biogenic sedimentation was more important for facies structure of pelagic zone than (on average) for continental margins. [ABSTRACT FROM AUTHOR]

The title complex, [Cu(NO3)2(C3H6N2O2)2], exists in the crystal structure as a monomer and possesses a crystallographically imposed center of symmetry. The Cu atom is coordinated by six O atoms [Cu—O = 1.9339 (10)–2.3964 (11) Å] from two chelating malonamide ligands and two terminal NO3 groups in a distorted octa­hedral geometry. The crystal packing is stabilized by inter­molecular N—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

A comparative analysis of two large Arctic sedimentary basins was performed: the Sverdrup and East Barents, with emphasis on the quantitative parameters of sedimentation in the Mesozoic, determined by A.B. Ronov's volumetric method. The similarities and differences of both basins are revealed, in particular, in sediment accumulation areas, in masses of sedimentary material per time unit, and in gross sand ratio. It was concluded that at the end of the Paleozoic and in the Mesozoic, both basins were close to each other but did not merge into one structure. In the Cenozoic, the distance between the basins increased due to spreading of the Eurasian Basin. [ABSTRACT FROM AUTHOR]

Recent studies demonstrated that in addition to Na+,K+-ATPase inhibition cardiotonic steroids (CTSs) affect diverse intracellular signaling pathways. This study examines the relative impact of [Na+]i/[K+]i-mediated and -independent signaling in transcriptomic changes triggered by the endogenous CTSs ouabain and marinobufagenin (MBG) in human umbilical vein endothelial cells (HUVEC). We noted that prolongation of incubation increased the apparent affinity for ouabain estimated by the loss of [K+]i and gain of [Na+]i. Six hour exposure of HUVEC to 100 and 3,000 nM ouabain resulted in elevation of the [Na+]i/[K+]i ratio by ~15 and 80-fold and differential expression of 258 and 2185 transcripts, respectively. Neither [Na+]i/[K+]i ratio nor transcriptome were affected by 6-h incubation with 30 nM ouabain. The 96-h incubation with 3 nM ouabain or 30 nM MBG elevated the [Na+]i/[K+]i ratio by ~14 and 3-fold and led to differential expression of 880 and 484 transcripts, respectively. These parameters were not changed after 96-h incubation with 1 nM ouabain or 10 nM MBG. Thus, our results demonstrate that elevation of the [Na+]i/[K+]i ratio is an obligatory step for transcriptomic changes evoked by CTS in HUVEC. The molecular origin of upstream [Na+]i/[K+]i sensors involved in transcription regulation should be identified in forthcoming studies. [ABSTRACT FROM AUTHOR]

The title complex, [CuCl2(C3H6N2O2)2], exists in the crystal structure as a monomer and possesses a crystallographically imposed center of symmetry. The Cu atom is coordinated by two Cl atoms [Cu—Cl = 2.7696 (3) Å] and four O atoms [Cu—O = 1.9484 (8) and 1.9769 (9) Å] from two chelating malonamide ligands in a distorted octa­hedral geometry. In the crystal structure, a three-dimensional hydrogen-bonding network is formed by inter­molecular N—H⋯O and N—H⋯Cl inter­actions. [ABSTRACT FROM AUTHOR]