237 research outputs found
Compartmentalized Connexin 43 S-Nitrosylation/Denitrosylation Regulates Heterocellular Communication in the Vessel Wall
Objective-To determine whether S-nitrosylation of connexins (Cxs) modulates gap junction communication between endothelium and smooth muscle. Methods and Results-Heterocellular communication is essential for endothelium control of smooth muscle constriction; however, the exact mechanism governing this action remains unknown. Cxs and NO have been implicated in regulating heterocellular communication in the vessel wall. The myoendothelial junction serves as a conduit to facilitate gap junction communication between endothelial cells and vascular smooth muscle cells within the resistance vasculature. By using isolated vessels and a vascular cell coculture, we found that Cx43 is constitutively S-nitrosylated on cysteine 271 because of active endothelial NO synthase compartmentalized at the myoendothelial junction. Conversely, we found that stimulation of smooth muscle cells with the constrictor phenylephrine caused Cx43 to become denitrosylated because of compartmentalized S-nitrosoglutathione reductase, which attenuated channel permeability. We measured S-nitrosoglutathione breakdown and NOx concentrations at the myoendothelial junction and found S-nitrosoglutathione reductase activity to precede NO release. Conclusion-This study provides evidence for compartmentalized S-nitrosylation/denitrosylation in the regulation of smooth muscle cell to endothelial cell communication. (Arterioscler Thromb Vasc Biol. 2011;31:399-407.
Plasminogen Activator Inhibitor-1 Regulates Myoendothelial Junction Formation
Rationale: Plasminogen activator inhibitor-1 (PAI-1) is a biomarker for several vascular disease states; however, its target of action within the vessel wall is undefined. Objective: Determine the ability of PAI-1 to regulate myoendothelial junction (MEJ) formation. Methods and Results: MEJs are found throughout the vasculature linking endothelial cells (ECs) and vascular smooth muscle cells. Using a vascular cell coculture we isolated MEJ fractions and performed two-dimensional differential gel electrophoresis. Mass spectrometry identified PAI-1 as being enriched within MEJ fractions, which we confirmed in vivo. In the vascular cell coculture, recombinant PAI-1 added to the EC monolayer significantly increased MEJs. Conversely, addition of a PAI-1 monoclonal antibody to the EC monolayer reduced the number of MEJs. This was also observed in vivo where mice fed a high fat diet had increased PAI-1 and MEJs and the number of MEJs in coronary arterioles of PAI-1(-/-) mice was significantly reduced when compared to C57Bl/6 mice. The presence of MEJs in PAI-1(-/-) coronary arterioles was restored when their hearts were transplanted into and exposed to the circulation of C57Bl/6 mice. Application of biotin-conjugated PAI-1 to the EC monolayer in vitro confirmed the ability of luminal PAI-1 to translocate to the MEJ. Functionally, phenylephrine-induced heterocellular calcium communication in the vascular cell coculture was temporally enhanced when recombinant PAI-1 was present, and prolonged when PAI-1 was absent. Conclusion: Our data implicate circulating PAI-1 as a key regulator of MEJ formation and a potential target for pharmacological intervention in diseases with vascular abnormalities (eg, diabetes mellitus). (Circ Res. 2010; 106: 1092-1102.
The phosphorylation state of eNOS modulates vascular reactivity and outcome of cerebral ischemia in vivo
NO plays critical roles in vascular function. We show that modulation of the eNOS serine 1179 (S1179) phosphorylation site affects vascular reactivity and determines stroke size in vivo. Transgenic mice expressing only a phosphomimetic (S1179D) form of eNOS show greater vascular reactivity, develop less severe strokes, and have improved cerebral blood flow in a middle cerebral artery occlusion model than mice expressing an unphosphorylatable (S1179A) form. These results provide a molecular mechanism by which multiple diverse cardiovascular risks, such as diabetes and obesity, may be centrally integrated by eNOS phosphorylation in vivo to influence blood flow and cardiovascular disease. They also demonstrate the in vivo relevance of posttranslational modification of eNOS in vascular function
Alpha(1)-adrenergic-mediated eNOS phosphorylation in intact arteries
Activation of arterial smooth muscle alpha(1)-adrenergic receptors results in vasoconstriction, as well as a secondary release of nitric oxide and slow vasodilation, presumably through gap junction communication from smooth muscle to endothelium. We hypothesized that this slow vasodilation is due to activation of eNOS through phosphorylation at Ser1179 and dephosphorylation at Thr495. Phosphorylation was measured by western blot using mouse mesenteric arteries that were cannulated and pressurized (75 mm Hg) and treated either by 1) 5 mm of phenylephrine superfusion (10(-5) M) (PE5), 2) 15 min of phenylephrine (PE15), 3) 15 min phenylephrine followed by acetylcholine (10(-4) M) (PE + ACh), or 4) 20 min time control with no treatment (NT) [4-5 arteries pooled per treatment per blot; 5 blots performed]. These treatments allowed correlation between vasomotor changes, namely maximal constriction (PE5), slow vasodilation (PE15), and maximal dilation (PE + ACh), and relative phosphorylation changes. Phosphorylation of eNOS at Ser1179 was increased relative to NT by more than 2-fold at PE5 and remained similarly increased at PE15 and PE + ACh. Phosphotylation of eNOS at Thr495 was less in all treatments relative to NT, but not significantly. Treatment with L-NAME (10(-4) M) or endothelial denudation indicated that the slow dilation in response to phenylephrine was completely due to nitric oxide synthase and was endothelial dependent. These results indicate that eNOS phosphorylation at Ser1179 occurs before the slow dilation and is not actively involved in this vasodilation or dilation to acetylcholine, but may play a permissive role in eNOS activation by other mechanisms. It is not yet known what mechanism is responsible for Ser1179 phosphorylation with phenylephrine stimulation. (C) 2012 Elsevier Inc. All rights reserved
The Iowa Homemaker vol.7, no.8
Memorial Hall by Ruth E. Morrison, Antescript
Dawn’s Awakening by Irma D. Garner, Antescript
The Evolution of Women’s Clubs by Margaret Looft, page 1
Farm and Home Week by Sylvia Pedersen, page 2
How Much Shall I Buy? by Margaret L. Marnette, page 4
Marketing in Egypt by Frances Thomas, page 5
Girls’ 4-H Page by Corline Morrell, page 6
Iowa State Home Economics Association by Marcia E. Turner, page 8
Home Economics Research at Iowa State by Harriett C. Brigham, page 10
Who’s There and Where by Vera Caulum, page 12
Better Homes Week by Kathryn Davis, page 13
Foreign Students Will Occupy “The Gables” by Ruth E. Morrison, page 14
Home Economics Vod-Vil by Gladys Parker, page 1
Children\u27s Judgments of Age
Age judgments of human figures by children, ranging in age from 3 through 9 years, were investigated. The stimuli consisted of 4 different male figures drawn according to typical physical characteristics of the middle-aged adult, adolescent child, and infant. The figures were reproduced in 2 sizes and were matched in all possible pairings. Ss\u27 accuracy in age judgments increased steadily over the 7 age levels. The errors of young Ss were primarily due to a figural-size response set. Older Ss made increasing use of other physical features in making their judgments. Implications of these findings were discussed with references to the theoretical framework of Piaget
THE ESTIMATION OF GENETIC DISTANCE BETWEEN GERMAN CATTLE BREEDS
Za budući izbor uzgoja potrebno je očuvanje genetske raznolikosti u životinja. U filogenetskim proučavanjima mikrosateliti su dokazani kao snažno sredstvo. (Bowcock et al. 1994.). Procjena genetskih udaljenosti što se temelji na učestalosti alela mikrosatelitskih markera pomoći će u procjeni veličine razlika između usko povezanih pasmina stoke. Pasmina Shorthom i Angler mogu se identificirati kao sporedne pasmine, pa je stoga razvoj programa očuvanja vrlo koristan. Prilagođenje pasmine Orginal Black Pied još nije jasno. Odredit će se dodatni markeri kako bi se povećala točnost procjene. Niti vrijednosti udaljenosti između Holsteina i mliječnog Red Pied niti slični uzgojni ciljevi čini se da nisu razuman razlog da se ove pasmine drže odijeljeno. Ovaj će rad biti od pomoći u odlučivanju o očuvanju pasmina u posebnim programima očuvanja konzervacijom in vivo i in vitro
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