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131.
Massaro D Alexander E Reiland K Hoffman EP Massaro GD Clerch LB 《American journal of physiology. Lung cellular and molecular physiology》2007,292(5):L1313-L1326
Alveolar regenerative gene expression is unidentified partly because its onset, after a regenerative stimulus, is unknown. Toward addressing this void, we used a mouse model in which calorie restriction produces alveolar loss, and ad libitum access to food after calorie restriction induces alveolar regeneration. We selected four processes (cell replication, angiogenesis, extracellular matrix remodeling, and guided cell motion) that would be required to convert a flat segment of alveolar wall into a septum that increases gas-exchange surface area. Global gene expression supportive of processes required to form a septum was present within 3 h of allowing calorie-restricted mice food ad libitum. One hour after providing calorie-restricted mice food ad libitum, RNA-level expression supportive of cell replication was present with little evidence of expression supportive of angiogenesis, extracellular matrix remodeling, or guided cell motion. Cell replication was more directly assayed by measuring DNA synthesis in lung. This measurement was made 3 h after allowing calorie-restricted mice food ad libitum because translation may be delayed. Ad libitum food intake, following calorie restriction, elevated DNA synthesis. Thus RNA expression 1 h after allowing calorie-restricted mice food ad libitum supported increased cell replication; measurements at 3 h revealed increased DNA synthesis and RNA expression, supportive of the three other processes required to form a septum. These findings identify the first hour after providing calorie-restricted mice ad libitum access to food as the onset of gene expression in this model that supports processes needed for alveolar regeneration. 相似文献
132.
Milinovich GJ Trott DJ Burrell PC Croser EL Al Jassim RA Morton JM van Eps AW Pollitt CC 《Environmental microbiology》2007,9(8):2090-2100
Carbohydrate-induced laminitis in horses is characterized by marked changes in the composition of the hindgut microbiota, from a predominantly Gram-negative population to one dominated by Gram-positive bacteria. The objective of this study was to monitor changes in the relative abundance of selected hindgut bacteria that have previously been implicated in the pathophysiology of equine laminitis using fluorescence in situ hybridization (FISH). Caecal cannulae were surgically implanted in five Standardbred horses and laminitis induced by oral administration of a bolus dose of oligofructose. Caecal fluid and faecal specimens were collected over a 48 h period at 2 to 4 h intervals post-oligofructose administration and subjected to FISH using probes specific for nine bacterial groups to determine changes in their relative abundance compared with total bacteria hybridizing to the generic EUBMIX probe. Additionally, hoof biopsies were taken over the course of the experiment at 6 h intervals and evaluated for histopathological changes consistent with laminitis, allowing changes in hindgut microbiota to be correlated with the onset of lesions in the foot. Of the microorganisms specifically targeted, streptococci of the Streptococcus bovis/equinus complex were the only bacteria that consistently proliferated in both caecal fluid and faeces immediately before the onset of histological signs of laminitis. Furthermore, lactobacilli, Enterobacteriaceae, Allisonella histaminiformans, enterococci, Bacteroides fragilis, Mitsuokella jalaludinii and Clostridium difficile did not establish significant populations in the hindgut before the onset of equine laminitis. 相似文献
133.
Connell E Darios F Broersen K Gatsby N Peak-Chew SY Rickman C Davletov B 《EMBO reports》2007,8(4):414-419
Syntaxin and Munc18 are, in tandem, essential for exocytosis in all eukaryotes. Recently, it was shown that Munc18 inhibition of neuronal syntaxin 1 can be overcome by arachidonic acid, indicating that this common second messenger acts to disrupt the syntaxin-Munc18 interaction. Here, we show that arachidonic acid can stimulate syntaxin 1 alone, indicating that it is syntaxin 1 that undergoes a structural change in the syntaxin 1-Munc18 complex. Arachidonic acid is incapable of dissociating Munc18 from syntaxin 1 and, crucially, Munc18 remains associated with syntaxin 1 after arachidonic-acid-induced syntaxin 1 binding to synaptosomal-associated protein 25 kDa (SNAP25). We also show that the same principle operates in the case of the ubiquitous syntaxin 3 isoform, highlighting the conserved nature of the mechanism of arachidonic acid action. Neuronal soluble N-ethyl maleimide sensitive factor attachment protein receptors (SNAREs) can be isolated from brain membranes in a complex with endogenous Munc18, consistent with a proposed function of Munc18 in vesicle docking and fusion. 相似文献
134.
Dominguez Almela Victoria Nolan Emma T. Winter Emily R. Britton J. Robert 《Hydrobiologia》2022,849(10):2253-2265
Hydrobiologia - Native communities can resist the establishment and invasion of alien species through consumptive and/or competitive interactions. The extent of consumptive resistance from... 相似文献
135.
Ward Delphi Melbourne-Thomas Jessica Pecl Gretta T. Evans Karen Green Madeline McCormack Phillipa C. Novaglio Camilla Trebilco Rowan Bax Narissa Brasier Madeleine J. Cavan Emma L. Edgar Graham Hunt Heather L. Jansen Jan Jones Russ Lea Mary-Anne Makomere Reuben Mull Chris Semmens Jayson M. Shaw Janette Tinch Dugald van Steveninck Tatiana J. Layton Cayne 《Reviews in Fish Biology and Fisheries》2022,32(1):65-100
Reviews in Fish Biology and Fisheries - Marine ecosystems and their associated biodiversity sustain life on Earth and hold intrinsic value. Critical marine ecosystem services include maintenance of... 相似文献
136.
pH is an important factor determining bacterial community composition in soil and water. We have directly determined the community tolerance (trait variation) to pH in communities from 22 lakes and streams ranging in pH from 4 to 9 using a growth-based method not relying on distinguishing between individual populations. The pH in the water samples was altered to up to 16 pH values, covering in situ pH ± 2.5 U, and the tolerance was assessed by measuring bacterial growth (Leu incorporation) instantaneously after pH adjustment. The resulting unimodal response curves, reflecting community tolerance to pH, were well modeled with a double logistic equation (mean R2 = 0.97). The optimal pH for growth (pHopt) among the bacterial communities was closely correlated with in situ pH, with a slope (0.89 ± 0.099) close to unity. The pH interval, in which growth was ≥90% of that at pHopt, was 1.1 to 3 pH units wide (mean 2.0 pH units). Tolerance response curves of communities originating from circum-neutral pH were symmetrical, whereas in high-pH (8.9) and especially in low-pH (<5.5) waters, asymmetric tolerance curves were found. In low-pH waters, decreasing pH was more detrimental for bacterial growth than increasing pH, with a tendency for the opposite for high-pH waters. A pH tolerance index, using the ratio of growth at only two pH values (pH 4 and 8), was closely related to pHopt (R2 = 0.83), allowing for easy determination of pH tolerance during rapid changes in pH. 相似文献
137.
138.
Rebecca A. Capel Emma L. Bolton Wee K. Lin Daniel Aston Yanwen Wang Wei Liu Xin Wang Rebecca-Ann B. Burton Duncan Bloor-Young Kai-Ting Shade Margarida Ruas John Parrington Grant C. Churchill Ming Lei Antony Galione Derek A. Terrar 《The Journal of biological chemistry》2015,290(50):30087-30098
Ca2+-permeable type 2 two-pore channels (TPC2) are lysosomal proteins required for nicotinic acid adenine dinucleotide phosphate (NAADP)-evoked Ca2+ release in many diverse cell types. Here, we investigate the importance of TPC2 proteins for the physiology and pathophysiology of the heart. NAADP-AM failed to enhance Ca2+ responses in cardiac myocytes from Tpcn2−/− mice, unlike myocytes from wild-type (WT) mice. Ca2+/calmodulin-dependent protein kinase II inhibitors suppressed actions of NAADP in myocytes. Ca2+ transients and contractions accompanying action potentials were increased by isoproterenol in myocytes from WT mice, but these effects of β-adrenoreceptor stimulation were reduced in myocytes from Tpcn2−/− mice. Increases in amplitude of L-type Ca2+ currents evoked by isoproterenol remained unchanged in myocytes from Tpcn2−/− mice showing no loss of β-adrenoceptors or coupling mechanisms. Whole hearts from Tpcn2−/− mice also showed reduced inotropic effects of isoproterenol and a reduced tendency for arrhythmias following acute β-adrenoreceptor stimulation. Hearts from Tpcn2−/− mice chronically exposed to isoproterenol showed less cardiac hypertrophy and increased threshold for arrhythmogenesis compared with WT controls. Electron microscopy showed that lysosomes form close contacts with the sarcoplasmic reticulum (separation ∼25 nm). We propose that Ca2+-signaling nanodomains between lysosomes and sarcoplasmic reticulum dependent on NAADP and TPC2 comprise an important element in β-adrenoreceptor signal transduction in cardiac myocytes. In summary, our observations define a role for NAADP and TPC2 at lysosomal/sarcoplasmic reticulum junctions as unexpected but major contributors in the acute actions of β-adrenergic signaling in the heart and also in stress pathways linking chronic stimulation of β-adrenoceptors to hypertrophy and associated arrhythmias. 相似文献
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