Host nutritional selenium status as a driving force for influenza virus mutations

Brough, George H.; Wu, Songwei; Cioffi, Donna L.; Moore, Timothy M.; Li, Ming; Dean, Nicholas M.; Stevens, Troy

doi:10.1096/fj.01-0108com

Cited by 225 publications

(184 citation statements)

References 11 publications

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“…Further, they reported that Jasplakinolide, which induced cortical actin assembly and inhibited Ca ϩϩ entry, also disrupted the coupling of TRPC1 with the type II IP 3 R. 24 TRPC1 has been suggested to play a role in SOCE in a number of other cell types, including salivary gland cells, 45 A549 and pulmonary artery cells, 46 and vascular smooth muscle cells, 47 although the mechanism of gating in these cells has not been elucidated. Our studies present new evidence that supports an indirect role for TRPC1 in cation entry in platelets.…”

Section: Discussionmentioning

confidence: 99%

Expression and role of TRPC proteins in human platelets: evidence that TRPC6 forms the store-independent calcium entry channel

Hassock

Zhu

Trost

et al. 2002

Blood

191

195

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Store-operated Ca ؉؉ entry (SOCE) is thought to comprise the major pathway for Ca ؉؉ entry in platelets. Recently, a number of transient receptor potential (TRP) proteins, which have been divided into 3 groups (TRPC, TRPM, and TRPV), have been suggested as SOCE channels. We report the expression and function of TRPC proteins in human platelets. TRPC6 is found at high levels and TRPC1 at low levels. Using purified plasma (PM) and intracellular membranes (IM), TRPC6 is found in the PM, but TRPC1 is localized to the IM. Using Fura-2-loaded platelets, we report that, in line with TRPC6 expression, 1-oleoyl-2-acetyl-sn-glycerol (OAG) stimulated the entry of Ca ؉؉ and Ba 2؉ independently of protein kinase C. Thrombin also induced the entry of Ca ؉؉ and Ba 2؉ , but thapsigargin, which depletes the stores, induced the entry of only Ca ؉؉ . Thus, thrombin activated TRPC6 via a SOCE-independent mechanism. In phosphorylation studies, we report that neither TRPC6 nor TRPC1 was a substrate for tyrosine kinases. TRPC6 was phosphorylated by cAMP-dependent protein kinase (cAMP-PK) and associated with other cAMP-PK substrates. TRPC1 was not phosphorylated by cAMP-PK but also associated with other substrates. Activation of cAMP-PK inhibited Ca ؉؉ but not Ba 2؉ entry induced by thrombin and neither Ca ؉؉ nor Ba 2؉ entry stimulated by OAG. These results suggest that TRPC6 is a SOCE-independent, nonselective cation entry channel stimulated by thrombin and OAG. TRPC6 is a substrate for cAMP-PK, although phosphorylation appears to not affect cation permeation. TRPC1 is located in IM, suggesting a role at the level of the stores. IntroductionPlatelet activation forms an integral component of hemostasis and contributes to the events leading to thrombosis. Complete activation of platelets by all stimulatory agents leads to an increase of cytosolic Ca ϩϩ levels, which triggers many intracellular signaling processes important for the expression of functional responses. 1 Conversely, the vasodilators prostacyclin (PGI 2 ) and nitric oxide (NO) inhibit platelet function, with inhibition of Ca ϩϩ elevation an identified mechanism. 2 Cytosolic Ca ϩϩ elevation occurs as a consequence of release of the cation from intracellular stores and influx from the outside medium. Whilst the mechanism for Ca ϩϩ release from the stores in nonexcitable cells is well accepted, Ca ϩϩ entry mechanisms are less understood. The key elements involved in Ca ϩϩ signaling include activated surface receptors that lead to the stimulation of phospholipase C (PLC), resulting in the hydrolysis of the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP 2 ) to release inositol 1,4,5-trisphosphate (IP 3 ) and diacylglycerol (DAG). IP 3 binds to the IP 3 receptor (IP 3 R) on intracellular stores, releasing Ca ϩϩ , and DAG is a potent activator of protein kinase C (PKC). Ca ϩϩ entry is thought to occur predominantly as a consequence of store depletion and has been referred to as store-operated Ca ϩϩ entry (SOCE) or capacitative Ca ϩϩ entry (CCE). 3 However, the d...

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Section: Discussionmentioning

confidence: 99%

Expression and role of TRPC proteins in human platelets: evidence that TRPC6 forms the store-independent calcium entry channel

Hassock

Zhu

Trost

et al. 2002

Blood

191

195

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“…We used two different approaches to address this hypothesis: the lanthanide mineral Gd 3ϩ , used as a nonspecific cation channel blocker, and a low [Ca 2ϩ ] perfusate, used to directly test the requirement for Ca 2ϩ entry. Gd 3ϩ blocks store depletion-induced Ca 2ϩ entry via transient receptor potential channels, which have been characterized as putative store-operated channels (2,14,25). Gd 3ϩ is difficult to use in vivo since it binds avidly to albumin (3), which may limit its efficacy with respect to blockade of Ca 2ϩ channels.…”

Section: Discussionmentioning

confidence: 99%

Role of EETs in regulation of endothelial permeability in rat lung

Alvarez

Gjerde

Townsley

2004

American Journal of Physiology-Lung Cellular and Molecular Phys

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This study tested the hypothesis that epoxyeicosatrienoic acids (EETs) derived from arachidonic acid via P-450 epoxygenases are soluble factors linking depletion of endoplasmic reticulum Ca2+ stores and store-dependent regulation of endothelial cell (EC) permeability in rat lung. EC permeability was measured via the capillary filtration coefficient ( Kf,c) in isolated, perfused rat lungs. 14,15-EET and 5,6-EET increased EC permeability, a response that was significantly different from that of 8,9-EET, 11,12-EET, and vehicle control. The permeability response to 14,15-EET was not significantly attenuated by the nonspecific Ca2+ channel blocker Gd3+ ( P = 0.068). In lungs perfused with low [Ca2+], 14,15-EET tended to increase EC permeability, although a significant increase in Kf,c was observed only following Ca2+ add-back. As positive control, we showed that the 3.7-fold increase in Kf,c evoked by thapsigargin (TG), a known activator of store depletion-induced Ca2+ entry, was blocked by both Gd3+ and low [Ca2+] buffer. Nonetheless, the permeability response to TG could not be blocked by the phospholipase A2 inhibitors mepacrine or methyl arachidonyl fluorophosphonate or the P-450 epoxygenase inhibitors 17-octadecynoic acid or propargyloxyphenyl hexanoic acid. Similarly, combined pretreatment with ibuprofen and dicyclohexylurea to block EET metabolism had no effect on the permeability response to TG. We conclude that EETs have a heterogeneous impact on EC permeability. Despite a requirement for Ca2+ entry with both TG and 14,15-EET, our data suggest that distinct signaling pathways or heterogeneity in EC responsiveness is responsible for the observed EC injury evoked by EETs and store depletion in the isolated rat lung.

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“…According to this model, the extent of store depletion is conveyed to PM by protein 4.1N, which links the cytoskeletal protein, spectrin, to TRPC4 [260] . The latter, in turn, contributes pore-forming subunits to the store-dependent channel along with TRPC1 according to the following stoichiometry, 1 TRPC1 and 3 TRPC4 [203,217,260,261] . The association between the two subunits is favoured by Cav-1, which also recruits InsP3R1 into the membranal signalplex [262] .…”

Section: +(Rt-pcr)mentioning

confidence: 99%

Update on vascular endothelial Ca²⁺signalling: A tale of ion channels, pumps and transporters

Moccia

Berra‐Romani²,

Tanzi³

2012

WJBC

110

192

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A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca 2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca 2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca 2+ signals, ranging from brief, localized Ca 2+ pulses to prolonged Ca 2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca 2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca 2+ releasing channels, which are located both on the plasma membrane and in a number of intracellular organelles, and Ca 2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca 2+ machinery in vascular ECs under both physiological and pathological conditions.

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Host nutritional selenium status as a driving force for influenza virus mutations

Cited by 225 publications

References 11 publications

Expression and role of TRPC proteins in human platelets: evidence that TRPC6 forms the store-independent calcium entry channel

Expression and role of TRPC proteins in human platelets: evidence that TRPC6 forms the store-independent calcium entry channel

Role of EETs in regulation of endothelial permeability in rat lung

Update on vascular endothelial Ca²⁺signalling: A tale of ion channels, pumps and transporters

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Host nutritional selenium status as a driving force for influenza virus mutations

Cited by 225 publications

References 11 publications

Expression and role of TRPC proteins in human platelets: evidence that TRPC6 forms the store-independent calcium entry channel

Expression and role of TRPC proteins in human platelets: evidence that TRPC6 forms the store-independent calcium entry channel

Role of EETs in regulation of endothelial permeability in rat lung

Update on vascular endothelial Ca2+signalling: A tale of ion channels, pumps and transporters

Contact Info

Product

Resources

About

Update on vascular endothelial Ca²⁺signalling: A tale of ion channels, pumps and transporters