Cysteinyl leukotriene type I receptor desensitization sustains Ca2+-dependent gene expression.

Receptor desensitization is a universal mechanism to turn off a biological response; in this process, the ability of a physiological trigger to activate a cell is lost despite the continued presence of the stimulus. Receptor desensitization of G-protein-coupled receptors involves uncoupling of the receptor from its G-protein or second-messenger pathway followed by receptor internalization. G-protein-coupled cysteinyl leukotriene type I (CysLT1) receptors regulate immune-cell function and CysLT1 receptors are an established therapeutic target for allergies, including asthma.

Mitofusin 2 regulates STIM1 migration from the Ca2+ store to the plasma membrane in cells with depolarized mitochondria.

Store-operated Ca2+ channels in the plasma membrane (PM) are activated by the depletion of Ca2+ from the endoplasmic reticulum (ER) and constitute a widespread and highly conserved Ca2+ influx pathway. After store emptying, the ER Ca2+ sensor STIM1 forms multimers, which then migrate to ER-PM junctions where they activate the Ca2+ release-activated Ca2+ channel Orai1. Movement of an intracellular protein to such specialized sites where it gates an ion channel is without precedence, but the fundamental question of how STIM1 migrates remains unresolved.

Effects of hydrogen sulfide on inflammation in caerulein-induced acute pancreatitis.

Background: Hydrogen sulfide (H(2)S), a gaseous mediator plays an important role in a wide range of physiological and pathological processes. H(2)S has been extensively studied for its various roles in cardiovascular and neurological disorders. However, the role of H(2)S in inflammation is still controversial.

Coupling of Ca(2+) microdomains to spatially and temporally distinct cellular responses by the tyrosine kinase Syk.

Communication between the cell surface and the nucleus is essential for regulated gene expression. In neurons, Ca(2+)-dependent gene transcription is sensitive to local Ca(2+) entry. In immune cells, excitation-transcription coupling is thought to involve global Ca(2+) signals.

Decoding of cytoplasmic Ca(2+) oscillations through the spatial signature drives gene expression.

Cytoplasmic Ca(2+) oscillations are a universal signaling mode that activates numerous cellular responses [1, 2]. Oscillations are considered the physiological mechanism of Ca(2+) signaling because they occur at low levels of stimulus intensity [3]. Ca(2+) oscillations are proposed to convey information in their amplitude and frequency, leading to activation of specific downstream targets [4-6].

Expression of nitric oxide synthase isoforms and nitric oxide production in acute pancreatitis and associated lung injury.

Background/aims: The role of nitric oxide (NO) has been increasingly implicated in the pathophysiology of acute pancreatitis (AP). Studies have shown increased NO production in AP although not all are agreeable on whether NO is beneficial or detrimental in AP. This study aims to profile NO production and NO synthase (NOS) expression in the pancreas and lungs in the progression of AP in mice to gain insights to the role played by different NOS isoforms.

Sustained activation of the tyrosine kinase Syk by antigen in mast cells requires local Ca2+ influx through Ca2+ release-activated Ca2+ channels.

Mast cell activation involves cross-linking of IgE receptors followed by phosphorylation of the non-receptor tyrosine kinase Syk. This results in activation of the plasma membrane-bound enzyme phospholipase Cgamma1, which hydrolyzes the minor membrane phospholipid phosphatidylinositol 4,5-bisphosphate to generate diacylglycerol and inositol trisphosphate. Inositol trisphosphate raises cytoplasmic Ca2+ concentration by releasing Ca2+ from intracellular stores.

Role of MCP-1 in endotoxemia and sepsis.

Sepsis is a complex clinical syndrome resulting from a harmful host inflammatory response to infection. Similarly, lipopolysaccharide (LPS) induced endotoxemia is marked by the activation of inflammatory responses, which can lead to shock, multiple organ damage and even death. Inflammatory mediator, chemokines are known to play an important role in the pathogenesis of sepsis and endotoxemia.

Pro-inflammatory effects of hydrogen sulphide on substance P in caerulein-induced acute pancreatitis.

Hydrogen sulphide (H(2)S), a novel gasotransmitter, has been recognized to play an important role in inflammation. Cystathionine-gamma-lyase (CSE) is a major H(2)S synthesizing enzyme in the cardiovascular system and DL-propargylglycine (PAG) is an irreversible inhibitor of CSE. Substance P (SP), a product of preprotachykinin-A (PPT-A) gene, is a well-known pro-inflammatory mediator which acts principally through the neurokinin-1 receptor (NK-1R).

Role of preprotachykinin-A gene products on multiple organ injury in LPS-induced endotoxemia.

Endotoxemia is a life-threatening, inflammatory condition that involves multiple organ injury and dysfunction. Preprotachykinin-A (PPT-A) gene products, substance P (SP), and neurokinin-A have been shown to play an important role in neurogenic inflammation. To investigate the role of PPT-A gene products on multiple organ injury in LPS-induced endotoxemia, endotoxemia was induced by LPS administration (10 mg/kg, i.

Hydrogen sulfide up-regulates substance P in polymicrobial sepsis-associated lung injury.

Hydrogen sulfide (H2S) has been shown to induce the activation of neurogenic inflammation especially in normal airways and urinary bladder. However, whether endogenous H2S would regulate sepsis-associated lung inflammation via substance P (SP) and its receptors remains unknown. Therefore, the aim of the study was to investigate the effect of H2S on the pulmonary level of SP in cecal ligation and puncture (CLP)-induced sepsis and its relevance to lung injury.

Role of substance P in hydrogen sulfide-induced pulmonary inflammation in mice.

We have shown earlier that H(2)S acts as a mediator of inflammation. In this study, we have investigated the involvement of substance P and neurogenic inflammation in H(2)S-induced lung inflammation. Intraperitoneal administration of NaHS (1-10 mg/kg), an H(2)S donor, to mice caused a significant increase in circulating levels of substance P in a dose-dependent manner.

Preprotachykinin-A gene products are key mediators of lung injury in polymicrobial sepsis.

Preprotachykinin-A (PPT-A) gene products substance P and neurokinin-A have been shown to play an important role in neurogenic inflammation. To investigate the role of PPT-A gene products in lung injury in sepsis, polymicrobial sepsis was induced by cecal ligation and puncture in PPT-A gene-deficient mice (PPT-A(-/-)) and the wild-type control mice (PPT-A(+/+)). PPT-A gene deletion significantly protected against mortality, delayed the onset of lethality, and improved the long-term survival following cecal ligation and puncture-induced sepsis.