Leukotriene C4 (BioDeep_00000003314)

描述信息

Leukotriene C4 (LTC4) is a cysteinyl leukotriene (CysLT), a family of potent inflammatory mediators. Eosinophils, one of the principal cell types recruited to and activated at sites of allergic inflammation, is capable of elaborating lipid mediators, including leukotrienes derived from the oxidative metabolism of arachidonic acid (AA). Potentially activated eosinophils may elaborate greater quantities of LTC4, than normal eosinophils. These activated eosinophils thus are primed for enhanced LTC4 generation in response to subsequent stimuli. Some recognized priming stimuli are chemoattractants (e.g. eotaxin, PAF) that may participate in the recruitment of eosinophils to sites of allergic inflammation. The mechanisms by which chemoattractants and other activating cytokines (e.g. interleukin (IL)-5) or extracellular matrix components (e.g. fibronectin) enhance eosinophil eicosanoid formation are pertinent to the functions of these eicosanoids as paracrine mediators of allergic inflammation. Some eosinophil-derived eicosanoids may be active in down-regulating inflammation. It is increasingly likely that eicosanoids synthesized within cells, including eosinophils, may have intracellular (e.g. intracrine) roles in regulating cell functions, in addition to the more recognized activities of eicosanoids as paracrine mediators of inflammation. Acting extracellularly, the cysteinyl leukotrienes (CysLTs) LTC4 and its extracellular derivatives, LTD4 and LTE4 are key paracrine mediators pertinent to asthma and allergic diseases. Based on their receptor-mediated capabilities, they can elicit bronchoconstriction, mucus hypersecretion, bronchial hyperresponsiveness, increased microvascular permeability, and additional eosinophil infiltration. Eosinophils are a major source of CysLTs and have been identified as the principal LTC4 synthase expressing cells in bronchial mucosal biopsies of asthmatic subjects (PMID: 12895596). Leukotrienes are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways.
Leukotriene c4, also known as ltc4 or 5s,6r-ltc(sub 4), is a member of the class of compounds known as oligopeptides. Oligopeptides are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds. Thus, leukotriene c4 is considered to be an eicosanoid lipid molecule. Leukotriene c4 is practically insoluble (in water) and a moderately acidic compound (based on its pKa). Leukotriene c4 can be synthesized from icosa-7,9,11,14-tetraenoic acid. Leukotriene c4 is also a parent compound for other transformation products, including but not limited to, leukotriene C4 methyl ester, 11,12-dihydro-(12R)-hydroxyleukotriene C4, and 11,12-dihydro-12-oxoleukotriene C4. Leukotriene c4 can be found in a number of food items such as gram bean, maitake, caraway, and burbot, which makes leukotriene c4 a potential biomarker for the consumption of these food products. Leukotriene c4 can be found primarily in blood and cerebrospinal fluid (CSF), as well as throughout most human tissues. In humans, leukotriene c4 is involved in several metabolic pathways, some of which include trisalicylate-choline action pathway, antipyrine action pathway, nepafenac action pathway, and fenoprofen action pathway. Leukotriene c4 is also involved in a couple of metabolic disorders, which include leukotriene C4 synthesis deficiency and tiaprofenic acid action pathway. Moreover, leukotriene c4 is found to be associated with eczema. Leukotriene C4 (LTC4) is a leukotriene. LTC4 has been extensively studied in the context of allergy and asthma. In cells of myeloid origin such as mast cells, its biosynthesis is orchestrated by translocation to the nuclear envelope along with co-localization of cytosolic phospholipase A2 (cPLA2), Arachidonate 5-lipoxygenase (5-LO), 5-lipoxygenase-activating protein (FLAP) and LTC4 synthase (LTC4S), which couples glutathione to an LTA4 intermediate.The MRP1 transporter then secretes cytosolic LTC4 and cell surface proteases further metabolize it by sequential cleavage of the γ-glutamyl and glycine residues off its glutathione segment, generating the more stable products LTD4 and LTE4. All three leukotrienes then bind at different affinities to two G-protein coupled receptors: CYSLTR1 and CYSLTR2, triggering pulmonary vasoconstriction and bronchoconstriction .

同义名列表

文献列表