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Eoxin
Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds that regulate inflammatory and immune responses). They are produced by human eosinophils (a class of white blood cells), mast cells, the L1236 Reed–Sternberg cell line derived from Hodgkin's lymphoma, and certain other tissues. These cells produce the eoxins by initially metabolizing arachidonic acid, an omega-6 (ω-6) fatty acid, via any enzyme possessing 15-lipoxygenase activity. The product of this initial metabolic step, 15(S)-hydroperoxyeicosatetraenoic acid, is then converted to a series of eoxins by the same enzymes that metabolize the 5-lipoxygenase product of arachidonic acid metabolism, i.e. 5-Hydroperoxy-eicosatetraenoic acid to a series of leukotrienes. That is, the eoxins are 14,15-disubstituted analogs of the 5,6-disubstituted leukotrienes. A closely related set of 15-lipoxygenase metabolites are derived from anandamide (i.e. arachidonic acid containing ethanolamine esterifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
15-Hydroxyeicosatetraenoic Acid
15-Hydroxyeicosatetraenoic acid (also termed 15-HETE, 15(''S'')-HETE, and 15''S''-HETE) is an eicosanoid, i.e. a metabolite of arachidonic acid. Various cell types metabolize arachidonic acid to 15(''S'')-hydroperoxyeicosatetraenoic acid (15(''S'')-HpETE). This initial hydroperoxide product is extremely short-lived in cells: if not otherwise metabolized, it is rapidly reduced to 15(''S'')-HETE. Both of these metabolites, depending on the cell type which forms them, can be further metabolized to 15-oxo-eicosatetraenoic acid (15-oxo-ETE), 5(''S''),15(''S'')-dihydroxy-eicosatetraenoic acid (5(''S''),15(''S'')-diHETE), 5-oxo-15(''S'')-hydroxyeicosatetraenoic acid (5-oxo-15(''S'')-HETE), a subset of specialized pro-resolving mediators viz., the lipoxins, a class of pro-inflammatory mediators, the eoxins, and other products that have less well-defined activities and functions. Thus, 15(''S'')-HETE and 15(''S'')-HpETE, in addition to having intrinsic biological activities, are key prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
15-Hydroxyicosatetraenoic Acid
15-Hydroxyeicosatetraenoic acid (also termed 15-HETE, 15(''S'')-HETE, and 15''S''-HETE) is an eicosanoid, i.e. a metabolite of arachidonic acid. Various cell types metabolize arachidonic acid to 15(''S'')-hydroperoxyeicosatetraenoic acid (15(''S'')-HpETE). This initial Peroxide, hydroperoxide product is extremely short-lived in cells: if not otherwise metabolized, it is rapidly reduced to 15(''S'')-HETE. Both of these metabolites, depending on the cell type which forms them, can be further metabolized to 15-oxo-eicosatetraenoic acid (15-oxo-ETE), 5(''S''),15(''S'')-dihydroxy-eicosatetraenoic acid (5(''S''),15(''S'')-diHETE), 5-oxo-15(''S'')-hydroxyeicosatetraenoic acid (5-oxo-15(''S'')-HETE), a subset of specialized pro-resolving mediators viz., the lipoxins, a class of pro-inflammatory mediators, the eoxins, and other products that have less well-defined activities and functions. Thus, 15(''S'')-HETE and 15(''S'')-HpETE, in addition to having intrinsic biological activities, are ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
15-lipoxygenase
ALOX15 (also termed arachidonate 15-lipoxygenase, 15-lipoxygenase-1, 15-LO-1, 15-LOX-1) is, like other lipoxygenases, a seminal enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ... in the metabolism of polyunsaturated fatty acids to a wide range of physiologically and pathologically important products. ▼ Gene Function Kelavkar and Badr (1999) stated that the ALOX15 gene product is implicated in antiinflammation, membrane remodeling, and cancer development/metastasis. Kelavkar and Badr (1999) described experiments yielding data that supported the hypothesis that loss of the TP53 gene, or gain-of-function activities resulting from the expression of its mutant forms, regulates ALOX15 promoter activity in human and in mouse, albeit in directionally opposite manners. These stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eicosanoid
Eicosanoids are lipid signaling, signaling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids (PUFAs) that are, similar to arachidonic acid, around 20 carbon units in length. Eicosanoids are a sub-category of oxylipins, i.e. oxidized fatty acids of diverse carbon units in length, and are distinguished from other oxylipins by their overwhelming importance as cell signaling molecules. Eicosanoids function in diverse physiological systems and pathological processes such as: mounting or inhibiting inflammation, allergy, fever and other immune responses; regulating the abortion of pregnancy and normal childbirth; contributing to the perception of pain; regulating cell growth; controlling blood pressure; and modulating the regional flow of blood to tissues. In performing these roles, eicosanoids most often act as autocrine signaling agents to impact their cells of origin or as paracrine signaling agents to impact cells in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALOX15
ALOX15 (also termed arachidonate 15-lipoxygenase, 15-lipoxygenase-1, 15-LO-1, 15-LOX-1) is, like other lipoxygenases, a seminal enzyme in the metabolism of polyunsaturated fatty acids to a wide range of physiologically and pathologically important products. ▼ Gene Function Kelavkar and Badr (1999) stated that the ALOX15 gene product is implicated in antiinflammation, membrane remodeling, and cancer development/metastasis. Kelavkar and Badr (1999) described experiments yielding data that supported the hypothesis that loss of the TP53 gene, or gain-of-function activities resulting from the expression of its mutant forms, regulates ALOX15 promoter activity in human and in mouse, albeit in directionally opposite manners. These studies defined a direct link between ALOX15 gene activity and an established tumor-suppressor gene located in close chromosomal proximity. Kelavkar and Badr (1999) referred to this as evidence that 15-lipoxygenase is a mutator gene. ▼ Mapping By PCR ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mast Cell
A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. Mast cells were discovered by Friedrich von Recklinghausen and later rediscovered by Paul Ehrlich in 1877. Although best known for their role in allergy and anaphylaxis, mast cells play an important protective role as well, being intimately involved in wound healing, angiogenesis, immune tolerance, defense against pathogens, and vascular permeability in brain tumors. The mast cell is very similar in both appearance and function to the basophil, another type of white blood cell. Although mast cells were once thought to be tissue-resident basophils, it has been shown that the two cells develop from different hematopoietic lineages and thus cannot be the same cells. Structure Mast cells ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoxin C4
Eoxin C4 (EXC4), also known as 14,15- leukotriene C4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted serially to EXA4, EXC4, EXD4, and EXE4 by LTC4 synthase, an unidentified gamma-glutamyltransferase, and an unidentified dipeptidase, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e. LTA4, LTC4, LTD4, and LTE4. This pathway is schematically shown as follows: EXA4 is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the downstream eoxins. The eoxins downstream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see eoxin Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoxin D4
Eoxin D4 (EXD4), also known as 14,15- leukotriene D4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted serially to EXA4, EXC4, EXD4, and EXE4 by LTC4 synthase, an unidentified gamma-glutamyltransferase, and an unidentified dipeptidase, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e. LTA4, LTC4, LTD4, and LTE4. This pathway is schematically shown as follows: EXA4 is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the downstream eoxins. The eoxins downstream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see eoxin Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoxin A4
Eoxin A4 (EXA4), also known as 14,15- leukotriene A4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted serially to EXA4, EXC4, EXD4, and EXE4 by LTC4 synthase, an unidentified gamma-glutamyltransferase, and an unidentified dipeptidase, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e. LTA4, LTC4, LTD4, and LTE4. This pathway is schematically shown as follows: EXA4 is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the downstream eoxins. The eoxins downstream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see eoxin Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoxin E4
Eoxin E4 (EXE4), also known as 14,15- leukotriene E4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted serially to EXA4, EXC4, EXD4, and EXE4 by LTC4 synthase, an unidentified gamma-glutamyltransferase, and an unidentified dipeptidase, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e. LTA4, LTC4, LTD4, and LTE4. This pathway is schematically shown as follows: EXA4 is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the downstream eoxins. The eoxins downstream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see eoxin Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachidonic Acid
Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega−6 fatty acid 20:4(ω−6), or 20:4(5,8,11,14). It is a precursor in the formation of leukotrienes, prostaglandins, and thromboxanes. Together with omega−3 fatty acids and other omega−6 fatty acids, arachidonic acid provides energy for body functions, contributes to cell membrane structure, and participates in the synthesis of eicosanoids, which have numerous roles in physiology as signaling molecules. Its name derives from the ancient Greek neologism ''arachis'' 'peanut', although peanut oil does not contain any arachidonic acid. Arachidonate is the name of the derived carboxylate anion ( conjugate base of the acid), salts, and some esters. Chemistry In chemical structure, arachidonic acid is a carboxylic acid with a 20-carbon chain and four '' cis''- double bonds; the first double bond is located at the sixth carbon from the omega end. Some chemistry sources define 'arachidonic acid' to designa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reed–Sternberg Cell
Reed–Sternberg cells (also known as lacunar histiocytes for certain types) are distinctive, giant cells found with light microscopy in biopsies from individuals with Hodgkin lymphoma. They are usually derived from B lymphocytes, classically considered crippled germinal center B cells. In the vast majority of cases, the immunoglobulin genes of Reed–Sternberg cells have undergone both V(D)J recombination and somatic hypermutation, establishing an origin from a germinal center or postgerminal center B cell. Despite having the genetic signature of a B cell, the Reed–Sternberg cells of classical Hodgkin lymphoma fail to express most B-cell–specific genes, including the immunoglobulin genes. The cause of this wholesale reprogramming of gene expression has yet to be fully explained. It presumably is the result of widespread epigenetic changes of uncertain etiology, but is partly a consequence of so-called "crippling" mutations acquired during somatic hypermutation. Seen a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
