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Essential Fatty Acid
Essential fatty acids, or EFAs, are fatty acids that are required by humans and other animals for normal physiological function that cannot be synthesized in the body. As they are not synthesized in the body, the essential fatty acids alpha-linolenic acid (ALA) and linoleic acid must be obtained from food or from a dietary supplement. Essential fatty acids are needed for various cellular metabolic processes and for the maintenance and function of tissues and organs. These fatty acids also are precursors to vitamins, cofactors, and derivatives, including prostaglandins, leukotrienes, thromboxanes, lipoxins, and others. Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega−3 fatty acid) and linoleic acid (an omega−6 fatty acid). These are supplied to the body either as the free fatty acid, or more commonly as some glyceride derivative. ALA can be converted into eicosapentaenoic acid and docosahexaenoic acid, but the conversion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an Branched chain fatty acids, unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important diet (nutrition), dietary sources of fuel for animals and important structural components for cell (biology), cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oi ... [...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] |
Aliphatic
In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated (in which all the C-C bonds are single, requiring the structure to be completed, or 'saturated', by hydrogen) like hexane, or unsaturated, like hexene and hexyne. Open-chain compounds, whether straight or branched, and which contain no rings of any type, are always aliphatic. Cyclic compounds can be aliphatic if they are not aromatic. Structure Aliphatics compounds can be saturated, joined by single bonds (alkanes), or unsaturated, with double bonds ( alkenes) or triple bonds ( alkynes). If other elements ( heteroatoms) are bound to the carbon chain, the most common being oxygen, nitrogen, sulfur, and chlorine, it is no longer a hydrocarbon, and therefore no longer an aliphatic compound. However, such compounds may still be referred to as aliph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes and mast cells, as well as Endothelium, endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. Due to their size, cytokines cannot cross the lipid bilayer of cells to enter the cytoplasm and therefore typically exert their functions by interacting with specific cytokine receptor, cytokine receptors on the target cell surface. Cytokines are especially important in the immune system; cytokines modulate the balance between humoral immunity, humoral and cell-mediated immunity, cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NF-κB
Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a family of transcription factor protein complexes that controls transcription (genetics), transcription of DNA, cytokine production and cell survival. NF-κB is found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, heavy metals, ultraviolet irradiation, oxidized LDL, and bacterial or viral antigens. NF-κB plays a key role in regulating the immune response to infection. Incorrect regulation of NF-κB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection, and improper immune development. NF-κB has also been implicated in processes of synaptic plasticity and memory. Discovery NF-κB was discovered by Ranjan Sen in the lab of Nobel laureate David Baltimore via its interaction with an 11-base pair sequence in the immunoglobulin light-chain Enhancer (genetics), enhancer in B cells. Later work ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid Raft
The cell membrane, plasma membranes of cells contain combinations of glycosphingolipids, cholesterol and protein Receptor (biochemistry), receptors organized in glycolipoprotein lipid microdomains termed lipid rafts. Their existence in cellular membranes remains controversial. Indeed, Kervin and Overduin imply that lipid rafts are misconstrued protein islands, which they propose form through a proteolipid code. Nonetheless, it has been proposed that they are specialized membrane microdomains which compartmentalize cellular processes by serving as organising centers for the assembly of signaling molecules, allowing a closer interaction of protein receptors and their effectors to promote kinetically favorable interactions necessary for the signal transduction. Lipid rafts influence membrane fluidity and membrane protein Protein targeting, trafficking, thereby regulating neurotransmission and receptor trafficking. Lipid rafts are more ordered and tightly packed than the surrounding bil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroprotectin
Protectin D1 also known as neuroprotectin D1 (when it acts in the nervous system) and abbreviated most commonly as PD1 or NPD1 is a member of the class of specialized proresolving mediators. Like other members of this class of polyunsaturated fatty acid metabolites, it possesses strong anti-inflammatory, anti-apoptotic and neuroprotective activity. PD1 is an aliphatic acyclic alkene 22 carbons in length with two hydroxyl groups at the 10 and 17 carbon positions and one carboxylic acid group at the one carbon position. Specifically, PD1 is an endogenous stereoselective lipid mediator classified as an autocoid protectin. Autacoids are enzymatically derived chemical mediators with distinct biological activities and molecular structures. Protectins are signaling molecules that are produced enzymatically from unsaturated fatty acids. Their molecular structure is characterized by the presence of a conjugated system of double bonds. PD1, like other protectins, is produced by the oxygenat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxyeicosatrienoic Acid
The epoxyeicosatrienoic acids or EETs are signaling molecules formed within various types of cells by the metabolism of arachidonic acid by a specific subset of cytochrome P450 enzymes, termed cytochrome P450 epoxygenases. They are nonclassic eicosanoids. EETs are generally short-lived, being rapidly converted from epoxides to less active or inactive dihydroxy-eicosatrienoic acids (diHETrEs) by a widely distributed cellular enzyme, soluble epoxide hydrolase (sEH), also termed epoxide hydrolase 2. The EETs consequently function as transiently acting, short-range hormones; that is, they work locally to regulate the function of the cells that produce them (i.e. they are Autocrine signalling, autocrine agents) or of nearby cells (i.e. they are Paracrine signalling, paracrine agents). The EETs have been most studied in animal models where they show the ability to lower blood pressure possibly by a) stimulating arterial Vasodilator, vasorelaxation and b) inhibiting the kidney's rete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepoxilin
Hepoxilins (Hx) are a set of epoxyalcohol metabolites of polyunsaturated fatty acids (PUFA), i.e. they possess both an epoxide and an alcohol (i.e. hydroxyl) residue. HxA3, HxB3, and their non-enzymatically formed isomers are nonclassic eicosanoid derived from acid the (PUFA), arachidonic acid. A second group of less well studied hepoxilins, HxA4, HxB4, and their non-enzymatically formed isomers are nonclassical eicosanoids derived from the PUFA, eicosapentaenoic acid. Recently, 14,15-HxA3 and 14,15-HxB3 have been defined as arachidonic acid derivatives that are produced by a different metabolic pathway than HxA3, HxB3, HxA4, or HxB4 and differ from the aforementioned hepoxilins in the positions of their hydroxyl and epoxide residues. Finally, hepoxilin-like products of two other PUFAs, docosahexaenoic acid and linoleic acid, have been described. All of these epoxyalcohol metabolites are at least somewhat unstable and are readily enzymatically or non-enzymatically to their correspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprostane
The isoprostanes are prostaglandin-like compounds formed ''in vivo'' from the free radical-catalyzed peroxidation of essential fatty acids (primarily arachidonic acid) without the direct action of cyclooxygenase (COX) enzymes. These nonclassical eicosanoid Nonclassic eicosanoids are biologically active Lipid signaling, signaling molecules made by oxygenation (medicine), oxygenation of twenty-carbon fatty acids other than the classic eicosanoids. Terminology : "Eicosanoid" is the collective term fo ...s possess potent biological activity as inflammatory mediators that augment the perception of pain. These compounds are accurate markers of lipid peroxidation in both animal and human models of oxidative stress. Elevated levels of isoprostanes are suspected of contributing to increased risk of heart attack in patients taking Coxibs. Isoprostanes and their metabolites have also been shown to be elevated in the urine of cigarette smokers, and have been suggested as bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurofuran
Neurofurans are 22-carbon compounds formed nonenzymatically by free radical mediated peroxidation of docosahexaenoic acid (DHA), an ω-3 essential fatty acid. The neurofurans are similar to the isofurans and are formed under similar conditions of oxidative stress, containing a substituted tetrahydrofuran ring. Measurement of the neurofurans may ultimately prove useful in diagnosis, timing, and selection of dosages in the treatment and chemoprevention of neurodegenerative disease A neurodegenerative disease is caused by the progressive loss of neurons, in the process known as neurodegeneration. Neuronal damage may also ultimately result in their death. Neurodegenerative diseases include amyotrophic lateral sclerosis, mul .... References Docosanoids {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isofuran
Isofurans are a family of organic compounds termed nonclassic eicosanoids. They arise nonenzymatically by free radical peroxidation of arachidonic acid. The isofurans are similar to the isoprostanes and are formed under similar conditions, but contain a substituted tetrahydrofuran ring. The concentration of oxygen affects this process; at elevated oxygen concentrations, the formation of isofurans is favored whereas the formation of isoprostanes is disfavored. Angiogenic potential Isofurans have also be found to have pro-angiogenic potential. Studies analyzing the affects of isofurans on rat brain endothelial cells (RBECs) show that they induce the growth of new blood vessels through promotion of endothelial cell proliferation, migration and cellular protection. Additionally, they have been found to play a role in the regulation of other pro-angiogenic signaling factors in RBECs. Role in blood storage and transfusion Isofurans, alongside F2-isoprostanes, accumulate in stored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
