Leukotriene B4

Last updated
Leukotriene B4
Leukotriene B4.svg
Names
Preferred IUPAC name
(5S,6Z,8E,10E,12R,14Z)-5,12-Dihydroxyicosa-6,8,10,14-tetraenoic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
KEGG
PubChem CID
UNII
  • InChI=1S/C20H32O4/c1-2-3-4-5-6-9-13-18(21)14-10-7-8-11-15-19(22)16-12-17-20(23)24/h6-11,14-15,18-19,21-22H,2-5,12-13,16-17H2,1H3,(H,23,24)/b8-7+,9-6-,14-10+,15-11-/t18-,19-/m1/s1 X mark.svgN
    Key: VNYSSYRCGWBHLG-AMOLWHMGSA-N X mark.svgN
  • InChI=1/C20H32O4/c1-2-3-4-5-6-9-13-18(21)14-10-7-8-11-15-19(22)16-12-17-20(23)24/h6-11,14-15,18-19,21-22H,2-5,12-13,16-17H2,1H3,(H,23,24)/b8-7+,9-6-,14-10+,15-11-/t18-,19-/m1/s1
    Key: VNYSSYRCGWBHLG-AMOLWHMGBE
  • CCCCC/C=C\C[C@H](/C=C/C=C/C=C\[C@H](CCCC(=O)O)O)O
Properties
C20H32O4
Molar mass 336.472 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Leukotriene B4 (LTB4) is a leukotriene involved in inflammation. It has been shown to promote insulin resistance in obese mice.

Contents

Biochemistry

LTB4 is a leukotriene involved in inflammation. It is produced from leukocytes in response to inflammatory mediators and is able to induce the adhesion and activation of leukocytes on the endothelium, allowing them to bind to and cross it into the tissue. [1] In neutrophils, it is also a potent chemoattractant, and is able to induce the formation of reactive oxygen species and the release of lysosomal enzymes by these cells. [1] It is synthesized by leukotriene-A4 hydrolase from leukotriene A4. [2]

Eicosanoid synthesis (leukotrienes at right) Eicosanoid synthesis.svg
Eicosanoid synthesis (leukotrienes at right)

Diabetes

A study at the University of California, San Diego School of Medicine has shown that LTB4 promotes insulin resistance in obese mice. [3] Obesity is the major cause of insulin resistance in type 2 diabetes. [4]

Related Research Articles

<span class="mw-page-title-main">Leptin</span> Hormone that inhibits hunger

Leptin is a protein hormone predominantly made by adipocytes. Its primary role is likely to regulate long-term energy balance.

<span class="mw-page-title-main">Eosinophil</span> Variety of white blood cells

Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. Along with mast cells and basophils, they also control mechanisms associated with allergy and asthma. They are granulocytes that develop during hematopoiesis in the bone marrow before migrating into blood, after which they are terminally differentiated and do not multiply.

<span class="mw-page-title-main">Tumor necrosis factor</span> Protein

Tumor necrosis factor is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homologous TNF domain.

<span class="mw-page-title-main">Lipopolysaccharide</span> Class of molecules found in the outer membrane of Gram-negative bacteria

Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by covalent bonds, and are found in the bacterial capsule, the outermost membrane of cell envelope of Gram-negative bacteria, such as E. coli and Salmonella. Today, the term endotoxin is often used synonymously with LPS, although there are a few endotoxins that are not related to LPS, such as the so-called delta endotoxin proteins produced by Bacillus thuringiensis.

<span class="mw-page-title-main">Adiponectin</span> Mammalian protein found in Homo sapiens

Adiponectin is a protein hormone and adipokine, which is involved in regulating glucose levels and fatty acid breakdown. In humans, it is encoded by the ADIPOQ gene and is produced primarily in adipose tissue, but also in muscle and even in the brain.

<span class="mw-page-title-main">Resistin</span> Mammalian protein found in Homo sapiens

Resistin also known as adipose tissue-specific secretory factor (ADSF) or C/EBP-epsilon-regulated myeloid-specific secreted cysteine-rich protein (XCP1) is a cysteine-rich peptide hormone derived from adipose tissue that in humans is encoded by the RETN gene.

<span class="mw-page-title-main">Leukotriene</span> Class of inflammation mediator molecules

Leukotrienes are a family of eicosanoid inflammatory mediators produced in leukocytes by the oxidation of arachidonic acid (AA) and the essential fatty acid eicosapentaenoic acid (EPA) by the enzyme arachidonate 5-lipoxygenase.

<span class="mw-page-title-main">Lipoxin</span> Acronym for lipoxygenase interaction product

A lipoxin (LX or Lx), an acronym for lipoxygenase interaction product, is a bioactive autacoid metabolite of arachidonic acid made by various cell types. They are categorized as nonclassic eicosanoids and members of the specialized pro-resolving mediators (SPMs) family of polyunsaturated fatty acid (PUFA) metabolites. Like other SPMs, LXs form during, and then act to resolve, inflammatory responses. Initially, two lipoxins were identified, lipoxin A4 (LXA4) and LXB4, but more recent studies have identified epimers of these two LXs: the epi-lipoxins, 15-epi-LXA4 and 15-epi-LXB4 respectively.

<span class="mw-page-title-main">Hyperinsulinemia</span> Abnormal increase in insulin in the bloodstream relative to glucose

Hyperinsulinemia is a condition in which there are excess levels of insulin circulating in the blood relative to the level of glucose. While it is often mistaken for diabetes or hyperglycaemia, hyperinsulinemia can result from a variety of metabolic diseases and conditions, as well as non-nutritive sugars in the diet. While hyperinsulinemia is often seen in people with early stage type 2 diabetes mellitus, it is not the cause of the condition and is only one symptom of the disease. Type 1 diabetes only occurs when pancreatic beta-cell function is impaired. Hyperinsulinemia can be seen in a variety of conditions including diabetes mellitus type 2, in neonates and in drug-induced hyperinsulinemia. It can also occur in congenital hyperinsulinism, including nesidioblastosis.

<span class="mw-page-title-main">CCL2</span> Mammalian protein found in Homo sapiens

The chemokine ligand 2 (CCL2) is also referred to as monocyte chemoattractant protein 1 (MCP1) and small inducible cytokine A2. CCL2 is a small cytokine that belongs to the CC chemokine family. CCL2 tightly regulates cellular mechanics and thereby recruits monocytes, memory T cells, and dendritic cells to the sites of inflammation produced by either tissue injury or infection.

An antileukotriene, also known as leukotriene modifier and leukotriene receptor antagonist, is a medication which functions as a leukotriene-related enzyme inhibitor or leukotriene receptor antagonist and consequently opposes the function of these inflammatory mediators; leukotrienes are produced by the immune system and serve to promote bronchoconstriction, inflammation, microvascular permeability, and mucus secretion in asthma and COPD. Leukotriene receptor antagonists are sometimes colloquially referred to as leukasts.

Arachidonate 5-lipoxygenase, also known as ALOX5, 5-lipoxygenase, 5-LOX, or 5-LO, is a non-heme iron-containing enzyme that in humans is encoded by the ALOX5 gene. Arachidonate 5-lipoxygenase is a member of the lipoxygenase family of enzymes. It transforms essential fatty acids (EFA) substrates into leukotrienes as well as a wide range of other biologically active products. ALOX5 is a current target for pharmaceutical intervention in a number of diseases.

<span class="mw-page-title-main">ALOX12</span> Protein-coding gene in the species Homo sapiens

ALOX12, also known as arachidonate 12-lipoxygenase, 12-lipoxygenase, 12S-Lipoxygenase, 12-LOX, and 12S-LOX is a lipoxygenase-type enzyme that in humans is encoded by the ALOX12 gene which is located along with other lipoyxgenases on chromosome 17p13.3. ALOX12 is 75 kilodalton protein composed of 663 amino acids.

Leukotriene B<sub>4</sub> receptor 2 Protein-coding gene in humans

Leukotriene B4 receptor 2, also known as BLT2, BLT2 receptor, and BLTR2, is an Integral membrane protein that is encoded by the LTB4R2 gene in humans and the Ltbr2 gene in mice.

<span class="mw-page-title-main">Free fatty acid receptor 4</span> Protein-coding gene in the species Homo sapiens

Free Fatty acid receptor 4 (FFAR4), also termed G-protein coupled receptor 120 (GPR120), is a protein that in humans is encoded by the FFAR4 gene. This gene is located on the long arm of chromosome 10 at position 23.33. G protein-coupled receptors reside on their parent cells' surface membranes, bind any one of the specific set of ligands that they recognize, and thereby are activated to trigger certain responses in their parent cells. FFAR4 is a rhodopsin-like GPR in the broad family of GPRs which in humans are encoded by more than 800 different genes. It is also a member of a small family of structurally and functionally related GPRs that include at least three other free fatty acid receptors (FFARs) viz., FFAR1, FFAR2, and FFAR3. These four FFARs bind and thereby are activated by certain fatty acids.

<span class="mw-page-title-main">Chemerin</span> Protein-coding gene in the species Homo sapiens

Chemerin, also known as retinoic acid receptor responder protein 2 (RARRES2), tazarotene-induced gene 2 protein (TIG2), or RAR-responsive protein TIG2 is a protein that in humans is encoded by the RARRES2 gene.

<span class="mw-page-title-main">12-Hydroxyeicosatetraenoic acid</span> Chemical compound

12-Hydroxyeicosatetraenoic acid (12-HETE) is a derivative of the 20 carbon polyunsaturated fatty acid, arachidonic acid, containing a hydroxyl residue at carbon 12 and a 5Z,8Z,10E,14Z Cis–trans isomerism configuration (Z=cis, E=trans) in its four double bonds. It was first found as a product of arachidonic acid metabolism made by human and bovine platelets through their 12S-lipoxygenase (i.e. ALOX12) enzyme(s). However, the term 12-HETE is ambiguous in that it has been used to indicate not only the initially detected "S" stereoisomer, 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE or 12S-HETE), made by platelets, but also the later detected "R" stereoisomer, 12(R)-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (also termed 12(R)-HETE or 12R-HETE) made by other tissues through their 12R-lipoxygenase enzyme, ALOX12B. The two isomers, either directly or after being further metabolized, have been suggested to be involved in a variety of human physiological and pathological reactions. Unlike hormones which are secreted by cells, travel in the circulation to alter the behavior of distant cells, and thereby act as Endocrine signalling agents, these arachidonic acid metabolites act locally as Autocrine signalling and/or Paracrine signaling agents to regulate the behavior of their cells of origin or of nearby cells, respectively. In these roles, they may amplify or dampen, expand or contract cellular and tissue responses to disturbances.

<span class="mw-page-title-main">Maresin</span> Chemical compound

Maresin 1 (MaR1 or 7R,14S-dihydroxy-4Z,8E,10E,12Z,16Z,19Z-docosahexaenoic acid) is a macrophage-derived mediator of inflammation resolution coined from macrophage mediator in resolving inflammation. Maresin 1, and more recently defined maresins, are 12-lipoxygenase-derived metabolites of the omega-3 fatty acid, docosahexaenoic acid (DHA), that possess potent anti-inflammatory, pro-resolving, protective, and pro-healing properties similar to a variety of other members of the specialized proresolving mediators (SPM) class of polyunsaturated fatty acid (PUFA) metabolites. SPM are dihydroxy, trihydroxy, and epoxy-hydroxy metabolites of long chain PUFA made by certain dioxygenase enzymes viz., cyclooxygenases and lipoxygenases. In addition to the maresins, this class of mediators includes: the 15-lipoxygenase (i.e. ALOX15 and/or possibly ALOX15B)-derived lipoxin A4 and B4 metabolites of the omega 6 fatty acid, arachidonic acid; the cyclooxygenase 2-derived resolvin E series metabolites of the omega 3 fatty acid, eicosapentaenoic acid; certain 15-lipoxygenase-derived resolvin D series metabolites of DHA; certain other 15-lipoxygenase-derived protectin D1 and related metabolites of DHA; and the more recently defined and therefore less fully studied 15-lipoxygenase-derived resolvin Dn-3DPA metabolites of the omega-3 fatty acid n-3 docosapentaenoic acid (n-3 DPA or clupanodonic acid), the cyclooxygenase 2-derived resolvin T metabolites of this clupanodonic acid, and the 15-lipoxygenase-derived products of the N-acetylated fatty acid amide of the DHA metabolite, docosahexaenoyl ethanolamide.

In recent years it has become apparent that the environment and underlying mechanisms affect gene expression and the genome outside of the central dogma of biology. It has been found that many epigenetic mechanisms are involved in the regulation and expression of genes such as DNA methylation and chromatin remodeling. These epigenetic mechanisms are believed to be a contributing factor to pathological diseases such as type 2 diabetes. An understanding of the epigenome of diabetes patients may help to elucidate otherwise hidden causes of this disease.

<span class="mw-page-title-main">12-Hydroxyheptadecatrienoic acid</span> Chemical compound

12-Hydroxyheptadecatrienoic acid (also termed 12-HHT, 12(S)-hydroxyheptadeca-5Z,8E,10E-trienoic acid, or 12(S)-HHTrE) is a 17 carbon metabolite of the 20 carbon polyunsaturated fatty acid, arachidonic acid. It was discovered and structurally defined in 1973 by P. Wlodawer, Bengt I. Samuelsson, and M. Hamberg, as a product of arachidonic acid metabolism made by microsomes (i.e. endoplasmic reticulum) isolated from sheep seminal vesicle glands and by intact human platelets. 12-HHT is less ambiguously termed 12-(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid to indicate the S stereoisomerism of its 12-hydroxyl residue and the Z, E, and E cis-trans isomerism of its three double bonds. The metabolite was for many years thought to be merely a biologically inactive byproduct of prostaglandin synthesis. More recent studies, however, have attached potentially important activity to it.

References

  1. 1 2 Cotran; Kumar, Collins (1999). Robbins Pathologic Basis of Disease. Philadelphia: W.B Saunders Company. ISBN   0-7216-7335-X.
  2. "LTA4H". uniprot. Retrieved 9 April 2013.
  3. "Molecular Link between Obesity and Type 2 Diabetes Reveals Potential Therapy". UC San Diego Health. Archived from the original on 2022-02-18.
  4. Li, P; Oh, DY; Bandyopadhyay, G; Lagakos, WS; Talukdar, S; Osborn, O; Johnson, A; Chung, H; Maris, M; Ofrecio, JM; Taguchi, S; Lu, M; Olefsky, JM (2015). "LTB4 promotes insulin resistance in obese mice by acting on macrophages, hepatocytes and myocytes". Nature Medicine. 21 (3): 239–247. doi:10.1038/nm.3800. PMC   4429798 . PMID   25706874.