Epi-lipoxins are trihydroxy (i.e. containing 3 hydroxyl residues) metabolites of arachidonic acid. They are 15R-epimers of their lipoxin counterparts; that is, the epi-lipoxins, 15-epi-lipoxin A4 (15-epi-LxA4) and 15-epi-lipoxin B4 (15-epi-LXB4), differ from their respective lipoxin A4 (LxA4) and lipoxin B4 (LxB4) epimers in that their 15-hydroxy residue has R rather than Schirality. Formulae for these lipoxins (Lx) are:
Chemical structure of 15-epi-lipoxin A4 (15-epi-LxA4)
The two-epi-Lx's as well as the two lx's are nonclassic eicosanoids that, like other members of the specialized pro-resolving mediators class of autocoids, form during and act to resolve inflammatory responses.[1][2][3] Synthesis of the lipoxins typically involves a lipoxygenase enzyme which acts to add a 15S-hydroxyl residue to the lipoxin precursor, arachidonic acid, whereas synthesis of the epi-lipoxins involves aspirin-pretreated cyclooxygenase 2 or a cytochrome P450 enzyme which adds a 15R-hydroxyl residue to arachidonic acid.[4] In acknowledgement of the role played by aspirin-treated cyclooxygenase 2 in forming these products, the epi-lipoxins are sometimes termed ATL which stands for Aspirin-Triggered Lipoxins.
The counter-regulatory role of the epi-lipoxins in serving as stop signals for diverse inflammation responses is detailed at the lipoxin site.
^Serhan CN (2001). "Lipoxins and aspirin-triggered 15-epi-lipoxins are endogenous components of antiinflammation: emergence of the counterregulatory side". Arch. Immunol. Ther. Exp. (Warsz.). 49 (3): 177–88. PMID 11478391.
^Chandrasekharan JA, Sharma-Walia N (2015). "Lipoxins: nature's way to resolve inflammation". Journal of Inflammation Research. 8: 181–92. doi:10.2147/JIR.S90380. PMC4598198. PMID 26457057.
^Romano M, Cianci E, Simiele F, Recchiuti A (2015). "Lipoxins and aspirin-triggered lipoxins in resolution of inflammation". European Journal of Pharmacology. 760: 49–63. doi:10.1016/j.ejphar.2015.03.083. PMID 25895638.
^Clària J, Serhan CN (1995). "Aspirin triggers previously undescribed bioactive eicosanoids by human endothelial cell-leukocyte interactions". Proc. Natl. Acad. Sci. U.S.A. 92 (21): 9475–9. Bibcode:1995PNAS...92.9475C. doi:10.1073/pnas.92.21.9475. PMC40824. PMID 7568157.
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lipoxin, trihydroxy, containing, hydroxyl, residues, metabolites, arachidonic, acid, they, epimers, their, lipoxin, counterparts, that, lipoxins, lipoxin, lxa4, lipoxin, lxb4, differ, from, their, respective, lipoxin, lxa4, lipoxin, lxb4, epimers, that, their,. Epi lipoxins are trihydroxy i e containing 3 hydroxyl residues metabolites of arachidonic acid They are 15R epimers of their lipoxin counterparts that is the epi lipoxins 15 epi lipoxin A4 15 epi LxA4 and 15 epi lipoxin B4 15 epi LXB4 differ from their respective lipoxin A4 LxA4 and lipoxin B4 LxB4 epimers in that their 15 hydroxy residue has R rather than S chirality Formulae for these lipoxins Lx are LxA4 5S 6R 15S trihydroxy 7E 9E 11Z 13E ETE LxB4 5S 14R 15S trihydroxy 6E 8Z 10E 12E ETE 15 epi LxA4 5S 6R 15R trihydroxy 7E 9E 11Z 13E eicosatetraenoic acid 15 epi LxB4 5S 14R 15R trihydroxy 6E 8Z 10E 12E eicosatrienoic acidChemical structure of 15 epi lipoxin A4 15 epi LxA4 The two epi Lx s as well as the two lx s are nonclassic eicosanoids that like other members of the specialized pro resolving mediators class of autocoids form during and act to resolve inflammatory responses 1 2 3 Synthesis of the lipoxins typically involves a lipoxygenase enzyme which acts to add a 15S hydroxyl residue to the lipoxin precursor arachidonic acid whereas synthesis of the epi lipoxins involves aspirin pretreated cyclooxygenase 2 or a cytochrome P450 enzyme which adds a 15R hydroxyl residue to arachidonic acid 4 In acknowledgement of the role played by aspirin treated cyclooxygenase 2 in forming these products the epi lipoxins are sometimes termed ATL which stands for Aspirin Triggered Lipoxins The counter regulatory role of the epi lipoxins in serving as stop signals for diverse inflammation responses is detailed at the lipoxin site See also editLipoxins Specialized pro resolving mediatorsReferences edit Serhan CN 2001 Lipoxins and aspirin triggered 15 epi lipoxins are endogenous components of antiinflammation emergence of the counterregulatory side Arch Immunol Ther Exp Warsz 49 3 177 88 PMID 11478391 Chandrasekharan JA Sharma Walia N 2015 Lipoxins nature s way to resolve inflammation Journal of Inflammation Research 8 181 92 doi 10 2147 JIR S90380 PMC 4598198 PMID 26457057 Romano M Cianci E Simiele F Recchiuti A 2015 Lipoxins and aspirin triggered lipoxins in resolution of inflammation European Journal of Pharmacology 760 49 63 doi 10 1016 j ejphar 2015 03 083 PMID 25895638 Claria J Serhan CN 1995 Aspirin triggers previously undescribed bioactive eicosanoids by human endothelial cell leukocyte interactions Proc Natl Acad Sci U S A 92 21 9475 9 Bibcode 1995PNAS 92 9475C doi 10 1073 pnas 92 21 9475 PMC 40824 PMID 7568157 nbsp This biochemistry article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Epi lipoxin amp oldid 1172914131, wikipedia, wiki, book, books, library,
