TY - JOUR
T1 - Human tear film and meibum. Very long chain wax esters and (O-acyl)-omega-hydroxy fatty acids of meibum
AU - Butovich, Igor A.
AU - Wojtowicz, Jadwiga C.
AU - Molai, Mike
N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2009/12/1
Y1 - 2009/12/1
N2 - Human meibum was targetly analyzed for the presence of intact wax esters (WEs) and related compounds by means of reverse-phase HPLC in combination with ion trap mass spectrometry. The major detected WEs were based on C18:n (n = 1-4) unsaturated FAs ranking in the following order of abundance: C18:1> C18:2> C18:3> C18:4. The major fatty alcohols (FAls) found in WE were of saturated nature and varied from C18:0 to C28:0. The three most abundant species were C18:1-FA esters of C24:0, C25:0, and C26:0-FAl. Typically, a major compound based on C18:1-FA and a saturated FAl was accompanied by a few related compounds based on a C18:2, C18:3, and C18:4-FA. Contrary to previous reports, no epoxy-WEs or epoxy-FAs were detected in fresh and 1-year-old meibum samples. More than 20 (O-acyl)-ω-hydroxy-FAs (OAHFAs) were observed. The main detected OAHFAs were based on very long-chain ω-hydroxy-FA (C30:1, C32:1, and C34:1) acylated through their ω-hydroxyls by a C18:1-FA. Due to their amphiphilic anionogenic nature, OAHFAs may be responsible for stabilization of the tear fi lm lipid layer by creating an interface between the vast pool of strictly nonpolar lipids of meibum (WEs, cholesteryl esters, etc.) and the aqueous subphase beneath it, a role previously attributed to phospholipids.
AB - Human meibum was targetly analyzed for the presence of intact wax esters (WEs) and related compounds by means of reverse-phase HPLC in combination with ion trap mass spectrometry. The major detected WEs were based on C18:n (n = 1-4) unsaturated FAs ranking in the following order of abundance: C18:1> C18:2> C18:3> C18:4. The major fatty alcohols (FAls) found in WE were of saturated nature and varied from C18:0 to C28:0. The three most abundant species were C18:1-FA esters of C24:0, C25:0, and C26:0-FAl. Typically, a major compound based on C18:1-FA and a saturated FAl was accompanied by a few related compounds based on a C18:2, C18:3, and C18:4-FA. Contrary to previous reports, no epoxy-WEs or epoxy-FAs were detected in fresh and 1-year-old meibum samples. More than 20 (O-acyl)-ω-hydroxy-FAs (OAHFAs) were observed. The main detected OAHFAs were based on very long-chain ω-hydroxy-FA (C30:1, C32:1, and C34:1) acylated through their ω-hydroxyls by a C18:1-FA. Due to their amphiphilic anionogenic nature, OAHFAs may be responsible for stabilization of the tear fi lm lipid layer by creating an interface between the vast pool of strictly nonpolar lipids of meibum (WEs, cholesteryl esters, etc.) and the aqueous subphase beneath it, a role previously attributed to phospholipids.
KW - Dry eye epoxides
KW - High pressure liquid chromatography
KW - Ion trap mass spectrometry
KW - Lipids
KW - Meibomian gland secretions
KW - Tear film lipid laver
KW - Tears
KW - Very long-chain fatty acids and alcohols
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U2 - 10.1194/jlr.M900252-JLR200
DO - 10.1194/jlr.M900252-JLR200
M3 - Article
C2 - 19535818
AN - SCOPUS:70849130750
VL - 50
SP - 2471
EP - 2485
JO - Journal of Lipid Research
JF - Journal of Lipid Research
SN - 0022-2275
IS - 12
ER -