|
1
|
Garcia-Queiruga J, Pena-Verdeal H, Sabucedo-Villamarin B, Paz-Tarrio M, Guitian-Fernandez E, Garcia-Resua C, Yebra-Pimentel E, Giraldez MJ. Meibum Lipidomic Analysis in Evaporative Dry Eye Subjects. Int J Mol Sci 2024; 25:4782. [PMID: 38731998 PMCID: PMC11083861 DOI: 10.3390/ijms25094782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024] Open
Abstract
Meibomian Glands (MG) are sebaceous glands responsible for the production of meibum, the main component of the Tear Film Lipid Layer (TFLL). The TFLL facilitates the spread of the tear film over the ocular surface, provides stability and reduces tear evaporation. Alterations in meibum composition lead to different ocular alterations like Meibomian Gland Dysfunction (MGD) and subsequent Evaporative Dry Eye (EDE). The aim of the present study was to investigate the composition and abundance of meibum lipids and their relationship with eyelid margin abnormalities, lipid layer patterns and MG status. The study utilizes a lipidomic approach to identify and quantify lipids in meibum samples using an Elute UHPLC system. This system considered all four dimensions (mass/charge, retention time, ion mobility and intensity) to provide the accurate identification of lipid species. Samples were categorized as healthy or low/no signs of alteration (group 1) or severe signs of alteration or EDE/MGD (group 2). The current investigation found differences in Variable Importance in Projection lipid abundance between both groups for the MGD signs studied. Changes in meibum composition occur and are related to higher scores in eyelid margin hyperaemia, eyelid margin irregularity, MG orifice plugging, MG loss and lipid layer pattern.
Collapse
Affiliation(s)
- Jacobo Garcia-Queiruga
- GI-2092 Optometry, Departamento de Física Aplicada, Facultad de Óptica y Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (J.G.-Q.); (H.P.-V.); (B.S.-V.); (C.G.-R.); (E.Y.-P.)
- AC-24 Optometry, Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Travesía da Choupana, 15701 Santiago de Compostela, Spain
| | - Hugo Pena-Verdeal
- GI-2092 Optometry, Departamento de Física Aplicada, Facultad de Óptica y Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (J.G.-Q.); (H.P.-V.); (B.S.-V.); (C.G.-R.); (E.Y.-P.)
- AC-24 Optometry, Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Travesía da Choupana, 15701 Santiago de Compostela, Spain
| | - Belen Sabucedo-Villamarin
- GI-2092 Optometry, Departamento de Física Aplicada, Facultad de Óptica y Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (J.G.-Q.); (H.P.-V.); (B.S.-V.); (C.G.-R.); (E.Y.-P.)
| | - Monica Paz-Tarrio
- Mass Spectrometry and Proteomic Unit, Área de Infraestruturas de Investigación, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (M.P.-T.); (E.G.-F.)
| | - Esteban Guitian-Fernandez
- Mass Spectrometry and Proteomic Unit, Área de Infraestruturas de Investigación, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (M.P.-T.); (E.G.-F.)
| | - Carlos Garcia-Resua
- GI-2092 Optometry, Departamento de Física Aplicada, Facultad de Óptica y Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (J.G.-Q.); (H.P.-V.); (B.S.-V.); (C.G.-R.); (E.Y.-P.)
- AC-24 Optometry, Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Travesía da Choupana, 15701 Santiago de Compostela, Spain
| | - Eva Yebra-Pimentel
- GI-2092 Optometry, Departamento de Física Aplicada, Facultad de Óptica y Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (J.G.-Q.); (H.P.-V.); (B.S.-V.); (C.G.-R.); (E.Y.-P.)
- AC-24 Optometry, Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Travesía da Choupana, 15701 Santiago de Compostela, Spain
| | - Maria J. Giraldez
- GI-2092 Optometry, Departamento de Física Aplicada, Facultad de Óptica y Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain; (J.G.-Q.); (H.P.-V.); (B.S.-V.); (C.G.-R.); (E.Y.-P.)
- AC-24 Optometry, Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Travesía da Choupana, 15701 Santiago de Compostela, Spain
| |
Collapse
|
|
3
|
Butovich IA, Lu H, McMahon A, Eule JC. Toward an animal model of the human tear film: biochemical comparison of the mouse, canine, rabbit, and human meibomian lipidomes. Invest Ophthalmol Vis Sci 2012; 53:6881-96. [PMID: 22918629 DOI: 10.1167/iovs.12-10516] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Secretions that are produced by meibomian glands (also known as meibum) are a major source of lipids for the ocular surface of humans and animals alike. Many animal species have been evaluated for their meibomian lipidomes. However, there have been a very small number of studies in which the animals were compared with humans side by side. Therefore, the purpose of this study was to compare meibum collected from humans and three typical laboratory animals, canines, mice, and rabbits, for their meibomian lipid composition in order to determine which animal species most resembles humans. METHODS High pressure liquid chromatography (HPLC) and gas-liquid chromatography (GLC) in combination with mass spectrometry were used to evaluate lipidomes of all tested species. RESULTS Among three tested animal species, mice were found to be the closest match to humans in terms of their meibomian lipidomes, while canines were the second closest species. The lipids of these three species were close to each other structurally and, for most lipid classes, quantitatively. The rabbit meibomian lipidome, on the other hand, was vastly different from lipidomes of all other tested species. Interestingly, a previously described class of lipids, acylated omega-hydroxy fatty acids (OAHFA), was found to be present in every tested species as the major amphiphilic component of meibum. CONCLUSIONS Our side by side comparison of the rabbit and the human meibum demonstrated their vast differences. Thus, the rabbit seems to be a poor animal model of the human tear film, at least when studying its biochemistry and biophysics.
Collapse
Affiliation(s)
- Igor A Butovich
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | | | | | | |
Collapse
|
|
5
|
Green-Church KB, Butovich I, Willcox M, Borchman D, Paulsen F, Barabino S, Glasgow BJ. The international workshop on meibomian gland dysfunction: report of the subcommittee on tear film lipids and lipid-protein interactions in health and disease. Invest Ophthalmol Vis Sci 2011; 52:1979-93. [PMID: 21450916 DOI: 10.1167/iovs.10-6997d] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Kari B Green-Church
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210-1280, USA
| | | | | | | | | | | | | |
Collapse
|
|
6
|
Řezanka T, Sigler K. Odd-numbered very-long-chain fatty acids from the microbial, animal and plant kingdoms. Prog Lipid Res 2009; 48:206-38. [DOI: 10.1016/j.plipres.2009.03.003] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 03/17/2009] [Accepted: 03/23/2009] [Indexed: 10/21/2022]
|
|
7
|
Abstract
PURPOSE This review is intended to bring to the informed reader the current state of knowledge about meibomian lipids and the art for analyzing them. METHODS At the forefront of any endeavor, there are controversies, and these, along with future directions in the field, are brought to the reader's attention. RESULTS Function and anatomy of meibomian glands are briefly covered, giving insight into possible mechanisms for secretory controls. Anatomically, some anomalies in meibomian gland distribution of different species, such as whales versus dolphins, are presented, and, for the first time, the structure of the meibomian glands in a selection of marsupials is presented. In attempting to make the literature more accessible, lipid structure and nomenclature are described, and these structures are related to their possible effects on the physicochemical properties of meibomian lipids. The advantages and disadvantages of various collection and storage techniques are described, as well as how gas chromatography and combined HPLC and mass spectrometry coupled with fragmentation are currently enabling us to determine the nature of the lipids in very small samples. CONCLUSIONS This review extends to discussing the lipids in tears (as opposed to meibomian gland lipids) and briefly highlights new thoughts about the interactions between proteins of the tear film and meibomian lipids. A model that includes proteins in the outer layer of the tear film is also presented. This model is currently being critically analyzed by the ocular community. It concludes briefly by highlighting possible further areas of research in this area.
Collapse
Affiliation(s)
- Igor A Butovich
- Department of Ophthalmology and Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | | |
Collapse
|
|
8
|
Butovich IA, Uchiyama E, Di Pascuale MA, McCulley JP. Liquid chromatography-mass spectrometric analysis of lipids present in human meibomian gland secretions. Lipids 2007; 42:765-76. [PMID: 17605062 DOI: 10.1007/s11745-007-3080-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 05/27/2007] [Indexed: 11/30/2022]
Abstract
The purpose of the study was to qualitatively characterize the major lipid species present in human meibomian gland secretions (MGS) by means of high-performance liquid chromatography with atmospheric pressure ionization mass spectrometric detection of the analytes (NP HPLC-MS). Two different NP HPLC-MS methods have been developed to analyze lipid species that were expected to be present in MGS. The first method was optimized for the analysis of relatively nonpolar lipids [wax esters (WE), di- and triacyl glycerols (DAG and TAG), cholesterol (Chl) and its esters (Chl-E), and ceramides (Cer)], while the second method was designed to separate and detect phospholipids. The major lipid species in MGS were found to be WE, Chl-E, and TAG. A minor amount of free Chl (less then 0.5% of the Chl-E fraction) was detected in MGS. No appreciable amounts of DAG and Cer were found in MGS. The second NP HPLC-MS method, capable of analyzing model mixtures of authentic phospholipids (e.g. phosphatidylglycerol, phosphatidylethanolamine, phosphatidic acid, phosphatidylinositol, phosphatidylserine, phosphatidylcholine, and sphingomyelin) in submicrogram/mL concentrations, showed little or no presence of these species in the MGS samples. These observations suggest that MGS are a major source of the nonpolar lipids of the WE and Chl-E families for the tear film lipid layer (TFLL), but not of the previously reported phospholipid components of the TFLL.
Collapse
Affiliation(s)
- Igor A Butovich
- Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390-9057, USA.
| | | | | | | |
Collapse
|
|
10
|
Carballeira NM, Pagán M. Total synthesis of the novel bacterial fatty acid 16-methyl-8(Z)-heptadecenoic acid. Chem Phys Lipids 2001; 113:23-7. [PMID: 11687224 DOI: 10.1016/s0009-3084(01)00137-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The recently discovered bacterial fatty acid 16-methyl-8(Z)-heptadecenoic acid was synthesized for the first time in four steps (22% overall yield) starting from commercially available 8-methylnonanoic acid. The synthetic approach provided enough material to corroborate the structure and stereochemistry of the acid, which was recently identified in a Micrococcus bacterium from Lake Pomorie in Bulgaria. Reference equivalent-chain length values in nonpolar capillary gas chromatography for methyl 16-methyl-8(Z)-heptadecenoate and methyl 16-methyl-8(E)-heptadecenoate are also reported. This information will be helpful in subsequent characterizations of these fatty acids, as well as in the total identification of the fatty acid profile of bacteria producing these compounds.
Collapse
Affiliation(s)
- N M Carballeira
- Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan 00931-3346, Puerto Rico.
| | | |
Collapse
|
|
11
|
Rubino FM, Zecca L. Application of triple quadrupole tandem mass spectrometry to the analysis of pyridine-containing derivatives of long-chain acids and alcohols. JOURNAL OF CHROMATOGRAPHY 1992; 579:1-12. [PMID: 1447335 DOI: 10.1016/0378-4347(92)80357-v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An improved derivatization procedure for the preparation of nicotinate and 3-picolinyl esters from mixtures of fatty alcohols and acids has been developed. The derivatives can be analysed by capillary gas chromatography on an SE-54 type column, which affords separation of the acid and alcohol derivatives with the same carbon chain. Detection with tandem mass spectrometric techniques on a triple quadrupole instrument is feasible, and yields informative spectra devoid of coeluting interferences.
Collapse
|