Triacylglyceride (TAG) profiles of integumentary lipids isolated from three bat species determined by matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI–TOF MS)

Abstract

Lipids secreted from sebaceous glands in bat integument may play a role in determining host pathogenicity by the fungus Geomyces destructans in white-nose syndrome (WNS). To investigate this, we have determined the triacylglycerol (TAG) profiles for three bat species: eastern red bats (Lasiurus borealis (Müller, 1776)), evening bats (Nycticeius humeralis (Rafinesque, 1818)), and big brown bats (Eptesicus fuscus (Beauvois, 1796)). Neutral lipids extracted from the hair and wing tissue were fractionated by preparative thin-layer chromatography (TLC) into four major lipid bands corresponding to cholesterol, free fatty acids (FFAs), TAGs, and sterol-wax esters. Densitometry showed higher proportions of TAGs in hair than from wing tissue. TAG bands were recovered and analyzed by matrix-assisted laser desorption-ionization time-offlight mass spectrometry (MALDI-TOF MS). Mass spectra showed sodiated TAG species with variable fatty acyl (FA) moieties range from m/z 715.6-911.8. High intensity ion peaks were consistent with 16:0 and 18:1 as dominant FA moieties, and these were identified as palmitic and oleic acids, respectively, by liquid chromatography electrospray ionization mass spectrometry. We determined significant differences in TAG profiles between three bat species by MALDI-TOF MS, providing the first description of integumentary lipids in bats. In this study, we performed the first TAG profiling of bats, which suggest such profiles may be species-specific in bats.Résumé : Les lipides sécrétés de glandes sébacées dans les téguments de chauves-souris pourraient jouer un rôle dans la dé-termination de la pathogénicité du champignon Geomyces destructans dans le syndrome du museau blanc (SMB). Pour examiner cette question, nous avons établi des profils des triacylglycérols (TAG) pour les trois espèces de chauves-souris suivantes : la chauve-souris rousse (Lasiurus borealis (Müller, 1776)), la chauve-souris vespérale (Nycticeius humeralis (Rafinesque, 1818)) et la sérotine brune (Eptesicus fuscus (Beauvois, 1796)). Des lipides neutres extraits des poils et de tissus alaires ont été fractionnés par chromatographie sur couche mince (CCM) préparative en quatre bandes de lipides correspondant aux cholestérols, aux acides gras libres (AGL), aux TAG et aux stérols estérifiés-esters cireux. L'analyse densitométrique a révélé de plus fortes proportions de TAG dans les poils que dans les tissus alaires. Les bandes de TAG ont été récupérées et analysées par spectrométrie de masse à désorption-ionisation par impact laser assistée par matrice et à temps de vol (MALDI-TOF MS). Les spectres de masse montraient des espèces de TAG sodiées de rapports m/z des fractions d'acyles gras (AG) allant de 751,6 à 911,8. Les pics d'ions de haute intensité concordaient avec des fractions d'AG dominantes de 16:0 et 18:0, identifiées comme étant les acides palmitique et oléique, respectivement, par chromatographie en phase liquide avec ionisation par électronébulisation couplée à la spectrométrie de masse. L'analyse par MALDI-TOF MS a permis de ...

Glycerophospholipid Analysis of Eastern Red Bat (Lasiurus Borealis) Hair by Electrospray Ionization Tandem Mass Spectrometry

“…With over 100 phospholipids known from mammals (Yamashita et al 2014), cataloging GPs present on fur, combined with sebum composition from other body regions (Pannkuk et al 2012, 2013a, 2013b), is a critical first step before making and testing predictions about the role of these lipid molecules in the ecology of free-living animals. L. borealis is a particularly interesting species for investigation due to a number of ecological and life history factors.…”

“…Hair of L. borealis (1.0 g) was removed with scissors and lipid was immediately isolated with chloroform:methanol (C:M) as previously described (Pannkuk et al 2012; 2013b) (Arkansas State University’s Institutional Biosafety Committee approval # 135349-1). This relatively non-destructive method minimized integral hair lipids rather than sebaceous secretions present in the sample.…”

“…While reports have discussed in detail bat sebaceous glands ultrastructure (Cortese and Nicholl, 1979; Nassar et al 2008), the chemical composition of bat sebum (Pannkuk, et al 2012; 2013a), and bat stratum corneum lipids (Muñoz-Garcia et al 2012), surprisingly little on GP composition of bat integumentary lipids is known. Furthermore, few studies have reported GP content of the hair surface.…”

Profiling the Triacylglyceride Contents in Bat Integumentary Lipids by Preparative Thin Layer Chromatography and MALDI-TOF Mass Spectrometry

“…Bat integument is characterized by being predominantly cholesterol, with lower amounts of TAGs, FFAs, squalene, and sterol/wax esters. Sebum lipid ratios in bats differ from humans in that squalene is present in low amounts (as opposed to up to 16% in humans), whilst cholesterol occurs in larger ratios (1 -7% in humans but 26 -62% in bats) 22,31 . Human hairs contain about 3% TAGs, while ratios up to 28% are found in Eastern red bat hair.…”

“…This paper presents a routine method to isolate and analyze integumentary lipids from the hair, sebaceous secretions and plagiopatagium of the Eastern red bat (Lasiurus borealis). This is used to determine interspecific variations in bat integumentary lipids to elucidate the disease process of White-Nose Syndrome (WNS) 22 . WNS is a fungal disease of bats and is caused by the newly described psychrophilic species Geomyces destructans [23][24][25] .…”