title: Imaging mass spectrometry detection of gangliosides species in the mouse brain following transient focal cerebral ischemia and long-term recovery.
abstract: Gangliosides, a member of the glycosphingolipid family, are heterogeneously expressed in biological membranes and are particularly enriched within the central nervous system. Gangliosides consist of mono- or poly-sialylated oligosaccharide chains of variable lengths attached to a ceramide unit and are found to be intimately involved in brain disease development. The purpose of this study is to examine the spatial profile of ganglioside species using matrix-assisted laser desorption/ionization (MALDI) imaging (IMS) following middle cerebral artery occlusion (MCAO) reperfusion injury in the mouse. IMS is a powerful method to not only discriminate gangliosides by their oligosaccharide components, but also by their carbon length within their sphingosine base. Mice were subjected to a 30 min unilateral MCAO followed by long-term survival (up to 28 days of reperfusion). Brain sections were sprayed with the matrix 5-Chloro-2-mercaptobenzothiazole, scanned and analyzed for a series of ganglioside molecules using an Applied Biosystems 4800 MALDI TOF/TOF. Traditional histological and immunofluorescence techniques were performed to assess brain tissue damage and verification of the expression of gangliosides of interest. Results revealed a unique anatomical profile of GM1, GD1 and GT1b (d18:1, d20:1 as well as other members of the glycosphingolipid family). There was marked variability in the ratio of expression between ipsilateral and contralateral cortices for the various detected ganglioside species following MCAO-reperfusion injury. Most interestingly, MCAO resulted in the transient induction of both GM2 and GM3 signals within the ipsilateral hemisphere; at the border of the infarcted tissue. Taken together, the data suggest that brain region specific expression of gangliosides, particularly with respect to hydrocarbon length, may play a role in neuronal responses to injury.
authors.affiliation: Experimental NeuroTherapeutics Laboratory, Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada. Shawn.Whitehead@nrc-cnrc.gc.ca
authors.forename: Shawn N
authors.initials: SN
authors.lastname: Whitehead
authors.forename: Kenneth H N
authors.initials: KH
authors.lastname: Chan
authors.forename: Sandhya
authors.initials: S
authors.lastname: Gangaraju
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Slinn
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.forename: Sheng T
authors.initials: ST
authors.lastname: Hou
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D054022:Cerebrum / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D005732:Gangliosides / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002546:Ischemic Attack, Transient / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D057054:Molecular Imaging; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013110:Sphingosine / Q000737:chemistry; D013997:Time Factors
chemical_list: D005732:Gangliosides; D013110:Sphingosine