title: ABCA8 stimulates sphingomyelin production in oligodendrocytes.
abstract: Members of the ABCA (ATP-binding cassette subfamily A) family are characterized by their ability to transport lipids across cellular membranes and regulate lipid homoeostasis in the brain and peripheral tissues. ABCA8 is a little-known member of this subfamily that was originally cloned from human brain libraries and has no known function. In an effort to elucidate the role of ABCA8 in the brain we first undertook a comprehensive analysis of its expression in the human brain. ABCA8 was differentially expressed in multiple regions of adult human brains with significantly higher expression in oligodendrocyte-enriched white matter regions compared with grey matter cortical regions. We then assessed the impact of ABCA8 on sphingomyelin production in oligodendrocyte and showed that ABCA8 was able to significantly stimulate both sphingomyelin synthase 1 expression and sphingomyelin production. Furthermore, ABCA8 expression in the prefrontal cortex across the human life span correlated strongly with age-associated myelination, and the myelinating gene p25α was significantly up-regulated with ABCA8. The present study represents the first extensive expression and functional study of ABCA8 in the human brain and the results strongly suggest that ABCA8 regulates lipid metabolism in oligodendrocytes and potentially plays a role in myelin formation and maintenance.
authors.affiliation: Neuroscience Research Australia, Sydney, NSW 2031, Australia. w.kim@unsw.edu.au
authors.forename: Woojin Scott
authors.initials: WS
authors.lastname: Kim
authors.forename: Jen-Hsiang T
authors.initials: JH
authors.lastname: Hsiao
authors.forename: Surabhi
authors.initials: S
authors.lastname: Bhatia
authors.forename: Elias N
authors.initials: EN
authors.lastname: Glaros
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Don
authors.forename: Shuichi
authors.initials: S
authors.lastname: Tsuruoka
authors.forename: Cynthia
authors.initials: C
authors.lastname: Shannon Weickert
authors.forename: Glenda M
authors.initials: GM
authors.lastname: Halliday
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002460:Cell Line; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009186:Myelin Sheath / Q000737:chemistry / Q000378:metabolism; D009836:Oligodendroglia / Q000737:chemistry / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D013109:Sphingomyelins / Q000096:biosynthesis*; D029867:Xenopus Proteins / Q000096:biosynthesis / Q000502:physiology; D055815:Young Adult
chemical_list: C468121:ABCA8 protein, Xenopus; C582675:ABCA8 protein, human; D018528:ATP-Binding Cassette Transporters; D013109:Sphingomyelins; D029867:Xenopus Proteins