title: Human and great ape red blood cells differ in plasmalogen levels and composition.
abstract: BACKGROUND
  Plasmalogens are ether phospholipids required for normal mammalian developmental, physiological, and cognitive functions. They have been proposed to act as membrane antioxidants and reservoirs of polyunsaturated fatty acids as well as influence intracellular signaling and membrane dynamics. Plasmalogens are particularly enriched in cells and tissues of the human nervous, immune, and cardiovascular systems. Humans with severely reduced plasmalogen levels have reduced life spans, abnormal neurological development, skeletal dysplasia, impaired respiration, and cataracts. Plasmalogen deficiency is also found in the brain tissue of individuals with Alzheimer disease.
  
  
  RESULTS
  In a human and great ape cohort, we measured the red blood cell (RBC) levels of the most abundant types of plasmalogens. Total RBC plasmalogen levels were lower in humans than bonobos, chimpanzees, and gorillas, but higher than orangutans. There were especially pronounced cross-species differences in the levels of plasmalogens with a C16:0 moiety at the sn-1 position. Humans on Western or vegan diets had comparable total RBC plasmalogen levels, but the latter group showed moderately higher levels of plasmalogens with a C18:1 moiety at the sn-1 position. We did not find robust sex-specific differences in human or chimpanzee RBC plasmalogen levels or composition. Furthermore, human and great ape skin fibroblasts showed only modest differences in peroxisomal plasmalogen biosynthetic activity. Human and chimpanzee microarray data indicated that genes involved in plasmalogen biosynthesis show cross-species differential expression in multiple tissues.
  
  
  CONCLUSIONS
  We propose that the observed differences in human and great ape RBC plasmalogens are primarily caused by their rates of biosynthesis and/or turnover. Gene expression data raise the possibility that other human and great ape cells and tissues differ in plasmalogen levels. Based on the phenotypes of humans and rodents with plasmalogen disorders, we propose that cross-species differences in tissue plasmalogen levels could influence organ functions and processes ranging from cognition to reproduction to aging.
authors.affiliation: Hugo W. Moser Research Institute at Kennedy Krieger, and Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Ann B
authors.initials: AB
authors.lastname: Moser
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Steinberg
authors.forename: Paul A
authors.initials: PA
authors.lastname: Watkins
authors.forename: Hugo W
authors.initials: HW
authors.lastname: Moser
authors.forename: Krishna
authors.initials: K
authors.lastname: Ramaswamy
authors.forename: Kimberly D
authors.initials: KD
authors.lastname: Siegmund
authors.forename: D Rick
authors.initials: DR
authors.lastname: Lee
authors.forename: John J
authors.initials: JJ
authors.lastname: Ely
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Ryder
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Hacia
mesh_terms: D000818:Animals; D053898:Biosynthetic Pathways; D002478:Cells, Cultured; D014676:Diet, Vegetarian; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006071:Gorilla gorilla; D006801:Humans; D008297:Male; D019974:Pan paniscus; D002679:Pan troglodytes / Q000378:metabolism*; D020675:Peroxisomes / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D010802:Phylogeny; D010955:Plasmalogens / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D011148:Pongo pygmaeus
chemical_list: D010743:Phospholipids; D010955:Plasmalogens