title: Diverse CD36 expression among Japanese population: defective CD36 mutations cause platelet and monocyte CD36 reductions in not only deficient but also normal phenotype subjects.
abstract: BACKGROUND
  CD36 is a multifunctional glycoprotein expressed on various human cells, including platelets and monocytes. Five CD36 gene mutations (C268T, 949insA, 329-339del, 1228-1239del and 629-631del/insAAAAC) are mainly responsible for CD36-deficient phenotypes in Japan. It has also been reported that platelet CD36 expression varies widely among normal phenotype individuals. Here, in order to obtain further insight into CD36 expression, we investigated the association between platelet and monocyte CD36 expression levels and defective mutations in the Japanese population.
  
  
  METHODS
  Blood samples were collected from 135 healthy Japanese volunteers. CD36 expression levels on platelets and monocytes were quantitatively analyzed by flow cytometry. Real-time PCR, PCR-RFLP and allele-specific PCR were performed to detect mutant genotypes.
  
  
  RESULTS
  In this population, we found 2 (1.5%) and 9 (6.7%) CD36-deficient subjects as type I and type II, respectively. Among normal phenotype subjects, CD36 expression levels ranged from 1,259 to 11,002 (4,487±2,017) molecules/platelet and from 211 to 5,150 (1,628±986) molecules/monocyte. Genotyping assay showed that heterozygotes with the defective mutations were present in normal (12.9%) and type II-deficient (66.7%) subjects, and that these heterozygous mutations led to decreases in CD36 surface expression on platelets and monocytes.
  
  
  CONCLUSIONS
  Heterozygous CD36 mutations, previously known to lead to deficiency in this molecule, are one of the factors responsible for the diversity of CD36 surface expression levels on platelets and monocytes in normal phenotype subjects.
authors: Graduate School of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan; Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
authors: Yuya
authors: Y
authors: Masuda
authors: Department of Clinical Laboratory of Medicine, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan; Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
authors: Shogo
authors: S
authors: Tamura
authors: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
authors: Kazuhiko
authors: K
authors: Matsuno
authors: Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan.
authors: Ayumi
authors: A
authors: Nagasawa
authors: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
authors: Koji
authors: K
authors: Hayasaka
authors: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
authors: Chikara
authors: C
authors: Shimizu
authors: Faculty of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan. Electronic address: moriyama@hs.hokudai.ac.jp.
authors: Takanori
authors: T
authors: Moriyama
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism*; D018955:CD36 Antigens / Q000032:analysis / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D010641:Phenotype; D011110:Polymorphism, Genetic; D055815:Young Adult
chemical_list: D018955:CD36 Antigens
keywords: CD36 deficiency; CD36 molecule expression; gene polymorphisms; monocytes; platelets