title: Haemin-enhanced expression of haem oxygenase-1 stabilizes erythrocyte-induced vulnerable atherosclerotic plaques.
abstract: OBJECTIVE
  Previous studies demonstrated that intraplaque haemorrhage increased the contents of cholesterol and oxidants in atherosclerotic plaques. The present study was aimed to test the hypothesis that enhanced expression of haem oxygenase-1 (HO-1) may stabilize vulnerable plaques.
  
  
  METHODS
  Intravascular ultrasound (IVUS) was performed to identify three similar abdominal aortic plaques in each of 58 fat-fed New Zealand rabbits after aortic balloon injury. With the guidance of IVUS, 50 microL autologous erythrocytes (RBC) or normal saline (NS) were injected from adventitia into two of the pre-selected plaques, respectively, whereas the third plaque served as a blank control. All rabbits were randomly divided into two groups, receiving intraperitoneal injection of haemin and saline respectively.
  
  
  RESULTS
  Compared with NS or control plaques, RBC plaques had more macrophage infiltration and lipid content, thinner plaque fibrous cap, and higher expression of inflammatory factors and incidence of plaque rupture. RBC plaques in the haemin group had about a 50% lower incidence of plaque rupture than those in the control group.
  
  
  CONCLUSIONS
  Haem oxygenase-1 may eliminate haem or other oxidants, exert unexpected anti-oxidative and anti-inflammatory effects and serve as a promising approach to the direct inhibition of erythrocyte-induced plaque instability.
authors.affiliation: Shandong University Qilu Hospital, Jinan, Shandong, China.
authors.forename: Hui Li
authors.initials: HL
authors.lastname: Lin
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Chun Xi
authors.initials: CX
authors.lastname: Liu
authors.forename: Xin Sheng
authors.initials: XS
authors.lastname: Xu
authors.forename: Meng Xiong
authors.initials: MX
authors.lastname: Tang
authors.forename: Hui Xia
authors.initials: HX
authors.lastname: Lv
authors.forename: Chang Jiang
authors.initials: CJ
authors.lastname: Li
authors.forename: Hui Wen
authors.initials: HW
authors.lastname: Sun
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.forename: Jiang
authors.initials: J
authors.lastname: Hong
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal; D050197:Atherosclerosis / Q000473:pathology*; D004912:Erythrocytes / Q000378:metabolism*; D005786:Gene Expression Regulation; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism*; D006427:Hemin / Q000494:pharmacology*; D050356:Lipid Metabolism; D008264:Macrophages / Q000378:metabolism; D011817:Rabbits; D018084:Ultrasonography, Interventional
chemical_list: D006427:Hemin; D051547:Heme Oxygenase-1