title: Rho-kinase-dependent F-actin rearrangement is involved in the release of endothelial microparticles during IFN-α-induced endothelial cell apoptosis.
abstract: BACKGROUND
  Activation of cytoskeleton regulator Rho-kinase during inflammatory stimulations plays a major role in cellular dysfunction and apoptosis. Because endothelial dysfunction may be influenced by increased circulating membrane microparticles (MPs), we hypothesized that inhibition of Rho-kinase can prevent interferon-α (IFN-α)-induced endothelial cell (EC) apoptosis and that protective effects of Rho-kinase inhibition are facilitated by prevention of F-actin rearrangement.
  
  
  METHODS
  In this study, Lewis rats were subjected to an intraperitoneal injection of IFN-α or IFN-α + Y-27632. FCM was performed to analyze circulating endothelial MPs (EMPs) from the blood samples of these animals by detecting the expression of CD144, CD62E, CD31, CD51, and CD54 on EMPs. IFN-α-induced pulmonary injury was assessed by measurement of lung wet-to-dry weight ratios and measurement of alveolar wall thickness. Human pulmonary microvascular ECs (HPMECs) were cultured with IFN-α or EMPs to elucidate the probable mechanisms of the release of EMPs.
  
  
  RESULTS
  Injection of IFN-α resulted in much higher levels of CD144 EMPs, CD62E EMPs, CD31 EMPs, CD51 EMPs, and CD54 EMPs. Pulmonary injury was also observed after injection of IFN-α. Furthermore, IFN-α induced F-actin rearrangement and apoptosis of HPMECs in vitro, and the Toll-like receptor 4/MyD88 and nuclear factor-κB pathways and EMPs per se played important roles in this process.
  
  
  CONCLUSIONS
  The results demonstrate that increased Rho-kinase activity causes the release of EMPs and cellular apoptosis. Moreover, HPMEC apoptosis that resulted from EMP stimulation indicates that EMPs can be considered as a potential target to regulate the rearrangement of cytoskeleton during endothelial cell apoptosis.
authors.affiliation: Emergency Department and Surgical Intensive Care Unit, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai, China. chengjingao2003@yahoo.cn
authors.forename: Chengjin
authors.initials: C
authors.lastname: Gao
authors.forename: Rongrong
authors.initials: R
authors.lastname: Li
authors.forename: Yuhao
authors.initials: Y
authors.lastname: Liu
authors.forename: Lijie
authors.initials: L
authors.lastname: Ma
authors.forename: Sheng
authors.initials: S
authors.lastname: Wang
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D000199:Actins / Q000187:drug effects / Q000378:metabolism; D000577:Amides / Q000494:pharmacology*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology / Q000528:radiation effects; D018929:Cell Culture Techniques; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology; D016898:Interferon-alpha / Q000494:pharmacology*; D008297:Male; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D011917:Rats, Inbred Lew; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
chemical_list: D000199:Actins; D000577:Amides; D015703:Antigens, CD; D007155:Immunologic Factors; D016898:Interferon-alpha; D011725:Pyridines; C108830:Y 27632; D054460:rho-Associated Kinases