Rho-kinase-dependent F-actin rearrangement is involved in the release of endothelial microparticles during IFN-α-induced endothelial cell apoptosis

J Trauma Acute Care Surg. 2012 Nov;73(5):1152-60. doi: 10.1097/TA.0b013e318265d04b.


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.

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / drug effects*
  • Actin Cytoskeleton / metabolism
  • Actin Cytoskeleton / pathology
  • Actins / drug effects
  • Actins / metabolism
  • Amides / pharmacology*
  • Animals
  • Antigens, CD / metabolism
  • Apoptosis / physiology
  • Apoptosis / radiation effects
  • Cell Culture Techniques
  • Cell-Derived Microparticles / metabolism*
  • Endothelial Cells / drug effects*
  • Endothelial Cells / metabolism
  • Endothelial Cells / pathology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / pathology
  • Humans
  • Immunologic Factors / pharmacology
  • Interferon-alpha / pharmacology*
  • Male
  • Pyridines / pharmacology*
  • Rats
  • Rats, Inbred Lew
  • rho-Associated Kinases / antagonists & inhibitors*


  • Actins
  • Amides
  • Antigens, CD
  • Immunologic Factors
  • Interferon-alpha
  • Pyridines
  • Y 27632
  • rho-Associated Kinases