HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 296/6/L870    most recent 90413.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Yao, W. Articles by Yuan, J. X.-J. PubMed PubMed Citation Articles by Yao, W. Articles by Yuan, J. X.-J.

EDITORIAL FOCUS

Identification of putative endothelial progenitor cells (CD34⁺CD133⁺Flk-1⁺) in endarterectomized tissue of patients with chronic thromboembolic pulmonary hypertension

Departments of ¹Medicine, ²Surgery, and ³Pathology, School of Medicine, University of California, San Diego, La Jolla, California

Submitted 4 August 2008 ; accepted in final form 5 March 2009

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by a fibrotic thrombus persisting and obliterating the lumen of pulmonary arteries; its pathogenesis remains poorly defined. This study investigates a potential contribution for progenitor cell types in the development of vascular obliteration and remodeling in CTEPH patients. Endarterectomized tissue from patients undergoing pulmonary thromboendarterectomy was collected and examined for the structure and cellular composition. Our data show an organized fibrin network structure in unresolved thromboemboli and intimal remodeling in vascular wall tissues, characterized by smooth muscle -actin (SM-A)-positive cell proliferation in proximal regions (adjacent to thromboemboli) and neoangiogenesis/recanalization in distal regions (downstream from thromboemboli). Cells that are positively stained with CD34 and fetal liver kinase-1 (Flk-1) (CD34⁺Flk-1⁺) were identified in both the proximal and distal vascular tissues; a subpopulation of CD34⁺Flk-1⁺CD133⁺ cells were further identified by immunostaining. Triple-positive cells are indicative of a population of putative endothelial progenitor cells or potential colony-forming units of endothelial cells. In addition, inflammatory cells (CD45⁺) and collagen-secreting cells (procollagen-1⁺) were detected in the proximal vascular wall. Some of the CD34⁺ cells in CTEPH cells isolated from proximal regions were also positive for SM-A. Our data indicate that putative progenitor cell types are present in the neointima of occluded vessels of CTEPH patients. It is possible that the microenvironment provided by thromboemboli may promote these putative progenitor cells to differentiate and enhance intimal remodeling.

pulmonary embolism; endarterectomy; vascular remodeling

This article has been cited by other articles:

				A. Ogawa, A. L. Firth, W. Yao, M. M. Madani, K. M. Kerr, W. R. Auger, S. W. Jamieson, P. A. Thistlethwaite, and J. X.-J. Yuan Inhibition of mTOR attenuates store-operated Ca2+ entry in cells from endarterectomized tissues of patients with chronic thromboembolic pulmonary hypertension Am J Physiol Lung Cell Mol Physiol, October 1, 2009; 297(4): L666 - L676. [Abstract] [Full Text] [PDF]

				S. Majka and D. F. Alvarez Neovascular capacity of endothelial progenitor cells in the adult pulmonary circulation Am J Physiol Lung Cell Mol Physiol, June 1, 2009; 296(6): L868 - L869. [Full Text] [PDF]