[Frontiers in Bioscience 14, 3608-3618, January 1, 2009]
EPC adhesion to arteries from diabetic and non-diabetic patients: effect of pioglitazone

Emilio Ruiz1, Santiago Redondo1, Antonio Gordillo-Moscoso1, Enrique Rodriguez2, Fernando Reguillo2, Jose Martinez-Gonzalez3, Teresa Tejerina1

1Department of Pharrmacology, School of Medicine, Universidad Complutense, 28040 Madrid, Spain, 2Cardiac Surgery Service, Hospital Clinico San Carlos, 28040 Madrid, Spain, 3Centro de Investigacion Cardiovascular (CSIC-ICCC), Hospital de la Santa Creu i Sant Pau, c/Antoni MĒ Claret 167, 08025 Barcelona, Spain

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Material and methods
3.1. Description of patients
3.2. Isolation and culture of human endothelial progenitor cells
3.3. EPC characterization by flow cytometry
3.4. 111In-oxine cell radiolabelling and EPC adhesion assay to human internal mammary arteries
3.5. Assessment of CXCR-4 expression by flow cytometry
3.6. Immunostaining of EPC
3.7. Immunohistochemical analysis of SDF-1 and COX-2
3.8. Statistical analysis
4. Results
4.1. Adhesion of EPC to human internal mammary arteries
4.2. Relationship between the expression of COX-2 and SDF-1 in human internal mammary arteries
4.3. Effect of pioglitazone on the adhesion of EPC to human internal mammary arteries
4.4. Mechanism of action of pioglitazone
5. Discussion
6. Acknowledgment
7. References

1. ABSTRACT

Endothelial progenitor cell (EPC) dysfunction is an important mediator of vascular disease in diabetes. We aimed to elucidate the mechanism of adhesion of EPC to diabetic and non-diabetic arteries and to study the effect of the anti-diabetic drug pioglitazone. Peripheral blood mononuclear cells were isolated from healthy donors. Human internal mammary arteries (HIMA) were isolated from patients who underwent coronary artery bypass surgery. EPC were labelled with 111In-oxine and perfused to HIMA in a perfusion chamber. Stromal derived factor-1 (SDF-1) and cyclooxygenase-2 (COX-2) were assessed by immunohistochemical analysis. CXCR-4 expression was assessed by flow cytometry. Adhesion of EPC was increased in HIMA from diabetic patients and was reduced after preincubation with 15 mM glucose for 72 h. EPC adhesion and CXCR-4 expression were inversely correlated. COX-2 and SDF-1 immunostaining in HIMA were positively correlated. Pioglitazone (1 mM) increased the adhesion of EPC to HIMA and the expression of CXCR-4 in EPC. Therefore, EPC-recruiting capability is increased in diabetic arteries, although EPC adhesion is notably impaired by high glucose concentrations. Interestingly, pioglitazone treatment enhances EPC adhesiveness.