Circulating endothelial progenitor cells in patients with cardiac syndrome X
Haim Shmilovich1, Varda Deutsch, Arie Roth
1Department of Cardiology, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel. jacobg@post.tau.ac.il
Insights
Patients with Cardiac Syndrome X (CSX) have more circulating endothelial progenitor cells (EPCs), but these cells show impaired function. This altered EPC phenotype may explain the complex pathogenesis of CSX.
Area of Science:
- Cardiovascular Research
- Cell Biology
- Vascular Biology
Background:
- Cardiac Syndrome X (CSX) is characterized by chest pain, abnormal functional tests, and normal coronary angiograms.
- Endothelial progenitor cells (EPCs) are crucial for vascular repair and tissue vascularization.
Purpose of the Study:
- To investigate the quantity and functional characteristics of circulating EPCs in patients diagnosed with CSX.
- To compare EPC numbers and functions between CSX patients and a matched control group.
Main Methods:
- Flow cytometry (FACS) was used to quantify EPCs (CD34+/KDR+ and CD34+/CD133+) in 17 CSX patients and 20 controls.
- EPC functional assays assessed proliferation, adherence to matrix and endothelial cells, and in vitro tube formation.
- Serum levels of soluble markers related to EPC mobilization and homing were analyzed.
Main Results:
- CSX patients exhibited significantly higher numbers of circulating EPCs compared to controls.
- EPCs from CSX patients showed reduced proliferative capacity and impaired in vitro tube formation.
- Enhanced EPC adherence to fibronectin and mature endothelial cells was observed in CSX patients.
- Serum vascular endothelial growth factor correlated with CD34+/KDR+ cells, and erythropoietin with CD34+/CD133+ cells.
Conclusions:
- Patients with CSX present with a distinct circulating EPC phenotype, characterized by increased numbers but impaired functionality.
- These findings offer insights into the underlying mechanisms contributing to the complex pathophysiology of Cardiac Syndrome X.
Background:
Cardiac syndrome X (CSX) encompasses the constellation of anginal chest pain in the presence of a pathological functional test and a normal coronary angiogram. Endothelial progenitor cells (EPCs) in the peripheral circulation contribute to tissue vascularisation.
Objective:
To investigate the number and functional properties of circulating EPCs in patients with CSX.
Methods:
17 patients with CSX and a referent population (n = 20) were matched for age, atherosclerotic risk factors and use of drugs. Numbers of EPCs were studied by FACS, and their functional properties, including their proliferative capacity, adherence to matrix and mature endothelial cells as well as their ability to support in vitro tube formation, were investigated. Levels of soluble markers that associate with peripheral mobilisation and homing were studied in the serum samples of all subjects.
Results:
Patients with CSX had significantly increased numbers of circulating EPCs as compared with the referent population (both CD34+/KDR and CD34+/CD133+). The proliferative capacity of EPCs and their ability to support in vitro tube formation were significantly impaired in patients with CSX as compared with the referent population. However, adhesiveness of EPCs from patients with CSX to fibronectin and cultured mature endothelial cells was enhanced as compared with the referent population. Serum vascular endothelial growth factor correlated with peripheral CD34+/KDR cell numbers, whereas serum concentration of erythropoietin correlated with the number of circulating CD34+/CD133+ cells
Conclusion:
Patients with CSX have a significantly altered circulating EPC phenotype that could potentially aid in understanding the complex pathogenesis of the syndrome.
