Abstract
Aims Mononuclear cells (MNCs) from patients with hereditary haemorrhagic telangiectasia type 1 (HHT1), a genetic disorder caused by mutations in endoglin, show a reduced ability to home to infarcted mouse myocardium. Stromal cell-derived factor-1a (SDF-1 alpha) and the chemokine receptor CXCR4 are crucial for homing and negatively influenced by CD26. The aim of this study was to gain insight into the impaired homing of HHT1-MNCs. Methods and results CXCR4 and CD26 expression on MNCs was determined by flow cytometry. Transwell migration to SDF-1 alpha was used to analyse in vitro migration. Experimentally induced myocardial infarction in mice, followed by tail vein injection of MNCs, was applied to study homing in vivo. HHT1-MNCs expressed elevated levels of CXCR4, but this was counterbalanced by high levels of CD26, resulting in decreased migration towards an SDF-1 alpha gradient in vitro. Migration was enhanced by inhibiting CD26 with Diprotin-A. While MNCs from healthy controls responded to transforming growth factor-beta stimulation by increasing CXCR4 and lowering CD26 expression levels, HHT1-MNCs did not react as efficiently: in particular, CD26 expression remained high. Inhibiting CD26 on MNCs increased the homing of human cells into the infarcted mouse heart. Interestingly, the defect in homing of HHT1-MNCs was restored by pre-incubating the HHT1-MNCs with Diprotin-A before injection into the tail vein. Conclusion We show that a decreased homing of HHT1-MNCs is caused by an impaired ability of the cells to respond to SDF-1 alpha. Our results suggest that modulating CD26 levels using inhibitors like Diprotin-A can restore homing in cases where increased expression of CD26 contributes to the underlying pathological mechanism.
Original language | English |
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Pages (from-to) | 494-502 |
Journal | Cardiovascular Research |
Volume | 85 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1 Feb 2010 |
Keywords
- Mononuclear cells
- Chemokines
- Genetics
- Myocardial infarction
- Migration