Elevated Inflammatory Parameter Levels Negatively Impact Populations of Circulating Stem Cells (CD133+), Early Endothelial Progenitor Cells (CD133+/VEGFR2+), and Fibroblast Growth Factor in Stroke Patients

BACKGROUND

Endothelial Progenitor Cells (EPCs) are important players in neovascularization, mobilized through signalling by Angiogenic Growth Factors (AGFs) such as Vascular Endothelial Growth Factor (VEGF) and fibroblast growth factor (FGF). In vitro, inflammatory parameters impair the function and influence of EPCs on AGFs. However, this connection is not clear in vivo. To understand the mechanisms of augmented arteriogenesis and angiogenesis in acute ischemic stroke (AIS) patients, we investigated whether circulating stem cells (CD133+), early endothelial progenitor cells (CD133+/VEGFR2+), and endothelial cells (ECs; CD34¯/CD133¯/VEGFR2+) were increasingly mobilized during AIS, and whether there were correlations between EPC levels, growth factor levels and inflammatory parameters.

METHODS

Data on demographics, classical vascular risk factors, neurological deficit information (assessed using the National Institutes of Health Stroke Scale), and treatment were collected from 43 consecutive AIS patients (group I). Risk factor control patients (group II) included 22 nonstroke subjects matched by age, gender, and traditional vascular risk factors. EPCs were measured by flow cytometry and the populations of circulating stem cells (CD133+), early EPCs (CD133+/VEGFR2+), and ECs (CD34¯/CD133¯/VEGFR2+) were analysed. Correlations between EPC levels and VEGF and FGF vascular growth factor levels as well as the influence of inflammatory parameters on EPCs and AGFs were assessed.

RESULTS

Patient ages ranged from 54 to 92 years (mean age 75.2 ± 11.3 years). The number of circulating CD34¯/CD133¯/VEGF-R2+ cells was significantly higher in AIS patients than in control patients (p < 0.05). VEGF plasma levels were also significantly higher in AIS patients compared to control patients on day 7 (p < 0.05). FGF plasma levels in patients with AIS were significantly higher than those in the control group on day 3 (p < 0.05). There were no correlations between increased VEGF and FGF levels and the number of CD133+, CD133+/VEGFR2+, or CD34¯/CD133¯/VEGFR2+ cells. Leukocyte levels, FGF plasma levels, and the number of early EPCs were negatively correlated on day 3. High sensitivity C-reactive protein levels and the number of CD133+ and CD133+/VEGFR2+ cells were negatively correlated on day 7. In addition, there was a negative correlation between fibrinogen levels and FGF plasma levels as well as the number of early EPCs (CD133+/VEGFR2+).

CONCLUSION

AIS patients exhibited increased numbers of early EPCs (CD133+/VEGFR2+) and AGF (VEGF and FGF) levels. A negative correlation between inflammatory parameters and AGFs and EPCs indicated the unfavourable influence of inflammatory factors on EPC differentiation and survival. Moreover, these correlations represented an important mechanism linking inflammation to vascular disease.

Statins Therapy is Associated with Increased Populations of Early Endothelial Progenitor (CD133+/VEGFR2+) and Endothelial (CD34-/CD133- /VEGFR2+) Cells in Patients with Acute Ischemic Stroke

BACKGROUND

Endothelial Progenitor Cells (EPCs) have been suggested to be a therapeutic option in Acute Ischemic Stroke (AIS). Statins modulate endothelial function and preserve blood flow to tissue exposed to an ischemic insult. We tested the hypothesis that statins therapy might augment circulating EPCs in patients with AIS.

METHODS

Demographic data, classical vascular risk factors, treatment and National Institutes of Health Stroke Scale data were prospectively collected from 43 consecutive AIS patients (group I), comprising - 30 treated with statins (group Statin(+)) and 13 untreated (group Statin (-)). Risk factor controls (group II) included 22 subjects matched by age, gender, and traditional vascular risk factors. EPCs were measured by flow cytometry - and the populations of circulating stem cells (CD133+), early EPCs (CD133+/VEGFR2+) and ECs CD34-/CD133-/VEGFR2+ cells were analyzed.

RESULTS

Patients ages ranged from 54 to 92 years (mean age 75.2 ± 11.3 years). The number of CD34-/CD133-/VEGF-R2+ cells was significantly lower in group I than II (p<0.05). In group Statin(+) neurological deficit on the 1st, 3rd and 7th day was significantly lower in comparison Statin(-) (p<0.05). We observed significantly more frequent "improvement> 50% or complete recovery" and less frequent death in the statin-treated group. The number of early EPCs and ECs was significantly higher in the treated group on the day 3rd (p < 0.05).

CONCLUSIONS

Statins treatment is likely to have a positive effect on spontaneous CD133+/ VEGFR2+ and CD34-/CD133-/VEGFR2+ cell mobilization triggered by a stroke.