Capturing VE-Cadherin-Positive Endothelial Progenitor Cells for in-stent Vascular Repair

Silencing of transient receptor potential canonical channel 4 inhibits endothelial progenitor cell angiogenesis by suppressing VEGF and SDF-1

OBJECTIVES

Endothelial progenitor cells (EPCs) play a crucial role in acquired angiogenesis and endothelial injury repair. Transient receptor potential canonical channel 4 (TRPC4), a key component of store-operated calcium channels, is essential for EPC function. While the role of TRPCs has been clarified in vascular diseases, the relationship between TRPC4 and EPC function, along with the underlying molecular mechanisms, remains unclear and requires further elucidation.

METHODS

EPCs were isolated from canine bone marrow and identified by morphology and flow cytometry. TRPC4 was transfected into EPCs using lentivirus or negative control, and its expression was assessed using real-time polymerase chain reaction (RT-PCR). Proliferation, migration, and tube formation were evaluated using Cell Counting Kit-8 (CCK-8), Transwell, and Matrigel assays, respectively. Levels of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

TRPC4 mRNA expression was significantly reduced in TRPC4-short hairpin RNA (shRNA) transfected EPCs compared to the normal control (NC)-shRNA groups. Migration and tube formation were significantly decreased after TRPC4 silencing, while proliferation showed no difference. Additionally, levels of SDF-1 and VEGF in EPCs were markedly reduced following TRPC4 silencing.

CONCLUSION

TRPC4 plays a crucial role in regulating angiogenesis in EPCs. Silencing of TRPC4 can lead to decreased angiogenesis by inhibiting VEGF and SDF-1 expression, suggesting that TRPC4 knockdown might be a novel therapeutic strategy for vascular diseases.

Applying Principles of Regenerative Medicine to Vascular Stent Development

Stents are a widely-used device to treat a variety of cardiovascular diseases. The purpose of this review is to explore the application of regenerative medicine principles into current and future stent designs. This review will cover regeneration-relevant approaches emerging in the current research landscape of stent technology. Regenerative stent technologies include surface engineering of stents with cell secretomes, cell-capture coatings, mimics of endothelial products, surface topography, endothelial growth factors or cell-adhesive peptides, as well as design of bioresorable materials for temporary stent support. These technologies are comparatively analyzed in terms of their regenerative effects, therapeutic effects and challenges faced; their benefits and risks are weighed up for suggestions about future stent developments. This review highlights two unique regenerative features of stent technologies: selective regeneration, which is to selectively grow endothelial cells on a stent but inhibit the proliferation and migration of smooth muscle cells, and stent-assisted regeneration of ischemic tissue injury.

Effects of Sitagliptin on the Coronary Flow Reserve, Circulating Endothelial Progenitor Cells and Stromal Cell-derived Factor-1alpha

Objective Circulating endothelial progenitor cells (EPCs) are regulated by stromal cell-derived factor-1alpha (SDF-1α) and are reduced in type 2 diabetes mellitus (DM). SDF-1α is a substrate of dipeptidyl-peptidase-4 (DPP-4), so we investigated whether or not DPP-4-inhibitors modulate EPC levels in type 2 DM patients with coronary artery disease (CAD). Methods Thirty patients with CAD and type 2 DM treated using an ordinary regimen were enrolled. EPC and SDF-1α levels were compared between those receiving additional 24-week treatment with a DPP-4-inhibitor (n=11) and no additional treatment (n=19). We determined the HbA1c, 1.5-Anhydro-D-glucitol (1,5-AG), coronary flow reserve (CFR), brain natriuretic peptide (BNP), E/e', and circulating EPC proportion and SDF-1α levels at baseline and the end of follow-up. The CFR was assessed using a dual-sensor-equipped guidewire. The primary endpoints were changes in the EPC count, SDF-1α levels, and CFR from baseline to the end of follow-up. The secondary endpoints were changes in the HbA1c and 1,5-AG, which are useful clinical markers of postprandial hyperglycemia, as well as the BNP and E/e'. Results After the 6-month follow-up, compared with ordinary regimen subjects, the patients receiving a DPP-4-inhibitor showed no significant increase in the EPC proportion (-0.01±0.50 vs. 0.02±0.77%, p=0.87), SDF-1α level (-600.4±653.6 vs. -283.2±543.1 pg/mL, p=0.18), or CFR (0.0±0.2 vs. 0.1±0.6, p=0.20), whereas both the 1.5-AG level (2.4±4.6 vs. -0.7±2.5 μg/dL, p=0.07) and HbA1c (-0.8±1.8 vs. 0.0±0.7%, p=0.02) were improved. There were no significant differences between the two groups in changes in the BNP and E/e'. Conclusion DPP-4 inhibition with sitagliptin did not increase or decrease the EPC proportion, SDF-1α level, or CFR, although the glycemic control was improved.

CD-34+ and VE-cadherin+ endothelial progenitor cells in preeclampsia and normotensive pregnancies

OBJECTIVE

The objective of our study was to determine levels of endothelial progenitor cells (EPCs) in preeclampsia and normotensive pregnant women.

STUDY DESIGN

Prospective cohort study of women with preeclampsia and normotensive pregnancies. EPCs were estimated by flow cytometry. Multiple linear regression was used to assess the association of EPCs with preeclampsia adjusting for maternal age, body mass index (BMI), gestation and ethnicity.

MAIN OUTCOME MEASURE

Levels of EPCs in preeclampsia and normotensive pregnancies, with CD-34 and vascular endothelial (VE)-cadherin as markers of EPCs. VE-cadherin is an endothelial cell adhesion molecule used to delineate endothelial lineage of EPCs.

RESULTS

There were thirty women in the preeclampsia group and thirty-three in the normotensive group. The two groups were similar except for the BMI and blood pressures, which were higher in preeclampsia. On multiple linear regression, EPCs numbers were significantly higher by 29 (95% confidence interval 11.7-46.6, p = 0.001) in preeclampsia compared to the normotensive group. There was significant positive correlation between EPCs and systolic blood pressure in preeclampsia (Spearman correlation coefficient 0.39, p = 0.03).

CONCLUSION

Although widely used in cardiovascular disease other than preeclampsia, this is the first study using VE-cadherin as a marker of endothelial lineage to define EPCs in preeclampsia. Our results suggest the higher number of EPCs in preeclampsia may be a response of the bone marrow to endothelial injury.