Leptin enhances the recruitment of endothelial progenitor cells into neointimal lesions after vascular injury by promoting integrin-mediated adhesion.

The adipocytokine leptin modulates vascular remodeling and neointima formation. Because endothelial progenitor cells (EPCs) participate in vascular repair, we analyzed the effects of leptin on human EPC function in vitro and in vivo. After 7 days in culture, EPCs expressed the leptin receptor and responded to leptin stimulation with increased STAT3 phosphorylation. Incubation of EPCs with leptin (at concentrations between 1 and 100 ng/mL) increased the number of EPCs adhering to vitronectin and fibronectin in a receptor-specific manner. It also enhanced the capacity of EPCs to incorporate into a monolayer of human endothelial cells and the adherence of these cells to activated platelets. Leptin upregulated alphavbeta5 and alpha4 integrin expression in EPCs, and the effects of leptin on EPC function could be prevented, at least in part, by RGD peptides and function-blocking antibodies. Intravenous injection of fluorescently labeled human EPCs into athymic nude mice shortly after vascular injury revealed that preincubation of EPCs with leptin augmented their accumulation within intimal lesions, accelerating reendothelialization and decreasing neointima formation in an alphavbeta5 and alpha4 integrin-dependent manner. Our findings suggest that leptin specifically modulates the adhesive properties and the homing potential of EPCs and may thus enhance their capacity to promote vascular regeneration in vivo.

Acute Stroke Interventions Performed by Cardiologists: Initial Experience in a Single Center.

OBJECTIVES: The aim of this study was to evaluate the technical and clinical success of acute stroke interventions performed in our interventional cardiology center. BACKGROUND: Dedicated interventional stroke centers remain limited. Interventional cardiologists have established networks of catheterization laboratories and the necessary infrastructure to provide around the clock interventional therapy. These networks may also provide the currently lacking universal rapid access to prompt stroke intervention. METHODS: Between July 2012 and July 2018, 70 consecutive patients underwent acute stroke intervention for large-vessel occlusions. Seventeen patients (24%) had tandem or multiple vessel occlusions. The majority (n = 63, 90%) were admitted via our local stroke unit, and 7 (10%) patients were transferred from other regional referral centers. RESULTS: In 43 (61%) patients, systemic fibrinolytic therapy was started after baseline imaging. Mean time between symptom onset and arrival to the cath lab was 138 min; mean door-to-vascular access time was 64 min; mean time between cath lab activation and its operational readiness was 13 min. In all cases, access to supra-aortic vessels was achieved. Mean time between femoral arterial puncture and lesion crossing was 26 min. Stent implantation for extracranial stenosis or dissection was performed in 14 (20%) cases. Thrombectomy of intracranial occlusions was done with a stent retriever (n = 64, 91%) or an aspiration system (n = 14, 20%). In 20 (28%) cases, a combination of techniques was used. Recanalization was technically successful (Thrombolysis In Cerebral Infarction flow grade 2b or 3) in 65 (93%) patients. The 30-day mortality was 18% (n = 13). Favorable clinical outcome, defined as a modified Rankin Scale score of 0 to 2, was achieved in 61% at 3-month follow-up. CONCLUSIONS: Acute stroke interventions can be performed safely and with high technical and clinical success by experienced interventional cardiologists.