Regulation of endothelial cell permeability by platelet-derived extracellular vesicles.

Background: Platelet (Plt)-derived extracellular vesicles (Plt-EVs) have hemostatic properties similar to Plts. In addition to hemostasis, Plts also function to stabilize the vasculature and maintain endothelial cell (EC) barrier integrity. We hypothesized that Plt-EVs would inhibit vascular EC permeability, similar to fresh Plts.

Serum from dengue virus-infected patients with and without plasma leakage differentially affects endothelial cells barrier function in vitro.

Background: Although most of cases of dengue infections are asymptomatic or mild symptomatic some individuals present warning signs progressing to severe dengue in which plasma leakage is a hallmark.

Methodology/principal Findings: The present study used Electric Cell-substrate Impedance Sensing (ECIS®) which allows for electrical monitoring of cellular barrier function measuring changes in Transendothelial Electric Resistance (TEER) to investigate the parameters associated with dengue induced leakage. Three groups of individuals were tested: dengue-positives with plasma leakage (leakage), dengue-positives without plasma leakage (no leakage), and dengue-negatives (control).

Platelets regulate vascular endothelial stability: assessing the storage lesion and donor variability of apheresis platelets.

Background: In current blood banking practices, platelets (PLTs) are stored in plasma at 22°C, with gentle agitation for up to 5 days. To date, the effects of storage and donor variability on PLT regulation of vascular integrity are not known.

Study Design And Methods: In this study, we examined the donor variability of leukoreduced fresh (Day 1) or stored (Day 5) PLTs on vascular endothelial barrier function in vitro and in vivo.

The effects of 22°C and 4°C storage of platelets on vascular endothelial integrity and function.

Background: Although a majority of the studies conducted to date on platelet (PLT) storage have been focused on PLT hemostatic function, the effects of 4°C PLTs on regulation of endothelial barrier permeability are still not known. In this study, we compared the effects of room temperature (22°C) stored and (4°C) stored PLTs on the regulation of vascular endothelial cell (EC) permeability in vitro and in vivo.

Study Design And Methods: Day 1, Day 5, and Day 7 leukoreduced apheresis PLTs stored at 4 or 22°C were studied in vitro and in vivo.

Wnt3a, a Protein Secreted by Mesenchymal Stem Cells Is Neuroprotective and Promotes Neurocognitive Recovery Following Traumatic Brain Injury.

Intravenous administration of bone marrow derived mesenchymal stem cells (MSCs) has been shown to reduce blood brain barrier compromise and improve neurocognition following traumatic brain injury (TBI). These effects occur in the absence of engraftment and differentiation of these cells in the injured brain. Recent studies have shown that soluble factors produced by MSCs mediate a number of the therapeutic effects.