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.

Modulating the endotheliopathy of trauma: Factor concentrate versus fresh frozen plasma.

Background: Transfusion of balanced ratios of plasma to platelets and red blood cells has been shown to reduce early death from exsanguination in trauma patients. Aside from hemostasis, recent work has shown that plasma reduces vascular endothelial permeability, inflammation, and organ edema after hemorrhagic shock (HS), all components of the endotheliopathy of trauma. We hypothesized that Kcentra could have protective effects on the endotheliopathy of trauma comparable with fresh frozen plasma (FFP).

TIMP3 Attenuates the Loss of Neural Stem Cells, Mature Neurons and Neurocognitive Dysfunction in Traumatic Brain Injury.

Mesenchymal stem cells (MSCs) have been shown to have potent therapeutic effects in a number of disorders including traumatic brain injury (TBI). However, the molecular mechanism(s) underlying these protective effects are largely unknown. Herein we demonstrate that tissue inhibitor of matrix metalloproteinase-3 (TIMP3), a soluble protein released by MSCs, is neuroprotective and enhances neuronal survival and neurite outgrowth in vitro.

Endothelial glycocalyx shedding and vascular permeability in severely injured trauma patients.

Background: The endothelial glycocalyx layer (EGL) is a key regulator of vascular permeability, cell adhesion, and inflammation. The EGL is primarily composed of syndecan-1, hyaluronic acid (HA), heparan sulfate (HS) and chondroitin sulfate (CS). While many studies have observed increased shedding of syndecan-1 during hemorrhagic shock, little is known about the shedding of other EGL components, and their effects on altered permeability and coagulation.

EDP-420, a bicyclolide (bridged bicyclic macrolide), is active against Mycobacterium avium.

Infection caused by Mycobacterium avium complex (MAC) is common in patients with immunosuppression, such as AIDS, and deficiencies of gamma interferon and interleukin-12, as well as patients with chronic lung diseases. Treatment of MAC disease is limited since few drugs show in vivo activity. We tested a new bridged bicyclic macrolide, EDP-420, against MAC in vitro and in beige mice.

Selective expression of the Cre recombinase in late-stage thymocytes using the distal promoter of the Lck gene.

Transgenic mouse lines were generated that express the Cre recombinase under the control of the distal promoter of the mouse Lck gene. Cre recombination in four of these lines of transgenic mice was characterized at the single cell level using ROSA26-regulated loxP-Stop-loxP-betageo and loxP-Stop-loxP-YFP reporter mouse lines. Two of the lines showed T cell-restricted Cre recombination, whereas the other two also expressed Cre in B cells, NK cells, and monocytes.