Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo-3

<p><b>Copyright information:</b></p><p>Taken from "Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo"</p><p>http://www.biomedcentral.com/1471-2172/8/31</p><p>BMC Immunology 2007;8():31-31.</p><p>Published online 28 Nov 2007</p><p>PMCID:PMC2217554.</p><p></p>o) addition of 1 mM Mnat 37°C for 30 min. Adherent (n = 7 mice) or control neutrophils (n = 5 mice) in percent of total cells added (A), microscopic images (B), increase of cell area (in μm, C) and frequency distribution of cell area (D) of adherent (n = 400 from 4 mice) and control neutrophils (n = 400 from 4 mice) upon stimulation for 30 min at 37°C. * indicates significant difference (p < 0.05), n.s., not significant

Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo-1

<p><b>Copyright information:</b></p><p>Taken from "Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo"</p><p>http://www.biomedcentral.com/1471-2172/8/31</p><p>BMC Immunology 2007;8():31-31.</p><p>Published online 28 Nov 2007</p><p>PMCID:PMC2217554.</p><p></p>chimeric mice (gray bar, n = 4)) and control mice (black bar, n = 6) before and during 15 min local administration of fMLP (1 μM). * indicates significant difference (p < 0.05) between chimeric and control mice

Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo-2

<p><b>Copyright information:</b></p><p>Taken from "Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo"</p><p>http://www.biomedcentral.com/1471-2172/8/31</p><p>BMC Immunology 2007;8():31-31.</p><p>Published online 28 Nov 2007</p><p>PMCID:PMC2217554.</p><p></p>uring gradual stimulation (A, right panel) leading to flattening out of the cell with a concomitant decrease in cell diameter perpendicular to the vessel wall (white arrows). Diameters of adherent leukocytes from chimeric mice (gray bar, n = 318 from 4 mice) and control mice (black bar, n = 419 from 6 mice) were measured perpendicular to the vessel wall before and during superfusion with fMLP (B). In addition, a cumulative frequency distribution of measured leukocyte diameters is given for (gray lines) and control leukocytes (black lines) after 1 min (dashed lines) and 15 min (solid lines) fMLP superfusion (C). * in (B): significant difference (p < 0.05) between chimeric and control mice. * in (C): significant difference (p < 0.05) in the distribution of control cell diameters at 15 min fMLP to all other groups

Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo-4

<p><b>Copyright information:</b></p><p>Taken from "Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo"</p><p>http://www.biomedcentral.com/1471-2172/8/31</p><p>BMC Immunology 2007;8():31-31.</p><p>Published online 28 Nov 2007</p><p>PMCID:PMC2217554.</p><p></p>ncy [(adherent cells/mmvessel surface area)/(systemic leukocyte count)] (B), and rolling flux fraction [%] (C) in chimeric mice (gray bar, n = 4) and control mice (black bar, n = 6). * indicates significant difference (p < 0.05) between chimeric and control mice

The Endothelial Glycocalyx Controls Interactions of Quantum Dots with the Endothelium and Their Translocation across the Blood–Tissue Border

Advances in the engineering of nanoparticles (NPs), which represent particles of less than 100 nm in one external dimension, led to an increasing utilization of nanomaterials for biomedical purposes. A prerequisite for their use in diagnostic and therapeutic applications, however, is the targeted delivery to the site of injury. Interactions between blood-borne NPs and the vascular endothelium represent a critical step for nanoparticle delivery into diseased tissue. Here, we show that the endothelial glycocalyx, which constitutes a glycoprotein–polysaccharide meshwork coating the luminal surface of vessels, effectively controls interactions of carboxyl-functionalized quantum dots with the microvascular endothelium. Glycosaminoglycans of the endothelial glycocalyx were found to physically cover endothelial adhesion and signaling molecules, thereby preventing endothelial attachment, uptake, and translocation of these nanoparticles through different layers of the vessel wall. Conversely, degradation of the endothelial glycocalyx promoted interactions of these nanoparticles with microvascular endothelial cells under the pathologic condition of ischemia–reperfusion, thus identifying the injured endothelial glycocalyx as an essential element of the blood–tissue border facilitating the targeted delivery of nanomaterials to diseased tissue

Giemsa-stained whole-mounts of TNF-α–treated cremaster muscles of WT, ST3Gal-IV, and CXCR2 mice were analyzed for the number of intravascular (A) and perivascular (B) leukocytes (mean ± SEM per mm surface area)

In addition, two typical micrographs are presented illustrating intra- and perivascular leukocyte distribution in TNF-α–treated cremaster muscle whole mounts of WT control mice (C) and ST3Gal-IV mice pretreated with E-selectin blocking mAb 9A9 (D). Data in A and B were obtained from at least three independent experiments per group. *, P < 0.05 versus WT mice. Bars, 50 μm.<p><b>Copyright information:</b></p><p>Taken from "Sialyltransferase ST3Gal-IV controls CXCR2-mediated firm leukocyte arrest during inflammation"</p><p></p><p>The Journal of Experimental Medicine 2008;205(6):1435-1446.</p><p>Published online 9 Jun 2008</p><p>PMCID:PMC2413039.</p><p></p

The number of rolling and adherent leukocytes from ST3Gal-IV and WT mice was determined in blood-perfused microflow chambers

(A) Rolling and (B) adherent leukocytes in autoperfused flow chambers (5.94 dynes/cm) coated with 20 μg/ml P-selectin and 15 μg/ml ICAM-1 with or without 15 μg/ml CXCL1. Data in A and B are presented as mean ± SEM from at least four mice and four flow chambers. *, P < 0.05 versus WT mice (B). (C) The percentage of transmigrated neutrophils from WT control mice, ST3Gal-IV mice, and WT control mice pretreated with neuraminidase was assessed in a transwell assay in which transwells were coated with an immortalized endothelial cell line, b.End5. In addition, transmigration of WT control neutrophils through a neuraminidase-pretreated b.End5 monolayer was analyzed. Data in C were determined from at least three independent experiments per group. *, P < 0.05 versus untreated WT control neutrophils (C). FOV, field of view.<p><b>Copyright information:</b></p><p>Taken from "Sialyltransferase ST3Gal-IV controls CXCR2-mediated firm leukocyte arrest during inflammation"</p><p></p><p>The Journal of Experimental Medicine 2008;205(6):1435-1446.</p><p>Published online 9 Jun 2008</p><p>PMCID:PMC2413039.</p><p></p

(A) Cell lysates of CXCR2-transfected and untransfected HEK293 cells were incubated with an mAb to CXCR2, followed by precipitation with protein A

Precipitates were treated with 20 U/ml neuraminidase for 60 min at 37°C, or were left untreated and analyzed by Western blotting for binding of biotinylated anti-CXCR2 antibody or biotinylated MAL-II, respectively. (B) Isolated human neutrophils were treated with the indicated dosages of neuraminidase for 30 min at 37°C, washed, and subsequently assayed for binding of I-labeled CXCL7 and I-labeled CXCL4. Specifically bound radioactivity was expressed as the percentage of WT control cells receiving no enzyme treatment. (C) Scatchard plot for CXCL7 binding to untreated and neuraminidase-treated (20 U/ml) human neutrophils. The binding data were curve fit to determine affinity constants for high and low affinity binding sites. (D) Neutrophils were treated with the indicated dosages of neuraminidase for 30 min at 37°C, washed, and subsequently assayed for elastase release in response to increasing concentrations of CXCL7, CXCL8, and fMLP. The residual responsiveness of neuraminidase-treated neutrophils was expressed as the percentage of that determined for untreated cells. Data in A–D represent means ± SD determined in three different experiments, each with blood from a different donor.<p><b>Copyright information:</b></p><p>Taken from "Sialyltransferase ST3Gal-IV controls CXCR2-mediated firm leukocyte arrest during inflammation"</p><p></p><p>The Journal of Experimental Medicine 2008;205(6):1435-1446.</p><p>Published online 9 Jun 2008</p><p>PMCID:PMC2413039.</p><p></p

data_sheet_1_The Yin and Yang of Tyrosine Kinase Inhibition During Experimental Polymicrobial Sepsis.DOCX

<p>Neutrophils are the first cells of our immune system to arrive at the site of inflammation. They release cytokines, e.g., chemokines, to attract further immune cells, but also actively start to phagocytose and kill pathogens. In the case of sepsis, this tightly regulated host defense mechanism can become uncontrolled and hyperactive resulting in severe organ damage. Currently, no effective therapy is available to fight sepsis; therefore, novel treatment targets that could prevent excessive inflammatory responses are warranted. Src Family tyrosine Kinases (SFK), a group of tyrosine kinases, have been shown to play a major role in regulating immune cell recruitment and host defense. Leukocytes with SFK depletion display severe spreading and migration defects along with reduced cytokine production. Thus, we investigated the effects of dasatinib, a tyrosine kinase inhibitor, with a strong inhibitory capacity on SFKs during sterile inflammation and polymicrobial sepsis in mice. We found that dasatinib-treated mice displayed diminished leukocyte adhesion and extravasation in tumor necrosis factor-α-stimulated cremaster muscle venules in vivo. In polymicrobial sepsis, sepsis severity, organ damage, and clinical outcome improved in a dose-dependent fashion pointing toward an optimal therapeutic window for dasatinib dosage during polymicrobial sepsis. Dasatinib treatment may, therefore, provide a balanced immune response by preventing an overshooting inflammatory reaction on the one side and bacterial overgrowth on the other side.</p