@article{SchuhmannGunrebenKleinschnitzetal.2016, author = {Schuhmann, Michael K. and Gunreben, Ignaz and Kleinschnitz, Christoph and Kraft, Peter}, title = {Immunohistochemical Analysis of Cerebral Thrombi Retrieved by Mechanical Thrombectomy from Patients with Acute Ischemic Stroke}, series = {International Journal of Molecular Sciences}, volume = {17}, journal = {International Journal of Molecular Sciences}, number = {3}, doi = {10.3390/ijms17030298}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166206}, pages = {298}, year = {2016}, abstract = {Mechanical thrombectomy is a novel treatment option for patients with acute ischemic stroke (AIS). Only a few studies have previously suggested strategies to categorize retrieved clots according to their histologic composition. However, these reports did not analyze potential biomarkers that are of importance in stroke-related inflammation. We therefore histopathologically investigated 37 intracerebral thrombi mechanically retrieved from patients with AIS, and focused on the composition of immune cells and platelets. We also conducted correlation analyses of distinctive morphologic patterns (erythrocytic, serpentine, layered, red, white, mixed appearance) with clinical parameters. Most T cells and monocytes were detected in erythrocytic and red clots, in which the distribution of these cells was random. In contrast, von Willebrand factor (vWF)-positive areas co-localized with regions of fibrin and collagen. While clots with huge amounts of vWF seem to be associated with a high National Institute of Health Stroke Scale score at admission, histologic findings could not predict the clinical outcome at discharge. In summary, we provide the first histologic description of mechanically retrieved intracerebral thrombi regarding biomarkers relevant for inflammation in ischemic stroke.}, language = {en} } @article{SchuhmannBittnerMeuthetal.2015, author = {Schuhmann, Michael K. and Bittner, Stefan and Meuth, Sven G. and Kleinschnitz, Christoph and Fluri, Felix}, title = {Fingolimod (FTY720-P) does not stabilize the blood-brain barrier under inflammatory conditions in an in vitro model}, series = {International Journal of Molecular Sciences}, volume = {16}, journal = {International Journal of Molecular Sciences}, doi = {10.3390/ijms161226177}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145047}, pages = {29454-29466}, year = {2015}, abstract = {Breakdown of the blood-brain barrier (BBB) is an early hallmark of multiple sclerosis (MS), a progressive inflammatory disease of the central nervous system. Cell adhesion in the BBB is modulated by sphingosine-1-phosphate (S1P), a signaling protein, via S1P receptors (S1P\(_1\)). Fingolimod phosphate (FTY720-P) a functional S1P\(_1\) antagonist has been shown to improve the relapse rate in relapsing-remitting MS by preventing the egress of lymphocytes from lymph nodes. However, its role in modulating BBB permeabilityin particular, on the tight junction proteins occludin, claudin 5 and ZO-1has not been well elucidated to date. In the present study, FTY720-P did not change the transendothelial electrical resistance in a rat brain microvascular endothelial cell (RBMEC) culture exposed to inflammatory conditions and thus did not decrease endothelial barrier permeability. In contrast, occludin was reduced in RBMEC culture after adding FTY720-P. Additionally, FTY720-P did not alter the amount of endothelial matrix metalloproteinase (MMP)-9 and MMP-2 in RBMEC cultures. Taken together, our observations support the assumption that S1P\(_1\) plays a dual role in vascular permeability, depending on its ligand. Thus, S1P\(_1\) provides a mechanistic basis for FTY720-P-associated disruption of endothelial barrierssuch as the blood-retinal barrierwhich might result in macular edema.}, language = {en} } @article{SchuhmannFluri2017, author = {Schuhmann, Michael K. and Fluri, Felix}, title = {Effects of fullerenols on mouse brain microvascular endothelial cells}, series = {International Journal of Molecular Sciences}, volume = {18}, journal = {International Journal of Molecular Sciences}, number = {8}, issn = {1422-0067}, doi = {10.3390/ijms18081783}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158072}, year = {2017}, abstract = {Fullerenols, water-soluble C60-fullerene derivatives, have been shown to exert neuroprotective effects in vitro and in vivo, most likely due to their capability to scavenge free radicals. However, little is known about the effects of fullerenols on the blood-brain barrier (BBB), especially on cerebral endothelial cells under inflammatory conditions. Here, we investigated whether the treatment of primary mouse brain microvascular endothelial cells with fullerenols impacts basal and inflammatory blood-brain barrier (BBB) properties in vitro. While fullerenols (1, 10, and 100 µg/mL) did not change transendothelial electrical resistance under basal and inflammatory conditions, 100 µg/mL of fullerenol significantly reduced erk1/2 activation and resulted in an activation of NFκB in an inflammatory milieu. Our findings suggest that fullerenols might counteract oxidative stress via the erk1/2 and NFκB pathways, and thus are able to protect microvascular endothelial cells under inflammatory conditions.}, language = {en} } @article{AlbertWeissenbergerMenclSchuhmannetal.2014, author = {Albert-Weissenberger, Christiane and Mencl, Stine and Schuhmann, Michael K. and Salur, Irmak and G{\"o}b, Eva and Langhauser, Friederike and Hopp, Sarah and Hennig, Nelli and Meuth, Sven G. and Nolte, Marc W. and Sir{\´e}n, Anna-Leena and Kleinschnitz, Christoph}, title = {C1-Inhibitor protects from focal brain trauma in a cortical cryolesion mice model by reducing thrombo-inflammation}, series = {Frontiers in Cellular Neuroscience}, volume = {8}, journal = {Frontiers in Cellular Neuroscience}, issn = {1662-5102}, doi = {10.3389/fncel.2014.00269}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119263}, pages = {269}, year = {2014}, abstract = {Traumatic brain injury (TBI) induces a strong inflammatory response which includes blood-brain barrier damage, edema formation and infiltration of different immune cell subsets. More recently, microvascular thrombosis has been identified as another pathophysiological feature of TBI. The contact-kinin system represents an interface between inflammatory and thrombotic circuits and is activated in different neurological diseases. C1-Inhibitor counteracts activation of the contact-kinin system at multiple levels. We investigated the therapeutic potential of C1-Inhibitor in a model of TBI. Male and female C57BL/6 mice were subjected to cortical cryolesion and treated with C1-Inhibitor after 1 h. Lesion volumes were assessed between day 1 and day 5 and blood-brain barrier damage, thrombus formation as well as the local inflammatory response were determined post TBI. Treatment of male mice with 15.0 IU C1-Inhibitor, but not 7.5 IU, 1 h after cryolesion reduced lesion volumes by ~75\% on day 1. This protective effect was preserved in female mice and at later stages of trauma. Mechanistically, C1-Inhibitor stabilized the blood-brain barrier and decreased the invasion of immune cells into the brain parenchyma. Moreover, C1-Inhibitor had strong antithrombotic effects. C1-Inhibitor represents a multifaceted anti-inflammatory and antithrombotic compound that prevents traumatic neurodegeneration in clinically meaningful settings.}, language = {en} }