@article{HoppAlbertWeissenbergerMencletal.2016, author = {Hopp, Sarah and Albert-Weissenberger, Christiane and Mencl, Stine and Bieber, Michael and Schuhmann, Michael K. and Stetter, Christian and Nieswandt, Bernhard and Schmidt, Peter M. and Monoranu, Camelia-Maria and Alafuzoff, Irina and Marklund, Niklas and Nolte, Marc W. and Sir{\´e}n, Anna-Leena and Kleinschnitz, Christoph}, title = {Targeting coagulation factor XII as a novel therapeutic option in brain trauma}, series = {Annals of Neurology}, volume = {79}, journal = {Annals of Neurology}, number = {6}, doi = {10.1002/ana.24655}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188800}, pages = {970-982}, year = {2016}, abstract = {Objective: Traumatic brain injury is a major global public health problem for which specific therapeutic interventions are lacking. There is, therefore, a pressing need to identify innovative pathomechanism-based effective therapies for this condition. Thrombus formation in the cerebral microcirculation has been proposed to contribute to secondary brain damage by causing pericontusional ischemia, but previous studies have failed to harness this finding for therapeutic use. The aim of this study was to obtain preclinical evidence supporting the hypothesis that targeting factor XII prevents thrombus formation and has a beneficial effect on outcome after traumatic brain injury. Methods: We investigated the impact of genetic deficiency of factor XII and acute inhibition of activated factor XII with a single bolus injection of recombinant human albumin-fused infestin-4 (rHA-Infestin-4) on trauma-induced microvascular thrombus formation and the subsequent outcome in 2 mouse models of traumatic brain injury. Results: Our study showed that both genetic deficiency of factor XII and an inhibition of activated factor XII in mice minimize trauma-induced microvascular thrombus formation and improve outcome, as reflected by better motor function, reduced brain lesion volume, and diminished neurodegeneration. Administration of human factor XII in factor XII-deficient mice fully restored injury-induced microvascular thrombus formation and brain damage. Interpretation: The robust protective effect of rHA-Infestin-4 points to a novel treatment option that can decrease ischemic injury after traumatic brain injury without increasing bleeding tendencies.}, language = {en} } @article{HoffmannSchmidtKeimetal.2011, author = {Hoffmann, Linda S and Schmidt, Peter M and Keim, Yvonne and Hoffmann, Carsten and Schmidt, Harald H H W and Stasch, Johannes-Peter}, title = {Fluorescence Dequenching Makes Haem-Free Soluble Guanylate Cyclase Detectable in Living Cells}, series = {PLOS ONE}, volume = {6}, journal = {PLOS ONE}, number = {8}, doi = {10.1371/journal.pone.0023596}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-139631}, pages = {e23596}, year = {2011}, abstract = {In cardiovascular disease, the protective NO/sGC/cGMP signalling-pathway is impaired due to a decreased pool of NO-sensitive haem-containing sGC accompanied by a reciprocal increase in NO-insensitive haem-free sGC. However, no direct method to detect cellular haem-free sGC other than its activation by the new therapeutic class of haem mimetics, such as BAY 58-2667, is available. Here we show that fluorescence dequenching, based on the interaction of the optical active prosthetic haem group and the attached biarsenical fluorophor FlAsH can be used to detect changes in cellular sGC haem status. The partly overlap of the emission spectrum of haem and FlAsH allows energy transfer from the fluorophore to the haem which reduces the intensity of FlAsH fluorescence. Loss of the prosthetic group, e. g. by oxidative stress or by replacement with the haem mimetic BAY 58-2667, prevented the energy transfer resulting in increased fluorescence. Haem loss was corroborated by an observed decrease in NO-induced sGC activity, reduced sGC protein levels, and an increased effect of BAY 58-2667. The use of a haem-free sGC mutant and a biarsenical dye that was not quenched by haem as controls further validated that the increase in fluorescence was due to the loss of the prosthetic haem group. The present approach is based on the cellular expression of an engineered sGC variant limiting is applicability to recombinant expression systems. Nevertheless, it allows to monitor sGC's redox regulation in living cells and future enhancements might be able to extend this approach to in vivo conditions.}, language = {en} }