TY - JOUR A1 - Wen, Lai A1 - Feil, Susanne A1 - Wolters, Markus A1 - Thunemann, Martin A1 - Regler, Frank A1 - Schmidt, Kjestine A1 - Friebe, Andreas A1 - Olbrich, Marcus A1 - Langer, Harald A1 - Gawaz, Meinrad A1 - de Wit, Cor A1 - Feil, Robert T1 - A shear-dependent NO-cGMP-cGKI cascade in platelets acts as an auto-regulatory brake of thrombosis JF - Nature Communications N2 - Mechanisms that limit thrombosis are poorly defined. One of the few known endogenous platelet inhibitors is nitric oxide (NO). NO activates NO sensitive guanylyl cyclase (NO-GC) in platelets, resulting in an increase of cyclic guanosine monophosphate (cGMP). Here we show, using cGMP sensor mice to study spatiotemporal dynamics of platelet cGMP, that NO-induced cGMP production in pre-activated platelets is strongly shear-dependent. We delineate a new mode of platelet-inhibitory mechanotransduction via shear-activated NO-GC followed by cGMP synthesis, activation of cGMP-dependent protein kinase I (cGKI), and suppression of Ca2+ signaling. Correlative profiling of cGMP dynamics and thrombus formation in vivo indicates that high cGMP concentrations in shear-exposed platelets at the thrombus periphery limit thrombosis, primarily through facilitation of thrombus dissolution. We propose that an increase in shear stress during thrombus growth activates the NO-cGMP-cGKI pathway, which acts as an auto-regulatory brake to prevent vessel occlusion, while preserving wound closure under low shear. KW - calcium signalling KW - fluorescence imaging KW - platelets KW - thrombosis Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233616 VL - 9 ER - TY - JOUR A1 - Herzberg, Moritz A1 - Scherling, Korbinian A1 - Stahl, Robert A1 - Tiedt, Steffen A1 - Wollenweber, Frank A. A1 - Küpper, Clemens A1 - Feil, Katharina A1 - Forbrig, Robert A1 - Patzig, Maximilian A1 - Kellert, Lars A1 - Kunz, Wolfgang G. A1 - Reidler, Paul A1 - Zimmermann, Hanna A1 - Liebig, Thomas A1 - Dieterich, Marianne A1 - Dorn, Franziska T1 - Late Thrombectomy in Clinical Practice: Retrospective Application of DAWN/DEFUSE3 Criteria within the German Stroke Registry JF - Clinical Neuroradiology N2 - Background and Purpose To provide real-world data on outcome and procedural factors of late thrombectomy patients. Methods We retrospectively analyzed patients from the multicenter German Stroke Registry. The primary endpoint was clinical outcome on the modified Rankin scale (mRS) at 3 months. Trial-eligible patients and the subgroups were compared to the ineligible group. Secondary analyses included multivariate logistic regression to identify predictors of good outcome (mRS ≤ 2). Results Of 1917 patients who underwent thrombectomy, 208 (11%) were treated within a time window ≥ 6–24 h and met the baseline trial criteria. Of these, 27 patients (13%) were eligible for DAWN and 39 (19%) for DEFUSE3 and 156 patients were not eligible for DAWN or DEFUSE3 (75%), mainly because there was no perfusion imaging (62%; n = 129). Good outcome was not significantly higher in trial-ineligible (27%) than in trial-eligible (20%) patients (p = 0.343). Patients with large trial-ineligible CT perfusion imaging (CTP) lesions had significantly more hemorrhagic complications (33%) as well as unfavorable outcomes. Conclusion In clinical practice, the high number of patients with a good clinical outcome after endovascular therapy ≥ 6–24 h as in DAWN/DEFUSE3 could not be achieved. Similar outcomes are seen in patients selected for EVT ≥ 6 h based on factors other than CTP. Patients triaged without CTP showed trends for shorter arrival to reperfusion times and higher rates of independence. KW - late thrombectomy KW - stroke KW - endovascular therapy KW - outcome Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264765 VL - 31 IS - 3 ER - TY - JOUR A1 - Frantz, Stefan A1 - Klaiber, Michael A1 - Baba, Hideo A. A1 - Oberwinkler, Heinz A1 - Völker, Katharina A1 - Gaßner, Birgit A1 - Bayer, Barbara A1 - Abeßer, Marco A1 - Schuh, Kai A1 - Feil, Robert A1 - Hofmann, Franz A1 - Kuhn, Michaela T1 - Stress-dependent dilated cardiomyopathy in mice with cardiomyocyte-restricted inactivation of cyclic GMP-dependent protein kinase I JF - European Heart Journal N2 - Aims: Cardiac hypertrophy is a common and often lethal complication of arterial hypertension. Elevation of myocyte cyclic GMP levels by local actions of endogenous atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) or by pharmacological inhibition of phosphodiesterase-5 was shown to counter-regulate pathological hypertrophy. It was suggested that cGMP-dependent protein kinase I (cGKI) mediates this protective effect, although the role in vivo is under debate. Here, we investigated whether cGKI modulates myocyte growth and/or function in the intact organism. Methods and results: To circumvent the systemic phenotype associated with germline ablation of cGKI, we inactivated the murine cGKI gene selectively in cardiomyocytes by Cre/loxP-mediated recombination. Mice with cardiomyocyte-restricted cGKI deletion exhibited unaltered cardiac morphology and function under resting conditions. Also, cardiac hypertrophic and contractile responses to β-adrenoreceptor stimulation by isoprenaline (at 40 mg/kg/day during 1 week) were unaltered. However, angiotensin II (Ang II, at 1000 ng/kg/min for 2 weeks) or transverse aortic constriction (for 3 weeks) provoked dilated cardiomyopathy with marked deterioration of cardiac function. This was accompanied by diminished expression of the \([Ca^{2+}]_i\)-regulating proteins SERCA2a and phospholamban (PLB) and a reduction in PLB phosphorylation at Ser16, the specific target site for cGKI, resulting in altered myocyte \(Ca^{2+}_i\) homeostasis. In isolated adult myocytes, CNP, but not ANP, stimulated PLB phosphorylation, \(Ca^{2+}_i\)-handling, and contractility via cGKI. Conclusion: These results indicate that the loss of cGKI in cardiac myocytes compromises the hypertrophic program to pathological stimulation, rendering the heart more susceptible to dysfunction. In particular, cGKI mediates stimulatory effects of CNP on myocyte \(Ca^{2+}_i\) handling and contractility. KW - cyclic KW - GMPcGMP-dependent protein kinase I KW - cardiac hypertrophy KW - natriuretic peptide KW - Ca2+i handling Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134693 VL - 34 ER -