TY - JOUR A1 - Rödel, Claudia Jasmin A1 - Otten, Cecile A1 - Donat, Stefan A1 - Lourenço, Marta Sofia Rocha A1 - Fischer, Dorothea A1 - Kuropka, Benno A1 - Paolini, Alessio A1 - Freund, Christian A1 - Abdelilah-Seyfried, Salim T1 - Blood Flow Suppresses Vascular Anomalies in a Zebrafish Model of Cerebral Cavernous Malformations JF - Circulation Research N2 - RATIONALE: Pathological biomechanical signaling induces vascular anomalies including cerebral cavernous malformations (CCM), which are caused by a clonal loss of CCM1/KRIT1 (Krev interaction trapped protein 1), CCM2/MGC4607, or CCM3/PDCD10. Why patients typically experience lesions only in lowly perfused venous capillaries of the cerebrovasculature is completely unknown. OBJECTIVE: In contrast, animal models with a complete loss of CCM proteins lack a functional heart and blood flow and exhibit vascular anomalies within major blood vessels as well. This finding raises the possibility that hemodynamics may play a role in the context of this vascular pathology. METHODS AND RESULTS: Here, we used a genetic approach to restore cardiac function and blood flow in a zebrafish model of CCM1. We find that blood flow prevents cardiovascular anomalies including a hyperplastic expansion within a large Ccm1-deficient vascular bed, the lateral dorsal aorta. CONCLUSIONS: This study identifies blood flow as an important physiological factor that is protective in the cause of this devastating vascular pathology. KW - animal models KW - cerebral cavernous malformations KW - endothelial cell KW - hemodynamics KW - zebrafish Y1 - 2019 U6 - https://doi.org/10.1161/CIRCRESAHA.119.315076 SN - 0009-7330 SN - 1524-4571 VL - 125 IS - 10 SP - E43 EP - E54 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Donat, Stefan A1 - Lourenco, Marta Sofia Rocha A1 - Paolini, Alessio A1 - Otten, Cecile A1 - Renz, Marc A1 - Abdelilah-Seyfried, Salim T1 - Heg1 and Ccm1/2 proteins control endocardial mechanosensitivity during zebrafish valvulogenesis JF - eLife N2 - Endothelial cells respond to different levels of fluid shear stress through adaptations of their mechanosensitivity. Currently, we lack a good understanding of how this contributes to sculpting of the cardiovascular system. Cerebral cavernous malformation (CCM) is an inherited vascular disease that occurs when a second somatic mutation causes a loss of CCM1/KRIT1, CCM2, or CCM3 proteins. Here, we demonstrate that zebrafish Krit1 regulates the formation of cardiac valves. Expression of heg1, which encodes a binding partner of Krit1, is positively regulated by blood-flow. In turn, Heg1 stabilizes levels of Krit1 protein, and both Heg1 and Krit1 dampen expression levels of klf2a, a major mechanosensitive gene. Conversely, loss of Krit1 results in increased expression of klf2a and notch1b throughout the endocardium and prevents cardiac valve leaflet formation. Hence, the correct balance of blood-flow-dependent induction and Krit1 protein mediated repression of klf2a and notch1b ultimately shapes cardiac valve leaflet morphology. Y1 - 2018 U6 - https://doi.org/10.7554/eLife.28939 SN - 2050-084X VL - 7 PB - eLife Sciences Publications CY - Cambridge ER - TY - JOUR A1 - Otten, Cecile A1 - Knox, Jessica A1 - Boulday, Gwenola A1 - Eymery, Mathias A1 - Haniszewski, Marta A1 - Neuenschwander, Martin A1 - Radetzki, Silke A1 - Vogt, Ingo A1 - Haehn, Kristina A1 - De Luca, Coralie A1 - Cardoso, Cecile A1 - Hamad, Sabri A1 - Igual Gil, Carla A1 - Roy, Peter A1 - Albiges-Rizo, Corinne A1 - Faurobert, Eva A1 - von Kries, Jens P. A1 - Campillos, Monica A1 - Tournier-Lasserve, Elisabeth A1 - Derry, William Brent A1 - Abdelilah-Seyfried, Salim T1 - Systematic pharmacological screens uncover novel pathways involved in cerebral cavernous malformations JF - EMBO molecular medicine N2 - Cerebral cavernous malformations (CCMs) are vascular lesions in the central nervous system causing strokes and seizures which currently can only be treated through neurosurgery. The disease arises through changes in the regulatory networks of endothelial cells that must be comprehensively understood to develop alternative, non-invasive pharmacological therapies. Here, we present the results of several unbiased small-molecule suppression screens in which we applied a total of 5,268 unique substances to CCM mutant worm, zebrafish, mouse, or human endothelial cells. We used a systems biology-based target prediction tool to integrate the results with the whole-transcriptome profile of zebrafish CCM2 mutants, revealing signaling pathways relevant to the disease and potential targets for small-molecule-based therapies. We found indirubin-3-monoxime to alleviate the lesion burden in murine preclinical models of CCM2 and CCM3 and suppress the loss-of-CCM phenotypes in human endothelial cells. Our multi-organism-based approach reveals new components of the CCM regulatory network and foreshadows novel small-molecule-based therapeutic applications for suppressing this devastating disease in patients. KW - angiogenesis KW - CCM KW - ERK5 KW - indirubin-3-monoxime KW - KLF2 Y1 - 2018 U6 - https://doi.org/10.15252/emmm.201809155 SN - 1757-4676 SN - 1757-4684 VL - 10 IS - 10 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Renz, Marc A1 - Otten, Cecile A1 - Faurobert, Eva A1 - Rudolph, Franziska A1 - Zhu, Yuan A1 - Boulday, Gwenola A1 - Duchene, Johan A1 - Mickoleit, Michaela A1 - Dietrich, Ann-Christin A1 - Ramspacher, Caroline A1 - Steed, Emily A1 - Manet-Dupe, Sandra A1 - Benz, Alexander A1 - Hassel, David A1 - Vermot, Julien A1 - Huisken, Jan A1 - Tournier-Lasserve, Elisabeth A1 - Felbor, Ute A1 - Sure, Ulrich A1 - Albiges-Rizo, Corinne A1 - Abdelilah-Seyfried, Salim T1 - Regulation of beta 1 Integrin-Klf2-Mediated angiogenesis by CCM proteins JF - Developmental cell N2 - Mechanotransduction pathways are activated in response to biophysical stimuli during the development or homeostasis of organs and tissues. In zebrafish, the blood-flow-sensitive transcription factor Klf2a promotes VEGF-dependent angiogenesis. However, the means by which the Klf2a mechanotransduction pathway is regulated to prevent continuous angiogenesis remain unknown. Here we report that the upregulation of klf2 mRNA causes enhanced egfl7 expression and angiogenesis signaling, which underlies cardiovascular defects associated with the loss of cerebral cavernous malformation (CCM) proteins in the zebrafish embryo. Using CCM-protein-depleted human umbilical vein endothelial cells, we show that the misexpression of KLF2 mRNA requires the extracellular matrix-binding receptor beta 1 integrin and occurs in the absence of blood flow. Downregulation of beta 1 integrin rescues ccm mutant cardiovascular malformations in zebrafish. Our work reveals a beta 1 integrin-Klf2-Egfl7-signaling pathway that is tightly regulated by CCM proteins. This regulation prevents angiogenic overgrowth and ensures the quiescence of endothelial cells. Y1 - 2015 U6 - https://doi.org/10.1016/j.devcel.2014.12.016 SN - 1534-5807 SN - 1878-1551 VL - 32 IS - 2 SP - 181 EP - 190 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Lombardo, Veronica A. A1 - Otten, Cecile A1 - Abdelilah-Seyfried, Salim T1 - Large-scale Zebrafish Embryonic Heart Dissection for Transcriptional Analysis JF - Journal of visualized experiments N2 - The zebrafish embryonic heart is composed of only a few hundred cells, representing only a small fraction of the entire embryo. Therefore, to prevent the cardiac transcriptome from being masked by the global embryonic transcriptome, it is necessary to collect sufficient numbers of hearts for further analyses. Furthermore, as zebrafish cardiac development proceeds rapidly, heart collection and RNA extraction methods need to be quick in order to ensure homogeneity of the samples. Here, we present a rapid manual dissection protocol for collecting functional/beating hearts from zebrafish embryos. This is an essential prerequisite for subsequent cardiac-specific RNA extraction to determine cardiac-specific gene expression levels by transcriptome analyses, such as quantitative real-time polymerase chain reaction (RT-qPCR). The method is based on differential adhesive properties of the zebrafish embryonic heart compared with other tissues; this allows for the rapid physical separation of cardiac from extracardiac tissue by a combination of fluidic shear force disruption, stepwise filtration and manual collection of transgenic fluorescently labeled hearts. KW - Developmental Biology KW - Issue 95 KW - zebrafish KW - embryo KW - heart KW - dissection KW - RNA KW - RT-qPCR Y1 - 2015 U6 - https://doi.org/10.3791/52087 SN - 1940-087X IS - 95 PB - JoVE CY - Cambridge ER -