Department of Medicine, University of California, San Diego, La Jolla, United States
Virginia Tran
Department of Medicine, University of California, San Diego, La Jolla, United States
Iftach Shaked
Department of Physics, University of California, San Diego, La Jolla, United States
Belinda Xue
Department of Medicine, University of California, San Diego, La Jolla, United States
Thomas Moore
Neurovascular Surgery Program, Section of Neurosurgery, Department of Surgery, University of Chicago School of Medicine and Biological Sciences, Chicago, United States
Rhonda Lightle
Neurovascular Surgery Program, Section of Neurosurgery, Department of Surgery, University of Chicago School of Medicine and Biological Sciences, Chicago, United States
Department of Physics, University of California, San Diego, La Jolla, United States; Section of Neurobiology, University of California San Diego, La Jolla, United States
Issam A Awad
Neurovascular Surgery Program, Section of Neurosurgery, Department of Surgery, University of Chicago School of Medicine and Biological Sciences, Chicago, United States
Mosaic inactivation of CCM2 in humans causes cerebral cavernous malformations (CCMs) containing adjacent dilated blood-filled multi-cavernous lesions. We used CRISPR-Cas9 mutagenesis to induce mosaic inactivation of zebrafish ccm2 resulting in a novel lethal multi-cavernous lesion in the embryonic caudal venous plexus (CVP) caused by obstruction of blood flow by intraluminal pillars. These pillars mimic those that mediate intussusceptive angiogenesis; however, in contrast to the normal process, the pillars failed to fuse to split the pre-existing vessel in two. Abortive intussusceptive angiogenesis stemmed from mosaic inactivation of ccm2 leading to patchy klf2a overexpression and resultant aberrant flow signaling. Surviving adult fish manifested histologically typical hemorrhagic CCM. Formation of mammalian CCM requires the flow-regulated transcription factor KLF2; fish CCM and the embryonic CVP lesion failed to form in klf2a null fish indicating a common pathogenesis with the mammalian lesion. These studies describe a zebrafish CCM model and establish a mechanism that can explain the formation of characteristic multi-cavernous lesions.
