Oscillatory contractile forces refine endothelial cell-cell interactions for continuous lumen formation governed by Heg1/Ccm1.

The formation and organization of complex blood vessel networks rely on various biophysical forces, yet the mechanisms governing endothelial cell-cell interactions under different mechanical inputs are not well understood. Using the dorsal longitudinal anastomotic vessel (DLAV) in zebrafish as a model, we studied the roles of multiple biophysical inputs and cerebral cavernous malformation (CCM)-related genes in angiogenesis. Our research identifies heg1 and krit1 (ccm1) as crucial for the formation of endothelial cell-cell interfaces during anastomosis. In mutants of these genes, cell-cell interfaces are entangled with fragmented apical domains. A Heg1 live reporter demonstrated that Heg1 is dynamically involved in the oscillatory constrictions along cell-cell junctions, whilst a Myosin live reporter indicated that heg1 and krit1 mutants lack actomyosin contractility along these junctions. In wild-type embryos, the oscillatory contractile forces at junctions refine endothelial cell-cell interactions by straightening junctions and eliminating excessive cell-cell interfaces. Conversely, in the absence of junctional contractility, the cell-cell interfaces become entangled and prone to collapse in both mutants, preventing the formation of a continuous luminal space. By restoring junctional contractility via optogenetic activation of RhoA, contorted junctions are straightened and disentangled. Additionally, haemodynamic forces complement actomyosin contractile forces in resolving entangled cell-cell interfaces in both wild-type and mutant embryos. Overall, our study reveals that oscillatory contractile forces governed by Heg1 and Krit1 are essential for maintaining proper endothelial cell-cell interfaces and thus for the formation of a continuous luminal space, which is essential to generate a functional vasculature.

Plasma water T2 detects age-stratified differences in cardiometabolic health among familial CCM patients with Hispanic CCM1 mutation.

Cerebral cavernous malformations (CCMs) are abnormal clusters of capillaries in the nervous system. This pilot study analyzed the cardiometabolic health status of individuals with familial CCMs caused by a rare mutation in the CCM1 gene (fCCM1). The aim was to compare plasma water T2 values from individuals with fCCM1 with values from metabolically unhealthy and healthy individuals with no known CCM mutations. This observational, cross-sectional study included 75 participants: 11 fCCM1 patients, 24 metabolically unhealthy and 40 metabolically healthy individuals. Plasma water T2, an early, global and practical marker of cardiometabolic health, was measured in the time domain using benchtop magnetic resonance relaxometry. The results were stratified by age (equal to or less than 45 vs. older than 45 years). Group means were compared using Welch's one-way ANOVA and post hoc Tukey-Kramer tests. Multivariable linear regression, with T2 as the outcome variable, was used to explore associations with age, gender, Hispanic ethnicity and fCCM1 status. In the younger age stratum, the fCCM1 group had a mean plasma water T2 value comparable to the metabolically healthy group (p = 0.6388), but higher than the unhealthy group (p < 0.0001). By contrast, in the older stratum, the mean plasma water T2 value for the fCCM1 group was comparable to the metabolically unhealthy group (p = 0.7819) and lower than the healthy group (p = 0.0005). Multivariable linear regression revealed that age and the interaction between age and fCCM1 status were significant predictors of T2, even after adjusting for gender and Hispanic ethnicity. Plasma water T2 shows potential as a biomarker for assessing the health status of individuals with fCCM1. Further research is needed to validate these preliminary observations and elucidate the association between CCMs and cardiometabolic health.

Circulating Blood Prognostic Biomarker Signatures for Hemorrhagic Cerebral Cavernous Malformations (CCMs).

Cerebral cavernous malformations (CCMs) are a neurological disorder characterized by enlarged intracranial capillaries in the brain, increasing the susceptibility to hemorrhagic strokes, a major cause of death and disability worldwide. The limited treatment options for CCMs underscore the importance of prognostic biomarkers to predict the likelihood of hemorrhagic events, aiding in treatment decisions and identifying potential pharmacological targets. This study aimed to identify blood biomarkers capable of diagnosing and predicting the risk of hemorrhage in CCM1 patients, establishing an initial set of circulating biomarker signatures. By analyzing proteomic profiles from both human and mouse CCM models and conducting pathway enrichment analyses, we compared groups to identify potential blood biomarkers with statistical significance. Specific candidate biomarkers primarily associated with metabolism and blood clotting pathways were identified. These biomarkers show promise as prognostic indicators for CCM1 deficiency and the risk of hemorrhagic stroke, strongly correlating with the likelihood of hemorrhagic cerebral cavernous malformations (CCMs). This lays the groundwork for further investigation into blood biomarkers to assess the risk of hemorrhagic CCMs.

mPR-Specific Actions Influence Maintenance of the Blood-Brain Barrier (BBB).

Cerebral cavernous malformations (CCMs) are characterized by abnormally dilated intracranial microvascular sinusoids that result in increased susceptibility to hemorrhagic stroke. It has been demonstrated that three CCM proteins (CCM1, CCM2, and CCM3) form the CCM signaling complex (CSC) to mediate angiogenic signaling. Disruption of the CSC will result in hemorrhagic CCMs, a consequence of compromised blood-brain barrier (BBB) integrity. Due to their characteristically incomplete penetrance, the majority of CCM mutation carriers (presumed CCM patients) are largely asymptomatic, but when symptoms occur, the disease has typically reached a clinical stage of focal hemorrhage with irreversible brain damage. We recently reported that the CSC couples both classic (nuclear; nPRs) and nonclassic (membrane; mPRs) progesterone (PRG)-receptors-mediated signaling within the CSC-mPRs-PRG (CmP) signaling network in nPR(-) breast cancer cells. In this report, we demonstrate that depletion of any of the three CCM genes or treatment with mPR-specific PRG actions (PRG/mifepristone) results in the disruption of the CmP signaling network, leading to increased permeability in the nPR(-) endothelial cells (ECs) monolayer in vitro. Finally, utilizing our in vivo hemizygous Ccm mutant mice models, we demonstrate that depletion of any of the three CCM genes, in combination with mPR-specific PRG actions, is also capable of leading to defective homeostasis of PRG in vivo and subsequent BBB disruption, allowing us to identify a specific panel of etiological blood biomarkers associated with BBB disruption. To our knowledge, this is the first report detailing the etiology to predict the occurrence of a disrupted BBB, an indication of early hemorrhagic events.

Whole-Genome Omics Elucidates the Role of CCM1 and Progesterone in Cerebral Cavernous Malformations within CmPn Networks.

Cerebral cavernous malformations (CCMs) are abnormal expansions of brain capillaries that increase the risk of hemorrhagic strokes, with CCM1 mutations responsible for about 50% of familial cases. The disorder can cause irreversible brain damage by compromising the blood-brain barrier (BBB), leading to fatal brain hemorrhages. Studies show that progesterone and its derivatives significantly impact BBB integrity. The three CCM proteins (CCM1, CCM2, and CCM3) form the CCM signaling complex (CSC), linking classic and non-classic progesterone signaling within the CmPn network, which is crucial for maintaining BBB integrity. This study aimed to explore the relationship between CCM1 and key pathways of the CmPn signaling network using three mouse embryonic fibroblast lines (MEFs) with distinct CCM1 expressions. Omics and systems biology analysis investigated CCM1-mediated signaling within the CmPn network. Our findings reveal that CCM1 is essential for regulating cellular processes within progesterone-mediated CmPn/CmP signaling, playing a crucial role in maintaining microvessel integrity. This regulation occurs partly through gene transcription control. The critical role of CCM1 in these processes suggests it could be a promising therapeutic target for CCMs.

Radiosurgery effects and adverse effects in symptomatic eloquent brain-located Cavernomas.

In this study, the dose schedule efficacy, safety and late adverse effects of stereotactic radiosurgery (SRS) were evaluated for patients with symptomatic cavernomas who were not eligible for surgery and treated with SRS. Between January 2013 and December 2018, 53 patients with cavernomas were treated using SRS with the CyberKnife® system. Patients' diseases were deeply located or were in subcortical functional brain regions. In addition to bleeding, 23 (43.4%) patients had epilepsy, 12 (22.6%) had neurologic symptoms and 16 patients (30.2%) had severe headaches. The median volume was 741 (range, 421-1351) mm3, and the median dose was 15 (range, 14-16) Gy in one fraction. After treatment, six (50%) of 12 patients with neurologic deficits still had deficits. Rebleeding after treatment developed in only two (3.8%) patients. The drug was completely stopped in 14 (60.9%) out of 23 patients who received epilepsy treatment, and the dose of levetiracetam decreased from 2000 mg to 1000 mg in four (17.3%) of nine patients. Radiologically, complete response (CR) was observed in 13 (24.5%) patients, and partial responses (PR) were observed in 32 (60.2%) patients. Clinical response of CR was observed in 30 (56.6%) patients, PR was observed in 16 (30.2%), stable disease (SD) was observed in three (5.7%) and four (7.5%) patients progressed. In conclusion, SRS applied in the appropriate dose schedule may be an effective and reliable method in terms of symptom control and prevention of rebleeding, especially in patients with inoperable cavernomas.

Plasma water T2 detects age-stratified differences in cardiometabolic health among familial CCM patients with Hispanic CCM1 mutation.

Introduction: Cerebral cavernous malformations (CCMs) are abnormal clusters of capillaries in the nervous system. This pilot study analyzed the cardiometabolic health status of individuals with familial CCMs caused by a rare mutation in the CCM1 gene (fCCM1). The aim was to compare plasma water T2 values from individuals with fCCM1 with values from metabolically unhealthy and healthy individuals with no known CCM mutations. Design: This observational, cross-sectional study included 75 participants: 11 fCCM1 patients, 24 metabolically unhealthy and 40 metabolically healthy individuals. Plasma water T2, an early, global and practical marker of cardiometabolic health, was measured in the time domain using benchtop magnetic resonance relaxometry. The results were stratified by age (equal to or less than 45 vs. older than 45 years). Group means were compared using Welch's one-way ANOVA and post hoc Tukey-Kramer tests. Multivariable linear regression, with T2 as the outcome variable, was used to explore associations with age, gender, Hispanic ethnicity and fCCM1 status. Results: In the younger age stratum, the fCCM1 group had a mean plasma water T2 value comparable to the metabolically healthy group (p=0.6388), but higher than the unhealthy group (p<0.0001). By contrast, in the older stratum, the mean plasma water T2 value for the fCCM1 group was comparable to the metabolically unhealthy group (p=0.7819) and lower than the healthy group (p=0.0005). Multivariable linear regression revealed that age and the interaction between age and fCCM1 status were significant predictors of T2, even after adjusting for gender and Hispanic ethnicity. Conclusion: Plasma water T2 shows potential as a biomarker for assessing the health status of individuals with fCCM1. Further research is needed to validate these preliminary observations and elucidate the association between CCMs and cardiometabolic health.

Molecular genetic features and clinical manifestations in Chinese familial cerebral cavernous malformation: from a novel KRIT1/CCM1 mutation (c.1119dupT) to an overall view.

Cerebral cavernous malformations (CCMs) are common vascular anomaly diseases in the central nervous system associated with seizures, cerebral microbleeds, or asymptomatic mostly. CCMs can be classified as sporadic or familial, with familial cerebral cavernous malformations (fCCMs) being the autosomal dominant manner with incomplete penetrance. Germline mutations of KRIT1, CCM2, and PDCD10 are associated with the pathogenesis of fCCMs. Till now, little is known about the fCCMs mutation spectrum in the Han Chinese population. In this study, we enrolled a large, aggregated family, 11/26 of the family members were diagnosed with CCMs by pathological or neuroradiological examination, with a high percentage (5/9) of focal spinal cord involvement. Genomic DNA sequencing verified a novel duplication mutation (c.1119dupT, p.L374Sfs*9) in exon 9 of the Krev interaction trapped 1 (KRIT1) gene. The mutation causes a frameshift and is predicted to generate a truncated KRIT1/CCM1 protein of 381 amino acids. All our findings confirm that c.1119dupT mutation of KRIT1 is associated with fCCMs, which enriched the CCM genes' mutational spectrum in the Chinese population and will be beneficial for deep insight into the pathogenesis of Chinese fCCMs. Additionally, with a retrospective study, we analyzed the molecular genetic features of Chinese fCCMs, most of the Chinese fCCMs variants are in the KRIT1 gene, and all these variants result in the functional deletion or insufficiency of the C-terminal FERM domain of the KRIT1 protein.

Familial CCM Genes Might Not Be Main Drivers for Pathogenesis of Sporadic CCMs-Genetic Similarity between Cancers and Vascular Malformations.

Cerebral cavernous malformations (CCMs) are abnormally dilated intracranial capillaries that form cerebrovascular lesions with a high risk of hemorrhagic stroke. Recently, several somatic "activating" gain-of-function (GOF) point mutations in PIK3CA (phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit p110α) were discovered as a dominant mutation in the lesions of sporadic forms of cerebral cavernous malformation (sCCM), raising the possibility that CCMs, like other types of vascular malformations, fall in the PIK3CA-related overgrowth spectrum (PROS). However, this possibility has been challenged with different interpretations. In this review, we will continue our efforts to expound the phenomenon of the coexistence of gain-of-function (GOF) point mutations in the PIK3CA gene and loss-of-function (LOF) mutations in CCM genes in the CCM lesions of sCCM and try to delineate the relationship between mutagenic events with CCM lesions in a temporospatial manner. Since GOF PIK3CA point mutations have been well studied in reproductive cancers, especially breast cancer as a driver oncogene, we will perform a comparative meta-analysis for GOF PIK3CA point mutations in an attempt to demonstrate the genetic similarities shared by both cancers and vascular anomalies.

Study of CCM Microvascular Endothelial Phenotype by an In Vitro Tubule Differentiation Model.

Cerebral cavernous malformation (CCM) proteins play critical roles for endothelial cell functions, including cytoskeletal remodeling, cell-cell interactions, cell polarity, tube formation, and angiogenesis. It has been shown that the mutation of even one of the CCM genes involved in CCMs can determine an alteration in the angiogenesis process, but the precise mechanism is yet to be clarified.Here using a model of cerebral microvascular endothelial cells (hBMEC) transiently silenced by CCM1, we tried to mimic the physiological conditions that occur in the presence of CCM1 gene know-down evaluating their ability to form tube structures through an in vitro angiogenesis assay.

Generation of CCM Phenotype by a Human Microvascular Endothelial Model.

Cerebral cavernous malformations (CCMs) is a disorder of endothelial cells predominantly localized in the brain. Although a complete inactivation of each CCM protein has been found in the affected endothelium of diseased patients and a necessary and additional role of microenvironment has been demonstrated to determine in vivo the occurrence of vascular lesions, a microvascular endothelial model based on knockdown of a CCM gene represents today a convenient method to study some of critical signaling events regulating pathogenesis of CCM. For these reasons, in our laboratory we developed a microvascular cerebral endothelial model of Krit1 deficiency performing silencing experiments of CCM1 gene (Krit1) with siRNA procedure.

Microscopy Techniques to Investigate CCM Pathogenesis.

Cellular techniques allow researchers to discover underlying mechanisms of pathogenesis of CCMs in vitro before carrying over into in vivo models; optimization of these techniques facilitates the rapid discovery of CCM-associated gene and protein targets. Here, we describe optimized cell culture applications which are essential for successful molecular techniques and will offer researchers effective methods for plasmid transfections, facilitating mammalian cell expression, subcellular localization, and fluorescence microscopy. RNA interference (RNAi) treatment of cells allows for various in vitro cellular assays as well as confocal microscopy experiments. Together, all these methods allow for an in-depth analysis of the cellular mechanisms underlying CCM pathogenesis to be explored and further dissected.