Effect of Simvastatin on Permeability in Cerebral Cavernous Malformation Type 1 Patients: Results from a Pilot Small Randomized Controlled Clinical Trial

Cerebral cavernous malformations - An overview on genetics, clinical aspects and therapeutic strategies

Cerebral cavernous malformations (CCMs) are abnormally packed blood vessels lined with endothelial cells, that do not exhibit intervening tight junctions, lack muscular and elastic layers and are usually surrounded by hemosiderin and gliosis. CCMs may be sporadic or familial autosomal dominant (FCCMs) caused by loss of function mutations in CCM1 (KRIT1), CCM2 (MGC4607), and CCM3 (PDCD10) genes. In the FCCMs, patients have multiple CCMs, different family members are affected, and developmental venous anomalies are absent. CCMs may be asymptomatic or may manifest with focal neurological deficits with or without associated hemorrhage andseizures. Recent studies identify a digenic "triple-hit" mechanism involving the aquisition of three distinct genetic mutations that culminate in phosphatidylinositol-3-kinase (PIK3CA) gain of function, as the basis for rapidly growing and clinically symptomatic CCMs. The pathophysiology of CCMs involves signaling aberrations in the neurovascular unit, including proliferative dysangiogenesis, blood-brain barrier hyperpermeability, inflammation and immune mediated processes, anticoagulant vascular domain, and gut microbiome-driven mechanisms. Clinical trials are investigating potential therapies, magnetic resonance imaging and plasma biomarkers for hemorrhage and CCMs-related epilepsy, as well as different techniques of neuronavigation and neurosonology to guide surgery in order to minimize post-operatory morbidity and mortality. This review addresses the recent data about the natural history, genetics, neuroimaging and therapeutic approaches for CCMs.

The lipid droplet in cancer: From being a tumor-supporting hallmark to clinical therapy

INTRODUCTION

Abnormal lipid metabolism, one of the hallmarks in cancer, has gradually emerged as a novel target for cancer treatment. As organelles that store and release excess lipids, lipid droplets (LDs) resemble "gears" and facilitate cancer development in the body.

AIM

This review discusses the life cycle of LDs, the relationship between abnormal LDs and cancer hallmarks, and the application of LDs in theragnostic and clinical contexts to provide a contemporary understanding of the role of LDs in cancer.

METHODS

A systematic literature search was conducted in PubMed and SPORTDiscus. Retrieve and summarize clinical trials of drugs that target proteins associated with LD formation using the Clinical Trials website. Create a schematic diagram of lipid droplets in the tumor microenvironment using Adobe Illustrator.

CONCLUSION

As one of the top ten hallmarks of cancer, abnormal lipid metabolism caused by excessive generation of LDs interrelates with other hallmarks. The crosstalk between excessive LDs and intracellular free fatty acids (FFAs) promotes an inflammatory environment that supports tumor growth. Moreover, LDs contribute to cancer metastasis and cell death resistance in vivo. Statins, as HMGCR inhibitors, are promising to be the pioneering commercially available anti-cancer drugs that target LD formation.

Trial Readiness of Cavernous Malformations With Symptomatic Hemorrhage, Part II: Biomarkers and Trial Modeling

BACKGROUND

Quantitative susceptibility mapping (QSM) and dynamic contrast-enhanced quantitative perfusion (DCEQP) magnetic resonance imaging sequences assessing iron deposition and vascular permeability were previously correlated with new hemorrhage in cerebral cavernous malformations. We assessed their prospective changes in a multisite trial-readiness project.

METHODS

Patients with cavernous malformation and symptomatic hemorrhage (SH) in the prior year, without prior or planned lesion resection or irradiation were enrolled. Mean QSM and DCEQP of the SH lesion were acquired at baseline and at 1- and 2-year follow-ups. Sensitivity and specificity of biomarker changes were analyzed in relation to predefined criteria for recurrent SH or asymptomatic change. Sample size calculations for hypothesized therapeutic effects were conducted.

RESULTS

We logged 143 QSM and 130 DCEQP paired annual assessments. Annual QSM change was greater in cases with SH than in cases without SH (P=0.019). Annual QSM increase by ≥6% occurred in 7 of 7 cases (100%) with recurrent SH and in 7 of 10 cases (70%) with asymptomatic change during the same epoch and 3.82× more frequently than clinical events. DCEQP change had lower sensitivity for SH and asymptomatic change than QSM change and greater variance. A trial with the smallest sample size would detect a 30% difference in QSM annual change during 2 years of follow-up in 34 or 42 subjects (1 and 2 tailed, respectively); power, 0.8, α=0.05.

CONCLUSIONS

Assessment of QSM change is feasible and sensitive to recurrent bleeding in cavernous malformations. Evaluation of an intervention on QSM percent change may be used as a time-averaged difference between 2 arms using a repeated measures analysis. DCEQP change is associated with lesser sensitivity and higher variability than QSM. These results are the basis of an application for certification by the US Food and Drug Administration of QSM as a biomarker of drug effect on bleeding in cavernous malformations.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03652181.

mTORC1 Inhibitor Rapamycin Inhibits Growth of Cerebral Cavernous Malformation in Adult Mice

BACKGROUND

Cerebral cavernous malformations (CCMs) are vascular malformations that frequently cause stroke. CCMs arise due to loss of function in one of the genes that encode the CCM complex, a negative regulator of MEKK3-KLF2/4 signaling in vascular endothelial cells. Gain-of-function mutations in PIK3CA (encoding the enzymatic subunit of the PI3K (phosphoinositide 3-kinase) pathway associated with cell growth) synergize with CCM gene loss-of-function to generate rapidly growing lesions.

METHODS

We recently developed a model of CCM formation that closely reproduces key events in human CCM formation through inducible CCM loss-of-function and PIK3CA gain-of-function in mature mice. In the present study, we use this model to test the ability of rapamycin, a clinically approved inhibitor of the PI3K effector mTORC1, to treat rapidly growing CCMs.

RESULTS

We show that both intraperitoneal and oral administration of rapamycin arrests CCM growth, reduces perilesional iron deposition, and improves vascular perfusion within CCMs.

CONCLUSIONS

Our findings further establish this adult CCM model as a valuable preclinical model and support clinical testing of rapamycin to treat rapidly growing human CCMs.

The First Potentially Causal Genetic Variant Documented in a Polish Woman with Multiple Cavernous Malformations of the Brain

Cerebral cavernous malformations (CCMs) are relatively common in the central nervous system. They occur in two forms, sporadic and familial (FCCMs). Three genes are recognized to be associated with FCCM, including CCM1, CCM2, and CCM3, the latter also called PDCD10. In this article, we describe a single-nucleotide variant in the PDCD10 gene in a 23-year-old Polish female with CCM. The NM_007217.4 (PDCD10): c.395+1G>A variant destroys the canonical splice donor site following exon 6. This is the first reported genetically characterized case of CCM (FCCM) in Poland.

Cavernous Angioma Symptomatic Hemorrhage (CASH) Trial Readiness II: Imaging Biomarkers and Trial Modeling

Background

Quantitative susceptibility mapping (QSM) and dynamic contrast enhanced quantitative perfusion (DCEQP) MRI sequences assessing iron deposition and vascular permeability were previously correlated with new hemorrhage in cavernous angiomas. We assessed their prospective changes in cavernous angiomas with symptomatic hemorrhage (CASH) in a multisite trial readiness project ( clinicaltrials.gov NCT03652181 ).

Methods

Patients with CASH in the prior year, without prior or planned lesion resection or irradiation were enrolled. Mean QSM and DCEQP of CASH lesion were acquired at baseline, and at 1- and 2-year follow-ups. Sensitivity and specificity of biomarker changes were analyzed in relation to predefined lesional symptomatic hemorrhage (SH) or asymptomatic change (AC). Sample size calculations for hypothesized therapeutic effects were conducted.

Results

We logged 143 QSM and 130 DCEQP paired annual assessments. Annual QSM change was greater in cases with SH than in cases without SH (p= 0.019). Annual QSM increase by ≥ 6% occurred in 7 of 7 cases (100%) with recurrent SH and in 7 of 10 cases (70%) with AC during the same epoch, and 3.82 times more frequently than clinical events. DCEQP change had lower sensitivity for SH and AC than QSM change, and greater variance. A trial with smallest sample size would detect a 30% difference in QSM annual change in 34 or 42 subjects (one and two-tailed, respectively), power 0.8, alpha 0.05.

Conclusions

Assessment of QSM change is feasible and sensitive to recurrent bleeding in CASH. Evaluation of an intervention on QSM percent change may be used as a time-averaged difference between 2 arms using a repeated measures analysis. DCEQP change is associated with lesser sensitivity and higher variability than QSM. These results are the basis of an application for certification by the U.S. F.D.A. of QSM as a biomarker of drug effect in CASH.

Kinases in cerebral cavernous malformations: Pathogenesis and therapeutic targets

Cerebral cavernous malformations (CCMs) are low-flow, hemorrhagic vascular lesions of the central nervous system of genetic origin, which can cause stroke-like symptoms and seizures. From the identification of CCM1, CCM2 and CCM3 as genes related to disease progression, molecular and cellular mechanisms for CCM pathogenesis have been established and the search for potential drugs to target CCM has begun. Broadly speaking, kinases are the major group signaling in CCM pathogenesis. These include the MEKK3/MEK5/ERK5 cascade, Rho/Rock signaling, CCM3/GCKIII signaling, PI3K/mTOR signaling, and others. Since the discovery of Rho/Rock in CCM pathogenesis, inhibitors for Rho signaling and subsequently other components in CCM signaling were discovered and applied in preclinical and clinical trials to ameliorate CCM progression. This review discusses the general aspects of CCM disease, kinase-mediated signaling in CCM pathogenesis and the current state of potential treatment options for CCM. It is suggested that kinase target drug development in the context of CCM might facilitate and meet the unmet requirement - a non-surgical option for CCM disease.

Magnetic susceptibility as a 1-year predictor of outcome in familial cerebral cavernous malformations: a pilot study

OBJECTIVES

To test whether quantitative susceptibility mapping (QSM) of cerebral cavernous malformations (CCMs) assessed at baseline may predict the presence or absence of haemorrhagic signs at 1-year follow-up.

METHODS

Familial CCM patients were enrolled in the longitudinal multicentre study Treat-CCM. The 3-T MRI scan allowed performing a semi-automatic segmentation of CCMs and computing the maximum susceptibility in each segmented CCM (QSMmax) at baseline. CCMs were classified as haemorrhagic and non-haemorrhagic at baseline and then subclassified according to the 1-year (t1) evolution. Between-group differences were tested, and the diagnostic accuracy of QSMmax in predicting the presence or absence of haemorrhagic signs in CCMs was calculated with ROC analyses.

RESULTS

Thirty-three patients were included in the analysis, and a total of 1126 CCMs were segmented. QSMmax was higher in haemorrhagic CCMs than in non-haemorrhagic CCMs (p < 0.001). In haemorrhagic CCMs at baseline, the accuracy of QSMmax in differentiating CCMs that were still haemorrhagic from CCMs that recovered from haemorrhage at t1 calculated as area under the curve (AUC) was 0.78 with sensitivity 62.69%, specificity 82.35%, positive predictive value (PPV) 93.3% and negative predictive value (NPV) 35.9% (QSMmax cut-off ≥ 1462.95 ppb). In non-haemorrhagic CCMs at baseline, AUC was 0.91 in differentiating CCMs that bled at t1 from stable CCMs with sensitivity 100%, specificity 81.9%, PPV 5.1%, and NPV 100% (QSMmax cut-off ≥ 776.29 ppb).

CONCLUSIONS

The QSMmax in CCMs at baseline showed high accuracy in predicting the presence or absence of haemorrhagic signs at 1-year follow-up. Further effort is required to test the role of QSM in follow-up assessment and therapeutic trials in multicentre CCM studies.

KEY POINTS

• QSM in semi-automatically segmented CCM was feasible. • The maximum magnetic susceptibility in a single CCM at baseline may predict the presence or absence of haemorrhagic signs at 1-year follow-up. • Multicentric studies are needed to enforce the role of QSM in predicting the CCMs' haemorrhagic evolution in patients affected by familial and sporadic forms.

Safety and efficacy of propranolol for treatment of familial cerebral cavernous malformations (Treat_CCM): a randomised, open-label, blinded-endpoint, phase 2 pilot trial

BACKGROUND

Observations in people with cerebral cavernous malformations, and in preclinical models of this disorder, suggest that the β-blocker propranolol might reduce the risk of intracerebral haemorrhage. We aimed to evaluate the safety and efficacy of prolonged treatment with propranolol to reduce the incidence of symptomatic intracerebral haemorrhage or focal neurological deficit in people with familial cerebral cavernous malformations.

METHODS

We conducted a randomised, open-label, blinded-endpoint, phase 2 pilot trial (Treat_CCM) at six national reference centres for rare diseases in Italy. People aged 18 years or older with symptomatic familial cerebral cavernous malformation were eligible for enrolment. Participants were randomly assigned (2:1) to receive either oral propranolol (20-320 mg daily) plus standard care (intervention group), or standard care alone (control group), for 24 months. Participants, caregivers, and investigators were aware of treatment group assignment. Participants had clinical assessments and 3 T brain MRI at baseline and at 12 and 24 months. The primary outcome was new occurrence of symptomatic intracerebral haemorrhage or focal neurological deficit attributable to cerebral cavernous malformation over 24 months. Outcome assessors were masked to treatment group assignment. The primary analysis was done in the intention-to-treat population. Because of the pilot study design, we chose a one-sided 80% CI, which could either exclude a clinically meaningful effect or show a signal of efficacy. This trial is registered with EudraCT, 2017-003595-30, and ClinicalTrials.gov, NCT03589014, and is closed to recruitment.

FINDINGS

Between April 11, 2018, and Dec 5, 2019, 95 people were assessed for eligibility and 83 were enrolled, of whom 57 were assigned to the propranolol plus standard care group and 26 to the standard care alone group. The mean age of participants was 46 years (SD 15); 48 (58%) were female and 35 (42%) were male. The incidence of symptomatic intracerebral haemorrhage or focal neurological deficit was 1·7 (95% CI 1·4-2·0) cases per 100 person-years (two [4%] of 57 participants) in the propranolol plus standard care group and 3·9 (3·1-4·7) per 100 person-years (two [8%] of 26) in the standard care alone group (univariable hazard ratio [HR] 0·43, 80% CI 0·18-0·98). The univariable HR showed a signal of efficacy, according to predefined criteria. The incidence of hospitalisation did not differ between groups (8·2 cases [95% CI 7·5-8·9] per 100 person-years in the propranolol plus standard care group vs 8·2 [95% CI 7·1-9·3] per 100 person-years in the standard care alone group). One participant in the standard care alone group died of sepsis. Three participants in the propranolol plus standard care group discontinued propranolol due to side-effects (two reported hypotension and one reported weakness).

INTERPRETATION

Propranolol was safe and well tolerated in this population. Propranolol might be beneficial for reducing the incidence of clinical events in people with symptomatic familial cerebral cavernous malformations, although this trial was not designed to be adequately powered to investigate efficacy. A definitive phase 3 trial of propranolol in people with symptomatic familial cerebral cavernous malformations is justified.

FUNDING

Italian Medicines Agency, Associazione Italiana per la Ricerca sul Cancro, Swedish Science Council, Knut and Alice Wallenberg Foundation, CARIPLO Foundation, Italian Ministry of Health.

Transcriptome Analysis Reveals Altered Expression of Genes Involved in Hypoxia, Inflammation and Immune Regulation in Pdcd10-Depleted Mouse Endothelial Cells

Cerebral cavernous malformations (CCM) are capillary malformations affecting the central nervous system and commonly present with headaches, epilepsy and stroke. Treatment of CCM is symptomatic, and its prevention is limited. CCM are often sporadic but sometimes may be multifocal and/or affect multiple family members. Heterozygous pathogenic variants in PDCD10 cause the rarest and apparently most severe genetic variant of familial CCM. We carried out an RNA-Seq and a Q-PCR validation analysis in Pdcd10-silenced and wild-type mouse endothelial cells in order to better elucidate CCM molecular pathogenesis. Ninety-four differentially expressed genes presented an FDR-corrected p-value < 0.05. A functionally clustered dendrogram showed that differentially expressed genes cluster in cell proliferation, oxidative stress, vascular processes and immune response gene-ontology functions. Among differentially expressed genes, the major cluster fell in signaling related to inflammation and pathogen recognition, including HIF1α and Nos2 signaling and immune regulation. Validation analysis performed on wild-type, Pdcd10-null and Pdcd10-null reconstituted cell lines was consistent with RNA-Seq data. This work confirmed previous mouse transcriptomic data in endothelial cells, which are recognized as a critical tissue for CCM formation and expands the potential molecular signatures of PDCD10-related familial CCM to alterations in inflammation and pathogen recognition pathways.

Tailored Treatment Options for Cerebral Cavernous Malformations

The diagnosis and treatment of cerebral cavernous malformations (CCMs), or cavernomas, continues to evolve as more data and treatment modalities become available. Intervention is necessary when a lesion causes symptomatic neurologic deficits, seizures, or has high risk of continued hemorrhage. Future medical treatment directions may specifically target the pathogenesis of these lesions. This review highlights the importance of individualized treatment plans based on specific CCM characteristics.

Association Between Beta-Blocker or Statin Drug Use and the Risk of Hemorrhage From Cerebral Cavernous Malformations

BACKGROUND

We aimed to determine the association between beta-blocker or statin drug use and the future risk of symptomatic intracranial hemorrhage or persistent/progressive focal neurological deficit from cerebral cavernous malformations (CCM).

METHODS

The population-based Scottish Audit of Intracranial Vascular Malformations prospectively identified adults resident in Scotland first diagnosed with CCM during 1999 to 2003 or 2006 to 2010. We compared the association between beta-blocker or statin drug use after first presentation and the occurrence of new intracranial hemorrhage or persistent/progressive focal neurological deficit due to CCM for up to 15 years of prospective follow-up. We confirmed proportional hazards and used survival analysis with multivariable adjustment for age, intracranial hemorrhage at CCM presentation, and brain stem CCM location.

RESULTS

Sixty-three (21%) of 300 adults used beta-blockers (27/63 [43%] used propranolol), and 73 (24%) used statin drugs over 3634 person-years of follow-up. At baseline, the only statistically significant imbalances in prespecified potential confounders were age by statin use and intracranial hemorrhage at presentation by beta-blocker use. Beta-blocker use was associated with a lower risk of new intracranial hemorrhage or persistent/progressive focal neurological deficit (adjusted hazard ratio, 0.09 [95% CI, 0.01-0.66]; P=0.018). Statin use was associated with a nonsignificant lower risk of intracranial hemorrhage or persistent/progressive focal neurological deficit (adjusted hazard ratio, 0.37 [95% CI, 0.01-1.07]; P=0.067).

CONCLUSIONS

Beta-blocker, but not statin, use was associated with a lower risk of intracranial hemorrhage or persistent/progressive focal neurological deficit in patients with CCM.

Fetal Familial Cerebral Cavernous Malformation With a Novel Heterozygous KRIT1 Variation

BACKGROUND AND OBJECTIVES

To identify fetal familial cerebral cavernous malformation (CCM) and a novel variation.

METHODS

A 37-year-old pregnant woman (G4P0) presented with right-handed numbness since 2 weeks at 31 weeks of gestation. Evaluation with brain MRI revealed multiple CCMs. As a result, fetal MRI, fetal whole exome sequencing, and maternal Sanger sequencing were performed.

RESULTS

The mother's brain MRI demonstrated numerous CCMs involving the brain stem, cerebral hemispheres, and cerebellum. Fetal MRI showed a CCM located in the left frontal lobe in susceptibility-weighted imaging (SWI). The neuroimaging characteristics of the mother and the fetus suggested that their CCMs may be familial. Genetic analysis revealed a novel variation in KRIT1 (c.1A>G, p.0?), also called CCM1, in the mother and the baby. The mother delivered a daughter at 32 weeks of gestation with an Apgar score of 10 by cesarean section.

DISCUSSION

This variation of the initial codon in the KRIT1 gene leads to a phenotype with an early-onset. To our knowledge, this is the first-ever reported case of fetal familial CCM and this novel variation. Brain MRI has excellent sensitivity and specificity, providing the best option for detecting CCMs, even in utero, primarily when SWI is used.

From Genes and Mechanisms to Molecular-Targeted Therapies: The Long Climb to the Cure of Cerebral Cavernous Malformation (CCM) Disease

Cerebral cavernous malformation (CCM) is a rare cerebrovascular disorder of genetic origin consisting of closely clustered, abnormally dilated and leaky capillaries (CCM lesions), which occur predominantly in the central nervous system. CCM lesions can be single or multiple and may result in severe clinical symptoms, including focal neurological deficits, seizures, and intracerebral hemorrhage. Early human genetic studies demonstrated that CCM disease is linked to three chromosomal loci and can be inherited as autosomal dominant condition with incomplete penetrance and highly variable expressivity, eventually leading to the identification of three disease genes, CCM1/KRIT1, CCM2, and CCM3/PDCD10, which encode for structurally unrelated intracellular proteins that lack catalytic domains. Biochemical, molecular, and cellular studies then showed that these proteins are involved in endothelial cell-cell junction and blood-brain barrier stability maintenance through the regulation of major cellular structures and mechanisms, including endothelial cell-cell and cell-matrix adhesion, actin cytoskeleton dynamics, autophagy, and endothelial-to-mesenchymal transition, suggesting that they act as pleiotropic regulators of cellular homeostasis, and opening novel therapeutic perspectives. Indeed, accumulated evidence in cellular and animal models has eventually revealed that the emerged pleiotropic functions of CCM proteins are mainly due to their ability to modulate redox-sensitive pathways and mechanisms involved in adaptive responses to oxidative stress and inflammation, thus contributing to the preservation of cellular homeostasis and stress defenses.In this introductory review, we present a general overview of 20 years of amazing progress in the identification of genetic culprits and molecular mechanisms underlying CCM disease pathogenesis, and the development of targeted therapeutic strategies.

Improving clinical interpretation of five KRIT1 and PDCD10 intronic variants

Cerebral cavernous malformation (CCM) is a vascular malformation of the central nervous system which may occur sporadically or segregate within families due to heterozygous variants in KRIT1/CCM1, MGC4607/CCM2 or PDCD10/CCM3. Intronic variants are not uncommon in familial CCM, but their clinical interpretation is often hampered by insufficient data supporting in silico predictions. Here, the mRNA analysis for two intronic unpublished variants (KRIT1 c.1147-7 T > G and PDCD10 c.395 + 2 T > G) and three previously published variants in KRIT1 but without data supporting their effects was carried out. This study demonstrated that all variants can induce a frameshift with the lack of residues located in the C-terminal regions and involved in protein-protein complex formation, which is essential for vascular homeostasis. These results support the introduction of mRNA analysis in the diagnostic pathway of familial CCM and expand the knowledge of abnormal splicing patterning in this disorder.

Treatment with Atorvastatin During Vascular Remodeling Promotes Pericyte-Mediated Blood-Brain Barrier Maturation Following Ischemic Stroke

We previously showed that newly formed vessels in ischemic rat brain have high blood-brain barrier (BBB) permeability at 3 weeks after stroke due to a lack of major endothelial tight junction proteins (TJPs), which may exacerbate edema in stroke patients. Atorvastatin was suggested a dose-dependent pro-angiogenic effect and ameliorating BBB permeability beyond its cholesterol-lowering effects. This study examined our hypothesis that, during vascular remodeling after stroke, treatment with atorvastatin could facilitate BBB maturation in remodeling vasculature in ischemic brain. Adult spontaneously hypertensive rats underwent middle cerebral artery occlusion with reperfusion (MCAO/RP). Atorvastatin, at dose of 3 mg/kg, was delivered daily starting at 14 days after MCAO/RP onset for 7 days. The rats were studied at multiple time points up to 8 weeks with multimodal-MRI, behavior tests, immunohistochemistry, and biochemistry. The delayed treatment of atorvastatin significantly reduced infarct size and BBB permeability, restored cerebral blood flow, and improved the neurological outcome at 8 weeks after MCAO/RP. Postmortem studies showed that atorvastatin promoted angiogenesis and stabilized the newly formed vessels in peri-infarct areas. Importantly, atorvastatin facilitated maturation of BBB properties in the new vessels by promoting endothelial tight junction (TJ) formation. Further in vivo and in vitro studies demonstrated that proliferating peri-vascular pericytes expressing neural-glial antigen 2 (NG2) mediated the role of atorvastatin on BBB maturation through regulating endothelial TJ strand formations. Our results suggested a therapeutic potential of atorvastatin in facilitating a full BBB integrity and functional stroke recovery, and an essential role for pericyte-mediated endothelial TJ formation in remodeling vasculature.