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[Image: see text] Cerebral cavernous malformations (CCMs) are hemorrhagic neurovascular lesions that affect more than 1 million people in the United States. Rapamycin inhibits CCM development and bleeding in murine models. The appropriate dosage to modify disease phenotype remains unknown. Current approved indications by the U.S. Food and Drug Administration and clinicaltrials.gov were queried for rapamycin human dosing for various indications. A systematic literature search was conducted on PubMed to investigate mouse dosimetry of rapamycin. In humans, low daily doses of

Introduction: Cavernous Angiomas (CAs) are vascular malformations characterized by clusters of blood-filled capillary spaces lined by “leaky” endothelium. While mutations in endothelial cells have long been recognized as necessary for lesion genesis, there is evidence of inflammation, response to hypoxia, and non-endothelial autonomous cell effects driving pathogenesis. Disrupted gene expression in the CA neurovascular unit (NVU) has been described but the contribution of each cell type has not been previously investigated. Methods: Six CA and four control brain samples were collected and frozen during surgical resection. The endothelial cells, pericytes, and neuroglia (astrocytes and neurons) were sorted, and the RNA was extracted and sequenced. The differentially expressed genes (DEGs) were identified ( p p p p Results: In endothelial cells, 362 DEGs were identified contributing to 54 enriched IPA pathways. In addition, 484 DEGs were found in pericytes and 50 IPA pathways were identified. The common functions between these two cell types were related to angiogenesis, extracellular matrix organization, cell adhesion, and platelet activation, while the function related to response to hypoxia was only shown in pericytes. Finally, 242 DEGs and 52 IPA pathways were identified in neuroglia cells. The associated pathway functions were related to inflammatory response and cell adhesion. The IPA results were further confirmed by the GO term and KEGG pathway analyses. Conclusion: We confirm that disrupted genes related to angiogenesis, blood-brain barrier integrity, cell adhesion and platelet activation in the CA lesion involve endothelial cells and pericytes primarily. Pericytes are particularly associated with disrupted genes related to response to hypoxia, while neuroglia is associated with greater gene disruptions related to inflammation. These results motivate novel mechanistic hypotheses regarding non-endothelial cell contributions to lesion pathobiology.

Background: Cerebral microbleeds (CMBs) are manifestations of age-related microangiopathies associated with an increased risk of hemorrhagic stroke and cognitive decline. The pathophysiology of this age-related breakdown of the neurovascular unit remain unclear. Understanding CMB cellular architecture is needed for gene, pathway, and mechanism analyses, to pave the way for biomarker and therapeutic development. Herein, we aim to systematically describe histopathological changes in the CMB lesional milieu. Methods: Eight CMBs, along with contralateral non-lesional tissue, were identified by gross appearance at autopsy by a neuropathologist. Samples were first stained with H&E, then Prussian blue for non-heme iron, to localize the lesion. This was followed by multiplex fluorescence staining of β-amyloid and individual cell types including astrocytes (GFAP + ), macrophages (CD163 + /Iba1 + ), microglia (CD163 - /Iba1 + ), B-cells (CD20 + ), T-cells (CD3 + ), and endothelium (CD31 + ). The cell types within the lesional milieu, defined as 200μm from the periphery of the CMB, were quantified using QuPath. Astrocyte and microglia morphology were assessed via fluorescence imaging. Results: One CMB contained dilated capillaries, 2 contained lipohyalinized arterioles, and 4 contained dystrophic arterioles due to amyloid angiopathy. Astrocytes and macrophages showed higher normalized cell counts in all CMB tissues compared with controls ( p and p , respectively). Astrocytes in 7 of 8 CMB milieux showed reactive morphological changes, including larger cell bodies with peripheral nuclei. Microglia had higher normalized cell counts in 4 CMB tissues, with senescence-associated amoeboid, as well as ramified, reactive morphologies. The lesional milieu also showed higher counts of B-cells in 7 CMB tissues and T-cells in 3 CMB tissues when compared with controls. Conclusions: We provide the first description of the cellular architecture of the CMB and the associated lesional milieu. Despite heterogeneity of disrupted vasculature, there are common features of glial reactive changes and inflammation in CMBs. These results offer a basis for additional study of the CMB transcriptome and individual roles of respective cell types in CMB pathology.

Background: Cerebral cavernous malformation is a common lesion affecting more than a million Americans, with potential severe sequelae. It is unclear how socioeconomic status (SES) and race influence access to specialized care, and the enrollment and adherence in clinical trials aimed at novel therapies for CCM. Methods: We analyzed a cohort of patients harboring CCM lesions screened for IRB approved research studies between 01/2010 -12/2021 at an accredited center of excellence for CCM, leading NIH funded clinical studies. Demographics, lesion location, history of hemorrhage, insurance type and area of deprivation index (ADI) were collected. Insurance type was categorized as commercial, Medicare/Medicaid, or out-of-pocket. The ADI ranking score was analyzed per decile with 1 (least disadvantaged) through 10 (most disadvantaged). Primary outcomes were clinical follow-up within a year from the 1 st visit for all CCM patients (excluding pregnancy), and enrollment/adherence among eligible subjects for first in disease NIH funded clinical trial [clinicaltrials.gov NCT02603328]. Statistical analysis (Chi 2 test; t-test) was applied to determine whether these differed in ADI groups, races or insurance type categories. Results: Despite the institution’s location in an area with majority African American population and lower SES, only 11.5% of subjects were African American, and the majority (52.8%) had a high SES (ADI 1-3). As expected, patients who had a symptomatic bleed were more likely to follow-up (p=0.01), and those with brainstem lesion were more likely to enroll and adhere in clinical trial (p=0.02). Correcting for these confounders, there was no difference in rates of clinical follow-up or enrollment/adherence among different ADI groups, races or insurance coverage. Conclusion: Access of disadvantaged patients and races to a center of excellence care and research remains limited despite geographic proximity to their community. Contrary to common belief, patients with poor SES and African Americans are as likely to follow-up and enroll/adhere in clinical trials, if provided access to specialized care. Mitigation efforts should target systemic causes of low access to specialized care among poor and African American patients.

Introduction: Age-related cerebral microbleeds (CMBs) are vascular changes associated with an increased risk of intracerebral hemorrhage (ICH) and neurocognitive decline. CMBs share a strikingly similar appearance on MRI to cerebral cavernous malformations (CCMs), which are leaky capillary lesions predisposing patients to brain bleeding. Our team had previously shown increased vascular permeability in CCM and in the brain of older subjects, with common circulating biomarkers of angiogenesis and inflammation. We examine here whether vascular permeability is greater in the aging brain harboring CBMs. Methods: Dynamic Contrast-Enhanced Quantitative Perfusion (DCEQP) MRI, which assesses vascular permeability, was acquired for 7 patients with CMBs (>50 years old), 10 old (>50 years old), and 9 young (18-30 years old) healthy subjects without CMBs. Cases with active brain disease, stroke or seizure in the prior year were excluded. DCEQP scans were co-registered onto their respective T1-weighted images, normalized using the Desikan-Killiany atlas, and finally segmented into white and gray matter within frontal, temporal, parietal, and occipital lobes. The mean permeability was calculated within each segmented area, and values were compared between the 3 groups of interest. Results: Increased permeability was observed within the frontal white and gray matter as well as the parietal gray matter of patients with CMBs compared to age matched old healthy controls (both: p Conclusion: We confirm that the human brain exhibits increased vascular permeability with aging, and this is more pronounced in brains harboring CMBs. This may provide insight into the pathogenesis of CMBs, potentially reflecting end stage age-related failure of the blood brain barrier, associated with frank bleeding. These results offer a starting point for the development of diagnostic and prognostic imaging biomarkers of CMBs, which can help stratify patients at higher risk of future ICH and cognitive decline.

Background: Increases in mean lesional iron content (≥6%) measurement by QSM and vascular permeability (≥40%) assessed by DCEQP MRI have been associated with new bleeding, and are used as monitoring biomarkers in NINDS funded 1st clinical trial of pharmacotherapy (clinicaltrials.gov NCT02603328) in cavernous angiomas with symptomatic hemorrhage (CASH). Plasma protein levels previously associated with CASH in diagnostic and prognostic contexts have never been compared to lesional QSM and DCEQP in the same subjects. Methods: Plasma samples and MRI sequences were simultaneously acquired during 1 year-epochs of prospective follow-up of CASH patients. Plasma levels of 16 proteins were assayed by ELISA and correlated with lesional QSM and DCEQP during the same epochs. Univariate correlations were followed by multivariate analyses combining multiple protein levels to minimize Akaike Information Criterion (AIC) and increase R 2 . Accuracy (AUC on receiver operating curves) and sum of squared error (SSE) are reported for associations achieving statistical significance with FDR correction. Results: None of the proteins individually correlated with QSM/DCEQP (continuous or categorical). Relative change of angiopoietin2, and absolute change of the combination (endoglin+IL1B+IL16) had the highest accuracy (AUC 78.7%, SD 0.062 and 98.4%, SD 0.013 respectively) for lesional QSM increase ≥6%. Relative change of endoglin+IL1B, and absolute change of angiopoetin2+endoglin+thromobomodulin+VEGF, had the highest accuracy (AUC 64.6%, SD 0.057 and 93.2%, SD 0.040 respectively) for lesional DCEQP increase ≥40%. Relative change in angiopoetin1 had the lowest SSE (8.87) with QSM change as a continuous variable, and relative change in lipopolysaccharide binding protein had the lowest SSE (469.06) with DCEQP change as continuous variable. Conclusion: Circulating proteins reflect changes in lesional iron content and permeability in CASH during prospective follow-up. Results are a proof of concept that blood tests could replace more complex and costly imaging biomarkers in the monitoring of hemorrhage in cavernous angiomas. Additional mechanistic plasma molecules (miRNAs and metabolites) may further enhance the accuracy of these monitoring biomarkers.

Cerebral cavernous malformations are acquired vascular anomalies that constitute a common cause of central nervous system hemorrhage and stroke. The past 2 decades have seen a remarkable increase in our understanding of the pathogenesis of this vascular disease. This new knowledge spans genetic causes of sporadic and familial forms of the disease, molecular signaling changes in vascular endothelial cells that underlie the disease, unexpectedly strong environmental effects on disease pathogenesis, and drivers of disease end points such as hemorrhage. These novel insights are the integrated product of human clinical studies, human genetic studies, studies in mouse and zebrafish genetic models, and basic molecular and cellular studies. This review addresses the genetic and molecular underpinnings of cerebral cavernous malformation disease, the mechanisms that lead to lesion hemorrhage, and emerging biomarkers and therapies for clinical treatment of cerebral cavernous malformation disease. It may also serve as an example for how focused basic and clinical investigation and emerging technologies can rapidly unravel a complex disease mechanism.

Patients with familial cerebral cavernous malformation (CCM) inherit germline loss of function mutations and are susceptible to progressive development of brain lesions and neurological sequelae during their lifetime. To date, no homologous circulating molecules have been identified that can reflect the presence of germ line pathogenetic CCM mutations, either in animal models or patients. We hypothesize that homologous differentially expressed (DE) plasma miRNAs can reflect the CCM germline mutation in preclinical murine models and patients. Herein, homologous DE plasma miRNAs with mechanistic putative gene targets within the transcriptome of preclinical and human CCM lesions were identified. Several of these gene targets were additionally found to be associated with CCM-enriched pathways identified using the Kyoto Encyclopedia of Genes and Genomes. DE miRNAs were also identified in familial-CCM patients who developed new brain lesions within the year following blood sample collection. The miRNome results were then validated in an independent cohort of human subjects with real-time-qPCR quantification, a technique facilitating plasma assays. Finally, a Bayesian-informed machine learning approach showed that a combination of plasma levels of miRNAs and circulating proteins improves the association with familial-CCM disease in human subjects to 95% accuracy. These findings act as an important proof of concept for the future development of translatable circulating biomarkers to be tested in preclinical studies and human trials aimed at monitoring and restoring gene function in CCM and other diseases.

Intracerebral hemorrhage (ICH) is a devastating form of stroke with high morbidity and mortality. This review article focuses on the epidemiology, cause, mechanisms of injury, current treatment strategies, and future research directions of ICH. Incidence of hemorrhagic stroke has increased worldwide over the past 40 years, with shifts in the cause over time as hypertension management has improved and anticoagulant use has increased. Preclinical and clinical trials have elucidated the underlying ICH cause and mechanisms of injury from ICH including the complex interaction between edema, inflammation, iron-induced injury, and oxidative stress. Several trials have investigated optimal medical and surgical management of ICH without clear improvement in survival and functional outcomes. Ongoing research into novel approaches for ICH management provide hope for reducing the devastating effect of this disease in the future. Areas of promise in ICH therapy include prognostic biomarkers and primary prevention based on disease pathobiology, ultra-early hemostatic therapy, minimally invasive surgery, and perihematomal protection against inflammatory brain injury.

Aldehyde dehydrogenases are versatile enzymes that serve a range of biochemical functions. Although traditionally considered metabolic housekeeping enzymes because of their ability to detoxify reactive aldehydes, like those generated from lipid peroxidation damage, the contributions of these enzymes to other biological processes are widespread. For example, the plant pathogen Pseudomonas syringae strain PtoDC3000 uses an indole-3-acetaldehyde dehydrogenase to synthesize the phytohormone indole-3-acetic acid to elude host responses. Here we investigate the biochemical function of AldC from PtoDC3000. Analysis of the substrate profile of AldC suggests that this enzyme functions as a long-chain aliphatic aldehyde dehydrogenase. The 2.5 Å resolution X-ray crystal of the AldC C291A mutant in a dead-end complex with octanal and NAD(+) reveals an apolar binding site primed for aliphatic aldehyde substrate recognition. Functional characterization of site-directed mutants targeting the substrate- and NAD(H)-binding sites identifies key residues in the active site for ligand interactions, including those in the “aromatic box” that define the aldehyde-binding site. Overall, this study provides molecular insight for understanding the evolution of the prokaryotic aldehyde dehydrogenase superfamily and their diversity of function.

Introduction: Cavernous angiomas (CAs) are common neurovascular lesions predisposing patients to seizures and hemorrhagic stroke. Recent evidence shows non-endothelial cell autonomous effects contribute to CA pathogenesis within the dysfunctional neurovascular units (NVUs), consisting of endothelial cells, pericytes, astrocytes, and microglia. Herein, we developed a single-cell isolation protocol to study the transcriptome of each of these cell populations. Method: CAs and control brain tissue were frozen in optimal cutting temperature compound immediately after surgical resection. Tissue was enzymatically digested with Collagenase Type IV and DNase I. The cell suspension was then filtered, washed, and pelleted. Cell debris and myelin were removed using 25% Percoll. A multispectral LED light was used for 30 minutes to reduce background autofluorescence. Cells were stained with a CD31, CD45, CD13, P2RY12, CD49f, GLAST, CD24 and CD90 antibody cocktail. Size, granularity, and antibody-specific gating were set to sort each cell population using the BD FACSymphony S6 Cell Sorter. After isolation, RNA was extracted for each cell population, and the quality was assessed. Cell-specific genes including VWF (endothelial cells), ACTA2 (pericytes ), AQP4 (astrocytes ) and IBA-1 (microglia ), as well as GAPDH were assessed with real-time qPCR (rt-qPCR) for validation. Results: Endothelial cells (CD31 + , CD13 - , CD45 - , CD49f - , GLAST - ), pericytes (CD13 + , CD31 - , CD45 - , CD49f - , GLAST - ), astrocytes (CD49f + , GLAST + ) and microglia (P2RY12 + , CD45 + , CD31 - , CD13 - , CD49f - , GLAST - ) were individually isolated from both 5 CA lesions and 5 control brain tissue using FACS sorting. RNA quantity ranged from 31 to 83 pg/μl, with RNA Integrity Number ranging from 1 to 8.7. Each cell population within the CA lesion was validated by showing differential expression of cell-specific genes. Conclusion: We have shown, for the first-time, feasibility of individual cell type isolation from frozen, surgically excised CA lesions. The RNA quantity and quality of each cell population was suitable for the establishment of cell-specific transcriptome libraries. These will help clarify individual cell type contributions to CA pathogenesis.

Introduction: Cavernous Angioma (CA) is a hemorrhagic neurovascular disease characterized by either a familial form with autosomal dominant germline mutations in one of three CCM genes or a sporadic form with somatic mutations of the same genes. Circulating proteins have been previously investigated as possible diagnostic and prognostic biomarkers of disease activity, with up to 86% and 88% sensitivity and specificity, respectively. We hypothesize that differentially expressed (DE) plasma microRNAs and metabolites in CA patients can be integrated with plasma proteins to increase the sensitivity and specificity of circulating CA biomarkers. Methods: Mechanistically relevant homologous DE miRNAs were identified between familial CA patients and preclinical murine models and validated in an independent cohort of patients using real time qPCR. In conjunction, DE metabolites were determined in CA patients using liquid-chromatography mass spectrometry. The interactions of these metabolites with the previously established CA transcriptome, proteome, and microbiome were queried to assess for mechanistic relevance. Optimal diagnostic models of proteins, DE miRNAs, and DE metabolites alone were next established. Plasma metabolites and miRNAs were then separately integrated with protein, using a machine learning-implemented, Bayesian approach to develop diagnostic CA biomarkers. Results: The optimal diagnostic biomarker model with only DE miRNAs performed at up to 68%, while proteins and metabolites achieved up to 68%, and 82% accuracy respectively. The optimal combination for proteins with miRNAs improved the diagnostic association of familial-CA disease to up to 94.7% sensitivity and 100% specificity. Integrating metabolites and proteins improved the diagnosis of CA disease and its clinical manifestations to 100% sensitivity and 100% specificity. Conclusion: Combining plasma proteins with miRNAs or metabolites can improve diagnostic accuracy of CA disease and its disease characteristics above any single molecular modality alone. Future studies should incorporate proteins, miRNAs, and metabolites to further increase diagnostic accuracy, and validate these in a larger cohort with control for demographic and disease features.

Introduction: Hemorrhagic microangiopathies (HMAs) are age-related cerebral microbleeds associated with an increased risk of cognitive decline and intracerebral hemorrhage (ICH). HMAs share a strikingly similar appearance on MRI to cerebral cavernous malformations (CCMs), which are clusters of leaky capillaries predisposing patients to brain bleeding. We hypothesize that HMAs and CCMs share common dysregulated genes and pathways reflecting hemorrhagic failure of the neurovascular unit. Thus, biomarkers developed in CCM may be applicable to HMA. Methods: Extracted mRNA from 5 HMA lesions collected at autopsy along with 3 non-lesional brain sections from the same patients was sequenced, and differentially expressed genes (DEGs) were identified. Enrichment analyses were performed using the Reactome database. Pathways related to postulated mechanisms of HMA were identified, as well as those overlapping pathways with a previously published CCM transcriptome. Dynamic Contrast-Enhanced Quantitative Perfusion (DCEQP) and Quantitative Susceptibility Mapping (QSM) MRIs were performed on 11 HMA patients, 12 age-matched, and 22 young healthy subjects assessing vascular permeability and iron content, as previously done in CCM. Mean permeability and QSM values were calculated for white and gray matter in the frontal, temporal, parietal, and occipital lobes. Results: Differential analyses of the HMA transcriptome identified 376 DEGs ( p p Conclusion: Transcriptomic commonalities suggest that similar pipelines for plasma and imaging biomarkers developed in CCM research may be adapted for risk assessment and monitoring of HMA. These will help improve the understanding of HMA pathogenesis and assist in patient management, offering a large public health impact.

BACKGROUND Cerebral cavernous angioma (CA) is a capillary vasculopathy affecting more than a million Americans with a small fraction of cases demonstrating lesional bleed or growth with major clinical sequelae. Perfusion and permeability are fundamental features of CA pathophysiology, but their role as prognostic biomarkers is unclear. PURPOSE To investigate whether perfusion or permeability lesional descriptors derived from dynamic contrast-enhanced quantitative perfusion (DCEQP) magnetic resonance imaging (MRI) can predict subsequent lesional bleed/growth in the year following imaging. STUDY TYPE Single-site case-controlled study. SUBJECTS Two hundred and five consecutively enrolled patients (63.4% female). FIELD STRENGTH/SEQUENCE Three-Tesla/T1 -mapping with contrast-enhanced dynamic two-dimensional (2D) spoiled gradient recalled acquisition (SPGR) sequences. ASSESSMENT Prognostic associations with bleed/growth (present or absent) in the following year were assessed in 745 CA lesions evaluated by DCEQP in the 205 patients in relation to lesional descriptors calculated from permeability and perfusion maps. A subgroup of 30 cases also underwent peripheral blood collection at the time of DCEQP scans and assays of plasma levels of soluble CD14, IL-1β, VEGF, and soluble ROBO4 proteins, whose weighted combination had been previously reported in association with future CA bleeding. STATISTICAL TESTS Mann-Whitney U-test for univariate analyses. Logistic regression models minimizing the Bayesian information criterion (BIC), testing sensitivity and specificity (receiver operating characteristic curves) of weighted combinations of parameters. RESULTS The best prognostic biomarker for lesional bleed or growth included brainstem lesion location, mean lesional permeability, and low-value perfusion cluster mean (BIC = 201.5, sensitivity = 77%, specificity = 72%, P

Cerebral cavernous malformations (CCM) are a neurovascular anomaly that may occur sporadically in otherwise healthy individuals, or be inherited by autosomal dominant mutations in the genes that encode the proteins of the CCM signaling complex (KRIT1, CCM2, or PDCD10)1–4. CCMs have long been known to follow a genetic two-hit model where lesion formation is initiated by somatic mutations resulting in biallelic loss of a CCM complex gene5–8. Recent studies have shown that somatic mutations in MAP3K3 and PIK3CA also contribute to CCM pathogenesis9–11; however, it remains unclear how these mutations contribute to sporadic versus familial cases. Here we show that somatic mutations in MAP3K3 are mutually exclusive with mutations in CCM complex genes and that mutations in MAP3K3 contribute to sporadic, but not familial CCM. Using single-nucleus DNA sequencing, we show that co-occurring MAP3K3 and PIK3CA mutations are present within the same clonal population of cells. Furthermore, we identify PIK3CA mutations in CCM-associated developmental venous anomalies (DVA). It has long been known that sporadic CCM often develop in the vicinity of a DVA. However, the underlying cause of this association is unknown12–14. In this first report of the molecular pathology of CCM-associated DVA, we find that the identical PIKC3A mutation is found in both the DVA and its associated CCM, but that an activating MAP3K3 mutation appears only in the CCM. These results support a mechanism where DVA develop as the result of a PIK3CA mutation, creating a region of the brain vasculature that functions as a genetic primer for CCM development following acquisition of an additional somatic mutation.

Cavernous angiomas with symptomatic hemorrhage (CASH) have a high risk of rebleeding, and hence an accurate diagnosis is needed. With blood flow and vascular leak as established mechanisms, we analyzed perfusion and permeability derivations of dynamic contrast-enhanced quantitative perfusion (DCEQP) MRI in 745 lesions of 205 consecutive patients. Thirteen respective derivations of lesional perfusion and permeability were compared between lesions that bled within a year prior to imaging (N = 86), versus non-CASH (N = 659) using machine learning and univariate analyses. Based on logistic regression and minimizing the Bayesian information criterion (BIC), the best diagnostic biomarker of CASH within the prior year included brainstem lesion location, sporadic genotype, perfusion skewness, and high-perfusion cluster area (BIC = 414.9, sensitivity = 74%, specificity = 87%). Adding a diagnostic plasma protein biomarker enhanced sensitivity to 100% and specificity to 85%. A slightly modified derivation achieved similar accuracy (BIC = 321.6, sensitivity = 80%, specificity = 82%) in the cohort where CASH occurred 3–12 months prior to imaging after signs of hemorrhage would have disappeared on conventional MRI sequences. Adding the same plasma biomarker enhanced sensitivity to 100% and specificity to 87%. Lesional blood flow on DCEQP may distinguish CASH after hemorrhagic signs on conventional MRI have disappeared and are enhanced in combination with a plasma biomarker.

Introduction: Diagnosis of cavernous angioma with symptomatic hemorrhage (CASH) requires MRI evidence of lesional bleeding associated directly with attributable symptoms. However, hemorrhagic signs of CASH may become clinically silent on conventional MRI after 3 months. As CASH is likely to rebleed for several years, accurate diagnosis of CASH that bled more than 3 months prior is needed. Hypothesis: Perfusion and permeability derivations of dynamic contrast-enhanced quantitative perfusion (DCEQP) MRI can diagnose CASH and predict bleeding/growth in CAs. Methods: CAs of 205 consecutively enrolled patients scanned with DCEQP during clinical visits were classified as CASH that bled 3 - 12 months prior (N = 55) versus non-CASH (N = 658) or CA with (N = 23) versus without (N = 721) bleeding/growth within a year after MRI. Demographics and 13 perfusion and 13 permeability derivations of DCEQP were assessed via machine learning and univariate analyses. Logistic regression models ln ( P / 1 - P ) = Σ (β i x i ) + β 0 were selected as the best diagnostic and prognostic biomarkers by minimizing the Bayesian information criterion (BIC). Results: The best diagnostic biomarker of CASH that bled 3 - 12 months prior (BIC = 321.6, Figure A) showed 80% sensitivity and 82% specificity. Permeability derivations did not add diagnostic efficacy when combined with perfusion. The best prognostic biomarker of bleeding/growth (BIC = 201.5, Figure B) showed 77% sensitivity and 72% specificity. Conclusion: Perfusion imaging may diagnose CASH even after hemorrhagic signs disappear on conventional MRI. A combination of permeability and perfusion derivations may help predict bleeding/growth in CAs.

Introduction: There is a current need for sensitive and specific biomarkers of Cerebral Cavernous Malformation (CCM) that can be readily translated from preclinical to human models to accurately diagnose and monitor disease states and response to novel therapeutics. MiRNAs are small non-coding RNAs that influence gene expression and whose levels can be affected by disease states. We hypothesize that there are human homologs of differentially expressed (DE) miRNA in the plasma of CCM murine models that can be identified in CCM patients. We further hypothesize that these miRNAs have gene targets within previously published CCM transcriptomes, mechanistically linking them to CCM disease. Methods: Plasma miRNAs from homozygous and heterozygous Ccm1 and Ccm3 mice, as well as their respective wild type controls were sequenced and analyzed. Putative gene targets of DE miRNAs [pCcm1 and Ccm3 mouse models were identified and assessed in the plasma of healthy controls (n=13), CCM1 (n=11), and CCM3 (n=11) patients using RT-qPCR. Results: 5 miRNAs in homozygous and 10 in heterozygous for Ccm1 , while 45 in homozygous and 2 in heterozygous for Ccm3 were DE in the plasma of mouse models (pmmu-miR-375-3p as DE in both Ccm1 +/- and Ccm3 -/- mice. RT-qPCR assays show that plasma relative quantification values of the human homolog hsa-miR-375-3p were higher in CCM3 than in CCM1 patients ( p p Conclusion: DE plasma miRNAs identified in mouse models with human homologs and putative gene targets mechanistically implicated in CCM disease may be used as candidate biomarkers for specific clinical contexts.

We previously demonstrated that lifelong antibiotic (ABX) perturbations of the gut microbiome in male APPPS1-21 mice lead to reductions in amyloid β (Aβ) plaque pathology and altered phenotypes of plaque-associated microglia. Here, we show that a short, 7-d treatment of preweaned male mice with high-dose ABX is associated with reductions of Aβ amyloidosis, plaque-localized microglia morphologies, and Aβ-associated degenerative changes at 9 wk of age in male mice only. More importantly, fecal microbiota transplantation (FMT) from transgenic (Tg) or WT male donors into ABX-treated male mice completely restored Aβ amyloidosis, plaque-localized microglia morphologies, and Aβ-associated degenerative changes. Transcriptomic studies revealed significant differences between vehicle versus ABX-treated male mice and FMT from Tg mice into ABX-treated mice largely restored the transcriptome profiles to that of the Tg donor animals. Finally, colony-stimulating factor 1 receptor (CSF1R) inhibitor-mediated depletion of microglia in ABX-treated male mice failed to reduce cerebral Aβ amyloidosis. Thus, microglia play a critical role in driving gut microbiome–mediated alterations of cerebral Aβ deposition.

Previous studies have reported robust inflammatory cell infiltration, synthesis of IgG, B-cell clonal expansion, deposition of immune complexes and complement within cerebral cavernous malformation (CCM) lesions. B-cell depletion has also been shown to reduce the maturation of CCM in murine models. We hypothesize that antigen(s) within the lesional milieu perpetuate the pathogenetic immune responses in CCMs. This study aims to identify those putative antigen(s) using monoclonal antibodies (mAbs) derived from plasma cells found in surgically removed human CCM lesions. We produced human mAbs from laser capture micro-dissected plasma cells from four CCM patients, and also germline-reverted versions. CCM mAbs were assayed using immunofluorescence on central nervous system (CNS) tissues and immunocytochemistry on human primary cell lines. Antigen characterization was performed using a combination of confocal microscopy, immunoprecipitation and mass spectrometry. Affinity was determined by enzyme-linked immunosorbent assay, and specificity by multi-color confocal microscopy and quantitative co-localization. CCM mAbs bound CNS tissue, especially endothelial cells and astrocytes. Non-muscle myosin heavy chain IIA (NMMHCIIA), vimentin and tubulin are three cytoskeleton proteins that were commonly targeted. Selection of cytoskeleton proteins by plasma cells was supported by a high frequency of immunoglobulin variable region somatic hypermutations, high affinity and selectivity of mAbs in their affinity matured forms, and profoundly reduced affinity and selectivity in the germline reverted forms. Antibodies produced by plasma cells in CCM lesions commonly target cytoplasmic and cytoskeletal autoantigens including NMMHCIIA, vimentin and tubulin that are abundant in endothelial cells and astrocytes. Binding to, and selection on autoantigen(s) in the lesional milieu likely perpetuates the pathogenetic immune response in CCMs. Blocking this in situ autoimmune response may yield a novel treatment for CCM.

Brain senescence is associated with impaired endothelial barrier function, angiogenic and inflammatory activity, and propensity to brain hemorrhage. The same pathological changes occur in cerebral cavernous malformations (CCM), a genetic neurovascular anomaly. We hypothesized common transcriptomic and plasma cytokine signatures in the aging brain and CCM. We identified 320 genes [fold change ≥1.5; p

Introduction: Studies on the natural clinical course of Cavernous Angioma (CA) have reported a Methods: Patients with CA diagnosis were prospectively enrolled in IRB approved database from 09/2009 to 02/2019 (N=327). Imaging and clinical follow-up were recommended annually, or sooner with new symptoms. Patients with 1 or more CA with maximum diameter >4 mm on T2 MRI, not excised or irradiated, and 1 or more clinical/imaging follow-up were included (N=192). New AH and SH were assessed per prospectively articulated criteria, and rates were estimated per lesion-year and patient-year, and NLF in familial cases. Results: There were no demographic or disease confounders among cases included and excluded from the study cohort, except for higher rates of prior SH and greater prevalence of cases with solitary lesion excluded because of surgical treatment. Total follow-up was 410 patient-years (2539 lesion-years). During prospective follow-up, the rate of AH was higher than the rate of SH (12.9% vs. 7.5% per patient-year and 2.1% vs. 1.2% per lesion -year, p=0.02 and p=0.01 respectively). Patients presenting with SH in the prior year had higher rate of AH than those presenting incidentally or with seizures (19.83% and 8.2% per patient-year respectively; p=0.003). A higher rate of NLF on T2 (p=0.0002) and SWI (p=0.0004) was also observed in patients with prior SH compared to stable patients. After an AH, 3 of 6 sporadic patients with solitary lesion and only 2 of 28 familial cases with multiple lesions underwent surgical resection of the lesion with AH. Conclusions: Subclinical imaging changes are more common than SH during prospective follow-up of CAs. They are more common in patients presenting with prior SH, and likely reflect a more sensitive biomarker of CA instability. AH more likely provokes a surgical decision in cases with solitary lesion than in familial cases with multiple lesions.

Introduction: Previous studies have reported robust inflammatory cell infiltration, selective synthesis of IgG, B-cell clonal expansion, and deposition of immune complexes and complement within Cerebral Cavernous Malformation (CCM) lesions. Furthermore,B-cell depletion has been shown to reduce the maturation of CCM in murine models. We hypothesize that specific autoantigen(s) within the lesional milieu trigger the pathogenetic immune responses in CCMs. This study aims to identify those putative autoantigen(s) using recombinant antibodies (rAbs) derived from plasma cells found in surgical human CCM lesions. Methods: CD138 + plasma cells were laser captured from fresh frozen surgically resected human CCM lesions. Clonally expanded immunoglobulin heavy- and light-chain variable region pairs were cloned into IgG expression vectors and expressed as monoclonal antibodies. Purified rAbs were assayed by immunofluorescence with CCM lesion tissue and normal brain tissue sections. rAbs assayed by immunocytochemistry with human primary cell line were used to further define the staining pattern. The cell lysates were immunoprecipitated with rAb, after protein purification by SDS-PAGE, and analyzed by Mass spectrometry. Results: In normal brain tissue, rAbs stained endothelial cells with limited staining of glial cells. In CCM lesional tissue, rAbs stained endothelial cells, glial cells as well as structures in the acellular matrix adjacent to caverns. In cultured Human Brain Microvascular Endothelial Cells (HBMECs) and Human Astrocytes (HAs), rAbs co-localized with cytoplasmic components. After HBMEC and HA cell lysates were immunoprecipitated with rAb, a Coomassie Stain detected bands of approximately 50 kDa. Conclusions: Our results suggest that autoantigen(s) in human CCM lesions are cytoplasmic components present in lesional tissue as well as in normal brain tissue. Molecular level identification of the triggering antigen is still ongoing by mass spectrometry. Identification of the autoantigen(s) in the lesional milieu might explain the propensity of lesion development from leaky endothelium in the neuroglial parenchyma. Characterization of the autoantigen triggers will open new venues for therapy or vaccine in this disease.

Background: Cellular senescence is associated with gene expression dysregulation affecting endothelial barrier function as well as angiogenic and inflammatory processes. These pathological changes occur in cerebral cavernous malformations (CCMs), a neurovascular anomaly predisposing patients to hemorrhagic stroke. We hypothesize common transcriptomic and biomarker signatures between the aging brain and CCMs. Method: Brain specific genes dysregulate in Younger (age < 30) and Older (age > 50) human brain parenchyma were identified using the Genotype-Tissue Expression database, and compared with differential transcriptome in microdissected neurovascular units of human CCM lesions. Brain white matter vascular permeability in areas devoid of lesions was measured in non-CCM (23 Younger, 27 Older), Sporadic-CCM (S-CCM) (26 Younger, 37 Older) and Familial-CCM (F-CCM) (41 Younger, 17 Older) using dynamic contrast-enhanced quantitative perfusion MRI. Plasma levels of 6 proteins with reported roles in CCMs were quantified, including VEGF, angiopoietin (ANG 1 & 2), CRP, thrombospondin 2 (THBS 2), and endoglin (ENG). All reported correlations were significant at P< 0.05, FDR corrected. Result: We identified 320 genes (absolute fold change≥1.5) commonly dysregulated in aging brain and CCM, related to inflammation and extracellular matrix organization pathways. Brain permeability was greater in Older non-CCM and S-CCM compared to Younger subjects. Brain permeability was higher in Younger F-CCM harboring germ line CCM mutations, than in both Younger non-CCM (p Conclusion: There are common transcriptomic, and brain permeability and plasma biomarker signatures in the aging brain and CCM, suggesting common dysregulated pathways. Biomarkers and potential therapies identified in a well characterized Mendelian neurovascular disease may be applicable to mitigate the same mechanistic aberrations in the aging brain.

Background Cerebral cavernous angioma (CA) is a capillary microangiopathy predisposing more than a million Americans to premature risk of brain hemorrhage. CA with recent symptomatic hemorrhage (SH), most likely to re-bleed with serious clinical sequelae, is the primary focus of therapeutic development. Signaling aberrations in CA include proliferative dysangiogenesis, blood-brain barrier hyperpermeability, inflammatory/immune processes, and anticoagulant vascular domain. Plasma levels of molecules reflecting these mechanisms and measures of vascular permeability and iron deposition on magnetic resonance imaging are biomarkers that have been correlated with CA hemorrhage. Objective To optimize these biomarkers to accurately diagnose cavernous angioma with symptomatic hemorrhage (CASH), prognosticate the risk of future SH, and monitor cases after a bleed and in response to therapy. Methods Additional candidate biomarkers, emerging from ongoing mechanistic and differential transcriptome studies, would further enhance the sensitivity and specificity of diagnosis and prediction of CASH. Integrative combinations of levels of plasma proteins and characteristic micro-ribonucleic acids may further strengthen biomarker associations. We will deploy advanced statistical and machine learning approaches for the integration of novel candidate biomarkers, rejecting noncorrelated candidates, and determining the best clustering and weighing of combined biomarker contributions. Expected outcomes With the expertise of leading CA researchers, this project anticipates the development of future blood tests for the diagnosis and prediction of CASH to clinically advance towards precision medicine. Discussion The project tests a novel integrational approach of biomarker development in a mechanistically defined cerebrovascular disease with a relevant context of use, with an approach applicable to other neurological diseases with similar pathobiologic features.

Cerebral cavernous malformations (CCMs) are dilated capillaries causing epilepsy and stroke. Inheritance of a heterozygous mutation in CCM3/PDCD10 is responsible for the most aggressive familial form of the disease. Here we studied the differences and commonalities between the transcriptomes of microdissected lesional neurovascular units (NVUs) from acute and chronic in vivo Ccm3/Pdcd10ECKO mice, and cultured brain microvascular endothelial cells (BMECs) Ccm3/Pdcd10ECKO. We identified 2409 differentially expressed genes (DEGs) in acute and 2962 in chronic in vivo NVUs compared to microdissected brain capillaries, as well as 121 in in vitro BMECs with and without Ccm3/Pdcd10 loss (fold change ≥ |2.0|; p

Supplemental Methods. Supplemental Results. Supplementary References. Figure S1. Statistical flow chart. Figure S2. Volcano plots of differentially expressed genes (DEGs) in acute and chronic in vivo neurovascular units (NVUs) and in vitro brain microvascular endothelial cells (BMECs). Figure S3. Dot plot comparing enriched gene ontology functions (p

OBJECT External ventricular drains (EVDs) are commonly used for CSF diversion but pose a risk of ventriculitis, with rates varying in frequency from 2% to 45%. Results of studies examining the utility of prolonged systemic antibiotic therapy for the prevention of EVD-related infection have been contradictory, and no study to date has examined whether this approach confers additional benefit in preventing ventriculitis when used in conjunction with antibiotic-coated EVDs (ac-EVDs). METHODS A prospective performance analysis was conducted over 4 years to examine the impact of discontinuing systemic antibiotic prophylaxis after insertion of an ac-EVD on rates of catheter-related ventriculitis. Ventriculitis and other nosocomial infections were ascertained by a qualified infection disease nurse using definitions based on published standards from the Centers for Disease Control and Prevention, comparing the period when patients received systemic antibiotic therapy for the duration of EVD treatment (Period 1) compared with only for the peri-insertion period (Period 2). Costs were analyzed and compared across the 2 time periods. RESULTS Over the 4-year study period, 866 patients were treated with ac-EVDs for a total of 7016 catheter days. There were 8 cases of ventriculitis, for an overall incidence of 0.92%. Rates of ventriculitis did not differ significantly between Period 1 and Period 2 (1.1% vs 0.4%, p = 0.22). The rate of nosocomial infections, however, was significantly higher in Period 1 (2.0% vs 0.0% in Period 2, p = 0.026). Cost savings of $162,516 were realized in Period 2 due to decreased drug costs and savings associated with the reduction in nosocomial infections. CONCLUSIONS Prolonged systemic antibiotic therapy following placement of ac-EVDs does not seem to reduce the incidence of catheter-related ventriculitis and was associated with a higher rate of nosocomial infections and increased cost.