# Investigating the intracellular vesicle-mediated mechanism contributing to cerebral cavernous malformation

> **NIH NIH R01** · YALE UNIVERSITY · 2022 · $418,750

## Abstract

Cerebral vascular malformations affect 1 in 100 to 200 of the general population with increased
risk for stroke, seizures and focal neurological deficits. Patients with inherited autosomal dominant
CCM carry loss of function mutations in one of three genes: CCM1, CCM2 and CCM3 (Pdcd10).
We have focused on CCM3 (Pdcd10) as both humans and mice with CCM3 loss exhibit more
severe phenotype than those with loss of CCM1 or CCM2. Why human CCM lesions are primarily
confined to the brain vasculature, despite ubiquitous expression of CCM proteins, remains unclear.
We have recently established an inducible Ccm3 deletion using a novel brain EC (BEC)-specific
Cre line (Pdcd10BECKO) that promoted CCM lesions in the brain. Importantly, the Pdcd10BECKO mice
survive up to 6-12 months, allowing us to visualize vascular lesion formation by live imaging, to
define the CCM pathogenesis, and to test therapeutics in adulthood. Our previous work shows
that CCM3 suppresses Unc13B-dependent exocytosis-mediated secretion of angiopoietin-2.
More recent study indicates that caveolae vesicle and its core protein caveolin-1 (Cav1) are
tightly controlled by CCM3, and dramatically increased in the brain microvascular ECs of Ccm3-
deficient mice. Since increased caveolae has been associated with increased BBB dysfunction,
we hypothesize that CCM3, by controlling intracellular vesicles in brain microvascular ECs,
regulates BBB integrity; loss of CCM3 induces abnormal vesicle trafficking, particularly caveolae-
mediated transcytosis and protein trafficking, leading to BBB dysfunction and vascular
malformation. We propose the following three specific aims and studies: 1) To determine the
contribution of caveolae and Cav1-mediated signaling to brain vascular malformations. We will
determine if Cav1 genetic defect prevents CCM lesion in Pdcd10BECKO mice, characterize BBB
function and caveolae-mediated transcytosis, characterize EC-pericyte association and EC lumen
dilation in DKO, and characterize novel gene expression and signaling pathways related to BBB
structure and function by single cell RNA-seq (scRNA-seq) analyses; 2) To define the mechanism
by which CCM3 regulates Cav1-Tie2 signaling and vascular stabilization. We will perform
biochemical and imaging experiments to determine if CCM3-regulated Tie2 is caveolae-specific,
determine the role of CCM3-Cav1-Tie2 signaling in regulating EC junction, EC-pericyte
association and vascular stabilization by in vitro models; 3) To determine the therapeutic effects
of Cav1-Tie2 signaling in CCM disease progression. We will test therapeutic effects of Tie2
inhibitor, genetic deletion of Tie2 on CCM disease, define Tie2-mediated gene expression and
signaling pathways by scRNA-seq, and determine the role of Tie2high ECs in CCM lesion formation.

## Key facts

- **NIH application ID:** 10372136
- **Project number:** 5R01HL157019-02
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** Jenny Huanjiao Zhou
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $418,750
- **Award type:** 5
- **Project period:** 2021-04-01 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10372136

## Citation

> US National Institutes of Health, RePORTER application 10372136, Investigating the intracellular vesicle-mediated mechanism contributing to cerebral cavernous malformation (5R01HL157019-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10372136. Licensed CC0.

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