Stroke and vascular dementia are important disabling disorders among the veteran population. Prevention of stroke has the potential to make a great impact, but a vast majority of stroke studies have focused on processes that occur after stroke. To identify molecular process which lead to stroke, we study the prototype human disorder Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), a hereditary stroke/dementia disorder caused by mutations in Notch3. Hallmark pathological features of CADASIL include: rarefication of arterial extracellular matrix, arterial granular osmiophilic material (GOM) deposition, and vascular Notch3 protein accumulation. The objective of this study is to define molecular processes that cause these abnormalities. Preliminary data demonstrates specific physical and functional interactions between Notch3 and LRP1, a protein known for its endocytic function. We will test the hypothesis that in CADASIL, mutant Notch3 in cerebral vessels impairs LRP1 endocytosis of Notch3, leading to Notch3 buildup and increased MMP expression. We suggest the following: mutant Notch3 in CADASIL dysfunctionally binds to LRP1, leading to LRP1 malfunction;decreased LRP1 results in inhibition of endocytosis of critical extracellular proteins, including Notch3 and MMPs. We propose to test this hypothetic cascade of events in three specific aims. First, we will determine at the molecular level whether mutant Notch3 proteins interact differently with LRP1 (compared to WT Notch3). Second, we will determine in cell cultures whether mutant Notch3 inhibits LRP1 dependent endocytosis. Third, we will quantitate Notch3 buildup in transgenic mice lacking key genes that participate in LRP1 endocytosis to test whether LRP1 is a true target of mutant Notch3 in vivo. These studies may shed light on important targets for prevention of stroke and vascular dementia. A vast literature already support a role for LRP1 and MMPs after stroke. These studies may identify an additional role for LRP1 and MMPs in vascular pathology prior to stroke and perhaps suggest novel methods for stroke and vascular dementia prevention therapy.

Public Health Relevance

Stroke and dementia are common among the veteran population, but effective therapies to prevent vascular disease and its effects on cognition have proven elusive. CADASIL serves as a prototype for vascular dementias and inherited stroke, and understanding the molecular underpinnings of vascular disease of the brain will provide information essential to the development of new treatment strategies that will benefit the veteran population. In this proposal, we will test whether the proteins Notch, LRP, and MMP cause damage in CADASIL. Successful identification of a role for these proteins in vascular diseases suggest that these pathways could potentially be targeted to prevent stroke and vascular dementia in veterans.

Agency
National Institute of Health (NIH)
Institute
Veterans Affairs (VA)
Type
Non-HHS Research Projects (I01)
Project #
5I01BX000375-03
Application #
8195411
Study Section
Cardiovascular Studies A (CARA)
Project Start
2009-04-01
Project End
2013-09-30
Budget Start
2011-10-01
Budget End
2012-09-30
Support Year
3
Fiscal Year
2012
Total Cost
Indirect Cost
Name
Veterans Health Administration
Department
Type
DUNS #
096318480
City
Ann Arbor
State
MI
Country
United States
Zip Code
48105
Gatti, John R; Zhang, Xiaojie; Korcari, Ejona et al. (2018) Redistribution of Mature Smooth Muscle Markers in Brain Arteries in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy. Transl Stroke Res :
Tsai, Ellen A; Gilbert, Melissa A; Grochowski, Christopher M et al. (2016) THBS2 Is a Candidate Modifier of Liver Disease Severity in Alagille Syndrome. Cell Mol Gastroenterol Hepatol 2:663-675.e2
Zhang, Xiaojie; Lee, Soo Jung; Young, Marian F et al. (2015) The small leucine-rich proteoglycan BGN accumulates in CADASIL and binds to NOTCH3. Transl Stroke Res 6:148-55
Zhang, Xiaojie; Lee, Soo Jung; Young, Kelly Z et al. (2014) Latent NOTCH3 epitopes unmasked in CADASIL and regulated by protein redox state. Brain Res 1583:230-6
Lee, Soo Jung; Zhang, Xiaojie; Wang, Michael M (2014) Vascular accumulation of the small leucine-rich proteoglycan decorin in CADASIL. Neuroreport 25:1059-63
Dong, Hairong; Ding, Haixia; Young, Kelly et al. (2013) Advanced intimal hyperplasia without luminal narrowing of leptomeningeal arteries in CADASIL. Stroke 44:1456-8
Zhang, Xiaojie; Meng, He; Wang, Michael M (2013) Collagen represses canonical Notch signaling and binds to Notch ectodomain. Int J Biochem Cell Biol 45:1274-80
Zhang, Xiaojie; Meng, He; Blaivas, Mila et al. (2012) Von Willebrand Factor permeates small vessels in CADASIL and inhibits smooth muscle gene expression. Transl Stroke Res 3:138-45
Wang, Michael M (2011) Notch signaling and Notch signaling modifiers. Int J Biochem Cell Biol 43:1550-62