von Willebrand factor (VWF) initiates hemostasis by tethering platelets to sites of vascular injury and participates in the coagulation by protecting the coagulation factor VIII (FVIII) against proteolytic degradation. A low VWF antigen and/or lack of large multimers can result in bleeding, whereas high levels and/or the presence of ultra?large VWF multimers are associated with thrombosis. This bidirectional activity suggests that VWF expression and adhesive activity are highly regulated to maintain active hemostasis without promoting thrombosis. Plasma VWF levels vary significantly among healthy subjects and there is increasing evidence that this variation is ethnically diverse. Environmental and genetic factors are known to contribute to variations in VWF synthesis, stability, adhesiveness, and clearance, but crucial questions remain. First, what is the relationship between VWF antigen and adhesive activity in healthy individuals? Second, how do genetic variations interact with environmental factors to modify the synthesis and activity of VWF, a known acute phase reactant? Third, how do ethnicity and aging influence the association of variants in the VWF gene with VWF adhesive activity and the development of thrombotic diseases? We hypothesize that 1) variation in the VWF gene influences not only VWF expression, but also adhesive activity; 2) there is a strong gene? environment interaction that influences VWF adhesive activity and this interaction is manifested through covariates as ethnicity, age and FVIII; and 3) evaluating VWF adhesive activity can improve risk assessments for thrombotic diseases compared to modeling VWF antigen alone. Our broad, long?term objective is to understand VWF biological activity and its modification of disease associations by ethnicity, aging and FVIII. There are three specific aims in this proposal. First is to characterize VWF adhesive activity in subjects from the Atherosclerosis Risk in Communities (ARIC) and the Japanese Suita cohorts, whose VWF antigen was consistently measured as low (? 50%) or high (? 200%) in samples collected over 25 years. VWF adhesive activity and rates of VWF synthesis and clearance will be determined to define 1) an intrinsic relationship between VWF levels and adhesive activity and 2) the impact of aging and ethnicity on this relationship. Second is to 1) identify genetic variants associated with VWF antigen and adhesive activity in subjects from three ethnic groups of European American, African Americans, and Japanese; 2) detect ethnic modifications of these associations; and 3) detect the genetic epistasis and novel molecular interactions that regulate the VWF antigen and adhesive activity. Third is to determine 1) if measuring VWF activity and rates of VWF synthesis? clearance improve risk predictions for myocardial infarction, ischemic stroke, and peripheral arterial disease than VWF antigen alone; 2) if subjects with low VWF and/or adhesive activity are protected from these diseases; and 3) how ethnicity and aging modify the risk. The research is highly relevant to the mission of NIH in combating aging?associated thrombotic and bleeding disorders to improve public health in the US.

Public Health Relevance

The proposed study is designed to 1) understand impacts of genetic and phenotypic variations on levels and activity of the adhesion factor von Willebrand factor in large US and Japanese populations; 2) study how ethnicity, aging and factor VIII modify these impacts; and 3) associate von Willebrand factor adhesive activity and genetic factors (in haplotypes) with myocardial infarction, stroke, and peripheral artery disease in ethnic diverse manners. The study could identify genetic and blood markers that are associated with novel risk traits for atherothrombotic diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL125957-03
Application #
9313320
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Kindzelski, Andrei L
Project Start
2015-09-01
Project End
2019-06-30
Budget Start
2017-07-01
Budget End
2018-06-30
Support Year
3
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Puget Sound Blood Center
Department
Type
DUNS #
092881085
City
Seattle
State
WA
Country
United States
Zip Code
98104
Wu, Yingang; Liu, Wei; Zhou, Yuan et al. (2018) von Willebrand factor enhances microvesicle-induced vascular leakage and coagulopathy in mice with traumatic brain injury. Blood 132:1075-1084
Yang, Xinyu; Li, Jiani; Fang, Yabo et al. (2018) Rho Guanine Nucleotide Exchange Factor ARHGEF17 Is a Risk Gene for Intracranial Aneurysms. Circ Genom Precis Med 11:e002099
Chen, Yiyun; Bartanus, Justin; Liang, Desheng et al. (2017) Characterization of chromosomal abnormalities in pregnancy losses reveals critical genes and loci for human early development. Hum Mutat 38:669-677
Nascimbene, Angelo; Hilton, Tristan; Konkle, Barbara A et al. (2017) von Willebrand factor proteolysis by ADAMTS-13 in patients on left ventricular assist device support. J Heart Lung Transplant 36:477-479
Zhou, Yong; Qin, Shizhen; Hilton, Tristan et al. (2017) Quantification of Von Willebrand Factor Cleavage by adamts-13 in Patients Supported by Left Ventricular Assist Devices. ASAIO J 63:849-853
Nascimbene, Angelo; Neelamegham, Sriram; Frazier, O H et al. (2016) Acquired von Willebrand syndrome associated with left ventricular assist device. Blood 127:3133-41
Li, J N; Carrero, I G; Dong, J F et al. (2015) Complexity and diversity of F8 genetic variations in the 1000 genomes. J Thromb Haemost 13:2031-40
Song, Jaewoo; Chen, Fengju; Campos, Marco et al. (2015) Quantitative Influence of ABO Blood Groups on Factor VIII and Its Ratio to von Willebrand Factor, Novel Observations from an ARIC Study of 11,673 Subjects. PLoS One 10:e0132626