Cores Overview

Overview

This Program Project Grant (PPG) is comprised of 3 cores that are all focused on von Willebrand disease and mechanisms causing its dysfunction, increased clearance or increased synthesis, and the role carbohydrate modification plays in VWF biology.Core A is the administrative core that will facilitate the exchange of information, data, patient samples, and biodata. It will also oversee the 10 Primary Clinical Centers that will be following our enrolled subjects. Core B will be doing whole genome sequencing of subjects with very low or absent VWF that have had normal VWF sequencing. Core C will develop animal models for each of the projects to further their studies on VWD mechanisms.

Core A: Administrative and Clinical Acquisition Core

Leader: Dr. Robert Montgomery

Aim of Core A: Led by Dr. Robert Montgomery, Core A oversees the administration and the continued acquisition of follow-up samples on enrolled patients with VWD or LVWF. It includes this PPG's administrative functions, such as the day-to-day communications between the projects themselves and the projects with the cores. Except for some type 3 VWD patients, there will be no further enrollment from the primary clinical centers into this PPG. However, primary clinical centers will be responsible for obtaining follow-up plasma and DNA samples when these individuals are seen in follow-up for their LVWF or VWD. These primary centers have previously worked with the Zimmerman PPG and recruited the targeted number of proposed subjects. Pam Christopherson is the senior research coordinator who tracks the timing and receipt of samples and also visits each center annually to optimize interactions and efficient clinical research activities. She has already worked with the centers to establish the interim BAT (iBAT). This assessment tool has been developed by Pam Christopherson in conjunction with Paula James from Queen's University, Thomas Abshire from the Blood Center of Wisconsin, and Dr. Montgomery. Core A has had to develop a new database over the past three years because RemedyMD was no longer supporting changes in the database. Pam Christopherson was instrumental in developing the Velos Database and also developing an inventory control system for the biorepository of more than 80,000 plasma and DNA samples. Maintaining the database and the biorepository is a critical function of this core and will make samples available for studies by Projects 1-4 and Core B. This biorepository has also been made available to clinical collaborators at the Primary Clinical Centers to undertake clinical projects using this data.

Core B: Genomics And Bioinformatics Core

Leader: Dr. Jorge Di Paola

Aim of Core B: Led by Dr. Jorge Di Paola, Core B oversees the genomics and bioinformatics core. It provides whole genome sequencing on subjects with VWD without a recognized sequence variation. This new core can be utilized to identify genes, pathways, or mechanisms that can cause VWD without a mutation in the coding region and consensus splice sites of the VWF gene. Such an approach would not have been economically possible until recently when the price for whole genome sequencing has decreased considerably. In order to optimize the potential for identifying candidate pathogenic sequence variants, we propose to do whole genome sequencing on all of our individuals with type 1 VWD or type 3 VWD with NSV and to augment these with a similar number of LVWF subjects. While we ideally would have liked to have looked at all of our LVWF subjects (218), the current costs would be prohibitive. If, in the future, whole genome sequencing costs are further reduced, we will add additional LVWF subjects. When we add additional LVWF subjects, we will select subjects based on the level of VWF in plasma. Thus, we will evaluate those with VWF levels between 30 and 40 IU/dL before we turn our attention to those with VWF levels between 40 and 50IU/dL. One could envision that we would find defects that could be evaluated in Projects 1, 2, 3, and 4 if the gene or the pathway were clear-cut. On the other hand, some genes might seem unrelated but might ultimately be responsible for pathogenic changes. Looking at family members of such index cases might help us to establish linkage and biological correlation. This latter activity would be done in Project 1 and be performed using PCR probes or PCR sequencing of family members or even other subjects with similar sequence variants. We would posit that the additional defect might be additive to any pathology caused by the previously identified sequence variant done via routine VWF coding region and consensus splice site sequencing. The Project Leaders will meet periodically to determine which genetic variants identified by Core B should be pursued further to determine definitive pathogenetic mechanisms. Periodic meetings (electronic) will help establish which project should pursue new genetic variants for further pathogenicity assessment. With our prior PPG/R01 cohort, many already have affected and unaffected family members can be tested for new genetic variants in Project 1.

Core B will provide data storage, management, and transfer. In some cases, the same abnormality might be seen in several different index cases, and the correlation with phenotyping data could also be achieved through Project 1.
Core B will provide local and public data sharing. This project will ensure that raw and analyzed sequencing data be submitted to stable repositories that are accepted by their search community and are in compliance with NIH data sharing policy (e.g., ClinVar).

Core C: Animal Models Core

Leader: Dr. Hartmut Weiler

Aim of Core C: Led by Dr. Hartmut Weiler, Core C developed animal models to explore new VWF regulatory pathways to confirm these as causes of VWD. It supports all of the projects in this program and proposes the development of animal models.

Core C will assist the Project Leaders in the experimental design of new animal models in either mice or rats. Dr. Weiler has extensive experience with developing animal models to study hemostatic mechanisms, and he has already developed several mice and rats for Project 1 using either traditional genetic approaches or more recently with CRISPR/Cas9 gene editing. Using one such approach in the rat, the core was able to eliminate the entire VWF coding region and thereby generate a model of type 3 VWD – the first VWD model to be developed in the rat...
Core C will generate and validate the required reagents for generating and validating the desired animal and will oversee the generation of genetically modified mice or rats by the transgenic core.
Core C will coordinate the distribution and cryopreservation of newly generated animal models so that they can be made available to other investigators once the animal has been appropriately studied and the new phenotype defined. This core is only for the generation of animal models and the assurance of model preservation. At that point, animals are transferred to the appropriate project or projects for further study and characterization.