Faculty Collaboration Database

Defective collagen binding and increased bleeding in a murine model of von Willebrand disease affecting collagen IV binding. J Thromb Haemost 2019 Jan;17(1):63-71

Date

12/20/2018

Pubmed ID

30565388

Pubmed Central ID

PMC6743498

DOI

10.1111/jth.14341

Scopus ID

2-s2.0-85058806961 (requires institutional sign-in at Scopus site)   12 Citations

Abstract

Essentials Defective binding to collagen IV has been seen in von Willebrand factor (VWF) A1 domain variants. We developed a murine model of defective VWF-collagen IV interactions with VWF variant p.R1399H. p.1399HH homozygous mice had decreased binding to collagen IV and increased bleeding times. p.1399HH homozygous mice had increased time to thrombosis and decreased platelet adhesion. SUMMARY: Background von Willebrand factor (VWF) binding to type IV collagen occurs via the VWF A1 domain, with p.R1399H being the most common VWF variant affecting this interaction. Objectives We generated a murine model of 1399H VWF to investigate its in vivo effects. Methods Mice expressing the murine 1399H variant were generated via gene targeting in embryonic stem cells. VWF antigen and VWF collagen binding were measured with ELISA. Tail bleeding time assays were performed by clipping a 3-mm segment. Ferric chloride-induced thrombosis was measured via ultrasound in the carotid artery. Platelet aggregation in response to collagens I and IV was measured. VWF-dependent platelet adhesion to collagen IV was measured under flow. Results Breeding of heterozygous p.R1399H and homozygous p.1399HH mice was observed to follow normal Mendelian ratios. No spontaneous bleeding was observed for any of the offspring. VWF expression was normal, but VWF binding to collagen IV was decreased in both heterozygous and homozygous offspring. Blood loss following tail resection was increased for p.1399HH mice, and occlusion times following ferric chloride-induced thrombosis were prolonged. Platelet aggregation was unaffected, but platelet adhesion to collagen IV under flow was diminished for p.1399HH mice. Conclusions These results show that a decrease in the ability of 1399H VWF to bind collagen IV under static conditions corresponds to a decrease in binding under flow conditions, an increased bleeding time, and a prolonged time to thrombosis. This study supports the potential for a bleeding phenotype in patients with aberrant VWF-collagen IV binding.

Author List

Slobodianuk TL, Kochelek C, Foeckler J, Kalloway S, Weiler H, Flood VH

Author

Veronica H. Flood MD Chief, Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Collagen Type IV
Disease Models, Animal
Hemorrhage
Hemostasis
Homozygote
Mice, Inbred C57BL
Mice, Transgenic
Mutation
Platelet Adhesiveness
Platelet Aggregation
Protein Binding
Protein Interaction Domains and Motifs
von Willebrand Diseases
von Willebrand Factor