Multimerin 1 supports platelet function in vivo and binds to specific GPAGPOGPX motifs in fibrillar collagens that enhance platelet adhesion

Alexander Leatherdale; D'Andra Parker; Subia Tasneem; Yiming Wang; Dominique Bihan; Arkadiusz Bonna; Samir W Hamaia; Peter L Gross; Heyu Ni; Bradley W Doble; David Lillicrap; Richard W Farndale; Catherine P M Hayward

doi:10.1111/jth.15171

Multimerin 1 supports platelet function in vivo and binds to specific GPAGPOGPX motifs in fibrillar collagens that enhance platelet adhesion

J Thromb Haemost. 2021 Feb;19(2):547-561. doi: 10.1111/jth.15171. Epub 2020 Dec 17.

Authors

Alexander Leatherdale¹, D'Andra Parker¹, Subia Tasneem¹, Yiming Wang^{2

3}, Dominique Bihan⁴, Arkadiusz Bonna⁴, Samir W Hamaia⁴, Peter L Gross⁵, Heyu Ni^{2

3}, Bradley W Doble⁶, David Lillicrap⁷, Richard W Farndale⁴, Catherine P M Hayward^{1

8}

Affiliations

¹ Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.
² Laboratory Medicine and Pathobiology, Keenan Research Centre, Li Ka-Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.
³ Canadian Blood Services Centre for Innovation, Ottawa, ON, Canada.
⁴ Biochemistry, Downing Site, University of Cambridge, Cambridge, UK.
⁵ Medicine, Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, ON, Canada.
⁶ Biochemistry and Biomedical Sciences, McMaster Stem Cell and Cancer Research Institute, McMaster University, Hamilton, ON, Canada.
⁷ Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, ON, Canada.
⁸ Hamilton Regional Laboratory Medicine Program, and Department of Medicine, McMaster University, Hamilton, ON, Canada.

Abstract

Background: Multimerin 1 (human: MMRN1, mouse: Mmrn1) is a homopolymeric, adhesive, platelet and endothelial protein that binds to von Willebrand factor and enhances platelet adhesion to fibrillar collagen ex vivo.

Objectives: To examine the impact of Mmrn1 deficiency on platelet adhesive function, and the molecular motifs in fibrillar collagen that bind MMRN1 to enhance platelet adhesion.

Methods: Mmrn1-deficient mice were generated and assessed for altered platelet adhesive function. Collagen Toolkit peptides, and other triple-helical collagen peptides, were used to identify multimerin 1 binding motifs and their contribution to platelet adhesion.

Results: MMRN1 bound to conserved GPAGPOGPX sequences in collagens I, II, and III (including GPAGPOGPI, GPAGPOGPV, and GPAGPOGPQ) that enhanced activated human platelet adhesion to collagen synergistically with other triple-helical collagen peptides (P < .05). Mmrn1^-/- and Mmrn1^+/- mice were viable and fertile, with complete and partial platelet Mmrn1 deficiency, respectively. Relative to wild-type mice, Mmrn1^-/- and Mmrn1^+/- mice did not have overt bleeding, increased median bleeding times, or increased wound blood loss (P ≥ .07); however, they both showed significantly impaired platelet adhesion and thrombus formation in the ferric chloride injury model (P ≤ .0003). Mmrn1^-/- platelets had impaired adhesion to GPAGPOGPX peptides and fibrillar collagen (P ≤ .03) and formed smaller aggregates than wild-type platelets when captured onto collagen, triple-helical collagen mimetic peptides, von Willebrand factor, or fibrinogen (P ≤ .008), despite preserved, low shear, and high shear aggregation responses.

Conclusions: Multimerin 1 supports platelet adhesion and thrombus formation and binds to highly conserved, GPAGPOGPX motifs in fibrillar collagens that synergistically enhance platelet adhesion.

Keywords: blood platelets; fibrillar collagens; multimerin; platelet adhesiveness; von Willebrand factor.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Blood Platelets
Blood Proteins*
Fibrillar Collagens
Mice
Platelet Adhesiveness*
von Willebrand Factor

Substances

Blood Proteins
Fibrillar Collagens
multimerin
von Willebrand Factor

Abstract

Publication types

MeSH terms

Substances

Grants and funding