Apolipoprotein A-IV polymorphisms Q360H and T347S attenuate its endogenous inhibition of thrombosis.
Biochem Biophys Res Commun
; 712-713: 149946, 2024 Jun 18.
Article
in En
| MEDLINE
| ID: mdl-38643717
ABSTRACT
Platelets are small anucleate cells that play a key role in thrombosis and hemostasis. Our group previously identified apolipoprotein A-IV (apoA-IV) as an endogenous inhibitor of thrombosis by competitive blockade of the αIIbß3 integrin on platelets. ApoA-IV inhibition of platelets was dependent on the N-terminal D5/D13 residues, and enhanced with absence of the C-terminus, suggesting it sterically hinders its N-terminal platelet binding site. The C-terminus is also the site of common apoA-IV polymorphisms apoA-IV-1a (T347S) and apoA-IV-2 (Q360H). Interestingly, both are linked with an increased risk of cardiovascular disease, however, the underlying mechanism remains unclear. Here, we generated recombinant apoA-IV and found that the Q360H or T347S polymorphisms dampened its inhibition of platelet aggregation in human platelet-rich plasma and gel-filtered platelets, reduced its inhibition of platelet spreading, and its inhibition of P-selectin on activated platelets. Using an ex vivo thrombosis assay, we found that Q360H and T347S attenuated its inhibition of thrombosis at both high (1800s-1) and low (300s-1) shear rates. We then demonstrate a conserved monomer-dimer distribution among apoA-IV WT, Q360H, and T347S and use protein structure modelling software to show Q360H and T347S enhance C-terminal steric hindrance over the N-terminal platelet-binding site. These data provide critical insight into increased cardiovascular risk for individuals with Q360H or T347S polymorphisms.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Apolipoproteins A
/
Thrombosis
/
Blood Platelets
/
Platelet Aggregation
Limits:
Humans
Language:
En
Journal:
Biochem Biophys Res Commun
Year:
2024
Type:
Article
Affiliation country:
Canada