Coagulation factor X interaction with macrophages through its N-glycans protects it from a rapid clearance.
Factor X (FX), a plasma glycoprotein playing a central role in coagulation has a long circulatory half-life compared to closely related coagulation factors. The activation peptide of FX has been shown to influence its clearance with two N-glycans as key determinants of FX's relatively long survival. To decipher FX clearance mechanism, organ biodistribution and cellular interactions of human plasma FX (pd-FX), recombinant FX (rFX), N-deglycosylated FX (N-degly-FX) and recombinant FX mutated at both N-glycosylation sites (rFX(N181A-N191A)) were evaluated. Biodistribution analysis of (125)I-labelled FX proteins after administration to mice revealed liver as major target organ for all FX variants. Liver tissue sections analysis showed an interaction of pd-FX and N-degly-FX to different cell types. These findings were confirmed in cell binding studies revealing that FX and FX without N-glycans interact with macrophages and hepatocytes, respectively. N-degly-FX appeared to be degraded in hepatocytes while interestingly pd-FX was not by macrophages. Furthermore, the chemical inactivation of macrophages by gadolinium chloride resulted in a significant decrease of circulating pd-FX into mice and not of N-degly-FX. Altogether our data lead to the conclusion that FX interaction with macrophages through its N-glycans protects it from a rapid clearance explaining its relatively long circulatory half-life.
INSERM Unit 770, Le Kremlin-Bicêtre, France.
Mohamad
M
Kurdi
Ghislaine
G
Cherel
Peter J
PJ
Lenting
Cécile V
CV
Denis
Olivier D
OD
Christophe
D000818:Animals; D001665:Binding Sites; D005170:Factor X / Q000235:genetics / Q000378:metabolism* / Q000493:pharmacokinetics*; D005260:Female; D005682:Gadolinium / Q000633:toxicity; D006031:Glycosylation; D006207:Half-Life; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000493:pharmacokinetics; D013194:Staining and Labeling; D014018:Tissue Distribution
D007457:Iodine Radioisotopes; D011134:Polysaccharides; D011994:Recombinant Proteins; D005170:Factor X; D005682:Gadolinium; C038958:gadolinium chloride