ATX is present in human platelets. (A) Gene expression in MKs. Mean of fluorescence intensity on Affymetrix MOE430A mouse array for GATA1, NFE2, integrin αIIb, integrin αV, integrin β3, fibrinogen α-chain, immunoglobulin heavy chain, and ATX were calculated from GEO dataset accession numbers GSM152271 and GSM152272, as previously established.21 (B) ATX expression in unstimulated human platelet lysate was detected by immunoblotting using anti-LysoPLD polyclonal antibody. Total CHO-dhfr+/ATX cell lysate and recombinant human ATX were used as controls. Integrin subunits αIIb and β3 were detected with specific antibodies. (C) Immunoprecipitation of ATX. Six releasates from aggregated platelets or supernatant from nonaggregated platelets were incubated with anti-LysoPLD antibody. ATX was immunodetected with the anti-LysoPLD antibody. (D) Image obtained from transmission electron microscopy of unstimulated human platelets. The grids were reacted with an anti-LysoPLD polyclonal antibody (top) or with 4F1 monoclonal antibody (bottom). The in situ localization of ATX was identified by gold particles after an amplification of the primary signal. AP, aggregated platelets; hATX, human ATX; NAP, nonaggregated platelets.