AADACL1 inhibition reduces PKCδ but not PKCθ phosphorylation in human platelets. (A) Human platelets were pretreated with the indicated concentrations of JW480 as in Figure 1 and stimulated with 0.375 to 1 μg/mL collagen. Platelets were lysed in 10 mM CHAPS buffer on ice, and PKCδ phosphothreonine 505 (T505) or PKCθ phosphothreonine 538 (T538) was detected with specific antibodies. Pleckstrin and total PKCδ served as loading controls for panels A and C, respectively. (B) Phosphorylation of T505 and T538 was quantified with ImageJ from data in panel A (*P < .05 for PKCδ T505 DMSO vs 10 μM JW480; n = 2). (C) Human platelets were treated with the indicated concentrations of HAG, stimulated with 0.375 μg/mL collagen, and then prepared as in panel A. (D) Phosphorylation of T505 and T538 was quantified with ImageJ from data in panel C (*P < .04 for PKCδ T505 in “no HAG” without collagen vs “no HAG” with collagen; **P < .02 for PKCδ T505 “no HAG” plus collagen vs 10 μM HAG plus collagen; n = 3).