Effect of calpain-mediated cleavage on CCL5 activity. (A) CCL5 release and cleavage after calpain activation in the absence and presence of calpeptin (Cpt, 10μM). (B) Cleavage of recombinant CCL5 by μ-calpain and chemotactic activity of full-length and calpain-cleaved CCL5 (ΔCCL5) on THP-1 cells in a Transwell chamber. (C) μ-calpain in releasates from resting platelets or platelets activated with thrombin alone or after stimulation with Ca2+ (5mM, 30 minutes) in the absence or in the presence of calpeptin (Cpt). (D) Calpain activity in plasma from healthy subjects and from patients with type 2 diabetes. (E) CCL5 and μ-calpain in circulating microparticles isolated from healthy subjects (CTL) and patients with type 2 diabetes (Dia). The graphs summarize data obtained with 5-6 subjects per group. *P < .05; **P < .01; ***P < .001 versus CTL/Sol; #P < .05 versus full-length CCL5.
