Dysregulation of PMN antigen expression in Type 2 diabetes may reflect a generalized defect of exocytosis: influence of hypertension and microalbuminuria

Defective exocytosis could underlie clinical and metabolic abnormalities in Type 2 diabetes. Because many SNARE proteins appear to be common mediators of exocytosis, we examined phorbol myristate acetate-stimulated expression of CD11b and CD69 on polymorphonuclear leukocytes (PMN) from Type 2 diabet ic subjects with hypertension and microalbuminuria (D-htma), hypertension o nly (D-ht) or uncomplicated (D-uc), and normal controls (NC) by now cytomet ry. CD11b expression was rapid (half maximal by 7 min), initially on all PM N. CD69 expression took place subsequently but on PMN that did not express CD11b. The proportion of CD11b-positive PMN at 30 min Tvas higher in all di abetic groups than in NC. Expression of CD11b was higher and CD69 lower in D-uc and D-htma but were similar in NC and D-ht. In Type 2 diabetes the tra nsition from the CD11b-positive to CD69-positive state is impaired. The def ect in the process of CD69 expression appeared most marked in diabetic subj ects with hypertension and microalbuminuria.