Enhanced laminin carbonylation by monocytes in diabetes mellitus

Objectives: Monocyte–extracellular matrix interactions have been implicated in atherosclerosis pathophysiology. In the present study we evaluated the oxidation of laminin by monocytes derived from either diabetic patients or healthy volunteers. Moreover, reactive oxygen species production was measured. Monocyte attachment and migration through oxidized and non-oxidized laminin were also studied. Design and methods: Laminin oxidation was tested by a sensitive ELISA assay in isolated monocytes. ROS production was measured with fluorescent indicators. 35S-methionine was used for evaluating monocyte attachment. Monocyte migration through laminin was examined on transwells. Results: Monocytes derived from patients with diabetes mellitus showed an increased ability to carbonylate and attach to laminin. Diabetic monocytes produced increased levels of ROS as compared to controls. Our results showed the involvement of the alpha2 integrin subunit in monocyte attachment to both native and oxidized laminin in control and diabetic monocytes. Conclusions: The results indicate a modified interaction between monocytes and laminin in diabetes.