Putrescine: a novel inhibitor of glycosylation-induced cross-links in laminin.

OBJECTIVE

To determine whether putrescine, a naturally occurring polyamine, is able to prevent nonenzymatic glycosylation-induced cross-linking of basement membrane components. Cross-linking, leading to the formation of advanced glycosylation end products (AGEs) has been proposed as a major mechanism contributing to structural and functional changes of the vascular wall, thus leading to microangiopathy.

METHODS

Laminin, a major basement membrane glycoprotein present in the microvasculature, was isolated and incubated in the presence of high glucose concentrations, in order to generate an in vitro diabetic environment. Putrescine was either present or absent from the incubation mixture. Formation of cross-links was assessed by two independent methods: gel electrophoresis and development of characteristic fluorescence.

RESULTS

Putrescine inhibited in a dose-dependent manner the formation of slower mobility bands in gel electrophoresis. Quantitation of the development of fluorescence characteristic of glycosylation-induced cross-links demonstrated that putrescine inhibited the formation of fluorescent products.

CONCLUSIONS

Putrescine may be a promising compound for inhibition of protein cross-linking and, therefore, could be used in the prevention of diabetic microangiopathy.