Peripheral leucocytes and tissue gene expression of granzyme B/perforin system and serpinB9: Impact on inflammation and insulin resistance in coronary atherosclerosis.

AIM: The imbalance between proapoptotic granzyme B (GZB)/perforin (PRF) system and proteinase inhibitor-9 (PI-9; serpinB9); the only known inhibitor of human GZB, has been demonstrated in atherosclerosis. However, their role in atherosclerosis with the impact of type 2 diabetes mellitus (DM) as well as their contribution to hallmarks of atherosclerosis is not clear.

SUBJECTS AND METHODS: ELISA for serum insulin, high sensitivity C-reactive protein (hsCRP) and GZB levels in atherosclerotic coronary artery diseases (CAD) patients were estimated in comparison to apparently healthy controls, while GZB, PRF and PI-9 mRNA expression levels were quantified by Taqman RT-PCR in both peripheral leucocytes and atherosclerotic tissues.

RESULTS: Atherosclerotic patients showed significantly higher insulin, hsCRP and GZB levels than controls. There was a significant increase in GZB mRNA expression and significant reduction in PI-9 mRNA in both patient peripheral leucocytes and atherosclerotic lesions, while PRF mRNA increased significantly only in atherosclerotic tissues. PI-9 mRNA levels were significantly lower in patients with diabetes than patients without diabetes. In contrast to positive modulating effect of GZB, regression analysis revealed negative modulating effect of PI-9 on inflammation and insulin resistance. Circulating PI-9 mRNA was inversely contributed to CAD severity.

CONCLUSIONS: GZB and PI-9 could be effective modulators for inflammation and insulin resistance in atherosclerosis.