Upregulated sulfatase and downregulated MMP-3 in thoracic aortic aneurysm.

BACKGROUND: Thoracic aortic aneurysm (TAA) formation is accompanied by degradation of extracellular matrix components (EMC). Numerous matrix metalloproteinases (MMPs) have been implicated in the process, but the involvement of MMP-3 remains unclear. Additionally, the changes in proteoglycan (PG) structure can alter the signal transduction pathways in TAA, though the enzymatic systems which originate them are not fully understood. OBJECTIVES: To measure MMP-3 and sulfatase levels in aneurysmal tissue, comparing them with non-aneurysmal vessels, and to investigate possible correlations with patients' serum levels in order to evaluate their potential usefulness in aiding aneurysm detection and monitoring. MATERIAL AND METHODS: The study included 74 patients (TAA: n = 42; control group: n = 32). Sulfatase activity was measured colometrically and MMP-3 levels were measured immunoenzymatically. RESULTS: Sulfatase activities were higher (p = 0.03) and MMP-3 concentrations lower (p = 0.014) in aneurysmal tissue than in normal aortic tissue. Medium-sized dilatations were associated with lower tissue MMP-3 concentrations than small dilatations (p = 0.033). No differences in sulfatase activity or MMP-3 concentration in the serum of TAA patients were observed in comparison with the controls. The serum and tissue levels of MMP-3 were correlated (r = 0.41; p < 0.001). The serum levels of MMP-3 were significantly lower in the female patients than in the male patients (p = 0.006). CONCLUSIONS: Our studies confirmed the lower MMP-3 levels in aneurysmal tissue, but the lack of a statistically confirmed reduction of MMP-3 in the blood serum seems to preclude its usefulness for diagnostic purposes. Our study points to the differences in MMP-3 behavior between TAA and abdominal aortic aneurysms. Significantly higher sulfatase activity in TAA tissue suggests a possible impact of sulfatase on signal transduction pathways involved in aneurysm formation.