Increased galectin-3 levels are associated with abdominal aortic aneurysm progression and inhibition of galectin-3 decreases elastase-induced AAA development.

Abdominal aortic aneurysm (AAA) evolution is unpredictable and no specific treatment exists for AAA, except surgery to prevent aortic rupture. Galectin-3 has been previously associated with CVD, but its potential role in AAA has not been addressed. Galectin-3 levels were increased in the plasma of AAA patients (n=225) compared with the control group (n=100). In addition, galectin-3 concentrations were associated with the need for surgical repair, independently of potential confounding factors. Galectin-3 mRNA and protein expression were increased in human AAA samples compared with healthy aortas. Experimental AAA in mice was induced via aortic elastase perfusion. Mice were treated intravenously with the galectin-3 inhibitor modified citrus pectin (MCP, 10 mg/kg, every other day) or saline. Similar to humans, galectin-3 serum and aortic mRNA levels were also increased in elastase-induced AAA mice compared with control mice. Mice treated with MCP showed decreased aortic dilation, as well as elastin degradation, vascular smooth muscle cell (VSMC) loss, and macrophage content at day 14 postelastase perfusion compared with control mice. The underlying mechanism(s) of the protective effect of MCP was associated with a decrease in galectin-3 and cytokine (mainly CCL5) mRNA and protein expression. Interestingly, galectin-3 induced CCL5 expression by a mechanism involving STAT3 activation in VSMC. Accordingly, MCP treatment decreased STAT3 phosphorylation in elastase-induced AAA. In conclusion, increased galectin-3 levels are associated with AAA progression, while galectin-3 inhibition decreased experimental AAA development. Our data suggest the potential role of galectin-3 as a therapeutic target in AAA.