Conclusion
Galectin-3 is the predominant gal and is colocalized with macrophages within atherosclerotic plaques. Intraplaque galectin-3 expression reflects the degree of plaque inflammation.
Methods
Galectins expression patterns in aortic atherosclerotic plaques and serum galectin-3 levels were investigated in 26-week-old apoE(-/-) (n=6) and C57BL/6 mice (n=9). To investigate the spatial and temporal patterns of galectin-1 and galectin-3 in plaques, high-cholesterol diet-fed 26-week-old (n=12) and 36-week-old apoE(-/-) mice (n=6) were sacrificed and their aortas were examined for galectins' expression using immunoblot analysis and immunohistochemical stain. 36-week-old apoE(-/-) mice were treated with atorvastatin (n=3, 0.57 mg/kg/day) for the evaluation of its effect on aortic galectins' expression.
Results
Immunoblot analyses showed that galectin-1 and galectin-3 were the predominant galectins expressed in murine atherosclerosis. The serum galectin-3 level was significantly higher in apoE(-/-) mice (p<0.001). While galectin-1 was weakly expressed in both intimal plaques and the media of atherosclerotic aortas, galectin-3 was heavily and exclusively accumulated in intimal plaques. Galectin-3 distribution was colocalized with plaque macrophages' distribution (r=0.66). As the degree of plaque extent and inflammation increased, the intraplaque galectin-3 expression levels proportionally elevated (p<0.01 vs. baseline), whereas galectin-1 expression had not elevated (p=0.14 vs. baseline). Atorvastatin treatment markedly reduced intraplaque galectin-3 and macrophage signals (p<0.001 vs. baseline), whereas it failed to reduce galectin-1 expression in the aortas.