Deficiency of the potent calcification inhibitor fetuin-A promotes cholesterol crystallization in murine gallbladder bile in vivo

Most gallstones have a pigment-rich, calcium salt nidus, consistent with calcium precipitation favoring heterogeneous nucleation of cholesterol crystals in bile. Recently we have shown that serum protein alpha2-Heremans-Schmid glycoprotein (AHSG, a.k.a. fetuin-A) is a systemically acting potent inhibitor of ectopic calcification (Schäfer et al. J Clin Invest 2003;112:357–66). Since fetuin-A is also present in bile, our aim now was to assess its effect(s) on cholesterol crystallization in gallbladder bile in vivo. Methods: Sixty male and female fetuin-A knockout [Ahsg (-/-)] mice and Ahsg (+/+) wild-type litterma…