Altered Hepatic Gene Expression under Choline-Deficient Conditions.

To elucidate mechanisms governing gene expression regulation in the liver in response to choline deficiency, we sought to identify genes responsive to choline-deficient conditions by conducting gene expression analysis in the livers of rats fed a choline-deficient diet. These rats exhibited reduced choline and betaine levels in their livers, and a group of genes linked to inflammatory responses and lipid metabolism was upregulated. Primary rat hepatocytes were cultured in choline-deficient medium to identify genes upregulated as intracellular choline and betaine levels decrease. Comparative analysis of gene expression profiles to identify regulated genes revealed that ubiquitin D (Ubd) expression is commonly upregulated under choline-deficient conditions in vivo and in cultured hepatocytes.