Enhanced glucose synthesis in three-dimensional hepatocyte collagen matrix.

Three-dimensional (3D) cell culture model offers a unique opportunity to study hepatocytes that require extracellular matrix to keep the cells at the differentiated state. In this report, we cultured isolated mouse hepatocytes in a 3D collagen matrix system and developed a protocol to measure glucose production at 3h, 6h, 18h and 24h after culture. The results demonstrated that hepatocytes cultured under 3D collagen matrix condition consistently produced glucose at 240-290 mg/10(6) cells for up to 24h. Contrarily, hepatocytes cultured under traditional monolayer condition produced less than 50 mg/10(6) cells glucose. We demonstrated higher expression of phosphoenolpyruvate carboxykinase (PEPCK), a key enzyme for the synthesis of glucose from pyruvate, and CCAAT/enhancer-binding protein alpha (C/EBPalpha), an important liver-specific transcription factor, under the 3D collagen matrix culture condition in comparison to the monolayer condition. Thus, the 3D collagen matrix system preserved metabolic function of hepatocytes and can be used as an in vitro model for studying hepatocyte glucose production and gluconeogenesis.