Metabolic Flux Analysis of Cultured Hepatocytes Exposed to Plasma

Christina Chan, François Berthiaume, Kyongbum Lee, Martin L. Yarmush

Research output: Contribution to journalArticle

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Abstract

Hepatic metabolism can be investigated using metabolic flux analysis (MFA), which provides a comprehensive overview of the intracellular metabolic flux distribution. The characterization of intermediary metabolism in hepatocytes is important for all biotechnological applications involving liver cells, including the development of bioartificial liver (BAL) devices. During BAL operation, hepatocytes are exposed to plasma or blood from the patient, at which time they are prone to accumulate intracellular lipids and exhibit poor liver-specific functions. In a prior study, we found that preconditioning the primary rat hepatocytes in culture medium containing physiological levels of insulin, as opposed to the typical supraphysiological levels found in standard hepatocyte culture media, reduced lipid accumulation during subsequent plasma exposure. Furthermore, supplementing the plasma with amino acids restored hepatospecific functions. In the current study, we used MFA to quantify the changes in intracellular pathway fluxes of primary rat hepatocytes in response to low-insulin preconditioning and amino acid supplementation. We found that culturing hepatocytes in medium containing lower physiological levels of insulin decreased the clearance of glucose and glycerol with a concomitant decrease in glycolysis. These findings are consistent with the general notion that low insulin, especially in the presence of high glucagon levels, downregulates glycolysis in favor of gluconeogenesis in hepatocytes. The MFA model shows that, during subsequent plasma exposure, low-insulin preconditioning upregulated gluconeogenesis, with lactate as the primary precursor in unsupplemented plasma, with a greater contribution from deaminated amino acids in amino acid-supplemented plasma. Concomitantly, low-insulin preconditioning increased fatty acid oxidation, an effect that was further enhanced by amino acid supplementation to the plasma. The increase in fatty acid oxidation reduced intracellular triglyceride accumulation. Overall, these findings are consistent with the notion that the insulin level in medium culture presets the metabolic machinery of hepatocytes such that it directly impacts on their metabolic behavior during subsequent plasma culture.

Original languageEnglish (US)
Pages (from-to)33-49
Number of pages17
JournalBiotechnology and Bioengineering
Volume81
Issue number1
DOIs
StatePublished - Jan 5 2003
Externally publishedYes

Profile

Metabolic Flux Analysis
Hepatocytes
Plasmas
Callosities
Insulin
Fluxes
Amino Acids
Amino acids
Liver
Fibrin
Culture Media
Artificial Liver
Gluconeogenesis
Glycolysis
Fatty Acids
Lipids
Fatty acids
Metabolism
Rats
Oxidation

Keywords

  • Bioartificial liver
  • Lipid metabolism
  • Metabolic flux analysis
  • Plasma
  • Preconditioning

ASJC Scopus subject areas

  • Biotechnology
  • Microbiology

Cite this

Metabolic Flux Analysis of Cultured Hepatocytes Exposed to Plasma. / Chan, Christina; Berthiaume, François; Lee, Kyongbum; Yarmush, Martin L.

In: Biotechnology and Bioengineering, Vol. 81, No. 1, 05.01.2003, p. 33-49.

Research output: Contribution to journalArticle

Chan C, Berthiaume F, Lee K, Yarmush ML. Metabolic Flux Analysis of Cultured Hepatocytes Exposed to Plasma. Biotechnology and Bioengineering. 2003 Jan 5;81(1):33-49. Available from, DOI: 10.1002/bit.10453

Chan, Christina; Berthiaume, François; Lee, Kyongbum; Yarmush, Martin L. / Metabolic Flux Analysis of Cultured Hepatocytes Exposed to Plasma.

In: Biotechnology and Bioengineering, Vol. 81, No. 1, 05.01.2003, p. 33-49.

Research output: Contribution to journalArticle

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