Label-free imaging and analysis of the effects of lipolysis products on primary hepatocytes

Iwan W. Schie, Jian Wu, Tyler Weeks, Mark A Zern, John C Rutledge, Thomas R Huser

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The increased accumulation of intracellular lipid droplets within hepatocytes is a pathologic hallmark of liver injury of various etiologies, especially non-alcoholic steatohepatitis (NASH). The dynamics, subcellular origin, and chemical composition of lipid droplets under various pathophysiologic conditions, however, remain poorly understood. We used coherent Raman microscopy and spontaneous Raman spectroscopy to monitor and analyze the formation of lipid droplets in living primary rat hepatocytes exposed to triglyceride-rich lipoprotein (TGRL) lipolysis products. After exposure to the complex fatty acid mixture released during the lipolysis process for 30 minutes, new lipid droplets rapidly appeared within hepatocytes and increased in size and number over the total observation period of 205 minutes. Raman spectroscopic analysis of individual intracellular lipid droplets before and after exposure to lipolysis products reveals that the major components of these droplets are esterified unsaturated fatty acids. We find that the fatty acid unsaturation ratio increases with droplet size. Control experiments with defined fatty acid mixtures reveal the complexity of the cellular response to assault by combinations of lipids.

Original languageEnglish (US)
Pages (from-to)425-434
Number of pages10
JournalJournal of Biophotonics
Volume4
Issue number6
DOIs
StatePublished - Jun 2011

Fingerprint

Lipolysis
lipids
Labels
Hepatocytes
Lipids
fatty acids
Imaging techniques
Fatty Acids
products
Fatty acids
Raman Spectrum Analysis
etiology
lipoproteins
Fatty Liver
Unsaturated Fatty Acids
Unsaturated fatty acids
Lipoproteins
spectroscopic analysis
Microscopy
Spectroscopic analysis

Keywords

  • Coherent anti-Stokes Raman scattering (CARS)
  • Lipolysis
  • Non-alcoholic fatty liver disease (NAFLD)
  • Non-alcoholic steatohepatitis (NASH)
  • Non-linear microscopy
  • Raman spectroscopy
  • Triglyceride-rich lipoproteins

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)
  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Label-free imaging and analysis of the effects of lipolysis products on primary hepatocytes. / Schie, Iwan W.; Wu, Jian; Weeks, Tyler; Zern, Mark A; Rutledge, John C; Huser, Thomas R.

In: Journal of Biophotonics, Vol. 4, No. 6, 06.2011, p. 425-434.

Research output: Contribution to journalArticle

Schie, Iwan W. ; Wu, Jian ; Weeks, Tyler ; Zern, Mark A ; Rutledge, John C ; Huser, Thomas R. / Label-free imaging and analysis of the effects of lipolysis products on primary hepatocytes. In: Journal of Biophotonics. 2011 ; Vol. 4, No. 6. pp. 425-434.
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