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Inducing and Characterizing Vesicular Steatosis in Differentiated HepaRG Cells
Published on: July 18, 2019
Distinct gene expression profiles characterize cellular responses to palmitate and oleate
Swapan K Das1, Ashis K Mondal, Steven C Elbein
1Section on Endocrinology and Metabolism, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA. sdas@wfubmc.edu
Journal of Lipid Research
|April 23, 2010
Summary
Chronic exposure to low-dose fatty acids, particularly unsaturated oleate, protects liver cells from saturated fatty acid-induced endoplasmic reticulum stress. This involves distinct transcriptional pathways and highlights PIK3IP1
Area of Science:
- Cellular biology
- Metabolic disease research
Background:
- Obesity is linked to insulin resistance and elevated free fatty acids (FFAs).
- Saturated fatty acids, but not unsaturated ones, induce endoplasmic reticulum (ER) stress in cell cultures.
Purpose of the Study:
- To investigate if chronic low-dose fatty acid exposure attenuates acute ER stress response.
- To compare the protective effects of unsaturated (oleate) versus saturated (palmitate) fatty acids.
Main Methods:
- Human hepatoma cells were exposed to chronic low-dose fatty acids.
- Acute stress response to saturated fatty acids was measured.
- Transcriptional responses and specific gene expressions (PIK3IP1, GADD45A) were analyzed.
- Small interfering RNA was used to block PIK3IP1.
Main Results:
- Chronic low-dose fatty acid exposure reduced palmitate-induced ER stress.
- Oleate provided significantly more protection than low-dose palmitate.
- Distinct transcriptional pathways were modulated by palmitate and oleate, including lipid metabolism and inflammatory cascades.
- Oleate blocked palmitate-induced PIK3IP1 and GADD45A/B expression, impacting PI3 kinase and p38 MAPK pathways.
Conclusions:
- Transcriptional responses to different fatty acids are distinct and can be discordant.
- PIK3IP1 plays a partial role in the protective effects of oleate against palmitate-induced ER stress.
- Findings suggest mechanisms for fatty acid-mediated regulation of ER stress and inflammation.
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