Abstract To investigate the relationship of endoplasmic reticulum stress and lipid metabolism imbalance in microencapsulated cells, we compared the expression of glucose regulating protein 78 (GRP78) and C/EBP homologous protein (CHOP) in HepG2 cells under different culture conditions using real-time PCR. Cell viability was measured by MTT and the content of cholesterol (CHO), triglyceride (TG) and albumin were evaluated through ELISA assay. The effect of 4-PBA treatment on above parameters were examined. Results show that the expression levels of GRP78 and CHOP in encapsulated cells were approximately 3.6 and 1.9 times higher than in monolayer cells (P<0.05). As for the contents of CHO and TG, they were elevated to 1.7 and 3.2 times higher than monolayer cells (P<0.05). With 1.0 mM 4-PBA treatment, genes expression of CHO and TG was reduced by 50% and 30%, respectively. Moreover, the contents of CHO and TG were reduced by 30% and 15%. The biosynthetic function was increased since day 10 with 4-PBA (P<0.05). In conclusion, endoplasmic reticulum stress exists in the microcapsules and affects lipid metabolism. Antagonist 4-PBA can prevent the inhibition effects of endoplasmic reticulum stress on cellular growth.
Key words ：
microencapsulated cells
endoplasmic reticulum stress
glucose regulating protein 78
C/EBP homologous protein
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