SWCNH (Single walled carbon nanohorn) supervises ER (Endoplasmic reticulum) stress through triggering autophagy process of hepatocytes, especially in hepatoma cell line HepG2

Backgrounds: The cellular homeostasis is major maintained by the catabolic pathway of autophagy. Our previous work indicated that SWCNH were associated with endoplasmic reticulum (ER) stress mediated by calcium flow and autophagic response. But, its mechanism was unclear. Methods: The regulation of SWCNH on the calcium flow then autophagy of liver cells were investigated through inducing ER stress with tunicamycin and SWCNH. The calcuim flow was determined using Fluo-3, then autophagy was examined with immunofluorescence or western blot for LC3, Beclin-1, ATG-5, and p62. Moreover, the apopototic protein of Bax and Bcl-2 was detected, too. Results: Tunicamycin-induced ER stress in hepatocytes was related to calcium flow, especially for hepatoma cell line HepG2. Moreover, SWCNH participated in the regulation of endoplasmic reticulum stress-related calcium flow. Besides, SWCNH induced hepatocyte autophagy and inhibited cell apoptosis, then mediated the process of hepatocyte autophagy. Conclusions: Tunicamycin-induced ER stress in hepatocytes was related to calcium flow. Moreover, SWCNH induced hepatocyte autophagy, inhibited cell apoptosis, and participated in the autophagy regulation of hepatocyte, especially for hepatoma cell line.

Experimental Study of Rhein Inhibits the Invasion and Migration of HepG2 Cells by ERK Signaling Pathway

Objective: To investigate the effectiveness of Rhein on the proliferation, invasion and migration of human hepatoma cell line HepG2 and its possible mechanism.Methods: Human hepatoma cell line HepG2 was treated with different concentrations of Rhein (Rhein treatment group) and culture in culture medium alone (control group).The proliferation activity of the cells was determined by methyl Thiazolyl Tetrazolium (MTT) colorimetry.Transwell assay detected the invasion and migration of cells in each group.Cell scratch test was used to detect the migration ability of cells in each group.Excella-phospho-excellar signal-regulated kinase (P-ERK) activity was determined by ELISA after treatment with 50μ mol/L Rhein at different times.Western blot was used to detect ERK protein expression in HepG2 cells treated with 50 μmol/L Rhein.Results: Compared with the control group, the proliferation activity, invasion and migration ability of HepG2 cells in the Rhein treatment group were all decreased (P< 0.05), and the p-ERK relative activity of HepG2 cells treated with Rhein was decreased (P < 0.05).Conclusion: Rhein inhibits the invasion and migration of HCC cells, possibly by inhibiting the ERK pathway

Mechanisms of the influence of adiponectin on apolipoproteins A-1 and B production by human hepatocytes

The aim of the study was to find out the mechanisms of the adiponectin effect on apolipoproteins (apo) A-1 and B production by human hepatocytes. Materials and methods. The study was performed on the human hepatoma cell line HepG2. The expression of the apoA-1 gene was evaluated at the mRNA level by quantitative PCR with reverse transcription, and the production of apo B by ELISA method. The activity of lipogenesis was assessed by the inclusion of labeled 14C-acetate in triglycerides, as well as by mRNA expression of lipogenesis genes, and by the estimation of total triglycerides content in cells. To determine the involvement of signaling pathways, the RNA interference method was used. Results. Knockdown of genes, coding the specific receptors, AMP-activated protein kinase, and its regulated transcription factors inhibited adiponectin-dependent stimulation of apoA-1 gene expression in hepatocytes. Adiponectin had no effect on lipogenesis and apo B production under basal conditions, but suppressed these processes induced by the addition of oleate. Conclusion. Adiponectin stimulates the production of apo A-1 in hepatocytes by inducing the transcription of the apoA-1 gene and suppresses the secretion of apo B by affecting lipogenesis. These effects may underlie the effect of adiponectin on lipoproteins metabolism.