A molecular and computational study of galbanic acid as a regulator of Sirtuin1 pathway in inhibiting lipid accumulation in HepG2 cells

Abstract

Introduction

Sirtuin1 (SIRT1) plays a crucial role in the pathophysiology of non-alcoholic fatty liver disease. We investigated the mechanistic role of galbanic acid (Gal) as a regulator of SIRT1 in silico and in vitro.

Methods

HepG2 cells were treated with Gal in the presence or absence of EX-527, a SIRT1-specific inhibitor, for 24 h. Sirtuin1 gene and protein expression were measured by RT-PCR and Western blotting, respectively. It has been docked to the allosteric reign of SIRT1 (PDB ID: 4ZZJ) to study the effect of Gal on SIRT1, and then the protein and complex molecular dynamic (MD) simulations had been studied in 100 ns.

Results

The semi-quantitative results of Oil red (p < .03) and TG level (p < .009) showed a significant reduction in lipid accumulation by treatment with Gal. Also, a significant increase was observed in the gene and protein expression of SIRT1 (p < .05). MD studies have shown that the average root mean square deviation (RMSD) was about 0.51 Å for protein structure and 0.66 Å for the complex. The average of radius of gyration (Rg) is 2.33 and 2.32 Å for protein and complex, respectively, and the pattern of root mean square fluctuation (RMSF) was almost similar.

Conclusion

Computational studies show that Gal can be a great candidate to use as a SIRT1 ligand because it does not interfere with the structure of the protein, and other experimental studies showed that Gal treatment with SIRT1 inhibitor increases fat accumulation in HepG2 cells.

Keywords:

• Galbanic acid
• Sirtuin1
• lipid accumulation
• HepG2 cells
• molecular dynamic

Acknowledgements

The authors are grateful to the Cellular and Molecular Biology Research Center of Mazandaran University of Medical Sciences for their utmost support and help in conducting the experiments.

Author contributions

H.M., A.Kh., and S.M were involved in project design and laboratory work. H.M., F.S., and H.Gh. collaborated on computational study. H.M., S.M., and A.Kh. collaborated in writing the article. H.M. and H.Sh. collaborated in data analysis.

Consent form

Not applicable.

Disclosure sstatement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This study was financially supported by the Babol University of Medical Sciences, Iran (No. 724132792).