Dataset Information

Astragaloside IV attenuates free fatty acid-induced ER stress and lipid accumulation in hepatocytes via AMPK activation.

ABSTRACT: Although the pathogenesis of non-alcoholic fatty liver disease (NAFLD) is not completely understood, the increased influx of free fatty acids (FFAs) into the liver and the FFA-induced hepatic endoplasmic reticulum (ER) stress are two crucial pathogenic processes in the initiation and development of NAFLD. In this study we investigated the effects of astragaloside IV (AS-IV), a bioactive compound purified from Astragali Radix, on FFA-induced lipid accumulation in hepatocytes and elucidated the underlying mechanisms. Human HepG2 cells and primary murine hepatocytes were exposed to FFAs (1 mmol/L, oleate/palmitate, 2:1 ratio) with or without AS-IV for 24 h. Exposure to FFAs induced marked lipid accumulation in hepatocytes, whereas co-treatment with AS-IV (100 μg/mL) significantly attenuated this phenomenon. Notably, AS-IV (50-200 μg/mL) concentration-dependently enhanced the phosphorylation of AMPK, acetyl-CoA carboxylase (ACC) and SREBP-1c, inhibited the accumulation and nuclear translocation of mature SREBP-1 and subsequently decreased the mRNA levels of lipogenic genes including acc1, fas and scd1. AS-IV treatment also concentration-dependently attenuated FFA-induced hepatic ER stress evidenced by the reduction of the key markers, GRP78, CHOP and p-PERK. Pretreated the cells with the AMPK inhibitor compound C (20 μmol/L) greatly diminished these beneficial effects of AS-IV. Our results demonstrate that AS-IV attenuates FFA-induced ER stress and lipid accumulation in an AMPK-dependent manner in hepatocytes, which supports its use as promising therapeutics for hepatic steatosis.

SUBMITTER: Zhou B

PROVIDER: S-EPMC5519246 | biostudies-other | 2017 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:Methods: We performed mRNA sequence analysis by deep sequencing, in triplicate, using Illumina HiSeq to assess the impact of PHLPP1 knockdown in regulating gene expression in RAW 264.7 cells treated with/without OxLDL. The transcriptome libraries were constructed using the NEB adapters and were sequenced on at 150 nucleotide read length using the paired-end chemistry. The raw reads were subjected to Adapter and low-quality reads removal by Trimmomatic -0.36v. The raw reads were subjected to contamination [structural RNA / low complexity sequences] removal by mapping with bowtie 2-2.2.1. The decontaminated data set was mapped to the mouse genome. Reads mapping to gene list were counted using feature count module of sub reads package. The read counts were normalized in DESeq2-3.5, and subject to differential expression analysis. Differentially expressed genes were selected based on log2-ratio change with p-value <0.05 (Student’s t-test, unpaired). Hierarchical clustering was performed with the programs Cluster (uncentered correlation; average linkage clustering) and Treeview. Results: To gain a deeper understanding of the role of PHLPP1 in lipid metabolism in macrophages, we performed mRNA Seq analysis to assess the gene expression changes in a mouse macrophage cell line. The experiment has been carried out in triplicates. Alignment of the reads showed 97% alignment to the reference mouse genome. Identification of the differentially expressed genes were then carried out by DESeq2 version 1.2.10 with stringent criteria (FDR <0.05% with 2 fold up and down regulation) which reveals in control treated vs. control (121-down, 396-Up), Test vs. Control - (326-down, 569 Up) and Test treated vs. control treated (1314-down, 1328 up) of DEG to be altered in expression respectively. Inference: RNA-seq analysis revealed that PHLPP1 knockdown parallel with OxLDL treatment resulted in diminished expression profile of cholesterol biosynthesis and lipid metabolism genes.

Dataset Information

Astragaloside IV attenuates free fatty acid-induced ER stress and lipid accumulation in hepatocytes via AMPK activation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets