Comparative Proteomics Analysis Reveals L-Arginine Activates Ethanol Degradation Pathways in HepG2 Cells

Abstract

L-Arginine (Arg) is a versatile amino acid that plays crucial roles in a wide range of physiological and pathological processes. In this study, to investigate the alteration induced by Arg supplementation in proteome scale, isobaric tags for relative and absolute quantification (iTRAQ) based proteomic approach was employed to comparatively characterize the differentially expressed proteins between Arg deprivation (Ctrl) and Arg supplementation (+Arg) treated human liver hepatocellular carcinoma (HepG2) cells. A total of 21 proteins were identified as differentially expressed proteins and these 21 proteins were all up-regulated by Arg supplementation. Six amino acid metabolism-related proteins, mostly metabolic enzymes, showed differential expressions. Intriguingly, Ingenuity Pathway Analysis (IPA) based pathway analysis suggested that the three ethanol degradation pathways were significantly altered between Ctrl and +Arg. Western blotting and enzymatic activity assays validated that the key enzymes ADH1C, ALDH1A1, and ALDH2, which are mainly involved in ethanol degradation pathways, were highly differentially expressed, and activated between Ctrl and +Arg in HepG2 cells. Furthermore, 10 mM Arg significantly attenuated the cytotoxicity induced by 100 mM ethanol treatment (P < 0.0001). This study is the first time to reveal that Arg activates ethanol degradation pathways in HepG2 cells.

Liver kinase B1/AMP‐activated protein kinase‐mediated regulation by gentiopicroside ameliorates P2X7 receptor‐dependent alcoholic hepatosteatosis

“…Ethanol also induced the mRNA and protein expression of CYP2E1 in HepG2 cells (Aljomah et al, ). Therefore, HepG2 cells are used to identify the effects of alcohol on human hepatocyte‐like cells without the complication of the many different cell types in liver (Pochareddy and Edenberg, ; Gao et al, ; Yan et al, ). RAW 264.7 cells and HepG2 cells were cultured in DMEM supplemented with 10% FBS, 100 units·mL −1 penicillin G and 100 mg·mL −1 streptomycin at 37°C under 5% CO 2 .…”

The Fatty Acid β-Oxidation Pathway is Activated by Leucine Deprivation in HepG2 Cells: A Comparative Proteomics Study

“…Previously, using the iTRAQ-based approach, we have characterized the proteome of HepG2 cells treated with either Gln deprivation or Arg supplementation 19, 20 . However, to our knowledge, there is no literature reporting proteome scale alterations induced by Leu deprivation in liver cells.…”

Cardiovascular Disease Related Proteomic Biomarkers of Alcohol Consumption

“…13 Several studies have investigated proteomic markers (up to 246 proteins) of extreme alcohol intake in cerebral cortex and hepatocellular carcinoma cell lines. [25][26][27][28] Statistical power of these studies was, however, limited due to small sample sizes (< 50). In addition, generalizability to general population was limited because extreme alcohol intake was the research focus in these previous studies.…”