title: Anti-oxidative stress effect of red ginseng in the brain is mediated by peptidyl arginine deiminase type IV (PADI4) repression via estrogen receptor (ER) β up-regulation.
abstract: OBJECTIVE
  Ginseng has been used as an anti-stress agent, and its active ingredient, ginsenoside, is similar in structure to estrogen. However, the effect of ginseng on the stressed brain is not completely understood. The aim of this study is to understand systematically how red ginseng (RG) affects gene expressions in the brain of immobilization (IMO) stressed mice to elucidate its underlying mechanism.
  
  
  METHODS
  For in vivo experiments, mice were stressed by immobilization for 30, 45, or 60 min, and gene expression in the mice brain was analyzed by microarray and system biology. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling (TUNEL) staining, and gene expression by Western blot or qPCR. For in vitro study, the SK-N-SH neuroblastoma cells were stressed by H2O2 exposure. The resultant cytotoxicity was measured by MTT assay, and gene expression by Western blot, ELISA, or qPCR.
  
  
  RESULTS
  Microarray analysis of genes in IMO stressed mice brains showed that RG administration prior to IMO stress downregulated >40 genes including peptidyl arginine deiminase type 4 (PADI4). Interestingly, PADI4 was up-regulated by various stresses such as H2O2, acrylamide, and tunicamycin in neuroblastoma SK-N-SH cells but inhibited by RG. IMO stress and in vitro H2O2 stress depressed the estrogen receptor (ER)-β expression but not ERα. However, RG treatment increased ERβ expression both in vivo and in vitro. Comparative analysis regarding the networks by systems biology revealed that TNF-α plays a critical role in IMO stress, and the cell death associated network was much higher than other categories. Consistently, the IMO stress induced TNF-α and Cox-2 expressions, malondialdehyde (MDA), and cell death in the brain, whereas RG administration inhibited these inductions in vivo. siRNA and transient expression studies revealed that ERβ inhibited the PADI4 expression.
  
  
  CONCLUSIONS
  PADI4 could be used as an oxidative stress marker. RG seems to inhibit oxidative stress-inducible PADI4 by up-regulating ERβ expression in the brain thus protecting brain cells from apoptosis.
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Su-Won 440-746, South Korea.
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Kim
authors.forename: In-Hye
authors.initials: IH
authors.lastname: Kim
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Lee
authors.forename: Cuong
authors.initials: C
authors.lastname: Thach Nguyen
authors.forename: Jung-Ah
authors.initials: JA
authors.lastname: Ha
authors.forename: Soo-Cheol
authors.initials: SC
authors.lastname: Lee
authors.forename: Sangdun
authors.initials: S
authors.lastname: Choi
authors.forename: Kwang-Tae
authors.initials: KT
authors.lastname: Choi
authors.forename: Suhkneung
authors.initials: S
authors.lastname: Pyo
authors.forename: Dong-Kwon
authors.initials: DK
authors.lastname: Rhee
mesh_terms: D020106:Acrylamide / Q000494:pharmacology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects / Q000235:genetics; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006867:Hydrolases / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000235:genetics; D005894:Panax / Q000737:chemistry*; D028321:Plant Preparations / Q000737:chemistry / Q000494:pharmacology*; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D014415:Tunicamycin / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D000893:Anti-Inflammatory Agents; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D028321:Plant Preparations; D014409:Tumor Necrosis Factor-alpha; D014415:Tunicamycin; D020106:Acrylamide; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D006867:Hydrolases; C000629235:PADI4 protein, human; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; C552151:peptidylarginine deiminase 4, mouse