Nrf2-dependent and Nrf2-independent induction of phase 2 detoxifying and antioxidant enzymes during keratinocyte differentiation.
As antioxidant enzymes can be actively modulated during keratinocyte (KC) differentiation, this study was aimed to evaluate the modulation of a group of phase 2 detoxifying and antioxidant enzymes (phase 2 enzymes) during KC differentiation. In postconfluence-induced differentiation model of KC, heme oxygenase-1 (HO-1), NADP(H):quinone oxidoreductase-1 (NQO-1), and glutathione S-transferase pi (GSTpi) were up-regulated at a transcriptional level. In Western blot analysis, the phase 2 enzymes were up-regulated by H(2)O(2), but down-regulated by N-acetyl cysteine, indicating the active role of reactive oxygen species for their expression during KC differentiation. When a redox-sensitive NF-E2 related factor-2 (Nrf2), a key transcriptional factor for phase 2 enzymes, was knocked down by small interfering RNA transfection in differentiated KCs, only NQO-1 was down-regulated in both mRNA and protein levels. In human skin, expression levels of the phase 2 enzymes were up-regulated in the differentiated KC in the normal epidermis and keratotic foci in squamous cell carcinoma, further supporting the differentiation-dependent expression of phase 2 enzymes in vivo. This study demonstrates that a group of phase 2 enzymes are modulated during KC differentiation via either Nrf2-dependent (NQO-1) or Nrf2-independent (HO-1 and GSTpi) ways.
Department of Dermatology, Research Center for Photomedicine, Chonnam National University Medical School, 8 Hak-dong, Gwangju, 501-757, Korea.
Mei Shan
MS
Piao
Jae-Jeong
JJ
Park
Jee-Young
JY
Choi
Dong-Hoon
DH
Lee
Sook Jung
SJ
Yun
Jee-Bum
JB
Lee
Seung-Chul
SC
Lee
D000111:Acetylcysteine / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism*; D002454:Cell Differentiation; D015536:Down-Regulation; D004790:Enzyme Induction; D051549:Glutathione S-Transferase pi / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology* / Q000201:enzymology*; D050217:Metabolic Detoxication, Phase II; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics* / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism; D015533:Transcriptional Activation; D015854:Up-Regulation
D000975:Antioxidants; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); D051549:Glutathione S-Transferase pi; D000111:Acetylcysteine