Inductive transcription and protective role of fish heme oxygenase-1 under hypoxic stress.
Heme oxygenase-1 is the rate-limiting enzyme in the degradation of heme into biliverdin, carbon monoxide and free divalent iron. In this study, we cloned heme oxygenase isoform 1 (CaHO-1) from a hypoxia-tolerant teleost fish Carassius auratus. The full-length cDNA of CaHO-1 is 1247 bp and encodes a protein of 272 amino acids. RT-PCR and real-time PCR analysis indicated that CaHO-1 was predominantly transcribed in posterior kidney, head kidney, gill and intestine, and induction of gene transcription was observed predominantly in posterior kidney under hypoxic stress. Moreover, the hypoxia-induced transcription was confirmed in goldfish larvae and in in vitro cultured CAB cells. Fluorescence of the HO-1-GFP fusion protein revealed a cytoplasmic and plasma membrane localization, which was consistent with the putative transmembrane structure. Subsequently, we established a stably transfected CAB/pcDNA3.1-HO-1 cell line and a control CAB/pcDNA3.1 cell line, and found that the number of dead cells was obviously reduced in the pcDNA3.1-HO-1-transfected group following 4 days of hypoxic (1% O(2)) treatment in comparison with numerous detached dead cells in the control pcDNA3.1-transfected cells. Furthermore, a significant cell viability difference between the two kinds of transfected cells during hypoxia-reoxygenation was revealed. Therefore, the data suggest that fish HO-1 might play a significant protective role in cells in response to hypoxic stress.
Wang
Dan
D
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Wuhan 430072, China.
Zhong
Xue-Ping
XP
Qiao
Zhi-Xian
ZX
Gui
Jian-Fang
JF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016923:Cell Death; D015687:Cell Hypoxia; D002470:Cell Survival; D002478:Cells, Cultured; D019610:Cytoprotection; D006054:Goldfish / Q000378:metabolism*; D051547:Heme Oxygenase-1 / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D021381:Protein Transport; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000201:enzymology; D014158:Transcription, Genetic
D051547:Heme Oxygenase-1; D010100:Oxygen