Identification of HIF-1α Promoter and Expression Regulation of HIF-1α Gene by LPS and Hypoxia in Zebrafish

Fish Physiol Biochem. 2013 Oct;39(5):1153-63. doi: 10.1007/s10695-013-9771-0. Epub 2013 Feb 8.

Abstract

The ubiquitously expressed hypoxia-inducible factor-1α (HIF-1α) acts as a key transcription factor in regulating metabolism, development, cellular survival, proliferation and pathology under hypoxia condition. Compared to mammals, fish are more vulnerable to hypoxia stress and contamination; however, the regulation of HIF-1α in fish remains obscure. In this study, zebrafish HIF-1α promoter was cloned and found to possess a CpG island located at -97 to +403, but the canonical TATA-box was absent. Aligning 240-bp HIF-1α proximal promoter region of zebrafish with other vertebrates showed more than 82 % identity with cyprinid fishes. Further luciferase analysis suggested that the minimal core promoter might locate at -134 to +97, and several putative transcription factor binding sites were found in this region by bioinformatic analysis. Moreover, it was shown that the zebrafish HIF-1α mRNA was significantly activated by 10 μg/mL lipopolysaccharide (LPS) under hypoxia condition and peaked at 8 h after treatment, suggesting LPS- and hypoxia-regulated zebrafish HIF-1α transcriptional activity in a synergistic pattern. This synergistic effect was closely related to the living environment of fish, indicating that this mechanism would be more conducive to fish survival.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Computational Biology
  • CpG Islands / genetics
  • DNA Primers / genetics
  • Fish Diseases / physiopathology*
  • Gene Expression Regulation / drug effects*
  • Hypoxia / physiopathology
  • Hypoxia / veterinary*
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Lipopolysaccharides / pharmacology*
  • Luciferases
  • Molecular Sequence Data
  • Plasmids / genetics
  • Promoter Regions, Genetic / genetics
  • Real-Time Polymerase Chain Reaction / veterinary
  • Sequence Analysis, DNA / veterinary
  • Sequence Homology
  • Species Specificity
  • Zebrafish / genetics*

Substances

  • DNA Primers
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Lipopolysaccharides
  • Luciferases