ZFIN ID: ZDB-PUB-121206-39
TCDD Inhibits Heart Regeneration in Adult Zebrafish
Hofsteen, P., Mehta, V., Kim, M.S., Peterson, R.E., and Heideman, W.
Date: 2013
Source: Toxicological sciences : an official journal of the Society of Toxicology   132(1): 211-221 (Journal)
Registered Authors: Heideman, Warren, Mehta, Vatsal, Peterson, Richard E.
Keywords: none
Microarrays: GEO:GSE33981
MeSH Terms:
  • Aldehyde Oxidoreductases/genetics
  • Animals
  • Cell Proliferation/drug effects
  • Collagen/metabolism
  • Heart/drug effects*
  • Heart/physiology
  • In Situ Hybridization
  • Oligonucleotide Array Sequence Analysis
  • Polymerase Chain Reaction
  • RNA, Messenger/genetics
  • Regeneration/drug effects*
  • Up-Regulation
  • Zebrafish
PubMed: 23204111 Full text @ Toxicol. Sci.
ABSTRACT

Normal adult zebrafish can completely regenerate lost myocardium following partial amputation of the ventricle apex. We report that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) significantly impairs this regeneration. Adult male zebrafish were injected with vehicle (control) or TCDD (70 ng/g, ip) one day prior to partial amputation of the ventricle apex. Gross observation and histological analysis of the amputated heart at 21 days post amputation (dpa) revealed that TCDD-exposed fish had not progressed beyond the initial clot formation stage, while the vehicle control fish showed substantial recovery and almost complete resolution of the formed clot. In contrast, hearts that were not surgically wounded showed no signs of TCDD-toxicity. Striking features in the TCDD-exposed hearts were the absence of the normal sheath of new tissue enveloping the wound, and the absence of intense cell proliferation at the site of the wound. In addition, the patterns of collagen deposition at the wound site were different between the TCDD and vehicle groups. Because the receptor for TCDD is the AHR ligand-activated transcriptional regulator, we examined the effects of TCDD exposure on gene expression in the ventricle using DNA microarrays. Samples were collected just prior to amputation and at 6 h and 7 d post amputation. TCDD-pretreated hearts had dysregulated expression of genes involved in heart function, tissue regeneration, cell growth, and extracellular matrix. Because embryonic, but not adult, hearts are major targets for TCDD-induced cardiotoxicity, we speculate that the need for embryonic-like cells in regeneration is connected with the effects of TCDD in inhibiting the response to wounding.

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