ZFIN ID: ZDB-PUB-160218-3
Cannabinoid receptor signaling regulates liver development and metabolism
Liu, L.Y., Alexa, K., Cortes, M., Schatzman-Bone, S., Kim, A.J., Mukhopadhyay, B., Cinar, R., Kunos, G., North, T.E., Goessling, W.
Date: 2016
Source: Development (Cambridge, England)   143: 609-22 (Journal)
Registered Authors: Goessling, Wolfram, North, Trista, Schatzman-Bone, Steph
Keywords: Cannabinoid receptor, Liver development, Methionine, Mouse, Zebrafish
MeSH Terms:
  • Animals
  • Cannabinoids/metabolism
  • Cell Count
  • Cell Proliferation/drug effects
  • Cysteine/pharmacology
  • Hepatocytes/cytology
  • Hepatocytes/drug effects
  • Hepatocytes/metabolism
  • Liver/drug effects
  • Liver/embryology*
  • Liver/metabolism*
  • Metabolomics
  • Methionine/metabolism
  • Mutation/genetics
  • Organ Size/drug effects
  • Receptor, Cannabinoid, CB1/metabolism*
  • Receptor, Cannabinoid, CB2/metabolism*
  • Signal Transduction*/drug effects
  • Stem Cells/cytology
  • Stem Cells/drug effects
  • Stem Cells/metabolism
  • Zebrafish/embryology*
  • Zebrafish/metabolism*
  • Zebrafish Proteins/metabolism*
PubMed: 26884397 Full text @ Development
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ABSTRACT
Endocannabinoid (EC) signaling mediates psychotropic effects and regulates appetite. By contrast, potential roles in organ development and embryonic energy consumption remain unknown. Here, we demonstrate that genetic or chemical inhibition of cannabinoid receptor (Cnr) activity disrupts liver development and metabolic function in zebrafish (Danio rerio), impacting hepatic differentiation, but not endodermal specification: loss of cannabinoid receptor 1 (cnr1) and cnr2 activity leads to smaller livers with fewer hepatocytes, reduced liver-specific gene expression and proliferation. Functional assays reveal abnormal biliary anatomy and lipid handling. Adult cnr2 mutants are susceptible to hepatic steatosis. Metabolomic analysis reveals reduced methionine content in Cnr mutants. Methionine supplementation rescues developmental and metabolic defects in Cnr mutant livers, suggesting a causal relationship between EC signaling, methionine deficiency and impaired liver development. The effect of Cnr on methionine metabolism is regulated by sterol regulatory element-binding transcription factors (Srebfs), as their overexpression rescues Cnr mutant liver phenotypes in a methionine-dependent manner. Our work describes a novel developmental role for EC signaling, whereby Cnr-mediated regulation of Srebfs and methionine metabolism impacts liver development and function.
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