Microbial metabolites regulate host lipid metabolism through NR5A-Hedgehog signalling

Nat Cell Biol. 2017 May;19(5):550-557. doi: 10.1038/ncb3515. Epub 2017 Apr 24.


Microorganisms and their hosts share the same environment, and microbial metabolic molecules (metabolites) exert crucial effects on host physiology. Environmental factors not only shape the composition of the host's resident microorganisms, but also modulate their metabolism. However, the exact molecular relationship among the environment, microbial metabolites and host metabolism remains largely unknown. Here, we discovered that environmental methionine tunes bacterial methyl metabolism to regulate host mitochondrial dynamics and lipid metabolism in Caenorhabditis elegans through an endocrine crosstalk involving NR5A nuclear receptor and Hedgehog signalling. We discovered that methionine deficiency in bacterial medium decreases the production of bacterial metabolites that are essential for phosphatidylcholine synthesis in C. elegans. Reductions of diundecanoyl and dilauroyl phosphatidylcholines attenuate NHR-25, a NR5A nuclear receptor, and release its transcriptional suppression of GRL-21, a Hedgehog-like protein. The induction of GRL-21 consequently inhibits the PTR-24 Patched receptor cell non-autonomously, resulting in mitochondrial fragmentation and lipid accumulation. Together, our work reveals an environment-microorganism-host metabolic axis regulating host mitochondrial dynamics and lipid metabolism, and discovers NR5A-Hedgehog intercellular signalling that controls these metabolic responses with critical consequences for host health and survival.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans / microbiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Genotype
  • Hedgehog Proteins / genetics
  • Hedgehog Proteins / metabolism*
  • Host-Pathogen Interactions
  • Lipogenesis*
  • Methionine / deficiency
  • Methionine / metabolism
  • Mitochondria / metabolism
  • Mitochondria / microbiology
  • Mitochondrial Dynamics
  • Patched Receptors / genetics
  • Patched Receptors / metabolism*
  • Phenotype
  • Phosphatidylcholines / biosynthesis*
  • Signal Transduction*
  • Time Factors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Caenorhabditis elegans Proteins
  • DNA-Binding Proteins
  • GRL-21 protein, C elegans
  • Hedgehog Proteins
  • PTR-24 protein, C elegans
  • Patched Receptors
  • Phosphatidylcholines
  • Transcription Factors
  • nuclear hormone receptor NHR-25, C elegans
  • 1,2-dilauroylphosphatidylcholine
  • Methionine