Specific oxylipins enhance vertebrate hematopoiesis via the receptor GPR132

  • Proc Natl Acad Sci U S A. 2018 Sep 11;115(37):9252-9257. doi: 10.1073/pnas.1806077115.
Jamie L Lahvic  1  2 ,  Michelle Ammerman  1  2 ,  Pulin Li  1  2 ,  Megan C Blair  1  2 ,  Emma R Stillman  1  2 ,  Eva M Fast  3  4 ,  Anne L Robertson  1  2 ,  Constantina Christodoulou  1  2 ,  Julie R Perlin  1  2 ,  Song Yang  1  2 ,  Nan Chiang  5 ,  Paul C Norris  5 ,  Madeleine L Daily  1  2 ,  Shelby E Redfield  1  2 ,  Iris T Chan  1  2 ,  Mona Chatrizeh  1  2 ,  Michael E Chase  1  2 ,  Olivia Weis  1  2 ,  Yi Zhou  1  2 ,  Charles N Serhan  5 ,  Leonard I Zon  6  2  3  4  7
Affiliations
  • 1. Stem Cell Program, Boston Children's Hospital, Boston, MA 02115.
  • 2. Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115.
  • 3. Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138.
  • 4. Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138.
  • 5. Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA 02115.
  • 6. Stem Cell Program, Boston Children's Hospital, Boston, MA 02115; [email protected].
  • 7. Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115.
PMID: 30139917 DOI: 10.1073/pnas.1806077115
Abstract

Epoxyeicosatrienoic Acids (EETs) are lipid-derived signaling molecules with cardioprotective and vasodilatory actions. We recently showed that 11,12-EET enhances hematopoietic induction and engraftment in mice and zebrafish. EETs are known to signal via G protein-coupled receptors, with evidence supporting the existence of a specific high-affinity receptor. Identification of a hematopoietic-specific EET receptor would enable genetic interrogation of EET signaling pathways, and perhaps clinical use of this molecule. We developed a bioinformatic approach to identify an EET receptor based on the expression of G protein-coupled receptors in cell lines with differential responses to EETs. We found 10 candidate EET receptors that are expressed in three EET-responsive cell lines, but not expressed in an EET-unresponsive line. Of these, only Recombinant GPR132 showed EET-responsiveness in vitro, using a luminescence-based β-arrestin recruitment assay. Knockdown of zebrafish gpr132b prevented EET-induced hematopoiesis, and marrow from GPR132 knockout mice showed decreased long-term engraftment capability. In contrast to high-affinity EET receptors, GPR132 is reported to respond to additional hydroxy-fatty acids in vitro, and we found that these same hydroxy-fatty acids enhance hematopoiesis in the zebrafish. We conducted structure-activity relationship analyses using both Cell Culture and zebrafish assays on diverse medium-chain Fatty Acids. Certain oxygenated, unsaturated free Fatty Acids showed high activation of GPR132, whereas unoxygenated or saturated Fatty Acids had lower activity. Absence of the carbon-1 position carboxylic acid prevented activity, suggesting that this moiety is required for receptor activation. GPR132 responds to a select panel of oxygenated polyunsaturated Fatty Acids to enhance both embryonic and adult hematopoiesis.

Keywords
GPCR; free fatty acid; hematopoiesis; zebrafish.
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