Murine endothelial serine palmitoyltransferase 1 (SPTLC1) is required for vascular development and systemic sphingolipid homeostasis

  1. Andrew Kuo
  2. Antonio Checa
  3. Colin Niaudet
  4. Bongnam Jung
  5. Zhongjie Fu
  6. Craig E Wheelock
  7. Sasha A Singh
  8. Masanori Aikawa
  9. Lois EH Smith
  10. Richard L Proia
  11. Timothy Hla  Is a corresponding author
  1. Boston Children's Hospital, United States
  2. Karolinska Institute, Sweden
  3. Brigham and Women's Hospital, United States
  4. National Institute of Diabetes and Digestive and Kidney Diseases, United States

Abstract

Serine palmitoyl transferase (SPT), the rate-limiting enzyme in the de novo synthesis of sphingolipids (SL), is needed for embryonic development, physiological homeostasis, and response to stress. The functions of de novo SL synthesis in vascular endothelial cells (EC), which line the entire circulatory system, are not well understood. Here we show that the de novo SL synthesis in EC not only regulates vascular development but also maintains circulatory and peripheral organ SL levels. Mice with an endothelial-specific gene knockout of SPTLC1 (Sptlc1 ECKO), an essential subunit of the SPT complex, exhibited reduced EC proliferation and tip/stalk cell differentiation, resulting in delayed retinal vascular development. In addition, Sptlc1 ECKO mice had reduced retinal neovascularization in the oxygen-induced retinopathy model. Mechanistic studies suggest that EC SL produced from the de novo pathway are needed for lipid raft formation and efficient VEGF signaling. Post-natal deletion of the EC Sptlc1 also showed rapid reduction of several SL metabolites in plasma, red blood cells, and peripheral organs (lung and liver) but not in the retina, part of the central nervous system (CNS). In the liver, EC de novo SL synthesis was important for acetaminophen-induced rapid ceramide elevation and hepatotoxicity. These results suggest that EC-derived SL metabolites are in constant flux between the vasculature, circulatory elements, and parenchymal cells of non-CNS organs. Taken together, our data point to the central role of the endothelial SL biosynthesis in maintaining vascular development, neovascular proliferation, non-CNS tissue metabolic homeostasis, and hepatocyte response to stress.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting files. Source data files have been provided for each figure.

Article and author information

Author details

  1. Andrew Kuo

    Vascular Biology Program, Boston Children's Hospital, Boston, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7263-8658
  2. Antonio Checa

    Unit of Integrative Metabolomics, Karolinska Institute, Stockholm, Sweden
    Competing interests
    No competing interests declared.
  3. Colin Niaudet

    Vascular Biology Program, Boston Children's Hospital, Boston, United States
    Competing interests
    No competing interests declared.
  4. Bongnam Jung

    Vascular Biology Program, Boston Children's Hospital, Boston, United States
    Competing interests
    No competing interests declared.
  5. Zhongjie Fu

    Department of Ophthalmology, Boston Children's Hospital, Boston, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8182-2983
  6. Craig E Wheelock

    Unit of Integrative Metabolomics, Karolinska Institute, Stockholm, Sweden
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8113-0653
  7. Sasha A Singh

    Center for Interdisciplinary Cardiovascular Sciences, Brigham and Women's Hospital, Boston, United States
    Competing interests
    No competing interests declared.
  8. Masanori Aikawa

    Center for Interdisciplinary Cardiovascular Sciences, Brigham and Women's Hospital, Boston, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9275-2079
  9. Lois EH Smith

    Department of Ophthalmology, Boston Children's Hospital, Boston, United States
    Competing interests
    Lois EH Smith, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7644-6410
  10. Richard L Proia

    Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0456-1270
  11. Timothy Hla

    Vascular Biology Program, Boston Children's Hospital, Boston, United States
    For correspondence
    timothy.hla@childrens.harvard.edu
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8355-4065

Funding

American Heart Association (Postdoctoral Fellowship,18POST33990339)

  • Andrew Kuo

National Heart, Lung, and Blood Institute (R35,HL135821)

  • Timothy Hla

National Eye Institute (R01,EY031715)

  • Timothy Hla

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Edward E Morrisey, University of Pennsylvania, United States

Ethics

Animal experimentation: This study was performed in strict accordance with the recommendationsin the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All ofthe animals were handled according to approved institutional animal care and use committee(IACUC) protocols (#19-10-4031R) of the Boston Children's Hospital. Every effort was made to minimize suffering.

Version history

  1. Received: March 22, 2022
  2. Preprint posted: March 23, 2022 (view preprint)
  3. Accepted: October 4, 2022
  4. Accepted Manuscript published: October 5, 2022 (version 1)
  5. Accepted Manuscript updated: October 7, 2022 (version 2)
  6. Version of Record published: October 18, 2022 (version 3)

Copyright

This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

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  1. Andrew Kuo
  2. Antonio Checa
  3. Colin Niaudet
  4. Bongnam Jung
  5. Zhongjie Fu
  6. Craig E Wheelock
  7. Sasha A Singh
  8. Masanori Aikawa
  9. Lois EH Smith
  10. Richard L Proia
  11. Timothy Hla
(2022)
Murine endothelial serine palmitoyltransferase 1 (SPTLC1) is required for vascular development and systemic sphingolipid homeostasis
eLife 11:e78861.
https://doi.org/10.7554/eLife.78861

Share this article

https://doi.org/10.7554/eLife.78861

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