Go to The Journal of Clinical Investigation
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Transfers
  • Advertising
  • Job board
  • Contact
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Immunology
    • Metabolism
    • Nephrology
    • Oncology
    • Pulmonology
    • All ...
  • Videos
  • Collections
    • Resource and Technical Advances
    • Clinical Medicine
    • Reviews
    • Editorials
    • Perspectives
    • Top read articles
  • JCI This Month
    • Current issue
    • Past issues

  • Current issue
  • Past issues
  • Specialties
  • In-Press Preview
  • Editorials
  • Viewpoint
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Transfers
  • Advertising
  • Job board
  • Contact
Loss of Sbds in zebrafish leads to neutropenia and pancreas and liver atrophy
Usua Oyarbide, … , Jacek Topczewski, Seth J. Corey
Usua Oyarbide, … , Jacek Topczewski, Seth J. Corey
Published August 6, 2020
Citation Information: JCI Insight. 2020;5(17):e134309. https://doi.org/10.1172/jci.insight.134309.
View: Text | PDF
Research Article Gastroenterology Hematology

Loss of Sbds in zebrafish leads to neutropenia and pancreas and liver atrophy

  • Text
  • PDF
Abstract

Shwachman-Diamond syndrome (SDS) is characterized by exocrine pancreatic insufficiency, neutropenia, and skeletal abnormalities. Biallelic mutations in SBDS, which encodes a ribosome maturation factor, are found in 90% of SDS cases. Sbds–/– mice are embryonic lethal. Using CRISPR/Cas9 editing, we created sbds-deficient zebrafish strains. Sbds protein levels progressively decreased and became undetectable at 10 days postfertilization (dpf). Polysome analysis revealed decreased 80S ribosomes. Homozygous mutant fish developed normally until 15 dpf. Mutant fish subsequently had stunted growth and showed signs of atrophy in pancreas, liver, and intestine. In addition, neutropenia occurred by 5 dpf. Upregulation of tp53 mRNA did not occur until 10 dpf, and inhibition of proliferation correlated with death by 21 dpf. Transcriptome analysis showed tp53 activation through upregulation of genes involved in cell cycle arrest, cdkn1a and ccng1, and apoptosis, puma and mdm2. However, elimination of Tp53 function did not prevent lethality. Because of growth retardation and atrophy of intestinal epithelia, we studied the effects of starvation on WT fish. Starved WT fish showed intestinal atrophy, zymogen granule loss, and tp53 upregulation — similar to the mutant phenotype. In addition, there was reduction in neutral lipid storage and ribosomal protein amount, similar to the mutant phenotype. Thus, loss of Sbds in zebrafish phenocopies much of the human disease and is associated with growth arrest and tissue atrophy, particularly of the gastrointestinal system, at the larval stage. A variety of stress responses, some associated with Tp53, contribute to pathophysiology of SDS.

Authors

Usua Oyarbide, Arish N. Shah, Wilmer Amaya-Mejia, Matthew Snyderman, Margaret J. Kell, Daniela S. Allende, Eliezer Calo, Jacek Topczewski, Seth J. Corey

×

Figure 1

Sbds and sbds expression during development.

Options: View larger image (or click on image) Download as PowerPoint
Sbds and sbds expression during development.
(A) Western blot of lysates...
(A) Western blot of lysates from 25–30 pooled WT embryos showing Sbds expression at different stages in WT zebrafish. (B) Sbds expression profile in WT zebrafish the first 10 dpf with eifl1a as housekeeping gene. Gene expression normalized to 1 dpf and efl1a. (C) Western blotting showing Sbds expression at 5 and 10 dpf. (D) Sbds mRNA expression at different ages for WT, heterozygous, and homozygous mutants for the sbdsnu132 mutation. Expression is normalized against β-actin. (E) Polysome profile of 15 dpf larvae shows an increase of 60S and lower 80S peaks on sucrose gradient in sbds mutants and heterozygotes compared with WT siblings. (F) Ratio of monosome with respect to 40S and 60S subunits. Mutants and heterozygotes showed a lower ratio compared with WT siblings. AUFS, absorbance units full scale.

Copyright © 2023 American Society for Clinical Investigation
ISSN 2379-3708

Sign up for email alerts