Zebrafish models of skeletal dysplasia induced by cholesterol biosynthesis deficiency

Rebecca A. Anderson, Kevin T. Schwalbach, Stephanie R. Mui, Elizabeth E. LeClair, Jolanta M. Topczewska, Jacek Topczewski*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Human disorders of the post-squalene cholesterol biosynthesis pathway frequently result in skeletal abnormalities, yet our understanding of the mechanisms involved is limited. In a forward-genetic approach, we have found that a late-onset skeletal mutant, named kolibernu7, is the result of a cis-acting regulatory mutation leading to loss of methylsterol monooxygenase 1 (msmo1) expression within pre-hypertrophic chondrocytes. Generated msmo1nu81 knockdown mutation resulted in lethality at larval stage. We demonstrated that this is a result of both cholesterol deprivation and sterol intermediate accumulation by creating a mutation eliminating activity of Lanosterol synthase (Lss). Our results indicate that double lssnu60;msmo1nu81 and single lssnu60 mutants survive significantly longer than msmo1nu81 homozygotes. Liver-specific restoration of either Msmo1 or Lss in corresponding mutant backgrounds suppresses larval lethality. Rescued mutants develop dramatic skeletal abnormalities, with a loss of Msmo1 activity resulting in a more-severe patterning defect of a near-complete loss of hypertrophic chondrocytes marked by col10a1a expression. Our analysis suggests that hypertrophic chondrocytes depend on endogenous cholesterol synthesis, and blocking C4 demethylation exacerbates the cholesterol deficiency phenotype. Our findings offer new insight into the genetic control of bone development and provide new zebrafish models for human disorders of the cholesterol biosynthesis pathway.

Original languageEnglish (US)
Article numberdmm042549
JournalDMM Disease Models and Mechanisms
Volume13
Issue number6
DOIs
StatePublished - Jun 2020
Externally publishedYes

Keywords

  • Cholesterol
  • Chondrodysplasia punctata
  • Lss
  • Msmo1
  • Skeletal dysplasia
  • Zebrafish

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Medicine (miscellaneous)
  • Immunology and Microbiology (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)

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