title: Inhibition of the 3-hydroxy-3-methyl-glutaryl-CoA reductase induces orofacial defects in zebrafish.
abstract: BACKGROUND
  Orofacial clefts (OFCs) are common birth defects, which include a range of disorders with a complex etiology affecting formation of craniofacial structures. Some forms of syndromic OFCs are produced by defects in the cholesterol pathway. The principal enzyme of the cholesterol pathway is the 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR). Our aim is to study whether defects of HMGCR function would produce orofacial malformation similar to those found in disorders of cholesterol synthesis.
  
  
  METHODS
  We used zebrafish hmgcrb mutants and HMGCR inhibition assay using atorvastatin during early and late stages of orofacial morphogenesis in zebrafish. To describe craniofacial phenotypes, we stained cartilage and bone and performed in situ hybridization using known craniofacial markers. Also, we visualized neural crest cell migration in a transgenic fish.
  
  
  RESULTS
  Our results showed that mutants displayed loss of cartilage and diminished orofacial outgrowth, and in some cases palatal cleft. Late treatments with statin show a similar phenotype. Affected-siblings displayed a moderate phenotype, whereas early-treated embryos had a minor cleft. We found reduced expression of the downstream component of Sonic Hedgehog-signaling gli1 in ventral brain, oral ectoderm, and pharyngeal endoderm in mutants and in late atorvastatin-treated embryos.
  
  
  CONCLUSIONS
  Our results suggest that HMGCR loss-of-function primarily affects postmigratory cranial neural crest cells through abnormal Sonic Hedgehog signaling, probably induced by reduction in metabolites of the cholesterol pathway. Malformation severity correlates with the grade of HMGCR inhibition, developmental stage of its disruption, and probably with availability of maternal lipids. Together, our results might help to understand the spectrum of orofacial phenotypes found in cholesterol synthesis disorders. Birth Defects Research (Part A) 106:814-830, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Programa de Anatomía y Biología del Desarrollo, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.|Instituto de Filosofía y Ciencias de la Complejidad (IFICC), Santiago, Chile.
authors.forename: Iskra A
authors.initials: IA
authors.lastname: Signore
authors.affiliation: Programa de Anatomía y Biología del Desarrollo, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Carolina
authors.initials: C
authors.lastname: Jerez
authors.affiliation: Programa de Anatomía y Biología del Desarrollo, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Diego
authors.initials: D
authors.lastname: Figueroa
authors.affiliation: Institute for Research in Dental Sciences, Facultad de Odontología, Universidad de Chile, Santiago, Chile.
authors.forename: José
authors.initials: J
authors.lastname: Suazo
authors.affiliation: Programa de Genética Humana, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Katherine
authors.initials: K
authors.lastname: Marcelain
authors.affiliation: Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Oscar
authors.initials: O
authors.lastname: Cerda
authors.affiliation: Programa de Anatomía y Biología del Desarrollo, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile. acolombo@med.uchile.cl.|Servicio de Anatomía Patológica, Hospital Clínico de la Universidad de Chile, Santiago, Chile. acolombo@med.uchile.cl.
authors.forename: Alicia
authors.initials: A
authors.lastname: Colombo Flores
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000201:enzymology / Q000235:genetics; D000818:Animals; D000069059:Atorvastatin / Q000009:adverse effects* / Q000494:pharmacology; D002971:Cleft Lip / Q000139:chemically induced / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D002972:Cleft Palate / Q000139:chemically induced / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D029961:Zebrafish Proteins; D000069059:Atorvastatin; D006903:Hydroxymethylglutaryl CoA Reductases
keywords: HMGCR; SHh-signaling; cholesterol pathway; orofacial cleft; orofacial malformation; statins; zebrafish