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Overexpression of Nell-1, a craniosynostosis-associated gene, induces apoptosis in osteoblasts during craniofacial

Xinli Zhang1, Dale Carpenter, Nobuyuki Bokui

  • 1Dental and Craniofacial Research Institute, University of California at Los Angeles, Los Angeles, California, USA.

Journal of Bone and Mineral Research : the Official Journal of the American Society for Bone and Mineral Research
|December 16, 2003
PubMed
Abstract

Insights

Nell-1 (a craniosynostosis-related gene) influences cranial bone cell development and programmed cell death. Its overexpression disrupts these processes, leading to craniofacial anomalies like premature suture closure.

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Genetics

Background:

  • Craniosynostosis (CS) is a congenital deformity characterized by premature cranial suture closure.
  • NELL-1 is a gene identified as overexpressed in CS patients and implicated in premature suture closure.
  • NELL-1 is proposed to promote osteoblast differentiation.

Purpose of the Study:

  • To investigate the cellular functions of Nell-1 in craniofacial development.
  • To elucidate the role of Nell-1 in osteoblast differentiation and apoptosis.
  • To understand how Nell-1 overexpression leads to craniofacial anomalies.

Main Methods:

  • Nell-1 was introduced into osteoblastic cells via viral infection and recombinant protein.
  • Apoptosis and gene expression assays were conducted.
  • Apoptosis was examined in calvaria of mice overexpressing Nell-1.

Main Results:

  • Nell-1 overexpression induced apoptosis and modulated apoptosis-related genes in osteoblastic cells.
  • This effect was specific to osteoblastic cells, not observed in fibroblasts.
  • Increased apoptosis was detected in the calvaria of Nell-1 overexpressing CS mouse models.

Conclusions:

  • Nell-1 expression modulates calvarial osteoblast differentiation and apoptosis pathways.
  • Overexpression of Nell-1 disrupts these pathways, causing craniofacial anomalies such as premature suture closure.

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