Altered gene expression in rat cranial neural crest cells exposed to a teratogenic glucose concentration in vitro: paradoxical downregulation of antioxidative defense genes

Birth Defects Res B Dev Reprod Toxicol. 2011 Oct;92(5):487-97. doi: 10.1002/bdrb.20321. Epub 2011 Aug 4.

Abstract

Background: Diabetic pregnancy is associated with increased risk of malformation in the infant. Diabetes-induced anomalies of the face and heart are strongly correlated with neural crest cell (NCC) maldevelopment. We aimed to study glucose-induced alterations of mRNA levels in cranial and trunk NCCs isolated from rat embryos with increased risk of developing mandibular and cardiac malformations in diabetic pregnancy.

Methods: Inbred Sprague-Dawley rat embryos were used for NCC isolation from neural tube explants. The migrating cells were exposed to 5.5 or 30 mmol/l glucose concentration for 48 hr, harvested, and prepared for gene expression measurement by RT-PCR or immunostaining with either distal-less (Dlx) or AP-2-α antibodies.

Results: Evaluation of the immunostained slides showed that approximately 75% of the cells were of NCC origin. Exposure to 30 mM glucose decreased mRNA levels of Copper-Zinc superoxide dismutase, manganese superoxide dismutase, extracellular superoxide dismutase, Catalase, Gpx-1, Nrf2, poly-ADP ribose polymerase, B-cell leukemia/lymphoma protein 2, and β-Catenin genes in cranial neural crest explant cultures. In addition, Pax-3, Pax-6, Wnt3a, and Apc mRNA levels were decreased by high glucose exposure in both cranial and trunk neural crest explant cultures.

Conclusion: Cranial NCCs diminish their mRNA levels of antioxidative enzymes and the Nrf2 response factor, as well as the antiapoptotic B-cell leukemia/lymphoma protein 2 gene, in response to increased ambient glucose concentration. Furthermore, both cranial and trunk NCC decrease the mRNA levels of the transcription factors Pax-3 and Pax-6, as well as key components of the Wnt pathway. These patterns of glucose-altered gene expression in a developmentally important cell population may be of etiological importance for NCC-associated malformations in diabetic pregnancy.

MeSH terms

  • Animals
  • Cells, Cultured
  • Diabetes Complications / genetics
  • Embryo, Mammalian / drug effects
  • Eye Proteins / biosynthesis
  • Female
  • Gene Expression / drug effects*
  • Gene Expression Regulation, Developmental / drug effects
  • Glucose / administration & dosage
  • Glucose / toxicity*
  • Homeodomain Proteins / biosynthesis
  • Neural Crest / cytology
  • Neural Crest / drug effects*
  • Neural Crest / embryology
  • Neural Crest / metabolism
  • PAX3 Transcription Factor
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors / biosynthesis
  • Pregnancy
  • Pregnancy in Diabetics / physiopathology*
  • Proto-Oncogene Proteins / drug effects
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Repressor Proteins / biosynthesis
  • Teratogens / toxicity*
  • Wnt Signaling Pathway / drug effects

Substances

  • Eye Proteins
  • Homeodomain Proteins
  • PAX3 Transcription Factor
  • PAX3 protein, rat
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Pax6 protein, rat
  • Proto-Oncogene Proteins
  • RNA, Messenger
  • Repressor Proteins
  • Teratogens
  • Glucose