Involvement of RBP4 in all‑trans retinoic acid induced cleft palate

Mol Med Rep. 2017 Nov;16(5):5915-5923. doi: 10.3892/mmr.2017.7327. Epub 2017 Aug 22.

Abstract

The current study was designed to elucidate the mechanism of retinol binding protein 4 (RBP4) in cleft palate induced by all‑trans retinoic acid (atRA). To establish a cleft palate model in C57BL/6J mice, pregnant mice were administered atRA (100 mg/kg) by gavage at the tenth embryonic stage (E10.0). Control groups were given the equivalent volume of corn oil. Pregnant mice were dissected at E12.5, E13.5 and E14.5 to obtain the embryonic palates. The expression levels of RBP4 in the embryonic palatal mesenchyme (EPM) were determined by immunohistochemistry, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Human embryonic palatal mesenchymal cells were exposed to atRA to detect the variation in RBP4 induced by atRA in vitro. Small interfering RNA was used to suppress the expression of RBP4, and a plasmid overexpressing RBP4 was used to examine upregulated expression. The cell counting kit‑8 assay was used to evaluate the effect of RBP4 on cell proliferation. The expression levels of p27 and cyclin D1 were determined by RT‑qPCR and western blotting, while the expression levels of extracellular signal‑related kinase (ERK) 1/2 and protein kinase B (AKT) were assessed by western blotting. At E14.5, RBP4 was strongly expressed in the EPM, while it was downregulated following atRA treatment, which induced cleft palate in vivo. In vitro experiments indicated that atRA suppressed the expression of RBP4 and altered the expression of p27 and cyclin D1 to cause growth inhibition. Knockdown of RBP4 resulted in decreased expression of cyclin D1 and increased p27, and suppressed proliferation. Overexpression of RBP4 reversed the inhibitory effect of atRA and promoted proliferation via the ERK1/2 and AKT signaling pathways. These results suggested that RBP4 was involved in cleft palate induced by atRA and it can be suppressed by atRA to cause growth inhibition in the embryonic palate.

MeSH terms

  • Animals
  • Cell Line
  • Cell Proliferation
  • Cleft Palate / chemically induced
  • Cleft Palate / genetics*
  • Cleft Palate / metabolism
  • Cleft Palate / pathology
  • Corn Oil / administration & dosage
  • Cyclin D1 / genetics
  • Cyclin D1 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p27 / genetics
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism
  • Disease Models, Animal
  • Embryo, Mammalian
  • Excipients / administration & dosage
  • Female
  • Gene Expression Regulation, Developmental*
  • Humans
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Pregnancy
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Retinol-Binding Proteins, Plasma / antagonists & inhibitors
  • Retinol-Binding Proteins, Plasma / genetics*
  • Retinol-Binding Proteins, Plasma / metabolism
  • Signal Transduction
  • Tretinoin / pharmacology*

Substances

  • Ccnd1 protein, mouse
  • Excipients
  • RBP4 protein, human
  • RNA, Small Interfering
  • Rbp4 protein, mouse
  • Retinol-Binding Proteins, Plasma
  • Cyclin D1
  • Cyclin-Dependent Kinase Inhibitor p27
  • Tretinoin
  • Corn Oil
  • Proto-Oncogene Proteins c-akt
  • Mapk1 protein, mouse
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3