Functional expression of BMP7 receptors in oral epithelial cells. Interleukin-17F production in response to BMP7

  • J Recept Signal Transduct Res. 2017 Oct;37(5):515-521. doi: 10.1080/10799893.2017.1360352.
Kensuke Nishio  1  2 ,  Yasumasa Ozawa  3 ,  Hisanori Ito  3 ,  Takashi Kifune  3 ,  Tatsuya Narita  1  2 ,  Toshimitsu Iinuma  1  2 ,  Nobuhito Gionhaku  1  2 ,  Masatake Asano  4  5
Affiliations
  • 1. a Department of Complete Denture Prosthodontics , Nihon University School of Dentistry , Tokyo , Japan.
  • 2. b Division of Advanced Dental Treatment, Dental Research Center , Nihon University School of Dentistry , Tokyo , Japan.
  • 3. c Division of Applied Oral Sciences , Nihon University Graduate School of Dentistry , Tokyo , Japan.
  • 4. d Department of Pathology , Nihon University School of Dentistry , Tokyo , Japan.
  • 5. e Division of Immunology and Pathobiology , Nihon University School of Dentistry , Tokyo , Japan.
PMID: 28812969 DOI: 10.1080/10799893.2017.1360352
Abstract

Background: Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-β (TGF-β) superfamily. Recently, BMP7 has been demonstrated to be produced by salivary glands and contribute to embryonic branching in mice. The BMP7 in saliva is thought to be delivered to the oral cavity and is expected to contact with stratified squamous epithelial cells which line the surface of oral mucosa. In this study, we attempted to investigate the effects of BMP7 on oral epithelial cells.

Methods: The expression of BMP receptors was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). OSCCs were stimulated with human recombinant BMP7 (hrBMP7) and the phosphorylation status of Smad1/5/8 was examined by western blotting. For microarray analysis, Ca9-22 cells were stimulated with 100 ng/mL of hrBMP7 and total RNA was extracted and subjected to Real-Time PCR. The 5'-untranslated region (5'-UTR) of IL-17 F gene was cloned to pGL4-basic vector and used for luciferase assay. Ca9-22 cells were pre-incubated with DM3189, a specific inhibitor of Smad1/5/8, for inhibition assay.

Results: All isoforms of type I and type II BMP receptors were expressed in both Ca9-22 and HSC3 cells and BMP7 stimulation resulted in the phosphorylation of Smad1/5/8 in both cell lines. The microarray analysis revealed the induction of interleukin-17 F (IL-17 F), netrin G2 (NTNG2) and hyaluronan synthase 1 (HAS1). Luciferase assay using the 5'-UTR of the IL-17 F gene revealed transcriptional regulation. Induced IL-17 F production was further confirmed at the protein level by ELISA. Smad1/5/8 inhibitor pretreatment decreased IL-17 F expression levels in the cells.

Keywords
Oral squamous cell carcinoma; Smad1/5/8; bone morphogenetic protein 7 (BMP7); interleukin-17F (IL17F).
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