口腔疾病防治 (Jul 2018)

cAMP⁃responsive⁃element⁃binding protein promotes the differentiation of human stem cells from the apical pa⁃ pilla via inhibition of the TGF⁃β1 pathway

  • GU Xuening,
  • QUAN Jiamiao,
  • GUO Yuqing,
  • LI Song

DOI
https://doi.org/10.12016/j.issn.2096⁃1456.2018.07.004
Journal volume & issue
Vol. 26, no. 7
pp. 428 – 433

Abstract

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Objective This study aimed to investigate the effect of cAMP ⁃ responsive ⁃ element ⁃ binding protein (CREB) overexpression on the differentiation of human stem cells from the apical papilla (hSCAPs), stimulated by trans⁃ forming growth factor⁃ beta (TGF⁃β1). Methods Cells were isolated from human immature third molars via enzymatic digestion. Four experimental groups were set up: ①a control group, receiving normal mineralization inducer (α⁃MEM, 10% FBS, 10 mmol/L β ⁃ sodium glycerophosphate, 50 μg/mL vitamin C, 10 nmol/L dexamethasone); ② a TGF ⁃ β1 group, receiving normal mineralization inducer and 5 μg/mL TGF⁃β1; ③ a TGF⁃β1+LV⁃empty group, receiving normal mineralization inducer and the transfected empty virus vector with 5 μg/mL TGF ⁃ β1; and ④ a TGF ⁃ β1+ ov ⁃CREB group, receiving normal mineralization inducer and the transfected CREB ⁃ overexpressing viral vector, with 5 μg/mL TGF⁃β1. The transfected cells were cultured in odontogenic medium in the presence or absence of TGF⁃β1 for 2 weeks. Alizarin red staining was used to detect mineralized nodules, and the mRNA expression of the mineralization genes runt⁃ related transcription factor 2 (RUNX2), dentin sialophosphoprotein (DSPP) and alkaline phosphatase (ALP) was mea⁃ sured by qPCR. Results Compared with the control group (1.12 ± 0.11), TGF⁃β1 inhibited the deposition of calcium minerals (0.67 ± 0.12) (P < 0.05) via hSCAPs and inhibited the mRNA expression of RUNX2 (0.60 ± 0.03), DSPP (0.43 ± 0.12) and ALP (0.69 ± 0.05) (P < 0.05). In contrast, overexpression of CREB attenuated the effect of TGF⁃β1 on hS⁃ CAPs, resulting in the development of a high number of mineralized nodules (1.27 ± 0.10) (P < 0.01) and increased RNA levels of RUNX2 (1.33 ± 0.07), DSPP (1.32 ± 0.11) and ALP (1.26 ± 0.03) (P＜0.05) compared with those in the TGF⁃β1 group. Conclusion Overexpressed CREB promotes odontogenic differentiation of hSCAPs by interfering with TGF⁃β1.

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