1. Academic Validation
  2. Nell-1 Enhances Osteogenic Differentiation of Pre-Osteoblasts on Titanium Surfaces via the MAPK-ERK Signaling Pathway

Nell-1 Enhances Osteogenic Differentiation of Pre-Osteoblasts on Titanium Surfaces via the MAPK-ERK Signaling Pathway

  • Cell Physiol Biochem. 2018;50(4):1522-1534. doi: 10.1159/000494651.
Mei-Jie Shen 1 2 Ge-Ge Wang 1 Yu-Zhen Wang 1 Jing Xie 1 Xi Ding 3
Affiliations

Affiliations

  • 1 Department of Stomatology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
  • 2 Department of Stomatology, the First People's Hospital of Tongxiang, Jiaxing, China.
  • 3 Department of Stomatology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Chinadingxizj@hotmail.com.
Abstract

Background/aims: This study aimed to investigate the effect of Nell-1 on the osteogenic behaviors of pre-osteoblasts on titanium (Ti) surfaces and to identify the underlying signaling pathway.

Methods: Nell-1 at different concentrations was added to culture medium to stimulate MC3T3-E1 subclone 14 on Ti surfaces. A CCK-8 colorimetric assay was used to detect cell proliferation. Alkaline Phosphatase activity (ALP) assay and enzyme-linked immunosorbent assay (ELISA) were used to evaluate ALP activity and the osteocalcin (OCN) secretion, respectively. Indicators of osteoblastic differentiation were assessed using real-time polymerase chain reaction analysis (RT-PCR). Western blot (WB) assay was used to analyze the expression changes of the osteogenic proteins and the mitogen-activated protein kinase (MAPK) pathway.

Results: Nell-1 significantly increased the osteogenic gene and protein expression levels of ALP, OCN, Runx2, Osteoprotegerin (OPG), collagen type I (Col-I), and Osterix (Osx) in pre-osteoblasts on Ti surfaces. The optimal concentration of Nell-1 was 100 ng/ ml. In addition, Nell-1 activated ERK and JNK, but not P38, in MC3T3-E1 cells on the Ti surface. Except for ALP and Col-I, the promotive effects of Nell-1 on the expression of osteogenic markers were suppressed by ERK Inhibitor U0126.

Conclusion: Certain concentrations of Nell-1 can promote the osteogenic differentiation of pre-osteoblasts on Ti surfaces by activating the MAPK/ERK signaling pathway.

Keywords

MAPK/ERK signaling pathway; Nell-1; Pre-osteoblasts; Titanium (Ti) surface.

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