Effects of Nel-like molecule-1 and bone morphogenetic protein 2 combination on rat pulp repair

  • Jiameng Wu
  • Qiang Wang
  • Qi Han
  • Hongfan Zhu
  • Mengyue Li
  • Yixuan Fang
  • Xiaoying WangEmail author
Original Paper


Nel-like molecule-1 (NELL-1) is a novel highly specific growth factor that can induce osteoblast differentiation and bone formation as well as odontoblast differentiation. Recent studies have suggested that NELL-1 can synergistically increase bone formation and regeneration with bone morphogenetic protein 2 (BMP2) and inhibit adverse effects induced by BMP2. This study aimed to evaluate the combined effects of NELL-1 and BMP2 on rat pulp repair. The experiment used healthy non-carious maxillary first molars from 60 Wistar rats. Exposed pulps were capped with NELL-1 plus BMP2, NELL-1 alone, and BMP2 alone, and each was absorbed onto a sterile collagen sponge. In the control samples, the collagen sponge alone and Dycal were used as capping agents. After l, 2 and 4 weeks, the rats were sacrificed. The formation of reparative dentin, as well the situation of pulp repair, was detected by hematoxylin-eosin (HE) staining; moreover, the expression of dentin specific protein-dentin sialophosphoprotein (DSPP) and the pro-inflammatory cytokines interleukin-6 (IL6) and interleukin-8 (IL8) was detected by immunohistochemical staining. Quantitative real-time PCR experiment was used to investigate the mRNA levels of IL6 and IL8. The results showed that pulp capping with NELL-1 plus BMP2 in rats had superior ability in inducing reparative dentin formation with dentin tubules and in reducing the inflammatory cell response compared with the other groups. These findings suggested that combined use of NELL-1 and BMP2 could positively regulate pulp repair.


Nel-like molecule-1 Bone morphogenetic protein 2 Pulp repair Pulp capping Reparative dentin formation 



Supported by Shandong Natural Science Foundation of China (Grant No. ZR2014HQ075) and Science and Technology Development Project of Jinan City (Grant No. 201805047).

Compliance with ethical standards

Conflict of interest

The authors deny any conflicts of interest related to this study.


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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School of StomatologyShandong UniversityJinanChina
  2. 2.Jinan Stomatological HospitalJinanChina

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