Effects of TGF-β1 on OPG/RANKL Expression of Cementoblasts and Osteoblasts Are Similar without Stress but Different with Mechanical Compressive Stress

Xianrui Yang,Jinlin Song,Huan Zeng,Xin Xu,Lan Huang,Tian Chen,Li Cao,Yanmin Wang,Aishu Ren,Xianglong Han,Ding Bai,Rui Shu

doi:10.1155/2015/718180

Xianrui Yang, Jinlin Song + Show 10 more

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https://doi.org/10.1155/2015/718180

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Abstract

Introduction. This study aimed to explore the effects of TGF-β1 on regulating activities of cementoblasts and osteoblasts with or without stress. Material and Methods. Human recombinant TGF-β1 was added with different doses. Immunohistochemical test of osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB ligand (RANKL) and Alizarin Red-S staining were conducted. Mechanical compressive stress was obtained by increasing the pressure of gaseous phase. OPG/RANKL expression was detected in both cells through quantitative real-time PCR. Results. Similar significant differences (P < 0.05) existed in OPG/RANKL change with increasing concentration of TGF-β1 without mechanical stress for cementoblasts and osteoblasts. However, under 3 h stress, OPG increased and RANKL decreased significantly (P < 0.01) but with similar OPG/RANKL change. Moreover, under 24 h stress, OPG change exhibited no difference (P > 0.05), but RANKL decreased significantly (P < 0.01) at 10 and 100 ng/mL TGF-β1 in cementoblasts. In osteoblasts, OPG increased significantly (P < 0.01) at 10 and 100 ng/mL, whereas RANKL decreased with statistical difference (P < 0.05) at 1 and 10 ng/mL. Conclusions. The effects of TGF-β1 on OPG/RANKL expression of cementoblasts and osteoblasts are similar even without mechanical stress. However, these effects are different under mechanical compressive stress.

Highlights

This study aimed to explore the effects of Transforming growth factor-β1 (TGF-β1) on regulating activities of cementoblasts and osteoblasts with or without stress
With the increasing TGF-β1 concentrations at 1, 10, and 100 ng/mL, OPG expression increased in OCCM-30 and MC3T3E1 cells (Figure 2), whereas receptor activator of nuclear factor-kappaB ligand (RANKL) expression decreased in both cells (Figure 3)
This finding indicated that TGF-β1 exhibits a negative effect on mineralization in cells, and the influence is more significant in OCCM-30 than in MC3T3-E1 (Figure 4)

Summary

Introduction

This study aimed to explore the effects of TGF-β1 on regulating activities of cementoblasts and osteoblasts with or without stress. Similar significant differences (P < 0.05) existed in OPG/RANKL change with increasing concentration of TGF-β1 without mechanical stress for cementoblasts and osteoblasts. Under 24 h stress, OPG change exhibited no difference (P > 0.05), but RANKL decreased significantly (P < 0.01) at 10 and 100 ng/mL TGF-β1 in cementoblasts. The effects of TGF-β1 on OPG/RANKL expression of cementoblasts and osteoblasts are similar even without mechanical stress. These effects are different under mechanical compressive stress. As force-sensitive type of cells, both cementoblasts and osteoblasts change their functions and activities under mechanical stress to regulate the resorption and formation of bone and cementum [2]. The osteogenic cell lineage MC3T3-E1, which behaves to primary osteoblasts, and the cementogenic cell lineage OCCM-30, which expresses specific cementum-derived attachment protein and differentiates into terminally differentiated cementocytes, were considered good models for in vitro studies [4, 5]

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