Response of cementoblast-like cells to mechanical tensile or compressive stress at physiological levels in vitro

Abstract

To clarify the role of cementoblast in orthodontic-related root resorption, this study was attempted to examine whether murine cementoblast-like cells are responsive to mechanical stress, and how mechanical forces regulate bone sialoprotein (BSP) and osteopontin (OPN) gene expression in these cells in vitro. In this force-loading model, defined and reproducible mechanical loadings of different magnitudes and types were applied up to 24 h. Besides a transitory and reversible change in cell proliferation, remarkable alterations in gene transcription of BSP and OPN were found. BSP mRNA was suppressed by the stresses. Three and six hours-loadings at 2,000 microstrain up-regulated the expression of OPN mRNA, while the other loadings inhibited it. The study also concluded that 4,000 microstrain was likely to exert more influence on cementoblast-like cells than 2,000 microstrain. Furthermore, no obvious evidence indicated the difference between tension and compression. These results suggested that cementoblast-like cells are sensitive to mechanical stress, and may play a role in regulating orthodontic-related root resorption/repair.

Intermittent parathyroid hormone (PTH) promotes cementogenesis and alleviates the catabolic effects of mechanical strain in cementoblasts

“…Further, molecular analysis showed that the expression levels of BSP, ALP, OCN, OPN, Runx2 and Osx decreased when OCCM-30 cells were exposed to mechanical strain. Consistently, a previous study showed that mechanical strain of 2000–4000 με inhibited cell proliferation and BSP expression in cementoblasts [22]. A study of human dental pulp stem cells also revealed that mechanical strain suppressed the expression of osteogenesis-related genes bone morphogenetic protein 2 (BMP2), OCN and ALP, as well as odontogenic differentiation-related genes dentin sialophosphoprotein (DSPP), dentin sialoprotein (DSP) and BSP [23].…”

Screening the Expression Changes in MicroRNAs and Their Target Genes in Mature Cementoblasts Stimulated with Cyclic Tensile Stress

“…The results of the ALP activity assay, the ALP staining and the Alizarin Red staining also corroborated that the tensile stress could promote the osteogenic differentiation and subsequent mineralization of OCCM-30 cells (Figure 2C,D). These results were in accordance with Huang et al and Yu et al who found an increase in the expression of OPN and BSP after 2000 μstrain tensile stimulation in OCCM-30 cells, and the elevation of these makers was greater under the application of 2000 µstrain than 4000 µstrain [6,11]. In fact, the promotion towards an osteoblastogenesis-like phenotype is a common biological effect of tensile stress for various periodontal cells, such as PDLSCs and osteoblasts.…”

“…In recent years, in vitro cell loading systems have been widely used to investigate the stress-induced changes in diverse cells, i.e., osteoblast, adipose-derived stem cells (ASCs), bone marrow stromal cells (BMSCs) and PDLSCs [1,6,11,28,29]. Cementoblasts have also been reported to be mechanosensitive.…”

“…Cementoblasts have also been reported to be mechanosensitive. Their morphology, proliferation and cementoblastogenesis could be significantly upregulated by tensile or compressive stress [5,6,11]. We selected 2000 µstrain of stress to simulate physiological stimulation, since it is widely considered equivalent to physiological loading in orthodontic tooth movement [5,11,30].…”

“…Under certain mechanical stress (no matter tensile or compressive), cementoblasts may undergo cementoblastogenesis. Except for a few unique characteristics, such as cementum protein 1 [4], cementoblastogenesis largely resembles the major characteristics of osteoblastogenesis, such as the upregulation of proliferation, bone sialoprotein (BSP) [6,11], osteopontin (OPN) [11] and alkaline phosphatase (ALP) activity [5]. With this principle, osteoinductive growth factors, such as bone morphogenetic proteins (BMPs), have been adopted to regenerate the periodontal complex.…”