Recombinant human bone morphogenetic protein‐9 potently induces osteogenic differentiation of human periodontal ligament fibroblasts

Abstract

To accomplish effective periodontal regeneration for periodontal defects, several regenerative methods using growth and differentiation factors, including bone morphogenetic proteins (BMPs), have been developed. Bone morphogenetic protein-9 exhibits the most potent osteogenic activity of this growth factor family. However, it is unclear whether exogenous BMP-9 can induce osteogenic differentiation in human periodontal ligament (PDL) fibroblasts. Here, we examined the effects of recombinant human (rh) BMP-9 on osteoblastic differentiation in human PDL fibroblasts in vitro, compared with rhBMP-2. Recombinant human BMP-9 potently induced alkaline phosphatase (ALP) activity, mineralization, and increased expression of runt-related transcription factor-2/core binding factor alpha 1 (RUNX2/CBFA1), osterix, inhibitor of DNA binding/differentiation-1 (ID1), osteopontin, and bone sialoprotein genes, compared with rhBMP-2. The levels of rhBMP-9-induced osterix and ALP mRNA were significantly reduced in activin receptor-like kinase-1 and -2 small interfering RNA (siRNA)-transfected human PDL fibroblasts. Recombinant human BMP-9-induced ALP activity was not inhibited by noggin, in contrast to rhBMP-2 induced ALP activity, which was. Phosphorylation of SMAD1/5/8 in human PDL fibroblasts was induced by addition of rhBMP-9. Recombinant human BMP-9-induced ALP activity was suppressed by SB203580, SP600125, and U0126, which are inhibitors of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2), respectively. Our data suggest that rhBMP-9 is a potent inducer of the differentiation of human PDL fibroblasts into osteoblast-like cells and that this may be mediated by the SMAD and mitogen-activated protein kinase (p38, ERK1/2, and JNK) pathways.

Superior bone‐inducing potential of rhBMP9 compared to rhBMP2

“…Therefore, other BMP family‐member proteins including BMP9 have especially been shown to play an important role in osteogenesis. rhBMP9 demonstrated more osteopromotive potential via different signaling cascades from rhBMP2 based on several in vitro studies …”

Effects of BMP9 and pulsed electromagnetic fields on the proliferation and osteogenic differentiation of human periodontal ligament stem cells

“…BMP9, an autocrine/paracrine cytokine in the liver, has been confirmed to be one of the most osteoinductive BMPs for inducing osteoblastic differentiation of MSCs both in vitro and in vivo using adenovirus‐transfection or recombinant human BMP9 methods [Kang et al, ; Fujioka‐Kobayashi et al, ; Li et al, ]. As reported, rhBMP9 increased expressions of Osterix, BSP, and OPN in hPDL fibroblasts compared with that stimulated by rhBMP2 [Fuchigami et al, ]. Several studies also demonstrate BMP9 has an effect on inducing spinal fusion and fracture non‐union repair in animal models [Dumont et al, ; Kimelman‐Bleich et al, ].…”

Guided bone regeneration with recombinant human bone morphogenetic protein 9 loaded on either deproteinized bovine bone mineral or a collagen barrier membrane

“…In a series of in vitro experiments, it was found that rhBMP9 demonstrated much higher expression of ALP and alizarin red staining on osteoprogenitor cells and periodontal ligament cells when compared to rhBMP2. [13][14][15] Moreover, 2 animal studies in rats demonstrated that rhBMP9 loaded on either an absorbable collagen or chitosan sponge significantly promoted new bone formation when compared to negative control samples. 16,17 While it is know that rhBMP9 has superior osteoinductive potential when compared to rhBMP2, the selection of a suitable carrier material is essential for its delivery, retention and release profile over time.…”

“…Interestingly, rhBMP9 has recently been made commercially available and compared to rhBMP2 for its regenerative potential. In a series of in vitro experiments, it was found that rhBMP9 demonstrated much higher expression of ALP and alizarin red staining on osteoprogenitor cells and periodontal ligament cells when compared to rhBMP2 . Moreover, 2 animal studies in rats demonstrated that rhBMP9 loaded on either an absorbable collagen or chitosan sponge significantly promoted new bone formation when compared to negative control samples .…”