CircHmbox1 Targeting miRNA-1247-5p Is Involved in the Regulation of Bone Metabolism by TNF-α in Postmenopausal Osteoporosis

Tumor necrosis factor-alpha (TNF-α) promotes osteoclasts differentiation to enhance bone resorption and inhibits osteoblasts differentiation to impair bone formation, which plays a central role in the development of postmenopausal osteoporosis (PMOP). Recent studies implicated an important role of circular RNAs (circRNAs) in osteoporosis. The purpose of this study is to investigate whether circRNAs might be implicated in TNF-α-regulated osteoclasts differentiation and osteoblasts differentiation in PMOP. QRT-PCR was applied to detect expression of circRNA-circHmbox1 and miR-1247-5p in TNF-α-induced osteoclasts differentiation. Western blot, TRAP staining, alkaline phosphatase staining, alizarin red S staining, transwell and cell transfection were conducted to confirm that TNF-α inhibited osteoblasts differentiation by exosomal with low circHmbox1 expression from osteoclasts. Bioinformatics analysis and luciferase reporter revealed the mechanisms of the circHmbox1/miR-1247-5p/B cell lymphoma 6 (Bcl6) interaction. In this study, we found that the level of circRNA-circHmbox1 was obviously reduced in TNF-α-induced osteoclast formation in vivo and in vitro. CircHmbox1 could inhibit RANKL-induced osteoclasts differentiation primarily through binding to microRNA-1247-5p. TNF-α decreased osteoblasts differentiation by exosomal with low circHmbox1 expression from osteoclasts. Mechanistic studies showed that microRNA-1247-5p regulated osteoclasts differentiation and osteoblasts differentiation by targeting Bcl6, which was confirmed to play opposite roles in osteoblasts differentiation and osteoclasts differentiation. Our results provide evidence that circHmbox1-targeting miR-1247-5p is involved in the regulation of bone metabolisms by TNF-α in PMOP.

TGFβ1 Suppressed Matrix Mineralization of Osteoblasts Differentiation by Regulating SMURF1–C/EBPβ–DKK1 Axis

Transforming growth factor β1 (TGFβ1) is a major mediator in the modulation of osteoblast differentiation. However, the underlying molecular mechanism is still not fully understood. Here, we show that TGFβ1 has a dual stage-dependent role in osteoblast differentiation; TGFβ1 induced matrix maturation but inhibited matrix mineralization. We discovered the underlying mechanism of the TGFβ1 inhibitory role in mineralization using human osteoprogenitors. In particular, the matrix mineralization-related genes of osteoblasts such as osteocalcin (OCN), Dickkopf 1 (DKK1), and CCAAT/enhancer-binding protein beta (C/EBPβ) were dramatically suppressed by TGFβ1 treatment. The suppressive effects of TGFβ1 were reversed with anti-TGFβ1 treatment. Mechanically, TGFβ1 decreased protein levels of C/EBPβ without changing mRNA levels and reduced both mRNA and protein levels of DKK1. The degradation of the C/EBPβ protein by TGFβ1 was dependent on the ubiquitin–proteasome pathway. TGFβ1 degraded the C/EBPβ protein by inducing the expression of the E3 ubiquitin ligase Smad ubiquitin regulatory factor 1 (SMURF1) at the transcript level, thereby reducing the C/EBPβ-DKK1 regulatory mechanism. Collectively, our findings suggest that TGFβ1 suppressed the matrix mineralization of osteoblast differentiation by regulating the SMURF1-C/EBPβ-DKK1 axis.

Phyto Effect of Punica granatum on the Remodelling of Maxilla Bone, Study of Osteoblast and Osteoclast

Punica granatum (PG) contained anthocyanin, the chemical compound that played significant role in increasing bone cell proliferabbitsion and osteoblasts differentiation in bone remodelling. This research was aimed at measuring the effect of Punicagranatum on maxilla bone remodelling relating to the profile of both osteoblast and osteoclast. Punicagranatum was extracted by using butanol while the analysis of bone remodelling was conducted by observing the profile of osteoblast and osteoclast cells using histopathologic method. Butanol hydrogel of Punicagranatum was abled to enhance bone reabsorption which was proven by the increase of osteoclast and new bone formation since the osteoblast was presented. Moreover, bone remodelling activity was characterised by increased collagen fibres and osteocyte cell, in addition, bone shape compactness was getting better. Statistical analysis revealed that the histoscore profile of osteoblast was influenced by butanol fraction dosage with significance level (p<0.05) which was at medium criteria according to Pearson correlation (r=0,6). While the effect of dosage on osteoclast was at significance level (p<0.05) but was poorly correlated with (r=0.01) and osteoblast frequency was dominant at the concentrabbitsion of 125 mg/ml and 250 mg/ml. On the other hand, at the concentrabbitsion of 175 mg/ml osteoclast presentation was found to be more dominant. The fraction of butanol PG was abled to induce osteoblast increment and osteoclast at the concentrabbitsion of (mg/ml) 125, 175, and 250 and accelerabbitse the remodelling of alveolar maxilla.

Osteoconductive material of a newly developed resin modified glass ionomer cement containing bioactive glasses for biomedical purposes

Hybridization of resin modified- glass ionomer cement (RMGIC) and bioactive glass (BAG) may result higher mechanical strength and resistance to disintegration, while less contain of polyacrylic acid would lead to bioactivity of the cement. In the present study we investigated the effect of BAG from the CaSiO3-Ca3(PO4)2 system addition to the bioactivity of RMGIC. The BAG containing 10, 15, and 20% of P2O5 (denoted as CSP10, 15, and 20) were used in the study to modify the powder of RMGIC, with apatite wollastonite (AWG) was chosen for a comparison. The surface bioactivity was assessed using XRD, FT-IR, and SEM analysis after specimen immersion in the simulated body fluid (SBF). Measurement of Ca, P, F, Sr, and Al was conducted for the remaining SBF. Cells studies were done to evaluate cell attachment, proliferation, and differentiation on the RMGIC containing BAG compared to the one without BAG. Results of Sr and Al analysis lead to the conclusion that addition of BAG may not influence stability of the matrix of the cement. It was also confirmed that addition of bioactive glass was positive factor indicating excellent ions exchange in SBF and spontaneous growth of apatite by consuming the Ca and P ions in the surrounding fluid. The ability of osteoblasts differentiation on the four types of bioactive cements were higher than that of RMGIC without BAG. These results might provide novel insights into the development of a new generation of osteoconductive biomedical materials.