ABSTRACT
PURPOSE: Osteitis refers to the development of new bone formation and remodeling of bone in chronic rhinosinusitis (CRS) patients; it is typically associated with eosinophilia, nasal polyps (NPs), and recalcitrant CRS. However, the roles of ossification in CRS with or without NPs remain unclear due to the lack of appropriate animal models. Thus, it is necessary to have a suitable animal model for greater advances in the understanding of CRS pathogenesis.METHODS: BALB/c mice were administered ovalbumin (OVA) and staphylococcal enterotoxin B (SEB). The numbers of osteoclasts and osteoblasts and bony changes were assessed. Micro computed tomography (micro-CT) scans were conducted to measure bone thickness. Immunofluorescence, immunohistochemistry, and quantitative polymerase chain reaction were performed to evaluate runt-related transcription factor 2 (RUNX2), osteonectin, interleukin (IL)-13, and RUNX2 downstream gene expression. Gene set enrichment analysis was performed in mucosal tissues from control and CRS patients. The effect of resveratrol was evaluated in terms of osteogenesis in a murine eosinophilic CRS NP model.RESULTS: The histopathologic changes showed markedly thickened bones with significant increase in osteoblast numbers in OVA/SEB-treated mice compared to the phosphate-buffered saline-treated mice. The structural changes in bone on micro-CT were consistent with the histopathological features. The expression of RUNX2 and IL-13 was increased by the administration of OVA/SEB and showed a positive correlation. RUNX2 expression mainly co-localized with osteoblasts. Bioinformatic analysis using human CRS transcriptome revealed that IL-13-induced bony changes via RUNX2. Treatment with resveratrol, a candidate drug against osteitis, diminished the expression of IL-13 and RUNX2, and the number of osteoblasts in OVA/SEB-treated mice.CONCLUSIONS: In the present study, we found the histopathological and radiographic evidence of osteogenesis using a previously established murine eosinophilic CRS NP model. This animal model could provide new insights into the pathophysiology of neo-osteogenesis and provide a basis for developing new therapeutics.
Subject(s)
Animals , Humans , Mice , Computational Biology , Core Binding Factor Alpha 1 Subunit , Enterotoxins , Eosinophilia , Eosinophils , Fluorescent Antibody Technique , Gene Expression , Immunohistochemistry , Interleukin-13 , Interleukins , Models, Animal , Mucous Membrane , Nasal Polyps , Nose , Osteitis , Osteoblasts , Osteoclasts , Osteogenesis , Osteonectin , Ovalbumin , Polymerase Chain Reaction , Sinusitis , Transcription Factors , TranscriptomeABSTRACT
AIM: To explore whether strontium ranelate ( Sr ) promotes osteogenic differentiation of rat bone mesenchymal stem cells (BMSCs) through the Hedgehog/Gli1 signaling pathway.METHODS:BMSCs were isolated from 4-week-old rats by adherent culture and induced to differentiate into osteoblasts .According to the experimental purposes , the cells were exposed to different concentrations of Sr , cyclopamine ( Cy, an inhibitor of Hedgehog receptor ) or Gli1-siR-NA.The expression of Gli1 and Runx2 in the cells was detected by Western blotting .The activity of alkaline phosphatase ( ALP) was measured by the method of colorimetry , and the mineralized nodules were observed under microscope with aliz-arin red staining .RESULTS:Exposure to Sr at concentrations of 0.1 to 5 mmol/L for 7 d markedly increased the expres-sion of Gli1 in the BMSCs , and the increase in Gli1 expression was the most obvious following Sr exposure at concentration of 3 mmol/L.Cy at concentration of 10 μmol/L inhibited Sr-induced up-regulation of Gli1 expression.Transfection of the BMSCs with Gli1-siRNA not only obviously inhibited Sr-induced up-regulation of Gli1 and Runx2 ( a downstream protein of Gli1) expression, but also antagonized Sr-induced enhancement of ALP activity and the formation of mineralized nodules . CONCLUSION:The Hedgehog/Gli1 pathway is involved in Sr-induced osteogenic differentiation of rat BMSCs .
ABSTRACT
Objective: To explore the effect of oxidative stress injury on the mechanism of vascular smooth muscle cell (VSMC) calciifcation induced by calcium and phosphorus in experimental rats. Methods: The VSMC calcification was induced by incubating the cells with calcium chloride (CaCl2) andβ-sodium glycerophosphate (β-GP) for 8 days, and the cells were divided into 4 groups: ① Control group, ② Calcification group,③ Calciifcation+H2O2 group, ④ Calciifcation+catalase group. The calcium nodule formation and calcium deposition in VSMC were detected by Alizarin red staining and o-cresolphthalein complexone method, the reactive oxygen species (ROS) was detected by DCFH-DA probe staining and the protein expression of Runx2 was examined by Western blot analysis. Results: Compared with Control group, Calciifcation group showed the higher ROS production, more calcium nodule and calcium deposition, higher Runx2 protein expression;while compared with Calciifcation group, the above indexes were even higher in Calciifcation+H2O2 group, P0.05. Conclusion: CaCl2 andβ-GP treatment may induce VSMC calciifcation via activating ROS-Runx2 signal pathway in experimental rats.