Effects of intermittent parathyroid hormone on cementoblast‐mediated periodontal repair

Abstract

Objectives To investigate the effects of intermittent parathyroid hormone on cementoblast‐mediated periodontal repair in the context of orthodontic‐induced root resorption. Materials and Methods The rat model of orthodontic‐induced root resorption was established. Sixty rats were randomly allocated into the experiment group (n = 30) and the control group (n = 30), either receiving a daily subcutaneous injection of recombinant human PTH or placebo vehicle. Enzyme‐linked immunosorbent assay, Micro‐computed tomography, hematoxylin and eosin staining, and immunohistochemistry staining were performed to detect the periodontal repair. In vitro, OCCM‐30 cells were exposed to intermittent PTH (incubated with PTH for the first 6 h in each 24‐h cycle). After three cycles, flow cytometry assay, alkaline phosphatase staining, and Alizarin red staining were performed. Quantitative real‐time polymerase chain reaction and Western blotting were employed to further determine the effects of intermittent PTH. Results Intermittent PTH‐responsive repair enhancement was detected with the expression of bone sialoprotein, osteocalcin, collagen‐1, and alkaline phosphatase significantly upregulated. Increased expressions of cementoblastic proteins were positively correlated to cycles of PTH administration. The proportion of cementoblasts in S and G2/M phases was increased; namely, intermittent PTH promoted cementoblast cell proliferation. Conclusions Intermittent parathyroid hormone administration promotes cementoblast‐mediated cementogenesis during periodontal repair in a time‐dependent manner.

Suppressing STAT3 activation impairs bone formation during maxillary expansion and relapse

“…Immunohistochemical staining of COL-I, Runx2, and ALP was conducted as previously described. 11 The sections were treated with 3% H 2 O 2 for 30 min at room temperature in the dark and washed three times with PBS. After 30 min incubation at room temperature with block solution containing 4% bovine serum albumin, sections were then soaked with primary antibodies dissolved in blocking solution: COL-I (dilution 1:150; ET1609-68), Runx2 (dilution 1:400; ET1612-47), and ALP (dilution 1:400, ET1607-53) from HuaBio (Hangzhou, China) at 4°C overnight.…”

“…An ALP assay kit (Beyotime, Shanghai, China) was used according to the manufacturer’s instructions and alizarin red staining performed as previously described. 11 The cells were rinsed with PBS thrice and fixed with 4% paraformaldehyde, followed by alizarin red staining (Sigma-Aldrich, St. Louis, USA). Images were visualized under a light microscope (Olympus IX71, Tokyo, Japan).…”

“…According to the previously published study, 11 Image J was used to analyze ALP activity and alizarin red staining images quantitatively. Images were converted into “RGB stack” and the threshold was adjusted to identify mineralization areas.…”