Pyroptosis, an inflammatory caspase-dependent programmed cell death, plays a vital role in maintaining tissue homeostasis and activating inflammatory responses. Orthodontic tooth movement (OTM) is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament (PDL) progenitor cells. However, whether and how force induces PDL progenitor cell pyroptosis, thereby influencing OTM and alveolar bone remodeling remains unknown. In this study, we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process. Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively. Using Caspase-1^-/- mice, we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1. Moreover, mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro, which influenced osteoclastogenesis. Mechanistically, transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells. Overall, this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli, indicating a promising approach to accelerate OTM by targeting Caspase-1.
Animals ; Humans ; Mice ; Rats ; Bone Remodeling/physiology* ; Caspase 1 ; Periodontal Ligament ; Pyroptosis ; Tooth Movement Techniques

Objective To predict the micro-level energy release rate in the rat femoral cortical bone and investigate the variation in the micro-level energy release rate with age.Methods Based on previous experimental data and numerical simulation of fracture modes for cortical bone,load-displacement curves and fracture modes measured by simulation and experiment were compared,and the micro-level energy release rates of rat femoral cortical bone at different months were predicted by back-calculation.Results It was predicted that the micro-level energy release rate of rat femoral cortical bone at 1-,3-,5-,7-,9-,11-,and 15-month age was 0.08-0.12,0.12-0.14,0.15-0.19,0.25-0.28,0.23-0.25,0.19-0.22,and 0.13-0.16 N/mm,respectively.Conclusions The decrease in the microlevel energy release rate with increasing age led to a decreasing failure load,indicating that the microlevel energy release rate is one of the main factors determining fracture occurrence;however,no significant decrease was observed at the time of fracture,indicating that the microlevel energy release rate was not linearly proportional to the fracture time.These results can help explain the mechanism of cortical bone fractures at the clinical level.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.

Objective:To investigate the effect of phosphorylated HSP27 on the proliferation and metastasis of nasopharyngeal carcinoma and its molecular mechanism. Methods:①Western blot assay was used to detect the expression levels of HSP27 and p-HSP27 in CNE1 and CNE2 cells of nasopharyngeal carcinoma. Inhibited the phosphorylation of HSP27, Transwell assay detected the metastasis ability of nasopharyngeal carcinoma cells. ②Nasopharyngeal carcinoma cell lines（CNE2-OE1 and CNE2-OE2） overexpressing phosphorylated and dephosphorylated mutants of HSP27 were synthesized, empty vector transfected CNE2 cells（CNE2-NC） were used as controls. The proliferation ability of the three groups of cells was detected by CCK8, and the expression levels of CyclinD1, Bax and Bcl-2 were detected by Western blot. Transwell was used to detect the migration and invasion ability of cells, and Western blot was used to detect the expression levels of E-cadherin, Vimentin, MMP2 and MMP9. Results:The expression level of HSP27 in CNE2 was higher than that of CNE1 cells, while the expression level of p-HSP27 was opposite. After inhibition of HSP27 phosphorylation, the invasion and migration ability of CNE1 cells decreased significantly, with no significant change in CNE2 cells. Compared with CNE2-NC, the growth rate of CNE2-OE1 decreased, and the growth rate of CNE2-OE2 increased. The expression level of CyclinD1 was down-regulated in CNE2-OE1 and higher in CNE2-OE2. The expression level of Bax in CNE2-OE1 was increased, while the expression of Bcl-2 was decreased. There was no significant change in the expression of Bax and Bcl-2 in CNE2-OE2. Compared with CNE2-NC, the migration ability of CNE2-OE1 was enhanced and the invasion ability was weakened, while the migration ability of CNE2-OE2 was weakened and the invasion ability was enhanced. There was no significant difference in the expression levels of E-cadherin was decreased in CNE2-OE1 and increased in CNE2-OE2. There was no significant difference in the expression levels of Vimentin among the three groups. The expression levels of MMP2 and MMP9 were up-regulated in CNE2-OE2, and slightly down-regulated in CNE2-OE1. Conclusion:HSP27 and p-HSP27 were differentially expressed in different nasopharyngeal carcinoma cells, and the metastasis ability of nasopharyngeal carcinoma was not only related to the expression level of HSP27, but also related to the level of p-HSP27. The p-HSP27 inhibited CNE 2 cell proliferation and promoted their apoptosis. As p-HSP27 plays different roles in different stages of nasopharyngeal carcinoma metastasis, it can increase the migration ability of CNE2 cells and reduce its invasion ability. p-HSP27 may induce EMT changes in CNE2 by down-regulating E-cadherin, thus promoting CNE2 migration, and may inhibit CNE2 invasion by down-regulating MMPs expression.
Humans ; Cell Proliferation ; Cell Line, Tumor ; Nasopharyngeal Carcinoma/pathology* ; Nasopharyngeal Neoplasms/pathology* ; Cell Movement ; HSP27 Heat-Shock Proteins/metabolism* ; Phosphorylation ; Neoplasm Metastasis ; Matrix Metalloproteinase 9/metabolism* ; Neoplasm Invasiveness ; Matrix Metalloproteinase 2/metabolism* ; Heat-Shock Proteins/metabolism* ; Cyclin D1/metabolism* ; Molecular Chaperones/metabolism* ; Cadherins/metabolism*

Pyroptosis,an inflammatory caspase-dependent programmed cell death,plays a vital role in maintaining tissue homeostasis and activating inflammatory responses.Orthodontic tooth movement(OTM)is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament(PDL)progenitor cells.However,whether and how force induces PDL progenitor cell pyroptosis,thereby influencing OTM and alveolar bone remodeling remains unknown.In this study,we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process.Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively.Using Caspase-1-/-mice,we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1.Moreover,mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro,which influenced osteoclastogenesis.Mechanistically,transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells.Overall,this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli,indicating a promising approach to accelerate OTM by targeting Caspase-1.