OBJECTIVES: To investigate the regulatory role of the NLRP3 signaling pathway in hepatocyte pyroptosis in nonalcoholic steatohepatitis (NASH) under hypoxia. METHODS: Twenty-four male C57BL/6 mice were randomized equally into hypoxic control (A), hypoxic NASH model (B), hypoxic NASH+NLRP3 inhibitor (C), and hypoxic NASH+caspase-1 inhibitor (D) groups. In groups B-D, the mice were fed a methionine choline-deficient (MCD) diet under hypoxic conditions (to simulate a 5000 m altitude) for 6 weeks; the mice in groups C and D received intraperitoneal injections of the respective inhibitors every other day. RESULTS: Compared with those in group A, the mice in group B showed significantly elevated serum levels of FBG, TC, TG, ALT and AST, increased liver lipid content, inflammatory cell infiltration and collagen fiber deposition, and enhanced hepatic expressions of NLRP3, caspase-1, IL-1β and GSDMD proteins, with obvious swelling, cristae breakage, vacuolization, and outer membrane disruption of the mitochondria, ribosome loss in the cytoplasm, destruction of the nuclear membrane, and pathological changes of the rough endoplasmic reticulum. Treatment with NLRP3 inhibitor and caspase-1 inhibitor both significantly lowered serum levels of TC, TG, ALT and AST (but without significantly affecting FBG) in the mouse models, and reduced liver lipid content, inflammatory cell infiltration, collagen deposition, and expression levels of NLRP3, caspase-1, GSDMD and IL-1β. The treatments also significantly improved pathological changes in the mitochondria, ribosomes and endoplasmic reticulum in liver tissues of the mice. CONCLUSIONS NLRP3 signaling pathway plays a key role in promoting hepatocyte pyroptosis in NASH mice under hypoxic condition, and inhibiting this pathway can effectively reduce liver inflammation, suggesting its potential as a therapeutic target for NASH treatment.
Animals ; Non-alcoholic Fatty Liver Disease/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Pyroptosis ; Mice, Inbred C57BL ; Male ; Hepatocytes/pathology* ; Signal Transduction ; Mice ; Hypoxia/metabolism* ; Caspase 1/metabolism* ; Interleukin-1beta/metabolism* ; Liver/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.

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

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.

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.