OBJECTIVE: To observe the effects of electroacupuncture at the pterygopalatine region on nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)-mediated pyroptosis and inflammatory factors in rats with allergic rhinitis (AR). METHODS: Twenty-four SD rats were randomly divided into a blank group, a model group, an acupuncture group and an electroacupuncture group, 6 rats in each group. Except for the blank group, OVA-induced AR model was established in the remaining groups. In the electroacupuncture group, the rats were treated with electroacupuncture at the bilateral pterygopalatine region, with disperse-dense wave, in frequency of 2 Hz/100 Hz and current of 0.5-1 mA, 15 min each time, once every other day, for 3 times. In the acupuncture group, the rats were treated with acupuncture at bilateral pterygopalatine region simply, without electrical stimulation. The rhinitis symptom score was observed, the pathomorphology of the nasal mucosa was observed by HE staining; the serum levels of OVA-specific immunoglobulin E (OVA-sIgE), interleukin (IL)-4, IL-6 and IL-1β were detected by ELISA; the mRNA expression of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), cysteinyl aspartate specific proteinase-1 (caspase-1) and IL-18 in the nasal mucosa was detected by real-time PCR; the protein expression of NLRP3, ASC, caspase-1 and IL-18 in the nasal mucosa was detected by Western blot. RESULTS: Compared with the blank group, in the model group, the rhinitis symptom score was increased (P<0.01), the serum levels of OVA-sIgE, IL-4, IL-6 and IL-1β were increased (P<0.05), the nasal mucosa showed pathomorphology of inflammatory infiltration; the mRNA and protein expression of NLRP3, ASC, caspase-1 and IL-18 in the nasal mucosa was increased (P<0.05). Compared with the model group, in the electroacupuncture group, the rhinitis symptom score was reduced (P<0.01), the pathology of the nasal mucosa was improved; the serum levels of OVA-sIgE, IL-4, IL-6 and IL-1β were decreased (P<0.05); the mRNA and protein expression of NLRP3, ASC, caspase-1 and IL-18 in the nasal mucosa was decreased (P<0.05). CONCLUSION Electroacupuncture at the pterygopalatine region can exerting the anti-inflammatory effect by inhibiting NLRP3-mediated pyroptosis and inflammatory factor imbalance, thus alleviate rhinitis symptoms in AR rats.
Animals ; Electroacupuncture ; NLR Family, Pyrin Domain-Containing 3 Protein/immunology* ; Rats ; Rats, Sprague-Dawley ; Rhinitis, Allergic/physiopathology* ; Pyroptosis ; Male ; Acupuncture Points ; Humans ; Female ; Interleukin-1beta/genetics* ; Interleukin-18/immunology* ; Interleukin-6/genetics* ; Caspase 1/immunology*

This study aims to investigate the therapeutic effects of the Coptidis Rhizoma-Scutellariae Radix on cytokine storm secondary lung injury(CSSLI) induced by CpG1826 in mice, and to elucidate the potential molecular mechanisms by which its major active components, i.e., coptisine and wogonin, alleviate CSSLI by inhibiting the mitochondrial permeability transition pore(mPTP)/nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3) inflammasome pyroptosis pathway. In vivo, a mouse model of CSSLI was established by CpG1826 induction. Pulmonary edema was assessed by lung wet-to-dry weight ratio(W/D), lung injury was evaluated by hematoxylin-eosin(HE) staining, and ultrastructural changes in lung tissue were observed by transmission electron microscopy(TEM). The levels of interleukin(IL)-1β, high mobility group box 1 protein(HMGB1), IL-18, and IL-1α in bronchoalveolar lavage fluid were measured by enzyme-linked immunosorbent assay(ELISA). The results showed that the decoction of the Coptidis Rhizoma-Scutellariae Radix significantly reduced pulmonary edema, alleviated lung injury, and decreased the concentrations of related cytokines in BALF more effectively than either single herb alone, thereby improving CSSLI. In vitro, a CpG1826-induced CSSLI model was established in mouse alveolar macrophage MH-S cells. Calcein-AM quenching was used to screen for the most effective monomer components from the herb pair in inhibiting mPTP opening. Coptisine(5, 10, 20 μmol·L~(-1)) and wogonin(10, 20, 40 μmol·L~(-1)) markedly inhibited mPTP opening, with optimal effects and a clear dose-dependent pattern. These components suppressed mPTP opening, thereby reducing the release of mitochondrial DNA(mtDNA) and the accumulation of reactive oxygen species(ROS), effectively reversing the CpG1826-induced decrease in mitochondrial membrane potential(MMP). Further studies revealed that both coptisine and wogonin inhibited pyroptosis and downregulated the expression of key proteins in the NLRP3/Caspase-1/gasdermin D(GSDMD) pathway. In conclusion, the Coptidis Rhizoma-Scutellariae Radix improves CpG1826-induced CSSLI in mice, and this effect is associated with the inhibition of the mPTP/NLRP3 pyroptosis pathway, providing scientific evidence for its clinical application and further development.
Animals ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Pyroptosis/drug effects* ; NLR Family, Pyrin Domain-Containing 3 Protein/immunology* ; Male ; Lung Injury/immunology* ; Cytokines/immunology* ; Scutellaria baicalensis/chemistry* ; Oligodeoxyribonucleotides/adverse effects* ; Mice, Inbred C57BL ; Coptis chinensis

Pyroptosis is an identified programmed cell death that has been highly linked to endoplasmic reticulum (ER) dynamics. However, the crucial proteins for modulating dynamic ER membrane curvature change that trigger pyroptosis are currently not well understood. In this study, a biotin-labeled chemical probe of potent pyroptosis inducer α-mangostin (α-MG) was synthesized. Through protein microarray analysis, reticulon-4 (RTN4/Nogo), a crucial regulator of ER membrane curvature, was identified as a target of α-MG. We observed that chemically induced proteasome degradation of RTN4 by α-MG through recruiting E3 ligase UBR5 significantly enhances the pyroptosis phenotype in cancer cells. Interestingly, the downregulation of RTN4 expression significantly facilitated a dynamic remodeling of ER membrane curvature through a transition from tubules to sheets, consequently leading to rapid fusion of the ER with the cell plasma membrane. In particular, the ER-to-plasma membrane fusion process is supported by the observed translocation of several crucial ER markers to the "bubble" structures of pyroptotic cells. Furthermore, α-MG-induced RTN4 knockdown leads to pyruvate kinase M2 (PKM2)-dependent conventional caspase-3/gasdermin E (GSDME) cleavages for pyroptosis progression. In vivo, we observed that chemical or genetic RTN4 knockdown significantly inhibited cancer cells growth, which further exhibited an antitumor immune response with anti-programmed death-1 (anti-PD-1). In translational research, RTN4 high expression was closely correlated with the tumor metastasis and death of patients. Taken together, RTN4 plays a fundamental role in inducing pyroptosis through the modulation of ER membrane curvature remodeling, thus representing a prospective druggable target for anticancer immunotherapy.
Pyroptosis/immunology* ; Humans ; Endoplasmic Reticulum/immunology* ; Animals ; Nogo Proteins/antagonists & inhibitors* ; Mice ; Cell Line, Tumor ; Xanthones/pharmacology* ; Neoplasms/pathology* ; Mice, Nude