Eclipta prostrata improves alveolar development of bronchopulmonary dysplasia via suppressing the NLRP3 inflammasome in a DLD-dependent manner.

Bronchopulmonary dysplasia (BPD), the most common late morbidity in preterm infants, is characterized by impaired alveolar development caused by persistent lung inflammation. Studies have shown that NOD-, LRR- and pyrin domain-containing 3 (NLRP3) inflammasome-mediated inflammation is critically involved in the development of BPD. As a traditional Chinese medicinal herb, Eclipta prostrata (EAP) exhibits potent anti-inflammatory properties. Our study aims to investigate whether EAP could improve the lung development of BPD by suppressing the lung inflammatory response. The BPD rat model was established by intra-amniotic injection of lipopolysaccharide (LPS) and postnatal exposure to hyperoxia. Changes in the NLRP3 inflammasome and pyroptosis were assessed by treatment with EAP. The effect of EAP on the NLRP3 inflammasome was tested in vitro using the THP-1 cell line and primary alveolar macrophages. Proteomics analysis was used to elucidate the mechanism of action of EAP. Histopathological and immunofluorescence results of lung tissues revealed that LPS and hyperoxia induced lung injury and triggered NLRP3 inflammasome activation and pyroptosis in alveolar macrophages. EAP ameliorated BPD lung injury, inhibited NLRP3 inflammasome activation and reduced gasdermin D (GSDMD) expression in alveolar macrophages. EAP downregulated the expression of NLRP3 inflammasome pathway molecules (NLRP3, caspase-1, and IL-1β) and GSDMD in LPS-stimulated THP-1 macrophages and primary alveolar macrophages. In addition, proteomics analysis identified that dihydrolipoamide dehydrogenase (DLD) interacted with EAP. Inhibition of DLD activity abolished the protective effects of EAP. Our study suggested that EAP could attenuate arrest of alveolar development via inhibiting NLRP3 inflammasome in a DLD-dependent way, and could be a potential therapeutic method for BPD.

Zheng X ，Tan Z ，Zhu D ，Zhao D ，Liu C ，Wang S ，Wang X ，Zhang Y ... -  《-》

Bufei Huoxue capsule alleviates silicosis by inhibiting the activation of nucleotide-like receptor containing pyrin domain 3 inflammasome and macrophages polarization based on network pharmacology.

Wenlu H ，Lin W ，Yun BO ，Shurun Z ，Songquan W ，Haiquan LI ，Chunlu BU ，Jie Z ，Xianmei Z ... -  《-》

Gastrodenol suppresses NLRP3/GSDMD mediated pyroptosis and ameliorates inflammatory diseases.

Pyroptosis, a form of inflammatory programmed cell death, plays a pivotal role in the pathogenesis of various diseases. This process is primarily mediated by the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3). Gastrodenol (Bismuth tripotassium dicitrate, GAS) is a mineral compound which is used to treat duodenal and gastric ulcers associated with Helicobacter pylori. In this study, GAS was found to exhibit protective effects against classical pyroptosis in macrophages. Specifically, GAS effectively inhibits the activation of the NLRP3 inflammasome, Gasdermin D (GSDMD)-mediated pyroptosis, and the secretion of pro-inflammatory cytokines. Mechanistically, GAS inhibited NLRP3 oligomerization and reduced the oligomerization of adaptor protein apoptosis-associated speck like protein containing a caspase activation and recruitment domain (ASC) by directly binding to NLRP3. The interaction between GAS and NLRP3 is primarily mediated through hydrogen bonding and hydrophobic forces. Hydrogen bonds are formed with PHE-727, LEU-723, and ASP-700. Remarkably, GAS treatment attenuated pyroptosis-mediated inflammatory diseases, including experimental autoimmune encephalomyelitis (EAE), lipopolysaccharide (LPS)-induced septic, and monosodium urate (MSU)-induced peritonitis in mice. To conclude, this is the first report that discovered clinical old medicine GAS as a potent inhibitor of pyroptosis and propose a novel therapeutic strategy for the prevention and treatment of NLRP3-GSDMD mediated diseases.

Chen P ，Wang Y ，Tang H ，Liu Z ，Wang J ，Wang T ，Xu Y ，Ji SL ... -  《-》

[Liuwei Buqi Formula delays progression of chronic obstructive pulmonary disease in rats by regulating the NLRP3/caspase-1/GSDMD pyroptosis pathway].

Mei L ，Zhang L ，Wu D ，Ding H ，Wang X ，Zhang X ，Wei Y ，Li Z ，Tong J ... -  《-》

Cadmium exposure triggers alveolar epithelial cell pyroptosis by inducing mitochondrial oxidative stress and activating the cGAS-STING pathway.

Cadmium is a ubiquitous toxic metal and environmental pollutant. More and more studies have shown that cadmium exposure can damage lung function. Alveolar epithelial cells (AECs) are structural cells that maintain the stability of lung function. The injury of AECs is an essential determinant of many lung diseases. In the lung, cadmium accumulation can cause damage to AECs. However, the specific mechanism is still unclear. This study aimed to explore the key mechanism underlying the injury of AECs caused by cadmium exposure. The main modes of death of AECs induced by cadmium exposure were evaluated in vivo and in vitro. Transcriptomic changes of AECs induced by cadmium exposure were analyzed using RNA-sequence. Mitochondrial ROS scavengers (mitoQ), voltage-dependent anion channel 1 (VDAC1) oligomer inhibitor (VBIT4), and cyclic GMP-AMP synthase (cGAS) inhibitor (RU.521) were used to assess whether cadmium exposure triggered pyroptosis of AECs by inducing mitochondrial stress to activate the cGAS-STING-NLRP3 axis. In this study, the expression of pyroptosis-related proteins was significantly up-regulated in the cadmium-exposed AECs, while the expression of apoptosis, necroptosis, and ferroptosis-related proteins had no significant up-regulated. The pan-caspase inhibitor ZVAD-FMK significantly reduced cell death. Thus, our research indicates that pyroptosis is the primary type of AEC death exported to cadmium. Mechanistically, RNA-seq and Western Blot results showed that cadmium exposure activated the cGAS-STING pathway in AECs and promoted pyroptosis by activating the NLRP3 inflammasome. Further investigation of the mechanism found that cadmium exposure caused mitochondrial oxidative stress, which led to mtDNA leakage into the cytoplasm and activated the cGAS-STING pathway. In addition, inhibition of the cGAS-STING pathway significantly alleviated lung injury induced by cadmium exposure in mice. Our study confirmed that pyroptosis of AECs was a vital mechanism of lung injury after cadmium exposure in a cGAS-STING-dependent manner, which may provide a new target for the treatment of lung diseases induced by cadmium exposure.

Zhang CY ，Ou AJ ，Jin L ，Yang NS ，Deng P ，Guan CX ，Huang XT ，Duan JX ，Zhou Y ... -  《Cell Communication and Signaling》