Benzyl isothiocyanate attenuates activation of the NLRP3 inflammasome in Kupffer cells and improves diet-induced steatohepatitis

Perfluorooctane sulfonate causes pyroptosis and lipid metabolism disorders through ROS-mediated NLRP3 inflammasome activation in grass carp hepatocyte

The surfactant perfluorooctane sulfonate (PFOS) is widely produced worldwide. It is a persistent organic pollutant in the aquatic environment and poses a serious threat to aquatic organisms, as PFOS exposure can cause liver injury in a wide range of organisms. However, it is unclear whether PFOS exposure-induced hepatocellular injury in fish is associated with ROS-mediated activation of NLRP3 inflammasome. In this study, various PFOS concentrations were applied to L8824 cells, a cell line of grass carp hepatocytes. The detrimental impacts of PFOS on oxidative stress, pyroptosis, lipid metabolism, and the discharge of inflammatory factors were examined. MCC950 and N-acetylcysteine were employed to hinder the PFOS-stimulated activation of the NLRP3 inflammasome and the excessive generation of reactive oxygen species in L8824 cells, respectively. This study demonstrated that treatment with PFOS resulted in oxidative stress and activation of NLRP3 inflammasome in L8824 cells. This led to increased expression levels of indicators related to pyroptosis, accompanied by the upregulation of pro-inflammatory cytokine expression as well as downregulation of anti-inflammatory factors. In addition, following PFOS exposure, the expression levels of genes related to lipid synthesis were upregulated and lipid catabolism-related genes were downregulated. Surprisingly, both N-acetylcysteine and MCC950 interventions significantly reduced PFOS-induced L8824 cell pyroptosis and lipid metabolism disorders. In conclusion, this research demonstrated that PFOS drives NLRP3 inflammasome activation through oxidative stress induced by reactive oxygen species overload. This in turn leads to pyroptosis and lipid metabolism disorders.

Andrographolide Attenuates Oxidized LDL-Induced Activation of the NLRP3 Inflammasome in Bone Marrow-Derived Macrophages and Mitigates HFCCD-Induced Atherosclerosis in Mice

Andrographolide (AND) is a bioactive component of the herb Andrographis paniculata and a well-known anti-inflammatory agent. Atherosclerosis is a chronic inflammatory disease of the vasculature, and oxidized LDL (oxLDL) is thought to contribute heavily to atherosclerosis-associated inflammation. The aim of this study was to investigate whether AND mitigates oxLDL-mediated foam cell formation and diet-induced atherosclerosis (in mice fed a high-fat, high-cholesterol, high-cholic acid [HFCCD] diet) and the underlying mechanisms involved. AND attenuated LPS/oxLDL-mediated foam cell formation, IL-1[Formula: see text] mRNA and protein (p37) expression, NLR family pyrin domain containing 3 (NLRP3) mRNA and protein expression, caspase-1 (p20) protein expression, and IL-1[Formula: see text] release in BMDMs. Treatment with oxLDL significantly induced protein and mRNA expression of CD36, lectin-like oxLDL receptor-1 (LOX-1), and scavenger receptor type A (SR-A), whereas pretreatment with AND significantly inhibited protein and mRNA expression of SR-A only. Treatment with oxLDL significantly induced ROS generation and Dil-oxLDL uptake; however, pretreatment with AND alleviated oxLDL-induced ROS generation and Dil-oxLDL uptake. HFCCD feeding significantly increased aortic lipid accumulation, ICAM-1 expression, and IL-1[Formula: see text] mRNA expression, as well as blood levels of glutamic pyruvic transaminase (GPT), total cholesterol, and LDL-C. AND co-administration mitigated aortic lipid accumulation, the protein expression of ICAM-1, mRNA expression of IL-1[Formula: see text] and ICAM-1, and blood levels of GPT. These results suggest that the working mechanisms by which AND mitigates atherosclerosis involve the inhibition of foam cell formation and NLRP3 inflammasome-dependent vascular inflammation as evidenced by decreased SR-A expression and IL-1[Formula: see text] release, respectively.

Isoquercitrin Attenuates Steatohepatitis by Inhibition of the Activated NLRP3 Inflammasome through HSP90

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease with a global prevalence of 25%. However, the medicines approved by the FDA or EMA are still not commercially available for the treatment of NAFLD. The NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome plays a crucial role in inflammatory responses, and the mechanisms related to steatohepatitis have been sufficiently clarified. NLRP3 has been widely evaluated as a potential target for multiple active agents in treating NAFLD. As a quercetin glycoside, isoquercitrin (IQ) has a broad inhibitory effect on oxidative stress, cancers, cardiovascular diseases, diabetes, and allergic reactions in vitro and in vivo. This study aimed to investigate the undercover mechanism of IQ in the treatment of NAFLD, particularly in anti-steatohepatitis, by suppressing the NLRP3 inflammasome. In this study, a methionine-choline-deficient induced steatohepatitis mice model was used to explore the effect of IQ on NAFLD treatment. Further mechanism exploration based on transcriptomics and molecular biology revealed that IQ inhibited the activated NLRP3 inflammasome by down-regulating the expression of heat shock protein 90 (HSP90) and suppressor of G-two allele of Skp1 (SGT1). In conclusion, IQ could alleviate NAFLD by inhibiting the activated NLRP3 inflammasome by suppressing the expression of HSP90.