The role and mechanism of pyroptosis and potential therapeutic targets in non-alcoholic fatty liver disease (NAFLD).

Non-alcoholic fatty liver disease (NAFLD) is a clinical pathological syndrome characterized by the excessive accumulation of fat within liver cells, which can progress to end-stage liver disease in severe cases, posing a threat to life. Pyroptosis is a distinct, pro-inflammatory form of cell death, differing from traditional apoptosis. In recent years, there has been growing research interest in the association between pyroptosis and NAFLD, encompassing the mechanisms and functions of pyroptosis in the progression of NAFLD, as well as potential therapeutic targets. Controlled pyroptosis can activate immune cells, eliciting host immune responses to shield the body from harm. However, undue activation of pyroptosis may worsen inflammatory responses, induce cellular or tissue damage, disrupt immune responses, and potentially impact liver function. This review elucidates the involvement of pyroptosis and key molecular players, including NOD-like receptor thermal protein domain associated protein 3(NLRP3) inflammasome, gasdermin D (GSDMD), and the caspase family, in the pathogenesis and progression of NAFLD. It emphasizes the promising prospects of targeting pyroptosis as a therapeutic approach for NAFLD and offers valuable insights into future directions in the field of NAFLD treatment.

Methylmercury induces inflammatory response and autophagy in microglia through the activation of NLRP3 inflammasome.

Methylmercury (MeHg) is a global environmental pollutant with neurotoxicity, which can easily crosses the blood-brain barrier and cause irreversible damage to the human central nervous system (CNS). CNS inflammation and autophagy are known to be involved in the pathology of neurodegenerative diseases. Meanwhile, MeHg has the potential to induce microglia-mediated neuroinflammation as well as autophagy. This study aims to further explore the exact molecular mechanism of MeHg neurotoxicity. We conducted in vitro studies using BV2 microglial cell from the central nervous system of mice. The role of inflammation and autophagy in the damage of BV2 cells induced by MeHg was determined by detecting cell viability, cell morphology and structure, reactive oxygen species (ROS), antioxidant function, inflammatory factors, autophagosomes, inflammation and autophagy-related proteins. We further investigated the relationship between the inflammatory response and autophagy induced by MeHg by inhibiting them separately. The results indicated that MeHg could invade cells, change cell structure, activate NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome and autophagosome, release a large amount of inflammatory factors and trigger the inflammatory response and autophagy. It was also found that MeHg could disrupt the antioxidant function of cells. In addition, the inhibition of NLRP3 inflammasome alleviated both cellular inflammation and autophagy, while inhibition of autophagy increased cellular inflammation. Our current research suggests that MeHg might induce BV2 cytotoxicity through inflammatory response and autophagy, which may be mediated by the NLRP3 inflammasome activated by oxidative stress.

Scutellariae Radix-Coptidis Rhizoma Treats Atherosclerosis via NLRP3 Inflammasome-mediated Pyroptosis of Macrophages / 中国实验方剂学杂志

ObjectiveTo investigate the therapeutic effect of Scutellariae Radix-Coptidis Rhizoma （SRCR） on atherosclerosis （AS） in mice and the effect of SRCR on macrophage pyroptosis in plaques via NOD-like receptor thermal protein domain-associated protein 3 （NLRP3） inflammasomes. MethodApoE-/- mice were fed with a high-fat diet for the modeling of AS and randomized into model， atorvastatin （5 mg·kg-1）， and low-， medium-， and high-dose （1.95， 3.9， 7.8 g·kg-1， respectively） SRCR groups. Normal C57BL/6J mice were selected as the control group. After 8 weeks of administration， hematoxylin-eosin staining was used to observe the pathological status of the aortic plaque. The lipid accumulation in aortic plaque was observed by oil red O staining. The serum levels of total cholesterol （TC）， triglyceride （TG）， high-density lipoprotein cholesterol （HDL-C）， and low-density lipoprotein cholesterol （LDL-C） in mice were measured. Immunofluorescence double staining was employed to detect the co-localized expression of EGF-like module-containing mucin-like hormone receptor-like 1 （EMR1）/NLRP3 and EMR1/gasdermin D （GSDMD）. The serum levels of interleukin-1β （IL-1β） and interleukin-18 （IL-18） were determined by enzyme-linked immunosorbent assay （ELISA）. The protein levels of NLRP3， apoptosis-associated speck-like protein （ASC）， Caspase-1， cleaved Caspase-1， GSDMD， N-terminus of GSDMD （GSDMD-NT）， pro-IL-1β， IL-1β， and IL-18 were determined by Western blot， and the mRNA levels of NLRP3， ASC， Caspase-1， GSDMD， IL-1β， and IL-18 were determined by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the control group， the model group showed obvious plaques， elevated serum levels of TG， TC， LDL-C， IL-1β， and IL-18 （P<0.01）， lowered serum level of HDL-C （P<0.01）， and up-regulated expression of NLRP3 inflammasomes and molecules related to pyroptosis in the aortic plaques （P<0.01）. Compared with the model group， SRCR， especially at the medium and high doses， alleviated the plaque pathology， reduced the lipid content in plaques （P<0.05， P<0.01）， recovered the serum lipid levels （P<0.05）， reduced the macrophage recruitment （P<0.01）， activation of NLRP3 inflammasomes， and pyroptosis in aortic root plaques （P<0.05）， lowered the serum IL-1β and IL-18 levels （P<0.01）， and down-regulated the protein levels of NLRP3， ASC， Caspase-1， cleaved Caspase-1， GSDMD， GSDMD-NT， pro-IL-1β， IL-1β， and IL-18 （P<0.05） and the mRNA levels of NLRP3， ASC， Caspase-1， GSDMD， IL-1β， and IL-18 in the aortic tissue （P<0.05）. ConclusionSRCR exerts a therapeutic effect on high-fat diet-induced AS in mice by inhibiting the activation NLRP3 inflammasomes and reducing the pyroptosis of macrophages in plaques.

Mechanism of Chaihu Qinggantang in Intervening NLRP3/IL-1β Pathway to Treat Granulomatous Lobular Mastitis in Rat Model / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Chaihu Qinggantang （CHQGT） in the treatment of granulomatous lobular mastitis （GLM） in the rat model. MethodSixty female rats were divided into a normal group， a model group， a prednisolone group （0.001 8 g·kg-1）， and three CHQGT low-dose， medium-dose， and high-dose groups （4.5， 8.9， 17.8 g·kg-1）. The tissue homogenates mixed with GLM lesion tissue and Fritner's reagent were used for modeling. After modeling， the treatment groups were given corresponding treatment factors， and the normal group and the model group were given the equal volume of normal saline. The changes in mammary gland of rats were observed after 14 d. Hematoxylin-eosin （HE） staining was used to observe the histopathological changes in breast samples. The mRNA expressions of NOD-like receptor thermal protein domain associated protein 3 （NLRP3） inflammasome， Caspase-1， and interleukin-1β （IL-1β） were detected by real-time quantitative fluorescence polymerase chain reaction （Real-time PCR）. The protein expressions of NLRP3， Caspase-1， IL-1β， and IL-18 were detected by Western bolt. ResultAs compared with the normal group， the breasts of rats in the model group were obviously swelling， and mammary gland inflammation index was significantly increased （P<0.01）. Pathological changes included the formation of granuloma centered on the lobule of mammary gland with a large number of inflammatory cells such as lymphocytes and plasma cells. The mRNA expressions of NLRP3， Caspase-1， and IL-1β， and the protein expressions of NLRP3， Caspase-1， IL-1β， and IL18 in the model group were significantly increased （P<0.01）. Compared with the model group， the treatment groups improved breast swelling， and the CHQGT medium and high-dose groups and the prednisolone group reduced inflammation index to some extent after treatment （P<0.05， P<0.01）. The inflammation degree of mammary gland was significantly improved， and inflammatory cells such as macrophages， lymphocytes， and plasma cells were reduced to varying degrees in pathological aspects. The mRNA expressions of NLRP3， Caspase-1， and IL-1β， and the protein expressions of NLRP3， Caspase-1， IL-1β， and IL-18 in the CHQGT high-dose group and the prednisolone group were significantly down-regulated （P<0.05， P<0.01）. ConclusionCHQGT inhibits inflammation and treats GLM in rats. The mechanism is possibly related to the inhibition of NLRP3/IL-1β signaling pathway， which provides a new target for the prevention and treatment of GLM by Qingxiao method.