Degrasyn alleviates osteoarthritis by blocking macrophagic pyroptosis via suppressing NLRP3/GSDMD signaling pathway and protecting chondrocytes.

Synovitis and cartilage destruction are crucial characteristics of osteoarthritis (OA). Inflammatory cytokines, such as IL-1ß, are secreted by synovial macrophages, leading to cartilage destruction. Pyroptosis is a lytic form of programmed cell death, which could be triggered by the NLRP3 inflammasome of macrophages. Pyroptosis promotes the secretion of IL-1ß and is supposed as a potential biomarker for OA. However, the function of Pyroptosis and NLRP3 inflammasome and its regulatory mechanism for activation is unclear in OA. In this study, we found that Degrasyn could alleviate the GSDMD-mediated pyroptosis of macrophages and the release of IL-1ß, caspase-1, and LDH. Furthermore, it selectively impedes the form of ASC oligomer and speckle to effectively suppress the NLRP3 inflammasome during its assembly phase. Notably, Degrasyn exhibited potential chondroprotective effects in a co-culture system. Additionally, these results also indicate that Degrasyn mitigates synovitis and cartilage damage in a murine model of destabilization of the medial meniscus (DMM)-induced OA. In summary, Degrasyn emerges as a promising pharmaceutical agent for synovitis, paving the way for innovative therapeutic approaches to OA. Our findings underscore the potential of Degrasyn as a viable candidate for OA therapeutics, demonstrating its ability to regulate pyroptosis and NLRP3 inflammasome activation.

Targeting macrophagic PIM-1 alleviates osteoarthritis by inhibiting NLRP3 inflammasome activation via suppressing mitochondrial ROS/Cl- efflux signaling pathway.

BACKGROUND: Osteoarthritis (OA), in which macrophage-driven synovitis is considered closely related to cartilage destruction and could occur at any stage, is an inflammatory arthritis. However, there are no effective targets to cure the progression of OA. The NOD-, LRR-,and pyrin domain-containing protein 3 (NLRP3) inflammasome in synovial macrophages participates in the pathological inflammatory process and treatment strategies targeting it are considered to be an effective approach for OA. PIM-1 kinase, as a downstream effector of many cytokine signaling pathways, plays a pro-inflammatory role in inflammatory disease. METHODS: In this study, we evaluated the expression of the PIM-1 and the infiltration of synovial macrophages in the human OA synovium. The effects and mechanism of PIM-1 were investigated in mice and human macrophages stimulated by lipopolysaccharide (LPS) and different agonists such as nigericin, ATP, Monosodium urate (MSU), and Aluminum salt (Alum). The protective effects on chondrocytes were assessed by a modified co-culture system induced by macrophage condition medium (CM). The therapeutic effect in vivo was confirmed by the medial meniscus (DMM)-induced OA in mice. RESULTS: The expression of PIM-1 was increased in the human OA synovium which was accompanied by the infiltration of synovial macrophages. In vitro experiments, suppression of PIM-1 by SMI-4a, a specific inhibitor, rapidly inhibited the NLRP3 inflammasome activation in mice and human macrophages and gasdermin-D (GSDME)-mediated pyroptosis. Furthermore, PIM-1 inhibition specifically blocked the apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization in the assembly stage. Mechanistically, PIM-1 inhibition alleviated the mitochondrial reactive oxygen species (ROS)/chloride intracellular channel proteins (CLICs)-dependent Cl- efflux signaling pathway, which eventually resulted in the blockade of the ASC oligomerization and NLRP3 inflammasome activation. Furthermore, PIM-1 suppression showed chondroprotective effects in the modified co-culture system. Finally, SMI-4a significantly suppressed the expression of PIM-1 in the synovium and reduced the synovitis scores and the Osteoarthritis Research Society International (OARSI) score in the DMM-induced OA model. CONCLUSIONS: Therefore, PIM-1 represented a new class of promising targets as a treatment of OA to target these mechanisms in macrophages and widened the road to therapeutic strategies for OA.

A novel risk signature for predicting brain metastasis in patients with lung adenocarcinoma.

BACKGROUND: Brain metastasis (BM) are a devastating consequence of lung cancer. This study was aimed to screen risk factors for predicting BM. METHODS: Using an in vivo BM preclinical model, we established a series of lung adenocarcinoma (LUAD) cell subpopulations with different metastatic ability. Quantitative proteomics analysis was used to screen and identify the differential protein expressing map among subpopulation cells. Q-PCR and Western-blot were used to validate the differential proteins in vitro. The candidate proteins were measured in LUAD tissue samples (n = 81) and validated in an independent TMA cohort (n = 64). A nomogram establishment was undertaken by performing multivariate logistic regression analysis. RESULTS: The quantitative proteomics analysis, qPCR and Western blot assay implied a five-gene signature that might be key proteins associated with BM. In multivariate analysis, the occurrence of BM was associated with age ≤ 65 years, high expressions of NES and ALDH6A1. The nomogram showed an area under the receiver operating characteristic curve (AUC) of 0.934 (95% CI, 0.881-0.988) in the training set. The validation set showed a good discrimination with an AUC of 0.719 (95% CI, 0.595-0.843). CONCLUSIONS: We have established a tool that is able to predict occurrence of BM in LUAD patients. Our model based on both clinical information and protein biomarkers will help to screen patient in high-risk population of BM, so as to facilitate preventive intervention in this part of the population.

Identification of mitophagy-related biomarkers and immune infiltration in major depressive disorder.

BACKGROUND: Major depressive disorder (MDD) is a life-threatening and debilitating mental health condition. Mitophagy, a form of selective autophagy that eliminates dysfunctional mitochondria, is associated with depression. However, studies on the relationship between mitophagy-related genes (MRGs) and MDD are scarce. This study aimed to identify potential mitophagy-related biomarkers for MDD and characterize the underlying molecular mechanisms. METHODS: The gene expression profiles of 144 MDD samples and 72 normal controls were retrieved from the Gene Expression Omnibus database, and the MRGs were extracted from the GeneCards database. Consensus clustering was used to determine MDD clusters. Immune cell infiltration was evaluated using CIBERSORT. Functional enrichment analyses were performed to determine the biological significance of mitophagy-related differentially expressed genes (MR-DEGs). Weighted gene co-expression network analysis, along with a network of protein-protein interactions (PPI), was used to identify key modules and hub genes. Based on the least absolute shrinkage and selection operator analysis and univariate Cox regression analysis, a diagnostic model was constructed and evaluated using receiver operating characteristic curves and validated with training data and external validation data. We reclassified MDD into two molecular subtypes according to biomarkers and evaluated their expression levels. RESULTS: In total, 315 MDD-related MR-DEGs were identified. Functional enrichment analyses revealed that MR-DEGs were mainly enriched in mitophagy-related biological processes and multiple neurodegenerative disease pathways. Two distinct clusters with diverse immune infiltration characteristics were identified in the 144 MDD samples. MATR3, ACTL6A, FUS, BIRC2, and RIPK1 have been identified as potential biomarkers of MDD. All biomarkers showed varying degrees of correlation with immune cells. In addition, two molecular subtypes with distinct mitophagy gene signatures were identified. CONCLUSIONS: We identified a novel five-MRG gene signature that has excellent diagnostic performance and identified an association between MRGs and the immune microenvironment in MDD.

The second-generation tyrosine kinase inhibitor afatinib inhibits IL-1ß secretion via blocking assembly of NLRP3 inflammasome independent of epidermal growth factor receptor signaling in macrophage.

Chronic inflammation might lead to many malignancies, and inadequate resolution could play a crucial role in tumor invasion, progression and metastases. Afatinib is a second-generation tyrosine kinase inhibitor targeting epidermal growth factor receptor in non-small cell lung cancer. Few studies showed the correlation of afatinib and the innate immune system especially macrophage. Our study showed that afatinib could block the activation of NLRP3 inflammasome in a dose-dependent manner in macrophage, and that afatinib could prevent the assembly of NLRP3 inflammasome. Besides, afatinib could inhibit NLRP3 inflammasome activation independent of EGFR signaling. Moreover, afatinib was able to alleviate the LPS-induced sepsis in vivo. These investigations provide significant experimental evidence in afatinib as therapeutic drug for non-small cell lung cancer or other tumors and NLRP3-related diseases, and explore new target for afatinib in macrophage.

Comprehensive analysis of endoplasmic reticulum stress and immune infiltration in major depressive disorder.

Background: Major depressive disorder (MDD) is a life-threatening, debilitating mental health condition. An important factor in the development of depression is endoplasmic reticulum stress (ERS). However, their roles in MDD have not yet been established. The goal of this study was to examine ERS and its underlying molecular mechanisms in MDD. Methods: We used data from two microarray datasets (GSE98793 and GSE39653) and the GeneCards database to examine the reticulum stress-related differentially expressed genes (ERSR-DEGs) associated with MDD. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA), and Gene Set Variation Analysis (GSVA) were used to further investigate the function and mechanism of ERS in MDD. Moreover, we constructed protein-protein interaction (PPI) networks to identify hub genes as well as the regulatory network of microRNAs (miRNAs), transcription factors (TFs), and potential drugs related to ERSR-DEGs. CIBERSORT was then used to evaluate the immune activity of MDD samples and conduct a correlation analysis between the hub genes and immune cells. Results: In total, 37 ERSR-DEGs and five hub genes were identified (NCF1, MAPK14, CASP1, CYBA, and TNF). Functional enrichment analysis revealed that ERSR-DEGs were predominantly enriched in inflammation-and immunity-related pathways, such as tumor necrosis factor signaling, NF-κB signaling, and Toll-like receptor signaling pathways. Additionally, 179 miRNAs, 25 TFs, and 15 potential drugs were tested for their interactions with the ERSR-DEGs. CIBERSORT found high proportions of Tregs, monocytes, and macrophages M0 in the MDD samples. Among these, hub genes showed a significant correlation with immune cell infiltration in patients with MDD. Conclusions: NCF1, MAPK14, CASP1, CYBA, and TNF are potential ERS-related biomarkers for the diagnosis of MDD. Our research has revealed a significant correlation between immune cells and ERS-related genes with MDD. Not only did our study contribute to a better understanding of the regulatory mechanisms of ERS in underlying MDD pathology, but it also established a paradigm for future studies on ERS.

SERPINE2/PN-1 regulates the DNA damage response and radioresistance by activating ATM in lung cancer.

Although the DNA damage response (DDR) is associated with the radioresistance characteristics of lung cancer cells, the specific regulators and underlying mechanisms of the DDR are unclear. Here, we identified the serine proteinase inhibitor clade E member 2 (SERPINE2) as a modulator of radiosensitivity and the DDR in lung cancer. Cells exhibiting radioresistance after ionizing radiation show upregulation of SERPINE2, and SERPINE2 knockdown improves tumor radiosensitivity in vitro and in vivo. Functionally, SERPINE2 deficiency causes a reduction in homologous recombination repair, rapid recovery of cell cycle checkpoints, and suppression of migration and invasion. Mechanistically, SERPINE2 knockdown inhibits the accumulation of p-ATM and the downstream repair protein RAD51 during DNA repair, and RAD51 can restore DNA damage and radioresistance phenotypes in lung cancer cells. Furthermore, SERPINE2 can directly interact with MRE11 and ATM to facilitate its phosphorylation in HR-mediated DSB repair. In addition, high SERPINE2 expression correlates with dismal prognosis in lung adenocarcinoma patients, and a high serum SERPINE2 concentration predicts a poor response to radiotherapy in non-small cell lung cancer patients. In summary, these findings indicate a novel regulatory mechanism by which SERPINE2 modulates the DDR and radioresistance in lung cancer.

Ticagrelor inhibits the NLRP3 inflammasome to protect against inflammatory disease independent of the P2Y12 signaling pathway.

Ticagrelor is the first reversibly binding oral P2Y12 receptor antagonist to inhibit platelet activation and has been approved by the Food and Drug Administration for the treatment of coronary artery disease. At present, the other pharmacological functions of ticagrelor remain poorly understood. The NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome plays a critical role in the innate immune system, but its excessive activation also contributes to the pathogenesis of complex diseases. In this study, we systematically examined the effects of ticagrelor on the NLRP3 inflammasome and found that ticagrelor inhibits NLRP3 inflammasome activation in macrophages independent of its classic inhibitory effect on the P2Y12 signaling pathway. Further mechanistic studies demonstrate that ticagrelor attenuates the oligomerization of apoptosis-associated speck-like protein containing a CARD (ASC) by blocking chloride efflux, an effect achieved through the degradation of chloride intracellular channel proteins (CLICs) and blockade of the translocation of CLICs to the plasma membrane. Moreover, experiments on lipopolysaccharide-induced sepsis and alum-induced peritonitis in mice confirmed that ticagrelor mitigates the severity of systemic inflammation independent of P2Y12 receptor antagonism. Importantly, oral administration of ticagrelor rapidly and strongly inhibited NLRP3 inflammasome activation in peripheral blood mononuclear cells from patients with acute coronary syndrome. Overall, our study reveals a novel pharmacological function of ticagrelor in addition to its classic antiplatelet properties, which suggests that ticagrelor may serve as a potential therapeutic agent for use in NLRP3-associated diseases.

Inhibition of histamine receptor H3 suppresses the growth and metastasis of human non-small cell lung cancer cells via inhibiting PI3K/Akt/mTOR and MEK/ERK signaling pathways and blocking EMT.

Recent evidence shows that the expression levels of histamine receptor H3 (Hrh3) are upregulated in several types of cancer. However, the role of Hrh3 in non-small cell lung cancer (NSCLC) has not been elucidated. In the present study, we showed that the expression levels of Hrh3 were significantly increased in NSCLC samples, and high levels of Hrh3 were associated with poor overall survival (OS) in NSCLC patients. In five human NSCLC cell lines tested, Hrh3 was significantly upregulated. In NSCLC cell lines H1975, H460, and A549, Hrh3 antagonist ciproxifan (CPX, 10-80 µM) exerted moderate and concentration-dependent inhibition on the cell growth and induced apoptosis, whereas its agonist RAMH (80 µM) reversed these effects. Furthermore, inhibition of Hrh3 by CPX or siRNA retarded the migration and invasion of NSCLC cells through inhibiting epithelial-mesenchymal transition (EMT) progression via reducing the phosphorylation of PI3K/Akt/mTOR and MEK/ERK signaling pathways. In nude mice bearing H1975 cell xenograft or A549 cell xenograft, administration of CPX (3 mg/kg every other day, intraperitoneal) significantly inhibited the tumor growth with increased E-cadherin and ZO-1 expression and decreased Fibronectin expression in tumor tissue. In conclusion, this study reveals that Hrh3 plays an important role in the growth and metastasis of NSCLC; it might be a potential therapeutic target against the lung cancer.

Myricetin inhibits NLRP3 inflammasome activation via reduction of ROS-dependent ubiquitination of ASC and promotion of ROS-independent NLRP3 ubiquitination.

Myricetin is a plant-derived flavonoid that exhibits diverse pharmacological properties. The NLRP3 (NLR family, pyrin domain-containing 3 protein) inflammasome is a cytosolic multiprotein complex that plays a critical role in the innate immune response and pathogenesis of multiple inflammatory disorders. The present study found that myricetin inhibited NLRP3 inflammasome assembly via promotion of reactive oxygen species (ROS)-independent ubiquitination of NLRP3 and reduction of ROS-dependent ubiquitination of ASC (apoptosis-associated speck-like protein containing a CARD), which disrupted the interaction between ASC and NLRP3 and inhibited ASC oligomerization. This effect was further confirmed in vivo using mouse models of lipopolysaccharide (LPS)-induced sepsis and alum-induced peritonitis. These results suggest the therapeutic value of myricetin by targeting NLRP3-driven inflammatory diseases.

[Development of Positioning and Navigation System Using for C-arm X-ray Apparatus for Minimally Invasive Surgeries].

On account of the problem that traditional C-arm X-ray apparatus cannot provide precise route guidance for minimally invasive surgeries, we designed and developed a laser positioning and navigation system based on C-arm X-ray apparatus, which can achieve precise positioning function and reduce the exposure of doctors and patients to radiation in minimally invasive surgeries under the linear guidance of a laser beam. Furthermore, this system can enhance the refinement level of surgical operation in minimally invasive surgeries.

Assessment of radiation exposure in balloon kyphoplasty using a new navigation system.

Study design: Randomized controlled trials of conventional and laser-navigated technology techniques for balloon kyphoplasty were carried out. Objective: To evaluate the effectiveness of a new laser navigation system in reducing the radiation dose in balloon kyphoplasty procedures. Material and methods: Sixty-seven randomized controlled trials involving a total of 75 lumbar vertebrae were treated. Thirty-four vertebrae were treated by regular fluoroscopic imaging alone, and the other 41 vertebrae were treated using the new laser navigation system. For each procedure the fluoroscopy dosage was documented using a Hitachi-Aloka Medical external dosimeter. The operation time was recorded. Results: The amount of radiation exposure in the control group was 870.59 ± 134.27 µSv. A significant reduction of the fluoroscopy usage in the navigated group was detected (503.5 ± 70.0 µSv (p < .0001)). In the control group, the average procedure time was 51.47 ± 8.30 minutes. The average procedure time in the navigated group was significantly reduced (39.26 ± 5.87 minutes (p < .0001)). Conclusion: The laser positioning and navigation system is an effective solution for reducing radiation exposure in balloon kyphoplasty. The increased technical effort may lead to a significant decrease of procedure time. The clinical trial No.: ChiCTR-INR-17013051.

Cypermethrin Promotes Lung Cancer Metastasis via Modulation of Macrophage Polarization by Targeting MicroRNA-155/Bcl6.

Cypermethrin (CYM), a type II pyrethroid, is widely used as an insecticide for agriculture and household. Cumulative evidence indicates that acute and chronic exposure to CYM might cause a number of health problems, such as cancer and neuronal system diseases. However, the molecular mechanism underlying this pathology is not known. The main objective of this study was to define the effects of CYM on macrophages and the implication of such effects in cancer metastasis and the potential mechanism involved. The effects of CYM on the macrophages were evaluated by detecting the expression of M1 and M2 macrophage polarization markers through ELISA, quantitative RT-PCR, and Western blot assay. Transwell and wound healing assays were used to test the migration of lung cancer cells after exposure to CYM in vitro and a metastasis animal model in vivo. Treatment with CYM significantly suppressed lipopolysaccharide (LPS)-induced M1 macrophage polarization and promoted a shift toward M2 macrophage status. Mechanistically, CYM downregulated miR-155 significantly, leading to enhanced expression of its target gene Bcl6, thereby reducing the expression of mitogen-activated protein kinase 4 (MKK4), an upstream kinase of c-Jun N-terminal kinases (JNK), and inhibiting JNK activation. Impaired JNK activation thus promoted a shift in macrophage polarization from the M1 to the M2 phenotype. Finally, CYM-treated macrophages promoted metastasis of Lewis lung cancer cells in both in vitro and in vivo models. Taken together, our findings show that CYM is able to inhibit the M1 polarization and promote the macrophages to the M2 phenotype, which plays an important role in tumor metastasis.

Promotion of Hernia Repair with High-Strength, Flexible, and Bioresorbable Silk Fibroin Mesh in a Large Abdominal Hernia Model.

The use of synthetic surgical meshes for abdominal hernia repair presents numerous challenges due to insufficient mechanical strength, nonabsorbability, and implant rigidity that leads to complications including chronic inflammatory reactions and adhesions. In this study, a naturally derived, high-strength, flexible, and bioresorbable silk fibroin mesh was developed by knitted textile engineering and biochemical manipulation. The mechanical properties of the mesh were optimized with the trial of different surface coating methods (thermal or chemical treatment) and 12 different knit patterns. Our silk fibroin mesh showed sufficient tensile strength (67.83 N longitudinally and 62.44 N vertically) which afforded the high mechanical strength required for abdominal hernia repair (16 N). Compared to the commonly used commercial nonabsorbable and absorbable synthetic meshes (Prolene mesh and Ultrapro mesh, respectively), the developed silk fibroin mesh showed advantages over other meshes, including lower elongation rate (47.14% longitudinally and 67.15% vertically, p < 0.001), lower stiffness (10-1000 fold lower, p < 0.001), and lower anisotropic behavior (λ = 0.32, p < 0.001). In a rat model of large abdominal hernia repair, our mesh facilitated effective hernia repair with minimal chronic inflammation which gradually decreased from 15 to 60 days postoperation, as well as lower adhesion formation rate and scores compared to control meshes. There was more abundant and organized collagen deposition, together with more pronounced neovascularization in the repaired tissue treated with silk fibroin mesh as compared to that treated with synthetic meshes. Besides, the silk fibroin mesh gradually transferred load-bearing responsibilities to the repaired host tissue as it was bioresorbed after implantation. Its isotropic architecture favored an ease of use during operations. In summary, our findings indicate that the use of knitted silk fibroin mesh provides a safe and effective alternative solution for large abdominal hernia repairs as it overcomes the prevailing limitations associated with synthetic meshes.

Mesenchymal phenotype of circulating tumor cells is associated with distant metastasis in breast cancer patients.

In this study, we investigated the relationship between the epithelial-mesenchymal transition phenotype of circulating tumor cells (CTCs) and distant metastasis in breast cancer patients. We analyzed the expression of epithelial (epithelial cell adhesion molecule, cytokeratin [CK]8, CK18 and CK19) and mesenchymal (vimentin and TWIST1) markers in CTCs from a large cohort of Chinese breast cancer patients (N=1083) using Canpatrol™ CTC assays. We identified CTCs in 84.9% (920/1083) of the breast cancer patients enrolled in this study. Among these 920 patients, 547 showed epithelial CTCs, 793 showed biphenotypic CTCs and 516 showed mesenchymal CTCs. Receiver operating characteristic (ROC) curves demonstrated circulation of both biphenotypic and mesenchymal CTCs (area under ROC curve value: 0.728; sensitivity: 68.7% and specificity: 71.6%) in patients was associated with distant metastasis. These findings demonstrate that the epithelial-mesenchymal transition phenotype of CTCs is a potential biomarker predictive of distant metastasis in breast cancer.

A rapid administration of GW4064 inhibits the NLRP3 inflammasome activation independent of farnesoid X receptor agonism.

GW4064 is a small molecule known to be an agonist of the nuclear farnesoid X receptor (FXR). We found that GW4064 inhibits the NLR family CARD domain containing 3 (NLRP3) inflammasome activation in an FXR-independent manner as evidenced by its similar inhibitory effect on NLRP3 inflammasome activation in FXR-deficient macrophages. Interestingly, GW4064 decreases the nigericin-induced oligomerization and ubiquitination of ASC which is critical for the NLRP3 inflammasome activation. In vivo results indicate that GW4064 could partially rescue the symptoms of NLRP3-dependent inflammatory disease models. These results not only necessitate cautious interpretation of the biological function of GW4064 as an FXR agonist, but also provide a potential therapeutic approach using GW4064 in the treatment of NLRP3-related diseases.

Importance of ROS-mediated autophagy in determining apoptotic cell death induced by physapubescin B.

Physapubescin B, a steroidal compound extracted from the plant Physalis pubescens L. (Solanaceae), has been reported to possess anti-cancer potential, whereas the molecular mechanism remains elusive. In this study, we first demonstrated that physapubescin B induced autophagy in human cancer cells based on the evidence that physapubescin B increased lipidation of microtubule-associated protein 1 light chain 3 (LC3) as well as number of GFP-LC3 puncta. We further examined the molecular mechanisms and found that physapubescin B enhanced the autophagic flux through promotion of reactive oxygen species (ROS)-mediated suppression of mammalian target of rapamycin complex I (mTORC1), the key negative regulator of autophagy. Additionally, excessive ROS caused by physapubescin B also induced p53-dependent apoptotic cell death. Furthermore, we provided evidence that inhibition of autophagy either by a chemical inhibitor or gene silencing promoted physapubescin B-induced apoptotic cell death, indicating that autophagy serves as a cell survival mechanism to protect cell death. Thus, our data provide a clue that inhibition of autophagy would serve as a novel strategy for enhancing the anti-cancer potential of physapubescin B.

Bile Acids Control Inflammation and Metabolic Disorder through Inhibition of NLRP3 Inflammasome.

Reciprocal interactions between the metabolic system and immune cells play pivotal roles in diverse inflammatory diseases, but the underlying mechanisms remain elusive. The activation of bile acid-mediated signaling has been linked to improvement in metabolic syndromes and enhanced control of inflammation. Here, we demonstrated that bile acids inhibited NLRP3 inflammasome activation via the TGR5-cAMP-PKA axis. TGR5 bile acid receptor-induced PKA kinase activation led to the ubiquitination of NLRP3, which was associated with the PKA-induced phosphorylation of NLRP3 on a single residue, Ser 291. Furthermore, this PKA-induced phosphorylation of NLRP3 served as a critical brake on NLRP3 inflammasome activation. In addition, in vivo results indicated that bile acids and TGR5 activation blocked NLRP3 inflammasome-dependent inflammation, including lipopolysaccharide-induced systemic inflammation, alum-induced peritoneal inflammation, and type-2 diabetes-related inflammation. Altogether, our study unveils the PKA-induced phosphorylation and ubiquitination of NLRP3 and suggests TGR5 as a potential target for the treatment of NLRP3 inflammasome-related diseases.

Cypermethrin Induces Macrophages Death through Cell Cycle Arrest and Oxidative Stress-Mediated JNK/ERK Signaling Regulated Apoptosis.

Cypermethrin is one of the most highly effective synthetic pyrethroid insecticides. The toxicity of cypermethrin to the reproductive and nervous systems has been well studied. However, little is known about the toxic effect of cypermethrin on immune cells such as macrophages. Here, we investigated the cytotoxicity of cypermethrin on macrophages and the underlying molecular mechanisms. We found that cypermethrin reduced cell viability and induced apoptosis in RAW 264.7 cells. Cypermethrin also increased reactive oxygen species (ROS) production and DNA damage in a dose-dependent manner. Moreover, cypermethrin-induced G1 cell cycle arrest was associated with an enhanced expression of p21, wild-type p53, and down-regulation of cyclin D1, cyclin E and CDK4. In addition, cypermethrin treatment activated MAPK signal pathways by inducing c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 ERK1/2 phosphorylation, and increased the cleaved poly ADP-ribose polymerase (PARP). Further, pretreatment with antioxidant N-acetylcysteine (NAC) effectively abrogated cypermethrin-induced cell cytotoxicity, G1 cell cycle arrest, DNA damage, PARP activity, and JNK and ERK1/2 activation. The specific JNK inhibitor (SP600125) and ERK1/2 inhibitor (PD98059) effectively reversed the phosphorylation level of JNK and ERK1/2, and attenuated the apoptosis. Taken together, these data suggested that cypermethrin caused immune cell death via inducing cell cycle arrest and apoptosis regulated by ROS-mediated JNK/ERK pathway.