The impact of AIM2 inflammasome-induced pyroptosis on acute gouty arthritis and asymptomatic hyperuricemia patients.

Objective: This study aimed to evaluate the role of absent in melanoma 2 (AIM2) inflammasome-mediated pyroptosis in the pathogenesis of acute gouty arthritis (AGA) and asymptomatic hyperuricemia(AHU). Methods: A cohort of 30 AGA patients, 30 AHU individuals, and 30 healthy controls (HC) was assembled. Demographic and biochemical data, along with blood samples, were collected. Serum double-stranded DNA (dsDNA) levels were quantified using a fluorescent assay. Transcriptomic and proteomic analysis of AIM2, Caspase-1, GSDMD, IL-1ß, and IL-18 in peripheral blood mononuclear cells was performed using qRT-PCR and Western blot. Enzyme-linked immunosorbent assay (ELISA) was employed to measure serum IL-1ß and IL-18. Spearman correlation analysis was utilized to assess relationships between variables. Results: Both AGA and AHU groups demonstrated elevated metabolic indicators and serum levels of dsDNA, IL-1ß, and IL-18 compared to the HC group. AGA patients exhibited higher inflammatory markers than the AHU group. In the AGA group, there was a significant increase in the mRNA and protein levels of AIM2, Caspase-1, GSDMD, IL-1ß, and IL-18 (P<0.05 to P<0.001). The AHU group showed higher AIM2, Caspase-1, GSDMD, and IL-18 mRNA levels than the HC group (P<0.001 to P<0.01), with a non-significant increase in AIM2, GSDMD, and IL-1ß proteins (P>0.05). In contrast, Caspase-1 and IL-18 proteins were significantly higher in the AHU group (P<0.05). Notable correlations were observed between AIM2 protein expression and levels of Caspase-1 and GSDMD in both AGA and AHU groups. In the AGA group, AIM2 protein correlated with IL-1ß, but not in the AHU group. The AIM2 protein in the AHU group was positively associated with IL-18, with no such correlation in the AGA group. Conclusion: AIM2 inflammasome may play a role in the inflammatory processes of AGA and AHU and that its activation may be related to the pyroptosis pathway.

Lipopolysaccharide-induced bacterial infection model: microRNA-370-3p participates in the anti-infection response by targeting the macrophage TLR4-NLRP3 caspase-1 cellular pyroptosis pathway.

OBJECTIVE: To explore the effect of miR-370-3p on LPS triggering, in particular its involvement in disease progression by targeting the TLR4-NLRP3-caspase-1 cellular pyroptosis pathway in macrophages. METHODS: Human macrophage RAW264.7 was divided into 6 groups: control, LPS, LPS + inhibitor-NC, LPS + miR-370-3p inhibitor, LPS + mimics-NC and LPS + miR-370-3p mimics. RT-qPCR was used to detect the expression level of miR-370-3p and analyzed comparatively. CCK-8 and flow cytometry assays were used to detect cell viability and apoptosis. ELISA assay was used to detect the levels of IL-1ß and TNF-α in the supernatant of the cells. The WB assay was used to detect TLR4, NLRP3, Caspase-1 and GSDMD levels. RESULTS: After LPS induction, macrophage miR-370-3p levels decreased, cell viability decreased, and apoptosis increased. At the same time, the levels of TLR4, NLRP3, Caspase-1 and GSDMD increased in the cells, and the levels of IL-1ß and TNF-α increased in the cell supernatant. Compared with the LPS group, the significantly higher expression level of miR-370-3p in the cells of the LPS + miR-370-3p mimics group was accompanied by significantly higher cell viability, significantly lower apoptosis rate, significantly lower levels of TLR4, NLRP3, Caspase-1, and GSDMD in the cells, and significantly lower levels of IL-1ß and TNF-α in the cell supernatant. CONCLUSION: MiR-370-3p may be involved in anti-infective immune responses by targeting and inhibiting the macrophage TLR4-NLRP3-caspase-1 cellular pyroptosis pathway.

Alveolar hypoxia induces organ-specific inflammasome-related inflammation in male mouse lungs.

Inflammation through activation of caspase-1, seems to play a role in pulmonary hypertension induced by alveolar hypoxia. Whether alveolar hypoxia induces caspase-1-mediated inflammation and influx of leukocytes in other organs than the lungs, is not known. Our aim was to explore sites of caspase-1-related inflammation in alveolar hypoxia. Wild type (WT) mice were exposed to environmental hypoxia or room-air, and organs were analyzed. Right heart catheterization was performed after 14 days of alveolar hypoxia in WT mice and mice transplanted with WT or caspase-1-/- bone marrow. Hypoxia induced leukocyte accumulation and increased caspase-1 protein in the lungs, not in other organs. WT mice transplanted with WT or caspase-1-/- bone marrow showed no difference in pulmonary leukocyte accumulation or development of pulmonary hypertension after alveolar hypoxia. Caspase-1 and IL-18 were detected in bronchial epithelium in WT mice, and hypoxia induced IL-18 secretion from bronchial epithelial cells. IL-18 stimulation generated IL-6 mRNA in monocytes. Phosphorylated STAT3 was increased in hypoxic lungs, not in other organs. Alveolar hypoxia induces caspase-1 activation and leukocyte accumulation specific to the lungs, not in other organs. Caspase-1 activation and IL-18 secretion from bronchial epithelial cells might initiate hypoxia-induced inflammation, leading to pulmonary hypertension.

Dexmedetomidine's protective mechanism against hyperoxic injury in neonatal rats.

Bronchopulmonary dysplasia (BPD) is a common serious complication of premature babies. No effective means control it. Hyperoxia damage is one of the important mechanisms of BPD. The reaserach confirmed pyroptosis existed in BPD. Dexmedetomidine is a new, high-specific α2 receptor agonist. Previous research foundation found that dexmedetomidine has a protective effect on BPD. To investigate how dexmedetomidine improves hyperoxic lung injury in neonatal mice by regulating pyroptosis. Neonatal rats were randomly divided into four groups: normal control group, hyperoxic injury group, air plus dexmedetomidine group, and hyperoxia plus dexmedetomidine group. After seven days the lungs of rats in each group were extracted, and the wet-to-dry weight ratio of the lung was measured. The lung injury in rats was observed using hematoxylin-eosin staining. Additionally, the expression and localization of nucleotide-binding oligomerization domain-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), and gasdermin D (GSDMD) proteins were examined in the lungs of rats using immunofluorescence staining. The mRNA levels of NLRP3, ASC, caspase-1, and interleukin 18 (IL-18) in the lungs of rats were determined using real-time PCR. Moreover, the protein levels of NLRP3, ASC, caspase-1/cleaved caspase-1, interleukin 1beta (IL-1ß), IL-18, and tunor necrosis factor alpha (TNF-α) were detected in lungs of rats using Western blot. The extent of mitochondrial damage in lung tissues of each group was observed by transmission electron microscopy. The lung tissue injury of the neonatal rats was significantly improved in the hyperoxia plus dexmedetomidine group compared to the hyperoxic injury group. Furthermore, the expressions of pyroptosis-related proteins such as NLRP3, ASC, cleaved-caspase-1, and GSDMD were significantly decreased, along with the expressions of inflammatory factors in lung tissues. By inhibiting the NLRP3/caspase-1/GSDMD pyroptosis pathway, dexmedetomidine reduces the activation and release of inflammatory factors and provides a protective effect against hyperoxic lung injury in neonatal mice.

Mechanism of Vaginal Epithelial Cell Pyroptosis Induced by the NLRP3 Inflammasome in Vulvovaginal Candidiasis.

PROBLEM: Vulvovaginal candidiasis (VVC) is a common mucosal fungal infection, and Candida albicans is the main causative agent. The NLRP3 inflammasome plays an important role in VVC, but the underlying mechanism is unknown. METHOD OF STUDY: Vaginal epithelial cells were divided into three groups: control, C. albicans strain SC5314 (wild-type, WT), and WT+ Matt Cooper Compound 950 (MCC950, a specific NLRP3 inhibitor). After human vaginal epithelial cells were pretreated with 1 µmol/L MCC950 for 2 h, C. albicans (MOI = 1) was cocultured with the human vaginal epithelial cells for 12 h. The cell supernatants were collected, LDH was detected, and the IL-1ß and IL-18 levels were determined by ELISA. The expression of the pyroptosis-related proteins NLRP3, Caspase-1 p20 and GSDMD was measured by Western blotting analysis. The protein expression of the pyroptosis-related N-terminus of GSDMD (GSDMD-N) was detected by immunofluorescence. RESULTS: In this study, we showed that the WT C. albicans strain induced pyroptosis in vaginal epithelial cells, as indicated by the LDH and proinflammatory cytokine levels and the upregulated levels of the pyroptosis-related proteins NLRP3, Caspase-1 p20, and GSDMD-N. MCC950 reversed the changes in the expression of these proteins and proinflammatory cytokines in vaginal epithelial cells. CONCLUSION: C. albicans activated the NLRP3 inflammasome to induce vaginal epithelial cell pyroptosis. MCC950 inhibited the NLRP3 inflammasome, reduced vaginal epithelial cell pyroptosis, and decreased the release of inflammatory cytokines.

Wogonin ameliorates the proliferation, inflammatory response, and pyroptosis in keratinocytes via NOD-like receptor family pyrin domain containing 3/Caspase-1/Gasdermin-D pathway.

BACKGROUND: Psoriasis refers to a highly prevalent and immunologically mediated dermatosis with considerable deterioration in life quality. Wogonin, a sort of flavonoid, has been mentioned to elicit protective activities in skin diseases. However, whether Wogonin is implicated in the treatment of psoriasis and its specific mechanisms are not fully understood. AIM: The present work attempted to elaborate the role of Wogonin during the process of psoriasis and to concentrate on the associated action mechanism. METHODS: Cell counting kit-8 (CCK-8) method was initially applied to assay the viability of human keratinocyte HaCaT cells treated by varying concentrations of Wogonin. To mimic psoriasis in vitro, HaCaT cells were exposed to M5 cytokines. CCK-8 and 5-Ethynyl-2'-deoxyuridine  assays were adopted for the measurement of cell proliferation. Inflammatory levels were examined with enzyme-linked immunosorbent assay. Immunofluorescence staining tested nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) and Caspase-1 expressions. Western blot examined the protein expressions of proliferation-, inflammation-, pyroptosis-associated factors, and NLRP3. RESULTS: Wogonin treatment antagonized the proliferation, inflammatory response, and NLRP3/caspase-1/Gasdermin-D (GSDMD)-mediated pyroptosis in M5-challenged HaCaT cells. Besides, NLRP3 elevation partially abrogated the effects of Wogonin on M5-induced proliferation, inflammatory response, and NLRP3/caspase-1/GSDMD-mediated pyroptosis in HaCaT cells. CONCLUSION: In a word, Wogonin might exert anti-proliferation, anti-inflammatory and anti-pyroptosis activities in M5-induced cell model of psoriasis and the blockade of NLRP3/Caspase-1/GSDMD pathway might be recognized as a potential mechanism underlying the protective mechanism of Wogonin in psoriasis, suggesting Wogonin as a prospective anti-psoriasis drug.

Tongqiao Yizhi granule repress the nuclear factor kappa-b/nucleotide oligomerization domain-like receptors 3/caspase-1 pyroptosis pathway in the hippocampus to counter vascular dementia in rats.

OBJECTIVE: To explore the mechanism by which Tongqiao Yizhi granule (, TQYZKL) intervenes pyroptosis to treat vascular dementia (VaD) in a rat model. METHODS: The rat model of VaD was established by two-vessel occlusion (2VO). The rats were randomly divided into Sham group, Model group, Nimodipine group, TQYZKL (6.2 g?kg-1?d-1), TQYZKL (12.4 g?kg-1?d-1), TQYZKL (24.8 g?kg-1?d-1). The Morris water maze (MWM) test was carried out to test the learning and memory function; Hematoxylin-eosin staining and transmission electron microscopy (TEM) to observe the pathological damage in the hippocampus; Tunel fluorescence staining to detect neuronal pyroptosis in the hippocampus. The expression levels of pyroptosis-related proteins, namely Golgi peripheral membrane protein p65 (P65), nucleotide oligomerization domain-like receptors 3 (NLRP3), caspase-1 and Gasdermin D (GSDMD), were detected using Western blotting and reverse transcription polymerase chain reaction. Moreover, the serum levels of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) were determined through the enzyme-linked immunosorbent assay. RESULTS: The study revealed that TQYZKL effectively improved the ability of VaD ratsto learn and memorize, relieved the pathological damage in the hippocampus, restored neuronal morphology, and reduced the expression of pyroptosis-related proteins P65, NLRP3, caspase-1, GSDMD-N, IL-18 and IL-1ß (P < 0.05). CONCLUSION: TQYZKL inhibits neuronal pyroptosis in the hippocampus of VaD rats by regulating nuclear factor kappa-B/NLRP3/caspase-1 signaling pathway, thus exerting a therapeutic effect on VaD in the rats.

Celastrol exerts antiarrhythmic effects in chronic heart failure via NLRP3/Caspase-1/IL-1ß signaling pathway.

OBJECTIVES: Celastrol has widespread therapeutic applications in various pathological conditions, including chronic inflammation. Previous studies have demonstrated the potent cardioprotective effects of celastrol. Nevertheless, limited attention has been given to its potential in reducing ventricular arrhythmias (VAs) following myocardial infarction (MI). Hence, this study aimed to elucidate the potential mechanisms underlying the regulatory effects of celastrol on VAs and cardiac electrophysiological parameters in rats after MI. METHODS: Sprague-Dawley rats were divided at random: the sham, MI, and MI + celastrol groups. The left coronary artery was occluded in the MI and MI + Cel groups. Electrocardiogram, heart rate variability (HRV), ventricular electrophysiological parameters analysis, histology staining of ventricles, Enzyme-linked immunosorbent assay (ELISA), western blotting and Quantitative real-time polymerase chain reaction (qRT-PCR) were performed to elucidate the underlying mechanism of celastrol. Besides, H9c2 cells were subjected to hypoxic conditions to create an in vitro model of MI and then treated with celastrol for 24 hours. Nigericin was used to activate the NLRP3 inflammasome. RESULTS: Compared with that MI group, cardiac electrophysiology instability was significantly alleviated in the MI + celastrol group. Additionally, celastrol improved HRV, upregulated the levels of Cx43, Kv.4.2, Kv4.3 and Cav1.2, mitigated myocardial fibrosis, and inhibited the NLRP3 inflammasome pathway. In vitro conditions also supported the regulatory effects of celastrol on the NLRP3 inflammasome pathway. CONCLUSIONS: Celastrol could alleviate the adverse effects of VAs after MI partially by promoting autonomic nerve remodeling, ventricular electrical reconstruction and ion channel remodeling, and alleviating ventricular fibrosis and inflammatory responses partly by through inhibiting the NLRP3/Caspase-1/IL-1ß pathway.

Mode of cell death in the penile cavernous tissue of type 1 diabetes mellitus rats.

BACKGROUND: Diabetes mellitus commonly causes endothelial cell and smooth muscle cell death in penile cavernous tissue. AIM: The study sought to study the mode of cell death in the penile cavernous tissue in type 1 diabetic rats. METHODS: A total of 36 Sprague Dawley rats 10 weeks of age were randomly divided into 2 groups: a normoglycemic group and type 1 diabetic group (intraperitoneal injection of Streptozotocin (STZ), 60 mg/kg). We randomly selected 6 rats from each group for tests at the end of 11, 14, and 18 weeks of age, respectively. All rats were able to eat and drink freely. The ratio of maximum intracavernous pressure to mean arterial pressure, concentration of serum testosterone, level of nitric oxide in the penile cavernosum, and expression of active caspase-1 (pyroptosis) and active caspase-3 (apoptosis) were determined. OUTCOMES: At the end of weeks 4 and 8 of type 1 diabetes, the proportions of endothelial cells and smooth muscle cells undergoing apoptosis and pyroptosis in penile cavernous tissue are different. RESULTS: The ratio of maximum intracavernous pressure to mean arterial pressure and nitric oxide levels were significantly lower in the 4- and 8-week diabetic groups than in the normoglycemic group (P < .01). Penile endothelial cell pyroptosis (5.67 ± 0.81%), smooth muscle cell apoptosis (23.72 ± 0.48%), total cell pyroptosis (9.67 ± 0.73%), and total apoptosis (10.52 ± 1.45%) were significantly greater in the 4-week diabetic group than in the normoglycemic group (P < .01). The proportion of endothelial cell pyroptosis (24.4 ± 3.69%), endothelial cell apoptosis (22.13 ± 2.43%), total cell pyroptosis (14.75 ± 0.93%), and total apoptosis (14.82 ± 1.08%) in the penile tissues of the 8-week diabetic group were significantly greater than those in the normoglycemic group (P < .01).The 8-week survival proportions of diabetic endothelial cells (38.86 ± 8.85%) and smooth muscle cells (44.46 ± 2.94%) was significantly lower than the 4-week survival proportions of endothelial cells (93.17 ± 8.07%) and smooth muscle cells (75.12 ± 4.76%) (P < .05). CLINICAL TRANSLATION: Inhibition of cell death by different methods at different stages may be the key to the treatment of type 1 diabetes-induced erectile dysfunction. STRENGTHS AND LIMITATIONS: The effect of type 1 diabetes on other types of cell death in penile cavernous tissue needs further study. CONCLUSION: The mode of death of endothelial cells in the cavernous tissue of the penis in the early stage in diabetic rats is dominated by pyroptosis, and the death of smooth muscle cells is dominated by apoptosis. Endothelial cell and smooth muscle cell death are not consistent at different stages of diabetes progression.

Re-positioning of low dose paclitaxel against depressive-like behavior and neuroinflammation induced by lipopolysaccharide in rats: Crosstalk between NLRP3/caspase-1/IL-1ß and Sphk1/S1P/ NF-κB signaling pathways.

AIMS: Depression is a potentially fatal illness affecting millions of individuals worldwide, across all age groups. Neuroinflammation is a key factor in depression development. Paclitaxel (PXL), a well-known chemotherapeutic agent has been used as therapy for several types of cancer. This study aims to evaluate the ameliorative effect of low-dose PXL against lipopolysaccharide (LPS)-induced depression in rats. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were administrated a single dose of LPS (5 mg/kg, i.p.); 2 h later, rats received PXL (0.3 mg/kg, i.p. three times/week) for one week. KEY FINDINGS: Low-dose PXL alleviated LPS-induced depressive-like behavior in rats as evidenced by significantly improving behavioral changes in both forced swim test (FST) and open field test (OFT), successfully mitigated depletion of monoamines (serotonin, norepinephrine, and dopamine), in addition to markedly decreasing lipid peroxidation with antioxidant levels elevation in brain tissues. Low-dose PXL substantially decreased inflammation triggered by LPS in brain tissue via repressing the expression of NLRP3 and its downstream markers level, caspase-1 and IL-1ß jointly with a corresponding decrease in proinflammatory cytokine levels (TNF-α). Furthermore, low-dose PXL remarkably down-regulated Sphk1/S1P signaling pathway. Concurrent with these biochemical findings, there was a noticeable improvement in the brain tissue's histological changes. SIGNIFICANCE: These findings prove the role of low-dose PXL in treatment of LPS-induced neuroinflammation and depressive-like behavior through their anti-depressant, antioxidant and anti-inflammatory actions. The suggested molecular mechanism may entail focusing the interconnection among Sphk1/S1P, and NLRP3/caspase-1/IL-1ß signaling pathways. Hence PXL could be used as a novel treatment against LPS-induced depression.

Activation of the NLRP3-CASP-1 inflammasome is restrained by controlling autophagy during Glaesserella parasuis infection.

Infection with Glaesserella parasuis, the primary pathogen behind Glässer's disease, is often associated with diverse clinical symptoms, including serofibrinous polyserositis, arthritis, and meningitis. Autophagy plays a dual role in bacterial infections, exerting either antagonistic or synergistic effects depending on the nature of the pathogen. Our previous studies have demonstrated that autophagy serves as a defense mechanism, combating inflammation and invasion caused by infection of highly virulent G. parasuis. However, the precise mechanisms remain to be elucidated. Pathogens exhibit distinct interactions with inflammasomes and autophagy processes. Herein, we explored the effect of autophagy on inflammasomes during G. parasuis infection. We found that G. parasuis infection triggers NLRP3-dependent pro-CASP-1-IL-18/IL-1ß processing and maturation pathway, resulting in increased release of IL-1ß and IL-18. Inhibition of autophagy enhances NLRP3 inflammasome activity, whereas stimulation of autophagy restricts it during G. parasuis infection. Furthermore, assembled NLRP3 inflammasomes undergo ubiquitination and recruit the autophagic adaptor, p62, facilitating their sequestration into autophagosomes during G. parasuis infection. These results suggest that the induction of autophagy mitigates inflammation by eliminating overactive NLRP3 inflammasomes during G. parasuis infection. Our research uncovers a mechanism whereby G. parasuis infection initiates inflammatory responses by promoting the assembly of the NLRP3 inflammasomes and activating NLRP3-CASP-1, both of which processes are downregulated by autophagy. This suggests that pharmacological manipulation of autophagy could be a promising approach to modulate G. parasuis-induced inflammatory responses.

Investigating the involvement of the NLRP3/ASC/caspase-1 and NF-κb/MAPK pathways in the pathogenesis of gouty arthritis: Insights from irradiated and non-irradiated Trifolium alexandrium L. extracts and some metabolites.

ETHNOPHARMACOLOGICAL RELEVANCE: Trifolium alexandrinum L. (TA), has traditionally been used in folk medicine for its anti-inflammatory properties against hyperuricemia and gout. However, the specific mechanisms of action of TA have not been thoroughly studied. AIM OF THE WORK: This study aimed to evaluate the protective effects of irradiated (TR25) and non-irradiated (TR0) Trifolium alexandrinum L. aqueous extract (TAAE), along with two isolated compounds, caffeine (CAF) and saponin (SAP), in a rat model of acute gouty arthritis (GA). MATERIALS AND METHODS: The GA model was established by injecting a monosodium urate (MSU) suspension into the knee joint. Synovial tissue pathology was assessed, and levels of TNF-α, IL-6, IL-1ß, NF-κB, mTOR, AKT1, PI3K, NLRP3, and ASC were measured by ELISA. mRNA expression of ERK1, JNK, and p-38 MAPK was detected using qRT-PCR, and Caspase-1 protein expression was assessed by immunohistochemical analysis. Knee swelling, uric acid levels, liver and kidney function, and oxidative stress markers were also evaluated. RESULTS: TAAE analysis identified 170 compounds, with 73 successfully identified using LC-HR-MS/MS, including caffeine citrate and theasapogenol B glycoside as the main constituents. The studied materials demonstrated significant protective effects against GA. TR25 administration significantly mitigated knee joint circumference compared to other treatments. It demonstrated potential in alleviating hyperuricemia, renal and hepatic impairments induced by MSU crystals. TR25 also alleviated oxidative stress and reduced levels of IL1ß, IL-6, TNF-α, and NF-κB. Weak Caspase-1 immune-positive staining was observed in the TR25 group. TR25 decreased NLRP3 and ASC expression, reducing inflammatory cytokine levels in GA. It effectively inhibited the PI3K, AKT, and mTOR signaling pathways, promoting autophagy. Additionally, TR25 suppressed ERK1, JNK, and p-38 MAPK gene expression in synovial tissue. These effects were attributed to various components in TAAE, such as flavonoids, phenolic acids, tannins, alkaloids, and triterpenes. CONCLUSION: Importantly, irradiation (25 KGy) enhanced the antioxidant effects and phtchemical contents of TAAE. Additionally, TR0, TR25, CAF, and SAP exhibited promising protective effects against GA, suggesting their therapeutic potential for managing this condition. These effects were likely mediated through modulation of the NLRP3/ASC/Caspase-1 and ERK/JNK/p-38 MAPK signaling pathways, as well as regulation of the PI3K/AKT/mTOR pathway. Further research is warranted to fully elucidate the underlying mechanisms and optimize their clinical applications.

Downregulation of ATP5F1D inhibits mtROS/NLRP3/caspase-1/GSDMD axis to suppress pyroptosis-mediated malignant progression of endometrial cancer.

PURPOSE: In developed countries, endometrial cancer (EC) is the most prevalent gynecological cancer and its occurrence is associated with chronic inflammation. ATP5F1D is a subunit of ATP synthase (complex V), as well as the important component of mitochondrial electron transport chain (ETC). ETC play compelling roles in carcinogenesis. To date, little is known about the role of ATP5F1D in EC. METHODS: ATP5F1D expression was identified in EC tissues and EC cell lines. We evaluated the influence of ATP5F1D on clinical features and prognosis based on TCGA database. The effects of ATP5F1D in EC malignant progression by applying loss-of-function assays in KLE and Ishikawa cell lines were detected by EdU, CCK-8, wound healing, Transwell, and flow cytometry assays. Additionally, electron microscope, LDH release, ELISA, mitochondrial ROS measurement, and Immunofluorescence were performed to demonstrate ATP5F1D can affect the pyroptosis of EC. To observe the anti-tumor effect on ATP5F1D silencing, we established an in vivo human endometrial tumor model using nude mice. RESULTS: ATP5F1D expression was significantly upregulated in EC and was associated with favorable prognosis. ATP5F1D knockdown inhibited the proliferation, invasion, and migration of EC cells. Similarly, in nude mice, ATP5F1D knockdown suppressed the growth EC cells. Knocking down ATP5F1D lead to decrease the production of mitochondrial ROS (mtROS) and inhibited pyroptosis of EC cells. CONCLUSION: Downregulation of ATP5F1D as a new therapeutic strategy that could mediate pyroptosis via suppressing mtROS/NLRP3/caspase-1/GSDMD pathway to inhibit EC progression.

Syringic acid suppresses Cutibacterium acnes-induced inflammation in human keratinocytes via regulating the NLRP3/caspase-1/IL-1ß signaling axis by activating PPARγ/Nrf2-antioxidant pathway.

BACKGROUND: Our previous studies have demonstrated a strong relationship betweenCutibacterium acnes(C. acnes), oxidative stress, and acne inflammation. Syringic acid (SA) is a plant widely used for its antimicrobial, anti-inflammatory, and antioxidant activities, but lacking data on acne. This study aims to investigate the effect and mechanism of SA on acne inflammation induced by C. acnes in vitro and in vivo. METHODS: After using the SA to expose HaCaT keratinocytes, we reevaluated the effect of the SA on cell viability, cell apoptosis, ROS, CAT, SOD, and other inflammatory variables in the heat-killed C. acnes-treated HaCaT cells. Next, to induce mice with acne inflammation, ICR mice were given an intradermal injection of live C. acnes into their right ears. The effect of SA on this inflammation was then examined. Moreover, we explored the mechanism of SA on PPARγ/Nrf2 and NLRP3/caspase-1/IL-1ß pathways by ELISA, immunofluorescence microscopy, and western blot assay. RESULTS: Heat-killed C. acnes triggered remarkable cell apoptosis, ROS production, interleukin (IL)-1ß, IL-18, IL-6, and TNF-α release, reduced SOD and CAT activity, and upregulated the expression of proteins in HaCaT cells, including up-regulating IL-1ß, PPARγ, Nrf2, HO-1, NQO1, NLRP3, and caspase-1, whereas SA inhibited these effects by partially impairing PPARγ activation. In addition, PPARγ silencing decreased C. acnes-induced IL-1ß secretion and the production of intracellular ROS, down-regulating the expression of Nrf2. Nrf2 activator (SFN) enhanced anti-inflammatory activity through antioxidant mechanisms, boosting intracellular ROS production, reducing SOD and CAT activity, and promoting the increase in ROS, HO-1, NQO1, and IL-1ß levels, while PPARγ inhibitor (GW662) effectively inhibited this effect in heat-killed C. acnes-treated cells. Finally, SA also exhibited notable improvements in ear redness, swelling, and the expression of PPARγ, NLRP3, and IL-1ß in vivo. CONCLUSIONS: SA inhibited C. acnes-induced inflammation via regulating the NLRP3/caspase-1/IL-1ß signaling axis by activating the PPARγ/Nrf2-antioxidant pathway, suggesting a new treatment possibility for acne vulgaris.

Sacubitril/valsartan alleviates sepsis-induced myocardial injury in rats via dual angiotensin receptor-neprilysin inhibition and modulation of inflammasome/caspase 1/IL1ß pathway.

Sepsis is a life-threatening situation that ultimately affects cardiac function, leading to cardiomyopathy and myocardial injury as a result of uncontrolled response to infection.Till now, there is limited effective treatment to rescue those cases. Thus, novel therapeutic strategies should be identified to achieve better outcomes for septic patients. For the first time, we aimed to evaluate the effect of sacubitril/valsartan (Sac/Val) on sepsis-induced cardiac injury. Wistar male adult albino rats were randomly divided into four groups; Group I received the vehicle; Group II was given the vehicle plus 1 ml saline containing viable Escherichia coli (E. coli) (2.1 × 109 cfu) by intraperitoneal (i.p.) injection on the 1st and 2nd days; Group III received i.p. injection as group II plus oral administration of Sac/Val (30 mg/kg/day) and Nitro- ω-L-arginine (L-NNA) (25 mg/kg/day) for 7 days. Group IV was administered i.p. injection as group II plus oral administration of Sac/Val (30 mg/kg/day) for 7 days. Our data (n = 10) revealed successful induction of sepsis as it showed a significant increase in the measured cardiac enzymes, malondialdehyde (MDA), angiotensin II (Ang II), neprilysin, inflammasome, caspase 1, interleukin (IL)1ß, and caspase 3 with cardiac histopathological changes, but there was a significant decrease in the antioxidants and blood pressure (BP). Co-administration of Sac/Val could obviously improve these changes. Interestingly, L-NNA given group showed a decrease in the cardioprotective effect of Sac/Val. Sac/Val could ameliorate sepsis induced cardiac damage via inhibition of Ang II and neprilysin with anti-inflammatory, anti-oxidant and anti-apoptotic properties.

Bavachinin, a main compound of Psoraleae Fructus, facilitates GSDMD-mediated pyroptosis and causes hepatotoxicity in mice.

Psoraleae Fructus (PF, Psoralea corylifolia L.), a traditional medicine with a long history of application, is widely used clinically for the treatment of various diseases. However, the reports of PF-related adverse reactions, such as hepatotoxicity, phototoxic dermatitis, and allergy, are increasing year by year, with liver injury being the mostly common. Our previous studies have demonstrated that PF and its preparations can cause liver injury in lipopolysaccharide (LPS)-mediated susceptibility mouse model, but the mechanism of PF-related liver injury is unclear. In this study, we showed that PF and bavachinin, a major component of PF, can directly induce the expression of caspase-1 and interleukin-1ß (IL-1ß), indicating that PF and bavachinin can directly triggered the activation of inflammasome. Furthermore, pretreatment with NLR family pyrin domain-containing 3 (NLRP3), NLR family CARD domain containing 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome inhibitors, containing MCC950, ODN TTAGGG (ODN) and carnosol, all significantly reversed bavachinin-induced inflammasome activation. Mechanistically, bavachinin dose-dependently promote Gasdermin D (GSDMD) post-shear activation and then induce mitochondrial reactive oxygen species (mtROS) production and this effect is markedly inhibited by pretreatment with N-Acetylcysteine amide (NAC). In addition, combination treatment of LPS and bavachinin significantly induced liver injury in mice, but not LPS or bavachinin alone, and transcriptome analysis further validated these results. Thus, PF and bavachinin can induce the activation of inflammasome by promoting GSDMD cleavage and cause hepatotoxicity in mice. Therefore, PF, bavachinin, and PF-related preparations should be avoided in patients with inflammasome activation-associated diseases.

Immunohistochemical Expression of Caspase1 and Epidermal Growth Factor Receptor in Invasive Breast Carcinoma and Their Biological and Prognostic Associations.

BACKGROUND: Despite advances in breast carcinoma therapies, drug resistance mechanisms as anti-apoptosis and anti-pyroptosis limit the application of these therapies. This work assesses the immunohistochemical (IHC) expression of Caspase1 and EGFR in breast carcinoma and analyzes their clinicopathological associations as prognostic markers and potential therapeutic targets. Caspase1/EGFR expression patterns are utilized to specify breast carcinoma patients who may benefit from these therapies. METHODS: After reviewing the hematoxylin and eosin-stained slides and the routine breast carcinoma IHC stains (estrogen receptors, progesterone receptors, HER2/NEU, Ki-67) by two pathologists and preparation of tissue microarray blocks, anti-Caspase-1 and EGFR IHC staining was performed using Horseradish Peroxidase (HRP) technique. Intensity and percentage-based scoring was applied dividing the 153 included breast carcinomas into Caspase1-negative and positive expression groups; and EGFR low and overexpression groups. Groups were statistically analyzed in relation to age, tumor size, histological and molecular subtype, grade, nodal status, metastasis/recurrence, TNM stage and Ki-67 proliferation index. Kaplan-Meier's analysis was used to compare disease-free survival (DFS) and overall survival (OS). Combined patterns based on Caspase1 and EGFR expression status were created to stratify patients into prognostic groups. RESULTS: Caspase1 was positive in 54.2% of breast carcinomas and its positivity was significantly associated with smaller tumor size, absence of metastasis/recurrence, luminal A and B molecular subtypes and longer OS (p<0.05). EGFR overexpression was detected in 32.7% of carcinomas and was significantly associated with larger tumor size, TNBLBC and a shorter OS (p<0.05). Caspase1-negative/EGFR-overexpression pattern comprised 14.4% of carcinomas and had the worst prognostic associations including larger tumor size, metastasis/recurrence, TNBLBC subtype and shortest OS (p=0.002, 0.002, 0.004 and ≤0.001 respectively).  Conclusions: Combined Caspase1/EGFR IHC expression may provide a tool for selection of patients who benefit from combined EGFR-inhibitors with miR-155-5p down-regulators or photodynamic therapy via induction of apoptosis/pyroptosis in EGFR-overexpression carcinomas through enhanced Caspase1 signaling.

Distinct sequential death complexes regulate pyroptosis and IL-1ß release in response to Yersinia blockade of immune signaling.

Pathogen infection of host cells triggers an inflammatory cell death termed pyroptosis via activation of inflammatory caspases. However, blockade of immune signaling kinases by the Yersinia virulence factor YopJ triggers cell death involving both apoptotic caspase-8 and pyroptotic caspase-1. While caspase-1 is normally activated within inflammasomes, Yersinia-induced caspase-1 activation is independent of known inflammasome components. We report that caspase-8 is an essential initiator, while caspase-1 is an essential amplifier of its own activation through two feed-forward loops involving caspase-1 auto-processing and caspase-1-dependent activation of gasdermin D and NLPR3. Notably, while Yersinia-induced caspase-1 activation and cell death are inflammasome-independent, IL-1ß release requires NLPR3 inflammasome activation. Mechanistically, caspase-8 is rapidly activated within multiple foci throughout the cell, followed by assembly of a canonical inflammasome speck, indicating that caspase-8 and canonical inflammasome complex assemblies are kinetically and spatially distinct. Our findings reveal that functionally interconnected but distinct death complexes mediate pyroptosis and IL-1ß release in response to pathogen blockade of immune signaling.

[Effect of zinc oxide nanoparticles on hypoxia and pyroptosis of rat neutrophils].

Objective: To investigate the effects of zinc oxide nanoparticles (ZnO-NPs) on neutrophil hypoxia and pyroptosis through nucleotide binding of oligomeric domain-like receptor protein 3 (NLRP3) inflammasome, and to analyze the role of pyroptosis on respiratory tract inflammotion induced by ZnO-NPs. Methods: In October 2022, primary cultured neutrophils were obtained from the abdominal aortic blood of SPF adult healthy SD rats. The neutrophils were treated with ZnO-NPs solution (0, 5, 10, 20 µg/ml) at different concentrations, and hypoxia group (5% O(2)) was set up. Hypoxia and reactive oxygen species (ROS) levels were detected by flow cytometry, and the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), cleaved Caspase-1 were measured by Western blot. The activity of lactic dehydrogenase (LDH) in the cell supernatant was measured by coloration, and the content of interleukin-1 beta (IL-1ß) in cell culture supernatant was detected by enzyme-linked immunosorbent assay (ELISA) . Results: Compared with the control group, hypoxia and ROS levels of neutrophils in hypoxia group and ZnO-NPs groups were significantly increased (P<0.05), and NLRP3, ASC, cleaved Caspase-1 protein expression levels, LDH activity and IL-1ß content were significantly increased (P<0.05). Compared with hypoxia group, hypoxia and ROS levels of neutrophils in 5 µg/ml and 10 µg/ml ZnO-NPs groups were significantly decreased (P<0.05), NLRP3, ASC, cleaved Caspase-1 protein expression levels, LDH activity, and IL-1ß content were decreased significantly (P<0.05). There were no significant differences in hypoxia, ROS levels, ASC, cleaved Caspase-1 protein expression levels, LDH activity, and IL-1ß content between the 20 µg/ml ZnO-NPs group and the hypoxia group (P>0.05) . Conclusion: ZnO-NPs treatment may activate the NLRP3 inflammasome to induce pyroptosis of neutrophils which may be related to ROS and hypoxia.

Hydrogen sulfide mitigates ox­LDL­induced NLRP3/caspase­1/GSDMD dependent macrophage pyroptosis by S­sulfhydrating caspase­1.

Macrophage pyroptosis mediates vascular inflammation and atherosclerosis (AS). Hydrogen sulfide (H2S) exerts a protective role in preventing inflammation and AS. However, its molecular mechanisms of regulating the pyroptosis signaling pathway and inhibiting macrophage pyroptosis remain unexplored. The present study aimed to determine whether H2S mitigates macrophage pyroptosis by downregulating the pyroptosis signaling pathway and S­sulfhydrating caspase­1 under the stimulation of oxidized low­density lipoprotein (ox­LDL), a pro­atherosclerotic factor. Macrophages derived from THP­1 monocytes were pre­treated using exogenous H2S donors sodium hydrosulfide (NaHS) and D,L­propargylglycine (PAG), a pharmacological inhibitor of endogenous H2S­producing enzymes, alone or in combination. Subsequently, cells were stimulated with ox­LDL or the desulfhydration reagent dithiothreitol (DTT) in the presence or absence of NaHS and/or PAG. Following treatment, the levels of H2S in THP­1 derived macrophages were measured by a methylene blue colorimetric assay. The pyroptotic phenotype of THP­1 cells was observed and evaluated by light microscopy, Hoechst 33342/propidium iodide fluorescent staining and lactate dehydrogenase (LDH) release assay. Caspase­1 activity in THP­1 cells was assayed by caspase­1 activity assay kit. Immunofluorescence staining was used to assess the accumulation of active caspase­1. Western blotting and ELISA were performed to determine the expression of pyroptosis­specific markers (NLRP3, pro­caspase­1, caspase­1, GSDMD and GSDMD­N) in cells and the secretion of pyroptosis­related cytokines [interleukin (IL)­1ß and IL­18] in the cell­free media, respectively. The S­sulfhydration of pro­caspase­1 in cells was assessed using a biotin switch assay. ox­LDL significantly induced macrophage pyroptosis by activating the pyroptosis signaling pathway. Inhibition of endogenous H2S synthesis by PAG augmented the pro­pyroptotic effects of ox­LDL. Conversely, exogenous H2S (NaHS) ameliorated ox­LDL­and ox­LDL + PAG­induced macrophage pyroptosis by suppressing the activation of the pyroptosis signaling pathway. Mechanistically, ox­LDL and the DTT increased caspase­1 activity and downstream events (IL­1ß and IL­18 secretion) of the caspase­1­dependent pyroptosis pathway by reducing S­sulfhydration of pro­caspase­1. Conversely, NaHS increased S­sulfhydration of pro­caspase­1, reducing caspase­1 activity and caspase­1­dependent macrophage pyroptosis. The present study demonstrated the molecular mechanism by which H2S ameliorates macrophage pyroptosis by suppressing the pyroptosis signaling pathway and S­sulfhydration of pro­caspase­1, thereby suppressing the generation of active caspase-1 and activity of caspase-1.