NOD-like Receptor Research Articles

Avicularin Treatment Ameliorates Ischemic Stroke Damage by Regulating Microglia Polarization and its Exosomes via the NLRP3 Pathway.

Avicularin (AL), an ingredient of Banxia, has anti-inflammatory properties in cerebral disease and regulates polarization of macrophages, but its effects on ischemic stroke (IS) damage have not been studied. In vivo, AL was administered by oral gavage to middle cerebral artery occlusion/reperfusion (MCAO/R) C57BL/6J mice in doses of 1.25, 2.5, and 5 mg/kg/day for seven days, and, in vitro, AL was added to treat oxygen-glucose deprivation (OGD)-BV2 cells. Modified neurological severity score, Triphenyltetrazolium chloride (TTC) staining, brain-water-content detection, TdT-mediated dUTP nick-end labeling (TUNEL) assay, flow cytometry, immunofluorescence assay, Enzyme linked immunosorbent assay (ELISA), and Western-blot analysis were used to investigate the functions and mechanism of the effect of AL treatment on IS. The exosomes of AL-treated microglia were studied by transmission electron microscope (TEM), nanoparticle tracking analyzer (NTA), and Western-blot analysis. AL treatment reduced the neurological severity score, infarct volume, brain-water content, neuronal apoptosis, and the release of inflammatory factors, that were induced by MCAO/R. Notably, M2 microglia polarization was promoted but M1 microglia polarization was inhibited by AL in the ischemic penumbra of MCAO/R mice. Subsequently, anti-inflammatory and polarization-regulating effects of AL were verified in vitro. Suppressed NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation was found in the ischemic penumbra of animal and Oxygen-Glucose Deprivation/Reoxygenation (OGD/R) cells treated with AL, as evidenced by decreasing NLRP3-inflammasome-related protein and downstream factors. After AL treatment, the anti-apoptosis effect of microglial exosomes on OGD/R primary cortical neurons was increased. AL reduce inflammatory responses and neuron death of IS-associated models by regulating microglia polarization by the NLRP3 pathway and by affecting microglial exosomes.

Mitochondrial modulation treating postoperative cognitive dysfunction neuroprotection via DRP1 inhibition by Mdivi1

This study investigated the role of mitochondrial dynamics in postoperative cognitive dysfunction (POCD) and assessed the therapeutic potential of mitochondrial modulation, particularly through the inhibition of dynamin-related protein 1 (DRP1) with Mdivi-1. Our findings indicated that DRP1 inhibition substantially mitigated neuroinflammation mediated by microglial cells, contributing to improved cognitive function in POCD models. The administration of Mdivi-1 led to a notable decrease in mitochondrial fission, reduced reactive oxygen species (ROS) production, and stabilization of mitochondrial membrane potential, all of which correlate with diminished neuroinflammation, as evidenced by lower NOD-like receptor family pyrin domain containing 3 (NLRP3)/ interleukin-1β (IL-1β) expression in microglial cells. Importantly, Mdivi-1 treatment was also found to enhance synaptic plasticity, increasing synaptic spine density in the hippocampal region of POCD mice. This improvement in mitochondrial health and synaptic integrity was paralleled by enhanced cognitive performance, as demonstrated in Y-maze tests. These results underscored the critical role of mitochondrial dynamics in the pathophysiology of POCD and suggested that targeting mitochondrial dysfunction, specifically through DRP1 inhibition, could be an effective approach for POCD treatment.

Electroacupuncture Promotes Gastric Motility by Suppressing Pyroptosis via NLRP3/Caspase-1/GSDMD Signaling Pathway in Diabetic Gastroparesis Rats.

To investigate the mechanism of electroacupuncture (EA) in treating diabetic gastroparesis (DGP) by inhibiting the activation of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome and pyroptosis mediated via NLRP3/cysteinyl aspartate specific proteinase-1 (caspase-1)/gasdermin D (GSDMD) signaling pathway. Forty Sprague-Dawley rats were randomly divided into 4 groups including the control, DGP model, EA, and MCC950 groups. The DGP model was established by a one-time high-dose intraperitoneal injection of 2% streptozotocin and a high-glucose and high-fat diet for 8 weeks. EA intervention was conducted at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) with sparse-dense wave for 15 min, and was administered for 3 courses of 5 days. After intervention, the blood glucose, urine glucose, gastric emptying, and intestinal propulsive rate were observed. Besides, HE staining was used to observe histopathological changes in gastric antrum tissues, and TUNEL staining was utilized to detect DNA damage. Protein expression levels of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), pro-caspase-1, caspase-1 and GSDMD were measured by Western blot. Immunofluorescence staining was employed to assess the activity of GSDMD-N. Lactate dehydrogenase (LDH) levels were detected by using a biochemical kit. DGP rats showed persistent hyperglycemia and a significant decrease in gastrointestinal motility (P<0.05 or P<0.01), accompanied by pathological damage in their gastric antrum tissues. Cellular DNA was obviously damaged, and the expressions of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD proteins were significantly elevated, along with enhanced fluorescence signals of GSDMD-N and increased LDH release (P<0.01). EA mitigated hyperglycemia, improved gastrointestinal motility in DGP rats and alleviated their pathological injury (P<0.05). Furthermore, EA reduced cellular DNA damage, lowered the protein levels of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD, suppressed GSDMD-N activity, and decreased LDH release (P<0.05 or P<0.01), demonstrating effects comparable to MCC950. EA promotes gastrointestinal motility and repairs the pathological damage in DGP rats, and its mechanism may be related to the inhibition of NLRP3 inflammasome and pyroptosis mediated by NLRP3/caspase-1/GSDMD pathway.

Positive Airway Pressure Treatment Effects on the Serum Nod-like Receptor Protein 3 and Nitric Oxide Levels in Obstructive Sleep Apnea Syndrome

Positive Airway Pressure Treatment Effects on the Serum Nod-like Receptor Protein 3 and Nitric Oxide Levels in Obstructive Sleep Apnea Syndrome

Paired single-cell RNA sequencing and T cell receptor sequencing reveals both pro- and anti-inflammatory roles of T cells in patients with calcific aortic valve disease

Abstract Background Calcified aortic valve disease (CAVD) is a chronic unresolvable inflammatory disorder that affects 25% of adults over 65 years old, leading to aortic stenosis, heart failure, and death [1]. Since the molecular mechanisms of its pathogenesis are not well understood, therapies to treat root causes of the disease remain to be developed, with valve replacement as the major intervention strategy currently. Increasing evidence indicates that substantial T cells infiltrate in the aortic valve during calcification, and clonal expanded CD8+ T cells have been identified in the calcificed aortic valve by bulk T cell receptor (TCR) repertoire sequencing [2]. Purpose To decipher T cell heterogenity and understand the precise mechanisms of T cell subsets involving CAVD progression as a basis for novel therapeutic targets. Methods In Cohort 1, we collected aortic valves from CAVD (n=3) and healthy (n=2) patients for single-cell RNA sequencing (scRNA-seq). In Cohort 2, we performed paired scRNA-seq and TCR sequencing (scTCR-seq) on aortic valves obtained from CAVD (n=3) and healthy (n=3) patients to evaluate both gene expression and clonality. Pathway enrichment analysis and cell-cell interaction analysis elucidated the function of T cells in the calcificied valves. Immunohistochemistry and fluorescence-activated cell sorting were recruited to verify the key findings. Results scRNA-seq demonstrated a conversion from anti-inflammatory regulatory T (Treg) cells towards pro-inflammatory T helper 17 (Th17) cells in the calcificied aortic valve. Paired scRNA-seq and scTCR-seq revealed CAVD-related signaling pathways (osteoclast differentiation, NOD-like receptor signaling pathways, IL-17 signaling pathways) significantly upregulated in highly expanded CD8+ T cells in the calcified valve, with upregulation of pro-inflammatory mediators such as IFNG, CCL4 and CCL5, suggesting pro-inflammation functions in clonally expanded T cells. Moreover, we characterized tissue-resident memory T cells, which resembled similar transcriptome and TCR clonality as exhausted T cells in calcified valves. These cells up-regulated anti-inflammation-related transcriptomes but their cellular fraction decreased in calcified valves, implying anti-inflammatory functions of these tissue-resident memory and exhausted T cells. Conclusion This study elucidates transcriptomic and immune profiling of T cells in the calcified aortic valve, therefore shedding light on the pathophysiological mechanisms underlying aortic valve calcification from the novel perspective of tissue-specific T lymphocytes, providing promising targets for immune checkpoint-based therapeutic interventions.

CircFndc3b Mediates Exercise-Induced Neuroprotection by Mitigating Microglial/Macrophage Pyroptosis via the ENO1/KLF2 Axis in Stroke Mice.

Circular RNA (circRNA) plays a pivotal role in regulating neurological damage post-ischemic stroke. Previous researches demonstrated that exercise mitigates neurological dysfunction after ischemic stroke, yet the specific contributions of circRNAs to exercise-induced neuroprotection remain unclear. This study reveals that mmu_circ_0001113 (circFndc3b) is markedly downregulated in the penumbral cortex of a mouse model subjected to middle cerebral artery occlusion (MCAO). However, exercise increased circFndc3b expression in microglia/macrophages, alleviating pyroptosis, reducing infarct volume, and enhancing neurological recovery in MCAO mice. Mechanistically, circFndc3b interacted with Enolase 1 (ENO1), facilitating ENO1's binding to the 3' Untranslated Region (3'UTR) of Krüppel-like Factor 2 (Klf2) mRNA, thereby stabilizing Klf2 mRNA and increasing its protein expression, which suppressed NOD-like Receptor Family Pyrin Domain Containing 3 (NLRP3) inflammasome-mediated microglial/macrophage pyroptosis. Additionally, circFndc3b enhanced ENO1's interaction with the 3'UTR of Fused in Sarcoma (FUS) mRNA, leading to increased FUS protein levels and promoting circFndc3b cyclization. These results suggest that circFndc3b mediates exercise-induced anti-pyroptotic effects via the ENO1/Klf2 axis, and a circFndc3b/ENO1/FUS positive feedback loop may potentiate exercise's neuroprotective effects. This study unveils a novel mechanism underlying exercise-induced neuroprotection in ischemic stroke and positions circFndc3b as a promising therapeutic target for stroke management, mimicking the beneficial effects of exercise.

Huang-Pu-Tong-Qiao Formula Alleviates Hippocampal Neuron Damage by Inhibiting NLRP3 Inflammasome-mediated Pyroptosis in Alzheimer's Disease.

Huang-Pu-Tong-Qiao (HPTQ), a Traditional Chinese Medicine formula, has achieved remarkable efficacy in clinically treating Alzheimer's disease (AD). Pyroptosis refers to the inflammatory necrosis of cells, which contributes to AD pathological progression. However, it is unclear whether the therapeutic effect of HPTQ on AD is related to reducing pyroptosis. In this study, the network pharmacology analysis was used to predict the molecular mechanism of HPTQ in treating AD and validated our hypothesis through mice and cell experiments. APP/PS1 transgenic mice and Aβ25-35-injured HT22 cells were used as AD models in vivo and in vitro. The pharmacological effects and mechanisms of HPTQ on AD were evaluated by Morris water maze, Y-maze, transmission electron microscope, immunofluorescence, Hoechst/PI staining, western blot, and ELISA. Network pharmacology reveals the correlation between the therapeutic effect of HPTQ on AD and the NOD-like receptor signaling pathway. In APP/PS1 mice, HPTQ reduced the escape latency and maintained cell membrane integrity. In HT22 cells, 15% HPTQ-medicated serum and 10 µM MCC950 increased cell viability and decreased PI positive rate compared with the Model group. In addition, HPTQ treatment in AD animal and cell models reduced the protein expressions of NLRP3, ASC, cleaved caspase-1, GSDMD, GSDMD-N, IL-1β, and IL-18. The experimental results of MCC950 specifically inhibiting the NLRP3 expression suggested that HPTQ might reduce neuronal pyroptosis by reducing NLRP3 inflammasome. Network pharmacology and experimental validation suggested that HPTQ alleviated NLRP3 inflammasome-mediated neuronal pyroptosis in AD, which could provide valuable candidate drugs for AD clinical treatment.

Ferulic Acid Interferes with Radioactive Intestinal Injury Through the DJ-1-Nrf2 and Sirt1-NF-κB-NLRP3 Pathways.

Radiation-induced intestinal injury is a common complication of radiotherapy for abdominal and pelvic malignancies. Due to its rapid proliferation, the small intestine is particularly sensitive to radiation, making it a critical factor limiting treatment. Ferulic acid (FA), a derivative of cinnamic acid, exhibits antioxidant, anti-inflammatory, and anti-radiation properties. In this study, we established a mouse model of radiation-induced intestinal injury using a dose of 11 Gy at a rate of 96.62 cGy/min. Our findings indicate that FA's protective effects against radiation-induced intestinal injury may be mediated through the parkinsonism-associated deglycase (DJ-1) nuclear factor erythroid 2-related factor 2 (Nrf2) and silent mating type information regulation 2 homolog 1 (Sirt1) nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) NOD-like receptor family, pyrin domain containing 3 (NLRP3). FA was found to mitigate changes in oxidative stress indices and inflammatory factors induced by radiation, as well as to attenuate radiation-induced pathological alterations in the small intestine. Furthermore, FA enhanced the expression of DJ-1 and Nrf2 at both the transcriptional and protein levels, inhibited NLRP3 protein fluorescence intensity, and reduced the expression of NLRP3, interleukin-18 (IL-18), and interleukin-1 beta (IL-1β). Additionally, FA suppressed the transcription and translation of NF-κB, NLRP3, cysteine-aspartic acid protease-1 (Caspase-1), IL-18, and IL-1β by upregulating Sirt1, thereby alleviating radiation-induced inflammatory injury in the small intestine. Thus, FA holds promise as an effective therapeutic agent for ameliorating radiation-induced intestinal injury.

Electroacupuncture improves cognitive function by modulating hippocampal lactate-mediated HIF-1α signaling pathway and inhibiting inflammation response in vascular dementia rats

To observe the effects of electroacupuncture (EA) stimulation of "Sishencong"(EX-HN1) and "Fengchi"(GB20) on lactate (Lac) content, expression of proline hydroxylase 2 (PHD2), hypoxia-inducible factor-1α (HIF-1α)/nuclear transcription factor- κB (NF- κB)/NOD-like receptor thermoprotein structural domain-associated protein 3 (NLRP3) signaling pathway, and inflammatory factors in hippocampal tissue of vascular dementia (VD) rats, so as to explore its mechanisms underlying improvement of VD. Male SD rats screened by Morris water maze tests were randomly divided into blank control, sham-operation, VD model and EA groups (12 rats in each group). The VD model was replicated using the 4-vessel occlusion (VO) method. EA (2 Hz, 1 mA) was applied to EX-HN1 and bilateral GB20 for 30 min, once daily for consecutive 21 days. Morris water maze test was employed to test the rat's memory learning ability before and after modeling and after the intervention. The hippocampal tissue was sampled for observing histopathologic changes with H.E. staining；and detecting Lac content with colorimetric method, and the contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-18 (also in serum) by using ELISA, respectively. The immunoactivity levels of PHD2, HIF-1α, and p-NF-κB p65 in hippocampal tissue were detected by immunohistochemistry, and the expression levels of PHD2, HIF-1α, NF-κB p65, p-NF-κB p65 and NLRP3 proteins in hippocampal tissue were detected by Western blot. Compared with the blank control and sham-operation groups, the escaping latency, Lac content in hippocampus, the TNF-α, IL-1β, and IL-18 contents in both hippocampus and serum, the immunoactivity of HIF-1α and p-NF-κB p65 and expression levels of HIF-1α, NF-κB p65, p-NF-κB p65, and NLRP3 proteins were significantly increased (P<0.01), while the number of original platform crossing, and PHD2 immunoactivity and protein expression level were significantly decreased (P<0.05, P<0.01) in the model group. Following EA intervention, modeling induced increase and decrease of the indexes mentioned above were all reversed in the EA group (P<0.05, P<0.01). H.E. staining showed disordered arrangement of neurons, uneven cytoplasm stain, blurred nucleolus or disappearance of nucleolus, dilated capillaries, many apoptotic bodies and increased inflammatory cells in the hippocampus tissue of the model group, which was improved to a certain extent in the EA group, including relatively regular arrangement of neurons, reduced apoptotic bodies and inflammatory cells, etc. in the hippocampus. EA stimulation of EX-HN1 and GB20 can improve the cognitive function in VD rats, which may be related to its functions in reducing Lac content, regulating the expression of HIF-1α pathway related proteins, and inhibiting inflammatory responses in the hippocampus tissue.

Acute Administration of Edaravone Improves Cognitive Impairment in a Mouse Model of mPFC Ischemia: Crosstalk Between Necroptosis, Neuroinflammation, and Antioxidant Defense.

Edaravone (Eda), a well-known free radical scavenger, has been reported as a possible therapeutic agent for ischemic stroke patients' recovery. This study aimed to investigate the effects of time-dependent treatment with Eda on medial prefrontal cortex (mPFC) ischemia. Mice were randomly allocated into six groups: control, sham, normal saline, Eda-I, Eda-II, and Eda-III. After induction of a photothrombotic ischemia in the mPFC region, Eda-I, Eda-II, and Eda-III groups received 3mg/kg Eda intraperitoneally at the times of 0, 2, and 6h post-surgery. After 1day of recovery, the mice underwent behavioral tests (open field, novel object recognition, and T-maze). Next, necroptosis, NOD-like receptor protein 3 (NLRP3), and nuclear factor erythroid 2-related factor 2 (Nrf2) pathway-related protein levels were measured in the lesioned area using western blot analysis. For double confirmation, IL-1β and IL-18 were also assessed by immunofluorescence in the area. Further, histological evaluations were performed to measure tissue damage. The results showed that mPFC ischemia impaired recognition and spatial working memory without affecting locomotor activity, while immediate Eda administration improved cognitive impairments. Furthermore, acute Eda treatment reduced RIP1, RIP3, and MLKL levels, inhibited NLRP3 inflammasome proteins (NLRP3, ASC, and Cas1), decreased IL-1β and IL-18, upregulated Nrf2 and its targets (NQO-1 and HO-1), and diminished tissue damage. Our results highlighted the effects of acute administration of Eda post-stroke on improving cognitive impairments by suppressing necroptosis and NLRP3 inflammasome pathways and activating the Nrf2 antioxidant defense mechanism.

Development and Evaluation of Real-Time Quantitative PCR Assays for Detection of Phellinus noxius Causing Brown Root Rot Disease.

Brown root rot disease (BRRD) is a highly destructive tree disease. Early diagnosis of BRRD has been challenging because the first symptoms and signs are often observed after extensive tissue colonization. Existing molecular detection methods, all based on the internal transcribed spacer (ITS) region, were developed without testing against global Phellinus noxius isolates, other wood-decay fungi, or host plant tissues. This study aimed to develop SYBR Green real-time quantitative PCR (qPCR) assays for P. noxius. The primer pair Pn_ITS_F/Pn_ITS_R targets the ITS, and the primer pair Pn_NLR_F/Pn_NLR_R targets a P. noxius-unique group of homologous genes identified through a comparative genomics analysis. The homologous genes belong to the nucleotide-binding-oligomerization-domain-like receptor (NLR) superfamily. The new primer pairs and a previous primer pair G1F/G1R were optimized for qPCR conditions and tested for specificity using 61 global P. noxius isolates, 5 other Phellinus species, and 22 non-Phellinus wood-decay fungal species. Although all three primer pairs could detect as little as 100 fg (approximately 2.99 copies) of P. noxius genomic DNA, G1F/G1R had the highest specificity and Pn_NLR_F/Pn_NLR_R had the highest efficiency. To avoid false positives, the cutoff quantification cycle values were determined as 34 for G1F/G1R, 29 for Pn_ITS_F/Pn_ITS_R, and 32 for Pn_NLR_F/Pn_NLR_R. We further validated these qPCR assays using Ficus benjamina seedlings artificially inoculated with P. noxius, six tree species naturally infected by P. noxius, rhizosphere soil, and bulk soil. The newly developed qPCR assays provide sensitive detection and quantification of P. noxius, which is useful for long-term monitoring of BRRD status.

TFEB signaling promotes autophagic degradation of NLRP3 to attenuate neuroinflammation in diabetic encephalopathy.

Diabetic encephalopathy (DE), a neurological complication of diabetes mellitus, has an unclear etiology. Shreds of evidence show that the Nucleotide-binding oligomerization domain-like receptor family protein 3 (NLRP3) inflammasome-induced neuroinflammation and transcription factor EB (TFEB)-mediated autophagy impairment may take part in DE development. The crosstalk between these two pathways and their contribution to DE remains to be explored. A mouse model of type 2 diabetes mellitus (T2DM) exhibiting cognitive dysfunction was created, along with high glucose (HG) cultured BV2 cells. Following, 3-methyladenine (3-MA) and rapamycin were utilized to modulate autophagy. To evaluate the potential therapeutic benefits of TFEB in DE, we overexpressed and knocked down TFEB in both mice and cells. Autophagy impairment and NLRP3 inflammasome activation were noticed in T2DM mice and HG-cultured BV2 cells. The inflammatory response caused by NLRP3 inflammasome activation was decreased by rapamycin-induced autophagy enhancement, while 3-MA treatment further deteriorated it. Nuclear translocation and expression of TFEB were hampered in HG-cultured BV2 cells and T2DM mice. Exogenous TFEB overexpression boosted NLRP3 degradation via autophagy, which in turn alleviated microglial activation as well as ameliorated cognitive deficits and neuronal damage. Additionally, TFEB knockdown exacerbated neuroinflammation by decreasing autophagy-mediated NLRP3 degradation. Our findings have unraveled the pathogenesis of a previously underappreciated disease, implying that the activation of NLRP3 inflammasome and impairment of autophagy in microglia are significant etiological factors in the DE. The TFEB-mediated autophagy pathway can reduce neuroinflammation by enhancing NLRP3 degradation. This could potentially serve as a viable and innovative treatment approach for DE.

DNA-Binding Protein A Is Actively Secreted in a Calcium-and Inflammasome-Dependent Manner and Negatively Influences Tubular Cell Survival.

DNA-binding protein A (DbpA) belongs to the Y-box family of cold shock domain (CSD) proteins that bind RNA/DNA and exert intracellular functions in cell stress, proliferation, and differentiation. Given the pattern of DbpA staining in inflammatory glomerular diseases, without adherence to cell boundaries, we hypothesized extracellular protein occurrence and specific functions. Lipopolysaccharide and ionomycin induce DbpA expression and secretion from melanoma and mesangial cells. Unlike its homologue Y-box-binding protein 1 (YB-1), DbpA secretion requires inflammasome activation, as secretion is blocked upon the addition of a NOD-like receptor protein-3 (NLRP3) inhibitor. The addition of recombinant DbpA enhances melanoma cell proliferation, migration, and competes with tumor necrosis factor (TNF) binding to its receptor (TNFR1). In TNF-induced cell death assays, rDbpA initially blocks TNF-induced apoptosis, whereas at later time points (>24 h), cells are more prone to die. Given that CSD proteins YB-1 and DbpA fulfill the criteria of alarmins, we propose that their release signals an inherent danger to the host. Some data hint at an extracellular complex formation at a ratio of 10:1 (DbpA:YB-1) of both proteins.

Copper Overload Promotes β-amyloid Induced NLRP3/Caspase-1/GSDMD-Mediated Pyroptosis in Alzheimer's Disease.

Alzheimer's disease (AD) is characterized by cognitive decline and abnormal protein accumulation. Copper imbalance and pyroptosis play significant roles in the pathogenesis of AD. Recent studies have suggested that dysregulated copper homeostasis contributed to β-amyloid accumulation, which may activate the NOD-like receptor protein 3 (NLRP3)-related pyroptosis pathway, promoting neuronal damages and AD progression. Therefore, the present study aims to investigates whether copper facilitates AD through exacerbating β-amyloid (Aβ) induced activation of NLRP3/Caspase-1/Gasdermin D (GSDMD)-mediated neuronal cell pyroptosis. Mouse hippocampal HT-22 cells were cultured with Aβ1-42 oligomer for 24 h as AD Model group. CuCl2 treatment was administered to the AD cell model, and cell survivability levels were detected by Cell Counting Kit-8 (CCK-8), TdT-mediated dUTP nick end labeling (TUNEL), and other relevant kits. Mitochondrial function was evaluated using Mitochondrial membrane potential dye JC-1 and transmission electron microscopy (TEM). After intervention with the NLRP3 inhibitor MCC950, activation of the NLRP3/Caspase-1/GSDMD pathway by copper ions (Cu2+) was confirmed via Western Blot. Thioredoxin T (ThT) fluorescence assay was performed to observe the aggregation effect of Aβ induced by Cu2+ overload. CuCl2 treatment of the AD cell model resulted in up-regulation of the levels of Lactate Dehydrogenase (LDH), Interleukin-1β (IL-1β), and IL-18 expression, which indicated activation of pyroptosis. We observed a significant decrease in mitochondrial membrane potential, mitochondrial swelling, and loss of mitochondrial cristae by fluorescence microscopy and TEM. ThT fluorescence imaging showed that Cu2+ promoted Aβ aggregation and up-regulated NLRP3, apoptosis-associated speck-like protein containing a CARD (ACS), Caspase-1, Cleaved Caspase-1, GSDMD, and Gasdermin D N-terminal (GSDMD-NT). The NLRP3 inhibitor MCC950 partially reversed Cu2+-mediated pyroptosis in HT-22 cells. Exposure to copper ions disrupt mitochondrial copper homeostasis, promotes Aβ aggregation, and activates NLRP3 inflammasomes, further promoting the Aβ aggregation activated pyroptosis in AD cell models.

Prognostic model for gastric cancer patients with COVID-19 and network pharmacology study on treatment by lentinan

Patients with gastric cancer (GC) are more susceptible to coronavirus disease 2019 (COVID-19), which further worsens their already challenging prognosis. However, there are no effective treatment options for these patients. Lentinan is a potent bioactive component with antiviral and antitumor effects. We hypothesized that lentinan might exert powerful pharmacological effects in patients with GC and COVID-19. In this study, a prognostic model of patients with GC/COVID-19 was constructed and used to apply a network pharmacology approach to reveal biological functions, drug targets, and molecular mechanisms of the action of lentinan against GC/COVID-19. Clinical analysis revealed key prognostic genes in patients with GC/COVID-19. The results of network pharmacology analysis suggested that the therapeutic effect of lentinan on GC/COVID-19 mainly involves the modulation of several neutrophil-related biological processes, as well as the nucleotide-binding and oligomerization domain-like receptor and interleukin-17 signaling pathways. In addition, C-X-C motif chemokine ligand 8, vascular endothelial growth factor A, ribonuclease 3, and F2 were identified as key genes of lentinan against GC/COVID-19. Key prognostic genes were identified in patients with GC/COVID-19 through the construction of a prognostic model. Pharmacological functions and signaling pathways of lentinan against GC/COVID-19 were revealed. These included the regulation of neutrophils and NOD-like receptor signaling pathways. The findings provide the first published evidence of the potential value of lentinan as a complementary therapy for GC/COVID-19.

Acylated Anthocyanins From Black Carrots and Their Related Phenolic Acids Diminish Priming and Activation of the NLRP3 Inflammasome in THP-1 Monocytes.

Excessive activation of the nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome contributes to chronic inflammation. Thus, targeting NLRP3 inflammasome activation by anthocyanins may prevent inflammatory diseases. Therefore, the present study determines the influence of a black carrot extract (BCE) with high amounts of acylated anthocyanins and their related phenolic acids on the NLRP3 inflammasome. THP-1 monocytes are pretreated with a BCE, cyanidin-3-glucoside (C3G), or hydroxycinnamic acids. NLRP3 inflammasome assembly is initiated by priming THP-1 monocytes with lipopolysaccharide and/or activating the NLRP3 inflammasome with nigericin. Flow cytometry is used to assess apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) speck formation, as well as ASC and NLRP3 protein expression. Caspase-1 activity is measured using a bioluminescent assay, and cytokine concentrations are determined by enzyme-linked immunosorbent assays (ELISA). C3G and phenolic acids diminish ASC and NLRP3 protein expression. In addition, C3G and phenolic acids attenuate ASC speck formation. Furthermore, the BCE and C3G decline caspase-1 activity. Consistently, IL-1β and IL-18 secretion are reduced upon NLRP3 inflammasome activation. The present study shows that a BCE with high amounts of acylated anthocyanins and their related phenolic acids diminish priming and activation of the NLRP3 inflammasome in THP-1 monocytes.

Three cases of autoinflammatory disease with novel NLRC4 mutations, and the first mutation reported in the CARD domain of NLRC4 associated with autoinflammatory infantile enterocolitis (AIFEC)

BackgroundGain of function (GOF) mutations in NOD-like receptor family CARD-containing 4 protein (NLRC4) gene induce a wide spectrum of autoinflammatory phenotypes. Currently, we categorize them into four groups: familial cold autoinflammatory syndrome (FCAS)4, autoinflammatory infantile enterocolitis (AIFEC), NLRC4-macrophage associated syndrome (MAS), and neonatal-onset multisystem inflammatory disease (NOMID). The rarity and complexity of the disease necessitate the description of new cases and a reexamination of our understanding of the condition.Case presentationsWe present three patients with NLRC4-GOF mutations and AIFEC phenotypes. The first patient is an infant girl with periodic fever, seizure, high inflammatory markers, and an episode of macrophage associated syndrome (MAS). History of recurrent fever episodes since childhood was reported in mother and maternal grandmother. A heterozygous mutation was found in CARD domain of NLRC4: c.A91C: p.Asn31His. The second patient is an adolescent boy with periodic fever, diarrhea, aphthous stomatitis, seizure, and central nervous system (CNS) vasculitis. A heterozygous mutation was found in NLRC4 gene: c.1202T > C. p. Val401Ala. The third patient is a child with chronic diarrhea and elevated inflammatory markers. We found a heterozygous mutation in NLRC4 gene: c.390delG: p.S132Afs*21. All mutations have been reported for the first time as NLRC4 mutations associated with autoinflammation. We introduced novel mutations in the CARD domain and between CARD and NBD domain in the first and third cases, respectively. All three children are under remission following treatment.ConclusionsNLRC4-GOF mutations can be associated with autoinflammation with diverse symptoms. Given the rarity of the disease and the possibility of new mutations being identified, the existence of a phenotype/genotype correlation has yet to be thoroughly investigated. The variety in manifestations and severity spectrum mandates a variety of treatments. Adalimumab has shown favorable outcomes in our AIFEC cases.

The Evolution of NLR Inflammasome and Its Mediated Pyroptosis in Metazoa.

Nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) inflammasomes are multiprotein signaling platforms that control the inflammatory response and coordinate antimicrobial defense. In the present study, the distribution of NLR, Caspase-1, and gasdermin (GSDM) homologues and their structural characteristics and evolutionary relationships were systematically analyzed in metazoa according to the genomes of species. In invertebrates, there were only NLRC and/or NLRD presented from sponge to amphioxus, and according to the evolutionary tree, NLR from sponge located in the most primitive position. Caspase-1 existed in some metazoan phyla (Brachiopoda, Ectoprocta, Arthropoda, Mollusca, Annelia, Nematoda, Platyelminthes, Coelenterate, and Porifera) and its activation sites were relatively conserved. The amino acid sequences and three-dimensional structures of N-terminal CARD/Death domain of NLR and Caspase-1 were similar in species from sponge to human. NLR and Caspase-1 co-existed in species of Brachiopoda, Mollusca, Annelia, Coelenterate, and Porifera. There was only GSDME or PJVK found in some phyla of invertebrates and their cleavage sites were conserved (DxxD). And it was predicted that the NLR inflammasome in inducing pyroptosis could occur in species of Brachiopoda, Mollusca, Annelia, and Coelenterate. These studies indicated that NLR inflammasome emerged early in sponges of metazoa, and NLR inflammasome in inducing pyroptosis first appeared in Coelenterate, suggesting that inflammasome and its mediated pyroptosis had existed in the early stage of metazoa, but they had been lost in many species during evolution.

Effects of Clausena lansium leaves volatile oil emulsion against Staphylococcus aureus in mice via autophagy modulation

BackgroundVolatile oil from fresh Clausena lansium (Lour.) Skeels (Rutaceae) (common name Wampee) has been previously extracted by our group from fresh C. lansium leaf and its components were qualitative and quantitatively analyzed by GC–MS. It altered the cell membrane permeability of Staphylococcus aureus and reduced the levels of inflammation factors. However, previous in vivo reports on the anti-inflammatory and the antibacterial properties against S. aureus are scarce. Hypothesis/PurposeTo evaluate the protective in vivo effects of Wampee leaves volatile oil emulsion (WVOE) against S. aureus-induced pneumonia and elucidate the underlying mechanisms of action. MethodsWild-type and nucleotide oligomerization domain-like receptor protein 3 (NLRP3)-deficient mice were used. Mice were treated with WVOE for 7 days, and subjected to S. aureus infection by nasal administration on day 5 for 48 h. Lung and blood samples were collected for assessing lung damage and protein abundance. Lung bacterial load, wet/dry ratio, C-reactive protein (CRP) levels, inflammatory cytokines secretion, and lung histopathological injury were examined. ResultsWVOE effectively reduced lung bacterial load, wet/dry ratio, and CRP levels increased following S. aureus infection in mice. WVOE decreased the secretion of inflammatory cytokines (IL-6 and TNF-α) and lung histopathological injury, and suppressed the NF-κB pathway and NLRP3 inflammasome activation. NLRP3-/- mice exhibited lower bacterial load, inflammatory cytokines levels and lung histopathological injury compared with mice in the model group. Autophagy was enhanced in S. aureus-infected mice, with higher levels of p-mTOR, Beclin-1, Atg 16L1, Atg7, p62, p-p62, and LC3II. WVOE administration restored the autophagy related protein levels. Autophagy was inhibited in NLRP3-/- mice of the control and model groups, and WVOE lost its ability to regulate the autophagy-related proteins enhanced upon S. aureus infection. WVOE enhanced autophagy to alleviate lung injury by inhibiting NLRP3-targeted P62. Furthermore, compared with the 3MA + model group, WVOE reduced the bacterial load and CRP levels, pulmonary septa narrowing, and congestion. NLRP3 protein expression increased due to autophagy inhibition. WVOE exerted a pharmacological effect through the PI3K/AKT/mTOR pathway. ConclusionWVOE regulated the PI3K/AKT/mTOR pathway and enhanced autophagy, with NLRP3 playing a crucial role. WVOE exhibited protective effects against S. aureus-induced pneumonia by inhibiting NLRP3 inflammasome activation and enhancing autophagy. These findings expand the understanding of antibacterial properties of WVOE, and provide novel insights into the therapeutic potential of WVOE in managing S. aureus infections.

Brain-Region-Specific Differences in Protein Citrullination/Deimination in a Pre-Motor Parkinson's Disease Rat Model.

The detection of early molecular mechanisms and potential biomarkers in Parkinson's disease (PD) remains a challenge. Recent research has pointed to novel roles for post-translational citrullination/deimination caused by peptidylarginine deiminases (PADs), a family of calcium-activated enzymes, in the early stages of the disease. The current study assessed brain-region-specific citrullinated protein targets and their associated protein-protein interaction networks alongside PAD isozymes in the 6-hydroxydopamine (6-OHDA) induced rat model of pre-motor PD. Six brain regions (cortex, hippocampus, striatum, midbrain, cerebellum and olfactory bulb) were compared between controls/shams and the pre-motor PD model. For all brain regions, there was a significant difference in citrullinated protein IDs between the PD model and the controls. Citrullinated protein hits were most abundant in cortex and hippocampus, followed by cerebellum, midbrain, olfactory bulb and striatum. Citrullinome-associated pathway enrichment analysis showed correspondingly considerable differences between the six brain regions; some were overlapping for controls and PD, some were identified for the PD model only, and some were identified in control brains only. The KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways identified in PD brains only were associated with neurological, metabolic, immune and hormonal functions and included the following: "Axon guidance"; "Spinocerebellar ataxia"; "Hippo signalling pathway"; "NOD-like receptor signalling pathway"; "Phosphatidylinositol signalling system"; "Rap1 signalling pathway"; "Platelet activation"; "Yersinia infection"; "Fc gamma R-mediated phagocytosis"; "Human cytomegalovirus infection"; "Inositol phosphate metabolism"; "Thyroid hormone signalling pathway"; "Progesterone-mediated oocyte maturation"; "Oocyte meiosis"; and "Choline metabolism in cancer". Some brain-region-specific differences were furthermore observed for the five PAD isozymes (PADs 1, 2, 3, 4 and 6), with most changes in PAD 2, 3 and 4 when comparing control and PD brain regions. Our findings indicate that PAD-mediated protein citrullination plays roles in metabolic, immune, cell signalling and neurodegenerative disease-related pathways across brain regions in early pre-motor stages of PD, highlighting PADs as targets for future therapeutic avenues.