Project description:AimAtp13a2 (Park9) gene encodes a transmembrane lysosomal P5-type ATPase (ATP13A2), and its missense or truncation mutations leads to lysosomal dysfunction and consequently results in neuronal death in the pathogenesis of Parkinson's disease (PD). Nevertheless, the roles of ATP13A2 in the biological features of astrocytes, especially in the regulation of PD-related neuroinflammation, have not been investigated.MethodsWe cultured primary neurons and astrocytes from mouse midbrain to investigate the mechanisms for astrocyte ATP13A2-regulated lysosomal function and neuroinflammation following 1-methyl-4-phenylpyridinium (MPP(+) ) treatment.ResultsWe found that astrocytes expressed considerable levels of ATP13A2 and deficiency of ATP13A2 in astrocyte-induced intense inflammation, which exacerbated dopaminergic neuron damage after exposure to MPP(+) . Notably, lack of ATP13A2 increased lysosomal membrane permeabilization and cathepsin B release, which in turn exacerbated activation of nod-like receptor protein 3 (NLRP3) inflammasome to produce excess IL-1β from astrocytes. Furthermore, overexpression of ATP13A2 reversed MPP(+) -induced cathepsin B release and NLRP3 inflammasome activation in astrocytes.ConclusionsOur results have revealed a novel role of ATP13A2 in modulating astrocyte-mediated neuroinflammation via NLRP3 inflammasome activation, thus bringing to light of a direct link between astrocyte lysosome and neuroinflammation in the pathological model of PD.
Project description:BackgroundPolycystic ovary syndrome (PCOS) is a frequent and complicated endocrine disease that remains a major reason for infertility. Bushenhuoluo Decotion (BSHLD) has been validated to exhibit curative effects on PCOS. This study was aimed to explore the potential mechanism underlying the therapeutic action of BSHLD.MethodsPCOS rat model was induced by dehydroepiandrosterone (DHEA). Serum hormone and cytokines levels and ovarian pathological alterations were measured to assess ovarian function. Exosomes (Exos) were identified by Transmission electron microscopy and Nanoparticle Tracking Analysis. RT-qPCR, Western blotting, immunohistochemical staining, and immunofluorescence staining were performed to detect molecule expressions. Proliferation and pyroptosis of granulosa cells (GCs) were evaluated by CCK-8 and flow cytometry, respectively. The binding relationship between miR-30a-5p and suppressor of cytokine signaling 3 (SOCS3) was verified by dual luciferase reporter and RIP assays.ResultsBSHLD treatment improved serum hormone abnormality, insulin sensitivity, and ovarian morphologic changes of PCOS rats. Moreover, BSHLD treatment restrained the excessive autophagy and pyroptosis in ovarian tissues of PCOS rats. Moreover, BSHLD reduced the expression of miR-30a-5p in serum, serum-derived Exos, and ovarian tissues, thus inhibiting autophagy and NLRP3-mediated pyroptosis in GCs. Mechanistically, SOCS3 was proved as a target of miR-30a-5p and could activate mTOR/P70S6K pathway to repress autophagy. The inhibitory effect of miR-30a-5p deficiency on autophagy and pyroptosis of GCs was attenuated by rapamycin.ConclusionCollectively, BSHLD suppressed autophagy and pyroptosis to improve POCS by regulating exosomal miR-30a-5p/SOCS3/mTOR signaling.
Project description:We commenced to analyze putative anti-pyroptosis effects of puerarin (PU) as mediated by the PP2A-HDAC1-NLRP3 pathway in acute lung injury (ALI). ALI animal and cell models were constructed, followed by treatment of PU. Then, the effect of HDAC1, PP2A, and NLRP3 on cell inflammation and pyroptosis was explored. The interaction between HDAC1 and PP2A as well as between PP2A and NLRP3 was analyzed. Our findings suggested that PU downregulated HDAC1 expression to alleviate symptoms of ALI. HDAC1 overexpression promoted inflammation induced by LPS, which reversed the inhibitory effect of PU on ALI. HDAC1 overexpression also decreased PP2A expression, suggesting that PP2A was involved in the effects of HDAC1 on LPS-induced inflammation. PP2A exerted inhibitory effects on NLRP3. Meanwhile, PU hindered the progression of ALI by silencing HDAC1 or overexpressing PP2A both in vivo and in vitro. Taken together, PU restrained pyroptosis of cells induced by NLRP3 inflammasome to abate ALI.
Project description:Alzheimer's disease (AD), an age-related degenerative disorder, is characterized by β-amyloid deposition, abnormal phosphorylation of tau proteins, synaptic dysfunction, neuroinflammation, and oxidative stress. Despite extensive research, there are no medications or therapeutic interventions to completely treat and reverse AD. Herein, we explore the potential of hydrocortisone (HC), a natural and endogenous glucocorticoid known to have potent anti-inflammatory properties, in an Aβ1-42-induced AD mouse model. Our investigation highlights the beneficial effects of HC administration on cognitive impairment, synaptic function enhancement, and neuronal protection in Aβ1-42-induced AD mice. Notably, HC treatment effectively suppresses the hyperactivation of microglia and astrocytes, leading to a reduction in proinflammatory factors and alleviation of neuroinflammation. Furthermore, HC intervention demonstrates the capacity to mitigate the generation of ROS and oxidative stress. These compelling findings underscore the potential therapeutic application of HC in AD and present promising opportunities for its utilization in AD prevention and treatment. The implications drawn from our findings indicate that hydrocortisone holds promise as a viable candidate for adjunctive use with other anti-AD drugs for the clinical management of patients presenting with moderate to severe AD.
Project description:Background: Following spinal cord injury (SCI), the inflammatory storm initiated by microglia/macrophages poses a significant impediment to the recovery process. Exosomes play a crucial role in the transport of miRNAs, facilitating essential cellular communication through the transfer of genetic material. However, the miRNAs from iPSC-NSCs-Exos and their potential mechanisms leading to repair after SCI remain unclear. This study aims to explore the role of iPSC-NSCs-Exos in microglia/macrophage pyroptosis and reveal their potential mechanisms. Methods: iPSC-NSCs-Exos were characterized and identified using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot. A mouse SCI model and a series of in vivo and in vitro experiments were conducted to investigate the therapeutic effects of iPSC-NSCs-Exos. Subsequently, miRNA microarray analysis and rescue experiments were performed to confirm the role of miRNAs in iPSC-NSCs-Exos in SCI. Mechanistic studies were carried out using Western blot, luciferase activity assays, and RNA-ChIP. Results: Our findings revealed that iPSC-NSCs-derived exosomes inhibited microglia/macrophage pyroptosis at 7 days post-SCI, maintaining myelin integrity and promoting axonal growth, ultimately improving mice motor function. The miRNA microarray showed let-7b-5p to be highly enriched in iPSC-NSCs-Exos, and LRIG3 was identified as the target gene of let-7b-5p. Through a series of rescue experiments, we uncovered the connection between iPSC-NSCs and microglia/macrophages, revealing a novel target for treating SCI. Conclusion: In conclusion, we discovered that iPSC-NSCs-derived exosomes can package and deliver let-7b-5p, regulating the expression of LRIG3 to ameliorate microglia/macrophage pyroptosis and enhance motor function in mice after SCI. This highlights the potential of combined therapy with iPSC-NSCs-Exos and let-7b-5p in promoting functional recovery and limiting inflammation following SCI.
Project description:Gut microbiota affects the functions of brains. However, its mechanism in sepsis remains unclear. This study evaluated the effect of metformin on ameliorating sepsis-related neurodamage by regulating gut microbiota and metabolites in septic rats. Cecal ligation and puncture (CLP) was used to establish the sepsis-related neurodamage animal models. Metformin therapy by gavage at 1 h after CLP administration was followed by fecal microbiota transplantation (FMT) to ensure the efficacy and safety of metformin on the sepsis-related neurodamage by regulating gut microbiota. The gut microbiota and metabolites were conducted by 16S rRNA sequencing and liquid chromatography-tandem mass spectrometry metabolomic analysis. The brain tissue inflammation response was analyzed by histopathology and reverse transcription-polymerase chain reaction (RT-PCR). This study reported brain inflammatory response, hemorrhage in sepsis-related neurodamage rats compared with the control group (C group). Surprisingly, the abundance of gut microbiota slightly increased in sepsis-related neurodamage rats than C group. The ratio of Firmicutes/Bacteroidetes was significantly increased in the CLP group than the C group. However, no difference was observed between the CLP and the metformin-treated rats (MET group). Interestingly, the abundance of Escherichia_Shigella increased in the MET group than the C and CLP groups, while Lactobacillaceae abundance decreased. Furthermore, Prevotella_9, Muribaculaceae, and Alloprevotella related to short-chain fatty acids production increased in the sepsis-related neurodamage of metformin-treated rats. Additionally, Prevotella_9 and Muribaculaceae correlated positively to 29 metabolites that might affect the inflammatory factors in the brain. The FMT assay showed that metformin improved sepsis-related neurodamage by regulating the gut microbiota and metabolites in septic rats. The findings suggest that metformin improves the sepsis-related neurodamage through modulating the gut microbiota and metabolites in septic rats, which may be an effective therapy for patients with sepsis-related neurodamage.
Project description:Binge alcohol use is increasing among aged adults (>65 years). Alcohol-related toxicity in aged adults is associated with neurodegeneration, yet the molecular underpinnings of age-related sensitivity to alcohol are not well described. Studies utilizing rodent models of neurodegenerative disease reveal heightened activation of Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Nod like receptor 3 (NLRP3) mediate microglia activation and associated neuronal injury. Our group, and others, have implicated hippocampal-resident microglia as key producers of inflammatory mediators, yet the link between inflammation and neurodegeneration has not been established in models of binge ethanol exposure and advanced age. Here, we report binge ethanol increased the proportion of NLRP3+ microglia in the hippocampus of aged (18-20 months) female C57BL/6N mice compared to young (3-4 months). In primary microglia, ethanol-induced expression of reactivity markers and NLRP3 inflammasome activation were more pronounced in microglia from aged mice compared to young. Making use of an NLRP3-specific inhibitor (OLT1177) and a novel brain-penetrant Nanoligomer that inhibits NF-κB and NLRP3 translation (SB_NI_112), we find ethanol-induced microglial reactivity can be attenuated by OLT1177 and SB_NI_112 in microglia from aged mice. In a model of intermittent binge ethanol exposure, SB_NI_112 prevented ethanol-mediated microglia reactivity, IL-1β production, and tau hyperphosphorylation in the hippocampus of aged mice. These data suggest early indicators of neurodegeneration occurring with advanced age and binge ethanol exposure are NF-κB- and NLRP3-dependent. Further investigation is warranted to explore the use of targeted immunosuppression via Nanoligomers to attenuate neuroinflammation after alcohol consumption in the aged.
Project description:AimsAccumulating evidence has suggested that airborne fine particulate matter (PM2.5) exposure is associated with an increased risk of ischemic stroke. However, the underlying mechanisms have not been fully elucidated. In this study, we aim to investigate the role and mechanisms of NLRP3 inflammasome and pyroptosis in ischemic stroke after PM2.5 exposure.MethodsThe BV-2 and HMC-3 microglial cell lines were established and subjected to oxygen-glucose deprivation and reoxygenation (OGD/R) with or without PM2.5 exposure. We used the CCK-8 assay to explore the effects of PM2.5 on cell viability of BV-2 and HMC-3 cells. Then, the effects of PM2.5 exposure on NLRP3 inflammasome and pyroptosis following OGD/R were detected by western blotting, ELISA, and the confocal immunofluorescence staining. Afterwards, NLRP3 was knocked down to further validate the effects of PM2.5 on cell viability, NLRP3 inflammasome activation, and pyroptosis after OGD/R in HMC-3 cells. Finally, the intracellular reactive oxygen species (ROS) was measured and the ROS inhibitor N-acetyl-L-cysteine (NAC) was used to investigate whether ROS was required for PM2.5-induced NLRP3 inflammasome activation and pyroptosis under ischemic conditions.ResultsWe found that PM2.5 exposure decreased the viability of BV-2 and HMC-3 cells in a dose- and time-dependent manner under ischemic conditions. Furthermore, PM2.5 exposure aggravated NLRP3 inflammasome activation and pyroptosis after OGD/R, as indicated by an increased expression of NLRP3, ASC, pro-caspase-1, Caspase-1, GSDMD, and GSDMD-N; increased production of IL-1β and IL-18; and enhanced Caspase-1 activity and SYTOX green uptake. However, shRNA NLRP3 treatment attenuated the effects of PM2.5 on cell viability, NLRP3 inflammasome activation, and pyroptosis. Moreover, we observed that PM2.5 exposure increased the production of intracellular ROS following OGD/R, while inhibiting ROS production with NAC partially attenuated PM2.5-induced NLRP3 inflammasome activation and pyroptosis under ischemic conditions.ConclusionThese results suggested that PM2.5 exposure triggered the activation of NLRP3 inflammasome and pyroptosis under ischemic conditions, which may be mediated by increased ROS production after ischemic stroke. These findings may provide a more enhanced understanding of the interplay between PM2.5 and neuroinflammation and cell death, and reveal a novel mechanism of PM2.5-mediated toxic effects after ischemic stroke.
Project description:Dilated cardiomyopathy (DCM) is one of the most common causes of heart failure, and the underlying mechanism remains largely elusive. Here we investigated whether NLRP3 inflammasome-mediated pyroptosis contributes to non-ischemic DCM and dissected the underlying mechanism. We found that hyper activated NLRP3 inflammasome with pyroptotic cell death of cardiomyocytes were presented in the myocardial tissues of DCM patients, which were negatively correlated with cardiac function. Doxorubicin (Dox)-induced DCM characterization disclosed that NLRP3 inflammasome activation and pyroptosis occurred in Dox-treated heart tissues, but were very marginal in either NLRP3-/- or caspase-1-/- mice. Mechanistically, Dox enhanced expressions of NOX1 and NOX4 and induced mitochondrial fission through dynamin-related protein 1 (Drp1) activation, leading to NLRP3 inflammasome-mediated pyroptosis in cardiomyocytes via caspase-1-dependent manner. Conversely, both inhibitions of NOX1 and NOX4 and Drp1 suppressed Dox-induced NLPR3 inflammasome activation and pyroptosis. The alterations of NOX1 and NOX4 expression, Drp1 phosphorylation and mitochondrial fission were validated in DCM patients and mice. Importantly, Dox-induced Drp1-mediated mitochondrial fission and the consequent NLRP3 inflammasome activation and pyroptosis were reversed by NOX1 and NOX4 inhibition in mice. This study demonstrates for the first time that cardiomyocyte pyroptosis triggered by NLRP3 inflammasome activation via caspase-1 causally contributes to myocardial dysfunction progression and DCM pathogenesis.
Project description:The spinal cord injury (SCI) is a detrimental neurological disease involving the primary mechanical injury and secondary inflammatory damage. Curtailing the detrimental neuroinflammation would be beneficial for spinal cord function recovery. Microglia reside in the spinal cord and actively participate in the onset, progression and perhaps resolution of post-SCI neuroinflammation. In the current study, we tested the effects of methylene blue on microglia both in vitro and in a rat SCI model. We found that methylene blue inhibited the protein levels of IL-1β and IL-18 rather than their mRNA levels in activated microglia. Further investigation indicated that methylene blue deceased the activation of NLRP3 inflammasome and NLRC4 inflammasome in microglia in vitro. Moreover, in the rat SCI model, the similar effect of methylene blue on post-SCI microglia was also observed, except that the activation of NLRC4 inflammasome was not seen. The inhibition of microglia NLRP3 inflammasome was associated with down-regulation of intracellular reactive oxygen species (ROS). The administration of methylene blue mitigated the overall post-SCI neuroinflammation, demonstrated by decreased pro-inflammatory cytokine production and leukocyte infiltrates. Consequently, the neuronal apoptosis was partially inhibited and the hind limb locomotor function was ameliorated by methylene blue treatment. Our research highlights the role of methylene blue in inhibiting post-SCI neuroinflammation, and suggests that methylene blue might be used for SCI therapy.