scholarly journals Luteolin Confers Cerebroprotection after Subarachnoid Hemorrhage by Suppression of NLPR3 Inflammasome Activation through Nrf2-Dependent Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Zi-Huan Zhang ◽  
Jia-Qiang Liu ◽  
Cheng-Di Hu ◽  
Xin-Tong Zhao ◽  
Fei-Yun Qin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Subarachnoid Hemorrhage ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Neuronal Degeneration ◽  
Antioxidant Systems ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Beneficial Effects ◽  
Nrf2 Activation

Luteolin (LUT) possesses multiple biologic functions and has beneficial effects for cardiovascular and cerebral vascular diseases. Here, we investigated the protective effects of LUT against subarachnoid hemorrhage (SAH) and the involvement of underlying molecular mechanisms. In a rat model of SAH, LUT significantly inhibited SAH-induced neuroinflammation as evidenced by reduced microglia activation, decreased neutrophil infiltration, and suppressed proinflammatory cytokine release. In addition, LUT markedly ameliorated SAH-induced oxidative damage and restored the endogenous antioxidant systems. Concomitant with the suppressed oxidative stress and neuroinflammation, LUT significantly improved neurologic function and reduced neuronal cell death after SAH. Mechanistically, LUT treatment significantly enhanced the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), while it downregulated nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation. Inhibition of Nrf2 by ML385 dramatically abrogated LUT-induced Nrf2 activation and NLRP3 suppression and reversed the beneficial effects of LUT against SAH. In neurons and microglia coculture system, LUT also mitigated oxidative stress, inflammatory response, and neuronal degeneration. These beneficial effects were associated with activation of the Nrf2 and inhibitory effects on NLRP3 inflammasome and were reversed by ML385 treatment. Taken together, this present study reveals that LUT confers protection against SAH by inhibiting NLRP3 inflammasome signaling pathway, which may be modulated by Nrf2 activation.

scholarly journals SIRT1 Promotes M2 Microglia Polarization via Reducing ROS-Mediated NLRP3 Inflammasome Signaling After Subarachnoid Hemorrhage

2021 ◽  
Vol 12 ◽  
Author(s):  
Da-Yong Xia ◽  
Jin-Long Yuan ◽  
Xiao-Chun Jiang ◽  
Min Qi ◽  
Nian-Sheng Lai ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Oxidative Damage ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Neuronal Degeneration ◽  
Sirtuin 1 ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Microglia Polarization ◽  
M1 Phenotype

Mounting evidence has suggested that modulating microglia polarization from pro-inflammatory M1 phenotype to anti-inflammatory M2 state might be a potential therapeutic approach in the treatment of subarachnoid hemorrhage (SAH) injury. Our previous study has indicated that sirtuin 1 (SIRT1) could ameliorate early brain injury (EBI) in SAH by reducing oxidative damage and neuroinflammation. However, the effects of SIRT1 on microglial polarization and the underlying molecular mechanisms after SAH have not been fully illustrated. In the present study, we first observed that EX527, a potent selective SIRT1 inhibitor, enhanced microglial M1 polarization and nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation in microglia after SAH. Administration of SRT1720, an agonist of SIRT1, significantly enhanced SIRT1 expression, improved functional recovery, and ameliorated brain edema and neuronal death after SAH. Moreover, SRT1720 modulated the microglia polarization shift from the M1 phenotype and skewed toward the M2 phenotype. Additionally, SRT1720 significantly decreased acetylation of forkhead box protein O1, inhibited the overproduction of reactive oxygen species (ROS) and suppressed NLRP3 inflammasome signaling. In contrast, EX527 abated the upregulation of SIRT1 and reversed the inhibitory effects of SRT1720 on ROS-NLRP3 inflammasome activation and EBI. Similarly, in vitro, SRT1720 suppressed inflammatory response, oxidative damage, and neuronal degeneration, and improved cell viability in neurons and microglia co-culture system. These effects were associated with the suppression of ROS-NLRP3 inflammasome and stimulation of SIRT1 signaling, which could be abated by EX527. Altogether, these findings indicate that SRT1720, an SIRT1 agonist, can ameliorate EBI after SAH by shifting the microglial phenotype toward M2 via modulation of ROS-mediated NLRP3 inflammasome signaling.

scholarly journals Crosstalk between Long-Term Sublethal Oxidative Stress and Detrimental Inflammation as Potential Drivers for Age-Related Retinal Degeneration

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Age Related Macular Degeneration ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Nuclear Factor ◽  
Rpe Cells ◽  
Age Related ◽  
Oxidative Insult

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.

scholarly journals Key Mechanisms and Potential Implications of Hericium erinaceus in NLRP3 Inflammasome Activation by Reactive Oxygen Species during Alzheimer’s Disease

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1664
Author(s):  
Marika Cordaro ◽  
Angela Trovato Salinaro ◽  
Rosalba Siracusa ◽  
Ramona D’Amico ◽  
Daniela Impellizzeri ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Nlrp3 Inflammasome ◽  
Neuronal Degeneration ◽  
Behavioral Changes ◽  
Antioxidant Systems ◽  
Inflammasome Activation ◽  
Protective Effects ◽  
Behavioral Alteration ◽  
Hericium Erinaceus

Alzheimer’s disease (AD) is the principal cause of dementia, and its incidence increases with age. Altered antioxidant systems and inflammation have an important role in the etiology of neurodegenerative disorders. In this study, we evaluated the effects of Hericium erinaceus, a nutritional mushroom with important antioxidant effects, in a rat model of AD. Animals were injected with 70 mg/Kg of AlCl3 daily for 6 weeks, and Hericium erinaceus was administered daily by gavage. Before the experiment’s end date, behavioral test training was performed. At the end of the study, behavioral changes were assessed, and the animals were euthanized. Brain tissues were harvested for further analysis. AlCl3 mainly accumulates in the hippocampus, the principal region of the brain involved in memory functions and learning. Hericium erinaceus administration reduced behavioral changes and hippocampal neuronal degeneration. Additionally, it reduced phosphorylated Tau levels, aberrant APP overexpression, and β-amyloid accumulation. Moreover, Hericium erinaceus decreased the pro-oxidative and pro-inflammatory hippocampal alterations induced by AD. In particular, it reduced the activation of the NLRP3 inflammasome components, usually activated by increased oxidative stress during AD. Collectively, our results showed that Hericium erinaceus has protective effects on behavioral alteration and histological modification associated with AD due to the modulation of the oxidative and inflammatory pathways, as well as regulating cellular brain stress.

scholarly journals Modulation of RAS and PI3-AKT pathway by Stavudine (d4T) in PBMC of Alzheimer’s Disease Patients

2020 ◽  
Author(s):  
Francesca La Rosa ◽  
Chiara Paola Zoia ◽  
Chiara Bazzini ◽  
Alessandra Bolognini ◽  
Saresella Marina ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Beclin 1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammasome Activation ◽  
Beneficial Effects ◽  
Nlrp3 Inflammasome Activation ◽  
Chaperone Mediated Autophagy ◽  
Inflammasome Activity

Abstract Background Aβ42-deposition plays a pivotal role in AD-pathogenesis by inducing the activation of microglial cells and neuroinflammation. This process is antagonized by microglia-mediated clearance of Aβ plaques. Activation of the NLRP3 inflammasome is involved in neuroinflammation and in the impairments of Aβ-plaques clearance. Stavudine (d4T) on the other hand down-regulates the NLRP3 inflammasome and stimulates autophagy-mediated Aβ-clearing in a TPH-1 cell line model. Methods We explored the effect of d4T on Aβ- autophagy using PBMC of AD patients that were primed with LPS and stimulated with Aβ in the absence/presence of d4T. We analyzed the NLRP3 inflammasome activity by measuring NLRP3-ASC complexes formation by AMNIS Flow-sight and pro-inflammatory cytokines (IL-1β, IL-18 and Caspase-1) production by enzyme-linked immunosorbent assay (ELISA). Western blot analyses were used to measure phosphorylation and protein expression of p38, CREB, ERK and AKT, p70, LAMP 2A, beclin-1 and Bax. Results data showed that d4T: 1) down regulates NLRP3 inflammasome activation and the production of down-stream proinflammatory cytokines even in PBMC; 2) stimulates the phosphorylation of AKT, ERK, p70 as well as LAMP2A production, but does modulate beclin-1, suggesting a selective effect of this compound on chaperone-mediated autophagy (CMA); 3) up regulates p-CREB and BAX, possibly diminishing Aβ–mediated cytotoxicity; and 4) reduces the phosphorylation of p-38, a protein involved in the production of proinflammatory cytokines. Conclusions d4T reduces the activation of the NLRP3 inflammasome and stimulates CMA autophagy as well as molecular mechanisms that modulate cytotoxicity and reduce inflammation in cells of AD patients. It might be interesting to verify the possibly beneficial effects of d4T in the clinical scenario.

scholarly journals Bushen-Yizhi Formula Alleviates Neuroinflammation via Inhibiting NLRP3 Inflammasome Activation in a Mouse Model of Parkinson’s Disease

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yousheng Mo ◽  
Erjin Xu ◽  
Renrong Wei ◽  
Baoluu Le ◽  
Lei Song ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Model ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Neuronal Degeneration ◽  
Interleukin 1 ◽  
Inflammasome Activation ◽  
Neuroprotective Effects ◽  
Nlrp3 Inflammasome Activation

Parkinson’s disease (PD), the second most common neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Although the molecular mechanisms underlying dopaminergic neuronal degeneration in PD remain unclear, neuroinflammation is considered as the vital mediator in the pathogenesis and progression of PD. Bushen-Yizhi Formula (BSYZ), a traditional Chinese medicine, has been demonstrated to exert antineuroinflammation in our previous studies. However, it remains unclear whether BSYZ is effective for PD. Here, we sought to assess the neuroprotective effects and explore the underlying mechanisms of BSYZ in a 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine- (MPTP-) induced mouse model of PD. Our results indicate that BSYZ significantly alleviates the motor impairments and dopaminergic neuron degeneration of MPTP-treated mice. Furthermore, BSYZ remarkably attenuates microglia activation, inhibits NLPR3 activation, and decreases the levels of inflammatory cytokines in MPTP-induced mouse brain. Also, BSYZ inhibits NLRP3 activation and interleukin-1βproduction of the 1-methyl-4-phenyl-pyridinium (MPP+) stimulated BV-2 microglia cells. Taken together, our results indicate that BSYZ alleviates MPTP-induced neuroinflammation probably via inhibiting NLRP3 inflammasome activation in microglia. Collectively, BSYZ may be a potential therapeutic agent for PD and the related neurodegeneration diseases.

scholarly journals Discovery and Quantitative Analysis of Nuclear Factor Erythroid 2-Related Factor (Nrf2) Activators in Maca (Lepidium meyenii) Using the Synthetic Macamides

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 401-401
Author(s):  
Dongyup Hahn ◽  
Taeho Lee ◽  
Sangkyu Lee ◽  
Jong-Sup Bae ◽  
MinKyun Na ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Quantitative Analysis ◽  
Molecular Mechanisms ◽  
Chemical Constituents ◽  
Related Factor ◽  
Herbaceous Plant ◽  
Nuclear Factor ◽  
Beneficial Effects ◽  
Lepidium Meyenii ◽  
Nrf2 Activation

Abstract Objectives Maca (Lepidium meyenii) is a biennial herbaceous plant of family Brassicaceae with various bioactivities such as reproductive health enhancement, antifatigue, antioxidation, neuroprotection, anticancer, hepatoprotection, and immunomodulation. But studies on molecular mechanisms beyond the phenomenal physiology are rare because the putative bioactive chemical constituents, macamides, a series of unique N-benzylamides with long-chain fatty acids are difficult to isolate from the natural maca specimen. In this study, ten macamides were chemically synthesized to investigate biological mechanisms underlying the various bioactivities. Methods Macamides were synthesized from benzylamides and commercially available fatty acids adding 1,1'-carbonyl diimidazole. Nrf2 activation of macamides were measured using U2OS cells in CP0. Quantitative analysis of bioactive macamides were performed using LC-MS/MS system and synthesized standard macamides. The difference in composition of macamides among three cultivars, yellow, red and black macas was also examined. Results Three of macamides exhibited moderate nuclear factor erythroid 2-related factor 2 (Nrf2) activation was observed from cell-based assay (EC50 7.3–16.5 μM), which might account for some of the known bioactivities of maca. Quantitative analysis of macamide compositions in maca specimen using LC-MS/MS was followed, which revealed the macamides with Nrf2 activation activity consist the majority among macamides contained in maca. Conclusions Among the bioactivities that have known as the beneficial effects of maca, bioactivities related to antioxidation might be accounted for the Nrf2 activation of macamides contained in maca. Funding Sources This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (2019R1F1A1051041).

scholarly journals Modulation of RAS and PI3-AKT pathway by Stavudine (d4T) in PBMC of Alzheimer’s Disease Patients

2020 ◽  
Author(s):  
Francesca La Rosa ◽  
Chiara Paola Zoia ◽  
Chiara Bazzini ◽  
Alessandra Bolognini ◽  
Marina Saresella ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Beclin 1 ◽  
Inflammasome Activation ◽  
Beneficial Effects ◽  
Nlrp3 Inflammasome Activation ◽  
Chaperone Mediated Autophagy ◽  
Nlrp3 Activity ◽  
Pro Inflammatory Cytokines

Abstract Background: Aβ42-deposition plays a pivotal role in AD-pathogenesis by inducing the activation of microglial cells and neuroinflammation. This process is antagonized by microglia-mediated clearance of Aβ plaques. Activation of the NLRP3 inflammasome is involved in neuroinflammation and in the impairments of Aβ-plaques clearance. Stavudine (d4T) on the other hand down-regulates the NLRP3 inflammasome and stimulates autophagy-mediated Aβ-clearing in a TPH-1 cell line model.We explored the effect of d4T on Aβ-autophagy using PBMC of AD patients that were primed with LPS and stimulated with Aβ in the absence/presence of d4T. We analyzed the NLRP3 activity by measuring NLRP3-ASC complexes formation by AMNIS Flow-sight and pro-inflammatory cytokines (IL-1β, IL-18 and Caspase-1) production by ELISA. Western blot analyses were used to measure phosphorylation and protein expression of p38, CREB, ERK and AKT, p70, LAMP 2A, Beclin-1 and Bax.Results: Data showed that d4T: 1) down regulates NLRP3 inflammasome activation and the production of down-stream proinflammatory cytokines even in PBMC; 2) stimulates the phosphorylation of AKT, ERK, p70 as well as LAMP2A production, but does modulate beclin-1, suggesting a selective effect of this compound on chaperone-mediated autophagy (CMA); 3) up regulates p-CREB and BAX, possibly diminishing Aβ-mediated cytotoxicity; and 4) reduces the phosphorylation of p-38, a protein involved in the production of pro-inflammatory cytokines.Conclusions: d4T reduces the activation of the NLRP3 inflammasome and stimulates CMA autophagy as well as molecular mechanisms that modulate cytotoxicity and reduce inflammation in cells of AD patients. It might be interesting to verify the possibly beneficial effects of d4T in the clinical scenario.

scholarly journals Molecular Mechanisms That Link Oxidative Stress, Inflammation, and Fibrosis in the Liver

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1279
Author(s):  
Erika Ramos-Tovar ◽  
Pablo Muriel
Keyword(s):  
Oxidative Stress ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Nuclear Factor Κb ◽  
Receptor Protein ◽  
Related Factor ◽  
Nuclear Factor ◽  
Interacting Protein ◽  
Caspase 1 ◽  
Ecm Proteins

Activated hepatic stellate cells (HSCs) and myofibroblasts are the main producers of extracellular matrix (ECM) proteins that form the fibrotic tissue that leads to hepatic fibrosis. Reactive oxygen species (ROS) can directly activate HSCs or induce inflammation or programmed cell death, especially pyroptosis, in hepatocytes, which in turn activates HSCs and fibroblasts to produce ECM proteins. Therefore, antioxidants and the nuclear factor E2-related factor-2 signaling pathway play critical roles in modulating the profibrogenic response. The master proinflammatory factors nuclear factor-κB (NF-κB) and the nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome may coordinate to produce and activate profibrogenic molecules such as interleukins 1β and 18, which effectively activate HSCs, to produce large amounts of fibrotic proteins. Furthermore, the NLRP3 inflammasome activates pro-caspase 1, which is upregulated by NF-κB, to produce caspase 1, which induces pyroptosis via gasdermin and the activation of HSCs. ROS play central roles in the activation of the NF-κB and NLRP3 signaling pathways via IκB (an inhibitor of NF-κB) and thioredoxin-interacting protein, respectively, thereby linking the molecular mechanisms of oxidative stress, inflammation and fibrosis. Elucidating these molecular pathways may pave the way for the development of therapeutic tools to interfere with specific targets.

scholarly journals Keap1 deletion accelerates mutant K-ras/p53-driven cholangiocarcinoma

2020 ◽  
Vol 318 (3) ◽  
pp. G419-G427 ◽  
Author(s):  
Tatsuhide Nabeshima ◽  
Shin Hamada ◽  
Keiko Taguchi ◽  
Yu Tanaka ◽  
Ryotaro Matsumoto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cancer Progression ◽  
Stress Responses ◽  
Target Genes ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Related Factor ◽  
Loss Of Function ◽  
P53 Expression ◽  
Nrf2 Activation

The activation of the Kelch-like ECH-associated protein 1 (Keap1)-NF-E2-related factor 2 (Nrf2) pathway contributes to cancer progression in addition to oxidative stress responses. Loss-of-function Keap1 mutations were reported to activate Nrf2, leading to cancer progression. We examined the effects of Keap1 deletion in a cholangiocarcinoma mouse model using a mutant K-ras/ p53 mouse. Introduction of the Keap1 deletion into liver-specific mutant K-ras/ p53 expression resulted in the formation of invasive cholangiocarcinoma. Comprehensive analyses of the gene expression profiles identified broad upregulation of Nrf2-target genes such as Nqo1 and Gstm1 in the Keap1-deleted mutant K-ras/ p53 expressing livers, accompanied by upregulation of cholangiocyte-related genes. Among these genes, the transcriptional factor Sox9 was highly expressed in the dysplastic bile duct. The Keap-Nrf2-Sox9 axis might serve as a novel therapeutic target for cholangiocarcinoma. NEW & NOTEWORTHY The Keap1-Nrf2 system has a wide variety of effects in addition to the oxidative stress response in cancer cells. Addition of the liver-specific Keap1 deletion to mice harboring mutant K-ras and p53 accelerated cholangiocarcinoma formation, together with the hallmarks of Nrf2 activation. This process involved the expansion of Sox9-positive cells, indicating increased differentiation toward the cholangiocyte phenotype.

Sign in / Sign up

Export Citation Format

Share Document