Lipoxin A4 Inhibits NLRP3 Inflammasome Activation in Rats With Non-compressive Disc Herniation Through the JNK1/Beclin-1/PI3KC3 Pathway

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.

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Divanillyl sulfone suppresses NLRP3 inflammasome activation via inducing mitophagy to ameliorate chronic neuropathic pain in mice

Journal of Neuroinflammation ◽

10.1186/s12974-021-02178-z ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Shuai Shao ◽

Cheng-Bo Xu ◽

Cheng-Juan Chen ◽

Gao-Na Shi ◽

Qing-Lan Guo ◽

...

Keyword(s):

Neuropathic Pain ◽

Nlrp3 Inflammasome ◽

Intrathecal Injection ◽

Beclin 1 ◽

Inflammasome Activation ◽

Chronic Neuropathic Pain ◽

Withdrawal Threshold ◽

Caspase 1 ◽

Nlrp3 Inflammasome Activation ◽

Related Proteins

Abstract Background Chronic neuropathic pain is a frequent sequel to peripheral nerve injury and maladaptive nervous system function. Divanillyl sulfone (DS), a novel structural derivative of 4,4′-dihydroxydibenzyl sulfoxide from a traditional Chinese medicine Gastrodia elata with anti-nociceptive effects, significantly alleviated neuropathic pain following intrathecal injection. Here, we aimed to investigate the underlying mechanisms of DS against neuropathic pain. Methods A chronic constrictive injury (CCI) mouse model of neuropathic pain induced by sciatic nerve ligation was performed to evaluate the effect of DS by measuring the limb withdrawal using Von Frey filament test. Immunofluorescence staining was used to assess the cell localizations and expressions of Iba-1, ASC, NLRP3, and ROS, the formation of autolysosome. The levels of NLRP3-related proteins (caspase-1, NLRP3, and IL-1β), mitophagy-related proteins (LC3, Beclin-1, and p62), and apoptosis-related proteins (Bcl-XL and Bax) were detected by Western blotting. The apoptosis of BV-2 cell and caspase activity were evaluated by flow cytometry. Results DS significantly alleviated the neuropathic pain by increasing the mechanical withdrawal threshold and inhibiting the activation of NLRP3 in CCI-induced model mice. Our findings indicated that DS promoted the mitophagy by increasing the LC3II and Beclin 1 and decreasing the levels of p62 protein in BV-2 cell. This is accompanied by the inhibition of NLRP3 activation, which was shown as inhibited the expression of NLRP3 in lysates as well as the secretion of mature caspase-1 p10 and IL-1β p17 in supernatants in cultured BV-2 microglia. In addition, DS could promote mitophagy-induced improvement of dysfunctional mitochondria by clearing intracellular ROS and restoring mitochondrial membrane potential. Conclusion Together, our findings demonstrated that DS ameliorate chronic neuropathic pain in mice by suppressing NLRP3 inflammasome activation induced by mitophagy in microglia. DS may be a promising therapeutic agent for chronic neuropathic pain.

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Activation of the alpha 7 nicotinic acetylcholine receptor mitigates osteoarthritis progression by inhibiting NF-κB/NLRP3 inflammasome activation and enhancing autophagy

PLoS ONE ◽

10.1371/journal.pone.0256507 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0256507

Author(s):

Xianjie Zhu ◽

Shiyou Dai ◽

Baohua Xia ◽

Jianbao Gong ◽

Bingzheng Ma

Keyword(s):

Acetylcholine Receptor ◽

Nicotinic Acetylcholine Receptor ◽

Western Blotting ◽

Nlrp3 Inflammasome ◽

Beclin 1 ◽

Inflammasome Activation ◽

Nicotinic Acetylcholine ◽

Nlrp3 Inflammasome Activation ◽

Anti Inflammatory ◽

Alpha 7

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by cartilage degradation. Alpha 7 nicotinic acetylcholine receptor (α7nAChR) is associated with inflammatory and metabolic responses in OA. However, the mechanisms underlying the pathological process of OA remain unclear. The aim of the present study was to examine the role and mechanisms of α7nAChR-mediated autophagy and anti-inflammatory response in chondroprotection. Monosodium iodoacetate (MIA)-induced Wistar rat OA model was used to assess the in vivo effects of the ɑ7nAChR agonist (PNU-282987). The histopathological characteristics of OA were evaluated by immunohistochemistry (IHC), and the levels of autophagy markers were determined by western blotting and transmission electron microscopy. The anti-inflammatory effect of the ɑ7nAChR agonist was assessed by IHC, quantitative real-time polymerase chain reaction, and western blotting. Parallel experiments to determine the molecular mechanisms through which the ɑ7nAChR agonist prevents OA were performed using interleukin-1β (IL-1β)-treated chondrocytes. Our results showed that PNU-282987 reduced cartilage degeneration and matrix metalloproteinase (MMP)-1 and MMP-13 expressions. Activating α7nAChR with PNU-282987 significantly promoted MIA/IL-1β-induced chondrocyte autophagy, as demonstrated by the increase in LC3-II/LC3-I ratio, Beclin-1 levels, and autophagosome number. Furthermore, treating chondrocyte with ULK1 siRNA attenuated the PNU282987-induced enhancement of LC3-II/LC3-I ratio and Beclin-1 level. Additionally, PNU282987 suppressed NF-κB/NLRP3 inflammasome activation by inhibiting the ROS/TXNIP pathway and suppressed tumor necrosis factor-ɑ and IL-1β secretion in MIA/IL-1β-treated chondrocytes. Our results demonstrate that the activation of α7nAChR promotes chondrocyte autophagy and attenuates inflammation to mitigate OA progression, providing a novel target for the treatment of OA.

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

10.21203/rs.3.rs-61796/v1 ◽

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.

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