Inflammation
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Postoperative ileus is a common complication after intra-abdominal surgery. Nitric oxide produced by macrophages in the inflamed gastrointestinal tract plays a crucial role in the pathogeny of postoperative ileus. Honokiol, extracted from the bark of Magnolia spp., is a natural compound with a biphenolic structure. ⋯ Honokiol significantly recovered gastrointestinal dysmotility and inhibited intestinal inflammation in postoperative ileus. Moreover, honokiol was suggested to have effects on macrophages, namely, inhibiting mRNA expression of proinflammatory cytokines and inducible nitric oxide synthase. Taken together, honokiol represents a potential novel therapeutic agent for postoperative ileus.
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Prostaglandin E2 (PGE2) is a key proinflammatory mediator that contributes to inflammatory hyperalgesia. Voltage-gated sodium channel 1.7 (Nav1.7) plays an important role in inflammatory pain. However, the modulation of Nav1.7 in inflammatory pain remains poorly understood. ⋯ Moreover, TMJ inflammation-induced upregulation of Nav1.7 expression and PGE2 levels in the TG could be reversed by COX-2-selective inhibitor meloxicam given by oral gavage, and meanwhile, the hyperalgesia of inflamed TMJ was also mitigated. So we concluded that PGE2 upregulated trigeminal ganglionic Nav1.7 expression to contribute to TMJ inflammatory pain in rats. Our finding suggests that PGE2 was an important regulator of Nav1.7 in TMJ inflammatory pain, which may help increase understanding on the hyperalgesia of peripheral inflammation and develop a new strategy to address inflammatory pain.
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Macrophages play a crucial role in host innate anti-Staphylococcus aureus defense, which is tightly regulated by multiple factors, including microRNAs. A recent study showed that miR-24 plays an important role in macrophage polarization. Here, we investigated the biological function of miR-24 in S. aureus-stimulated macrophages. ⋯ Additionally, miR-24 overexpression inhibited CHI3L1 expression and downregulated the downstream MAPK pathway in S. aureus-stimulated macrophages. Finally, CHI3L1 overexpression rescued macrophage polarization and MAPK pathway inhibition induced by miR-24 mimic transfection in S. aureus-stimulated macrophages. In conclusion, the data suggest that miR-24 serves as a molecular regulator in S. aureus-induced macrophage polarization through targeting of CHI3L1 and regulation of the MAPK pathway, which may provide a promising therapeutic target for S. aureus-related infections and inflammatory diseases.
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The aim of this study was to identify the role of thioredoxin-interacting protein (TXNIP) and its interaction with antioxidants in the activation of the fructose-induced NOD-like receptor protein 3 (NLRP3) inflammasome in human macrophages. The study was performed with U937 and THP-1 macrophage cell lines. Total reactive oxygen species (ROS) were measured by flow cytometry. ⋯ Intracellular shuttling of TXNIP from the nucleus into the mitochondria was detected under stimulation with fructose, which was also attenuated by antioxidants quercetin and ascorbic acid but not butylated hydroxyanisole. Treatment of macrophages with fructose promoted the association between TXNIP and NLRP3 in the cytosol, sequentially resulting in the activation of the NLRP3 inflammasome. This study revealed that intracellular TXNIP protein is a critical regulator of activation of the fructose-induced NLRP3 inflammasome, which can be effectively blocked by the antioxidants quercetin and ascorbic acid.
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Lidocaine (Lido) is reported to suppress inflammatory responses and exhibit a therapeutic effect in models of cecal ligation and puncture (CLP)-induced acute lung injury (ALI). The receptor for advanced glycation end product (RAGE) exerts pro-inflammatory effects by enhancing pro-inflammatory cytokine production. However, the precise mechanism by which Lido confers protection against ALI is not clear. ⋯ Furthermore, Lido significantly reduced CLP-induced upregulation of HMGB1 and RAGE expression and activation of the NF-κB and MAPK signaling pathways. With the use of RAGE KO rats, we demonstrate here that RAGE deficiency attenuates the protective effect of Lido against CLP-induced lung inflammatory cell infiltration and histopathological lung injury. These results suggest that RAGE deficiency attenuates the protective effect of Lido against CLP-induced ALI by attenuating the pro-inflammatory cytokines production.