Exosome Release Promotes Inflammatory Resolution in Activated and Aged Microglia

Proper regulation of inflammatory responses is critical for effective function of microglia, in both physiological and disease states. While the mechanisms that drive microglia activation are well characterized, the pathways leading to inflammatory resolution and immune homeostasis have yet to be fully elucidated. Using RNA interference, pharmacological inhibition and genetic knockout mouse model approaches, we show that exosome release promotes immune homeostasis in activated and aged microglia. We demonstrate that induction of anti-inflammatory pathways enhances release of exosomes containing immune proteins and microRNAs. Functionally, inhibition of exosome release alters trafficking of exosome cargo, such as miR-155, in activated microglia resulting in increased cellular retention of these cargo molecules. Concordantly, we identify increased miR-155 activity leading to sustained activation of pro-inflammatory pathways as a potential mechanism underlying impaired inflammatory resolution due to inhibition of microglia exosome release. Similarly, inhibition of augmented exosome release in aged microglia exacerbates inflammatory activation, demonstrating conservation of the immune modulatory effects of exosome release in microglia. Taken together, our study identifies exosomes as novel components of an anti-inflammatory mechanism utilized by activated and aged microglia to restore immune homeostasis.

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Immunomodulatory role of paliperidone in the poly(I:C) model of schizophrenia

European Psychiatry ◽

10.1016/j.eurpsy.2016.01.541 ◽

2016 ◽

Vol 33 (S1) ◽

pp. s220-s221

Author(s):

K. MacDowell ◽

E. Munarriz-Cuezva ◽

D. Martín-Hernández ◽

A. Sayd ◽

B. García-Bueno ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Inflammatory Responses ◽

Poly I:C ◽

Mrna Levels ◽

Behavioral Test ◽

Inflammatory Pathways ◽

Anti Inflammatory ◽

Cellular Markers ◽

Endogenous Antioxidant

IntroductionAlterations on the innate inflammatory response may underlie the pathophysiology of psychiatric diseases, but the mechanisms implicated remain elusive. Current antipsychotics modulate pro/anti-inflammatory pathways, but the specific mechanisms involved remain elusive. One attractive possibility is the regulation of the intracellular signalling pathways of the innate immune receptors Toll-like 3 (TLR3), which triggers antiviral and inflammatory responses.AimsTo elucidate the regulatory role of paliperidone on maternal immune activation (MIA) induced alterations on TLR3 pathway and on the two emerging endogenous antiinflammatory/antioxidant mechanisms NRF2/antioxidant enzymes pathway and the cytokine milieu regulating M1/M2 polarization in microglia.MethodsPregnant mice were treated with the synthetic Toll-like Receptor 3 (TLR3) agonist Poly(I:C) in gestational day 9 and chronically treated with paliperidone (0,05 mg/kg i.p.) in adult offspring. Animals were sacrificed one day after treatment and behavioral test. Inflammation oxidative stress-related mediators were analysed at mRNA and protein level in prefrontal cortex samples. In addition, behavioral test t-maze was conducted.ResultsPaliperidone prevented TLR3 pathway activation and the subsequent MIA-induced neuroinflammatory response. Also, paliperidone induced an increment in the activity and protein expression of nuclear NRF2, as well as increased mRNA levels of the antioxidant enzymes HO1, SOD and catalase in the MIA model. Otherwise, paliperidone increases the antiinflammatory cytokines levels TGFβ and IL-10 in favour of a M2 microglia profile and increased the levels of the M2 cellular markers ArgI and FOLR2.ConclusionsThe modulation of neuroinflammation and enhancement of endogenous antioxidant/anti-inflammatory pathways by current and new antipsychotics could represent an interesting therapeutic strategy for the future.Disclosure of interestThe authors have not supplied their declaration of competing interest.

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Novel Anti-inflammatory Effects of Canagliflozin Involving Hexokinase II in Lipopolysaccharide-Stimulated Human Coronary Artery Endothelial Cells

Cardiovascular Drugs and Therapy ◽

10.1007/s10557-020-07083-w ◽

2020 ◽

Author(s):

Laween Uthman ◽

Marius Kuschma ◽

Gregor Römer ◽

Marleen Boomsma ◽

Jens Kessler ◽

...

Keyword(s):

Endothelial Cells ◽

Coronary Artery ◽

Inflammatory Responses ◽

Vascular Inflammation ◽

Glycolytic Enzyme ◽

Human Coronary Artery ◽

Hexokinase Ii ◽

Protein Levels ◽

Inflammatory Mechanism ◽

Anti Inflammatory

Abstract Purpose Vascular inflammation and disturbed metabolism are observed in heart failure and type 2 diabetes mellitus. Glycolytic enzyme hexokinase II (HKII) is upregulated by inflammation. We hypothesized that SGLT2 inhibitors Canagliflozin (Cana), Empagliflozin (Empa) or Dapagliflozin (Dapa) reduces inflammation via HKII in endothelial cells, and that HKII-dependent inflammation is determined by ERK1/2, NF-κB. and/or AMPK activity in lipopolysaccharide (LPS)-stimulated human coronary artery endothelial cells (HCAECs). Methods HCAECs were pre-incubated with 3 μM or 10 μM Cana, 1 μM, 3 μM or 10 μM Empa or 0.5 μM, 3 μM or 10 μM Dapa (16 h) and subjected to 3 h LPS (1 μg/mL). HKII was silenced via siRNA transfection. Interleukin-6 (IL-6) release was measured by ELISA. Protein levels of HK I and II, ERK1/2, AMPK and NF-κB were detected using infra-red western blot. Results LPS increased IL-6 release and ERK1/2 phosphorylation; Cana prevented these pro-inflammatory responses (IL-6: pg/ml, control 46 ± 2, LPS 280 ± 154 p < 0.01 vs. control, LPS + Cana 96 ± 40, p < 0.05 vs. LPS). Cana reduced HKII expression (HKII/GAPDH, control 0.91 ± 0.16, Cana 0.71 ± 0.13 p < 0.05 vs. control, LPS 1.02 ± 0.25, LPS + Cana 0.82 ± 0.24 p < 0.05 vs. LPS). Empa and Dapa were without effect on IL-6 release and HKII expression in the model used. Knockdown of HKII by 37% resulted caused partial loss of Cana-mediated IL-6 reduction (pg/ml, control 35 ± 5, LPS 188 ± 115 p < 0.05 vs. control, LPS + Cana 124 ± 75) and ERK1/2 activation by LPS. In LPS-stimulated HCAECs, Cana, but not Empa or Dapa, activated AMPK. AMPK activator A769662 reduced IL-6 release. Conclusion Cana conveys anti-inflammatory actions in LPS-treated HCAECs through 1) reductions in HKII and ERK1/2 phosphorylation and 2) AMPK activation. These data suggest a novel anti-inflammatory mechanism of Cana through HKII.

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Basal anti-inflammatory responses in cultured endothelial cells exposed to two conjugated linoleic acids

Proceedings of The Nutrition Society ◽

10.1017/s0029665120004310 ◽

2020 ◽

Vol 79 (OCE2) ◽

Author(s):

Carina Valenzuela ◽

Elizabeth Miles ◽

Philip Calder

Keyword(s):

Inflammatory Responses ◽

Adhesion Assay ◽

Dependent Manner ◽

Relative Expression ◽

Inflammatory Pathways ◽

Expression Of Genes ◽

Low Concentrations ◽

Genes Encoding ◽

Anti Inflammatory ◽

Pre Treatment

AbstractConjugated linoleic acid (CLA) isomers have been shown to possess anti-atherosclerotic properties, which may be related to the downregulation of inflammatory pathways. Whether low concentrations of CLAs are able to affect basal, unstimulated endothelial cell (EC) responses is not clear. The aim of this study was to evaluate the effects of two CLAs (cis-9, trans-11 and trans-10, cis-12) on basal inflammatory responses by ECs.EA.hy926 cells (HUVEC lineage) were cultured under standard conditions and exposed to CLAs (1 and 10 μM) for 48 hours. MTT assay was performed to determine cell viability; incorporation of FA was confirmed by gas chromatography; inflammatory mediators were assessed by multiplex immunoassay; the relative expression of genes encoding transcription factors and inflammatory cytokines was assessed through real-time PCR and static adhesion assay was used to evaluate monocyte attachment to the EC monolayer.CLAs were incorporated into ECs in a dose-dependent manner. Pre-treatment with CLA9,11 (1 uM) significantly reduced unstimulated, basal concentrations of MCP-1 (p < 0.05), and CLA10,12 at 10 uM had the same effect (p < 0.05). Both CLAs at 10 uM increased the relative expression of NFκβ (p < 0.01 and p < 0.05, respectively), while decreasing the relative expression of PPARα (p < 0.0001), COX-2 (p < 0.0001) and IL-6 (p < 0.0001). In contrast, no effect was observed in the adhesion assay for either CLA.These results suggest that both CLAs at a low concentration have a neutral or modest anti-inflammatory effect in basal conditions, which may influence endothelial function and risk of vascular disease. Interestingly, at these low CLA concentrations some pro-inflammatory genes are upregulated while others are down regulated. This suggests complex effects of CLAs on inflammatory pathways.

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Inhibition of Inflammatory Responses by Centella asiatica via Suppression of IRAK1-TAK1 in Mouse Macrophages

The American Journal of Chinese Medicine ◽

10.1142/s0192415x20500548 ◽

2020 ◽

Vol 48 (05) ◽

pp. 1103-1120

Author(s):

Young-Chang Cho ◽

Huong Lan Vuong ◽

Jain Ha ◽

Sewoong Lee ◽

Jiyoung Park ◽

...

Keyword(s):

Transforming Growth Factor ◽

Inflammatory Responses ◽

Centella Asiatica ◽

Prostaglandin E ◽

Methanol Fraction ◽

Raw 264.7 Macrophages ◽

Inflammatory Mechanism ◽

Mouse Macrophages ◽

Mitogen Activated Protein ◽

Anti Inflammatory

Centella asiatica (L.) Urb. (C. asiatica) has been widely treated for inflammation-related diseases in China for thousands of years. While C. asiatica showed relevant effects as traditional medicine, the mechanism of C. asiatica suppressing inflammation has not been thoroughly investigated. Therefore, this study was conducted to reveal the anti-inflammatory mechanism of methanol fraction from C. asiatica (MCA) at the molecular level in murine macrophages. Levels of inflammation-related mediators were observed with treatment of MCA. MCA significantly suppressed nitric oxide production and iNOS expression in RAW 264.7 macrophages. Prostaglandin E2 production was alleviated by MCA via the downregulation of cyclooxygenase-2. MCA treatment also reduced pro-inflammatory tumor necrosis factor-[Formula: see text] and interleukin (IL)-6 levels. LPS/D-GalN-induced acute hepatitis in mouse was alleviated by MCA treatment. In addition, MCA decreased the phosphorylation of inhibitory [Formula: see text]B[Formula: see text] (I[Formula: see text]B[Formula: see text]) at Ser32/36 and thereby blocked I[Formula: see text]B[Formula: see text] degradation. TXY motif phosphorylation in the activation loops of mitogen-activated protein kinases (MAPKs) was also suppressed by MCA treatment. Further investigation revealed that MCA inhibited transforming growth factor-[Formula: see text]-activated kinase 1 (TAK1) phosphorylation and IL-1 receptor-associated kinase (IRAK1) degradation, the upstream kinases activating nuclear factor [Formula: see text]B and MAPKs. Taken together, MCA exhibited anti-inflammatory properties via the downregulation of IRAK1-TAK1 signaling pathways.

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Study on Anti-Inflammatory Activity of Niloticin by Targeting MD-2 Based on Computer-Aided Drug Design and Biolayer Interferometry

Annals of Hematology & Oncology ◽

10.26420/annhematoloncol.2021.1370 ◽

2021 ◽

Vol 8 (10) ◽

Author(s):

Chen G ◽

◽

Liu Y ◽

Zhang M ◽

Xu Y ◽

...

Keyword(s):

Inflammatory Responses ◽

Inflammatory Activity ◽

Myeloid Differentiation ◽

Control Group ◽

Toll Like Receptor ◽

Expression Levels ◽

Biolayer Interferometry ◽

Inflammatory Mechanism ◽

Anti Inflammatory ◽

Cortex Phellodendri

Niloticin is an active compound from Cortex phellodendri, but its antiinflammatory activity has not yet been explored. The aim of the present study was to assess the drug potential of niloticin and to study the MD-2-targeting mechanism of its anti-inflammatory activity. Niloticin’s drug potential was analyzed using the Traditional Chinese Medicine Systems Pharmacology Database. Molecular docking and biolayer interferometry technology were used to explore the anti-inflammatory mechanism of niloticin by targeting myeloid differentiation protein 2 (MD-2), which mediates a series of Toll-Like Receptor (TLR) 4-dependent inflammatory responses. The cytokines involved in the LPSTLR4/ MD-2-NF-κB pathway were evaluated by ELISA, RT-PCR, and western blot. The results showed that niloticin has drug potential and could bind to MD- 2. Niloticin had no impact on cell viability. Niloticin could significantly decrease the levels of NO, IL-6, TNF-a, and IL-1β (P<0.01) induced by LPS. IL-1β, IL-6, iNOS, TNF-a, and COX-2 mRNA expression levels were decreased by niloticin (all P<0.01). Compared with the control group, TLR4, p65, MyD88, p-p65, and iNOS expression levels induced by LPS were suppressed by niloticin (all P<0.01). In conclusion, niloticin is a potential MD-2 antagonist. It might interact with MD-2 to play an anti-inflammatory role by suppressing the activation of the LPS-TLR4/MD-2-NF-κB signaling pathway.

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Syk-Mediated Suppression of Inflammatory Responses by Cordyceps bassiana

The American Journal of Chinese Medicine ◽

10.1142/s0192415x17500677 ◽

2017 ◽

Vol 45 (06) ◽

pp. 1217-1232 ◽

Cited By ~ 3

Author(s):

Woo Seok Yang ◽

Gyeong Sug Nam ◽

Mi-Yeon Kim ◽

Jae Youl Cho

Keyword(s):

Inflammatory Responses ◽

Fruit Body ◽

Water Extract ◽

Signaling Cascades ◽

Anticancer Activities ◽

Inflammatory Mechanism ◽

Anti Inflammatory ◽

Oxide Synthase ◽

Inducible Nitric Oxide

The fruit body of artificially cultivated Cordyceps bassiana has been reported to exhibit anti-inflammatory and anticancer activities. Although it has been suggested that the fruit body has neutraceutic and pharmaceutic biomaterial potential, the exact anti-inflammatory molecular mechanism has not been fully elucidated. In this study, we demonstrated the immunopharmacologic activity of Cordyceps bassiana under in vitro conditions and investigated its anti-inflammatory mechanism. Water extract (Cm-WE) of the fruit body of artificially cultivated Cordyceps bassiana without polysaccharide fractions reduced the expression of the proinflammatory genes cyclooxygenase (COX)-2, interleukin (IL)-12, and inducible nitric oxide synthase (iNOS) and promoted the expression of the anti-inflammatory gene IL-10 in lipopolysaccharide (LPS)-treated RAW264.7 cells. In addition, this fraction suppressed proliferation and interferon (IFN)-[Formula: see text] production in splenic T lymphocytes. Cm-WE blocked the activation of nuclear factor (NF)-[Formula: see text]B and activator protein (AP)-1 and their upstream inflammatory signaling cascades, including Syk, MEK, and JNK. Using kinase assays, Syk was identified as the target enzyme most strongly inhibited by Cm-WE. These results strongly suggest that Cm-WE suppresses inflammatory responses by inhibiting Syk kinase activity, with potential implications for novel neutraceutic and pharmaceutic biomaterials.

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An anti-inflammatory activation sequence governs macrophage transcriptional dynamics during tissue injury

10.1101/2021.09.28.462132 ◽

2021 ◽

Author(s):

Nicolas Denans ◽

Nhung T. T. Tran ◽

Madeleine E. Swall ◽

Daniel C. Diaz ◽

Jillian Blanck ◽

...

Keyword(s):

Single Cell Analysis ◽

Tissue Injury ◽

Loss Of Function ◽

Inflammatory Pathways ◽

Tissue Repair And Regeneration ◽

Sensory Hair Cell ◽

Inflammatory Activation ◽

Anti Inflammatory ◽

Spatio Temporal

AbstractMacrophages are essential for tissue repair and regeneration. Yet, the molecular programs, as well as the timing of their activation during and after tissue injury are poorly defined. Using a high spatio-temporal resolution single cell analysis of macrophages coupled with live imaging after sensory hair cell death in zebrafish, we find that the same population of macrophages transitions through a sequence of three major anti-inflammatory activation states. Macrophages first show a signature of glucocorticoid activation, then IL10 signaling and finally the induction of oxidative phosphorylation by IL4/Polyamine signaling. Importantly, loss-of-function of glucocorticoid and IL10 signaling shows that each step of the sequence is independently activated. Our results provide the first evidence that macrophages, in addition to a switch from M1 to M2, sequentially and independently transition though three anti-inflammatory pathways in vivo during tissue injury in a regenerating organ.One-Sentence SummaryWe show that macrophages are sequentially activated by three different anti-inflammatory pathways during tissue injury.

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