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

2020 ◽  
Vol 48 (05) ◽  
pp. 1103-1120
Author(s):  
Young-Chang Cho ◽  
Huong Lan Vuong ◽  
Jain Ha ◽  
Sewoong Lee ◽  
Jiyoung Park ◽  
...  

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.

2020 ◽  
Vol 15 (4) ◽  
pp. 1934578X2092048 ◽  
Author(s):  
Hyun-Kyu Kang ◽  
Chang-Gu Hyun

Recently, additional therapeutic potentials of classical antibiotics are gaining considerable attention. The discovery of penicillin in the 1920s had a major impact on the history of human health. Penicillin has been used for the treatment for fatal microbial infections in humans and has led to the discovery of several new antibiotics. d-(+)-Cycloserine (DCS) is an antibiotic isolated from Streptomyces orchidaceous and is used in conjunction with other drugs in the treatment of tuberculosis. However, there have been no studies on the anti-inflammatory effects of DCS in RAW 264.7 macrophage cell line. To investigate the anti-inflammatory effects of DCS, we examined the ability of DCS to inhibit the inflammatory responses in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages in this study. Cell viability was analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cells were pretreated with various concentrations (2, 4, and 6 mM) of DCS, then treated with 1 μg/mL LPS to detect its anti-inflammatory effects. d-(+)-Cycloserine inhibited the production of nitric oxide (NO) in a concentration-dependent manner, and to some extent, inhibited the production of prostaglandin E2. Consistent with these findings, DCS suppressed the expression of pro-inflammatory cytokines such as interleukin (IL)-1β and IL-6. However, it had no effect on the expression of tumor necrosis factor-α. Western blot analysis demonstrated that DCS inhibited inducible nitric oxide synthase and suppressed cyclooxygenase type-2 (COX-2) expression. In addition, investigation of its effects on nuclear factor kappa B signaling showed that DCS inhibited phosphorylation of inhibitory kappa B-α (IκB-α) and increased intracellular IκB-α in a concentration-dependent manner. Furthermore, DCS inhibited the phosphorylation of LPS-induced extracellular signal-regulated kinase, however it did not affect phosphorylation of c-jun N-terminal kinase and p38. Further studies confirmed that the inhibition of phosphorylation of IκB-α was mediated through the inhibition of phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway. To determine the applicability of DCS to the skin, cytotoxicity on HaCaT keratinocytes was measured following treatment with various concentrations (2, 4, 6, 8, and 10 mM) of DCS using MTT assay. These results suggest that DCS may be used as a potential drug for the treatment of inflammatory diseases.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Woo Seok Yang ◽  
Yung Chul Park ◽  
Ji Hye Kim ◽  
Hye Ri Kim ◽  
Tao Yu ◽  
...  

Nanostructured, self-assembling peptides hold promise for a variety of regenerative medical applications such as 3D cell culture systems, accelerated wound healing, and nerve repair. The aim of this study was to determine whether the self-assembling peptide K5 can be applied as a carrier of anti-inflammatory drugs. First, we examined whether the K5 self-assembling peptide itself can modulate various cellular inflammatory responses. We found that peptide K5 significantly suppressed the release of tumor-necrosis-factor- (TNF-)αand prostaglandin E2(PGE2) from RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Similarly, there was inhibition of cyclooxygenase- (COX-) 2 mRNA expression assessed by real-time PCR, indicating that the inhibition is at the transcriptional level. In agreement with this finding, peptide K5 suppressed the translocation of the transcription factors activator protein (AP-1) and c-Jun and inhibited upstream inflammatory effectors including mitogen activated protein kinase (MAPK), p38, and mitogen-activated protein kinase kinase 3/6 (MKK 3/6). Whether this peptide exerts its effects via a transmembrane or cytoplasmic receptor is not clear. However, our data strongly suggest that the nanostructured, self-assembling peptide K5 may possess significant anti-inflammatory activity via suppression of the p38/AP-1 pathway.


Author(s):  
Hyun Ju Park ◽  
Sang-Mi Jo ◽  
Seok Hee Seo ◽  
Myoungsook Lee ◽  
Yunkyoung Lee ◽  
...  

Wild ginseng, Panax ginseng Meyer, is a traditional medicine widely used in Asia. Due to low reward and high costs, wild ginseng is produced by a plant cell culture technique called cultured ginseng roots (GR). The health benefits of wild ginseng have been well studied, but the potential health effects of GR are largely unknown. Thus, we investigated the role of a GR extract (GRE) on inflammatory responses. We firstly investigated the anti-inflammatory potential of GRE in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. GRE (100 μg/mL) dampened pro-inflammatory gene expression, cytokine release, reactive oxygen species (ROS) production, and mitogen-activated protein kinase (MAPK) activation. These anti-inflammatory responses by GRE were confirmed in mouse bone marrow-derived macrophages (BMDMs), which showed that GRE could inhibit inflammation with the induction of antioxidant levels. LPS was recently reported to impair mitochondrial bioenergetics in mouse macrophages. We next measured the mitochondrial oxygen consumption rate (OCR), determining mitochondrial function. LPS treatment downregulated OCR; however, GRE partially restored the LPS-mediated energy homeostasis defects. Furthermore, GRE-pretreated conditioned media (CM) obtained from mouse macrophages decreased CM-mediated adipocyte inflammation. Collectively, these data suggested that GRE attenuated LPS-induced inflammation, and it might be partially involved in the protection from mitochondrial dysfunction in macrophages and adipocytes.


Author(s):  
Laween Uthman ◽  
Marius Kuschma ◽  
Gregor Römer ◽  
Marleen Boomsma ◽  
Jens Kessler ◽  
...  

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.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 17-19
Author(s):  
Shuhui Li

Abstract Lipocalin 2 (Lcn2) is an essential component of the innate immune system and exerts significant immunomodulatory effects in vitro. The aim of current study was to investigate the expression profile of Lcn2 during inflammatory process and explore the role of Lcn2 in the anti-inflammatory responses. Western blot, real-time quantitative PCR, immunofluorescence (IF) and enzyme-linked immunosorbent assay (ELISA) were employed. Firstly, we evaluated the temporospatial expression of Lcn2 of mice after inflammatory stimuli by lipopolysaccharides (LPS). In vivo, LPS induced both mRNA and protein levels of Lcn2 significantly (P &lt; 0.01) in liver, jejunum and ileum. Lcn2 exhibited a continuous increase by 8 h and peaked by 24 h post challenges. Secondly, we challenged Lcn2-deficient (Lcn2-/-) mice and wild-type (WT) mice with peripheral LPS and determined effects on inflammation. In contrast to WT mice, Lcn2-/- mice showed distinct inflammatory injury in liver, jejunum, ileum and spleen with significantly elevated pro-inflammatory cytokines interleukin-6 (IL-6) and interleukin-1b (IL-1b) and decreased anti-inflammatory cytokine interleukin-10 (IL-10). Thirdly, we isolated bone marrow-derived macrophages (BMDM) from Lcn2-/- mice and WT mice to evaluate their functions. After LPS challenge, Lcn2-/- BMDM showed aggravated inflammatory reaction as pro-inflammatory factors tumour necrosis factor-α (TNF-α), IL-6, IL-1b and inducible nitric oxide synthase (iNOS) increased (P &lt; 0.05) while anti-inflammatory cytokines IL-10, transforming growth factor β1 (TGF-β1) and arginase-1(Arg-1) decreased significantly (P &lt; 0.05) compared with WT BMDM. This phenomenon could be relieved when adding recombinant Lcn2 (P &lt; 0.05). The exogenous addition of Lcn2 on mice RAW264.7 macrophages stimulated by LPS also conformed this point. These findings demonstrated that Lcn2 served as a potent protective factor in response to systemic inflammation, and elevated Lcn2 expression during inflammatory conditions was presumed to play an effective role in alleviating inflammatory responses.


2009 ◽  
Vol 421 (3) ◽  
pp. 473-482 ◽  
Author(s):  
Bärbel Schröfelbauer ◽  
Johanna Raffetseder ◽  
Maria Hauner ◽  
Andrea Wolkerstorfer ◽  
Wolfgang Ernst ◽  
...  

The triterpene glycoside glycyrrhizin is the main active compound in liquorice. It is used as a herbal medicine owing to its anticancer, antiviral and anti-inflammatory properties. Its mode of action, however, remains widely unknown. In the present study, we aimed to elucidate the molecular mechanism of glycyrrhizin in attenuating inflammatory responses in macrophages. Using microarray analysis, we found that glycyrrhizin caused a broad block in the induction of pro-inflammatory mediators induced by the TLR (Toll-like receptor) 9 agonist CpG-DNA in RAW 264.7 cells. Furthermore, we found that glycyrrhizin also strongly attenuated inflammatory responses induced by TLR3 and TLR4 ligands. The inhibition was accompanied by decreased activation not only of the NF-κB (nuclear factor κB) pathway but also of the parallel MAPK (mitogen-activated protein kinase) signalling cascade upon stimulation with TLR9 and TLR4 agonists. Further analysis of upstream events revealed that glycyrrhizin treatment decreased cellular attachment and/or uptake of CpG-DNA and strongly impaired TLR4 internalization. Moreover, we found that the anti-inflammatory effects were specific for membrane-dependent receptor-mediated stimuli, as glycyrrhizin was ineffective in blocking Tnfa (tumour necrosis factor α gene) induction upon stimulation with PMA, a receptor- and membrane-independent stimulus. These observations suggest that the broad anti-inflammatory activity of glycyrrhizin is mediated by the interaction with the lipid bilayer, thereby attenuating receptor-mediated signalling.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Eun-Jin Yang ◽  
Young Min Ham ◽  
Kyong-Wol Yang ◽  
Nam Ho Lee ◽  
Chang-Gu Hyun

During our ongoing screening program designed to determine the anti-inflammatory potential of natural compounds, we isolated sargachromenol fromSargassum micracanthum. In the present study, we investigated the anti-inflammatory effects of sargachromenol on lipopolysaccharide (LPS)-induced inflammation in murine RAW 264.7 macrophage cells and the underlying mechanisms. Sargachromenol significantly inhibited the LPS-induced production of nitric oxide (NO) and prostaglandin E2(PGE2) in a dose-dependent manner. It also significantly inhibited the protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner in LPS-stimulated macrophage cells. Further analyses showed that sargachromenol decreased the cytoplasmic loss of inhibitorκBα(IκBα) protein. These results suggest that sargachromenol may exert its anti-inflammatory effects on LPS-stimulated macrophage cells by inhibiting the activation of the NF-κB signaling pathway. In conclusion, to our knowledge, this is the first study to show that sargachromenol isolated fromS. micracanthumhas an effective anti-inflammatory activity. Therefore, sargachromenol might be useful for cosmetic, food, or medical applications requiring anti-inflammatory properties.


2018 ◽  
Author(s):  
Joe C. Udeochu ◽  
Cesar Sanchez-Diaz ◽  
Alvan Cai ◽  
Anna Jovicic ◽  
Saul A. Villeda

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.


Author(s):  
Hussein Al-Hakeim ◽  
Ahmed Jasim Twayej ◽  
Arafat Hussein Al-Dujaili ◽  
Michael Maes

Major Depression Disorder (MDD) is accompanied by an immune response characterized by increased levels of pro-inflammatory and immune-regulatory cytokines and cytokine-induced stimulation of indoleamine-2,3-dioxygenase (IDO). There is also some evidence that anti-inflammatory drugs may have a clinical efficacy in MDD.The aim of this study is to examine the clinical effects of an eight-week combinatorial treatment of ketoprofen (a nonsteroidal anti-inflammatory drug) combined or not with sertraline, on serum levels of IDO, interferon (IFN)-&gamma;, interleukin (IL)-4 and transforming growth factor (TGF)-&beta;1 in association with changes in the Beck-Depression Inventory-II (BDI-II). The study included 140 MDD patients and 40 normal controls. The pre-treatment serum levels of IDO, IFN-&gamma;, TGF-&beta;1 and IL-4 were significantly higher in MDD patients compared with the control group. Treatment with sertraline with or without ketoprofen significantly reduced the increased baseline production of all 4 biomarkers to levels which were similar as those of normal controls. Ketoprofen add-on had a significantly greater effect on IDO and BDI-II as compared with placebo. The reductions in IDO, IL-4 and TGF-&beta;1 during treatment were significantly associated with those in the BDI-II.In conclusion, the clinical efficacy of both sertraline + ketoprofen may be ascribed at least in part to attenuated IDO levels and immune-inflammatory responses in MDD. Moreover, add-on treatment with ketoprofen may augment the efficacy of sertraline by attenuating IDO. However, these treatments may also significantly reduce the more beneficial properties of T helper-2 and T regulatory (Treg) immune subsets. Future research should develop immune treatments that target the immune-inflammatory response in MDD, while enhancing the compensatory immune-regulatory system (CIRS).


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