scholarly journals A Novel Polysaccharide Isolated From Fresh Longan (Dimocarpus longan Lour.) Activates Macrophage via TLR2/4-Mediated PI3/AKT and MyD88/TRAF6 Pathways

2021 ◽  
Vol 12 ◽  
Author(s):  
Haibo Lan ◽  
Wu Li ◽  
Jucai Xu ◽  
Yuzhe Yang ◽  
Zhaolun Tan ◽  
...  

A novel immunomodulatory polysaccharide (LP4) with a molecular weight 6.31 × 104 g/mol was purified from fresh longan pulp. It was composed of mannose, glucose, glucuronic acid, galactose, xylose, arabinose, galacturonic acid, fucose, and rhamnose in a molar percentage of 36:31:10:7:4:4:3:2:2, and mainly linked by (1→6)-β-Man, (1→4)-β-Glc and (1→6)-α-Glc. LP4 can obviously enhance the phagocytosis of macrophages and promote the proliferation of lymphocytes. After treating macrophages with LP4 (12.5–50 μg/ml), the production of IL-1β and TNF-α was significantly increased. These increases of cytokines were suppressed when the TLR2/TLR4 receptors were inhibited by anti-TLR2 and/or anti-TLR4 antibodies. Moreover, the mRNA expression of INOS, AKT, PI3K, TRAF6 and MyD88 was significantly suppressed by TLR2/TLR4 antibodies. These results indicated that LP4 induced macrophage activation mainly via the TLR2 and TLR4-induced PI3K/AKT and MyD88/TRAF6 pathways.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3550-3550
Author(s):  
Maciej Bogdan Maniecki ◽  
Mette Munk Lauridsen ◽  
Troels Bygum Knudsen ◽  
Jesper Stentoft ◽  
Bjarne Kuno Møller ◽  
...  

Abstract BACKGROUND: The monocyte/macrophage system plays important roles in host defense, regulation of immune responses, tissue repair, neovascularization, and inflammation. These diverse roles are performed by specific subpopulations of macrophages that are differently activated by surrounding stimuli, simplified by the M1-M2 dichotomy of classically activated (M1), pro-inflammatory cells and alternatively activated (M2), anti-inflammatory cells. Macrophages, however, display a large degree of flexibility and are able to switch between activation states (1) The hemoglobin scavenger receptor CD163 is expressed exclusively on monocytes and macrophages, and its expression is strongly induced by anti-inflammatory stimuli like IL10 and glucocorticoid, making CD163 an ideal M2 macrophage marker (2) Furthermore a soluble variant of CD163 (sCD163) is shed from the cell surface to plasma by protease mediated cleavage of the receptor. The shedding of sCD163 is dependent on a pro-inflammatory signal such as toll-like receptor (TLR) activation by LPS (3) These unique properties led us to investigate whether an index of combined soluble- and monocyte membrane CD163 could be used as a surrogate marker for macrophage activation. MATERIALS AND METHODS: Blood sample were obtained from 53 patients with malignant hematological disease and 74 healthy individuals. The cellular (mCD163) and soluble (sCD163) CD163 expression were measured by flow cytometry and ELISA respectively. In addition, blood mRNA expression of inflammatory markers (IL-1β, IL-6, IL-8, IL-10, and TNF-α) was determined by RT-qPCR. Normalized values of sCD163 and mCD163 were calculated by dividing each value by the median value of the healthy population. The MAcS-index was then calculated as the ratio between normalized sCD163 and normalized mCD163. A MAcS-index > 1 indicates relative increase in sCD163 as compared to mCD163, suggested to reflect a predominant M1 activation. RESULTS AND DISCUSSION: The MAcS-index of healthy individuals clustered around 1 (2.5–97.5 percentile: 0.28–3.11), whereas the MAcS-index of the patients varied from 0.06 to 5139, with 4% below the 2.5 % limit of healthy individuals, and 60% above the 97.5 upper limit of healthy individuals. The MAcS-index in infected patients (with assumed M1 activation) was clearly elevated: The index was significantly higher in patients with clinical signs of infection (median: 9.01; range: 1.41–3490) and patients in antibiotic therapy (median: 9.74; range: 0.91–5139) compared to non-infected patients (median: 2.53; range: 0.058–551.5, p<0.05) and non-treated patients (median: 0.97; range: 0.058– 450.8, p<0.0001), respectively. In contrast, patients in glucocorticoid treatment (assumed to drive an M2 activation phenotype) had significantly lower index (median: 1.1; range: 0.058–551) than patients without glucocorticoid treatment (median: 9.4; range: 0.57– 3490), p<0.05. mRNA expression analysis revealed that patients with MAcS-index above upper reference limit expressed higher levels of IL-1β, IL-6, IL-8, and TNF-α compared to patients with MAcS-index within reference range. Patients with malignant myeloma (median: 0.89; range: 0.63–1.51) had significantly lower MAcS-index than patients with AML (median: 20.71; range: 0.57–2214) (p<0.005) and lymphoma (median: 4.34; range 0.058–5139) (p<0.01), suggesting a differentiation towards an anti-inflammatory state. CONCLUSION: We present a CD163-derived macrophage activation switch (MAcS)- index, which seems able to differentiate between (predominantly) pro-inflammatory and anti-inflammatory macrophage activation. The index needs further validation, however, may be very useful for monitoring diseases with macrophage involvement and response to therapeutic interventions.


2004 ◽  
Vol 31 (S 1) ◽  
Author(s):  
A Hug ◽  
J Haas ◽  
A Viehöver ◽  
B Fritz ◽  
B Storch-Hagenlocher ◽  
...  

2007 ◽  
Vol 2 (04) ◽  
Author(s):  
P Tsiotra ◽  
C Tsigos ◽  
E Yfanti ◽  
E Anastasiou ◽  
SA Raptis

2019 ◽  
Vol 16 (3) ◽  
pp. 251-260 ◽  
Author(s):  
Elaine Wan Ling Chan ◽  
Emilia Tze Ying Yeo ◽  
Kelly Wang Ling Wong ◽  
Mun Ling See ◽  
Ka Yan Wong ◽  
...  

<P>Background: Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder that eventually leads to severe cognitive impairment. Although the exact etiologies of AD still remain elusive, increasing evidence suggests that neuroinflammation cascades mediated by microglial cells are associated with AD. Piper sarmentosum Roxb. (PS) is a medicinal plant reported to possess various biological properties, including anti-inflammatory, anti-psychotic and anti-oxidant activity. However, little is known about the anti-inflammatory activity of PS roots despite their traditional use to treat inflammatory- mediated ailments. Objective: This study aimed to evaluate the anti-inflammatory and neuroprotective properties of extracts obtained from the roots of PS against beta-amyloid (Aβ)-induced microglial toxicity associated with the production of pro-inflammatory mediators. Method: BV2 microglial cells were treated with hexane (RHXN), dichloromethane (RDCM), ethyl acetate (REA) and methanol (RMEOH) extracts of the roots of PS prior to activation by Aβ. The production and mRNA expression of pro-inflammatory mediators were evaluated by Griess reagent, ELISA kits and RT-qPCR respectively. The phosphorylation status of p38α MAPK was determined via western blot assay. BV2 conditioned medium was used to treat SH-SY5Y neuroblastoma cells and the neuroprotective effect was assessed using MTT assay. Results: PS root extracts, in particular RMEOH significantly attenuated the production and mRNA expression of IL-1β, IL-6 and TNF-α in Aβ-induced BV2 microglial cells. In addition, RHXN, REA and RMEOH extracts significantly reduced nitric oxide (NO) level and the inhibition of NO production was correlated with the total phenolic content of the extracts. Further mechanistic studies suggested that PS root extracts attenuated the production of cytokines by regulating the phosphorylation of p38α MAPK in microglia. Importantly, PS root extracts have protective effects against Aβ-induced indirect neurotoxicity either by inhibiting the production of NO, IL-1β, IL-6, and TNF-α in BV2 cells or by protecting SHSY5Y cells against these inflammatory mediators. Conclusions: These findings provided evidence that PS root extracts confer neuroprotection against Aβ- induced microglial toxicity associated with the production of pro-inflammatory mediators and may be a potential therapeutic agent for inflammation-related neurological conditions including Alzheimer’s disease (AD).</P>


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1230
Author(s):  
Sumin Pyeon ◽  
Ok-Kyung Kim ◽  
Ho-Geun Yoon ◽  
Shintae Kim ◽  
Kyung-Chul Choi ◽  
...  

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by immune hypersensitivity reaction. The cause of AD is unclear, but its symptoms have a negative effect on quality of life; various treatment methods to alleviate these symptoms are underway. In the present study, we aimed to evaluate in vitro antioxidant and anti-inflammatory effects of Rubus coreanus water extract (RCW) on AD. Total phenolic compounds and flavonoid content of RCW were 4242.40 ± 54.84 mg GAE/g RCE and 1010.99 ± 14.75 mg CE/g RCW, respectively. RCW reduced intracellular reactive oxygen species level and increased the action of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated HaCaT cells. Moreover, mRNA expression of the pro-inflammatory cytokines, including TNF-α, interleukin-1β, and interleukin-6, was downregulated by RCW in the TNF-α/IFN-γ-stimulated cells. The levels of inflammatory chemokines (thymus- and activation-regulated chemokine; eotaxin; macrophage-derived chemokine; regulated on activation, normal T-cell expressed and secreted; and granulocyte-macrophage colony-stimulating factor) and intercellular adhesion molecule-1 were decreased in the TNF-α/IFN-γ-stimulated HaCaT cells after RCW treatment. Additionally, the mRNA expression levels of filaggrin and involucrin, proteins that form the skin, were increased by RCW. Furthermore, RCW inhibited the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway in the TNF-α/IFN-γ-stimulated HaCaT cells. Collectively, the present investigation indicates that RCW is a potent substance that inhibits AD.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Daniel P Harris

TNF-α initiates the expression of genes involved in the recruitment, adhesion, and transmigration of leukocytes to sites of inflammation. Here, we report that the protein arginine methyltransferase PRMT5 is required for the transcriptional induction of the pro-inflammatory chemokine CXCL10 (IP-10) in endothelial cells. Depletion of PRMT5 by siRNA results in significantly diminished TNF-α-induced CXCL10 mRNA expression, but does not affect expression of other chemokines, such as MCP-1 or IL-8. Chromatin immunoprecipitation experiments of the CXCL10 proximal promoter show the presence of symmetrical dimethylated arginine (sDMA)-containing proteins upon exposure to TNF-α. This methylation is completely lost when PRMT5 is removed from cells by siRNA. Using immunoprecipitation, we show that PRMT5 enhances CXCL10 expression by methylating the RelA (p65) subunit of NF-κB. In summary, we have identified that PRMT5 is a novel regulator of CXCL10 expression. Further, we have discovered that PRMT5 methylates NF-κB, a finding which may further knowledge of the post-translational code governing NF-κB regulation and target specificity.


2009 ◽  
Vol 107 (3) ◽  
pp. 853-858 ◽  
Author(s):  
Christina M. Dieli-Conwright ◽  
Tanya M. Spektor ◽  
Judd C. Rice ◽  
E. Todd Schroeder

Hormone therapy (HT) is a potential treatment to relieve symptoms of menopause and prevent the onset of disease such as osteoporosis in postmenopausal women. We evaluated changes in markers of exercise-induced skeletal muscle damage and inflammation [serum creatine kinase (CK), serum lactate dehydrogenase (LDH), and skeletal muscle mRNA expression of IL-6, IL-8, IL-15, and TNF-α] in postmenopausal women after a high-intensity resistance exercise bout. Fourteen postmenopausal women were divided into two groups: women not using HT (control; n = 6, 59 ± 4 yr, 63 ± 17 kg) and women using traditional HT (HT; n = 8, 59 ± 4 yr, 89 ± 24 kg). Both groups performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on the Cybex dynamometer at 60°/s with 20-s rest periods between sets. Muscle biopsies of the vastus lateralis were obtained from the exercised leg at baseline and 4 h after the exercise bout. Gene expression was determined by RT-PCR for IL-6, IL-8, IL-15, and TNF-α. Blood draws were performed at baseline and 3 days after exercise to measure CK and LDH. Independent t-tests were performed to test group differences (control vs. HT). A probability level of P ≤ 0.05 was used to determine statistical significance. We observed significantly greater changes in mRNA expression of IL-6, IL-8, IL-15, and TNF-α ( P ≤ 0.01) in the control group compared with the HT group after the exercise bout. CK and LDH levels were significantly greater after exercise ( P ≤ 0.01) in the control group. Postmenopausal women not using HT experienced greater muscle damage after maximal eccentric exercise, indicating a possible protective effect of HT against exercise-induced skeletal muscle damage.


2002 ◽  
Vol 283 (3) ◽  
pp. R698-R709 ◽  
Author(s):  
Robert A. Frost ◽  
Gerald J. Nystrom ◽  
Charles H. Lang

The purpose of the present study was to examine the regulation of tumor necrosis factor (TNF)-α and interleukin (IL)-6 by lipopolysaccharide (LPS) in C2C12 myoblasts and mouse skeletal muscle. LPS produced dose- and time-dependent increases in TNF-α and IL-6 mRNA content in C2C12 myoblasts. The LPS-induced cytokine response could be mimicked by peptidoglycan from the cell wall of Staphylococcus aureus but not by zymosan A, a cell wall component from Saccharomyces cerevisiae. Ongoing protein synthesis was not necessary for the increase in the two cytokine mRNAs. The transcriptional inhibitor 5,6-dichloro-β-d-ribofuranosyl-benzimidazole blocked LPS-stimulated IL-6 mRNA expression without changing its mRNA half-life. The anti-inflammatory glucocorticoid dexamethasone selectively blocked LPS-stimulated IL-6 mRNA accumulation but not TNF-α. In contrast, the proteasomal inhibitor MG-132 blocked TNF-α mRNA expression but not IL-6. Exposure of myoblasts to LPS was associated with a rapid decrease in the inhibitor of nuclear factor-κB (I κB, α, and ε), and this response was also blocked by MG-132. Treatment of myocytes with IL-1 or TNF-α also increased IL-6 mRNA content, but the increase in IL-6 mRNA due to LPS could not be prevented by pretreatment with antagonists to either IL-1 or TNF. Under in vivo conditions, LPS increased the plasma concentration of TNF-α and IL-6 and stimulated the accumulation of their mRNAs in multiple tissues including skeletal muscle from wild-type mice. In contrast, the ability of LPS to stimulate the same cytokines was markedly decreased in mice that harbor a mutation in the Toll-like receptor 4. Our data suggest that LPS stimulates cytokine expression not only in classical immune tissues but also in skeletal muscle.


2019 ◽  
Vol 11 (16) ◽  
pp. 2081-2094 ◽  
Author(s):  
Tingting Guo ◽  
Zhenzhong Su ◽  
Qi Wang ◽  
Wei Hou ◽  
Junyao Li ◽  
...  

Aim: Thus far, the anti-inflammatory effect of vanillin in acute lung injury (ALI) has not been studied. This study aimed to investigate the effect of vanillin in lipopolysaccharide (LPS)-induced ALI. Results & methodology: Our study detected the anti-inflammatory effects of vanillin by ELISA and western blot, respectively. Pretreatment of mice with vanillin significantly attenuated LPS-stimulated lung histopathological changes, myeloperoxidase activity and expression levels of proinflammatory cytokines by inhibiting the phosphorylation activities of ERK1/2, p38, AKT and NF-κB p65. In addition, vanillin inhibited LPS-induced TNF-α and IL-6 expression in RAW264.7 cells via ERK1/2, p38 and NF-κB signaling. Conclusion: Vanillin can inhibit macrophage activation and lung inflammation, which suggests new insights for clinical treatment of ALI.


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