scholarly journals Astragalus membranaceus Injection Suppresses Production of Interleukin-6 by Activating Autophagy through the AMPK-mTOR Pathway in Lipopolysaccharide-Stimulated Macrophages

2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Xiaoyan Zhang ◽  
Taigang Liang ◽  
Wanxia Yang ◽  
Lanfang Zhang ◽  
Shuting Wu ◽  
...  

Astragalus membranaceus (AM), used in traditional Chinese medicine, has been shown to enhance immune functions, and recently, its anti-inflammatory effects were identified. However, the mechanisms of action remain unclear. Most studies have shown that autophagy might be involved in the immune response of the body, including inflammation. Here, we developed an inflammatory model by stimulating macrophages with lipopolysaccharides (LPS) to explore the anti-inflammatory effect and mechanisms of AM injection from the perspective of the regulation of autophagy. Immunoblot, immunofluorescence, and ELISA were used to determine the effects of AM injection on the production of interleukin-6 (IL-6) and alterations of autophagy markers. It was found that AM injection reduced the expression of IL-6 in LPS-stimulated macrophages and reversed the LPS-induced inhibition of cellular autophagy. After treatment with inhibitors of signaling pathways, it was shown that LPS downregulated autophagy and upregulated the production of IL-6 in macrophages via the protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. AM injection reversed the effects of LPS by activating the AMP-activated protein kinase (AMPK) instead of inhibiting Akt. These results were further confirmed by testing activators and siRNA silencing of AMPK. Hence, these 2 distinct signaling molecules appear to exert opposite effects on mTOR, which integrates information from multiple upstream signaling pathways, negatively regulating autophagy. In addition, we demonstrated that autophagy might play a key role in regulating the production of IL-6 by testing activators and inhibitors of autophagy and siRNA silencing of ATG5. These findings showed that AM injection might enhance autophagy by activating AMPK and might further play a repressive effect on the LPS-stimulated expression of IL-6. This study explored the relationship between autophagy, signaling pathways, and the production of inflammatory factors in a model of endotoxin infection and treatment with AM injection.

Author(s):  
Jingshuang Li ◽  
Hui Wang ◽  
Lili Zhang ◽  
Ni An ◽  
Wan Ni ◽  
...  

Abstract. Capsaicin, the main constituent in chili, is an extremely spicy vanillin alkaloid and is found in several Capsicum species in China. Traditionally, it has been used to treat inflammatory diseases such as allergic rhinitis, neuralgia after shingles, refractory female urethral syndrome, spontaneous recalcitrant anal pruritus, and solid tumors. Constant stimulation of the body by inflammatory factors can lead to chronic inflammation. Capsaicin possesses anti-inflammatory activity; however, the underlying mechanism is unknown. We investigated the effect of capsaicin on the secretion of macrophage inflammatory factors in a lipopolysaccharide-induced inflammation model using 56 healthy, SPF grade, BALB/c mice. To this end, mice peritoneal macrophages were isolated and stimulated with lipopolysaccharide (1 μg/mL) and capsaicin (25, 50, 75, or 100 μg/mL) for 24 h. At all concentrations tested, capsaicin significantly promoted the phagocytosis of neutral red dye by macrophages. Furthermore, the gene expression and secretion of inflammatory cytokines significantly increased after induction with lipopolysaccharide (P<0.01); the interleukin (IL)-6 level was 204 μg/mL, tumor necrosis factor (TNF)-α level was 860 μg/mL, and nitric oxide (NO) level was 19.8 μg/mL. However, the treatment with capsaicin reduced their levels (P<0.01) and protein expression of lipopolysaccharide-induced extracellular signal-related kinase 1/2 and p65 (P<0.05). Overall, capsaicin reduced the secretion of inflammatory cytokines (P<0.01), interleukins, TNF-α (P<0.01), and NO by inhibiting the nuclear factor-kappa B and microtubule-associated protein kinase signaling pathways, and thereby reduced lipopolysaccharide-induced inflammatory response in macrophages.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiyue Zhang ◽  
Li Du ◽  
Jinrong Zhang ◽  
Chunyan Li ◽  
Jie Zhang ◽  
...  

Acute lung injury (ALI) is a respiratory disease that leads to death in severe cases. Hordenine (Hor), a barley-derived natural product, has various biological activities, including anti-inflammatory, and anti-oxidation activities. We investigated the effect of Hor on lipopolysaccharide-induced ALI and its potential mechanism. The anti-inflammatory effects of Hor were detected using in vivo and in vitro models by enzyme-linked immunosorbent assay, real-time polymerase chain reaction, western blotting, and molecular docking simulations. Hor inhibited increases in the levels of inflammatory factors both in vivo and in vitro, and its anti-inflammatory effect inhibited activation of protein kinase B, nuclear factor-κB, and mitogen-activated protein kinase signaling. Hor alleviated lipopolysaccharide-induced ALI by inhibiting inflammatory cytokine increases in vivo and in vitro and shows potential for preventing inflammatory disease.


2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Haiyan Wang ◽  
Xue Lin ◽  
Xiaoyan Pu

Abstract Background The lung is an important target organ for hypoxia treatment, and hypoxia can induce several diseases in the body. Methods We performed transcriptome sequencing for the lungs of rats exposed to plateau hypoxia at 0 day and 28 days. Sequencing libraries were constructed, and enrichment analysis of the differentially expressed genes (DEGs) was implemented using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, experimental validation was executed by quantitative real-time PCR (qRT-PCR) and western blot. Results The results showed that the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) signaling pathway that was involved in immunity may play a crucial function in lung injury caused by plateau hypoxia. And the expressions of NOD1, NOD2, IL-1β, TNF-α, IL-6, and IL-18 were higher at 28 days of exposure to plateau hypoxia than that at 0 day. Similarly, CARD9, MYD88, p38 MAPK, and NF-κB p65, which are related to the NF-κB and MAPK signaling pathways, also demonstrated increased expression at 28 days exposure to plateau hypoxia than at 0 day. Conclusions Our study suggested that the NF­κBp65 and p38 MAPK signaling pathways may be activated in the lungs of rats during plateau hypoxia. Upregulated expression of NF­κBp65 and p38 MAPK can promote the transcription of downstream inflammatory factors, thereby aggravating the occurrence and development of lung tissue remodeling.


Marine Drugs ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 127
Author(s):  
Xing-Wei Xiang ◽  
Xiao-Ling Zhou ◽  
Rui Wang ◽  
Cong-Han Shu ◽  
Yu-Fang Zhou ◽  
...  

Bioactive peptides isolated from marine organisms have shown to have potential anti-inflammatory effects. This study aimed to investigate the intestinal protection effect of low molecular peptides (Mw < 1 kDa) produced through enzymatic hydrolysis of tuna processing waste (tuna bioactive peptides (TBP)) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in BALB/c mice. Here, we randomly divided twenty-four male BALB/c mice into four groups: (i) normal (untreated), (ii) DSS-induced model colitis, (iii) low dose TBP+DSS-treated (200 mg/kg/d), and (iv) high dose TBP+DSS-treated groups (500 mg/kg/d). The results showed that TBP significantly reduced mice weight loss and improved morphological and pathological characteristics of colon tissues. In addition, it increased the activities of antioxidant enzymes (SOD and GSH-Px) and decreased inflammatory factors (LPS, IL-6, and TNF-α) expression. TBP increased the gene expression levels of some tight junction (TJ) proteins. Moreover, TBP increased the short-chain fatty acids (SCFAs) levels and the diversity and imbalance of intestinal flora. Therefore, TBP plays some protective roles in the intestinal tract by enhancing antioxidant and anti-inflammatory abilities of the body, improving the intestinal barrier and metabolic abnormalities, and adjusting intestinal flora imbalance.


2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110209
Author(s):  
Yun Sil Kang ◽  
You Chul Chung ◽  
Jung No Lee ◽  
Bong Seok Kim ◽  
Chang-Gu Hyun

Coumarin derivatives, such as esculetin, have various physiological functions, including antioxidant, anti-inflammatory, antibacterial, antiviral, and anti-cancer. 6,7-Dihydroxy-4-methylcoumarin (6,7-DH-4MC) is a derivative of esculetin, and its anti-inflammatory effect and mechanism in macrophages have not been studied. In this study, the anti-inflammatory activity of 6,7-DH-4MC was evaluated by measuring the expression of inflammatory factors (NO and PGE2) and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in LPS-stimulated RAW 264.7 macrophages. The results revealed that 6,7-DH-4MC significantly reduced NO levels and PGE2 expression without inducing cytotoxicity; it was confirmed that the inhibition of NO and PGE2 expression was related to iNOS and COX-2 downregulation in response to 6,7-DH-4MC treatment. Moreover, 6,7-DH-4MC decreased the levels of pro-inflammatory cytokines, such as IL-1β and IL-6, in a dose-dependent manner. Mechanistic studies revealed reduced phosphorylation of ERK and p38-MAPK upon 6,7-DH-4MC treatment. Furthermore, the degradation of IκB-α and phosphorylation of NF-κB in cells treated with LPS were interrupted by 6,7-DH-4MC treatment. These results suggest that 6,7-DH-4MC is a potential therapeutic agent for inflammatory diseases. To the best of our knowledge, this is the first report demonstrating the anti-inflammatory effects of 6,7-DH-4MC in RAW 264.7 cells via MAPK and NF-κB signaling pathways.


2020 ◽  
Vol 12 ◽  
Author(s):  
Rakesh Kumar Chauhan ◽  
Pramod Kumar Sharma ◽  
Shikha Srivastava

Abstract:: Rheumatoid Arthritis is a chronic progressive inflammatory auto-immune disease in which the immune system of the body attacks its cartilage and joints lining. It not only affects synovial joints but also many other sites including heart, blood vessels, and skins. It is more common in females than in males. The exact cause of rheumatoid arthritis is not well established but the hypothesis reported in the literature is that in the development stage of the disease, both genetics and environmental factors can play an inciting role. Along with these factors alteration in the normal physiology of enzymatic action, acts as a trigger to develop this condition. Numerous signaling pathways involved in the pathogenesis of Rheumatoid Arthritis involves activation of mitogen-activated protein kinase, kinases Janus family, P-38 Mitogen-Activated Protein Kinase, Nuclear Factor-kappa B. Interleukin-1 to play a proinflammatory cytokine that plays an important role in inflammation in RA. These are also associated with an increase in neutrophil, macrophage and lymphocytic chemotaxis, mast cell degranulation, activation, maturation and survival of T-cells and B-cells activated. These signaling pathways also show that p38α downregulation in myeloid cells exacerbates the severity of symptoms of arthritis. Thus, present review carters about the detail of different signaling pathways and their role in rheumatoid arthritis.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3690-3690
Author(s):  
Matthias Krusch ◽  
Julia Salih ◽  
Ingrid Kumbier ◽  
Carolin Fenner ◽  
Lothar Kanz ◽  
...  

Abstract Abstract 3690 Poster Board III-626 The phosphatidylinositol 3-kinase – protein kinase B – mammalian target of rapamycin (PI3K – AKT – mTOR) pathway was found to be abnormally activated in many malignancies. Thus, protein kinase (PK) inhibitors (PKI) targeting different signaling molecules of this pathway are presently under clinical evaluation e.g. in sarcoma, multiple myeloma, or renal cell cancer. However, PK are also responsible for most of the signal transduction in immune effector cells and control various effector mechanisms including proliferation, cellular cytotoxicity, and cytokine release. Among those immunoregulatory signaling pathways, the PI3K – AKT – mTOR pathway was found to play a central role in TLR-mediated release of cytokines in macrophages and DC as well as in the regulation of T cell functions. Little is known about the role of this pathway in NK cell-mediated anti-tumor reactivity. Here we analyzed the tumor cell-induced activation of PI3K, AKT, and mTOR in NK cells and the consequences of an inhibition of these molecules by therapeutic PKI for NK cell anti-tumor reactivity. We found that, in response to tumor target cells, PI3K, AKT, and mTOR are consecutively activated in NK cells as revealed by western blot analyses using phospho-specific antibodies. Presence of the specific PI3K-inhbitor BKM-120 concentration-dependently inhibited cytotoxicity and IFN-g production of NK cells, which is in line with available data defining PI3K as a central regulator of NK cell target recognition. The mTOR inhibitors Sirolimus, Temsirolimus, and Everolimus did not alter cytotoxicity but significantly impaired NK cell IFN-γ production. In contrast, Triciribine, a compound which inhibits the phosphorylation and thus activation of AKT, did not influence cytotoxicity and, tantalizingly, even enhanced NK cell IFN-γ production. Thus, after target cell recognition and the activation of proximal PK like PI3K, different and at least partially independent signaling events govern NK cell cytokine production and cellular cytotoxicity. While the activity of PI3K followed by the activation of mitogen-activated PK is known to be crucial for NK cell cytotoxicity, we here identified the AKT – mTOR pathway as a yet unknown central component in the regulation of NK cell IFN-γ production. Moreover, in light of the important role of NK cells in tumor immune surveillance our data indicate that the choise and dosing of the most suitable PKI for a given cancer patient requires careful consideration. In the future it will be critical to define potential differences in immunosuppressive and immunostimulatory side effects of different compounds among the rapidly growing assortment of multi-targeted PKI to enable therapeutic approaches combining targeting of crucial signaling pathways in tumor cells with immunotherapy. Disclosures: No relevant conflicts of interest to declare.


2014 ◽  
Vol 194 (2) ◽  
pp. 584-594 ◽  
Author(s):  
Yanfang Peipei Zhu ◽  
Jonathan R. Brown ◽  
Duygu Sag ◽  
Lihua Zhang ◽  
Jill Suttles

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