scholarly journals Terpenoids from Abies holophylla Attenuate LPS-Induced Neuroinflammation in Microglial Cells by Suppressing the JNK-Related Signaling Pathway

2021 ◽  
Vol 22 (2) ◽  
pp. 965
Author(s):  
Lalita Subedi ◽  
Silvia Yumnam

We have previously reported that phytochemicals from Abies holophylla exhibit anti-inflammatory and neuroprotective effects by decreasing nitrite production and increasing nerve growth factor production. However, the exact mechanism underscoring these effects has not been revealed. In the present study, we aimed to explore the underlying anti-inflammatory mechanisms of A. holophylla and its phytochemicals. We studied various solvent fractions of A. holophylla and found the chloroform and hexane sub-fractions showed the most significant anti-neuroinflammatory effects in lipopolysaccharide (LPS)-activated murine microglia. Concomitantly, the terpenoids isolated from chloroform and hexane fractions showed similar anti-neuroinflammatory effects with significant inhibition of NO and reactive oxygen species production, and decreased protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase. Interestingly, these terpenoids inhibited the phosphorylation of c-Jun N-terminal kinase (JNK), which further inhibited the production of pro-inflammatory mediators, including prostaglandin E2, tumor necrosis factor, and interleukins (IL-6 and IL-1β), with a potency greater than that of the well-known iNOS inhibitor NG-mono-methyl-L-arginine (L-NMMA). These results suggest that the chloroform- and hexane-soluble fraction mediated the mitogen-activated protein kinase (MAPK) inhibition, in particular the JNK pathway, thereby lowering the inflammatory cascades in LPS-activated murine microglia. Thus, our study suggests that the chloroform and hexane fractions of A. holophylla and their terpenoids may be potential drug candidates for drug discovery against LPS-induced neuroinflammation and neuroinflammatory-related neurodegeneration.

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Manman Wang ◽  
Jiao Li ◽  
Jiageng Cai ◽  
Lijun Cheng ◽  
Xuewen Wang ◽  
...  

Background. Our previous study demonstrated that the expression of miR-16 was downregulated in the cell and animal models of atherosclerosis (AS), a main contributor to coronary artery disease (CAD). Overexpression of miR-16 inhibited the formation of foam cells by exerting anti-inflammatory roles. These findings indicated miR-16 may be an anti-atherogenic and CAD miRNA. The goal of this study was to further validate the expression of miR-16 in CAD patients and explore its therapeutic roles in an AS animal model. Methods. A total of 40 CAD patients and 40 non-CAD people were prospectively registered in our study. The AS model was established in ApoE-/- mice fed a high-fat diet. The model mice were randomly treated with miR-16 agomiR (n=10) or miR-negative control (n=10). Hematoxylin-eosin staining was conducted for histopathological examination in thoracic aorta samples. ELISA and immunohistochemistry were performed to determine the expression levels of inflammatory factors (IL-6, TNF-α, MCP-1, IL-1β, IL-10, and TGF-β). qRT-PCR and western blotting were carried out to detect the mRNA and protein expression levels of PDCD4, miR-16, and mitogen-activated protein kinase pathway-related genes. Results. Compared with the normal control, miR-16 was downregulated in the plasma and peripheral blood mononuclear cell of CAD patients, and its expression level was negatively associated with IL-6 and the severity of CAD evaluated by the Gensini score, but positively related with IL-10. Injection of miR-16 agomiR in ApoE-/- mice reduced the formation of atherosclerotic plaque and suppressed the accumulation of proinflammatory factors (IL-6, TNF-α, MCP-1, and IL-1β) in the plasma and tissues but promoted the secretion of anti-inflammatory factors (IL-10 and TGF-β). Mechanism analysis showed overexpression of miR-16 might downregulate target mRNA PDCD4 and then activate p38 and ERK1/2, but inactivate the JNK pathway. Conclusions. Our findings suggest miR-16 may be a potential diagnostic biomarker and therapeutic target for atherosclerotic CAD.


2013 ◽  
Vol 111 (3) ◽  
pp. 452-464 ◽  
Author(s):  
Gina Cecilia Pistol ◽  
Mihail Alexandru Gras ◽  
Daniela Eliza Marin ◽  
Florentina Israel-Roming ◽  
Mariana Stancu ◽  
...  

Zearalenone (ZEA) is an oestrogenic mycotoxin produced byFusariumspecies, considered to be a risk factor from both public health and agricultural perspectives. In the presentin vivostudy, a feeding trial was conducted to evaluate thein vivoeffect of a ZEA-contaminated diet on immune response in young pigs. The effect of ZEA on pro-inflammatory (TNF-α, IL-8, IL-6, IL-1β and interferon-γ) and anti-inflammatory (IL-10 and IL-4) cytokines and other molecules involved in inflammatory processes (matrix metalloproteinases (MMP)/tissue inhibitors of matrix metalloproteinases (TIMP), nuclear receptors: PPARγ and NF-κB1, mitogen-activated protein kinases (MAPK): mitogen-activated protein kinase kinase kinase 7 (TAK1)/mitogen-activated protein kinase 14 (p38α)/mitogen-activated protein kinase 8 (JNK1)/ mitogen-activated protein kinase 9 (JNK2)) in the liver of piglets was investigated. The present results showed that a concentration of 316 parts per billion ZEA leads to a significant decrease in the levels of pro- and anti-inflammatory cytokines at both gene expression and protein levels, correlated with a decrease in the levels of other inflammatory mediators, MMP and TIMP. The results also showed that dietary ZEA induces a dramatic reduction in the expressions ofNF-κB1andTAK1/p38αMAPK genes in the liver of the experimentally intoxicated piglets, and has no effect on the expression ofPPARγmRNA. The present results suggest that the toxic action of ZEA begins in the upstream of the MAPK signalling pathway by the inhibition of TAK1, a MAPK/NF-κB activator. In conclusion, the present study shows that ZEA alters several important parameters of the hepatic cellular immune response. From an economic point of view, these data suggest that, in pigs, ZEA is not only a powerful oestrogenic mycotoxin but also a potential hepatotoxin when administered through the oral route. Therefore, the present results represent additional data from cellular and molecular levels that could be taken into account in the determination of the regulation limit of the tolerance to ZEA.


2007 ◽  
Vol 405 (3) ◽  
pp. 617-623 ◽  
Author(s):  
Emma V. Jones ◽  
Mark J. Dickman ◽  
Alan J. Whitmarsh

The JNK (c-Jun N-terminal kinase)/mitogen-activated protein kinase signalling pathway is a major mediator of stress responses in cells, including the response to DNA damage. DNA damage also causes the stabilization and activation of p73, a member of the p53 family of transcription factors. p73, like p53, can mediate apoptosis by up-regulating the expression of pro-apoptotic genes, including Bax (Bcl2-associated X protein) and PUMA (p53 up-regulated modulator of apoptosis). Changes in p73 expression have been linked to tumour progression, particularly in neuroblastomas, whereas in tumours that feature inactivated p53 there is evidence that p73 may mediate the apoptotic response to chemotherapeutic agents. In the present study, we demonstrate a novel link between the JNK signalling pathway and p73. We use pharmacological and genetic approaches to show that JNK is required for p73-mediated apoptosis induced by the DNA damaging agent cisplatin. JNK forms a complex with p73 and phosphorylates it at several serine and threonine residues. The mutation of JNK phosphorylation sites in p73 abrogates cisplatin-induced stabilization of p73 protein, leading to a reduction in p73 transcriptional activity and reduced p73-mediated apoptosis. Our results demonstrate that the JNK pathway is an important regulator of DNA damage-induced apoptosis mediated by p73.


2017 ◽  
Vol 43 (2) ◽  
pp. 540-552 ◽  
Author(s):  
Hany H. Arab ◽  
Samir A. Salama ◽  
Tamer M. Abdelghany ◽  
Hany A. Omar ◽  
El-Shaimaa A. Arafa ◽  
...  

Background/Aims: Camel milk (CM) has shown beneficial anti-inflammatory actions in several experimental and clinical settings. So far, its effect on rheumatoid arthritis (RA) has not been previously explored. Thus, the current work aimed to evaluate the effects of CM in Adjuvant-induced arthritis and air pouch edema models in rats, which mimic human RA. Methods: CM was administered at 10 ml/kg orally for 3 weeks starting on the day of Freund’s adjuvant paw inoculation. The levels of TNF-α and IL-10 were measured by ELISA while the protein expression of NF-κBp65, COX-2 and iNOS was detected by immunohistochemistry. The expression of MAPK target proteins was assessed by Western blotting. Results: CM attenuated paw edema, arthritic index and gait score along with dorsal pouch inflammatory cell migration. CM lowered the TNF-α and augmented the anti-inflammatory IL-10 levels in sera and exudates of arthritic rats. It also attenuated the expression of activated NF-κBp65, COX-2 and iNOS in the lining of the dorsal pouch. Notably, CM inhibited the MAPK pathway signal transduction via lowering the phosphorylation of p38 MAPK, ERK1/2 and JNK1/2 in rat hind paws. Additionally, CM administration lowered the lipid peroxide and nitric oxide levels and boosted glutathione and total anti-oxidant capacity in sera and exudates of animals. Conclusion: The observed CM downregulation of the arthritic process may support the interest of CM consumption as an adjunct approach for the management of RA.


10.1038/74680 ◽  
2000 ◽  
Vol 6 (4) ◽  
pp. 422-428 ◽  
Author(s):  
Leo E. Otterbein ◽  
Fritz H. Bach ◽  
Jawed Alam ◽  
Miguel Soares ◽  
Hong Tao Lu ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jia Tang ◽  
Takashi Saito

Aim. To analyze the effect of three mitogen-activated protein kinase (MAPK) inhibitors, namely, SB202190 (p38 inhibitor), SP600125 (JNK inhibitor), and PD98059 (ERK inhibitor) in Dex-stimulated MDPC-23 cell differentiation and mineralization. Methods. Experiment was divided into five groups, control (cells without Dex and inhibitors treatment), Dex (cells with Dex treatment but without inhibitors), Dex + SB202190, Dex + SP600125, and Dex + PD98059. Cell differentiation was assessed by alkaline phosphatase (ALP) activity assay and real time RT-PCR. Cell mineralization was investigated by alizarin red staining. Results. Exposure to SB202190 (20 μM) significantly decreased the mineral deposition in Dex-treated cells as demonstrated by alizarin red staining. Treatment of SP600125 (20 μM) attenuated the mineralization as well, albeit at a lower degree as compared to SB202190 (20 μM). Similarly, SB202190 (20 μM) completely abrogated the ALP activity stimulated by Dex at six days in culture, while no changes were observed with regard to ALP activity in SP600125 (20 μM) and PD98059 (20 μM) treated cells. The upregulation of bone sialoprotein (BSP), ALP, and osteopontin (OPN) in Dex challenged cells was completely inhibited by SB202190. Conclusion. Blockade of p38-MAPK signaling pathway resulted in significant inhibition of ALP activity, mineralization, and downregulation of osteogenic markers. The data implicated that p38 signaling pathway plays a critical role in the regulation of MDPC-23 cells differentiation and mineralization.


Open Biology ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 180256 ◽  
Author(s):  
Noelia Pinal ◽  
Manuel Calleja ◽  
Ginés Morata

The Jun N-terminal kinase (JNK) is a member of the mitogen-activated protein kinase family. It appears to be conserved in all animal species where it regulates important physiological functions involved in apoptosis, cell migration, cell proliferation and regeneration. In this review, we focus on the functions of JNK in Drosophila imaginal discs, where it has been reported that it can induce both cell death and cell proliferation. We discuss this apparent paradox in the light of recent findings and propose that the pro-apoptotic and the pro-proliferative functions are intrinsic properties of JNK activity. Whether one function or another is predominant depends on the cellular context.


2020 ◽  
Vol 150 (7) ◽  
pp. 1731-1737
Author(s):  
Qi Xu ◽  
Ziyu Chen ◽  
Borong Zhu ◽  
Gaorui Wang ◽  
Qi Jia ◽  
...  

ABSTRACT Background Parkinson's disease (PD) is a common neurodegenerative disorder. Cinnamon procyanidin oligomers (CPOs) are flavonoids with many claimed health benefits. Objective This study aimed to elucidate the neuroprotection of A-type CPOs (CPO-A) and the underlying mechanisms in cultured cell and animal models of PD. Methods Thirty male mice (C57BL/6, 9-wk old) were assigned to 3 groups (n = 10), and were given daily gavage of saline [control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) groups] or CPO-A (150 mg/kg, CPO-A group) during days 1–15 and daily intraperitoneal injections of saline (control group) or MPTP (20 mg/kg; MPTP and MPTP + CPO-A groups) during days 11–15. After the motor behavior test, all mice were killed on day 16 to collect the substantia nigra (SN) for assaying the neuroprotective effects of CPO-A. SH-SY5Y cells were treated with 12.5 μM CPO-A for 2 h or 3 activators of stress-related kinases (5–25 μM) for 12–48 h followed by 1 mM 1-methyl-4-phenylpyridinium (MPP+) for assays of viability, morphology, and stress status. Results Compared with the control, the MPTP treatment decreased (P < 0.05) locomotor activity by 21%, and tyrosine hydroxylase (TH) positive neurons by 55% and Th mRNA concentration by 51% in the SN. The CPO-A treatment attenuated or restored (P < 0.05) these changes and inhibited (P < 0.05) the MPTP-induced activation of P38 mitogen-activated protein kinase (P38MAPK) and P53, along with the downstream expression of BCL-2 associated X protein (BAX) in the SN. In SH-SY5Y cells, the CPO-A treatment blocked (P < 0.01) the MPP+-induced accumulation of intracellular reactive oxygen species and neurotoxicity. However, this protection was abolished (P < 0.05) by activators of the P38MAPK/P53/BAX pathway. Conclusion CPO-A protected against MPP+-induced cytotoxicity in SH-SY5Y cells and MPTP-induced neurotoxicity in mice by regulating the P38MAPK/P53/BAX signaling. Our findings reveal a novel role and mechanism of a food flavonoid CPO-A in preventing neurodegeneration.


2017 ◽  
Vol 45 (04) ◽  
pp. 847-861 ◽  
Author(s):  
Chia-Yang Li ◽  
Katsuhiko Suzuki ◽  
Yung-Li Hung ◽  
Meng-Syuan Yang ◽  
Chung-Ping Yu ◽  
...  

Aloe, a polyphenolic anthranoid-containing Aloe vera leaves, is a Chinese medicine and a popular dietary supplement worldwide. In in vivo situations, polyphenolic anthranoids are extensively broken down into glucuronides and sulfate metabolites by the gut and the liver. The anti-inflammatory potential of aloe metabolites has not been examined. The aim of this study was to investigate the anti-inflammatory effects of aloe metabolites from in vitro (lipopolysaccharides (LPS)-activated RAW264.7 macrophages) and ex vivo (LPS-activated peritoneal macrophages) to in vivo (LPS-induced septic mice). The production of proinflammatory cytokines (TNF-[Formula: see text] and IL-12) and NO was determined by ELISA and Griess reagents, respectively. The expression levels of iNOS and MAPKs were analyzed by Western blot. Our results showed that aloe metabolites inhibited the expression of iNOS, decreased the production of TNF-[Formula: see text], IL-12, and NO, and suppressed the phosphorylation of MAPKs by LPS-activated RAW264.7 macrophages. In addition, aloe metabolites reduced the production of NO, TNF-[Formula: see text] and IL-12 by murine peritoneal macrophages. Furthermore, aloe administration significantly reduced the NO level and exhibited protective effects against sepsis-related death in LPS-induced septic mice. These results suggest that aloe metabolites exerted anti-inflammatory effects in vivo, and that these effects were associated with the inhibition of inflammatory mediators. Therefore, aloe could be considered an effective therapeutic agent for the treatment of sepsis.


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