scholarly journals Interactions of TLR4 and PPARγ, Dependent on AMPK Signalling Pathway Contribute to Anti-Inflammatory Effects of Vaccariae Hypaphorine in Endothelial Cells

2017 ◽  
Vol 42 (3) ◽  
pp. 1227-1239 ◽  
Author(s):  
Haijian Sun ◽  
Xuexue Zhu ◽  
Wei Lin ◽  
Yuetao Zhou ◽  
Weiwei Cai ◽  
...  

Background /Aims: Accumulating evidence indicates that endothelial inflammation is one of the critical determinants in pathogenesis of atherosclerotic cardiovascular disease. Our previous studies had demonstrated that Vaccariae prevented high glucose or oxidative stress-triggered endothelial dysfunction in vitro. Very little is known about the potential effects of hypaphorine from Vaccariae seed on inflammatory response in endothelial cells. Methods: In the present study, we evaluated the anti-inflammatory effects of Vaccariae hypaphorine (VH) on lipopolysaccharide (LPS)-challenged endothelial EA.hy926 cells. The inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein 1 (MCP-1) and vascular cellular adhesion molecule-1 (VCAM-1) were measured by real-time PCR (RT-PCR). The expressions of adenosine monophosphate-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), toll-like receptor 4 (TLR4), peroxisome proliferator-activated receptor γ (PPARγ) were detected by Western blotting or immunofluorescence. Results: We showed that LPS stimulated the expressions of TNF-α, IL-1β, MCP-1, VCAM-1 and TLR4, but attenuated the phosphorylation of AMPK and ACC as well as PPARγ protein levels, which were reversed by VH pretreatment. Moreover, we observed that LPS-upregulated TLR4 protein expressions were inhibited by PPARγ agonist pioglitazone, and the downregulated PPARγ expressions in response to LPS were partially restored by knockdown of TLR4. The negative regulation loop between TLR4 and PPARγ response to LPS was modulated by AMPK agonist AICAR (5-Aminoimidazole-4-carboxamide riboside or acadesine) or A769662. Conclusions: Taken together, our results suggested that VH ameliorated LPS-induced inflammatory cytokines production in endothelial cells via inhibition of TLR4 and activation of PPARγ, dependent on AMPK signalling pathway.

2004 ◽  
Vol 24 (19) ◽  
pp. 8691-8704 ◽  
Author(s):  
Masashi Akaike ◽  
Wenyi Che ◽  
Nicole-Lerner Marmarosh ◽  
Shinsuke Ohta ◽  
Masaki Osawa ◽  
...  

ABSTRACT Peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors that form a subfamily of the nuclear receptor gene family. Since both flow and PPARγ have atheroprotective effects and extracellular signal-regulated kinase 5 (ERK5) kinase activity is significantly increased by flow, we investigated whether ERK5 kinase regulates PPARγ activity. We found that activation of ERK5 induced PPARγ1 activation in endothelial cells (ECs). However, we could not detect PPARγ phosphorylation by incubation with activated ERK5 in vitro, in contrast to ERK1/2 and JNK, suggesting a role for ERK5 as a scaffold. Endogenous PPARγ1 was coimmunoprecipitated with endogenous ERK5 in ECs. By mammalian two-hybrid analysis, we found that PPARγ1 associated with ERK5a at the hinge-helix 1 region of PPARγ1. Expressing a hinge-helix 1 region PPARγ1 fragment disrupted the ERK5a-PPARγ1 interaction, suggesting a critical role for hinge-helix 1 region of PPARγ in the ERK5-PPARγ interaction. Flow increased ERK5 and PPARγ1 activation, and the hinge-helix 1 region of the PPARγ1 fragment and dominant negative MEK5β significantly reduced flow-induced PPARγ activation. The dominant negative MEK5β also prevented flow-mediated inhibition of tumor necrosis factor alpha-mediated NF-κB activation and adhesion molecule expression, including vascular cellular adhesion molecule 1 and E-selectin, indicating a physiological role for ERK5 and PPARγ activation in flow-mediated antiinflammatory effects. We also found that ERK5 kinase activation was required, likely by inducing a conformational change in the NH2-terminal region of ERK5 that prevented association of ERK5 and PPARγ1. Furthermore, association of ERK5a and PPARγ1 disrupted the interaction of SMRT and PPARγ1, thereby inducing PPARγ activation. These data suggest that ERK5 mediates flow- and ligand-induced PPARγ activation via the interaction of ERK5 with the hinge-helix 1 region of PPARγ.


Circulation ◽  
2015 ◽  
Vol 131 (suppl_2) ◽  
Author(s):  
Fu-Chen Huang Huang ◽  
Ho-Chang Kuo ◽  
Hong-Ren Yu

Kawasaki disease (KD) is an acute febrile vasculitis of childhood and is the leading cause of acquired heart disease in children in the developed world. If untreated, KD can result in coronary aneurysms in 25% of patients, who are at risk of myocardial infarction, sudden death, and congestive heart failure. Despite the success, 10-20% of children will have persistent or recrudescent fever after their first infusion of IVIG. These patients are at increased risk of developing coronary artery abnormalities. Additional therapies should be explored to decrease the incidence of coronary arteritis complication and improve the prognosis in Kawasaki disease. Induced autophagy with resveratrol confers cardioprotection during ischemia and reperfusion in rats. KD is associated with elevated production of inflammatory cytokines, causing damage to the coronary arteries. Serum TNF-alpha levels are elevated in KD, which was supposed to activate the endothelial cells. As a result, adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cellular adhesion molecule-1(VCAM-1) are expressed in the endothelial cells, and leucocytes adhere firmly to endothelial cells. The leucocytes then damage the endothelial cells and smooth muscle cells and cause vasculitis. In this study, we examined the anti-inflammatory effects of resveratrol on TNF-alpha-induced adhesion molecule expression (VCAM-1 and ICAM-1) and cytokine production (interleukin (IL)-1beta, IL-6 and IL-8) in HCAECs. Pretreatment with resveratrol significantly inhibited TNF-alpha-induced adhesion molecules and cytokines production in HCAECs via the activation of autophagy. Our results suggest that adjunctive resveratrol therapy may modulate the inflammatory response during KD vasculitis and explore the role of autophagy in the pathogenesis of the complication and the promising therapy.


2013 ◽  
Vol 41 (05) ◽  
pp. 1065-1077 ◽  
Author(s):  
Christian Stumpf ◽  
Quiaoling Fan ◽  
Christian Hintermann ◽  
Dorette Raaz ◽  
Ingrid Kurfürst ◽  
...  

Inflammation plays a crucial role in the pathophysiology of atherosclerosis. Besides cytokines, chemokines and cell adhesion molecules, CD40 and P-selectin play important roles as key regulators of the inflammatory process in atherosclerosis. Danshen (DS) is commonly used in traditional Chinese medicine for therapy of cardiovascular diseases such as coronary artery disease. The aim of the present study was to evaluate the protective effects of DS with respect to possible anti-inflammatory effects. Human umbilical vein endothelial cells as well as platelets were incubated with an extract of DS or one of its major ingredients salvianolic acid B (Sal B), tanshinone IIA (Tansh) and protocatechuic acid (Protoc) under tumor necrosis factor (TNF)-α or ADP stimulation. Expression of CD40 and cellular adhesion molecules (VCAM-1/ICAM-1) were assessed via flow cytometry. Levels of interleukin (IL)-6, IL-8, monocyte-chemoattractant-protein (MCP)-1 as well as soluble VCAM1 and ICAM-1 in the supernatants were examined via luminex based analysis. Treatment with DS attenuated TNF-α induced expression of CD40. Furthermore, the expression of VCAM-1 and ICAM-1 as well as the release of soluble VCAM-1 and ICAM-1 were downregulated. In the cell supernatants we also observed a significant reduction of IL-6, IL8 and MCP-1. DS and its major ingredients, Sal B and Protoc, significantly inhibited TNF-induced expression and release of adhesion molecules, cytokines and chemokines as well as ADP-induced expression of platelet P-selectin. Because of the key roles of inflammatory mediators in the etiology of atherosclerosis, this work provides useful insight in understanding the pharmacological efficacy of Chinese herbal medicine.


2020 ◽  
Vol 90 (1-2) ◽  
pp. 103-112 ◽  
Author(s):  
Michael J. Haas ◽  
Marilu Jurado-Flores ◽  
Ramadan Hammoud ◽  
Victoria Feng ◽  
Krista Gonzales ◽  
...  

Abstract. Inflammatory and oxidative stress in endothelial cells are implicated in the pathogenesis of premature atherosclerosis in diabetes. To determine whether high-dextrose concentrations induce the expression of pro-inflammatory cytokines, human coronary artery endothelial cells (HCAEC) were exposed to either 5.5 or 27.5 mM dextrose for 24-hours and interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor α (TNF α) levels were measured by enzyme immunoassays. To determine the effect of antioxidants on inflammatory cytokine secretion, cells were also treated with α-tocopherol, ascorbic acid, and the glutathione peroxidase mimetic ebselen. Only the concentration of IL-1β in culture media from cells exposed to 27.5 mM dextrose increased relative to cells maintained in 5.5 mM dextrose. Treatment with α-tocopherol (10, 100, and 1,000 μM) and ascorbic acid (15, 150, and 1,500 μM) at the same time that the dextrose was added reduced IL-1β, IL-6, and IL-8 levels in culture media from cells maintained at 5.5 mM dextrose but had no effect on IL-1β, IL-6, and IL-8 levels in cells exposed to 27.5 mM dextrose. However, ebselen treatment reduced IL-1β, IL-6, and IL-8 levels in cells maintained in either 5.5 or 27.5 mM dextrose. IL-2 and TNF α concentrations in culture media were below the limit of detection under all experimental conditions studied suggesting that these cells may not synthesize detectable quantities of these cytokines. These results suggest that dextrose at certain concentrations may increase IL-1β levels and that antioxidants have differential effects on suppressing the secretion of pro-inflammatory cytokines in HCAEC.


Author(s):  
Reza Afrisham ◽  
Sahar Sadegh-Nejadi ◽  
Reza Meshkani ◽  
Solaleh Emamgholipour ◽  
Molood Bagherieh ◽  
...  

Introduction: Obesity is a disorder with low-grade chronic inflammation that plays a key role in the hepatic inflammation and steatosis. Moreover, there are studies to support the role of exosomes in the cellular communications, the regulation of metabolic homeostasis and immunomodulatory activity. Accordingly, we aimed to evaluate the influence of plasma circulating exosomes derived from females with normal-weight and obesity on the secretion of inflammatory cytokines in human liver cells. Methods: Plasma circulating exosomes were isolated from four normal (N-Exo) and four obese (O-Exo) women. The exosomes were characterized and approved for CD63 expression (common exosomal protein marker) and morphology/size using the western blot and TEM methods, respectively. The exosomes were used for stimulation of HepG2 cells in vitro. After 24 h incubation, the protein levels of TNF-α,IL-6, and IL-1β were measured in the culture supernatant of HepG2 cells using the ELISA kit. Results: The protein levels of IL-6 and TNF-α in the cells treated with O-Exo and N-Exo reduced significantly in comparison with control group (P=0.039 and P<0.001 respectively), while significance differences were not found between normal and obese groups (P=0.808, and P=0.978 respectively). However, no significant differences were found between three groups in term of IL-1β levels (P=0.069). Based on the correlation analysis, the protein levels of IL-6 were positively correlated with TNF-α (r 0.978, P<0.001). Conclusion: These findings suggest that plasma circulating exosomes have probably anti-inflammatory properties independently from body mass index and may decrease the secretion of inflammatory cytokines in liver. However, further investigations in vitro and in vivo are needed to address the anti-inflammatory function of N-Exo and O-Exo in human liver cells and/or other cells.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1247
Author(s):  
Sarah Belperain ◽  
Zi Yae Kang ◽  
Andrew Dunphy ◽  
Brandon Priebe ◽  
Norman H. L. Chiu ◽  
...  

Cardiovascular disease (CVD) has become an increasingly important topic in the field of medical research due to the steadily increasing rates of mortality caused by this disease. With recent advancements in nanotechnology, a push for new, novel treatments for CVD utilizing these new materials has begun. Carbon Nanodots (CNDs), are a new form of nanoparticles that have been coveted due to the green synthesis method, biocompatibility, fluorescent capabilities and potential anti-antioxidant properties. With much research pouring into CNDs being used as bioimaging and drug delivery tools, few studies have been completed on their anti-inflammatory potential, especially in the cardiovascular system. CVD begins initially by endothelial cell inflammation. The cause of this inflammation can come from many sources; one being tumor necrosis factor (TNF-α), which can not only trigger inflammation but prolong its existence by causing a storm of pro-inflammatory cytokines. This study investigated the ability of CNDs to attenuate TNF-α induced inflammation in human microvascular endothelial cells (HMEC-1). Results show that CNDs at non-cytotoxic concentrations reduce the expression of pro-inflammatory genes, mainly Interleukin-8 (IL-8), and interleukin 1 beta (IL-1β). The uptake of CNDs by HMEC-1s was examined. Results from the studies involving channel blockers and endocytosis disruptors suggest that uptake takes place by endocytosis. These findings provide insights on the interaction CNDs and endothelial cells undergoing TNF-α induced cellular inflammation.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shengchao Zhang ◽  
Jiankai Fang ◽  
Zhanhong Liu ◽  
Pengbo Hou ◽  
Lijuan Cao ◽  
...  

Abstract Background Muscle stem cells (MuSCs) are absolutely required for the formation, repair, and regeneration of skeletal muscle tissue. Increasing evidence demonstrated that tissue stem cells, especially mesenchymal stem cells (MSCs), can exert therapeutic effects on various degenerative and inflammatory disorders based on their immunoregulatory properties. Human mesenchymal stem cells (hMSCs) treated with interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were reported to possess anti-inflammatory functions by producing TNF-stimulated gene 6 (TSG-6). However, whether human muscle stem cells (hMuSCs) also possess TSG-6 mediated anti-inflammatory functions has not been explored. Methods The ulcerative colitis mouse model was established by subjecting mice to dextran sulfate sodium (DSS) in drinking water for 7 days. hMuSCs were pretreated with IFN-γ and TNF-α for 48 h and were then transplanted intravenously at day 2 of DSS administration. Body weights were monitored daily. Indoleamine 2,3-dioxygenase (IDO) and TSG-6 in hMuSCs were knocked down with short hairpin RNA (shRNA) and small interfering RNA (siRNA), respectively. Colon tissues were collected for length measurement and histopathological examination. The serum level of IL-6 in mice was measured by enzyme-linked immunosorbent assay (ELISA). Real-time PCR and Western blot analysis were performed to evaluate gene expression. Results hMuSCs treated with inflammatory factors significantly ameliorated inflammatory bowel disease (IBD) symptoms. IDO and TSG-6 were greatly upregulated and required for the beneficial effects of hMuSCs on IBD. Mechanistically, the tryptophan metabolites, kynurenine (KYN) or kynurenic acid (KYNA) produced by IDO, augmented the expression of TSG-6 through activating their common receptor aryl hydrocarbon receptor (AHR). Conclusion Inflammatory cytokines-treated hMuSCs can alleviate DSS-induced colitis through IDO-mediated TSG-6 production.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1035
Author(s):  
Maha Sellami ◽  
Shamma Al-muraikhy ◽  
Hend Al-Jaber ◽  
Hadaia Al-Amri ◽  
Layla Al-Mansoori ◽  
...  

Background: Exercise-associated immune response plays a crucial role in the aging process. The aim of this study is to investigate the effect of sport intensity on cytokine levels, oxidative stress markers and telomere length in aging elite athletes. Methods: In this study, 80 blood samples from consenting elite athletes were collected for anti-doping analysis at an anti-doping laboratory in Italy (FMSI). Participants were divided into three groups according to their sport intensity: low-intensity skills and power sports (LI, n = 18); moderate-intensity mixed soccer players (MI, n = 31); and high-intensity endurance sports (HI, n = 31). Participants were also divided into two age groups: less than 25 (n = 45) and above 25 years old (n = 35). Serum levels of 10 pro and anti-inflammatory cytokines and two antioxidant enzymes were compared in age and sport intensity groups and telomere lengths were measured in their respective blood samples. Results: Tumor necrosis factor-alpha (TNF-α) was the only cytokine showing significantly higher concentration in older athletes, regardless of sport intensity. Interleukin (IL)-10 increased significantly in HI regardless of age group, whereas IL-6 concentration was higher in the older HI athletes. IL-8 showed a significant interaction with sport intensity in different age groups. Overall, significant positive correlations among levels of IL-6, IL-10, IL-8 and TNF-α were identified. The antioxidant catalase activity was positively correlated with levels of TNF-α. Telomere length increased significantly with sport intensity, especially in the younger group. Conclusion: HI had longer telomeres and higher levels of pro- and anti-inflammatory cytokines, suggesting less aging in HI compared to low and moderate counterparts in association with heightened immune response. Investigation of the functional significance of these associations on the health and performance of elite athletes is warranted.


Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Masaaki Korai ◽  
Kenji Shimada ◽  
Hajime Furukawa ◽  
Kosuke Wada ◽  
Yuan Wei ◽  
...  

Background and Purpose: Peroxisome proliferator-activated receptor gamma (PPARγ) plays a role in regulating not only lipid and glucose metabolism but also atherosclerosis and inflammation which are associated with intracranial aneurysmal rupture. It has been suggested that PPARγ is present in various kinds of cell types including macrophages which we reported to contribute to intracranial aneurysm formation. In addition, macrophage PPARγ regulates inflammatory cytokines negatively. Therefore we hypothesized that macrophage PPARγ is protective against intracranial aneurysmal rupture. We tested this hypothesis by using our own established mouse model of intracranial aneurysm. Methods: Intracranial aneurysms were induced in male mice using a combination of a single injection of elastase into the cerebrospinal fluid and the deoxycorticosterone acetate (DOCA) salt hypertension. Six days after aneurysm induction, we started 2-week treatment with vehicle or PPARγ agonist (pioglitazone:PGZ) or clodronate liposome. PPARγ antagonist (GW9662) was added to PGZ treatment. We induced aneurysms to macrophage-specific PPARγ knockout mice and treated them with vehicle or PGZ with the same protocol mentioned above. Aneurysmal rupture was detected by neurological symptoms and confirmed by the presence of intracranial aneurysms with subarachnoid hemorrhage. Results: Both PGZ and depletion of macrophage by clodronate liposome reduced the incidence of ruptured aneurysms and rupture rate. PGZ treatment decreased the inflammatory cytokines that were increased in cerebral arteries of mice with aneurysm induction compared to mice without aneurysm induction. To examine whether the macrophage PPARγ is associated with intracranial aneurysmal rupture, we administered PGZ to macrophage-specific PPARγ knock out mice. PGZ did not have protective effect against aneurysmal rupture in macrophage-specific PPARγ knock out mice although it exerted protective effects in wild type mice. Conclusion: PPARγ activation is protective against intracranial aneurysmal rupture by suppressing inflammatory cytokines and macrophage PPARγ is associated with this protective effects.


2017 ◽  
Vol 43 (5) ◽  
pp. 2074-2087 ◽  
Author(s):  
Liling Yang ◽  
Xiangjun Zhou ◽  
Weijuan Huang ◽  
Qin Fang ◽  
Jianlan Hu ◽  
...  

Background/Aims: Forsythia suspensa Vahl. (Oleaceae) fruits are widely used in traditional Chinese medicine to treat pneumonia, typhoid, dysentery, ulcers and oedema. Antibacterial and anti-inflammatory activities have been reported for phillyrin (PHN), the main ingredient in Forsythia suspensa Vahl fruits, in vitro. However, the underlying mechanisms in vivo remain poorly defined. In this study, we discovered that PHN exerted potent anti-inflammatory effects in lethal LPS-induced neutrophil inflammation by suppressing the MyD88-dependent signalling pathway in zebrafish. Methods: LPS-yolk microinjection was used to induce a lethal LPS-infected zebrafish model. The effect of PHN on the survival of zebrafish challenged with lethal LPS was evaluated using survival analysis. The effect of PHN on neutrophil inflammation grading in vivo was assessed by tracking neutrophils with a transgenic line. The effects of PHN on neutrophil production and migration were analysed by SB+ cell counts during consecutive hours after modelling. Additionally, key cytokines and members of the MyD88 signalling pathway that are involved in inflammatory response were detected using quantitative RT-PCR. To assess gene expression changes during consecutive hours after modelling, the IL-1β, IL-6, TNF-α, MyD88, TRIF, ERK1/2, JNK, IκBa and NF-κB expression levels were measured. Results: PHN could protect zebrafish against a lethal LPS challenge in a dose-dependent manner, as indicated by decreased neutrophil infltration, reduced tissue necrosis and increased survival rates. Up-regulated IL-1β, IL-6 and TNF-α expression also showed the same tendencies of depression by PHN. Critically, PHN significantly inhibited the LPS-induced activation of MyD88, IκBa, and NF-κB but did not affect the expression of ERK1/2 MAPKs or JNK MAPKs in LPS-stimulated zebrafish. Additionally, PHN regulated the MyD88/IκBα/NF-κB signalling pathway by controlling IκBα, IL-1β, IL-6, and TNF-α expression. Conclusion: This study provides a rationale for the clinical application of PHN as an anti-inflammatory agent.


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