scholarly journals Adipokine omentin-1 enhances atherosclerotic plaque stability by binding to macrophage integrin receptor

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Z.J Wang ◽  
X.Z Lin ◽  
Y.J Zhou

Abstract Background Omentin-1 is a novel cytokine which is primarily released by epicardial adipose tissues, and the molecule structure analysis revealed that it contained a fibrinogen-like domain. Clinical studies considered that the expression of omentin-1 is tightly associated with the development of cardiovascular diseases. In this research, we sought to investigate the effect of omentin-1 on already-established atherosclerotic lesion in ApoE−/− mouse and find out the cellular receptor of omentin-1 in macrophages. Methods We investigated the effect of omentin-1 on the plaque phenotype by implanting the ALZET minipump (which can continuously inject omentin-1 solution into mice's jugular vein) in western diet-treated ApoE−/− mice. To validate the conjugation of omentin-1 to integrin receptor αvβ3 and αvβ5, we performed immunoprecipitation experiment. Confocal microscopy was used to verify the spatial co-localization of omentin-1 and integrin receptors. Results In vivo studies showed that the administration of omentin-1 increased the collagen content and the average fibrous cap thickness of atherosclerotic plaque in ApoE−/− mice. Omentin-1 mitigated the formation of necrotic cores within the plaque, and reduced the foam cell infiltration concomitantly. Immunohistochemistry analysis of the atherosclerotic lesion from the aorta of mice revealed that the intravenous infusion of omentin-1 can suppress expression of inflammatory cytokines in vivo. Immunoprecipitation experiment and confocal microscopy analysis confirmed the binding of omentin-1 to integrin receptor αvβ3 and αvβ5. To further study the mechanism by which omentin-1 had exerted its protective function, we used human myeloid leukemia mononuclear cell line (THP1) and oxidized low density lipoprotein (ox-LDL) to establish macrophage-derived foam cell model in vitro. Cell studies demonstrated that omentin-1 can attenuated the apoptosis and inflammatory cytokines secretion in ox-LDL-induced macrophages. Besides, omentin-1 can promote the phosphorylation of integrin-relevant signaling pathway in macrophage. After adding the cilengitide (inhibitor of integrin receptor αvβ3 and αvβ5) or intervening the expression of integrin subunit αv, the phenomenon induced by omentin-1 were potently suppressed. Moreover, flowcytometry analysis provided the evidence that omentin-1 had a negative effect on macrophage efferocytosis ability. Conclusions The administration of adipokine omentin-1 can inhibit the necrotic cores formation and pro-inflammatory cytokines expression within the atherosclerotic lesion. The mechanism might be the inhibition of apoptosis and the secretion of pro-inflammatory cytokines in macrophage by binding to integrin receptor αvβ3 and αvβ5. Effect of omentin-1 on AS plaques. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National natural science foundation of China

2020 ◽  
Vol 35 (3) ◽  
pp. 233-238
Author(s):  
Muflihatul Muniroh

AbstractThe exposure of methylmercury (MeHg) has become a public health concern because of its neurotoxic effect. Various neurological symptoms were detected in Minamata disease patients, who got intoxicated by MeHg, including paresthesia, ataxia, gait disturbance, sensory disturbances, tremors, visual, and hearing impairments, indicating that MeHg could pass the blood-brain barrier (BBB) and cause impairment of neurons and other brain cells. Previous studies have reported some expected mechanisms of MeHg-induced neurotoxicity including the neuroinflammation pathway. It was characterized by the up-regulation of numerous pro-inflammatory cytokines expression. Therefore, the use of anti-inflammatories such as N-acetyl-l-cysteine (NAC) may act as a preventive compound to protect the brain from MeHg harmful effects. This mini-review will explain detailed information on MeHg-induced pro-inflammatory cytokines activation as well as possible preventive strategies using anti-inflammation NAC to protect brain cells, particularly in in vivo and in vitro studies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroto Nakajima ◽  
Atsushi Miyashita ◽  
Hiroshi Hamamoto ◽  
Kazuhisa Sekimizu

AbstractIn this study, we investigated a new application of bubble-eye goldfish (commercially available strain with large bubble-shaped eye sacs) for immunological studies in fishes utilizing the technical advantage of examining immune cells in the eye sac fluid ex vivo without sacrificing animals. As known in many aquatic species, the common goldfish strain showed an increased infection sensitivity at elevated temperature, which we demonstrate may be due to an immune impairment using the bubble-eye goldfish model. Injection of heat-killed bacterial cells into the eye sac resulted in an inflammatory symptom (surface reddening) and increased gene expression of pro-inflammatory cytokines observed in vivo, and elevated rearing temperature suppressed the induction of pro-inflammatory gene expressions. We further conducted ex vivo experiments using the immune cells harvested from the eye sac and found that the induced expression of pro-inflammatory cytokines was suppressed when we increased the temperature of ex vivo culture, suggesting that the temperature response of the eye-sac immune cells is a cell autonomous function. These results indicate that the bubble-eye goldfish is a suitable model for ex vivo investigation of fish immune cells and that the temperature-induced infection susceptibility in the goldfish may be due to functional impairments of immune cells.


2021 ◽  
Vol 160 (6) ◽  
pp. S-574-S-575
Author(s):  
Maria Jesus Villanueva-Millan ◽  
Maritza Sanchez ◽  
Walter Morales ◽  
Gabriela Leite ◽  
Stacy Weitsman ◽  
...  

2021 ◽  
Author(s):  
Cheng Ding ◽  
Chuang Yang ◽  
Tao Cheng ◽  
Xingyan Wang ◽  
Qiaojie Wang ◽  
...  

Abstract Background:Inflammatory osteolysis is a major complication of total joint replacement surgery that can cause prosthesis failure and necessitate revision surgery. Macrophages are key effector immune cells in inflammatory responses, but excessive M1-polarization of dysfunctional macrophages leads to the secretion of pro-inflammatory cytokines and severe loss of bone tissue. Here, we report the development of macrophage-biomimetic porous SiO2-coated ultrasmall Se particles (Porous Se@SiO2 nanospheres) for the management of inflammatory osteolysis. Results: Macrophage-membrane-coated porous Se@SiO2 nanospheres(M-Se@SiO2) can attenuate lipopolysaccharide (LPS)-induced inflammatory osteolysis by a dual-immunomodulatory effect. As macrophage membrane decoys, these nanoparticles reduce toxin levels and neutralize pro-inflammatory cytokines. Moreover, the release of Se can induce the polarization of macrophages toward the anti-inflammatory M2-phenotype. These effects are mediated via the inhibition of p65, p38, and extracellular signal-regulated kinase(ERK) signaling. Additionally, the immune environment created by M-Se@SiO2 reduces the inhibition of osteogenic differentiation caused by pro-inflammation cytokines, confirmed through in vitro and in vivo experiments.Conclusion: Our findings suggest that M-Se@SiO2 has an immunomodulatory role in LPS-induced inflammation and bone remodeling, which demonstrates that M-Se@SiO2 is a promising engineered nano-platform for the treatment of osteolysis arising after arthroplasty.


Author(s):  
Bruna Lima Correa ◽  
Nadia El Harane ◽  
Ingrid Gomez ◽  
Hocine Rachid Hocine ◽  
José Vilar ◽  
...  

Abstract Aims The cardioprotective effects of human induced pluripotent stem cell-derived cardiovascular progenitor cells (CPC) are largely mediated by the paracrine release of extracellular vesicles (EV). We aimed to assess the immunological behaviour of EV-CPC, which is a prerequisite for their clinical translation. Methods and results Flow cytometry demonstrated that EV-CPC expressed very low levels of immune relevant molecules including HLA Class I, CD80, CD274 (PD-L1), and CD275 (ICOS-L); and moderate levels of ligands of the natural killer (NK) cell activating receptor, NKG2D. In mixed lymphocyte reactions, EV-CPC neither induced nor modulated adaptive allogeneic T cell immune responses. They also failed to induce NK cell degranulation, even at high concentrations. These in vitro effects were confirmed in vivo as repeated injections of EV-CPC did not stimulate production of immunoglobulins or affect the interferon (IFN)-γ responses from primed splenocytes. In a mouse model of chronic heart failure, intra-myocardial injections of EV-CPC, 3 weeks after myocardial infarction, decreased both the number of cardiac pro-inflammatory Ly6Chigh monocytes and circulating levels of pro-inflammatory cytokines (IL-1α, TNF-α, and IFN-γ). In a model of acute infarction, direct cardiac injection of EV-CPC 2 days after infarction reduced pro-inflammatory macrophages, Ly6Chigh monocytes, and neutrophils in heart tissue as compared to controls. EV-CPC also reduced levels of pro-inflammatory cytokines IL-1α, IL-2, and IL-6, and increased levels of the anti-inflammatory cytokine IL-10. These effects on human macrophages and monocytes were reproduced in vitro; EV-CPC reduced the number of pro-inflammatory monocytes and M1 macrophages, while increasing the number of anti-inflammatory M2 macrophages. Conclusions EV-CPC do not trigger an immune response either in in vitro human allogeneic models or in immunocompetent animal models. The capacity for orienting the response of monocyte/macrophages towards resolution of inflammation strengthens the clinical attractiveness of EV-CPC as an acellular therapy for cardiac repair.


PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e109387 ◽  
Author(s):  
Malin Wennström ◽  
Shorena Janelidze ◽  
Cecilie Bay-Richter ◽  
Lennart Minthon ◽  
Lena Brundin

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Xu ◽  
X Yang ◽  
S Ding ◽  
J Qian ◽  
J Ge

Abstract Background Atherosclerotic plaque formation and rupture is the primary cause for cardiovascular diseases. It's known that cell death and inflammation are crucial processes leading to atherosclerosis, which involves an important role of histamine. The aim of the present study is to determine the function of signal transducer and activator of transcription 6 (STAT6) in histamine-induced macrophage pyroptosis and plaque instability. Methods We constructed APOE/STAT6 double knock out (DKO) mice via hybridization of ApoE−/− and STAT6−/− mice. 20 ApoE−/− mice (control) and 20 DKO mice were challenged with high-fat diet for 12 weeks while 10 in each group were intraperitoneally infused with histamine (400ug/kg) every other day. The extent and instability of atherosclerotic plaque were determined by oil-red staining, HE staining, immunofluorescence staining and electron microscopy. Changes in subsets of immune cells were evaluated by flow cytometry. Plasma cytokines were assessed by ELISA. Microarray analysis was applied to detect gene expressions while Western blot and real-time PCR was used to assess gene expression levels. Results Morphology studies revealed that histamine could promote plaque formation and vulnerability in ApoE−/− mice, whereas this effect was inhibited in DKO mice. FACS data showed that histamine injection could increase CD11b+Ly6Chigh M1 macrophages differentiation and pyroptosis and facilitate foam cells formation in ApoE−/− mice, which was also inhibited in DKO mice. Microarray analysis and in vitro studies exhibited that histamine could induce the up-regulation of pyrotosis-related proteins such as NLRP3, caspase-1 and MMPs via a STAT6-dependent pathway to promote macrophage pyroptosis and foam cell formation. Conclusions We have characterized a novel role for histamine in modulating atherosclerotic lesion development and progression. Moreover, our work have figured out the detailed mechanisms by which histamine modulates the pyroptosis of macrophages and the progress of unstable atherosclerotic plaques. We envision that this study may provide several potential therapeutic targets benefit for atherosclerosis treatment.


2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Anna K Gazha ◽  
Lyudmila A. Ivanushko ◽  
Eleonora V. Levina ◽  
Sergey N. Fedorov ◽  
Tatyana S. Zaporozets ◽  
...  

The action of seven polyhydroxylated sterol mono- and disulfates (1-7), isolated from ophiuroids, on innate and adaptive immunity was examined in in vitro and in vivo experiments. At least, three of them (1, 2 and 4) increased the functional activities of neutrophils, including levels of oxygen-dependent metabolism, adhesive and phagocytic properties, and induced the expression of pro-inflammatory cytokines TNF-α and IL-8. Compound 4 was the most active for enhancing the production of antibody forming cells in the mouse spleen.


2021 ◽  
Vol 11 ◽  
Author(s):  
Leon Islas-Weinstein ◽  
Brenda Marquina-Castillo ◽  
Dulce Mata-Espinosa ◽  
Iris S. Paredes-González ◽  
Jaime Chávez ◽  
...  

The cholinergic system is present in both bacteria and mammals and regulates inflammation during bacterial respiratory infections through neuronal and non-neuronal production of acetylcholine (ACh) and its receptors. However, the presence of this system during the immunopathogenesis of pulmonary tuberculosis (TB) in vivo and in its causative agent Mycobacterium tuberculosis (Mtb) has not been studied. Therefore, we used an experimental model of progressive pulmonary TB in BALB/c mice to quantify pulmonary ACh using high-performance liquid chromatography during the course of the disease. In addition, we performed immunohistochemistry in lung tissue to determine the cellular expression of cholinergic system components, and then administered nicotinic receptor (nAChR) antagonists to validate their effect on lung bacterial burden, inflammation, and pro-inflammatory cytokines. Finally, we subjected Mtb cultures to colorimetric analysis to reveal the production of ACh and the effect of ACh and nAChR antagonists on Mtb growth. Our results show high concentrations of ACh and expression of its synthesizing enzyme choline acetyltransferase (ChAT) during early infection in lung epithelial cells and macrophages. During late progressive TB, lung ACh upregulation was even higher and coincided with ChAT and α7 nAChR subunit expression in immune cells. Moreover, the administration of nAChR antagonists increased pro-inflammatory cytokines, reduced bacillary loads and synergized with antibiotic therapy in multidrug resistant TB. Finally, in vitro studies revealed that the bacteria is capable of producing nanomolar concentrations of ACh in liquid culture. In addition, the administration of ACh and nicotinic antagonists to Mtb cultures induced or inhibited bacterial proliferation, respectively. These results suggest that Mtb possesses a cholinergic system and upregulates the lung non-neuronal cholinergic system, particularly during late progressive TB. The upregulation of the cholinergic system during infection could aid both bacterial growth and immunomodulation within the lung to favor disease progression. Furthermore, the therapeutic efficacy of modulating this system suggests that it could be a target for treating the disease.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
L Xu ◽  
Y Dai ◽  
K Yao ◽  
H Yang ◽  
A Sun ◽  
...  

Abstract Background Vulnerable plaques are characterized by infiltration of inflammatory cells, playing a key role in the progression of acute coronary events. It's important to clarify the inflammatory mechanism of unstable plaque formation. Several clinical trials have demonstrated that dapagliflozin could reduce major adverse cardiac events in whether diabetic or non-diabetic patients. However, the underlying cardioprotective mechanism of dapagliflozin remains unclear. This study was aimed to investigate the role of dapagliflozin in regulating macrophage pyroptosis and vulnerable plaque formation. Methods 20 ApoE−/− mice (control) were fed with high fat diet while another 20 ApoE−/− mice were challenged with high fat diet plus dapagliflozin for 12 weeks. The extent and instability of atherosclerotic plaque was determined by oil-red staining, HE staining, immunofluorescence staining and electron microscopy. Changes in subsets of immune cells were evaluated by flow cytometry. Plasma cytokines were assessed by ELISA. Microarray analysis was applied to detect gene expressions while Western blot and real-time PCR was used to assess gene expression levels. Results Morphology studies revealed that dapagliflozin could inhibit plaque formation and reduce instability in ApoE−/− mice. FACS data showed that dapagliflozin could decrease CD11b+Ly6Chigh M1 macrophages differentiation and inhibit foam cells formation in ApoE−/− mice. Microarray analysis and in vitro studies exhibited that dapagliflozin could induce the down regulation of NLRP3, caspase-1, IL-1β, IL-18 and MMP-7/10/12/14 to retard macrophage pyroptosis and foam cell formation. Conclusions We have characterized a novel role for dapagliflozin in modulating atherosclerotic lesion development and progression. We envision that this study may provide several potential therapeutic targets for treatment of acute coronary syndromes. FUNDunding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Shanghai Sailing Program


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