Simvastatin attenuates sympathetic hyperinnervation to prevent atrial fibrillation during the postmyocardial infarction remodeling process

2012 ◽  
Vol 113 (12) ◽  
pp. 1937-1944 ◽  
Author(s):  
Tao Yu ◽  
Wei Zhu ◽  
Beiyin Gu ◽  
Shuai Li ◽  
Fabing Wang ◽  
...  

Statin, as a 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitor, has been shown to prevent atrial fibrillation (AF) due to its anti-inflammatory and antioxidant effects. However, it is still not known whether statin can improve autonomic remodeling to prevent AF. In the present study, using an in vivo rat myocardial infarction (MI) model, we aimed to test whether simvastatin can attenuate nerve sprouting and sympathetic hyperinnervation to prevent AF during the post-MI remodeling process. Our data demonstrate that simvastatin, delivered 3 days after MI for 4 wk, can result in significant decreases in plasma levels of both TNF-α (239 ± 23 pg/ml) and IL-1β (123 ± 11 pg/ml) compared with MI rats without therapy (TNF-α, 728 ± 57 pg/ml; IL-1β, 213 ± 21 pg/ml; P < 0.05), which, however, were still higher than sham-operated rats (TNF-α, 194 ± 20 pg/ml; IL-1β, 75 ± 8 pg/ml; P < 0.05). The similar pattern of changes in inflammation responses was also observed in TNF-α and IL-1β protein expression in the left atrium free wall. The suppressed inflammation responses were associated with reduced superoxide and malondialdehyde generation in the atrium. These changes account for decreases in neural growth factor expression at levels of both mRNA (1.2 ± 0.09 AU vs. MI group, 1.78 ± 0.16 AU) and protein (1.57 ± 0.17 AU vs. MI group, 2.24 ± 0.19 AU; P < 0.05), thus resulting in reduced nerve sprouting and sympathetic hyperinnervation. Accordingly, the rate adaptation of the atrial effective refractory period also recovered, leading to the decreased inducibility of AF. These data suggest that simvastatin administration after MI can prevent AF through reduced sympathetic hyperinnervation.

2021 ◽  
Vol 8 ◽  
Author(s):  
Shanqing He ◽  
Youcheng Wang ◽  
Yajun Yao ◽  
Zhen Cao ◽  
Junkui Yin ◽  
...  

Aims: To investigate the role of KCa3. 1 inhibition in macrophage pro-inflammatory polarization and vulnerability to atrial fibrillation (AF) in a canine model with prolonged rapid atrial pacing.Materials and Methods: Twenty beagle dogs (weighing 8–10 kg) were randomly assigned to a sham group (n = 6), pacing group (n = 7) and pacing+TRAM-34 group (n = 7). An experimental model of AF was established by rapid pacing. TRAM-34 was administered to the Pacing+TRAM-34 group by slow intravenous injection (10 mg/kg), 3 times each day. After 7 days of pacing, the electrophysiology was measured in vivo. The levels of interleukin-1β (IL-1β), monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), CD68, c-Fos, p38, and NF-κB p65 in both atriums were measured by Western blotting, and the levels of inducible nitric oxide synthase (iNOS) and arginase1 (Arg-1) were measured by real-time PCR. Macrophage and KCa3.1 in macrophage in the atrium were quantized following double labeled immunofluorescent.Results: Greater inducibility of AF, an extended duration of AF and lower atrial effective refractory period (AERP) were observed in the pacing group compared with those in the sham group. Both CD68-labeled macrophage and the expression of KCa3.1 in macrophage were elevated in the pacing group and inhibited by TRAM-34, led to higher iNOS expression, lower Arg-1 expression, elevated levels of IL-1β, MCP-1, and TNF-α in the atria, which could be reversed by TRAM-34 treatment (all P &lt; 0.01). KCa3.1 channels were possibly activated via the p38/AP-1/NF-κB signaling pathway.Conclusions: Inhibition of KCa3.1 suppresses vulnerability to AF by attenuating macrophage pro-inflammatory polarization and inflammatory cytokine secretion in a canine model with prolonged rapid atrial pacing.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ryuichi Kambayashi ◽  
Hiroko Izumi-Nakaseko ◽  
Ai Goto ◽  
Kazuya Tsurudome ◽  
Hironori Ohshiro ◽  
...  

Oseltamivir has been shown to prolong the atrial conduction time and effective refractory period, and to suppress the onset of burst pacing-induced atrial fibrillation in vitro. To better predict its potential clinical benefit as an anti-atrial fibrillatory drug, we performed translational studies by assessing in vivo anti-atrial fibrillatory effect along with in vivo and in vitro electropharmacological analyses. Oseltamivir in intravenous doses of 3 (n = 6) and 30 mg/kg (n = 7) was administered in conscious state to the persistent atrial fibrillation model dogs to confirm its anti-atrial fibrillatory action. The model was prepared by tachypacing to the atria of chronic atrioventricular block dogs for &gt; 6 weeks. Next, oseltamivir in doses of 0.3, 3 and 30 mg/kg was intravenously administered to the halothane-anesthetized intact dogs to analyze its in vivo electrophysiological actions (n = 4). Finally, its in vitro effects of 10–1,000 μM on IK,ACh, IKur, IKr, INa and ICaL were analyzed by using cell lines stably expressing Kir3.1/3.4, KV1.5, hERG, NaV1.5 or CaV1.2, respectively (n = 3 for IK,ACh and IKr or n = 6 for IKr, INa and ICaL). Oseltamivir in doses of 3 and 30 mg/kg terminated the atrial fibrillation in 1 out of 6 and in 6 out of 7 atrial fibrillation model dogs, respectively without inducing any lethal ventricular arrhythmia. Its 3 and 30 mg/kg delayed inter-atrial conduction in a frequency-dependent manner, whereas they prolonged atrial effective refractory period in a reverse frequency-dependent manner in the intact dogs. The current assay indicated that IC50 values for IK,ACh and IKr were 160 and 231 μM, respectively, but 1,000 µM inhibited INa, ICaL and IKur by 22, 19 and 13%, respectively. The extent of INa blockade was enhanced at faster beating rate and more depolarized resting membrane potential. Oseltamivir effectively terminated the persistent atrial fibrillation, which may be largely due to the prolongation of the atrial effective refractory period and inter-atrial conduction time induced by IK,ACh and IKr inhibitions along with INa suppression. Thus, oseltamivir can exert a powerful anti-atrial fibrillatory action through its ideal multi-channel blocking property; and oseltamivir would become a promising seed compound for developing efficacious and safe anti-atrial fibrillatory drugs.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1507
Author(s):  
Min Jeong Kim ◽  
Hyun-Hee Kang ◽  
Yeung Jin Seo ◽  
Kyung-Min Kim ◽  
Young-Jun Kim ◽  
...  

Although various physiological activities of compounds obtained from Paeonia lactiflora have been reported, the effects of P. lactiflora extract (PLE) on early atherosclerosis remain unclear. Therefore, in this study, we investigated the in vitro and in vivo antiatherosclerosis and in vitro antioxidant effects of PLE and its compounds. PLE suppresses the tumor necrosis factor (TNF)-α-induced capacity of THP-1 cells to adhere to human umbilical vein endothelial cells (HUVECs), vascular cell adhesion molecule (VCAM)-1 expression, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling in HUVECs. PLE also suppresses TNF-α-induced nuclear translocation of NF-κB p65 from cytosol as well as the enhanced TNFA and C-C motif chemokine ligand 2 (CCL2) mRNA expression in HUVECs. We identified and quantified the following PLE compounds using high-performance liquid chromatography with diode array detection: methyl gallate, oxypaeoniflorin, catechin, albiflorin, paeoniflorin, benzoic acid, benzoylpaeoniflorin, and paeonol. Among these, methyl gallate had the strongest inhibitory effect on monocyte adherence to TNF-α-induced HUVECs and the VCAM-1 expression. Reverse transcriptase real-time quantitative polymerase chain reaction showed that PLE compounds had a dissimilar inhibition effect on TNF-α-induced mRNA expression levels of CCL2, TNFA, and IL6 in HUVECs. Except for paeonol, the compounds inhibited lipopolysaccharide (LPS)-induced reactive oxygen species production in RAW264.7 cells. In vivo, oral administration of PLE improved TNF-α-induced macrophage infiltration to the vascular endothelium and expression of VCAM-1, as well as IL6 and TNFA gene expression in the main artery of mice. PLE could be useful as a nutraceutical material against early atherosclerosis via the combined effects of its components.


2001 ◽  
Vol 86 (11) ◽  
pp. 1257-1263 ◽  
Author(s):  
Attilio Bondanza ◽  
Angelo Manfredi ◽  
Valérie Zimmermann ◽  
Matteo Iannacone ◽  
Angela Tincani ◽  
...  

SummaryScavenger phagocytes are mostly responsible for the in vivo clearance of activated or senescent platelets. In contrast to other particulate substrates, the phagocytosis of platelets does not incite pro-inflammatory responses in vivo. This study assessed the contribution of macrophages and dendritic cells (DCs) to the clearance of activated platelets. Furthermore, we verified whether antibodies against the β2 Glycoprotein I (β2GPI), which bind to activated platelets, influence the phenomenon. DCs did not per se internalise activated platelets. In contrast, macrophages efficiently phagocytosed platelets. In agreement with the uneventful nature of the clearance of platelets in vivo, phagocytosing macrophages did not release IL-1β, TNF-α or IL-10. β2GPI bound to activated platelets and was required for their recognition by anti-ββ2GPI antibodies. DCs internalised platelets opsonised by anti-ββ2GPI antibodies. The phagocytosis of opsonised platelets determined the release of TNF-α and IL-1β by DCs and macrophages. Phagocytosing macrophages, but not DCs, secreted the antiinflammatory cytokine IL-1β0. We conclude that anti-ββ2GPI antibodies cause inflammation during platelet clearance and shuttle platelet antigens to antigen presenting DCs.


2019 ◽  
Vol 20 (12) ◽  
pp. 1055-1063 ◽  
Author(s):  
Faris Alrumaihi ◽  
Khaled S. Allemailem ◽  
Ahmad Almatroudi ◽  
Mohammed A. Alsahli ◽  
Arif Khan ◽  
...  

Objective: The present study was aimed to evaluate the effect of the aqueous extract of Tinospora cordifolia (AETC) against cyclophosphamide-induced immunosuppression and systemic Candida albicans infection in a murine model. Methods: The protective effect of AETC against cyclophosphamide-induced leukopenia was evaluated by quantitative and qualitative analysis of the leukocytes. The immune-stimulating potential of AETC on macrophages was assessed by determining the levels of secreted cytokines. To determine the direct antifungal activity, AETC or fluconazole was administered to C. albicans infected mice. The efficacy of treatment was assessed by determining the survival rate, kidney fungal burden, the organ index and liver inflammation parameters. Results: Cyclophosphamide administration resulted in substantial depletion of leukocytes, whereas AETC treatment induced the recovery of leukocytes in cyclophosphamide-injected mice. Moreover, AETC treatment of macrophages resulted in enhanced secretion of IFN-γ, TNF-α and IL-1β. C. albicans infected mice treated with AETC at the doses of 50 and 100 mg/kg exhibited 40% and 60% survival rate, whereas the mice treated with fluconazole at a dose of 50 mg/kg showed 20% survival rate. Like survival data, the fungal load was found to be the lowest in the kidney tissues of mice treated with AETC at a dose of 100 mg/kg. Interestingly, mice infected with C. albicans demonstrated improvement in the organ indices and liver functioning after AETC treatment. Conclusion: These results suggest that AETC may potentially be used to rejuvenate the weakened immune system and eliminate systemic candidiasis in mice.


1995 ◽  
Vol 15 (7) ◽  
pp. 872-878 ◽  
Author(s):  
Thomas M. Stulnig ◽  
Helmut Klocker ◽  
H. James Harwood ◽  
Günther Jürgens ◽  
Dieter Schönitzer ◽  
...  

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qilu Wei ◽  
Ning Kong ◽  
Xiaohui Liu ◽  
Run Tian ◽  
Ming Jiao ◽  
...  

Abstract Background Osteoarthritis (OA) is a disease of the entire joint involving synovial fibrosis and inflammation. Pathological changes to the synovium can accelerate the progression of OA. Pirfenidone (PFD) is a potent anti-fibrotic drug with additional anti-inflammatory properties. However, the influence of PFD on OA is unknown. Methods Proliferation of human fibroblast-like synoviocytes (FLSs) after treatment with TGF-β1 or PFD was evaluated using a Cell Counting Kit-8 assay and their migration using a Transwell assay. The expression of fibrosis-related genes (COL1A1, TIMP-1, and ACTA-2) and those related to inflammation (IL-6 and TNF-α) was quantified by real-time quantitative PCR. The protein expression levels of COL1A1, α-SMA (coded by ACTA-2), IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay. A rabbit model of OA was established and then PFD was administered by gavage. The expression of genes related to fibrosis (COL1A1, TIMP-1, and ADAM-12) and inflammation (IL-6 and TNF-α) was measured using RNA extracted from the synovium. Synovial tissue was examined histologically after staining with H&E, Masson’s trichrome, and immunofluorescence. Synovitis scores, the volume fraction of collagen, and mean fluorescence intensity were calculated. Degeneration of articular cartilage was analyzed using a Safranin O-fast green stain and OARSI grading. Results The proliferation of FLSs was greatest when induced with 2.5 ng/ml TGF-β1 although it did not promote their migration. Therefore, 2.5 ng/ml TGF-β1 was used to stimulate the FLSs and evaluate the effects of PFD, which inhibited the migration of FLSs at concentrations as low as 1.0 mg/ml. PFD decreased the expression of COL1A1 while TGF-β1 increased both mRNA and protein expression levels of IL-6 but had no effect on α-SMA or TNF-α expression. PFD decreased mRNA expression levels of COL1A1, IL-6, and TNF-α in vivo. H&E staining and synovitis scores indicated that PFD reduced synovial inflammation, while Masson’s trichrome and immunofluorescence staining suggested that PFD decreased synovial fibrosis. Safranin O-Fast Green staining and the OARSI scores demonstrated that PFD delayed the progression of OA. Conclusions PFD attenuated synovial fibrosis and inflammation, and postponed the progression of osteoarthritis in a modified Hulth model of OA in rabbits, which was related to its anti-fibrotic and anti-inflammatory properties.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3005
Author(s):  
Kanchan Bhardwaj ◽  
Ana Sanches Silva ◽  
Maria Atanassova ◽  
Rohit Sharma ◽  
Eugenie Nepovimova ◽  
...  

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2529
Author(s):  
Haeyeop Kim ◽  
Woo Seok Yang ◽  
Khin Myo Htwe ◽  
Mi-Nam Lee ◽  
Young-Dong Kim ◽  
...  

Dipterocarpus tuberculatus Roxb. has been used traditionally as a remedy for many diseases, especially inflammation. Therefore, we analyzed and explored the mechanism of the anti-inflammatory effect of a Dipterocarpus tuberculatus Roxb. ethanol extract (Dt-EE). Dt-EE clearly and dose-dependently inhibited the expression of pro-inflammatory cytokines such as IL-6, TNF-α, and IL-1β in lipopolysaccharide (LPS)-treated RAW264.7 cells. Also, Dt-EE suppressed the activation of the MyD88/TRIF-mediated AP-1 pathway and the AP-1 pathway related proteins JNK2, MKK4/7, and TAK1, which occurred as a result of inhibiting the kinase activity of IRAK1 and IRAK4, the most upstream factors of the AP-1 pathway. Finally, Dt-EE displayed hepatoprotective activity in a mouse model of hepatitis induced with LPS/D-galactosamine (D-GalN) through decreasing the serum levels of alanine aminotransferase and suppressing the activation of JNK and IRAK1. Therefore, our results strongly suggest that Dt-EE could be a candidate anti-inflammatory herbal medicine with IRAK1/AP-1 inhibitory and hepatoprotective properties.


Author(s):  
Hongli Zhou ◽  
Minyu Zhou ◽  
Yue Hu ◽  
Yanin Limpanon ◽  
Yubin Ma ◽  
...  

AbstractAngiostrongylus cantonensis (AC) can cause severe eosinophilic meningitis or encephalitis in non-permissive hosts accompanied by apoptosis and necroptosis of brain cells. However, the explicit underlying molecular basis of apoptosis and necroptosis upon AC infection has not yet been elucidated. To determine the specific pathways of apoptosis and necroptosis upon AC infection, gene set enrichment analysis (GSEA) and protein–protein interaction (PPI) analysis for gene expression microarray (accession number: GSE159486) of mouse brain infected by AC revealed that TNF-α likely played a central role in the apoptosis and necroptosis in the context of AC infection, which was further confirmed via an in vivo rescue assay after treating with TNF-α inhibitor. The signalling axes involved in apoptosis and necroptosis were investigated via immunoprecipitation and immunoblotting. Immunofluorescence was used to identify the specific cells that underwent apoptosis or necroptosis. The results showed that TNF-α induced apoptosis of astrocytes through the RIP1/FADD/Caspase-8 axis and induced necroptosis of neurons by the RIP3/MLKL signalling pathway. In addition, in vitro assay revealed that TNF-α secretion by microglia increased upon LSA stimulation and caused necroptosis of neurons. The present study provided the first evidence that TNF-α was secreted by microglia stimulated by AC infection, which caused cell death via parallel pathways of astrocyte apoptosis (mediated by the RIP1/FADD/caspase-8 axis) and neuron necroptosis (driven by the RIP3/MLKL complex). Our research comprehensively elucidated the mechanism of cell death after AC infection and provided new insight into targeting TNF-α signalling as a therapeutic strategy for CNS injury.


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