Modulation of transglutaminase 2 activity in H9c2 cells by PKC and PKA signalling: a role for transglutaminase 2 in cytoprotection

PubMed Central

Almami, Ibtesam; Dickenson, John M; Hargreaves, Alan J; Bonner, Philip L R

2014-01-01

BACKGROUND AND PURPOSE Tissue transglutaminase (TG2) has been shown to mediate cell survival in many cell types. In this study, we investigated whether the role of TG2 in cytoprotection was mediated by the activation of PKA and PKC in cardiomyocyte-like H9c2 cells. EXPERIMENTAL APPROACH H9c2 cells were extracted following stimulation with phorbol-12-myristate-13-acetate (PMA) and forskolin. Transglutaminase activity was determined using an amine incorporating and a protein crosslinking assay. The presence of TG isoforms (TG1, 2, 3) was determined using Western blot analysis. The role of TG2 in PMA- and forskolin-induced cytoprotection was investigated by monitoring H2O2-induced oxidative stress in H9c2 cells. KEY RESULTS Western blotting showed TG2 >> TG1 protein expression but no detectable TG3. The amine incorporating activity of TG2 in H9c2 cells increased in a time and concentration-dependent manner following stimulation with PMA and forskolin. PMA and forskolin-induced TG2 activity was blocked by PKC (Ro 31-8220) and PKA (KT 5720 and Rp-8-Cl-cAMPS) inhibitors respectively. The PMA- and forskolin-induced increases in TG2 activity were attenuated by the TG2 inhibitors Z-DON and R283. Immunocytochemistry revealed TG2-mediated biotin-X-cadaverine incorporation into proteins and proteomic analysis identified known (β-tubulin) and novel (α-actinin) protein substrates for TG2. Pretreatment with PMA and forskolin reversed H2O2-induced decrease in MTT reduction and release of LDH. TG2 inhibitors R283 and Z-DON blocked PMA- and forskolin-induced cytoprotection. CONCLUSIONS AND IMPLICATIONS TG2 activity was stimulated via PKA- and PKC-dependent signalling pathways in H9c2 cells These results suggest a role for TG2 in cytoprotection induced by these kinases. PMID:24821315

Role of calreticulin in the sensitivity of myocardiac H9c2 cells to oxidative stress caused by hydrogen peroxide.

PubMed

Ihara, Yoshito; Urata, Yoshishige; Goto, Shinji; Kondo, Takahito

2006-01-01

Calreticulin (CRT), a Ca2+-binding molecular chaperone in the endoplasmic reticulum, plays a vital role in cardiac physiology and pathology. Oxidative stress is a main cause of myocardiac apoptosis in the ischemic heart, but the function of CRT under oxidative stress is not fully understood. In the present study, the effect of overexpression of CRT on susceptibility to apoptosis under oxidative stress was examined using myocardiac H9c2 cells transfected with the CRT gene. Under oxidative stress due to H2O2, the CRT-overexpressing cells were highly susceptible to apoptosis compared with controls. In the overexpressing cells, the levels of cytoplasmic free Ca2+ ([Ca2+]i) were significantly increased by H2O2, whereas in controls, only a slight increase was observed. The H2O2-induced apoptosis was enhanced by the increase in [Ca2+]i caused by thapsigargin in control cells but was suppressed by BAPTA-AM, a cell-permeable Ca2+ chelator in the CRT-overexpressing cells, indicating the importance of the level of [Ca2+]i in the sensitivity to H2O2-induced apoptosis. Suppression of CRT by the introduction of the antisense cDNA of CRT enhanced cytoprotection against oxidative stress compared with controls. Furthermore, we found that the levels of activity of calpain and caspase-12 were elevated through the regulation of [Ca2+]i in the CRT-overexpressing cells treated with H2O2 compared with controls. Thus we conclude that the level of CRT regulates the sensitivity to apoptosis under oxidative stress due to H2O2 through a change in Ca2+ homeostasis and the regulation of the Ca2+-calpain-caspase-12 pathway in myocardiac cells.

Fluoride induces apoptosis in H9c2 cardiomyocytes via the mitochondrial pathway.

PubMed

Yan, Xiaoyan; Wang, Lu; Yang, Xia; Qiu, Yulan; Tian, Xiaolin; Lv, Yi; Tian, Fengjie; Song, Guohua; Wang, Tong

2017-09-01

Numerous studies have shown that chronic excessive fluoride intake can adversely affect different organ systems. In particular, the cardiovascular system is susceptible to disruption by a high concentration of fluoride. The objectives of this study were to explore the mechanism of apoptosis by detecting the toxic effects of different concentrations of sodium fluoride (NaF) in H9c2 cells exposed for up to 96 h. NaF not only inhibited H9c2 cell proliferation but also induced apoptosis and morphological damage. With increasing NaF concentrations, early apoptosis of H9c2 cells was increased while the mitochondrial membrane potential was decreased. Compared with the control group, the mRNA levels of caspase-3, caspase-9, and cytochrome c all increased with increasing concentrations of NaF. In summary, these data suggest that apoptosis is involved in NaF-induced H9c2 cell toxicity and that activation of the mitochondrial pathway may occur. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impaired ALDH2 activity decreases the mitochondrial respiration in H9C2 cardiomyocytes.

PubMed

Mali, Vishal R; Deshpande, Mandar; Pan, Guodong; Thandavarayan, Rajarajan A; Palaniyandi, Suresh S

2016-02-01

Reactive oxygen species (ROS)-mediated reactive aldehydes induce cellular stress. In cardiovascular diseases such as ischemia-reperfusion injury, lipid-peroxidation derived reactive aldehydes such as 4-hydroxy-2-nonenal (4HNE) are known to contribute to the pathogenesis. 4HNE is involved in ROS formation, abnormal calcium handling and more importantly defective mitochondrial respiration. Aldehyde dehydrogenase (ALDH) superfamily contains NAD(P)(+)-dependent isozymes which can detoxify endogenous and exogenous aldehydes into non-toxic carboxylic acids. Therefore we hypothesize that 4HNE afflicts mitochondrial respiration and leads to cell death by impairing ALDH2 activity in cultured H9C2 cardiomyocyte cell lines. H9C2 cardiomyocytes were treated with 25, 50 and 75 μM 4HNE and its vehicle, ethanol as well as 25, 50 and 75 μM disulfiram (DSF), an inhibitor of ALDH2 and its vehicle (DMSO) for 4 h. 4HNE significantly decreased ALDH2 activity, ALDH2 protein levels, mitochondrial respiration and mitochondrial respiratory reserve capacity, and increased 4HNE adduct formation and cell death in cultured H9C2 cardiomyocytes. ALDH2 inhibition by DSF and ALDH2 siRNA attenuated ALDH2 activity besides reducing ALDH2 levels, mitochondrial respiration and mitochondrial respiratory reserve capacity and increased cell death. Our results indicate that ALDH2 impairment can lead to poor mitochondrial respiration and increased cell death in cultured H9C2 cardiomyocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

Mitoprotective antioxidant EUK-134 stimulates fatty acid oxidation and prevents hypertrophy in H9C2 cells.

PubMed

Purushothaman, Sreeja; Nair, R Renuka

2016-09-01

Oxidative stress is an important contributory factor for the development of cardiovascular diseases like hypertension-induced hypertrophy. Mitochondrion is the major source of reactive oxygen species. Hence, protecting mitochondria from oxidative damage can be an effective therapeutic strategy for the prevention of hypertensive heart disease. Conventional antioxidants are not likely to be cardioprotective, as they cannot protect mitochondria from oxidative damage. EUK-134 is a salen-manganese complex with superoxide dismutase and catalase activity. The possible role of EUK-134, a mitoprotective antioxidant, in the prevention of hypertrophy of H9C2 cells was examined. The cells were stimulated with phenylephrine (50 μM), and hypertrophy was assessed based on cell volume and expression of brain natriuretic peptide and calcineurin. Enhanced myocardial lipid peroxidation and protein carbonyl content, accompanied by nuclear factor-kappa B gene expression, confirmed the presence of oxidative stress in hypertrophic cells. Metabolic shift was evident from reduction in the expression of medium-chain acyl-CoA dehydrogenase. Mitochondrial oxidative stress was confirmed by the reduced expression of mitochondria-specific antioxidant peroxiredoxin-3 and enhanced mitochondrial superoxide production. Compromised mitochondrial function was apparent from reduced mitochondrial membrane potential. Pretreatment with EUK-134 (10 μM) was effective in the prevention of hypertrophic changes in H9C2 cells, reduction of oxidative stress, and prevention of metabolic shift. EUK-134 treatment improved the oxidative status of mitochondria and reversed hypertrophy-induced reduction of mitochondrial membrane potential. Supplementation with EUK-134 is therefore identified as a novel approach to attenuate cardiac hypertrophy and lends scope for the development of EUK-134 as a therapeutic agent in the management of human cardiovascular disease.

MicroRNA-449a Inhibition Protects H9C2 Cells Against Hypoxia/Reoxygenation-Induced Injury by Targeting the Notch-1 Signaling Pathway.

PubMed

Cheng, Jing; Wu, Qianfu; Lv, Rong; Huang, Li; Xu, Banglong; Wang, Xianbao; Chen, Aihua; He, Fei

2018-05-07

The present study aimed to detect the expression of miR-449a and investigate the effect of miR-449a on cell injury in cardiomyocytes subjected to hypoxia/ reoxygenation (H/R) and its underlying mechanisms. The expression of miR-449a was determined using reverse transcription-polymerase chain reaction in both neonatal rat ventricular myocytes and H9C2 cells. For gain-of-function and loss-of-function studies, H9C2 cells were transfected with either miR-449a mimics or miR-449a inhibitor. The target gene of miR-449a was confirmed by a dual-luciferase reporter assay. Apoptosis was analyzed by both flow cytometry using Annexin V and propidium iodide and transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL). Necrosis was confirmed by the detection of lactate dehydrogenase release. The cell viability was measured using the methylthiotetrazole method. The protein levels of Notch-1, Notch-1 intracellular domain, hairy and enhancer of split-1 (Hes-1), and apoptosis-related genes were measured by Western blot analysis. MiR-449a was significantly upregulated in both neonatal rat ventricular myocytes and H9C2 cells subjected to H/R. However, H/R-induced cell apoptosis and necrosis were markedly reduced by miR-449a inhibition. By targeting Notch-1, miR-449a regulated the Notch-1/ Hes-1 signaling pathway. The blockade of the Notch signaling pathway partly abolished the protective effect of miR-449a suppression against H/R injury, whereas the overexpression of Notch-1 intracellular domain partly reversed the effect of miR-449a overexpression on H/R-induced cell injury. The present study suggested that miR-449a inhibition protected H9C2 cells against H/R-induced cell injury by targeting the Notch-1 signaling pathway, providing a novel insight into the molecular basis of myocardial ischemia-reperfusion injury and a potential therapeutic target. © 2018 The Author(s). Published by S. Karger AG, Basel.

Mitochondrial dysfunction in H9c2 cells during ischemia and amelioration with Tribulus terrestris L.

PubMed

Reshma, P L; Sainu, Neethu S; Mathew, Anil K; Raghu, K G

2016-05-01

The present study investigates the protective effect of partially characterized Tribulus terrestris L. fruit methanol extract against mitochondrial dysfunction in cell based (H9c2) myocardial ischemia model. To induce ischemia, the cells were maintained in an ischemic buffer (composition in mM -137 NaCl, 12 KCl, 0.5 MgCl2, 0.9 CaCl2, 20 HEPES, 20 2-deoxy-d-glucose, pH-6.2) at 37°C with 0.1% O2, 5% CO2, and 95% N2 in a hypoxia incubator for 1h. Cells were pretreated with various concentrations of T. terrestris L. fruit methanol extract (10 and 25μg/ml) and Cyclosporin A (1μM) for 24h prior to the induction of ischemia. Different parameters like lactate dehydrogenase release, total antioxidant capacity, glutathione content and antioxidant enzymes were investigated. Studies were conducted on mitochondria by analyzing alterations in mitochondrial membrane potential, integrity, and dynamics (fission and fusion proteins - Mfn1, Mfn2, OPA1, Drp1 and Fis1). Various biochemical processes in mitochondria like activity of electron transport chain (ETC) complexes, oxygen consumption and ATP production was measured. Ischemia for 1h caused a significant (p≤0.05) increase in LDH leakage, decrease in antioxidant activity and caused mitochondrial dysfunction. T. terrestris L. fruit methanol extract pretreatment was found effective in safeguarding mitochondria via its antioxidant potential, mediated through various bioactives. HPLC of T. terrestris L. fruit methanol extract revealed the presence of ferulic acid, phloridzin and diosgenin. T. terrestris L. fruit ameliorate ischemic insult in H9c2 cells by safeguarding mitochondrial function. This validates the use of T. terrestris L. against heart disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Long Non-Coding RNA H19 Protects H9c2 Cells against Hypoxia-Induced Injury by Targeting MicroRNA-139.

PubMed

Gong, Li-Cheng; Xu, Hai-Ming; Guo, Gong-Liang; Zhang, Tao; Shi, Jing-Wei; Chang, Chang

2017-01-01

Acute myocardial infarction (AMI) occurs when blood supply to the heart is diminished (ischemia) for long time; ischemia is primarily caused due to hypoxia. The present study evaluated the effects of long non-coding RNA H19 on hypoxic rat H9c2 cells and mouse HL-1 cells. Hypoxic injury was confirmed by measuring cell viability, migration and invasion, and apoptosis using MTT, Transwell and flow cytometry assays, respectively. H19 expression after hypoxia was estimated by qRT-PCR. We then measured the effects of non-physiologically expressed H19, knockdown of miR-139 with or without H19 silence, and abnormally expressed Sox8 on hypoxia-induced H9c2 cells. Moreover, the interacted miRNA for H19 and downstream target gene were virtually screened and verified. The involved signaling pathways and the effects of abnormally expressed H19 on contractility of HL-1 cells were explored via Western blot analysis. Hypoxia induced decreases of cell viability, migration and invasion, increase of cell apoptosis and up-regulation of H19. Knockdown of H19 increased hypoxia-induced injury in H9c2 cells. H19 acted as a sponge for miR-139 and H19 knockdown aggravated hypoxia-induced injury by up-regulating miR-139. Sox8 was identified as a target of miR-139, and its expression was negatively regulated by miR-139. The mechanistic studies revealed that overexpression of Sox8 might decrease hypoxia-induced cell injury by activating the PI3K/AKT/mTOR pathway and MAPK. Besides, H19 promoted contractility of HL-1 cells. These findings suggest that H19 alleviates hypoxia-induced myocardial cell injury by miR-139-mediated up-regulation of Sox8, along with activation of the PI3K/AKT/mTOR pathway and MAPK. © 2017 The Author(s). Published by S. Karger AG, Basel.

Tanshinone IIA protects H9c2 cells from oxidative stress-induced cell death via microRNA-133 upregulation and Akt activation.

PubMed

Gu, Yunfei; Liang, Zhuo; Wang, Haijun; Jin, Jun; Zhang, Shouyan; Xue, Shufeng; Chen, Jianfeng; He, Huijuan; Duan, Kadan; Wang, Jing; Chang, Xuewei; Qiu, Chunguang

2016-08-01

The aim of the present study was to investigate the cardioprotective effect of tanshinone IIA and the underlying molecular mechanisms. An in vitro model of oxidative stress injury was established in cardiac H9c2 cells, and the effects of tanshinone IIa were investigated using cell viability, reverse transcription-quantitative polymerase chain reaction and western blotting assays. The results demonstrated that tanshinone IIA protects H9c2 cells from H 2 O 2 -induced cell death in a concentration-dependent manner, via a mechanism involving microRNA-133 (miR-133), and that treatment with TIIA alone exerted no cytotoxic effects on H9c2. In order to further elucidate the mechanisms underlying the actions of TIIA, reverse transcription-quantitative polymease chain reaction and western blot analysis were performed. Reductions in miR-133 expression levels induced by increasing concentrations of H 2 O 2 were reversed by treatment with tanshinone IIA. In addition, the inhibition of miR-133 by transfection with an miR-133 inhibitor abolished the cardioprotective effects of tanshinone IIA against H 2 O 2 -induced cell death. Furthermore, western blot analysis demonstrated that tanshinone IIA activated Akt kinase via the phosphorylation of serine 473. Inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway by pretreatment with the PI3K specific inhibitors wortmannin and LY294002 also eliminated the cardioprotective effects of tanshinone IIA against H 2 O 2 -induced cell death. Western blot analysis demonstrated that H 2 O 2 -induced reductions in B cell lymphoma 2 (Bcl-2) expression levels were reversed by tanshinone IIA. In addition, the effect of tanshinone IIA on Bcl-2 protein expression level in an oxidative environment was suppressed by a PI3K inhibitor, wortmannin, indicating that tanshinone IIA exerts cardioprotective effects against H 2 O 2 -induced cell death via the activation of the PI3K/Akt signal transduction pathway and the consequent

Live imaging of H3K9 acetylation in plant cells

PubMed Central

Kurita, Kazuki; Sakamoto, Takuya; Yagi, Noriyoshi; Sakamoto, Yuki; Ito, Akihiro; Nishino, Norikazu; Sako, Kaori; Yoshida, Minoru; Kimura, Hiroshi; Seki, Motoaki; Matsunaga, Sachihiro

2017-01-01

Proper regulation of histone acetylation is important in development and cellular responses to environmental stimuli. However, the dynamics of histone acetylation at the single-cell level remains poorly understood. Here we established a transgenic plant cell line to track histone H3 lysine 9 acetylation (H3K9ac) with a modification-specific intracellular antibody (mintbody). The H3K9ac-specific mintbody fused to the enhanced green fluorescent protein (H3K9ac-mintbody-GFP) was introduced into tobacco BY-2 cells. We successfully demonstrated that H3K9ac-mintbody-GFP interacted with H3K9ac in vivo. The ratio of nuclear/cytoplasmic H3K9ac-mintbody-GFP detected in quantitative analysis reflected the endogenous H3K9ac levels. Under chemically induced hyperacetylation conditions with histone deacetylase inhibitors including trichostatin A, Ky-2 and Ky-14, significant enhancement of H3K9ac was detected by H3K9ac-mintbody-GFP dependent on the strength of inhibitors. Conversely, treatment with a histone acetyltransferase inhibitor, C646 caused a reduction in the nuclear to cytoplasmic ratio of H3K9ac-mintbody-GFP. Using this system, we assessed the environmental responses of H3K9ac and found that cold and salt stresses enhanced H3K9ac in tobacco BY-2 cells. In addition, a combination of H3K9ac-mintbody-GFP with 5-ethynyl-2′-deoxyuridine labelling confirmed that H3K9ac level is constant during interphase. PMID:28418019

Hydrogen gas protects against serum and glucose deprivation‑induced myocardial injury in H9c2 cells through activation of the NF‑E2‑related factor 2/heme oxygenase 1 signaling pathway.

PubMed

Xie, Qiang; Li, Xue-Xiang; Zhang, Peng; Li, Jin-Cao; Cheng, Ying; Feng, Yan-Ling; Huang, Bing-Sheng; Zhuo, Yu-Feng; Xu, Guo-Hua

2014-08-01

Ischemia or hypoxia‑induced myocardial injury is closely associated with oxidative stress. Scavenging free radicals and/or enhancing endogenous antioxidative defense systems may be beneficial for the impediment of myocardial ischemic injury. Hydrogen (H2) gas, as a water‑ and lipid‑soluble small molecule, is not only able to selectively eliminate hydroxyl (·OH) free radicals, but also to enhance endogenous antioxidative defense systems in rat lungs and arabidopsis plants. However, thus far, it has remained elusive whether H2 gas protects cardiomyocytes through enhancement of endogenous antioxidative defense systems. In the present study, the cardioprotective effect of H2 gas against ischemic or hypoxic injury was investigated, along with the underlying molecular mechanisms. H9c2 cardiomyoblasts (H9c2 cells) were treated in vitro with a chemical hypoxia inducer, cobalt chloride (CoCl2), to imitate hypoxia, or by serum and glucose deprivation (SGD) to imitate ischemia. Cell viability and intracellular ·OH free radicals were assessed. The role of an endogenous antioxidative defense system, the NF‑E2‑related factor 2 (Nrf2)/heme oxygenase 1 (HO‑1) signaling pathway, was evaluated. The findings revealed that treatment with CoCl2 or SGD markedly reduced cell viability in H9c2 cells. H2 gas‑rich medium protected against cell injury induced by SGD, but not that induced by CoCl2. When the cells were exposed to SGD, levels of intracellular ·OH free radicals were markedly increased; this was mitigated by H2 gas‑rich medium. Exposure of the cells to SGD also resulted in significant increases in HO‑1 expression and nuclear Nrf2 levels, and the HO‑1 inhibitor ZnPP IX and the Nrf2 inhibitor brusatol aggravated SGD‑induced cellular injury. H2 gas‑rich medium enhanced SGD‑induced upregulation of HO‑1 and Nrf2, and the HO‑1 or Nrf2 inhibition partially suppressed H2 gas‑induced cardioprotection. Furthermore, following genetic silencing of Nrf

MYBL2 protects against H9c2 injury induced by hypoxia via AKT and NF‑κB pathways.

PubMed

Shao, Mingfeng; Ren, Zexiang; Zhang, Rongjun

2018-03-01

Cardiovascular diseases have become one of the major public health problems in many countries. The downregulation of MYBL2 was found in H9c2 and native cardiomyocytes cells after hypoxia treatment. The present study aimed to investigate the effects of MYB proto‑oncogene like 2 (MYBL2) on H9c2 injury induced by hypoxia. Reverse transcription‑quantitative polymerase chain reaction and western blot were performed on H9c2 cells to determine the mRNA and protein levels of MYBL2, respectively. Small interfering RNA (siRNA) was employed to downregulate MYBL2 expression in H9c2 cells to investigate changes in cell proliferation and apoptosis. Cell proliferation was assessed by a Cell Counting kit‑8 assay and the percentage of apoptotic cells was determined using an Annexin V‑fluorescein isothiocyanate/propidium iodide apoptosis detection kit. The nuclear factor‑κB (NF‑κB) and AKT signaling pathways in H9c2 cells were investigated by western blot analysis. The results demonstrated that the overexpression of MYBL2 promoted cell proliferation and suppressed apoptosis. Furthermore, overexpression of MYBL2 suppressed the expression of phosphorylated (p)‑AKT, p‑NF‑κB inhibitor α, p‑p65 and B‑cell CLL/lymphoma 3 (Bcl‑3). The results indicated that MYBL2 may improve cell viability and inhibit H9c2 apoptosis via the inhibition of AKT and NF‑κB pathways. Therefore, MYBL2 may be a potential therapeutic target for the treatment of myocardial infarction.

Cardiac progenitor cell‑derived exosomes promote H9C2 cell growth via Akt/mTOR activation.

PubMed

Li, Shentang; Jiang, Jie; Yang, Zuocheng; Li, Zhuoying; Ma, Xing; Li, Xin

2018-05-21

Exosomes are cell‑derived vesicles released from a variety of mammalian cells that are involved in cell‑to‑cell signalling. It has been reported that cardiac progenitor cells (CPCs) derived from an adult heart are one of the most promising stem cell types for cardioprotection and repair. The mammalian target of rapamycin (mTOR) signalling pathway is a pivotal regulator in CPCs, therefore, CPC‑derived exosomes were used in the present study to investigate whether it can promote H9C2 cell growth through the protein kinase B (PKB, or Akt)/mTOR signalling pathway. The CPCs were isolated from Sprague‑Dawley hearts. Following treatment with a specific medium, the exosomes were purified and identified by electron micrograph and western blot assays, using CD63 and CD81 as markers. The methyl‑thiazolyl‑tetrazolium and 5‑ethynyl‑2'‑deoxyuridine methods were used to detect H9C2 cell growth. The expression of Akt and mTOR were detected by western blot analysis following treatment with 200 or 400 µg/ml of exosomes for 24 or 48 h, respectively. It was found that, compared with higher concentrations of exosomes, prolonging the duration of exposure promoted cell growth. Accordingly, CPC‑derived exosomes stimulated the expression of Akt to a marked degree; groups treated with exosomes for 48 h showed higher expression of Akt than those treated for 24 h at the same concentration. mTOR was also stimulated by CPC‑derived exosomes. The activation of mTOR increased in accordance with the treatment time at an exosome concentration of 200 µg/ml and decreased with treatment time at an exosome concentration of 400 µg/ml. In conclusion, the present study demonstrated that CPC‑derived exosomes promoted H9C2 cell growth via the activation of Akt/mTOR in a time‑dependent manner at a relatively low exosome concentration, which may provide a novel therapy for cardiovascular disease.

Pim-2 protects H9c2 cardiomyocytes from hypoxia/reoxygenation-induced apoptosis via downregulation of Bim expression.

PubMed

Xu, Yan; Xing, Yawei; Xu, Yanjie; Huang, Chahua; Bao, Huihui; Hong, Kui; Cheng, Xiaoshu

2016-12-01

We know that silencing Bim, a pro-apoptosis protein, significantly attenuates glucose and oxygen-deprived induced apoptosis in cardiomyocytes. However, the mechanisms underlying the regulation of the Bim activation in the heart have remained unknown. Pim-2 is one of three Pim serine/threonine kinase family members thought to be involved in cell survival and proliferation. H9c2 cardiomyocytes were subjected to a hypoxia/reoxygenation (H/R) condition in vitro, mimicking ischemic/reperfusion injury in vivo. H/R augmented the expression of Bim, Cyt C, and Pim-2 and induced H9c2 cell apoptosis. Overexpression of Pim-2 attenuated apoptosis which induced by H/R in H9c2 cells, via downregulation of Bim and Cyt C expression. Silencing of Pim-2 promoted H/R-induced apoptosis via upregulation of Bim and Cyt C expression. Co-IP revealed the interaction between Pim-2 and Bim protein, with Bim Ser 65 phosphorylated by Pim-2. Furthermore, blocking proteasome activity by MG132 prevented Bim degradation, and Bim S65A mutation could reverse the anti-apoptotic role of Pim-2 which induced by H/R. These data demonstrated that Pim-2 is a novel Bim-interacting protein, which negatively regulates Bim degradation and protects H9c2 cardiomyocytes from H/R-induced apoptosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Cyclic mechanical stretch enhances BMP9-induced osteogenic differentiation of mesenchymal stem cells.

PubMed

Song, Yang; Tang, Yinhong; Song, Jinlin; Lei, Mingxing; Liang, Panpan; Fu, Tiwei; Su, Xudong; Zhou, Pengfei; Yang, Li; Huang, Enyi

2018-04-01

The purpose of this study was to investigate whether mechanical stretch can enhance the bone morphogenetic protein 9 (BMP9)-induced osteogenic differentiation in MSCs. Recombinant adenoviruses were used to overexpress the BMP9 in C3H10T1/2 MSCs. Cells were seeded onto six-well BioFlex collagen I-coated plates and subjected to cyclic mechanical stretch [6% elongation at 60 cycles/minute (1 Hz)] in a Flexercell FX-4000 strain unit for up to 12 hours. Immunostaining and confocal microscope were used to detect cytoskeleton organization. Cell cycle progression was checked by flow cytometry. Alkaline phosphatase activity was measured with a Chemiluminescence Assay Kit and was quantified with a histochemical staining assay. Matrix mineralization was examined by Alizarin Red S Staining. Mechanical stretch induces cytoskeleton reorganization and inhibits cell proliferation by preventing cells entry into S phase of the cell cycle. Although mechanical stretch alone does not induce the osteogenic differentiation of C3H10T1/2 MSCs, co-stimulation with mechanical stretch and BMP9 enhances alkaline phosphatase activity. The expression of key lineage-specific regulators (e.g., osteocalcin (OCN), SRY-related HMG-box 9, and runt-related transcription factor 2) is also increased after the co-stimulation, compared to the mechanical stretch stimulation along. Furthermore, mechanical stretch augments the BMP9-mediated bone matrix mineralization of C3H10T1/2 MSCs. Our results suggest that mechanical stretch enhances BMP9-induced osteoblastic lineage specification in C3H10T1/2 MSCs.

A1 adenosine receptor-induced phosphorylation and modulation of transglutaminase 2 activity in H9c2 cells: A role in cell survival.

PubMed

Vyas, Falguni S; Hargreaves, Alan J; Bonner, Philip L R; Boocock, David J; Coveney, Clare; Dickenson, John M

2016-05-01

The regulation of tissue transglutaminase (TG2) activity by the GPCR family is poorly understood. In this study, we investigated the modulation of TG2 activity by the A1 adenosine receptor in cardiomyocyte-like H9c2 cells. H9c2 cells were lysed following stimulation with the A1 adenosine receptor agonist N(6)-cyclopentyladenosine (CPA). Transglutaminase activity was determined using an amine incorporating and a protein cross linking assay. TG2 phosphorylation was assessed via immunoprecipitation and Western blotting. The role of TG2 in A1 adenosine receptor-induced cytoprotection was investigated by monitoring hypoxia-induced cell death. CPA induced time and concentration-dependent increases in amine incorporating and protein crosslinking activity of TG2. CPA-induced increases in TG2 activity were attenuated by the TG2 inhibitors Z-DON and R283. Responses to CPA were blocked by PKC (Ro 31-8220), MEK1/2 (PD 98059), p38 MAPK (SB 203580) and JNK1/2 (SP 600125) inhibitors and by removal of extracellular Ca(2+). CPA triggered robust increases in the levels of TG2-associated phosphoserine and phosphothreonine, which were attenuated by PKC, MEK1/2 and JNK1/2 inhibitors. Fluorescence microscopy revealed TG2-mediated biotin-X-cadaverine incorporation into proteins and proteomic analysis identified known (Histone H4) and novel (Hexokinase 1) protein substrates for TG2. CPA pre-treatment reversed hypoxia-induced LDH release and decreases in MTT reduction. TG2 inhibitors R283 and Z-DON attenuated A1 adenosine receptor-induced cytoprotection. TG2 activity was stimulated by the A1 adenosine receptor in H9c2 cells via a multi protein kinase dependent pathway. These results suggest a role for TG2 in A1 adenosine receptor-induced cytoprotection. Copyright © 2016 Elsevier Inc. All rights reserved.

Ursolic Acid-enriched herba cynomorii extract induces mitochondrial uncoupling and glutathione redox cycling through mitochondrial reactive oxygen species generation: protection against menadione cytotoxicity in h9c2 cells.

PubMed

Chen, Jihang; Wong, Hoi Shan; Ko, Kam Ming

2014-01-27

Herba Cynomorii (Cynomorium songaricum Rupr., Cynomoriaceae) is one of the most commonly used 'Yang-invigorating' tonic herbs in Traditional Chinese Medicine (TCM). An earlier study in our laboratory has demonstrated that HCY2, an ursolic acid-enriched fraction derived from Herba Cynomorii, increased mitochondrial ATP generation capacity (ATP-GC) and induced mitochondrial uncoupling as well as a cellular glutathione response, thereby protecting against oxidant injury in H9c2 cells. In this study, we demonstrated that pre-incubation of H9c2 cells with HCY2 increased mitochondrial reactive oxygen species (ROS) generation in these cells, which is likely an event secondary to the stimulation of the mitochondrial electron transport chain. The suppression of mitochondrial ROS by the antioxidant dimethylthiourea abrogated the HCY2-induced enhancement of mitochondrial uncoupling and glutathione reductase (GR)-mediated glutathione redox cycling, and also protected against menadione-induced cytotoxicity. Studies using specific inhibitors of uncoupling protein and GR suggested that the HCY2-induced mitochondrial uncoupling and glutathione redox cycling play a determining role in the cytoprotection against menadione-induced oxidant injury in H9c2 cells. Experimental evidence obtained thus far supports the causal role of HCY2-induced mitochondrial ROS production in eliciting mitochondrial uncoupling and glutathione antioxidant responses, which offer cytoprotection against oxidant injury in H9c2 cells.

Molecular identification for epigallocatechin-3-gallate-mediated antioxidant intervention on the H2O2-induced oxidative stress in H9c2 rat cardiomyoblasts.

PubMed

Chen, Wei-Cheng; Hsieh, Shih-Rong; Chiu, Chun-Hwei; Hsu, Ban-Dar; Liou, Ying-Ming

2014-06-09

Epigallocatechin-3-gallate (EGCG) has been documented for its beneficial effects protecting oxidative stress to cardiac cells. Previously, we have shown the EGCG-mediated cardiac protection by attenuating reactive oxygen species and cytosolic Ca2+ in cardiac cells during oxidative stress and myocardial ischemia. Here, we aimed to seek a deeper elucidation of the molecular anti-oxidative capabilities of EGCG in an H2O2-induced oxidative stress model of myocardial ischemia injury using H9c2 rat cardiomyoblasts. Proteomics analysis was used to determine the differential expression of proteins in H9c2 cells cultured in the conditions of control, 400 μM H2O2 exposure for 30 min with and/or without 10 to 20 μM EGCG pre-treatment. In this model, eight proteins associated with energy metabolism, mitochondrial electron transfer, redox regulation, signal transduction, and RNA binding were identified to take part in EGCG-ameliorating H2O2-induced injury in H9c2 cells. H2O2 exposure increased oxidative stress evidenced by increases in reactive oxygen species and cytosolic Ca2+ overload, increases in glycolytic protein, α-enolase, decreases in antioxidant protein, peroxiredoxin-4, as well as decreases in mitochondrial proteins, including aldehyde dehydrogenase-2, ornithine aminotransferase, and succinate dehydrogenase ubiquinone flavoprotein subunit. All of these effects were reversed by EGCG pre-treatment. In addition, EGCG attenuated the H2O2-induced increases of Type II inositol 3, 4-bisphosphate 4-phosphatase and relieved its subsequent inhibition of the downstream signalling for Akt and glycogen synthase kinase-3β (GSK-3β)/cyclin D1 in H9c2 cells. Pre-treatment with EGCG or GSK-3β inhibitor (SB 216763) significantly improved the H2O2-induced suppression on cell viability, phosphorylation of pAkt (S473) and pGSK-3β (S9), and level of cyclin D1 in cells. Collectively, these findings suggest that EGCG blunts the H2O2-induced oxidative effect on the Akt activity

Molecular identification for epigallocatechin-3-gallate-mediated antioxidant intervention on the H2O2-induced oxidative stress in H9c2 rat cardiomyoblasts

PubMed Central

2014-01-01

Background Epigallocatechin-3-gallate (EGCG) has been documented for its beneficial effects protecting oxidative stress to cardiac cells. Previously, we have shown the EGCG-mediated cardiac protection by attenuating reactive oxygen species and cytosolic Ca2+ in cardiac cells during oxidative stress and myocardial ischemia. Here, we aimed to seek a deeper elucidation of the molecular anti-oxidative capabilities of EGCG in an H2O2-induced oxidative stress model of myocardial ischemia injury using H9c2 rat cardiomyoblasts. Results Proteomics analysis was used to determine the differential expression of proteins in H9c2 cells cultured in the conditions of control, 400 μM H2O2 exposure for 30 min with and/or without 10 to 20 μM EGCG pre-treatment. In this model, eight proteins associated with energy metabolism, mitochondrial electron transfer, redox regulation, signal transduction, and RNA binding were identified to take part in EGCG-ameliorating H2O2-induced injury in H9c2 cells. H2O2 exposure increased oxidative stress evidenced by increases in reactive oxygen species and cytosolic Ca2+ overload, increases in glycolytic protein, α-enolase, decreases in antioxidant protein, peroxiredoxin-4, as well as decreases in mitochondrial proteins, including aldehyde dehydrogenase-2, ornithine aminotransferase, and succinate dehydrogenase ubiquinone flavoprotein subunit. All of these effects were reversed by EGCG pre-treatment. In addition, EGCG attenuated the H2O2-induced increases of Type II inositol 3, 4-bisphosphate 4-phosphatase and relieved its subsequent inhibition of the downstream signalling for Akt and glycogen synthase kinase-3β (GSK-3β)/cyclin D1 in H9c2 cells. Pre-treatment with EGCG or GSK-3β inhibitor (SB 216763) significantly improved the H2O2-induced suppression on cell viability, phosphorylation of pAkt (S473) and pGSK-3β (S9), and level of cyclin D1 in cells. Conclusions Collectively, these findings suggest that EGCG blunts the H2O2-induced oxidative

ERβ targets ZAK and attenuates cellular hypertrophy via SUMO-1 modification in H9c2 cells.

PubMed

Pai, Peiying; Shibu, Marthandam Asokan; Chang, Ruey-Lin; Yang, Jaw-Ji; Su, Chia-Chi; Lai, Chao-Hung; Liao, Hung-En; Viswanadha, Vijaya Padma; Kuo, Wei-Wen; Huang, Chih-Yang

2018-06-22

Aberrant expression of leucine zipper- and sterile ɑ motif-containing kinase (ZAK) observed in pathological human myocardial tissue is associated with the progression and elevation of hypertrophy. Our previous reports have correlated high levels of estrogen (E2) and abundant estrogen receptor (ER) α with a low incidence of pathological cardiac-hypertrophy and heart failure in the premenopause female population. However, the effect of elevated ERβ expression is not well known yet. Therefore, in this study, we have analyzed the cardioprotective effects and mechanisms of E2 and/or ERβ against ZAK overexpression-induced cellular hypertrophy. We have used transient transfection to overexpress ERβ into the ZAK tet-on H9c2 cells that harbor the doxycycline-inducible ZAK plasmid. The results show that ZAK overexpression in H9c2 cells resulted in hypertrophic effects, which was correlated with the upregulation of p-JNK and p-p38 MAPKs and their downstream transcription factors c-Jun and GATA-4. However, ERβ and E2 with ERβ overexpressions totally suppressed the effects of ZAK overexpression and inhibited the levels of p-JNK, p-p38, c-Jun, and GATA-4 effectively. Our results further reveal that ERβ directly binds with ZAK under normal conditions; however, ZAK overexpression reduced the association of ZAK-ERβ. Interestingly, increase in ERβ and E2 along with ERβ overexpression both enhanced the binding strengths of ERβ and ZAK and reduced the ZAK protein level. ERβ overexpression also suppressed the E3 ligase-casitas B-lineage lymphoma (CBL) and attenuated CBL-phosphoinositide 3-kinase (PI3K) protein association to prevent PI3K protein degradation. Moreover, ERβ and/or E2 blocked ZAK nuclear translocation via the inhibition of small ubiquitin-like modifier (SUMO)-1 modification. Taken together, our results further suggest that ERβ overexpression strongly suppresses ZAK-induced cellular hypertrophy and myocardial damage. © 2018 Wiley Periodicals, Inc.

Sulforaphane protects H9c2 cardiomyocytes from angiotensin II-induced hypertrophy.

PubMed

Wu, Q-Q; Zong, J; Gao, L; Dai, J; Yang, Z; Xu, M; Fang, Y; Ma, Z-G; Tang, Q-Z

2014-05-01

Cardiac hypertrophy is an adaptive process of the heart in response to various stimuli, but sustained cardiac hypertrophy will finally lead to heart failure. Sulforaphane-extracted from cruciferous vegetables of the genus Brassica such as broccoli, brussels sprouts, and cabbage-has been evaluated for its anticarcinogenic and antioxidant effects. To investigate the effect of sulforaphane on angiotensin II (Ang II)-induced cardiac hypertrophy in vitro. Embryonic rat heart-derived H9c2 cells were co-incubated with sulforaphane and Ang II. The cell surface area and mRNA levels of hypertrophic markers were measured to clarify the effect of sulforaphane on cardiac hypertrophy. The underlying mechanism was further investigated by detecting the activation of Akt and NF-κB signaling pathways. We found that H9c2 cells pretreated with sulforaphane were protected from Ang II-induced hypertrophy. The increasing mRNA levels of ANP, BNP, and β-MHC in Ang II-stimulated cells were also down-regulated after sulforaphane treatment. Moreover, sulforaphane repressed the Ang II-induced phosphorylation of Akt, GSK3β, mTOR, eIF4e, as well as of IκBα and NF-κB. Based on our results, sulforaphane attenuates Ang II-induced hypertrophy of H9c2 cardiomyocytes mediated by the inhibition of intracellular signaling pathways including Akt and NF-κB.

Preparation and Characterization of Selenium Incorporated Guar Gum Nanoparticle and Its Interaction with H9c2 Cells

PubMed Central

Soumya, Rema Sreenivasan; Vineetha, Vadavanath Prabhakaran; Reshma, Premachandran Latha; Raghu, Kozhiparambil Gopalan

2013-01-01

This study deals with the preparation and characterization of selenium incorporated guar gum nanoparticle (SGG), and its effect on H9c2 cardiomyoblast. Herein, nanoprecipitation techniques had been employed for the preparation of SGG nanoparticle. The prepared nanoparticle had been subjected to various types of analytical techniques like transmission electron microscopy (TEM), X-ray diffraction (XRD) and particle size analysis to confirm the characteristics of nanoparticle as well as for selenium incorporation. Physical characterization of nanoparticle showed that the size of nanoparticles increase upto ∼69–173 nm upon selenium incorporation from ∼41–132 nm. Then the prepared nanoparticles were evaluated for its effect on H9c2 cells. In this regard, the effect of nanoparticle on various vital parameters of H9c2 cells was studied. Parameters like cell viability, uptake of selenium incorporated guar gum nanoparticle by the cells, effect of SGG on DNA integrity, apoptosis, reactive oxygen species generation, alteration in transmembrane potential of mitochondria and cytoskeletal integrity had been investigated. Viability results showed that up to 25 nM of SGG was safe (10.31%) but beyond that it induces cytotoxicity. Cellular uptake of selenium showed that cell permeability for SGG is significantly high compared to normal selenium (7.2 nM of selenium for 25 nM SGG compared with 5.2 nM selenium for 25 nM sodium selenite). There was no apoptosis with SGG and also it protects DNA from hydroxyl radical induced breakage. Likewise no adverse effect on mitochondria and cytoskeleton was observed for 25 nM of SGG. Overall results reveal that SGG is highly suitable for biomedical research application. PMID:24098647

β-Sitosterol enhances cellular glutathione redox cycling by reactive oxygen species generated from mitochondrial respiration: protection against oxidant injury in H9c2 cells and rat hearts.

PubMed

Wong, Hoi Shan; Chen, Na; Leong, Pou Kuan; Ko, Kam Ming

2014-07-01

Herba Cistanches (Cistanche deserticola Y. C. Ma) is a 'Yang-invigorating' tonic herb in Chinese medicine. Preliminary chemical analysis indicated that β-sitosterol (BS) is one of the chemical constituents in an active fraction of Herba Cistanches. To investigate whether BS is an active ingredient of Herba Cistanches, the effects of BS on H9c2 cells and rat hearts were examined. The results indicated that BS stimulated the mitochondrial ATP generation capacity in H9c2 cells, which was associated with the increased production of mitochondrial reactive oxygen species. BS also stimulated mitochondrial state 3 and state 4 respiration, with the resultant decrease in coupling efficiency. BS produced an up-regulation of cellular glutathione redox cycling and protected against hypoxia/reoxygenation-induced apoptosis in H9c2 cells. However, the protective effect of BS against myocardial ischemia/reperfusion injury was seen in female but not male rats ex vivo. The cardioprotection afforded by BS was likely mediated by an up-regulation of mitochondrial glutathione redox cycling in female rat hearts. In conclusion, the ensemble of results suggests that BS is an active ingredient of Herba Cistanches. The gender-dependent effect of BS on myocardial protection will further be investigated. Copyright © 2013 John Wiley & Sons, Ltd.

Pharmacological discrimination of plasmalemmal and mitochondrial sodium-calcium exchanger in cardiomyocyte-derived H9c2 cells.

PubMed

Namekata, Iyuki; Hamaguchi, Shogo; Tanaka, Hikaru

2015-01-01

We examined the effects of SEA0400 and CGP-37157 on the plasmalemmal Na(+)-Ca(2+) exchanger (NCX) and mitochondrial NCX using H9c2 cardiomyocytes loaded with Ca(2+)-sensitive fluorescent probes. The plasmalemmal NCX activity, which was measured as the increase in cytoplasmic Ca(2+) concentration after application of low Na(+) extracellular solution, was inhibited by SEA0400 but not by CGP-37157. The mitochondrial NCX activity, which was measured in permeabilized H9c2 cells as the decrease in mitochondrial Ca(2+) concentration after application of Ca(2+)-free extramitochondrial solution, was inhibited by CGP-37157 but not by SEA0400. These results indicate that SEA0400 and CGP-37157 act as selective inhibitors towards plasmalemmal and mitochondrial NCX, respectively, and provide pharmacological evidence that the plasmalemmal and mitochondrial NCX are distinct molecular entities.

The long noncoding RNA THRIL knockdown protects hypoxia-induced injuries of H9C2 cells through regulating miR-99a.

PubMed

Xia, Jingwen; Jiang, Nianxin; Li, Yansong; Wei, Yong; Zhang, Xuan

2018-05-10

Myocardial infarction (MI) is a leading cause of disease with high morbidity and mortality worldwide. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in heart disease pathogenesis. This study aimed to investigate the effect and the molecular basis of THRIL on hypoxia-injured H9C2 cells. THRIL, miR-99a and Brahma-related gene 1 (Brg1) expression in H9C2 cells were altered by transient transfections. The cells were subjected to hypoxia for 4 h, and then the levels of THRIL, miR-99a and Brg1 were investigated. Cell viability, migration and invasion, and apoptotic cells were respectively measured by trypan blue exclusion assay, transwell migration assay and flow cytometry assay. Dual luciferase reporter assay was conducted to verify the interaction between miR-99a and THRIL. Furthermore, levels of apoptosis-, PI3K/AKT and mTOR pathways-related factors were measured by western blotting. Hypoxia induced an increase of THRIL but a reduction of miR-99a and Brg1. THRIL inhibition significantly attenuated hypoxia-induced cell injuries, as increased cell viability, migration and invasion, and decreased cell apoptosis. THRIL negatively regulated miR-99a expression through sponging with miR-99a binding site, and miR-99a inhibition abolished the protective effects of THRIL knockdown against hypoxia-induced injury in H9C2 cells. Furthermore, miR-99a positively regulated the expression of Brg1. Brg1 inhibition promoted hypoxia-induced cell injuries, while Brg1 overexpression alleviated hypoxia-induced cell injuries. Moreover, Brg1 overexpression activated PI3K/AKT and mTOR pathways. This study demonstrates that THRIL inhibition represents a protective effect against hypoxia-induced injuries in H9C2 cells by up-regulating miR-99a expression.

Histone H3K9 Demethylase JMJD2B Activates Adipogenesis by Regulating H3K9 Methylation on PPARγ and C/EBPα during Adipogenesis

PubMed Central

Jang, Min-Kyung; Kim, Ji-Hyun; Jung, Myeong Ho

2017-01-01

Previous studies have shown that tri- or di-methylation of histone H3 at lysine 9 (H3K9me3/me2) on the promoter of the peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) contribute to the repression of PPARγ and C/EBPα and inhibition of adipogenesis in 3T3-L1 preadipocytes. The balance of histone methylation is regulated by histone methyltransferases and demethylases. However, it is poorly understood which demethylases are responsible for removing H3K9me3/me2 on the promoter of PPARγ and C/EBPα. JMJD2B is a H3K9me3/me2 demethylase that was previously shown to activate adipogenesis by promoting mitotic clonal expansion. Nevertheless, it remains unclear whether JMJD2B plays a role in the regulation of adipogenesis by removing H3K9me3/me2 on the promoter of PPARγ and C/EBPα and subsequently activating PPARγ and C/EBPα expression. Here, we showed that JMJD2B decreased H3K9me3/me2 on the promoter of PPARγ and C/EBPα, which in turn stimulated the expression of PPARγ and C/EBPα. JMJD2B knockdown using siRNA in 3T3-L1 preadipocytes repressed the expression of PPARγ and C/EBPα, resulting in inhibition of adipogenesis. This was accompanied by increased enrichment of H3K9me3/me2 on the promoter of PPARγ and C/EBPα. In contrast, overexpression of JMJD2B increased the expression of PPARγ and C/EBPα, which was accompanied by decreased enrichment of H3K9me3/me2 on the promoter and activated adipogenesis. Together, these results indicate that JMJD2B regulates PPARγ and C/EBPα during adipogenesis. PMID:28060835

Role of transglutaminase 2 in A1 adenosine receptor- and β2-adrenoceptor-mediated pharmacological pre- and post-conditioning against hypoxia-reoxygenation-induced cell death in H9c2 cells.

PubMed

Vyas, Falguni S; Nelson, Carl P; Dickenson, John M

2018-01-15

Pharmacologically-induced pre- and post-conditioning represent attractive therapeutic strategies to reduce ischaemia/reperfusion injury during cardiac surgery and following myocardial infarction. We have previously reported that transglutaminase 2 (TG2) activity is modulated by the A 1 adenosine receptor and β 2 -adrenoceptor in H9c2 cardiomyoblasts. The primary aim of this study was to determine the role of TG2 in A 1 adenosine receptor and β 2 -adrenoceptor-induced pharmacological pre- and post-conditioning in the H9c2 cells. H9c2 cells were exposed to 8h hypoxia (1% O 2 ) followed by 18h reoxygenation, after which cell viability was assessed by monitoring mitochondrial reduction of MTT, lactate dehydrogenase release and caspase-3 activation. N 6 -cyclopentyladenosine (CPA; A 1 adenosine receptor agonist), formoterol (β 2 -adrenoceptor agonist) or isoprenaline (non-selective β-adrenoceptor agonist) were added before hypoxia/reoxygenation (pre-conditioning) or at the start of reoxygenation following hypoxia (post-conditioning). Pharmacological pre- and post-conditioning with CPA and isoprenaline significantly reduced hypoxia/reoxygenation-induced cell death. In contrast, formoterol did not elicit protection. Pre-treatment with pertussis toxin (G i/o -protein inhibitor), DPCPX (A 1 adenosine receptor antagonist) or TG2 inhibitors (Z-DON and R283) attenuated the A 1 adenosine receptor-induced pharmacological pre- and post-conditioning. Similarly, pertussis toxin, ICI 118,551 (β 2 -adrenoceptor antagonist) or TG2 inhibition attenuated the isoprenaline-induced cell survival. Knockdown of TG2 using small interfering RNA (siRNA) attenuated CPA and isoprenaline-induced pharmacological pre- and post-conditioning. Finally, proteomic analysis following isoprenaline treatment identified known (e.g. protein S100-A6) and novel (e.g. adenine phosphoribosyltransferase) protein substrates for TG2. These results have shown that A 1 adenosine receptor and β 2 -adrenoceptor

Synthesis, structure and reactivity of rare-earth metallacarborane alkyls [η(1):η(5)-O(CH2)2C2B9H9]Ln(σ:η(1)-CH2C6H4-o-NMe2)(THF)2.

PubMed

Yang, Jingying; Xie, Zuowei

2015-04-14

Rare-earth metallacarborane alkyls can be stabilized by the incorporation of a functional sidearm into both π and σ ligands. Reaction of [Me3NH][7,8-O(CH2)2-7,8-C2B9H10] with one equiv. of Ln(CH2C6H4-o-NMe2)3 gave metallacarborane alkyls [η(1):η(5)-O(CH2)2C2B9H9]Ln(σ:η(1)-CH2C6H4-o-NMe2)(THF)2 (Ln = Y (), Gd (), Er ()) via alkane elimination. They represent the first examples of rare-earth metallacarborane alkyls. Treatment of with RN[double bond, length as m-dash]C[double bond, length as m-dash]NR (R = Cy, (i)Pr) or 2-benzoylpyridine afforded the corresponding mono-insertion products [η(1):η(5)-O(CH2)2C2B9H9]Y[η(2)-(RN)2C(CH2C6H4-o-NMe2)](DME) (R = Cy (), (i)Pr ()) or [η(1):η(5)-O(CH2)2C2B9H9]Y[C5H4NC(Ph)(CH2C6H4-o-NMe2)O](THF)2 (), respectively. Complex also reacted with ArNCO or ArNC (Ar = 2,6-diisopropylphenyl, 2,6-dimethylphenyl) to give di-insertion products [η(1):η(5)-O(CH2)2C2B9H9]Y[OC([double bond, length as m-dash]NC6H3Me2)N(C6H3Me2)C(CH2C6H4-o-NMe2)O](THF)2 () or [η(1):η(5)-O(CH2)2C2B9H9]Y[C([double bond, length as m-dash]NC6H3(i)Pr2)C([double bond, length as m-dash]NC6H3(i)Pr2)(CH2C6H4-o-NMe2)](DME) (). These results showed that the reactivity pattern of the Ln-C σ bond in rare-earth metallacarborane alkyls was dependent on the nature of the unsaturated organic molecules. New complexes were characterized by various spectroscopic techniques and elemental analysis. Some were further confirmed by single-crystal X-ray analysis.

5-AIQ inhibits H2O2-induced apoptosis through reactive oxygen species scavenging and Akt/GSK-3β signaling pathway in H9c2 cardiomyocytes.

PubMed

Park, Eun-Seok; Kang, Jun Chul; Kang, Do-Hyun; Jang, Yong Chang; Yi, Kyu Yang; Chung, Hun-Jong; Park, Jong Seok; Kim, Bokyung; Feng, Zhong-Ping; Shin, Hwa-Sup

2013-04-01

Poly(adenosine 5'-diphosphate ribose) polymerase (PARP) is a nuclear enzyme activated by DNA strand breaks and plays an important role in the tissue injury associated with ischemia and reperfusion. The aim of the present study was to investigate the protective effect of 5-aminoisoquinolinone (5-AIQ), a PARP inhibitor, against oxidative stress-induced apoptosis in H9c2 cardiomyocytes. 5-AIQ pretreatment significantly protected against H2O2-induced cell death, as determined by the XTT assay, cell counting, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and Western blot analysis of apoptosis-related proteins such as caspase-3, Bax, and Bcl-2. Upregulation of antioxidant enzymes such as manganese superoxide dismutase and catalase accompanied the protective effect of 5-AIQ on H2O2-induced cell death. Our data also showed that 5-AIQ pretreatment protected H9c2 cells from H2O2-induced apoptosis by triggering activation of Akt and glycogen synthase kinase-3β (GSK-3β), and that the protective effect of 5-AIQ was diminished by the PI3K inhibitor LY294002 at a concentration that effectively abolished 5-AIQ-induced Akt and GSK-3β activation. In addition, inhibiting the Akt/GSK-3β pathway by LY294002 significantly attenuated the 5-AIQ-mediated decrease in cleaved caspase-3 and Bax activation and H9c2 cell apoptosis induction. Taken together, these results demonstrate that 5-AIQ prevents H2O2-induced apoptosis in H9c2 cells by reducing intracellular reactive oxygen species production, regulating apoptosis-related proteins, and activating the Akt/GSK-3β pathway. Copyright © 2013 Elsevier Inc. All rights reserved.

5-AIQ inhibits H{sub 2}O{sub 2}-induced apoptosis through reactive oxygen species scavenging and Akt/GSK-3β signaling pathway in H9c2 cardiomyocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Eun-Seok; Kang, Jun Chul; Kang, Do-Hyun

2013-04-01

Poly(adenosine 5′-diphosphate ribose) polymerase (PARP) is a nuclear enzyme activated by DNA strand breaks and plays an important role in the tissue injury associated with ischemia and reperfusion. The aim of the present study was to investigate the protective effect of 5-aminoisoquinolinone (5-AIQ), a PARP inhibitor, against oxidative stress-induced apoptosis in H9c2 cardiomyocytes. 5-AIQ pretreatment significantly protected against H{sub 2}O{sub 2}-induced cell death, as determined by the XTT assay, cell counting, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and Western blot analysis of apoptosis-related proteins such as caspase-3, Bax, and Bcl-2. Upregulation of antioxidant enzymes such as manganese superoxidemore » dismutase and catalase accompanied the protective effect of 5-AIQ on H{sub 2}O{sub 2}-induced cell death. Our data also showed that 5-AIQ pretreatment protected H9c2 cells from H{sub 2}O{sub 2}-induced apoptosis by triggering activation of Akt and glycogen synthase kinase-3β (GSK-3β), and that the protective effect of 5-AIQ was diminished by the PI3K inhibitor LY294002 at a concentration that effectively abolished 5-AIQ-induced Akt and GSK-3β activation. In addition, inhibiting the Akt/GSK-3β pathway by LY294002 significantly attenuated the 5-AIQ-mediated decrease in cleaved caspase-3 and Bax activation and H9c2 cell apoptosis induction. Taken together, these results demonstrate that 5-AIQ prevents H{sub 2}O{sub 2}-induced apoptosis in H9c2 cells by reducing intracellular reactive oxygen species production, regulating apoptosis-related proteins, and activating the Akt/GSK-3β pathway. - Highlights: ► 5-AIQ, a PARP inhibitor, decreased H{sub 2}O{sub 2}-induced H9c2 cell death and apoptosis. ► 5-AIQ upregulated antioxidant Mn-SOD and catalase, while decreasing ROS production. ► 5-AIQ decreased H{sub 2}O{sub 2}-induced increase in cleaved caspase-3 and Bax and decrease in Bcl2. ► 5-AIQ activated Akt and

The effect of Astragalus polysaccharides on attenuation of diabetic cardiomyopathy through inhibiting the extrinsic and intrinsic apoptotic pathways in high glucose -stimulated H9C2 cells.

PubMed

Sun, Shuqin; Yang, Shuo; Dai, Min; Jia, Xiujuan; Wang, Qiyan; Zhang, Zheng; Mao, Yongjun

2017-06-13

Apoptosis plays a critical role in the progression of diabetic cardiomyopathy (DC). Astragalus polysaccharides (APS), an extract of astragalus membranaceus (AM), is an effective cardioprotectant. Currently, little is known about the detailed mechanisms underlying cardioprotective effects of APS. The aims of this study were to investigate the potential effects and mechanisms of APS on apoptosis employing a model of high glucose induction of apoptosis in H9C2 cells. A model of high glucose induction of H9C2 cell apoptosis was adopted in this research. The cell viabilities were analyzed by MTT assay, and the apoptotic response was quantified by flow cytometry. The expression levels of the apoptosis related proteins were determined by Real-time PCR and western blotting. Incubation of H9C2 cells with various concentrations of glucose (i.e., 5.5, 12.5, 25, 33 and 44 mmol/L) for 24 h revealed that cell viability was reduced by high glucose dose-dependently. Pretreatment of cells with APS could inhibit high glucose-induced H9C2 cell apoptosis by decreasing the expressions of caspases and the release of cytochrome C from mitochondria to cytoplasm. Further experiments also showed that APS could modulate the ratio of Bcl-2 to Bax in mitochondria. APS decreases high glucose-induced H9C2 cell apoptosis by inhibiting the expression of pro-apoptotic proteins of both the extrinsic and intrinsic pathways and modulating the ratio of Bcl-2 to Bax in mitochondria.

ϵ-Polylysine-Capped Mesoporous Silica Nanoparticles as Carrier of the C9h Peptide to Induce Apoptosis in Cancer Cells.

PubMed

de la Torre, Cristina; Domínguez-Berrocal, Leticia; Murguía, José R; Marcos, M Dolores; Martínez-Máñez, Ramón; Bravo, Jerónimo; Sancenón, Félix

2018-02-06

Apoptotic signaling pathways are altered in numerous pathologies such as cancer. In this scenario, caspase-9/PP2Acα interaction constitutes a key target with pharmacological interest to re-establish apoptosis in tumor cells. Very recently, a short peptide (C9h) known to disrupt caspase-9/PP2Acα interaction with subsequent apoptosis induction was described. Here, we prepared two sets of mesoporous silica nanoparticles loaded with safranin O (S2) or with C9h peptide (S4) and functionalized with ϵ-polylysine as capping unit. Aqueous suspensions of both nanoparticles showed negligible cargo release whereas in the presence of pronase, a marked delivery of safranin O or C9h was observed. Confocal microscopy studies carried out with HeLa cells indicated that both materials were internalized and were able to release their entrapped cargos. Besides, a marked decrease in HeLa cell viability (ca. 50 %) was observed when treated with C9h-loaded S4 nanoparticles. Moreover, S4 provides peptide protection from degradation additionally allowing for a dose reduction to observe an apoptotic effect when compared with C9h alone or in combination with a cell-penetrating peptide (i.e., Mut3DPT-C9h). Flow cytometry studies, by means of Annexin V-FITC staining, showed the activation of apoptotic pathways in HeLa as a consequence of S4 internalization, release of C9h peptide and disruption of caspase-9/PP2Acα interaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

3'-Azido-2',3'-dideoxythymidine induced deficiency of thymidine kinases 1, 2 and deoxycytidine kinase in H9 T-lymphoid cells.

PubMed

Gröschel, Bettina; Kaufmann, Andreas; Höver, Gerold; Cinatl, Jaroslav; Doerr, Hans Wilhelm; Noordhuis, Paul; Loves, Willem J P; Peters, Godefridus J; Cinatl, Jindrich

2002-07-15

Continuous cultivation of T-lymphoid H9 cells in the presence of 3'-azido-2',3'-dideoxythymidine (AZT) resulted in a cell variant cross-resistant to both thymidine and deoxycytidine analogs. Cytotoxic effects of AZT, 2',3'-didehydro-3'-deoxythymidine as well as different deoxycytidine analogs such as 2',3'-dideoxycytidine, 2',2'-difluoro-2'-deoxycytidine (dFdC) and 1-ss-D-arabinofuranosylcytosine (Ara-C) were strongly reduced in H9 cells continuously exposed to AZT when compared to parental cells (>8.3-, >6.6-, >9.1-, 5 x 10(4)-, 5 x 10(3)-fold, respectively). Moreover, anti-HIV-1 effects of AZT, d4T, ddC and 2',3'-dideoxy-3'-thiacytidine (3TC) were significantly diminished (>222-, >25-, >400-, >200-fold, respectively) in AZT-resistant H9 cells. Study of cellular mechanisms responsible for cross-resistance to pyrimidine analogs in AZT-resistant H9 cells revealed decreased mRNA levels of thymidine kinase 1 (TK1) and lack of deoxycytidine kinase (dCK) mRNA expression. The loss of dCK gene expression was confirmed by western blot analysis of dCK protein as well as dCK enzyme activity assay. Moreover, enzyme activity of TK1 and TK2 was reduced in AZT-resistant cells. In order to determine whether lack of dCK affected the formation of the active triphosphate of the deoxycytidine analog dFdC, dFdCTP accumulation and retention was measured in H9 parental and AZT-resistant cells after exposure to 1 and 10 microM dFdC. Parental H9 cells accumulated about 30 and 100 pmol dFdCTP/10(6) cells after 4hr, whereas in AZT-resistant cells no dFdCTP accumulation was detected. These results demonstrate that continuous treatment of H9 cells in the presence of AZT selected for a thymidine analog resistant cell variant with cross-resistance to deoxycytidine analogs, due to deficiency in TK1, TK2, and dCK.

Glycyrrhetinic acid protects H9c2 cells from oxygen glucose deprivation-induced injury through the PI3K/AKt signaling pathway.

PubMed

Wang, Liqin; Zhang, Yuyan; Wan, Haitong; Jin, Weifeng; Yu, Li; Zhou, Huifen; Yang, Jiehong

2017-01-01

Glycyrrhetinic acid (GA) is an ingredient of triterpene saponins found in Gancao (Radix Glycyrrhizae). Here, we investigated the protective effects of GA in H9c2 cells, and explored its possible mechanism of action. Different concentrations of GA were used to treat H9c2 cells under oxygen glucose deprivation. We analyzed cell necrosis and apoptosis using optical microscopy, Hoechst 33342 staining, FITC-annexin V/PI double-staining and lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and interleukin (IL)-1β assays. Changes in related pro-apoptosis and anti-apoptosis proteins were detected by Western blot. Optical microscopy showed that GA improved cell morphology, including cell shrinkage, cauliflower-like membrane blebbing, and even some cell debris. Meanwhile, GA also ameliorated cell nuclei characteristics such as nucleus size, chromatin condensation and bright staining from Hoechst 33342 staining. GA also lowered the apoptotic rate and the levels of LDH, CK-MB and IL-1β in a dose-dependent manner. Furthermore, GA treatment increased Bcl-2 protein expression and decreased caspase-8 and Bax protein expression, while elevating the Bcl-2/Bax ratio. GA preconditioning increased p-AKt protein expression; however, after adding LY 294002, the p-AKt expression decreased obviously. Our results demonstrated that GA could protect H9c2 cells from apoptosis in a dose-dependent manner, and the potential mechanism might be related to the PI3K/AKt signaling pathway.

Melatonin inhibits AP-2β/hTERT, NF-κB/COX-2 and Akt/ERK and activates caspase/Cyto C signaling to enhance the antitumor activity of berberine in lung cancer cells

PubMed Central

Zhang, Changlin; Qin, Lijun; Wang, Jingshu; Yu, Zhenlong; Shi, Dingbo; Xiao, Xiangsheng; Xie, Fangyun; Huang, Wenlin; Deng, Wuguo

2016-01-01

Melatonin, a molecule produced throughout the animal and plant kingdoms, and berberine, a plant derived agent, both exhibit antitumor and multiple biological and pharmacological effects, but they have never been combined altogether for the inhibition of human lung cancers. In this study, we investigated the role and underlying mechanisms of melatonin in the regulation of antitumor activity of berberine in lung cancer cells. Treatment with melatonin effectively increased the berberine-mediated inhibitions of cell proliferation, colony formation and cell migration, thereby enhancing the sensitivities of lung cancer cells to berberine. Melatonin also markedly increased apoptosis induced by berberine. Further mechanism study showed that melatonin promoted the cleavage of caspse-9 and PARP, enhanced the inhibition of Bcl2, and triggered the releasing of cytochrome C (Cyto C), thereby increasing the berberine-induced apoptosis. Melatonin also enhanced the berberine-mediated inhibition of telomerase reverses transcriptase (hTERT) by down-regulating the expression of AP-2β and its binding on hTERT promoter. Moreover, melatonin enhanced the berberine-mediated inhibition of cyclooxygenase 2 (COX-2) by inhibiting the nuclear translocation of NF-κB and its binding on COX-2 promoter. Melatonin also increased the berberine-mediated inhibition of the phosphorylated Akt and ERK. Collectively, our results demonstrated that melatonin enhanced the antitumor activity of berberine by activating caspase/Cyto C and inhibiting AP-2β/hTERT, NF-κB/COX-2 and Akt/ERK signaling pathways. Our findings provide new insights in exploring the potential therapeutic strategies and novel targets for lung cancer treatment. PMID:26672764

On the causes and consequences of the uncoupler-like effects of quercetin and dehydrosilybin in H9c2 cells

PubMed Central

Mouithys-Mickalad, Ange; Dostal, Zdenek; Serteyn, Didier; Modriansky, Martin

2017-01-01

Quercetin and dehydrosilybin are polyphenols which are known to behave like uncouplers of respiration in isolated mitochondria. Here we investigated whether the effect is conserved in whole cells. Following short term incubation, neither compound uncouples mitochondrial respiration in whole H9c2 cells below 50μM. However, following hypoxia, or long term incubation, leak (state IV with oligomycin) oxygen consumption is increased by quercetin. Both compounds partially protected complex I respiration, but not complex II in H9c2 cells following hypoxia. In a permeabilised H9c2 cell model, the increase in leak respiration caused by quercetin is lowered by increased [ADP] and is increased by adenine nucleotide transporter inhibitor, atractyloside, but not bongkrekic acid. Both quercetin and dehydrosilybin dissipate mitochondrial membrane potential in whole cells. In the case of quercetin, the effect is potentiated post hypoxia. Genetically encoded Ca++ sensors, targeted to the mitochondria, enabled the use of fluorescence microscopy to show that quercetin decreased mitochondrial [Ca++] while dehydrosilybin did not. Likewise, quercetin decreases accumulation of [Ca++] in mitochondria following hypoxia. Fluorescent probes were used to show that both compounds decrease plasma membrane potential and increase cytosolic [Ca++]. We conclude that the uncoupler-like effects of these polyphenols are attenuated in whole cells compared to isolated mitochondria, but downstream effects are nevertheless apparent. Results suggest that the effect of quercetin observed in whole and permeabilised cells may originate in the mitochondria, while the mechanism of action of cardioprotection by dehydrosilybin may be less dependent on mitochondrial uncoupling than originally thought. Rather, protective effects may originate due to interactions at the plasma membrane. PMID:28977033

Inhibition of gap junction intercellular communication is involved in silica nanoparticles-induced H9c2 cardiomyocytes apoptosis via the mitochondrial pathway.

PubMed

Du, Zhong-Jun; Cui, Guan-Qun; Zhang, Juan; Liu, Xiao-Mei; Zhang, Zhi-Hu; Jia, Qiang; Ng, Jack C; Peng, Cheng; Bo, Cun-Xiang; Shao, Hua

2017-01-01

Gap junction intercellular communication (GJIC) between cardiomyocytes is essential for synchronous heart contraction and relies on connexin-containing channels. Connexin 43 (Cx43) is a major component involved in GJIC in heart tissue, and its abnormal expression is closely associated with various cardiac diseases. Silica nanoparticles (SNPs) are known to induce cardiovascular toxicity. However, the mechanisms through which GJIC plays a role in cardiomyocytes apoptosis induced by SNPs remain unknown. The aim of the present study is to determine whether SNPs-decreased GJIC promotes apoptosis in rat cardiomyocytes cell line (H9c2 cells) via the mitochondrial pathway using CCK-8 Kit, scrape-loading dye transfer technique, Annexin V/PI double-staining assays, and Western blot analysis. The results showed that SNPs elicited cytotoxicity in H9c2 cells in a time- and concentration-dependent manner. SNPs also reduced GJIC in H9c2 cells in a concentration-dependent manner through downregulation of Cx43 and upregulation of P-Cx43. Inhibition of gap junctions by gap junction blocker carbenoxolone disodium resulted in decreased survival and increased apoptosis, whereas enhancement of the gap junctions by retinoic acid led to enhanced survival but decreased apoptosis. Furthermore, SNPs-induced apoptosis through the disrupted functional gap junction was correlated with abnormal expressions of the proteins involved in the mitochondrial pathway-related apoptosis such as Bcl-2/Bax, cytochrome C, Caspase-9, and Caspase-3. Taken together, our results provide the first evidence that SNPs-decreased GJIC promotes apoptosis in cardiomyocytes via the mitochondrial pathway. In addition, downregulation of GJIC by SNPs in cardiomyocytes is mediated through downregulation of Cx43 and upregulation of P-Cx43. These results suggest that in rat cardiomyocytes cell line, GJIC plays a protective role in SNPs-induced apoptosis and that GJIC may be one of the targets for SNPs-induced biological

Resveratrol prevents doxorubicin-induced cardiotoxicity in H9c2 cells through the inhibition of endoplasmic reticulum stress and the activation of the Sirt1 pathway.

PubMed

Lou, Yu; Wang, Zhen; Xu, Yi; Zhou, Ping; Cao, Junxian; Li, Yuanshi; Chen, Yeping; Sun, Junfeng; Fu, Lu

2015-09-01

Treatment with doxorubicin (DOX) is one of the major causes of chemotherapy-induced cardiotoxicity and is therefore, the principal limiting factor in the effectiveness of chemotherapy for cancer patients. DOX‑induced heart failure is thought to result from endoplasmic reticulum (ER) stress and cardiomyocyte apoptosis. Resveratrol (RV), a polyphenol antioxidant found in red wine, has been shown to play a cardioprotective role. The aim of the present study was to examine the effects of RV on DOX‑induced cardiotoxicity in H9c2 cells. We hypothesized that RV would protect H9c2 cells against DOX‑induced ER stress and subsequent cell death through the activation of the Sirt1 pathway. Our results demonstrated that the decrease observed in the viability of the H9c2 cells following exposure to DOX was accompanied by a significant increase in the expression of the ER stress‑related proteins, glucose‑regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP). However, we found that RV downregulated the expression of ER stress marker protein in the presence of DOX and restored the viability of the H9c2 cells. Exposure to RV or DOX alone only slightly increased the protein expression of Sirt1, whereas a significant increase in Sirt1 protein levels was observed in the cells treated with both RV and DOX. The Sirt1 inhibitor, nicotinamide (NIC), partially neutralized the effects of RV on the expression of Sirt1 in the DOX‑treated cells and completely abolished the effects of RV on the expression of GRP78 and CHOP. The findings of our study suggest that RV protects H9c2 cells against DOX‑induced ER stress through ER stabilization, and more specifically through the activation of the Sirt1 pathway, thereby leading to cardiac cell survival.

Insufficiency of pro-heparin-binding epidermal growth factor-like growth factor shedding enhances hypoxic cell death in H9c2 cardiomyoblasts via the activation of caspase-3 and c-Jun N-terminal kinase.

PubMed

Uetani, Teruyoshi; Nakayama, Hironao; Okayama, Hideki; Okura, Takafumi; Higaki, Jitsuo; Inoue, Hirofumi; Higashiyama, Shigeki

2009-05-01

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a cardiogenic and cardiohypertrophic growth factor. ProHB-EGF, a product of the Hb-egf gene and the precursor of HB-EGF, is anchored to the plasma membrane. Its ectodomain region is shed by a disintegrin and metalloproteases (ADAMs) when activated by various stimulations. It has been reported that an uncleavable mutant of Hb-egf, uc-Hb-egf, produces uc-proHB-EGF, which is not cleaved by ADAMs and causes dilation of the heart in knock-in mice. This suggests that the shedding of proHB-EGF is essential for the development and survival of cardiomyocytes: however, the molecular mechanism involved has remained unclear. In this study, we investigated the relationship between uc-proHB-EGF expression and cardiomyocyte survival. Human uc-proHB-EGF was adenovirally introduced into the rat cardiomyoblast cell line H9c2, and the cells were cultured under normoxic and hypoxic conditions. Uc-proHB-EGF-expressing H9c2 cells underwent apoptosis under normoxic conditions, which distinctly increased under hypoxic conditions. Furthermore, we observed an increased Caspase-3 activity, reactive oxygen species accumulation, and an increased c-Jun N-terminal kinase (JNK) activity in the uc-proHB-EGF-expressing H9c2 cells. Treatment of the uc-proHB-EGF transfectants with inhibitors of Caspase-3, reactive oxygen species, and JNK, namely, Z-VAD-fmk, N-acetylcysteine, and SP600125, respectively, significantly reduced hypoxic cell death. These data indicate that insufficiency of proHB-EGF shedding under hypoxic stress leads to cardiomyocyte apoptosis via Caspase-3- and JNK-dependent pathways.

Globular Adiponectin, Acting via AdipoR1/APPL1, Protects H9c2 Cells from Hypoxia/Reoxygenation-Induced Apoptosis

PubMed Central

Park, Min; Youn, ByungSoo; Zheng, Xi-long; Wu, Donghai; Xu, Aimin; Sweeney, Gary

2011-01-01

Cardiomyocyte apoptosis is an important remodeling event contributing to heart failure and adiponectin may mediate cardioprotective effects at least in part via attenuating apoptosis. Here we used hypoxia-reoxygenation (H/R) induced apoptosis in H9c2 cells to examine the effect of adiponectin and cellular mechanisms of action. We first used TUNEL labeling in combination with laser scanning cytometry to demonstrate that adiponectin prevented H/R-induced DNA fragmentation. The anti-apoptotic effect of adiponectin was also verified via attenuation of H/R-induced phosphatidylserine exposure using annexin V binding. H/R-induced apoptosis via the mitochondrial-mediated intrinsic pathway of apoptosis as assessed by cytochrome c release into cytosol and caspase-3 activation, both of which were attenuated by adiponectin. Mechanistically, we demonstrated that adiponectin enhanced anti-oxidative potential in these cells which led to attenuation of the increase in intracellular reactive oxygen species (ROS) caused by H/R. To further address the mechanism of adiponctins anti-apoptotic effects we used siRNA to efficiently knockdown adiponectin receptor (AdipoR1) expression and found that this attenuated the protective effects of adiponectin on ROS production and caspase 3 activity. Knockdown of APPL1, an important intracellular binding partner for AdipoR, also significantly reduced the ability of adiponectin to prevent H/R-induced ROS generation and caspase 3 activity. In summary, H/R-induced ROS generation and activation of the intrinsic apoptotic pathway was prevented by adiponectin via AdipoR1/APPL1 signaling and increased anti-oxidant potential. PMID:21552570

Cardioprotective effects of calcitonin gene-related peptide in isolated rat heart and in H9c2 cells via redox signaling.

PubMed

Tullio, Francesca; Penna, Claudia; Cabiale, Karine; Femminò, Saveria; Galloni, Marco; Pagliaro, Pasquale

2017-06-01

The calcitonin-gene-related-peptide (CGRP) release is coupled to the signaling of Angeli's salt in determining vasodilator effects. However, it is unknown whether CGRP is involved in Angeli's salt cardioprotective effects and which are the mechanisms of protection. We aimed to determine whether CGRP is involved in myocardial protection induced by Angeli's salt. We also analyzed the intracellular signaling pathway activated by CGRP. Isolated rat hearts were pre-treated with Angeli's salt or Angeli's salt plus CGRP 8-37 , a specific CGRP-receptor antagonist, and subjected to ischemia (30-min) and reperfusion (120-min). Moreover, we studied CGRP-induced protection during oxidative stress (H 2 O 2 ) and hypoxia/reoxygenation protocols in H9c2 cardiomyocytes. Cell vitality and mitochondrial membrane potential (ΔYm, MMP) were measured using MTT and JC-1 dyes. Angeli's salt reduced infarct size and ameliorated post-ischemic cardiac function via a CGRP-receptor-dependent mechanism. Pre-treatment with CGRP increased H9c2 survival upon challenging with either H 2 O 2 (redox stress) or hypoxia/reoxygenation (H/R stress). Under these stress conditions, reduction in MMP and cell death were partly prevented by CGRP. These CGRP beneficial effects were blocked by CGRP 8-37. During H/R stress, pre-treatment with either CGRP-receptor, protein kinase C (PKC) or mitochondrial K ATP channel antagonists, and pre-treatment with an antioxidant (2-mercaptopropionylglycine) blocked the protection mediated by CGRP. In conclusion, CGRP is involved in the cardioprotective effects of Angeli's salt. In H9c2 cardiomyocytes, CGRP elicits PKC-dependent and mitochondrial-K ATP -redox-dependent mechanisms. Hence, CGRP is an important factor in the redox-sensible cardioprotective effects of Angeli's salt. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Differential behaviour of epicardial adipose tissue-secretomes with high and low orosomucoid levels from patients with cardiovascular disease in H9C2 cells.

PubMed

Lage, Ricardo; Moscoso, Isabel; Fernández-Trasancos, Ángel; Cebro, María; Couselo, Marinela; Fandiño-Vaquero, Rubén; Bravo, Susana B; Sierra, Juan; González-Juanatey, José Ramón; Eiras, Sonia

2015-11-15

Epicardial adipose tissue releases orosomucoid (ORM), an acute phase protein with multiple modulatory and protective properties. We aimed to identify the effect of EAT-supernatants according to their ORM levels on H9C2 cells. H9C2 were cultured with EAT-secretomes or ORM protein itself on a Real-Time Cell Analyser. Secretome proteins identification was performed by LC-mass spectrometry according to their ORM levels. Two of them were validated by ELISA in EAT-supernatants from 42 patients. ORM effect on H9C2 and neonatal rat cardiomyocytes apoptosis under hypoxia with or without fatty acid treatment was determined by Annexin-V flow cytometry measurement. Caspase-3 expression levels were determined by western blot in H9C2. Our results showed a differential effect of EAT-secretomes according their ORM levels. Although additional secreted proteins can contribute to their beneficial effects, ORM reduced hypoxia-induced apoptosis through caspase-3 inhibition. Our data showed the cardioprotective role of ORM and suggest that its quantification on EAT secretomes might help us to find new secreted factors with a cardioprotective role. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Enhanced humoural and cellular immune responses to influenza H7N9 antigen HA1-2 fused with flagellin in chickens.

PubMed

Song, Li; Xiong, Dan; Hu, Maozhi; Kang, Xilong; Pan, Zhiming; Jiao, Xinan

2017-06-21

Sudden increases in the number of human A (H7N9) cases reported during December and January have been observed in previous years. Most reported infection cases are due to prior exposure to live poultry or potentially contaminated environments. Low pathogenicity of influenza A (H7N9) virus in avian species complicates timely discovery of infected birds. Therefore, there is a pressing need to develop safe and effective anti-H7N9 vaccines for poultry to reduce the risk of human infection and prevent the emergence of novel mutated strains. In addition to a good antigen, an effective vaccine also requires an appropriate adjuvant to enhance its immunogenicity. Previously, we generated an H7N9 influenza recombinant subunit vaccine (HA1-2-fliC), in which haemagglutinin globular head domain (HA1-2) was fused with flagellin (fliC), a potent TLR5 ligand, and demonstrated that HA1-2-fliC elicited effective HA1-2-specific immune responses in mice. In this study, we determined flagellin-induced expression profiles of cytokines and chemokines in different types of avian immune cells in vitro and ex vivo. We found that flagellin significantly increased the expression levels of CXCL inflammatory chemokines (CXCLi1 and CXCLi2) and CCL chemokines (MIP-1β and MCP-3) in avian macrophage HD11 cells. In addition, HA1-2-fliC induced significant upregulation of cytokines (IL-1β, IL-6, IL-18 and IFN-γ) and chemokines (CXCLi1, CXCLi2 and MIP-1β) in ex vivo splenic lymphocytes and peripheral blood mononuclear cells (PBMCs), suggesting that flagellin promoted immune responses of avian cells in vitro. We also evaluated specific humoural and cellular immune responses induced by HA1-2-fliC and found that chickens immunised intramuscularly with HA1-2-fliC showed significantly higher HA1-2-specific immunoglobulin (Ig)G titers in serum. Furthermore, HA1-2-fliC potentiated cellular immune responses, as reflected by an increase in CD4 + and CD8 + T cells and proliferation of PBMCs. Significantly

Clusterin protects H9c2 cardiomyocytes from oxidative stress-induced apoptosis via Akt/GSK-3β signaling pathway

PubMed Central

Jun, Hyoung-Oh; Kim, Dong-hun; Lee, Sae-Won; Lee, Hye Shin; Seo, Ji Hae; Kim, Jeong Hun; Kim, Jin Hyoung; Yu, Young Suk; Min, Bon Hong

2011-01-01

Clusterin is a secretory glycoprotein, which is highly up-regulated in a variety of normal and injury tissues undergoing apoptosis including infarct region of the myocardium. Here, we report that clusterin protects H9c2 cardiomyocytes from H2O2-induced apoptosis by triggering the activation of Akt and GSK-3β. Treatment with H2O2 induces apoptosis of H9c2 cells by promoting caspase cleavage and cytochrome c release from mitochondria. However, co-treatment with clusterin reverses the induction of apoptotic signaling by H2O2, thereby recovers cell viability. The protective effect of clusterin on H2O2-induced apoptosis is impaired by PI3K inhibitor LY294002, which effectively suppresses clusterin-induced activation of Akt and GSK-3β. In addition, the protective effect of clusterin is independednt on its receptor megalin, because inhibition of megalin has no effect on clusturin-mediated Akt/GSK-3β phosphoylation and H9c2 cell viability. Collectively, these results suggest that clusterin has a role protecting cardiomyocytes from oxidative stress and the Akt/GSK-3β signaling mediates anti-apoptotic effect of clusterin. PMID:21270507

Disruption of dopamine D1/D2 receptor complex is involved in the function of haloperidol in cardiac H9c2 cells.

PubMed

Lencesova, L; Szadvari, I; Babula, P; Kubickova, J; Chovancova, B; Lopusna, K; Rezuchova, I; Novakova, Z; Krizanova, O; Novakova, M

2017-12-15

Haloperidol is an antipsychotic agent and acts as dopamine D2 receptor (D2R) antagonist, as a prototypical ligand of sigma1 receptors (Sig1R) and it increases expression of type 1 IP 3 receptors (IP 3 R1). However, precise mechanism of haloperidol action on cardiomyocytes through dopaminergic signaling was not described yet. This study investigated a role of dopamine receptors in haloperidol-induced increase in IP 3 R1 and Sig1R, and compared physiological effect of melperone and haloperidol on basic heart parameters in rats. We used differentiated NG-108 cells and H9c2 cells. Gene expression, Western blot and immunofluorescence were used to evaluate haloperidol-induced differences; proximity ligation assay (PLA) and immunoprecipitation to determine interactions of D1/D2 receptors. To evaluate cardiac parameters, Wistar albino male rats were used. We have shown that antagonism of D2R with either haloperidol or melperone results in upregulation of both, IP 3 R1 and Sig1R, which is associated with increased D2R, but reduced D1R expression. Immunofluorescence, immunoprecipitation and PLA support formation of heteromeric D1/D2 complexes in H9c2 cells. Treatment with haloperidol (but not melperone) caused decrease in systolic and diastolic blood pressure and significant increase in heart rate. Because D1R/D2R complexes can engage Gq-like signaling in other experimental systems, these results are consistent with the possibility that disruption of D1R/D2R complex in H9c2 cells might cause a decrease in IP 3 R1 activity, which in turn may account for the increase expression of IP 3 R and Sig1R. D2R is probably not responsible for changes in cardiac parameters, since melperone did not have any effect. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Rethinking Sensitized Luminescence in Lanthanide Coordination Polymers and MOFs: Band Sensitization and Water Enhanced Eu Luminescence in [Ln(C15H9O5)3(H2O)3]n (Ln = Eu, Tb).

PubMed

Einkauf, Jeffrey D; Kelley, Tanya T; Chan, Benny C; de Lill, Daniel T

2016-08-15

A coordination polymer [Ln(C15H9O9)3(H2O)3]n (1-Ln = Eu(III), Tb(III)) assembled from benzophenonedicarboxylate was synthesized and characterized. The organic component is shown to sensitize lanthanide-based emission in both compounds, with quantum yields of 36% (Eu) and 6% (Tb). Luminescence of lanthanide coordination polymers is currently described from a molecular approach. This methodology fails to explain the luminescence of this system. It was found that the band structure of the organic component rather than the molecular triplet state was able to explain the observed luminescence. Deuterated (Ln(C15H9O9)3(D2O)3) and dehydrated (Ln(C15H9O9)3) analogues were also studied. When bound H2O was replaced by D2O, lifetime and emission increased as expected. Upon dehydration, lifetimes increased again, but emission of 1-Eu unexpectedly decreased. This reduction is reasoned through an unprecedented enhancement effect of the compound's luminescence by the OH/OD oscillators in the organic-to-Eu(III) energy transfer process.

Volume properties and refraction of aqueous solutions of bisadducts of light fullerene C60 and essential amino acids lysine, threonine, and oxyproline (C60(C6H13N2O2)2, C60(C4H8NO3)2, and C60(C5H9NO2)2) at 25°C

NASA Astrophysics Data System (ADS)

Semenov, K. N.; Ivanova, N. M.; Charykov, N. A.; Keskinov, V. A.; Kalacheva, S. S.; Duryagina, N. N.; Garamova, P. V.; Kulenova, N. A.; Nabieva, A.

2017-02-01

Concentration dependences of the density of aqueous solutions of bisadducts of light fullerene C60 and essential amino acids are studied by pycnometry. Concentration dependences of the average molar volumes and partial volumes of components (H2O and corresponding bisadducts) are calculated for C60(C6H13N2O2)2-H2O, C60(C4H8NO3)2-H2O, and C60(C5H9NO2)2-H2O binary systems at 25°C. Concentration dependences of the indices of refraction of C60(C6H13N2O2)2-H2O, C60(C4H8NO3)2-H2O, and C60(C5H9NO2)2-H2O binary systems are determined at 25°C. The concentration dependences of specific refraction and molar refraction of bisadducts and aqueous solutions of them are calculated.

Schisandrin B elicits a glutathione antioxidant response and protects against apoptosis via the redox-sensitive ERK/Nrf2 pathway in H9c2 cells.

PubMed

Chiu, Po Yee; Chen, Na; Leong, Po Kuan; Leung, Hoi Yan; Ko, Kam Ming

2011-04-01

This study investigated the signal transduction pathway involved in the cytoprotective action of (-)schisandrin B [(-)Sch B, a stereoisomer of Sch B]. Using H9c2 cells, the authors examined the effects of (-)Sch B on MAPK and Nrf2 activation, as well as the subsequent eliciting of glutathione response and protection against apoptosis. Pharmacological tools, such as cytochrome P-450 (CYP) inhibitor, antioxidant, MAPK inhibitor, and Nrf2 RNAi, were used to delineate the signaling pathway. (-)Sch B caused a time-dependent activation of MAPK in H9c2 cells, with the degree of ERK activation being much larger than that of p38 or JNK. The MAPK activation was followed by an increase in the level of nuclear Nrf2, an indirect measure of Nrf2 activation, and the eliciting of a glutathione antioxidant response. The activation of MAPK and Nrf2 seemed to involve oxidants generated from a CYP-catalyzed reaction with (-)Sch B. Both ERK inhibition by U0126 and Nrf2 suppression by Nrf2 RNAi transfection largely abolished the cytoprotection against hypoxia/reoxygenation-induced apoptosis in (-)Sch B-pretreated cells. (-)Sch B pretreatment potentiated the reoxygenation-induced ERK activation, whereas both p38 and JNK activations were suppressed. Under the condition of ERK inhibition, Sch B treatment did not protect against ischemia/reperfusion injury in an ex vivo rat heart model. The results indicate that (-)Sch B triggers a redox-sensitive ERK/Nrf2 signaling, which then elicits a cellular glutathione antioxidant response and protects against hypoxia/reoxygenation-induced apoptosis in H9c2 cells. The ERK-mediated signaling is also likely involved in the cardioprotection afforded by Sch B in vivo.

Rate Coefficients of C2H with C2H4, C2H6, and H2 from 150 to 359 K

NASA Technical Reports Server (NTRS)

Opansky, Brian J.; Leone, Stephen R.

1996-01-01

Rate coefficients for the reactions C2H with C2H4, C2H6, and H2 are measured over the temperature range 150-359 K using transient infrared laser absorption spectroscopy. The ethynyl radical is formed by photolysis of C2H2 with a pulsed excimer laser at 193 nm, and its transient absorption is monitored with a color center laser on the Q(sub 11)(9) line of the A(sup 2) Pi-Chi(sup 2) Sigma transition at 3593.68 cm(exp -1). Over the experimental temperature range 150-359 K the rate constants of C2H with C2H4, C2H6, and H2 can be fitted to the Arrhenius expressions k(sub C2H4) = (7.8 +/- 0.6) x 10(exp -11) exp[(134 +/- 44)/T], k(sub C2H6) = (3.5 +/- 0.3) x 10(exp -11) exp[(2.9 +/- 16)/T], and k(sub H2) = (1.2 +/- 0.3) x 10(exp -11) exp[(-998 +/- 57)]/T cm(exp 3) molecule(exp -1) sec(exp -1). The data for C2H with C2H4 and C2H6 indicate a negligible activation energy to product formation shown by the mild negative temperature dependence of both reactions. When the H2 data are plotted together with the most recent high-temperature results from 295 to 854 K, a slight curvature is observed. The H2 data can be fit to the non-Arrhenius form k(sub H2) = 9.2 x 10(exp -18) T(sup 2.17 +/- 0.50) exp[(-478 +/- 165)/T] cm(exp 3) molecules(exp -1) sec(exp -1). The curvature in the Arrhenius plot is discussed in terms of both quantum mechanical tunneling of the H atom from H2 to the C2H radical and bending mode contributions to the partition function.

17Beta-estradiol protects against oxidative stress-induced cell death through the glutathione/glutaredoxin-dependent redox regulation of Akt in myocardiac H9c2 cells.

PubMed

Urata, Yoshishige; Ihara, Yoshito; Murata, Hiroaki; Goto, Shinji; Koji, Takehiko; Yodoi, Junji; Inoue, Satoshi; Kondo, Takahito

2006-05-12

The GSH/glutaredoxin (GRX) system is involved in the redox regulation of certain enzyme activities, and this system protects cells from H2O2-induced apoptosis by regulating the redox state of Akt (Murata, H., Ihara, Y., Nakamura, H., Yodoi, J., Sumikawa, K., and Kondo, T. (2003) J. Biol. Chem. 278, 50226-50233). Estrogens, such as 17beta-estradiol (E2), play an important role in development, growth, and differentiation and appear to have protective effects on oxidative stress mediated by estrogen receptor alpha (ERalpha). However, the role of the ERbeta-mediated pathway in this cytoprotection and the involvement of E2 in the redox regulation are not well understood. In the present study, we demonstrated that E2 protected cardiac H9c2 cells, expressing ERbeta from H2O2-induced apoptosis concomitant with an increase in the activity of Akt. E2 induced the expression of glutaredoxin (GRX) as well as gamma-glutamylcysteine synthetase, a rate-limiting enzyme for the synthesis of GSH. Inhibitors for both gamma-glutamylcysteine synthetase and GRX and ICI182,780, a specific inhibitor of ERs, abolished the protective effect of E2 on cell survival as well as the activity of Akt, suggesting that ERbeta is involved in the cytoprotection and redox regulation by E2. Transcription of the GRX gene was enhanced by E2. The promoter activity of GRX was up-regulated by an ERbeta-dependent element. These results suggest that the GRX/GSH system is involved in the cytoprotective and genomic effects of E2 on the redox state of Akt, a pathway that is mediated, at least in part, by ERbeta. This mechanism may also play an antiapoptotic role in cancer cells during carcinogenesis or chemotherapy.

TSA protects H9c2 cells against thapsigargin-induced apoptosis related to endoplasmic reticulum stress-mediated mitochondrial injury.

PubMed

Li, Zhiping; Liu, Yan; Dai, Xinlun; Zhou, Qiangqiang; Liu, Xueli; Li, Zeyu; Chen, Xia

2017-05-01

Endoplasmic reticulum stress (ERS) activates an adaptive unfolded protein response (UPR) that facilitates cellular repair, however, under prolonged ER stress, the UPR can ultimately trigger apoptosis thereby terminating damaged cells. Recently, TSA has shown protective effects on ERS and its mechanisms related to ER pathway has been previously characterized. However, whether TSA exerts its protective role via metabolic events remain largely undefined. Objectives : To explore the possible involvement of the metabolic changes during ERS and to better understand how TSA influence mitochondrial function to facilitate cellular adaptation. Results : TSA is an inhibitor of histone deacetylase which could significantly inhibit H9c2 cell apoptosis induced by Thapsigargin (TG). It also intervene the decrease of mitochondrial membrane potential. By immunofluorescence staining, we have shown that GRP78 was concentrated in the perinuclear region and co-localized with ER. However, treatments with TG and TSA could let it overlap with the mitochondrial marker MitoTracker. Cellular fractionation also confirmed the location of GRP78 in mitochondrion. TSA decreases ERS-induced cell apoptosis and mitochondrial injury may related to enhance the location of GRP78 in mitochondrion.

MELATONIN ENHANCES JUNCTIONAL TRANSFER IN NORMAL C3H/1OT1/2 CELLS

EPA Science Inventory

There is strong evidence that pineal melatonin is involved in controlling neoplastic processes. e have reported that physiological, but not pharmacological or subphysiological, concentrations of melatonin enhance intercellular communication in normal C3H/1OT1/2 fibroblasts. ap ju...

Chlamydia psittaci infection increases mortality of avian influenza virus H9N2 by suppressing host immune response.

PubMed

Chu, Jun; Zhang, Qiang; Zhang, Tianyuan; Han, Er; Zhao, Peng; Khan, Ahrar; He, Cheng; Wu, Yongzheng

2016-07-11

Avian influenza virus subtype H9N2 (H9N2) and Chlamydia psittaci (C. psittaci) are frequently isolated in chickens with respiratory disease. However, their roles in co-infection remain unclear. We tested the hypothesis that C. psittaci enhances H9N2 infection through suppression of host immunity. Thus, 10-day-old SPF chickens were inoculated intra-tracheally with a high or low virulence C. psittaci strain, and were simultaneously vaccinated against Newcastle disease virus (NDV). Significant decreases in body weight, NDV antibodies and immune organ indices occurred in birds with the virulent C. psittaci infection, while the ratio of CD4+/CD8+ T cells increased significantly compared to that of the lower virulence strain. A second group of birds were inoculated with C. psittaci and H9N2 simultaneously (C. psittaci+H9N2), C. psittaci 3 days prior to H9N2 (C. psittaci/H9N2), or 3 days after H9N2 (H9N2/C. psittaci), C. psittaci or H9N2 alone. Survival rates were 65%, 80% and 90% in the C. psittaci/H9N2, C. psittaci+H9N2 and H9N2/C. psittaci groups, respectively and respiratory clinical signs, lower expression of pro-inflammatory cytokines and higher pathogen loads were found in both C. psittaci/H9N2 and C. psittaci+H9N2 groups. Hence, virulent C. psittaci infection suppresses immune response by inhibiting humoral responses and altering Th1/Th2 balance, increasing mortality in H9N2 infected birds.

Chlamydia psittaci infection increases mortality of avian influenza virus H9N2 by suppressing host immune response

PubMed Central

Chu, Jun; Zhang, Qiang; Zhang, Tianyuan; Han, Er; Zhao, Peng; Khan, Ahrar; He, Cheng; Wu, Yongzheng

2016-01-01

Avian influenza virus subtype H9N2 (H9N2) and Chlamydia psittaci (C. psittaci) are frequently isolated in chickens with respiratory disease. However, their roles in co-infection remain unclear. We tested the hypothesis that C. psittaci enhances H9N2 infection through suppression of host immunity. Thus, 10-day-old SPF chickens were inoculated intra-tracheally with a high or low virulence C. psittaci strain, and were simultaneously vaccinated against Newcastle disease virus (NDV). Significant decreases in body weight, NDV antibodies and immune organ indices occurred in birds with the virulent C. psittaci infection, while the ratio of CD4+/CD8+ T cells increased significantly compared to that of the lower virulence strain. A second group of birds were inoculated with C. psittaci and H9N2 simultaneously (C. psittaci+H9N2), C. psittaci 3 days prior to H9N2 (C. psittaci/H9N2), or 3 days after H9N2 (H9N2/C. psittaci), C. psittaci or H9N2 alone. Survival rates were 65%, 80% and 90% in the C. psittaci/H9N2, C. psittaci+H9N2 and H9N2/C. psittaci groups, respectively and respiratory clinical signs, lower expression of pro-inflammatory cytokines and higher pathogen loads were found in both C. psittaci/H9N2 and C. psittaci+H9N2 groups. Hence, virulent C. psittaci infection suppresses immune response by inhibiting humoral responses and altering Th1/Th2 balance, increasing mortality in H9N2 infected birds. PMID:27405059

B-type natriuretic peptide attenuates endoplasmic reticulum stress in H9c2 cardiomyocytes underwent hypoxia/reoxygenation injury under high glucose/high fat conditions.

PubMed

Chang, Pan; Zhang, Mingyang; Zhang, Xiaomeng; Li, Guohua; Hu, Haiyan; Wu, Juan; Wang, Xihui; Yang, Zihua; Zhang, Jing; Chen, Weiguo; Ren, Minggang; Li, Xin; Zhu, Miaozhang; Chen, Baoying; Yu, Jun

2018-04-22

Exogenously administered B-type natriuretic peptide (BNP) has been shown to provide cardioprotection against various heart diseases. However, the underlying mechanisms remain elusive. This study explores whether BNP exerts its cardioprotection against hypoxia/reoxygenation (H/R) injury under high glucose/high fat (HG/HF) conditions in cardiac H9c2 cells and uncovers the underlying mechanisms. Our data revealed that BNP significantly increased the cell viability and decreased the release of lactate dehydrogenase (LDH) and creatine kinase (CK), with a maximal effect at the BNP concentration of 10 -7  mol/L. In addition, by analyzing the activation of cleaved caspase-3 and by Annexin V-FITC/PI staining, we showed that BNP attenuated H/R-induced cell apoptosis in HG/HF conditions. Western blot analysis showed enhanced phosphorylation of protein kinase RNA (PKR)-like endoplastmic reticulum (ER) kinase (PERK) and eukaryotic initiation factor 2α (eIF2α)(one of the three main signaling pathways in endoplastmic reticulum (ER) stress), and increased expression of GRP78 and CHOP proteins (ER stress-related proteins) in H9c2 cells which underwent H/R in HG/HF conditions. Treatment with BNP or 8-Br-cGMP (an analog of cGMP) reversed this activation. However, this effect was significantly weakened by KT-5823, a selective cGMP-dependent protein kinase G (PKG) inhibitor. In addition, similar to BNP, treatment with a specific inhibitor of ER stress tauroursodeoxycholic acid (TUDCA) protected the cells against H/R injury exposed to HG/HF conditions. In conclusion, these findings demonstrated that BNP effectively protected cells against H/R injury under HG/HF conditions by inhibiting the ER stress via activation of the cGMP-PKG signaling pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

Kinetics of the R + NO2 reactions (R = i-C3H7, n-C3H7, s-C4H9, and t-C4H9) in the temperature range 201-489 K.

PubMed

Rissanen, Matti P; Arppe, Suula L; Eskola, Arkke J; Tammi, Matti M; Timonen, Raimo S

2010-04-15

The bimolecular rate coefficients of four alkyl radical reactions with NO(2) have been measured in direct time-resolved experiments. Reactions were studied under pseudo-first-order conditions in a temperature-controlled tubular flow reactor coupled to a laser photolysis/photoionization mass spectrometer (LP-PIMS). The measured reaction rate coefficients are independent of helium bath gas pressure within the experimental ranges covered and exhibit negative temperature dependence. For i-C(3)H(7) + NO(2) and t-C(4)H(9) + NO(2) reactions, the dependence of ordinate (logarithm of reaction rate coefficients) on abscissa (1/T or log(T)) was nonlinear. The obtained results (in cm(3) s(-1)) can be expressed by the following equations: k(n-C(3)H(7) + NO(2)) = ((4.34 +/- 0.08) x 10(-11)) (T/300 K)(-0.14+/-0.08) (203-473 K, 1-7 Torr), k(i-C(3)H(7) + NO(2)) = ((3.66 +/- 2.54) x 10(-12)) exp(656 +/- 201 K/T)(T/300 K)(1.26+/-0.68) (220-489 K, 1-11 Torr), k(s-C(4)H(9) + NO(2)) = ((4.99 +/- 0.16) x 10(-11))(T/300 K)(-1.74+/-0.12) (241-485 K, 2 - 12 Torr) and k(t-C(4)H(9) + NO(2)) = ((8.64 +/- 4.61) x 10(-12)) exp(413 +/- 154 K/T)(T/300 K)(0.51+/-0.55) (201-480 K, 2-11 Torr), where the uncertainties shown refer only to the 1 standard deviations obtained from the fitting procedure. The estimated overall uncertainty in the determined bimolecular rate coefficients is about +/-20%.

Berberine treatment prevents cardiac dysfunction and remodeling through activation of 5'-adenosine monophosphate-activated protein kinase in type 2 diabetic rats and in palmitate-induced hypertrophic H9c2 cells.

PubMed

Chang, Wenguang; Zhang, Ming; Meng, Zhaojie; Yu, Yang; Yao, Fan; Hatch, Grant M; Chen, Li

2015-12-15

Diabetic cardiomyopathy is the major cause of death in type 2 diabetic patients. Berberine is an isoquinoline alkaloid extract from traditional chinese herbs and its hypoglycemic and hypolipidemic effects make it a promising drug for treatment of type 2 diabetes. We examined if berberine improved cardiac function and attenuated cardiac hypertrophy and fibrosis in high fat diet and streptozotocin induced-type 2 diabetic rats in vivo and reduced expression of hypertrophy markers in palmitate-induced hypertrophic H9c2 cells in vitro. Treatment of diabetic animals with berberine partially improved cardiac function and restored fasting blood insulin, fasting blood glucose, total cholesterol, and triglyceride levels to that of control. In addition, berberine treatment of diabetic animals increased cardiac 5'-adenosine monophosphate-activated protein kinase (AMPK) and protein kinase B (AKT) activation and reduced glycogen synthase kinase 3 beta (GSK3β) activation compared to control. Palmitate incubation of H9c2 cells resulted in cellular hypertrophy and decreased expression of alpha-myosin heavy chain (α-MHC) and increased expression of beta-myosin heavy chain (β-MHC) compared to controls. Berberine treatment of palmitate-incubated H9c2 cells reduced hypertrophy, increased α-MHC expression and decreased β-MHC expression. In addition, berberine treatment of palmitate-incubated H9c2 cells increased AMPK and AKT activation and reduced GSK3β activation. The presence of the AMPK inhibitor Compound C attenuated the effects of berberine. The results strongly indicate that berberine treatment may be protective against the development of diabetic cardiomyopathy. Copyright © 2015 Elsevier B.V. All rights reserved.

Conversion of (η(5)-C2B9H10R)TaX3 (X = Me, NMe2) to (η(6)-C2B9H10R)TaX' (X' = NMe2, azaallyl) in the absence of a reducing agent: synthesis and structure of tantallacarboranes incorporating an arachno-η(6)-C2B9(4-) ligand.

PubMed

Xiang, Li; Xie, Zuowei

2014-08-04

Heating a benzene solution of [η(5)-(Me2NCH2CH2)C2B9H10] Ta(NMe2)3 (1) in the presence of pyridine gave an unprecedented complex [η(1):η(6)-(Me2NCH2CH2)C2B9H10]Ta (NMe2)(NC5H5) (2). On the other hand, reaction of (η(5)-C2B9H11)TaMe3 with adamantly isonitrile (AdNC) in dimethoxyethane (DME) at room temperature afforded another unexpected complex (η(6)-C2B9H11)Ta[η(3)-C,C,N-CH2C(CH3)NAd](DME) (4). These results show that pyridine and DME are essential for the formation of 2 and 4, respectively. It is suggested that the nido-η(5)-C2B9H10R(2−) ligand in tantallacarboranes takes up two electrons released by reductive elimination to form an arachno-η(6)-C2B9H10R(4−) fragment via the cage C–C bond cleavage.

Pan-histone deacetylase inhibitors regulate signaling pathways involved in proliferative and pro-inflammatory mechanisms in H9c2 cells

PubMed Central

2012-01-01

Background We have shown previously that pan-HDAC inhibitors (HDACIs) m-carboxycinnamic acid bis-hydroxamide (CBHA) and trichostatin A (TSA) attenuated cardiac hypertrophy in BALB/c mice by inducing hyper-acetylation of cardiac chromatin that was accompanied by suppression of pro-inflammatory gene networks. However, it was not feasible to determine the precise contribution of the myocytes- and non-myocytes to HDACI-induced gene expression in the intact heart. Therefore, the current study was undertaken with a primary goal of elucidating temporal changes in the transcriptomes of cardiac myocytes exposed to CBHA and TSA. Results We incubated H9c2 cardiac myocytes in growth medium containing either of the two HDACIs for 6h and 24h and analyzed changes in gene expression using Illumina microarrays. H9c2 cells exposed to TSA for 6h and 24h led to differential expression of 468 and 231 genes, respectively. In contrast, cardiac myocytes incubated with CBHA for 6h and 24h elicited differential expression of 768 and 999 genes, respectively. We analyzed CBHA- and TSA-induced differentially expressed genes by Ingenuity Pathway (IPA), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Core_TF programs and discovered that CBHA and TSA impinged on several common gene networks. Thus, both HDACIs induced a repertoire of signaling kinases (PTEN-PI3K-AKT and MAPK) and transcription factors (Myc, p53, NFkB and HNF4A) representing canonical TGFβ, TNF-α, IFNγ and IL-6 specific networks. An overrepresentation of E2F, AP2, EGR1 and SP1 specific motifs was also found in the promoters of the differentially expressed genes. Apparently, TSA elicited predominantly TGFβ- and TNF-α-intensive gene networks regardless of the duration of treatment. In contrast, CBHA elicited TNF-α and IFNγ specific networks at 6 h, followed by elicitation of IL-6 and IFNγ-centered gene networks at 24h. Conclusions Our data show that both CBHA and TSA induced similar, but not identical, time-dependent, gene

Curcumin induces the apoptotic intrinsic pathway via upregulation of reactive oxygen species and JNKs in H9c2 cardiac myoblasts.

PubMed

Zikaki, Kyriaki; Aggeli, Ioanna-Katerina; Gaitanaki, Catherine; Beis, Isidoros

2014-06-01

Curcumin derived from the rhizome of turmeric (Curcuma longa L.), is a well known coloring culinary agent, that has therapeutic properties against diverse pathologies such as cancer, atherosclerosis and heart failure. Given the salutary potential of curcumin, deciphering its mode of action particularly in cardiac cells, is of outstanding value. Accumulating evidence implicates curcumin in the regulation of multiple signaling pathways leading to cell survival or apoptosis. Therefore, the present study aimed at elucidating the molecular mechanisms triggered by curcumin in H9c2 cells. Curcumin was found to activate p38-mitogen-activated protein kinase (p38-MAPK) as well as c-jun NH2 terminal kinases (JNKs), in a dose- and time-dependent manner. We also observed curcumin to impair cell survival by promoting apoptosis, evidenced by chromatin condensation, poly(ADP-ribose) polymerase (PARP) and caspase-3 cleavage, as well as Bax translocation and cytochrome c release into the cytosol. Curcumin-induced apoptosis was ascribed to JNKs, since hindering their activity abolished PARP fragmentation. Furthermore, we identified curcumin to exert a pro-oxidative activity, with 2',7'-dichlorofluorescin diacetate (DCFH-DA) staining revealing up-regulation of reactive oxygen species (ROS) levels and anti-oxidants found to abrogate PARP cleavage. In conclusion, curcumin was found to stimulate the apoptotic cell death of H9c2 cells by upregulating ROS generation and triggering activation of JNKs. With reports underscoring the capacity of curcumin to perturb the cellular redox balance ensuring survival or enhancing apoptosis, determination of its mode of action appears to be critical. Future studies should assess the appropriate administration conditions of curcumin, so as to optimize its therapeutic potential against cardiovascular pathologies.

[The effect of Foxc2 overexpression on the osteogenic properties of C3H10T1/2 cells].

PubMed

Wang, Min-Jiao; Si, Jia-Wen; Li, Hong-Liang; Ouyang, Ning-Juan; Shen, Guo-Fang

2016-08-01

To investigate the effect of Foxc2 overexpression on osteogenic and adipogenic differentiation of C3H10T1/2 cells. C3H10T1/2 cells were transfected with plenti-Foxc2 and selected with puromycin for stable clones. The expression of Foxc2 was determined by real-time PCR and Western blot. Cell proliferation was detected by CCK-8 kit. Cell cycle and apoptosis were detected by flow cytometry. The level of osteogenic biomarkers Runx2, OPN, OCN and adipogenic biomarker PPARγ were quantified by real-time PCR and Western blot. Alkaline phosphatase (ALP) staining and oil red staining were conducted to evaluate the effect of Foxc2 overexpression on osteogenic and adipogenic differentiation. Statistical analysis was performed using SPSS 17.0 software package. C3H10T1/2-Foxc2 cell line was successfully constructed and verified by direct sequencing and Foxc2 overexpression in vitro. Cell proliferation was reduced and cell cycle was blocked in G1/G0 phase. Enhanced ALP staining and reduced oil red staining were observed in C3H10T1/2-Foxc2 cells as compared with the control. Foxc2 overexpression up-regulated Runx2, OPN, OCN during osteogenic differentiation and down-regulated PPARγduring adipogenic differentiation. C3H10T1/2 cell line stably expressing Foxc2 gene was successfully established, cell proliferation was reduced, osteogenesis biomarkers were up-regulated during the osteogenesis by overexpression Foxc2, PPARγwas down-regulated during adipogenesis.

Comprehensive benchmarking reveals H2BK20 acetylation as a distinctive signature of cell-state-specific enhancers and promoters.

PubMed

Kumar, Vibhor; Rayan, Nirmala Arul; Muratani, Masafumi; Lim, Stefan; Elanggovan, Bavani; Xin, Lixia; Lu, Tess; Makhija, Harshyaa; Poschmann, Jeremie; Lufkin, Thomas; Ng, Huck Hui; Prabhakar, Shyam

2016-05-01

Although over 35 different histone acetylation marks have been described, the overwhelming majority of regulatory genomics studies focus exclusively on H3K27ac and H3K9ac. In order to identify novel epigenomic traits of regulatory elements, we constructed a benchmark set of validated enhancers by performing 140 enhancer assays in human T cells. We tested 40 chromatin signatures on this unbiased enhancer set and identified H2BK20ac, a little-studied histone modification, as the most predictive mark of active enhancers. Notably, we detected a novel class of functionally distinct enhancers enriched in H2BK20ac but lacking H3K27ac, which was present in all examined cell lines and also in embryonic forebrain tissue. H2BK20ac was also unique in highlighting cell-type-specific promoters. In contrast, other acetylation marks were present in all active promoters, regardless of cell-type specificity. In stimulated microglial cells, H2BK20ac was more correlated with cell-state-specific expression changes than H3K27ac, with TGF-beta signaling decoupling the two acetylation marks at a subset of regulatory elements. In summary, our study reveals a previously unknown connection between histone acetylation and cell-type-specific gene regulation and indicates that H2BK20ac profiling can be used to uncover new dimensions of gene regulation. © 2016 Kumar et al.; Published by Cold Spring Harbor Laboratory Press.

Comprehensive benchmarking reveals H2BK20 acetylation as a distinctive signature of cell-state-specific enhancers and promoters

PubMed Central

Kumar, Vibhor; Rayan, Nirmala Arul; Muratani, Masafumi; Lim, Stefan; Elanggovan, Bavani; Xin, Lixia; Lu, Tess; Makhija, Harshyaa; Poschmann, Jeremie; Lufkin, Thomas; Ng, Huck Hui; Prabhakar, Shyam

2016-01-01

Although over 35 different histone acetylation marks have been described, the overwhelming majority of regulatory genomics studies focus exclusively on H3K27ac and H3K9ac. In order to identify novel epigenomic traits of regulatory elements, we constructed a benchmark set of validated enhancers by performing 140 enhancer assays in human T cells. We tested 40 chromatin signatures on this unbiased enhancer set and identified H2BK20ac, a little-studied histone modification, as the most predictive mark of active enhancers. Notably, we detected a novel class of functionally distinct enhancers enriched in H2BK20ac but lacking H3K27ac, which was present in all examined cell lines and also in embryonic forebrain tissue. H2BK20ac was also unique in highlighting cell-type-specific promoters. In contrast, other acetylation marks were present in all active promoters, regardless of cell-type specificity. In stimulated microglial cells, H2BK20ac was more correlated with cell-state-specific expression changes than H3K27ac, with TGF-beta signaling decoupling the two acetylation marks at a subset of regulatory elements. In summary, our study reveals a previously unknown connection between histone acetylation and cell-type-specific gene regulation and indicates that H2BK20ac profiling can be used to uncover new dimensions of gene regulation. PMID:26957309

Estrogen and/or Estrogen Receptor α Inhibits BNIP3-Induced Apoptosis and Autophagy in H9c2 Cardiomyoblast Cells.

PubMed

Chen, Bih-Cheng; Weng, Yi-Jiun; Shibu, Marthandam Asokan; Han, Chien-Kuo; Chen, Yueh-Sheng; Shen, Chia-Yao; Lin, Yueh-Min; Viswanadha, Vijaya Padma; Liang, Hsin-Yueh; Huang, Chih-Yang

2018-04-26

The process of autophagy in heart cells maintains homeostasis during cellular stress such as hypoxia by removing aggregated proteins and damaged organelles and thereby protects the heart during the times of starvation and ischemia. However, autophagy can lead to substantial cell death under certain circumstances. BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), a hypoxia-induced marker, has been shown to induce both autophagy and apoptosis. A BNIP3-docked organelle, e.g., mitochondria, also determines whether autophagy or apoptosis will take place. Estrogen (E2) and estrogen receptor (ER) alpha (ERα) have been shown to protect the heart against mitochondria-dependent apoptosis. The aim of the present study is to investigate the mechanisms by which ERα regulates BNIP3-induced apoptosis and autophagy, which is associated with hypoxic injury, in cardiomyoblast cells. An in vitro model to mimic hypoxic injury in the heart by engineering H9c2 cardiomyoblast cells to overexpress BNIP3 was established. Further, the effects of E2 and ERα in BNIP3-induced apoptosis and autophagy were determined in BNIP3 expressing H9c2 cells. Results from TUNEL assay and Immunoflourecense assay for LC3 puncta formation, respectively, revealed that ERα/E2 suppresses BNIP3-induced apoptosis and autophagy. The Western blot analysis showed ERα/E2 decreases the protein levels of caspase 3 (apoptotic marker), Atg5, and LC3-II (autophagic markers). Co-immunoprecipitation of BNIP3 and immunoblotting of Bcl-2 and Rheb showed that ERα reduced the interaction between BNIP3 and Bcl-2 or Rheb. The results confirm that ERα binds to BNIP3 causing a reduction in the levels of functional BNIP3 and thereby inhibits cellular apoptosis and autophagy. In addition, ERα attenuated the activity of the BNIP3 promoter by binding to SP-1 or NFκB sites.

Enhancement of SV40 transformation by treatment of C3H2K cells with uv light and caffeine. I. Combined effect of uv light and caffeine. [Mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ide, T.; Anzai, K.; Andoh, T.

1975-08-01

Treatment of cultured mouse cells, C3H2K, with uv light and/or caffeine enhanced the frequency of SV40-induced transformation. This enhancement depends upon the doses of uv and caffeine and the mode of combination of these agents. Irradiation of cells with increasing doses of uv just before infection resulted in approximately 2-fold enhancement of the transformation frequency up to a dose of 90 ergs/mm/sup 2/ and 3.3-fold at 150 ergs/mm/sup 2/. Addition of 1 mM caffeine to the medium for 4 days subsequent to infection brought about a 2-fold enhancement. When cells were irradiated and treated with 1 mM caffeine, the enhancementmore » was approximately 4-fold up to a uv dose of 90 ergs/mm/sup 2/ and 5.9-fold at 150 ergs/mm/sup 2/. When 0.1 to 4 mM caffeine was added for 4 days postinfection, the absolute number of transformations increased, and an enhancement ratio of 1.3 to 6.8 resulted. After the addition of the same increasing doses of caffeine to uv-irradiated cells (75 ergs/mm/sup 2/), the enhancement of transformation frequency was even higher ranging 2.0 to 13.3. The transformation frequencies thus obtained by the double treatment were always higher than those predicted if uv and caffeine acted additively. The transformation frequency was little affected by the addition of dibutyrylcyclic AMP and theophylline.« less

Liraglutide attenuates NLRP3 inflammasome-dependent pyroptosis via regulating SIRT1/NOX4/ROS pathway in H9c2 cells.

PubMed

Chen, Ao; Chen, Zhangwei; Xia, Yan; Lu, Danbo; Yang, Xiangdong; Sun, Aijun; Zou, Yunzeng; Qian, Juying; Ge, Junbo

2018-05-05

The glucagon-like peptide-1 analog liraglutide has been proved to exert cardioprotective role via activating prosurvival pathways and suppressing inflammation. The activation of NLRP3 inflammasome plays an important role in ischemic injury. The effect of liraglutide on NLRP3 inflammasome-dependent pyroptosis remains unclear. In this study, we established a double stimulation model with TNF-α and hypoxia to mimic ischemic environment and to induce NLRP3 inflammasome activation in H9c2 cardiomyoblasts. Pretreatment with 100 nM liraglutide could efficiently inhibit TNF-α and hypoxia-induced inflammasome activation, as evidenced by the decreased expression of NLRP3, caspase-1 p20 and Gasdermin D N-terminal fragment. Meanwhile, the pyroptosis was also demonstrated to be suppressed, indicated by the increased cell viability and decreased lactate dehydrogenase release in the cells. Mechanistically, liraglutide reversed the level of SIRT1 and the selective SIRT1 inhibitor EX 527 significantly abolished the anti-pyroptosis role of liraglutide. Furthermore, liraglutide diminished the levels of ROS generation and NOX4 expression, which could also be blocked by EX 527. Our results uncovered the anti-pyroptosis role of liraglutide in TNF-α and hypoxia-stimulated H9c2 cells, which was associated with SIRT1/NOX4/ROS pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

Suppression of antioxidant Nrf-2 and downstream pathway in H9c2 cells by advanced glycation end products (AGEs) via ERK phosphorylation.

PubMed

Ko, Shun-Yao; Chang, Shu-Shing; Lin, I-Hsuan; Chen, Hong-I

2015-11-01

Diabetic cardiomyopathy is related to oxidative stress and correlated with the presence of advanced glycation end products (AGEs). In a clinical setting, AGEs can be detected in patients presenting diabetic cardiomyopathy; however, the underlying mechanism has yet to be elucidated. In our previous study, AGEs increase cell hypertrophy via ERK phosphorylation in a process closely related to ROS production. Thus, we propose that AGEs regulate the antioxidant gene nuclear factor-erythroid 2-related factor (Nrf-2). In H9c2 cells treated with AGEs, the expression of Nrf-2 was reduced; however, ERK phosphorylation was shown to increase. Treatment with H2O2 was also shown to increase Nrf-2 and ERK phosphorylation. In cells pretreatment with ROS scavenger NAC, the effects of H2O2 were reduced; however, the effects of the AGEs remained largely unchanged. Conversely, when cells were pretreated with PD98059 (ERK inhibitor), the expression of Nrf-2 was recovered following treatment with AGEs. Our results suggest that AGEs inhibit Nrf-2 via the ERK pathway; however, this influence is partly associated with ROS. Our finding further indicated that AGEs possess both ROS-dependent and ROS-independent pathways, resulting in a reduction in Nrf-2. This report reveals an important mechanism underlying the regulation of diabetic cardiomyopathy progression by AGEs. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Peroxisome proliferator-activated receptor delta (PPARdelta) activation protects H9c2 cardiomyoblasts from oxidative stress-induced apoptosis.

PubMed

Pesant, Matthieu; Sueur, Stéphanie; Dutartre, Patrick; Tallandier, Mireille; Grimaldi, Paul A; Rochette, Luc; Connat, Jean-Louis

2006-02-01

Activation of peroxisome proliferator-activated receptor alpha (PPARalpha) and PPARgamma plays beneficial roles in cardiovascular disorders such as atherosclerosis and heart reperfusion. Although PPARalpha and gamma have been documented to reduce oxidative stress in the vasculature and the heart, the role of PPARdelta remains poorly studied. We focused on PPARdelta function in the regulation of oxidative stress-induced apoptosis in the rat cardiomyoblast cell line H9c2. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we showed that PPARdelta is the predominantly expressed isotype whereas PPARalpha was weakly detected. By performing cell viability assays, we also showed that the selective PPARdelta agonist GW501516 protected cells from H(2)O(2)-induced cell death. The protective effect of GW501516 was due to an inhibition of H(2)O(2)-triggered apoptosis as shown by annexin-V labeling, DNA fragmentation analysis, and caspase-3 activity measurement. We demonstrated by transient transfection of a dominant negative mutant of PPARdelta that the protection induced by GW501516 was totally dependent on PPARdelta. Semi-quantitative RT-PCR and Western blotting analysis demonstrated that GW501516 treatment upregulated catalase. Moreover, forced overexpression of catalase inhibited H(2)O(2)-triggered apoptosis, as evidenced by annexin-V labeling. Taken together, our results account for an important role of PPARdelta in inhibiting the onset of oxidative stress-induced apoptosis in H9c2 cells. PPARdelta appears to be a new therapeutic target for the regulation of heart reperfusion-associated oxidative stress and stimulation of enzymatic antioxidative defences.

Tribulus terrestris (Linn.) Attenuates Cellular Alterations Induced by Ischemia in H9c2 Cells Via Antioxidant Potential.

PubMed

Reshma, P L; Lekshmi, V S; Sankar, Vandana; Raghu, K G

2015-06-01

Tribulus terrestris L. was evaluated for its cardioprotective property against myocardial ischemia in a cell line model. Initially, methanolic extract was prepared and subjected to sequential extraction with various solvents. The extract with high phenolic content (T. terrestris L. ethyl acetate extract-TTME) was further characterized for its chemical constituents and taken forward for evaluation against cardiac ischemia. HPLC analysis revealed the presence of phenolic compounds like caffeic acid (12.41 ± 0.22 mg g(-1)), chlorogenic acid (0.52 ± 0.06 mg g(-1)) and 4-hydroxybenzoic acid (0.60 ± 0.08 mg g(-1)). H9c2 cells were pretreated with TTME (10, 25, 50 and 100 µg/ml) for 24 h before the induction of ischemia. Then ischemia was induced by exposing cells to ischemia buffer, in a hypoxic chamber, maintained at 0.1% O2, 95% N2 and 5% CO2, for 1 h. A significant (p ≤ 0.05) increase in reactive oxygen species generation (56%), superoxide production (18%), loss of plasma membrane integrity, dissipation of transmembrane potential, permeability transition pore opening and apoptosis had been observed during ischemia. However, pretreatment with TTME was found to significantly (p ≤ 0.05) attenuate the alterations caused by ischemia. The overall results of this study partially reveal the scientific basis of the use of T. terrestris L. in the traditional system of medicine for heart diseases. Copyright © 2015 John Wiley & Sons, Ltd.

Herba Cistanches stimulates cellular glutathione redox cycling by reactive oxygen species generated from mitochondrial respiration in H9c2 cardiomyocytes.

PubMed

Wong, Hoi Shan; Ko, Kam Ming

2013-01-01

Earlier findings demonstrated that pretreatment of Herba Cistanches [the dried whole plant of Cistanche deserticola Y.C. Ma (Orobanchaceae)], a "Yang-invigorating" Chinese tonic herb, stimulated the ATP-generation capacity (ATP-GC) in mitochondria isolated from rat heart ex vivo. The enhancement of mitochondrial ATP-GC by Herba Cistanches was associated with induction of glutathione antioxidant status and protection against ischemia/reperfusion (I/R) injury in rat hearts. This study investigated the relationship between enhancements in mitochondrial ATP-GC and glutathione antioxidant status in H9c2 cardiomyocytes using a semipurified fraction of Herba Cistanches (HCF1). HCF1 (10-300 ng/mL) was tested for its effects on mitochondrial ATP generation, glutathione antioxidant status and protection against oxidant injury in H9c2 cardiomyocytes and rat hearts. HCF1 at 30 ng/mL increased mitochondrial ATP-GC and ADP-stimulated state 3 respiration (by 50 and 100%, respectively) in H9c2 cardiomyocytes. The stimulation of mitochondrial respiration was associated with the induction of mitochondrial uncoupling (27%) and enhancement of cellular glutathione redox cycling as well as protection against hypoxia/reoxygenation (hypox/reoxy)-induced apoptosis (by 60%). While HCF1 treatment increased reactive oxygen species generation from mitochondrial respiration in H9c2 cardiomyocytes, pretreatment with antioxidants (DMTU) abrogated the HCF1-induced cellular responses and the associated cytoprotective effect. HCF1 pretreatment (1.14 and 3.41 mg/kg × 14) also protected against myocardial I/R injury in rats (by 13 and 32%), presumably mediated by the induction of glutathione antioxidant response. The long-term intake of HCF1 may offer a prospect for the prevention of ischemic heart disease.

8,9-dihydroxy-8,9-dihydrodibenzo[a,l]pyrene is a potent morphological cell-transforming agent in C3H10T(1)/(2)Cl8 mouse embryo fibroblasts in the absence of detectable stable covalent DNA adducts.

PubMed

Nesnow, S; Davis, C; Padgett, W T; Adams, L; Yacopucci, M; King, L C

2000-06-01

The comparative genotoxic effects of racemic trans-8,9-dihydroxy-8, 9-dihydrodibenzo[a,l]pyrene (trans-DB[a,l]P-8,9-diol), the metabolic K-region dihydrodiol of dibenzo[a,l] pyrene (DB[a,l]P) (dibenzo[def, p]chrysene) and DB[a,l]P in transformable mouse embryo C3H10T(1)/(2)Cl8 (C3H10T(1)/(2)) fibroblasts was investigated. The C3H10T(1)/(2) mouse embryo morphological cell-transforming activities of these polycyclic aromatic hydrocarbons (PAHs) were assayed using concentration-response studies. At concentrations of 33 nM and above both trans-DB[a,l]P-8,9-diol and DB[a,l]P produced significant (and similar) numbers of type II and III foci per dish and numbers of dishes with type II and II foci. Concomitant cytotoxicity studies revealed a reduction in colony survival of approximately 25% up to 198 nM for both PAHs. DNA adducts of trans-DB[a,l]P-8,9-diol and DB[a,l]P in C3H10T(1)/(2) cells were analyzed by a (32)P-post-labeling TLC/HPLC method. No adducts were observed in the DNA of C3H10T(1)/(2) cells treated with trans-DB[a, l]P-8,9-diol at concentrations that induced morphological cell transformation. Under the same exposure and chromatographic conditions, DNA adducts of deoxyadenosine and deoxyguanosine derived from the fjord region anti-DB[a,l]P-11,12-diol-13,14-epoxide and syn-DB[a,l]P-11,12-diol-13,14-epoxide were observed in the DNA of DB[a,l]P-treated cells. These results indicate that trans-DB[a,l]P-8, 9-diol has intrinsic genotoxic activity equal to that of DB[a,l]P, based on morphological cell transformation of mouse embryo fibroblasts. The activity of trans-DB[a,l]P-8,9-diol is apparently not associated with the formation of observable stable covalent DNA adducts. These results suggest that under appropriate conditions, trans-DB[a,l]P-8,9-diol may serve as an intermediate in the genotoxicity of DB[a,l]P.

Bauhinia championii Flavone Attenuates Hypoxia-Reoxygenation Induced Apoptosis in H9c2 Cardiomyocytes by Improving Mitochondrial Dysfunction.

PubMed

Liao, Ping; Sun, Guibo; Zhang, Chan; Wang, Min; Sun, Yao; Zhou, Yuehan; Sun, Xiaobo; Jian, Jie

2016-11-04

This study aimed to determine the effects of Bauhinia championii flavone (BCF) on hypoxia-reoxygenation (H/R) induced apoptosis in H9c2 cardiomyocytes and to explore potential mechanisms. The H/R model in H9c2 cardiomyocytes was established by 6 h of hypoxia and 12 h of reoxygenation. Cell viability was detected by CCK-8 assay. Apoptotic rate was measured by Annexin V/PI staining. Levels of mitochondria-associated ROS, mitochondrial transmembrane potential (∆Ψm) and mitochondrial permeability transition pores (MPTP) opening were assessed by fluorescent probes. ATP production was measured by ATP assay kit. The release of cytochrome c, translocation of Bax, and related proteins were measured by western blotting. Our results showed that pretreatment with BCF significantly improved cell viability and attenuated the cardiomyocyte apoptosis caused by H/R. Furthermore, BCF increased ATP production and inhibited ROS-generating mitochondria, depolarization of ΔΨm, and MPTP opening. Moreover, BCF pretreatment decreased Bax mitochondrial translocation, cytochrome c release, and activation of caspase-3, as well as increased the expression of p-PI3K, p-Akt, and the ratio of Bcl-2 to Bax. Interestingly, a specific inhibitor of phosphatidylinositol 3-kinase, LY294002, partly reversed the anti-apoptotic effect of BCF. These observations indicated that BCF pretreatment attenuates H/R-induced myocardial apoptosis strength by improving mitochondrial dysfunction via PI3K/Akt signaling pathway.

Protection of Luteolin-7-O-glucoside against apoptosis induced by hypoxia/reoxygenation through the MAPK pathways in H9c2 cells.

PubMed

Chen, Shenjie; Yang, Bingsheng; Xu, Yifei; Rong, Yiqing; Qiu, Yuangang

2018-05-01

Myocardial hypertrophy is often associated with myocardial infarction. Luteolin-7-O-glucoside (LUTG) has the prosperity of preventing cardiomyocyte injury. The current study aimed to explore the potential protective effect of LUTG and its relevant mechanisms in the heart. To establish the cardiac hypertrophy model in vitro, Angiotensin II (Ang II) was used to stimuli H9c2 cells in this study. The CCK‑8 assay showed that LUTG pretreatment improved cell viability of cardiomyocytes co‑treated with Ang II and ischemia/reperfusion. LUTG decreased the reactive oxygen species levels. Furthermore, it was demonstrated LUTG could reduce the release amount of lactate dehydrogenase and recover the catalase activity according to the flow cytometry analysis, and activity detection, respectively in Ang II‑H/R‑treated H9c2 cells. In addition, the flow cytometry analysis showed that the pretreatment of LUTG mitigated cell apoptosis induced by hypoxia/reoxygenation in the cardiac hypertrophy model. Meanwhile, reverse transcription‑quantitative polymerase chain reaction and western blot assays showed that the apoptosis‑related genes, including poly (ADP‑ribose) polymerase, Fas, Fasl and Caspase‑3 were downregulated at the transcriptional and translational levels. Notably, the protien expression of phosphorylated (p)‑extracellular signal‑regulated kinas (ERK) 1/2, p‑janus kinase and p‑P38 were reduced, while the expression of p‑ERK5 was elevated in the LUTG pretreatment groups compared with the hypoxia/reoxygenation treatment group. Based on these results, it was suggested that the anti‑apoptosis effect of LUTG may be associated with regulating the activation of mitogen‑activated protein kinases signaling pathways.

Effects of pomegranate seed oil on oxidant/antioxidant balance in heart and kidney homogenates and mitochondria of diabetic rats and high glucose-treated H9c2 cell line

PubMed Central

Mollazadeh, Hamid; Boroushaki, Mohammad Taher; Soukhtanloo, Mohammad; Afshari, Amir Reza; Vahedi, Mohammad Mahdi

2017-01-01

Objective: Oxidative stress is a major cause of diabetes complications. The present study aimed to investigate the beneficial effects of Pomegranate Seed Oil (PSO) on diabetes-induced changes in oxidant/antioxidant balance of the kidney, heart and mitochondria from rats and H9c2 cell line. Materials and Methods: In these in vivo and in vitro studies, male rats were divided into four groups (twelve each): group 1 served as control, group 2-4 received a single dose of streptozotocin (60 mg/kg, i.p), groups 3 and 4 received PSO (0.36 and 0.72 mg/kg/daily, gavage), respectively. After three weeks, six rats of each group and one week later the remaining animals were anaesthetized and the hearts and kidneys were removed and homogenized. Mitochondrial fractions were separated and enzyme activities were measured in each sample. H9c2 cells were pretreated with high levels of glucose (35 mM), and then, incubated with PSO. Finally, cell viability test, reactive oxygen species production and lipid peroxidation were evaluated. Results: Significant reduction in enzymes activity (Superoxide dismutase, Glutathione S-transferase and Paraoxonase 1), compensatory elevation in Glutathione Reductase, Glutathione Peroxidase and Catalase activity followed by reduction after one week and significant elevation in Oxidative Stress Index (OSI) were observed in diabetic group. PSO treatment resulted in a significant increase in enzymes activity and decreased OSI values compared to diabetic group in both tissue and mitochondrial fractions. PSO remarkably decreased glucose-induced toxicity, ROS level and lipid peroxidation in H9c2 cells. Conclusion: Results suggested that PSO has a protective effect against diabetes-induced alterations in oxidant/antioxidant balance in tissues, mitochondrial and H9c2 cell line. PMID:28884082

Sodium arsenite represses the expression of myogenin in C2C12 mouse myoblast cells through histone modifications and altered expression of Ezh2, Glp, and Igf-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Gia-Ming; Present address: The University of Chicago, Section of Hematology/Oncology, 900 E. 57th Street, Room 7134, Chicago, IL 60637; Bain, Lisa J., E-mail: lbain@clemson.edu

2012-05-01

Arsenic is a toxicant commonly found in water systems and chronic exposure can result in adverse developmental effects including increased neonatal death, stillbirths, and miscarriages, low birth weight, and altered locomotor activity. Previous studies indicate that 20 nM sodium arsenite exposure to C2C12 mouse myocyte cells delayed myoblast differentiation due to reduced myogenin expression, the transcription factor that differentiates myoblasts into myotubes. In this study, several mechanisms by which arsenic could alter myogenin expression were examined. Exposing differentiating C2C12 cells to 20 nM arsenic increased H3K9 dimethylation (H3K9me2) and H3K9 trimethylation (H3K9me3) by 3-fold near the transcription start site ofmore » myogenin, which is indicative of increased repressive marks, and reduced H3K9 acetylation (H3K9Ac) by 0.5-fold, indicative of reduced permissive marks. Protein expression of Glp or Ehmt1, a H3-K9 methyltransferase, was also increased by 1.6-fold in arsenic-exposed cells. In addition to the altered histone remodeling status on the myogenin promoter, protein and mRNA levels of Igf-1, a myogenic growth factor, were significantly repressed by arsenic exposure. Moreover, a 2-fold induction of Ezh2 expression, and an increased recruitment of Ezh2 (3.3-fold) and Dnmt3a (∼ 2-fold) to the myogenin promoter at the transcription start site (− 40 to + 42), were detected in the arsenic-treated cells. Together, we conclude that the repressed myogenin expression in arsenic-exposed C2C12 cells was likely due to a combination of reduced expression of Igf-1, enhanced nuclear expression and promoter recruitment of Ezh2, and altered histone remodeling status on myogenin promoter (− 40 to + 42). -- Highlights: ► Igf-1 expression is decreased in C2C12 cells after 20 nM arsenite exposure. ► Arsenic exposure alters histone remodeling on the myogenin promoter. ► Glp expression, a H3–K9 methyltransferase, was increased in arsenic-exposed cells

H9N2 Influenza Whole Inactivated Virus Combined with Polyethyleneimine Strongly Enhances Mucosal and Systemic Immunity after Intranasal Immunization in Mice

PubMed Central

Qin, Tao; Yin, Yinyan; Huang, Lulu; Yu, Qinghua

2015-01-01

Influenza whole inactivated virus (WIV) is more immunogenic and induces protective antibody responses compared with other formulations, like split virus or subunit vaccines, after intranasal mucosal delivery. Polyethyleneimine (PEI), an organic polycation, is widely used as a reagent for gene transfection and DNA vaccine delivery. Although PEI recently has demonstrated potent mucosal adjuvant activity for viral subunit glycoprotein antigens, its immune activity with H9N2 WIV is not well demonstrated. Here, mice were immunized intranasally with H9N2 WIV combined with PEI, and the levels of local respiratory tract and systemic immune responses were measured. Compared to H9N2 WIV alone, antigen-specific IgA levels in the local nasal cavity, trachea, and lung, as well as levels of IgG and its subtypes (IgG1 and IgG2a) in the serum, were strongly enhanced with the combination. Similarly, the activation and proliferation of splenocytes were markedly increased. In addition, PEI is superior as an H9N2 WIV delivery system due to its ability to greatly increase the viral adhesion to mucosal epithelial cells and to enhance the cellular uptake and endosomal escape of antigens in dendritic cells (DCs) and further significantly activate DCs to mature. Taken together, these results provided more insights that PEI has potential as an adjuvant for H9N2 particle antigen intranasal vaccination. PMID:25673304

pPKCδ activates SC35 splicing factor during H9c2 myoblastic differentiation.

PubMed

Zara, Susi; Falconi, Mirella; Rapino, Monica; Zago, Michela; Orsini, Giovanna; Mazzotti, Giovanni; Cataldi, Amelia; Teti, Gabriella

2011-01-01

Although Protein Kinase C (PKC) isoforms' role in the neonatal and adult cardiac tissue development and ageing has been widely described "in vivo", the interaction of such enzymes with specific nuclear substrates needs to be investigated. The aim of our research has been the study of the expression, localization and interaction with the splicing factor SC35 of PKC isoforms (α, δ, ε, ζ) and their potential role in modulating the transcription machinery. H9c2 cells induced to myoblast differentiation in the presence of 1% Horse Serum (HS) have represented our experimental model. The expression of PKC isoforms, their distribution and interaction with SC35 have been evaluated by western blotting, co-immunoprecipitation and double gold immunolabeling for transmission and scanning electron microscopy. Our results show PKCδ as the most expressed isoform in differentiated cells. Surprisingly, the distribution of PKCδ and SC35 does not show any significant modification between 10%FBS and 1%HS treated samples and no co-localization is observed. Moreover the interaction between the phosphorylated form of PKCδ (pPKCδ) and SC35 increases, is distributed and co-localizes within the nucleus of differentiated H9c2. These data represent reasonable evidence of pPKCδ mediated SC35 splicing factor activation, suggesting its direct effect on transcription via interaction with the transcription machinery. Furthermore, this co-localization represents a crucial event resulting in downstream changes in transcription of components which determine the morphological modifications related to cardiomyoblast differentiated phenotype.

Knockdown of CkrL by shRNA deteriorates hypoxia/reoxygenation-induced H9C2 cardiomyocyte apoptosis and survival inhibition Via Bax and downregulation of P-Erk1/2.

PubMed

Zhang, Zhi-Sheng; Yang, Dong-Yan; Fu, Yan-Bo; Zhang, Lei; Zhao, Qian-Ping; Li, Gang

2015-03-01

Integrin β1 subunit and its downstream molecule integrin-linked kinase and focal adhesion kinase have been confirmed to be essential to cell survival and inhibition of apoptosis and hypoxia/reoxygenation (H/R)-induced injuries in cardiomyocytes. However, it is still unclear whether CrkL [v-crk avian sarcoma virus CT-10 oncogene homolog (Crk)-like], which acts also as a component of the integrin pathway, could also affect H/R-induced injuries in the cardiomyocytes. The rat-derived H9C2 cardiomyocytes were infected with a CrkL small hairpin RNA interference recombinant lentivirus, which knockdowns the endogenous CrkL expression in the cardiomyocytes. Apoptosis, cell proliferation and survival were examined in the H9C2 cardiomyocytes treated with either H/R or not. Results showed that knockdown of CrkL could significantly increase apoptosis and inhibition of the cell proliferation and survival and deteriorate the previously mentioned injuries induced by H/R. In contrast, overexpression of human CrkL could relieve the exacerbation of the previously mentioned injuries induced by CrkL knockdown in the H9C2 cardiomyocytes via regulation of Bax and extracellular signal-regulated kinase1/2 (p-ERK1/2). In conclusion, these results confirmed that knockdown of CrkL could deteriorate H/R-induced apoptosis and cell survival inhibition in rat-derived H9C2 cardiomyocytes via Bax and downregulation of p-ERK1/2. It implies that CrkL could mitigate H/R-induced injuries in the cardiomyocytes. Copyright © 2015 John Wiley & Sons, Ltd.

Enhanced cyclooxygenase-2 expression levels and metalloproteinase 2 and 9 activation by Hexachlorobenzene in human endometrial stromal cells.

PubMed

Chiappini, Florencia; Bastón, Juan Ignacio; Vaccarezza, Agustina; Singla, José Javier; Pontillo, Carolina; Miret, Noelia; Farina, Mariana; Meresman, Gabriela; Randi, Andrea

2016-06-01

Hexachlorobenzene (HCB) is an organochlorine pesticide that induces toxic reproductive effects in laboratory animals. It is a dioxin-like compound and a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is characterized by the presence of functional endometrial tissues outside the uterine cavity. Experimental studies indicate that exposure to organochlorines can interfere with both hormonal regulation and immune function to promote endometriosis. Altered expression of metalloproteinases (MMPs) in patients with endometriosis, suggests that MMPs may play a critical role. In the endometriotic lesions, prostaglandin E2 (PGE2) produced by cyclooxygenase-2 (COX-2), binds to its EP4 receptor (EP4), and via c-Src kinase induces MMPs activation, promoting endometriosis. We examined the HCB action on MMP-2 and MMP-9 activities and expression, COX-2 levels, PGE2 signaling, and the AhR involvement in HCB-induced effects. We have used different in vitro models: (1) human endometrial stromal cell line T-HESC, (2) primary cultures of Human Uterine Fibroblast (HUF), and (3) primary cultures of endometrial stromal cells from eutopic endometrium of control (CESC) and subjects with endometriosis (EESC). Our results show that HCB enhances MMP-2 and MMP-9 activities in T-HESC, HUF and ESC cells. The MMP-9 levels were elevated in all models, while the MMP-2 expression only increased in ESC cells. HCB enhanced COX-2 and EP4 expression, PGE2 secretion and the c-Src kinase activation in T-HESC. Besides, we observed that AhR is implicated in these HCB-induced effects. In conclusion, our results show that HCB exposure could contribute to endometriosis development, affecting inflammation and invasion parameters of human endometrial cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Isorhamnetin protects against hypoxia/reoxygenation-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes.

PubMed

Zhao, Ting-Ting; Yang, Tian-Lun; Gong, Li; Wu, Pei

2018-05-03

To unveil the possible protective role of isorhamnetin, an immediate 3'-O-methylated metabolite of quercetin, in cardiomyocyte under hypoxia/reoxygenation (H/R) condition and the underlying mechanisms involved, H9c2 cardiomyocytes were exposed to the vehicle or H/R for 6 h (2 h of hypoxia following by 4 h of reoxygenation) with isorhamnetin (0, 3, 6, 12, 25, 50 μM for 4 h prior to H/R exposure). Apoptosis was evaluated by TUNEL staining, flow cytometry analysis and western blot assay for cleaved caspase-3. Myocardial injure in vivo was determined by infarct size using TTC staining, histological damage using H&E staining and myocardial apoptosis. Here, we found that isorhamnetin dose-dependently protected H9c2 cardiomyocytes against H/R-induced injure, as evidenced by the reduction in lactate dehydrogenase (LDH) levels, increases in cell viability, superoxide dismutase (SOD) and catalase (CAT) activity, with the maximal effects at 25 μΜ. In addition, isorhamnetin treatment significantly inhibited apoptosis in H/R-induced H9c2 cardiomyocytes and ameliorated H/R-induced myocardial injure in vivo, concomitant with the upregulation of sirtuin 1 (SIRT1) expression. Mechanism studies demonstrated that isorhamnetin pretreatment remarkably abolished H/R-induced downregulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expressions and upregulation of NADPH oxidase-2/4 (NOX-2/4) expressions in cardiomyocytes. However, SIRT1 inhibition (Sirtinol) not only inhibited isorhamnetin-induced Nrf2/HO-1 upregulation and NOX-2/4 downregulation, but also alleviated its anti-apoptotic effects. Taken together, these data indicate that isorhamnetin can exhibit positive effect on H/R-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes, which is partly attributable to the upregulation of SIRT1 and Nrf2/HO-1-mediated antioxidant signaling pathway. Copyright © 2017. Published by Elsevier B.V.

Transcriptional deregulation of oncogenic myocyte enhancer factor 2C in T-cell acute lymphoblastic leukemia.

PubMed

Nagel, Stefan; Venturini, Letizia; Meyer, Corinna; Kaufmann, Maren; Scherr, Michaela; Drexler, Hans G; Macleod, Roderick A F

2011-02-01

Myocyte enhancer factor 2C (MEF2C) encodes a transcription factor which is ectopically expressed in T-cell acute lymphoblastic leukemia (T-ALL) cell lines, deregulated directly by ectopically expressed homeodomain protein NKX2-5 or by loss of promoter regions via del(5)(q14). Here, we analyzed the MEF2C 5'-region, thus identifying potential regulatory binding sites for GFI1B, basic helix-loop-helix proteins, STAT5, and HOXA9/HOXA10. Chromatin immunoprecipitation and overexpression analyses demonstrated direct activation by GFI1B and LYL1 and inhibition by STAT5. HOXA9/HOXA10 activated expression of NMYC which in turn mediated MEF2C repression, indicating an indirect mode of regulation via NMYC interactor (NMI) and STAT5. Lacking comma: Chromosomal deletion of the STAT5 binding site in LOUCY cells reduced protein levels of STAT5 in some MEF2C-positve T-ALL cell lines, and the presence of inhibitory IL7-JAK-STAT5 signaling highlighted the repressive impact of this factor in MEF2C regulation. Taken together, our results indicate that the expression of MEF2C in T-ALL cells is principally deregulated via activating leukemic transcription factors GFI1B or NKX2-5 and by escaping inhibitory developmental STAT5 signaling.

Fabrication of 2D SnS2/g-C3N4 heterojunction with enhanced H2 evolution during photocatalytic water splitting.

PubMed

Liu, Enzhou; Chen, Jibing; Ma, Yongning; Feng, Juan; Jia, Jia; Fan, Jun; Hu, Xiaoyun

2018-08-15

In this work, the 2D SnS 2 /g-C 3 N 4 heterojunctions were successfully prepared by heating the homogeneous dispersion of SnS 2 nanosheets and g-C 3 N 4 nanosheets using a microwave muffle. SEM, TEM and HRTEM images indicated that the SnS 2 nanosheets were loaded on the surface of the g-C 3 N 4 nanosheets. The UV-vis spectra show that the absorption intensity of the as-prepared samples was increased and the absorption range was also extended from 420 nm to approximately 600 nm. The H 2 production rate over 5 wt% SnS 2 /g-C 3 N 4 can reach 972.6 μmol·h -1 ·g -1 under visible light irradiation (λ > 420 nm) using TEOA as the sacrifice agent and Pt as the electron trap, which is 2.9 and 25.6 times higher than those of the pristine g-C 3 N 4 and SnS 2 , respectively. According to the obtained PL spectra, photocurrent and EIS spectra, the enhanced performance for H 2 generation over the heterojunctions is primarily ascribed to the rapid charge transfer arising from the suitable band gap positions leading to an improved photocatalytic performance. The recycling experiments indicated that the as-prepared composites exhibit good stability in H 2 production. Additionally, a possible enhanced mechanism for H 2 evolution was deduced based on the results obtained by various characterization techniques. Copyright © 2018 Elsevier Inc. All rights reserved.

Icariin attenuates angiotensin II-induced hypertrophy and apoptosis in H9c2 cardiomyocytes by inhibiting reactive oxygen species-dependent JNK and p38 pathways

PubMed Central

ZHOU, HENG; YUAN, YUAN; LIU, YUAN; DENG, WEI; ZONG, JING; BIAN, ZHOU-YAN; DAI, JIA; TANG, QI-ZHU

2014-01-01

Icariin, the major active component isolated from plants of the Epimedium family, has been reported to have potential protective effects on the cardiovascular system. However, it is not known whether icariin has a direct effect on angiotensin II (Ang II)-induced cardiomyocyte enlargement and apoptosis. In the present study, embryonic rat heart-derived H9c2 cells were stimulated by Ang II, with or without icariin administration. Icariin treatment was found to attenuate the Ang II-induced increase in mRNA expression levels of hypertrophic markers, including atrial natriuretic peptide and B-type natriuretic peptide, in a concentration-dependent manner. The cell surface area of Ang II-treated H9c2 cells also decreased with icariin administration. Furthermore, icariin repressed Ang II-induced cell apoptosis and protein expression levels of Bax and cleaved-caspase 3, while the expression of Bcl-2 was increased by icariin. In addition, 2′,7′-dichlorofluorescein diacetate incubation revealed that icariin inhibited the production of intracellular reactive oxygen species (ROS), which were stimulated by Ang II. Phosphorylation of c-Jun N-terminal kinase (JNK) and p38 in Ang II-treated H9c2 cells was blocked by icariin. Therefore, the results of the present study indicated that icariin protected H9c2 cardiomyocytes from Ang II-induced hypertrophy and apoptosis by inhibiting the ROS-dependent JNK and p38 pathways. PMID:24940396

XL413, a cell division cycle 7 kinase inhibitor enhanced the anti-fibrotic effect of pirfenidone on TGF-β1-stimulated C3H10T1/2 cells via Smad2/4.

PubMed

Jin, Shu-fang; Ma, Hai-long; Liu, Zhong-long; Fu, Shui-ting; Zhang, Chen-ping; He, Yue

2015-12-10

Pirfenidone is an orally bioavailable synthetic compound with therapeutic potential for idiopathic pulmonary fibrosis. It is thought to act through antioxidant and anti-fibrotic pathways. Pirfenidone inhibits proliferation and/or myofibroblast differentiation of a wide range of cell types, however, little studies have analyzed the effect of pirfenidone on the mesenchymal stem cells, which play an important role on the origin of myofibroblasts. We recently found that pirfenidone had anti-proliferative activity via G1 phase arrest and cell division cycle 7 (Cdc7) kinase expression decrease in transforming growth factor-β1 (TGF-β1)-stimulated murine mesenchymal stem C3H10T1/2 cells. Pirfenidone also had inhibiting effect on the migration and α-SMA expression. Moreover, in this study we showed for the first time that Cdc7 inhibitor XL413 enhanced the anti-fibrotic activity of pirfenidone via depressed the expression of Smad2/4 proteins, and also prevented the nuclear accumulation and translocation of Smad2 protein. In conclusion, we demonstrated that pirfenidone inhibited proliferation, migration and differentiation of TGF-β1-stimulated C3H10T1/2 cells, which could be enhanced by Cdc7 inhibitor XL413, via Smad2/4. Combination with pirfenidone and XL413 might provide a potential candidate for the treatment of TGF-β1 associated fibrosis. It needs in vivo studies to further validate its therapeutic function and safety in the future. Copyright © 2015 Elsevier Inc. All rights reserved.

Polyphenol-rich apple (Malus domestica L.) peel extract attenuates arsenic trioxide induced cardiotoxicity in H9c2 cells via its antioxidant activity.

PubMed

Vineetha, Vadavanath Prabhakaran; Girija, Seetharaman; Soumya, Rema Sreenivasan; Raghu, Kozhiparambil Gopalan

2014-03-01

Evidences suggest that apple peel has a wide range of polyphenols having antioxidant activity and its consumption has been linked with improved health benefits. Arsenic trioxide (ATO) is a very effective drug for the treatment of acute promyelocytic leukemia (APL) but it leads to cardiotoxicity mediated through alterations in various cardiac ion channels and by increasing the intracellular calcium level and reactive oxygen species (ROS). The aim of the present investigation was to study the effect of methanolic extract of apple peel (APME) and aqueous extract of apple peel (APAE) on ATO (5 μM) induced toxicity in the H9c2 cardiac myoblast cell line. We estimated the cellular status of innate antioxidant enzymes, level of ROS, mitochondrial superoxide, glutathione and intracellular calcium with ATO and apple peel extracts. Prior to the cell line based study, we had evaluated the antioxidant potential of apple peel extract by 1,1-diphenyl-2-picrylhydrazyl (DPPH), total reducing power (TRP), superoxide anion and hydroxyl radical scavenging activity, in addition to quantifying total phenolic and flavonoid content. Both the extracts showed considerable antioxidant activity in cell-free chemical assays. In addition, both APME and APAE prevented the alteration in antioxidant status induced by ATO in H9c2 cells. Significant differential alterations had been observed in the activity of lactate dehydrogenase, superoxide dismutase, catalase, glutathione, glutathione peroxidase, thioredoxin reductase, xanthine oxidase, calcium overload and caspase 3 activity with ATO. The overall result revealed the protective property of polyphenol-rich apple peel extract against ATO induced cardiac toxicity via its antioxidant activity.

First-Principles Study of Novel Two-Dimensional (C4H9NH3)2PbX4 Perovskites for Solar Cell Absorbers.

PubMed

Wang, Da; Wen, Bo; Zhu, Ya-Nan; Tong, Chuan-Jia; Tang, Zhen-Kun; Liu, Li-Min

2017-02-16

Low-dimensional perovskites (A 2 BX 4 ), in which the A cations are replaced by different organic cations, may be used for photovoltaic applications. In this contribution, we systematically study the two-dimensional (2D) (C 4 H 9 NH 3 ) 2 PbX 4 (X═Cl, Br and I) hybrid perovskites by density functional theory (DFT). A clear structures-properties relationship, with the photophysical characteristics directly related to the dimensionality and material compositions, was established. The strong s-p antibonding couplings in both bulk and monolayer (C 4 H 9 NH 3 ) 2 PbI 4 lead to low effective masses for both holes (m h *) and electrons (m e *). However, m h * increases in proportion to the decreasing inorganic layer thickness, which eventually leads to a slightly shifted band edge emission found in 2D perovskites. Notably, the 2D (C 4 H 9 NH 3 ) 2 PbX 4 perovskites exhibit strong optical transitions in the visible light spectrum, and the optical absorption tunings can be achieved by varying the compositions and the layer thicknesses. Such work paves an important way to uncover the structures-properties relationship in 2D perovskites.

Ethanol stimulates glucose uptake and translocation of GLUT-4 in H9c2 myotubes via a Ca(2+)-dependent mechanism.

PubMed

Yu, B; Schroeder, A; Nagy, L E

2000-12-01

Short-term exposure to ethanol impairs glucose homeostasis, but the effects of ethanol on individual components of the glucose disposal pathway are not known. To understand the mechanisms by which ethanol disrupts glucose homeostasis, we have investigated the direct effects of ethanol on glucose uptake and translocation of GLUT-4 in H9c2 myotubes. Short-term treatment with 12.5-50 mM ethanol increased uptake of 2-deoxyglucose by 1.8-fold in differentiated myotubes. Pretreatment of H9c2 myotubes with 100 nM wortmannin, an inhibitor of phosphatidylinositol 3-kinase, had no effect on ethanol-induced increases in 2-deoxyglucose uptake. In contrast, preincubation with 25 microM dantrolene, an inhibitor of Ca(2+) release from the sarcoplasmic reticulum, blocked the stimulation of 2-deoxyglucose uptake by ethanol. Increased 2-deoxyglucose uptake after ethanol treatment was associated with a decrease in small intracellular GLUT-4 vesicles and an increase in GLUT-4 localized at the cell surface. In contrast, ethanol had no effect on the quantity of GLUT-1 and GLUT-3 at the plasma membrane. These data demonstrate that physiologically relevant concentrations of ethanol disrupt the trafficking of GLUT-4 in H9c2 myotubes resulting in translocation of GLUT-4 to the plasma membrane and increased glucose uptake.

EVALUATION OF BENZO[C]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T1/2CL8 CELLS

EPA Science Inventory

EVALUATION OF BENZO[c]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T?CL8 CELLS

Abstract The morphological cell transforming activities of three dihydrodiols of benzo[c]chrysene (B[c]C), trans-B[c]C-7,8-diol, trans-B[c]C-9...

The Clustered, Regularly Interspaced, Short Palindromic Repeats-associated Endonuclease 9 (CRISPR/Cas9)-created MDM2 T309G Mutation Enhances Vitreous-induced Expression of MDM2 and Proliferation and Survival of Cells.

PubMed

Duan, Yajian; Ma, Gaoen; Huang, Xionggao; D'Amore, Patricia A; Zhang, Feng; Lei, Hetian

2016-07-29

The G309 allele of SNPs in the mouse double minute (MDM2) promoter locus is associated with a higher risk of cancer and proliferative vitreoretinopathy (PVR), but whether SNP G309 contributes to the pathogenesis of PVR is to date unknown. The clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonuclease (Cas) 9 from Streptococcus pyogenes (SpCas9) can be harnessed to manipulate a single or multiple nucleotides in mammalian cells. Here we delivered SpCas9 and guide RNAs using dual adeno-associated virus-derived vectors to target the MDM2 genomic locus together with a homologous repair template for creating the mutation of MDM2 T309G in human primary retinal pigment epithelial (hPRPE) cells whose genotype is MDM2 T309T. The next-generation sequencing results indicated that there was 42.51% MDM2 G309 in the edited hPRPE cells using adeno-associated viral CRISPR/Cas9. Our data showed that vitreous induced an increase in MDM2 and subsequent attenuation of p53 expression in MDM2 T309G hPRPE cells. Furthermore, our experimental results demonstrated that MDM2 T309G in hPRPE cells enhanced vitreous-induced cell proliferation and survival, suggesting that this SNP contributes to the pathogenesis of PVR. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Nucleosome eviction along with H3K9ac deposition enhances Sox2 binding during human neuroectodermal commitment

PubMed Central

Du, Yanhua; Liu, Zhenping; Cao, Xinkai; Chen, Xiaolong; Chen, Zhenyu; Zhang, Xiaobai; Zhang, Xiaoqing; Jiang, Cizhong

2017-01-01

Neuroectoderm is an important neural precursor. However, chromatin remodeling and its epigenetic regulatory roles during the differentiation of human neuroectodermal cells (hNECs) from human embryonic stem cells (hESCs) remain largely unexplored. Here, we obtained hNECs through directed differentiation from hESCs, and determined chromatin states in the two cell types. Upon differentiation, H2A.Z-mediated nucleosome depletion leads to an open chromatin structure in promoters and upregulates expression of neuroectodermal genes. Increase in H3K9ac signals and decrease in H3K27me3 signals in promoters result in an active chromatin state and activate neuroectodermal genes. Conversely, decrease in H3K9ac signals and increase in H3K27me3 signals in promoters repress pluripotency genes. Moreover, H3K9ac signals facilitate the pluripotency factor Sox2 binding to target sites unique to hNECs. Knockdown of the acetyltransferase Kat2b erases H3K9ac signals, disrupts Sox2 binding, and fails the differentiation. Our results demonstrate a hierarchy of epigenetic regulation of gene expression during the differentiation of hNECs from hESCs through chromatin remodeling. PMID:28475175

Mesenchymal stromal cell treatment prevents H9N2 avian influenza virus-induced acute lung injury in mice.

PubMed

Li, Yan; Xu, Jun; Shi, Weiqing; Chen, Cheng; Shao, Yan; Zhu, Limei; Lu, Wei; Han, XiaoDong

2016-10-28

The avian influenza virus (AIV) can cross species barriers and expand its host range from birds to mammals, even humans. Avian influenza is characterized by pronounced activation of the proinflammatory cytokine cascade, which perpetuates the inflammatory response, leading to persistent systemic inflammatory response syndrome and pulmonary infection in animals and humans. There are currently no specific treatment strategies for avian influenza. We hypothesized that mesenchymal stromal cells (MSCs) would have beneficial effects in the treatment of H9N2 AIV-induced acute lung injury in mice. Six- to 8-week-old C57BL/6 mice were infected intranasally with 1 × 10 4 MID 50 of A/HONG KONG/2108/2003 [H9N2 (HK)] H9N2 virus to induce acute lung injury. After 30 min, syngeneic MSCs were delivered through the caudal vein. Three days after infection, we measured the survival rate, lung weight, arterial blood gas, and cytokines in both bronchoalveolar lavage fluid (BALF) and serum, and assessed pathological changes to the lungs. MSC administration significantly palliated H9N2 AIV-induced pulmonary inflammation by reducing chemokines and proinflammatory cytokines levels, as well as reducing inflammatory cell recruit into the lungs. Thus, H9N2 AIV-induced lung injury was markedly alleviated in mice treated with MSCs. Lung histopathology and arterial blood gas analysis were improved in mice with H9N2 AIV-induced lung injury following MSC treatment. MSC treatment significantly reduces H9N2 AIV-induced acute lung injury in mice and is associated with reduced pulmonary inflammation. These results indicate a potential role for MSC therapy in the treatment of clinical avian influenza.

A novel compound DT-010 protects against doxorubicin-induced cardiotoxicity in zebrafish and H9c2 cells by inhibiting reactive oxygen species-mediated apoptotic and autophagic pathways.

PubMed

Tang, Fan; Zhou, Xinhua; Wang, Liang; Shan, Luchen; Li, Chuwen; Zhou, Hefeng; Lee, Simon Ming-Yuen; Hoi, Maggie Pui-Man

2018-02-05

Doxorubicin (Dox) is an effective anti-cancer agent but limited by its cardiotoxicity, thus the search for pharmacological agents for enhancing anti-cancer activities and protecting against cardiotoxicity has been a subject of great interest. We have previously reported the synergistic anti-cancer effects of a novel compound DT-010. In the present study, we further investigated the cardioprotective effects of DT-010 in zebrafish embryos in vivo and the molecular underlying mechanisms in H9c2 cardiomyocytes in vitro. We showed that DT-010 prevented the Dox-induced morphological distortions in the zebrafish heart and the associated cardiac impairments, and especially improved ventricular functions. By using H9c2 cells model, we showed that DT-010 directly inhibited the generation of reactive oxygen species by Dox and protected cell death and cellular damage. We further observed that DT-010 protected against Dox-induced myocardiopathy via inhibiting downstream molecular pathways in response to oxidative stress, including reactive oxygen species-mediated MAPK signaling pathways ERK and JNK, and apoptotic pathways involving the activation of caspase 3, caspase 7, and PARP signaling. Recent studies also suggest the importance of alterations in cardiac autophagy in Dox cardiotoxicity. We further showed that DT-010 could inhibit the induction of autophagosomes formation by Dox via regulating the upstream Akt/AMPK/mTOR signaling. Since Dox-induced cardiotoxicity is multifactorial, our results suggest that multi-functional agent such as DT-010 might be an effective therapeutic agent for combating cardiotoxicity associated with chemotherapeutic agents such as Dox. Copyright © 2017 Elsevier B.V. All rights reserved.

The protective effect of lipid emulsion in preventing bupivacaine-induced mitochondrial injury and apoptosis of H9C2 cardiomyocytes.

PubMed

Chen, Zhe; Jin, Zhousheng; Xia, Yun; Zhao, Shishi; Xu, Xuzhong; Papadimos, Thomas J; Wang, Quanguang

2017-11-01

Lipid emulsion (LE) has been shown to be effective in the resuscitation of bupivacaine-induced cardiac arrest, but the precise mechanism of this action has not been fully elucidated. Pursuant to this lack of information on the mechanism in which LE protects the myocardium during bupivacaine-induced toxicity, we explored mitochondrial function and cell apoptosis. H9C2 cardiomyocytes were used in study. Cells were randomly divided in different groups and were cultivated 6 h, 12 h, and 24 h. The mitochondria were extracted and mitochondrial ATP content was measured, as was mitochondrial membrane potential, the concentration of calcium ion (Ca2+), and the activity of Ca2+-ATP enzyme (Ca2+-ATPase). Cells from groups Bup1000, LE group, and Bup1000LE were collected to determine cell viability, cell apoptosis, and electron microscopy scanning of mitochondrial ultrastructure (after 24 h). We found that LE can reverse the inhibition of the mitochondrial function induced by bupivacaine, regulate the concentration of calcium ion in mitochondria, resulting in the protection of myocardial cells from toxicity induced by bupivacaine.

PEDF and PEDF-derived peptide 44mer inhibit oxygen-glucose deprivation-induced oxidative stress through upregulating PPARγ via PEDF-R in H9c2 cells.

PubMed

Zhuang, Wei; Zhang, Hao; Pan, Jiajun; Li, Zhimin; Wei, Tengteng; Cui, Huazhu; Liu, Zhiwei; Guan, Qiuhua; Dong, Hongyan; Zhang, Zhongming

2016-04-08

Pigment epithelial-derived factor (PEDF) is a glycoprotein with broad biological activities including inhibiting oxygen-glucose deprivation(OGD)-induced cardiomyocytes apoptosis through its anti-oxidative properties. PEDF derived peptide-44mer shows similar cytoprotective effect to PEDF. However, the molecular mechanisms mediating cardiomyocytes apoptosis have not been fully established. Here we found that PEDF and 44mer decreased the content of ROS. This content was abolished by either PEDF-R small interfering RNA (siRNA) or PPARγ antagonist. The level of Lysophosphatidic acid (LPA) and phospholipase A2 (PLA2) was observed as drawn from the ELISA assays. PEDF and 44mer sequentially induced PPARγ expression was observed both in qPCR and Western blot assays. The level of LPA and PLA2 and PPARγ expression increased by PEDF and 44mer was significantly attenuated by PEDF-R siRNA. However, PEDF and 44mer inhibited the H9c2 cells and cultured neonatal rat myocardial cells apoptosis rate. On the other hand, TUNEL assay and cleavage of procaspase-3 showed that PEDF-R siRNA or PPARγ antagonist increased the apoptosis again. We conclude that under OGD condition, PEDF and 44mer reduce H9c2 cells apoptosis and inhibit OGD-induced oxidative stress via its receptor PEDF-R and the PPARγ signaling pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

Beyond Crystal Engineering: Significant Enhancement of C2H2/CO2 Separation by Constructing Composite Material.

PubMed

Wu, Hui Qiong; Yan, Chang Sheng; Luo, Feng; Krishna, Rajamani

2018-04-02

Different from the established crystal engineering method for enhancing gas-separation performance, we demonstrate herein a distinct approach. In contrast to the pristine MOF (metal-organic framework) material, the C 2 H 2 /CO 2 separation ability for the resultant Ag NPs (nanoparticle)@Fe 2 O 3 @MOF composite material, estimated from breakthrough calculations, is greatly enhanced by 2 times, and further magnified up to 3 times under visible light irradiation.

Origin of Photovoltage Enhancement via Interfacial Modification with Silver Nanoparticles Embedded in an a-SiC:H p-Type Layer in a-Si:H Solar Cells.

PubMed

Li, Tiantian; Zhang, Qixing; Ni, Jian; Huang, Qian; Zhang, Dekun; Li, Baozhang; Wei, Changchun; Yan, Baojie; Zhao, Ying; Zhang, Xiaodan

2017-03-29

We used silver nanoparticles (Ag-NPs) embedded in the p-type semiconductor layer of hydrogenated amorphous silicon (a-Si:H) solar cells in the Schottky barrier contact design to modify the interface between aluminum-doped ZnO (ZnO:Al, AZO) and p-type hydrogenated amorphous silicon carbide (p-a-SiC:H) without plasmonic absorption. The high work function of the Ag-NPs provided a good channel for the transport of photogenerated holes. A p-type nanocrystalline SiC:H layer was used to compensate for the real surface defects and voids on the surface of Ag-NPs to reduce recombination at the AZO/p-type layer interface, which then enhanced the photovoltage of single-junction a-Si:H solar cells to values as high as 1.01 V. The Ag-NPs were around 10 nm in diameter and thermally stable in the p-type a-SiC:H film at the solar-cell process temperature. We will also show that a wide range of photovoltages between 1.01 and 2.89 V could be obtained with single-, double-, and triple-junction solar cells based on the single-junction a-Si:H solar cells with tunable high photovoltage. These solar cells are suitable photocathodes for solar water-splitting applications.

CpG Oligodeoxynucleotides Facilitate Delivery of Whole Inactivated H9N2 Influenza Virus via Transepithelial Dendrites of Dendritic Cells in Nasal Mucosa

PubMed Central

Qin, Tao; Yin, Yinyan; Yu, Qinghua; Huang, Lulu; Wang, Xiaoqing; Lin, Jian

2015-01-01

ABSTRACT The spread of the low-pathogenicity avian H9N2 influenza virus has seriously increased the risk of a new influenza pandemic. Although whole inactivated virus (WIV) vaccine via intranasal pathway is the effective method of blocking virus transmission, the mucosal barrier seems to be a major factor hampering its development. CpG oligodeoxynucleotides, a known adjuvant, can target downstream dendritic cells (DCs) and effectively enhance the mucosal and systemic immune responses. However, the ability of CpGs to assist H9N2 WIV in transepithelial transport remains unknown. Here, in vitro and in vivo, we showed that CpGs provided assistance for H9N2 WIV in recruiting DCs to the nasal epithelial cells (ECs) and forming transepithelial dendrites (TEDs) to capture luminal viruses. CD103+ DCs participated in this process. Chemokine CCL20 from nasal ECs played a key role in driving DC recruitment and TED formation. Virus-loaded DCs quickly migrated into the draining cervical lymph nodes (CLNs) for antigen presentation. In addition, the competence of CpGs was independent of direct epithelial transport via the transcellular or paracellular pathway. Taken together, our data demonstrated that CpGs enhanced the transport of H9N2 WIV via TEDs of nasal DCs, which might be a novel mechanism for optimal adaptive immune responses. IMPORTANCE This paper demonstrates by both an in vivo and an in vitro coculture model that CpG oligodeoxynucleotides, known as an adjuvant generally targeting downstream immune responses, also are crucial for the transport of H9N2 WIV across nasal epithelial cells (ECs) via the uptake of transepithelial dendrites (TEDs). Our results prove for the first time to our knowledge that the immune-potentiating mechanism of CpGs is based on strengthening the transepithelial uptake of H9N2 WIV in nasal mucosa. These findings provide a fresh perspective for further improvement of intranasal influenza vaccines, which are urgently needed in the face of the

Phase Equilibria and Transport Properties in the Systems AgNO3/RCN/H2O. R = CH3, C2H5, C3H7, C4H,, C6H5, and C6H5CH2

NASA Astrophysics Data System (ADS)

Das, Surjya P.; Wittekopf, Burghard; Weil, Konrad G.

1988-11-01

Silver nitrate can form homogeneous liquid phases with some organic nitriles and water, even when there is no miscibility between the pure liquid components. We determined the shapes of the single phase regions in the ternary phase diagram for the following systems: silver nitrate /RCN /H2O with R =CH3, C3H7, C6H5, and C6H5CH2 at room temperature and for R =C6H5 also at 60 °C and O °C. Furthermore we studied kinematic viscosities, electrical conductivities, and densities of mixtures containing silver nitrate, RCN, and water with the mole ratios X /4 /1 (0.2≦ X ≦S 3.4). In these cases also R = C2H5 and C4H9 were studied. The organic nitriles show different dependences of viscosity and conductivity on the silver nitrate content from the aliphatic ones.

Improved oxidative tolerance in suspension-cultured cells of C4-pepctransgenic rice by H2O2 and Ca(2+) under PEG-6000.

PubMed

Qian, Baoyun; Li, Xia; Liu, Xiaolong; Wang, Man

2015-06-01

To understand the molecular responses of PC (Overexpressing the maize C4-pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC)), to drought stress at cell level, we analyzed changes in the levels of signaling molecules (hydrogen peroxide (H2O2), calcium ion (Ca(2+)), and nitric oxide (NO)) in suspension-cultured PC and wild-type (WT) rice (Oryza sativa L.) cell under drought stress induced by 20% polyethylene glycol 6000 (PEG-6000). Results demonstrated that PC improved drought tolerance by enhancing antioxidant defense, retaining higher relative water content, survival percentages, and dry weight of cells. In addition, PEPC activity in PC under PEG treatment was strengthened by addition of H2O2 inhibitor, dimethylthiourea (DMTU) and NO synthesis inhibitor, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), respectively, while that in PC was weakened by addition of free calcium chelator, ethylene glycol-bis(b-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) + calcium channel outflow inhibitor, ruthenium red (RR) + plasma membrane channel blocker La(NO3)3, but EGTA + RR did not. Results also showed that NO and Ca(2+) was lying downstream of H2O2 in drought-induced signaling. Calcium ion was also involved in the expression of C4-pepc in PC. These results suggested that PC could improve oxidative tolerance in suspension-cultured cells and the acquisition of this tolerance required downregulation of H2O2 and the entry of extracellular Ca(2+) into cells across the plasma membrane for regulation of PEPC activity and C4-pepc expression. © 2014 Institute of Botany, Chinese Academy of Sciences.

Atrazine activates multiple signaling pathways enhancing the rapid hCG-induced androgenesis in rat Leydig cells.

PubMed

Pogrmic-Majkic, Kristina; Fa, Svetlana; Samardzija, Dragana; Hrubik, Jelena; Kaisarevic, Sonja; Andric, Nebojsa

2016-08-10

Atrazine (ATR) is an endocrine disruptor that affects steroidogenic process, resulting in disruption of reproductive function of the male and female gonads. In this study, we used the primary culture of peripubertal Leydig cells to investigate the effect of ATR on the rapid androgen production stimulated by human chorionic gonadotropin (hCG). We demonstrated that ATR activated multiple signaling pathways enhancing the rapid hCG-stimulated androgen biosynthesis in Leydig cells. Low hCG concentration (0.25ng/mL) caused cAMP-independent, but ERK1/2-dependent increase in androgen production after 60min of incubation. Co-treatment with ATR for 60min enhanced the cAMP production in hCG-stimulated cells. Accumulation of androgens was prevented by addition of U0126, N-acetyl-l-cysteine and AG1478. Co-treatment with hCG and ATR for 60min did not alter steroidogenic acute regulatory protein (Star) mRNA level in Leydig cells. After 120min, hCG further increased androgenesis in Leydig cells that was sensitive to inhibition of the cAMP/PKA, ERK1/2 and ROS signaling pathways. Co-treatment with ATR for 120min further enhanced the hCG-induced androgen production, which was prevented by inhibition of the calcium, PKC and EGFR signaling cascades. After 120min, ATR enhanced the expression of Star mRNA in hCG-stimulated Leydig cells through activation of the PKA and PKC pathway. Collectively, these data suggest that exposure to ATR caused perturbations in multiple signaling pathways, thus enhancing the rapid hCG-dependent androgen biosynthesis in peripubertal Leydig cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Quantitative proteomics and systems analysis of cultured H9C2 cardiomyoblasts during differentiation over time supports a 'function follows form' model of differentiation.

PubMed

Kankeu, Cynthia; Clarke, Kylie; Van Haver, Delphi; Gevaert, Kris; Impens, Francis; Dittrich, Anna; Roderick, H Llewelyn; Passante, Egle; Huber, Heinrich J

2018-05-17

The rat cardiomyoblast cell line H9C2 has emerged as a valuable tool for studying cardiac development, mechanisms of disease and toxicology. We present here a rigorous proteomic analysis that monitored the changes in protein expression during differentiation of H9C2 cells into cardiomyocyte-like cells over time. Quantitative mass spectrometry followed by gene ontology (GO) enrichment analysis revealed that early changes in H9C2 differentiation are related to protein pathways of cardiac muscle morphogenesis and sphingolipid synthesis. These changes in the proteome were followed later in the differentiation time-course by alterations in the expression of proteins involved in cation transport and beta-oxidation. Studying the temporal profile of the H9C2 proteome during differentiation in further detail revealed eight clusters of co-regulated proteins that can be associated with early, late, continuous and transient up- and downregulation. Subsequent reactome pathway analysis based on these eight clusters further corroborated and detailed the results of the GO analysis. Specifically, this analysis confirmed that proteins related to pathways in muscle contraction are upregulated early and transiently, and proteins relevant to extracellular matrix organization are downregulated early. In contrast, upregulation of proteins related to cardiac metabolism occurs at later time points. Finally, independent validation of the proteomics results by immunoblotting confirmed hereto unknown regulators of cardiac structure and ionic metabolism. Our results are consistent with a 'function follows form' model of differentiation, whereby early and transient alterations of structural proteins enable subsequent changes that are relevant to the characteristic physiology of cardiomyocytes.

Combination of Nigella sativa with Glycyrrhiza glabra and Zingiber officinale augments their protective effects on doxorubicin-induced toxicity in h9c2 cells.

PubMed

Hosseini, Azar; Shafiee-Nick, Reza; Mousavi, Seyed Hadi

2014-12-01

The use of doxorubicin (DOX) is limited by its dose-dependent cardio toxicity in which reactive Oxygen Species (ROS) play an important role in the pathological process. The aim of this study was to evaluate the protective effect of three medicinal plants, Nigella sativa (N), Glycyrrhiza glabra (G) and Zingiber officinale (Z), and their combination (NGZ), against DOX-induced apoptosis and death in H9c2 cells. The cells were incubated with different concentrations of each extract or NGZ for 4 hr which continued in the presence or absence of 5µM doxorubicin for 24 hr. Cell viability and the apoptotic rate were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and propidium iodide (PI) staining assays, respectively. The level of ROS and lipid peroxidation were measured by fluorimetric methods. Treatment with doxorubicin increased ROS generation, enhanced malondialdehyde (MDA) formation, and induced apoptosis. Co-treatment of the cells with each herb extract increased viability of cells dose-dependently with a maximum protection effect of about 30%, and their potencies were N>G>Z. The combination of the threshold dose of each extract (NGZ) produced a similar effect, which was increased dose-dependently to a maximum protection of 70%. These effects were correlated with the effects of NGZ on ROS and MDA. All of the extracts have some protective effects against DOX-induced toxicity in cardiomyocytes with similar efficacies, but with different potencies. However, NGZ produced much higher protective effect via reducing oxidative stress and inhibiting of apoptotic induction processes. Further investigations are needed to determine the effects of NGZ on DOX chemotherapy.

Combination of Nigella sativa with Glycyrrhiza glabra and Zingiber officinale augments their protective effects on doxorubicin-induced toxicity in h9c2 cells

PubMed Central

Hosseini, Azar; Shafiee-Nick, Reza; Mousavi, Seyed Hadi

2014-01-01

Objective(s): The use of doxorubicin (DOX) is limited by its dose-dependent cardio toxicity in which reactive Oxygen Species (ROS) play an important role in the pathological process. The aim of this study was to evaluate the protective effect of three medicinal plants, Nigella sativa (N), Glycyrrhiza glabra (G) and Zingiber officinale (Z), and their combination (NGZ), against DOX-induced apoptosis and death in H9c2 cells. Materials and Methods: The cells were incubated with different concentrations of each extract or NGZ for 4 hr which continued in the presence or absence of 5µM doxorubicin for 24 hr. Cell viability and the apoptotic rate were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and propidium iodide (PI) staining assays, respectively. The level of ROS and lipid peroxidation were measured by fluorimetric methods. Results: Treatment with doxorubicin increased ROS generation, enhanced malondialdehyde (MDA) formation, and induced apoptosis. Co-treatment of the cells with each herb extract increased viability of cells dose-dependently with a maximum protection effect of about 30%, and their potencies were N>G>Z. The combination of the threshold dose of each extract (NGZ) produced a similar effect, which was increased dose-dependently to a maximum protection of 70%. These effects were correlated with the effects of NGZ on ROS and MDA. Conclusion: All of the extracts have some protective effects against DOX-induced toxicity in cardiomyocytes with similar efficacies, but with different potencies. However, NGZ produced much higher protective effect via reducing oxidative stress and inhibiting of apoptotic induction processes. Further investigations are needed to determine the effects of NGZ on DOX chemotherapy. PMID:25859303

Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation.

PubMed

Cheng, Yuanyuan; Xia, Zhengyuan; Han, Yifan; Rong, Jianhui

2016-01-01

The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation.

Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation

PubMed Central

Cheng, Yuanyuan; Xia, Zhengyuan; Han, Yifan; Rong, Jianhui

2016-01-01

The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation. PMID:27034732

Curcumin enhances the mitomycin C-induced cytotoxicity via downregulation of MKK1/2-ERK1/2-mediated Rad51 expression in non-small cell lung cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ko, Jen-Chung; Department of Nursing, Yuanpei University, HsinChu, Taiwan; Graduate Institute of Technology Law, National Chiao Tung University, Taiwan

2011-09-15

Curcumin (diferuloylmethane), a major active component of turmeric (Curcuma longa), has been reported to suppress the proliferation of a wide variety of tumor cells. Rad51 is a key protein in the homologous recombination (HR) pathway of DNA double-strand break repair, and HR represents a novel target for cancer therapy. A high expression of Rad51 has been reported in chemo- or radio-resistant carcinomas. Therefore, in the current study, we will examine whether curcumin could enhance the effects of mitomycin C (MMC), a DNA interstrand cross-linking agent, to induce cytotoxicity by decreasing Rad51 expression. Exposure of two human non-small lung cancer (NSCLC)more » cell lines (A549 and H1975) to curcumin could suppress MMC-induced MKK1/2-ERK1/2 signal activation and Rad51 protein expression. Enhancement of ERK1/2 activation by constitutively active MKK1/2 (MKK1/2-CA) increased Rad51 protein levels in curcumin and MMC co-treated human lung cells. Moreover, the synergistic cytotoxic effect induced by curcumin combined with MMC was decreased by MKK1-CA-mediated enhancement of ERK1/2 activation by a significant degree. In contrast, MKK1/2 inhibitor, U0126 was shown to augment the cytotoxicity of curcumin and MMC through downregulation of ERK1/2 activation and Rad51 expression. Depletion of endogenous Rad51 expression by siRad51 RNA transfection significantly enhanced MMC and/or curcumin induced cell death and cell growth inhibition. In contrast, an overexpression of Rad51 protected lung cancer cells from synergistic cytotoxic effects induced by curcumin and MMC. We concluded that Rad51 inhibition may be an additional action mechanism for enhancing the chemosensitization of MMC by curcumin in NSCLC. - Highlights: > Curcumin downregulates MKK-ERK-mediated Rad51 expression. > Curcumin enhances mitomycin C-induced cytotoxicity. > Rad51 protects cells from cytotoxic effects induced by curcumin and mitomycin C. > Rad51 inhibition enhances the chemosensitization of

A Single Mutation at Position 190 in Hemagglutinin Enhances Binding Affinity for Human Type Sialic Acid Receptor and Replication of H9N2 Avian Influenza Virus in Mice

PubMed Central

Teng, Qiaoyang; Xu, Dawei; Shen, Weixia; Liu, Qinfang; Rong, Guangyu; Li, Xuesong; Yan, Liping; Yang, Jianmei; Chen, Hongjun; Yu, Hai

2016-01-01

ABSTRACT H9N2 avian influenza virus (AIV) has an extended host range, but the molecular basis underlying H9N2 AIV transmission to mammals remains unclear. We isolated more than 900 H9N2 AIVs in our 3-year surveillance in live bird markets in China from 2009 to 2012. Thirty-seven representative isolates were selected for further detailed characterization. These isolates were categorized into 8 genotypes (B64 to B71) and formed a distinct antigenic subgroup. Three isolates belonging to genotype B69, which is a predominant genotype circulating in China, replicated efficiently in mice, while the viruses tested in parallel in other genotypes replicated poorly, although they, like the three B69 isolates, have a leucine at position 226 in the hemagglutinin (HA) receptor binding site, which is critical for binding human type sialic acid receptors. Further molecular and single mutation analysis revealed that a valine (V) residue at position 190 in HA is responsible for efficient replication of these H9N2 viruses in mice. The 190V in HA does not affect virus receptor binding specificity but enhances binding affinity to human cells and lung tissues from mouse and humans. All these data indicate that the 190V in HA is one of the important determinants for H9N2 AIVs to cross the species barrier to infect mammals despite multiple genes conferring adaptation and replication of H9N2 viruses in mammals. Our findings provide novel insights on understanding host range expansion of H9N2 AIVs. IMPORTANCE Influenza virus hemagglutinin (HA) is responsible for binding to host cell receptors and therefore influences the viral host range and pathogenicity in different species. We showed that the H9N2 avian influenza viruses harboring 190V in the HA exhibit enhanced virus replication in mice. Further studies demonstrate that 190V in the HA does not change virus receptor binding specificity but enhances virus binding affinity of the H9N2 virus to human cells and attachment to lung tissues

A Single Mutation at Position 190 in Hemagglutinin Enhances Binding Affinity for Human Type Sialic Acid Receptor and Replication of H9N2 Avian Influenza Virus in Mice.

PubMed

Teng, Qiaoyang; Xu, Dawei; Shen, Weixia; Liu, Qinfang; Rong, Guangyu; Li, Xuesong; Yan, Liping; Yang, Jianmei; Chen, Hongjun; Yu, Hai; Ma, Wenjun; Li, Zejun

2016-11-01

H9N2 avian influenza virus (AIV) has an extended host range, but the molecular basis underlying H9N2 AIV transmission to mammals remains unclear. We isolated more than 900 H9N2 AIVs in our 3-year surveillance in live bird markets in China from 2009 to 2012. Thirty-seven representative isolates were selected for further detailed characterization. These isolates were categorized into 8 genotypes (B64 to B71) and formed a distinct antigenic subgroup. Three isolates belonging to genotype B69, which is a predominant genotype circulating in China, replicated efficiently in mice, while the viruses tested in parallel in other genotypes replicated poorly, although they, like the three B69 isolates, have a leucine at position 226 in the hemagglutinin (HA) receptor binding site, which is critical for binding human type sialic acid receptors. Further molecular and single mutation analysis revealed that a valine (V) residue at position 190 in HA is responsible for efficient replication of these H9N2 viruses in mice. The 190V in HA does not affect virus receptor binding specificity but enhances binding affinity to human cells and lung tissues from mouse and humans. All these data indicate that the 190V in HA is one of the important determinants for H9N2 AIVs to cross the species barrier to infect mammals despite multiple genes conferring adaptation and replication of H9N2 viruses in mammals. Our findings provide novel insights on understanding host range expansion of H9N2 AIVs. Influenza virus hemagglutinin (HA) is responsible for binding to host cell receptors and therefore influences the viral host range and pathogenicity in different species. We showed that the H9N2 avian influenza viruses harboring 190V in the HA exhibit enhanced virus replication in mice. Further studies demonstrate that 190V in the HA does not change virus receptor binding specificity but enhances virus binding affinity of the H9N2 virus to human cells and attachment to lung tissues from humans and mouse

Evaluation of the Protective Efficacy of Poly I:C as an Adjuvant for H9N2 Subtype Avian Influenza Inactivated Vaccine and Its Mechanism of Action in Ducks.

PubMed

Zhang, Aiguo; Lai, Hanzhang; Xu, Jiahua; Huang, Wenke; Liu, Yufu; Zhao, Dawei; Chen, Ruiai

2017-01-01

Current commercial H9 avian influenza vaccines cannot provide satisfactory protective immunity against antigenic variant influenza viruses in ducks. Poly I:C, when used as an adjuvant, improves humoral and cellular immunity in many animals but has not been tested in ducks. In this study, we investigated the protective efficacy of Poly I:C as an adjuvant for an inactivated H9N2 Avian influenza vaccine in ducks. We found that an H9N2 vaccine administered with poly I:C (H9-PIC vaccine) induced a significantly more rapid response with higher anti-influenza antibody titers than those of the vaccine alone (H9 vaccine). Moreover, virus shedding was reduced in ducks immunized with the H9-PIC vaccine after challenge with an H9 subtype antigenic variant viruses. IFN-α, IFN-γ, IL-6 and MHC-II mRNA levels were all elevated in ducks receiving the H9-PIC vaccine. In addition, lower expression level of MHC-I may be a reason for inefficient protective ability against heterologous influenza viruses in H9-PIC vaccination of ducks. In conclusion, poly I:C adjuvant enhanced both humoral and cellular immune responses in ducks induced by immunization of inactivated H9N2 vaccine.

Evaluation of the Protective Efficacy of Poly I:C as an Adjuvant for H9N2 Subtype Avian Influenza Inactivated Vaccine and Its Mechanism of Action in Ducks

PubMed Central

Zhang, Aiguo; Lai, Hanzhang; Xu, Jiahua; Huang, Wenke; Liu, Yufu; Zhao, Dawei; Chen, Ruiai

2017-01-01

Current commercial H9 avian influenza vaccines cannot provide satisfactory protective immunity against antigenic variant influenza viruses in ducks. Poly I:C, when used as an adjuvant, improves humoral and cellular immunity in many animals but has not been tested in ducks. In this study, we investigated the protective efficacy of Poly I:C as an adjuvant for an inactivated H9N2 Avian influenza vaccine in ducks. We found that an H9N2 vaccine administered with poly I:C (H9-PIC vaccine) induced a significantly more rapid response with higher anti-influenza antibody titers than those of the vaccine alone (H9 vaccine). Moreover, virus shedding was reduced in ducks immunized with the H9-PIC vaccine after challenge with an H9 subtype antigenic variant viruses. IFN-α, IFN-γ, IL-6 and MHC-II mRNA levels were all elevated in ducks receiving the H9-PIC vaccine. In addition, lower expression level of MHC-I may be a reason for inefficient protective ability against heterologous influenza viruses in H9-PIC vaccination of ducks. In conclusion, poly I:C adjuvant enhanced both humoral and cellular immune responses in ducks induced by immunization of inactivated H9N2 vaccine. PMID:28135294

Genome-wide profiling of microRNAs reveals novel insights into the interactions between H9N2 avian influenza virus and avian dendritic cells.

PubMed

Lin, Jian; Xia, Jing; Zhang, Tian; Zhang, Keyun; Yang, Qian

2018-05-10

The antigen-presenting ability of dendritic cells (DCs) plays an important and irreplaceable role in recognising and clearing viruses. Antiviral responses must rapidly defend against infection while minimising inflammatory damage, but the mechanisms that regulate the magnitude of response within an infected cell are not well understood. MicroRNAs (microRNAs), small non-coding RNAs, can regulate mouse or avian DCs to inhibit the infection and replication of avian influenza virus (AIV). Here, we performed a global analysis to understand how avian DCs respond to H9N2 AIV and provide a potential mechanism to explain how avian microRNAs can defend against H9N2 AIV replication. First, we found that both active and inactive H9N2 AIV enhanced the ability of DCs to present antigens and activate T lymphocytes. Next, total microarray analyses suggested that H9N2 AIV stimulation involved protein localisation, nucleotide binding, leucocyte transendothelial migration and MAPK signalling. Moreover, we constructed 551 transcription factor (TF)-miRNA-mRNA loops based on the above analyses. Furthermore, we found that the haemagglutinin (HA) fragment, neither H5N1-HA or H9N2-HA, could not activate DCs, while truncated HA greatly increased the immune function of DCs by activating ERK and STAT3 signalling pathways. Lastly, our results not only suggested that gga-miR1644 targets muscleblind-like protein 2 (MBNL2) to enhance the ability of avian DCs to inhibit virus replication, but also suggested that gga-miR6675 targets the nuclear localisation sequence of polymerase basic protein 1 (PB1) to trigger the silencing of PB1 genes, resulting in the inhibition of H9N2 AIV replication. Altogether, our innovative study will shed new light on the role of avian microRNAs in evoking avian DCs and inhibiting virus replication.

JMJD1A, H3K9me1, H3K9me2 and ADM expression as prognostic markers in oral and oropharyngeal squamous cell carcinoma.

PubMed

Maia, Lucas de Lima; Peterle, Gabriela Tonini; Dos Santos, Marcelo; Trivilin, Leonardo Oliveira; Mendes, Suzanny Oliveira; de Oliveira, Mayara Mota; Dos Santos, Joaquim Gasparini; Stur, Elaine; Agostini, Lidiane Pignaton; Couto, Cinthia Vidal Monteiro da Silva; Dalbó, Juliana; de Assis, Aricia Leone Evangelista Monteiro; Archanjo, Anderson Barros; Mercante, Ana Maria Da Cunha; Lopez, Rossana Veronica Mendoza; Nunes, Fábio Daumas; de Carvalho, Marcos Brasilino; Tajara, Eloiza Helena; Louro, Iúri Drumond; Álvares-da-Silva, Adriana Madeira

2018-01-01

Jumonji Domain-Containing 1A (JMJD1A) protein promotes demethylation of histones, especially at lysin-9 of di-methylated histone H3 (H3K9me2) or mono-methylated (H3K9me1). Increased levels of H3 histone methylation at lysin-9 (H3K9) is related to tumor suppressor gene silencing. JMJD1A gene target Adrenomeduline (ADM) has shown to promote cell growth and tumorigenesis. JMJD1A and ADM expression, as well as H3K9 methylation level have been related with development risk and prognosis of several tumor types. We aimed to evaluate JMJD1A, ADM, H3K9me1 and H3K9me2expression in paraffin-embedded tissue microarrays from 84 oral and oropharyngeal squamous cell carcinoma samples through immunohistochemistry analysis. Our results showed that nuclear JMJD1A expression was related to lymph node metastasis risk. In addition, JMJD1A cytoplasmic expression was an independent risk marker for advanced tumor stages. H3K9me1 cytoplasmic expression was associated with reduced disease-specific death risk. Furthermore, high H3K9me2 nuclear expression was associated with worse specific-disease and disease-free survival. Finally, high ADM cytoplasmic expression was an independent marker of lymph node metastasis risk. JMJD1A, H3K9me1/2 and ADM expression may be predictor markers of progression and prognosis in oral and oropharynx cancer patients, as well as putative therapeutic targets.

JMJD1A, H3K9me1, H3K9me2 and ADM expression as prognostic markers in oral and oropharyngeal squamous cell carcinoma

PubMed Central

Peterle, Gabriela Tonini; dos Santos, Marcelo; Trivilin, Leonardo Oliveira; Mendes, Suzanny Oliveira; de Oliveira, Mayara Mota; dos Santos, Joaquim Gasparini; Stur, Elaine; Agostini, Lidiane Pignaton; Couto, Cinthia Vidal Monteiro da Silva; Dalbó, Juliana; de Assis, Aricia Leone Evangelista Monteiro; Archanjo, Anderson Barros; Mercante, Ana Maria Da Cunha; Lopez, Rossana Veronica Mendoza; Nunes, Fábio Daumas; de Carvalho, Marcos Brasilino; Tajara, Eloiza Helena; Louro, Iúri Drumond; Álvares-da-Silva, Adriana Madeira

2018-01-01

Aims Jumonji Domain-Containing 1A (JMJD1A) protein promotes demethylation of histones, especially at lysin-9 of di-methylated histone H3 (H3K9me2) or mono-methylated (H3K9me1). Increased levels of H3 histone methylation at lysin-9 (H3K9) is related to tumor suppressor gene silencing. JMJD1A gene target Adrenomeduline (ADM) has shown to promote cell growth and tumorigenesis. JMJD1A and ADM expression, as well as H3K9 methylation level have been related with development risk and prognosis of several tumor types. Methods and results We aimed to evaluate JMJD1A, ADM, H3K9me1 and H3K9me2expression in paraffin-embedded tissue microarrays from 84 oral and oropharyngeal squamous cell carcinoma samples through immunohistochemistry analysis. Our results showed that nuclear JMJD1A expression was related to lymph node metastasis risk. In addition, JMJD1A cytoplasmic expression was an independent risk marker for advanced tumor stages. H3K9me1 cytoplasmic expression was associated with reduced disease-specific death risk. Furthermore, high H3K9me2 nuclear expression was associated with worse specific-disease and disease-free survival. Finally, high ADM cytoplasmic expression was an independent marker of lymph node metastasis risk. Conclusion JMJD1A, H3K9me1/2 and ADM expression may be predictor markers of progression and prognosis in oral and oropharynx cancer patients, as well as putative therapeutic targets. PMID:29590186

Full-dimensional quantum dynamics study of the H{sub 2} + C{sub 2}H → H + C{sub 2}H{sub 2} reaction on an ab initio potential energy surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Liuyang; University of Chinese Academy of Sciences, Beijing 100049; Shao, Kejie

2016-05-21

This work performs a time-dependent wavepacket study of the H{sub 2} + C{sub 2}H → H + C{sub 2}H{sub 2} reaction on a new ab initio potential energy surface (PES). The PES is constructed using neural network method based on 68 478 geometries with energies calculated at UCCSD(T)-F12a/aug-cc-pVTZ level and covers H{sub 2} + C{sub 2}H↔H + C{sub 2}H{sub 2}, H + C{sub 2}H{sub 2} → HCCH{sub 2}, and HCCH{sub 2} radial isomerization reaction regions. The reaction dynamics of H{sub 2} + C{sub 2}H → H + C{sub 2}H{sub 2} are investigated using full-dimensional quantum dynamics method. The initial-state selected reactionmore » probabilities are calculated for reactants in eight vibrational states. The calculated results showed that the H{sub 2} vibrational excitation predominantly enhances the reactivity while the excitation of bending mode of C{sub 2}H slightly inhibits the reaction. The excitations of two stretching modes of C{sub 2}H molecule have negligible effect on the reactivity. The integral cross section is calculated with J-shift approximation and the mode selectivity in this reaction is discussed. The rate constants over 200-2000 K are calculated and agree well with the experimental measured values.« less

Enhanced visible light photocatalytic H2-production of g-C3N4/WS2 composite heterostructures

NASA Astrophysics Data System (ADS)

Akple, Maxwell Selase; Low, Jingxiang; Wageh, S.; Al-Ghamdi, Ahmed. A.; Yu, Jiaguo; Zhang, Jun

2015-12-01

As a clean and renewable solar H2-production system to address the increasing global environmental crisis and energy demand, photocatalytic hydrogen production from water splitting using earth abundant materials has received a lot of attention. In this study, WS2-graphitic carbon nitride (g-C3N4) composites were prepared using WO3 and thiourea as precursors through a gas-solid reaction. Different amount of WS2 were loaded on g-C3N4 to form the heterostructures and the composite samples exhibited enhanced photocatalytic activity for H2 production under visible light. The composite sample with 0.01 wt% WS2 exhibited the highest H2-production rate of 101 μmol g-1 h-1, which was even better than that of the Pt-C3N4 sample with the same loading content. The high photocatalytic activity was attributed to the formation of heterojunction between g-C3N4 and WS2 cocatalyst which allowed for effective separation of photogenerated charge carriers. This work showed the possibility for the utilization of low cost WS2 as an efficient cocatalyst to promote the photocatalytic H2 production of g-C3N4.

The nido-osmaboranes [2,2,2-(CO)(PPh(3))(2)-nido-2-OsB(5)H(9)] and [6,6,6-(CO)(PPh(3))(2)-nido-6-OsB(9)H(13)].

PubMed

Bould, J; Kennedy, J D; Thomas, R L; Rath, N P; Barton, L

2001-11-01

The structural characterization of the osmahexaborane 2-carbonyl-2,2-bis(triphenylphosphine)-nido-2-osmahexaborane(9), [Os(B(5)H(9))(C(18)H(15)P)(2)(CO)], (I), a metallaborane analogue of B(6)H(10), confirms the structure proposed from NMR spectroscopy. The structure of the osmadecaborane 6-carbonyl-6,6-bis(triphenylphosphine)-nido-6-osmadecaborane(13), [Os(B(9)H(13))(C(18)H(15)P)(2)(CO)], (IV), is similarly confirmed. The short basal B-B distance of 1.652 (8) A in (I), not bridged by an H atom, mirrors that in the parent hexaborane(10) [1.626 (4) A].

Observations of CH4, C2H6, and C2H2 in the stratosphere of Jupiter

NASA Technical Reports Server (NTRS)

Sada, P. V.; Bjoraker, G. L.; Jennings, D. E.; McCabe, G. H.; Romani, P. N.

1998-01-01

We have performed high-resolution spectral observations at mid-infrared wavelengths of CH4 (8.14 micrometers), C2H6 (12.16 micrometers), and C2H2 (13.45 micrometers) on Jupiter. These emission features probe the stratosphere of the planet and provide information on the carbon-based photochemical processes taking place in that region of the atmosphere. The observations were performed using our cryogenic echelle spectrometer CELESTE, in conjunction with the McMath-Pierce 1.5-m solar telescope between November 1994 and February 1995. We used the methane observations to derive the temperature profile of the jovian atmosphere in the 1-10 mbar region of the stratosphere. This profile was then used in conjunction with height-dependent mixing ratios of each hydrocarbon to determine global abundances for ethane and acetylene. The resulting mixing ratios are 3.9(+1.9)(-1.3) x 10(-6) for C2H6 (5 mbar pressure level), and 2.3 +/- 0.5 x 10(-8) for C2H2 (8 mbar pressure level), where the quoted uncertainties are derived from model variations in the temperature profile which match the methane observation uncertainties. c1998 Academic Press.

Enhancement of a-Si:H solar cell efficiency by Y2O3 : Yb3+, Er3+ near infrared spectral upconverter

NASA Astrophysics Data System (ADS)

Markose, Kurias K.; Anjana, R.; Subha, P. P.; Antony, Aldrin; Jayaraj, M. K.

2016-09-01

The optical properties of Yb3+/Er3+ doped Y2O3 upconversion phosphor and the enhancement of efficiency of a-Si:H solar cell on incorporation of upconverter are investigated. The Y2O3 host material has high corrosion resistance, thermal stability, chemical stability, low toxicity and relatively low phonon energy (≈ 500 cm-1). Y2O3:Yb3+ (x %): Er3+ (y %) upconversion nanophosphors with different dopant concentrations were synthesized via simple hydrothermal method followed by a heat treatment at 1200°C for 12 hrs. Highly crystalline, quasi-spherical, body centered cubic Y2O3 structure was obtained. The structure, phase and morphology of the nanocrystals were determined using x-ray diffraction and SEM. Following pumping at 980 nm two dominant emission bands were observed at about 550 nm(green) and 660 nm(red), corresponding to 2H11/2, 4S3/2 -> 4I15/2 and 4F9/2 -> 4I15/2 transitions respectively. The dependence of emission intensity on pump power shows that the mechanism involved is two photon absorption. The upconversion phosphor along with a binder is coupled behind the a-Si:H solar cell which absorbs transmitted sub-band-gap photons and emits back the upconverted visible light which can be absorbed by the solar cell. Under suitable intensity of illumination the solar cell short circuit current is found to be increased on adding the upconversion layer.

Influenza H7N9 and H9N2 Viruses: Coexistence in Poultry Linked to Human H7N9 Infection and Genome Characteristics

PubMed Central

Yu, Xinfen; Jin, Tao; Cui, Yujun; Pu, Xiaoying; Li, Jun; Xu, Jin; Liu, Guang; Jia, Huijue; Liu, Dan; Song, Shili; Yu, Yang; Xie, Li; Huang, Renjie; Ding, Hua; Kou, Yu; Zhou, Yinyan; Wang, Yayu; Xu, Xun; Yin, Ye; Wang, Jian; Guo, Chenyi; Yang, Xianwei; Hu, Liangping; Wu, Xiaopeng; Wang, Hailong; Liu, Jun; Zhao, Guoqiu; Zhou, Jiyong; Gao, George F.; Yang, Ruifu; Wang, Jun

2014-01-01

ABSTRACT Avian influenza virus A of the novel H7N9 reassortant subtype was recently found to cause severe human respiratory infections in China. Live poultry markets were suspected locations of the human H7N9 infection sources, based on the cases' exposure histories and sequence similarities between viral isolates. To explore the role of live poultry markets in the origin of the novel H7N9 virus, we systematically examined poultry and environmental specimens from local markets and farms in Hangzhou, using real-time reverse transcription-PCR (RT-PCR) as well as high-throughput next-generation sequencing (NGS). RT-PCR identified specimens positive for the H7 and N9 genomic segments in all of the 12 poultry markets epidemiologically linked to 10 human H7N9 cases. Chickens, ducks, and environmental specimens from the markets contained heavily mixed subtypes, including H7, N9, H9, and N2 and sometimes H5 and N1. The idea of the coexistence of H7N9 and H9N2 subtypes in chickens was further supported by metagenomic sequencing. In contrast, human H7N9 infection cases (n = 31) were all negative for H9N2 virus according to real-time RT-PCR. The six internal segments were indistinguishable for the H7N9 and H9N2 viruses. The H9, N2, and internal-segment sequences were very close to the sequence of the H9N2 virus circulating in chickens in China recently. Our results provide direct evidence that H9N2 strains coexisted with the novel human-pathogenic H7N9 influenza virus in epidemiologically linked live poultry markets. Avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus and continues to do so. IMPORTANCE Our results suggest that avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus, a novel reassortant avian influenza virus A subtype, and continues to do so. The finding helps shed light on how the H7N9 virus emerged, spread, and transmitted to humans. It is of

Influenza H7N9 and H9N2 viruses: coexistence in poultry linked to human H7N9 infection and genome characteristics.

PubMed

Yu, Xinfen; Jin, Tao; Cui, Yujun; Pu, Xiaoying; Li, Jun; Xu, Jin; Liu, Guang; Jia, Huijue; Liu, Dan; Song, Shili; Yu, Yang; Xie, Li; Huang, Renjie; Ding, Hua; Kou, Yu; Zhou, Yinyan; Wang, Yayu; Xu, Xun; Yin, Ye; Wang, Jian; Guo, Chenyi; Yang, Xianwei; Hu, Liangping; Wu, Xiaopeng; Wang, Hailong; Liu, Jun; Zhao, Guoqiu; Zhou, Jiyong; Pan, Jingcao; Gao, George F; Yang, Ruifu; Wang, Jun

2014-03-01

Avian influenza virus A of the novel H7N9 reassortant subtype was recently found to cause severe human respiratory infections in China. Live poultry markets were suspected locations of the human H7N9 infection sources, based on the cases' exposure histories and sequence similarities between viral isolates. To explore the role of live poultry markets in the origin of the novel H7N9 virus, we systematically examined poultry and environmental specimens from local markets and farms in Hangzhou, using real-time reverse transcription-PCR (RT-PCR) as well as high-throughput next-generation sequencing (NGS). RT-PCR identified specimens positive for the H7 and N9 genomic segments in all of the 12 poultry markets epidemiologically linked to 10 human H7N9 cases. Chickens, ducks, and environmental specimens from the markets contained heavily mixed subtypes, including H7, N9, H9, and N2 and sometimes H5 and N1. The idea of the coexistence of H7N9 and H9N2 subtypes in chickens was further supported by metagenomic sequencing. In contrast, human H7N9 infection cases (n = 31) were all negative for H9N2 virus according to real-time RT-PCR. The six internal segments were indistinguishable for the H7N9 and H9N2 viruses. The H9, N2, and internal-segment sequences were very close to the sequence of the H9N2 virus circulating in chickens in China recently. Our results provide direct evidence that H9N2 strains coexisted with the novel human-pathogenic H7N9 influenza virus in epidemiologically linked live poultry markets. Avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus and continues to do so. Our results suggest that avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus, a novel reassortant avian influenza virus A subtype, and continues to do so. The finding helps shed light on how the H7N9 virus emerged, spread, and transmitted to humans. It is of considerable

CD86 and beta2-adrenergic receptor signaling pathways, respectively, increase Oct-2 and OCA-B Expression and binding to the 3'-IgH enhancer in B cells.

PubMed

Podojil, Joseph R; Kin, Nicholas W; Sanders, Virginia M

2004-05-28

Stimulation of CD86 (formerly known as B7-2) and/or the beta2-adrenergic receptor on a CD40 ligand/interleukin-4-activated B cell increased the rate of mature IgG1 transcription. To identify the mechanism responsible for this effect, we determined whether CD86 and/or beta2-adrenergic receptor stimulation regulated transcription factor expression and binding to the 3'-IgH enhancer in vitro and in vivo. We showed that CD86 stimulation increased the nuclear localization of NF-kappaB1 (p50) and phosphorylated RelA (p65) and increased Oct-2 expression and binding to the 3'-IgH enhancer, in a protein kinase C-dependent manner. These effects were lost when CD86-deficient or NF-kappaB1-deficient B cells were used. CD86 stimulation also increased the level of IkappaB-alpha phosphorylation but in a protein kinase C-independent manner. Beta2-adrenergic receptor stimulation increased CREB phosphorylation, OCA-B expression, and OCA-B binding to the 3'-IgH enhancer in a protein kinase A-dependent manner, an effect lost when beta2-adrenergic receptor-deficient B cells were used. Also, the beta2-adrenergic receptor-induced increase in the level of mature IgG1 transcript was lost when OCA-B-deficient B cells were used. These data are the first to show that CD86 stimulation up-regulates the expression of the transcription factor Oct-2 in a protein kinase C- and NF-kappaB1-dependent manner, and that beta2-adrenergic receptor stimulation up-regulates the expression of the coactivator OCA-B in a protein kinase A-dependent manner to cooperate with Oct-2 binding to the 3'-IgH enhancer.

1H NMR relaxometry and quadrupole relaxation enhancement as a sensitive probe of dynamical properties of solids—[C(NH2)3]3Bi2I9 as an example

NASA Astrophysics Data System (ADS)

Florek-Wojciechowska, M.; Wojciechowski, M.; Jakubas, R.; Brym, Sz.; Kruk, D.

2016-02-01

1H nuclear magnetic resonance relaxometry has been applied to reveal information on dynamics and structure of Gu3Bi2I9 ([Gu = C(NH2)3] denotes guanidinium cation). The data have been analyzed in terms of a theory of quadrupole relaxation enhancement, which has been extended here by including effects associated with quadrupole (14N) spin relaxation caused by a fast fluctuating component of the electric field gradient tensor. Two motional processes have been identified: a slow one occurring on a timescale of about 8 × 10-6 s which has turned out to be (almost) temperature independent, and a fast process in the range of 10-9 s. From the 1H-14N relaxation contribution (that shows "quadrupole peaks") the quadrupole parameters, which are a fingerprint of the arrangement of the anionic network, have been determined. It has been demonstrated that the magnitude of the quadrupole coupling considerably changes with temperature and the changes are not caused by phase transitions. At the same time, it has been shown that there is no evidence of abrupt changes in the cationic dynamics and the anionic substructure upon the phase transitions.

PB2-Q591K Mutation Determines the Pathogenicity of Avian H9N2 Influenza Viruses for Mammalian Species

PubMed Central

Wang, Congrong; Lee, Horace Hok Yeung; Yang, Zi Feng; Mok, Chris Ka Pun; Zhang, Zhi

2016-01-01

Background Influenza A subtype H9N2 is widespread and prevalent in poultry. It has repeatedly transmitted zoonotically to cause mild influenza-like illness in humans and is regarded as a potential pandemic candidate. In additon, the six internal genes of H7N9 and H10N8 viruses which caused infection in human in China as well as some of the highly pathogenic H5N1 strains are origined from H9N2. Previous studies have shown that the mammalian adaptation PB2-Q591K contributes to the pathogenicity of H5N1 and H7N9 viruses. However, the role of the PB2-Q591K mutation in H9N2 subtype is still not well understood. Methods To define and compare the individual role of PB2-Q591K substitution in the PB2 gene segment of H9N2 in relation to polymerase activity, replication competence and the pathogenicity using in vitro and in vivo models. Results The PB2-Q591K mutation in H9N2 virus enhanced the polymerase activity and virus replication in human NHBE cells when compared to the wild type strain. Mice infected with the PB2 mutant showed significant weight loss, higher virus replication and immune responses in the lungs. Conclusions Our evidences suggest that the PB2-Q591K, in addition to the -E627K mutation in H9N2 enhanced the pathogenicity in mammalian host. PMID:27684944

Alpinate Oxyphyllae Fructus Inhibits IGFII-Related Signaling Pathway to Attenuate Ang II-Induced Pathological Hypertrophy in H9c2 Cardiomyoblasts.

PubMed

Tsai, Chuan-Te; Chang, Yung-Ming; Lin, Shu-Luan; Chen, Yueh-Sheng; Yeh, Yu-Lan; Padma, Viswanadha Vijaya; Tsai, Chin-Chuan; Chen, Ray-Jade; Ho, Tsung-Jung; Huang, Chih-Yang

2016-03-01

Angiotensin II (Ang II) is a very important cardiovascular disease inducer and may cause cardiac pathological hypertrophy and remodeling. We evaluated a Chinese traditional medicine, alpinate oxyphyllae fructus (AOF), for therapeutic efficacy for treating Ang II-induced cardiac hypertrophy. AOF has been used to treat patients with various symptoms accompanying hypertension and cerebrovascular disorders in Korea. We investigated its protective effect against Ang II-induced cytoskeletal change and hypertrophy in H9c2 cells. The results showed that treating cells with Ang II resulted in pathological hypertrophy, such as increased expression of transcription factors NFAT-3/p-NFAT-3, hypertrophic response genes (atrial natriuretic peptide [ANP] and b-type natriuretic peptide [BNP]), and Gαq down-stream effectors (PLCβ3 and calcineurin). Pretreatment with AOF (60-100 μg/mL) led to significantly reduced hypertrophy. We also found that AOF pretreatment significantly suppressed the cardiac remodeling proteins, metalloproteinase (MMP9 and MMP2), and tissue plasminogen activator (tPA), induced by Ang II challenge. In conclusion, we provide evidence that AOF protects against Ang II-induced pathological hypertrophy by specifically inhibiting the insulin-like growth factor (IGF) II/IIR-related signaling pathway in H9c2 cells. AOF might be a candidate for cardiac hypertrophy and ventricular remodeling prevention in chronic cardiovascular diseases.

Tauroursodeoxycholic acid inhibits endoplasmic reticulum stress, blocks mitochondrial permeability transition pore opening, and suppresses reperfusion injury through GSK-3ß in cardiac H9c2 cells.

PubMed

Xie, Yuxi; He, Yonggui; Cai, Zhiliang; Cai, Jianhang; Xi, Mengyao; Zhang, Yidong; Xi, Jinkun

2016-01-01

This study investigates whether inhibition of endoplasmic reticulum (ER) stress prevents opening of the mitochondrial permeability transition pore (mPTP) and evaluates the corresponding signaling pathways involved in this process. Exposure of cardiac H9c2 cells to 800 µM H 2 O 2 for 20 min opened mPTP in response to oxidative stress, as demonstrated by quenching of tetramethylrhodamine ethyl ester (TMRE) fluorescence. Oxidative stress-induced mPTP opening was rescued by the ER stress inhibitor tauroursodeoxycholic acid (TUDCA) in a dose-dependent manner at low concentrations. The PI3K and PKG inhibitors LY294002 and KT5823 inhibited the effect of TUDCA on mPTP opening, suggesting the involvement of PI3K/Akt and PKG signaling pathways. TUDCA significantly increased glycogen synthase kinase 3 (GSK-3β) phosphorylation at Ser-9, with peak effect at 30 µM TUDCA. The level of GRP78 (ER chaperone) expression was significantly upregulated by 30 µM TUDCA. TUDCA-induced increases in Akt and GSK-3β phosphorylation were inhibited by LY294002, whereas KT5823 suppressed TUDCA-induced increases in VASP and GSK-3β phosphorylation. Oxidative stress severely affected cell morphology and ultrastructure. TUDCA prevented H 2 O 2 -induced ER swelling and mitochondrial damage. TUDCA boosted the viability of cells disrupted by ischemia/reperfusion (I/R), indicating that TUDCA eased reperfusion injury. However, TUDCA did not improve the viability of cells expressing the constitutively active GSK-3β mutant (GSK-3β-S9A-HA) that were subjected to I/R, suggesting an essential role of GSK-3β inactivation in TUDCA-mediated cardioprotection against reperfusion damage. These data indicate that ER stress inhibition prevents mPTP opening and attenuates reperfusion injury through GSK-3β inactivation. The PI3K/Akt and PKG pathways may mediate GSK-3β inactivation.

The FAQUIRE Approach: FAst, QUantitative, hIghly Resolved and sEnsitivity Enhanced 1H, 13C Data.

PubMed

Farjon, Jonathan; Milande, Clément; Martineau, Estelle; Akoka, Serge; Giraudeau, Patrick

2018-02-06

The targeted analysis of metabolites in complex mixtures is a challenging issue. NMR is one of the major tools in this field, but there is a strong need for more sensitive, better-resolved, and faster quantitative methods. In this framework, we introduce the concept of FAst, QUantitative, hIghly Resolved and sEnsitivity enhanced (FAQUIRE) NMR to push forward the limits of metabolite NMR analysis. 2D 1 H, 13 C 2D quantitative maps are promising alternatives for enhancing the spectral resolution but are highly time-consuming because of (i) the intrinsic nature of 2D, (ii) the longer recycling times required for quantitative conditions, and (iii) the higher number of scans needed to reduce the level of detection/quantification to access low concentrated metabolites. To reach this aim, speeding up the recently developed QUantItative Perfected and pUre shifted HSQC (QUIPU HSQC) is an interesting attempt to develop the FAQUIRE concept. Thanks to the combination of spectral aliasing, nonuniform sampling, and variable repetition time, the acquisition time of 2D quantitative maps is reduced by a factor 6 to 9, while conserving a high spectral resolution thanks to a pure shift approach. The analytical potential of the new Quick QUIPU HSQC (Q QUIPU HSQC) is evaluated on a model metabolite sample, and its potential is shown on breast-cell extracts embedding metabolites at millimolar to submillimolar concentrations.

Growth hormone facilitates 5'-azacytidine-induced myogenic but inhibits 5'-azacytidine-induced adipogenic commitment in C3H10T1/2 mesenchymal stem cells.

PubMed

Jia, Dan; Zheng, Weijiang; Jiang, Honglin

2018-06-01

The C3H10T1/2 cells are considered mesenchymal stem cells (MSCs) because they can be induced to become the progenitor cells for myocytes, adipocytes, osteoblasts, and chondrocytes by the DNA methyltransferase inhibitor 5'-azacytidine. In this study, we determined the effect of growth hormone (GH) on the myogenic and adipogenic lineage commitment in C3H10T1/2 cells. The C3H10T1/2 cells were treated with recombinant bovine GH in the presence or absence of 5'-azacytidine for 4 days. The myogenic commitment in C3H10T1/2 cells was assessed by immunostaining them for MyoD, the marker for myoblasts, and by determining their capacity to differentiate into the multinucleated myotubes. The adipogenic commitment in C3H10T1/2 cells was assessed by determining their ability to differentiate into adipocytes. Myotubes and adipocyteswere identified by immunocytochemistry and Oil Red O staining, respectively. C3H10T1/2 cells treated with 5'-azacytidine and GH for 4 days contained a greater percentage of MyoD-positive cells than those treated with 5'-axacytidine alone (P < 0.05). The former generated more myotubes than the latter upon induced myoblast differentiation (P < 0.05). However, C3H10T1/2 cells treated with GH alone did not form any myotubes. C3H10T1/2 cells treated with 5'-azacytidine formed adipocytes upon adipocyte differentiation induction, whereas C3H10T1/2 cells treated with GH alone did not form any adipocytes. C3H10T1/2 cells treated with both 5'-azacytidine and GH formed fewer adipocytes than those treated with 5'-azacytidine alone (P < 0.05). Both GHR and IGF-I mRNA expression in C3H10T1/2 cells were increased by 5'-azacytidine (P < 0.05), but neither was affected by GH. Overall, this study showed that GH enhanced 5'-azacytidine-induced commitment in C3H10T1/2 cells to myoblasts but inhibited 5'-azacytidine-induced commitment to preadipocytes. These results support the possibility that GH stimulates skeletal muscle growth and inhibits adipose

H9N2 influenza virus isolated from minks has enhanced virulence in mice.

PubMed

Xue, R; Tian, Y; Hou, T; Bao, D; Chen, H; Teng, Q; Yang, J; Li, X; Wang, G; Li, Z; Liu, Q

2018-06-01

H9N2 is one of the major subtypes of influenza virus circulating in poultry in China, which has a wide host range from bird to mammals. Two H9N2 viruses were isolated from one mink farm in 2014. Phylogenetic analysis showed that internal genes of the H9N2 viruses have close relationship with those of H7N9 viruses. Interestingly, two H9N2 were separated in phylogenetic trees, indicating that they are introduced to this mink farm in two independent events. And further mice studies showed that one H9N2 caused obvious weight loss and 20% mortality in infected mice, while another virus did not cause any clinical sign in mice infected at the same dose. Genetic analysis indicated that the virulent H9N2 contain a natural mutation at 701N in PB2 protein, which was reported to contribute to mammalian adaptation. However, such substitution is absent in the H9N2 avirulent to mice. Circulation of H9N2 in mink may drive the virus to adapt mammals; continual surveillance of influenza virus in mink was warranted. © 2018 Blackwell Verlag GmbH.

Enhanced Production of a Recombinant Multidomain Thermostable GH9 Processive Endo-1,4-β-Glucanase (CenC) from Ruminiclostridium thermocellum in a Mesophilic Host Through Various Cultivation and Induction Strategies.

PubMed

Haq, Ikram Ul; Akram, Fatima

2017-09-01

Commonly, unintentional induction and inadvertently preparing medium for engineered Escherichia coli BL21 CodonPlus (DE3)-RIPL, give poor or variable yields of heterologous proteins. Therefore, to enhance the activity and production of an industrially relevant recombinant processive endo-1,4-β-glucanase (CenC) propagated in Escherichia coli BL21 CodonPlus(DE3)-RIPL through various cultivation and induction strategies. Investigation of various growth media and induction parameters revealed that high-cell-density and optimal CenC expression were obtained in ZYBM9 medium induced either with 0.5 mM IPTG/150 mM lactose, after 6 h induction at 37 °C; and before induction, bacterial cells were given heat shock (42 °C) for 1 h when culture density (OD 600nm ) reached at 0.6. Intracellular enzyme activity was enhanced by 6.67 and 3.20-fold in ZYBM9 and 3×ZYBM9 medium, respectively, under optimal conditions. Using YNG auto-induction medium, activity was 2.5-fold increased after 10 h incubation at 37 °C. Approximately similar results were obtained by transferring the optimized process at the bioreactor level. Results showed that the effective process strategy is essential to enhance recombinant bacterial cell mass and enzyme production from small to large-scale. To the best of our knowledge, this is the first ever report on enhanced production of thermostable processive endo-1,4-β-glucanase cloned from Ruminiclostridium thermocellum, which is a suitable candidate for industrial applications. Graphical Abstract Flow Chart Summary of Enhanced Production of a Recombinant Multidomain Thermostable GH9 Processive Endo-1,4-β-glucanase from Ruminiclostridium thermocellum.

Efficient replication and strong induction of innate immune responses by H9N2 avian influenza virus in human dendritic cells.

PubMed

Westenius, Veera; Mäkelä, Sanna M; Ziegler, Thedi; Julkunen, Ilkka; Österlund, Pamela

2014-12-01

Avian influenza A (H9N2) viruses have occasionally been identified in humans with upper respiratory tract infections. The novel H7N9/2013 virus identified in China shows that a low pathogenic avian influenza (LPAI) virus can be highly pathogenic in humans. Therefore, it is important to understand virus-host cell interactions and immune responses triggered by LPAI viruses in humans. We found that LPAI A/Hong Kong/1073/99 (H9N2) virus replicated efficiently in human dendritic cells (DCs). The H9N2 virus induced strong IFN gene expression although with different kinetics than seasonal influenza A/Beijing/353/89 (H3N2) virus. IFN inducible antiviral proteins were produced in H9N2 virus-infected cells at the same level as in H3N2 infection. The H9N2 virus was extremely sensitive to the antiviral actions of type I IFNs. These results indicate that the avian influenza H9N2 virus is inducing a strong antiviral IFN response in human DCs. Copyright © 2014 Elsevier Inc. All rights reserved.

The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals

PubMed Central

Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-01-01

H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans. PMID:27094903

The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals.

PubMed

Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-04-20

H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans.

Deep extractive and oxidative desulfurization of dibenzothiophene with C5H9NO·SnCl2 coordinated ionic liquid.

PubMed

Li, Fa-tang; Kou, Cheng-guang; Sun, Zhi-min; Hao, Ying-juan; Liu, Rui-hong; Zhao, Di-shun

2012-02-29

A new C5H9NO·SnCl2 coordinated ionic liquid (IL) was prepared by reacting N-methyl-pyrrolidone with anhydrous SnCl2. Desulfurization of dibenzothiophene (DBT) via extraction and oxidation with C5H9NO·SnCl2 IL as extractant, H2O2 and equal mol of CH3COOH as oxidants was investigated. The Nernst partition coefficients k(N) of C5H9NO·SnCl2 IL for the DBT in n-octane was above 5.0, showing its excellent extraction ability. During the oxidative desulfurization process, the optimal molar ratio of H2O2/DBT was six. Sulfur removal of DBT in n-octane was 94.8% in 30 min at 30 °C under the conditions of H2O2/DBT molar ratio of six and V (IL):V (oil)=1:3. Moreover, the sulfur removal increased with increasing temperature because of the high reaction rate constant, low viscosity, and high solubility of dibenzothiophene-sulfone in the IL. The kinetics of oxidative desulfurization of DBT was also investigated, and the apparent activation energy was found to be 32.5 kJ/mol. The IL could be recycled six times without a significant decrease in activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Synthesis, DFT calculations of structure, vibrational and thermal decomposition studies of the metal complex Pb[Mn(C3H2O4)2(H2O)2].

PubMed

Gil, Diego M; Carbonio, Raúl E; Gómez, María Inés

2015-04-15

The metallo-organic complex Pb[Mn(C3H2O4)2(H2O)2] was synthesized and characterized by IR and Raman spectroscopy and powder X-ray diffraction methods. The cell parameters for the complex were determined from powder X-ray diffraction using the autoindexing program TREOR, and refined by the Le Bail method with the Fullprof program. A hexagonal unit cell was determined with a=b=13.8366(7)Å, c=9.1454(1)Å, γ=120°. The DFT calculated geometry of the complex anion [Mn(C3H2O4)2(H2O)2](2-) is very close to the experimental data reported for similar systems. The IR and Raman spectra and the thermal analysis of the complex indicate that only one type of water molecules is present in the structure. The thermal decomposition of Pb[Mn(C3H2O4)2(H2O)2] at 700 °C in air produces PbO and Pb2MnO4 as final products. The crystal structure of the mixed oxide is very similar to that reported for Pb3O4. Copyright © 2015 Elsevier B.V. All rights reserved.

Mechanism of improved maintenance of 2,3-diphosphoglycerate in stored blood by the xanthone compound 2-(2-hydroxyethoxy)-6-(1-H-tetrazole-5-yl)xanthen-9-one (BW A440C).

PubMed

Beutler, E; Forman, L; West, C; Gelbart, T

1988-03-15

The effect of the xanthone derivative 2-(2-hydroxyethoxy)-6-(1-H-tetrazole-5-yl)xanthen-9-one (BW A440C) on red cells was studied. When added to stored red cells at a concentration of 6 mM, greatly improved preservation of 2,3-diphosphoglycerate (2,3-DPG) was observed. There was no effect on internal pH of the erythrocyte. At a concentration 0.500 mM, many red cell enzyme activities were inhibited completely. At a 0.500 mM concentration, however, inhibition of pyruvate kinase and diphosphoglycerate phosphatase was most striking. Inhibition of either of these enzymes could result in elevation of 2,3-DPG levels. BW A440C in concentrations which elevated 2,3-DPG levels in humans caused a decrease in 2,3-DPG levels in rabbits and markedly impaired the viability of 21-day stored rabbit erythrocytes.

Synthesis and crystal structure of the [Co{sub 2}(Nicotinamide){sub 4}(C{sub 4}H{sub 9}COO){sub 4}(H{sub 2}O)] complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sadikov, G. G., E-mail: sadgg@igic.ras.ru; Antsyshkina, A. S.; Koksharova, T. V.

2007-09-15

The [Co{sub 2}L{sub 4}(C{sub 4}H{sub 9}COO){sub 4}(H{sub 2}O)] coordination compound of cobalt(II) valerate with nicotinamide (L) is synthesized and studied by IR spectroscopy. The crystal structure of the synthesized compound is determined. The crystals are triclinic, and the unit cell parameters are as follows: a = 10.2759(10) A, b = 16.3858(10) A, c = 16.4262(10) A, {alpha} = 100.538(10) deg., {beta} = 101.199(10) deg., {gamma} = 90.813 (10) deg., Z = 2, and space group P1-bar. The structural units of the crystal are dimeric molecular complexes in which pairs of cobalt atoms are linked by triple bridges formed by oxygenmore » atoms of two bidentately coordinated valerate anions and a water molecule. The octahedral coordination of each cobalt atom is complemented by the pyridine nitrogen atoms of two nicotinamide ligands and the oxygen atom of the monodentate valerate group. The hydrocarbon chains of the valerate anions are disordered over two or three positions each.« less

Role of angiopoietin-2 in the cardioprotective effect of fibroblast growth factor 21 on ischemia/reperfusion-induced injury in H9c2 cardiomyocytes

PubMed Central

Hu, Shuoqiang; Cao, Shujun; Liu, Jinghua

2017-01-01

Fibroblast growth factor 21 (FGF21) exerts a protective effect in ischemia/reperfusion (I/R)-induced cardiac injury. However, the exact molecular mechanism underlying the FGF21 action remains unclear. The present study aimed to evaluate the role of angiopoietin-2 (Angpt2) in the cardioprotective effect of FGF21. For this purpose, the H9C2 cell line was subjected to simulated I/R or aerobic conditions with or without FGF21 administration. Certain groups were also transfected with Angpt2 small interfering RNA (siRNA). Cell viability, apoptosis rate and cell migration were examined, and the expression levels of Angpt2, glucose transporter 1 (GLUT1) and caspase-3 were measured by quantitative polymerase chain reaction (qPCR) and western blot analyses. The results demonstrated that FGF21 administration suppressed apoptosis and increased the cell migration ability following I/R-induced injury. qPCR and western blot data showed a decreased level of GLUT1 after I/R-induced injury, which was reversed by FGF21 administration. Furthermore, inhibition of Angpt2 expression using siRNA enhanced the cardioprotective effect of FGF21 by upregulation of GLUT1. In conclusion, FGF21 administration protected against I/R-induced injury in cardiomyocytes, and further inhibition of Angpt2 with FGF21 administration induced the expression of GLUT1, which may promote the energy metabolism in cardiomyocytes, consequently resulting in a more efficient cardioprotective effect. These results suggested that FGF21 administration and inhibition of Angpt2 could be a novel therapeutic approach for I/R-induced cardiac injury. PMID:28672998

Spinosad induces programmed cell death involves mitochondrial dysfunction and cytochrome C release in Spodoptera frugiperda Sf9 cells.

PubMed

Yang, Mingjun; Wang, Bo; Gao, Jufang; Zhang, Yang; Xu, Wenping; Tao, Liming

2017-02-01

Spinosad, a reduced-risk insecticide, acts on the nicotinic acetylcholine receptors and the gamma-aminobutyric acid receptor in the nervous system of target insects. However, its mechanism of action in non-neural insect cells is unclear. This study aimed to evaluate mitochondrial functional changes associated with spinosad in Spodoptera frugiperda (Sf9) insect cells. Our results indicate that in Sf9 cells, spinosad induces programmed cell death and mitochondrial dysfunction through enhanced reactive oxygen species production, mitochondrial permeability transition pore (mPTP) opening, and mitochondrial membrane potential collapse, eventually leading to cytochrome C release and apoptosis. The cytochrome C release induced by spinosad treatment was partly inhibited by the mPTP inhibitors cyclosporin A and bongkrekic acid. Subsequently, we found that spinosad downregulated Bcl-2 expression and upregulated p53 and Bax expressions, activated caspase-9 and caspase-3, and triggered PARP cleavage in Sf9 cells. These findings suggested that spinosad-induced programmed cell death was modulated by mitochondrial dysfunction and cytochrome C release. Copyright © 2016 Elsevier Ltd. All rights reserved.

PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses

PubMed Central

Xiao, Chencheng; Ma, Wenjun; Sun, Na; Huang, Lihong; Li, Yaling; Zeng, Zhaoyong; Wen, Yijun; Zhang, Zaoyue; Li, Huanan; Li, Qian; Yu, Yuandi; Zheng, Yi; Liu, Shukai; Hu, Pingsheng; Zhang, Xu; Ning, Zhangyong; Qi, Wenbao; Liao, Ming

2016-01-01

Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts. PMID:26782141

X-ray diffraction analysis of 4- and 4'-substituted C n H2 n + 1O-C6H3(OH)-CH=N-C6H4-C m H2 m + 1 ( n/ m = 2/1 and 3/4) salicylideneanilines

NASA Astrophysics Data System (ADS)

Kuz'mina, L. G.; Navasardyan, M. A.; Mikhailov, A. A.

2017-11-01

X-ray diffraction study of two crystalline modifications of C2H5O-C6H3(OH)-CH=N-C6H4-CH3 ( 1a, sp. gr. P21/ n, and 1b, sp. gr. C2/c) and C3H7O-C6H3(OH)-CH=N-C6H4-C4H9 ( 2, sp. gr. P212121) has been performed. The 1a crystal structure contains two independent molecules. The molecules are conformationally nonrigid with respect to the mutual rotation of benzene rings; the dihedral angles between their planes are 29.19° and 26.00° in the independent molecules of 1a, 18.72° in the molecule of 1b, and 50.35° in the molecule of 2. The crystal packing of the compounds is discussed.

Bradykinin-potentiating PEPTIDE-10C, an argininosuccinate synthetase activator, protects against H2O2-induced oxidative stress in SH-SY5Y neuroblastoma cells.

PubMed

Querobino, Samyr Machado; Ribeiro, César Augusto João; Alberto-Silva, Carlos

2018-05-01

Bradykinin-potentiating peptides (BPPs - 5a, 7a, 9a, 10c, 11e, and 12b) of Bothrops jararaca (Bj) were described as argininosuccinate synthase (AsS) activators, improving l-arginine availability. Agmatine and polyamines, which are l-arginine metabolism products, have neuroprotective properties. Here, we investigated the neuroprotective effects of low molecular mass fraction from Bj venom (LMMF) and two synthetic BPPs (BPP-10c, cell line against H 2 O 2 -induced oxidative stress. The neuroprotective effects against H 2 O 2 -induced were analyzed by reactive oxygen species (ROS - DCFH) production; lipid peroxidation (TBARS); intracellular GSH; AsS, iNOS, and NF-kB expressions; nitrite levels (Griess); mitochondrial membrane potential (TMRM); and antioxidant activity (DPPH). Analysis of variance followed by Tukey's post hoc test were calculated for statistical comparisons. Pre-treatment with both BPPs significantly reduced cell death induced by H 2 O 2 , but BPP-10c showed higher protective capacity than BPP-12b. LMMF pretreatment was unable to prevent the reduction of cell viability caused by H 2 O 2 . The neuroprotective mechanism of BPP-10c against oxidative stress was investigated. BPP-10c reduced ROS generation and lipid peroxidation in relation to cells treated only with H 2 O 2 . BBP-10c increased AsS expression and was not neuroprotective in the presence of MDLA, a specific inhibitor of AsS. BPP-10c reduced iNOS expression and nitrate levels but decreased NF-kB expression. Furthermore, BPP-10c protected the mitochondrial membrane against oxidation. Overall, we demonstrated for the first time neuroprotective mechanisms of BPPs against oxidative stress, opening new perspectives to the study and application of these peptides for the treatment of neurodegenerative diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

The use of biodegradable PLGA nanoparticles to mediate SOX9 gene delivery in human mesenchymal stem cells (hMSCs) and induce chondrogenesis.

PubMed

Kim, Jae-Hwan; Park, Ji Sun; Yang, Han Na; Woo, Dae Gyun; Jeon, Su Yeon; Do, Hyun-Jin; Lim, Hye-Young; Kim, Jung Mo; Park, Keun-Hong

2011-01-01

In stem cell therapy, transfection of specific genes into stem cells is an important technique to induce cell differentiation. To perform gene transfection in human mesenchymal stem cells (hMSCs), we designed and fabricated a non-viral vector system for specific stem cell differentiation. Several kinds of gene carriers were evaluated with regard to their transfection efficiency and their ability to enhance hMSCs differentiation. Of these delivery vehicles, biodegradable poly (DL-lactic-co-glycolic acid) (PLGA) nanoparticles yielded the best results, as they complexed with high levels of plasmid DNA (pDNA), allowed robust gene expression in hMSCs, and induced chondrogenesis. Polyplexing with polyethylenimine (PEI) enhanced the cellular uptake of SOX9 DNA complexed with PLGA nanoparticles both in vitro and in vivo. The expression of enhanced green fluorescent protein (EGFP) and SOX9 increased up to 75% in hMSCs transfected with PEI/SOX9 complexed PLGA nanoparticles 2 days after transfection. SOX9 gene expression was evaluated by RT-PCR, real time-qPCR, glycosaminoglycan (GAG)/DNA levels, immunoblotting, histology, and immunofluorescence. Copyright © 2010 Elsevier Ltd. All rights reserved.

SETDB1 modulates PRC2 activity at developmental genes independently of H3K9 trimethylation in mouse ES cells

PubMed Central

Fei, Qi; Yang, Xiaoqin; Jiang, Hua; Wang, Qian; Yu, Yanyan; Yu, Yiling; Yi, Wei; Zhou, Shaolian; Chen, Taiping; Lu, Chris; Atadja, Peter; Liu, Xiaole Shirley; Li, En; Zhang, Yong; Shou, Jianyong

2015-01-01

SETDB1, a histone methyltransferase responsible for methylation of histone H3 lysine 9 (H3K9), is involved in maintenance of embryonic stem (ES) cells and early embryonic development of the mouse. However, how SETDB1 regulates gene expression during development is largely unknown. Here, we characterized genome-wide SETDB1 binding and H3K9 trimethylation (H3K9me3) profiles in mouse ES cells and uncovered two distinct classes of SETDB1 binding sites, termed solo and ensemble peaks. The solo peaks were devoid of H3K9me3 and enriched near developmental regulators while the ensemble peaks were associated with H3K9me3. A subset of the SETDB1 solo peaks, particularly those near neural development–related genes, was found to be associated with Polycomb Repressive Complex 2 (PRC2) as well as PRC2-interacting proteins JARID2 and MTF2. Genetic deletion of Setdb1 reduced EZH2 binding as well as histone 3 lysine 27 (H3K27) trimethylation level at SETDB1 solo peaks and facilitated neural differentiation. Furthermore, we found that H3K27me3 inhibits SETDB1 methyltransferase activity. The currently identified reciprocal action between SETDB1 and PRC2 reveals a novel mechanism underlying ES cell pluripotency and differentiation regulation. PMID:26160163

Meridional Variations of C2H2 and C2H6 in Jupiter's Atmosphere from Cassini CIRS Infrared Spectra

NASA Technical Reports Server (NTRS)

Nixon, C. A.; Achterberg, R. K.; Conrath, B. J.; Irwin, P. G. J.; Fouchet, T.; Parrish, P. D.; Romani, P. N.; Abbas, M.; LeClair, A.; Strobel, D.

2004-01-01

Hydrocarbons such as acetylene (C2H2) and ethane (C2H6) are important tracers in Jupiter's atmosphere, constraining our models of the chemical and dynamical processes. However, our knowledge of the vertical and meridional variations of their abundances has remained sparse. During the flyby of the Cassini spacecraft in December 2000, the Composite Infrared Spectrometer (CIRS) instrument was used to map the spatial variation of emissions from 10-1400 cm(sup -1) (1000-7 microns). In this paper we analyze a zonally-averaged set of CIRS spectra taken at the highest (0.5 cm(sup -1)) resolution, to infer atmospheric temperatures in the stratosphere at 0.5-20 mbar via the v4 band of CH4, and in the troposphere at 150-400 mbar, via the H2 absorption at 600-800 cm(sup -1). Simultaneously, we retrieve the abundances of C2H2 and C2H6 via the v5 and vg bands respectively. Tropospheric absorption and stratospheric emission are highly anti-correlated at the CIRS resolution, introducing a non-uniqueness into the retrievals, such that vertical gradient and column abundance cannot both be found without additional constraints. Assuming profile gradients from photochemical calculations, we show that the column abundance of C2H2 decreases sharply towards the poles by a factor approximately 4, while C2H6 is unchanged in the north and increasing in the south, by a factor approximately 1.8. An explanation for the meridional trends is proposed in terms of a combination of photochemistry and dynamics. Poleward, the decreasing UV flux is predicted to decrease the abundances of C2H2 and C2H6 by factors 2.7 and 3.5 respectively at a latitude 70 deg. However, the lifetime of C2H6 in the stratosphere (5 x 10(exp 9)) is much longer than the dynamical timescale for meridional motions inferred from SL-9 debris (5 x 10(exp 8 s)), and therefore the constant or rising abundance towards high latitudes likely indicates that meridional mixing dominates over photochemical effects. For C2H2, the opposite

A polysaccharide of Dendrobium officinale ameliorates H2O2-induced apoptosis in H9c2 cardiomyocytes via PI3K/AKT and MAPK pathways.

PubMed

Zhang, Jing-Yi; Guo, Ying; Si, Jin-Ping; Sun, Xiao-Bo; Sun, Gui-Bo; Liu, Jing-Jing

2017-11-01

Dendrobium officinale is one valuable traditional Chinese medicine, which has skyscraping medicinal value. Polysaccharide is the main active ingredient in D. officinale; its antioxidant activity is a hot research topic nowadays. Oxidative stress plays an important role in the pathological progress of a variety of cardiovascular disease, as one of key factors of cardiomyocyte apoptosis. This research adopts a model of H 2 O 2 induction-H9c2 cardiomyocytes apoptosis, aiming to study the effect of Dendrobium officinale Polysaccharide (DOP-GY) for cardiomyocyte apoptosis caused by oxidative stress and its possible mechanism. Our results showed that pretreatment of DOP-GY (low dose: 6.25μg/mL, medium dose: 12.5μg/mL, high dose: 25μg/mL) followed by a 2h incubation with 200μM H 2 O 2 elevated the survival rate, cutted the LDH leakage, reduced lipid peroxidation damage, improved the activity of the endogenous antioxidant enzymes. In addition, the pretreatment of DOP-GY significantly inhibited the production of ROS, declined of the mitochondrial membrane potential, down-regulated pro-apoptosis protein and up-regulated anti-apoptosis protein. The protective effect was correlated with the PI3K/Akt and MAPK signal pathway. Collectively, these observations suggest that DOY-GY has the potential to exert cardioprotective effects against H 2 O 2 -induced H9c2 cardiomyocyte apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

IFIT1 Expression Patterns Induced by H9N2 Virus and Inactivated Viral Particle in Human Umbilical Vein Endothelial Cells and Bronchus Epithelial Cells.

PubMed

Feng, Bo; Zhang, Qian; Wang, Jianfang; Dong, Hong; Mu, Xiang; Hu, Ge; Zhang, Tao

2018-04-30

IFIT1 (also known as ISG56) is a member of the interferon-inducible protein with tetratricopeptide repeats (IFITs) family. IFITs are strongly induced by type I interferon (IFN), double-stranded RNA and virus infection. Here, we investigated IFIT1 expression in human umbilical vein endothelial cells (HUVECs) and in human bronchus epithelial cells (BEAS-2Bs) induced by the H9N2 virus and inactivated viral particle at different time points. We also investigated the effect of H9N2 virus and viral particle infection on IFN-α/β production, and assessed whether hemagglutinin or neuraminidase protein induced IFIT1 expression. Results showed that both H9N2 virus infection and viral particle inoculation induced the expression of IFIT1 at mRNA and protein levels in the two cell lines. Hemagglutinin or neuraminidase protein binding alone is not sufficient to induce IFIT1 expression. Surprisingly, the expression patterns of IFIT1 in response to H9N2 virus and viral particles in the two cell lines were opposite, and production kinetics of IFN-α/β also differed. An additional finding was that induction of IFIT1 in response to H9N2 virus infection or viral particle inoculation was more sensitive in HUVECs than in BEAS-2Bs. Our data offers new insight into the innate immune response of endothelial cells to H9N2 virus infection.

IFIT1 Expression Patterns Induced by H9N2 Virus and Inactivated Viral Particle in Human Umbilical Vein Endothelial Cells and Bronchus Epithelial Cells

PubMed Central

Feng, Bo; Zhang, Qian; Wang, Jianfang; Dong, Hong; Mu, Xiang; Hu, Ge; Zhang, Tao

2018-01-01

IFIT1 (also known as ISG56) is a member of the interferon-inducible protein with tetratricopeptide repeats (IFITs) family. IFITs are strongly induced by type I interferon (IFN), double-stranded RNA and virus infection. Here, we investigated IFIT1 expression in human umbilical vein endothelial cells (HUVECs) and in human bronchus epithelial cells (BEAS-2Bs) induced by the H9N2 virus and inactivated viral particle at different time points. We also investigated the effect of H9N2 virus and viral particle infection on IFN-α/β production, and assessed whether hemagglutinin or neuraminidase protein induced IFIT1 expression. Results showed that both H9N2 virus infection and viral particle inoculation induced the expression of IFIT1 at mRNA and protein levels in the two cell lines. Hemagglutinin or neuraminidase protein binding alone is not sufficient to induce IFIT1 expression. Surprisingly, the expression patterns of IFIT1 in response to H9N2 virus and viral particles in the two cell lines were opposite, and production kinetics of IFN-α/β also differed. An additional finding was that induction of IFIT1 in response to H9N2 virus infection or viral particle inoculation was more sensitive in HUVECs than in BEAS-2Bs. Our data offers new insight into the innate immune response of endothelial cells to H9N2 virus infection. PMID:29629559

Enhancement of C2C12 differentiation by perfluorocarbon-mediated oxygen delivery.

PubMed

Fujita, Hideaki; Shimizu, Kazunori; Morioka, Yuki; Nagamori, Eiji

2010-09-01

We have studied the effect of enhanced oxygen delivery by perfluorocarbons on the differentiation of C2C12 cells. The extent of differentiation was assessed by means of phase contrast/fluorescence microscopy, active tension measurement and the glucose consumption/lactate production rates. We found that enhanced oxygen delivery is suitable for full differentiation of C2C12 cells. Copyright 2010 The Society for Biotechnology, Japan. All rights reserved.

Diselenophosphate-Induced Conversion of an Achiral [Cu 20 H 11 {S 2 P(O i Pr) 2 } 9 ] into a Chiral [Cu 20 H 11 {Se 2 P(O i Pr) 2 } 9 ] Polyhydrido Nanocluster

DOE PAGES

Dhayal, Rajendra S.; Liao, Jian-Hong; Wang, Xiaoping; ...

2015-11-09

A polyhydrido copper nanocluster, [Cu 20H 11{Se 2P(OiPr) 2} 9] (2 H), which exhibits an intrinsically chiral inorganic core of C-3 symmetry, was synthesized from achiral [Cu 20H 11{S 2P(OiPr) 2} 9] (1(H)) of C-3h symmetry by a ligand-exchange method. Likewise, the structure has a distorted cuboctahedral Cu-13 core, two triangular faces of which are capped along the C-3 axis, one by a Cu-6 cupola and the other by a single Cu atom. The Cu-20 framework is further stabilized by 9 diselenophosphate and 11 hydride ligands. The number of hydride, phosphorus, and selenium resonances and their splitting patterns in multinuclearmore » NMR spectra of 2(H) indicate that the chiral Cu20H11 core retains its C-3 symmetry in solution. Moreover, the 11 hydride ligands were located by neutron diffraction experiments and shown to be capping (3)-H and interstitial (5)-H ligands (in square-pyramidal and trigonal-bipyramidal cavities), as supported by DFT calculations on [Cu 20H 11(Se 2PH 2) 9] (2 H') as a simplified model.« less

Hydrogenation and Deuteration of C{sub 2}H{sub 2} and C{sub 2}H{sub 4} on Cold Grains: A Clue to the Formation Mechanism of C{sub 2}H{sub 6} with Astronomical Interest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobayashi, Hitomi; Kawakita, Hideyo; Hidaka, Hiroshi

We quantitatively investigated the hydrogen addition reactions of acetylene (C{sub 2}H{sub 2}) and ethylene (C{sub 2}H{sub 4}) on amorphous solid water (ASW) at 10 and 20 K relevant to the formation of ethane (C{sub 2}H{sub 6}) on interstellar icy grains. We found that the ASW surface enhances the reaction rates for C{sub 2}H{sub 2} and C{sub 2}H{sub 4} by approximately a factor of 2 compared to those on the pure-solid C{sub 2}H{sub 2} and C{sub 2}H{sub 4} at 10 K, probably due to an increase in the sticking coefficient and adsorption energy of the H atoms on ASW. In contrastmore » to the previous proposal that the hydrogenation rate of C{sub 2}H{sub 4} is orders of magnitude larger than that of C{sub 2}H{sub 2}, the present results show that the difference in hydrogenation rates of C{sub 2}H{sub 2} and C{sub 2}H{sub 4} is only within a factor of 3 on both the surfaces of pure solids and ASW. In addition, we found the small kinetic isotope effect for hydrogenation/deuteration of C{sub 2}H{sub 2} and C{sub 2}H{sub 4} at 10 K, despite the requirement of quantum tunneling. At 20 K, the reaction rate of deuteration becomes even larger than that of hydrogenation. These unusual isotope effects might originate from a slightly larger number density of D atoms than H atoms on ASW at 20 K. The hydrogenation of C{sub 2}H{sub 2} is four times faster than CO hydrogenation and can produce C{sub 2}H{sub 6} efficiently through C{sub 2}H{sub 4} even in the environment of a dark molecular cloud.« less

Arsenic silences hepatic PDK4 expression through activation of histone H3K9 methylatransferase G9a

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xi; Wu, Jianguo; Choiniere, Jonathan

It is well established that increased liver cancer incidence is strongly associated with epigenetic silencing of tumor suppressor genes; the latter is contributed by the environmental exposure to arsenic. Pyruvate dehydrogenase kinase 4 (PDK4) is a mitochondrial protein that regulates the TCA cycle. However, the epigenetic mechanisms mediated by arsenic to control PDK4 expression remain elusive. In the present study, we showed that histone methyltransferase G9a- and Suv39H-mediated histone H3 lysine 9 (H3K9) methylations contributed to PDK4 silencing in hepatic cells. The PDK4 expression was induced by G9a inhibitor BRD4770 (BRD) and Suv39H inhibitor Chaetocin (CHA). In contrast, arsenic exposuremore » decreased PDK4 expression by inducing G9a and increasing H3K9 di- and tri-methylations levels (H3K9me2/3). In addition, arsenic exposure antagonizes the effect of BRD by enhancing the enrichment of H3K9me2/3 in the PKD4 promoter. Moreover, knockdown of G9a using siRNA induced PDK4 expression in HCC cells. Furthermore, arsenic decreased hepatic PDK4 expression as well as diminished the induction of PDK4 by BRD in mouse liver and hepatocytes. Overall, the results suggest that arsenic causes aberrant repressive histone modification to silence PDK4 in both HCC cells and in mouse liver. - Graphical abstract: Schematic showing arsenic-mediated epigenetic pathway that inhibits PDK4 expression. (A) BRD induces PDK4 expression by decreasing G9a protein and histone H3K9me2 and H3K9me3 levels as well as diminishing their recruitment to the PDK4 promoter. (B) Arsenic counteracts the effect of BRD by increasing histone H3K9me2 and H3K9me3 levels as well as enhancing their enrichment to the PDK4 promoter. Display Omitted - Highlights: • Histone methyltrasferase G9a inhibitor BRD induces PDK4 expression. • Arsenic decreases PDK4 expression and increases H3K9me2 and me3 levels. • Arsenic enhances H3K9me2/me3 enrichment in the PDK4 promoter. • Arsenic antagonizes the

PPARδ activation protects H9c2 cardiomyoblasts from LPS‑induced apoptosis through the heme oxygenase‑1‑mediated suppression of NF‑κB activation.

PubMed

Shi, Yao; Jiang, Hong; Yang, Xiaobo

2017-06-01

The aim of the present study was to investigate the protective effect of the selective peroxisome proliferator-activated receptor δ (PPARδ) agonist GW501516 (GW) on lipopolysaccharide (LPS)‑induced apoptosis in the rat cardiomyoblast cell line H9c2, and to investigate the possible underlying mechanisms. Cell viability was estimated using the MTT assay. Apoptosis was estimated by flow cytometry using Annexin V‑fluorescein isothiocyanate/propidium iodide staining and caspase‑3 activity assay. The protein level of heme oxygenase‑1 (HO‑1), cleaved caspase‑3 (CC3), apoptosis regulator Bcl‑2 (bcl‑2), apoptosis regulator BAX (bax) and nuclear factor‑κB (NF‑κB) p65 was measured by western blot analysis. The results demonstrated that pretreatment with GW inhibited the LPS‑induced increase in the rate of apoptosis. Pretreatment with GW also increased the bcl‑2/bax ratio, and decreased CC3 protein expression as well as caspase‑3 activity, in LPS‑stimulated H9c2 cells. Further studies demonstrated that GW inhibited LPS‑induced NF‑κB nuclear translocation in a dose‑dependent manner. In addition, GW induced HO‑1 protein expression in a dose‑dependent manner. ZnPP‑IX, an inhibitor of HO‑1, reversed the inhibitory effect of GW on LPS‑induced NF‑κB activation, leading to the attenuation of PPARδ‑mediated apoptosis resistance. In conclusion, these results suggest that PPARδ activation exerts an anti‑apoptotic effect in LPS‑stimulated H9c2 cardiomyoblasts, potentially through heme oxygenase‑1‑mediated suppression of NF‑κB activation. PPARδ appears to be a promising therapeutic target for the treatment of sepsis‑associated cardiac dysfunction.

H9N2-specific IgG and CD4+CD25+ T cells in broilers fed a diet supplemented with organic acids.

PubMed

Lee, In Kyu; Bae, Suhan; Gu, Min Jeong; You, Sun Jong; Kim, Girak; Park, Sung-Moo; Jeung, Woon-Hee; Ko, Kwang Hyun; Cho, Kyung Jin; Kang, Jung Sun; Yun, Cheol-Heui

2017-05-01

Organic acids have long been known for their beneficial effects on growth performance in domestic animals. However, their impact on immune responses against viral antigens in chickens is unclear. The present study aimed to investigate immunological parameters in broilers immunized with a H9N2 vaccine and/or fed a diet containing organic acids (citric, formic, and lactic acids). We allotted 1-day-old broilers into 4 groups: control (C), fed a diet supplemented with organic acids (O), administered a H9N2 vaccine (V), and fed a diet supplemented with organic acids and administered a H9N2 vaccine (OV). Blood and spleen samples were taken at 2, 7 and 14 d post vaccination (DPV). At 14 DPV, total and H9N2-specific IgG levels were significantly lower in the OV group than in the V group. However, it was intriguing to observe that at 2 DPV, the percentage of CD4+CD25+ T cells was significantly higher in the OV group than in the other groups, indicating the potential induction of regulatory T cells by organic acids. In contrast, at 2 DPV, the percentage of CD4+CD28+ T cells were significantly lower in the OV group than in the other groups, suggesting that CD28 molecules are down-regulated by the treatment. The expression of CD28 on CD4+ T cells, up-regulated by the stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin (Iono), was inhibited upon organic acid treatment in OV group. In addition, the proliferation of lymphocytes, stimulated with formalin-inactivated H9N2, was significantly higher in the V group than in the OV group. Alpha 1-acid glycoprotein (AGP) production was significantly lower in the OV group than in the V group, suggesting that the organic acids inhibited the inflammation caused by the vaccination. Overall, induction of regulatory CD4+CD25+ T cells, coinciding with the decrease of H9N2-specific antibodies, was observed in broilers fed organic acids. © 2016 Poultry Science Association Inc.

KEY COMPARISON: Final report on CCQM-K9.2: Subsequent key comparison on pH determination of phosphate buffer by Harned cell measurements

NASA Astrophysics Data System (ADS)

Spitzer, Petra; Giera, Janine; Fraga, Isabel C.; Tønnes Jakobsen, Pia; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina

2008-01-01

CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were 15 °C, 25 °C, 37 °C. CCQM-K9.2, CCQM-K.9 and the first supplementary comparison CCQM-K9.1 [5] are activities of the Electrochemical Working Group (EAWG) of the CCQM. All three comparisons were coordinated by the PTB, Germany. The Danish Primary Laboratory (DPL) successfully took part in the CCQM-K9. Meanwhile the primary set-up for pH in Denmark moved from DPL affiliated to Radiometer Medical to DFM, Denmark. The subsequent comparison allows assessing the degree of equivalence for the measurement of pH at DFM after the move. Due to the interest of other laboratories in demonstrating their progress in pH measurements on the primary level the CCQM-K9.2 supplementary comparison was extended to other participants than DFM, namely NMIJ, VNIIFTRI, INMETRO and CMI. The reported quantity for CCQM-K9.2 was not the pH of the sample but the acidity function at zero chloride molality (see chapter 12). To calculate the pH value from the acidity function it is necessary to know the ionic strength of the sample buffer solution, which was undisclosed by the coordinator. With the exception of the Czech Metrology Institute, CMI, good agreement in the determined acidity function is found between the participants. The results reported by DFM and by PTB agree within their measurement uncertainty at all measurement temperatures. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report

The role of immune cell subpopulations in the growth and rejection of TC-1/A9 tumors in novel mouse strains differing in the H2-D haplotype and NKC domain.

PubMed

Indrová, Marie; Rossowska, Joanna; Pajtasz-Piasecka, Elzbieta; Mikyšková, Romana; Richter, Jan; Rosina, Jozef; Sedlacek, Radislav; Fišerová, Anna

2018-03-01

The present study aimed to elucidate the role of cluster of differentiation (CD)8+, CD4+, natural killer (NK), and myeloid (CD11b+) cells in the course of the growth and rejection of experimental major histocompatibility complex (MHC) class I-deficient, HPV16 E6/E7-associated TC-1/A9 tumors in mice. Stable mouse lines (F 30 ) generated by inbreeding of Balb/c and C57BL/6 strains, which were characterized by H-2Db+d-NK1.1neg (B6-neg) and H-2Db-d+NK1.1high (Balb-high) phenotypes, were used for the present study. The novel strains spontaneously regressed tumors in 70-90% of cases. Ex vivo histological analysis of the tumor microenvironment in cryosections showed an indirect correlation between the growth of the transplanted tumor (progressor vs. regressor mice) and the proportion of immunocompetent cell infiltration in the tumors. The regressor mice exhibited a higher infiltration of tumors with CD4+ and CD8+ cells, and in Balb-high with NK cells as well, compared with the progressors. All tumor transplants also indicated a huge infiltration of CD11b+ cells, but this infiltration was not dependent on the stage of the TC-1/A9 tumor development. Depletion of individual cell subpopulations in vivo exhibited different effects on the tumor development in the two strains. Elimination of CD8-positive cells enhanced growth of TC-1/A9 tumor transplants in both hybrid stains, whereas CD4+ cell depletion affected rejection of TC-1/A9 tumors in the B6-neg mice only. Depletion of NK cells with anti-asialo GM1 antibody in the Balb-high strain led to enhancement of tumor growth, which was more pronounced after depletion of the NK1.1+ subpopulation. On the other hand, depletion of NK cells with anti-asialo GM1 in B6-neg mice did not affect the regression of TC-1/A9 tumor transplants, but increased the CD11b+ cell infiltration. In summary, these results indicate that co-operation of particular subsets of immunocompetent cells is essential for the rejection of TC-1/A9 tumor transplants

Absence of PDGF-induced, PKC-independent c-fos expression in a chemically transformed C3H/10T1/2 cell clone.

PubMed

Vassbotn, F S; Skar, R; Holmsen, H; Lillehaug, J R

1992-09-01

The effect of platelet-derived growth factor (PDGF) on c-fos mRNA transcription was studied in the immortalized mouse embryo fibroblast C3H/10T1/2 Cl 8 (10T1/2) cells and the chemically transformed, tumorigenic subclone C3H/10T1/2 Cl 16 (Cl 16). In the 10T1/2 cells as well as the Cl 16 subclone, the dose-dependent PDGF stimulation of c-fos mRNA synthesis was similar in both logarithmically growing and confluent cultures. c-fos mRNA was induced severalfold by 12-O-tetradecanoylphorbol-13-acetate (TPA) in both 10T1/2 and Cl 16. Down-regulation of protein kinase C (PKC) activity by TPA pretreatment inhibited PDGF-stimulated c-fos mRNA expression in Cl 16 cells but did not affect this induction in the 10T1/2 cells. This inhibition was not a general phenomenon of 3-methylcholanthrene-mediated transformation of 10T1/2 cells since experiments with another transformed 10T1/2 cell clone, C3H/10T1/2 TPA 482, gave qualitatively the same results as the 10T1/2 cells. Receptor binding experiments showed that the nontransformed and transformed cells had a comparable number of PDGF receptors, 1.3 x 10(5) and 0.7 x 10(5) receptors per cell, respectively. Furthermore, cAMP-induced c-fos expression induced by forskolin is formerly shown to be independent of PKC down-regulation. In our experiments, forskolin induced c-fos expression in both clones. However, PKC down-regulation inhibited the forskolin-induced c-fos expression in Cl 16 cells. This apparently demonstrates cross talk between PKC and PKA in the c-fos induction pathway. The present results provide evidence for an impaired mechanism for activating c-fos expression through PKC-independent, PDGF-induced signal transduction in the chemically transformed Cl 16 fibroblasts compared to that in nontransformed 10T1/2 cells.

Enhancement in c-Si solar cells using 16 nm InN nanoparticles

NASA Astrophysics Data System (ADS)

Imtiaz Chowdhury, Farsad; Alnuaimi, Aaesha; Alkis, Sabri; Ortaç, Bülend; Aktürk, Selçuk; Alevli, Mustafa; Dietz, Nikolaus; Kemal Okyay, Ali; Nayfeh, Ammar

2016-05-01

In this work, 16 nm indium nitride (InN) nanoparticles (NPs) are used to increase the performance of thin-film c-Si HIT solar cells. InN NPs were spin-coated on top of an ITO layer of c-Si HIT solar cells. The c-Si HIT cell is a stack of 2 μm p type c-Si, 4-5 nm n type a-Si, 15 nm n+ type a-Si and 80 nm ITO grown on a p+ type Si substrate. On average, short circuit current density (Jsc) increases from 19.64 mA cm-2 to 21.54 mA cm-2 with a relative improvement of 9.67% and efficiency increases from 6.09% to 7.09% with a relative improvement of 16.42% due to the presence of InN NPs. Reflectance and internal/external quantum efficiency (IQE/EQE) of the devices were also measured. Peak EQE was found to increase from 74.1% to 81.3% and peak IQE increased from 93% to 98.6% for InN NPs coated c-Si HIT cells. Lower reflection of light due to light scattering is responsible for performance enhancement between 400-620 nm while downshifted photons are responsible for performance enhancement from 620 nm onwards.

Experimental ion mobility measurements in Xe-C2H6

NASA Astrophysics Data System (ADS)

Perdigoto, J. M. C.; Cortez, A. F. V.; Veenhof, R.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

2017-10-01

In this paper we present the results of the ion mobility measurements made in gaseous mixtures of xenon (Xe) with ethane (C2H6) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 Td to 25 Td range (2.4-6.1 kVṡcm-1ṡ bar-1), at room temperature. The time of arrival spectra revealed two peaks throughout the entire range studied which were attributed to ion species with 3-carbons (C3H5+, C3H6+ C3H8+ and C3H9+) and with 4-carbons (C4H7+, C4H9+ and C4H10+). Besides these, and for Xe concentrations above 70%, a bump starts to appear at the right side of the main peak for reduced electric fields higher than 20 Td, which was attributed to the resonant charge transfer of C2H6+ to C2H6 that affects the mobility of its ion products (C3H8+ and C3H9+). The time of arrival spectra for Xe concentrations of 20%, 50%, 70% and 90% are presented, together with the reduced mobilities as a function of the Xe concentration calculated from the peaks observed for the low reduced electric fields and pressures studied.

Human galectin-9 on the porcine cells affects the cytotoxic activity of M1-differentiated THP-1 cells through inducing a shift in M2-differentiated THP-1 cells.

PubMed

Jung, Sung Han; Hwang, Jeong Ho; Kim, Sang Eun; Kim, Young Kyu; Park, Hyo Chang; Lee, Hoon Taek

2017-07-01

In xenotransplantation, immune rejection by macrophages occurs rapidly and remains a major obstacle. Studies to control immune rejection in macrophages have been continuing to date. Recent studies have reported that human galectin-9 (hGal-9) can regulate the function of regulatory T cells (Treg), as well as cytotoxicity T cells (CTL) and natural killer cells (NK). Although the effect of hGal-9 on lymphocytes has been well studied, the relationship between hGal-9 and myeloid cells has been scarcely studied. To confirm the decreased cytotoxic activity effect by hGal-9 in M1-differentiated THP-1 cells, we established the hGal-9 expressing transgenic porcine cell line. hGal-9 siRNA was transfected to transgenic cells and recombinant hGal-9 (rhGal-9) was treated to co-culturing condition, and then, flow cytometry assay was conducted for analyzing the cytotoxic activity of M1-differentiated THP-1 cells. Related inflammatory cytokines (IL-1β, IL-10, TNF-α, IL-6, IL-12, IL-23, and TGF-β) and related enzymes (iNOS and Arginase 1) were analyzed by qPCR and Western blot assay. To identify the shift in M1/M2-differentiated THP-1 cells, expression levels of CCR7, CD163, iNOS, and Arginase 1 and population of M2 marker positive cells were analyzed. The expression levels of pro-inflammatory cytokines in M1-differentiated THP-1 cells co-cultured with hGal-9-expressing porcine kidney epithelial cells were decreased, but not in co-cultured THP-1 cells. However, the expression levels of anti-inflammatory cytokines were also increased in co-cultured M1-differentiated THP-1 cells. The cytotoxicity effect of M1-differentiated THP-1 cells on transgenic cells was decreased while the expression levels of anti-inflammatory cytokines and M2 macrophages-related molecules were increased. M2 differentiation program was turned on while M1 program was turned down by enhancing the phosphorylation levels of Akt and PI3K and the expression level of PPAR-γ. Due to these changes, differentiation

GSK-3β promotes PA-induced apoptosis through changing β-arrestin 2 nucleus location in H9c2 cardiomyocytes.

PubMed

Chang, Fen; Liu, Jing; Fu, Hui; Wang, Jinlan; Li, Fang; Yue, Hongwei; Li, Wenjing; Zhao, Jing; Yin, Deling

2016-09-01

Palmitic acid (PA), a type of saturated fatty acids, induces cardiovascular diseases by causing cardiomyocyte apoptosis with unclear mechanisms. Akt participates in PA-induced cardiomyocyte apoptosis. GSK-3β is a substrate of Akt, we investigated its role in PA-induced apoptosis. We reveal that PA inhibits GSK-3β phosphorylation accompanied by inactivation of Akt in H9c2 cardiomyocytes. We also reveal that inhibition the activity of GSK-3β by its inhibitor LiCl or knockdown by siRNA significantly attenuates PA-induced cardiomyocyte apoptosis, this suggesting that GSK-3β plays a pro-apoptotic role. To detect its downstream factors, we analyzed the roles of JNK, p38 MAPK and β-arrestin 2 (β-Arr2). Here, we report that GSK-3β regulate PA-induced cardiomyocyte apoptosis by affecting the distribution of β-Arr2. PA diminishes the protein level of β-Arr2 and changes its distribution from nucleus to cytoplasm. Either inhibition of β-Arr2 by its siRNA or overexpression of its protein level by transfection of β-Arr2 full-length plasmid promotes PA-induced cardiomyocyte apoptosis, which remind us to focus on the changes of its location. β-Arr2 siRNA decreased the background level of β-Arr2 in nucleus in normal H9c2 cells. Overexpression of β-Arr2 increased cytoplasm level of β-Arr2 as PA did. While LiCl, the inhibitor of GSK-3β decreased PA-induced apoptosis, accompany with increased nucleus level of β-Arr2. Then we concluded that GSK-3β is closely associated with cardiomyocyte apoptosis induced by PA, it performs its pro-apoptotic function by affecting the location of β-Arr2. LiCl inhibits PA-induced cardiomyocyte apoptosis, which might provide novel therapeutic for cardiovascular diseases induced by metabolic syndrome.

Enhanced photocatalytic H2-production activity of C-dots modified g-C3N4/TiO2 nanosheets composites.

PubMed

Li, Yang; Feng, Xionghan; Lu, Zhexue; Yin, Hui; Liu, Fan; Xiang, Quanjun

2018-03-01

As a new carbon-based material, carbon dots (C-dots) have got widely preference because of its excellent electronic transfer capability. In this work, a novel ternary layered C-dots/g-C 3 N 4 /TiO 2 nanosheets (CGT) composite photocatalysts were prepared by impregnation precipitation methods. The optimal ternary CGT composite samples revealed high photocatalytic hydrogen evolution rate in triethanolamine aqueous solutions, which exceeded the rate of the optimal g-C 3 N 4 /TiO 2 composite sample by a factor of 5 times. The improved photocatalytic activity is owed to the positive effects of C-dots and layered heterojunction structure of TiO 2 nanosheets and g-C 3 N 4 sheets. C-dots in the CGT composites can serve as electron reservoirs to capture the photo-induced electrons. The well-defined layered heterojunction structure of CGT provides the intimate contact and the strong interaction of anatase TiO 2 nanosheets and g-C 3 N 4 sheets via face-to-face orientation, which restrains the recombination of photogenerated charge carriers, and thus enhances the photocatalytic H 2 -production activity. Electron paramagnetic resonance and transient photocurrent response proved the strong interaction and improved interfacial charge transfer of TiO 2 nanosheets and g-C 3 N 4 sheets, respectively. The mechanism of improving the photocatalytic H 2 -evolution activity was further confirmed by time-resolved fluorescence, electron paramagnetic resonance, transient photocurrent response and electrochemical impedance spectroscopy. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel reassortant H9N2 viruses in pigeons and evidence for antigenic diversity of H9N2 viruses isolated from quails in Egypt.

PubMed

Kandeil, Ahmed; El-Shesheny, Rabeh; Maatouq, Asmaa; Moatasim, Yassmin; Cai, Zhipeng; McKenzie, Pamela; Webby, Richard; Kayali, Ghazi; Ali, Mohamed A

2017-04-01

The endemicity of avian influenza viruses (AIVs) among Egyptian poultry represents a public health risk. Co-circulation of low pathogenic AIV H9N2 subtype with highly pathogenic AIV H5N1 subtype in Egyptian farms provides a possibility to generate novel reassortant viruses. Here, the genetic characteristics of surface glycoproteins of 59 Egyptian H9N2 viruses, isolated between 2013 and 2015, were analysed. To elucidate the potential of genetic reassortment, 10 H9N2 isolates were selected based on different avian hosts (chickens, ducks, pigeons and quails) and phylogenetic analyses of their full genome sequences were conducted. Additionally, we performed antigenic analysis to further investigate the antigenic evolution of H9N2 viruses isolated during 2011-2015. Different viral characteristics including receptor-binding affinity and drug resistance of representative Egyptian H9N2 viruses were further investigated. The surface glycoproteins of current Egyptian H9N2 viruses were closely related to viruses of the G1-like lineage isolated from Egypt. Several genetic markers that enhance virulence in poultry and transmission to humans were detected. Analysis of the full genome of 10 H9N2 isolates indicated that two pigeon isolates inherited five internal genes from Eurasian AIVs circulating in wild birds. Antigenic conservation of different Egyptian H9N2 isolates from chickens, pigeons and ducks was observed, whereas quail isolates showed antigenic drift. The Egyptian H9N2 viruses preferentially bound to the human-like receptor rather than to the avian-like receptor. Our results suggest that the endemic H9N2 viruses in Egypt contain elements that may favour avian-to-human transmission and thus represent a public health risk.