Nardosinone Protects H9c2 Cardiac Cells from Angiotensin Ⅱ-induced Hypertrophy

Pathological cardiac hypertrophy induced by angiotensin Ⅱ （Ang Ⅱ ） can subsequently give rise to heart failure, a leading cause of mortality. Nardosinone is a pharmacologically active compound extracted from the roots ofNardostachys chinensis, a well-known traditional Chinese medicine. In order to investigate the effects of nardosinone on Ang Ⅱ-induced cardiac cell hypertrophy and the related mechanisms, the myoblast cell line H9c2, derived from embryonic rat heart, was treated with nardosi- none （25, 50, 100, and 200μmol/L） or Ang Ⅱ （1 μmol/L）. Then cell surface area and mRNA expression of classical markers of hypertrophy were detected. The related protein levels in PI3K/Akt/mTOR and MEK/ERK signaling pathways were examined by Western blotting. It was found that pretreatment with nardosinone could significantly inhibit the enlargement of cell surface area induced by Ang Ⅱ. The mRNA expression of ANP, BNP and 13-MHC was obviously elevated in Ang Ⅱ-treated H9c2 cells, which could be effectively blocked by nardosinone at the concentration of 100μmol/L. Further study revealed that the protective effects of nardosinone might be mediated by repressing the phosphorylation of related proteins in PI3K/Akt and MEK/ERK signaling pathways. It was suggested that the inhibitory effect of nardosinone on Ang Ⅱ-induced hypertrophy in H9c2 cells might be mediated by targeting PI3K/Akt and MEK/ERK signaling pathways.

Paeoniflorin reduces cardiotoxicity of aconitine in H9c2 cells

OBJECTIVE Aconitine(ACO)as the main active component in Aconitum carmichaelii debeaux(family Ranunlaceae),has highly toxicity in heart and the mechanisms are not clear yet.Paeoniflorin(PF),the main chemical ingredient in Herbaceous peony,can protect heart hurt by antioxidant,vasodilator effect and other effects.In this study,we focused on investigating the mechanism of PF reducing the cardiotoxicity of ACO.METHODS We chose H9c2 cells as experimental subject.MTT,Western blotting and real-time PCR were used to measure cell proliferation,apoptosis,ion channels and oxidative stress.RESULTS Cell proliferation in ACO+PF group was significantly increased compared with ACO group;the ratio with Bcl-2 and Bax and the level of p53 were upregulated by PF,while the level of caspase-3 was lightly reduced.The expression of SCN5A mRNA significantly was increased in ACO+PF group,while the expres⁃sion of RyR2 and Cx43 mRNA was dropped.Compared with ACO group,extracellular LDH and intracellular MDA were highly decreased,while intracellular SOD was regulated.CONCLUSION Cardiotoxicity of ACO in H9c2 cells was signifi⁃cantly decreased by PF.

Hyperbaric oxygen protects against PC12 and H9C2 cell damage caused by oxygen-glucose deprivation/reperfusion via the inhibition of cell apoptosis and autophagy

In this study,we investigated the protective effect of hyperbaric oxygen(HBO)on PC12 and H9C2 cell damage caused by oxygen-glucose deprivation/reperfusion and its possible mechanism.PC12 and H9C2 cell oxygen-glucose deprivation/reperfusion model were established.Cells were divided into a control group,model group,hyperbaric air(HBA)group and HBO group.The cell viability was detected by the CCK8 assay.Hoechst 33342 and PI staining assays and mitochondrial membrane potential(MMP)assays were used to detect cell apoptosis.The ultrastructure of cells,including autophagosomes,lysosomes,and apoptosis,were examined using a transmission electron microscope.The expression of autophagy-related proteins was detected by cellular immunofluorescence and immunocytochemistry.Our results showed that HBO can significantly improve the vitality of damaged PC12 and H9C2 cells caused by oxygen–glucose deprivation/reperfusion.HBO can significantly inhibit apoptosis of PC12 and H9C2 cells caused by oxygenglucose deprivation/reperfusion.Importantly,we found that the protective mechanism of PC12 and H9C2 cell damage caused by oxygen-glucose deprivation/reperfusion may be related to the inhibition of the autophagy pathway.In this study,the results of cellular immunofluorescence and immunocytochemistry experiments showed that the 4E-BP1,p-AKt and mTOR levels of PC12 and H9C2 cells in the model group decreased,while the levels of LC3B,Atg5 and p53 increased.However,after HBO treatment,these autophagy-related indexes were reversed.In addition,observation of the cell ultrastructure with transmission electron microscopy found that in the model group,a significant increase in the number of autophagic vesicles was observed.In the HBO group,a decrease in autophagic vesicles was observed.The study demonstrated that hyperbaric oxygen protects against PC12 and H9C2 cell damage caused by oxygen-glucose deprivation/reperfusion via the inhibition of cell apoptosis and autophagy.

Effects of Different Doses of Doxorubicin on H9C2 Cells

Objective: To study the effect of different doses of doxorubicin on H9C2 cells and to provide a reference for the clinical study of doxorubicin. Methods: Doxorubicin (1, 2, 4, 6, 10 ug/ml) was co-cultured with H9C2 cells for 6, 12 and 24 hours. The morphological changes of cells were observed, and the cell inhibition rates of different time and drug concentration were calculated. Results: Doxorubicin could inhibit the activity of cardiomyocytes in a dose-dependent manner from 1 to 10 ug/ml. Conclusion: A certain dose of doxorubicin has a toxic effect on cardiomyocytes and can cause cardiomyocyte necrosis and apoptosis.

Polysaccharide extracts of Cirsium japonicum protect rat H9c2 myocardial cells from oxidative stress induced by hydrogen peroxide

Daji （Cirsium japonicum） has been applied against gastric disorders, lung diseases, and cardiovascular problems in thetraditional Chinese medicinal system. The present study was to investigate the protective effects of Daji （Cirsiumjaponicum） polysaccharide extracts （CJP） against hydrogen peroxide （H2O2） shock in rat H9c2 myocardial cells. First,CJP was isolated by hot water extraction and ethanol precipitation; it was then characterized by high performance liquidchromatography and infrared spectrum analysis. Rat H9c2 cells were subjected to H2O2 treatment to establish a cellinjury model. The 3- （4,5- dimethylthiazol- 2-yl）-2,5- diphenyltetrazolium bromide assay showed that CJP pretreatmentsignificantly ameliorated the H2O2 injury in a dose-dependent manner. Furthermore, the cell apoptosis induced by H2O2was markedly inhibited by CJP pretreatment, whereas the cleavage level of caspase-3, -8, and -9 was reduced. Inaddition, the p38 mitogen-activated protein kinase pathway might be involved in the protective effect of CJP onmyocardial cells. Therefore, we conclude that polysaccharide extracts of Daji （Cirsium japonicum） protect rat H9c2myocardial cells from oxidative stress induced by H2O2.

Effect of Different Culture Media on the Proliferation of Avian Influenza Virus H9 Subtypes in MDCK Cells

[Objective] To screen the best culture media for the proliferation of avian influenza virus （AIV） H9 subtypes in MDCK cells. [Method] The DMEM containing 10% （V/V） newborn calf serum, low-serum containing medium （ MEM-MD-611 ） and serum-free medium （SFE4Mega） were used to culture the MDCK monolayer ceils, which were then inoculated with different dilutions of AIV H9 subtypes, and the 3 kinds of media were al- so used as the maintenance solution to culture the virus. The cytopathic changes were observed at every 24 h, and the HA titers of the culture su- pernatants were also determined. [ Result] After culturing for 72 -96 h, the HA titers of the serum-free media were higher than that of low-serum culture media, while the HA titers were higher in the low-serum media than in the serum containing media. [ Conclusion] The 3 kinds of media can all used for the proliferation of AIV_ but the low-serum culture medium （MEM-MD-611 ） and serum-free medium （SFE4Meaa3 are preferred.

阿魏酸预处理对阿霉素诱导H9c2心肌细胞损伤的保护作用

目的研究阿魏酸(FA)对阿霉素(DOX)诱导H9c2心肌细胞损伤的影响。方法 1μmol·L-1DOX处理H9c2细胞24 h,建立心肌损伤模型。FA预处理组,10、20、40μmol·L-1FA预处理2 h后,再与DOX共培养24 h。CCK-8比色法测定细胞生存率;相差显微镜观察细胞形态学改变;生化试剂盒检测LDH、CK、MDA、SOD;DCF-DA荧光染色流式细胞术检测细胞内活性氧;AO-EB染色、DNA琼脂糖凝胶电泳检测细胞凋亡;Western blot法测定caspase-3、Bax、Bcl-2表达。结果 DOX降低H9c2细胞生存率,诱导氧化应激损伤和细胞凋亡。FA预处理剂量依赖性提高细胞生存率,减轻LDH、CK外漏和损伤细胞形态学改变。FA减少ROS生成,降低细胞MDA水平,增加SOD酶活性,抑制DOX诱导的氧化应激。FA下调促凋亡蛋白caspase-3和Bax,上调凋亡抑制蛋白Bcl-2,减少心肌细胞凋亡。结论 FA可抑制DOX诱导的氧化应激和心肌细胞凋亡,减轻心肌损伤。

H9与HepG-2体外共培养上清对HepG-2增殖迁移及凋亡的影响

目的:研究胚胎干细胞H9与肝癌细胞株Hep G-2共培养上清对肝癌细胞Hep G-2增殖、迁移及凋亡的影响,并探讨其可能机制。方法:体外共培养H9与Hep G-2,于不同时间即12、24、36、48 h取得上清,并把不同浓度上清即20%、40%、60%、80%作用于Hep G-2细胞,于倒置荧光显微镜下观察细胞的生长情况和形态变化;用MTS法检测不同浓度上清分别作用Hep G-2细胞24、48 h后细胞的增殖情况;应用流式细胞术检测细胞的凋亡情况;用Hochest33258染色检测细胞的凋亡情况;Transwell小室法检测上清对细胞侵袭迁移的影响。结果:不同浓度的共培养上清液均对Hep G-2细胞的增殖有一定的抑制作用,并且40%浓度及以上的浓度能明显促进肝癌细胞的凋亡,主要是早期和晚期凋亡,小室法也看出,上清对肝癌细胞的侵袭和迁移也具有明显的抑制作用,同时,上清对正常的肝细胞L02无明显的作用。结论:胚胎干细胞与肝癌细胞Hep G-2共培养上清能够在体外明显抑制肝癌细胞Hep G-2的增殖、迁移和侵袭,并且促进其凋亡,并且具有浓度依赖性,共培养时间越长,抑制效果越好。说明此上清具有一定的抗肿瘤效应。

H9亚型禽流感病毒感染引起MDCK细胞内抗氧化功能的变化

将传代MDCK细胞以8×104/cm2的密度接种于6孔细胞培养板,H9亚型禽流感病毒以不同剂量0(对照组)、10-3(高剂量组)、10-4(中剂量组)、10-5×EID50(低剂量组)分别接种,检测H9亚型禽流感病毒对MDCK细胞内抗氧化功能的影响。结果表明,与对照组相比,高剂量H9亚型禽流感病毒接种MDCK细胞使细胞内过氧化氢(H2O2)和羟基自由基(·OH)含量均显著增加(P>0.05),细胞内超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力均显著下降(P>0.05),细胞内的丙二醛(MDA)含量显著增加(P>0.05)。说明H9亚型禽流感病毒可显著提高MDCK细胞内活性氧自由基(ROS)含量,并降低抗氧化酶活力,阻碍ROS在细胞内的清除机制,引起细胞脂质过氧化作用,从而损伤细胞。

不同培养基对H9亚型禽流感病毒在MDCK细胞上的增殖效果研究

[目的]比较3种培养基对H9亚型禽流感病毒在MDCK细胞上的增殖效果。[方法]采用DMEM+10%血清、低血清培养基(MEM-MD-611)、无血清培养基(SFE4Mega)3种培养基制备MDCK细胞单层,分别接种不同稀释度的H9亚型禽流感病毒。然后,分别加入含10μg/ml胰蛋白酶的3种培养基作为维持液,培养病毒,每隔24 h观察其细胞病变,并测定上清HA滴度。[结果]在培养72～96 h时,无血清培养基病毒液的HA滴度高于低血清培养基,而低血清培养基则高于含血清培养基。[结论]3种培养基均可用于制备禽流感病毒抗原,其中无血清培养基、低血清培养基更适用于流感病毒抗原的制备。

H9亚型禽流感病毒对MDCK细胞增殖及其培养基过氧化氢含量的影响

为了探讨H9亚型禽流感病毒对MDCK细胞增殖及其培养基过氧化氢含量的影响,将不同剂量的H9亚型禽流感病毒接种MDCK细胞单层,吸附1.5h后弃去再加入新的DMEM维持液,每隔12h取上清液测定HA滴度、乳酸脱氢酶(LDH)活力以及过氧化氢(H2O2)含量。同时,本试验采用MTT法测定不同剂量病毒接种对MDCK细胞增殖的影响。结果表明,以10-3EID50、10-4EID50病毒剂量接种细胞后,病毒HA滴度分别在36h和48h达到滴度最大值(9log2)以及LHD活力的最大值,上清液中H2O2含量在48h时显著(P<0.05)高于空白对照组和低剂量病毒接种组;接种病毒后36h以内对MDCK细胞生长具有显著地(P<0.05)促进作用,之后会显著(P<0.05)抑制细胞的增殖。综上所述,H9亚型禽流感病毒能在前期促进MDCK细胞的增殖,随着病毒增殖对细胞损伤加大,LDH漏出量增加,促凋亡因子H2O2参与介导了这一过程。

复方大青叶注射液对体外培养HT-H9细胞CXCR4启动子活性的影响

目的:探讨复方大青叶注射液对体外培养HT-H9细胞中CXCR4启动子活性的作用。方法:克隆人CX-CR4启动子序列,构建报告载体pGL4.17-CXCR4;转染HT-H9细胞株,G418筛选后分组,高、低剂量实验组分别用200、100mg/L大青液注射液处理,设注射水对照组、空白对照组和未转染对照组;各组处理24h后,进行荧光素酶活性检测。结果:成功构建含人CXCR4启动子序列的报告载体PGL4.17-CXCR4;5组荧光素酶活性比较差异有统计学意义(F=135.510,P<0.001)。复方大青叶注射液高剂量组与低剂量组荧光素酶活性均明显低于对照组(P<0.01)。结论:复方大青叶注射液能够有效抑制体外培养HT-H9细胞中CXCR4启动子活性。

miR-139-5p低表达重组慢病毒的构建及其在H9c2细胞的表达验证

目的构建miR-139-5p低表达慢病毒载体,检测其在H9c2细胞的表达效果。方法根据大鼠miR-139-5p序列,设计合成其靶点序列,并合成寡核苷酸双链,克隆入慢病毒载体p GC-LV,与p Helper 1.0和p Helper 2.0共转染293T细胞,包装病毒。收取病毒上清液,纯化后感染H9c2细胞。荧光倒置显微镜下观察感染效率,实时定量PCR检测慢病毒感染后H9c2细胞中miR-139-5p的相对表达量。结果成功构建miR-139-5p低表达慢病毒载体,病毒感染H9c2细胞的效率超过95%,miR-139-5p表达明显减少。结论成功构建了miR-139-5p低表达慢病毒载体,包装的病毒可在H9c2细胞中实现抑制miR-139-5p表达的效果。

Sanguinarine Attenuates Lipopolysaccharide-induced Inflammation and Apoptosis by Inhibiting the TLR4/NF-KB Pathway in H9c2 Cardiomyocytes

The inflammatory response is involved in the pathogenesis of the most common types of heart disease. Sanguinarine （SAN） has various pharmacological properties such as anti-inflammatory, antioxidant, antibacterial, antitumor, and immune-enhancing properties. However, few studies have investigated the effects of SAN on lipopolysaceharide （LPS）-induced inflammatory and apoptotic responses in H9c2 cardiomyocytes. Therefore, in this study, H9c2 cells were co-treated with SAN and LPS, and the mRNA levels of pro-inflammation markers and the apoptosis rate were measured to clarify the effect of SAN on cardiac inflammation. The underlying mechanism was further investigated by detecting the activation of Toll-like receptor （TLR）4/nuclear faetor-κB （NF-κB） signaling pathways. As a result, increased mRNA expression of interleukin （IL）-1β, IL-6, and TNFα induced by LPS was attenuated after SAN treatment; LPS-induced apoptosis ofHge2 cardiomyocytes and cleaved-caspase 8, 9, 3 were all significantly reduced by SAN. Further experiments showed that the beneficial effect of SAN on blocking the inflammation and apoptosis of H9c2 cardiomyocytes induced by LPS was associated with suppression of the TLR4/NF-κB signaling pathway. It was suggested that SAN suppressed the LPS-induced inflammation and apoptosis of H9c2 cardiomyocytes, which may be mediated by inhibition of the TLR4/NF-κB signaling pathway. Thus, SAN may be a feasible therapy to treat sepsis patients with cardiac dysfunction.

Conservation of T cell epitopes between seasonal influenza viruses and the novel influenza A H7N9 virus

A novel avian influenza A(H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian influenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 influenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal influenza and avian influenza H7N9 was comparable to that with the highly pathogenic avian influenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses(compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our findings predict significant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.

Regulation of PM_(2.5)on mitochondrial damage in H9c2 cells through miR-421/SIRT3 pathway and protective effect of miR-421 inhibitor and resveratrol

Fine particulate matter(PM_(2.5))exposure is associated with cardiovascular disease(CVD)morbidity and mortality.Mitochondria are sensitive targets of PM_(2.5),and mitochondrial dysfunction is closely related to the occurrence of CVD.The epigenetic mechanism of PM_(2.5)-triggered mitochondrial injury of cardiomyocytes is unclear.This study focused on the mi R-421/SIRT3 signaling pathway to investigate the regulatory mechanism in cardiac mitochondrial dynamics imbalance in rat H9c2 cells induced by PM_(2.5).Results illustrated that PM_(2.5)impaired mitochondrial function and caused dynamics homeostasis imbalance.Besides,PM_(2.5)up-regulated mi R-421 and down-regulated SIRT3 gene expression,along with decreasing p-FOXO3a(SIRT3 downstream target gene)and p-Parkin expression and triggering abnormal expression of fusion gene OPA1 and fission gene Drp1.Further,mi R-421 inhibitor(mi R-421i)and resveratrol significantly elevated the SIRT3 levels in H9c2 cells after PM_(2.5)exposure and mediated the expression of SOD2,OPA1 and Drp1,restoring the mitochondrial morphology and function.It suggests that mi R-421/SIRT3 pathway plays an epigenetic regulatory role in mitochondrial damage induced by PM_(2.5)and that mi R-421i and resveratrol exert protective effects against PM_(2.5)-incurred cardiotoxicity.

人类胚胎干细胞分化研究

目的分别观察神经分化培养液和视黄酸对人类胚胎干细胞分化的作用。方法采用无滋养层细胞方法培养H9细胞,用化学成分确定的神经分化培养液诱导H9细胞神经分化,检测神经细胞特征蛋白表达;用视黄酸(RA)培养液诱导H9细胞分化,检测分化过程中内质网应激蛋白BIP蛋白表达变化。结果神经分化培养液诱导H9细胞分化成神经细胞;RA诱导的H9细胞分化过程中,BIP的表达随分化上调。结论人类胚胎干细胞分化提供了衍生神经细胞的潜在细胞来源和发育研究的平台。

MicroRNA-4279通过靶向核心启动子区域上调Notch-1基因表达进而抑制细胞凋亡

【目的】寻找与Notch-1基因核心启动子结合的micro RNA(miRNA)并阐明其调控功能,研究免疫细胞肿瘤的发生发展机制。【方法】首先使用生物信息学手段筛选与Notch-1基因核心启动子区域结合的miRNA,进而利用荧光素酶报告系统对其调控作用进行实验验证;通过突变核心启动子上的结合位点进一步确定该miRNA特异性靶向基因核心启动子区域。检测转染该miRNA后H9细胞中Notch-1的mRNA与内源蛋白表达水平。另外通过转染该miRNA并用H2O2诱导凋亡,研究该miRNA对H9细胞凋亡的影响。进一步在上述实验条件下,使用siRNA降低靶基因(Notch-1)的表达,然后检测miRNA对H9细胞系的凋亡的影响。【结果】首先通过软件预测,我们发现了miR-4279可以与Notch-1的核心启动子序列结合。荧光素酶报告实验表明miR-4279可以增强Notch-1启动子的转录活性;而在miR-4279的靶位点引入突变后,该增强作用消失。RT-qPCR和Western Blot实验表明miR-4279能够显著增强内源Notch-1 mRNA与蛋白的表达。H2O2诱导凋亡实验表明,miR-4279可以抑制H9细胞的凋亡。siRNA干扰实验表明,当Notch-1通路被抑制后,miR-4279导致的细胞凋亡抑制的效果消失。【结论】miR-4279通过靶向Notch-1基因核心启动子区域,特异性增加Notch-1基因的表达,进而增强H9细胞对H2O2诱导的凋亡的抗性。

Roles of transient receptor potential channel 6 in glucose-induced cardiomyocyte injury

BACKGROUND Diabetic cardiomyopathy(DCM) is a serious complication of end-stage diabetes that presents symptoms such as cardiac hypertrophy and heart failure. The transient receptor potential channel 6(TRPC6) protein is a very important selective calcium channel that is closely related to the development of various cardiomyopathies.AIM To explore whether TRPC6 affects cardiomyocyte apoptosis and proliferation inhibition in DCM.METHODS We compared cardiac function and myocardial pathological changes in wild-type mice and mice injected with streptozotocin(STZ), in addition to comparing the expression of TRPC6 and P-calmodulin-dependent protein kinase Ⅱ(P-CaMKⅡ) in them. At the same time, we treated H9C2 cardiomyocytes with high glucose and then evaluated the effects of addition of SAR, a TRPC6 inhibitor, and KN-93, a CaMKⅡ inhibitor, to such H9C2 cells in a high-glucose environment.RESULTS We found that STZ-treated mice had DCM, decreased cardiac function, necrotic cardiomyocytes, and limited proliferation. Western blot and immunofluorescence were used to detect the expression levels of various appropriate proteins in the myocardial tissue of mice and H9C2 cells. Compared to those in the control group, the expression levels of the apoptosis-related proteins cleaved caspase 3 and Bax were significantly higher in the experimental group, while the expression of the proliferation-related proteins proliferating cell nuclear antigen(PCNA) and CyclinD1 was significantly lower. In vivo and in vitro, the expression of TRPC6 and P-CaMKⅡ increased in a high-glucose environment. However, addition of inhibitors to H9C2 cells in a high-glucose environment resulted in alleviation of both apoptosis and proliferation inhibition.CONCLUSION The inhibition of apoptosis and proliferation of cardiomyocytes in a high-glucose environment may be closely related to activation of the TRPC6/P-CaMKⅡ pathway.

DPF2干扰慢病毒感染人胚胎干细胞建立稳定细胞系

目的对DPF2干扰慢病毒感染H9细胞,获得稳定的人胚胎干细胞克隆细胞系的方法学探讨。方法将各型带有GFP荧光标签的DPF2-RNAi慢病毒导入H9细胞中,嘌呤霉素筛选前后,相差和荧光显微镜下观察细胞形态和细胞感染效率;Western blot鉴定感染后的各组H9细胞系内DPF2蛋白表达水平。结果成功获得慢病毒感染后的H9稳定细胞系,成功筛选出#25540 DPF2-RNAi慢病毒,其沉默或敲低H9细胞的效率更高,稳定性更好。结论应用携带DPF2-RNAi的慢病毒感染人胚胎干细胞,使目标基因沉默,探索建立稳定细胞系的方法,为进一步研究提供细胞模型。