SENP2-mediated SERCA2a deSUMOylation increases calcium overload in cardiomyocytes to aggravate myocardial ischemia/reperfusion injury / 中华医学杂志(英文版)

BACKGROUND@#Sarcoplasmic reticulum calcium ATPase 2a (SERCA2a) is a key protein that maintains myocardial Ca 2+ homeostasis. The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation (small ubiquitin-like modifier) process after ischemia/reperfusion injury (I/RI) in vitro and in vivo .@*METHODS@#Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout (KO) and wild-type mice with I/RI were compared. SUMO-relevant protein expression and localization were detected by quantitative real-time PCR (RT-qPCR), Western blotting, and immunofluorescence in vitro and in vivo . Serca2a-SUMOylation, infarct size, and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes, were detected by immunoprecipitation, triphenyltetrazolium chloride (TTC)-Evans blue staining, and echocardiography respectively.@*RESULTS@#The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO + I/RI groups. Senp1 and Senp2 messenger ribose nucleic acid (mRNA) and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI. However, the highest levels in HL-1 cells were recorded at 12 h. Senp2 expression increased in the cytoplasm, unlike that of Senp1. Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline, reduced the infarction area, and improved cardiac function, while inhibition of Senp1 protein could not restore the above indicators.@*CONCLUSION@#I/RI activated Senp1 and Senp2 protein expression, which promoted Serca2a-deSUMOylation, while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.

Mechanism of Buyang Huanwu Decoction in protecting ischemic myocardium by regulating platelet autophagy in rats with acute myocardial infarction / 中国中药杂志

This study explored the effects of Buyang Huanwu Decoction(BYHWD) on platelet activation and differential gene expression after acute myocardial infarction(AMI). SD rats were randomly divided into a sham-operated group, a model group, a positive drug(aspirin) group, and a BYHWD group. Pre-treatment was conducted for 14 days with a daily oral dose of 1.6 g·kg~(-1) BYHWD and 0.1 g·kg~(-1) aspirin. The AMI model was established using the high ligation of the left anterior descending coronary artery method. The detection indicators included myocardial infarct size, heart function, myocardial tissue pathology, peripheral blood flow perfusion, platelet aggregation rate, platelet membrane glycoprotein CD62p expression, platelet transcriptomics, and differential gene expression. The results showed that compared with the sham-operated group, the model group showed reduced ejection fraction and cardiac output, decreased peripheral blood flow, and increased platelet aggregation rate and CD62p expression, and activated platelets. At the same time, TXB_2 content increased and 6-keto-PGF1α content decreased in serum. Compared with the model group, BYHWD increased ejection fraction and cardiac output, improved blood circulation in the foot and tail regions and cardiomyocytes arrangement, reduced myocardial infarct size and inflammatory infiltration, down-regulated platelet aggregation rate and CD62p expression, reduced serum TXB_2 content, and increased 6-keto-PGF1α content. Platelet transcriptome sequencing results revealed that BYHWD regulated mTOR-autophagy pathway-related genes in platelets. The differential gene expression levels were detected using real-time quantitative PCR. BYHWD up-regulated mTOR, down-regulated autophagy-related FUNDC1 and PINK genes, and up-regulated p62 gene expression. The results demonstrated that BYHWD could regulate platelet activation, improve blood circulation, and protect ischemic myocardium in AMI rats, and its mechanism is related to the regulation of the mTOR-autophagy pathway in platelets.

Potential implications of ketone body metabolism changes and ketogenic therapy in the treatment of heart failure / 中华危重病急救医学

Heart failure (HF) has become a major challenge in the treatment of global cardiovascular diseases. Great progress has been made in the drug treatment of HF, however, rehospitalization rate and mortality of patients with HF are still high. Hence, there is an urgent need to explore new treatment strategy and new underlying pathogenic mechanisms. In recent years, some researchers have suggested that regulation of ketone body metabolism may become a potentially promising therapeutic approach for HF. Some studies showed that the oxidative utilization of fatty acids and glucose was decreased in the failing heart, accompanied by the increase of ketone body oxidative metabolism. The enhancement of ketone body metabolism in HF is a compensatory change during HF. The failing heart preferentially uses ketone body oxidation to provide energy, which helps to improve the body's cardiac function. This review will discuss the potential significance of ketone body metabolism in the treatment of HF from three aspects: normal myocardial ketone body metabolism, the change of ketone body metabolism in HF, the effect of ketogenic therapy on HF and its treatment.

Protective mechanism of tetramethylpyrazine on cardiovascular system / 中国中药杂志

Tetramethylpyrazine is the main component of Ligusticum chuanxiong. Studies have found that tetramethylpyrazine has a good protective effect against cardiovascular diseases. In the heart, tetramethylpyrazine can reduce myocardial ischemia/reperfusion injury by inhibiting oxidative stress, regulating autophagy, and inhibiting cardiomyocyte apoptosis. Tetramethylpyrazine can also reduce the damage of cardiomyocytes caused by inflammation, relieve the fibrosis and hypertrophy of cardiomyocytes in infarcted myocardium, and inhibit the expansion of the cardiac cavity after myocardial infarction. In addition, tetramethylpyrazine also has a protective effect on the improvement of familial dilated cardiomyopathy. Besides, the mechanisms of tetramethylpyrazine on blood vessels are more abundant. It can inhibit endothelial cell apoptosis by reducing oxidative stress, maintain vascular endothelial function and homeostasis by inhibiting inflammation and glycocalyx degradation, and protect vascular endothelial cells by reducing iron overload. Tetramethylpyrazine also has a certain inhibitory effect on thrombosis. It can play an anti-thrombotic effect by reducing inflammatory factors and adhesion molecules, inhibiting platelet aggregation, and suppressing the expression of fibrinogen and von Willebrand factor. In addition, tetramethylpyrazine can also reduce the level of blood lipid in apolipoprotein E-deficient mice, inhibit the subcutaneous deposition of lipids, inhibit the transformation of macrophages into foam cells, and inhibit the proliferation and migration of vascular smooth muscle cells, thereby reducing the formation of atherosclerotic plaque. In combination with network pharmacology, the protective mechanism of tetramethylpyrazine on the cardiovascular system may be mainly achieved through the regulation of phosphatidylinositol 3 kinase/protein kinase B(PI3K/Akt), hypoxia-inducible factor 1(HIF-1), and mitogen-activated protein kinase(MAPK) pathways. Tetramethylpyrazine hydrochloride and sodium chloride injection has been approved for clinical application, but some adverse reactions have been found in clinical application, which need to be paid attention to.

Danhong Injection Up-regulates miR-125b in Endothelial Exosomes and Attenuates Apoptosis in Post-Infarction Myocardium / 中国结合医学杂志

OBJECTIVE@#To investigate the involvement of endothelial cells (ECs)-derived exosomes in the anti-apoptotic effect of Danhong Injection (DHI) and the mechanism of DHI-induced exosomal protection against postinfarction myocardial apoptosis.@*METHODS@#A mouse permanent myocardial infarction (MI) model was established, followed by a 14-day daily treatment with DHI, DHI plus GW4869 (an exosomal inhibitor), or saline. Phosphate-buffered saline (PBS)-induced ECs-derived exosomes were isolated, analyzed by miRNA microarray and validated by droplet digital polymerase chain reaction (ddPCR). The exosomes induced by DHI (DHI-exo), PBS (PBS-exo), or DHI+GW4869 (GW-exo) were isolated and injected into the peri-infarct zone following MI. The protective effects of DHI and DHI-exo on MI hearts were measured by echocardiography, Masson's trichrome staining, and TUNEL apoptosis assay. The Western blotting and quantitative reverse transcription PCR (qRT-PCR) were used to evaluate the expression levels of miR-125b/p53-mediated pathway components, including miR-125b, p53, Bak, Bax, and caspase-3 activities.@*RESULTS@#DHI significantly improved cardiac function and reduced infarct size in MI mice (P<0.01), which was abolished by the GW4869 intervention. DHI promoted the exosomal secretion in ECs (P<0.01). According to the results of exosomal miRNA microarray assay, 30 differentially expressed miRNAs in the DHI-exo were identified (28 up-regulated miRNAs and 2 down-regulated miRNAs). Among them, DHI significantly elevated miR-125b level in DHI-exo and DHI-treated ECs, a recognized apoptotic inhibitor impeding p53 signaling (P<0.05). Remarkably, treatment with DHI and DHI-exo attenuated apoptosis, elevated miR-125b expression level, inhibited capsase-3 activity, and down-regulated the expression levels of proapoptotic effectors (p53, Bak, and Bax) in post-MI hearts, whereas these effects were blocked by GW4869 (P<0.05 or P<0.01).@*CONCLUSION@#DHI and DHI-induced exosomes inhibited apoptosis, promoted the miR-125b expression level, and regulated the p53 apoptotic pathway in post-infarction myocardium.

Advances in extracardiac mechanisms for heart failure with preserved ejection fraction / 中南大学学报(医学版)

Heart failure with preserved ejection fraction (HFpEF) is a syndrome with highly heterogeneous clinical symptoms, and its incidence has been increasing in recent years. Compared with heart failure with reduced ejection fraction (HFrEF), HFpEF has a worse prognosis. Traditional therapies targeting the internal mechanisms of the heart show limited or inefficacy on HFpEF, and new therapeutic targets for HFpEF are expected to be found by focusing on the extracardiac mechanisms. Recent studies have shown that cardiopulmonary pathophysiological interaction exacerbates the progression of HFpEF. Hypertension, systemic vascular injury, and inflammatory response lead to coronary microvascular dysfunction, myocardial hypertrophy, and coronary microvascular remodeling. Acute kidney injury affects myocardial energy production, induces oxidative stress and catabolism of myocardial protein, which leads to myocardial dysfunction. Liver fibrosis mediates heart injury by abnormal protein deposition and inflammatory factors production. Skeletal muscle interacts with the sympathetic nervous system by metabolic signals. It also produces muscle factors, jointly affecting cardiac function. Metabolic syndrome, gut microbiota dysbiosis, immune system diseases, and iron deficiency promote the occurrence and development of HFpEF through metabolic changes, oxidative stress, and inflammatory responses. Therefore, the research on the extracardiac mechanisms of HFpEF has certain implications for model construction, mechanism research, and treatment strategy formulation.

Inhibidores del cotransportador de sodio-glucosa tipo 2: Efecto de los mecanismos moleculares en el miocardio / Sodium-glucose cotransporter 2 inhibitors: Effect of molecular mechanisms on the myocardium

Resumen Los receptores del cotransportador de sodio-glucosa han demostrado una gran relevancia en la función miocárdica. Los receptores tipo 1 se encuentran en el miocardio en valores bajos, sin embargo, se elevan en patologías cardiacas por medio de distintos mecanismos moleculares. Por otra parte, los receptores tipo 2 están ausentes en el miocardio. Los fármacos que inhiben este receptor tienen beneficio cardiovascular evidente en estudios clínicos y experimentales, principalmente en pacientes con diabetes mellitus tipo 2 e insuficiencia cardiaca, en los que se ha demostrado una reducción de la mortalidad por causas cardiovasculares y reducción en hospitalización por insuficiencia cardiaca. Existen interrogantes sobre el mecanismo de acción directo de este grupo antihiperglicemiantes sobre el cardiomiocito y se han desarrollado hipótesis y teorías para explicar este efecto. El objetivo de este artículo es revisar y analizar los diferentes mecanismos metabólicos, estructurales, funcionales y mitocondriales en un contexto molecular de los inhibidores del cotransportador sodio-glucosa tipo 2. La acción fisiopatológica del receptor tipo 1 en el miocardio también es importante y se encuentran en desarrollo estudios clínicos para establecer el efecto de su inhibición a nivel cardíaco.

Abstract Sodium-glucose cotransporter receptors have demonstrated relevance in myocardial function. Type 1 receptors are found in the myocardium in low values, however, they are elevated in cardiac pathologies by means of different molecular mechanisms. On the other hand, type 2 receptors are absent in the myocardium. The drugs that inhibit this receptor have been shown to have a cardiovascular benefit demonstrated in clinical and experimental studies, mainly in patients with type 2 diabetes mellitus and heart failure, presenting a reduction in mortality due to cardiovascular causes and a reduction in hospitalization due to heart failure. Due to the above, many questions arise about the mechanism of direct action of this antihyperglycemic group on cardiomyocyte, which is why they have been developed from hypotheses and theories to clarify this action by medicines. The objective of this article is to analyze the different metabolic, structural, functional and mitochondrial mechanisms in a molecular context of the inhibitors of the sodium-glucose cotransporter type 2. On the other hand, to analyze the pathophysiological action of the type 1 receptor in the myocardium, since that future clinical studies will be developed to establish the effect with its inhibition at the cardiac level.

Skin Ultrastructure and the Changes of HIF-2α, H-FABP Expression in the Myocardium of Electric Shock Death Rats / 法医学杂志

Objective To observe the skin ultrastructure change of electric shock death rats and to test the expression changes of hypoxia-inducible factor-2α （HIF-2α） and heart type-fatty acid-binding protein （H-FABP） of myocardial cells, in order to provide basis for forensic identification of electric shock death. Methods The electric shock model of rats was established. The 72 rats were randomly divided into control group, electric shock death group and postmortem electric shock group. Each group was divided into three subgroups, immediate （0 min）, 30 min and 60 min after death. The skin changes of rats were observed by HE staining, the changes of skin ultrastructure were observed by scanning electron microscopy, and the expression of HIF-2α and H-FABP in rats myocardium was tested by immunohistochemical staining. Results The skin in the electric shock death group and postmortem electric shock group had no significant difference through the naked eye or by HE staining. Under the scanning electron microscope, a large number of cellular debris, cells with unclear boundaries, withered cracks, circular or elliptical holes scattered on the cell surface and irregular edges were observed. A large number of spherical foreign body particles were observed. Compared with the control group, the expression of HIF-2α in all electric shock death subgroups increased, reaching the peak immediately after death. In the postmortem electric shock group, HIF-2α expression only increased immediately after death, but was lower than that of electric shock death group （P<0.05）. Compared with the control group, the expression of H-FABP in all subgroups of electric shock death group and postmortem electric shock group significantly decreased. The expression of H-FABP in all subgroups of electric shock death group was lower than that of the postmortem electric shock group （P<0.05）. Conclusion Electric shock can increase HIF-2α expression and decrease H-FABP expression in the myocardium, which may be of forensic significance for the determination of electric shock death and identification of antemortem and postmortem electric shock.

Construction of a Stable Expression Cell Line of Human Phospholamban / 法医学杂志

OBJECTIVES@#To construct a cell line that can stably express human phospholamban(PLN) and initially explore its application in the study of myocardial toxicity mechanism.@*METHODS@#FastCloning method was used to insert the open reading frame sequence of target gene PLN into eukaryotic expression vector pcDNA5/FRT/TO(hereinafter referred to as pDFT) to construct the pDFT-PLN-Flag plasmid. The Flp-InTM T-RExTM 293 cells were generated by cotransfection of the constructed plasmid and pOG44 plasmid to express the target gene. Successfully recombined monoclonal cell lines were screened by hygromycin B resistance. Western blot and indirect immunofluorescence (IFA) were used to examine the expression of the target protein in recombinant cells. After the cell line was exposed to aconitine, it was verified by Western blot to detect changes in PLN protein phosphorylation.@*RESULTS@#After PCR amplification of the recombinant plasmid and DNA electrophoresis, the length of the amplified product is the same as the known PLN gene fragment, which is consistent with the open reading frame (ORF) sequence of the human PLN gene after sequencing. IFA and Western blot showed that the constructed proliferation cell line can stably express high levels of human PLN under induction and regulation. Preliminary results showed that the phosphorylation level of Thr17-PLN decreased after two hours of exposure to 1 μmol/L aconitine.@*CONCLUSIONS@#This human cell line can stably express PLN and can be used to study the mechanism of action of aconitine on the cell at molecular level.

Effects of Physical Training on the Myocardium of Oxariectomized LDLr Knockout Mice: MMP 2/9, Collagen I/III, Inflammation and Oxidative Stress / Efeitos do Treinamento Físico sobre o Miocárdio de Camundongos LDLr Knockout Ovariectomizadas: MMP-2 e -9, Colágeno I/III, Inflamação e Estresse Oxidativo

Abstract Background: The emergence of coronary heart disease is increased with menopause, physical inactivity and with dyslipidemia. Physical training is known to promote the improvement of cardiovascular functions. Objective: To investigate the effects of aerobic physical training on the left ventricle in ovariectomized LDL knockout mice. Methods: Thirty animals were divided into 6 groups (n = 5): Sedentary non-ovariectomized control; Sedentary ovariectomized control; Trained ovariectomized control; Sedentary non-ovariectomized LDL-knockout, sedentary ovariectomized LDL-knockout and trained ovariectomized LDL-knockout. We analyzed the average parameters of apparent density of collagen fibers types I and III, and metalloproteinase type 2 and type 9, were considered significant p < 0.05. Results: The results showed that the proposed exercise protocol altered the volume of type I collagen fibers, altered collagen remodeling parameters (MMP-2), and also reduced the 8-hydroxy-2'-deoxyguanosine (8OHdG) oxidative stress parameter. Conclusion: Moderate intensity aerobic training acts on collagen fiber volume, on collagen remodeling with the reduction of oxidative stress in the left ventricles of ovariectomized LDL-knockout mice.

Resumo Fundamento: O surgimento da doença cardíaca coronariana aumenta com a menopausa, inatividade física e dislipidemia. Sabe-se que o treinamento físico promove a melhora das funções cardiovasculares Objectivo: Investigar os efeitos do treinamento físico aeróbico sobre o ventrículo esquerdo em camundongos LDL knockout ovariectomizadas. Métodos: Trinta animais foram divididos em 6 grupos (n = 5): controle sedentário não ovariectomizado, controle sedentário ovariectomizado, controle treinado ovariectomizado, sedentário LDL-knockout não ovariectomizado, sedentário LDL-knockout ovariectomizado e treinado LDL-knockout ovariectomizado. Analisamos os parâmetros médios da densidade de volume de fibras colágenas tipo I e III, e metaloproteinases 2 e 9. Valores de p < 0,05 foram considerados significativos. Resultados: Os resultados mostram que o protocolo de exercício proposto alterou o volume de fibras colágenas do tipo I e os parâmetros de remodelamento do colágeno (MMP-2), e ainda reduziu o parâmetro de estresse oxidativo do 8-hidroxi-2'-deoxiganosina (8-OhdG). Conclusão: O treinamento aeróbico de intensidade moderada age sobre o volume das fibras colágenas e sobre o remodelamento de colágeno, com redução do estresse oxidativo em ventrículos esquerdos de camundongos ovariectomizados LDLr Knockout.

Protective effect of L-carnitine on myocardial injury in rats with heatstroke

Abstract Purpose: To investigate the protective effect of L-carnitine on myocardial injury in rats with heatstroke. Methods: orty-eight rats were randomly divided into control, heatstroke and 25, 50 and 100 mg/kg L-carnitine groups. The last three groups were treated with 25, 50 and 100 mg/kg L-carnitine, respectively, for seven successive days. Then, except for the control group, the other four groups were transferred into the environment with ambient temperature of (39.5 ± 0.4 °C) and relative humidity of (13.5 ± 2.1%) for 2 h. The core temperature (Tc), mean arterial pressure (MAP), heart rate (HR) and serum and myocardial indexes were detected. Results: Compared with the heatstroke group, in the 100 mg/kg L-carnitine group, the Tc was significantly decreased, the MAP and HR were significantly increased, the serum creatine kinase, lactate dehydrogenase, alkaline phosphatase, aspartate aminotransferase, tumor necrosis factor α and interleukin 1β levels were significantly decreased, the myocardial superoxide dismutase and glutathione peroxidase levels were significantly increased, the myocardial malondialdehyde level was significantly decreased and the cardiomyocyte apoptosis index and myocardial caspase-3 protein expression level were remarkably decreased (p < 0.05). Conclusions: The L-carnitine pretreatment can alleviate the myocardial injury in heatstroke rats through reducing the inflammatory response, oxidative stress and cardiomyocyte apoptosis.

Reduction of oxidative stress improves insulin signaling in cardiac tissue of obese mice / Redução do estresse oxidativo melhora a sinalização da insulina em tecido cardíaco de camundongos obesos

ABSTRACT Objective To evaluate the effects of oxidative stress on insulin signaling in cardiac tissue of obese mice. Methods Thirty Swiss mice were equally divided (n=10) into three groups: Control Group, Obese Group, and Obese Group Treated with N-acetylcysteine. After obesity and insulin resistance were established, the obese mice were treated with N-acetylcysteine at a dose of 50mg/kg daily for 15 days via oral gavage. Results Higher blood glucose levels and nitrite and carbonyl contents, and lower protein levels of glutathione peroxidase and phosphorylated protein kinase B were observed in the obese group when compared with their respective control. On the other hand, treatment with N-acetylcysteine was effective in reducing blood glucose levels and nitrite and carbonyl contents, and significantly increased protein levels of glutathione peroxidase and phosphorylated protein kinase B compared to the Obese Group. Conclusion Obesity and/or a high-lipid diet may result in oxidative stress and insulin resistance in the heart tissue of obese mice, and the use of N-acetylcysteine as a methodological and therapeutic strategy suggested there is a relation between them.

RESUMO Objetivo Avaliar os efeitos do estresse oxidativo sobre a sinalização da insulina em tecido cardíaco de camundongos obesos. Métodos Utilizaram-se 30 camundongos Swiss subdivididos igualmente (n=10) em três grupos: Grupo Controle, Grupo Obeso e Grupo Obeso Tratado com N-acetilcisteína. Após estabelecidas a obesidade e a resistência à insulina, os camundongos obesos foram tratados diariamente, durante 15 dias, via gavagem oral, com N-acetilcisteína na dose de 50mg/kg. Resultados Observaram-se maiores níveis de glicose sanguínea, conteúdos de nitrito e carbonil, e menores níveis proteicos de glutationa peroxidase e proteína quinase B fosforilada no Grupo Obeso quando comparado a seu respectivo controle. Por outro lado, o tratamento com N-acetilcisteína se mostrou eficiente em diminuir os níveis glicêmicos, os conteúdos de nitrito e carbonil, e aumentar significativamente os níveis proteicos de glutationa peroxidase e proteína quinase B fosforilada, quando comparados ao Grupo Obeso. Conclusão Obesidade e/ou dieta hiperlipídica levam a estresse oxidativo e à resistência à insulina no tecido cardíaco de camundongos obesos, e o uso da N-acetilcisteína como estratégia metodológica e terapêutica sugeriu haver relação entre ambos.

Repercussions of adjuvant-induced arthritis on body composition, soleus muscle, and heart muscle of rats

This study investigated the repercussions of adjuvant-induced arthritis (AIA) on body composition and the structural organization of the soleus and cardiac muscles, including their vascularization, at different times of disease manifestation. Male rats were submitted to AIA induction by intradermal administration of 100 μL of Mycobacterium tuberculosis (50 mg/mL), in the right hind paw. Animals submitted to AIA were studied 4 (AIA4), 15 (AIA15), and 40 (AIA40) days after AIA induction as well as a control group of animals not submitted to AIA. Unlike the control animals, AIA animals did not gain body mass throughout the evolution of the disease. AIA reduced food consumption, but only on the 40th day after induction. In the soleus muscle, AIA reduced the wet mass in a time-dependent manner but increased the capillary density by the 15th day and the fiber density by both 15 and 40 days after induction. The diameter of the soleus fiber decreased from the 4th day after AIA induction as well as the capillary/fiber ratio, which was most evident on the 40th day. Moreover, AIA induced slight histopathological changes in the cardiac muscle that were more evident on the 15th day after induction. In conclusion, AIA-induced changes in body composition as well as in the soleus muscle fibers and vasculature have early onset but are more evident by the 15th day after induction. Moreover, the heart may be a target organ of AIA, although less sensitive than skeletal muscles.

Sex-Related Effects of Prenatal Stress on Region-Specific Expression of Monoamine Oxidase A and β Adrenergic Receptors in Rat Hearts / Efeitos Sexo-Específicos de Estresse Pré-Natal na Expressão Região-Específica de Monoamina Oxidase A e Receptores Adrenérgicos Β no Coração de Ratos

Abstract Background: Prenatal stress may increase risk of developing cardiovascular disorders in adulthood. The cardiotoxic effects of catecholamines are mediated via prolonged adrenergic receptor stimulation and increased oxidative stress upon their degradation by monoamine oxidase A (MAO-A). Objectives: We investigated long-term effects of prenatal stress on β (1, 2, 3) adrenergic receptors and MAO-A gene expression in the hearts of adult rat offspring. Methods: Pregnant rats were exposed to unpredictable mild stress during the third week of gestation. RNA was isolated from left ventricular apex and base of adult offspring. Quantitative PCR was used to measure gene expression in collected ventricular tissue samples. The level of significance was set to p < 0.05. Results: β3 adrenergic receptor mRNA was undetectable in rat left ventricle. β1 adrenergic receptor was the predominantly expressed subtype at the apical and basal left ventricular myocardium in the control females. Male offspring from unstressed mothers displayed higher apical cardiac β1 than β2 adrenergic receptor mRNA levels. However, β1 and β2 adrenergic receptor mRNAs were similarly expressed at the ventricular basal myocardium in males. Unlike males, prenatally stressed females exhibited decreased β1 adrenergic receptor mRNA expression at the apical myocardium. Prenatal stress did not affect cardiac MAO-A gene expression. Conclusions: Collectively, our results show that prenatal stress may have exerted region- and sex-specific β1 and β2 adrenergic receptor expression patterns within the left ventricle.

Resumo Fundamento: Estresse pré-natal pode aumentar os riscos de desenvolver doenças cardiovasculares na idade adulta. Os efeitos cardiotóxicos de catecolaminas são mediados pela estimulação prolongada dos receptores adrenérgicos e pelo aumento do estresse oxidativo após sua degradação pela monoamina oxidase A (MAO-A). Objetivos: Investigamos os efeitos a longo prazo de estresse pré-natal nos receptores β (1, 2, 3) adrenérgicos e na expressão do gene MAO-A nos corações da prole adulta de ratos. Método: Ratas prenhes foram expostas a estresse crônico moderado imprevisível durante a terceira semana de gestação. O RNA foi isolado do ápice e da base do ventrículo esquerdo da prole adulta. Utilizou-se PCR quantitativa em tempo real para medir a expressão gênica nas amostras de tecido ventricular coletadas. O nível de significância foi estabelecido em p < 0,05. Resultados: Foi indetectável o mRNA do receptor adrenérgico β3 no ventrículo esquerdo dos ratos. O receptor adrenérgico β1 foi o subtipo mais expresso no miocárdio ventricular esquerdo apical e basal nas fêmeas controle. A prole masculina das mães não estressadas apresentou níveis cardíacos apicais de mRNA do receptor adrenérgico β1 mais altos do que os de β2. Porém, mRNAs dos receptores adrenérgicos β1 e β2 foram expressos de forma semelhante no miocárdio basal ventricular na prole masculina em geral. Ao contrário da prole masculina, a prole feminina exposta ao estresse pré-natal exibiu uma expressão diminuída do mRNA do receptor adrenérgico β1 no miocárdio apical. O estresse pré-natal não afetou a expressão gênica de MAO-A cardíaca. Conclusões: Coletivamente, nossos resultados mostram que estresse pré-natal pode ter exercido padrões de expressão região- e sexo-específica dos receptores adrenérgicos β1 e β2 no ventrículo esquerdo.

Pharmacological evaluation of Mongolian medicine Syringa pinnatifolia fraction I against acute myocardial ischemia in mice / 中国中药杂志

Syringa pinnatifolia Hemsl.( SP) is a representative Mongolian folk medicine with the effects of inhibiting Heyi related diseases,clearing heat and relieving pain. It has been used for the treatment of Heyi-induced heart tingling,heart palpitations,upset,insomnia and other symptoms. Total ethanol extract( T) and major fraction( M) of SP have been evaluated its anti-ischemic effects,and the mechanism was related to the regulation of cyclooxygenase( COX)-mediated inflammatory pathway and p53-mediated apoptosis pathway in our previous studies. This study reports the chemical fractionation on M by which to obtain subfractions( I and M_3),and the pharmacological evaluation of M,I,and M_3 against myocardial ischemia in mice. The result showed that I and M reduced the values of LVEDd and LVEDs,significantly increased EF and FS values,increased serum CK-MB and LDH levels in mice,and reduced in inflammatory cells infiltration and collagen deposition in the infarcted myocardial tissue,suggesting that M and I possess the same degree anti-myocardial is chemia equally whereas M_3 has no this effect. Related mechanism studies suggested that I can reduce the expression of COX-1,COX-2 and p53 protein in myocardial tissue in a dose-dependent manner. This study lays the foundation for further chemical segmentation and clarification of pharmacological substance groups,paving the way for the full use and benefits to be use of systematic biological methods to analyze the pharmacological basis of SP against myocardial ischemia.

Mechanisms of Toxicity and Cardiotoxicity of Alcohol Extract from Root, Stem and Leaf of Chloranthus Serratus / 法医学杂志

Objective To compare the differences of cardiotoxicity of alcohol extract from root, stem and leaf of Chloranthus serratus in the rats, and discuss preliminarily its mechanism of toxicity. Methods Rats were randomly divided into four groups: blank, root alcohol, stem alcohol and leaf alcohol, with 8 in each group. After 14 days of continuous intragastric administration, the body mass change curves were drawn. The cardiac coefficient was calculated. The contents of creatine kinase （CK）, creatine kinase isoenzyme （CK-MB）, lactate dehydrogenase （LDH） and α-hydroxybutyrate dehydrogenase （α-HBDH） as well as the content changes of oxidative stress indexes - total superoxide dismutase （T-SOD） and malondialdehyde （MDA） in the serum of rats were detected. The cardiac pathomorphology changes in the rats were observed. The expression of intercellular adhesion molecule （ICAM-1） and heme oxygenase （HO-1） in myocardial tissue was detected. Results Body mass growth rate： stem alcohol group was the smallest, followed by leaf alcohol group. The difference of cardiac coefficient of every group had no statistical significance （P>0.05）. The myocardial tissues of stem alcohol group suffered the most serious damage, followed by the leaf alcohol group. The contents of CK, CK-MB, LDH and α-HBDH in stem alcohol group increased （P<0.05）. The increase of MDA content and decrease of T-SOD content in stem alcohol group had statistical significance compared with the blank group and root alcohol group, while the leaf alcohol group only had statistical significance in the decrease of T-SOD content compared with the blank group （P<0.05）. The positive expression of ICAM-1 enhanced and the expression of HO-1 protein decreased in every group after the intervention of different extracts. The change trend was stem alcohol > leaf alcohol > root alcohol group. Conclusion The alcohol extract from the stem has the highest cardiotoxicity, followed by the leaf extract, and its mechanism of toxicity may be related to oxidative stress.

Heat shock proteins: protection and potential biomarkers for ischemic injury of cardiomyocytes after surgery

Abstract The heat shock proteins are endogenous proteins with the ability to act as molecular chaperones. Methods that provide cell protection by way of some damage can positively influence the results of surgery. The present review summarizes current knowledge concerning the cardioprotective role of the heat shock proteins as occurs in heart damage, including relevant information about the stresses that regulate the expression of these proteins and their potential role as biomarkers of heart disease.

Involvement of catecholamines in the myocardium of rats submitted to experimental model of portal hypertension / Envolvimento das catecolaminas no miocárdio de ratos submetidos a modelo experimental de hipertensão portal

ABSTRACT Background: The role of autonomic nervous system in the development and maintenance of portal hypertension is not fully elucidated. It is known that the gene expression of norepinephrine in the superior mesenteric artery varies with time, and it may contribute for splanchnic vasodilation and its consequent hemodynamic repercussions. It is still not known exactly how the adrenergic expression behaves at the heart level in the initial stages of this process. Aim: To evaluate the immunohistochemical expression of the enzyme tyrosine hydroxylase (tyrosine 3-monooxygenase), involved in the synthesis of norepinephrine, in the myocardium of rats submitted to partial ligation of the portal vein. Methods: Twenty-four Wistar rats were divided into two groups: Sham Operated and Portal Hypertension. The partial ligation was performed in the Portal Hypertension group, and after 1/6/24 h and 3/5/14 days the animals were euthanized. Immunohistochemical analysis was performed to quantify the expression of the stained enzyme using the ImageJ program. Results: The Portal Hypertension group expressed percentages between 4.6-6% of the marked area, while the Sham Operated group varied between 4-5%. Although there was no statistical significance, the percentage stained in the Portal Hypertension group followed an increasing pattern in the first 6 h and a decreasing pattern after 24 h, which was not observed in the Sham Operated group. Conclusion: The expression of noradrenaline in rat myocardium during the first two weeks after partial ligation of the portal vein, with tyrosine hydroxylase as marker, did not show differences between groups over time.

RESUMO Racional: O papel do sistema nervoso autônomo na hipertensão portal não está completamente elucidado. Sabe-se que, nessa condição, a expressão gênica da norepinefrina na artéria mesentérica superior modifica-se com o tempo, podendo ser importante contribuinte para a vasodilatação esplâncnica e suas repercussões hemodinâmicas. Apesar dos estudos sobre as repercussões cardiovasculares na hipertensão portal, ainda não se sabe como a expressão adrenérgica se comporta a nível cardíaco nas etapas iniciais desse processo. Objetivo: Avaliar a expressão imunoistoquímica da enzima tirosina hidroxilase (tirosina 3-mono-oxigenase), relacionada à síntese da norepinefrina, no miocárdio de ratos submetidos à ligadura parcial da veia porta. Métodos: Foram utilizados 24 ratos, distribuídos em dois grupos: Sham Operated e Hipertensão Portal. A ligadura parcial da veia porta foi realizada apenas no grupo Hipertensão Portal e, após 1/6/24 h e 3/5/14 dias, os animais foram eutanasiados. Foi feita a análise imunoistoquímica para quantificar a expressão da enzima corada, utilizando o programa ImageJ. Resultados: No grupo Hipertensão Portal, o miocárdio expressou percentuais entre 4,6-6% de área marcada, enquanto que no grupo Sham Operated variou entre 4-5%, sem significância estatística. Apenas no grupo Hipertensão Portal, a porcentagem corada pela enzima seguiu padrão crescente nas primeiras 6 h e decrescente após 24 h. Conclusão: A expressão da noradrenalina no miocárdio de ratos durante as primeiras duas semanas após a ligadura parcial da veia porta, tendo como marcador a enzima tirosina hidroxilase, não apresentou diferenças entre grupos ao longo do tempo.

Cardiac protein expression patterns are associated with distinct inborn exercise capacity in non-selectively bred rats

In the present study, we successfully demonstrated for the first time the existence of cardiac proteomic differences between non-selectively bred rats with distinct intrinsic exercise capacities. A proteomic approach based on two-dimensional gel electrophoresis coupled to mass spectrometry was used to study the left ventricle (LV) tissue proteome of rats with distinct intrinsic exercise capacity. Low running performance (LRP) and high running performance (HRP) rats were categorized by a treadmill exercise test, according to distance run to exhaustion. The running capacity of HRPs was 3.5-fold greater than LRPs. Protein profiling revealed 29 differences between HRP and LRP rats (15 proteins were identified). We detected alterations in components involved in metabolism, antioxidant and stress response, microfibrillar and cytoskeletal proteins. Contractile proteins were upregulated in the LVs of HRP rats (α-myosin heavy chain-6, myosin light chain-1 and creatine kinase), whereas the LVs of LRP rats exhibited upregulation in proteins associated with stress response (aldehyde dehydrogenase 2, α-crystallin B chain and HSPβ-2). In addition, the cytoskeletal proteins desmin and α-actin were upregulated in LRPs. Taken together, our results suggest that the increased contractile protein levels in HRP rats partly accounted for their improved exercise capacity, and that proteins considered risk factors to the development of cardiovascular disease were expressed in higher amounts in LRP animals.

Interleukin-6 contributes to myocardial damage in pregnant rats with reduced uterine perfusion pressure

Preeclampsia is one of the most frequent and difficult illnesses in pregnancy, which jeopardizes both mother and fetus. There are several diagnostic criteria for preeclampsia. However, the preeclampsia-associated myocardial damage has not been described. In this study, we employed reduced uterine perfusion pressure (RUPP) to generate a rat model of preeclampsia for the evaluation of myocardial damage in late-gestation rats. The expressions of cardiac injury markers were analyzed by immunohistochemistry and ELISA. The arterial pressure and myocardial tissue velocities were also measured. The role of interleukin (IL)-6 in RUPP-associated myocardial damage was further explored. The results showed that RUPP rats had significant myocardial damage, as demonstrated by the high expressions of myoglobin, creatine kinase isoenzyme, cardiac troponin I, and brain natriuretic peptide. In addition, RUPP increased the mean arterial pressure and the early transmitral flow velocity to mitral annulus early diastolic velocity ratio (E/Ea). Furthermore, IL-6 deteriorated these abnormalities, whereas inhibition of IL-6 significantly relieved them. In conclusion, our study demonstrated that RUPP rats displayed myocardial damage in an IL-6-dependent manner.