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ObjectiveTo observe the difference in the efficacy of three kinds of traditional Chinese medicine （TCM） injections on rat model of heart failure induced by transverse aortic constriction （TAC）， explore the TCM syndrome of the model based on the theory of correspondence of prescription and syndrome， and reveal the biological basis of prescription-syndrome from the perspective of metabolism. MethodRats were treated with TAC for modeling and were divided into Shenmai injection group （6.0 mL·kg-1）， model group， Danhong injection group （6.0 mL·kg-1）， Shenfu injection group （6.0 mL·kg-1） and trimetazidine group （10 mg·kg-1）， and sham operation group was set up as control. After drug intervention for 15 days， echocardiography， serum N-terminal pro-brain natriuretic peptide （NT-proBNP） and myocardial histopathological staining were performed for each group， so as to compare the efficacy to select the effective injection. Colorimetry was used to detect the serum glucolipid metabolism after the intervention of the effective injection， and ultra high performance liquid chromatography-mass spectrometry was used to observe the metabolites and related metabolic pathways in myocardial tissue. ResultCompared with the sham operation group， the left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （FS） in the model group decreased （P<0.01）， while the left ventricular end-diastolic diameter （LVIDd）， left ventricular internal diameter at end-systole （LVIDs） and NT-proBNP level increased （P<0.01）. Compared with model group， LVEF and FS increased （P<0.01）， LVIDd， LVIDs and NT-proBNP level decreased （P<0.05， P<0.01） in Danhong injection group， NT-proBNP level in Shenfu injection group decreased （P<0.05）， LVIDd and NT-proBNP level increased （P<0.05， P<0.01） in Shenmai injection group， in trimetazidine group， LVEF and FS increased （P<0.01）， while LVIDs and NT-proBNP level decreased （P<0.05， P<0.01）. Serum glucose， low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels in Danhong injection group and trimetazidine group were adjusted by callbacks （P<0.01， P<0.05）. There were the callback of 9 myocardial metabolites in Danhong injection group， including glycine， serine and threonine metabolism， glyoxylate and dicarboxylate metabolism， glycerol phospholipid metabolism. There were the callback of 10 myocardial metabolites in trimetazidine group， including glycerol phospholipid metabolism. ConclusionThe efficacy of Danhong injection on heart failure model induced by TAC is significant and superior to Shenfu injection and Shenmai injection， suggesting that the model is closely related to heart-blood stasis. The biological mechanism of Danhong injection interfering with the model involves regulating the metabolic disorder of lipid， glucose， amino acid and butyric acid.
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ObjectiveTo study the pathological process and changes of metabolites in myocardial tissue of heart failure induced by transverse aortic constriction （TAC） in rats. MethodRats were treated with TAC operation and divided into TAC-30 d group and TAC-60 d group， and sham operation group at the same period was set up as control. Echocardiography and pathological staining of myocardial tissue were performed on rats in each group. Enzyme-linked immunosorbent assay was used to determine the expression of amino-terminal pro-brain natriuretic peptide （NT-proBNP） and adenosine triphosphate （ATP） in serum. Liquid chromatography-mass spectrometry was used to observe the changes of metabolites and related pathways in myocardial tissue， the mobile phase consisted of 25 mmol·L-1 ammonium acetate and 25 mmol·L-1 ammonia hydroxide in water （A） and acetonitrile （B） for gradient elution （0-0.5 min， 95%B； 0.5-7 min， 95%-65%B； 7-8 min， 65%-40%B； 8-9 min， 40%B； 9-9.1 min， 40%-95%B； 9.1-12 min， 95%B）， electrospray ionization was used under positive and negative ion detection modes， acquisition range was m/z 70-1 050. ResultCompared with the sham-30 d group， the left ventricular internal diameter at end-systole （LVIDs） in TAC-30 d group was significantly decreased （P<0.01）， and left ventricular ejection fraction （LVEF）， fraction shortening （FS）， left ventricular end-diastolic posterior wall thickness （LVPWd）， left vebtricular end-systolic posterior wall thickness （LVPWs） were significantly increased （P<0.01）， there were cardiomyocyte arrangement disorder， edema， collagen fibre hyperplasia， the content of NT-probNP was significantly increased， while the content of ATP was significantly decreased （P<0.01）， and 15 metabolites with abnormal expression were involved in pyrimidine metabolic pathway， pantothenic acid and coenzyme A biosynthesis pathway. Compared with the sham-60 d group， LVEF and FS in the TAC-60 d group were significantly decreased （P<0.01）， and left ventricular internal diameter at end-diastole （LVIDd）， LVIDs and LVPWd were increased （P<0.05， P<0.01）， the edema of myocardial cells increased obviously， myocardium fibers degenerated， coagulation necrosis appeared， and a large amount of collagen fibers were deposited， the expression of NT-proBNP increased and the expression of ATP decreased （P<0.01）， there were 21 metabolites with abnormal expression， involving pyrimidine metabolic pathway， and starch and sucrose metabolic pathway. ConclusionAt 30 d after TAC， there are myocardial hypertrophy， lipid metabolism disorder， pyrimidine metabolism disorder and energy imbalance. At 60 d after TAC， there are heart failure， aggravation of lipid metabolism disorder， excessive activation of glucose metabolism， and continuous disorder of pyrimidine metabolism.
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BACKGROUND: Heart failure (HF) is the leading cause of death in western countries. Cardiac dysfunction is accompanied by skeletal alterations resulting in muscle weakness and fatigue. Exercise is an accepted interventional approach correcting cardiac and skeletal dysfunction, thereby improving mortality, re-hospitalization and quality of life. Animal models are used to characterize underpinning mechanisms. Transverse aortic constriction (TAC) results in cardiac pressure overload and finally HF. Whether exercise training improves cardiac remodeling and peripheral cachexia in the TAC mouse model was not analyzed yet. In this study, 2 weeks post TAC animals were randomized into two groups either performing a moderate exercise program (five times per week at 60% VO2 max for 40 min for a total of 8 weeks) or staying sedentary. RESULTS: In both TAC groups HF characteristics reduced ejection fraction (- 15% compared to sham, p < 0.001), cardiac remodeling (+ 22.5% cardiomyocyte cross sectional area compared to sham; p < 0.001) and coronary artery congestion (+ 34% diameter compared to sham; p = 0.008) were observed. Unexpectedly, peripheral cachexia was not detected. Furthermore, compared to sedentary group animals from the exercise group showed aggravated HF symptoms [heart area + 9% (p = 0.026), heart circumference + 7% (p = 0.002), right ventricular wall thickness - 30% (p = 0.003)] while muscle parameters were unchanged [Musculus soleus fiber diameter (p = 0.55), Musculus extensor digitorum longus contraction force (p = 0.90)]. CONCLUSION: The severe TAC model is inappropriate to study moderate exercise effects in HF with respect to cardiac and skeletal muscle improvements. Further, the phenotype induced by different TAC procedures should be well documented and taken into account when planning experiments.
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Animals , Mice , Quality of Life , Heart Failure , Muscle, Skeletal , Disease Models, Animal , Heart Ventricles , Mice, Inbred C57BLABSTRACT
Calnexin is a lectin-like molecular chaperone protein on the endoplasmic reticulum, mediating unfolded protein responses, the endoplasmic reticulum Ca homeostasis, and Ca signals conduction. In recent years, studies have found that calnexin plays a key role in the heart diseases. This study aims to explore the role of calnexin in the activation of cardiac fibroblasts. A transverse aortic constriction (TAC) mouse model was established to observe the activation of cardiac fibroblasts , and the cardiac fibroblasts activation model was established by transforming growth factor β1 (TGFβ1) stimulation. The adenovirus was respectively used to gene overexpression and silencing calnexin in cardiac fibroblasts to elucidate the relationship between calnexin and cardiac fibroblasts activation, as well as the possible underlying mechanism. We confirmed the establishment of TAC model by echocardiography, hematoxylin-eosin, Masson, and Sirius red staining, and detecting the expression of cardiac fibrosis markers in cardiac tissues. After TGFβ1 stimulation, markers of the activation of cardiac fibroblast, and proliferation and migration of cardiac fibroblast were detected by quantitative PCR, Western blot, EdU assay, and wound healing assay respectively. The results showed that the calnexin expression was reduced in both the TAC mice model and the activated cardiac fibroblasts. The overexpression of calnexin relieved cardiac fibroblasts activation, in contrast, the silencing of calnexin promoted cardiac fibroblasts activation. Furthermore, we found that the endoplasmic reticulum stress was activated during cardiac fibroblasts activation, and endoplasmic reticulum stress was relieved after overexpression of calnexin. Conversely, after the silencing of calnexin, endoplasmic reticulum stress was further aggravated, accompanying with the activation of cardiac fibroblasts. Our data suggest that the overexpression of calnexin may prevent cardiac fibroblasts against activation by alleviating endoplasmic reticulum stress.
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Objective To investigate intestinal microbiota changes of model mice with transverse aortic constriction (TAC) to find a new target point for preventing and treating cardiovascular disease. Methods Twelve C57BL/6 mice were randomly divided into TAC model group (group TN) and control group (group N) of 6 mice each. The group TN received minimally invasive surgery for ligating the aorta to make its constriction to the appropriate degree, while the group N received same operation but no constriction. Faecal samples were collected 22 days after the treatment. Intestinal flora were determined by 16S rDNA pyrosequencing and bioinformatics clustering analysis were performed with software of Quantitative Insights into Microbial Ecology. Results A higher abundance of Parabacteroides and a lower abundances of Lactobacillaceae, Lactobacillus and Cocleatum were present in TAC mice compared with the controls. Conclusion Intestinal flora changes would take place in the TAC mice. Intestinal flora may be a potential target for prevention and treatment of cardiovascular diseases, but further validation should be performed to verify the relationship between those intestinal flora changes and disease progression in animal models.
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Objective To observe the pathological changes of heart failure caused by transverse aortic constriction in rats.Methods Partial thoracotomy was performed to the second rib and the transverse aortic constriction was performed between the innominate and left carotid arteries to establish a model of heart failure in 24 rats.The same operation was performed on another 8 rats, except for the ligation of the transverse aorta.Echocardiographic assessment, hemodynamic measurement, myocardial histopathological examination and NT-proBNP measurement were performed to the sham group at 12 weeks and model group at 4 weeks, 8 weeks, 12 weeks after the operation.Result At 4 weeks after the operation, NT-proBNP, EF, FS and -dp/dtmax of the model group was significantly increased and LVESV, +dp/dtmax of the model group were significantly decreased (P<0.05).At 8 weeks after the operation, EF and-dp/dtmax of the model group were increased and +dp/dtmax of the model group was significantly decreased (P<0.05).At 12 weeks after the operation, NT-proBNP, EF and +dp/dtmax of the model group were decreased, and LVESV, LVEDV and -dp/dtmax of the model group were increased (P<0.05).The cardiomyocytes became hypertrophic and lined up in disorder at 4 weeks after the operation.Pathologic examination of the myocardial tissue showed connective tissue proliferation and inflammatory cell infiltration at 8 weeks after the operation, and cardiomyocyte apoptosis and collagen fiber deposition at 12 weeks after the operation.Conclusions Transverse aortic constriction induces heart failure in rats.The pathological processes are compensatory hypertrophy at 4 weeks after the operation, initial reaction of decompensation at 8 weeks after the operation, and heart failure at 12 weeks after the operation.
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Objective: To observe the protective roll of atorvastatin on post-operative cardiac remodeling induced by transverse aortic constriction (TAC) in experimental mice with its possible mechanism. Methods: A total of 48 C57BL/6 mice were randomly divided into 4 groups: Sham group, TAC group, TAC + valsartan group and TAC + atorvastatin group,n=12 in each group. Myocardial hypertrophy model was successfully established at 4 weeks after the operation, and then the animals were further treated by normal saline, valsartan 5mg/kg and atorvastatin 10mg/kg respectively for 8 weeks. Left ventricular anterior wall thickness at diastole (LVAWd), left ventricular posterior wall thickness at diastole (LVPWd), LVEF and left ventricular fractional shortening (FS) were examined by echocardiography, cardiac hypertrophy indexes were calculated. Protein expression of NF-κB was detected by Western blot analysis, cardiac tissue hydroxyproline (Hyp) level was measured by alkaline hydrolysis, serum levels of TNF-α, IL-1β were determined by ELISA, cardiac collagen deposition was identiifed by HE and Masson staining. Results: Compared with Sham group, TAC group had increased LVAWd, LVPWd, cardiac hypertrophy indexes and increased area of cardiac fibrosis, allP Conclusion: Atorvastatin had protective roll on myocardial hypertrophy induced by pressure overload in experimental mice, which might be related to its anti-inlfammatory effect.
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Objective: To explore the effect of exercise preconditioning (EP) on pathological cardiac hypertrophy and heart failure (HF) in pressure over-loaded experimental rats. Methods:A total of 60 SD rats at the age of 6 weeks were randomly divided into 3 groups, n=20 in each group. Sham-operation group, Transverse aortic constriction (TAC) group and EP + TAC group. The cardiac function and structure were evaluated by echocardiography, patholgical changes and HF biomarkers were examined for EP effect at 4 and 8 weeks after TAC. Results:Compared with Sham-operation group, the cardiac function and structure had obvious changes in the other 2 groups. Compared with TAC group, the ejection fraction in EP+ TAC group increased 15%, the heart weight index and left ventricular weight index decrease 15.7%and 20%respectively at 8 weeks after TAC, all P Conclusion: EP may improve cardiac pathological hypertrophy in pressure over-loaded rats at the early stage, and delay the heart failure process.
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Objective: To explore a novel animal model of physiological cardiac hypertrophy induced by long-term passive wheel running. Methods: Forty male Sprague-Dawley rats were randomly divided into four groups (n=10): normal control group, passive wheel running(PWR) group, sham operation group, and transverse aortic constriction(TAC) group.PWR group received passive wheel movement training, TAC group received aortic arch narrow operation, sham operation group did not receive ligature thoracic aorta, and other treatments were similar to that of TAC group; no treatment was given to the normal control group. Five weeks after training or operation, a comparison was made between different groups. The modeling results of PWR were assessed by echocardiography, morphology, and molecular hypertrophic-markers for heart failure. Results: Echocardiography findings showed that thickness of the left ventricle wall in PWR group was significantly increased compared with the normal control group, and that in the TAC group was significantly increased compared with the sham operation group (P<0.01); the stroke volume and ejection fraction were also significantly different between PWR and normal control group and between the TAC group and sham operation group(P<0.01). The left ventricle internal diameter at end-diastole was not significantly different from that of normal control group, but that in the TAC group was decreased by 38% compared with the sham operation group (P<0.01), indicating that the cardiac structures were significantly different between PWR and TAC groups. Compared with the normal control group, the heart weight/body weight ratio, left ventricular weight/body weight ratio and lung weight/body weight ratio were increased by 25.0%, 37.3% and 23.8% in PWR rats, respectively; compared with the sham group, the above indicators were increased by 31.6%, 38.8% and 56.6% in TAC rats, respectively(P<0.05 or P<0.01). Compared with the normal control group, the expression levels of atria natriuretic peptide (ANP)and brain natriuretic peptide (BNP)were 0.67-fold and 0.48-fold of those in PWR group(P<0.05), and those in the TAC group were 1.98-fold and 2.03-fold those of the sham operation group (P<0.05). Conclusion: Long-term PWR training can induce physiological cardiac hypertrophy in rats, which may provide a novel way for establishing physiological cardiac hypertrophy animal models.
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Objective To determinate the effects of sodium tanshinone ⅡA sulfonate(STS)on cardiomyocyte hypertrophy and explore the relative effects of STS on mitogen-activated protein kinase signal transduction system in rats with cardiomyocyte hypertrophy through constricting the thoracic aorta.Methods The models of cardiomyocyte hypertrophy were established in vivo,and the thoracic aorta was partially tied between the right innominate and the left common carotid arteries.The rats were randomly divided into 6 groups(n=8/group)as follows:①sham,②transverse aortic constriction(TAC),③TAC+low-dose Tan(TAC+LT)(5 mg/kg),④TAC+middle-dose Tan(TAC+MT)(10 mg/kg),⑤TAC+high-dose Tan(TAC+HT)(20 mg/kg),and ⑥ TAC+Val(10 mg/kg).After treatment for 8 weeks,echocardiography was performed to observe the changes in hypertrophy and heart function,and heart samples were cut into transverse sections and stained with hematoxylin and eosin(H&E).The MAPKs protein expression in the cardiomyocytes was detected by Western blot.Results The heart weight index(HWI),left ventricular mass index(LVMI)and cross-sectional diameter of cardiomyocytes(CD),left ventricular posterior wall thickness(LVWT),and interventricular septal thickness(IVS)were significantly increased in TAC group as compared with sham group.The relative parameters in STS groups and Val group were reduced as compared with those in TAC group.Western blot analysis revealed the p-ERK and p-p38 expression was significantly decreased in TAC group as compared with sham group(P＜0.01).The p-ERK expression was significantly decreased in STS groups and Val group as compared with TAC group(P＜0.05).The TAC+HT group,TAC+MT group and Val group had significantly higher p-p38 expression than TAC group(P＜0.05).Conclusion Tanshinone ⅡA could regulate the expression of protein in MAPK pathway to exert its inhibitory effects on hypertrophy of cardiomyocytes.