Myocardial Cell Apoptosis Index Research Articles

Pterostilbene-Loaded Polydopamine Nanoparticles Down-Regulate Tumor Necrosis Factor-α and Improve Myocardial Function in Mice with Acute Myocardial Infarction

TNF-α expression is related to myocardial function damage and recovery in patients with acute myocardial infarction, but its mechanism is not clear. 50 SD mice, 10 in each group, were in this study divided into TNF-α group, Notch1/eIF3a agonist group, model group, positive control group, and control group. The cardiac function score, myocardial infarction volume, myocardial cell apoptosis index, TNF-α expression, and Notch1/eIF3a pathway factor expression were observed. The size of polydopamine nanoparticles carrying pterostilbene was about 15.5 nm, and cardiac function score, myocardial infarction volume, myocardial cell apoptosis index, and myocardial cell apoptosis number in the model group and Notch1/eIF3a agonist group were higher than model group and Notch1/eIF3a agonist group (P < 0.05). Compared with model group, the Notch1/eIF3a agonist group, TNF-α group, and positive control group showed no differences (P > 0.05). The model group and Notch1/eIF3a agonist group had highest inflammatory response and lowest oxidative stress, which were significantly different from other groups (P < 0.05). The expression of TNF-α in Notch1/eIF3a agonist group, model group, and positive control group all decreased, which was significantly different from other groups (P < 0.05). The expressions of p-IL-6 and p-eIF3a in model group, Notch1/eIF3a agonist group and positive control group were all highest (P < 0.05). Carrying Pterostilbene-loaded polydopamine nanoparticles (PPNs) therefore inhibits apoptosis of cardiomyocytes, Notch1/eIF3a signaling pathway and inflammatory response and oxidative stress of myocardial system, and protects cardiomyocytes of model mice.

Cardioprotective Effects of Tetrahydropalmatine on Acute Myocardial Infarction in Rats.

Tetrahydropalmatine (THP) is an active component of Corydalis yanhusuo W. T. Wang. The current study investigates the possible cardioprotective effects of tetrahydropalmatine in acute myocardial ischemia (AMI) rats. The anterior descending coronary artery of SD rats was ligated to establish an AMI model. After two weeks of gavage of THP, cardiac function was determined by echocardiography. The organ index and the infarct size were assessed after the experiment, and the histopathological myocardial tissue changes were observed. In addition, the apoptosis index of myocardial cells was detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The levels of SOD, MDA, CAT, GSH-Px, BNP, and cTn-I were measured by enzyme-linked immunosorbent assay. To determine relevant proteins, the Western blot and molecular docking were applied. Compared with the model group, THP could enhance rat cardiac ejection function to improve cardiac function, drastically lessen the infarct size, reduce myocardial cell damage and inflammatory cell infiltration. THP might also prevent ischemic myocardial damage by inhibiting myocardial cell apoptosis and efficiently reducing oxidative stress. Specifically, THP could decrease MDA, BNP, c-TnI activities, as well as the expression of Bax and Caspase-3 protein, while increasing SOD, GSH-Px, CAT activities, and Bcl-2 level. Furthermore, THP could significantly promote the phosphorylation of PI3K and Akt proteins. The involved pathways and proteins have also been verified through molecular docking. According to these findings, THP may preserve the myocardium due to its anti-oxidant and anti-apoptotic properties.

Preparation of Puerarin Nanocrystals and Their Application on Rats with Myocardial Ischemic Injury Combined with Electroacupuncture-PC6 (Neiguan)

The effect of electroacupuncture PC6 (Neiguan) combined with puerarin nanocrystal preparation (PUE-NP) on myocardial injury and autophagy in a rat model with myocardial ischemia was explored in this study. PUE-NPs were first prepared, and there was an analysis on the fourier transform infrared spectroscopy (FTIR), particle size distribution of nanocrystalline preparation, Zeta potential, and X-ray diffractometry (XRD) characterization, so as to analyze the difference in the in vitro cumulative release rate of PUE and PUE-NPs. Secondly, Sprague-Dawley (SD) rats were taken as the subjects investigated. Besides, they were divided randomly into a sham surgery group (Sham), a myocardial ischemia model group (Model), an electroacupuncture Neiguan acupoint pretreatment model group (EA+M), an electroacupuncture Neiguan acupoint pretreatment combined with PUE treatment model group (EA+PUE+M), and an acupuncture Neiguan point pretreatment combined with PUENPs treatment model group (EA+PUE-NPs+M). Then, the rats were treated with abdominal anesthesia, and their serums were extracted to detect the differences in serum creatine kinase MB isoenzyme (CK-MB) and lactate dehydrogenase (LDH) concentrations. After the rats were sacrificed, myocardial tissues were taken out, and the Western blot, hematoxylin-eosin (HE) staining, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining were employed to detect apoptosis index, pathological changes of myocardial tissue morphology, and expression differences of autophagy-related protein, such as Beclin-1, LC3, and mammalian target of rapamycin (mTOR). It was found that the average particle size of PUE-NPs was 155.9±17.3 nm, and the average Zeta potential was −15.3±2.1 mV. FTIR and XRD maps displayed that PUE-NPs nanoparticles were successfully prepared, and had a longer lasting in vitro release rate compared with PUE bulk drugs. The results of animal experiments indicated that the myocardial infarction area, serum LDH and CK-MB concentration, and myocardial cell apoptosis index, LC3II/I ratio, mTOR phosphorylation level, and Beclin-1 protein expression level of rats from the EA+M group, EA+PUE+M group, and EA+PUENPs+ M group reduced sharply compared with the model group (P < 0.05). Compared with the EA+M group, the above indicators of rats from the EA+PUE+M group and EA+PUE-NPs +M group dropped steeply (P < 0.05). Besides, the above indicators of rats from the EA +PUE-NPs+M group were lower obviously than those indicators of the EA+PUE+M group (P < 0.05). In conclusion, the above results revealed that the combination of electroacupuncture PC6 (Neiguan) and PUE preparation could improve myocardial cell apoptosis and autophagy levels in rats with myocardial ischemia, while the improvement effect of combining PUE-NPs was more marked.

People’s Hospital Of Huishan

To explore the mechanism of hypertension caused by sorafenib in liver cancer-bearing rats based on Vascular Endothelial-Growth Factor (VEGF) signal pathway. After the three groups (blank, liver cancer and Spontaneously Hypertensive Rat (SHR) groups, n = 30) were administered orally with sorafenib (2 mg/kg), the non-invasive tail arterial pressure measurement was employed to determine the changes in blood pressure (BP). Enzyme-linked immunosorbent assay measured the changes of VEGF and Nitric Oxide (NO) in serum. The expressions of Kinase insert Domain Receptor tyrosine kinase (KDR-CD), endothelial Nitric Oxide Synthase (eNOS), Bax and Bcl-2 were detected by Western blot. TUNEL assay detected the Apoptosis Index (AI) of cardiomyocyte. CD31 immunohistochemical staining was observed the changes of Myocardial Capillary Density (MCD). The BP and VEGF levels of the blank and SHR groups were not significantly (P > 0.05) different from those in the before treatment cohort, while the BP of the liver cancer group was significantly (P < 0.05) higher. VEGF level was significantly (P < 0.05) lower than before. Compared with the blank group, the levels of NO, KDR-CD, eNOS, Bcl-2/Bax and MCD in the liver cancer group were significantly (P < 0.05) lower than those in the after administration, while the myocardial cell AI increased significantly (P < 0.05). After antagonist intervention, the BPs and myocardial AI of the liver cancer and SHR groups were significantly lower than before the intervention. Besides, levels of KDR-CD, eNOS, Bcl-2/Bax protein, MCD, serum VEGF and NO were significantly higher than before the intervention (P<0.05). Induction mechanism of hypertension induced by sorafenib may be owing to the inhibition of the VEGF signaling pathway, and reduction of endothelial cells proliferation leading to blockade of NO synthesis. This causes vasoconstriction, while promoting myocardial cell apoptosis and decreasing capillary density, thereby inducing the occurrence of hypertension.

Protective effects of salvia miltiorrhiza and ligustrazine injection preconditioning on ischemia-reperfusion injury of rat

Objective To investigate the protective effect of salvia miltiorrhiza ligustrazine injection (SLI) pretreatment on myocardial cells after myocardial ischemia reperfusion injury in rats and its potential mechanism. Methods Thirty health male Sprague-Dawley rats were randomly divided into three groups, Sham group (Sham), myocardial ischemia-reperfusion injury model group (I/R), salvia miltiorrhiza ligustrazine treatment group (I/R+ SLI). Except Sham group, myocardial ischemia-reperfusion injury models were established in vivo in rats. The pathological changes of electrocardiogram (ECG) in each group of rats were observed and the myocardial infarction area was measured well. The apoptosis of myocardial cells was detected by TUNEL. Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the mRNA expression levels of apoptosis-related genes B cell lymphoma/leukemia-2 (bcl-2), bcl-2 associated X protein (bax) and cysteinyl aspartate-specific protease (Caspase)-3. Statisticalanalysis of data using the statistical product and service solutions 19.0 software. Results Compared with I/R group, ECG waveform in I/R+ SLI group is obviously improved, ST segment changes are reduced, and waveform is close to normal. Myocardial infarction area (32.14±3.09) and myocardial cell apoptosis index (19.09±13.91) were decreased significantly (t=10.684, t=9.012, P< 0.01). The expression level of bcl-2 mRNA (4.52±0.50) in myocardial cells was significantly increased (t=19.834, P<0.01), while the expression levels of bax and Caspase-3 mRNA (2.73±0.29, 3.00±0.36) were significantly decreased, with significant differences (t=10.976, 14.936, P<0.01). Conclusion SLI can effectively reduce myocardial injury induced by myocardial ischemia-reperfusion and has certain protective effect on cardiac function. Its mechanism may be related to inhibiting myocardial cell apoptosis. Key words: Salvia miltiorrhiza ligustrazine; Myocardial ischemia/Reperfusion; Apoptosis

MiR-181a affects myocardial ischemia-reperfusion injury in rats via regulating akt signaling pathway.

The aim of this study was to explore the influence of the micro ribonucleic acid (miR)-181a on myocardial ischemia-reperfusion injury (MIRI) in rats by regulating the protein kinase B (Akt) signaling pathway. A total of 30 male Sprague-Dawley rats were randomly divided into three groups, including: sham operation group (Sham group), ischemia-reperfusion group (I/R group), and miR group (MiR-181a group). The model of myocardial ischemia-reperfusion was successfully established in rats. The concentration of blood nitric oxide (NO) was detected by the relative kits. Myocardial apoptosis in rats of the three groups was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Furthermore, the expressions of myocardial cell apoptosis-related proteins and tumor necrosis factor-α (TNF-α), and the degree of Akt phosphorylation were determined by Western blotting. Compared with Sham group and miR-181a group, I/R group exhibited significantly elevated left ventricular end-diastolic pressure (LVEDP) (p<0.05). However, the left ventricular end-systolic pressure (LVESP), stroke work (SW), differential pressure (DP), end-systolic pressure-volume relationship (ESPVR), and end-diastolic pressure-volume relationship (EDPVR) significantly decreased in the I/R group (p<0.05). In comparison with miR-181a group, the apoptosis index of myocardial cells was remarkably elevated in the I/R group, showing statistically significant differences (p<0.05). The protein bands were analyzed using the Quantity One detection software. The results demonstrated that, compared with the Sham group, I/R group showed significantly elevated expressions of cysteine-aspartic protease (Caspase)-3 and TNF-α in rat myocardial tissues (p<0.05). However, the protein levels of Akt and endothelial NO synthase (eNOS) phosphorylation and NO in rat myocardial cells were significantly down-regulated (p<0.05). MiR-181a activates Akt to promote the phosphorylation of its downstream protein eNOS, inhibit the apoptosis of myocardial cells, and alleviate MIRI.

Alda‑1, an aldehyde dehydrogenase‑2 agonist, improves long‑term survival in rats with chronic heart failure following myocardial infarction.

Alda-1, an aldehyde dehydrogenase 2 (ALDH2) agonist, has been demonstrated to reduce injury caused by acute myocardial infarction (MI) and ischemia/reperfusion. The present study aimed to investigate whether oral administration of Alda-1 improved long-term survival of rats with chronic heart failure (CHF) post-MI. MI model rats treated daily with Alda-1 exhibited an increase in 20-week survival rate compared with untreated MI rats. Alda-1 treatment decreased the heart weight/body weight ratio, collagen volume, left ventricular (LV) internal diameter at the end of diastole and LV internal diameter at the end of systole, while increasing LV ejection fraction with evident LV fractional shortening. Myocardial cell apoptosis index, the activity of caspase-3 and the expression of cleaved-caspase-3 were also reduced by Alda-1 treatment. The protective effects of Alda-1 were associated with reduced 4-hydroxynonenal accumulation. The results of the present study revealed that the long-term treatment with Alda-1 prevented the progression of ventricular remodeling and improved the long-term survival of rats with CHF post-MI.

Simvastatin prevented myocardium of diabetes rats from apoptosis through inhibition of oxidative stress

To investigate the protective effects and the possible mechanisms of simvastatin on myocardial injury induced by diabetes. Twenty-four SD rats (180~220)g were randomly divided into control group (control, n=8) and modeled groups(n=16), the modeled groups were injected with streptozotocin intraperitoneally to induce diabetes. Then the modeled rats were randomly divided into diabetes mellitus group (DM group, n=8) and diabetes mellitus + simvastatin group (DM+S group, n=8). Rats in DM+S group were treated with simvastatin at the dose of 40 mg/(kg·d)by gavage for 4 weeks, and the other two groups were treated with the same amount of saline. At the end of experiments, the heart tissues were collected for further observation. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in heart tissues were measured by spectrophotometry; HE staining of rat heart slides was used to observe the pathological changes; TUNEL assay was used to determine the apoptosis index of myocardial cells in each groups; The distribution of p53 in the heart tissues was evaluated by immunohistochemistry; Western blot was used to detect the expressions of p53, p53-phospho-serine 15, Bax and Bcl-2 in the heart tissues. ①Compared with control group, the content of malondialdehyde (MDA) was increased while the activity of superoxide dismutase (SOD) was decreased significantly in DM group (P<0.01). After simvastatin administration, the activity of SOD was increased and the content of MDA was decreased significantly (P<0.01). ② HE staining results showed that the myocardial cells in the DM group were disorganized, with unclear morphological structure and a large number of inflammatory cells infiltration. Compared with DM group, the myocardial morphology in DM+S group was improved significantly. ③TUNEL staining results showed that the apoptosis index of myocardial cells in DM group was increased significantly compared with that of control group, and the apoptosis index was decreased significantly after the treatment of simvastatin (P<0.01).④ Immunohistochemistry showed that compared with control group,the expression of p53 in DM group was increased significantly, and was expressed in both cytoplasm and nucleus, while the expression of p53 in DM+S group was decreased and the expression of p53 in nucleus was decreased significantly (P<0.01). ⑤ The results of Western blot showed that the expression levels of p53, p53-phospho-serine15 and Bax were higher than those in control group, and the expression of Bcl-2 was lower than that in control group (P<0.01). After simvastatin administration, the expression levels of p53,p53-phospho-serine 15 (P<0.01) and Bax were decreased significantly (P<0.05) and the expression of Bcl-2 was increased (P<0.05). Simvastatin exerted protective effects on myocardial injury caused by diabetes through improving the abnormal morphological changes of diabetic myocardium, alleviating oxidative stress and inhibiting apoptosis of myocardial cells. The mechanism is related to the regulation of apoptosis pathway mediated by p53.

Advanced Interfere Treatment of Diabetic Cardiomyopathy Rats by aFGF-Loaded Heparin-Modified Microbubbles and UTMD Technique.

This study aims to investigate the preclinical performance and mechanism of a novel strategy of aFGF-loaded heparin-modified microbubbles (aFGF-HMB) combined with ultrasound-targeted microbubble destruction (UTMD) technique for diabetic cardiomyopathy (DCM) prevention. Type 1 diabetic rats were induced by streptozotocin. Twelve weeks after intervention, indexes from transthoracic echocardiography and cardiac catheterization showed that the left ventricular function in the aFGF-HMB/UTMD group was significantly improved compared with diabetes control (DM). From Picrosirius Red staining and TUNEL staining, the aFGF-HMB/UTMD group showed significant difference from the other groups. The cardiac collagen volume fraction (CVF) and myocardial cell apoptosis index (AI) in aFGF-HMB/UTMD group decreased to 7.2% and 7.11% respectively, compared with the DM group (CVF=24.5% and AI =20.3% respectively). The results of myocardial microvascular density (MCD) also proved the strongest inhibition of aFGF-HMB/UTMD group on DCM progress. CD31 staining of aFGF-HMB/UTMD group reached 22 n/hrp, much higher than that of DM group (9 n/hrp). These results confirmed that the abnormalities including left ventricular dysfunction, myocardial fibrosis, cardiomyocytes apoptosis and microvascular rarefaction could be suppressed by twice weekly aFGF treatments for 12 consecutive weeks (free aFGF or aFGF-HMB+/-UTMD), with the strongest improvements observed in the aFGF-HMB/UTMD group (P<0.05 vs free aFGF or aFGF-HMB). Western blot analyses of heart tissue further revealed the highest aFGF, anti-apoptosis protein (Bcl-2), VEGF-C, pAkt, pFoxo-3a levels and strongest reduction in pro-apoptosis proteins (Bax) level in aFGF-HMB/UTMD group. Overall, aFGF-HMB combined with UTMD technique might be developed as an effective strategy to prevent DCM in future clinical therapy.

Protective effect of Lai Fu Cheng Qi decoction on severe acute pancreatitis-induced myocardial injury in a rat model.

The aim of the present study was to evaluate the effects of Lai Fu Cheng Qi decoction on myocardial injury in rats with severe acute pancreatitis (SAP). In total, 30 rats were randomly divided into sham, SAP and decoction treatment groups. SAP was induced by a retrograde pancreatic duct injection of 5% sodium taurocholate in the SAP and decoction treatment groups. Rats in decoction treatment group also received intragastric administration of Lai Fu Cheng Qi decoction. The serum levels of creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were detected using an automatic biochemical analyzer. In addition, myocardial Na+-K+-ATPase activity was analyzed using a spectrophotometric method and the mitochondrial membrane potential was measured by flow cytometry. Myocardial apoptosis was assessed using a TUNEL assay and pathological changes to the heart and pancreas were detected by hematoxylin and eosin staining. Compared with the rats in the sham group, rats in the SAP and decoction treatment groups exhibited significantly higher levels of serum CK-MB and LDH, apoptosis index and pathological scores, and had significantly lower levels of Na+-K+-ATPase activity and mitochondrial membrane potential. However, when compared with the SAP group, the serum levels of CK-MB and LDH, the pathological scores of the pancreas and heart, and the myocardial cell apoptosis index in the decoction treatment group were significantly lower. Furthermore, the Na+-K+-ATPase activity and mitochondrial membrane potential were significantly increased in the decoction treatment group when compared with the SAP group. Therefore, Lai Fu Cheng Qi decoction was shown to exert a protective effect on myocardial injury induced by SAP in rats.

PI3K-Akt/eNOS in remote postconditioning induced by brief pulmonary ischemia

Postconditioning, a series of brief ischemia-reperfusion sequences given before an ischemic heart undergoes sustained reperfusion, has been shown to lessen ischemia/reperfusion injury. The current study establishes a rabbit model of myocardial ischemia-reperfusion and studied the effects of pulmonary remote postconditioning in this model. Serum levels of creatine kinase (CK), superoxide dismutase (SOD), and malondialdehyde (MDA), protein expression of endothelial nitric oxide synthase (eNOS), Rho kinase (ROCK- 2), and protein kinase B (Akt) in myocardial cells and the apoptosis index of myocardial cells were examined. Pulmonary remote postconditioning decreased CK, significantly decreased MDA, and increased SOD. Postconditioning significantly increased eNOS protein expression. Administration of eNOS inhibitor, L-NAME, dramatically suppressed the postconditioning-induced eNOS protein expression and serum SOD level, but significantly increased MDA level. The two longer sessions of postconditioning increased Akt, although this increase was not accompanied by changes in levels of the Akt inhibitor, ROCK-2. Blocking eNOS activity with L-NAME had no visible effect on either Akt or ROCK-2. Our results suggest a role for Akt in remote postconditioning-induced myocardial protection, but do not support an involvement of eNOS in Akt-mediated action.

Use of Wave Intensity Analysis of Carotid Arteries in Identifying and Monitoring Left Ventricular Systolic Function Dynamics in Rabbits

Wave intensity analysis (WIA) of the carotid artery was conducted to determine the changes that occur in left ventricular systolic function after administration of doxorubicin in rabbits. Each randomly selected rabbit was subject to routine ultrasound, WIA of the carotid artery, cardiac catheterization and pathologic examination every week and was followed for 16 wk. The first positive peak (WI1) of the carotid artery revealed that left ventricular systolic dysfunction occurred earlier than conventional indexes of heart function. WI1 was highly, positively correlated with the maximum rate of rise in left ventricular pressure in cardiac catheterization (r = 0.94, p < 0.01) and moderately negatively correlated with the apoptosis index of myocardial cells, an indicator of myocardial damage (r = −0.69, p < 0.01). Ultrasound WIA of the carotid artery sensitively reflects early myocardial damage and cardiac function, and the result is highly consistent with cardiac catheterization findings and the apoptosis index of myocardial cells.

ASSA13-03-23 Effects Caused by Postconditioning of Mouse Heart Suffering from Reperfusion Injury and Mechanisms Induced by Reperfusion Injury Salvage Kinase

Objective Explore cardioprotective mechanisms induced by reperfusion injury salvage kinase (ERK1/2) signal transduction pathways changes in isolated mouse hearts. Methods Established Langendorff perfused mouse heart model, 96 C57BL mouse hearts were divided to 4 groups: 1) I/R control: 30 min global ischemia and 2 h reperfusion; 2) IPC:IPC with 3 episodes of 10 s of ischemia and 10 s reperfusion after 30 min ischemia and before 2 h reperfusion; 3) IPC+ERK1/2 inhibitor PD98059 (10– 5 mol/L for 15 min); 4) I/R+ERK1/2 inhibitor PD98059 (10– 5 mol/L for 15 min). The effects of IPC on Ischemic size, myocardial cell apoptosis index, phospho-protein kinase (P-ERK1/2) and phospho-protein kinase B(P-Akt) were measured. Expressions of apoptosis related proteins, including Bax, Bcl-2 and Cyt.C, in cytosolic and membrane fraction were detected by Western blot. Results Following 180min reperfusion, infarct size was significantly reduced in postconditioning group (32.8 ± 3. 8)% compared with I/R group hearts [(48.1 ± 4.8)%, P Conclusions Postconditioning plays a pivotal role in reducing myocardial infarct size after ischemia/reperfusion injury. IPC right before reperfusion but not after reperfusion attenuated I/R injury of isolated mouse hearts via the upstream target, ERK1/2-MAPK signal transduction pathway which mediated the expression of Bcl-2/Bax and the release of mitochondrial Cyt.C.

Effects of continue exhaustive running on rat cardiovascular ultrastructure, myocardial apoptosis and vessel function

ObjectiveTo observe the effects of continue exhaustive running on rat cardiovascular ultrastructure, myocardial apoptosis and vessel function.MethodsTwenty four male Wistar rats were assigned to sedentary control group adaptive running group...