Three new species and two newly recorded species of Tachininae from Tibet, China (Arthropoda, Insecta, Diptera, Tachinidae).

During our studying of the fauna of Tibet, China, many specimens of the subfamily Tachininae (Diptera, Tachinidae) were collected and examined. Three species are described here as new to science, Leskialatisurstylasp. nov., Trichoformosomyiacuonaensissp. nov., and Tachinajilongensissp. nov., and two species, Nemoraeajavana (Brauer & Bergenstamm, 1894) and N.echinata Mesnil, 1953, are newly recorded from Tibet. In addition to their descriptions, illustrations, and diagnoses, three identification keys are provided. The specimens in this study are kept in the Insect Collection of Shenyang Normal University, China (SYNU).

Two new species and one newly recorded species of Tachinidae from Chongqing, China (Diptera: Calyptratae).

Tachinid specimens (Diptera, Tachinidae) from Yintiaoling National Nature Reserve, Chongqing, Oriental China were collected and examined, two species are recognized and new to science, Billaea yintiaoling sp. nov., Leskia flavitugula sp. nov., and L. miranda Mesnil is newly recorded for China. Here their descriptions, illustration and keys to species of Chinese species of Billaea and Leskia are provided. The specimens in this study are kept in the Insect Collection, Shenyang Normal University, China (SYNU).

Comparison of efficacy and safety of His-Purkinje system pacing versus cardiac resynchronisation therapy in patients with pacing-induced cardiomyopathy: protocol for a randomised controlled trial.

INTRODUCTION: Recent studies have shown that the His-Purkinje system pacing (HPSP) can achieve electrocardiomechanical synchronisation, and thus improve cardiac function. For patients with pacing-induced cardiomyopathy (PICM) who should be treated with pacemaker upgrade, the HPSP is a viable alternative to cardiac resynchronisation therapy (CRT). However, no randomised controlled trial has been performed to evaluate the efficacy and safety of HPSP in patients with PICM. The present study compared the efficacy and safety of HPSP with that of traditional CRT in the treatment of patients with PICM. METHODS AND ANALYSIS: This study is a single-centre, randomised controlled non-inferiority trial. This trial was carried out at the cardiac centre of Beijing Anzhen Hospital. A total of 46 patients with PICM who needed pacemaker upgrade treatment between January 2022 and December 2023 will be enrolled in this study. Patients will be randomised into an investigational group (HPSP) and a control group (CRT) at a 1:1 ratio. The primary outcome is the duration of QRS complex (QRS width), and the secondary outcomes are NT-proBNP (N terminal pro B type natriuretic peptide), C reactive protein, the number of antibiotics used, left ventricular ejection fraction, end systolic volume, end diastolic volume, the hospitalisation duration, the incidence of postoperative infection, pacemaker parameters (threshold, sensing and impedance), the 6-minute walking test, and quality of life (36-Item Short Form Survey scale), all-cause mortality, cardiovascular death, heart failure-related rehospitalisation rate, other rehospitalisation rates, major complication rates and procedure costs. ETHICS AND DISSEMINATION: This study has been approved by the Beijing Anzhen Hospital Medical Ethics Committee (No. 2020043X). TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR2000034265).

Study on the Curative Effect and Safety of Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation via Zero-Fluoroscopy Transseptal Puncture under the Dual Guidance of Electroanatomical Mapping and Intracardiac Echocardiography.

AIMS: 3D electroanatomical mapping combined with intracardiac echocardiography- (EAM-ICE-) guided transseptal puncture has been proven safe and effective during the radiofrequency catheter ablation (RFCA) procedure used to treat paroxysmal atrial fibrillation (PAF). In this study, we aimed to compare the curative effect and safety of RFCA via F (fluoroscopy) and zero-fluoroscopy transseptal puncture guided by EAM-ICE in patients with PAF. METHODS AND RESULTS: A prospective study in which 110 patients with PAF were included and assigned to two groups was conducted. Fifty-five (50%) patients were enrolled in the EAM-ICE group, whereas the other 55 (50%) patients were enrolled in the F group. There were no significant differences in baseline characteristics between the two groups. The transseptal duration time was longer in the EAM-ICE group (19.8 ± 3.0 min vs. 8.6 ± 1.2 min, p ≤ 0.01); however, fluoroscopy was not used in the EAM-ICE group compared with the F group (0 mGy vs. 109.1 ± 57.9 mGy). Similarly, there was also no significant difference in the recurrence rate of atrial fibrillation between the EAM-ICE and F groups (25.5% vs. 18.2%, p=0.356). CONCLUSION: RFCA via EAM-ICE-guided zero-fluoroscopy transseptal puncture in patients with PAF is safe and effective for long-term follow-up.

Efficacy and safety of left bundle branch area pacing versus right ventricular apex pacing in patients with atrioventricular block: study protocol for a randomised controlled trial.

INTRODUCTION: Left bundle branch area pacing (LBBaP) is a relatively new approach for physiologic pacing. A limited number of retrospective clinical studies, featuring small sample sizes, have shown that compared with right ventricular apex pacing (RVAP), the QRS duration of postoperative ECG in LBBaP patients is narrower and the cardiac systolic function is improved. However, there have been no randomised controlled trials (RCTs) evaluating the efficacy and safety of LBBaP in patients with atrioventricular block (AVB). Therefore, the current study intends to address the paucity in RCT data evaluating LBBaP versus RVAP in AVB patients. ANALYSIS AND METHODS: This study is a single-centre, randomised controlled superiority trial to be conducted at the Cardiac Centre of Beijing Anzhen Hospital. From January 2021 to December 2023, 210 consecutive AVB patients meeting the inclusion criteria and receiving pacemaker implantation will be enrolled. Participants will be randomly divided into an experimental group (LBBaP) and a control group (RVAP) at a 1:1 ratio. The primary outcome is left ventricular ejection fraction (LVEF), which will be assessed by echocardiography. The secondary outcomes in this study are synchrony of left ventricular systole, NT-proBNP, LVEDD, the 6-min walk distance, quality of life (SF-36 scale), all-cause mortality, cardiovascular death events, rehospitalisation rate and major complication rate. ETHICS AND DISSEMINATION: This study was approved by the Medical Ethics Committee of Beijing Anzhen Hospital (No. 2020021X). The results of the trial will be presented at national and international conferences. We hypothesise that compared with RVAP, LBBaP will be superior for treating patients with AVB. This trial will provide evidence-based suggestion for the majority of electrophysiologists in pacing implantation. TRIAL REGISTRATION: ChiCTR2000034335.

Recurrence Plot-Based Approach for Cardiac Arrhythmia Classification Using Inception-ResNet-v2.

The present study addresses the cardiac arrhythmia (CA) classification problem using the deep learning (DL)-based method for electrocardiography (ECG) data analysis. Recently, various DL techniques have been utilized to classify arrhythmias, with one typical approach to developing a one-dimensional (1D) convolutional neural network (CNN) model to handle the ECG signals in the time domain. Although the CA classification in the time domain is very prevalent, current methods' performances are still not robust or satisfactory. This study aims to develop a solution for CA classification in two dimensions by introducing the recurrence plot (RP) combined with an Inception-ResNet-v2 network. The proposed method for nine types of CA classification was tested on the 1st China Physiological Signal Challenge 2018 dataset. During implementation, the optimal leads (lead II and lead aVR) were selected, and then 1D ECG segments were transformed into 2D texture images by the RP approach. These RP-based images as input signals were passed into the Inception-ResNet-v2 for CA classification. In the CPSC, Georgia, and the PTB_XL ECG databases of the PhysioNet/Computing in Cardiology Challenge 2020, the RP-based method achieved an average F1-score of 0.8521, 0.8529, and 0.8862, respectively. The results suggested the excellent generalization ability of the proposed method. To further assess the performance of the proposed method, we compared the 2D RP-image-based solution with the published 1D ECG-based works on the same dataset. Also, it was compared with two traditional ECG transform into 2D image methods, including the time waveform of the ECG recordings and time-frequency images based on continuous wavelet transform (CWT). The proposed method achieved the highest average F1-score of 0.844, with only two leads of the 12-lead ECG original data, which outperformed other works. Therefore, the promising results indicate that the 2D RP-based method has a high clinical potential for CA classification using fewer lead ECG signals.

A New Method for Detecting Myocardial Ischemia Based on ECG T-Wave Area Curve (TWAC).

In recent years, coronary heart disease (CHD) has become one of the main diseases that endanger human health, with a high mortality and disability rate. Myocardial ischemia (MI) is the main symptom in the development of CHD. Continuous and severe myocardial ischemia will lead to myocardial infarction. The clinical manifestations of MI are mainly the changes of ST-T segment of ECG, that is, ST segment and T wave. Nearly one third of patients with CHD, however, has no obvious ECG changes. In this paper, a new method for detecting MI based on the T-wave area curve (TWAC) was proposed. Through observation and analysis of clinical data, it was found that there exist significant correlation between the morphology of TWAC and MI. The TWAC morphology of normal subject is smooth and gentle, while the TWAC morphology of patients with coronary stenosis is mostly jagged, and the curve becomes more severe with more severe stenosis. The preliminary test results show that the sensitivity, specificity, and accuracy of the proposed method for detecting MI are 84.3, 83.6, and 84%, respectively. This study shows that the TWAC based approach may be an effective method for detecting MI, especially for the CHD patients with no obvious ECG changes.

Prevalence of abnormal and borderline electrocardiogram changes in 13, 079 Chinese amateur marathon runners.

BACKGROUND: The 12-lead electrocardiogram (ECG) has been adopted as an important component of preparticipation cardiovascular screening. However, there are still controversies in the screening and few studies with a large sample size have reported the results of ECGs of marathon runners. Therefore, the purpose of this study was to assess the prevalence of normal, borderline, and abnormal ECG changes in marathon runners. METHODS: The 12-lead ECG data of 13,079 amateur marathon runners between the ages of 18 and 35 years were included for analysis. The prevalence of ECG abnormalities among different gender groups was compared with chi-square tests. RESULTS: In terms of training-related changes, sinus bradycardia, sinus arrhythmia, and left ventricular high voltage were found in approximately 15, 5, and 3.28% of the participants, respectively. The incidence of right axis deviation in the marathon runners was 1.78%, which was slightly higher than the incidence of left axis deviation (0.88%). No more than 0.1% of the amateur marathon runners exhibited ST-segment depression, T wave inversion (TWI), premature ventricular contraction, pathologic Q waves, and prolonged QT interval. CONCLUSIONS: Training-related ECG changes, including sinus bradycardia, sinus arrhythmia, and left ventricular high voltage, were common in amateur marathon runners. Most abnormal ECG changes, including ST-segment depression, TWI, premature ventricular contraction, pathologic Q waves, and prolonged QT interval, were infrequently found in amateur marathon runners. The data also suggested Chinese amateur marathon runners may have a relatively lower prevalence of ECG abnormalities than black and white runners.

Preliminary Study: Learning the Impact of Simulation Time on Reentry Location and Morphology Induced by Personalized Cardiac Modeling.

Personalized cardiac modeling is widely used for studying the mechanisms of cardiac arrythmias. Due to the high demanding of computational resource of modeling, the arrhythmias induced in the models are usually simulated for just a few seconds. In clinic, it is common that arrhythmias last for more than several minutes and the morphologies of reentries are not always stable, so it is not clear that whether the simulation of arrythmias for just a few seconds is long enough to match the arrhythmias detected in patients. This study aimed to observe how long simulation of the induced arrhythmias in the personalized cardiac models is sufficient to match the arrhythmias detected in patients. A total of 5 contrast enhanced MRI datasets of patient hearts with myocardial infarction were used in this study. Then, a classification method based on Gaussian mixture model was used to detect the infarct tissue. For each reentry, 3 s and 10 s were simulated. The characteristics of each reentry simulated for different duration were studied. Reentries were induced in all 5 ventricular models and sustained reentries were induced at 39 stimulation sites in the model. By analyzing the simulation results, we found that 41% of the sustained reentries in the 3 s simulation group terminated in the longer simulation groups (10 s). The second finding in our simulation was that only 23.1% of the sustained reentries in the 3 s simulation did not change location and morphology in the extended 10 s simulation. The third finding was that 35.9% reentries were stable in the 3 s simulation and should be extended for the simulation time. The fourth finding was that the simulation results in 10 s simulation matched better with the clinical measurements than the 3 s simulation. It was shown that 10 s simulation was sufficient to make simulation results stable. The findings of this study not only improve the simulation accuracy, but also reduce the unnecessary simulation time to achieve the optimal use of computer resources to improve the simulation efficiency and shorten the simulation time to meet the time node requirements of clinical operation on patients.

Serum-Soluble ST2 Is a Novel Biomarker for Evaluating Left Atrial Low-Voltage Zone in Paroxysmal Atrial Fibrillation.

BACKGROUND Paroxysmal atrial fibrillation (pAF) recurrence after radiofrequency catheter ablation (RFCA) is linked to low-voltage zone (LVZ). This study explored whether serum soluble ST2 (sST2) levels can predict the size of LVZs in patients with pAF. MATERIAL AND METHODS A total of 177 patients with pAF treated with RFCA were consecutively enrolled in this study. One hundred twenty-five patients (70.6%) with <20% LVZ were assigned to Group A, and 52 patients (29.4%) with a LVZ >20% were assigned to Group B. Levels of soluble ST2 (sST2), growth and differentiation factor (GDF-15) and tissue inhibitor of MMP1 (TIMP-1) were measured. RESULTS The sST2 levels were higher in Group B than in Group A (23.9±3.3 vs. 30.9±5.0 ng/mL, P<0.000). In multivariable logistic regression analysis, sST2 was the only independent parameter for predicting left atrial LVZ (odds ratio, 1.611 [1.379-1.882]; P<0.001). The cut-off value of sST2 obtained by receiver operating characteristic (ROC) analysis was 26.65 ng/mL for prediction of LVZ (sensitivity: 86.5%, specificity: 84.8%). The under-curve area was 0.895 (0.842-0.948) (P<0.001). At 12-month follow-up, patients with sST2 <26.65 ng/mL had more patients free from atrial arrhythmias compared to patients with sST2 >26.65 ng/mL (88.6% vs. 69.8%, P<0.01). CONCLUSIONS We demonstrated that sST2 levels are higher in pAF patients with LVZ >20% compared to those with a smaller LVZ. Also increased sST2 levels can serve as a novel predictor of AF recurrence rate in patients who have undergone RFCA.

Zero-fluoroscopy transseptal puncture guided by right atrial electroanatomical mapping combined with intracardiac echocardiography: A single-center experience.

BACKGROUND: Right atrial electroanatomical mapping may be combined with SoundStar 3D diagnostic ultrasound catheter (EAM-ICE) as a zero-fluoroscopy procedure for radiofrequency catheter ablation (RFCA). We aimed to evaluate the efficiency and safety of zero-fluoroscopy transseptal puncture guided by EAM-ICE and fluoroscopy combined with intracardiac echocardiography (F-ICE) in patients with paroxysmal atrial fibrillation (PAF). HYPOTHESIS: Zero-fluoroscopy transseptal puncture is an effective and safe procedure. METHODS: This study had a prospective design. A total of 57 patients with PAF were enrolled and assigned to two groups. Twenty-seven patients were enrolled in the EAM-ICE group, and 30 patients were enrolled in the F-ICE group. RESULTS: There were no statistically significant differences in baseline patient characteristics between groups. Transseptal puncture was successful in all patients (57/57, 100%). Total procedure time and duration of transseptal puncture were lower in the F-ICE group (199.4 ± 26.0 minutes vs 150.7 ± 22.1 minutes, P = 0.000; 118.4 ± 19.7 vs 70.5 ± 13.5 minutes, P = 0.000). There was no use of fluoroscopy in the EAM-ICE group (0 mGy vs 70.5 ± 13.5 mGy); the duration of fluoroscopy in the EAM-ICE group was negligible (0 minutes vs 5.4 ± 1.9 minutes). No procedural complication occurred in either group. CONCLUSIONS: EAM-ICE guided zero-fluoroscopy transseptal puncture is an effective and safe procedure.

Targeting HMGB1 ameliorates cardiac fibrosis through restoring TLR2-mediated autophagy suppression in myocardial fibroblasts.

BACKGROUND: Extracellular high-mobility group box 1 (HMGB1) has been identified as playing a critical role in the pathogenesis of tissue fibrosis. However, the underlying mechanism of its involvement in cardiac fibrosis is still not well-defined. Here, we aim to investigate whether toll-like receptor 2 (TLR2) contributes to the extracellular HMGB1-mediated development and progression of cardiac fibrosis. METHODS: A mouse model of cardiac fibrosis was induced by subcutaneous injection of isoproterenol (ISO). Glycyrrhizic acid (GA), an inhibitor of HMGB1 derived from natural products, was simultaneously administered by intraperitoneal injection. Echocardiography, H&E and Sirius red staining were used to evaluate cardiac function and fibrosis. The myocardial expression of autophagy-associated proteins was examined using immunoblotting. Cardiac fibroblasts were treated with different concentrations of HMGB1 to examine the expression levels of α-SMA, collagen I and autophagy markers. Interactions of HMGB1/TLR2 and α-SMA/p62 were examined by immunoprecipitation and immunofluorescence. RESULTS: ISO-treated mice showed characteristic cardiac fibrosis, increased expression and co-localization of HMGB1 and TLR2, as well as impaired autophagic signals in myocardial tissues, which could be prevented by silencing TLR2. Exogenous administration of HMGB1 blocked the autophagic flux in fibroblasts, which caused extensive accumulation of collagen I and α-SMA. In addition, cardiac fibrosis was alleviated by GA treatment through abrogating the interaction between HMGB1 and TLR2. CONCLUSIONS: Our study suggests that the interaction between TLR2 and HMGB1 contributes to the pathogenesis of cardiac fibrosis via suppressing fibroblast autophagy, and that inhibiting HMGB1 with GA provides therapeutic benefits for the treatment of fibroproliferative heart diseases.

Cervical cancer cell-derived angiopoietins promote tumor progression.

Metastatic or recurrent cervical cancer has limited treatment options and a high rate of mortality. Although anti-vascular endothelial growth factor drugs have shown great promise as a therapeutic target for treatment of advanced cervical cancer, drug resistance and class-specific side effects negate long-term benefits. The identification of alternative anti-angiogenic factors will be critical for future drug development for advanced or recurrent cervical cancer. In this study, we found that angiopoietins and Tie receptors were highly expressed in cervical cancer cells. Tie-2 expression in tumor cells predicted poorer prognosis. Wound closure assay and Transwell assay showed that upregulated or downregulated Ang-1 and Ang-2 expression promoted or reduced cervical cancer cell lines migration and invasion, respectively. In subcutaneous xenograft models of cervical cancer, downregulation of Ang-1 and Ang-2 attenuated tumor growth. The expression of vimentin and endomucin and microvessel density were all significantly decreased in the siAng-1 group and siAng-2 group relative to the infection control group. Our data support that dual inhibition of Ang-1 and Ang-2 may be an alternative target for anti-angiogenic adjuvant therapy in advanced or recurrent cervical squamous cell cancer.

The ratio of serum Angiopoietin-1 to Angiopoietin-2 in patients with cervical cancer is a valuable diagnostic and prognostic biomarker.

OBJECTIVES: Angiopoietins have been found to play essential roles in tumor angiogenesis. The present study was aimed at investigating the diagnostic and prognostic values of serum angiopoietin 1 and 2 (sAng-1 and sAng-2) in cervical cancer. METHODS: The sAng-1 and sAng-2 concentrations were analyzed in 77 women with cervical cancer, 44 women with cervical intraepithelial neoplasia (CIN) and 43 women without cervical lesions by enzyme-linked immunosorbent assay. The diagnostic values of sAng-1, sAng-2 and sAng-1/sAng-2 were evaluated by receiver operating characteristic (ROC) curves. The Ang-1 and Ang-2 expression in cervical cancer tissues as well as microvessel density (MVD), were assessed by immunohistochemistry. RESULTS: The concentration of sAng-2 gradually increased and the sAng-1/Ang-2 ratio was gradually decreased from normal control to CIN, then to squamous cell cancer, and the sAng-1/sAng-2 ratio was also significantly decreased in adenocarcinoma. The area under ROC curves of sAng-2 and sAng-1/sAng-2 ratio for discriminating cervical cancer from normal were 0.744 and 0.705, respectively. Decreased sAng-1/sAng-2 was significantly associated with advanced tumor stage, poor differentiation, lymph-vascular space invasion and high MVD. sAng-2 was positively correlated with the Ang-2 expression in cervix epithelia. A high sAng-1/sAng-2 ratio was associated with a longer progression-free survival and a longer overall survival in cervical cancer patients. CONCLUSIONS: These findings suggest that sAng-2 and the sAng-1/sAng-2 ratio may be valuable diagnostic and prognostic biomarkers for cervical cancer.

Increased Local Sympathetic Nerve Activity During Pathogenesis of Ventricular Arrhythmias Originating from the Right Ventricular Outflow Tract.

BACKGROUND The contribution of local sympathetic nerves to ventricular arrhythmia (VA) originating from the right ventricular outflow tract (RVOT) has not been elucidated. This study used a canine model to investigate the anatomical changes of the RVOT associated with VA, and the distribution of local sympathetic nerves. MATERIAL AND METHODS The RVOT-VA canine model (6 dogs) was induced with a circular catheter and high-frequency stimulation (100 Hz) in the middle of the pulmonary artery trunk. Six dogs who were not given stimulation served as the control group. The serum levels of neurotransmitters, the extent of myocardial extension, and the sympathetic nerve density of the RVOT were also analyzed. RESULTS Ventricular arrhythmias, including premature ventricular contractions, were induced in the experimental group after high-frequency stimulation. Dogs from the RVOT-VA group showed enhanced myocardial extension and sympathetic nerve density in the septal wall as compared with those of the free wall of the RVOT. In the RVOT-VA dogs, serum norepinephrine and neuropeptide Y and the sympathetic nerve density were significantly higher compared with the control group. CONCLUSIONS Stimulation of the pulmonary artery could activate local sympathetic nerves and enhance myocardial extension, which may be the foundation of RVOT-VA. The RVOT voltage transitional zone positively correlated with myocardial extension, which may serve as an important target for the radiofrequency catheter ablation of RVOT-VA clinically.

Voltage combined with pace mapping is simple and effective for ablation of noninducible premature ventricular contractions originating from the right ventricular outflow tract.

BACKGROUND: Premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) can resist conventional mapping strategies. Studies regarding optimal mapping and ablation methods for patients with noninducible RVOT-PVCs are limited. We retrospectively evaluated the efficacy and safety of a novel mapping strategy for these cases: voltage mapping combined with pace mapping. HYPOTHESIS: METHODS: We retrospectively included symptomatic patients (n = 148; 76 males; age, 44.5 ± 1.4 years) with drug-refractory PVCs originating from the RVOT, who underwent radiofrequency catheter ablation (RFCA), and stratified them as Group 1 and Group 2. Group 1 patients had noninducible RVOT-PVCs, determined after programmed stimulation, burst pacing, and isoproterenol infusion (n = 21; 12 males; age, 39.5 ± 10.8 years). Group 2 patients had inducible PVCs. Group 1 patients were subjected to voltage mapping combined with pace mapping; Group 2 underwent conventional mapping. In all patients prior to RFCA, detailed 3-dimensional electroanatomic voltage maps of the RVOT were obtained during sinus rhythm using the CARTO system. RESULTS: Patients from both groups had similar success and complication rates associated with the RFCA. In Group 2, 89% (113/127) experienced the earliest and the successful ablation points in the voltage transitional zone. During the follow-up (36 ± 8 months), patients from both groups suffered similar rates of PVC relapse (2/21 and 7/127, respectively; P = 0.826). CONCLUSIONS: Voltage mapping combined with pace mapping is effective and safe for patients with noninducible RVOT-PVCs determined by conventional methods.

Rho-Kinase inhibitor fasudil suppresses high glucose-induced H9c2 cell apoptosis through activation of autophagy.

INTRODUCTION: Cardiac cell apoptosis plays a crucial role in the progression of diabetic cardiomyopathy. Recent studies have shown that fasudil, a Rho-kinase (ROCK) inhibitor, inhibits cardiac cell apoptosis; however, the underlying mechanism remains unclear. AIM: This study aimed to investigate whether fasudil protects H9c2 cells from high glucose-induced apoptosis via activation of autophagy. METHODS: Rat cardiomyocyte H9c2 cells were treated with high glucose and used as a diabetic cardiomyopathy model. Cell survival rate, apoptosis, and subcellular morphology were examined using the MTT assay, flow cytometry, and electron microscopy, respectively. ROCK1 and ROCK2 mRNA levels were determined using quantitative real-time PCR. Bcl-2 and Bax, myosin phosphatase target subunit-1 (MYPT-1), phosphorylated (p)-MYPT1, LC3-II/LC3-I, Beclin-1, soluble and insoluble P62 protein levels were determined by Western blot analysis. RESULTS: Fasudil reversed the high glucose-induced inhibition of cell proliferation and suppressed high glucose-induced early apoptosis. Fasudil also reversed the high glucose-suppressed Bcl-2 levels and decreased the high glucose-induced Bax levels. Further, Fasudil suppressed ROCK levels, expression, promoted autophagy via increasing the LC3-II/LC3-I ratio, Beclin-1 expression, and the number of autophagosomes in H9c2 cells treated with high glucose. These effects of fasudil were abrogated by 3-methyladenine (3-MA), an autophagy inhibitor. CONCLUSION: Fasudil inhibited high glucose-induced apoptosis in rat H9c2 cells through activating autophagy.

Sequential changes of endoplasmic reticulum stress and apoptosis in myocardial fibrosis of diabetes mellitus-induced rats.

The endoplasmic reticulum (ER) is an organelle in which proteins form their appropriate structures. However, several of these proteins become unfolded or misfolded when exposed to stimuli, including hyperglycemia, oxidative stress, ischemia, disturbance of calcium homeostasis and overexpression of abnormal proteins, which activates ER stress and the unfolded protein response (UPR). To date, investigations have demonstrated that ER stress is important in diabetic myocardial fibrosis by inducing cardiac cell apoptosis. Therefore, in the present study, the polymerase chain reaction, western blotting analysis and tissue staining were performed to identify the changes in UPR signaling proteins and apoptotic proteins in diabetic rats at different time points, and to determine whether the myocardial fibrosis is associated with ER-stress-mediated apoptosis using a diabetes mellitus (DM) rat model. It was found that the upregulation of ER stress markers and apoptotic molecules developed over time. It was also demonstrated that anti­apoptotic markers and proapoptotic markers were activated early following model establishment, and then decreased in months 4 and 5. The changes in myocardial fibrosis were found to accelerate in a time-dependent manner with apoptosis in the DM rats.

Sequential changes in autophagy in diabetic cardiac fibrosis.

Autophagy is considered to be associated with cardiac fibrosis. However, whether autophagy accelerates or ameliorates fibrosis remains to be elucidated. In the present study, 36 rats were divided into two groups: Control rats and diabetic rats. The diabetic rats were established by feeding the animals a high fat diet combined with streptozotocin. From the two groups, six rats were sacrificed after 1, 6 and 7 months. Cardiac systolic functions were measured. The collagen volume fraction was calculated using Masson's trichome staining and the mRNA expression levels of type­I and type­III collagen were measured using reverse transcription­quantitative polymerase chain reaction (RT­qPCR) to assess the levels of cardiac fibrosis. The protein contents of microtubule­associated protein 1 light chain 3 (LC3) and sequestosome 1 (P62) were evaluated using western blotting, and the mRNA expression of Beclin 1 was measured using RT­qPCR, in order to assess autophagy. The results revealed that, in the diabetic rats, cardiac fibrosis developed and cardiac systolic function was reduced. In the hearts of the diabetic rats, the mRNA expression levels of collagen type I and III, and Beclin1 were upregulated; the ratio of the protein level of LC3­II/LC3­I was increased and the content of P62 was decreased. All the changes were aggravated as time increased. The changes in autophagy were correlated with those of cardiac fibrosis, suggesting that autophagy may have a synergistic role in diabetic cardiac fibrosis.

Toll-like receptor 4 knockout protects against isoproterenol-induced cardiac fibrosis: the role of autophagy.

BACKGROUND: Toll-like receptor 4 participates in the process of acute heart injury. The underlying mechanisms of its protection are multifactorial, but we hypothesized that toll-like receptor-mediated autophagy control plays a vital role. The purpose of this study was to clarify the effect of autophagy on cardiac fibrosis. METHODS: Cardiac fibrosis was induced by subcutaneous isoproterenol (ISO) injection, and rapamycin was simultaneously administered orally for 14 days. Animal echocardiography was then used to evaluate the success of the cardiac fibrosis model, and the mice were killed after the echocardiography examination. RESULTS: Toll-like receptor 4 knockout (TLR4 KO) mice had better heart function than did wild-type (WT) mice (P < .05). Rapamycin treatment reduced the left ventricular ejection fraction to 23.5% (P < .05), and the collagen volume fraction of the ISO and ISO plus rapamycin groups was 5.9% and 25.9%, respectively, in TLR4 KO mice. Compared with the WT mice, Beclin 1 and autophagy were downregulated in TLR4 KO mice (P < .05); however, the ISO plus rapamycin group had higher autophagy activity than did the ISO group in TLR4 KO mice (P < .05). CONCLUSIONS: Our results suggest that TLR4 KO-induced cardioprotection against ISO-induced cardiac fibrosis is associated with reduced autophagy induction. Cardiac fibroblast autophagy participates in its own activation. The moderate inhibition of autophagic activity may be a new strategy for treating cardiac fibrosis.