Rat Myocardial Cells Research Articles

Nanosecond pulse electric field treatment initiates mitochondrial apoptosis pathway by inducing mitochondrial morphological changes in myocardial cells.

As an emerging myocardial ablation technique, the mechanism of nanosecond pulse electric field (nsPEF) ablation is currently less studied. Mitochondria are one of the important membrane structure organelles in cells, participating in numerous life activities within the cell. This study aimed to explore the morphological changes of mitochondria in living cells following nsPEF treatment. Myocardial cells were treated with a self-made solid-state LTD high-voltage nanosecond pulse generator with a pulse width of 100ns for 80 times. The changes in mitochondrial membrane potential and cell apoptosis in rat myocardial cells after nsPEFs were investigated using JC-1 assay kit, apoptosis double staining assay kit, and mitochondrial fluorescence probe. The results showed that after nsPEF treatment, the mitochondrial membrane potential decreased, apoptosis increased, and the average mitochondrial area decreased from 0.48 µm2 in live myocardial cells to 0.16 µm2. The average circumference ranges from 3.17µm dropped to 1.60µm. The shape factor decreased from 1.92 to 1.41. The aspect ratio has decreased from 2.16 to 1.59. nsPEF treatment induces changes in the morphology of myocardial cell mitochondria. Based on the results of mitochondrial membrane potential and apoptosis, it can be inferred that under this equipment and parameter conditions, nsPEF treatment first causes changes in mitochondrial morphology, and then initiates the mitochondrial apoptosis pathway, which may provide experimental basis for investigating the potential mechanism of nsPEF ablation of myocardial cells.

Rap1GAP exacerbates myocardial infarction by regulating the AMPK/SIRT1/NF-κB signaling pathway

Rap1 GTPase-activating protein (Rap1GAP) is an important tumor suppressor. The purpose of this study was to investigate the role of Rap1GAP in myocardial infarction (MI) and its potential mechanism. Left anterior descending coronary artery ligation was performed on cardiac-specific Rap1GAP conditional knockout (Rap1GAP-CKO) mice and control mice with MI. Seven days after MI, Rap1GAP expression in the hearts of control mice peaked, the expression of proapoptotic markers (Bax and cleaved caspase-3) increased, the expression of antiapoptotic factors (Bcl-2) decreased, and the expression of the inflammatory factors IL-6 and TNF-α increased; thus, apoptosis occurred, inflammation, infarct size, and left ventricular dysfunction increased, while the heart changes caused by MI were alleviated in Rap1GAP-CKO mice. Mouse heart tissue was obtained for transcriptome sequencing, and gene set enrichment analysis (GSEA) was used to analyze Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We found that Rap1GAP was associated with the AMPK and NF-κB signaling pathways and that Rap1GAP inhibited AMPK/SIRT1 and activated the NF-κB signaling pathway in model animals. Similar results were observed in primary rat myocardial cells subjected to oxygen–glucose deprivation (OGD) to induce ischemia and hypoxia. Activating AMPK with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) reversed the damage caused by Rap1GAP overexpression in cardiomyocytes. In addition, the coimmunoprecipitation results showed that exogenous Rap1GAP interacted with AMPK. Rap1GAP was verified to regulate the AMPK SIRT1/NF-κB signaling pathway and exacerbate the damage to myocardial cells caused by ischemia and hypoxia. In conclusion, our results suggest that Rap1GAP promotes MI by modulating the AMPK/SIRT1/NF-κB signaling pathway and that Rap1GAP may be a therapeutic target for MI treatment in the future.

Tetrandrine downregulates TRPV2 expression to ameliorate myocardial ischemia/reperfusion injury in rats via regulation of cardiomyocyte apoptosis, calcium homeostasis and mitochondrial function

Our previous study has indicated that tetrandrine (TET) can target miR-202-5p to repress the activation of transient receptor potential vanilloid type 2 (TRPV2), eventually ameliorating the progression of myocardial ischemia/reperfusion injury (MI/RI). This study is aimed to further ascertain the detailed mechanisms between TET and TRPV2 in MI/RI pathogenesis. Here, a myocardial I/R injury rat model and a hypoxia-reoxygenation (H/R) model in rat myocardial cell line (H9C2 cells) were established. We reported that pronounced upregulation of TRPV2 was observed in I/R rats and H/R-induced H9C2 cells. Silencing of TRPV2 could improve cardiac function and myocardial injury, reduced infarction size, and promoted cardiomyocyte proliferation in I/R rats. In I/R rats or H/R-induced H9C2 cells, cardiomyocyte apoptosis was inhibited by knocking-down TRPV2. Meanwhile, the silenced TRPV2 or TET treatment ameliorated the damaged mitochondrial structure, mitigated ROS generation, restored the impaired ΔΨM, inhibited mPTP opening and alleviated Ca2+ overload in H/R-induced H9C2 cells. The results obtained from the overexpression of TRPV2 were contrary to those depicted above. Moreover, TET could downregulate TRPV2 expression, while the overexpression of TRPV2 could reverse the above protective effects of TET in H/R-induced H9C2 cells. The results indicated that TET may function as a TRPV2 blocking agent, thereby attenuating the progression of MI/RI through modulation of cardiomyocyte apoptosis, calcium homeostasis and mitochondrial function. These findings offer a theoretical foundation for potential clinical application of TET therapy in patients with MI/RI.

Inhibiting MiR-320a promotes myocardial apoptosis in myocardial infarction rats through activating VEGF pathway.

To detect the expressions of vascular endothelial growth factor (VEGF) and micro ribonucleic acid (miR)-320a in myocardial cells of rats with myocardial infarction (MI), and to study the detailed mechanism of the role of miR-320a in myocardial apoptosis in MI rats. The Sprague-Dawley rat model of MI was established, and the rats were randomly divided into a control group (n=8), recombinant adeno-associated virus (rAAV)-miR-320a group (n=8) and rAAV-miR-320a TuDs group (n=8). The corresponding rAAV (1×1011 virion-like particles) was intravenously injected. At 2 weeks after the injection of rAAV, all rats were euthanatized, and the organs were collected, frozen in liquid nitrogen and stored at -80°C for further experiments. The total RNA and total protein were extracted from heart tissues, and the expression levels of rAAV-miR-320a and rAAV-miR-320aTuDs in heart tissues were determined via reverse transcription-polymerase chain reaction (RT-PCR). Moreover, RT-PCR and Western blotting were performed to detect the mRNA and protein expressions in heart tissues, respectively. At the same time, myocardial apoptosis was evaluated through flow cytometry. After treatment with miR-320a TuDs, the mRNA and protein expressions of VEGF in heart tissues in MI were significantly increased (P<0.05). The results of flow cytometry showed that miR-320a TuDs intervention could promote myocardial apoptosis in MI (P<0.05). In addition, the results of Western blotting revealed that miR-320a TuDs could facilitate the activation of the VEGF signaling pathway in heart tissues in MI (P<0.05). Inhibiting miR-320a can promote myocardial apoptosis through activating the VEGF signaling pathway in myocardial cells in MI.

Resistin Induces Cardiomyocyte Hypertrophy in H9c2 Embryonic Rat Myocardial Cells via Inhibition of MiR-489-3p

Resistin Induces Cardiomyocyte Hypertrophy in H9c2 Embryonic Rat Myocardial Cells via Inhibition of MiR-489-3p

Effect of Wenyang Zhenshuai Granules on autophagy and apoptosis of myocardial cells in septic rats via regulating miR-132-3p/UCP2 expression

This study aimed to investigate the effect of Wenyang Zhenshuai Granules(WYZSG) on autophagy and apoptosis of myocardial cells in rats with sepsis via regulating the expression of microRNA-132-3p(miR-132-3p)/uncoupling protein 2(UCP2). Sixty SD rats were randomly divided into modeling group(n=50) and sham operation group(n=10). The sepsis rat model was constructed by cecal ligation and perforation in the modeling group. The successfully modeled rats were randomly divided into WYZSG low-, medium-and high-dose groups, model group and positive control group. Rats in the sham operation group underwent opening and cecum division but without perforation and ligation. Hematoxylin-eosin(HE) staining was used to observe the pathological changes of rat myocardial tissue. Myocardial cell apoptosis was detected by TdT-mediated dUTP nick end labeling(TUNEL) assay. Real-time quantitative polymerase chain reaction(RT-qPCR) was performed to detect the expression of miR-132-3p and the mRNA expressions of UCP2, microtubule-associated protein light chain 3(LC3-Ⅱ/LC3-Ⅰ), Beclin-1 and caspase-3 in rat myocardial tissue. The protein expressions of UCP2, LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 in myocardial tissue were detected by Western blot. Dual luciferase reporter assay was used to verify the regulatory relationship between miR-132-3p and UCP2. The myocardial fibers of sepsis model rats were disordered, and there were obvious inflammatory cell infiltration as well as myocardial cell edema and necrosis. With the increase of the WYZSG dose, the histopathological changes of myocardium were improved to varying degrees. Compared with the conditions in the sham operation group, the survival rate and left ventricular ejection fraction(LVEF) of rats in the model group, positive control group and WYZSG low-, medium-and high-dose groups were decreased, and the myocardial injury score and apoptosis rate were increased. Compared with the model group, the positive control group and WYZSG low-, medium-and high-dose groups had elevated survival rate and LVEF, and lowered myocardial injury score and apoptosis rate. The expression of miR-132-3p and the mRNA and protein expressions of UCP2 in myocardial tissue in the model group, positive control group and WYZSG low-, medium-and high-dose groups were lower, while the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 were higher than those in the sham operation group. Compared with model group, the positive control group and the WYZSG low-, medium-and high-dose groups had an up-regulation in the expression of miR-132-3p and the mRNA and protein expressions of UCP2, while a down-regulation in the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3. WYZSG inhibited excessive autophagy and apoptosis of myocardial cells in septic rats and improved myocardial injury, possibly by regulating the expression of miR-132-3p/UCP2.

EEF1A2 accelerates the protein translation of chemokine in rat myocardial cells induced by ischemia-reperfusion

How to reduce the damage caused by myocardial ischemia-reperfusion (IR) in a timely manner to save patients' lives is still a great clinical challenge. Although dexmedetomidine (DEX) has been reported to protect the myocardium, the regulatory mechanism of gene translation responding to IR injury and DEX protection is poorly understood. In this study, IR rat model with DEX and the antagonist yohimbine (YOH) pretreatment were established, and RNA sequencing was carried out to seek the important regulators in differential expressed genes. A series of cytokines and chemokine as well as eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) were induced by IR compared to control and compromised by DEX pretreatment compared to IR, then reversed by YOH. Immunoprecipitation was conducted to identify that peroxiredoxin 1 (PRDX1) interacted with EEF1A2 and contributed to the recruitment of EEF1A2 on mRNA molecules of cytokines and chemokine. Knockdown of PRDX1 could weaken the enhancive effect of EEF1A2 for gene translation of IL6, CXCL2 and CXCL11 under the IR condition, and indeed reduce cell apoptosis of cardiomyocytes. We also determined that the RNA motif “USCAGDCU” at 5′ UTR could be particularly recognized by PRDX1. Destruction of this motif at the 5’ UTR of IL6, CXCL2 and CXCL11 by CRISPR-CAS9 could result in the loss occupancies of EEF1A2 and PRDX1 on the mRNA of these three genes. Our observations showed the importance of PRDX1 in the reasonable control of cytokine and chemokine expression to prevent excessive inflammatory response to cell damage.

Effects of astaxanthin on microRNA expression in a rat cardiomyocyte anoxia-reoxygenation model.

Introduction: The protective effects of astaxanthin against myocardial ischemia-reperfusion injuries are well documented, although the mechanisms are not defined. Methods: The anoxia-reoxygenation injury model was established after astaxanthin treated H9c2 cells for 24 h. Cell viability, lactate dehydrogenase, oxidative stress level and western blot were tested. Secondly, measured the effects of astaxanthin pretreatment on microRNA expression in a rat myocardial cell anoxia-reoxygenation injury model. Results: After anoxia-reoxygenation injury, in a dose dependent manner, astaxanthin increased cell viability, superoxide dismutase and glutathione peroxidase activity, decreased lactate dehydrogenase and malondialdehyde levels, downregulated protein expression of caspase-3, caspase-8, nuclear factor erythroid-2-related factor 2 and heme oxygenase-1, and upregulated the Bcl-2/Bax ratio. High-throughput sequencing and qPCR showed that microRNAs rno-miR-125b-5p and rno-let-7c-1-3p were differentially expressed (|log2| ≥ 0.585, q < 0.1) between the normal, anoxia-reoxygenation, and astaxanthin (1.25 μM) groups. Kyoto Encyclopedia of Genes and Genomes and GO Gene ontology pathway enrichment analyses showed that TNF signaling, axon guidance, NF-κB signaling pathway, and other pathways displayed differentially expressed microRNA target genes associated with myocardial injuries. Discussion: These results suggested that thetarget genes of rno-miR-125b-5p were enriched in inflammation and apoptosis-related signaling pathways. Also, the results imply that simultaneous targeting of these related signaling pathways could significantly prevent myocardial anoxia-reoxygenation injury in the presence of astaxanthin.

Histological Changes in Liver and Cardiac Rat Tissues after Exposure to Chitosan Nanoparticles Orally

Background: As safe natural biopolymer, chitosan is resulting from chitin deacetylation. Owing to its antimicrobial and antifungal effects, chitosan and/or its biological derivatives have gained extensive interest. The antibacterial activity of chitosan exhibits only in a low pH medium since its solubility above pH 6 is poor. Several factors affect chitosan antibacterial action such as chitosan type, polymerization degree, and certain other chemicophysical features. Objectives: The current study was intended to inspect the chitosan injury on hepatic and myocardial cells in rats in different concentrations. Materials and Methods: Chitosan was purchased and prepared at various concentrations. Laboratory Wistar albino rats were orally fed with different concentrations of chitosan. Histological examination of rat liver and cardiac tissues was performed accordingly. Results: A noticeable increase in animal weight is seen as the concentration of chitosan increases. Normal histological appearance with slight hemorrhaging and abnormal histological appearance with more abundant hemorrhaging and cellular vacuolation were present in liver tissues. Profound histological damage with more abundant hemorrhaging and lymphocytic infiltration along with sinusoid enlargement in the liver as well as districted nuclei was also present. Cardiac tissues were less affected by changes in chitosan concentration. Liver histological changes are attributed to the metabolic breakdown of chitosan in the liver. A noticeable decrease in vascular thickness is seen in both cardiac and liver vascular networks. Conclusion: The study found that chitosan has robust cytotoxic influences on certain organs. However histological damage is more prominent and is seen in rat liver tissues. Histological damage is confirmed by the abnormality of histological and cellular damage seen.

Electrohydrodynamic printing of submicron-microscale hybrid scaffolds with improved cellular adhesion and proliferation behaviors

Electrohydrodynamic (EHD) printing has been considered as a mature strategy to mimic the hierarchical microarchitectures in native extracellular matrix (ECM). Most of the EHD-printed scaffolds possess single-dimensional fibrous structures, which cannot mimic the multi-dimensional architectures for enhanced cellular behaviors. Here we developed a two-nozzle EHD printing system to fabricate hybrid scaffolds involving submicron and microscale features. The polyethylene oxide- polycaprolactone (PEO-PCL) submicron fibers were fabricated via solution-based EHD printing with a width of 527 ± 56 nm. The PCL microscale fibers were fabricated via melt-based EHD printing with a width of 11.2 ± 2.3 μm. The hybrid scaffolds were fabricated by printing the submicron and microscale fibers in a layer-by-layer manner. The microscale scaffolds were utilized as a control group. Rat myocardial cells (H9C2 cells) were cultured on the two kinds of scaffolds for the culturing period of 1, 3 and 5 d. Biological results indicated that H9C2 cells showed enhanced adhesion and proliferation behaviors on the hybrid scaffold than those on the pure microscale scaffold. This work offers a facile and scalable strategy to fabricate multiscale synthetic scaffolds, which might be further explored to regulate cellular behaviors in the fields of tissue regeneration and biomedical engineering.

Effects of bepridil on early cardiac development of zebrafish.

Bepridil is a commonly used medication for arrhythmia and heart failure. It primarily exerts hemodynamic effects by inhibiting Na+/K+ movement and regulating the Na+/Ca2+ exchange. In comparison to other Ca2+ inhibitors, bepridil has a long half-life and a complex pharmacology. Additionally, it is widely used in antiviral research and the treatment of various diseases. However, the toxicity of this compound and its other possible effects on embryonic development are unknown. In this study, we investigated the toxicity of bepridil on rat myocardial H9c2 cells. After treatment with bepridil, the cells became overloaded with Ca2+ and entered a state of cytoplasmic vacuolization and nuclear abnormality. Bepridil treatment resulted in several morphological abnormalities in zebrafish embryo models, including pericardium enlargement, yolk sac swelling, and growth stunting. The hemodynamic effects on fetal development resulted in abnormal cardiovascular circulation and myocardial weakness. After inhibiting the Ca2+ transmembrane, the liver of zebrafish larvae also displayed an ectopic and deficient spatial location. Additionally, the results of the RNA-seq analysis revealed the detailed gene expression profiles and metabolic responses to bepridil treatment in zebrafish embryonic development. Taken together, our study provides an important evaluation of antiarrhythmic agents for clinical use in prenatal heart patients.

Silencing lncRNA 93358 Inhibits the Apoptosis of Myocardial Cells in Myocardial Infarction Rats by Inducing the Expression of SLC8A1.

Objective To explore the inhibitor effects and mechanism of lncRNA 93358 against the apoptosis of myocardial cells in rats with myocardial infarction. Methods The myocardial infarction model was established in rats, which were identified by cardiac ultrasound. TTC staining was used to evaluate the degree of heart infarction, and HE staining was utilized to determine the pathological state in myocardial tissues. The apoptotic state in myocardial tissues was confirmed by TUNEL assay. lncRNA 93358 was screened out using a high-throughput sequencing which was confirmed by RT-qPCR. The interaction between miR-466c-3p and SLC8A1 was identified using the dual-luciferase reporter assay. The expression level of Bax, Bcl-2, and SLC8A1 was determined in lncRNA 93358 knockdown cells using RT-qPCR and Western blotting Results Massive myocardial necrosis was observed in model rats according to the results of TTC staining, HE staining, and TUNEL assay. lncRNA 93358 and Bax were found significantly upregulated, and Bcl-2 and SLC8A1 were greatly downregulated in model rats, which were dramatically reversed by the knockdown of lncRNA 93358, accompanied by the decline area of myocardial necrosis and decreased apoptotic myocardial cells. Conclusion Silencing lncRNA 93358 inhibits the apoptosis of myocardial cells in rats with myocardial infarction by inducing the expression of SLC8A1.

Stanniocalcin 1 alleviates myocardial ischemia-reperfusion injury through inhibiting inflammation and apoptosis of myocardial cells.

Myocardial ischemia-reperfusion injury (MIRI) is the main cause of death from ischemic heart diseases. Stanniocalcin 1 (STC1) has a potential therapeutic effect on MIRI. The purpose of this study is to investigate the effect of STC1 on inflammation and apoptosis of myocardium in MIRI. We used rats to make ischemia-reperfusion (I/R) models and determined the efficiency of modeling by 2, 3, 5-triphenyl tetrazolium chloride staining, echocardiography, and lactate dehydrogenase detection. We injected subcutaneously recombinant human STC1 (2.5 μg/kg, 5 μg/kg) into rats daily one week before modeling to detect the effect of STC1 pretreatment on inflammation and apoptosis of rat myocardial cells. In addition, we cultured rat myocardial cell lines (H9c2 cells) to investigate the effect of STC1 on myocardial cells. The cardiac function and structure of I/R rats were obviously destroyed. After treating rats with STC1, we found that the cardiac function and structure of the rats were significantly improved. In addition, STC1 reduced the expression of inflammatory factors and apoptosis levels in rat myocardium. Stimulation of STC1 also improved the viability of H9c2 cells in vitro. Therefore, STC1 can alleviate MIRI by inhibiting inflammation and apoptosis. It indicated that STC1 may have a potential therapeutic effect on MIRI.

Rhaponticum carthamoides improved energy metabolism and oxidative stress through the SIRT6/Nrf2 pathway to ameliorate myocardial injury

BackgroundRhaponticum carthamoides (Willd.) Iljin (Rha) is a member of the family Compositae that is widely used in folk medicine as a dietary supplement to treat cardiovascular diseases (CVDs), such as senile cardiac insufficiency, and to restore myocardial function after surgery. Sirtuin 6 (SIRT6), an NAD+-dependent class III histone deacetylase, plays a considerable role in the administration of CVDs. However, the specific effects and mechanism of Rha on myocardial injury remain unknown. PurposeThis study aimed to explore the therapeutic potential of Rha against myocardial injury as well as its underlying mechanisms in vivo and in vitro. MethodsA myocardial ischaemia model was established in male SD rats by subcutaneously injecting ISO. The rats were gavaged with Rha (40, 80, 160 mg/kg) or Rho (6 ml/kg) for 14 successive days and then injected subcutaneously with ISO or saline solution on the 13th and 14th days. The positive effects of Rha against myocardial injury in rats were evaluated by ECG assessment, BP measurements, H&E staining, and myocardial enzyme detection. Biochemical indicators of energy metabolism and oxidative stress, such as NAD+/NADH, ATP, and MDA, were analysed by assay kits to assess the effects of Rha. The protein and mRNA expression levels of SIRT6 and Nrf2 in the myocardium were determined by western blotting and real-time PCR. ResultsOur results showed that Rha ameliorated myocardial ischaemia and inhibited energy metabolism disorders (NAD+/NADH ratio, ATP, and LD) and oxidative stress (SOD, ROS, etc.) in rat myocardial tissue and H9c2 cells. In addition, Rha upregulated SIRT6 and Nrf2 expression in myocardial injury. Mechanistic studies then found that SIRT6 knockdown reduced the expression of Nrf2 as well as the effects of Rha on the levels of ATP, LD, and ROS, whereas activation of Nrf2 improved the effects of Rha in cells. In summary, Rha might exert its cardioprotective effects via the SIRT6-mediated Nrf2 signaling pathway. ConclusionThe results suggest that Rha regulates energy metabolism and oxidative stress through the SIRT6/Nrf2 signaling pathway to play a protective role in myocardial injury.

Alleviation of Myocardial Inflammation in Diabetic Rats by Flavonoid Extract of Helichrysum Arenarium and Its Effect on Damaged Myocardial Cells Induced by High Glucose.

ObjectiveTo investigate the effects of helichrysum arenarium flavonoid extract on high glucose damaged cardiomyocytes and the alleviation of myocardial inflammation in diabetic rats.MethodsThe study was divided into two parts, the first part was a cellular experiment in which a high-glucose cardiomyocyte injury model (H9C2) was established using a high-glucose culture medium, divided into low (group N1, 6.25 μg/mL), medium (group N2, 12.5 μg/mL), high dose group (group N3, 25 μg/mL) of helichrysum arenarium intervention and a model control group. The levels of enzyme activities [creatine kinase (CK) and lactate dehydrogenase (LDH)] in each group of H9c2 cells were measured by Enzyme-linked immunosorbent assay (ELISA), the expression levels of apoptotic proteins (Bax and Bcl-2) by western blot (WB), and the expression levels of inflammatory factors [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6)] by RT-qPCR. The second part is animal experiments, after establishing the diabetic rat model, we used helichrysum arenarium flavonoid extract to intervene SD rats, divided into helichrysum arenarium intervention low (group S1, 250 mg/kg), medium (group S2, 500 mg/kg), high dose group (group S3, 1 g/kg), SD rat model group. Hematoxylin-eosin (HE) staining was used to observe myocardial tissue lesions, and Real Time Quantitative PCR (RT-qPCR) method was used to detect inflammatory (TNF-α, IL-1β, and IL-6) infiltration in myocardial tissue.ResultsCellular experiments: The activity levels of enzymes such as CK and LDH and the levels of inflammatory factors such as TNF-α, IL-1β, and IL-6 in damaged cardiac myocytes were significantly decreased after helichrysum arenarium intervention; the expression levels of Bax protein were significantly down-regulated and the expression levels of Bcl-2 protein expression were significantly up-regulated. Animal experiment: HE staining showed that the model group had widened intercellular spaces, interstitial edema and obvious inflammatory cell infiltration in cardiac muscle tissue. After the intervention of helichrysum arenarium, the collagen fibers of rat myocardial cells were significantly reduced and cell degeneration was alleviated. Animal experiment: HE staining showed that the model group had widened intercellular spaces, interstitial edema and obvious inflammatory cell infiltration in cardiac muscle tissue. After the intervention of helichrysum arenarium, the collagen fibers of rat myocardial cells were significantly reduced and cell degeneration was alleviated; the levels of TNF-α, IL-1β, IL-6 and other inflammatory factors in myocardial tissues were significantly decreased.ConclusionThe helichrysum arenarium flavonoid extract can reduce the degree of damage of H9C2 cells induced by high glucose and decrease the cellular inflammatory response, and its mechanism of action may be achieved by regulating the apoptotic factors Bax and Bcl-2. In addition, the extract of helichrysum arenarium can reduce the histopathological damage of myocardium in diabetic rats, decrease the inflammatory response in the tissue, and achieve the effect of myocardial protection.

Study on the Mechanism and Oxidative Stress of Compound Danshen on the Degradation of Cx43 and Improvement of Myocardial Apoptosis in ICM Rats.

In order to investigate the mechanism by which Salvia miltiorrhiza degrades connexin 43 (Cx43) and improves myocardial cell apoptosis and oxidative stress in rats with myocardial ischemia (ICM), male SD rats of pure grade are selected (32 rats), adaptively bred for 1 week, and then bred in SPF medium. They are randomly divided into a normal group, a model group, a low-dose Danshen group, and a high-dose group, with 8 rats in each group. HE staining and immunohistochemistry are performed. Serum samples are detected using kits according to instructions, including nitric oxide (NO) and endothelin-1 (ET-1); malondialdehyde (MDA), ELISA for superoxide dismutase (SOD), and vascular cell adhesion molecules (VCAM-1); western blot for detection of cardiac Cx43 protein expression; immunohistochemistry to detect Cx43 expression; and detection of myocardial ischemia. For ICM rats, the application of high-dose compound Salvia miltiorrhiza can effectively prevent the degradation of Cx43 protein, improve the apoptosis of myocardial cells in rats, and have a certain protective effect on ischemic myocardium in rats.

Effects of moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) combined with benazepril on myocardial cells apoptosis index and apoptosis-related proteins cytochrome c and apoptosis-inducing factor in rats with chronic heart failure.

To observe the effects of moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) combined with benazepril on myocardial cells apoptosis index, the expression levels of apoptosis-related proteins cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) in chronic heart failure (CHF) rats. Sixty-five rats were randomly divided into normal group () and model-I group (). After modeling, CHF rats in model-I group were divided into model group, moxibustion group, benazepril group, moxibustion plus benazepril group (abbreviated as aibei group, the same below), 10 rats in each group. Echocardiogram index was examined by echocardiography. Hemodynamic indices were measured by rat cardiac function meter. Serum B-type brain natriuretic peptide (BNP) was detected by enzyme-linked immunosorbent assay. Myocardial cells apoptosis index was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling staining. Pathological changes of myocardial tissues were observed by hematoxylin and eosin staining. The expression levels of Cyt-C and AIF in myocardial tissues were detected by Western blot. Compared with normal group, ejection fraction and left ventricular diameter shortening rate in model-Ⅰ group were significantly reduced, myocardial cells of rats in model group exhibited unclear transverse striations, cells swellings and vacuoles, cardiac functions were deteriorated, serum BNP level, myocardial cells apoptosis index, and the expression levels of Cyt-C and AIF were significantly increased. Compared with model group, myocardial cells of rats in moxibustion group, benazepril group, and aibei group were dyed more evenly, muscle fibers were arranged relatively neatly, cardiac functions were improved, serum BNP level, myocardial cells apoptosis index, and the expression levels of Cyt-C and AIF were significantly decreased. Compared with aibei group, cardiac functions were worsened, myocardial cells apoptosis index, and the expression levels of Cyt-C and AIF were increased. Moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) combined with benazepril could improve CHF better than moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) or benazepril alone. The mechanisms might be that they can inhibit the expressions of Cyt-C and AIF, and inhibit the apoptosis of cardiomyocytes.

Remifentanil Anesthesia on the Expression of Apoptosis-Related Proteins Bcl-2 and Bax in Rat Myocardial Cells with Ischemia-Reperfusion Injury

Ischemia-reperfusion damage to the myocardium is inevitable. This study mainly explored the effect of remifentanil anesthesia on the expression of apoptosis-related proteins Bcl-2 and Bax in rat myocardial ischemia-reperfusion injury. Select 48 mice (n=6). First, prepare solutions of different concentrations of remifentanil. A model of ischemia-reperfusion cardiomyocytes was established, and 6 slices of tissue were taken from each specimen, and the positive cells were observed with an optical microscope and magnified 100 times. Bcl-2 and Bax were positive in the cytoplasm and yellowish-brown particles in the inner membrane. According to the distribution of positive cells, randomly select 3 clear fields of view from each part, count the number of positive cells in each field, and then take the average of the proportion of positive cells to get Bcl-2 or Bax protein-positive Index (PEI). Comparison of mRNA levels in each group: Compared with the R3 group, the ratio of the M, R1, and R2 groups increased, and the mRNA expression level of the M group increased almost 3 times, P&lt;0.05. The results of the study show that remifentanil reduces the mortality of myocardial cells by regulating the appearance of Bcl-2 and Bax proteins, and has a certain protective effect on the rat heart during myocardial ischemia and reperfusion. There is no statistically significant difference in the protective effect of remifentanil on myocardial ischemia-reperfusion.

Cardioprotective Effect of Cilostazol on Ischemia-Reperfusion Injury Model.

To clarify the potential protective role of cilostazol on rat myocardial cells with ischemia-reperfusion injury (IRI) models. The study was conducted with three groups of 10 Wistar rats (control group, rats without any coronary ischemia; sham group, rats with coronary ischemia but without cilostazol administration; and cilostazol group, rats with coronary ischemia and cilostazol administration). The level of myocardial injuries was measured by analyzing cardiac troponin T and creatine kinase MB levels in blood samples. In tissue samples, adenosine triphosphate (ATP), nitric oxide, superoxide dismutase (SOD), and malondialdehyde were used to determine the amount of tissue damage. Tissues were stained with hematoxylin-eosin method, and samples were examined under light microscope. The mean level of ATP was 104.4 in the cilostazol group and 149.1 in the sham group (P=0.044). SOD level was significantly higher in the cilostazol group than in the sham group (2075.3 vs. 1783.7, P=0.043). According to histopathological examination, all samples were classified as G0 in the control group. In the sham group, one sample was categorized as G1, six samples as G2, and three samples as G3. In the cilostazol group, nine samples and one sample were categorized as G1 and G2, respectively (P=0.011). Cilostazol has beneficial effects on Wistar rats' myocardial cells in regard to decreasing inflammatory process, necrosis, and fibrosis. Our findings revealed that the use of cilostazol significantly decreased ATP and increased SOD levels in Wistar rats' myocardial cells after IRI.

Bellidifolin from Gentianella acuta (Michx.) Hulten protects H9c2 cells from hydrogen peroxide-induced injury via the PI3K-Akt signal pathway

Cardiovascular disease is the most common disease in the world and the first among the causes of human death. Its morbidity and mortality increase annually, but no effective treatment is available. Therefore, new drugs should be developed to treat cardiovascular disease. Gentianella acuta (Michx.) Hulten (G. acuta) is an important Mongolian medicine in China and elicits protective effects on cardiovascular health. In this study, liquid chromatography-mass spectrometry (LC-MS) combined with network pharmacology was used to screen the main active ingredients and confirm that bellidifolin was one of the main components for the treatment of ischemic heart disease. Then, rat myocardial (H9c2) cells injury model induced by hydrogen peroxide (H2O2) in vitro was established to verify the effect of bellidifolin on oxidative stress stimulation, including determination of antioxidant enzyme activity and apoptosis. Transcriptome sequencing, qRT-PCR, and western blot were performed to further verify the antioxidant stress mechanism of bellidifolin. Results showed that bellidifolin pretreatment decreased the rate of apoptosis and the levels of lactate dehydrogenase (LDH), creatine kinase (CK), and alanine aminotransferase (ALT). Conversely, it increased the contents of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in a dose-dependent manner, indicating that bellidifolin caused a protective effect on cardiomyocyte injury. Bellidifolin minimized the H2O2-induced cell injury by activating the PI3K-Akt signal pathway and downregulating glycogen synthase kinase-3β (GSK-3β) and p-Akt1/Akt1. Therefore, this work revealed that G. acuta has a good development prospect as an edible medicinal plant in cardiovascular disease. Its bellidifolin component is a potential therapeutic agent for cardiovascular disease induced by oxidative stress damage.