OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment of "biaoben acupoint combination" on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury (MIRI) and explore its mechanism. METHODS: Fifty male SD rats were randomly divided into a sham-operation group, a model group, an EA pretreatment group, an EA pretreatment + Compound C group and an EA pretreatment+ML385 group, 10 rats in each group. In the EA pretreatment, the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, EA was delivered at bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, with continuous wave and 2 Hz of frequency, 1 mA of current, once daily for consecutive 7 days. On day 8, in the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, 30 min before model preparation, the intraperitoneal injection with Compound C (0.3 mg/kg) and ML385 (30 mg/kg) was administered respectively. Except in the sham-operation group, the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups. In the sham-operation group, the thread was not ligated. After modeling, the content of reactive oxygen species (ROS) in the ischemic area was measured by flow cytometry, superoxide dismutase (SOD) was detected using xanthine oxidase method, and malondialdelyde (MDA) was detected using thiobarbituric acid (TBA) chromatometry. The morphology of myocardial tissue in the ischemic area was observed with HE staining, and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy. Using immunofluorescence analysis, the positive expression of mitochondrial fission factor (MFF), mitochondrial fission 1 protein antibody (Fis1) and dynamin-related protein 1 (Drp1) was detected; and with immunohistochemical method used, the protein expression of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor E2-associated factor2 (Nrf2) and Drp1 in the ischemic area was detected. RESULTS: Compared with the sham-operation group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 increased in the model group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 decreased (P<0.01), and the protein expression of Drp1 elevated (P<0.01). Compared with the model group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01), and the protein expression of Drp1 declined (P<0.01); and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the positive expression of MFF, Fis1 and Drp1, and the protein expression of Drp1 were all reduced (P<0.01). When compared with the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01, P<0.05), and the protein expression of Drp1 decreased (P<0.05). In comparison with the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the cardiac muscle fiber rupture, cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group. The morphological changes were similar among the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group. CONCLUSION Electroacupuncture pretreatment of "biaoben acupoint combination" attenuates myocardial injury in MIRI rats, probably through promoting the phosphorylation of AMPK and Nrf2, inhibiting the excessive mitochondrial fission induced by Drp1, and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Myocardial Reperfusion Injury/physiopathology* ; Myocytes, Cardiac/cytology* ; Rats ; Acupuncture Points ; Mitochondrial Dynamics ; Humans ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/genetics* ; Superoxide Dismutase/metabolism*

Cardiovascular disease remains the leading cause of death in China, with its morbidity and mortality continue to rise. Ferroptosis, a unique form of iron-dependent cell death, plays a major role in many heart diseases. The classical mechanisms of ferroptosis include iron metabolism disorder, oxidative antioxidant imbalance and lipid peroxidation. Recent studies have found many additional mechanisms of ferroptosis, such as coenzyme Q10, ferritinophagy, lipid autophagy, mitochondrial metabolism disorder, and the regulation by nuclear factor erythroid 2-related factor 2 (NRF2). This article reviews recent advances in understanding the mechanisms of ferroptosis and its role in heart failure, myocardial ischemia/reperfusion injury, diabetic cardiomyopathy, myocardial toxicity of doxorubicin, septic cardiomyopathy, and arrhythmia. Furthermore, we discuss the potential of ferroptosis inhibitors/inducers as therapeutic targets for heart diseases, suggesting that ferroptosis may be an important intervention target of heart diseases.
Ferroptosis/physiology* ; Humans ; Heart Diseases/physiopathology* ; NF-E2-Related Factor 2/physiology* ; Animals ; Myocardial Reperfusion Injury/physiopathology* ; Lipid Peroxidation ; Heart Failure/physiopathology* ; Iron/metabolism* ; Diabetic Cardiomyopathies/physiopathology* ; Ubiquinone/analogs & derivatives*

This study investigated the effects of total flavonoids of Dracocephalum moldavica(TFDM) on apoptosis in rat H9c2 cells induced by endoplasmic reticulum stress(ERS) established by oxygen-glucose deprivation and reoxygenation(OGD/R) injury and tunicamycin(TM), and explored the potential mechanisms. After successful modeling, the following groups were set in this experiment: control group, model(OGD/R or TM) group, and TFDM low-, medium-, and high-dose groups(12.5, 25, and 50 μg·mL~(-1)). The OGD/R injury model was constructed in vitro. Cell proliferation was assessed using the cell counting kit-8(CCK-8) method. The levels of lactate dehydrogenase(LDH) and creatine kinase MB isoenzyme(CKMB) in the cell supernatant were detected. Western blot was used to assess the expression of ERS-related proteins, including glucose regulatory protein 78(GRP78), C/EBP homologous protein(CHOP), activating transcription factor 6(ATF6), and apoptotic proteins B-cell lymphoma 2(Bcl-2) and Bcl-2-associated X protein(Bax). Apoptosis was detected using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL) method. In the TM-induced ERS model, Western blot was used to measure the expression of ERS pathway-related proteins GRP78, CHOP, inositol-requiring enzyme 1(IRE1), X-box binding protein 1(XBP1), protein kinase RNA-like endoplasmic reticulum kinase(PERK), eukaryotic initiation factor 2α(eIF2α), ATF6, p-ATF6, and apoptotic proteins Bcl-2, Bax, cysteinyl aspartate specific proteinase-12(caspase-12), and cleaved caspase-12. Gene expression of GRP78, CHOP, PERK, and ATF6 was detected by real-time fluorescence quantitative PCR(RT-qPCR). Apoptosis was again detected using the TUNEL method. The results showed that in the OGD/R model, compared with the control group, the levels of LDH and CKMB in the cell supernatant were significantly increased in the OGD/R group. Compared with the OGD/R group, the levels of LDH and CKMB in the TFDM group were significantly reduced. Western blot results revealed that compared with the control group, the expression of ERS-related proteins and Bax in the OGD/R group was significantly increased, while the expression of Bcl-2 was significantly decreased. Compared with the OGD/R group, the expression of ERS-related proteins and Bax in the TFDM groups was significantly reduced, and the expression of Bcl-2 was significantly increased. TUNEL assay showed that apoptosis was significantly decreased after TFDM treatment. In the TM-induced ERS experiment, compared with the control group, the expression of ERS-related genes, ERS-related proteins, and apoptotic proteins in the TM group was significantly increased, while the expression of Bcl-2 was significantly decreased. Compared with the TM group, the expression of ERS-related genes, ERS-related proteins, and apoptotic proteins in the TFDM group was significantly reduced, and the expression of Bcl-2 was significantly increased. These results suggest that ERS exists in the OGD/R-injured H9c2 cell model, and TFDM can effectively inhibit ERS-induced apoptosis. The mechanism may be related to the downregulation of ERS pathway-related proteins and apoptotic proteins.
Animals ; Endoplasmic Reticulum Stress/drug effects* ; Apoptosis/drug effects* ; Rats ; Flavonoids/pharmacology* ; Glucose/metabolism* ; Cell Line ; Lamiaceae/chemistry* ; Drugs, Chinese Herbal/pharmacology* ; Oxygen/metabolism* ; Reperfusion Injury/physiopathology* ; Myocytes, Cardiac/cytology*

OBJECTIVES: To evaluate the effect of eye acupuncture on neural function and angiogenesis of ischemic cerebral tissue in rats, and explore the roles of METTL3-mediated m⁶A methylation and the HIF-1α/VEGF-A signal axis in mediating this effect. METHODS: Fifty SD rats were randomized into normal control group, sham-operated group, model group, eye acupuncture group and DMOG (a HIF-1α agonist) group. Rat models of cerebral ischemia/reperfusion injury (CIRI) were established using a modified thread thrombus method, and the changes in neurological deficits of the rats after interventions were evaluated. TTC and Nissl staining were used to examine the changes in infarction size and neuronal injury, and cerebral angiogenesis was detected by double-immunofluorescence staining. m⁶A methylation modification level in the brain tissue was detected by ELISA, and RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of METTL3 and HIF-1α/VEGF-A. RESULTS: Compared with the control and sham-operated rats, the CIRI rats had significantly higher neurological deficit scores with larger cerebral infarction area, a greater number of CD31- and EDU-positive new vessels, higher expression levels of HIF-1α and VEGF-A, reduced number of Nissl bodies and m6A methylation level, and lowered METTL3 protein and mRNA expressions. All these changes were significantly improved by interventions with eye acupuncture after modeling or intraperitoneal injections of DMOG for 7 consecutive days prior to modeling, and the effects of the two interventions were similar. CONCLUSIONS Eye acupuncture can improve neurological deficits in CIRI rat models possibly by promoting cortical angiogenesis via upregulating METTL3-mediated m⁶A methylation and regulating the HIF-1α/VEGF-A signal axis.
Animals ; Rats, Sprague-Dawley ; Methyltransferases/metabolism* ; Reperfusion Injury/physiopathology* ; Methylation ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Rats ; Vascular Endothelial Growth Factor A/metabolism* ; Brain Ischemia/metabolism* ; Acupuncture Therapy ; Male ; Up-Regulation ; Neovascularization, Physiologic ; Angiogenesis ; Adenosine/analogs & derivatives*

OBJECTIVES: To investigate the molecular mechanism by which salvianolic acid B (Sal-B) modulates mitochondrial functional homeostasis and alleviates myocardial ischemia-reperfusion (I/R) injury in mice. METHODS: Mouse cardiomyocyte HL-1 cells were pretreated with 5 μmol/L Sal-B with or without sh-Sirt1 transfection before exposure to hypoxia-reoxygenation (HR), and the changes in ATP production, mitochondrial superoxide activity, substrate oxidation level were evaluated. In the animal experiment, 36 C57BL/6J mice were randomized into 3 groups (n=12) for sham operation or ligation of the left anterior coronary artery to induce myocardial I/R injury with or without intravenous injection of Sal-B+I/R (50 mg/kg). In the rescue experiment, 60 adult C57BL/6J mice were randomized into 5 groups (n=12): sham-operated group, myocardial I/R group, Sal-B+I/R group, I/R+Sal-B+Sirt1fl/fl group, and I/R+Sal-B+cKO-Sirt1 group. Myocardial injury was evaluated with HE staining, and cardiac function was assessed by measurement of the ejection fraction and fractional shortening using echocardiography. RESULTS: In HL-1 cells with HR injury, Sal-B pretreatment significantly increased cellular ATP production, reduced mitochondrial superoxide anion levels, and enhanced oxygen consumption level. In the mouse models of myocardial I/R injury, Sal-B pretreatment markedly ameliorated I/R-induced structural disarray of the cardiac myocytes and improved cardiac ejection. Cycloheximide chase with Western blotting and ubiquitination assays after Sirt1-IP showed that Sal-B significantly inhibited Sirt1 degradation in HL-1 cells. Sirt1 knock-down reversed Sal-B-induced increases in ATP production, reduction in superoxide, and elevation of OCR in HL-1 cells. Cardiomyocyte-specific Sirt1 knockout obviously reversed Sal-B-mediated improvement in cardiac ejection function and myocardial structure damage in mice with myocardial I/R injury. CONCLUSIONS Sal-B promotes mitochondrial functional homeostasis in cardiomyocytes with HR injury and improves cardiac function in mice after myocardial I/R by inhibiting Sirt1 protein degradation.
Animals ; Sirtuin 1/metabolism* ; Myocardial Reperfusion Injury/physiopathology* ; Mice, Inbred C57BL ; Mice ; Myocytes, Cardiac/drug effects* ; Benzofurans/pharmacology* ; Homeostasis/drug effects* ; Male ; Mitochondria/drug effects* ; Depsides

OBJECTIVES: To investigate the protective effects and potential mechanisms of Shenhua Tablet (, SHT) on the toll-like receptors (TLRs)-mediated signaling pathways in a rat model of kidney ischemia-reperfusion injury (IRI). METHODS: Sixty male Wistar rats were randomly divided into 5 groups: sham surgery, model control, astragaloside (150 mg•kg•d), low- and high-dose SHT (1.5 and 3.0 g•kg•d, repectively) groups. One week after drug treatment, rats underwent surgery to establish the IRI models. At 24 h and 72 h after the modeling, serum creatinine (Scr) and blood urea nitrogen (BUN) were analyzed; pathological damage were scored after periodic acid-Schiffstaining. TLR2, TLR4 and myeloid differentiation factor 88 (MyD88) protein and mRNA expressions were detected by inmmunohistochemistry, Western blot and qPCR. Tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) protein expressions were detected by enzyme linked immunosorbent assay. RESULTS: Compared with the sham group, the model group exhibited severe change in renal function (Scr: 189.42±21.50, P<0.05), pathological damage (damage score: 4.50±0.55, P<0.05), and the expression levels of TLR2, TLR4, MyD88, TNF-α, IL-6 were significantly higher than other groups. Meanwhile, the levels of TLRs in model group showed upward tendency from 24 to 72 h, unparalleled with pathological and functional changes. The aforementioned parameters were alleviated to a certain extent, and, in addition to TLRs, presented the obvious downward trending from the 24 to 72 h after the intervention in the SHT and astragaloside groups relative to the model (P<0.05); in particular, the most significant mitigation of these changes was observed in the SHT-H group (P<0.05). CONCLUSION TLRs may be an important spot to treat and research in acute kidney injury. SHT could effectively mitigate renal injuries and promote recovery of IRI injuries through suppression of degeneration induced by up-regulation of TLR2 and TLR4 expression levels in the MyD88-dependent signaling pathway and exhibit some dose dependence.
Animals ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Kidney ; blood supply ; drug effects ; Male ; Myeloid Differentiation Factor 88 ; analysis ; genetics ; Rats ; Rats, Wistar ; Reperfusion Injury ; physiopathology ; prevention & control ; Signal Transduction ; drug effects ; Tablets ; Toll-Like Receptors ; analysis ; drug effects ; genetics

Polyamines (putrescine, spermidine, and spermine) are essential polycations that play important roles in various physiological and pathophysiological processes in mammalian cells. The study was to investigate their role in cardioprotection against ischemia/reperfusion (I/R) injury and the underlying mechanism. Isolated hearts from male Sprague-Dawley rats were Langendorff-perfused and cardiac I/R was achieved by 30 min of global ischemia followed by 120 min of reperfusion. Different concentrations of polyamines (0.1, 1, 10, and 15 μmol/L of putrescine, spermidine, and spermine), cyclosporin A (0.2 μmol/L), or atractyloside (20 μmol/L) were given 10 min before the onset of reperfusion. The hemodynamics were monitored; the lactate dehydrogenase (LDH) levels in the coronary effluent were measured spectrophotometrically; infarct size was determined by the 2,3,5-triphenyltetrazolium chloride staining method; and mitochondrial permeability transition pore (MPTP) opening was determined spectrophotometrically by the Ca-induced swelling of isolated cardiac mitochondria. The results showed that compared to I/R alone, 0.1 and 1 μmol/L polyamines treatment improved heart function, reduced LDH release, decreased infarct size, and these effects were inhibited by atractyloside (MPTP activator). In isolated mitochondria from normal rats, 0.1 and 1 μmol/L polyamines treatment inhibited MPTP opening. However, 10 and 15 μmol/L polyamines treatment had the opposite effects, and these effects were inhibited by cyclosporin A (MPTP inhibitor). Our findings showed that polyamines may have either protective or damaging effects on hearts suffering from I/R by inhibiting or activating MPTP opening.
Animals ; Cyclosporine ; pharmacology ; Male ; Mitochondria, Heart ; physiology ; Mitochondrial Membrane Transport Proteins ; physiology ; Myocardial Reperfusion Injury ; physiopathology ; Polyamines ; metabolism ; Rats ; Rats, Sprague-Dawley

The aim of this study was to investigate the regulatory role of retinoid X receptor (RXR)-mediated oxidative stress pathway in rat pulmonary ischemia/reperfusion injury (PIRI) and the underlying mechanism. Seventy-seven male Sprague-Dawley (SD) rats were randomly divided into 7 groups (n = 11): control group, sham group, sham+9-cis-retinoid acid (9-cRA, RXR agonist) group, sham+HX531 (RXR inhibitor) group, ischemia/reperfusion (I/R) group, I/R+9-cRA group, and I/R+HX531 group. The unilateral lung I/R model was established by obstruction of left lung hilus for 30 min and reperfusion for 180 min in vivo. The rats in I/R+9-cRA and I/R+HX531 groups were given intraperitoneal injection of 9-cRA and HX531 before thoracotomy. After reperfusion, the left lung tissue was taken to evaluate the lung tissue injury, and the oxidative stress-related indexes of the lung tissue were detected by the corresponding kits. The lung tissue morphology and the ultrastructure of the alveolar epithelial cells were observed by HE staining and transmission electron microscope, respectively. The protein expression of RXR in lung tissue was observed by immunofluorescence labeling method, and the expression level of nuclear factor E2-related factor (Nrf2) protein was detected by Western blot. The results showed that, compared with the sham group, the I/R group exhibited obviously injured lung tissue, decreased SOD activity, increased MDA content and MPO activity, and down-regulated expression level of Nrf2 protein. Compared with the I/R group, the I/R+9-cRA group showed alleviated lung tissue injury, increased activity of SOD, decreased MDA content and MPO activity, and up-regulated expression levels of RXR and Nrf2 protein. The above-mentioned improvement effects of 9-cRA were reversed by HX531 treatment. These results suggest that RXR activation can effectively protect the lung tissue against I/R injury, and the mechanism may involve the activation of Nrf2 signaling pathway, the enhancement of antioxidant level and the reduction of oxidative stress response.
Animals ; Lung ; physiopathology ; Male ; NF-E2-Related Factor 2 ; physiology ; Oxidative Stress ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; Retinoid X Receptors ; physiology ; Signal Transduction

OBJECTIVETo observe the in vivo effect of Danlou Tablet (, DLT) on myocardial ischemia and reperfusion (I/R) injury.

METHODSDLT effects were evaluated in mouse heart preparation using 30-min coronary occlusion followed by 24-h reperfusion and compared among sham group (n=6), I/R group (n=8), IPC group (ischemia preconditioning, n=6) and DLT group (I/R with DLT pretreatment for 3 days, 750 mg•kg•day, n=8). The effects of DLT were characterized in infarction size (IS) compared with risk region (RR) and left ventricle using the Evans blue/triphenyltetrazolium chloride double dye staining method in vivo. Furthermore, the dose-dependent effect of DLT on I/R injury was evaluated by double staining method. Five different concentrations of DLT (0.625, 1.25, 2.5, 5 and 10 g•kg•day) were chosen in this study, and dose-response curve of DLT was obtained on these data.

RESULTSThe ratio of IS to left ventricle was significantly smaller in the DLT and IPC groups than the I/R group (P<0.05 or P<0.01), the ratio of IS to RR was also reduced in the DLT and IPC groups (P<0.01), while there were no differences in RR among the four groups (P>0.05). Experiments showed incidence of arrhythmias was reduced in the DLT group (P<0.01). Furthermore, DLT produced a dose-dependent inhibitory effect with a half maximal inhibitory concentration of 1.225 g•kg•day.

CONCLUSIONSOur research concluded that DLT was effective in reducing I/R injury in mice, and provided experimental supports for the clinical use of DLT.

Animals ; Arrhythmias, Cardiac ; drug therapy ; pathology ; physiopathology ; Body Temperature ; drug effects ; Cardiotonic Agents ; pharmacology ; therapeutic use ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Heart Rate ; drug effects ; Heart Ventricles ; drug effects ; pathology ; physiopathology ; Male ; Mice, Inbred C57BL ; Myocardial Reperfusion Injury ; drug therapy ; pathology ; physiopathology ; Risk Factors ; Tablets

BackgroundOxygen-glucose deprivation-nutrition resumption (OGD-NR) models on H9c2 cells are commonly used in vitro models of simulated myocardial ischemia-reperfusion injury (MIRI), but no study has assessed whether these methods for establishing in vitro models can effectively imitate the characteristics of MIRI in vivo. This experiment was designed to analyze the feasibility of six OGD-NR models of MIRI.

MethodsBy searching the PubMed database using the keywords "myocardial reperfusion injury H9c2 cells," we obtained six commonly used OGD-NR in vitro models of MIRI performed on H9c2 cells from more than 400 published papers before January 30, 2017. For each model, control (C), simulated ischemia (SI), and simulated ischemia-reperfusion (SIR) groups were assigned, and cell morphology, lactate dehydrogenase (LDH) release, adenosine triphosphate (ATP) levels, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and inflammatory cytokines were examined to evaluate the characteristics of cell injury. Subsequently, a coculture system of cardiomyocyte-endothelial-macrophage was constructed. The coculture system was dealt with SI and SIR treatments to test the effect on cardiomyocytes survival.

ResultsFor models 1, 2, 3, 4, 5, and 6, SI treatment caused morphological damage to cells, and subsequent SIR treatment did not cause further morphological damage. In the models 1, 2, 3, 4, 5 and 6, LDH release was significantly higher in the SI groups than that in the C group (P < 0.05), and was significantly lower in the SIR groups than that in the SI groups (P < 0.05), except for no significant differences in the LDH release between C, SI and SIR groups in model 6 receiving a 3-h SI treatment. In models 1, 2, 3, 4, 5, and 6, compared with the C group, ATP levels of the SI groups significantly decreased (P < 0.05), ROS levels increased (P < 0.05), and MMP levels decreased (P < 0.05). Compared with the SI group, ATP level of the SIR groups was significantly increased (P < 0.05), and there was no significant ROS production, MMP collapse, and over inflammatory response in the SIR groups. In a coculture system of H9c2 cells-endothelial cells-macrophages, the proportion of viable H9c2 cells in the SIR groups was not reduced compared with the SI groups.

ConclusionAll the six OGD-NR models on H9c2 cells in this experiment can not imitate the characteristics of MIRI in vivo and are not suitable for MIRI-related study.

Apoptosis ; Glucose ; metabolism ; Humans ; Myocardial Reperfusion Injury ; physiopathology ; Myocytes, Cardiac ; physiology ; Oxygen ; metabolism