Infarction In Rats Research Articles

Enhancement of cardiac angiogenesis in a myocardial infarction rat model using selenium alone and in combination with PTXF: the role of Akt/HIF-1α signaling pathway

Ischemic heart diseases such as myocardial infarction (MI) are a global health problem and a leading cause of mortality worldwide. Angiogenesis is an important approach for myocardial healing following ischemia. Thus, this study aimed to explore the potential cardiac angiogenic effects of selenium (Se), alone and in combination with the tumor necrosis factor-alpha inhibitor, pentoxifylline (PTXF), via Akt/HIF-1α signaling. MI was induced in rats using two subcutaneous doses of isoprenaline (ISP) at a 24-h interval (150 mg/kg). One week later, rats were orally given Se (150 µg/kg/day), PTXF (50 mg/kg/day), or Se/PTXF combination. ISP-induced myocardial damage was evident by increased HW/TL ratios, ST segment elevation, and increased serum levels of CK-MB, LDH, and troponin-I. ISP increased the cardiac levels of the lipid peroxidation marker MDA; the pro-inflammatory cytokines IL-6, IL-1β, and TNF-α; and the pro-apoptotic protein Bax and caspase-3. In contrast, the cardiac levels of the antioxidant markers GSH and SOD and the anti-apoptotic marker Bcl-2 were reduced. Furthermore, ISP markedly increased the cardiac levels of p-Akt and HIF-1α proteins and the cardiac gene expression of ANGPT-1, VEGF, and FGF-2. Treatment with Se both alone and in combination with PTXF ameliorated the ISP-induced myocardial damage and further increased cardiac angiogenesis via Akt/HIF-1α signaling. Se/PTXF combined therapy was more beneficial than individual treatments. Our study revealed for the first time the cardiac angiogenic effects of Se both alone and in combination with PTXF in myocardial infarction, suggesting that both may be promising candidates for clinical studies.Graphical

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.

MiR-182 promotes apoptosis of neural cells in cerebral infarction rats by PI3K/AKT signaling pathway.

To explore the effects of micro ribonucleic acid (miR)-182 on the proliferation and apoptosis of neural cells in cerebral infarction rats and its underlying mechanism. The rat model of cerebral infarction was established, and neural cells were extracted accordingly. The cell proliferation ability was detected via cell counting kit-8 (CCK8) assay. In addition, the apoptosis rate was determined through flow cytometry and the activity of active caspase-3. Furthermore, the interaction between miR-182 and PI3K was explored via dual luciferase reporter assay, and the protein expression levels were observed via Western blotting. The neural cells in mouse brain tissues significantly decreased in the model group compared with that in the control group via HE stain. Additionally, the expression level of miR-182 was significantly increased in the model group compared with that in the control group. Furthermore, overexpression of miR-182 could inhibit the proliferation of neural cells through inducing cell apoptosis. Besides, the results of the luciferase reporter assay showed that the relative luciferase activity in neural cells could be inhibited by the transfection with miR-182 (P<0.05). Overexpression of miR-182 significantly reduced the protein expression levels of phosphatidylinositol 3-hydroxy kinase (PI3K) and p-AKT. MiR-182 induces apoptosis of neural cells through inhibiting the PI3K/AKT signaling pathway, which plays an important regulatory role in the apoptosis of neural cells in cerebral infarction rats.

Molecular mechanism of angiogenesis for cerebral infarction rats by acupuncture intervention based on sonic hedgehog signaling pathway

BackgroundTo study the factors of the Sonic Hedgehog (Shh) signaling pathway after permanent cerebral ischemic and the effects by acupuncture. MethodsMale Wistar rats were divided into Electro-acupuncture (EA) group, Model Control (MC) group, and blank control (Control) group. EA and MC were divided into 9 phases, namely 1 h, 3 h, 6 h, 9 h, 12 h, 24 h, 3 d, 7 d, and 12 d after the operation. The neurological deficits and permanent cerebral ischemic volume were observed. The immunofluorescence method was used to examine the angiogenesis. (Polymerase Chain Reaction) PCR and (Immunohistochemistry) IHC were used to test the changes in Shh, Ptch, Smo, and Gli2 mRNA and proteins. ResultsThe neurological severity scores (NSS) of the Control was 0, the score of the EA group was less than that of the MC. The cerebral permanent ischemic volume of the Control was 0 %, and the EA group's was smaller than that of the MC. The expression of copositive cells in the EA group was higher than the MC's from 12 h to 12 d, and the EA group had more peripheral blood vessels. The rat brain expressions of Shh, Ptch, Smo and Gli2 mRNA and proteins in the MC was higher than that of the Control, the rat brain expression of the EA group was higher than that of the MC. ConclusionsEA can upregulate the expression of the Shh signaling pathway factors, thereby promoting angiogenesis.

Treatment with empagliflozin improves cardiac function in infarcted animals associated with increased baroreflex sensitivity

Abstract Background Several clinical and experimental studies have shown an improvement in cardiac function in infarcted patients and animals (diabetic or not) when treated with empagliflozin, as well as an improvement in outcomes in patients with heart failure with reduced ejection fraction or with preserved ejection fraction. Hypothesis: Treatment with empagliflozin for 14 days (10 mg/kg) improves cardiac function in infarcted rats, secondary to increased baroreflex sensitivity. Methods Wistar rats were divided into 2 groups: AMI - acute myocardial infarction (n=8) and AMI+EMPA - acute myocardial infarction + Empagliflozin (n=8). The animals in both groups were anesthetized and submitted to thoracotomy and ligature of the left coronary artery. The animals in the AMI+EMPA group received daily, through oral gavage, 10 mg/kg of empagliflozin, for 14 days. After this period, an echocardiographic examination was performed, followed by cannulation of the femoral vein and artery, to assess hemodynamic parameters and baroreflex activity. The results were evaluated for normality. Data were compared by Student's t tests. And the relationship between the parameters was tested by Pearson's correlation. Results are presented as mean and standard deviation. Results In the echocardiographic evaluation, an improvement in diastolic function indexes was observed in the AMI+EMPA group in relation to the AMI group: E'/A' ratio (1.584 ± 0.437 vs 0.589 ± 0.129), E/E' ratio (14.11 ± 3.946 vs 29.92 ± 6.878) and systolic function: SF (29.30% ± 7.974 vs 19.20% ± 2.445), EF (53.86% ± 11.78 vs 37.91% ± 4.212), FAC (39.31% ± 7.135 vs 23.51 ± 3.940). There was a reduction in mean blood pressure in the AMI+EMPA group (102.4 mmHg ± 6,408) compared to the AMI group (110.7 mmHg ± 8,514) and in diastolic blood pressure (84.4 mmHg ± 3.889 vs 92.8 mmHg ± 7.664). In the assessment of baroreflex sensitivity, an improvement in tachy and bradycardic indexes was observed in the treated animals: tachycardic index (5.021 bpm/mmHg ± 0.346 vs 3.214 bpm/mmHg ± 0.418) and bradycardic index (1.569 bpm/mmHg ± 0.148 vs 0.73 bpm/ mmHg ± 0.046). In addition, the systolic function expressed by the FAC was positively associated with the reflex tachycardic index (p: 0.008; r: 0.616) and to the E'/A' ratio (p: 0.025; r: 0.576) and negatively with PAD (p: 0.040; r: -0.503). Conclusion Treatment with Empagliflozin in infarcted rats was able to improve left ventricular systolic and diastolic function associated with improved performance of arterial baroreceptors.

Methotrexate associated with nanoparticles decreases NLRC4 inflammasome expression in infarcted rat hearts

Abstract Abstract: Following myocardial infarction (MI), molecules released from necrotic myocytes sensitize nucleotide-binding receptors (NLRs), activate inflammasome complex, and initiate acute inflammatory process and interleukin (IL)-1β production, essential for tissue damage resolution. However, excessive IL-1β production impairs cardiac remodeling. After MI, IL-1β is released by the NLRP3 inflammasome; involvement of the NLRC4 inflammasome in post-MI remodeling has not been established. Methotrexate (MTX) carried by lipid core nanoparticles in low density emulsion (MTX-LDE) reduces post-MI inflammatory process and improves cardiac function in rodents. Purpose To evaluate the influence of early treatment with MTX-LDE on myocardial expression of NLRP3 and NLRC4 inflammasomes in infarcted rats. Methods Male Wistar rats were divided into three groups: control (Sham, n=6); MI (n=6); and MI treated with MTX-LDE (MI-MTX, n=6). MI was induced by ligation of the left anterior descending coronary artery. Twenty-four hours later, the MI-MTX group was treated with 1 mg/kg of MTX-LDE, intraperitoneally. Euthanasia was performed 72 hours after surgery under anaesthesia with ketamine and xylazine. Infarct size was assessed by histology. Myocardial expression of NLRC4, NLRP3, ASC, pro-caspase-1, caspase-1, pro-IL-1β and IL-1β was quantified by Western blotting. IL-1β concentration in serum and heart macerate supernatant was analyzed by ELISA. Statistical: ANOVA or Kruskal-Wallis; 5% significance level. Results Rats with MI lower than 30% of the left ventricle total area were excluded. Infarct size was larger in the MI-MTX group (43,8 ± 5,4) than MI (36,2 ± 6,22). NLRC4 and caspase-1 expression and IL-1β serum concentration were higher in MI than Sham and MI-MTX. Myocardial IL-1β concentration was higher in MI and MI-MTX than Sham and lower in MI-MTX than MI. NLRP3, ASC, pro-caspase-1, and IL-1β protein expression did not differ between groups. Conclusion Our study shows for the first time that NLRC4 inflammasome protein expression increases acutely after myocardial infarction in rats. Early treatment with nanoparticles-derived methotrexate reduces myocardial NLRC4 inflammasome expression and myocardial and serum IL-1β concentration.

Therapeutic potential of pharmacological inhibition of programmed apoptosis, necroptosis, and ferroptosis in improving left ventricular function in post-myocardial infarction rats

Abstract Background Heart failure (HF) is considered the most fatal complicating sequelae after myocardial infarction (MI). Various types of programmed cell deaths (PCDs), including apoptosis, necroptosis, and ferroptosis, have been documented as the pathological progression following MI. Although novel pharmacologically specific cell death inhibitors of apoptosis, necroptosis, and ferroptosis have been shown to exert cardioprotection against acute MI and reperfusion injury, their beneficial effects have never been investigated in a post-MI-induced HF model. Purpose To investigate the therapeutic efficacy and potential underlying mechanisms of inhibitors of apoptosis, necroptosis, and ferroptosis in post-MI rats. Methods Adult male Wistar rats were assigned to the sham (n = 6) and the MI groups (n = 30) via a permanent LAD occlusion. After 1-week LAD ligation, MI rats were divided into 5 subgroups: 1) vehicle (3% DMSO/day, IP, CON, n = 6), 2) enalapril (10 mg/kg/day, PO, ENA, n = 6), 3) apoptosis inhibitor zVAD-FMK (1 mg/kg/day, IP, zVAD, n = 6), 4) necroptosis inhibitor Necrostatin-1 (1.65 mg/kg/day, IP, Nec-1, n = 6), or 5) ferroptosis inhibitor Ferrostatin-1 (2 mg/kg/day, IP, Fer-1, n = 6) for 4 weeks. Then, echocardiography for LV function was performed, and the hearts were removed to determine pertinent apoptosis, necroptosis, and ferroptosis proteins by immunoblotting assays. Malondialdehyde (MDA) levels for myocardial oxidative stress were quantified. Results Post-MI rats exhibited worsening LV dysfunction, as indicated by a markedly reduced %LV ejection fraction (LVEF) (Fig. 1A). Post-MI rats showed higher MDA levels in cardiac tissue, indicating myocardial oxidative stress (Fig. 1B). Furthermore, post-MI rats had elevated expressions of proteins related to apoptosis (Cleaved caspase3/Caspase 3) and necroptosis (pMLKL/tMLKL), but not ferroptosis (ACSL4/GAPDH) (Fig. 1C-E). As a standard treatment for MI, enalapril reduced not only myocardial oxidative stress, but also apoptosis and necroptosis activation, thereby enhancing %LVEF after MI (Fig 1A-D). Notably, treatment of post-MI rats with the apoptosis inhibitor zVAD-FMK, necroptosis inhibitor Necrostatin-1, and ferroptosis inhibitor Ferroptosin-1 ameliorated LV dysfunction and myocardial oxidative stress upregulation (Fig A-B). Interestingly, treatment with zVAD, Nec-1, and Fer-1 effectively attenuated both myocardial apoptosis and necroptosis activation after MI (Fig 1C-D). Conclusion Post-MI increased myocardial oxidative stress and activated multiple PCDs, including apoptosis and necroptosis but not ferroptosis, thus leading to LV dysfunction. Apoptosis and necroptosis inhibitors effectively mitigated oxidative stress and myocardial death, resulting in improved LV function in post-MI rats. These findings highlight the therapeutic potential of inhibiting apoptosis and necroptosis as promising pharmacological interventions to improve clinical outcomes for post-MI patients.

Abstract 14223: Vector Analysis for Left Ventricular Wall Motion by Optical Flow With Echocardiographic Images in Myocardial Infarction Rat Model

Background/Research Questions: Alternative evaluation of cardiac function may be established in echocardiography-based vector analysis of the ventricular wall motion property. Vector acceleration and direction have the potential to assess cardiac kinetic energy and dynamics. Optical flow is suitable for vector analysis, because ventricular wall motion can be estimated as visible and quantitative vectors by optical flow from 2D echocardiographic images. Aims: This study aimed to establish a vector analysis for ventricular wall motion via optical flow with echocardiography. Methods: Coronary artery ligation rat model was used in this study. Before surgery (Pre) and four weeks after surgery (MI), short axis echocardiographic images in mid portion were obtained and analyzed by optical flow for left ventricular regional wall motion. Vector accelerations and directions were measured in both systolic and diastolic phases. Vector directions were classified into inward (ID), outward (OD), and circumferential direction (counterclockwise: CC, clockwise: CW). Following echocardiography, a rat was sacrificed for histological evaluation. Results: Pathological myocardial infarction was noted in the anterolateral lesion. Comparing average vector accelerations, MI had significantly smaller acceleration vectors in both systolic and diastolic phase (Pre vs. MI in systolic: 0.006±0.002 vs. 0.002±0.001 mm/s 2 , P&lt;0.001, Pre vs. MI in diastolic: 0.007±0.002 vs. 0.002±0.001 mm/s 2 , P&lt;0.001). Regarding total vector direction, CC and CW significantly increased in MI (P&lt;0.01). In the anterolateral lesion, ID and OD were the main vector directions in Pre. In contrast, CC and CW vectors significantly increased in MI (P&lt;0.0001). Conclusions: Optical flow effectively visualized cardiac wall motions and quantify them as vectors in echocardiographic images. The technique clarified left ventricular wall vector property alterations between healthy and infarcted hearts.

Unveiling the Cardioprotective Power: Liquid Chromatography–Mass Spectrometry (LC–MS)-Analyzed Neolamarckia cadamba (Roxb.) Bosser Leaf Ethanolic Extract against Myocardial Infarction in Rats and In Silico Support Analysis

Neolamarckia cadamba (Roxb.) Bosser, a member of the Rubiaceae family, is a botanical species with recognized therapeutic properties. It is commonly used in traditional medicine to treat cardiac ailments and other disorders. However, the precise active constituents and the potential mechanisms by which they manage cardiovascular disorders remain unclear. Therefore, this study aimed to ascertain the bioactive components and investigate their underlying mechanisms of action. N. cadamba is used to treat cardiovascular disorders using the integrated metabolomic methodology. An HPLC-QTOF-MS/MS analysis determined the potential chemicals in the N. cadamba leaf ethanol extract (NCEE). A thorough investigation of the NCEE samples used in this study led to the identification of 32 phytoconstituents. Of the 32 compounds, 19 obeyed Lipinski’s rule of five (RO5). A molecular docking study directed towards HMG-CoA reductase used 19 molecules. The reference drug atorvastatin indicated a binding energy of −3.9 kcal/mol, while the other substances, Cinchonain Ib and Dukunolide B, revealed binding energies of −5.7 and −5.3 kcal/mol, respectively. Both phytocompounds showed no toxicity and exhibited favorable pharmacokinetic properties. In vivo study results concluded that treatment with NCEE significantly reduced the cardiac myocardial infarction (MI) marker CK-MB and atherogenic risk indices, such as the atherogenic index plasma (AIP), cardiac risk ratio (CRR), and atherogenic coefficient (AC) in isoproterenol-induced MI rats. In MI rats, NCEE therapy significantly improved the antioxidant system of the heart tissue, as evidenced by the increased levels of GSH and SOD, lower levels of the oxidative stress marker MDA, and significantly decreased HMG-CoA activity. Additionally, electrocardiogram (ECG) signals from rats treated with NCEE resembled those treated with traditional atorvastatin to treat myocardial infarction. This study used H&amp;E staining to show that administering NCEE before treatment reduced cardiac myocyte degeneration in rats with myocardial infarction, increased the presence of intact nuclei, and increased myocardial fiber strength. The potential cardioprotective effect observed in myocardial infarction (MI) rats treated with NCEE can be extrapolated from computational data to be caused by Cinchonain Ib.

Potential therapeutic effect of Salvia coccinea leaf extract in chronic disorders: Myocardial infarction, cataract, and arthritis in rat

Aqueous extract from Salvia coccinea leaf (AESL) has been shown its unique anti-oxidant effect via Nuclear factor (NF)-kappa (κ)B pathway in human monocytic THP-1 ​cells and pharmacological effect on inflammatory diseases like diabetes in rats. Using AESL, which possess antioxidant activity by scavenging radicals and decreasing oxidative stress, would be a promising strategy for the treatment of other inflammatory disorders like myocardial infarction, arthritis, and cataract. This study was designed to evaluate the ameliorating effects of AESL on isoproterenol (Iso)-induced myocardium infarction (MI), selenite-induced cataractogenesis, and complete Freund's adjuvant-induced arthritis in Wistar rats. In this study, AESL ameliorated pathological changes in Iso-induced MI heart muscles and Electro Cardio Gram pattern, 35–80 ​% protection of the cataractogenesis, and prevented the apoptosis induced by selenite in the rat lens. Both pre and post-treatment of AESL (600 ​mg/kg, bw) showed no swelling of the joint and, 35 days treatment showed significant prevention against bony destruction as depicted by less narrowing of joint spaces and soft tissue swelling when compared with control rats. Oral administration of AESL inhibited the Iso-induced increase in serum and myocardial lipid peroxidation, aspartate transaminase, alanine transaminase, creatine kinase, troponin-I, and troponin-T, and lactate dehydrogenase of myocardium infarction rats. Significant increases in the activity of superoxide dismutase, catalase, glutathione peroxidase, and a reduced level of glutathione, were observed in AESL treated cataract rat lens. The results demonstrate that AESL is useful in, in addition to diabetes, controlling myocardium infarction, cataracts, and arthritis.

β-caryophyllene blocks reactive oxygen species-mediated hyperlipidemia in isoproterenol-induced myocardial infarcted rats

Myocardial infarction (MI) is a leading cause of death. Lipid-lowering interventions have been shown to decrease coronary events and mortality of MI and heart failure. In this investigation, we assessed the anti-hyperlipidemic effects of β-caryophyllene in isoproterenol-induced myocardial infarcted rats. β-Caryophyllene (20 mg/kg body weight) pre-and co-treatment was given to rats orally, daily, for 3 weeks. Isoproterenol (100 mg/kg body weight) was administered to rats to induce MI. The levels of serum cardiac troponins T and I, serum and heart total cholesterol, triglycerides, free fatty acids, and the levels of serum low-density and very low-density lipoprotein-cholesterols were augmented, and the level of serum high-density lipoprotein-cholesterol was lessened in myocardial infarcted rats. Further, the activity/levels of liver 3-hydroxy-3-methylglutaryl-coenzyme A reductase and plasma thiobarbituric acid reactive substances were amplified and the activity/levels of heart glutathione –S- transferase, vitamin C, and vitamin E were lessened by isoproterenol. A down-regulated expression of liver sterol regulatory element-binding protein-2 and liver low-density lipoprotein-receptor genes was observed by a reverse transcription-polymerase chain reaction study. Moreover, histopathology of Sudan III staining revealed an accumulation of fats in the heart of isoproterenol-induced rats. Nevertheless, β-caryophyllene pre-and co-treatment blocked alterations in all the parameters examined in isoproterenol-induced rats and inhibited the risk of MI. Moreover, the in vitro study revealed the potent free radical scavenging and antioxidant effects of β-caryophyllene. β-Caryophyllene's antioxidant and anti-hyperlipidemic properties are the possible mechanisms for the observed protective effects in this investigation.

MiR-432-5p Inhibits the Ferroptosis in Cardiomyocytes Induced by Hypoxia/Reoxygenation via Activating Nrf2/SLC7A11 Axis by Degrading Keap1.

Early reperfusion into the myocardium after ischemia causes myocardial ischemia-reperfusion (I/R) injury and ferroptosis was involved. Ischemia activates the expression of a series of oxidative stress genes and their downstream regulatory genes, including ferroptosis-related genes such as nuclear factor E2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and SLC7A11. This study adopted primary cardiomyocytes and I/R in rats to evaluate the ferroptosis and changing of Nrf2-SLC7A11/heme oxygenase-1 (HO-1) in vitro and in vivo. Online analysis tools were used to predict the possible target Kelch-like ECH-associated protein 1 (Keap1) of miR-432-5p. The mimic of miR-432-5p plasmid was constructed to verify the effect of miR-432-5p on ferroptosis. We found that hypoxia/reoxygenation (H/R) in cardiomyocytes and I/R in rats induced lipid peroxidation and ferroptosis in cardiomyocytes. The activation of the Nrf2-SLC7A11/HO-1 pathway protects cardiomyocytes from ferroptosis. Downregulation of miR-432-5p has been confirmed in H/R cardiomyocytes (in vitro) and cardiomyocytes in myocardial infarction rats (in vivo). Upregulation of miR-432-5p inhibited ferroptosis of cardiomyocytes induced by RAS-selective lethal 3 (RSL3), an inhibitor of GPX4 and ferroptosis inducer through decreasing the binding protein of Nrf2, Keap1, which was confirmed by bioinformatics and mutation assay. Knockdown Nrf2 attenuates the protection effect of miR-432-5p on H/R cardiomyocytes. Intravenous delivery of liposome carriers of miR-432-5p remarkably ameliorated cardiomyocyte impairment in the I/R animal model. In conclusion, miR-432-5p inhibits the ferroptosis in cardiomyocytes induced by H/R by activating Nrf2/SLC7A11 axis by degrading Keap1 and is a potential drug target for clinical myocardial infarction treatment.

A Convergent fabrication of silk fibroin nanoparticles on quercetin loaded metal-organic frameworks for promising nanocarrier of myocardial infraction

The biomacromolecule silk fibroin (SF) may be constructed to promote biomimetic nucleation and nanostructures of inorganic nanomaterials, offering it a promising candidate for use in various biomimetic applications. We combined SF-NPs and ZIF-8-NPs to fabricate new drug vehicles that effectively release the drug. SF nanoparticles (SF-NPs) were assembled into quercetin (QCT), a myocardial drug added to fabricate QSF-NPs. By acting as a template for the ZIF-8 nucleation onto the surface, the QSF-NPs fabricated core-shell-structured nanocomposites (named QSF@Z-NCs) with ZIF-8 as the core-shell and the QSF-NPs. The biocompatibility analysis using the MTT assay revealed that the developed QCT, SF-NPs, and QSF@Z-NCs are not harmful to cardiac myoblast (H9C2) cells. The in vivo model demonstrated that H9C2 cells encouraged cardiomyocyte fibre regeneration in myocardial infarction rats. We fabricated a brand-new technique using H9C2 cells and QSF@Z-NCs that might encourage the healing processes in myocardial ischemia cells. This study's results demonstrate that it successfully treats myocardial injury.

Protective effect of luteolin on cardiac ischemia/reperfusion injury in rats with myocardial infarction through ERK/JNK signaling pathway

Due to the increased incidence of cardiovascular diseases, the incidence of cardiac ischemia/reperfusion injury (IRI) is also on the rise. Luteolin has a certain protective effect on myocardium. Therefore, this study focuses on whether luteolin can protect IRI in rats with myocardial infarction. A myocardial infarction rat model was prepared and the isolated heart was treated to induce cardiac ischemia-reperfusion injury. British biodegradable packaging company (BIOPAC) biological signal collector detects myocardial indicators; semi-automatic biochemical analyzer detects myocardial infarct size; hematoxylin-eosin (HE) staining observes pathological changes along with analysis of the levels of ERK, JNK, and Caspase-3 and proliferation and apoptosis of myocardial cells. Luteolin can improve the myocardial index level of rats with myocardial infarction and increase survival rate; the rats in luteolin group have the smallest myocardial infarction area, and the myocardial tissue is tightly arranged, the myocardial collagen is significantly reduced, and the myocardial injury index is significantly reduced. Luteolin inhibited the proliferation, migration and apoptosis of cardiomyocytes. Caspase-3, ERK, and JNK expression in the ERK/JNK agonist group was the most obvious. Their levels were highest in the luteolin+ERK/JNK agonist group (vs. other groups, P &lt;0.05), which was higher than ERK/JNK agonist group. Luteolin can inhibit Caspase-3 expression by activating ERK/JNK signaling pathway, thereby reducing myocardial injury.

The effect of high-intensity interval training and quercetin nanoliposome consumption on angiogenesis indexes in the heart tissue of myocardial infarction rats

Background: Myocardial infarction is the death of the heart muscle tissue that causes tissue damage and inflammation. Quercetin consumption and interval training can probably prevent the progression of this condition in the active parts of the myocardium by activating angiogenesis pathways and stimulating hypoxia factor-1a (HIF-1a) at the onset of infarction. Objectives: This study investigates the effect of high-intensity interval training and quercetin nanoliposome consumption on angiogenesis indexes in the heart tissue of myocardial infarction rats. Methods: In this experimental study, 30 male rats weighing 250 ± 20 g were randomly divided into five groups including: 1) myocardial infarction + training, 2) myocardial infarction + supplement, 3) myocardial infarction + training + supplement, 4) healthy control, and 5) myocardial infarction. Myocardial infarction was induced by subcutaneous injection of soprenaline hydrochloride at a dose of 80 mg / kg. Groups 2 and 3 received quercetin daily at a dose of 0.25 mg / kg body weight by gavage. Groups 1 and 3 performed 5 sessions of training protocol per week for 8 weeks. The Smirnov-Kolmogorov, one-way analysis of variance and Tukey’s post hoc test were used to analyze the data and the alpha level less than 0.05 was considered as a significant level. Results: Interval training and quercetin supplementation had a significant effect on increasing VEGF and HIF-1a gene expression (P=0.0009). Conclusion: The combined effect of interval training and quercetin consumption may prevent the progression of myocardial infarction by activating angiogenesis factors VEGF and HIF-1a in the early stages, and may play an effective role in preventing this disease.

Mature human induced pluripotent stem cell-derived cardiomyocytes promote angiogenesis through alpha-B crystallin

BackgroundHuman induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) can be used to treat heart diseases; however, the optimal maturity of hiPSC-CMs for effective regenerative medicine remains unclear. We aimed to investigate the benefits of long-term cultured mature hiPSC-CMs in injured rat hearts.MethodsCardiomyocytes were differentiated from hiPSCs via monolayer culturing, and the cells were harvested on day 28 or 56 (D28-CMs or D56-CMs, respectively) after differentiation. We transplanted D28-CMs or D56-CMs into the hearts of rat myocardial infarction models and examined cell retention and engraftment via in vivo bioluminescence imaging and histological analysis. We performed transcriptomic sequencing analysis to elucidate the genetic profiles before and after hiPSC-CM transplantation.ResultsUpregulated expression of mature sarcomere genes in vitro was observed in D56-CMs compared with D28-CMs. In vivo bioluminescence imaging studies revealed increased bioluminescence intensity of D56-CMs at 8 and 12 weeks post-transplantation. Histological and immunohistochemical analyses showed that D56-CMs promoted engraftment and maturation in the graft area at 12 weeks post-transplantation. Notably, D56-CMs consistently promoted microvessel formation in the graft area from 1 to 12 weeks post-transplantation. Transcriptomic sequencing analysis revealed that compared with the engrafted D28-CMs, the engrafted D56-CMs enriched genes related to blood vessel regulation at 12 weeks post-transplantation. As shown by transcriptomic and western blot analyses, the expression of a small heat shock protein, alpha-B crystallin (CRYAB), was significantly upregulated in D56-CMs compared with D28-CMs. Endothelial cell migration was inhibited by small interfering RNA-mediated knockdown of CRYAB when co-cultured with D56-CMs in vitro. Furthermore, CRYAB overexpression enhanced angiogenesis in the D28-CM grafts at 4 weeks post-transplantation.ConclusionsLong-term cultured mature hiPSC-CMs promoted engraftment, maturation and angiogenesis post-transplantation in infarcted rat hearts. CRYAB, which was highly expressed in D56-CMs, was identified as an angiogenic factor from mature hiPSC-CMs. This study revealed the benefits of long-term culture, which may enhance the therapeutic potential of hiPSC-CMs.

Pharmacokinetic evaluation of 24 representative components of Ling-Gui-Zhu-Gan decoction in acute myocardial infarction model rats via a validated ultrahigh-performance liquid chromatography-tandem mass spectrometry method.

Ling-Gui-Zhu-Gan decoction (LGZGD), one of the 100 herbal classic formulas, is clinically used to treat chronic heart failure with remarkable curative effect. However, LGZGD pharmacokinetic parameters in pathological model rats are poorly understood, in particular for special components. As physicochemical properties are specific to each representative component, no standard sample preparation is available for absolute quantification of representative components of LGZGD in rat plasma. A specific, sensitive and high-throughput ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS) method capturing 24 representative components was developed and applied to evaluate the pharmacokinetic parameters of LGZGD in acute myocardial infarction (AMI) rat plasma after intragastric administration (2.4, 4.8 and 9.6g/kg). Precipitation and extraction were selected and optimized for plasma preparation, and isopropanol precipitation could offer higher recovery and broader coverage. It was expected that AMI could cause less absorption and slower elimination of most of active components of LGZGD. Most of newly reported special components absorbed quickly and eliminated slowly. The average elimination half-life of the 24 representative components was 10.09 h, which is consistent with the dosage of LGZGD (twice daily). The specificity, linearity, precision and accuracy, recovery, matrix effect and stability were validated according to Food and Drug Administration guidance. The validation results demonstrated that the method could be applied to evaluate the pharmacokinetic parameters of LGZGD in AMI rats. The pharmacokinetic parameters showed substantial improvement in quality research of LGZGD, thereby laying the groundwork for preclinical and clinical trials in chronic heart failure clinical efficacy.

Improved Cardiac Function in Postischemic Rats Using an Optimized Cardiac Reprogramming Cocktail Delivered in a Single Novel Adeno-Associated Virus.

Cardiac reprogramming is a technique to directly convert nonmyocytes into myocardial cells using genes or small molecules. This intervention provides functional benefit to the rodent heart when delivered at the time of myocardial infarction or activated transgenically up to 4 weeks after myocardial infarction. Yet, several hurdles have prevented the advancement of cardiac reprogramming for clinical use. Through a combination of screening and rational design, we identified a cardiac reprogramming cocktail that can be encoded in a single adeno-associated virus. We also created a novel adeno-associated virus capsid that can transduce cardiac fibroblasts more efficiently than available parental serotypes by mutating posttranslationally modified capsid residues. Because a constitutive promoter was needed to drive high expression of these cell fate-altering reprogramming factors, we included binding sites to a cardiomyocyte-restricted microRNA within the 3' untranslated region of the expression cassette that limits expression to nonmyocytes. After optimizing this expression cassette to reprogram human cardiac fibroblasts into induced cardiomyocyte-like cells in vitro, we also tested the ability of this capsid/cassette combination to confer functional benefit in acute mouse myocardial infarction and chronic rat myocardial infarction models. We demonstrated sustained, dose-dependent improvement in cardiac function when treating a rat model 2 weeks after myocardial infarction, showing that cardiac reprogramming, when delivered in a single, clinically relevant adeno-associated virus vector, can support functional improvement in the postremodeled heart. This benefit was not observed with GFP (green fluorescent protein) or a hepatocyte reprogramming cocktail and was achieved even in the presence of immunosuppression, supporting myocyte formation as the underlying mechanism. Collectively, these results advance the application of cardiac reprogramming gene therapy as a viable therapeutic approach to treat chronic heart failure resulting from ischemic injury.

Stacking thick perfusable human microvascular grafts enables dense vascularity and rapid integration into infarcted rat hearts

Fabrication of large-scale engineered tissues requires extensive vascularization to support tissue survival and function. Here, we report a modular fabrication approach, by stacking of patterned collagen membranes, to generate thick (2 mm and beyond), large, three-dimensional, perfusable networks of endothelialized vasculature. In vitro, these perfusable vascular networks exhibit remodeling and evenly distributed perfusion among layers, while maintaining their patterned, open-lumen architecture. Compared to non-perfusable, self-assembled vasculature, constructs with perfusable vasculature demonstrated increased gene expression indicative of vascular development and angiogenesis. Upon implantation onto infarcted rat hearts, perfusable vascular networks attain greater host vascular integration than self-assembled controls, indicated by 2.5-fold greater perfused vascular density measured by histological analysis and 5-fold greater perfusion rate measured by optical microangiography. Together, the success of fabricating thick, perfusable tissues with dense vascularity and rapid anastomoses represents an important step forward for vascular bioengineering, and paves the way towards more complex, large scale, highly metabolic engineered tissues.

Spatial patterns of intrinsic brain activity in rats with capsular stroke.

To explore the neural changes of brain activity in rats with circumscribed capsular infarcts to find a new therapeutic target for promoting the functional recovery. A total of 18 capsular infarct rats and 18 normal rats were conducted in this study. All animal use procedures were strictly in accordance with the guide for the care and use of laboratory animals. After establishing the photothrombotic capsular infarct model, the functional magnetic resonance imaging (fMRI) data were collected and analyzed. The fMRI results indicated that the passive movement would induce strong activation in caudate, putamen, frontal association somatosensory cortex, thalamus dorsolateral, and thalamus midline dorsal in control group, and the passive movement would only induce limited activation mostly in somatosensory cortex, thalamus dorsolateral, and thalamus midline dorsal in capsular infarct models. Capsular infarct makes the cortical activity weaken in sensory-related cortex and subcortical nuclei, including capsular area and thalamus. Such findings imply that the posterior limb of internal capsule (PLIC) is connected to these structures in function, interacts together with them, and, accordingly, the lesion of PLIC manifests the related symptoms.