Rat Coronary Arteries Research Articles

Bushen Huoxue Yiqi Formula Alleviates Cardiac Fibrosis in Ischemic Heart Failure through SIRT1/Notch1 Pathway-Mediated EndMT

BackgroundCardiac fibrosis plays a crucial role in the development of heart failure (HF) following myocardial infarction (MI). Endothelial-mesenchymal transition (EndMT) is one of the key drivers of cardiac fibrosis and subsequent cardiac dysfunction. The traditional Chinese medicine formula Bushen Huoxue Yiqi Formula (BHYF) is an effective prescription for treating HF, significantly improving cardiac function in patients. However, the underlying mechanisms of BHYF's efficacy remain inadequately understood. ObjectiveThis study aims to determine whether BHYF ameliorates HF by inhibiting cardiac fibrosis and to elucidate the intrinsic mechanisms involved. MethodsA post-MI HF model was established by ligating the left anterior descending coronary artery in rats, and human umbilical vein endothelial cells (HUVEC) were stimulated with hypoxia/reoxygenation (H/R) in vitro. Active compounds in BHYF were identified using HPLC. Cardiac function and morphology were assessed using echocardiography, TTC staining, HE staining, Masson's trichrome, and Sirius Red staining. The mechanism of action of BHYF was evaluated using Western blotting, immunohistochemistry, and immunofluorescence. ResultsA total of 98 compounds, including glycosides, phenolic compounds, carboxylic acids, and others, were identified or preliminarily identified. BHYF improved cardiac function and myocardial damage in rats with MI-induced HF and mitigated cardiac fibrosis by inhibiting EndMT. Mechanistically, BHYF treatment inhibited EndMT by modulating the SIRT1/Notch1 pathway, thereby exerting anti-fibrotic effects in the heart. ConclusionTargeting EndMT based on the SIRT1/Notch1 pathway, BHYF may represent a novel antifibrotic therapeutic strategy, providing a scientific basis for the development of new cardiovascular drugs.

The effect of the liposomal form of alteplase on the effectiveness of thrombolysis in coronary arteries in acute myocardial infarction

A liposomal (Lip) formulation of tissue plasminogen activator, alteplase (AlT), has been developed. The quantitative and qualitative composition of the liposomes, as well as their physicochemical properties and proteolytic activity, have been studied in relation to the thrombolytic liposomal form. It was determined that a formulation consisting of liposomes with a phosphatidylcholine/cholesterol ratio of 1.5 : 1, and lipids/alteplase ratio of 1 : 1, is optimal for treating acute myocardial infarction (AMI) in experimental models. At different component ratios, liposomes had a negative zeta potential value greater than 30 mV, indicating their aggregative stability, even after storage for two days at 20 degrees Celsius. Liposomes derived from soy phosphatidylcholine showed greater colloidal stability with a zeta potential of approximately –57 mV and a lower hydrodynamic diameter of approximately 140 nanometers, compared to liposomes derived from egg phosphatidylcholine, which had a zeta potential around –35.4 mV and a hydrodynamic diameter around 220 nanometers. The initial content of free AlT in the liposome supernatant from egg phosphatidylcholine (Lipeg) was 15.0 ± 4.0 %. During the incubation period of 4 days, the concentration of free AlT decreased to 9.0 ± 4.5 %. In contrast, in liposomes derived from soy phosphatidylcholine (LipS), the content of free AlT increased from 11.0 ± 4.5 % to 32.5 ± 6.0 % over the same incubation period. The value of the proteolytic activity of tissue plasminogen activator (tPA) in the compositions of Lipeg(AlT) and Lips (AlT) depends on the type of phosphatidylcholine. The initial tPA activity in Lipeg (AlT) was 36.0 %, and after 1 day, it increased to 45 %. In Lips (AlT), the initial activity was 61.0 % and increased to 66 % after 1 day. When using the liposomal form of alteplase for delivery into the coronary arteries of rats with acute myocardial infarction (AMI), a more complete fibrin lysis is noted compared to animals receiving the native form of the drug. The developed system of targeted delivery of alteplase using soy liposomes has been shown to significantly improve the degree of coronary artery lumen restoration by more than 15 %, compared to the use of a conventional drug (p < 0.05).

Abstract 3094: Traditional Chinese Medicine Buyang Huanwu Decoction Regulates The Platelet Gpvi And Its Downstream Protein Signaling Pathways,inhibiting Thrombosis And Preventing Cardiovascular Disease.

Background: Coronary heart disease Qi-Deficiency and Blood Stasis Syndrome will lead to the body of platelets disorders, blood viscosity, conducive to the formation of thrombosis, Buyang Huanwu Decoction (BYHWD) is a classic Chinese medicine treatment of Qi-Deficiency and Blood Stasis Syndrome. Platelet glycoprotein VI (GPVI) plays a crucial role in collagen-induced activation and aggregation of platelets. GPVI has become the focus of new approaches to antithrombotic therapy. Methods: After 6 weeks of irregular sleep deprivation in rats with syndrome of deficiency of qi and blood stasis formed, the coronary heart disease model was established by ligation of the left anterior descending coronary artery in rats. The dosage of 1 mL/100 g was given by intragastric administration for 14 days after operation. Results: The purpose of this study was to investigate the effects of BYHWD on platelet granule secretion and platelet function in vitro. We found that BYHWD can significantly reduce the platelet aggregation induced by ADP and collagen, significantly reduce the median expression of CD62p and the ratio of activated platelets, and reduce the concentration of fluorescent calcium ions in platelets. Under the electron microscope observation found that under the action of BYHWD, the ultrastructure of rat platelets pseudopodia reduced, aggregation reduced, rat coronary inner wall platelets, thrombus mass adhesion reduced, and the inner wall was smoother. In addition, BYHWD can regulate GPVI and its downstream proteins. Compared with the coronary heart disease group with syndrome of blood stasis, BYHWD can significantly reduce the expression of GPVI. Significantly reduced the expression of Syk, CALDAG-GEFI, significantly reduced the expression of IP 3 and significantly reduced the degree of PLCγ 2 of rats. Decreased the degranulation reaction of the rat blood, significantly decreased the level of TXA 2 , 5-HT in the rat blood, and significantly decreased the content of the rat blood COX-1 in the rat serum. Conclusion: Therefore, BYHWD can regulate GPVI and its downstream protein signaling pathways, reduce platelet over-activation, degranulation reaction, thereby inhibiting thrombosis, protecting heart function and preventing cardiovascular disease.

Sini decoction alleviates inflammation injury after myocardial infarction through regulating arachidonic acid metabolism

ObjectiveMyocardial inflammation during myocardial infarction (MI) could be inhibited by regulating arachidonic acid (AA) metabolism. Recent studies demonstrated that Sini Decoction (SND) was identified to be an effective prescription for treating heart failure (HF) caused by MI. But the anti-inflammatory mechanism of SND remained unclear. The work was designed to investigate the anti-inflammatory mechanism of SND through the AA metabolism pathway in vitro and in vivo experiments. MethodsAn inflammatory injury model of H9c2 cells was established by lipopolysaccharide (LPS)-stimulated macrophage-conditioned medium (CM). The MI model was built by the ligation of left anterior descending (LAD) branch of coronary artery in rat. Meanwhile, the rats were divided into five groups: sham group, MI group, MI + Celecoxib group, MI + low-dose SND group (SND-L) and MI + high-dose SND group (SND-H). Cardiac function, histopathological changes and serum cytokines were examined four weeks later. Western blot analysis was conducted to verify the key enzymes levels in the AA metabolic pathway, including phospholipase A2 (PLA2), cyclooxygenases (COXs) and lipoxygenases (LOXs). ResultsThese in vivo results demonstrated that SND could improve the cardiac function and pathological changes of rats with MI, and regulate the key inflammatory molecules in the AA metabolism pathway, including sPLA2, COX-1, COX-2, 5-LOX and 15-LOX. In vitro, SND could decrease the release of pro-inflammatory cytokines including TNF-α and IL-6 and inhibit cell apoptosis in CM-induced H9c2 cells. Moreover, SND could protect H9c2 cells from the damage of CM by regulating nuclear factor kappa-B (NF-κB) signal pathway and the expression of COX-2. ConclusionSND may be a drug candidate for anti-inflammatory treatment during MI by regulating the multiple targets in the AA metabolism pathway.

Doxorubicin alters G-protein coupled receptor-mediated vasocontraction in rat coronary arteries.

Doxorubicin (Doxo)-associated cardio-and vasotoxicity has been recognised as a serious complication of cancer chemotherapy. The purpose of this novel paper was to determine the effect of Doxo on G-protein coupled receptor (GPCR)-mediated vasocontraction located on vascular smooth muscle cells. Rat left anterior descending artery segments were incubated for 24h with 0.5 µM Doxo. The vasocontractile responses by activation of endothelin receptor type A (ETA) and type B (ETB), serotonin receptor 1B (5-HT1B) and thromboxane A2 prostanoid receptor (TP) were investigated by a sensitive myography using specific agonists, while the specificity of the GPCR agonists was verified by applying selective antagonists (i.e. ETA and ETB agonist = 10- 14-10- 7.5 M endothelin-1 (ET-1); ETA antagonist = 10 µM BQ123; ETB agonists = 10- 14-10- 7.5 M sarafotoxin 6c (S6c) and ET-1; ETB antagonist = 0.1 µM BQ788; 5-HT1B agonist = 10- 12-10- 5.5 M 5-carboxamidotryptamine (5-CT); 5-HT1B antagonist = 1 µM GR55562; TP agonist = 10- 12-10- 6.5 M U46619; TP antagonist = 1 µM Seratrodast). Our results show that 0.5 µM Doxo incubation of LAD segments leads to an increased VSMC vasocontraction through the ETB, 5-HT1B and TP GPCRs, with a 2.2-fold increase in ETB-mediated vasocontraction at 10- 10.5 M S6c, a 2.0-fold increase in 5-HT1B-mediated vasocontraction at 10- 5.5 M 5-CT, and a 1.3-fold increase in TP-mediated vasocontraction at 10- 6.5 M U46619. Further studies unravelling the involvement of intracellular GPCR signalling pathways will broaden our understanding of the Doxo-induced vasotoxicity, and thus pave the way to mitigate the adverse effects by potential implementation of adjunct therapy options.

Fuyu Decoction ameliorates myocardial fibrosis in rat model of heart failure by regulating Nrf2/GPX4-mediated ferroptosis

This study aims to investigate the effect and mechanism of Fuyu Decoction(FYD) in the treatment of myocardial fibrosis in the rat model of heart failure(HF). Sixty Wistar rats were randomized into a modeling group(n=50) and a sham group(n=10). A post-myocardial infarction HF model was established by ligating the left anterior descending coronary artery in rats. The successfully modeled rats were assigned into model, low-dose(2.5 g·kg~(-1)) FYD(FYD-L), high-dose(5.0 g·kg~(-1)) FYD(FYD-H), and FYD+Nrf2 inhibitor(ML385, 30 mg·kg~(-1)) groups(n=10). FYD was administrated by gavage and ML385 by intraperitoneal injection. The rats in the sham and model groups were administrated with equal amounts of normal saline by gavage. After 8 weeks of intervention, the cardiac function indicators were measured, and the myocardial tissue morphology and collagen deposition were observed. The positive expression of collagens Ⅰ and Ⅲ, apoptosis, and oxidative stress were examined, and the levels of Fe~(2+) and reactive oxygen species(ROS) were determined. The protein levels of nuclear factor erythroid 2-related factor 2(Nrf2), solute carrier family 7 member 11(SLC7A11), glutathione peroxidase 4(GPX4), and acyl-coenzyme A synthase long chain family member 4(ACSL4) in the myocardial tissue were determined. Compared with sham group, the model group showed decreased left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), increased left ventricular end internal dimension in systole(LVIDs), left ventricular internal diameter in diastole(LVIDd), and myocardial collagen deposition, positive expression of collagens Ⅰ and Ⅲ, elevated apoptosis rate and malondialdehyde(MDA), Fe~(2+), and ROS levels, lowered superoxide dismutase(SOD) and glutathione peroxidase(GSH) levels, down-regulated protein levels of Nrf2, SLC7A11, and GPX4, and up-regulated protein level of ACSL4. Compared with the model group, the above indicators were restored by FYD. Moreover, ML385 reversed the protective effect of FYD on myocardial fibrosis in HF rats. In conclusion, FYD can inhibit ferroptosis by activating the Nrf2/GPX4 pathway, thereby ameliorating myocardial fibrosis in HF rats.

Empagliflozin Induces Vascular Relaxation in Rat Coronary Artery Due to Activation of BK Channels.

The aim of this study was to investigate the effects and mechanisms of SGLT2 inhibitor empagliflozin on diabetic coronary function. A rat diabetic model was established by injection of streptozotocin. Rats in the treated group were administered empagliflozin by gavage and rat coronary vascular tensions were measured after eight weeks. Large conductance calcium activated K+ channel currents were recorded using a patch clamp technique, while human coronary artery smooth muscle cells were used to explore the underlying mechanisms. After incubation with empagliflozin (10, 30, 100, 300, 1000 μmol/L), the Δ relaxation % of rat coronary arteries were 2.459 ± 1.304, 3.251 ± 1.119, 6.946 ± 3.407, 28.36 ± 11.47, 86.90 ± 3.868, respectively. Without and with empagliflozin in the bath solution, BK channel opening probabilities at a membrane potential of +60 mV were 0.0458 ± 0.0517 and 0.3413 ± 0.2047, respectively (p < 0.05, n = 4 cells). After incubation with iberiotoxin, the Δ tensions of rat coronary arteries in the control (Ctrl), untreated (DM), low empagliflozin (10 mg/kg/d)-treated (DM+L-EMPA) and high empagliflozin (30mg/kg/d)-treated (DM+H-EMPA) group were 103.20 ± 5.85, 40.37 ± 22.12, 99.47 ± 28.51, 78.06 ± 40.98, respectively (p < 0.01 vs Ctrl, n = 3-7; p < 0.001 vs DM+L-EMPA, n = 5-7). Empagliflozin restored high glucose-induced downregulation of Sirt1, Nrf2, and BK-β1, while the effect of empagliflozin disappeared in the presence of EX-527, a Sirt1 selective inhibitor. Empagliflozin has a vasodilation effect on the coronary arteries in a concentration-dependent manner and can activate BK channels via the Sirt1-Nrf2 mechanism.

Investigating the Cardiovascular Benefits of Dapagliflozin: Vasodilatory Effect on Isolated Rat Coronary Arteries

Dapagliflozin, a sodium–glucose co-transporter 2 (SGLT2) inhibitor, is an antidiabetic medication that reduces blood glucose. Although it is well known that dapagliflozin has additional benefits beyond glycemic control, such as reducing blood pressure and lowering the risk of cardiovascular events, no sufficient research data are available on the direct effect of dapagliflozin on cardiovascular function. Thus, in this study, we investigated the direct vascular effect of dapagliflozin on isolated rat coronary arteries. The left descending coronary arteries of 13-week-old male Sprague Dawley rats were cut into segments 2–3 mm long and mounted in a multi-wire myography system to measure isometric tension. Dapagliflozin effectively reduced blood vessel constriction induced by U-46619 (500 nM) in coronary arteries regardless of the endothelium. Treatment with an eNOS inhibitor (L-NNA, 100 μM), sGC inhibitor (ODQ, 5 μM), or COX inhibitor (indomethacin, 3 μM) did not affect the vasodilation induced by dapagliflozin. The application of a Ca2+-activated K+ channel (KCa) blocker (TEA, 2 mM), voltage-dependent K+ channel (KV) blocker (4-AP, 2 mM), ATP-sensitive K+ channel blocker (KATP) glibenclamide (3 μM), and inward-rectifier K+ channel (KIR) blocker (BaCl2, 30 μM) did not affect the dapagliflozin-induced vasodilation either. The treatment with dapagliflozin decreased contractile responses induced by the addition of Ca2+, which suggested that the extracellular Ca2+ influx was inhibited by dapagliflozin. Treatment with dapagliflozin decreased the phosphorylation level of the 20 kDa myosin light chain (MLC20) in vascular smooth muscle cells. In the present study, we found that dapagliflozin has a significant vasodilatory effect on rat coronary arteries. Our findings suggest a novel pharmacologic approach for the treatment of cardiovascular diseases in diabetic patients through the modulation of Ca2+ homeostasis via dapagliflozin administration.

Japanese Quince Fruit Juice Exerts a Cardioprotective Effect in a Model of Diet-Induced Metabolic Syndrome in Rats

Summary The current study aimed to evaluate the influence of Japanese quince (Chaenomeles japonica) fruit juice (JQFJ) on the myocardium and on the coronary arteries of rats with diet-induced metabolic syndrome (MS). Male Wistar rats (n=50) were divided into 5 groups: Control, MS, MS+JQFJ2.5, MS+JQFJ5 and MS+JQFJ10. MS was induced with a high-fat high-fructose diet for 10 weeks. During that period, all animals were daily orally treated with distilled water (Control and MS groups) or with JQFJ at doses of 2.5 ml/kg, 5 ml/kg and 10 ml/kg (the other three groups, respectively). At the end of the experiment, the myocardium and coronary arteries were examined histopathologically. In group MS, necrotic endothelial cells and exposed basal membrane were observed. JQFJ at 2.5 ml/kg reduced the impairment but activated endothelial cells were still found. JQFJ at 5 ml/kg and 10 ml/kg prevented coronary artery endothelium damage, preserving the normal morphology. The myocardium in MS group presented with cardiomyocyte degeneration and increased distance between the cells. In group MS+JQFJ2.5, the degeneration was decreased. In groups MS+JQFJ5 and MS+JQFJ10, the histology of the myocardium resembled that of the control group. In the current histopathological evaluation, JQFJ prevented the MS-induced impairment of myocardium and coronary arteries.

Aldehyde Dehydrogenase 2 Preserves Mitochondrial Function in the Ischemic Heart: A Redox-dependent Mechanism for AMPK Activation by Thioredoxin-1.

Aldehyde dehydrogenase 2 (ALDH2) protects the ischemic heart by activating adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling. However, the molecular mechanisms linking ALDH2 and AMPK signaling are not fully understood. This study aimed to explore the potential mechanisms linking ALDH2 and AMPK in myocardial ischemic injury. An ischemic model was established by ligating the left anterior descending coronary artery in rats. The overexpression or knockdown of ALDH2 in H9c2 cells treated with oxygen-glucose deprivation was obtained through lentivirus infection. Transferase-mediated dUTP nick-end labeling was used to evaluate apoptosis in an ischemic rat model and oxygen-glucose deprivation cells. ALDH2 activity, mitochondrial oxidative stress markers, adenosine triphosphate, respiratory control ratio, and cell viability in H9c2 cells were evaluated using a biological kit and 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide. Protein expression of ALDH2 , 4-hydroxynonenal, thioredoxin-1 (Trx-1), and AMPK-proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) signaling pathway was detected through Western blotting. ALDH2 activation reduced ischemic-induced myocardial infarct size and apoptosis. ALDH2 protected mitochondrial function by enhancing mitochondrial respiratory control ratio and adenosine triphosphate production, alleviated mitochondrial oxidative stress, and suppressed myocardial apoptosis. Moreover, ALDH2 attenuated ischemia-induced oxidative stress and maintained Trx-1 levels by reducing 4-hydroxynonenal, thereby promoting AMPK-PGC-1α signaling activation. Inhibiting Trx-1 or AMPK abolished the cardioprotective effect of ALDH2 on ischemia. ALDH2 alleviates myocardial injury through increased mitochondrial biogenesis and reduced oxidative stress, and these effects were achieved through Trx1-mediating AMPK-PGC1-α signaling activation.

Upregulation of Orai Channels Contributes to Aging-Related Vascular Alterations in Rat Coronary Arteries.

Vascular territories display heterogeneous sensitivity to the impacts of aging. The relevance of the STIM/Orai system to vascular function depends on the vascular bed. We aimed to evaluate the contribution of the STIM/Orai system to aging-related vascular dysfunction in rat coronary circulation. Vascular function was evaluated according to myography in coronary arteries from young (three-month-old) and older (twenty-month-old) rats. The effects of aging and STIM/Orai inhibition on the contraction and relaxation of the coronary arteries and on the protein expression of STIM-1, Orai1, and Orai3 in these vessels were determined. Aging-related hypercontractility to serotonin and endothelin-1 in arteries from male rats was reversed by STIM/Orai inhibition with YM-58483 or by specifically blocking the Orai1 channel with Synta66. The inhibitory effects of Synta66 on coronary vasoconstriction were also observed in older female rats. YM-58483 relaxed serotonin- but not KCl-contracted arteries from males. STIM/Orai inhibition improved defective endothelial vasodilations in aged arteries, even in the presence of NO synthase and cyclooxygenase inhibitors, but not in KCl-contracted segments. YM-58483 significantly enhanced relaxations to calcium-activated potassium channel stimulation in aged vessels. Increased protein expression of Orai1 and Orai3 was detected in arterial homogenates and sections from older rats. Upregulation of the Orai channel contributes to aging-related coronary dysfunction, revealing a potential target in reducing CVD risk.

Abstract P1170: Changes In Endothelin Signaling In A Long-term Rat Coronary Culture Resembles Chronic Coronary Syndrome

Background: Coronary artery disease generates changes in the structure and function of the blood vessels. 48hrs organ culture (mimicking the acute loss of blood flow) of coronary arteries induces the upregulation of contractile endothelin type B (ETB) receptors, resembling the pattern seen in ischemic heart disease. MEK inhibitors (U0126 and Trametinib), can acutely inhibit the upregulation of these receptors, illustrating the importance of this pathway. The 48hrs organ culture model has been proven successful for translation in acute ischemic disease, but arterial changes have not been studied in a long-term chronic model which could be important for chronic coronary syndrome. Purpose: 1) Investigate the changes of ETB receptors after incubation in a long-term optimized medium for organ culture, mimicking the reduction of blood flow in chronic coronary syndrome and 2) determine whether Trametinib, would have treatment effect on the upregulation of ETB receptors in both long term and short term culture. Methods: Rat coronary arteries were incubated in organ culture for 48hrs in DMEM ± trametinib (“acute”) or in a long-term optimized medium for organ culture for 14 days (“chronic”). After the incubation, arteries were mounted stainless steel wires (40 μm) on a Mulvany-Halpern arterial wire myograph and cumulative concentration response curves were made to measure arterial contractility to the ETB receptor specific agonist Sarafotoxin (S6c). Trametinib was added at time 0 (for both the acute and chronic organ culture) or 7 days delayed. Results: For the “acute” culture, we observed a high contractile effect in response to S6c (Emax=136.5±18%). The presence of Trametinib greatly reduced this contractile effect (Emax=10±1.9%) and arteries were comparable to fresh (Emax=0.8±0.7%). The rat coronary arteries in the “chronic” culture maintained their ability to contract in response to potassium, and S6c had a strong contractile effect (Emax=74.64±17%). Interestingly, neither trametinib addition at time 0 nor at day 7 could inhibit the functional upregulation of ETB in the chronic model. Conclusion: Chronic coronary syndrome may require new inhibitors of ETB receptor upregulation. This could be investigated with our new long-term rat coronary artery model.

Mechanisms of Yangxin Tongmai Formula for blood stasis syndrome in coronary heart disease rats based on untargeted plasma metabolomics and intestinal flora 16S rRNA sequencing

ObjectiveTo investigate the correlations between intestinal flora, plasma metabolites, and blood stasis syndrome in coronary heart disease (CHD), and the mechanisms of Yangxin Tongmai Formula (养心通脉方, YXTMF) for blood stasis syndrome in CHD rats. MethodsA total of 18 specific pathogen free (SPF) male Sqrague-Dawley (SD) rats were used to establish CHD rat models with blood stasis syndrome, which were then randomized into model, YXTMF, and atorvastatin calcium (AVT) groups, with six rats in each group, and were intervened through gavage for two weeks. Subsequently, additional six rats that received normal diet were included as normal group. The pathological changes in the CHD rat models were identified by hematoxylin-eosin (HE) staining. The electrocardiogram, hemodynamics, and lipid profiles of the rats were detected as well. The untargeted plasma metabolomics of rats were analyzed by liquid chromotography-tandem mass spectrometry (LC-MS/MS), their ileal mucosal flora by 16S rRNA sequencing, and the correlation between the two results were also analyzed. ResultsThe whole blood viscosity, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) of rats in the model group increased compared with those in the control group (P < 0.05). In the model group, the proliferation of endothelial cells in the coronary artery of rats was damaged, with quite a few vacuolated pathological changes observed. However, the endothelial lesions in the coronary artery of rats were alleviated in the intervention groups (YXTMF and AVT groups). With the use of LC-MS/MS, a total of 33 potential endogenous metabolites were identified in plasma, among which 1-methylhistidine, N-acetylhistamine, progesterone, and deoxycorticosterone were expected to be the differential metabolites in CHD rats with blood stasis syndrome. The 16S rRNA sequencing results showed that improved diversity and abundance of intestinal flora were observed in the YXTMF group. The correlation analysis suggested that Hydrogenophaga, Limnohabitans, and Polaromonas, which were highly related to the formation of blood stasis syndrome in CHD patients, were positively correlated with plasma metabolites such as 5-hydroxyindole, N-acetylhistamine, and progesterone (P < 0.01), but were negatively correlated with plasma metabolites such as L-arginine, homoarginine, and Boc-beta-cyano-L-alanine (P < 0.01). After YXTMF intervention, Lactobacillus, Corynebacterium, and Candidatus Nitrososphaera were positively correlated with plasma metabolites such as Boc-β-cyano-L-alanine, stachydrine, and naringenin (P < 0.05), while negatively correlated with 5-hydroxyindole, N-acetylhistamine, and oleoylethanolamide (P < 0.05). ConclusionYXTMF could alleviate blood stasis syndrome in CHD rats through improving their plasma metabolisms achieved by regulating the intestinal flora.

Effect of optimized new Shengmai powder on exercise tolerance in rats with heart failure by regulating the ubiquitin-proteasome signaling pathway.

Decreased exercise tolerance is a common symptom in patients with heart failure, which is closely related to protein degradation and apoptosis regulated by the ubiquitin-proteasome signaling (UPS) pathway. In this study, the effect of Chinese medicine, optimized new Shengmai powder, on exercise tolerance in rats with heart failure was investigated via the UPS pathway. The heart failure model was prepared by ligating the left anterior descending branch of the coronary artery in rats, in which the sham-operated group was only threaded and not ligated. Rats (left ventricular ejection fraction ≤ 45%) were randomly divided into the following groups: model group, YHXSMS group, Benazepril group, and proteasome inhibitor Oprozomib group, and they were administered the corresponding drugs by gavage for 4 weeks. The cardiac function of rats was evaluated by performing an echocardiography examination and a hemodynamic test and the exercise tolerance was done by conducting an exhaustive swimming test. The mechanism was revealed by TUNEL detection, immunohistochemistry, immunofluorescence analysis, Western blot, and quantitative real-time PCR. The study showed that there was a decrease in cardiac function and exercise tolerance of rats in the model group and also destruction of cardiac and skeletal muscle fibers, a proliferation of collagen tissue, and an increment of apoptosis. Our study suggested that optimized new Shengmai powder could exert antiapoptotic effects on myocardial and skeletal muscle cells and improve myocardial contractility and exercise tolerance by inhibiting the overactivation of the UPS pathway, downregulating MAFbx, and Murf-1 overexpression, inhibiting the activation of the JNK signaling pathway, upregulating bcl-2 expression, and decreasing bax and caspase-3 levels. The study showed that the optimized new Shengmai powder could improve cardiac function and exercise tolerance in rats with heart failure through the UPS pathway.

Morroniside Regulates Endothelial Cell Function via the EphrinB Signaling Pathway after Oxygen-Glucose Deprivation In Vitro.

Proangiogenic treatment is a potential treatment for acute myocardial infarction (AMI). Morroniside was previously discovered to increase post-AMI angiogenesis in rats as well as the proliferation of rat coronary artery endothelial cells (RCAECs). However, the effects of morroniside on other endothelial cell (EC) functions and underlying mechanisms are unknown. To further clarify the vascular biological activity of morroniside, this work focused on investigating how morroniside influenced endothelial cell functions, such as cell viability, tube formation capacity, migration, and adhesion, and to explore the signaling pathway. Oxygen-glucose deprivation causes ischemic damage in RCAECs (OGD). In vitro investigations were carried out to explore the involvement of morroniside in EC function and pathways mediated by ephrinB. The results revealed that the number of BrdU+ cells and cell viability in the high-dose group were considerably greater than in the OGD group (P < 0.05). The ability of tube formation evaluated by total tube length, tube-like structural junction, and tube area was significantly higher in the morroniside group than in the OGD group (P < 0.001). Morroniside considerably improved migration and adhesion abilities compared to OGD group (P < 0.05, P < 0.01, P < 0.001). The protein expression levels of the ephrinB reverse signaling pathway were substantially greater in the morroniside group than in the OGD group (P < 0.05, P < 0.01). In conclusion, the current study demonstrated that morroniside modulates endothelial cell function via ephrinB reverse signaling pathways and provided a novel insight and therapeutic strategy into vascular biology.

Plasma metabolomic analysis reveals the therapeutic effects of Jiashen tablets on heart failure.

Heart failure is a chronic progressive condition that significantly affects the quality of life of patients with high hospitalization and mortality rates. Jiashen tablets (JST), a Chinese herbal formula, have been reported to be an effective treatment against heart failure, however the underlying mechanisms remain obscure. This study was designed to determine the effect of JST on the treatment of heart failure and delineate the underlying mechanisms by an untargeted metabolomics approach. The chronic heart failure model was established by the permanent ligation of the left anterior descending coronary artery in rats. The cardiac functions of rats, including left ventricular ejection fraction (LVEF) and fractional shortening (LVFS), left ventricular internal diameter end diastole (LVIDd) and end systole (LVIDs), and interventricular septum thickness in diastole (IVSd) and in systole (IVSs), were measured by echocardiography. Biochemical analysis and histopathological examination were also performed to evaluate therapeutic effects of JST for treating heart failure. UHPLC-QTOF-MS/MS coupled with multivariate statistical analyses were applied for plasma metabolic profiling to identify biomarkers and potential mechanisms of JST in the treatment of heart failure. Jiashen tablets could improve the cardiac function of heart failure rats and thus ameliorate heart failure via enhancing rat LVEF and LVFS and decreasing LVIDd, LVIDs, IVSd, and IVSs. Results of biochemical analysis and histopathological examination revealed that JST could reduce the serum lactate dehydrogenase (LDH) activity and the level of NT-pro BNP, markers of heart failure and myocardial damage, and inhibit myocardial fibrosis. Furthermore, in metabolomics analysis, a total of 210 metabolites with significant differences were identified between heart failure rats and normal rats, among which 29 metabolites were significantly restored after JST treatment. These metabolites were primarily involved in tryptophan metabolism, branched-chain amino acid metabolism, fatty acids β-oxidation, and glycerophospholipid metabolism. The present study illustrated the therapeutic effect of JST for the treatment of heart failure and delineated the underlying mechanisms mainly relating to the regulation of amino acid metabolism and lipid metabolism in heart failure rats.

Cardio protective effect of intermittent fasting on the lumen area ratio of the coronary artery in rats with a high-calorie diet

Atherosclerosis is a principal cause of coronary artery disease (CAD), one of the major causes of global premature mortality and morbidity. The glycolysis pathway will process excess carbohydrates in a high-calorie diet (HCD) into triglycerides, which, if accumulated, will cause an increase in the concentration of atherogenic triglyceride-rich lipoproteins. Therefore, intermittent fasting (IF) is a recommended lifestyle to prevent CAD through metabolic reprogramming pathways. This study was designed to evaluate the cardioprotective effect of eight weeks of IF 5:2 on the lumen area ratio of the coronary artery in rats with four weeks of HCD. A total of 24 Wistar male albino rats were divided into SD (standard diet), IF (IF 5:2), HCD (daily injection 0.013 g/gBW glucose), and IF-HCD (IF 5:2 and HCD). At the end of the experiment, all the rats were sacrificed. The coronary artery preparations were stained with H&amp;E stain, then evaluated with the OLYMPUS cellSens Standard to measure the arterial lumen area. The statistical analysis was done using Brown Forsythe test. In this study, no significant differences between all groups, and the effect of IF will only be seen if an HCD intervention has a significant effect. However, the IF group achieved the highest mean in the arterial lumen area ratio (SD=0.526±0.097; IF=0.631±0.021; HCD=0.611±0.064; IF-HCD=0.594±0.060). In conclusion, IF 5:2 may have a cardioprotective effect in healthy individuals, but the effect is unknown in individuals with HCD.

Cardio protective effect of intermittent fasting on the lumen area ratio of the coronary artery in rats with a high-calorie diet

Cardio protective effect of intermittent fasting on the lumen area ratio of the coronary artery in rats with a high-calorie diet

Chronic catestatin treatment reduces atrial fibrillation susceptibility via improving calcium handling in post-infarction heart failure rats

BackgroundAbnormal Ca2+ handling is a pivotal element of atrial fibrillation (AF) substrates. Catestatin (CST) modulates intracellular Ca2+ handling in cardiomyocytes (CMs). We investigated the effects of CST administration on atrial Ca2+ handling and AF susceptibility in rats with post-infarction heart failure (HF). MethodsMyocardial infarction (MI) was established by ligation of the left anterior descending coronary artery in rats. Two-week later, rats with post-infarction HF were randomly treated with saline (MI group) or CST (MI + CST group) for 4-week. Cellular Ca2+ imaging was performed by incubating atrial CMs with Fura-2 AM. An in vitro electrophysiological study was performed to assess the vulnerability to action potential duration (APD) alternans and AF. Ca2+ handling proteins expression was determined using western blotting. ResultsIn atrial CMs, compared with the sham group, the sarcoplasmic reticulum (SR) Ca2+ load, Ca2+ transient (CaT) amplitude, and threshold for Ca2+ alternans were significantly decreased, but the diastolic intracellular Ca2+ level, SR Ca2+ leakage, and spontaneous Ca2+ events were markedly increased in the MI group. However, CST attenuated these Ca2+-handling abnormalities induced by post-infarction HF. Moreover, vulnerability to atrial APD alternans and AF was significantly increased in isolated hearts from the MI group compared to the sham group, whereas all effects were prevented by CST. CST treatment also preserved SR Ca2+-ATPase protein expression but decreased the protein levels of phosphorylated-ryanodine receptor 2 and phosphorylated-Ca2+/calmodulin-dependent protein kinase II in atria from post-infarction HF rats. ConclusionChronic CST treatment reduces AF vulnerability in rats with MI-induced HF by improving Ca2+ handling.

PCSK9 Knockdown Can Improve Myocardial Ischemia/Reperfusion Injury by Inhibiting Autophagy

This study investigates the effect and mechanism of proprotein convertase subtilisin/Kexin type 9 (PCSK9) on myocardial ischemia-reperfusion injury (MIRI) and provides a reference for clinical prevention and treatment of acute myocardial infarction (AMI). We established a rat model of myocardial ischemia/reperfusion (I/R) and AC16 hypoxia/reoxygenation (H/R) model. A total of 48 adult 7-week-old male Sprague-Dawley rats were randomly assigned to three groups (n = 16): control, I/R, and I/R + SiRNA. In I/R and I/R + siRNA groups, myocardial ischemia was induced via occlusion of the left anterior descending branch (LAD) of the coronary artery in rats in I/R group for 30min and reperfused for 3days. To assess the myocardial injury, the rats were subjected to an electrocardiogram (ECG), cardiac function tests, cardiac enzymes analysis, and 2,3,5-triphenyl tetrazolium chloride (TTC)/Evan Blue (EB) staining. Meanwhile, differences in the expression of autophagy-level proteins and Bcl-2/adenovirus E1B 19-kDa interacting protein (Bnip3) signaling-related proteins were determined by protein blotting. In vitro and in vivo experimental studies revealed that siRNA knockdown of PCSK9 reduced the expression of autophagic protein Beclin-1, light chain 3 (LC3) compared to normal control-treated cells and control-operated groups. Simultaneously, the expression of Bnip3 pathway protein was downregulated. Furthermore, the PCSK9-mediated small interfering RNA (siRNA) group injected into the left ventricular wall significantly improved cardiac function and myocardial infarct size. In ischemic/hypoxic circumstances, PCSK9 expression was dramatically increased. PCSK9 knockdown alleviated MIRI via Bnip3-mediated autophagic pathway, inhibited inflammatory response, reduced myocardial infarct size, and protected cardiac function.