Nicorandil enhances the efficacy of mesenchymal stem cell therapy in isoproterenol-induced heart failure in rats

Regulation and Pharmacology of the Cyclic GMP and Nitric Oxide Pathway in Embryonic and Adult Stem Cells

This review summarizes recent advances in understanding the role of the nitric oxide (NO) and cyclic GMP (cGMP) pathway in stem cells. The levels of expression of various components of the pathway are changed during the differentiation of pluripotent embryonic stem cells. In undifferentiated stem cells, NO regulates self-renewal and survival predominantly through cGMP-independent mechanisms. Natriuretic peptides influence the growth of undifferentiated stem cells by activating particulate isoforms of guanylyl cyclases in a cGMP-mediated manner. The differentiation, recruitment, survival, migration, and homing of partially differentiated precursor cells of various types are sensitive to regulation by endogenous levels of NO and natriuretic peptides produced by stem cells, within surrounding tissues, and by the application of various pharmacological agents known to influence the cGMP pathway. Numerous drugs and formulations target various components of the cGMP pathway to influence the therapeutic efficacy of stem cell-based therapies. Thus, pharmacological manipulation of the cGMP pathway in stem cells can be potentially used to develop novel strategies in regenerative medicine.

Therapeutic potential of nicorandil beyond anti-anginal drug: A review on current and future perspectives

Nicorandil (NIC) is a well-known anti-anginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines. It shows an efficacy equivalent to that of classic anti-anginal agents. NIC has also been used clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis. Different mechanisms have been involved in the protective effects of nicorandil in various diseases, including opening of adenosine triphosphate-sensitive potassium (KATP) channel and donation of nitric oxide (NO). In recent years, NIC has been found to show numerous pharmacological activities such as neuroprotective, nephroprotective, hepatoprotective, cardioprotective, and testicular protective effects, among other beneficial effects on the body. The present review dwells on the pharmacological potentials of NIC beyond its anti-anginal action.

Nicorandil-Pretreated Mesenchymal Stem Cell-Derived Exosomes Facilitate Cardiac Repair After Myocardial Infarction via Promoting Macrophage M2 Polarization by Targeting miR-125a-5p/TRAF6/IRF5 Signaling Pathway

Background

Exosomes derived from bone marrow mesenchymal stem cells (MSC-exo) have been considered as a promising cell-free therapeutic strategy for ischemic heart disease. Cardioprotective drug pretreatment could be an effective approach to improve the efficacy of MSC-exo. Nicorandil has long been used in clinical practice for cardioprotection. This study aimed to investigate whether the effects of exosomes derived from nicorandil pretreated MSC (MSCNIC-exo) could be enhanced in facilitating cardiac repair after acute myocardial infarction (AMI).

Methods

MSCNIC-exo and MSC-exo were collected and injected into the border zone of infarcted hearts 30 minutes after coronary ligation in rats. Macrophage polarization was detected 3 days post-infarction, cardiac function as well as histological pathology were measured on the 28th day after AMI. Macrophages were separated from the bone marrow of rats for in vitro model. Exosomal miRNA sequencing was conducted to identify differentially expressed miRNAs between MSCNIC-exo and MSC-exo. MiRNA mimics and inhibitors were transfected to MSCs or macrophages to explore the specific mechanism.

Results

Compared to MSC-exo, MSCNIC-exo showed superior therapeutic effects on cardiac functional and structural recovery after AMI and markedly elevated the ratio of CD68+ CD206+/ CD68+cells in infarcted hearts 3 days post-infarction. The notable ability of MSCNIC-exo to promote macrophage M2 polarization was also confirmed in vitro. Exosomal miRNA sequencing and both in vivo and in vitro experiments identified and verified that miR-125a-5p was an effector of the roles of MSCNIC-exo in vivo and in vitro. Furthermore, we found miR-125a-5p promoted macrophage M2 polarization by inhibiting TRAF6/IRF5 signaling pathway.

Conclusion

This study suggested that MSCNIC-exo could markedly facilitate cardiac repair post-infarction by promoting macrophage M2 polarization by upregulating miR-125a-5p targeting TRAF6/IRF5 signaling pathway, which has great potential for clinical translation.

Role of canagliflozin in ameliorating isoprenaline induced cardiomyocyte oxidative stress via the heme oxygenase-1 mediated pathway

Canagliflozin (CZ) is commonly prescribed for management of type-2 diabetes mellitus (T2DM); it also can reduce the risk of myocardial infarction. We used 80 albino Wistar rats to investigate the cardioprotective potential of CZ against oxidative stress caused by administration of isoprenaline (ISO). We found that ISO stimulates production of reactive oxygen species and that CZ administration caused up-regulation of antioxidants and down-regulation of oxidants due to nuclear factor erythroid-2 related factor-2, as well as by enhancement of the heme oxygenase-1 mediated cascade. CZ monotherapy may play a cardioprotective role in diabetic patients. CZ possesses strong antioxidant potential that ameliorates cardiac damage induced by ISO administration.

Cardioprotective and Antianginal Efficacy of Nicorandil: A Comprehensive Review

ABSTRACT

Angina pectoris remains a significant burden despite advances in medical therapy and coronary revascularization. Many patients (up to 30%) with angina have normal coronary arteries, with coronary microvascular disease and/or coronary artery vasospasm being major drivers of the myocardial demand-supply mismatch. Even among patients revascularized for symptomatic epicardial coronary stenosis, recurrent angina remains highly prevalent. Medical therapy for angina currently centers around 2 disparate goals, viz secondary prevention of hard clinical outcomes and symptom control. Vasodilators, such as nitrates, have been first-line antianginal agents for decades, along with beta-blockers and calcium channel blockers. However, efficacy in symptoms control is heterogenous, depending on underlying mechanism(s) of angina in an individual patient, often necessitating multiple agents. Nicorandil (NCO) is an antianginal agent first discovered in the late 1970s with a uniquely dual mechanism of action. Like a typical nitrate, it mediates medium-large vessel vasodilation through nitric oxide. In addition, NCO has adenosine triphosphate (ATP)-dependent potassium channel agonist activity (K ATP ), mediating microvascular dilatation. Hence, it has proven effective in both coronary artery vasospasm and coronary microvascular disease, typically challenging patient populations. Moreover, emerging evidence suggests that cardiomyocyte protection against ischemia through ischemic preconditioning may be mediated through K ATP agonism. Finally, there is now fairly firm evidence in favor of NCO in terms of hard event reduction among patients with stable coronary artery disease, following myocardial infarction, and perhaps even among patients with congestive heart failure. This review aims to summarize the mechanism of action of NCO, its efficacy as an antianginal, and current evidence behind its impact on hard outcomes. Finally, we review other cardiac and emerging noncardiac indications for NCO use.

Modulatory effect of rupatadine on mesenchymal stem cell-derived exosomes in hepatic fibrosis in rats: A potential role for miR-200a

AIMS

Mesenchymal stem cell-derived exosomes (MSC-EXOs) have emerged as a promising approach in regenerative medicine for management of different diseases. However, the maintenance of their efficacy after in vivo transplantation is still a major concern. The present investigation aimed to assess the modulatory effect of rupatadine (RUP) on MSC-EXOs in diethylnitrosamine (DEN)-induced liver fibrosis (LF), and to explore the possible underlying mechanism.

MAIN METHODS

LF was induced in rats by i.p. injection of DEN (100 mg/kg) once per week for 6 successive weeks. Rats were then treated with RUP (4 mg/kg/day, p.o.) for 4 weeks with or without a single i.v. administration of MSC-EXOs. At the end of the experiment, animals were euthanized and serum and liver were separated for biochemical, and histological measurements.

KEY FINDINGS

The combined MSC-EXOs/RUP therapy provided an additional improvement towards inhibition of DEN-induced LF compared to MSC-EXOs group alone. These outcomes could be mediated through antioxidant, anti-inflammatory, and anti-fibrotic effects of RUP which created a more favorable environment for MSC-EXOs homing, and action. This in turn would enhance more effectively miR-200a expression which reduced oxidative stress, inflammation, necroptosis pathway, and subsequently fibrosis as revealed by turning off TGF-β1/α-SMA expression, and hedgehog axis.

SIGNIFICANCE

The present findings reveal that RUP enhanced the anti-fibrotic efficacy of MSC-EXOs when used as a combined therapy. This was revealed through attenuation of PAF/RIPK3/MLKL/HMGB1, and TGF-β1/hedgehog signaling pathways with a significant role for miR-200a.

Enhancers of mesenchymal stem cell stemness and therapeutic potency

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a range of cell types, including osteoblasts, chondrocytes, myocytes, and adipocytes. Multiple preclinical investigations and clinical trials employed enhanced MSCs-dependent therapies in treatment of inflammatory and degenerative diseases. They have demonstrated considerable and prospective therapeutic potentials even though the large-scale use remains a problem. Several strategies have been used to improve the therapeutic potency of MSCs in cellular therapy. Treatment of MSCs utilizing pharmaceutical compounds, cytokines, growth factors, hormones, and vitamins have shown potential outcomes in boosting MSCs' stemness. In this study, we reviewed the current advances in enhancing techniques that attempt to promote MSCs' therapeutic effectiveness in cellular therapy and stemness in vivo with potential mechanisms and applications.

Cyclocreatine Phosphate: A Novel Bioenergetic/Anti-Inflammatory Drug That Resuscitates Poorly Functioning Hearts and Protects against Development of Heart Failure

Irreversible myocardial injury causes the exhaustion of cellular adenosine triphosphate (ATP) contributing to heart failure (HF). Cyclocreatine phosphate (CCrP) was shown to preserve myocardial ATP during ischemia and maintain cardiac function in various animal models of ischemia/reperfusion. We tested whether CCrP administered prophylactically/therapeutically prevents HF secondary to ischemic injury in an isoproterenol (ISO) rat model. Thirty-nine rats were allocated into five groups: control/saline, control/CCrP, ISO/saline (85 and 170 mg/kg/day s.c. for 2 consecutive days), and ISO/CCrP (0.8 g/kg/day i.p.) either administrated 24 h or 1 h before ISO administration (prophylactic regimen) or 1 h after the last ISO injection (therapeutic regimen) and then daily for 2 weeks. CCrP protected against ISO-induced CK-MB elevation and ECG/ST changes when administered prophylactically or therapeutically. CCrP administered prophylactically decreased heart weight, hs-TnI, TNF-α, TGF-β, and caspase-3, as well as increased EF%, eNOS, and connexin-43, and maintained physical activity. Histology indicated a marked decrease in cardiac remodeling (fibrin and collagen deposition) in the ISO/CCrP rats. Similarly, therapeutically administered CCrP showed normal EF% and physical activity, as well as normal serum levels of hs-TnI and BNP. In conclusion, the bioenergetic/anti-inflammatory CCrP is a promising safe drug against myocardial ischemic sequelae, including HF, promoting its clinical application to salvage poorly functioning hearts.

Therapeutic Potential of Mesenchymal Stem Cells versus Omega n − 3 Polyunsaturated Fatty Acids on Gentamicin-Induced Cardiac Degeneration

This study compared the cardioprotective action of mesenchymal stem cells (MSCs) and PUFAs in a rat model of gentamicin (GM)-induced cardiac degeneration. Male Wistar albino rats were randomized into four groups of eight rats each: group I (control group), group II (gentamicin-treated rats receiving gentamicin intraperitoneally (IP) at dose of 100 mg/kg/day for 10 consecutive days), group III (gentamicin and PUFA group receiving gentamicin IP at dose of 100 mg/kg/day for 10 consecutive days followed by PUFAs at a dose of 100 mg/kg/day for 4 weeks), and group IV (gentamicin and MSC group receiving gentamicin IP at dose of 100 mg/kg/day followed by a single dose of MSCs (1 × 10⁶)/rat IP). Cardiac histopathology was evaluated via light and electron microscopy. Immunohistochemical detection of proliferating cell nuclear antigen (PCNA), caspase-3 (apoptosis), Bcl2, and Bax expression was performed. Moreover, cardiac malonaldehyde (MDA) content, catalase activity, and oxidative stress parameters were biochemically evaluated. Light and electron microscopy showed that both MSCs and PUFAs had ameliorative effects. Their actions were mediated by upregulating PCNA expression, downregulating caspase-3 expression, mitigating cardiac MDA content, catalase activity, and oxidative stress parameters. MSCs and PUFAs had ameliorative effects against gentamicin-induced cardiac degeneration, with MSCs showing higher efficacy compared to PUFAs.

Combination of mesenchymal stem cells and nicorandil: an emerging therapeutic challenge against COVID-19 infection-induced multiple organ dysfunction

The recent COronaVIrus Disease (COVID)-19 pandemic has placed an unprecedented burden on the drug development opportunity to prevent the onset of multi-organ failure.

Emerging experimental reports have highlighted the beneficial effects of mesenchymal stem cell (MSC) administration against COVID-19. MSCs and their derived exosomes may attenuate SARS-CoV-2-induced inflammatory response through managing the immune cell function and cytokine expression. Although these are promising results, the exposure of MSCs to chemical compounds with pharmacological activities may further improve their homing, survival, and paracrine machinery.

Nicorandil (N-[2-hydroxyethyl]-nicotinamide nitrate), an established adenosine triphosphate-sensitive potassium channel opener, is recently hypothesized to modulate inflammation as well as cell injury and death in COVID-19-affected lungs through inhibiting reactive oxygen species levels and apoptosis. Since it also exerts protective effects against hypoxia-induced MSC apoptosis, we assumed that transplanted MSCs combined to long-term nicorandil administration may survive longer in a severely inflamed microenvironment and have more beneficial effects in the treatment of SARS-CoV-2 infection than MSCs alone.

Effect of nicorandil on the spatial arrangement of primary motor cortical neurons in the sub-acute phase of stroke in a rat model

INTRODUCTION

Ischemic stroke remains a major cause of disability and death worldwide. The density and the spatial distribution of the primary motor (M1) cortical neurons are important in signal transmission and control the movement-related functions. Recently, the neuroprotective effect of nicorandil in cerebral ischemia was described through its anti-apoptosis, antioxidant and anti-inflammatory properties. This study aimed to determine the effects of nicorandil on the neurobehavioral outcome, infarct size, and density, and spatial distribution of M1 cortical neurons after cerebral ischemia.

METHODS

Thirty Sprague-Dawley rats were randomly divided into three groups. Sham underwent surgery without middle cerebral artery occlusion (MCAO) and drug. The MCAO and treatment groups after MCAO received saline or nicorandil 2, 24, 48, and 72 h after the induction of brain ischemia. Neurobehavioral tests were performed, brains removed, sectioned, and stained by 2,3,5-triphenyltetrazolium chloride (TTC) to estimate the size of the infarction and Nissl staining to evaluate the numerical density, mean area, and the distribution pattern of M1 cortical neurons, using Voronoi spatial tessellation.

RESULTS

Although nicorandil treatment significantly decreased the neurological deficits and density of neuronal neighbors, it could not preserve the normal regular spatial distributions of M1 cortical neurons after MCAO. It also could not significantly improve motor function or reduce ischemic lesion size.

CONCLUSIONS

Treatment using the present dose of nicorandil during sub-acute ischemic stroke could not increase neuronal density or preserve the normal regular spatial distributions after MCAO. However, it had beneficial effects on neurobehavioral and motor function and somewhat reduced ischemic lesion size.

Boosting Akt Pathway by Rupatadine Modulates Th17/Tregs Balance for Attenuation of Isoproterenol-Induced Heart Failure in Rats

Disruption of Th17/Tregs homeostasis plays a crucial role in governing the immune response during myocardial fibrosis and its progression to heart failure. The present study aimed to assess for the first time the possible protection afforded by rupatadine against isoproterenol-induced heart failure in rats. It also explored the role of PI3k/Akt as a possible mechanistic pathway, through which rupatadine could modulate Th17/Tregs balance to display its effect. Isoproterenol (85 and 170 mg/kg/day) was injected subcutaneously for 2 successive days, respectively and rupatadine (4 mg/kg/day) was then given orally for 14 days with or without wortmannin (PI3K/Akt inhibitor). Rupatadine succeeded to completely ameliorate isoproterenol-induced cardiac dysfunction as demonstrated by improvements of electrocardiographic and echocardiographic measurements. Moreover, rupatadine prevented the marked elevation of PAF and oxidative stress in addition to Th17 promoting cytokines (IL-6, IL-23, and TGF-β). Accordingly, rupatadine prevented Th17 stimulation or expansion as indicated by increased Foxp3/RORγt ratio and decreased production of its pro-inflammatory cytokine (IL-17). Rupatadine treatment mitigated isoproterenol-induced activation of STAT-3 signaling and the imbalance in p-Akt/total Akt ratio affording marked decrease in atrogin-1 and apoptotic biomarkers. Finally, this therapy was effective in averting cardiac troponin loss and reverting the histological alterations as assessed by myocardial fibrosis and hypertrophy grading. Contrariwise, co-administration of wortmannin mostly attenuated the protective effects of rupatadine affording more or less similar results to that of isoproterenol-untreated rats. In conclusion, rupatadine could be an effective therapy against the development of isoproterenol-induced heart failure where PI3K/Akt pathway seems to play a crucial role in its protective effect.

Nourin-Associated miRNAs: Novel Inflammatory Monitoring Markers for Cyclocreatine Phosphate Therapy in Heart Failure

Background: Cyclocreatine phosphate (CCrP) is a potent bioenergetic cardioprotective compound known to preserve high levels of cellular adenosine triphosphate during ischemia. Using the standard Isoproterenol (ISO) rat model of heart failure (HF), we recently demonstrated that the administration of CCrP prevented the development of HF by markedly reducing cardiac remodeling (fibrosis and collagen deposition) and maintaining normal ejection fraction and heart weight, as well as physical activity. The novel inflammatory mediator, Nourin is a 3-KDa formyl peptide rapidly released by ischemic myocardium and is associated with post-ischemic cardiac inflammation. We reported that the Nourin-associated miR-137 (marker of cell damage) and miR-106b-5p (marker of inflammation) are significantly upregulated in unstable angina patients and patients with acute myocardial infarction, but not in healthy subjects. Objectives: To test the hypothesis that Nourin-associated miR-137 and miR-106b-5p are upregulated in ISO-induced “HF rats” and that the administration of CCrP prevents myocardial injury (MI) and reduces Nourin gene expression in “non-HF rats”. Methods: 25 male Wistar rats (180–220 g) were used: ISO/saline (n = 6), ISO/CCrP (0.8 g/kg/day) (n = 5), control/saline (n = 5), and control/CCrP (0.8 g/kg/day) (n = 4). In a limited study, CCrP at a lower dose of 0.4 g/kg/day (n = 3) and a higher dose of 1.2 g/kg/day (n = 2) were also tested. The Rats were injected SC with ISO for two consecutive days at doses of 85 and 170 mg/kg/day, respectively, then allowed to survive for an additional two weeks. CCrP and saline were injected IP (1 mL) 24 h and 1 h before first ISO administration, then daily for two weeks. Serum CK-MB (U/L) was measured 24 h after the second ISO injection to confirm myocardial injury. After 14 days, gene expression levels of miR-137 and miR-106b-5p were measured in serum samples using quantitative real-time PCR (qPCR). Results: While high levels of CK-MB were detected after 24 h in the ISO/saline rats indicative of MI, the ISO/CCrP rats showed normal CK-MB levels, supporting prevention of MI by CCrP. After 14 days, gene expression profiles showed significant upregulation of miR-137 and miR-106b-5p by 8.6-fold and 8.7-fold increase, respectively, in the ISO/saline rats, “HF rats,” compared to the control/saline group. On the contrary, CCrP treatment at 0.8 g/kg/day markedly reduced gene expression of miR-137 by 75% and of miR-106b-5p by 44% in the ISO/CCrP rats, “non-HF rats,” compared to the ISO/Saline rats, “HF rats.” Additionally, healthy rats treated with CCrP for 14 days showed no toxicity in heart, liver, and renal function. Conclusions: Results suggest a role of Nourin-associated miR-137 and miR-106b-5p in the pathogenesis of HF and that CCrP treatment prevented ischemic injury in “non-HF rats” and significantly reduced Nourin gene expression levels in a dose–response manner. The Nourin gene-based mRNAs may, therefore, potentially be used as monitoring markers of drug therapy response in HF, and CCrP—as a novel preventive therapy of HF due to ischemia.

The Protective Effects of Compound 21 and Valsartan in Isoproterenol-Induced Myocardial Injury in Rats

This study investigated the protective effects of Compound 21 (C21), the first specific non-peptide AT2 receptor agonist, on cardiac injury in rats with isoproterenol-induced heart failure in vivo and compared it with valsartan, an AT1 receptor antagonist. In this study, 56 Wistar albino male rats (estimated body weights 250-400 g) were divided into eight groups (n = 7). Group 1 (Control) received no drug. Group 2 (ISO) was given 180 mg/kg of isoproterenol subcutaneously (s.c.); two doses were administered at 24-h intervals on days 29 and 30 of the experiment. Groups 3, 4, and 5 were given valsartan (30 mg/kg orally), C21 (0.03 mg/kg intraperitoneally), and a combination of Valsartan + C21, respectively, for 30 days. Groups 6, 7, and 8 were administered Valsartan, C21, and Valsartan + C21 in the same application, duration, and dose, respectively, and isoproterenol (180 mg/kg s.c.) was given on days 29 and 30 of the experiment. Transthoracic echocardiography was performed on the rats at the beginning and end of the experiment. Blood pressure, heart rate, and ECG alterations were monitored via a carotid artery cannula at the end of the experiment. Histopathological and biochemical measurements were performed on the cardiac tissue of the rats. For histopathological findings, C21 and Valsartan + C21 combination therapy significantly reduced the development of heart failure compared to valsartan alone. Also, the protective effect of C21 on myocardial injury was superior to that of valsartan. According to the results of echocardiographic and biochemical evaluations, C21, and Valsartan showed protective effects against heart failure. C21, valsartan, and combined therapy significantly prevented the decrease of ejection fraction. This report describes the cardioprotective effects of C21 and valsartan in ISO-induced myocardial damage.

Enrichment of alpha-linolenic acid in rodent diet reduced oxidative stress and inflammation during myocardial infarction

Myocardial infarction (MI) is an irreversible event caused by cardiac ischemia and may be fatal. Studies reported that increased intake of n-3 polyunsaturated fatty acids (PUFA) namely, eicosapentaenoic acid and docosahexaenoic acid reduce the risk of cardiovascular disease and lower the incidence of MI. Nonetheless, the cardioprotective effect of plant n-3-PUFA such as α-linolenic acid (ALA) in the diet is not conclusive. In this study, Sprague Dawley rats were supplemented with isocaloric diets enriched with ALA rich flaxseed (FS) and flaxseed oil (FSO), and normal chow (Control) for 4 weeks. MI was induced by isoproterenol (ISO) injection. Results showed that all ALA-enriched diets displayed cardioprotection against MI. The heart to body weight ratio, plasma LDH activity and plasma cTnI were reduced compared to ISO and was prominent in FS diet. ALA and EPA were up-regulated in both tissues and plasma by ALA-diets compared to Control and remained higher than ISO groups. Notably, LOX-mediated HETEs decreased whereas LOX-mediated HDHAs were elevated in both tissues and plasma of ALA-enriched diets compared to ISO. In addition, non-enzymatic oxidized products from arachidonic acid including 15-F_2t-IsoP were reduced in both tissues and plasma of MI rats supplemented with ALA-enriched diets while those from n-3 PUFAs including F₄-NeuroPs, PhytoPs and PhytoFs were elevated compared to control. ALA-enriched diets particularly flaxseed reduced gene expressions of inflammatory cytokines namely IL-1β, IL-6 and TNFα and prevented the down regulation of antioxidant catalase in the heart tissues. In conclusion ALA-enriched diets potentially exerted cardioprotection through the regulation of anti-inflammatory and anti-oxidative mediators from n-3 PUFA autooxidation.

Huoxin Pill () Attenuates Cardiac Fibrosis by Suppressing TGF-β1/Smad2/3 Pathway in Isoproterenol-Induced Heart Failure Rats

OBJECTIVE

To evaluate the effects of Huoxin Pill (, HXP) on cardiac fibrosis and heart failure (HF) in isoproterenol (ISO)-induced HF rats.

METHODS

Thirty Wistar rats were randomly divided into 5 groups including control, HF, isosorbide mononitrate (ISMN), HXP low (HXP-L), and HXP high (HXP-H) groups (n=6 for each group) according to the complete randomization method. Rats were pretreated with ISMN (5 mg/kg daily), low concentration of HXP (10 mg/kg daily) or high concentration of HXP (30 mg/kg daily) or equal volume of saline by intragastric administration for 1 week, followed by intraperitoneal injection of ISO (10 mg/kg, 14 days), and continually intragastric administrated with above medicines or saline for additional 6 weeks. The effects of HXP treatment on the cardiac function, heart weight index (HWI), pathological changes, and collagen content were further assessed. Moreover, the role of HXP on activation of transforming growth factor- β 1 (TGF-β 1)/Smads pathway was further explored using immunohistochemistry (IHC) and Western-blot assay.

RESULTS

HXP treatment significantly alleviated the decrease of ejection fraction (EF) and fractional shortening (FS), while decreased the elevation of left ventricular end-systolic volume (LVESV) in ISO-induced HF rats (P<0.05). Moreover, HXP treatment obviously attenuated the increase of HWI and serum level of creatine kinase MB (CK-MB, P<0.05), as well as pathological changes in ISO-induced HF rats. Further determination indicated that HXP treatment alleviated the elevation of collagen I and collagen III protein expression in cardiac tissues of ISO-induced HF rats. Furthermore, HXP treatment significantly down-regulated the increase of TGF-β 1 and p-Smad2/3 protein expression in cardiac tissues of HF rats (P<0.05), while did not affect the expression of total Smad2/3.

CONCLUSIONS

HXP attenuated heart failure and cardiac fibrosis in ISO-induced HF rats by suppression of TGF-β 1/Smad2/3 pathway.

Efficacy and Mode of Action of Mesenchymal Stem Cells in Non-Ischemic Dilated Cardiomyopathy: A Systematic Review

Non-ischemic dilated cardiomyopathy (NIDCM) constitutes one of the most common causes to non-ischemic heart failure. Despite treatment, the disease often progresses, causing severe morbidity and mortality, making novel treatment strategies necessary. Due to the regenerative actions of mesenchymal stem cells (MSCs), they have been proposed as a treatment for NIDCM. This systematic review aims to evaluate efficacy and mode of action (MoA) of MSC-based therapies in NIDCM. A systematic literature search was conducted in Medline (Pubmed) and Embase. A total of 27 studies were included (3 clinical trials and 24 preclinical studies). MSCs from different tissues and routes of delivery were reported, with bone marrow-derived MSCs and direct intramyocardial injections being the most frequent. All included clinical trials and 22 preclinical trials reported an improvement in cardiac function following MSC treatment. Furthermore, preclinical studies demonstrated alterations in tissue structure, gene, and protein expression patterns, primarily related to fibrosis and angiogenesis. Consequently, MSC treatment can improve cardiac function in NIDCM patients. The MoA underlying this effect involves anti-fibrosis, angiogenesis, immunomodulation, and anti-apoptosis, though these processes seem to be interdependent. These encouraging results calls for larger confirmatory clinical studies, as well as preclinical studies utilizing unbiased investigation of the potential MoA.

Mapping current research and identifying hotspots on mesenchymal stem cells in cardiovascular disease

BACKGROUND

Mesenchymal stem cells (MSCs) have important research value and broad application prospects in the cardiovascular disease. This study provides information on the latest progress, evolutionary path, frontier research hotspots, and future research developmental trends in this field.

METHODS

A knowledge map was generated by CiteSpace and VOSviewer analysis software based on data obtained from the literature on MSCs in the cardiovascular field.

RESULTS

The USA and China ranked at the top in terms of the percentage of articles, accounting for 34.306% and 28.550%, respectively. The institution with the highest number of research publications in this field was the University of Miami, followed by the Chinese Academy of Medical Sciences and Harvard University. The research institution with the highest ACI value was Harvard University, followed by the Mayo Clinic and the University of Cincinnati. The top three subjects in terms of the number of published articles were cell biology, cardiovascular system cardiology, and research experimental medicine. The journal with the most publications in this field was Circulation Research, followed by Scientific Reports and Biomaterials. The direction of research on MSCs in the cardiovascular system was divided into four parts: (1) tissue engineering, scaffolds, and extracellular matrix research; (2) cell transplantation, differentiation, proliferation, and signal transduction pathway research; (3) assessment of the efficacy of stem cells from different sources and administration methods in the treatment of acute myocardial infarction, myocardial hypertrophy, and heart failure; and (4) exosomes and extracellular vesicles research. Tissue research is the hotspot and frontier in this field.

CONCLUSION

MSC research has presented a gradual upward trend in the cardiovascular field. Multidisciplinary intersection is a characteristic of this field. Engineering and materials disciplines are particularly valued and have received attention from researchers. The progress in multidisciplinary research will provide motivation and technical support for the development of this field.

Activated ROCK/Akt/eNOS and ET-1/ERK pathways in 5-fluorouracil-induced cardiotoxicity: modulation by simvastatin

5-Fluorouracil (5-FU) is used in the treatment of different solid tumors; however, its use is associated with rare, but serious cardiotoxicity. Nevertheless, the involvement of ROCK/NF-κB, Akt/eNOS and ET-1/ERK1/2 trajectories in the cardiotoxic effect and in the potential cardioprotective upshot of simvastatin has been elusive. Male Wistar rats were allocated into 5-FU (50 mg/kg/week; i.p, 6 weeks), simvastatin (15 mg/kg/day; p.o, 8 weeks) treated groups and simvastatin + 5-FU, besides the normal control group. 5-FU-induced cardiotoxicity boosted the serum level of N-terminal pro-brain (B-type) natriuretic peptide (NT-proBNP), aortic contents of endothelin (ET)-1 and thromboxane (TX) A2, as well as cardiac contents of NADPH oxidases (Nox), cyclooxygenase (COX)-2, malondialdehyde (MDA), phosphorylated Akt (p-Akt), phosphorylated extracellular signal-regulated kinase (p-ERK)1/2 and the protein expressions of rho-kinase (ROCK) and caspase-3. On the other hand, it suppressed cardiac reduced glutathione (GSH) and phosphorylated endothelial nitric oxide synthase (p-eNOS). Contrariwise, co-administration with simvastatin overcame these disturbed events and modulated the ROCK/NF-κB, Akt/eNOS and ET-1/ERK1/2 signaling pathways. This study highlights other mechanisms than coronary artery spasm in the 5-FU cardiotoxicity and reveals that NT-proBNP is a potential early marker in this case. Moreover, the cross-talk between ROCK/ NF-κB, ROS/COX-2/TXA2, Akt/eNOS and ET-1/ERK1/2 pathways contributes via different means to upsetting the vasoconstriction/vasodilatation equilibrium as well as endothelial cell function and finally leads to cardiomyocyte stress and death-the modulation of these trajectories offers simvastatin its potential cardio-protection against 5-FU.

Canagliflozin ameliorates renal oxidative stress and inflammation by stimulating AMPK-Akt-eNOS pathway in the isoprenaline-induced oxidative stress model

Diabetes is a leading cause of chronic kidney disease, and the high prevalence of sympathetic nervous system (SNS) hyperactivity in diabetic patients makes them further susceptible to SNS-mediated oxidative stress and accelerated kidney damage. Here, we investigated if canagliflozin can reverse isoprenaline (ISO)-induced renal oxidative damage in rats, a model that mimics SNS overstimulation-induced organ injuries in humans. We found that ISO administration elevates renal oxidative stress markers including malondialdehyde (MDA), advanced protein oxidation product (APOP), myeloperoxidase (MPO) and nitric oxide (NO), while depleting levels of endogenous antioxidants such as catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH). Strikingly, canagliflozin treatment of ISO-treated rats not only prevents elevation of oxidative stress markers but also rescues levels of depleted antioxidants. Our results also show that canagliflozin stimulates antioxidant/anti-inflammatory signaling pathways involving AMP-activated protein kinase (AMPK), Akt and eNOS, and inhibits iNOS and NADPH oxidase isoform 4 (NOX4), all of which are associated with oxidative stress and inflammation. Further, canagliflozin prevents ISO-induced apoptosis of kidney cells by inhibiting Bax protein upregulation and caspase-3 activation. Histological examination of kidney sections reveal that canagliflozin attenuates ISO-mediated increases in inflammatory cell infiltration, collagen deposition and fibrosis. Finally, consistent with these findings, canagliflozin treatment improves kidney function in ISO-treated rats, suggesting that the antioxidant effects may be clinically translatable.

Canagliflozin attenuates isoprenaline-induced cardiac oxidative stress by stimulating multiple antioxidant and anti-inflammatory signaling pathways

The antidiabetic drug canagliflozin is reported to possess several cardioprotective effects. However, no studies have investigated protective effects of canagliflozin in isoprenaline (ISO)-induced cardiac oxidative damage-a model mimicking sympathetic nervous system (SNS) overstimulation-evoked cardiac injuries in humans. Therefore, we investigated protective effects of canagliflozin in ISO-induced cardiac oxidative stress, and their underlying molecular mechanisms in Long-Evans rat heart and in HL-1 cardiomyocyte cell line. Our data showed that ISO administration inflicts pro-oxidative changes in heart by stimulating production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). In contrast, canagliflozin treatment in ISO rats not only preserves endogenous antioxidants but also reduces cardiac oxidative stress markers, fibrosis and apoptosis. Our Western blotting and messenger RNA expression data demonstrated that canagliflozin augments antioxidant and anti-inflammatory signaling involving AMP-activated protein kinase (AMPK), Akt, endothelial nitric oxide synthase (eNOS), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). In addition, canagliflozin treatment attenuates pro-oxidative, pro-inflammatory and pro-apoptotic signaling mediated by inducible nitric oxide synthase (iNOS), transforming growth factor beta (TGF-β), NADPH oxidase isoform 4 (Nox4), caspase-3 and Bax. Consistently, canagliflozin treatment improves heart function marker in ISO-treated rats. In summary, we demonstrated that canagliflozin produces cardioprotective actions by promoting multiple antioxidant and anti-inflammatory signaling.

Chronic peripheral ghrelin injection exerts antifibrotic effects by increasing growth differentiation factor 15 in rat hearts with myocardial fibrosis induced by isoproterenol

This study aimed to investigate the anti-fibrotic effects of ghrelin in isoproterenol (ISO)-induced myocardial fibrosis and the underlying mechanism. Sprague-Dawley rats were randomized to control, ISO, and ISO + ghrelin groups. ISO (2 mg/kg per day, subcutaneous) or vehicle was administered once daily for 7 days, then ghrelin (100 microg/kg per day, subcutaneous) was administered once daily for the next 3 weeks. Ghrelin treatment greatly improved the cardiac function of ISO-treated rats. Ghrelin also decreased plasma brain natriuretic peptide level and ratios of heart weight to body weight and left ventricular weight to body weight. Ghrelin significantly reduced myocardial collagen area and hydroxyproline content, accompanied by decreased mRNA levels of collagen type I and III. Furthermore, ghrelin increased plasma level of growth differentiation factor 15 (GDF15) and GDF15 mRNA and protein levels in heart tissues, which were significantly decreased with ISO alone. The phosphorylation of Akt at Ser473 and GSK-3beta at Ser9 was decreased with ISO, and ghrelin significantly reversed the downregulation of p-Akt and p-GSK-3beta. Mediated by GDF15, ghrelin could attenuate ISO-induced myocardial fibrosis via Akt-GSK-3beta signaling.

Nicorandil: A drug with ongoing benefits and different mechanisms in various diseased conditions

Nicorandil is a well-known antianginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines. It shows an efficacy equivalent to that of classic antianginal agents. Nicorandil has also been applied clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis. Different mechanisms have been involved in the protective effects of nicorandil in various diseases through either opening of adenosine triphosphate-sensitive potassium (KATP) channel or donation of nitric oxide (NO). The predominance or participation of any of these proposed mechanisms depends on the dose of nicorandil used, the location of diseased conditions, and if this mechanism is still functioning or not. The protection afforded by nicorandil has been shown to be mainly attributed to KATP channel opening in experimental models of myocardial and pulmonary fibrosis as well as renal injury or glomerulonephritis, whereas NO donation predominates as a mechanism of protection in hepatic fibrosis and inflammatory bowel diseases. Therefore, in different diseased conditions, it is important to know which mechanism plays the major role in nicorandil-induced curative or protective effects. This can bring new insights into the proper use of selected medication and its recommended dose for targeting certain disease.

Lercanidipine boosts the efficacy of mesenchymal stem cell therapy in 3-NP-induced Huntington's disease model rats via modulation of the calcium/calcineurin/NFATc4 and Wnt/β-catenin signalling pathways

3-Nitropropionic acid (3-NP) induces a spectrum of Huntington's disease (HD)-like neuropathologies in the rat striatum. The present study aimed to demonstrate the neuroprotective effect of lercanidipine (LER) in rats with 3-NP-induced neurotoxicity, address the possible additional protective effect of combined treatment with bone marrow-derived mesenchymal stem cells (BM-MSCs) and LER, and investigate the possible involvement of the Ca²⁺/calcineurin (CaN)/nuclear factor of activated T cells c4 (NFATc4) and Wnt/β-catenin signalling pathways. Rats were injected with 3-NP (10 mg/kg/day, i.p.) for two weeks and were divided into four subgroups; the first served as the control HD group, the second received a daily dose of LER (0.5 mg/kg, i.p.), the third received a single injection of BM-MSCs (1 x 106/rat, i.v.) and the last received a combination of both BM-MSCs and LER. The combined therapy improved motor and behaviour performance. Meanwhile, this treatment led to a marked reduction in striatal cytosolic Ca^2+, CaN, tumour necrosis factor-alpha, and NFATc4 expression and the Bax/Bcl2 ratio. Combined therapy also increased striatal brain-derived neurotrophic factor, FOXP3, Wnt, and β-catenin protein expression. Furthermore, haematoxylin-eosin and Nissl staining revealed an amelioration of striatum tissue injury with the combined treatment. In conclusion, the current study provides evidence for a neuroprotective effect of LER and/or BM-MSCs in 3-NP-induced neurotoxicity in rats. Interestingly, combined LER/BM-MSC therapy was superior to cell therapy alone in inhibiting 3-NP-induced neurological insults via modulation of the Ca²⁺/CaN/NFATc4 and Wnt/β-catenin signalling pathways. LER/BM-MSC combined therapy may represent a feasible approach for improving the beneficial effects of stem cell therapy in HD.

Protective effect of histone methyltransferase NSD3 on ISO-induced cardiac hypertrophy

Nuclear receptor-binding SET domain 3 (NSD3) is a lysine methyltransferase that plays important roles in multiple biological activities; however; its potential roles in the cardiovascular system remain unknown. In this study, we found that NSD3 expression is reduced by isoproterenol (ISO) stimuli both in vitro and in vivo. Overexpression of NSD3 attenuates ISO-induced cardiomyocyte hypertrophy. Mechanistically, ISO treatment decreases H3K27me2/3 modifications on the atrial natriuretic factor (ANF) promoter by suppressing NSD3 and inhibits the association between NSD3 and bromodomain-containing protein 4 (BRD4), thus suppressing the BRD4-mediated H3K27ac modifications, which ultimately promote ANF transcription and cardiomyocyte hypertrophy. In conclusion, NSD3 decreases ANF expression and, thereby, attenuates ISO-induced cardiomyocyte hypertrophy.

Growth differentiation factor 11 is involved in isoproterenol‑induced heart failure

The present study aimed to investigate the potential effects of growth differentiation factor 11 (GDF11) on isoproterenol (ISO)-induced heart failure (HF) and identify the underlying molecular mechanisms. A rat model of HF was induced in vivo by intraperitoneally administering ISO (5 mg/kg/day) for 7 days. After 4 weeks following establishment of the HF model, hemodynamic analysis demonstrated that ISO induced a significant increase in the left ventricular end-diastolic pressure and a decrease in the left ventricular systolic pressure and maximum contraction velocity. The plasma levels of myocardial injury markers, including lactate dehydrogenase (LDH), creatine kinase (CK), CK-muscle/brain which were determined using the corresponding assay kits and plasma brain natriuretic peptide which was detected by an ELISA kit, an important biomarker of HF, increased following ISO treatment. Furthermore, levels of GDF11 expression and protein, which were estimated using reverse transcription-quantitative polymerase chain reaction and an ELISA kit in plasma and western blotting in the heart tissue, respectively, significantly increased following ISO treatment. To demonstrate the effects of ISO on GDF11 production in cardiomyocytes, H9C2 cells (a cardiomyoblast cell line derived from embryonic rat heart tissue) were treated with ISO (50 nM) for 24 h in vitro; it was revealed that GDF11 protein and mRNA expression levels significantly increased following ISO treatment. In addition, recombinant GDF11 (rGDF11) administered to ISO-treated H9C2 cells resulted in decreased proliferation, which was detected via a CCK-8 assay, and increased LDH levels and cell apoptosis of cells, which was determined using Caspase-3 activity and Hoechst 33258 staining. Additionally, rGDF11 increased the levels of reactive oxygen species and malondialdehyde due to the upregulation of nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) following rGDF11 treatment. Conversely, GDF11 knockdown reduced ISO-induced apoptosis by inhibiting oxidative stress injury. The results suggested that GDF11 production was upregulated in ISO-induced rats with HF and in ISO-treated H9C2 cells, and that rGDF11 treatment increased ISO-induced oxidative stress injury by upregulating Nox4 in H9C2 cells.

JMJD3 inhibition protects against isoproterenol-induced cardiac hypertrophy by suppressing β-MHC expression

Jumonji domain-containing protein D3 (JMJD3), a histone 3 lysine 27 (H3K27) demethylase, has been extensively studied for their participation in development, cellular physiology and a variety of diseases. However, its potential roles in cardiovascular system remain unknown. In this study, we found that JMJD3 played a pivotal role in the process of cardiac hypertrophy. JMJD3 expression was elevated by isoproterenol (ISO) stimuli both in vitro and in vivo. Overexpression of wild-type JMJD3, but not the demethylase-defective mutant, promoted cardiomyocyte hypertrophy, as implied by increased cardiomyocyte surface area and the expression of hypertrophy marker genes. In contrary, JMJD3 silencing or its inhibitor GSK-J4 suppressed ISO-induced cardiac hypertrophy. Mechanistically, JMJD3 was recruited to demethylate H3K27me3 at the promoter of β-MHC to promote its expression and cardiac hypertrophy. Thus, our results reveal that JMJD3 may be a key epigenetic regulator of β-MHC expression in cardiomyocytes and a potential therapeutic target for cardiac hypertrophy.

Nicorandil alleviates ovalbumin-induced airway inflammation in a mouse model of asthma

Nicorandil is an antianginal drug that has anti-inflammatory property. This study aimed to investigate the effects of nicorandil on allergic asthma induced by ovalbumin (OVA) in mice in comparison with dexamethasone. Mice were sensitized to OVA (on days 0 and 7) and challenged with OVA three times (on days 14, 15 and 16). Nicorandil was given orally for 5 days 1 h before OVA treatment in days of challenge. Progression of asthma was accompanied by significant elevation in the lung/body weight index, LDH, total protein, IL-13 and NF-κB levels besides inflammatory cell counts in BALF; Also pulmonary MDA and NO contents were significantly increased but GSH and SOD levels were decreased. Histopathological alterations in lung tissues were also observed. In contrast, nicorandil treatment significantly alleviated OVA-induced lung injury. In conclusion, our results proposed that nicorandil is equivalent to dexamethasone in ameliorating allergic asthma by restoring oxidant/antioxidant balance and reducing inflammation.

The protective effect of nicorandil on cardiomyocyte apoptosis after coronary microembolization by activating Nrf2/HO-1 signaling pathway in rats

BACKGROUND

Myocardial apoptosis is considered to be the chief cause of progressive cardiac dysfunction induced by coronary microembolization (CME), and the Nrf2/HO-1 signaling pathway is involved in CME-induced myocardial apoptosis. Nicorandil (NIC) has multiple beneficial cardiovascular effects on myocardial injury. Therefore, this study was undertaken to analyze the role of NIC pretreatment in the inhibiting myocardial apoptosis after CME in rats.

METHODS

Forty rats were divided into Sham group, CME group, CME plus NIC (NIC) group, and CME plus AAV9-Nrf2 (AAV9-Nrf2) group (n = 10 per group). CME-induced myocardial apoptosis model was established through injecting plastic microspheres (42 μM) into the left ventricle except the Sham group. NIC group received nicorandil 3 mg/(kg.d) for 7 days before the operation. Cardiac function was assessed by echocardiography. The mRNA expression level of Nrf2 was detected by RT-PCR. The protein expression levels of Nrf2, HO-1, Bcl-2, Bax and cleaved caspase-3 were detected by Western blot. The size of the microinfarction area was measured by HBFP staining; myocardial apoptosis was analyzed by TUNEL staining.

RESULTS

Compared with the sham group, the cardiac function and the expression level of Nrf2, HO-1 and Bcl-2were decreased, while myocardial apoptosis and the expression of Bax and cleaved caspase-3 were increased in the CME group. Compared with the CME group, cardiac function was significantly improved, the expression levels of Nrf2, HO-1, and Bcl-2 were increased, the expression of Bax and cleaved caspase-3 were decreased, and the myocardial apoptosis was attenuated in the NIC group and AAV9-Nrf2 group.

CONCLUSION

NIC pretreatment effectively inhibit CME-induced myocardial apoptosis and improve cardiac function. The protective effects are mediated through the activation of the Nrf2/HO-1 signaling in cardiomyocytes.

The Role of β-Adrenergic Overstimulation in the Early Stages of Renal Injury

BACKGROUND/AIMS

To assess the possible contribution of the β-adrenergic overstimulation in early stages of renal injury, the present study evaluated, in rats, the effects of the β-adrenoceptor agonist isoproterenol (ISO) on renal function and morphology, as well as the renal mRNA and protein expression of the NADPH oxidase isoform 4 (Nox 4) and subunit p22phox, endoplasmic reticulum (ER) stress, pro-inflammatory, pro-apoptotic and renin-angiotensin system (RAS) components.

METHODS

Wistar rats received ISO (0.3 mg.kg-1.day-1 s.c.) or vehicle (control) for eight days. At the end of the treatment, food and water intake, urine output and body weight gain were evaluated and renal function studies were performed. Renal tissue was used for the morphological, quantitative PCR and immunohistochemical studies.

RESULTS

ISO did not change metabolic parameters or urine output. However it induced a decrease in renal blood flow and an increase in the filtration fraction. These changes were accompanied by increased cortical mRNA and protein expression for the renal oxidative stress components including Nox 4 and p22phox; ER stress, pro-inflamatory, pro-apoptotic as well as RAS components. ISO also induced a significant increase in medullar renin protein expression.

CONCLUSION

These findings support relevant information regarding the contribution of specific β-adrenergic hyperactivity in early stage of renal injury, indicating the reactive oxygen species, ER stress and intrarenal RAS as important factors in this process.

Nicorandil modulated macrophages activation and polarization via NF-κb signaling pathway

Nicorandil, a drug with both nitrate-like and ATP-sensitive potassium (K_ATP) channel-activating properties, has been well demonstrated in various aspects of myocardial infarction (MI), especially in inhibiting cell apoptosis and increasing coronary flow. However, the role of nicorandil in regulating inflammation and angiogenesis following myocardial infarction is still unrevealed. In the present study, we explored the effect of nicorandil on macrophage phenotype transition and inflammation regulation and the potential underlying mechanisms. For the phenotype transition and phagocytosis ability of macrophages detection, flow cytometry analysis was used. The inflammation factors were measured with ELISA and qRT-PCR. Western blot was used to assess the levels of NF-κb and its target genes and VEGF expression. The tube formation ability of endothelial cells was examined on matrigel. We discovered that nicorandil can obviously inhibit the differentiation of monocytes into mature macrophages and decrease M1 phenotype transition both in peritoneal macrophages and cultured macrophage cell line in normal or hypoxia and serum deprivation (H/SD) conditions. Meanwhile, nicorandil can induce an anti-inflammatory M2 phenotype. Thereby, nicorandil regulated macrophages switching to M1/M2 status. Our data further showed that NF-κb and the expression of its target genes were pivotal players in the regulation of macrophages phenotype. Besides, we also showed that nicorandil can promote the tube formation and VEGF expression in endothelial cells. We concluded that nicorandil may serve as an effective modulator of NF-κb signaling pathway during the pathogenesis of MI via regulating M1/M2 status and promoting angiogenesis.