Local infiltration of neuropeptide Y as a potential therapeutic agent against apoptosis and fibrosis in a swine model of hypercholesterolemia and chronic myocardial ischemia

Bayliss Starling Prize Lecture 2023: Neuropeptide-Y being 'unsympathetic' to the broken hearted

William Bayliss and Ernest Starling are not only famous as pioneers in cardiovascular physiology, but also responsible for the discovery of the first hormone (from the Greek 'excite or arouse'), the intestinal signalling molecule and neuropeptide secretin in 1902. Our research group focuses on neuropeptides and neuromodulators that influence cardiovascular autonomic control as potential biomarkers in disease and tractable targets for therapeutic intervention. Acute myocardial infarction (AMI) and chronic heart failure (CHF) result in high levels of cardiac sympathetic stimulation, which is a poor prognostic indicator. Although beta-blockers improve mortality in these conditions by preventing the action of the neurotransmitter noradrenaline, a substantial residual risk remains. Recently, we have identified the sympathetic co-transmitter neuropeptide-Y (NPY) as being released during AMI, leading to larger infarcts and life-threatening arrhythmia in both animal models and patients. Here, we discuss recently published data demonstrating that peripheral venous NPY levels are associated with heart failure hospitalisation and mortality after AMI, and all cause cardiovascular mortality in CHF, even when adjusting for known risk factors (including brain natriuretic peptide). We have investigated the mechanistic basis for these observations in human and rat stellate ganglia and cardiac tissue, manipulating NPY neurochemistry at the same time as using state-of-the-art imaging techniques, to establish the receptor pathways responsible for NPY signalling. We propose NPY as a new mechanistic biomarker in AMI and CHF patients and aim to determine whether specific NPY receptor blockers can prevent arrhythmia and attenuate the development of heart failure.

Cannabinoid Receptor-2 agonist AM1241 Attenuates Myocardial Ischemia-Reperfusion-Induced Oxidative Stress in Rats via Nrf2/HO-1 Pathway

OBJECTIVE

The cannabinoid receptor-2 agonist AM1241 exhibits notable cardioprotective effects against myocardial infarction, positioning it as a promising therapeutic candidate for cardiovascular disease. This study explores AM1241's protective role in myocardial ischemia-reperfusion (IR) injury and its association with the Nrf2/HO-1 pathway.

METHODS

In an established Sprague-Dawley rat IR model, AM1241's impact on cardiac injury was assessed through echocardiography, 2,3,5-triphenyl tetrazolium chloride staining, and histological analysis. H9c2 cells underwent hypoxia-reoxygenation, with AM1241's influence on cell viability determined by the CCK-8 assay. Reactive oxygen species (ROS) production was measured using the DCFH-DA assay, and Nrf2 and HO-1 protein expressions were evaluated through immunofluorescence and Western blot.

RESULTS

Myocardial ischemia-reperfusion injury (MIRI) increased infarct size, inflammatory cell presence, oxidative and nitrosative stress, impaired cardiac function, and elevated apoptosis rates. AM1241 mitigated these effects, enhancing cell viability, reducing ROS production, and upregulating Nrf2 and HO-1 expression. The antioxidant effect of AM1241 was inhibited by ML385 intervention.

CONCLUSIONS

AM1241 attenuates oxidative stress, alleviates MIRI, and activates the Nrf2/HO-1 signaling pathway, underscoring its potential as a therapeutic strategy for MIRI.

Multiomics analysis of canine myocardium after circumferential pulmonary vein ablation: Effect of neuropeptide Y on long-term reinduction of atrial fibrillation

Catheter ablation (CA) is an essential method for the interventional treatment of atrial fibrillation (AF), and it is very important to reduce long-term recurrence after CA. The mechanism of recurrence after CA is still unclear. We established a long-term model of beagle canines after circumferential pulmonary vein ablation (CPVA). The transcriptome and proteome were obtained using high-throughput sequencing and TMT-tagged LC-MS/LC analysis, respectively. Differentially expressed genes and proteins were screened and enriched, and the effect of fibrosis was found and verified in tissues. A downregulated protein, neuropeptide Y (NPY), was selected for validation and the results suggest that NPY may play a role in the long-term reinduction of AF after CPVA. Then, the molecular mechanism of NPY was further investigated. The results showed that the atrial effective refractory period (AERP) was shortened and fibrosis was increased after CPVA. Atrial myocyte apoptosis was alleviated by NPY intervention, and Akt activation was inhibited in cardiac fibroblasts. These results suggest that long-term suppression of NPY after CPVA may lead to induction of AF through promoting cardiomyocyte apoptosis and activating the Akt pathway in cardiac fibroblasts, which may make AF more likely to reinduce.

Neuropeptide Y attenuates cardiac remodeling and deterioration of function following myocardial infarction

Plasma levels of neuropeptide Y (NPY) are elevated in patients with acute myocardial infarction (AMI), but its role in AMI remains unclear, which was examined here in NPY wild-type/knockout (WT/KO) mice treated with/without exogenous NPY and its Y1 receptor antagonist (Y1Ra) BIBP 3226. We found that AMI mice lacking NPY developed more severe AMI than WT mice with worse cardiac dysfunction, progressive cardiac inflammation and fibrosis, and excessive apoptosis but impairing angiogenesis. All of these changes were reversed when the NPY KO mice were treated with exogenous NPY in a dose-dependent manner. Interestingly, treatment with NPY also dose dependently attenuated AMI in WT mice, which was blocked by BIBP 3226. Phenotypically, cardiac NPY was de novo expressed by infiltrating macrophages during the repairing or fibrosing process in heart-failure patients and AMI mice. Mechanistically, NPY was induced by transforming growth factor (TGF)-β1 in bone marrow-derived macrophages and signaled through its Y1R to exert its pathophysiological activities by inhibiting p38/nuclear factor κB (NF-κB)-mediated M1 macrophage activation while promoting the reparative M2 phenotype in vivo and in vitro. In conclusion, NPY can attenuate AMI in mice. Inhibition of cardiac inflammation and fibrosis while enhancing angiogenesis but reducing apoptosis may be the underlying mechanisms through which NPY attenuates cardiac remodeling and deterioration of function following AMI.

The Effects of Neuropeptide Y Overexpression on the Mouse Model of Doxorubicin-Induced Cardiotoxicity

Doxorubicin is a potent anticancer drug with cardiotoxicity hampering its use. Neuropeptide Y (NPY) is the most abundant neuropeptide in the heart and a co-transmitter of the sympathetic nervous system that plays a role in cardiac diseases. The aim of this work was to study the impact of NPY on doxorubicin-induced cardiotoxicity. Transgenic mice overexpressing NPY in noradrenergic neurons (NPY-OE^DβH) and wild-type mice were treated with a single dose of doxorubicin. Doxorubicin caused cardiotoxicity in both genotypes as demonstrated by decreased weight gain, tendency to reduced ejection fraction, and changes in the expression of several genes relevant to cardiac pathology. Doxorubicin resulted in a tendency to lower ejection fraction in NPY-OE^DβH mice more than in wild-type mice. In addition, gain in the whole body lean mass gain was decreased only in NPY-OE^DβH mice, suggesting a more severe impact of doxorubicin in this genotype. The effects of doxorubicin on genes expressed in the heart were similar between NPY-OE^DβH and wild-type mice. The results demonstrate that doxorubicin at a relatively low dose caused significant cardiotoxicity. There were differences between NPY-OE^DβH and wild-type mice in their responses to doxorubicin that suggest NPY to increase susceptibility to cardiotoxicity. This may point to the therapeutic implications as suggested for NPY system in other cardiovascular diseases.

Neuropeptide Y predicts cardiovascular events in chronic kidney disease patients: a cohort study

BACKGROUND

Neuropeptide Y (NPY) is a multifaceted sympathetic neurotransmitter regulating reflex cardiovascular control, myocardial cell growth, inflammation and innate immunity. Circulating NPY levels predict cardiovascular mortality in patients with end stage kidney disease on dialysis but this relationship has never been tested in predialysis chronic kidney disease (CKD) patients.

METHODS

We investigated the relationship between circulating NPY and the risk for cardiovascular events (Fine & Gray competing risks model) in a cohort of 753 stages 2-5 CKD patients over a median follow-up of 36 months.

RESULTS

Independently of other risk factors, plasma NPY was directly related with the glomerular filtration rate (β = -0.19, P < 0.001) but was independent of systemic inflammation as quantified by serum IL6 and C reactive protein. Over follow-up 112 patients had cardiovascular events and 12 died. In analyses fully adjusted for traditional risk factors and a large series of CKD-specific risk factors and considering death as a competing event (Fine and Gray model) a 0.25 μmol/l increase in NPY robustly predicted the incident risk for cardiovascular events (subdistribution hazard ratio: 1.25; 95% confidence interval: 1.09-1.44; P = 0.002). Furthermore, the fully adjusted NPY - cardiovascular outcomes relationship was modified by age (P = 0.012) being quite strong in young patients but weaker in the old ones.

CONCLUSION

NPY is an independent, robust predictor of cardiovascular events in predialysis CKD patients and the risk for such events is age-dependent being maximal in young patients. These findings suggest that NPY may play a role in the high risk of cardiovascular disease in this population.

Neuropeptide Y and chronic kidney disease progression: a cohort study

Background

Neuropeptide Y (NPY) is a sympathetic neurotransmitter that has been implicated in various disorders including obesity, gastrointestinal and cardiovascular diseases.

Methods

We investigated the relationship between circulating NPY and the progression of the glomerular filtration rate (GFR) and proteinuria and the risk for a combined renal endpoint (>30% GFR loss, dialysis/transplantation) in two European chronic kidney disease (CKD) cohorts including follow-up of 753 and 576 patients for 36 and 57 months, respectively.

Results

Average plasma NPY was 104 ± 32 pmol/L in the first CKD cohort and 119 ± 41 pmol/L in the second one. In separate analyses of the two cohorts, NPY associated with the progression of the estimated GFR (eGFR) and proteinuria over time in both unadjusted and adjusted {eGFR: -3.60 mL/min/1.73 m2 [95% confidence interval (CI): -4.46 to - 2.74] P < 0.001 and -0.83 mL/min/1.73 m2 (-1.41 to - 0.25, P = 0.005); proteinuria: 0.18 g/24 h (0.11-0.25) P < 0.001 and 0.07 g/24 h (0.005-0.14) P = 0.033} analyses by the mixed linear model. Accordingly, in a combined analysis of the two cohorts accounting for the competitive risk of death (Fine and Gray model), NPY predicted (P = 0.005) the renal endpoint [sub-distribution hazard ratio (SHR): 1.09; 95% CI: 1.03-1.16; P = 0.005] and the SHR in the first cohort (1.14, 95% CI: 1.04-1.25) did not differ (P = 0.25) from that in the second cohort (1.06, 95% CI: 0.98-1.15).

Conclusions

NPY associates with proteinuria and faster CKD progression as well as with a higher risk of kidney failure. These findings suggest that the sympathetic system and/or properties intrinsic to the NPY molecule may play a role in CKD progression.

Platelet Lysate-Derived Neuropeptide y Influences Migration and Angiogenesis of Human Adipose Tissue-Derived Stromal Cells

Neuropeptide Y (NPY), a powerful neurotransmitter of the central nervous system, is a key regulator of angiogenesis and biology of adipose depots. Intriguingly, its peripheral vascular and angiogenic powerful activity is strictly associated to platelets, which are source of clinical hemoderivates, such as platelet lysate (PL), routinely employed in several clinical applications as wound healing, and to preserve ex vivo the progenitor properties of the adipose stromal cells pool. So far, the presence of NPY in PL and its biological effects on the adipose stromal cell fraction (ASCs) have never been investigated. Here, we aimed to identify endogenous sources of NPY such as PL-based preparations and to investigate which biological properties PL-derived NPY is able to exert on ASCs. The results show that PL contains a high amount of NPY, which is in part also excreted by ASCs when stimulated with PL. The protein levels of the three main NPY subtype receptors (Y1, Y2, Y5) are unaltered by stimulation of ASCs with PL, but their inhibition through selective pharmacological antagonists, considerably enhances migration, and a parallel reduction of angiogenic features of ASCs including decrease in VEGF mRNA and intracellular calcium levels, both downstream targets of NPY. The expression of VEGF and NPY is enhanced within the sites of neovascularisation of difficult wounds in patients after treatment with leuco-platelet concentrates. Our data highlight the presence of NPY in PL preparations and its peripheral effects on adipose progenitors.

NPY Impairs Cell Viability and Mitochondrial Membrane Potential Through Ca2+ and p38 Signaling Pathways in Neonatal Rat Cardiomyocytes

NPY is involved in stress cardiomyopathy. However, the associated mechanism for NPY-induced stress cardiomyopathy remains unclear. In this study, we aimed to explore potential cell signaling pathways that are related to NPY-mediated cell viability in neonatal rat cardiomyocytes. We found that NPY induced cell viability suppression in cultured cardiomyocytes in a dose-dependent manner. After NPY treatment, expression of CaN and p-CAMKII increased significantly, and phosphorylation of p38 but not ERK and JNK was changed. Moreover, NPY treatment significantly increased PGC-1α (the key factor of mitochondrial biogenesis and energy metabolism) expression but decreased mitochondrial membrane potential in cultured cardiomyocytes. More importantly, the blockage of CaN, CAMKII, and p38 signaling pathways by their inhibitors could rescue the reduced cell viability and mitochondrial membrane potential in NPY-treated cardiomyocytes. Collectively, our data demonstrated that NPY mediated cell viability and mitochondrial membrane potential in cardiomyocytes through CaN, CAMKII, and p38 signaling pathways.

Novel targets and future strategies for acute cardioprotection: Position Paper of the European Society of Cardiology Working Group on Cellular Biology of the Heart

Ischaemic heart disease and the heart failure that often results, remain the leading causes of death and disability in Europe and worldwide. As such, in order to prevent heart failure and improve clinical outcomes in patients presenting with an acute ST-segment elevation myocardial infarction and patients undergoing coronary artery bypass graft surgery, novel therapies are required to protect the heart against the detrimental effects of acute ischaemia/reperfusion injury (IRI). During the last three decades, a wide variety of ischaemic conditioning strategies and pharmacological treatments have been tested in the clinic-however, their translation from experimental to clinical studies for improving patient outcomes has been both challenging and disappointing. Therefore, in this Position Paper of the European Society of Cardiology Working Group on Cellular Biology of the Heart, we critically analyse the current state of ischaemic conditioning in both the experimental and clinical settings, provide recommendations for improving its translation into the clinical setting, and highlight novel therapeutic targets and new treatment strategies for reducing acute myocardial IRI.

Effects of Neuropeptide Y on Stem Cells and Their Potential Applications in Disease Therapy

Neuropeptide Y (NPY), a 36-amino acid peptide, is widely distributed in the central and peripheral nervous systems and other peripheral tissues. It takes part in regulating various biological processes including food intake, circadian rhythm, energy metabolism, and neuroendocrine secretion. Increasing evidence indicates that NPY exerts multiple regulatory effects on stem cells. As a kind of primitive and undifferentiated cells, stem cells have the therapeutic potential to replace damaged cells, secret paracrine molecules, promote angiogenesis, and modulate immunity. Stem cell-based therapy has been demonstrated effective and considered as one of the most promising treatments for specific diseases. However, several limitations still hamper its application, such as poor survival and low differentiation and integration rates of transplanted stem cells. The regulatory effects of NPY on stem cell survival, proliferation, and differentiation may be helpful to overcome these limitations and facilitate the application of stem cell-based therapy. In this review, we summarized the regulatory effects of NPY on stem cells and discussed their potential applications in disease therapy.

The role of neuropeptides in adverse myocardial remodeling and heart failure

In addition to traditional neurotransmitters of the sympathetic and parasympathetic nervous systems, the heart also contains numerous neuropeptides. These neuropeptides not only modulate the effects of neurotransmitters, but also have independent effects on cardiac function. While in most cases the physiological actions of these neuropeptides are well defined, their contributions to cardiac pathology are less appreciated. Some neuropeptides are cardioprotective, some promote adverse cardiac remodeling and heart failure, and in the case of others their functions are unclear. Some have both cardioprotective and adverse effects depending on the specific cardiac pathology and progression of that pathology. In this review, we briefly describe the actions of several neuropeptides on normal cardiac physiology, before describing in more detail their role in adverse cardiac remodeling and heart failure. It is our goal to bring more focus toward understanding the contribution of neuropeptides to the pathogenesis of heart failure, and to consider them as potential therapeutic targets.

Neuropeptide Y3-36 incorporated into PVAX nanoparticle improves functional blood flow in a murine model of hind limb ischemia

We generated a novel nanoparticle called PVAX, which has intrinsic antiapoptotic and anti-inflammatory properties. This nanoparticle was loaded with neuropeptide Y_3-36 (NPY_3-36), an angiogenic neurohormone that plays a central role in angiogenesis. Subsequently, we investigated whether PVAX-NPY_3-36 could act as a therapeutic agent and induce angiogenesis and vascular remodeling in a murine model of hind limb ischemia. Adult C57BL/J6 mice (n = 40) were assigned to treatment groups: control, ischemia PBS, ischemia PVAX, ischemia NPY_3-36, and Ischemia PVAX-NPY_3-36 Ischemia was induced by ligation of the femoral artery in all groups except control and given relevant treatments (PBS, PVAX, NPY_3-36, and PVAX-NPY_3-36). Blood flow was quantified using laser Doppler imaging. On days 3 and 14 posttreatment, mice were euthanized to harvest gastrocnemius muscle for immunohistochemistry and immunoblotting. Blood flow was significantly improved in the PVAX-NPY_3-36 group after 14 days. Western blot showed an increase in angiogenic factors VEGF-R2 and PDGF-β (P = 0.0035 and P = 0.031, respectively) and antiapoptotic marker Bcl-2 in the PVAX-NPY_3-36 group compared with ischemia PBS group (P = 0.023). Proapoptotic marker Smad5 was significantly decreased in the PVAX-NPY_3-36 group as compared with the ischemia PBS group (P = 0.028). Furthermore, Y₂ receptors were visualized in endothelial cells of newly formed arteries in the PVAX-NPY_3-36 group. In conclusion, we were able to show that PVAX-NPY_3-36 can induce angiogenesis and arteriogenesis as well as improve functional blood flow in a murine model of hind limb ischemia.NEW & NOTEWORTHY Our research project proposes a novel method for drug delivery. Our patented PVAX nanoparticle can detect areas of ischemia and oxidative stress. Although there have been studies about delivering angiogenic molecules to areas of ischemic injury, there are drawbacks of nonspecific delivery as well as short half-lives. Our study is unique because it can specifically deliver NPY_3-36 to ischemic tissue and appears to extend the amount of time therapy is available, despite NPY_3-36's short half-life.

Neuropeptide Y is an angiogenic factor in cardiovascular regeneration

In diabetic cardiomyopathy, there is altered angiogenic signaling and increased oxidative stress. As a result, anti-angiogenic and pro-inflammatory pathways are activated. These disrupt cellular metabolism and cause fibrosis and apoptosis, leading to pathological remodeling. The autonomic nervous system and neurotransmitters play an important role in angiogenesis. Therapies that promote angiogenesis may be able to relieve the pathology in these disease states. Neuropeptide Y (NPY) is the most abundantly produced and expressed neuropeptide in the central and peripheral nervous systems in mammals and plays an important role in promoting angiogenesis and cardiomyocyte remodeling. It produces effects through G-protein-coupled Y receptors that are widely distributed and also present on the myocardium. Some of these receptors are also involved in diseased states of the heart. NPY has been implicated as a potent growth factor, causing cell proliferation in multiple systems while the NPY3-36 fragment is selective in stimulating angiogenesis and cardiomyocyte remodeling. Current research is focusing on developing a drug delivery mechanism for NPY to prolong therapy without having significant systemic consequences. This could be a promising innovation in the treatment of diabetic cardiomyopathy and ischemic heart disease.

Early Cellular Changes in the Ascending Aorta and Myocardium in a Swine Model of Metabolic Syndrome

Background

Metabolic syndrome is associated with pathological remodeling of the heart and adjacent vessels. The early biochemical and cellular changes underlying the vascular damage are not fully understood. In this study, we sought to establish the nature, extent, and initial timeline of cytochemical derangements underlying reduced ventriculo-arterial compliance in a swine model of metabolic syndrome.

Methods

Yorkshire swine (n = 8 per group) were fed a normal diet (ND) or a high-cholesterol (HCD) for 12 weeks. Myocardial function and blood flow was assessed before harvesting the heart. Immuno-blotting and immuno-histochemical staining were used to assess the cellular changes in the myocardium, ascending aorta and left anterior descending artery (LAD).

Results

There was significant increase in body mass index, blood glucose and mean arterial pressures (p = 0.002, p = 0.001 and p = 0.024 respectively) in HCD group. At the cellular level there was significant increase in anti-apoptotic factors p-Akt (p = 0.007 and p = 0.002) and Bcl-xL (p = 0.05 and p = 0.01) in the HCD aorta and myocardium, respectively. Pro-fibrotic markers TGF-β (p = 0.01), pSmad1/5 (p = 0.03) and MMP-9 (p = 0.005) were significantly increased in the HCD aorta. The levels of pro-apoptotic p38MAPK, Apaf-1 and cleaved Caspase3 were significantly increased in aorta of HCD (p = 0.03, p = 0.04 and p = 0.007 respectively). Similar changes in coronary arteries were not observed in either group. Functionally, the high cholesterol diet resulted in significant increase in ventricular end systolic pressure and–dp/dt (p = 0.05 and p = 0.007 respectively) in the HCD group.

Conclusion

Preclinical metabolic syndrome initiates pro-apoptosis and pro-fibrosis pathways in the heart and ascending aorta, while sparing coronary arteries at this early stage of dietary modification.

Modulation of Hypercholesterolemia-Induced Oxidative/Nitrative Stress in the Heart

Hypercholesterolemia is a frequent metabolic disorder associated with increased risk for cardiovascular morbidity and mortality. In addition to its well-known proatherogenic effect, hypercholesterolemia may exert direct effects on the myocardium resulting in contractile dysfunction, aggravated ischemia/reperfusion injury, and diminished stress adaptation. Both preclinical and clinical studies suggested that elevated oxidative and/or nitrative stress plays a key role in cardiac complications induced by hypercholesterolemia. Therefore, modulation of hypercholesterolemia-induced myocardial oxidative/nitrative stress is a feasible approach to prevent or treat deleterious cardiac consequences. In this review, we discuss the effects of various pharmaceuticals, nutraceuticals, some novel potential pharmacological approaches, and physical exercise on hypercholesterolemia-induced oxidative/nitrative stress and subsequent cardiac dysfunction as well as impaired ischemic stress adaptation of the heart in hypercholesterolemia.

Role of neuropeptides in cardiomyopathies

The role of neuropeptides in cardiomyopathy-associated heart failure has been garnering more attention. Several neuropeptides--Neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), calcitonin gene related peptide (CGRP), substance P (SP) and their receptors have been studied in the various types of cardiomyopathies. The data indicate associations with the strength of the association varying depending on the kind of neuropeptide and the nature of the cardiomyopathy--diabetic, ischemic, inflammatory, stress-induced or restrictive cardiomyopathy. Several neuropeptides appear to alter regulation of genes involved in heart failure. Demonstration of an association is an essential first step in proving causality or establishing a role for a factor in a disease. Understanding the complexity of neuropeptide function should be helpful in establishing new or optimal therapeutic strategies for the treatment of heart failure in cardiomyopathies.