Endothelial C-Type Natriuretic Peptide Is a Critical Regulator of Angiogenesis and Vascular Remodeling

Endothelium- and Fibroblast-Derived C-Type Natriuretic Peptide Prevents the Development and Progression of Aortic Aneurysms

BACKGROUND

Thoracic aortic aneurysm (AA) and abdominal AA are life-threatening diseases characterized by dilation, inflammation, and structural weakness; development of pharmacological therapies is desperately needed. CNP (C-type natriuretic peptide) plays a key role in vascular homeostasis, mediating vasodilator, anti-inflammatory, and antiatherogenic actions. Because such processes drive AA, we determined the role of endogenous CNP in offsetting pathogenesis.

METHODS

Tissue from patients with AA was analyzed to determine the consequences on CNP signaling. Ascending and suprarenal aortic diameters were assessed at baseline and following Ang II (angiotensin II; 1.44 mg/kg per day) infusion in wild-type, endothelium-restricted (ecCNP-/-), fibroblast-restricted (fbCNP-/-), global CNP (gbCNP-/-), or global NPR-C-/- mice infected with an adeno-associated virus expressing a proprotein convertase subtilisin/kexin type 9 gain-of-function mutation or backcrossed to an apoE-/- background. At 28 days, aortas were harvested for RT-qPCR and histological analyses. CNP (0.2 mg/kg per day) was infused to rescue any adverse phenotype.

RESULTS

Aneurysmal tissue from patients with thoracic AA and abdominal AA revealed that CNP and NPR-C (natriuretic peptide receptor-C) expression were overtly perturbed. ecCNP-/-, fbCNP-/-, and gbCNP-/- mice exhibited an aggravated phenotype compared with wild-type mice in both ascending and suprarenal aortas, exemplified by greater dilation, fibrosis, elastin degradation, and macrophage infiltration. CNP and NPR-C expression was also dysregulated in murine thoracic AA and abdominal AA, accompanied by increased accumulation of mRNA encoding markers of inflammation, extracellular matrix remodeling/calcification, fibrosis, and apoptosis. CNP also prevented activation of isolated macrophages and vascular smooth muscle cells. An essentially identical phenotype was observed in NPR-C-/- mice and while administration of CNP protected against disease severity in wild-type animals, this phenotypic rescue was not apparent in NPR-C-/- mice.

CONCLUSIONS

Endothelium- and fibroblast-derived CNP, via NPR-C activation, plays important roles in attenuating AA formation by preserving aortic structure and function. Therapeutic strategies aimed at mimicking CNP bioactivity hold potential to reduce the need for surgical intervention.

Single-cell analysis identifies the CNP/GC-B/cGMP axis as marker and regulator of modulated VSMCs in atherosclerosis

A balanced activity of cGMP signaling contributes to the maintenance of cardiovascular homeostasis. Vascular smooth muscle cells (VSMCs) can generate cGMP via three ligand-activated guanylyl cyclases, the NO-sensitive guanylyl cyclase, the atrial natriuretic peptide (ANP)-activated GC-A, and the C-type natriuretic peptide (CNP)-stimulated GC-B. Here, we study natriuretic peptide signaling in murine VSMCs and atherosclerotic lesions. Correlative profiling of pathway activity and VSMC phenotype at the single-cell level shows that phenotypic modulation of contractile VSMCs to chondrocyte-like plaque cells during atherogenesis is associated with a switch from ANP/GC‑A to CNP/GC‑B signaling. Silencing of the CNP/GC-B axis in VSMCs results in an increase of chondrocyte-like plaque cells. These findings indicate that the CNP/GC-B/cGMP pathway is a marker and atheroprotective regulator of modulated VSMCs, limiting their transition to chondrocyte-like cells. Overall, this study highlights the plasticity of cGMP signaling in VSMCs and suggests analogies between CNP-dependent remodeling of bone and blood vessels.

Endogenous C-type natriuretic peptide offsets the pathogenesis of steatohepatitis, hepatic fibrosis, and portal hypertension

Metabolic dysfunction-associated steatotic liver disease (MASLD), hepatic fibrosis, and portal hypertension constitute an increasing public health problem due to the growing prevalence of obesity and diabetes. C-type natriuretic peptide (CNP) is an endogenous regulator of cardiovascular homeostasis, immune cell reactivity, and fibrotic disease. Thus, we investigated a role for CNP in the pathogenesis of MASLD. Wild-type (WT), global CNP (gbCNP-/-), and natriuretic peptide receptor-C (NPR-C-/-) knockout mice were fed a choline-deficient defined amino acid diet or administered CCl4. Liver damage was assessed by histological and biochemical analyses, with steatosis and portal vein size determined by ultrasound. Portal vein pressure and reactivity were measured in vivo and ex vivo, respectively. Pharmacological CNP delivery was used to evaluate prospective therapeutic benefit, and plasma CNP concentration was compared in controls and patients with cirrhosis. Circulating CNP concentration was lower in patients with cirrhosis compared with controls. gbCNP-/- mice were more susceptible, versus WT, to advanced steatohepatitis and hepatic fibrosis, characterized by increased immune cell infiltration, fibrosis, ballooning, plasma alanine aminotransferase concentration, and up-regulation of markers driving these processes. gbCNP-/- mice had increased portal vein diameter and pressure, underpinned by CNP insensitivity. NPR-C-/- animals recapitulated, comparatively, the exaggerated pathogenic phenotype in gbCNP-/- mice, whereas CNP reduced hepatic stellate cell proliferation via NPR-B-dependent inhibition of extracellular signal-related kinase 1/2. Administration of CNP reversed many aspects of disease severity. These data define a new intrinsic role for CNP in offsetting the pathogenesis of MASLD, hepatic fibrosis, and portal hypertension and the potential for targeting CNP signaling for treating these disorders.

Endothelial cell-cardiomyocyte cross-talk: understanding bidirectional paracrine signaling in cardiovascular homeostasis and disease

To maintain homeostasis in the heart, endothelial cells and cardiomyocytes engage in dynamic cross-talk through paracrine signals that regulate both cardiac development and function. Here, we review the paracrine signals that endothelial cells release to regulate cardiomyocyte growth, hypertrophy and contractility, and the factors that cardiomyocytes release to influence angiogenesis and vascular tone. Dysregulated communication between these cell types can drive pathophysiology of disease, as seen in ischemia-reperfusion injury, diabetes, maladaptive hypertrophy, and chemotherapy-induced cardiotoxicity. Investingating the role of cross-talk is critical in developing an understanding of tissue homeostasis, regeneration, and disease pathogenesis, with the potential to identify novel targets for diagnostic and therapeutic purposes.

Cardiomyocyte-derived C-type natriuretic peptide diminishes myocardial ischaemic injury by promoting revascularisation and limiting fibrotic burden

BACKGROUND

C-type natriuretic peptide (CNP) is a significant player in the maintenance of cardiac and vascular homeostasis regulating local blood flow, platelet and leukocyte activation, heart structure and function, angiogenesis and metabolic balance. Since such processes are perturbed in myocardial infarction (MI), we explored the role of cardiomyocyte-derived CNP, and pharmacological administration of the peptide, in offsetting the pathological consequences of MI.

METHODS

Wild type (WT) and cardiomyocyte-restricted CNP null (cmCNP-/-) mice were subjected to left anterior descending coronary artery (LADCA) ligation and acute effects on infarct size and longer-term outcomes of cardiac repair explored. Heart structure and function were assessed by combined echocardiographic and molecular analyses. Pharmacological administration of CNP (0.2 mg/kg/day; s.c.) was utilized to assess therapeutic potential.

RESULTS

Compared to WT littermates, cmCNP-/- mice had a modestly increased infarct size following LADCA ligation but without significant deterioration of cardiac structural and functional indices. However, cmCNP-/- animals exhibited overtly worse heart morphology and contractility 6 weeks following MI, with particularly deleterious reductions in left ventricular ejection fraction, dilatation, fibrosis and revascularization. This phenotype was largely recapitulated in animals with global deletion of natriuretic peptide receptor (NPR)-C (NPR-C-/-). Pharmacological administration of CNP rescued the deleterious pathology in WT and cmCNP-/-, but not NPR-C-/-, animals.

CONCLUSIONS AND IMPLICATIONS

Cardiomyocytes synthesize and release CNP as an intrinsic protective mechanism in response to MI that reduces cardiac structural and functional deficits; these salutary actions are primarily NPR-C-dependent. Pharmacological targeting of CNP may represent a new therapeutic option for MI.

C-type natriuretic peptide (CNP): The cardiovascular system and beyond

C-type natriuretic peptide (CNP) represents the 'local' member of the natriuretic peptide family, functioning in an autocrine or paracrine capacity to modulate a hugely diverse portfolio of physiological processes. Whilst the best-characterised of these regulatory roles are in the cardiovascular system, akin to its predominantly endocrine siblings atrial (ANP) and brain (BNP) natriuretic peptides, CNP governs many additional, unrelated mechanisms including bone growth, gamete maturation, auditory processing, and neuronal integrity. Furthermore, there is currently great interest in mimicking the biological activity of CNP for therapeutic gain in many of these disparate organ systems. Herein, we provide an overview of the physiology, pathophysiology and pharmacology of CNP in both cardiovascular and non-cardiovascular settings.

Exploring the Therapeutic Potential of C-Type Natriuretic Peptide for Preeclampsia

BACKGROUND

Preeclampsia is a serious condition of pregnancy, complicated by aberrant maternal vascular dysfunction. CNP (C-type natriuretic peptide) contributes to vascular homeostasis, acting through NPR-B (natriuretic peptide receptor-B) and NPR-C (natriuretic peptide receptor-C). CNP mitigates vascular dysfunction of arteries in nonpregnant cohorts; this study investigates whether CNP can dilate maternal arteries in ex vivo preeclampsia models.

METHODS

Human omental arteries were dissected from fat biopsies collected during cesarean section. CNP, NPR-B, and NPR-C mRNA expression was assessed in arteries collected from pregnancies complicated by preeclampsia (n=6) and normotensive controls (n=11). Using wire myography, we investigated the effects of CNP on dilation of arteries from normotensive pregnancies. Arteries were preconstricted with either serum from patients with preeclampsia (n=6) or recombinant ET-1 (endothelin-1; vasoconstrictor elevated in preeclampsia; n=6) to model vasoconstriction associated with preeclampsia. Preconstricted arteries were treated with recombinant CNP (0.001-100 µmol/L) or vehicle and vascular relaxation assessed. In further studies, arteries were preincubated with NPR-B (5 µmol/L) and NPR-C (10 µmol/L) antagonists before serum-induced constriction (n=4-5) to explore mechanistic signaling.

RESULTS

CNP, NPR-B, and NPR-C mRNAs were not differentially expressed in omental arteries from preeclamptic pregnancies. CNP potently stimulated maternal artery vasorelaxation in our model of preeclampsia (using preeclamptic serum). Its vasodilatory actions were driven through the activation of NPR-B predominantly; antagonism of this receptor alone dampened CNP vasorelaxation. Interestingly, CNP did not reduce ET-1-driven omental artery constriction.

CONCLUSIONS

Collectively, these data suggest that enhancing CNP signaling through NPR-B offers a potential therapeutic strategy to reduce systemic vascular constriction in preeclampsia.

Modified C-type natriuretic peptide normalizes tumor vasculature, reinvigorates antitumor immunity, and improves solid tumor therapies

Deficit of oxygen and nutrients in the tumor microenvironment (TME) triggers abnormal angiogenesis that produces dysfunctional and leaky blood vessels, which fail to adequately perfuse tumor tissues. Resulting hypoxia, exacerbation of metabolic disturbances, and generation of an immunosuppressive TME undermine the efficacy of anticancer therapies. Use of carefully scheduled angiogenesis inhibitors has been suggested to overcome these problems and normalize the TME. Here, we propose an alternative agonist-based normalization approach using a derivative of the C-type natriuretic peptide (dCNP). Multiple gene expression signatures in tumor tissues were affected in mice treated with dCNP. In several mouse orthotopic and subcutaneous solid tumor models including colon and pancreatic adenocarcinomas, this well-tolerated agent stimulated formation of highly functional tumor blood vessels to reduce hypoxia. Administration of dCNP also inhibited stromagenesis and remodeling of the extracellular matrix and decreased tumor interstitial fluid pressure. In addition, treatment with dCNP reinvigorated the antitumor immune responses. Administration of dCNP decelerated growth of primary mouse tumors and suppressed their metastases. Moreover, inclusion of dCNP into the chemo-, radio-, or immune-therapeutic regimens increased their efficacy against solid tumors in immunocompetent mice. These results demonstrate the proof of principle for using vasculature normalizing agonists to improve therapies against solid tumors and characterize dCNP as the first in class among such agents.

Cuproptosis and copper deficiency in ischemic vascular injury and repair

Ischemic vascular diseases are on the rise globally, including ischemic heart diseases, ischemic cerebrovascular diseases, and ischemic peripheral arterial diseases, posing a significant threat to life. Copper is an essential element in various biological processes, copper deficiency can reduce blood vessel elasticity and increase platelet aggregation, thereby increasing the risk of ischemic vascular disease; however, excess copper ions can lead to cytotoxicity, trigger cell death, and ultimately result in vascular injury through several signaling pathways. Herein, we review the role of cuproptosis and copper deficiency implicated in ischemic injury and repair including myocardial, cerebral, and limb ischemia. We conclude with a perspective on the therapeutic opportunities and future challenges of copper biology in understanding the pathogenesis of ischemic vascular disease states.

C-type natriuretic peptide/cGMP/FoxO3 signaling attenuates hyperproliferation of pericytes from patients with pulmonary arterial hypertension

Pericyte dysfunction, with excessive migration, hyperproliferation, and differentiation into smooth muscle-like cells contributes to vascular remodeling in Pulmonary Arterial Hypertension (PAH). Augmented expression and action of growth factors trigger these pathological changes. Endogenous factors opposing such alterations are barely known. Here, we examine whether and how the endothelial hormone C-type natriuretic peptide (CNP), signaling through the cyclic guanosine monophosphate (cGMP) -producing guanylyl cyclase B (GC-B) receptor, attenuates the pericyte dysfunction observed in PAH. The results demonstrate that CNP/GC-B/cGMP signaling is preserved in lung pericytes from patients with PAH and prevents their growth factor-induced proliferation, migration, and transdifferentiation. The anti-proliferative effect of CNP is mediated by cGMP-dependent protein kinase I and inhibition of the Phosphoinositide 3-kinase (PI3K)/AKT pathway, ultimately leading to the nuclear stabilization and activation of the Forkhead Box O 3 (FoxO3) transcription factor. Augmentation of the CNP/GC-B/cGMP/FoxO3 signaling pathway might be a target for novel therapeutics in the field of PAH.

Head-to-head comparison of relevant cell sources of small extracellular vesicles for cardiac repair: Superiority of embryonic stem cells

Small extracellular vesicles (sEV) derived from various cell sources have been demonstrated to enhance cardiac function in preclinical models of myocardial infarction (MI). The aim of this study was to compare different sources of sEV for cardiac repair and determine the most effective one, which nowadays remains limited. We comprehensively assessed the efficacy of sEV obtained from human primary bone marrow mesenchymal stromal cells (BM-MSC), human immortalized MSC (hTERT-MSC), human embryonic stem cells (ESC), ESC-derived cardiac progenitor cells (CPC), human ESC-derived cardiomyocytes (CM), and human primary ventricular cardiac fibroblasts (VCF), in in vitro models of cardiac repair. ESC-derived sEV (ESC-sEV) exhibited the best pro-angiogenic and anti-fibrotic effects in vitro. Then, we evaluated the functionality of the sEV with the most promising performances in vitro, in a murine model of MI-reperfusion injury (IRI) and analysed their RNA and protein compositions. In vivo, ESC-sEV provided the most favourable outcome after MI by reducing adverse cardiac remodelling through down-regulating fibrosis and increasing angiogenesis. Furthermore, transcriptomic, and proteomic characterizations of sEV derived from hTERT-MSC, ESC, and CPC revealed factors in ESC-sEV that potentially drove the observed functions. In conclusion, ESC-sEV holds great promise as a cell-free treatment for promoting cardiac repair following MI.

CNP Ameliorates Macrophage Inflammatory Response and Atherosclerosis

BACKGROUND

CNP (C-type natriuretic peptide), an endogenous short peptide in the natriuretic peptide family, has emerged as an important regulator to govern vascular homeostasis. However, its role in the development of atherosclerosis remains unclear. This study aimed to investigate the impact of CNP on the progression of atherosclerotic plaques and elucidate its underlying mechanisms.

METHODS

Plasma CNP levels were measured in patients with acute coronary syndrome. The potential atheroprotective role of CNP was evaluated in apolipoprotein E-deficient (ApoE-/-) mice through CNP supplementation via osmotic pumps, genetic overexpression, or LCZ696 administration. Various functional experiments involving CNP treatment were performed on primary macrophages derived from wild-type and CD36 (cluster of differentiation 36) knockout mice. Proteomics and multiple biochemical analyses were conducted to unravel the underlying mechanism.

RESULTS

We observed a negative correlation between plasma CNP concentration and the burden of coronary atherosclerosis in patients. In early atherosclerotic plaques, CNP predominantly accumulated in macrophages but significantly decreased in advanced plaques. Supplementing CNP via osmotic pumps or genetic overexpression ameliorated atherosclerotic plaque formation and enhanced plaque stability in ApoE-/- mice. CNP promoted an anti-inflammatory macrophage phenotype and efferocytosis and reduced foam cell formation and necroptosis. Mechanistically, we found that CNP could accelerate HIF-1α (hypoxia-inducible factor 1-alpha) degradation in macrophages by enhancing the interaction between PHD (prolyl hydroxylase domain-containing protein) 2 and HIF-1α. Furthermore, we observed that CD36 bound to CNP and mediated its endocytosis in macrophages. Moreover, we demonstrated that the administration of LCZ696, an orally bioavailable drug recently approved for treating chronic heart failure with reduced ejection fraction, could amplify the bioactivity of CNP and ameliorate atherosclerotic plaque formation.

CONCLUSIONS

Our study reveals that CNP enhanced plaque stability and alleviated macrophage inflammatory responses by promoting HIF-1α degradation, suggesting a novel atheroprotective role of CNP. Enhancing CNP bioactivity may offer a novel pharmacological strategy for treating related diseases.

Functionalized lipid nanoparticles modulate the blood-brain barrier and eliminate α-synuclein to repair dopamine neurons

The challenge in the clinical treatment of Parkinson's disease lies in the lack of disease-modifying therapies that can halt or slow down the progression. Peptide drugs, such as exenatide (Exe), with potential disease-modifying efficacy, have difficulty in crossing the blood-brain barrier (BBB) due to their large molecular weight. Herein, we fabricate multi-functionalized lipid nanoparticles (LNP) Lpc-BoSA/CSO with BBB targeting, permeability-increasing and responsive release functions. Borneol is chemically bonded with stearic acid and, as one of the components of Lpc-BoSA/CSO, is used to increase BBB permeability. Immunofluorescence results of brain tissue of 15-month-old C57BL/6 mice show that Lpc-BoSA/CSO disperses across the BBB into brain parenchyma, and the amount is 4.21 times greater than that of conventional LNP. Motor symptoms of mice in Lpc-BoSA/CSO-Exe group are significantly improved, and the content of dopamine is 1.85 times (substantia nigra compacta) and 1.49 times (striatum) that of PD mice. α-Synuclein expression and Lewy bodies deposition are reduced to 51.85% and 44.72% of PD mice, respectively. Immunohistochemical mechanism studies show AKT expression in Lpc-BoSA/CSO-Exe is 4.23 times that of PD mice and GSK-3β expression is reduced to 18.41%. Lpc-BoSA/CSO-Exe could reduce the production of α-synuclein and Lewy bodies through AKT/GSK-3β pathway, and effectively prevent the progressive deterioration of Parkinson's disease. In summary, Lpc-BoSA/CSO-Exe increases the entry of exenatide into brain and promotes its clinical application for Parkinson's disease therapy.

Single-cell chromatin profiling reveals genetic programs activating proregenerative states in nonmyocyte cells

Cardiac regeneration requires coordinated participation of multiple cell types whereby their communications result in transient activation of proregenerative cell states. Although the molecular characteristics and lineage origins of these activated cell states and their contribution to cardiac regeneration have been studied, the extracellular signaling and the intrinsic genetic program underlying the activation of the transient functional cell states remain largely unexplored. In this study, we delineated the chromatin landscapes of the noncardiomyocytes (nonCMs) of the regenerating heart at the single-cell level and inferred the cis-regulatory architectures and trans-acting factors that control cell type-specific gene expression programs. Moreover, further motif analysis and cell-specific genetic manipulations suggest that the macrophage-derived inflammatory signal tumor necrosis factor-α, acting via its downstream transcription factor complex activator protein-1, functions cooperatively with discrete transcription regulators to activate respective nonCM cell types critical for cardiac regeneration. Thus, our study defines the regulatory architectures and intercellular communication principles in zebrafish heart regeneration.

C-atrial natriuretic peptide (ANP)4-23 attenuates renal fibrosis in deoxycorticosterone-acetate-salt hypertensive mice

Epithelial-mesenchymal transition (EMT) plays a critical role in hypertension-induced renal fibrosis, a final pathway that leads to end-stage renal failure. C-Atrial natriuretic peptide (ANP)4-23, a specific agonist of natriuretic peptide receptor-C (NPR-C), has been reported to have protective effects against hypertension. However, the role of C-ANP4-23 in hypertension-associated renal fibrosis has not yet been elucidated. In this study, mice were randomly divided into SHAM group, DOCA-salt group and DOCA-salt + C-ANP4-23 group. Renal morphology changes, renal function and fibrosis were detected. Human proximal tubular epithelial cells (HK2) stimulated by aldosterone were used for cell function and mechanism study. The DOCA-salt treated mice exhibited hypertension, kidney fibrosis and renal dysfunction, which were attenuated by C-ANP4-23. Moreover, C-ANP4-23 inhibited DOCA-salt treatment-induced renal EMT as evidenced by decrease of the mesenchymal marker alpha-smooth muscle actin (ACTA2) and vimentin and increase of epithelial cell marker E-cadherin. In HK2 cells, aldosterone induced EMT response, which was also suppressed by C-ANP4-23. The key transcription factors (twist, snail, slug and ZEB1) involved in EMT were increased in the kidney of DOCA-salt-treated mice, which were also suppressed by C-ANP4-23. Mechanistically, C-ANP4-23 inhibited the aldosterone-induced translocation of MR from cytosol to nucleus without change of MR expression. Furthermore, C-ANP4-23 rescued the enhanced expression of NADPH oxidase (NOX) 4 and oxidative stress after aldosterone stimulation. Aldosterone-induced Akt and Erk1/2 activation was also suppressed by C-ANP4-23. Our data suggest that C-ANP4-23 attenuates renal fibrosis, likely through inhibition of MR activation, enhanced oxidative stress and Akt and Erk1/2 signaling pathway.

Natriuretic Peptide Receptors (NPRs) as a Potential Target for the Treatment of Heart Failure

PURPOSE OF REVIEW

Heart failure is defined as a complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. The natriuretic peptide is known to exert its biological action on the kidney, heart, blood vessels, renin-angiotensin system, autonomous nervous system, and central nervous system. The natriuretic peptide-natriuretic receptor system plays an important role in the regulation of blood pressure and body fluid volume through its pleiotropic effects.

RECENT FINDINGS

The clinical and animal studies suggest that natriuretic peptide-natriuretic receptors are important targets for the treatment of heart failure and other cardiovascular diseases. Even though attempts targeting natriuretic peptide receptors are underway for heart failure treatment, they seem insufficient despite the receptor systems' potential. This review summarizes natriuretic peptide-natriuretic receptor system's physiological actions and potential target for the treatment of heart failure. Natriuretic peptides play multiple roles in different parts of the body, almost all of the activities related to this receptor system appear to have the potential to be harnessed to treat heart failure or symptoms associated with heart failure.

NPRC deletion mitigated atherosclerosis by inhibiting oxidative stress, inflammation and apoptosis in ApoE knockout mice

Previous studies suggested a beneficial effect of natriuretic peptides in animal models of cardiovascular disease, but the role of natriuretic peptide receptor C (NPRC) in the pathogenesis of atherosclerosis (AS) remains unknown. This study was designed to test the hypothesis that NPRC may promote AS lesion formation and instability by enhancing oxidative stress, inflammation, and apoptosis via protein kinase A (PKA) signaling. ApoE-/- mice were fed chow or Western diet for 12 weeks and NPRC expression was significantly increased in the aortic tissues of Western diet-fed mice. Systemic NPRC knockout mice were crossed with ApoE-/- mice to generate ApoE-/-NPRC-/- mice, and NPRC deletion resulted in a significant decrease in the size and instability of aortic atherosclerotic lesions in ApoE-/-NPRC-/- versus ApoE-/- mice. In addition, endothelial cell-specific NPRC knockout attenuated atherosclerotic lesions in mice. In contrast, endothelial cell overexpression of NPRC aggravated the size and instability of atherosclerotic aortic lesions in mice. Experiments in vitro showed that NPRC knockdown in human aortic endothelial cells (HAECs) inhibited ROS production, pro-inflammatory cytokine expression and endothelial cell apoptosis, and increased eNOS expression. Furthermore, NPRC knockdown in HAECs suppressed macrophage migration, cytokine expression, and phagocytosis via its effects on endothelial cells. On the contrary, NPRC overexpression in endothelial cells resulted in opposite effects. Mechanistically, the anti-inflammation and anti-atherosclerosis effects of NPRC deletion involved activation of cAMP/PKA pathway, leading to downstream upregulated AKT1 pathway and downregulated NF-κB pathway. In conclusion, NPRC deletion reduced the size and instability of atherosclerotic lesions in ApoE-/- mice via attenuating inflammation and endothelial cell apoptosis and increasing eNOS expression by modulating cAMP/PKA-AKT1 and NF-κB pathways. Thus, targeting NPRC may provide a promising approach to the prevention and treatment of atherosclerosis.

NPRC deletion attenuates cardiac fibrosis in diabetic mice by activating PKA/PKG and inhibiting TGF-β1/Smad pathways

Cardiac fibrosis plays a key role in the progression of diabetic cardiomyopathy (DCM). Previous studies demonstrated the cardioprotective effects of natriuretic peptides. However, the effects of natriuretic peptide receptor C (NPRC) on cardiac fibrosis in DCM remains unknown. Here, we observed that myocardial NPRC expression was increased in mice and patients with DCM. NPRC-/- diabetic mice showed alleviated cardiac fibrosis, as well as improved cardiac function and remodeling. NPRC knockdown in both cardiac fibroblasts and cardiomyocytes decreased collagen synthesis and proliferation of cardiac fibroblasts. RNA sequencing identified that NPRC deletion up-regulated the expression of TGF-β-induced factor homeobox 1 (TGIF1), which inhibited the phosphorylation of Smad2/3. Furthermore, TGIF1 up-regulation was mediated by the activation of cAMP/PKA and cGMP/PKG signaling induced by NPRC deletion. These findings suggest that NPRC deletion attenuated cardiac fibrosis and improved cardiac remodeling and function in diabetic mice, providing a promising approach to the treatment of diabetic cardiac fibrosis.

Tree of life: endothelial cell in norm and disease, the good guy is a partner in crime!

Undeniably, endothelial cells (EC) contribute to the maintenance of the homeostasis of the organism through modulating cellular physiology, including signaling pathways, through the release of highly active molecules as well as the response to a myriad of extrinsic and intrinsic signaling factors. Review the data from the current literature on the EC role in norm and disease. Endothelium maintains a precise balance between the released molecules, where EC dysfunction arises when the endothelium actions shift toward vasoconstriction, the proinflammatory, prothrombic properties after the alteration of nitric oxide (NO) production and oxidative stress. The functions of the EC are regulated by the negative/positive feedback from the organism, through EC surface receptors, and the crosstalk between NO, adrenergic receptors, and oxidative stress. More than a hundred substances can interact with EC. The EC dysfunction is a hallmark in the emergence and progression of vascular-related pathologies. The paper concisely reviews recent advances in EC (patho) physiology. Grasping EC physiology is crucial to gauge their potential clinical utility and optimize the current therapies as well as to establish novel nanotherapeutic molecular targets include; endothelial receptors, cell adhesion molecules, integrins, signaling pathways, enzymes; peptidases.

Myokine Musclin Is Critical for Exercise-Induced Cardiac Conditioning

This study investigates the role and mechanisms by which the myokine musclin promotes exercise-induced cardiac conditioning. Exercise is one of the most powerful triggers of cardiac conditioning with proven benefits for healthy and diseased hearts. There is an emerging understanding that muscles produce and secrete myokines, which mediate local and systemic "crosstalk" to promote exercise tolerance and overall health, including cardiac conditioning. The myokine musclin, highly conserved across animal species, has been shown to be upregulated in response to physical activity. However, musclin effects on exercise-induced cardiac conditioning are not established. Following completion of a treadmill exercise protocol, wild type (WT) mice and mice with disruption of the musclin-encoding gene, Ostn, had their hearts extracted and exposed to an ex vivo ischemia-reperfusion protocol or biochemical studies. Disruption of musclin signaling abolished the ability of exercise to mitigate cardiac ischemic injury. This impaired cardioprotection was associated with reduced mitochondrial content and function linked to blunted cyclic guanosine monophosphate (cGMP) signaling. Genetic deletion of musclin reduced the nuclear abundance of protein kinase G (PKGI) and cyclic adenosine monophosphate (cAMP) response element binding (CREB), resulting in suppression of the master regulator of mitochondrial biogenesis, peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), and its downstream targets in response to physical activity. Synthetic musclin peptide pharmacokinetic parameters were defined and used to calculate the infusion rate necessary to maintain its plasma level comparable to that observed after exercise. This infusion was found to reproduce the cardioprotective benefits of exercise in sedentary WT and Ostn-KO mice. Musclin is essential for exercise-induced cardiac protection. Boosting musclin signaling might serve as a novel therapeutic strategy for cardioprotection.

Molecular dynamics simulations and in vitro studies of hybrid decellularized leaf-peptide-polypyrrole composites for potential tissue engineering applications

Tissue engineering (TE) aims to repair and regenerate damaged tissue by an assimilation of optimal combination of cells specific to the tissue with an appropriate biomaterial. In this work, a new biomaterial for potential cardiac TE applications was developed by utilizing a combination of in silico studies and in vitro experiments. Molecular dynamics (MD) simulations for the formation of the novel composite prepared from the decellularized leaf components cellulose and pectin along with the VEGF derived peptide (NYLTHRQ) and polypyrrole (PPy) was carried out to assess self-assembly, mechanical properties, and interactions with integrin and NPR-C receptors which are commonly found in cells of cardiac tissue. Results of molecular dynamics simulations indicated the successful formation of stable assemblies. MD simulations also revealed that the scaffold successfully interacted with integrin and NPR-C receptors. As a proof of concept, beet leaves were decellularized (DC) and cross-linked with NYLTHRQ and PPy using layer-by-layer assembly. Decellularization (DC) was confirmed by DNA and protein quantification. Incorporation of the NYLTHRQ peptide and polypyrrole was confirmed by FTIR spectroscopy and SEM imaging. The DC-NYLTHRQ-PPy scaffold was seeded with co-cultured cardiomyocytes and vascular smooth muscle cells. The scaffold promoted cell proliferation and adhesion. Actin and Troponin T immunofluorescence staining showed the presence of these critical cardiomyocyte markers. Thus, for the first time we have developed a decellularized leaf-peptide-PPy composite scaffold by a combination of in silico studies and laboratory analyses that may have potential applications in cardiac TE.Communicated by Ramaswamy H. Sarma.

Angiotensin receptor-neprilysin inhibitor improves coronary collateral perfusion

Background

We investigated the pleiotropic effects of an angiotensin receptor-neprilysin inhibitor (ARNi) on collateral-dependent myocardial perfusion in a rat model of coronary arteriogenesis, and performed comprehensive analyses to uncover the underlying molecular mechanisms.

Methods

A rat model of coronary arteriogenesis was established by implanting an inflatable occluder on the left anterior descending coronary artery followed by a 7-day repetitive occlusion procedure (ROP). Coronary collateral perfusion was measured by using a myocardial particle infusion technique. The putative ARNi-induced pro-arteriogenic effects were further investigated and compared with an angiotensin-converting enzyme inhibitor (ACEi). Expression of the membrane receptors and key enzymes in the natriuretic peptide system (NPS), renin-angiotensin-aldosterone system (RAAS) and kallikrein-kinin system (KKS) were analyzed by quantitative polymerase chain reaction (qPCR) and immunoblot assay, respectively. Protein levels of pro-arteriogenic cytokines were measured by enzyme-linked immunosorbent assay, and mitochondrial DNA copy number was assessed by qPCR due to their roles in arteriogenesis. Furthermore, murine heart endothelial cells (MHEC5-T) were treated with a neprilysin inhibitor (NEPi) alone, or in combination with bradykinin receptor antagonists. MHEC5-T proliferation was analyzed by colorimetric assay.

Results

The in vivo study showed that ARNis markedly improved coronary collateral perfusion, regulated the gene expression of KKS, and increased the concentrations of relevant pro-arteriogenic cytokines. The in vitro study demonstrated that NEPis significantly promoted MHEC5-T proliferation, which was diminished by bradykinin receptor antagonists.

Conclusion

ARNis improve coronary collateral perfusion and exert pro-arteriogenic effects via the bradykinin receptor signaling pathway.

Role of Cardiac Natriuretic Peptides in Heart Structure and Function

Cardiac natriuretic peptides (NPs), atrial NP (ANP) and B-type NP (BNP) are true hormones produced and released by cardiomyocytes, exerting several systemic effects. Together with C-type NP (CNP), mainly expressed by endothelial cells, they also exert several paracrine and autocrine activities on the heart itself, contributing to cardiovascular (CV) health. In addition to their natriuretic, vasorelaxant, metabolic and antiproliferative systemic properties, NPs prevent cardiac hypertrophy, fibrosis, arrhythmias and cardiomyopathies, counteracting the development and progression of heart failure (HF). Moreover, recent studies revealed that a protein structurally similar to NPs mainly produced by skeletal muscles and osteoblasts called musclin/osteocrin is able to interact with the NPs clearance receptor, attenuating cardiac dysfunction and myocardial fibrosis and promoting heart protection during pathological overload. This narrative review is focused on the direct activities of this molecule family on the heart, reporting both experimental and human studies that are clinically relevant for physicians.

C-type natriuretic peptide preserves central neurological function by maintaining blood-brain barrier integrity

C-type natriuretic peptide (CNP) is highly expressed in the central nervous system (CNS) and key to neuronal development; however, a broader role for CNP in the CNS remains unclear. To address this deficit, we investigated behavioral, sensory and motor abnormalities and blood-brain barrier (BBB) integrity in a unique mouse model with inducible, global deletion of CNP (gbCNP-/-). gbCNP-/- mice and wild-type littermates at 12 (young adult) and 65 (aged) weeks of age were investigated for changes in gait and motor coordination (CatWalk™ and rotarod tests), anxiety-like behavior (open field and elevated zero maze tests), and motor and sensory function (modified neurological severity score [mNSS] and primary SHIRPA screen). Vascular permeability was assessed in vivo (Miles assay) with complementary in vitro studies conducted in primary murine brain endothelial cells. Young adult gbCNP-/- mice had normal gait but reduced motor coordination, increased locomotor activity in the open field and elevated zero maze, and had a higher mNSS score. Aged gbCNP-/- animals developed recurrent spontaneous seizures and had impaired gait and wide-ranging motor and sensory dysfunction. Young adult and aged gbCNP-/- mice exhibited increased BBB permeability, which was partially restored in vitro by CNP administration. Cultured brain endothelial cells from gbCNP-/- mice had an abnormal ZO-1 protein distribution. These data suggest that lack of CNP in the CNS impairs tight junction protein arrangement and increases BBB permeability, which is associated with changes in locomotor activity, motor coordination and late-onset seizures.

Endogenous Vasoactive Peptides and Vascular Aging-Related Diseases

Vascular aging is a specific type of organic aging that plays a central role in the morbidity and mortality of cardiovascular and cerebrovascular diseases among the elderly. It is essential to develop novel interventions to prevent/delay age-related vascular pathologies by targeting fundamental cellular and molecular aging processes. Endogenous vasoactive peptides are compounds formed by a group of amino acids connected by peptide chains that exert regulatory roles in intercellular interactions involved in a variety of biological and pathological processes. Emerging evidence suggests that a variety of vasoactive peptides play important roles in the occurrence and development of vascular aging and related diseases such as atherosclerosis, hypertension, vascular calcification, abdominal aortic aneurysms, and stroke. This review will summarize the cumulative roles and mechanisms of several important endogenous vasoactive peptides in vascular aging and vascular aging-related diseases. In addition, we also aim to explore the promising diagnostic function as biomarkers and the potential therapeutic application of endogenous vasoactive peptides in vascular aging-related diseases.

The loading of C-type natriuretic peptides improved hemocompatibility and vascular regeneration of electrospun poly(ε-caprolactone) grafts

As a result of thrombosis or intimal hyperplasia, synthetic artificial vascular grafts had a low success rate when they were used to replace small-diameter arteries (inner diameter < 6 mm). C-type natriuretic peptides (CNP) have anti-thrombotic effects, and can promote endothelial cell (EC) proliferation and inhibit vascular smooth muscle cell (SMC) over-growth. In this study, poly(ε-caprolactone) (PCL) vascular grafts loaded with CNP (PCL-CNP) were constructed by electrospinning. The PCL-CNP grafts were able to continuously release CNP at least 25 days in vitro. The results of scanning electron microscopy (SEM) and mechanical testing showed that the loading of CNP did not change the microstructure and mechanical properties of the PCL grafts. In vitro blood compatibility analysis displayed that PCL-CNP grafts could inhibit thrombin activity and reduce platelet adhesion and activation. In vitro cell experiments demonstrated that PCL-CNP grafts activated ERK1/2 and Akt signaling in human umbilical vein endothelial cells (HUVECs), as well as increased cyclin D1 expression, enhanced proliferation and migration, and increased vascular endothelial growth factor (VEGF) secretion and nitric oxide (NO) production. The rabbit arteriovenous (AV)-shunt ex vitro indicated that CNP loading significantly improved the antithrombogenicity of PCL grafts. The assessment of vascular grafts in rat abdominal aorta implantation model displayed that PCL-CNP grafts promoted the regeneration of ECs and contractile SMCs, modulated macrophage polarization toward M2 phenotype, and enhanced extracellular matrix remodeling. These findings confirmed for the first time that loading CNP is an effective approach to improve the hemocompatibility and vascular regeneration of synthetic vascular grafts. STATEMENT OF SIGNIFICANCE: Small-diameter (< 6 mm) vascular grafts (SDVGs) have not been made clinically available due to their prevalence of thrombosis, limited endothelial regeneration and intimal hyperplasia. The incorporation of bioactive molecules into SDVGs serves as an effective solution to improve hemocompatibility and endothelialization. In this study, for the first time, we loaded C-type natriuretic peptides (CNP) into PCL grafts by electrospunning and confirmed the effectiveness of loading CNP on improving the hemocompatibility and vascular regeneration of artificial vascular grafts. Regenerative advantages included enhancement of endothelialization, modulation of macrophage polarization toward M2 phenotypes, and improved contractile smooth muscle cell regeneration. Our investigation brings attention to CNP as a valuable bioactive molecule for modifying cardiovascular biomaterial.

Origin and function of activated fibroblast states during zebrafish heart regeneration

The adult zebrafish heart has a high capacity for regeneration following injury. However, the composition of the regenerative niche has remained largely elusive. Here, we dissected the diversity of activated cell states in the regenerating zebrafish heart based on single-cell transcriptomics and spatiotemporal analysis. We observed the emergence of several transient cell states with fibroblast characteristics following injury, and we outlined the proregenerative function of collagen-12-expressing fibroblasts. To understand the cascade of events leading to heart regeneration, we determined the origin of these cell states by high-throughput lineage tracing. We found that activated fibroblasts were derived from two separate sources: the epicardium and the endocardium. Mechanistically, we determined Wnt signalling as a regulator of the endocardial fibroblast response. In summary, our work identifies specialized activated fibroblast cell states that contribute to heart regeneration, thereby opening up possible approaches to modulating the regenerative capacity of the vertebrate heart.

Single-cell RNA sequencing and spatiotemporal analysis of the regenerating zebrafish heart identify transient proregenerative fibroblast-like cells that are derived from the epicardium and the endocardium. Wnt signalling regulates the endocardial fibroblast response.

CNP, the Third Natriuretic Peptide: Its Biology and Significance to the Cardiovascular System

Simple Summary

CNP is the third natriuretic peptide to be isolated and is widely expressed in the central nervous system, osteochondral system, and vascular system. The receptor that is mainly targeted by CNP is GC-B, which differs from GC-A, the receptor targeted by the other two natriuretic peptides, ANP and BNP. Consequently, the actions of CNP differ somewhat from those of ANP and BNP. Research into the actions of CNP has shown that CNP attenuates cardiac remodeling in animal models of cardiac hypertrophy, myocardial infarction, and myocarditis. Studies examining CNP/GC-B signaling showed that it contributes to the prevention of cardiac stiffness. Endogenous CNP, perhaps acting in part through CNP/NPR-C signaling, contributes to the regulation of vascular function and blood pressure. CNP regulates vascular remodeling and angiogenesis via CNP/GC-B/CGK signaling. CNP attenuates interstitial fibrosis and fibrosis-related gene expression in pressure overload and myocardial infarction models. The clinical application of CNP as a therapeutic agent for cardiovascular diseases is anticipated.

Abstract

The natriuretic peptide family consists of three biologically active peptides: ANP, BNP, and CNP. CNP is more widely expressed than the other two peptides, with significant levels in the central nervous system, osteochondral system, and vascular system. The receptor that is mainly targeted by CNP is GC-B, which differs from GC-A, the receptor targeted by ANP and BNP. Consequently, the actions of CNP differ somewhat from those of ANP and BNP. CNP knockout leads to severe dwarfism, and there has been important research into the role of CNP in the osteochondral system. As a result, a CNP analog is now available for clinical use in patients with achondroplasia. In the cardiovascular system, CNP and its downstream signaling are involved in the regulatory mechanisms underlying myocardial remodeling, cardiac function, vascular tone, angiogenesis, and fibrosis, among others. This review focuses on the roles of CNP in the cardiovascular system and considers its potential for clinical application in the treatment of cardiovascular diseases.

Study of endothelial function and vascular stiffness in patients affected by dilated cardiomyopathy on treatment with sacubitril/valsartan

BACKGROUND

The multiple beneficial effects of sacubitril/valsartan in the treatment of heart failure with reduced ejection fraction are vastly known, but still no or few mentions have been made regarding its effects on endothelial dysfunction and arterial stiffness.

PATIENTS AND METHODS

To understand more deeply if sacubitril/valsartan may have a role on endothelial function and arterial stiffness, 15 patients with dilated cardiomyopathy with reduced left ventricular ejection fraction (LVEF) were evaluated through transthoracic echocardiography, peripheral arterial tonometry (EndoPAT^®) and applanation tonometry (SphygmoCor^® Px system). These noninvasive exams were performed at the beginning of the study and after 6 months of sacubitril/valsartan treatment.

RESULTS

Aortic stiffness parameters didn't differ after 6 months of treatment. Augmentation pressure (P=0.889), augmentation index (P=0.906) and sphygmic wave velocity (P=0.263) increased slightly, but they weren't found to be statistically significant. Systolic, diastolic, and differential central arterial pressure didn't differ at the beginning and at the end of the study. RHI (reactive hyperemia index) increased significantly after 6 months (P=0.001) as well as augmentation index corrected for 75 bpm. Ejection fraction (32.21% ± 5.7 to 38.43% ± 8.4; P=0.010) and diastolic dysfunction degree (P=0.021) improved. There was an improvement in mitral regurgitation that wasn't statistically significant (P=0.116). TAPSE didn't change while pulmonary systolic arterial pressure increased, although not significantly (22.83 mmHg ± 4 to 27.33 mmHg ± 6; P=0.068) and within the normal range values.

CONCLUSIONS

Even though in a study with a limited number of patients, sacubitril/valsartan improved endothelial function, left ventricular function, MR, and diastolic function significantly in patients with dilated cardiomyopathy and reduced LVEF. It showed no effects on vascular stiffness.

Identification of active compounds and molecular mechanisms of Dalbergia tsoi Merr.et Chun to accelerate wound healing

As a traditional Chinese medicine, Dalbergia tsoi Merr.et Chun (JZX) has been used for the treatment of wounds since ancient times. However, the active compounds and molecular mechanisms of JZX in the acceleration of wound healing are still unknown. Herein, we explored the main active compounds and key molecular mechanisms by which JZX accelerates wound healing. The ethanol extract of JZX was subjected to UPLC-Q-Orbitrap HRMS analysis to identify the main compounds. The pharmacological effect of JZX on wound healing was evaluated using a mouse excision wound model. Network pharmacology was utilized to predict the effective compounds and related signal transduction pathways of JZX that were involved in accelerating wound healing. The predicted key signaling pathways were then validated by immunohistochemical analysis. Interactions between the active compounds and therapeutic targets were confirmed by molecular docking analysis. JZX accelerated wound healing, improved tissue quality, and inhibited inflammation and oxidative stress. Moreover, our results suggested that the active components of JZX, such as butin, eriodyctiol, and formononetin, are the key compounds that facilitate wound treatment. Our studies also indicated that JZX accelerated wound healing by regulating the PI3K/Akt signaling pathway and inducing the expression of TGF-β1, FGF2, VEGFA, ECM1, and α-SMA at different stages of skin wound healing. The JZX extract accelerates wound healing by reducing inflammation and inhibiting oxidative stress, regulating the PI3K/Akt signaling pathway, and promoting the expression of growth factors, suggesting that JZX has potential clinical applicability in wound treatment.

C-type natriuretic peptide is a pivotal regulator of metabolic homeostasis

The global mortality, morbidity, and healthcare costs associated with cardiometabolic disease, including obesity, diabetes, hypertension, and dyslipidemia, are substantial and represent an expanding unmet medical need. Herein, we have identified a physiological role for C-type natriuretic peptide (CNP) in regulating key processes, including thermogenesis and adipogenesis, which combine to coordinate metabolic function and prevent the development of cardiometabolic disorders. This protective mechanism, which is in part mediated via an autocrine action of CNP on adipocytes, is underpinned by activation of cognate natriuretic peptide receptors (NPR)-B and NPR-C. This mechanism advances the fundamental understanding of energy homeostasis and glucose handling and offers the promise of improving the treatment of cardiometabolic disease.

Thermogenesis and adipogenesis are tightly regulated mechanisms that maintain lipid homeostasis and energy balance; dysfunction of these critical processes underpins obesity and contributes to cardiometabolic disease. C-type natriuretic peptide (CNP) fulfills a multimodal protective role in the cardiovascular system governing local blood flow, angiogenesis, cardiac function, and immune cell reactivity. Herein, we investigated a parallel, preservative function for CNP in coordinating metabolic homeostasis. Global inducible CNP knockout mice exhibited reduced body weight, higher temperature, lower adiposity, and greater energy expenditure in vivo. This thermogenic phenotype was associated with increased expression of uncoupling protein-1 and preferential lipid utilization by mitochondria, a switch corroborated by a corresponding diminution of insulin secretion and glucose clearance. Complementary studies in isolated murine and human adipocytes revealed that CNP exerts these metabolic regulatory actions by inhibiting sympathetic thermogenic programming via G_i-coupled natriuretic peptide receptor (NPR)-C and reducing peroxisome proliferator-activated receptor-γ coactivator-1α expression, while concomitantly driving adipogenesis via NPR-B/protein kinase-G. Finally, we identified an association between CNP/NPR-C expression and obesity in patient samples. These findings establish a pivotal physiological role for CNP as a metabolic switch to balance energy homeostasis. Pharmacological targeting of these receptors may offer therapeutic utility in the metabolic syndrome and related cardiovascular disorders.

LSD1 downregulates p21 expression in vascular smooth muscle cells and promotes neointima formation

Neointima formation is characterized by the proliferation of vascular smooth muscle cells (VSMC). Although lysine-specific demethylase 1 (LSD1) has critical functions in several diseases, its role in neointima formation remains to be clarified. In this study, we aimed to explore the crucial role of LSD1 on neointima formation using a carotid artery injury model in mice. We observed that aberrant LSD1 expression was increased in human and mouse stenotic arteries and platelet-derived growth factor-BB (PDGF-BB)-treated VSMC. Furthermore, LSD1 knockdown significantly mitigated neointima formation in vivo and inhibited PDGF-BB-induced VSMC proliferation in vitro. We further uncovered that LSD1 overexpression exhibited opposite phenotypes in vivo and in vitro. Finally, LSD1 knockdown inhibited VSMC proliferation by increasing p21 expression, which is associated with LSD1 mediated di-methylated histone H3 on lysine 4 (H3K4me2) modification. Taken together, our data suggest that LSD1 may be a potential therapeutic target for the treatment of neointima formation.

Skeletal muscle derived Musclin protects the heart during pathological overload

Cachexia is associated with poor prognosis in chronic heart failure patients, but the underlying mechanisms of cachexia triggered disease progression remain poorly understood. Here, we investigate whether the dysregulation of myokine expression from wasting skeletal muscle exaggerates heart failure. RNA sequencing from wasting skeletal muscles of mice with heart failure reveals a reduced expression of Ostn, which encodes the secreted myokine Musclin, previously implicated in the enhancement of natriuretic peptide signaling. By generating skeletal muscle specific Ostn knock-out and overexpressing mice, we demonstrate that reduced skeletal muscle Musclin levels exaggerate, while its overexpression in muscle attenuates cardiac dysfunction and myocardial fibrosis during pressure overload. Mechanistically, Musclin enhances the abundance of C-type natriuretic peptide (CNP), thereby promoting cardiomyocyte contractility through protein kinase A and inhibiting fibroblast activation through protein kinase G signaling. Because we also find reduced OSTN expression in skeletal muscle of heart failure patients, augmentation of Musclin might serve as therapeutic strategy.

Role of natriuretic peptides in the cardiovascular-adipose communication: a tale of two organs

Natriuretic peptides have long been known for their cardiovascular function. However, a growing body of evidence emphasizes the role of natriuretic peptides in the energy metabolism of several substrates in humans and animals, thus interrelating the heart, as an endocrine organ, with various insulin-sensitive tissues and organs such as adipose tissue, muscle skeletal, and liver. Adipose tissue dysfunction is associated with altered regulation of the natriuretic peptide system, also indicated as a natriuretic disability. Evidence points to a contribution of this natriuretic disability to the development of obesity, type 2 diabetes mellitus, and cardiometabolic complications; although the causal relationship is not fully understood at present. However, targeting the natriuretic peptide pathway may improve metabolic health in obesity and type 2 diabetes mellitus. This review will focus on the current literature on the metabolic functions of natriuretic peptides with emphasis on lipid metabolism and insulin sensitivity. Natriuretic peptide system alterations could be proposed as one of the linking mechanisms between adipose tissue dysfunction and cardiovascular disease.

Npr2 mutant mice show vasodilation and undeveloped adipocytes in mesentery

Objective

The biological importance for the signaling of C-type natriuretic peptide (CNP) and natriuretic peptide receptor B (NPR-B) has been recognized. However, the details remain unclear and are debatable. The Npr2 is a gene of NPR-B, and we previously reported a unique phenotype of a spontaneous mutant mouse lacking Npr2 (Npr2^slw/slw), such as severe ileus-like disorder with bloodless blood vessels. In this study, we analyzed the bloodless mesenteric vascular morphology of Npr2^slw/slw by histological observation to clarify the effects of the CNP/NPR-B signal deficiency.

Results

Blood vessels in the mesentery were clearly dilated in the preweaning Npr2^slw/slw mice. Additionally, in the Npr2^slw/slw mice, the lacteals were partially dilation or randomly direction mucosal epithelial cells in villi, and mesenteric adipocytes were undeveloped. These findings provide important information for understanding the role of CNP/NPR-B signals on intestine with mesentery.

A Novel Resveratrol Analog Upregulates SIRT1 Expression and Ameliorates Neointima Formation

Neointima formation is a serious complication caused by mechanical trauma to the vessel. (R)-4,6-dimethoxy-3-(4-methoxy phenyl)-2,3-dihydro-1H-indanone [(R)-TML 104] is a synthesized analog of the natural product resveratrol sesquiterpenes (±)-isopaucifloral F. The present study aimed to investigate the effects and underlying mechanisms of (R)-TML104 on neointima formation. Our results showed that (R)-TML104 prevented neointima formation based on a carotid artery injury model in mice. Furthermore, (R)-TML104 inhibited platelet-derived growth factor-BB (PDGF-BB)-induced vascular smooth muscle cells (VSMC) phenotypic transformation, evidenced by increased α-smooth muscle actin, reduced VSMC proliferation, and migration. Simultaneously, (R)-TML104 upregulated sirtuin-1 (SIRT1) expression in VSMC. We further uncovered that SIRT1 expression is critical for the inhibitory effects of (R)-TML104 on PDGF-BB-induced VSMC phenotypic transformation in vitro and injury-induced neointima formation in vivo. Finally, (R)-TML104-upregulated SIRT1 inhibited PDGF-BB-induced VSMC phenotypic transformation by downregulating nicotinamide adenine dinucleotide phosphate oxidase 4 expression via decreasing nuclear factor-κB acetylation. Taken together, these results revealed that (R)-TML104 upregulates SIRT1 expression and ameliorates neointima formation. Therefore, the application of (R)-TML104 may constitute an effective strategy to ameliorate neointima formation.

Functional coordination of non-myocytes plays a key role in adult zebrafish heart regeneration

Cardiac regeneration occurs primarily through proliferation of existing cardiomyocytes, but also involves complex interactions between distinct cardiac cell types including non-cardiomyocytes (non-CMs). However, the subpopulations, distinguishing molecular features, cellular functions, and intercellular interactions of non-CMs in heart regeneration remain largely unexplored. Using the LIGER algorithm, we assemble an atlas of cell states from 61,977 individual non-CM scRNA-seq profiles isolated at multiple time points during regeneration. This analysis reveals extensive non-CM cell diversity, including multiple macrophage (MC), fibroblast (FB), and endothelial cell (EC) subpopulations with unique spatiotemporal distributions, and suggests an important role for MC in inducing the activated FB and EC subpopulations. Indeed, pharmacological perturbation of MC function compromises the induction of the unique FB and EC subpopulations. Furthermore, we developed computational algorithm Topologizer to map the topological relationships and dynamic transitions between functional states. We uncover dynamic transitions between MC functional states and identify factors involved in mRNA processing and transcriptional regulation associated with the transition. Together, our single-cell transcriptomic analysis of non-CMs during cardiac regeneration provides a blueprint for interrogating the molecular and cellular basis of this process.

Sex-specific mortality prediction by pro-C-type natriuretic peptide measurement in a prospective cohort of patients with ST-elevation myocardial infarction

OBJECTIVE

To determine the predictive value of pro-C-type natriuretic peptide (pro-CNP) measurement in plasma sampled on admission from patients presenting with ST-elevation myocardial infarction (STEMI).

DESIGN

Prospective cohort study.

SETTING

Two University Hospitals in Denmark.

PARTICIPANTS

1760 consecutive patients (470 females and 1290 males) with confirmed STEMI.

MAIN OUTCOMES AND MEASURES

The main outcome was all-cause mortality at 1 year after presentation and the primary measure was pro-CNP concentration in plasma at admission in all patients and longitudinal measurements in a consecutive subgroup of 287 patients. A reference population (n=688) defined cut-off values of increased pro-CNP concentrations.

RESULTS

In all patients, an increased pro-CNP concentration was associated with a higher all-cause mortality after 1 year (HR 1.6, 95% CI 1.1 to 2.4, P_logrank=0.009) including an interaction of sex (p=0.03). In separate sex-stratified analyses, female patients showed increased all-cause mortality (HR_{1 year} 2.6, 95% CI 1.5 to 4.6), P_logrank <0.001), whereas no differences were found in male patients (HR_{1 year} 1.1, 95% CI 0.7 to 1.9, P_logrank=0.66). After adjusting for potential risk factors, we found increased pro-CNP concentrations≥the median value to be independently associated with increased risk of mortality in female patients within 1 year (HR per 1 pmol/L increase: 1.04, 95% CI 1.01 to 1.06, p=0.007). Moreover, we found indications of sex differences in pro-CNP concentrations over time (higher pro-CNP in males (4.4, 95% CI -0.28 to 9.1 pmol/L, p=0.07) and interaction of sex and time (p=0.13)), and that hypertension was independently associated with higher pro-CNP (4.5, 95% CI 0.6 to 8.4 pmol/L, p=0.03).

CONCLUSIONS

In female but not male patients presenting with STEMI, high concentrations of pro-CNP (≥median) at admission independently indicate a higher risk of all-cause mortality. The findings are remarkably specific for female patients, suggesting a different vascular phenotype beyond traditional measures of coronary artery flow compared with male patients.

Irisin Enhances Angiogenesis of Mesenchymal Stem Cells to Promote Cardiac Function in Myocardial Infarction via PI3k/Akt Activation

Background and Objectives

With the growing incidence of acute myocardial infarction (MI), angiogenesis is vital for cardiac function post-MI. The role of bone marrow mesenchymal stem cells (BMSCs) in angiogenesis has been previously confirmed. Irisin is considered a potential vector for angiogenesis. The objective of the present study was to investigate the potential role of irisin in the angiogenesis of BMSCs.

Methods and Results

In vivo, irisin-treated BMSCs (BMSCs＋irisin) were transplanted into an MI mouse model. On day 28 post-MI, blood vessel markers were detected, and cardiac function and infarct areas of mice were evaluated. In vitro, paracrine effects were assessed by examining tube formation in human umbilical vein endothelial cells (HUVECs) co-cultured with the BMSCs＋irisin supernatant. The scratch wound-healing assay was performed to evaluate HUVEC migration. Western blotting was performed to determine PI3k/Akt pathway activation in the BMSCs＋irisin group. Transplantation of BMSCs＋irisin promoted greater angiogenesis, resulting in better cardiac function in the MI mouse model than in controls. In the BMSC＋irisin group, HUVECs demonstrated enhanced tube formation and migration. Activation of the PI3k/Akt pathway was found to be involved in mediating the role of irisin in the angiogenesis of BMSCs.

Conclusions

In cardiovascular diseases such as MI, irisin administration can enhance angiogenesis of BMSCs and promote cardiac function via the PI3k/Akt pathway, optimizing the therapeutic effect based on BMSCs transplantation.

C-Type Natriuretic Peptide Ameliorates Vascular Injury and Improves Neurological Outcomes in Neonatal Hypoxic-Ischemic Brain Injury in Mice

C-type natriuretic peptide (CNP) is an important vascular regulator that is present in the brain. Our previous study demonstrated the innate neuroprotectant role of CNP in the neonatal brain after hypoxic-ischemic (HI) insults. In this study, we further explored the role of CNP in cerebrovascular pathology using both in vivo and in vitro models. In a neonatal mouse HI brain injury model, we found that intracerebroventricular administration of recombinant CNP dose-dependently reduces brain infarct size. CNP significantly decreases brain edema and immunoglobulin G (IgG) extravasation into the brain tissue, suggesting a vasculoprotective effect of CNP. Moreover, in primary brain microvascular endothelial cells (BMECs), CNP dose-dependently protects BMEC survival and monolayer integrity against oxygen-glucose deprivation (OGD). The vasculoprotective effect of CNP is mediated by its innate receptors NPR2 and NPR3, in that inhibition of either NPR2 or NPR3 counteracts the protective effect of CNP on IgG leakage after HI insult and BMEC survival under OGD. Of importance, CNP significantly ameliorates brain atrophy and improves neurological deficits after HI insults. Altogether, the present study indicates that recombinant CNP exerts vascular protection in neonatal HI brain injury via its innate receptors, suggesting a potential therapeutic target for the treatment of neonatal HI brain injury.

Angiotensin Receptor Blocker and Neprilysin Inhibitor Suppresses Cardiac Dysfunction by Accelerating Myocardial Angiogenesis in Apolipoprotein E-Knockout Mice Fed a High-Fat Diet

Materials and Methods

Male apolipoprotein E-knockout mice fed a high-fat diet were divided into control (CTL), valsartan (30 mg/kg) (VAL), sacubitril (30 mg/kg) (SAC), and valsartan plus sacubitril (30 mg/kg each) (VAL/SAC) groups after 4 weeks of prefeeding and were subsequently treated for 12 weeks.

Results

The VAL/SAC group exhibited significantly higher serum brain natriuretic peptide levels; more subtle changes in left ventricular systolic diameter, fractional shortening, and ejection fraction, and significantly higher expression levels of natriuretic peptide precursor B and markers of angiogenesis, including clusters of differentiation 34, vascular endothelial growth factor A, and monocyte chemotactic protein 1, than the CTL group.

Conclusions

Valsartan plus sacubitril preserved left ventricular systolic function in apolipoprotein E-knockout mice fed a high-fat diet. This result suggests that myocardial angiogenic factors induced by ARNI might provide cardioprotective effects.

Small extracellular vesicles containing miR-486-5p promote angiogenesis after myocardial infarction in mice and nonhuman primates

Stem cell-derived small extracellular vesicles (sEVs) promote angiogenesis after myocardial infarction (MI). However, the components of sEVs that contribute to these effects and the safety and efficiency of engineered sEV treatment for MI remain unresolved. Here, we observed improved cardiac function, enhanced vascular density, and smaller infarct size in mice treated with the sEVs from hypoxia-preconditioned (HP) mesenchymal stem cells (MSCs) (HP-sEVs) than in mice treated with normoxia-preconditioned (N) MSCs (N-sEVs). MicroRNA profiling revealed a higher abundance of miR-486-5p in HP-sEVs than in N-sEVs, and miR-486-5p inactivation abolished the benefit of HP-sEV treatment, whereas miR-486-5p up-regulation enhanced the benefit of N-sEV treatment. Matrix metalloproteinase 19 (MMP19) abundance was lower in HP-sEV-treated than N-sEV-treated mouse hearts but was enriched in cardiac fibroblasts (CFs), and Mmp19 was identified as one of the target genes of miR-486-5p. Conditioned medium from CFs that overexpressed miR-486-5p or silenced MMP19 increased the angiogenic activity of endothelial cells; however, medium from CFs that simultaneously overexpressed Mmp19 and miR-486-5p abolished this effect. Mmp19 silencing in CFs reduced the cleavage of extracellular vascular endothelial growth factor (VEGF). Furthermore, miR-486-5p-overexpressing N-sEV treatment promoted angiogenesis and cardiac recovery without increasing arrhythmia complications in a nonhuman primate (NHP) MI model. Collectively, this study highlights the key role of sEV miR-486-5p in promoting cardiac angiogenesis via fibroblastic MMP19-VEGFA cleavage signaling. Delivery of miR-486-5p-engineered sEVs safely enhanced angiogenesis and cardiac function in an NHP MI model and may promote cardiac repair.

The cGMP system: components and function

The cyclic guanosine monophosphate (cGMP) signaling system is one of the most prominent regulators of a variety of physiological and pathophysiological processes in many mammalian and non-mammalian tissues. Targeting this pathway by increasing cGMP levels has been a very successful approach in pharmacology as shown for nitrates, phosphodiesterase (PDE) inhibitors and stimulators of nitric oxide-guanylyl cyclase (NO-GC) and particulate GC (pGC). This is an introductory review to the cGMP signaling system intended to introduce those readers to this system, who do not work in this area. This article does not intend an in-depth review of this system. Signal transduction by cGMP is controlled by the generating enzymes GCs, the degrading enzymes PDEs and the cGMP-regulated enzymes cyclic nucleotide-gated ion channels, cGMP-dependent protein kinases and cGMP-regulated PDEs. Part A gives a very concise introduction to the components. Part B gives a very concise introduction to the functions modulated by cGMP. The article cites many recent reviews for those who want a deeper insight.

Renal Natriuretic Peptide Receptor-C Deficiency Attenuates NaCl Cotransporter Activity in Angiotensin II-Induced Hypertension

Genome-wide association studies have identified that NPR-C (natriuretic peptide receptor-C) variants are associated with elevation of blood pressure. However, the mechanism underlying the relationship between NPR-C and blood pressure regulation remains elusive. Here, we investigate whether NPR-C regulates Ang II (angiotensin II)-induced hypertension through sodium transporters activity. Wild-type mice responded to continuous Ang II infusion with an increased renal NPR-C expression. Global NPR-C deficiency attenuated Ang II-induced increased blood pressure both in male and female mice associated with more diuretic and natriuretic responses to a saline challenge. Interestingly, Ang II increased both total and phosphorylation of NCC (NaCl cotransporter) abundance involving in activation of WNK4 (with-no-lysine kinase 4)/SPAK (Ste20-related proline/alanine-rich kinase) which was blunted by NPR-C deletion. NCC inhibitor, hydrochlorothiazide, failed to induce natriuresis in NPR-C knockout mice. Moreover, low-salt and high-salt diets-induced changes of total and phosphorylation of NCC expression were normalized by NPR-C deletion. Importantly, tubule-specific deletion of NPR-C also attenuated Ang II-induced elevated blood pressure, total and phosphorylation of NCC expression. Mechanistically, in distal convoluted tubule cells, Ang II dose and time-dependently upregulated WNK4/SPAK/NCC kinase pathway and NPR-C/Gi/PLC/PKC signaling pathway mediated NCC activation. These results demonstrate that NPR-C signaling regulates NCC function contributing to sodium retention-mediated elevated blood pressure, which suggests that NPR-C is a promising candidate for the treatment of sodium retention-related hypertension.

Shexiang Baoxin Pill Attenuates Ischemic Injury by Promoting Angiogenesis by Activation of Aldehyde Dehydrogenase 2

ABSTRACT

Promoting angiogenesis is a critical treatment strategy for ischemic cardiovascular diseases. Shexiang Baoxin Pill (SBP), a traditional Chinese medicine, has been reported to be capable of relieving angina and improve heart function by promoting angiogenesis. The aim of this study was to determine the role of mitochondrial aldehyde dehydrogenase 2 (ALDH2) in SBP-induced angiogenesis. Left femoral artery ligation was performed in wild-type mice (WT) and ALDH2 knockout mice, which were administrated with SBP (20 mg/kg/d) or equal volume saline per day by gastric gavage for 2 weeks. Perfusion recovery, angiogenesis in chronic hind limb ischemia, was significantly improved in the WT + SBP group than in the WT group. However, these beneficial effects were absent in ALDH2 knockout mice. In vitro, hypoxia impaired the ability of proliferation, migration and tube formation, sprouting angiogenesis, and promoted apoptosis in cardiovascular microvascular endothelial cells, whereas the hypoxia damage was restored by SBP. The protective effect of SBP was remarkably weakened by ALDH2 knockdown. Furthermore, SBP suppressed hypoxia-induced ALDH2/protein kinase B (AKT)/mammalian target of rapamycin pathways. In conclusion, this study demonstrated that SBP protected lower limb from ischemia injury through the ALDH2-dependent pathway. The protective mechanism of SBP in cardiovascular microvascular endothelial cells was partly mediated through ALDH2/AKT/mammalian target of rapamycin pathways.

C-type natriuretic peptide-induced relaxation through cGMP-dependent protein kinase and SERCA activation is impaired in two kidney-one clip rat aorta

AIMS

Hypertension underlies endothelial dysfunction, and activation of vasorelaxation signaling with low dependence on nitric oxide (NO) represents a good alternative for vascular modulation. C-type natriuretic peptide (CNP) causes relaxation by increasing cyclic guanosine 3',5'-monophosphate (cGMP) or Gi-protein activation through its natriuretic peptide receptor-B or -C, respectively. We have hypothesized that CNP could exerts its effects and could overcome endothelial dysfunction in two kidney-one clip (2K-1C) hypertensive rat aorta. Here, we investigate the intracellular signaling involved in CNP effects in hypertension.

MATERIALS AND METHODS

The 2K-1C hypertension was induced in male Wistar rats (200 g). CNP-induced vascular relaxation and cGMP production were investigated in rat thoracic aortas. The natriuretic peptide receptor-B and -C localization was evaluated by immunofluorescence. Calcium mobilization was assessed in endothelial cells from rat aortas.

KEY FINDINGS

CNP induced similar relaxation in normotensive and 2K-1C hypertensive rat aortas, which increased after endothelium removal. CNP-induced relaxation involved natriuretic peptide receptor-B and -C activation in 2K-1C rats. Nitric oxide synthase (NOS) and soluble guanylyl cyclase (sGC) counter-regulated CNP-particulate GC (pGC) activation in aortas. CNP reduced endothelial calcium and increased cGMP production, which was lower in 2K-1C. CNP-induced cGMP-dependent protein kinase (PKG) and sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase (SERCA) activation was impaired in 2K-1C rat aorta.

SIGNIFICANCE

Our results indicated CNP triggered relaxation through its natriuretic peptide receptor-B and -C in 2K-1C rat aortas, and that CNP-induced relaxation overcomes endothelial dysfunction in hypertension. In addition, NOS and sGC activities counter-regulate CNP-pGC activation to induce vascular relaxation.