Soluble guanylate cyclase as an emerging therapeutic target in cardiopulmonary disease

Discovery of the first isoform-specific sGC activator: Selective activation of GC-1 by runcaciguat

Drug research and development programmes targeting soluble guanylyl cyclase (sGC) have been highly successful, leading to the launch of the sGC stimulators riociguat for pulmonary hypertension (2013) and vericiguat for chronic heart failure (2021). As the main receptor for nitric oxide, sGC plays a vital role in various physiological processes. It consists of an alpha and a beta subunit, with two distinct isoforms identified in humans: GC-1 (α1/β1) and GC-2 (α2/β1). Growing evidence indicates that these isoforms engage in different downstream signalling pathways, indicating that isoform-specific approaches could lead to novel therapeutic opportunities and reduce potential side effects. In this study, we performed concentration-response measurements with the sGC activators BAY 60-2770, BI 703704 and runcaciguat (BAY 1101042) in cell systems expressing each isoform and in purified enzymes. We found that runcaciguat selectively activated GC-1, while acting as a competitive antagonist to other activators in GC-2, without interfering with nitric oxide. BAY 60-2770 and BI 703704 activated both isoforms, albeit with varying efficacy. Our findings challenge the historical view that the two sGC isoforms are functionally indistinguishable. In fact, we demonstrate that the isoforms can be activated independently, highlighting their distinct functional profiles. Notably, runcaciguat is the first sGC activator identified to selectively target GC-1 at therapeutic concentrations. This selective targeting of isoforms not only opens avenues for new therapeutic strategies but also provides an alternative to knockout animal models for investigating isoform-specific functions.

The soluble guanylate cyclase (sGC) stimulator vericiguat inhibits platelet activation and thrombosis

BACKGROUND

Vericiguat, a soluble guanylate cyclase (sGC) stimulator, is used to treat chronic heart failure. Vericiguat can directly bind to the sGC in the absence of NO or stabilize the binding of NO to sGC, thereby stimulating cGMP production. Vericiguat correlates closely with the platelet activation. However, the precise effect of vericiguat on platelet activation and thrombosis in vivo remains to be elucidated.

METHODS

We investigated the effects of vericiguat on agonist-induced platelet aggregation, secretion, integrin αIIbβ3 activation, spreading, clot retraction, and thrombus formation in vivo, elucidating the underlying mechanisms. Additionally, we performed whole blood aggregometry and Microfluidic whole-blood perfusion assay to determine whether vericiguat could alleviate thrombosis.

RESULTS

Vericiguat concentration-dependently inhibited aggregation and ATP release induced by agonists both in human and mouse platelets. P-selection expression, integrin αIIbβ3 activation, spreading, and clot retraction induced by thrombin were all inhibited by vericiguat. Mechanistically, vericiguat bound to the sGC in platelets, avtivating the cGMP/PKG signaling pathway to inhibit the platelet. Vericiguat also inhibited the FeCl3-injured thrombus formation in mesenteric arterioles in wild-type (WT) mice and pulmonary vascular thrombi after constructing the pulmonary embolism model. Oral administration of vericiguat for 2 weeks attenuated thromboembolism in brain, too.

CONCLUSION

Vericiguat directly inhibits platelet activation and thrombosis in vivo by binding to the sGC and activating cGMP/PKG pathway. In addition to the treatment for chronic heart failure, it may have therapeutic advantages in treating thrombotic diseases.

Advances and future outlook in clinical trials for treating systemic sclerosis-interstitial lung disease

INTRODUCTION

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is a common complication of systemic sclerosis (SSc), contributing significantly to morbidity and mortality. We aim to bridge knowledge gaps, inform clinical practice, and identify future research directions in this rapidly evolving field.

AREAS COVERED

This review provides a comprehensive analysis of the current understanding and emerging advances in the diagnosis, risk stratification, and treatment of SSc-ILD. High-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) remain cornerstones of diagnosis, but limitations in sensitivity underscore the need for biomarkers such as Chemokine (C-C motif) Ligand 18 (CCL18), Krebs von den Lungen-6 (KL-6), Interleukin-6 (IL-6), and C-reactive protein (CRP) to enhance prognostic precision and treatment personalization. Therapeutic strategies emphasize immunosuppressants alongside antifibrotic agents. Emerging combination therapies and advanced modalities, including hematopoietic stem cell transplantation and chimeric antigen receptor T-cell therapy, show promise in refractory cases. Ongoing clinical trials exploring innovative targets highlight the evolving therapeutic landscape. The review emphasizes challenges in clinical trial design, advocating for adaptive and platform trial methodologies to address disease heterogeneity and enhance treatment sensitivity.

EXPERT OPINION

Advances in biomarkers, composite indices, and personalized therapeutic approaches are key to overcoming existing limitations and improving outcomes for patients with SSc-ILD.

In the Era of Cardiovascular-Kidney-Metabolic Syndrome in Cardio-Oncology: From Pathogenesis to Prevention and Therapy

Cardiovascular-kidney-metabolic (CKM) syndrome represents a complex interplay between cardiovascular disease (CVD), chronic kidney disease (CKD), and metabolic disorders, significantly impacting cancer patients. The presence of CKM syndrome in cancer patients not only worsens their prognosis but also increases the risk of major adverse cardiovascular events (MACE), reduces quality of life (QoL), and affects overall survival (OS). Furthermore, several anticancer therapies, including anthracyclines, tyrosine kinase inhibitors, immune checkpoint inhibitors, and hormonal treatments, can exacerbate CKM syndrome by inducing cardiotoxicity, nephrotoxicity, and metabolic dysregulation. This review explores the pathophysiology of CKM syndrome in cancer patients and highlights emerging therapeutic strategies to mitigate its impact. We discuss the role of novel pharmacological interventions, including sodium-glucose cotransporter-2 inhibitors (SGLT2i), proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), and soluble guanylate cyclase (sGC) activators, as well as dietary and lifestyle interventions. Optimizing the management of CKM syndrome in cancer patients is crucial to improving OS, enhancing QoL, and reducing MACE. By integrating cardiometabolic therapies into oncologic care, we can create a more comprehensive treatment approach that reduces the burden of cardiovascular and renal complications in this vulnerable population. Further research is needed to establish personalized strategies for CKM syndrome prevention and treatment in cancer patients.

Short-term outpatient follow-up of vericiguat treatment in patients hospitalized for heart failure

Background

Vericiguat-a novel oral soluble guanylate cyclase stimulator-was developed for the treatment of chronic heart failure (HF). Although the value of vericiguat therapy in chronic HF has been gradually recognized, its safety and efficacy in the acute phase of HF remain elusive.

Methods

100 patients with acute HF receiving vericiguat therapy at the China-Japan Union Hospital of Jilin University between September 2022 and June 2023 were retrospectively analyzed. An external control was built from real-world data of acute HF subjects contemporaneously hospitalized in the same hospital using a propensity score matching (PSM) method.

Results

After a median follow-up of 68 days, 80 patients completed at least one outpatient follow-up or had an endpoint event and cardiovascular death occurred in 6 patients. We matched 75 external control patients for this purpose. In single-arm study, overall, although systolic blood pressure (SBP) decreased significantly before and after treatment, there was little change in SBP in the SBP low group (baseline SBP less than 120mmHg) (from 109 mmHg to 105 mmHg, p = 0.109). Estimated glomerular filtration rate (eGFR) and serum potassium did not change significantly (p = 0.521 and 0.070, respectively). However, compared with the renal function normal group, eGFR showed a slower downward trend in the renal insufficiency group (p = 0.025). After using the PSM method, significant improvements in left ventricular ejection fraction and N-terminal pro-B-type natriuretic peptide were seen in both groups before and after treatment. There was no significant difference between the two groups. However, the downward trend in eGFR was even less significant in the vericiguat group, with significant differences between the two groups (p = 0.024).

Conclusions

Vericiguat is feasible in acute HF, even in patients with hypotension and renal dysfunction. At the same time, vericiguat may have a potential renoprotective effect, which warrants further exploration.

Nitric oxide: Potential therapeutic target in Heat Stress-induced Multiple Organ Dysfunction

As climate change intensifies, urgent action is needed to address global warming and its associated health risks, particularly in vulnerable regions. Rising global temperature and increasing frequency of heatwaves present a hidden health risk, disrupting the body's temperature regulation and leading to severe consequences such as heat stress-induced multiple organ dysfunction (HS-MOD). Multiple organ injury triggered by heat stress involves complex molecular pathways such as nitric oxide dysregulation, inflammation, oxidative stress, mitochondrial dysfunction, calcium homeostasis disruption, and autophagy impairment that contribute to cellular damage. Understanding these molecular pathways is crucial for developing targeted therapeutic interventions to alleviate the impact of heat stress (HS). As we explore numerous therapeutic strategies, a remarkable molecule captures our attention: nitric oxide (NO). This colorless gas, mainly produced by nitric oxide synthase (NOS) enzymes, plays crucial roles in various body functions. From promoting vasodilation and neurotransmission to regulating the immune response, platelet function, cell signaling, and reproductive health, NO stands out for its versatility. Exploring it as a promising treatment for heat stress-induced multiple organ injury highlights its distinctive features in the journey towards effective therapeutic interventions. This involves exploring both pharmacological avenues, considering the use of NO donors and antioxidants, and non-pharmacological strategies, such as adopting nitrate-rich diets and engaging in exercise regimens. This review highlights the concept of heat stress, the molecular framework of the disease, and treatment options based upon some new interventions.

Vericiguat prevents high glucose-mediated impaired vascular smooth muscle cGMP production and vasorelaxation

Normal endothelial cell dependent vascular smooth muscle cell function is mediated by nitric oxide (NO), which stimulates soluble guanylyl cyclase (sGC) production of the second messenger cyclic guanosine monophosphate (cGMP) leading to increased protein kinase G (PKG) activity and vascular smooth muscle relaxation. NO bioavailability is impaired in high glucose (HG). We tested the hypothesis that the sGC sensitizer vericiguat reverses HG-mediated decreased sGC activity in two experimental models, human aortic vascular smooth muscle cells (HVSMCs) and isolated mouse aortic rings. HVSMCs were exposed to normal glucose (NG) or to HG with or without 1 μm vericiguat for 24 h and cGMP and PKG activity were measured. Murine aortic rings were incubated in NG or HG for 24 h. Following incubation, the aortic rings were placed in an organ chamber bath containing the same NG or HG concentration used during the incubation. Dose-response curves to increasing concentrations of acetylcholine (ACh) and sodium nitroprusside were constructed for four groups: control (NG), NG + vericiguat, HG, and HG + vericiguat. As compared with the results in the NG group, cGMP production and PKG activity were significantly impaired in the HG cells incubated without, but not in those incubated with, vericiguat. In isolated aortic rings, ACh-mediated relaxation was impaired following treatment with HG, but not when a HG group was treated with vericiguat. The findings suggest clinical studies are warranted to investigate the potential of sGC sensitization as a therapeutic intervention to improve vascular NO-cGMP signaling endothelium -dependent function that is impaired in HG settings such as diabetes and the metabolic syndrome.

[MD, Doctor of Medical Science, Head of the Department of Pulmonary Hypertension and Heart Diseases, Myasnikov Clinical Cardiology Institute]

The review addresses principal approaches to intensifying therapy in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). The position of Russian experts on the strategy of switching within one class of PAH-specific therapy is presented. Particular attention is paid to the strategy of therapy optimization in the form of replacing phosphodiesterase type 5 inhibitors with a stimulator of soluble guanylate cyclase (riociguat) in patients with PAH and inoperable/residual CTEPH who cannot not achieve treatment goals on phosphodiesterase type 5 inhibitors. The authors analyzed and identified the criteria justifying the choice of a specific therapy strategy in favor of switching from a phosphodiesterase type 5 inhibitor to riociguat.

Soluble guanylyl cyclase stimulators and activators: Promising drugs for the treatment of hypertension?

Nitric oxide (NO)-stimulated cyclic guanosine monophosphate (cGMP) is a key regulator of cardiovascular health, as NO-cGMP signalling is impaired in diseases like pulmonary hypertension, heart failure and chronic kidney disease. The development of NO-independent sGC stimulators and activators provide a novel therapeutic option to restore altered NO signalling. sGC stimulators have been already approved for the treatment of pulmonary arterial hypertension (PAH), chronic thromboembolic pulmonary hypertension (CTEPH), and chronic heart failure (HFrEF), while sGC activators are currently in phase-2 clinical trials for CKD. The best characterized effect of increased cGMP via the NO-sGC-cGMP pathway is vasodilation. However, to date, none of the sGC agonists are in development for hypertension (HTN). According to WHO, the global prevalence of uncontrolled HTN continues to rise, contributing significantly to cardiovascular mortality. While there are effective antihypertensive treatments, many patients require multiple drugs, and some remain resistant to all therapies. Thus, in addition to improved diagnosis and lifestyle changes, new pharmacological strategies remain in high demand. In this review we explore the potential of sGC stimulators and activators as novel antihypertensive agents, starting with the overview of NO-sGC-cGMP signalling, followed by potential mechanisms by which the increase in cGMP may regulate vascular tone and BP. These effects may encompass not only acute vasodilation, but also mid-term and chronic effects, such as the regulation of salt and water balance, as well as mitigation of vascular ageing and remodelling. The main section summarizes the preclinical and clinical evidence supporting the BP-lowering efficacy of sGC agonists.

Stimulating Soluble Guanylyl Cyclase with the Clinical Agonist Riociguat Restrains the Development and Progression of Castration-Resistant Prostate Cancer

Castration-resistant prostate cancer (CRPC) is incurable and fatal, making prostate cancer the second leading cancer-related cause of death for American men. CRPC results from therapeutic resistance to standard-of-care androgen deprivation (AD) treatments, through incompletely understood molecular mechanisms, and lacks durable therapeutic options. In this study, we identified enhanced soluble guanylyl cyclase (sGC) signaling as a mechanism that restrains CRPC initiation and growth. Patients with aggressive, fatal CRPC exhibited significantly lower serum levels of the sGC catalytic product cyclic GMP (cGMP) compared with the castration-sensitive stage. In emergent castration-resistant cells isolated from castration-sensitive prostate cancer populations, the obligate sGC heterodimer was repressed via methylation of its β subunit. Genetically abrogating sGC complex formation in castration-sensitive prostate cancer cells promoted evasion of AD-induced senescence and concomitant castration-resistant tumor growth. In established castration-resistant cells, the sGC complex was present but in a reversibly oxidized and inactive state. Subjecting CRPC cells to AD regenerated the functional complex, and cotreatment with riociguat, an FDA-approved sGC agonist, evoked redox stress-induced apoptosis. Riociguat decreased castration-resistant tumor growth and increased apoptotic markers, with elevated cGMP levels correlating significantly with lower tumor burden. Riociguat treatment reorganized the tumor vasculature and eliminated hypoxic tumor niches, decreasing CD44+ tumor progenitor cells and increasing the radiosensitivity of castration-resistant tumors. Thus, this study showed that enhancing sGC activity can inhibit CRPC emergence and progression through tumor cell-intrinsic and extrinsic effects. Riociguat can be repurposed to overcome CRPC, with noninvasive monitoring of cGMP levels as a marker for on-target efficacy. Significance: Soluble guanylyl cyclase signaling inhibits castration-resistant prostate cancer emergence and can be stimulated with FDA-approved riociguat to resensitize resistant tumors to androgen deprivation, providing a strategy to prevent and treat castration resistance.

Shifting Paradigms in the Management of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a long-term condition characterised by increased resistance to blood flow in the pulmonary circulation. The disease has a progressive course and is associated with a poor prognosis. Without treatment, PAH is associated with mortality in <3 years. Over the past decade, many advances have been made in revising the haemodynamic definition, clinical classification, risk calculation score, treatment options etc. Suggestions from the Sixth World Symposium on Pulmonary Hypertension were incorporated into a literature review that was included in the European Society of Cardiology/European Respiratory Society (ESC/ERS)'s most recent iteration of their guidelines in 2022. The traditional cut-off for pulmonary hypertension (PH), i.e., mean pulmonary artery pressure (mPAP) >25 mm Hg, has been challenged by observational cohort studies, which have shown poor outcomes for values of 21-24 mmHg; the new consensus is that PH is defined at mPAP >20 mm Hg. Although the gold standard for diagnosis and the major source of therapy guidance continues to be right cardiac catheterisation, echocardiography remains the initial test of choice. A multidisciplinary approach is highly recommended when treating PH patients and careful evaluation of patients will aid in proper diagnosis and prognosis. Pharmacotherapy for PAH has seen a paradigm shift with the successful use of newer agents in more extensive, longer and more inclusive trials driven by hard endpoints. Macitentan, selexipag and riociguat are three oral agents that have shown astounding success in PAH randomised studies in the past decade. Upfront combination therapy with two agents is now becoming the norm (following the AMBITION, OPTIMA and ITALY trials) and the momentum is shifting towards triple therapy as for essential hypertension. More recently, inhaled treprostinil was shown to improve exercise capacity in PH associated with interstitial lung disease in the phase III INCREASE study and has been granted regulatory approval for World Health Organization group 3 PH. A new class of drug, sotatercept (a tumour growth factor-β signalling inhibitor), has also been recently approved by the Food and Drug Administration for management of PAH based on positive results from the phase III STELLAR study. Pulmonary artery denervation and balloon pulmonary angioplasty have emerged as viable alternatives in PH that are resistant to drug therapy. This article aims to summarise the key changes and recent advances in diagnosis and managing PH in general, with an emphasis on certain subgroups.

The need for inhaled phosphodiesterase inhibitors in chronic obstructive pulmonary disease

INTRODUCTION

The therapeutic implications of phosphodiesterase (PDE) inhibitors have attracted interest because PDEs are regarded as an intracellular target to be exploited for therapeutic advancements in the treatment of COPD. At present, the only approved approach for the treatment of COPD with PDE inhibitors is the use of an oral PDE4 inhibitor. However, this treatment is not widely employed, primarily due to the narrow therapeutic index associated with oral PDE4 inhibitors, which significantly limits the tolerable dose. The inhalation route represents a viable alternative to the oral route for improving the therapeutic index of PDE4 inhibitors.

AREAS COVERED

The development of inhaled PDE4 inhibitors, with a focus on tanimilast and ensifentrine, the latter of which is a dual PDE3/PDE4 inhibitor.

EXPERT OPINION

The inhalation route offers several advantages regarding the delivery of PDE inhibitors for the management of COPD. Tanimilast and ensifentrine have been shown to improve lung function, reduce exacerbations and enhance quality of life in COPD patients. However, it has not yet been determined which type of COPD patient might benefit more from inhaled PDE4 inhibitors, and it remains unclear whether concomitant inhibition of PDE3 and PDE4 confers a significant benefit compared to blocking PDE4 alone in COPD.

Complement Immune System in Pulmonary Hypertension-Cooperating Roles of Circadian Rhythmicity in Complement-Mediated Vascular Pathology

Originally discovered in the 1890s, the complement system has traditionally been viewed as a "compliment" to the body's innate and adaptive immune response. However, emerging data have shown that the complement system is a much more complex mechanism within the body involved in regulating inflammation, gene transcription, attraction of macrophages, and many more processes. Sustained complement activation contributes to autoimmunity and chronic inflammation. Pulmonary hypertension is a disease with a poor prognosis and an average life expectancy of 2-3 years that leads to vascular remodeling of the pulmonary arteries; the pulmonary arteries are essential to host homeostasis, as they divert deoxygenated blood from the right ventricle of the heart to the lungs for gas exchange. This review focuses on direct links between the complement system's involvement in pulmonary hypertension, along with autoimmune conditions, and the reliance on the complement system for vascular remodeling processes of the pulmonary artery. Furthermore, circadian rhythmicity is highlighted as the disrupted homeostatic mechanism in the inflammatory consequences in the vascular remodeling within the pulmonary arteries, which could potentially open new therapeutic cues. The current treatment options for pulmonary hypertension are discussed with clinical trials using complement inhibitors and potential therapeutic targets that impact immune cell functions and complement activation, which could alleviate symptoms and block the progression of the disease. Further research on complement's involvement in interstitial lung diseases and pulmonary hypertension could prove beneficial for our understanding of these various diseases and potential treatment options to prevent vascular remodeling of the pulmonary arteries.

Modified Zhenwu Decoction improved intestinal barrier function of experimental colitis through activation of sGC-mediated cGMP/PKG signaling

BACKGROUND

The invasion of luminal antigens and an aberrant immune response resulting from a disrupted physical epithelial barrier are the key characteristics of ulcerative colitis (UC). The restoration of damaged epithelial function is crucial for maintaining mucosal homeostasis and disease quiescence. Current therapies for UC primarily focus on suppressing inflammation. However, most patients fail to respond to therapy or develop secondary resistance over time, emphasizing the need to develop novel therapeutic targets for UC. Our study aimed to identify the potential targets of a novel modified herbal formula from the Zhen Wu Decoction, namely CDD-2103, which has demonstrated promising efficacy in treating chronic colitis.

METHODS

The effect of CDD-2103 on epithelial barrier function was examined using in vitro and ex vivo models of tissue injury, as well as a chronic colitis C57BL/6 mouse model. Transcriptomic analysis was employed to profile gene expression changes in colonic tissues following treatment with CDD-2103.

RESULTS

Our in vivo experiments demonstrated that CDD-2103 dose-dependently reduced disease severity in mice with chronic colitis. The efficacy of CDD-2103 was mediated by a reduction in goblet cell loss and the enhancement of tight junction protein integrity. Mechanistically, CDD-2103 suppressed epithelial cell apoptosis and tight junction protein breakdown by activating the soluble guanynyl cyclase (sGC)-mediated cyclic guanosine monophosphate (cGMP)/PKG signaling cascade. Molecular docking analysis revealed strong sGC ligand recognition by the CDD-2103-derived molecules, warranting further investigation.

CONCLUSION

Our study revealed a novel formulation CDD-2103 that restores intestinal barrier function through the activation of sGC-regulated cGMP/PKG signaling. Furthermore, our findings suggest that targeting sGC can be an effective approach for promoting mucosal healing in the management of UC.

Pharmacological management of heart failure: a patient-centred approach

INTRODUCTION

Heart failure (HF) is a global health challenge that requires a multidisciplinary approach. Despite recent advances in pharmacological and interventional therapy, morbidity and mortality in these patients remain high. For this reason, and because of its interplay with other cardiovascular and non-cardiovascular diseases, HF represents a major area of research, with new trials being published every year and international guidelines constantly updated.

AREAS COVERED

The authors review the current status and possible future developments in HF pharmacotherapy.

EXPERT OPINION

The treatment of HF has made significant advances in recent years, and the current recommendations are based on large outcome trials. This has led to significant reductions in both mortality and morbidity, but the death rate remains unacceptably high. In this context, a patient-centered approach that considers comorbidities and specific clinical scenarios when dosing HF medication is essential. Prevention of hospital admissions for cardiac decompensation is of utmost importance in patients with HF as is the enablement of activities of daily living, an endpoint which has only recently been incorporated into major HF trials.

Soluble GC stimulators and activators: Past, present and future

The discovery of soluble GC (sGC) stimulators and sGC activators provided valuable tools to elucidate NO-sGC signalling and opened novel pharmacological opportunities for cardiovascular indications and beyond. The first-in-class sGC stimulator riociguat was approved for pulmonary hypertension in 2013 and vericiguat very recently for heart failure. sGC stimulators enhance sGC activity independent of NO and also act synergistically with endogenous NO. The sGC activators specifically bind to, and activate, the oxidised haem-free form of sGC. Substantial research efforts improved on the first-generation sGC activators such as cinaciguat, culminating in the discovery of runcaciguat, currently in clinical Phase II trials for chronic kidney disease and diabetic retinopathy. Here, we highlight the discovery and development of sGC stimulators and sGC activators, their unique modes of action, their preclinical characteristics and the clinical studies. In the future, we expect to see more sGC agonists in new indications, reflecting their unique therapeutic potential.

Comparison of sGC activator and sGC stimulator in 5/6 nephrectomized rats on high-salt-diet

Introduction

Soluble guanylate cyclase (sGC) stimulators and activators are known to enhance kidney function in various models of chronic kidney disease (CKD) by increasing cyclic guanosine monophosphate (cGMP). Their differential effects on CKD progression, particularly under conditions of oxidative stress, remain unexplored by direct comparative studies.

Methods

We conducted a side-by-side comparison using 5/6 nephrectomized rats on a high salt diet (5/6Nx+HSD) to evaluate the efficacy of the sGC stimulator BAY 41-8543 and the sGC activator BAY 60-2770 in CKD progression. BAY 41-8543 (1 mg/kg; twice daily) and BAY 60-2770 (1 mg/kg; once daily) were administered by gavage for 11 weeks.

Results

The 5/6Nx+HSD model led to increased plasma creatinine, proteinuria, and blood pressure. Both BAY 41-8543 and BAY 60-2770 significantly reduced systolic and diastolic blood pressure to a similar extent but did not improve renal function parameters. Notably, BAY 60-2770 reduced renal fibrosis, including interstitial fibrosis and glomerulosclerosis, whereas BAY 41-8543 did not. These antifibrotic effects of BAY 60-2770 were independent of blood pressure reduction. Proteomic analysis revealed that BAY 60-2770 corrected the upregulation of 9 proteins associated with apoptosis and fibrosis, including Caspase-3, MKK6 (Mitogen-Activated Protein Kinase Kinase 6), Prdx5 (Peroxiredoxin-5), in the 5/6Nx+HSD group.

Discussion

In contrast, BAY 41-8543 had no significant impact on these proteins. sGC activators were more effective than sGC stimulators in reducing renal fibrosis in 5/6 nephrectomized rats on a high salt diet, and this effect was due to modulation of apoptosis-associated proteins beyond the control of blood pressure.

The influence of paraventricular nucleus of the hypothalamus soluble guanylate cyclase on autonomic and neuroendocrine responses to acute restraint stress in rats

The paraventricular nucleus of the hypothalamus (PVN) regulates physiological and behavioural responses evoked by stressful stimuli, but the local neurochemical and signalling mechanisms involved are not completely understood. The soluble guanylate cyclase (sGC) within the PVN is implicated in autonomic and cardiovascular control in rodents under resting conditions. However, the involvement of PVN sGC-mediated signalling in stress responses is unknown. Therefore, we investigated the role of sGC within the PVN in cardiovascular, autonomic, neuroendocrine, and local neuronal responses to acute restraint stress in rats. Bilateral microinjection of the selective sGC inhibitor ODQ (1 nmol/100 nl) into the PVN reduced both the increased arterial pressure and the drop in cutaneous tail temperature evoked by restraint stress, while the tachycardia was enhanced. Intra-PVN injection of ODQ did not alter the number of Fos-immunoreactive neurons in either the dorsal cap parvocellular (PaDC), ventromedial (PaV), medial parvocellular (PaMP), or lateral magnocelllular (PaLM) portions of the PVN following acute restraint stress. Local microinjection of ODQ into the PVN did not affect the restraint-induced increases in plasma corticosterone concentration. Taken together, these findings suggest that sGC-mediated signalling in the PVN plays a key role in acute stress-induced pressor responses and sympathetically mediated cutaneous vasoconstriction, whereas the tachycardiac response is inhibited. Absence of an effect of ODQ on corticosterone and PVN neuronal activation in and the PaV and PaMP suggests that PVN sGC is not involved in restraint-evoked hypothalamus-pituitary-adrenal (HPA) axis activation and further indicates that autonomic and neuroendocrine responses are dissociable at the level of the PVN.

Prostacyclin pathway vasodilators in patients with chronic thromboembolic pulmonary hypertension (CTEPH): A systemic review and meta-analysis of randomized controlled trials

Although surgical and interventional therapy has emerged as the primary treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH), there remains a subset of patients who need medication therapy. This study aimed to evaluate the efficacy and safety outcomes of prostacyclin pathway vasodilators, providing further insight for clinical decision-making. A literature search was conducted in PubMed, Embase, and CENTRAL databases from inception to December 2023. Literature screening and quality assessment were carried out with the Cochrane Risk of Bias Tool. Data analysis was conducted using RevMan 5.4 software. We included 6 randomized controlled trials with 387 patients. Prostacyclin pathway vasodilators demonstrated a significant improvement in PVR (-125.26 dynes·sec·cm-5, 95%CI: -219.29 to -31.23, Z = 2.61, and p < 0.009), RAP (-0.78 mmHg, 95%CI: -1.52 to -0.04, Z = 2.06, and p = 0.04), cardiac index (0.62, 95%CI: 0.54 to 0.69, Z = 16.13, and p < 0.00001), and the number of patients showing improvement in WHO functional class (3.86, 95%CI: 1,92 to 7.77, Z = 3.79, and p = 0.0002) compared to controls, moreover, a trend towards improvement was observed in mPAP, 6MWD, and NT-proBNP. Regarding the safety endpoints, no significant difference was found in both groups in terms of serious adverse events and all-cause deaths. The prostacyclin pathway vasodilators present therapeutic potential for CTEPH patients with inoperable or persistent/recurrent PH after PEA/BPA primarily characterized by distal small-vessel and microvasculopathy. However, the current clinical evidence remains insufficient and controversial, necessitating further validation.

Screening a Compound Library to Identify Additives That Boost Cytochrome P450 Enzyme Function in Vascularised Liver Spheres

To accurately study human organ function and disease 'in the dish', it is necessary to develop reliable cell-based models that closely track human physiology. Our interest lay with the liver, which is the largest solid organ in the body. The liver is a multifunctional and highly regenerative organ; however, severe liver damage can have dire consequences for human health. A common cause of liver damage is adverse reactions to prescription drugs. Therefore, the development of predictive liver models that capture human drug metabolism patterns is required to optimise the drug development process. In our study, we aimed to identify compounds that could improve the metabolic function of stem cell-derived liver tissue. Therefore, we screened a compound library to identify additives that improved the maturity of in vitro-engineered human tissue, with the rationale that by taking such an approach, we would be able to fine-tune neonatal and adult cytochrome P450 metabolic function in stem cell-derived liver tissue.

Therapeutics for sickle cell disease intravascular hemolysis

Sickle cell disease (SCD) is a genetic disorder predominantly affecting individuals of African descent, with a significant global health burden. SCD is characterized by intravascular hemolysis, driven by the polymerization of mutated hemoglobin within red blood cells (RBCs), leading to vascular inflammation, organ damage, and heme toxicity. Clinical manifestations include acute pain crises, hemolytic anemia, and multi-organ dysfunction, imposing substantial morbidity and mortality challenges. Current therapeutic strategies mitigate these complications by increasing the concentration of RBCs with normal hemoglobin via transfusion, inducing fetal hemoglobin, restoring nitric oxide signaling, inhibiting platelet-endothelium interaction, and stabilizing hemoglobin in its oxygenated state. While hydroxyurea and gene therapies show promise, each faces distinct challenges. Hydroxyurea's efficacy varies among patients, and gene therapies, though effective, are limited by issues of accessibility and affordability. An emerging frontier in SCD management involves harnessing endogenous clearance mechanisms for hemolysis products. A recent work by Heggland et al. showed that CD-36-like proteins mediate heme absorption in hematophagous ectoparasite, a type of parasite that feeds on the blood of its host. This discovery underscores the need for further investigation into scavenger receptors (e.g., CD36, SR-BI, SR-BII) for their possible role in heme uptake and detoxification in mammalian species. In this review, we discussed current SCD therapeutics and the specific stages of pathophysiology they target. We identified the limitations of existing treatments and explored potential future developments for novel SCD therapies. Novel therapeutic targets, including heme scavenging pathways, hold the potential for improving outcomes and reducing the global burden of SCD.

Examination of the Suitability of Vericiguat in Non-Heart Failure with Preserved Ejection Fraction Patients with Improved Ejection Fraction

Background/Objectives: Vericiguat has been shown to reduce cardiovascular mortality and hospitalisation for heart failure in patients with reduced ejection fraction. While Vericiguat is considered one of the standard treatments for heart failure, it is unclear under which conditions Vericiguat would be most effective. With a focus on the prognosis and improved EF of heart failure, we aimed to investigate in which cases Vericiguat is suitable for use in addition to standard cardioprotective drugs. Methods: We prospectively compared echocardiograms taken before and after the administration of Vericiguat in 46 patients with non-dialysis and without heart failure with preserved ejection fraction (non-HFpEF) (left ventricle ejection fraction [LVEF] < 50%) who were able to continue Vericiguat in addition to other standard heart failure drugs (the "Fantastic Four") for more than 6 months at our hospital. Patients who showed an improvement of 10 points or more in LVEF were defined as improved EF+. Results: LVEF improved significantly from 38 [33-45]% at the time of administration to 46 [35-54.5]% at 6 months (p < 0.001). When comparing patients with and without improved EF, a significant difference was observed in the Hb (OR = 1.66, 95%CI = 1.12-2.83, p = 0.028), early introduction (OR = 12.5, 95%CI = 1.58-149, p = 0.025), and initiation of Vericiguat after the administration of the Fantastic Four (OR = 9.79, 95%CI = 1.71-100.2, p = 0.022). Conclusions: In this study, the early administration of Vericiguat, haemoglobin value, and initiation of Vericiguat after the introduction of the Fantastic Four were identified as independent factors for eligibility in non-dialysis, non-HFpEF patients who were able to continue GDMT treatment for more than 6 months after adding Vericiguat.

Beyond quadruple therapy: the potential roles for ivabradine, vericiguat, and omecamtiv mecarbil in the therapeutic armamentarium

Quadruple therapy is effective for patients with heart failure with reduced ejection fraction, providing significant clinical benefits, including reduced mortality. Clinicians are now in an era focused on how to initiate and titrate quadrable therapy in the early phase of the disease trajectory, including during heart failure hospitalization. However, patients with heart failure with reduced ejection fraction still face a significant "residual risk" of mortality and heart failure hospitalization. Despite the effective implementation of quadruple therapy, high mortality and rehospitalization rates persist in heart failure with reduced ejection fraction, and many patients cannot maximize therapy due to side effects such as hypotension and renal dysfunction. In this context, ivabradine, vericiguat, and omecamtiv mecarbil may have adjunct roles in addition to quadruple therapy (note that omecamtiv mecarbil is not currently approved for clinical use). However, the contemporary use of ivabradine and vericiguat is relatively low globally, likely due in part to the under-recognition of the role of these therapies as well as costs. This review offers clinicians a straightforward guide for bedside evaluation of potential candidates for these medications. Quadruple therapy, with strong evidence to reduce mortality, should always be prioritized for implementation. As second-line therapies, ivabradine could be considered for patients who cannot achieve optimal heart rate control (≥ 70 bpm at rest) despite maximally tolerated beta-blocker dosing. Vericiguat could be considered for high-risk patients who have recently experienced worsening heart failure events despite being on quadrable therapy, but they should not have N-terminal pro-B-type natriuretic peptide levels exceeding 8000 pg/mL. In the future, omecamtiv mecarbil may be considered for severe heart failure (New York Heart Association class III to IV, ejection fraction ≤ 30%, and heart failure hospitalization within 6 months) when current quadrable therapy is limited, although this is still hypothesis-generating and requires further investigation before its approval.

Kidney Dysfunction, Hepatic Impairment, and Lipid Metabolism Abnormalities in Patients with Precapillary Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a global health issue that has profound medical and research implications.

METHODS

This retrospective study examined changes in renal and liver function, as well as lipid metabolism, over a 12-month period in 49 adult patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). All cases were admitted, managed, and followed up with in the PH Center, County Emergency Clinical Hospital of Targu Mures, Romania.

RESULTS

Kidney dysfunction was observed in 12.24% of cases at baseline, decreasing to 8.16% at 12 months, and CTEPH patients were more affected. In particular, CTEPH patients exhibited an improvement in renal function, confirmed by an increase in their glomerular filtration rates. Hepatic impairment was present in 57.14% of subjects at baseline, declining to 42.86% at 12 months, with significant improvements noted in the PAH group. Lipid metabolic dysregulations were experienced by 22.45% of all patients at baseline, decreasing to 16.33% at 6 months, with a slow elevation to 24.49% at 12 months, but with no statistically significant differences. Pharmacological regimens were adjusted in accordance with the PH groups, a patient's functional and clinical response, and laboratory tests.

CONCLUSIONS

Our results demonstrate the multi-organ damage in PH and the importance of individualized treatment approaches.

VERICIGUAT RESCUES CYCLIC GUANOSINE MONOPHOSPHATE PRODUCTION IN HUMAN AORTIC VASCULAR SMOOTH MUSCLE CELLS AND AUGMENTS VASORELAXATION IN AORTIC RINGS EXPOSED TO HIGH GLUCOSE

Background

Normal endothelial cell dependent vascular smooth muscle cell function is mediated by nitric oxide (NO), which stimulates soluble guanylyl cyclase (sGC) production of the second messenger, cyclic guanosine monophosphate (cGMP) leading to increased protein kinase G (PKG) activity and vascular smooth muscle relaxation. NO bioavailability is impaired in inflammatory settings, such as high glucose (HG). We examined whether the direct sGC sensitizer/stimulator vericiguat, augments cGMP production in human vascular smooth muscle cells (HVSMC) exposed to high glucose and explored its effect on vasorelaxation.

Methods

Aortic HVSMCs were exposed to HG for 24h. In the treatment group, cells also received 1uM vericiguat for 24h. After incubation, cGMP and PKG activity were measured. Additionally, thoracic murine aortas were exposed to HG or to normal glucose (NG) control. The rings were then placed in an organ chamber bath and dose response curves to increasing doses of acetylcholine (Ach) and sodium nitroprusside were constructed for three groups: control (normal glucose), HG alone, and HG + vericiguat.

Results

HVSMCs exposed to HG produced significantly less cGMP than those exposed to NG. cGMP production in the presence of HG was rescued when treated with 1uM vericiguat. Additionally, PKG activity was impaired in the presence of HG and enzyme activity was restored with vericiguat. In isolated mouse aortic rings, ACh mediated relaxation was impaired following treatment with HG, but was improved when a HG group was treated with vericiguat.

Conclusions

The sGC sensitizer/stimulator vericiguat restored cGMP production and PKG activity in the setting of HG. Vericiguat enhanced ACh-mediated vasorelaxation in the setting of HG. The findings suggest clinical studies are warranted to investigate the potential of sGC sensitization/stimulation as a therapeutic intervention to improve vascular endothelial-dependent function that is impaired in pro-inflammatory settings that are associated with the development of atherosclerotic disease.

NOS2 and COX-2 Co-Expression Promotes Cancer Progression: A Potential Target for Developing Agents to Prevent or Treat Highly Aggressive Breast Cancer

Nitric oxide (NO) and reactive nitrogen species (RNS) exert profound biological impacts dictated by their chemistry. Understanding their spatial distribution is essential for deciphering their roles in diverse biological processes. This review establishes a framework for the chemical biology of NO and RNS, exploring their dynamic reactions within the context of cancer. Concentration-dependent signaling reveals distinctive processes in cancer, with three levels of NO influencing oncogenic properties. In this context, NO plays a crucial role in cancer cell proliferation, metastasis, chemotherapy resistance, and immune suppression. Increased NOS2 expression correlates with poor survival across different tumors, including breast cancer. Additionally, NOS2 can crosstalk with the proinflammatory enzyme cyclooxygenase-2 (COX-2) to promote cancer progression. NOS2 and COX-2 co-expression establishes a positive feed-forward loop, driving immunosuppression and metastasis in estrogen receptor-negative (ER-) breast cancer. Spatial evaluation of NOS2 and COX-2 reveals orthogonal expression, suggesting the unique roles of these niches in the tumor microenvironment (TME). NOS2 and COX2 niche formation requires IFN-γ and cytokine-releasing cells. These niches contribute to poor clinical outcomes, emphasizing their role in cancer progression. Strategies to target these markers include direct inhibition, involving pan-inhibitors and selective inhibitors, as well as indirect approaches targeting their induction or downstream effectors. Compounds from cruciferous vegetables are potential candidates for NOS2 and COX-2 inhibition offering therapeutic applications. Thus, understanding the chemical biology of NO and RNS, their spatial distribution, and their implications in cancer progression provides valuable insights for developing targeted therapies and preventive strategies.

Possible retinotoxicity of long-term vardenafil treatment

Phosphodiesterase (PDE) inhibitors - such as vardenafil - are used primarily for treating erectile dysfunction via increasing cyclic guanosine monophosphate (cGMP) levels. Recent studies have also demonstrated their significant cardioprotective effects in several diseases, including diabetes, upon long-term, continuous application. However, PDE inhibitors are not specific for PDE5 and also inhibit the retinal isoform. A sustained rise in cGMP in photoreceptors is known to be toxic; therefore, we hypothesized that long-term vardenafil treatment might result in retinotoxicity. The hypothesis was tested in a clinically relevant animal model of type 2 diabetes mellitus. Histological experiments were performed on lean and diabetic Zucker Diabetic Fatty rats. Half of the animals were treated with vardenafil for six months, and the retinal effects were evaluated. Vardenafil treatment alleviated rod outer segment degeneration but decreased rod numbers in some positions and induced changes in the interphotoreceptor matrix, even in control animals. Vardenafil treatment decreased total retinal thickness in the control and diabetic groups and reduced the number of nuclei in the outer nuclear layer. Müller cell activation was detectable even in the vardenafil-treated control animals, and vardenafil did not improve gliosis in the diabetic group. Vardenafil-treated animals showed complex retinal alterations with improvements in some parameters while deterioration in others. Our results point towards the retinotoxicity of vardenafil, even without diabetes, which raises doubts about the retinal safety of long-term continuous vardenafil administration. This effect needs to be considered when approving PDE inhibitors for alternative indications.

Vericiguat Use in Patients with Heart Failure in Real-World Settings during the First Year after the Drug Authorization in Japan

Background: Vericiguat was developed to treat patients with heart failure (HF). Currently, limited data are available to characterize vericiguat-treated patients in real-world clinical settings. Methods: This retrospective cohort study was done using a Japanese hospital administrative database to describe the use of vericiguat in patients with HF in real-world settings. Adult patients diagnosed with HF prescribed vericiguat between 1 July 2021 and 30 September 2022 were included. Patient characteristics at the initiation of vericiguat treatment, patterns of HF medication use, and vericiguat dose titrations were assessed within the first 90 days of treatment. Results: The study included 829 patients who were initiated on vericiguat therapy. The mean age was 75.5 years and 69.0% were male. Hypertension, coronary artery disease, and diabetes mellitus were present in 91.7, 71.3, and 60.1% of patients, respectively. Most patients had previously received HF medications, with high percentages using angiotensin-receptor blocker neprilysin inhibitors (ARNI; 43.9%) and sodium-glucose cotransporter-2 inhibitors (54.4%). During the first 90 days of vericiguat treatment, 65.8% of the patients were uptitrated from their starting dose, and 32.3% had reached the maximal daily dose. The median time to reach the maximal daily dose was 34 days. The multivariable model identified that initiating vericiguat treatment in an outpatient setting and using ARNI before initiating vericiguat treatment were factors significantly associated with reaching the maximal daily dose of vericiguat at any given time, whereas older age, chronic kidney disease, hyperkalemia, and anemia were not associated. Conclusions: These findings provide early insights into the use of vericiguat, which aid in optimizing the combinations and/or sequences of HF treatment incorporating vericiguat therapy.

Chronic circadian rhythm disorder induces heart failure with preserved ejection fraction-like phenotype through the Clock-sGC-cGMP-PKG1 signaling pathway

Emerging evidence has documented that circadian rhythm disorders could be related to cardiovascular diseases. However, there is limited knowledge on the direct adverse effects of circadian misalignment on the heart. This study aimed to investigate the effect of chronic circadian rhythm disorder on heart homeostasis in a mouse model of consistent jetlag. The jetlag model was induced in mice by a serial 8-h phase advance of the light cycle using a light-controlled isolation box every 4 days for up to 3 months. Herein, we demonstrated for the first time that chronic circadian rhythm disorder established in the mouse jetlag model could lead to HFpEF-like phenotype such as cardiac hypertrophy, cardiac fibrosis, and cardiac diastolic dysfunction, following the attenuation of the Clock-sGC-cGMP-PKG1 signaling. In addition, clock gene knock down in cardiomyocytes induced hypertrophy via decreased sGC-cGMP-PKG signaling pathway. Furthermore, treatment with an sGC-activator riociguat directly attenuated the adverse effects of jetlag model-induced cardiac hypertrophy, cardiac fibrosis, and cardiac diastolic dysfunction. Our data suggest that circadian rhythm disruption could induce HFpEF-like phenotype through downregulation of the clock-sGC-cGMP-PKG1 signaling pathway. sGC could be one of the molecular targets against circadian rhythm disorder-related heart disease.

Comorbidities, Treatment and Survival Rates of Chronic Thromboembolic Pulmonary Hypertension in a Regional Centre

Background/Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by a multitude of underlying causes, treatment modalities and prognostic outcomes. Our aim was to evaluate the underlying causes, comorbidities and survival rates of CTEPH patients. Methods: A retrospective analysis was conducted regarding the evolution of CTEPH patients confirmed by right heart catheterization under treatment with specific vasodilator medication in our centre between 2008 and 2023. Results: We treated 14 CTEPH patients, 78.57% female, 52.79 ± 13.64 years at inclusion, representing 11.29% of our pulmonary arterial hypertension registry. Initially, the distribution of patients' NYHA class was II-14.28%, III-71.42% and IV-14.28%. In total, 71.42% of these patients were technically operable due to the central location of the thrombus, but 42.85% presented severe comorbidities and 28.57% refused the surgery or it was financially inaccessible. Only four patients were operated on by pulmonary endarterectomy (PEA). Unfortunately, all the post-PEA patients had persistent pulmonary hypertension and had to continue vasodilator treatment. Overall, 64.28% of patients had monotherapy, 21.42% double therapy and 14.28% triple therapy. Regarding underlying causes and comorbidities, we found the following incidences: 78.57% chronic venous insufficiency, 42.85% obesity, 35.71% thyroid disease, hypertension and hyperuricemia, 21.42% thrombophilia and ischemic heart disease, 14.28% atrial fibrillation, vasculitis and lung disease, and 14.28% neoplastic history and diabetes. Seven patients died (50%), six of whom were unoperated and one of whom was lost (abandoned the program). The survival rates at 1, 3, 5 and 7 years for unoperated patients were 100%, 58.3%, 29.2% and 29.2% versus 100%, 75%, 75% and 75% in post-PEA patients. Conclusions: CTEPH, marked by delayed diagnosis, multiple comorbidities and limited intervention options, requires proactive screening and comprehensive multimodal therapies, including PEA, to improve survival rates.

Cost-Utility Analysis of Vericiguat in Heart Failure with Reduced Ejection Fraction After Worsening Heart Failure Events in China

OBJECTIVE

Vericiguat is a new medication to demonstrate clinical efficacy in heart failure with reduced ejection fraction (HFrEF) after worsening heart failure (WHF) events, but its cost-utility was unknown. We aimed to assess the cost-utility of combining the application of vericiguat with standard treatment in HFrEF patients who had WHF events.

METHODS

A multistate Markov model was implemented to mimic the economic results of HFrEF patients who had WHF events in China after receiving vericiguat or placebo. An analysis of cost-utility was conducted; most parameters were set according to the published studies and related databases. All the utilities and costs were decreased at a rate of 5% annually. The incremental cost-effectiveness ratios (ICERs) were the primary outcome measure. We also conducted sensitivity analyses.

RESULTS

Over a 20 year lifetime horizon, additional use of vericiguat led to an elevated cost from US$9725.03 to US$20,660.76 at the current vericiguat costs. This was related to increased quality-adjusted life years (QALYs) from 2.50 to 2.66, along with an ICER of US$65,057.24 per QALY, which was over the willingness-to-pay (WTP) threshold of US$36,096.30 per QALY. If the vericiguat costs were discounted at 80%, it contributed to an ICER of US$12,226.77 per QALY. Additional use of vericiguat for patients with plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) of ≤ 5314 pg per ml produced an ICER of US$23,688.46 per QALY. The outcomes of the one-way sensitivity analysis showed the risk of death from cardiovascular disease in both groups was variable with the highest sensitivity. The probabilistic sensitivity analysis showed that 41.6% of the mimicked population receiving vericiguat combined with standard therapy was cost-effective at the WTP threshold of US$36,096.30 per QALY.

CONCLUSIONS

From the perspective of Chinese public healthcare system, the combined use of vericiguat and standard treatment in patients with HFrEF following WHF events did not generate advantages in cost-utility in China but was a cost-effective therapeutic strategy for those who with plasma NT-proBNP of ≤ 5314 pg per ml.

Drug Therapy for Acute and Chronic Heart Failure with Preserved Ejection Fraction with Hypertension: A State-of-the-Art Review

In this comprehensive state-of-the-art review, we provide an evidence-based analysis of current drug therapies for patients with heart failure with preserved ejection fraction (HFpEF) in the acute and chronic phases with concurrent hypertension. Additionally, we explore the latest developments and emerging evidence on the efficacy, safety, and clinical outcomes of common and novel drug treatments in the management of HFpEF with concurrent hypertension. During the acute phase of HFpEF, intravenous diuretics, mineralocorticoid receptor antagonists (MRAs), and vasodilators are pivotal, while in the chronic phase, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have proven effective in enhancing clinical outcomes. However, the use of calcium channel blockers in HFpEF with hypertension should be approached with caution, owing to their potential negative inotropic effects. We also explored emerging drug therapies for HFpEF, such as sodium-glucose co-transporter 2 (SGLT2) inhibitors, angiotensin receptor-neprilysin inhibitor (ARNI), soluble guanylate cyclase (sGC) stimulators, novel MRAs, and ivabradine. Notably, SGLT2 inhibitors have shown promise in reducing heart failure hospitalizations and cardiovascular mortality in patients with HFpEF, regardless of their diabetic status. Additionally, ARNI and sGC stimulators have demonstrated potential in improving symptoms, functional capacity, and quality of life. Nonetheless, additional research is necessary to pinpoint optimal treatment strategies for HFpEF with concurrent hypertension. Furthermore, long-term studies are essential to assess the durability and sustained benefits of emerging drug therapies. Identification of novel targets and mechanisms underlying HFpEF pathophysiology will pave the way for innovative drug development approaches in the management of HFpEF with concurrent hypertension.

Integrated bioinformatics analysis and experimental animal models identify a robust biomarker and its correlation with the immune microenvironment in pulmonary arterial hypertension

Background

Pulmonary arterial hypertension (PAH) represents a substantial global risk to human health. This study aims to identify diagnostic biomarkers for PAH and assess their association with the immune microenvironment through the utilization of sophisticated bioinformatics techniques.

Methods

Based on two microarray datasets, differentially expressed genes (DEGs) were detected, and hub genes underwent a sequence of machine learning analyses. After pathways associated with PAH were assessed by gene enrichment analysis, the identified genes were validated using external datasets and confirmed in a monocrotaline (MCT)-induced rat model. In addition, three algorithms were employed to estimate the proportions of various immune cell types, and the link between hub genes and immune cells was substantiated.

Results

Using SVM, LASSO, and WGCNA, we identified seven hub genes, including (BPIFA1, HBA2, HBB, LOC441081, PI15, S100A9, and WIF1), of which only BPIFA1 remained stable in the external datasets and was validated in an MCT-induced rat model. Furthermore, the results of the functional enrichment analysis established a link between PAH and both metabolism and the immune system. Correlation assessment showed that BPIFA1 expression in the MCP-counter algorithm was negatively associated with various immune cell types, positively correlated with macrophages in the ssGSEA algorithm, and correlated with M1 and M2 macrophages in the CIBERSORT algorithm.

Conclusion

BPIFA1 serves as a modulator of PAH, with the potential to impact the immune microenvironment and disease progression, possibly through its regulatory influence on both M1 and M2 macrophages.

Vericiguat suppresses ventricular tachyarrhythmias inducibility in a rabbit myocardial infarction model

BACKGROUND

The VICTORIA trial demonstrated a significant decrease in cardiovascular events through vericiguat therapy. This study aimed to assess the potential mechanisms responsible for the reduction of cardiovascular events with vericiguat therapy in a rabbit model of myocardial infarction (MI).

METHODS

A chronic MI rabbit model was created through coronary artery ligation. Following 4 weeks, the hearts were harvested and Langendorff perfused. Subsequently, electrophysiological examinations and dual voltage-calcium optical mapping studies were conducted at baseline and after administration of vericiguat at a dose of 5 μmol/L.

RESULTS

Acute vericiguat therapy demonstrated a significant reduction in premature ventricular beat burden and effectively suppressed ventricular arrhythmic inducibility. The electrophysiological influences of vericiguat therapy included an increased ventricular effective refractory period, prolonged action potential duration, and accelerated intracellular calcium (Cai) homeostasis, leading to the suppression of action potential and Cai alternans. The pacing-induced ventricular arrhythmias exhibited a reentrant pattern, attributed to fixed or functional conduction block in the peri-infarct zone. Vericiguat therapy effectively mitigated the formation of cardiac alternans as well as the development of reentrant impulses, providing additional anti-arrhythmic benefits.

CONCLUSIONS

In the MI rabbit model, vericiguat therapy demonstrates anti-ventricular arrhythmia effects. The vericiguat therapy reduces ventricular ectopic beats, inhibiting the initiation of ventricular arrhythmias. Furthermore, the therapy successfully suppresses cardiac alternans, preventing conduction block and, consequently, the formation of reentry circuits.

Comparative efficacy of vericiguat to sacubitril/valsartan for patients with heart failure reduced ejection fraction: Systematic review and network meta-analysis

BACKGROUND

Despite the established efficacy of vericiguat compared to placebo, uncertainties remain regarding its comparative efficacy to sacubitril/valsartan for patients with heart failure reduced ejection fraction (HFrEF). This study aimed to assess the relative efficacy of vericiguat and sacubitril/valsartan through a systematic review, network meta-analysis, and non-inferiority tests.

METHODS

A systematic review was conducted to identify the randomized phase 3 clinical trials involving vericiguat and sacubitril/valsartan. The hazard ratios (HRs) with 95% confidence intervals (CI) for cardiovascular death (CVD) and hospitalization due to HF (hHF) were extracted from these trials and synthesized via network meta-analysis. Non-inferiority testing of vericiguat was performed using a fixed-margin method with a predefined non-inferiority margin (1.24). Sensitivity analyses explored the impact of the time from hHF to screening.

RESULTS

Among the 1366 studies, two trials (VICTORIA and PARADIGM-HF) met the inclusion criteria. Network meta-analysis demonstrated that the HR for CVD or hHF with vericiguat did not significantly differ from that for sacubitril/valsartan (HR: 0.88, 95% CI:0.62-1.23). The upper limit of the 95% CI was less than the predefined margin of 1.24, confirming vericiguat's non-inferiority to sacubitril/valsartan. Sensitivity analyses affirmed the robustness of the base-case results.

CONCLUSION

Vericiguat exhibited a comparable risk of CVD or hHF when contrasted with sacubitril/valsartan. Importantly, in patients with HFrEF, vericiguat's efficacy was not statistically inferior to that of sacubitril/valsartan. These findings reinforce the potential of vericiguat as a viable treatment option for this patient population.

Pericyte signaling via soluble guanylate cyclase shapes the vascular niche and microenvironment of tumors

Pericytes and endothelial cells (ECs) constitute the fundamental components of blood vessels. While the role of ECs in tumor angiogenesis and the tumor microenvironment is well appreciated, pericyte function in tumors remains underexplored. In this study, we used pericyte-specific deletion of the nitric oxide (NO) receptor, soluble guanylate cyclase (sGC), to investigate via single-cell RNA sequencing how pericytes influence the vascular niche and the tumor microenvironment. Our findings demonstrate that pericyte sGC deletion disrupts EC-pericyte interactions, impairing Notch-mediated intercellular communication and triggering extensive transcriptomic reprogramming in both pericytes and ECs. These changes further extended their influence to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Inhibition of pericyte sGC has minimal impact on quiescent vessels but significantly increases the vulnerability of angiogenic tumor vessels to conventional anti-angiogenic therapy. In conclusion, our findings elucidate the role of pericytes in shaping the tumor vascular niche and tumor microenvironment and support pericyte sGC targeting as a promising strategy for improving anti-angiogenic therapy for cancer treatment.

Regional variations in allergen-induced airway inflammation correspond to changes in soluble guanylyl cyclase heme and expression of heme oxygenase-1

Asthma is characterized by airway remodeling and hyperreactivity. Our earlier studies determined that the nitric oxide (NO)-soluble guanylyl cyclase (sGC)-cGMP pathway plays a significant role in human lung bronchodilation. However, this bronchodilation is dysfunctional in asthma due to high NO levels, which cause sGC to become heme-free and desensitized to its natural activator, NO. In order to determine how asthma impacts the various lung segments/lobes, we mapped the inflammatory regions of lungs to determine whether such regions coincided with molecular signatures of sGC dysfunction. We demonstrate using murine models of asthma (OVA and CFA/HDM) that the inflamed segments of these murine lungs can be tracked by upregulated expression of HO1 and these regions in turn overlap with regions of heme-free sGC as evidenced by a decreased sGC-α1β1 heterodimer and an increased response to heme-independent sGC activator, BAY 60-2770, relative to naïve uninflamed regions. We also find that NO generated from iNOS upregulation in the inflamed segments has a higher impact on developing heme-free sGC as increasing iNOS activity correlates linearly with elevated heme-independent sGC activation. This excess NO works by affecting the epithelial lung hemoglobin (Hb) to become heme-free in asthma, thereby causing the Hb to lose its NO scavenging function and exposing the underlying smooth muscle sGC to excess NO, which in turn becomes heme-free. Recognition of these specific lung segments enhances our understanding of the inflamed lungs in asthma with the ultimate aim to evaluate potential therapies and suggest that regional and not global inflammation impacts lung function in asthma.

Vericiguat in patients with heart failure across the spectrum of left ventricular ejection fraction: a patient-level, pooled meta-analysis of VITALITY-HFpEF and VICTORIA

Vericiguat, the newest soluble guanylate cyclase (sGC) drug, is potentially beneficial in treating heart failure (HF). However, most studies have only confirmed the significant impact of sGC in patients with reduced left ventricular ejection fraction (LVEF). Therefore, the main objective of this meta-analysis was to comparatively analyze the effects of Vericiguat in the entire LVEF range based on previous studies. According to PubMed, Web of Science, Cochrane, and Embase databases, randomized controlled studies in the full LVEF stage range were screened, and two extensive clinical studies on Vericiguat, namely VICTORIA (LVEF<45%) and VITALITY-HFpEF (LVEF≥45%) were identified for analysis and systematic evaluation. We separately assessed the rates of primary outcomes, cardiovascular death, and serious adverse events in both studies. The results of our research confirmed that although the criteria for the primary outcome were not the same in the two extensive studies, it was evident that there was no difference in the primary outcome between the experimental Vericiguat group and the placebo group in the VITALITY-HFpEF (LVEF≥45%) (P=0.45), whereas the primary outcome of VICTORIA (LVEF<45%) was significantly improved with the administration of Vericiguat showing a significant improvement (RR 0.93; 95% CI 0.87 to 1.00), but the effect of Vericiguat on cardiovascular mortality was not significant across the full range of LVEF (RR 0.97; 95% CI 0.86 to 1.09), and the incidence of total serious adverse events did not differ significantly between the two studies (RR 0.96; 95% CI 0.89 to 1.03). Surprisingly, partial subgroups analysis of serious adverse events found that vericiguat treatment reduced the incidence of all-cause death, Cardiac disorders, Hypotension, and Hypertension in patients with LVEF<45%, with a particular effect on the incidence of Cardiac disorders. Taken together, Vericiguat had a significant benefit in HF patients with LVEF<45%, especially in patients with LVEF<24%; it had a less pronounced effect in HF patients with LVEF ≥45%, but no adverse effects were observed.

Towards etiological treatments in cardiomyopathies

This review proposes to look at the evolution of cardiomyopathy treatments in the light of advances in diagnostic techniques, which have enabled to move from a mechanistic to a phenotypic and then etiological approach. The article goes beyond the ejection fraction approach, and look at new therapies that target the pathophysiological pathways of cardiomyopathies, either by targeting the phenotype, or by targeting the etiology. The evolution of HCM treatments is detailed, culminating in the latest etiological treatments such as mavacamten in sarcomeric HCM, tafamidis in transthyretin cardiac amyloidosis and migalastat in Fabry disease. Myosin stimulators are reviewed in the treatment of DCM, before opening perspectives for gene therapy, which proposes direct treatment of the culprit mutation.

Identification of new multi-substituted 1H-pyrazolo[3,4-c]pyridin-7(6H)-ones as soluble guanylyl cyclase (sGC) stimulators with vasoprotective and anti-inflammatory activities

Herein, we describe the rational design, synthesis and in vitro functional characterization of new heme-dependent, direct soluble guanylyl cyclase (sGC) agonists. These new compounds bear a 1H-pyrazolo[3,4-c]pyridin-7(6H)-one skeleton, modified to enable efficient sGC binding and stimulation. To gain insights into structure-activity relationships, the N6-alkylation of the skeleton was explored, while a pyrimidine ring, substituted with various C5'-polar groups, was installed at position C3. Among the newly synthesized 1H-pyrazolo[3,4-c]pyridin-7(6H)-ones, derivatives 14b, 15b and 16a display characteristic features of sGC "stimulators" in A7r5 vascular smooth muscle cells in vitro. They strongly synergize with the NO donor, sodium nitroprusside (SNP) in inducing cGMP generation in a manner that requires the presence of a reduced heme moiety associated with sGC, and elevate the cGMP-responsive phosphorylation of the protein VASP at Ser239. In line with their sGC stimulating capacity, docking calculations of derivatives 16a, 15(a-c) on a cryo-EM structure of human sGC (hsGC) in an ΝΟ-activated state indicated the implication of 1H-pyrazolo[3,4-c]pyridin-7(6H)-one skeleton in efficient bonding interactions with the recently identified region that binds known sGC stimulators, while the presence of either a N6-H or N6-methyl group pointed to enhanced binding affinity. Moreover, the in vitro functional effects of our newly identified sGC stimulators were compatible with a beneficial role in vascular homeostasis. Specifically, derivative 14b reduced A7r5 cell proliferation, while 16a dampened the expression of adhesion molecules ICAM-1 and P/E-Selectin in Human Umbilical Vein Endothelial Cells (HUVECs), as well as the subsequent adhesion of U937 leukocytes to the HUVECs, triggered by tumor necrosis factor alpha (TNF-α) or interleukin-1 beta (IL-1β). The fact that these compounds elevate cGMP only in the presence of NO may indicate a novel way of interaction with the enzyme and may make them less prone than other direct sGC agonists to induce characteristic hypotension in vivo.

Heart Failure: Recent Advances and Breakthroughs

Heart failure (HF) is a common clinical condition encountered in various healthcare settings with a vast socioeconomic impact. Recent advancements in pharmacotherapy have led to the evolution of novel therapeutic agents with a decrease in hospitalization and mortality rates in HF with reduced left ventricular ejection fraction (HFrEF). Lately, the introduction of artificial intelligence (AI) to construct decision-making models for the early detection of HF has played a vital role in optimizing cardiovascular disease outcomes. In this review, we examine the newer therapies and evidence behind goal-directed medical therapy (GDMT) for managing HF. We also explore the application of AI and machine learning (ML) in HF, including early diagnosis and risk stratification for HFrEF.

Pulmonary Hypertension in Underrepresented Minorities: A Narrative Review

Minoritized racial and ethnic groups suffer disproportionately from the incidence and morbidity of pulmonary hypertension (PH), as well as its associated cardiovascular, pulmonary, and systemic conditions. These disparities are largely explained by social determinants of health, including access to care, systemic biases, socioeconomic status, and environment. Despite this undue burden, minority patients remain underrepresented in PH research. Steps should be taken to mitigate these disparities, including initiatives to increase research participation, combat inequities in access to care, and improve the treatment of the conditions associated with PH.

Decoding signaling mechanisms: unraveling the targets of guanylate cyclase agonists in cardiovascular and digestive diseases

Soluble guanylate cyclase agonists and guanylate cyclase C agonists are two popular drugs for diseases of the cardiovascular system and digestive systems. The common denominator in these conditions is the potential therapeutic target of guanylate cyclase. Thanks to in-depth explorations of their underlying signaling mechanisms, the targets of these drugs are becoming clearer. This review explains the recent research progress regarding potential drugs in this class by introducing representative drugs and current findings on them.

Promising Cerebral Blood Flow Enhancers in Acute Ischemic Stroke

Ischemic stroke presents a major global economic and public health burden. Although recent advances in available endovascular therapies show improved functional outcome, a good number of stroke patients are either ineligible or do not have access to these treatments. Also, robust collateral flow during acute ischemic stroke independently predicts the success of endovascular therapies and the outcome of stroke. Hence, adjunctive therapies for cerebral blood flow (CBF) enhancement are urgently needed. A very clear overview of the pial collaterals and the role of genetics are presented in this review. We review available evidence and advancement for potential therapies aimed at improving CBF during acute ischemic stroke. We identified heme-free soluble guanylate cyclase activators; Sanguinate, remote ischemic perconditioning; Fasudil, S1P agonists; and stimulation of the sphenopalatine ganglion as promising potential CBF-enhancing therapeutics requiring further investigation. Additionally, we outline and discuss the critical steps required to advance research strategies for clinically translatable CBF-enhancing agents in the context of acute ischemic stroke models.

Nitric oxide and thiols: Chemical biology, signalling paradigms and vascular therapeutic potential

Nitric oxide (• NO) interactions with biological thiols play crucial, but incompletely determined, roles in vascular signalling and other biological processes. Here, we highlight two recently proposed signalling paradigms: (1) the formation of a vasodilating labile nitrosyl ferrous haem (NO-ferrohaem) facilitated by thiols via thiyl radical generation and (2) polysulfides/persulfides and their interaction with • NO. We also describe the specific (bio)chemical routes in which • NO and thiols react to form S-nitrosothiols, a broad class of small molecules, and protein post-translational modifications that can influence protein function through catalytic site or allosteric structural changes. S-Nitrosothiol formation depends upon cellular conditions, but critically, an appropriate oxidant for either the thiol (yielding a thiyl radical) or • NO (yielding a nitrosonium [NO+ ]-donating species) is required. We examine the roles of these collective • NO/thiol species in vascular signalling and their cardiovascular therapeutic potential.

Inhaled nitric oxide: can it serve as a savior for COVID-19 and related respiratory and cardiovascular diseases?

Nitric oxide (NO), as an important gaseous medium, plays a pivotal role in the human body, such as maintaining vascular homeostasis, regulating immune-inflammatory responses, inhibiting platelet aggregation, and inhibiting leukocyte adhesion. In recent years, the rapid prevalence of coronavirus disease 2019 (COVID-19) has greatly affected the daily lives and physical and mental health of people all over the world, and the therapeutic efficacy and resuscitation strategies for critically ill patients need to be further improved and perfected. Inhaled nitric oxide (iNO) is a selective pulmonary vasodilator, and some studies have demonstrated its potential therapeutic use for COVID-19, severe respiratory distress syndrome, pulmonary infections, and pulmonary hypertension. In this article, we describe the biochemistry and basic characteristics of NO and discuss whether iNO can act as a "savior" for COVID-19 and related respiratory and cardiovascular disorders to exert a potent clinical protective effect.

Identification and characterization of the new generation soluble guanylate cyclase stimulator BAY-747 designed for the treatment of resistant hypertension

BACKGROUND AND PURPOSE

First-generation soluble guanylate cyclase (sGC) stimulators have shown clinical benefit in pulmonary hypertension (riociguat) and chronic heart failure (vericiguat). However, given the broad therapeutic opportunities for sGC stimulators, tailored molecules for distinct indications are required.

EXPERIMENTAL APPROACH

We report the high-throughput screening (HTS)-based discovery of a second generation of sGC stimulators from a novel imidazo[1,2-a]pyridine lead series. An intense medicinal chemistry programme resulted in the discovery of the sGC stimulator BAY 1165747 (BAY-747). The pharmacokinetic profile of BAY-747 was determined in different species, and it was broadly characterized in pharmacological model systems relevant for vasodilatation and hypertension.

KEY RESULTS

BAY-747 is a highly potent sGC stimulator in vitro. In addition, BAY-747 showed an excellent pharmacokinetic profile with long half-life and low peak-to-trough ratio. BAY-747 was investigated in experimental in vivo models of malignant and resistant hypertension (rHT). In spontaneously hypertensive (SH) rats, BAY-747 caused a dose-related and long-lasting decrease in mean arterial blood pressure (MAP). Oral treatment over 12 days resulted in a persistent decrease. BAY-747 provided additional benefit when dosed on top of losartan, amlodipine or spironolactone and even on top of triple combinations of frequently used antihypertensive drugs. In a new canine model of rHT, BAY-747 caused a dose-related and long-lasting (>6 h) MAP decrease.

CONCLUSION AND IMPLICATIONS

BAY-747 is a potent, orally available sGC stimulator. BAY-747 shows long-acting pharmacodynamic effects with a very low peak-to-trough ratio. BAY-747 could be a treatment alternative for patients with hypertension, especially those not responding to standard-of-care therapy.

Ligand Control of Dinitrosyl Iron Complexes for Selective Superoxide-Mediated Nitric Oxide Monooxygenation and Superoxide-Dioxygen Interconversion

Through nitrosylation of [Fe-S] proteins, or the chelatable iron pool, a dinitrosyl iron unit (DNIU) [Fe(NO)2] embedded in the form of low-molecular-weight/protein-bound dinitrosyl iron complexes (DNICs) was discovered as a metallocofactor assembled under inflammatory conditions with elevated levels of nitric oxide (NO) and superoxide (O2-). In an attempt to gain biomimetic insights into the unexplored transformations of the DNIU under inflammation, we investigated the reactivity toward O2- by a series of DNICs [(NO)2Fe(μ-MePyr)2Fe(NO)2] (1) and [(NO)2Fe(μ-SEt)2Fe(NO)2] (3). During the superoxide-induced conversion of DNIC 1 into DNIC [(K-18-crown-6-ether)2(NO2)][Fe(μ-MePyr)4(μ-O)2(Fe(NO)2)4] (2-K-crown) and a [Fe3+(MePyr)x(NO2)y(O)z]n adduct, stoichiometric NO monooxygenation yielding NO2- occurs without the transient formation of peroxynitrite-derived •OH/•NO2 species. To study the isoelectronic reaction of O2(g) and one-electron-reduced DNIC 1, a DNIC featuring an electronically localized {Fe(NO)2}9-{Fe(NO)2}10 electronic structure, [K-18-crown-6-ether][(NO)2Fe(μ-MePyr)2Fe(NO)2] (1-red), was successfully synthesized and characterized. Oxygenation of DNIC 1-red leads to the similar assembly of DNIC 2-K-crown, of which the electronic structure is best described as paramagnetic with weak antiferromagnetic coupling among the four S = 1/2 {FeIII(NO-)2}9 units and S = 5/2 Fe3+ center. In contrast to DNICs 1 and 1-red, DNICs 3 and [K-18-crown-6-ether][(NO)2Fe(μ-SEt)2Fe(NO)2] (3-red) display a reversible equilibrium of "3 + O2- ⇋ 3-red + O2(g)", which is ascribed to the covalent [Fe(μ-SEt)2Fe] core and redox-active [Fe(NO)2] unit. Based on this study, the supporting/bridging ligands in dinuclear DNIC 1/3 (or 1-red/3-red) control the selective monooxygenation of NO and redox interconversion between O2- and O2 during reaction with O2- (or O2).

Vericiguat: The Fifth Harmony of Heart Failure with Reduced Ejection Fraction

Heart failure with reduced ejection fraction is a chronic and progressive syndrome that continues to be a substantial financial burden for health systems in Western countries. Despite remarkable advances in pharmacologic and device-based therapy over the last few years, patients with heart failure with reduced ejection fraction have a high residual risk of adverse outcomes, even when treated with optimal guideline-directed medical therapy and in a clinically stable state. Worsening heart failure episodes represent a critical event in the heart failure trajectory, carrying high residual risk at discharge and dismal short- or long-term prognosis. Recently, vericiguat, a soluble guanylate cyclase stimulator, has been proposed as a novel drug whose use is already associated with a reduction in heart failure-related hospitalizations in patients in guideline-directed medical therapy. In this review, we summarized the pathophysiology of the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate cascade in patients with heart failure with reduced ejection fraction, the pharmacology of vericiguat as well as the evidence regarding their use in patients with HFrEF. Finally, tips and tricks for its use in standard clinical practice are provided.