Circulating levels of stress associated peptide Urocortin in heart failure patients

Urocortins as biomarkers in cardiovascular disease

The urocortins (Ucns) belong to the corticotropin-releasing factor (CRF) family of peptides and have multiple effects within the central nervous and the cardiovascular systems. With growing evidence indicating significant cardioprotective properties and cardiovascular actions of these peptides, the question arises as to whether the plasma profiles of the Ucns are altered in pathologic settings. While reports have shown conflicting results and findings have not been corroborated in multiple independent cohorts, it seems likely that plasma Ucn concentrations are elevated in multiple cardiovascular conditions. The degree of increase and accurate determination of circulating values of the Ucns requires further validation.

Assessment of clinical data on urocortins and their therapeutic potential in cardiovascular diseases: A systematic review and meta-analysis

Heart failure (HF) and cardiovascular diseases present public health challenges. Although great progress was achieved in their treatment, there is continuous need for new therapies. Urocortins of the corticotropin neuropeptide family were reported to exert beneficial effects in animal models of HF and cardiovascular diseases. We aimed to assess the available clinical evidence on the potential role of urocortins in HF and other cardiovascular diseases. We explored MEDLINE, Embase, CENTRAL, and Scopus databases. Twenty‐seven studies were included in the qualitative and 15 studies (2005 patients) in the quantitative syntheses. Available data allowed us to meta‐analyze the blood pressure (BP) lowering and heart rate (HR) increasing effects of urocortin 2 in HF with reduced ejection fraction. We applied meta‐regression to explore the association between left ventricular ejection fraction and serum urocortin 1 and urocortin 2 levels. Short‐term urocortin 2 infusion decreased mean arterial pressure in chronic HF with reduced ejection fraction (mean difference = −9.161 mmHg, 95% confidence interval [CI] −12.661 to −5.660 mmHg, p < 0.001). Such infusions increased HR mildly (mean difference = 5.629 beats/min, 95% CI 1.612 to 9.646 beats/min, p = 0.006). Although some studies reported increased urocortin 1 and urocortin 2 levels in HF with growing severity, our meta‐regressions failed to confirm associations between blood urocortin levels and left ventricular ejection fraction. Clinical evidence confirms short‐term BP lowering effects of urocortin 2, whereas individual studies report additional beneficial effects. Further clinical investigations are necessary to confirm the latter and the long‐term value of these peptides in cardiovascular diseases. Review protocol: CRD42020163203.

Corticotropin-Releasing Hormone Family and Their Receptors in the Cardiovascular System

The identification of corticotropin-releasing hormone (CRH) has led to the discovery of a growing family of ligands and receptors. CRH receptor 1 (CRHR1) and CRHR2 are mammalian G-protein coupled receptors (GPCRs) with high affinity for CRH and the CRH family of peptides. CRHR1 is predominantly expressed in the brain and plays a vital role in the hypothalamic-pituitary-adrenal (HPA) axis stress responses by secreting adrenal corticotropic hormone (ACTH). CRHR2 is predominantly expressed in the heart, and a CRHR2-specific ligand, urocortin 2 (UCN2), shows positive cardiac chronotropic and inotropic effects through 3´,5´-cyclic adenosine monophosphate (cAMP) signaling in response to CRHR2-mediated Gαs activation in mice and humans. Central administration of the CRH family of peptides increases mean arterial pressure through CRHR1 activation, whereas peripheral administration of the peptides decreases mean arterial pressure through CRHR2 activation. These observations have led to further investigations of CRHR2 as an important and unique GPCR in the physiological and pathological functioning of the cardiovascular (CV) system. Moreover, recent clinical trials demonstrate CRHR2 as a potentially therapeutic target in the treatment of heart failure. We present recent reviews of the role of CRHRs in basic CV physiology and in the pathophysiology of CV diseases.

Natural and synthetic peptides in the cardiovascular diseases: An update on diagnostic and therapeutic potentials

Several peptides play an important role in physiological and pathological conditions into the cardiovascular system. In addition to well-known vasoactive agents such as angiotensin II, endothelin, serotonin or natriuretic peptides, the vasoconstrictor Urotensin-II (Uro-II) and the vasodilators Urocortins (UCNs) and Adrenomedullin (AM) have been implicated in the control of vascular tone and blood pressure as well as in cardiovascular disease states including congestive heart failure, atherosclerosis, coronary artery disease, and pulmonary and systemic hypertension. Therefore these peptides, together with their receptors, become important therapeutic targets in cardiovascular diseases (CVDs). Circulating levels of these agents in the blood are markedly modified in patients with specific CVDs compared with those in healthy patients, becoming also potential biomarkers for these pathologies. This review will provide an overview of current knowledge about the physiological roles of Uro-II, UCN and AM in the cardiovascular system and their implications in cardiovascular diseases. It will further focus on the structural modifications carried out on original peptide sequences in the search of analogues with improved physiochemical properties as well as in the delivery methods. Finally, we have overviewed the possible application of these peptides and/or their precursors as biomarkers of CVDs.

The evaluation of the clinical utility of urocortin 1 and adrenomedullin versus proBNP in systolic heart failure

Objective:

Urocortin 1 (UCN1) has vasodilator, diuretic, and natriuretic effects, and its expression increases in heart failure (HF). Adrenomedullin (ADM) increases cardiac output and lowers blood pressure in healthy men and in patients with heart failure. The aim of the study was to determine UCN1 and ADM levels in patients with HF, to evaluate the relationship of UCN1 and ADM with various clinical parameters, and to assess UCN1 and ADM as diagnostic markers in HF, in comparison with pro-brain natriuretic peptide (pro-BNP).

Methods:

We investigated serum levels of UCN1, ADM, and pro-BNP in 86 consecutive patients with systolic HF [ejection fraction (EF) ≤45%] and 85 healthy controls. Serum UCN1, ADM, and pro-BNP levels were measured with the ELISA method. Transthoracic echocardiography was performed to determine left ventricular EF and pulmonary artery systolic pressure.

Results:

UCN1 and ADM levels were higher in HF patients (446.2±145.7 pg/mL, p<0.001; 87.9±4.2 pg/mL, p<0.001 respectively). UCN1 was positively correlated with pro-BNP (r=0.963, p<0.001), ADM (r=0.915, p<0.001), and NYHA (r=0.879, p<0.001); ADM was positively correlated with pro-BNP (r=0.956, p<0.001) and NYHA (r=0.944, p<0.001). Receiver operating characteristic curves yielded an area under the curve of 1.00 (p<0.001) for UCN1, 1.00 (p<0.001) for ADM, and 0.99 (p<0.001) for pro-BNP in the diagnosis of HF.

Conclusion:

UCN1 and ADM increase with worsening HF and left ventricular dysfunction. They may be used as diagnostic biomarkers in systolic HF, but the incremental value of measuring UCN1 and ADM in patients tested for pro-BNP is questionable.

Targeting urocortin signaling pathways to enhance cardioprotection: is it time to move from bench to bedside?

Despite the exponential growth in medical knowledge, cardiovascular diseases (CVDs) contribute to more than one-third of worldwide morbidity and mortality. A range of therapies already exist for established CVDs, although there is significant interest in further understanding their pathogenesis. The urocortins (Ucns) are peptide members of the corticotrophin-releasing factor family, a group of evolutionary conserved peptides with homologues in fish, amphibians and mammals and considered to play a pivotal role in energy homeostasis and local tissue repair. A number of preclinical studies in vitro, in-vivo and ex-vivo have defined a multifaceted effect of Ucns on the cardiovascular system. Different G-protein coupled signaling and protein-kinase pathways have been shown to be activated by Ucns, together with different transcriptional and translational effects, all of which preferentially converge on the mitochondria, where the modulation of apoptosis is considered their principal action. It has been demonstrated in experimental models, and consequentially suggested in human diseases, that Ucn-mediated inhibition of apoptosis can be exploited for the improvement of both therapeutic and preventative strategies against CVDs. Specifically, some unavoidable iatrogenic ischemia/reperfusion (I/R) injuries, e.g. during cardiac surgery or percutaneous coronary angioplasty, may greatly benefit from the anti-apoptotic effect of Ucns. However, few studies on the topic have been employed in humans to date. Therefore, this review will focus on the different intra-cellular mechanisms of action of Urocortins, and detail the different Ucn-mediated pathways identified so far. It will also highlight the limited evidence already existing in human clinical and surgical settings, as well as emphasize the potential uses of Ucns in human cardiac pathology.

Urotensin II and urocortin trigger the expression of myostatin, a negative regulator of cardiac growth, in cardiomyocytes

Urotensin II (UII) and urocortin (UCN) are potent contributors to the physiopathology of heart failure. Our study investigated the effects of UII and UCN on the expression of myostatin (Mstn) in primary culture of adult cardiomyocytes. Adult rat cardiomyocytes were stimulated for 48 h with UII and UCN. Cell size and protein content were determined. Mstn gene expression was determined by real time quantitative polymerase chain reaction. Treatment with UII and UCN stimulates hypertrophy of adult cardiomyocytes. This effect was associated with a twofold increase of Mstn gene expression. We have established for the first time that the two hypertrophic peptides UII and UCN stimulate the expression of Mstn.

Distribution of urocortins and corticotropin-releasing factor receptors in the cardiovascular system

Urocortins are human homologues of urotensin I, a fish corticotropin-releasing-factor- (CRF-) like peptide secreted from the urophysis. There are three urocortins: urocortin 1, urocortin 2, and urocortin 3 in mammals. We have shown that urocortin 1 and urocortin 3 are endogenously synthesized in the myocardial cells of human heart and may act on CRF type 2 receptor (CRFR2) expressed in the heart. Expression levels of urocortin 1 in the heart and plasma urocortin 1 levels are elevated in patients with heart failure. Recent studies have shown that urocortins have various biological actions in the cardiovascular system, such as a vasodilator action, a positive inotropic action, a cardioprotective action against ischemia/reperfusion injury, and suppressive actions against the renin angiotensin system and the sympathetic nervous system. Urocortins and CRFR2 may therefore be a potential therapeutic target for cardiovascular diseases, such as congestive heart failure, hypertension, and myocardial infarction.

Diagnosing destabilized heart failure in the emergency setting: current and future biomarker tests

Acute or destabilized heart failure (DHF) is characterized by new or worsening signs and symptoms of heart failure leading to admission to an emergency department. Biomarkers may support the diagnosis, the prognosis and the management of DHF patients. The aim of this review article is to discuss and evaluate the clinical usefulness of both recognized and potential new biomarker tests for use in heart failure.

Relevance of urocortins to cardiovascular disease

Acquired cardiovascular diseases such as coronary heart disease, peripheral artery disease and related vascular problems contribute to more than one-third of worldwide morbidity and mortality. In many instances, particularly in the under developed world, cardiovascular diseases are diagnosed at a late stage limiting the scope for improving outcomes. A range of therapies already exist for established cardiovascular disease, although there is significant interest in further understanding disease pathogenesis in order to improve diagnosis and achieve primary and secondary therapeutic goals. The urocortins are a group of recently defined peptide members of the corticotrophin-releasing factor family. Previous pre-clinical work and human association studies suggest that urocortins have potential to exert some beneficial and other detrimental effects on the heart and major blood vessels. More current evidence however favours beneficial effects of urocortins, for example these peptides have been shown to inhibit production of reactive oxygen species and vascular cell apoptosis, and thus may have potential to antagonise the progression of cardiovascular disease. This review summarises published data on the potential role of urocortins in cardiovascular disease.

Urocortin-2 induces vasorelaxation of coronary arteries isolated from patients with heart failure

1. Urocortin-2 (Ucn2) is a vasoactive peptide belonging to the corticotrophin-releasing factor (CRF) family that has potent cardiovascular actions. It has been suggested that Ucn2 participates in the pathophysiology of heart failure. However, little is known about the mechanisms underlying the action of Ucn2 in human coronary arteries. The aim of the present study was to assess the effects of Ucn2 on the vascular tone of human coronary arteries dissected from heart failure patients. 2. Human coronary arteries were dissected from the hearts of patients subjected to orthotopic heart transplantation. Coronary arteries were obtained from 17 patients with heart failure due to dilated cardiomyopathy of ischaemic origin in Stage III-IV of the New York Heart Association classification. Changes in tone were measured in arterial rings using force transducers. 3. Application of increasing concentrations of Ucn2 (5-20 nmol/L) to arterial rings precontracted with agonists induced dose-dependent relaxation of the coronary artery, which was independent of endothelial cell activation. Furthermore, the inhibition of the adenylyl cyclase by MDL-12 (100 nmol/L) and protein kinase A (PKA) by H89 (1 μmol/L) prevented Ucn2-mediated relaxation of coronary artery rings. 4. The results of the present study suggest that, in heart failure patients, Ucn2 could be useful in modulating coronary artery circulation independent of endothelial integrity through mechanisms that involve adenylyl cyclase activation and PKA stimulation. The findings warrant further investigation of the role of Ucn2 in circulatory regulation and its potential therapeutic application in heart disease.

Urocortin-induced cardiomyocytes hypertrophy is associated with regulation of the GSK-3β pathway

Urocortin-1 (UCN), a member of the corticotropin-releasing factor, is a cardioprotective peptide, and is also involved in cardiac hypertrophy. The involvement of GSK-3β, a pivotal kinase in cardiac hypertrophy, in response to UCN is not yet documented. Cardiomyocytes from adult rats were stimulated for 48 h with UCN. Cell size, protein, and DNA contents were determined. Phosphorylated and total forms GSK-3β and the total amount of β-catenin were quantified by Western immunoblots. The effects of astressin, a UCN competitive receptor antagonist, were also evaluated. UCN increased cell size and the protein-to-DNA ratio, in accordance with a hypertrophic response. This effect was associated with increased phosphorylation of GSK-3β and marked accumulation of β-catenin, a downstream element to GSK-3β. All these effects were prevented by astressin and LY294002, an inhibitor of the phosphatidyl-inositol-3-kinase. UCN-induced cardiomyocytes hypertrophy is associated with regulation of GSK-3β, a pivotal kinase involved in cardiac hypertrophy, in a PI3K-dependent manner. Furthermore, the pharmacological blockade of UCN receptors was able to prevent UCN-induced hypertrophy, which leads to inhibition of the Akt/GSK-3β pathway.

Expression of urocortin peptides in canine myocardium and plasma

Urocortin (Ucn) peptides are the endogenous ligands for the corticotropin-releasing factor type 2 receptor (CRFR2). They have potentially important roles in cardiovascular physiology in health and disease, and show promise as therapeutics for congestive heart failure. Analysis of canine heart tissue showed mRNA expression of Ucn 1, Ucn 3 and CRFR2 in all heart chambers. Immunohistochemistry also demonstrated Ucns 1 and 3 expression in cardiomyocytes. To assess the potential usefulness of circulating Ucns as markers of heart disease, plasma samples from 45 dogs with cardiac disease and 15 controls were analysed by radioimmunoassay. Both Ucns 1 and 3 were measurable but the presence of cardiac disease did not alter their concentrations. Therefore, whilst Ucns are expressed in canine myocardium (where they may play a role in the endogenous neurohumoral response to cardiac disease or failure) they do not appear to be sensitive biomarkers of cardiac disease in our canine patient population.