Plasma urocortin in acute myocardial infarction 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.

Urocortin Role in Ischemia Cardioprotection and the Adverse Cardiac Remodeling

Despite the considerable progress in strategies of myocardial protection, ischemic heart diseases (IHD) and consequent heart failure (HF) remain the main cause of mortality worldwide. Several procedures are used routinely to guarantee the prompt and successful reestablishment of blood flow to preserve the myocardial viability of infarcted hearts from ischemia injuries. However, ischemic heart reperfusion/revascularization triggers additional damages that occur when oxygen-rich blood re-enters the vulnerable myocardial tissue, which is a phenomenon known as ischemia and reperfusion (I/R) syndrome. Complications of I/R injuries provoke the adverse cardiac remodeling, involving inflammation, mishandling of Ca²⁺ homeostasis, apoptotic genes activation, cardiac myocytes loss, etc., which often progress toward HF. Therefore, there is an urgent need to develop new cardioprotective therapies for IHD and HF. Compelling evidence from animal studies and pilot clinical trials in HF patients suggest that urocortin (Ucn) isoforms, which are peptides associated with stress and belonging to the corticotropin releasing factor family, have promising potential to improve cardiovascular functions by targeting many signaling pathways at different molecular levels. This review highlights the current knowledge on the role of urocortin isoforms in cardioprotection, focusing on its acute and long-term effects.

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.

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.

Urocortin 2 in cardiovascular health and disease

Urocortin (Ucn)-2 - corticotropin-releasing hormone receptor 2 signaling has favorable effects in the cardiovascular system, including coronary vasodilatation, with increased coronary blood flow and conductance and augmented cardiac contractility and output, as well as protection against ischemia/reperfusion injury. Indeed, several animal studies have confirmed the salutary therapeutic effects of Ucn-2 in chronic heart failure, with improvements in cardiac performance and animal survival. In addition, recent clinical trials have demonstrated the benefits of Ucn-2 in patients with stable chronic heart failure on optimal medical therapy.

Vasoprotective effects of urocortin 1 against atherosclerosis in vitro and in vivo

AIM

Atherosclerosis is the complex lesion that consists of endothelial inflammation, macrophage foam cell formation, vascular smooth muscle cell (VSMC) migration and proliferation, and extracellular matrix production. Human urocortin 1 (Ucn1), a 40-amino acid peptide member of the corticotrophin-releasing factor/urotensin I family, has potent cardiovascular protective effects. This peptide induces potent and long-lasting hypotension and coronary vasodilation. However, the relationship of Ucn1 with atherosclerosis remains unclear. The present study was performed to clarify the effects of Ucn1 on atherosclerosis.

METHODS

We assessed the effects of Ucn1 on the inflammatory response and proliferation of human endothelial cells (ECs), human macrophage foam cell formation, migration and proliferation of human VSMCs, extracellular matrix expression in VSMCs, and the development of atherosclerosis in apolipoprotein E-deficient (Apoe-/-) mice.

RESULTS

Ucn1 significantly suppressed cell proliferation without inducing apoptosis, and lipopolysaccharide-induced up-regulation of monocyte chemoattractant protein-1 and intercellular adhesion molecule-1 in human ECs. Ucn1 significantly reduced oxidized low-density lipoprotein-induced foam cell formation with a significant down-regulation of CD36 and acyl-CoA:cholesterol acyltransferase 1 in human monocyte-derived macrophages. Ucn1 significantly suppressed the migration and proliferation of human VSMCs and increased the activities of matrix metalloproteinase-2 (MMP2) and MMP9 in human VSMCs. Intraperitoneal injection of Ucn1 into Apoe-/- mice for 4 weeks significantly retarded the development of aortic atherosclerotic lesions.

CONCLUSIONS

This study provided the first evidence that Ucn1 prevents the development of atherosclerosis by suppressing EC inflammatory response and proliferation, macrophage foam cell formation, and VSMC migration and proliferation. Thus, Ucn1 could serve as a novel therapeutic target for atherosclerotic cardiovascular diseases.

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.

Clinical perspectives of urocortin and related agents for the treatment of cardiovascular disease

The effects of corticotropin-releasing hormone, also known as corticotropin-releasing factor (CRF), on the cardiovascular system have been intensively researched since its discovery. Moreover, the actions of urocortin (Ucn) I on the cardiovascular system have also been intensively scrutinized following the cloning and identification of its receptor, CRF receptor type 2 (CRFR2), in peripheral tissues including the heart. Given the cardioprotective actions of CRFR2 ligands, the clinical potential of not only Ucn I but also Ucn II and III, which were later identified as more specific ligands for CRFR2, has received considerable attention from researchers. In addition, recent work has indicated that CRF type 1 receptor may be also involved in cardioprotection against ischemic/reperfusion injury. Here we provide a historical overview of research on Ucn I and related agents, their effects on the cardiovascular system, and the clinical potential of the use of such agents to treat cardiovascular diseases.

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.