The role of human urotensin-II in patients with hypertrophic cardiomyopathy

Circulating Biomarkers in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is the most common genetic heart disease. Biomarkers, molecules measurable in the blood, could inform the clinician by aiding in diagnosis, directing treatment, and predicting outcomes. We present an updated review of circulating biomarkers in hypertrophic cardiomyopathy representing key pathologic processes including wall stretch, myocardial necrosis, fibrosis, inflammation, hypertrophy, and endothelial dysfunction, in addition to their clinical significance.

Identifying Circulating Urotensin II and Urotensin II-Related Peptide-Generating Enzymes in the Human Plasma Fraction Cohn IV-4

Urotensin II (UII) and UII-related peptide (URP) are vasoactive peptide hormones causing strong vasoconstriction or vasodilation, depending on the type of blood vessel. In humans, the active forms are resulting from proteolytic cleavage of their inactive precursor protein. In blood plasma, a defined protease converting the inactive UII and URP precursors into their active forms has not been identified yet. Using mass spectrometry-based enzyme screening for detecting UII- and URP-converting enzymes, the human plasma fraction Cohn IV-4 was chromatographed, and the resulting fractions were screened for UII- or URP-generating activity. Plasma kallikrein (PK) as a UII- and URP-generating protease was identified. URP generation was also found for the serine protease factor XIa, plasmin, thrombin, and, to a smaller extent, factor XIIa. It was demonstrated that in the Cohn IV-4 fraction, PK accounts for a significant amount of UII- and URP-generating activity.

Urotensin II induces activation of NLRP3 and pyroptosis through calcineurin in cardiomyocytes

Cell pyroptosis, a new type of programmed cell death, has been recently reported to play important roles in the development of cardiac remodeling. How cardiomyocyte pyroptosis is induced remains to be elucidated. Urotensin II (UII) has been known closely related to cardiac remodeling and the development of heart failure. Inhibition of UII receptors has been shown to be effective in the treatment of cardiac hypertrophy and remodeling. However, it is not clear whether UII might induce cardiomyocyte pyroptosis. We here examined the effect of UII treatment on pyroptosis in cultured cardiomyocytes. Treatment of cardiomyocyes of neonatal rats with UII (500 nmol/l) for 48 hours induced a significant pyroptosis as evidenced by not only increased cell death but also upregulated expression levels of NLR family pyrin domain containing 3 (NLRP3), caspase-1, IL-1β, IL-18 and gasdermin D (GMDSD)-N which are important markers for the identification of cell pyroptosis. All these pyroptosis responses induced by UII were abrogated by an inhibitor of NLRP3. Moreover, the antagonist of UII receptor, Urantide abolished UII- induced cardiomyocyte pyroptosis. Additionally, inhibition of calcineurin by cyclosporin A rather than that of CaMKII by KN93 suppressed the UII-upregulated expression levels of those pyroptosis markers. We therefore demonstrate that UII might induce cardiomyocyte pyroptosis through calcineurin.

Urotensin II Induces Cardiac Fibrosis through the TGF-β/Smad Signaling Pathway during the Development of Cardiac Hypertrophy

Myocardial fibrosis is an important pathological phenomenon of cardiac remodeling that is induced by hypertension, myocardial ischemia, valvular heart disease, hypertrophic cardiomyopathy, and other heart diseases and can progress to heart failure. Urotensin II (UII) is regarded as a cardiovascular autacoid/hormone that is not only the most potent vasoconstrictor in mammals but also involved in cardiac remodeling. However, the molecular mechanisms responsible for UII-induced cardiac fibrosis have not yet been fully elucidated. Therefore, we aimed to investigate the effect of UII on myocardial fibrosis in cardiac hypertrophy and the mechanism of UII-induced cardiac fibrosis. Cardiac tissue from mice subjected to Transverse aortic constriction (TAC) was collected. Cardiac hypertrophy, myocardial fibrosis, and the expression of UII protein were assessed using echocardiography and pathological and molecular biological analyses. The effect of UII on fibrosis was evaluated in UII-treated mice and isolated rat primary cardiac fibroblasts, and the results indicated that UII induced significant myocardial fibrosis and increases in the proliferation and fibrotic responses both in mice and cultured fibroblasts. Mechanistically, UII treatment induced activation of the TGF-β/Smad signaling pathway, which was suppressed by the UII receptor antagonist. In conclusion, UII plays critical roles in cardiac fibrosis by modulating the TGF-β/Smads signaling pathway, which may be a promising therapeutic target in hypertrophic cardiomyopathy and related problems, such as cardiac remodeling and heart failure.

Urotensin II levels in patients with inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are associated with increased cardiovascular risk and have increased overall cardiovascular burden. On the other hand, urotensin II (UII) is one of the most potent vascular constrictors with immunomodulatory effect that is connected with a number of different cardiometabolic disorders as well. Furthermore, patients with ulcerative colitis have shown increased expression of urotensin II receptor in comparison to healthy controls. Since the features of IBD includes chronic inflammation and endothelial dysfunction as well, it is plausible to assume that there is connection between increased cardiac risk in IBD and UII.

AIM

To determine serum UII levels in patients with IBD and to compare them to control subjects, as well as investigate possible associations with relevant clinical and biochemical parameters.

METHODS

This cross sectional study consecutively enrolled 50 adult IBD patients (26 with Crohn’s disease and 24 with ulcerative colitis) and 50 age and gender matched controls. Clinical assessment was performed by the same experienced gastroenterologist according to the latest guidelines. Ulcerative Colitis Endoscopic Index of Severity and Simple Endoscopic Score for Crohn’s Disease were used for endoscopic evaluation. Serum levels of UII were determined using the enzyme immunoassay kit for human UII, according to the manufacturer’s instructions.

RESULTS

IBD patients have significantly higher concentrations of UII when compared to control subjects (7.57 ± 1.41 vs 1.98 ± 0.69 ng/mL, P < 0.001), while there were no significant differences between Crohn’s disease and ulcerative colitis patients (7.49 ± 1.42 vs 7.65 ± 1.41 ng/mL, P = 0.689). There was a significant positive correlation between serum UII levels and high sensitivity C reactive peptide levels (r = 0.491, P < 0.001) and a significant negative correlation between serum UII levels and total proteins (r = -0.306, P = 0.032). Additionally, there was a significant positive correlation between serum UII levels with both systolic (r = 0.387, P = 0.005) and diastolic (r = 0.352, P = 0.012) blood pressure. Moreover, serum UII levels had a significant positive correlation with Ulcerative Colitis Endoscopic Index of Severity (r = 0.425, P = 0.048) and Simple Endoscopic Score for Crohn’s Disease (r = 0.466, P = 0.028) scores. Multiple linear regression analysis showed that serum UII levels retained significant association with high sensitivity C reactive peptide (β ± standard error, 0.262 ± 0.076, P < 0.001) and systolic blood pressure (0.040 ± 0.017, P = 0.030).

CONCLUSION

It is possible that UII is involved in the complex pathophysiology of cardiovascular complications in IBD patients, and its purpose should be investigated in further studies.

Novel insights into the role of urotensin II in cardiovascular disease

Urotensin II (UII) is a vasoactive peptide that interacts with a specific receptor called the UT receptor. UII has been implicated in cardiovascular regulation, with promising therapeutic applications based on UT receptor antagonism. The endogenous ligands of the UT receptor: UII and urotensin-related peptide (URP), differentially bind and activate this receptor. Also, the receptor localization is not restricted to the plasma membrane, possibly inducing different physiological responses that could support its inconsistent, but potent, vasoactive activity. These properties could explain the disappointing outcomes in clinical studies, in contrast to the positive preclinical results regarding heart failure, pulmonary hypertension, atherosclerosis and diabetes mellitus. These aspects should be considered in future investigations to a better comprehension of the role of UII as a potential therapeutic target.

Urotensin II: an inflammatory cytokine

Urotensin II (UII) is a polypeptide molecule with neurohormone-like activity. It has been confirmed that UII is widely distributed in numerous organs of different animal species from fish to mammals, including humans. The UII receptor is orphan G-protein coupled receptor 14, also known as UT. The tissue distribution of UII and UT is highly consistent, and their expression may be regulated by autocrine and paracrine mechanisms. In the body, UII has many physiological and pathophysiological activities, such as vasoconstrictor and vasodilatory actions, cell proliferation, pro-fibrosis, neuroendocrine activity, insulin resistance, and carcinogenic and inflammatory effects, which have been recognized only in recent years. In fact, UII is involved in the process of inflammatory injury and plays a key role in the onset and development of inflammatory diseases. In this paper, we will review the roles UII plays in inflammatory 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.