Urotensin II levels are an important marker for the severity of portal hypertension in children

Birth Weight Standard Deviation Score is a Significant Determinant of Serum Urotensin-II Levels at Term-Equivalent Age in Preterm Infants

OBJECTIVE

Urotensin II (U-II) is a potent vasoconstrictor peptide, and increased U-II levels are associated with atherosclerosis and hypertension in adults. Low birth weight (LBW) infants have higher risks of such diseases in the future. A small number of nephrons is one of possible mechanism underlying these risks in LBW infants, while vascular elasticity and cardiac function might be another important factor. The objective of this study is to evaluate U-II levels in preterm LBW infants at an early stage of life and determine perinatal factors associated with U-II levels.

STUDY DESIGN

The study population consisted of 57 preterm LBW infants (26 males and 31 females), including 49 appropriate for gestational age (AGA) and 8 small for gestational age (SGA) infants, born at a gestational age of ≤34 weeks with a mean birth weight of 1,589 g. Serum U-II levels were measured at term-equivalent age to evaluate perinatal factors related to serum U-II levels.

RESULTS

Preterm SGA infants had significantly higher serum U-II levels than preterm AGA infants at term-equivalent age (p = 0.019). Serum U-II levels in preterm LBW infants at term-equivalent age were inversely correlated with birth weight standard deviation (SD) score in a simple regression analysis (r =  - 0.395, p = 0,002) and the correlation was maintained in the multiple regression analysis.

CONCLUSION

Our results indicate that birth weight SD score might be associated with serum U-II levels in preterm LBW infants at term-equivalent age. Further studies are required to determine whether U-II levels at an early stage of life might influence the risk of atherosclerosis and hypertension.

KEY POINTS

· U-II is a potent vasoconstrictor.. · We evaluated serum U-II levels in preterm infants.. · Fetal growth is negatively related to serum U-II levels..

The Role of Urotensin-II in Obesity and Metabolic Syndrome in Pediatric Population

Background: Urotensin-II (U-II) is a short cyclic peptide that is widely recognized as one of the most potent vasoconstrictors. U-II plays a role in the pathophysiology of MS, participating in the development of essential hypertension, insulin resistance, hyperglycemia, and a proinflammatory state. Methods: This study comprised 52 obese children and adolescents with a body mass index (BMI) z score > 2, aged 10 to 18 years. Serum levels of U-II were assessed using an enzyme-linked immunosorbent assay along with other standard biochemical parameters. Results: Elevated serum levels of U-II were recorded in the group of obese subjects with MS when compared with the group of obese subjects without MS (4.99 (8.97–3.16) vs. 4.17 (5.17–2.03) ng/mL, median and IQR, p = 0.026). Furthermore, a subgroup of study subjects with high blood pressure had significantly higher U-II levels in comparison with the normotensive subgroup (4.98 (7.19–3.22) vs. 3.32 (5.06–1.97) ng/mL, p = 0.027), while the subgroup with a positive family history of high blood pressure had significantly higher U-II levels when compared with subjects who had a negative family history of elevated blood pressure (5.06 (6.83–4.45) vs. 3.32 (6.13–2.21) ng/mL, p = 0.039). Conclusions: To the best of the author’s knowledge, this is the first study on the levels of U-II in obese children and adolescents, including a possible link to MS.

Plasma Urotensin II levels in children and adolescents with chronic kidney disease: a single-centre study

Background

Increased plasma Urotensin II (UII) levels have been found in adults with renal diseases. Studies in children are scarce. The objective of the study is to estimate plasma UII levels in subjects with chronic kidney disease (CKD) stages 3 to 5 and renal transplant recipients (RTR). In addition, the correlation of UII with anthropometric features and biochemical parameters was assessed.

Methods

Fifty-four subjects, aged 3 to 20 years old, 23 with CKD, 13 with end-stage kidney disease (ESKD) undergoing hemodialysis (HD) and 18 RTR were enrolled. A detailed clinical evaluation was performed. Biochemical parameters of renal and liver function were measured. Plasma UII levels were measured in all patients and in 117 healthy controls, using a high sensitive enzyme immunoassay (EIA) kit. All data were analyzed using STATA™ (Version 10.1).

Results

Median UII and mean log-transformed UII levels were significantly higher in CKD and RTR patients compared to healthy subjects (p < 0.001). HD patients had higher but not statistically significant UII and log-UII levels than controls. UII levels increased significantly at the end of the HD session and were higher than controls and in line to those of other patients. The geometric scores of UII in HD (before dialysis), CKD and RTR patients increased respectively by 42, 136 and 164% in comparison with controls. Metabolic acidosis was associated with statistical significant change in log-UII levels (p = 0.001). Patients with metabolic acidosis had an increase in UII concentration by 76% compared to those without acidosis.

Conclusions

Children and adolescents with CKD, particularly those who are not on HD and RTR, have significantly higher levels of UII than healthy subjects. UII levels increase significantly at the end of the HD session. The presence of metabolic acidosis affects significantly plasma UII levels.

The G Protein-Coupled Receptor UT of the Neuropeptide Urotensin II Displays Structural and Functional Chemokine Features

The urotensinergic system was previously considered as being linked to numerous physiopathological states, including atherosclerosis, heart failure, hypertension, pre-eclampsia, diabetes, renal disease, as well as brain vascular lesions. Thus, it turns out that the actions of the urotensin II (UII)/G protein-coupled receptor UT system in animal models are currently not predictive enough in regard to their effects in human clinical trials and that UII analogs, established to target UT, were not as beneficial as expected in pathological situations. Thus, many questions remain regarding the overall signaling profiles of UT leading to complex involvement in cardiovascular and inflammatory responses as well as cancer. We address the potential UT chemotactic structural and functional definition under an evolutionary angle, by the existence of a common conserved structural feature among chemokine receptorsopioïdergic receptors and UT, i.e., a specific proline position in the transmembrane domain-2 TM2 (P2.58) likely responsible for a kink helical structure that would play a key role in chemokine functions. Even if the last decade was devoted to the elucidation of the cardiovascular control by the urotensinergic system, we also attempt here to discuss the role of UII on inflammation and migration, likely providing a peptide chemokine status for UII. Indeed, our recent work established that activation of UT by a gradient concentration of UII recruits Gαi/o and Gα13 couplings in a spatiotemporal way, controlling key signaling events leading to chemotaxis. We think that this new vision of the urotensinergic system should help considering UT as a chemotactic therapeutic target in pathological situations involving cell chemoattraction.

Circulating levels of the vasoactive peptide urotensin II in patients with acute coronary syndrome and stable coronary artery disease

Urotensin II (UII) is a vasoactive peptide with various roles in cardiovascular physiology and pathophysiology. There is an accumulating evidence implicating UII in atherosclerosis and coronary artery disease, making it an important target in acute coronary syndrome (ACS). In this study, we sought to determine the plasma levels of UII in ACS patients within 48 h of clinical presentation and after a 12-week recovery period. We compared them to patients with stable coronary artery disease (CAD) and a control group of normolipidemic subjects without known CAD. Using a highly sensitive ELISA technique, we measured plasma UII in 27 ACS patients, 26 stable CAD patients and 22 age-matched controls. ACS patients had significantly elevated plasma UII during the first 48 h of clinical presentation compared to stable CAD patients and controls. We also found significant positive correlations between UII and CRP and with triglycerides and a significant negative correlation between UII and EF. There was no correlation with LDL-C. In conclusion, plasma UII levels were elevated in patients with acute coronary syndrome, particularly immediately after clinical presentation. This suggests an upregulation of UII expression in ACS.

Progress in understanding role of urotensin Ⅱ in hepatic cirrhosis

Urotensin Ⅱ (UⅡ) is a potent vasoactive substance that can result in vasoactive response through interaction with its specific orphan G-protein-coupled receptor GPR-14. In addition to the role of vasoactivity, UⅡ can promote mitosis and fibrosis. The vascular role of UⅡ is to some degree both species- and disease-specific. Studies have found that plasma levels of UⅡ are elevated in patients with cirrhosis, but the relationship between plasma levels of UⅡ and the development of chronic liver disease and portal hypertension has yet to be fully elucidated. This review focuses on the potential relevance of UⅡ as vasoactive substance in chronic liver disease and the site where UⅡ is overproduced.

Noninvasive evaluation of portal hypertension: emerging tools and techniques

Portal hypertension is the main cause of complications in patients with cirrhosis. However, evaluating the development and progression of portal hypertension represents a challenge for clinicians. There has been considerable focus on the potential role of noninvasive markers of portal hypertension that could be used to stratify patients with respect to the stage of portal hypertension and to monitor disease progression or treatment response in a longitudinal manner without having to undertake repeated invasive assessment. The pathogenesis of portal hypertension is increasingly understood and emerging knowledge of the vascular processes that underpin portal hypertension has paved the way for exploring novel biomarkers of vascular injury, angiogenesis, and endothelial dysfunction. In this paper we focus on the pathogenesis of portal hypertension and potential non-invasive biomarkers with particular emphasis on serum analytes.