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While the urotensinergic system plays a role in influencing various pathologies, its potential remains untapped because of the absence of therapeutically effective urotensin II receptor (UTR) modulators. Herein, we developed analogues of human urotensin II ( h U-II ) peptide in which, along with well-known antagonist-oriented modifications, the Glu 1 residue was subjected to single-point mutations. The generated library was tested by a calcium mobilization assay and ex vivo experiments, also in competition with selected ligands. Interestingly, many derivatives showed noncompetitive modulation that was rationalized by the lateral allostery concept applied to a G protein-coupled receptor (GPCR) multimeric model. UPG-108 showed an unprecedented ability to double the efficacy of h U-II , while UPG-109 and UPG-111 turned out to be negative allosteric modulators of UTR. Overall, our investigation will serve to explore and highlight the expanding possibilities of modulating the UTR system through N-terminally modified h U-II analogues and, furthermore, will aim to elucidate the intricate nature of such a GPCR system.

Intimal hyperplasia (IH) is a common pathological feature of vascular proliferative diseases, such as atherosclerosis and restenosis after angioplasty. Urotensin II (UII) and its receptor (UTR) are widely expressed in cardiovascular tissues. However, it remains unclear whether the UII/UTR system is involved in IH. Right unilateral common carotid artery ligation was performed and maintained for 21 days to induce IH in UTR knockout (UTR -/- ) and wild-type (WT) mice. Histological analysis revealed that compared with WT mice, UTR-deficient mice exhibited a decreased neointimal area, angiostenosis and intima-media ratio. Immunostaining revealed fewer smooth muscle cells (SMCs), endothelial cells and macrophages in the lesions of UTR -/- mice than in those of WT mice. Protein interaction analysis suggested that the UTR may affect cell proliferation by regulating YAP and its downstream target genes. In vitro experiments revealed that UII can promote the proliferation and migration of SMCs, and western blotting also revealed that UII increased the protein expression of RhoA, CTGF, Cyclin D1 and PCNA and downregulated p-YAP protein expression, while these effects could be partly reversed by urantide. To evaluate the translational value of UTRs in IH management, WT mice were also treated with two doses of urantide, a UTR antagonist, to confirm the benefit of UTR blockade in IH progression. A high dose of urantide (600 μg/kg/day), rather than a low dose (60 μg/kg/day), successfully improved ligation-induced IH compared with that in mice receiving vehicle. The results of the present study suggested that the UII/UTR system may regulate IH partly through the RhoA-YAP signaling pathway., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest with respect to the publication of this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: To explore the molecular mechanism of Astragaloside IV (AS-IV) in alleviating renal fibrosis by inhibiting Urotensin II-induced pyroptosis and epithelial-mesenchymal transition of renal tubular epithelial cells., Methods: Forty SD rats were randomly divided into control group without operation: gavage with 5ml/kg/d water for injection and UUO model group: gavage with 5ml/kg/d water for injection; UUO+ AS-IV group (gavage with AS-IV 20mg/kg/d; and UUO+ losartan potassium group (gavage with losartan potassium 10.3mg/kg/d, with 10 rats in each group. After 2 weeks, Kidney pathology, serum Urotensin II, and cAMP concentration were detected, and the expressions of NLRP3, GSDMD-N, Caspase-1, and IL-1β were detected by immunohistochemistry. Rat renal tubular epithelial cells were cultured in vitro, and different concentrations of Urotensin II were used to intervene for 24h and 48h. Cell proliferation activity was detected using the CCK8 assay. Suitable concentrations of Urotensin II and intervention time were selected, and Urotensin II receptor antagonist (SB-611812), inhibitor of PKA(H-89), and AS-IV (15ug/ml) were simultaneously administered. After 24 hours, cells and cell supernatants from each group were collected. The cAMP concentration was detected using the ELISA kit, and the expression of PKA, α-SMA, FN, IL-1β, NLRP3, GSDMD-N, and Caspase-1 was detected using cell immunofluorescence, Western blotting, and RT-PCR., Results: Renal tissue of UUO rats showed renal interstitial infiltration, tubule dilation and atrophy, renal interstitial collagen fiber hyperplasia, and serum Urotensin II and cAMP concentrations were significantly higher than those in the sham operation group (p <0.05). AS-IV and losartan potassium intervention could alleviate renal pathological changes, and decrease serum Urotensin II, cAMP concentration levels, and the expressions of NLRP3, GSDMD-N, Caspase-1, and IL-1β in renal tissues (p <0.05). Urotensin II at a concentration of 10-8 mol/L could lead to the decrease of cell proliferation, (p<0.05). Compared with the normal group, the cAMP level and the PKA expression were significantly increased (p<0.05). After intervention with AS-IV and Urotensin II receptor antagonist, the cAMP level and the expression of PKA were remarkably decreased (p<0.05). Compared with the normal group, the expression of IL-1β, NLRP3, GSDMD-N, and Caspase-1 in the Urotensin II group was increased (p<0.05), which decreased in the AS-IV and H-89 groups., Conclusion: AS-IV can alleviate renal fibrosis by inhibiting Urotensin II-induced pyroptosis of renal tubular epithelial cells by regulating the cAMP/PKA signaling pathway., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The urotensinergic system, involved in the development and/or progression of numerous pathological conditions, is composed of one G protein-coupled receptor (UT) and two endogenous ligands known as urotensin II (UII) and urotensin II-related peptide (URP). These two structurally related hormones, which exert common and divergent effects, are thought to play specific biological roles. In recent years, we have characterized an analog termed urocontrin A (UCA), i.e. [Pep 4 ]URP, which is capable of discriminating the effects of UII from URP. Such an action could allow the delineation of the respective functions of these two endogenous ligands. In an effort to define the molecular determinants involved in this behavior and to improve the pharmacological profile of UCA, we introduced modifications from urantide, considered for some time as a lead compound for the development of UT antagonists, into UCA and assessed the binding, contractile activity and G protein signaling of these newly developed compounds. Our results show that UCA and its derivatives exert probe-dependent effects on UT antagonism, and we have further identified [Pen 2 , Pep 4 ]URP as a G q biased ligand with an insurmountable antagonism in our aortic ring contraction assay., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Idiopathic scoliosis (IS) is the most common spinal deformity diagnosed in childhood or early adolescence, while the underlying pathogenesis of this serious condition remains largely unknown. Here, we report zebrafish ccdc57 mutants exhibiting scoliosis during late development, similar to that observed in human adolescent idiopathic scoliosis (AIS). Zebrafish ccdc57 mutants developed hydrocephalus due to cerebrospinal fluid (CSF) flow defects caused by uncoordinated cilia beating in ependymal cells. Mechanistically, Ccdc57 localizes to ciliary basal bodies and controls the planar polarity of ependymal cells through regulating the organization of microtubule networks and proper positioning of basal bodies. Interestingly, ependymal cell polarity defects were first observed in ccdc57 mutants at approximately 17 days postfertilization, the same time when scoliosis became apparent and prior to multiciliated ependymal cell maturation. We further showed that mutant spinal cord exhibited altered expression pattern of the Urotensin neuropeptides, in consistent with the curvature of the spine. Strikingly, human IS patients also displayed abnormal Urotensin signaling in paraspinal muscles. Altogether, our data suggest that ependymal polarity defects are one of the earliest sign of scoliosis in zebrafish and disclose the essential and conserved roles of Urotensin signaling during scoliosis progression., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Xie et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Accumulated evidence shows that elevated urotensin II (UII) levels are associated with cardiovascular diseases. However, the role of UII in the initiation, progression, and regression of atherosclerosis remains to be verified. Different stages of atherosclerosis were induced in rabbits by a 0.3% high cholesterol diet (HCD) feeding, and either UII (5.4 μg/kg/h) or saline was chronically infused via osmotic mini-pumps. UII promoted atherosclerotic fatty streak formation in ovariectomized female rabbits (34% increase in gross lesion and 93% increase in microscopic lesion), and in male rabbits (39% increase in gross lesion). UII infusion significantly increased the plaque size of the carotid and subclavian arteries (69% increase over the control). In addition, UII infusion significantly enhanced the development of coronary lesions by increasing plaque size and lumen stenosis. Histopathological analysis revealed that aortic lesions in the UII group were characterized by increasing lesional macrophages, lipid deposition, and intra-plaque neovessel formation. UII infusion also significantly delayed the regression of atherosclerosis in rabbits by increasing the intra-plaque macrophage ratio. Furthermore, UII treatment led to a significant increase in NOX2 and HIF-1α/VEGF-A expression accompanied by increased reactive oxygen species levels in cultured macrophages. Tubule formation assays showed that UII exerted a pro-angiogenic effect in cultured endothelial cell lines and this effect was partly inhibited by urantide, a UII receptor antagonist. These findings suggest that UII can accelerate aortic and coronary plaque formation and enhance aortic plaque vulnerability, but delay the regression of atherosclerosis. The role of UII on angiogenesis in the lesion may be involved in complex plaque development.

The Purpose of the Article: To identify novel small molecule antagonists of Urotensin II receptor with acceptable pharmacological profile., Materials and Methods: Structure-activity-relationship (SAR) studies on 2-{ N -[(2,4,5-trichlorophenoxy) acetyl]- N -methylamino}-3-pyrrolidinepropanamide series were conducted and shortlisted compounds were synthesized and evaluated in in vitro cell-based assays. Human and mouse Urotensin II receptor overexpressing CHO cells were used for calcium release and radioligand binding assays. Initial molecules in this series had solubility and inter-species variability issue in the calcium release assay. We, therefore, conducted SAR to overcome these 2 issues and molecules with accepted in vitro profile were evaluated further in mouse pressor response model to generate the in vivo proof of concept for UII receptor antagonization., Results and Conclusions: We report herewith identification of 2-{ N -[(2,4,5-trichlorophenoxy)acetyl]- N -methylamino}-3-pyrrolidinepropanamides series to obtain novel small molecule antagonists of Urotensin II receptor with acceptable pharmacological profile.

Urotensin II (UII) is a kind of fish somatostatins cyclic peptide, which was originally extracted from the caudal neurosecretory system (CNSS). The system of UII and UII receptor (UIIR) has been reported to have multiple physiological regulatory functions, such as cardiovascular control, osmoregulation, and lipid metabolism. However, the effect of UII and UIIR on the ovarian development has not been covered. This study investigated the expression pattern of UII and UIIR in the ovarian follicles and explored their impact on ovarian development in olive flounder Paralichthys olivaceus. The results showed that the highest UII and UIIR mRNA levels were observed at stage II and stage III follicles during ovarian development, respectively. In situ hybridization revealed that a strong signal of UII was expressed in the oocyte nuclei of stage II follicles, however, UIIR was found in the follicle cells and oocyte cytoplasm of stage II and stage III follicles. Similarly, immunohistochemistry found positive signal of UII was detected in the oocyte nuclei of stage II follicles. The results from in vitro culture of olive flounder follicles suggested the expression of UII and UIIR mRNA levels significantly increased by 10 IU/ml human chorionic gonadotropin (hCG) for 9 h. Furthermore, the transcriptional expression of UII and UIIR was not statistically significantly changed by 17α, 20β-dihydroxy-4-pregnen-3-one (DHP). These results firstly suggested that UII and UII receptor may play vital roles in regulating ovarian growth in olive flounder., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022. Published by Elsevier Inc.)

Urotensin receptor (UT) is a G-protein-coupled receptor, whose endogenous ligand is urotensin-II (U-II). Skeletal muscle mass is regulated by various conditions, such as nutritional status, exercise, and diseases. Previous studies have pointed out that the urotensinergic system is involved in skeletal muscle metabolism and function, but its mechanism remains unclear, especially given the lack of research on the effect and mechanism of fasting. In this study, UT receptor knockout mice were generated to evaluate whether UT has effects on fasting induced skeletal muscle atrophy. Furthermore, the UT antagonist palosuran (3, 10, 30 mg/kg) was intraperitoneally administered daily for 5 days to clarify the therapeutic effect of UT antagonism. Our results found the mice that fasted for 48 h exhibited skeletal muscle atrophy, accompanied by enhanced U-II levels in both skeletal muscles and blood. UT receptor knockout effectively prevented fasting-induced skeletal muscle atrophy. The UT antagonist ameliorated fasting-induced muscle atrophy in mice as determined by increased muscle strengths, weights, and muscle fiber areas (including fast, slow, and mixed types). In addition, the UT antagonist reduced skeletal muscle atrophic markers, including F-box only protein 32 (FBXO32) and tripartite motif containing 63 (TRIM63). Moreover, the UT antagonist was also observed to enhance PI3K/AKT/mTOR while inhibiting autophagy signaling. In summary, our study provides the first evidence that UT antagonism may represent a novel therapeutic approach for the treatment of fasting-induced skeletal muscle atrophy., Competing Interests: Conflict of interest The authors declare no competing interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Urotensin II (U-II) and its receptor (UT) are involved in the pathogenesis of various diseases; however, their association with the development of cystitis has not been elucidated. The present study was designed to investigate the functional role of U-II/UT signaling in cyclophosphamide (CYP)-induced cystitis. A total of 60 female rats were randomly divided into the control and CYP-treated groups. Intraperitoneal injection of CYP successfully induced cystitis in rats of the CYP-treated group. The protein and mRNA expression levels of U-II and UT were significantly enhanced in rat bladder tissues of the CYP-treated group. Furthermore, the results of the immunofluorescence staining analysis demonstrated that CYP treatment apparently increased the expression levels of UT in the urothelium layer, detrusor smooth muscle, and bladder interstitial Cajal-like cells. The selective antagonist of UT, SB657510 (10 μm), significantly suppressed the CYP-induced increase in the spontaneous contractions of muscle strips and ameliorated the bladder hyperactivity of CYP-treated rats. Moreover, CYP treatment significantly increased the protein expression levels of Ras homolog family member (Rho) A and Rho-associated protein kinase 2 in rat bladder tissues. Following pretreatment with the Rho-kinase inhibitor Y-27632 (10 μm), the inhibitory effects of SB657510 (10 μm) on the spontaneous contractions of muscle strips were eliminated. In conclusion, the results of the present study suggested that activation of U-II/UT signaling promoted the development of cystitis-associated-bladder hyperactivity by targeting the RhoA/Rho-kinase pathway, indicating that the U-II/UT signaling could serve as a novel target for the treatment of interstitial cystitis/bladder pain syndrome., (© 2022 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia, Ltd on behalf of Kaohsiung Medical University.)

Beyond the CNS, urotensin II (UII) and its receptor (UT) are functionally expressed in peripheral tissues of the endocrine, cardiovascular, and renal systems. The expression levels of UII and UT in the kidney and circulating UII levels are increased in diabetes. UII also promotes mesangial proliferation and matrix accumulation in vitro. Here, we evaluate the effect of UT deletion on the development of hyperglycemia and diabetic kidney disease (DKD) in streptozotocin (STZ)-treated mice. Ten-week-old WT and UT knockout (KO) mice were injected with STZ for 5 days to induce diabetes. Blood glucose levels were measured weekly, and necropsy was performed 12 weeks after STZ injection. UT ablation slowed hyperglycemia and glucosuria in STZ-treated mice. UT KO also ameliorated STZ-induced increase in HbA1c, but not STZ-induced decrease in plasma insulin levels. However, STZ-induced increases in plasma glucagon concentration and immunohistochemical staining for glucagon in pancreatic islets were lessened in UT KO mice. UT ablation also protected against STZ-induced kidney derangements, including albuminuria, mesangial expansion, glomerular lesions, and glomerular endoplasmic reticulum stress. UT is expressed in a cultured pancreatic alpha cell line, and its activation by UII triggered membrane depolarization, T- and L-type voltage-gated Ca2+channel-dependent Ca2+influx, and glucagon secretion. These findings suggest that apart from direct action on the kidneys to cause injury, UT activation by UII may result in DKD by promoting hyperglycemia via induction of glucagon secretion by pancreatic alpha cells.

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.

The urotensin 2 (uts2) gene family consists of four paralogs called uts2, uts2-related peptide (urp), urp1 and urp2. uts2 is known to exert a large array of biological effects, including osmoregulation, control of cardiovascular functions and regulation of endocrine activities. Lately, urp1 and urp2 have been shown to regulate axial straightening during embryogenesis. In contrast, much less is known about the roles of urp. The aim of the present study was to investigate the expression and the functions of urp by using the zebrafish as a model. For this purpose, we determined the expression pattern of the urp gene. We found that urp is expressed in motoneurons of the brainstem and the spinal cord, as in tetrapods. This was confirmed with a new Tg(urp:gfp) fluorescent reporter line. We also generated a urp knockout mutant by using CRISPR/Cas9-mediated genome editing and analysed its locomotor activity in larvae. urp mutant did not exhibit any apparent defect of spontaneous swimming when compared to wild-type. We also tested the idea that urp may represent an intermediary of urp1 and urp2 in their role on axial straightening. We found that the upward bending of the tail induced by the overexpression of urp2 in 24-hpf embryos was not altered in urp mutants. Our results indicate that urp does probably not act as a relay downstream of urp2. In conclusion, the present study showed that zebrafish urp gene is primarily expressed in motoneurons but is apparently dispensable for locomotor activity in the early larval stages., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Urotensin I (UI), a member of the corticotropin-releasing hormone family of peptides, regulates a diverse array of physiological functions, including appetite regulation, defensive behavior and stress response. In this study, firstly, the tissue-specific distribution of UI mRNA in olive flounder (Paralichthys olivaceus) was characterized and we found that UI mRNA was highly expressed in caudal neurosecretory system (CNSS) tissue. Secondly, alignment analysis found that a conserved cAMP response binding (CREB) site and a TATA element were located in the proximal promoter of UI gene. In addition, treatment of forskolin activatated cAMP-CREB pathway and induced the up-regulation of UI mRNA in cultured CNSS, suggesting the role of CREB in regulating the UI mRNA expression. Furthermore, plasma UI concentration and UI mRNA in CNSS showed obvious daily rhythm, with higher values in the daytime while lower values in the nighttime. Thirdly, using bold personality (BP) and shy personality (SP) flounder as an animal model, we found that flounder exhibited significantly higher locomotor activity in the nighttime than in the daytime (P < 0.001), and BP flounder showed significantly higher locomotor activity (P < 0.001) compared with SP flounder both in the daytime and nighttime. Analysis of feeding behavior revealed that BP flounder showed a shorter latency to feed and more attacks to prey. Furthermore, the qPCR and immunohistochemistry results showed that BP flounder expressed significantly lower level of UI mRNA and protein in CNSS tissue. Collectively, our study suggested that the UI plays an important role in locomotor activity and appetite regulation, which provides a basis for understanding the mechanism of defensive behavior and animal personality in flounder., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Urp1 and Urp2 are two neuropeptides of the urotensin II family identified in teleost fish and mainly expressed in cerebrospinal fluid (CSF)-contacting neurons. It has been recently proposed that Urp1 and Urp2 are required for correct axis formation and maintenance. Their action is thought to be mediated by the receptor Uts2r3, which is specifically expressed in dorsal somites. In support of this view, it has been demonstrated that the loss of uts2r3 results in severe scoliosis in adult zebrafish. In the present study, we report for the first time the occurrence of urp2, but not of urp1 , in two tetrapod species of the Xenopus genus. In X. laevis , we show that urp2 mRNA-containing cells are CSF-contacting neurons. Furthermore, we identified utr4, the X. laevis counterparts of zebrafish uts2r3, and we demonstrate that, as in zebrafish, it is expressed in the dorsal somatic musculature. Finally, we reveal that, in X. laevis, the disruption of utr4 results in an abnormal curvature of the antero-posterior axis of the tadpoles. Taken together, our results suggest that the role of the Utr4 signalling pathway in the control of body straightness is an ancestral feature of bony vertebrates and not just a peculiarity of ray-finned fishes.

Atherosclerosis is the leading cause of human death, and its occurrence and development are related to the urotensin II (UII) and UII receptor (UT) system and the biological function of vascular smooth muscle cells (VSMCs). During atherosclerosis, impaired biological function VSMCs may promote atherosclerotic plaque formation. The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway is an important mediator of signal transduction; however, the role of this signaling pathway in atherosclerosis and VSMCs remains unknown. This study aimed to investigate the effects of urantide on the JAK2/STAT3 signaling pathway in atherosclerosis. We examined the effect of urantide on the UII/UT system and the JAK2/STAT3 signaling pathway in a high fat diet induced atherosclerosis rat model and studied the effect and mechanism of urantide on the phenotypic transformation of VSMCs. We found that the UII/UT system and JAK2/STAT3 signaling pathway were highly activated in the thoracic aorta in atherosclerotic rats and in ox-LDL- and UII-induced VSMCs. After urantide treatment, the pathological changes in atherosclerotic rats were effectively improved, and the activities of the UII/UT system and JAK2/STAT3 signaling pathway were inhibited. Moreover, urantide effectively inhibited proliferation and migration and reversed the phenotypic transformation of VSMCs. These results demonstrated that urantide may control the JAK2/STAT3 signaling pathway by antagonizing the UII/UT system, thereby maintaining the biological function of VSMCs and potentially preventing and curing atherosclerosis., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose : We studied the expression of urotensin II (UII) and its relationships with markers of pyroptosis in preeclampsia. Methods : 48 pregnant subjects were recruited consisting of 28 severe preeclampsia pregnancies (SPE) and 20 healthy pregnancies. We detected expressions of UII and markers of pyroptosis such as NLR-family pyrin domain (PYD)-containing 3 (NLRP-3), caspase-1/4/5, interleukin-1β (IL-1β), and gasdermin D (GSDMD) in placentas of patients with SPE and healthy pregnancies. Results : SPE group have higher expression of UII and NLRP-3, caspase-1, interleukin-1β (IL-1β), and GSDMD than that normal controls by IHC, real-time PCR, and western blot. IHC analysis manifests that the expressions of UII and pyroptosis-related molecules are mainly located in the placental cytotrophoblasts. Expressions of UII mRNA and protein are significantly positively correlated with pyroptosis marker such as NLRP3, caspase-1, GSDMD mRNA and protein by Pearson correlation analysis. Moreover, UII, NLRP-3, caspase-1, interleukin-1β (IL-1β), and GSDMD are positively related with systolic blood pressure, meanwhile caspase-1 and GSDMD are positively correlated with urine protein in SPE patients. We firstly verify that UII has a positive correlation with pyroptosis markers in placentas of preeclampsia patients; besides, pyroptosis-related proteins are positively correlated with systolic blood pressure and urine protein in patients with severe preeclampsia.

Sterculia tragacantha (ST) Lindl leaf is commonly used locally in the management of diabetes mellitus (DM) and its complications. This study was aimed at assessing the valuable effects of ST leaf on streptozotocin-diabetic cardiomyopathy (DCM). Streptozotocin was administered intraperitoneally to the experimental animals to induce DM, and hence, placed on different doses of ST for 14 days. Thereafter, on the 15 th day of the experiment, the animals were euthanized, and a number of cardiomyopathy indices were investigated. The diabetic rats exhibited a momentous increase in hyperlipidemia, lipid peroxidation as well as a significant (p < 0.05) decline in antioxidant enzyme activities. The serum creatine kinase MB (CK-MB), C-reactive protein (CRP), cardiac troponin I, tumour necrosis factor-alpha (TNF-α) and urotensin II expression revealed a significant (p < 0.05) upsurge in diabetic rats. Also, the expression of GLUT4 and fatty acid-binding protein 3 (FABP3) were significantly (p < 0.05) reduced in diabetic rats. However, at the conclusion of the experimental trial ST significantly (p < 0.05) attenuated hyperlipidemia, oxidative stress biomarkers by augmenting the antioxidant enzyme activities and decrease in lipid peroxidation, ameliorated CK-MB, CRP, cardiac troponin I, TNF-α, and urotensin-II levels, and improved GLUT4 and FABP3 expressions. Similarly, the administration of ST prevented histological alterations in the heart of diabetic animals. Therefore, the obtained results suggest that ST could mitigate DCM in streptozotocin-induced diabetic rats.

Urotensin II (UII) is involved, via the UII receptor (UTR), in many physiological and pathological processes, including vasoconstriction, locomotion, osmoregulation, immune response, and metabolic syndrome. In silico studies have revealed the presence of four or five distinct UTR (UTR1-UTR5) gene sequences in nonmammalian vertebrates. However, the functionality of these receptor subtypes and their associations to signaling pathways are unclear. In this study, full-length cDNAs encoding four distinct UTR subtypes (UTR1, UTR3, UTR4, and UTR5) were isolated from the western clawed frog (Xenopus tropicalis). In functional analyses, homologous Xenopus UII stimulation of cells expressing UTR1 or UTR5 induced intracellular calcoum mobilization and phosphorylation of extracellular signal-regulated kinase 1/2. Cells expressing UTR3 or UTR4 did not show this response. Furthermore, UII induced the phosphorylation of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) through the UII-UTR1/5 system. However, intracellular cAMP accumulation was not observed, suggesting that UII-induced CREB phosphorylation is caused by a signaling pathway different from that involving Gs protein. In contrast, the administration of UII to cells increased the phosphorylation of guanine nucleotide exchange factor-H1 (GEF-H1) and myosin light chain 2 (MLC2) in all UTR subtypes. These results define four distinct UTR functional subtypes and are consistent with the molecular evolution of UTR subtypes in vertebrates. Further understanding of signaling properties associated with UTR subtypes may help in clarifying the functional roles associated with UII-UTR interactions in nonmammalian vertebrates., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Insulin resistance may become the most powerful predictor of future development of type 2 diabetes mellitus (T2DM) and a therapeutic target for the treatment of the same. Both Resistin, an adipose derived peptide hormone and Urotensin II a potent vasoconstrictor, are reported to be involved in the development of insulin resistance and T2DM but the results remain contradictory. Therefore, investigations were carried out to study the association of T2DM and single nucleotide polymorphism (SNP) in Resistin (RETN) gene at rs3745367 (+ 299 G > A) and Urotensin II (UTS2) gene at rs228648 (+ 143 G > A) and rs2890565 (+ 3836 C > T) in a North Indian population. Method: The present case-control study, conducted from August 2017 to July 2020, involved 168 T2DM patients and 102 healthy controls. SNPs rs3745367, rs228648 and rs2890565 were amplified from genomic DNA in the studied samples by polymerase chain reaction (PCR) using specific primers. The amplified products were genotyped by restriction fragment length polymorphism (RFLP) using particular restriction endonucleases. Clinical parameters viz. glycosylated haemoglobin (HbA1c), fasting blood glucose (FBG), high density lipoprotein cholesterol (HDL-C), triglycerides (TG), total cholesterol (CHL) and fasting insulin were determined by enzymatic methods. Result and conclusion: A statistically significant association between T2DM and RETN gene at SNP rs3745367 (p = 0.001) and UTS2 gene at SNP rs2890565 (p = 0.001) was observed. In RETN gene SNP rs3745367, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were found to be higher in GA + AA combined genotype than in GG genotype for T2DM subjects. Regression analysis revealed that SNP rs2890565 and HOMA-IR were independently associated with the risk of development of T2DM when three SNPs were taken as independent variable adjusted for clinical variables. Among four haplotypes, A/T was found associated with increased risk of T2DM as determined for rs228648 and rs2890565 of UTS2 gene. It can be concluded from these results that polymorphism at rs3745367 of RETN gene and at rs2890565 of UTS2 gene are associated with risk of T2DM in North Indian population.

Reissner fibre (RF), discovered by the 19 th -century German anatomist Ernst Reissner, is a filamentous structure present in cerebrospinal fluid (CSF). RF forms by aggregation of a glycoprotein called SCO-spondin (Sspo), but its function has remained enigmatic. Recent studies have shown that zebrafish sspo mutants develop a curved embryonic body axis. Zebrafish embryos with impaired cilia motility also develop curved bodies, which arises from failure of expression of urotensin related peptide ( urp ) genes in CSF-contacting neurons (CSF-cNs), impairing downstream signalling in trunk muscles. Here, we show that sspo mutants can survive into adulthood, but display severe curvatures of the vertebral column, resembling the common human spine disorder idiopathic scoliosis (IS). sspo mutants also exhibit significant reduction of urp gene expression from CSF-cNs. Consistent with epinephrine in CSF being bound by RF and required for urp expression, treating sspo mutants with this catecholamine rescued expression of the urp genes and axial defects. More strikingly, providing Urp2, specifically in the CSF-cNs, rescued body curvature of sspo homozygotes during larval stages as well as in the adult. These findings bridge existing gaps in our knowledge between cilia motility, RF, Urp signalling and spine deformities, and suggest that targeting the Urotensin pathway could provide novel therapeutic avenues for IS., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Objective: To investigate the role of urantide in the prevention and treatment of atherosclerotic nephropathy by antagonizing the urotensin II/urotensin receptor (UII/UT) system and regulating JAK2/STAT3 signaling pathway., Methods: Atherosclerosis (AS) rats were treated with urantide at a concentration of 30 μg/kg for 3, 7, 14 days., Results: An excessive expression of UII and its receptor G protein-coupled receptor 14 (GPR14) was seen in AS rat kidneys and the expression was significantly reduced after urantide administration. Either body weight, renal functions of urea nitrogen, urine proteins and anion gaps or expression of kidney injury-related genes Agtr1α, Nox4, Cyba and Ncf1 were improved after AS rats were treated with urantide. After antagonizing the UII/GPR14 system by using urantide, the expression of genes and proteins in the JAK2/STAT3 and ERK pathways was decreased, and the nuclear protein p-STAT3 and p-ERK were obviously decreased. p-JAK2 and p-STAT3 were decreased in the urantide group in a time-dependent manner. The UII/GPR14 system and JAK2/STAT3 signals were localized in tubules and then glomeruli to affect renal reabsorption and filtration., Conclusion: Urantide can effectively block the UII/GPR14 system by regulating the JAK2/STAT3 signaling pathway to prevent and treat atherosclerosis-related kidney injury. At this stage, effective inhibition of inflammatory signaling pathways is of great significance in the treatment of atherosclerosis., Competing Interests: Declaration of competing interest The authors declare that the research was conducted without any commercial or financial interest, which could be understood as a potential conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The aim of the present study was to investigate the effect of urantide on collagen metabolism in the hearts of rats with atherosclerosis (AS) by evaluating the expression of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway constituents. Urantide was delivered to rats with AS via tail vein injection for 3, 7 and 14 days. Serological indicators were identified by an automated biochemical analyzer. Histomorphological changes in the cardiac tissue of rats were observed by pathological staining techniques. The expression of genes and proteins was assessed using reverse transcription‑quantitative PCR and western blot analysis, respectively. Localization of proteins was detected by immunofluorescence. Overexpression of urotensin II (UII) and its receptor, G protein‑coupled receptor 14 (GPR14), was observed in the hearts of rats with AS and the expression of both proteins significantly declined after urantide administration. Triglyceride, total cholesterol, low‑density lipoprotein, high‑density lipoprotein and calcium levels were improved in rats with AS following treatment with urantide. Notably, urantide was able to antagonize the UII/GPR14 system. Urantide treatment resulted in markedly decreased expression levels of matrix metalloproteinase 2 (MMP‑2), collagen type I/III, and genes and proteins in the JAK2/STAT3 pathway. By contrast, TIMP metallopeptidase inhibitor 2 (TIMP‑2) levels were increased. In addition, the MMP‑2/TIMP‑2 protein ratio was significantly decreased in rats treated with urantide compared with AS rats with no urantide treatment. Constituents of the JAK2/STAT3 pathway and collagen type I/III were found to be localized in the diseased tissue and blood vessels of the hearts of rats with AS. In conclusion, urantide was able to effectively block the UII/GPR14 system by regulating the JAK2/STAT3 pathway and collagen metabolism. Inhibition of the UII/GPR14 system may prevent and potentially treat atherosclerotic myocardial fibrosis. Based on the current results, it was hypothesized that collagen metabolism may be associated with the JAK2/STAT3 pathway.

Introduction: Diabetes mellitus (DM) is a primary disease of the carbohydrate metabolism that is characterised by absolute or relative insulin deficiency, or insulin resistance. Although life expectancy is low for diabetic patients, the prognosis has been improved in recent decades. Metformin is an oral antidiabetic that reduces insulin resistance and plasma glucose levels by decreasing glucose production in the liver. It can be used as a standalone treatment or in combination with other antidiabetic medications or insulin. Urotensin 2 (U-II), which is one of the most effective known vasoconstrictor peptides, was observed to act as a vasoconstrictor in diseases such as hypertension and heart failure, and to induce vasodilation in healthy volunteers. Some studies have proposed that the activation of the U-II system could lead to metabolic syndrome. Certain studies have determined a link between DM and U-II. However, there exist no studies on the effects of U-II in recently diagnosed type 2 DM patients after metformin treatment. This study aims to investigate the plasma and saliva levels of U-II at diagnosis and after a three-month metformin treatment in recently diagnosed type 2 DM patients, and to compare these levels to those of healthy volunteers., Material and Methods: Our study compared 30 recently diagnosed type 2 DM patients to their states after three-month metformin treatment and 30 healthy volunteers., Results: When compared with the control group, there was no significant increase in the plasma and saliva U-II levels of recently diagnosed type 2 DM patients. We determined a statistically significant increase in the plasma and saliva ureotensin-2 levels of recently diagnosed type 2 DM patients after a three-month metformin treatment (p < 0.05)., Conclusions: It was concluded that the patients with type 2 DM have a multifactorial aetiopathogenesis and an increase in U-II levels after metformin treatment. Metformin has no known effect on the U-II metabolism; therefore, the findings need confirmation through more clinical and experimental studies with more participants.

The urotensinergic system, comprised of a G protein-coupled receptor (UT) and two endogenous ligands named urotensin II (UII) and urotensin II-related peptide (URP), has garnered significant attention due to its involvement in the initiation and/or the evolution of various diseases. Accordingly, multiple studies using animal models have demonstrated that UT antagonists may have utility as potential therapeutic agents for treating atherosclerosis, pulmonary arterial hypertension, heart failure, and cancer. Unfortunately, clinical investigations of UT antagonist candidates showed limited efficacy in humans. This system, which has yet to be effectively targeted, therefore remains to be therapeutically exploited. Here, we discuss various hypotheses that could explain the in vivo failure of UT antagonists., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The caudal neurosecretory system (CNSS) is a part of stress response system, a neuroendocrine structure unique to fish. To gain a better understanding of the physiological roles of CNSS in fluid homeostasis, we characterized the tissue distribution of urotensin I (UI) expression in European flounder (Platichthys flesus), analyzed the effect chronic exposure to seawater (SW) or freshwater (FW), transfer from SW to FW, and reverse transfer on mRNA levels of UI, L-type Ca 2+ channels and Ca-activated K + channels transcripts in CNSS. The tissue distribution demonstrated that the CNSS is dominant sites of UI expression, and UI mRNA level in fore brain appeared greater than other non-CNSS tissues. There were no consistent differences in CNSS UI expression or urophysis UI content between SW- and FW-adapted fish in July and September. After transfer from SW to FW, at 8 h CNSS UI expression was significantly increased, but urophysis UI content was no significantly changes. At 24 h transfer from SW to FW, expression of CNSS UI was no apparent change and urophysis UI content was reduced. At 8 h and 24 h after transfer from FW to SW UI expression and urophysis UI content was no significantly effect. The expression of bursting dependent L-type Ca 2+ channels and Ca-activated K + channels in SW-adapted fish significantly decreased compared to those in FW-adapted. However, there were no differences in transfer from SW to FW or from FW to SW at 8 h and 24 h. Thus, these results suggest CNSS UI acts as a modulator in response to osmotic stress and plays important roles in the body fluid homeostasis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

New Findings: What is the central question of this study? Urotensin II is upregulated in patients in the later stages of chronic kidney disease (CKD), particularly in individuals requiring dialysis. Could treatment with a urotensin II receptor antagonist slow progression of renal disease? What is the main finding and its importance? In the rat, expression of urotensin II and its receptor increased, extending into cortical structures as CKD progressed towards end-stage renal failure. Subchronic treatment with a urotensin receptor antagonist slowed but did not prevent progression of CKD. This suggests that urotensin II contributes to the decline in renal function in CKD., Abstract: Elevated serum and urine urotensin II (UII) concentrations have been reported in patients with end-stage chronic kidney disease (CKD). Similar increases in UII and its receptor, UT, have been reported in animal models of CKD, but only at much earlier stages of renal dysfunction. The aim of this study was to characterize urotensin system expression as renal disease progresses to end-stage failure in a ⅚ subtotal nephrectomy (SNx) rat model. Male Sprague-Dawley rats underwent SNx or sham surgery and were killed at 8 weeks postsurgery [early (E)] or immediately before end-stage renal failure [30 ± 3 weeks postsurgery; late (L)]. Systolic blood pressure, urinary albumin:creatinine ratio and glomerulosclerosis index were all increased in SNx-E rats compared with sham-E by 8 weeks postsurgery. These changes were associated with an increase in renal immunoreactive UII staining but little change in UT expression. As CKD progressed to end-stage disease in the SNx-L group, markers of renal function deteriorated further, in association with a marked increase in immunoreactive UII and UT staining. Subchronic administration of a UT antagonist, SB-611812, at 30 mg kg -1  day -1 for 13 weeks, in a separate group of SNx rats resulted in a 2 week delay in the increase in both systolic blood pressure and urinary albumin:creatinine ratio observed in vehicle-treated SNx but did not prevent the progression of renal dysfunction. The urotensin system is upregulated as renal function deteriorates in the rat; UT antagonism can slow but not prevent disease progression, suggesting that UII plays a role in CKD., (© 2018 The Authors. Experimental Physiology Published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

In accordance with their common but also divergent physiological actions, human urotensin II (1) and urotensin II-related peptide (2) could stabilize specific urotensin II receptor (UTR) conformations, thereby activating different signaling pathways, a feature referred to as biased agonism or functional selectivity. Sequential N-methylation of the amides in the conserved core sequence of 1, 2, and fragment U-II 4-11 (3) shed light on structural requirements involved in their functional selectivity. Thus, 18 N-methylated UTR ligands were synthesized and their biological profiles evaluated using in vitro competition binding assays, ex vivo rat aortic ring bioassays and BRET-based biosensor experiments. Biological activity diverged from that of the parent structures contingent on the location of amide methylation, indicating relevant hydrogen-bond interactions for the function of the endogenous peptides. Conformational analysis of selected N-methyl analogs indicated the importance of specific amide residues of 2 for the distinct pharmacology relative to 1 and 3.

Songbirds communicate through learned vocalizations, using a forebrain circuit with convergent similarity to vocal-control circuitry in humans. This circuit is incomplete in female zebra finches, hence only males sing. We show that the UTS2B gene, encoding Urotensin-Related Peptide (URP), is uniquely expressed in a key pre-motor vocal nucleus (HVC), and specifically marks the neurons that form a male-specific projection that encodes timing features of learned song. UTS2B-expressing cells appear early in males, prior to projection formation, but are not observed in the female nucleus. We find no expression evidence for canonical receptors within the vocal circuit, suggesting either signalling to other brain regions via diffusion or transduction through other receptor systems. Urotensins have not previously been implicated in vocal control, but we find an annotation in Allen Human Brain Atlas of increased UTS2B expression within portions of human inferior frontal cortex implicated in human speech and singing. Thus UTS2B (URP) is a novel neural marker that may have conserved functions for vocal communication.

The aims of this study are to explore the correlation between the expressions of urotensin II (UII) and autophagic markers (LC3 and P62) in patients with severe preeclampsia (SPE). A total of 64 pregnant subjects were recruited, including 29 healthy pregnancies and 35 preeclamptic patients (7 mild preeclamptic (MPE) patients and 28 SPE patients). UII and autophagic markers expression in placenta specimens was investigated by immunohistochemistry (IHC), RT-qPCR, and western blot. IHC analysis manifested that the expressions of UII and autophagic markers were mainly located in the placental cytotrophoblast and syncytiotrophoblast. Western blot and IHC analysis both indicated that the expression of UII was significantly correlated with autophagic marker LC3II (by western blot) or LC3 (by IHC) (r = 0.495, P = 0.010; r = 0.816, P = 0.007). Moreover, SPE group had higher expression of UII and LC3II, lower expression of P62 than that of normal controls. The expression of LC3II was positively related with systolic blood pressure (SBP) and urinary protein level (SBP (r = 0.501, P = 0.003) and urine protein quantitation (r = 0.509, P = 0.022)), whereas P62 had negative correlation with SBP. We first verify that UII has positive correlation with autophagic marker LC3 in placentas of preeclampsia patients; besides, autophagic levels are positively correlated with SBP and urine protein in patients with SPE.

The peptide urotensin II (UII) mediates multiple physiology effects in mammals and fishes, and UII expression shows a tissue-specific pattern. However the mechanism is still unknown. In the present study high level of UII mRNA was detected in the caudal neurosecretory system (CNSS) of the olive flounder when compared to other tissues. We examined whether epigenetic mechanisms of DNA methylation are involved in UII gene expression. Methylation DNA immune precipitation (MeDIP) assay showed low methylation of UII promoter in CNSS tissue compared with muscle and spinal cord. Methylation of UII promoter was further assessed through bisulphate sequencing analysis. Low level methylation (31%) in CpG island of UII promoter was detected in CNSS tissue, while methylation status in muscle and spinal cord was 89% and 91%, respectively. In addition, high conserved sites of Hoxd4 in UII promoter were found. Activation of Hoxd4 mRNA using transretinoic acid (RA) resulted in 18-fold increase of UII mRNA expression in CNSS and high locomotor activity in medaka, confirming that Hoxd4 is also involved in UII gene transcriptional regulation. Taken together, our data provide the first evidence of the epigenetic mechanism of promoter methylation in transcriptional regulation of UII expression in a tissue-specific manner, and Hoxd4 may also participate in UII gene transcription in flounder., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Urotensin II (UII) contributes to cardiovascular diseases by activating vasoactive peptides. The present study aimed to determine the effect of UII on aldosterone (ALD) and its receptor in cultured adventitial fibroblasts (AFs) and the tunica adventitia of rat vessels to explore the possible mechanisms underlying vascular remodeling. Expression levels of aldosterone and its receptor on tunica adventitia were determined using immunohistochemistry. Growth‑arrested AFs and tunica adventitia from rat vessels were incubated with UII and inhibitors of various signal transduction pathways. ALD receptor (ALD‑R) mRNA expression levels and ALD protein exoression levels were determined by reverse transcription‑quantitative polymerase chain reaction and ELISA, respectively. Aldosterone and its receptors were expressed on tunica adventitia. UII promoted ALD protein secretion from cells in a dose‑ and time‑dependent manner. ALD‑R mRNA expression in cells was also dysregulated. Furthermore, the effects of UII were substantially inhibited by treatment with the inhibitors PD98059, Y‑27632, H‑7, CSA and nicardipine. These results were further verified in the tunica adventitia of rat vessels. The present findings indicated that UII stimulated ALD protein secretion and ALD‑R mRNA expression in AFs and in the tunica adventitia of rat vessels; moreover, this effect may be mediated by signal transduction pathways involving MAPK, Rho, PKC, calcineurin and Ca2+. UII may also contribute to vascular remodeling by stimulating the production of ALD and its receptor.

This study aimed to investigate the potential role of urotensin-II receptors in sepsis-induced lung injury in diabetic mice using urotensin-II receptor agonists and antagonists. A total of 110 male CD1 mice were used in this study. Diabetes was induced by 200mg/kg streptozotocin. One month after diabetes induction, the cecal ligation and puncture-induced polymicrobial sepsis model was applied in the diabetic and non-diabetic mice. Low and high doses of human urotensin-II agonist (HU-II) and antagonist (palosuran) were administered one hour after sepsis induction. HU-II administration was repeated in two-hour intervals. Blood and tissue samples were collected at 6 and 12H after sepsis induction for biochemical, molecular, and histopathologic examinations. Regarding to the lungs mRNA expression and immunohistochemistry results of TNF-α, IL1 β, IL6, and NF-κB, it was observed that cytokine levels significantly increased in the diabetes group and the sepsis groups compared to the healthy group; this increase was significantly higher in the diabetes-sepsis groups. Our biochemical (superoxide dismutase, glutathione, and malondialdehyde) and histopathological findings in the lungs also supported these results. All increased parameters were significantly reduced dose-dependently by the administration of palosuran, an urotensin receptor antagonist. mRNA expression of urotensin-II and its receptor were examined in the lung tissue. Palosuran administration significantly reduced the urotensin-II and urotensin-II receptor levels that increased in the damaged tissue. This study has shown that urotensin-II and urotensin-II receptors contribute to the aggravation of sepsis-induced lung injury in diabetic mice; palosuran prevents this damage by antagonizing urotensin-II receptors., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: The aim of this study was to evaluate the possible roles of endothelin-1 and angiotensin-II in urotensin-II vasoconstriction and in endothelial dysfunction induced by mercury., Background: Urotensin-II, the most potent vasoactive peptide, is entwined with the cardiovascular diseases and has been labelled as a new pathophysiological biomarker., Methods: Rat aortic rings were pre-incubated with sb-710411, bq-123, and captopril. Doses of human urotensin-II with increased concentrations were applied in all groups in the presence or absence of mercury chloride. In another set of the experiment, aortic rings were treated with a single dose of mercury chloride in the presence of each of the above blockers., Results: Angiotensin-II and endothelin-1 mediated the vascular responses to the peptide urotensin-II under conditions of both intact endothelium and endothelial impairments induced by mercury. Urotensin-II, angiotensin-II and endothelin-1 significantly participated in vascular responses to mercury chloride., Conclusion: The novel finding was that urotensin-II is potentiated under the condition of endothelial dysfunction. Endothelin-1 and angiotensin-II pathways could be heavily exploited in modulating endothelial dysfunction impacts and peptide vascular actions (Tab. 1, Fig. 4, Ref. 30).

Background: The aim of this study was to identify the possible relationship of 5-fluorouracil (5-FU)-related arterial vasoconstriction with urotensin-2 (UT-2), which has a high potential as an endogenic vasoconstrictor., Methods: We assigned the patients to 1 of 3 groups. Patients in group 1 received a bolus of 5-FU, those in group 2 a continuous infusion (CI) of 5-FU, and those in group 3 no 5-FU, which was also a control group. Pre- and post-treatment UT-2 levels and brachial arterial diameters were measured and recorded in all patients., Results: 132 patients were included in the study. Pre- and post-treatment brachial artery diameters were similar in all groups: in group 1 (3.28 ± 0.52 vs. 3.25 ± 0.44 mm, p = 0.740), in group 2 (3.57 ± 0.47 vs. 3.46 ± 0.45 mm, p = 0.441) and in the control group (3.51 ± 0.52 vs. 3.25 ± 0.44 mm, p = 0.818). Pre- and post-treatment UT-2 levels were significantly different in each group: in group 1 (39.5 ± 30.9 vs. 56.7 ± 27.1 ng/ml, p = 0.0001), in group 2 (37.7 ± 33.7 vs. 62.5 ± 37.7 ng/ml, p = 0.0001) and in the control group (52.9 ± 40.2 vs. 60.8 ± 40.7 ng/ml, p = 0.006)., Conclusion: Our findings suggest that UT-2 has a high potential as a vasoconstrictor agent in our bodies and its level increases through a bolus or CI 5-FU. Increased UT-2 levels are likely to play a role in 5-FU-related cardiac toxicity pathogenesis., (© 2018 S. Karger GmbH, Freiburg.)

Urotensin II (UT II) is an important factor of cellular homeostasis. This regulatory peptide is involved in the pathophysiology of many disorders. For example, it plays an important role in the pathogenesis of acute and chronic diseases, stressful and adaptive reactions of the body, in the development of cardiovascular pathologies, metabolic syndrome, inflammation, liver cirrhosis, renal failure, diabetic nephropathy, reproductive dysfunction, progression of psychosomatic, psychoendocrinal and psychiatric disorders. In this concern, the involvement of UT II in the pathophysiology of many processes determines the perspectives for the development of blockers of urotensin receptors for the treatment of the aforementioned diseases. It is important that even today this kind of perspective is feasible due to the synthesis of a series of GPR14 blockers. The objective of this review is to discuss current molecular mechanisms of biological activity, regulatory functions of UT II, its role in the pathogenesis of different nosologies, as well as analysis of the possible routes of exposure to GPR14 as potential therapeutic targets., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

While sharing common biological activity, the two endogenous ligands of the G protein-coupled receptor UT, e.g. urotensin II (UII) and urotensin II-related peptide (URP), also exhibit distinct effects that could be explained by distinct interactions with their cognate receptor (UT). Accordingly, introduction of a similar substitution at the intracyclic Tyr residue in UII and URP led to compounds with divergent pharmacologic profiles. Hypothesizing that the Tyr 6 residue of URP is a key-element to understand the specific activation of UT by URP, we undertook a study of the structure-activity relationship in which this particular residue was replaced by non-natural and constrained amino acids. Each compound was evaluated for its ability to bind UT, to induce rat aortic ring contraction and to activate Gq and G 12 signaling pathways. We identified [Pep 6 ]URP, that binds UT with an affinity similar to that of URP, but behaves as a biased ligand. Used as an antagonist, this peptide is also able to selectively reduce the maximal aortic contraction of URP but not UII. Our results suggest that the orientation of the Tyr residue can stabilize at least two different conformations of UT, leading to biased signaling and a probe-dependent allosteric effect., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Aristolochic acid is a component of many types of Chinese medicine, which are commonly used to treat almost all human diseases. However, aristolochic acid may cause nephropathy. Urotensin II (UII) and transforming growth factor (TGF)‑β1 are important signaling factors, which are expressed at elevated levels during the development of nephropathy. However, the association between UII and TGF‑β1 expression remains unclear. In the current study, the regulatory association between UII and TGF‑β1 expression was investigated using a rat aristolochic acid nephropathy model and the NRK‑52E cell line. The expression levels of UII and TGF‑β1 were identified to be constantly increased in the rat aristolochic acid nephropathy model, even 10 days after administration of Aristolochiae manshuriensis decoction was terminated. Notably, increases in the TGF‑β1 expression levels occurred later than those of UII. Furthermore, UII enhanced TGF‑β1 expression in, and secretion from, NRK‑52E cells. These data indicate that UII and TGF‑β1 are important in the development of aristolochic acid nephropathy, and UII enhances TGF‑β1 expression levels and secretion during aristolochic acid nephropathy. However, the underlying mechanisms for the precise roles of UII and TGF‑β1 as well as the method by which UII regulates the expression TGF‑β1 in aristolochic acid nephropathy remain to be elucidated in future studies.

The model of urotensin II (UII)-induced cardiomyocyte hypertrophy has been widely used in studies on hypertrophy. However, the molecular mechanisms responsible for UII-induced cardiomyocyte hypertrophy have not yet been fully elucidated. It has been demonstrated that cardiomyocyte hypertrophy induced by UII is associated with changes in the intracellular Ca2+ concentration. In the present study, we investigated whether the cAMP-dependent protein kinase A (PKA)‑mediated upregulation of the phosphorylation levels of phospholamban (PLN) at Ser16 contributes to UII-induced cardiomyocyte hypertrophy. After primary cultures of neonatal rat cardiomyocytes were exposed to UII for 48 h, cell size, protein/DNA contents and intracellular Ca2+ levels were detected. Western blot analysis was used to quantify the phosphorylated and total forms of PKA, PLN and the total amount of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA)2a. UII increased the cell size, the protein/DNA ratio and the intracellular Ca2+ levels, consistent with the characteristics of hypertrophic response. In addition, exposure to UII upregulated the phosphorylation levels of PKA, and the expression levels of its downstream proteins, PLN and SERCA2a. However, treatment with PKA inhibitor (KT-5720) reversed all these effects of UII. On the whole, our results suggest that UII induces cardiomyocyte hypertrophy through the PKA-mediated upregulation of PLN phosphorylation at Ser16, which provides a new experimental foundation for the prevention and/or treatment of cardiac hypertrophy.

Conformation and dynamics of the vasoconstrictive peptides human urotensin II (UII) and urotensin related peptide (URP) have been investigated by both unrestrained and enhanced-sampling molecular-dynamics (MD) simulations and NMR spectroscopy. These peptides are natural ligands of the G-protein coupled urotensin II receptor (UTR) and have been linked to mammalian pathophysiology. UII and URP cannot be characterized by a single structure but exist as an equilibrium of two main classes of ring conformations, open and folded, with rapidly interchanging subtypes. The open states are characterized by turns of various types centered at K 8 Y 9 or F 6 W 7 predominantly with no or only sparsely populated transannular hydrogen bonds. The folded conformations show multiple turns stabilized by highly populated transannular hydrogen bonds comprising centers F 6 W 7 K 8 or W 7 K 8 Y 9 . Some of these conformations have not been characterized previously. The equilibrium populations that are experimentally difficult to access were estimated by replica-exchange MD simulations and validated by comparison of experimental NMR data with chemical shifts calculated with density-functional theory. UII exhibits approximately 72% open:28% folded conformations in aqueous solution. URP shows very similar ring conformations as UII but differs in an open:folded equilibrium shifted further toward open conformations (86:14) possibly arising from the absence of folded N-terminal tail-ring interaction. The results suggest that the different biological effects of UII and URP are not caused by differences in ring conformations but rather by different interactions with UTR.

The aims of this study are to observe irisin and urotensin II (UII) levels in serum and placenta in normal pregnant and preeclamptic women and investigate the relationship between expressions irisin and UII, and their association with blood pressure. A total of 67 pregnant subjects were recruited, including 31 healthy and 36 preeclamptic pregnant women. Serum irisin and UII concentrations were measured. Expressions of fibronectin type III domain-containing protein 5 (FNDC5) (irisin precursor) and UII in placenta specimens were performed. There was no significant difference of serum irisin levels between severe preeclamptic (SPE)) patients, mild preeclamptic (MPE) patients and normal controls, while serum UII was significantly higher in preeclamptic women than normal pregnancy. There was no relationship between serum UII and irisin levels. In patients with preeclampsia, serum irisin was negatively associated with systolic and diastolic blood pressure(r = -0.350, P = 0.004, r = -0.307, P = 0.011), while serum UII was positively associated with systolic blood pressure (r = 0.291, P = 0.031). Serum irisin, UII, urinary protein level, BMI and serum creatinine were the independent determinants of blood pressure in preeclampsia by multiple regression analysis. Protein expression of FNDC5 and UII was upregulated in placenta of patients with SPE and positively correlated with systolic blood pressure and urinary protein level. We firstly verify that serum irisin and placental irisin precursor expressions have differently correlated with blood pressure. Expressions of irisin and urotensin II have relationships with blood pressure in patients with preeclampsia.

Urotensin II and Urotensin-II receptors are important molecular factors that regulate vasoconstriction and all the diseases that are linked to abnormalities in blood pressure regulation (i.e.: hypertension, kidney diseases, cirrhosis etc.). Recently, Urotensin II and its receptor have also been involved in metabolic syndrome, diabetes and schizophrenia. Recent strong findings suggest that Urotensin II and its receptor are involved in the onset and development of different epithelial cancers. Indeed, it was reported that cell growth, motility and invasion in human breast, bladder, prostate, colorectal and glioblastoma cancer cells were regulated by Urotensin II and Urotensin-II receptor axis. This axis also regulated focal adhesion kinase and small Guanosine-5'-triphosphate binding proteins that likely had a role in motility and invasion mediated by Urotensin-II receptor. Additionally, its expression on tumour tissues is variably associated to the prediction of the clinical outcome of the patients and it can be considered an alternative molecular marker to be used as prognostic factor in human cancers. In conclusion, a new weapon in the treatment of human cancers is highlighting a new scenario for the future., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Urotensin II (UII) was first recognized for its constrictive and natriuretic properties in fish almost 40 years ago, and recent studies have suggested that it exerts pro-fibrotic effects in a number of cell lines. In this study, we aimed to evaluate the role of UII in extracellular matrix (ECM) synthesis and secretion in advanced glycation end product (AGE)-stimulated rat proximal tubular epithelial cells (NRK-52E cells). UII promoted the proliferation of the NRK-52E cells in a dose-dependent manner over a concentration range of 10-10-10-8 mol/l and this effect was partly inhibited by both nimodipine and EDTA. Furthermore, AGE-BSA promoted the mRNA and protein expression of UII, fibronectin (FN) and collagen IV (ColIV) in the NRK-52E cells in a dose- and time-dependent manner. In addition, UII promoted the mRNA expression and protein secretion of transforming growth factor (TGF)-β1, FN and Col IV by the NRK-52E cells. Our results suggest that UII promotes the proliferation of NRK-52E cells, an effect which is mediated by the influx of extracellular calcium ions. In addition, our data indicate that AGEs promote UII expression in NRK-52E cells, and that TGF-β1 signaling is a candidate pathway mediating the involvement of UII in renal fibrosis. Collectively, our data suggest that the UII-TGF-β1 signaling may be an important factor in tubulointerstitial nephropathy in diabetes.

The urotensin II/urotensin receptor (UII/UT) system can mediate inflammatory liver injury in acute liver failure (ALF); however; the related mechanism is not clear. In this study, we confirmed that lipopolysaccharide/D-galactosamine (LPS/D-GalN) induced up-regulation of liver interferon regulatory factor 3 (IRF3) in ALF mice, whereas the UT antagonist urantide inhibited the up-regulated liver IRF3. LPS stimulation induced IRF3 transcription and nuclear translocation and promoted the secretion of interleukin-6 (IL-6), interferon (IFN)-β, and IFN-γ in Kupffer cells (KCs); these effects in LPS-stimulated KCs were inhibited by urantide. Knockdown of IRF3 using an adenovirus expressing an IRF3 shRNA inhibited IFN-β transcription and secretion as well as tumor necrosis factor (TNF)-α and IL-1β secretion from LPS-stimulated KCs; additionally, IL-10 transcription and secretion were promoted in response to LPS. However, LPS-stimulated TNF-α and IL-1β mRNA was not affected in the KCs. The IRF3 shRNA also did not have a significant effect on the NF-κB p65 subunit and p38MAPK protein phosphorylation levels in the nuclei of LPS-stimulated KCs. Therefore, IRF3 expression and activation depended on the signal transduction of the UII/UT system, and played important roles in UII/UT-mediated immune inflammatory injury in the liver but did not affect NF-κB and p38 MAPK activity., Competing Interests: The authors have declared that no competing interest exist.

This study investigated possible role of U-II and its receptor expression in inflammation by using UTR agonist and antagonist in carrageenan induced acute inflammation. Rats were divided into 5 groups as (1) Healthy control, (2) Carrageenan control, (3) Carrageenan +Indomethacin 20mg/kg, orally, (4) Carrageenan +AC7954 (U-II receptor agonist, intraperitoneally) 30mg/kg and (5) Carrageenan +SB657510 (UTR antagonist, intraperitoneally) 30mg/kg. 1h after drug administration, carrageenan was injected. At the 3rd hour after carrageenan injection, agonist produced no effect while antagonist 63% anti-inflammatory effect respectively. UTR and UT-II expression increased in carrageenan induced paw tissue. Antagonist administration prevented the decrease in an antioxidant system and also capable to decrease TNF-α and IL-6 mRNA expressions. This study showed the role of urotensin II receptors in the physiopathogenesis of acute inflammatory response that underlying many diseases accompanied by inflammation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The present study aimed to investigate the role and mode of action of urotensin II (U II) in the occurrence and progression of cardiac fibrosis in a pressure‑overload rat model. Coarctation of the abdominal aorta was used to establish an animal model, and postoperative echocardiography, hemodynamic detection, hematoxylin and eosin staining, Masson staining and immunohistochemistry were performed to assess the changes in cardiac function and pathology. The expression levels of U II, G‑protein‑coupled receptor 14 and collagen (Col) I and Col III in the myocardial tissues were also analyzed. Neonatal rat fibroblasts were isolated, cultured and subsequently, generations 3‑5 were randomly divided into different groups for the detection of Col I and Col III levels by enzyme‑linked immunosorbent assay and western blotting. The protein expression levels were markedly increased in the model group, and this increase correlated with an increase in myocardial fibrosis. In cultured neonatal rat fibroblast cells, 10‑8 mol/l U II significantly stimulated the synthesis of Col I and Col III (P<0.01) compared with the control group. Compared with the U II group, the administration of KT5720 (1 mol/l) or SB‑611812 (1 mol/l) significantly reduced the synthesis and expression levels of Col I and Col III (P<0.05). U II may exert an important role in the process of myocardial fibrosis in chronic pressure‑overload rats, and the cyclic adenosine monophosphate‑protein kinase A signaling pathway may be partly involved in this process.

Multiform glioblastomas (GBM) are the most frequent and aggressive primary brain tumors in adults. The poor prognosis is due to neo-angiogenesis and cellular invasion, processes that require complex chemotaxic mechanisms involving motility, migration and adhesion. Understanding these different cellular events implies identifying receptors and transduction pathways that lead to and promote either migration or adhesion. Here we establish that glioma express the vasoactive peptide urotensin II (UII) and its receptor UT and that UT-mediated signaling cascades are involved in glioma cell migration and adhesion. Components of the urotensinergic systems, UII and UT, are widely expressed in patient-derived GBM tissue sections, glioma cell lines and fresh biopsy explants. Interestingly, gradient concentrations of UII produced chemoattracting migratory/motility effects in glioma as well as HEK293 cells expressing human UT. These effects mainly involved the G13/Rho/rho kinase pathway while partially requiring Gi/o/PI3K components. In contrast, we observed that homogeneous concentrations of UII drastically blocked cell motility and stimulated cell-matrix adhesions through a UT/Gi/o signaling cascade, partially involving phosphatidylinositol-3 kinase. Finally, we provide evidence that, in glioma cells, homogeneous concentration of UII allowed translocation of Gα13 to the UT receptor at the plasma membrane and increased actin stress fibers, lamellipodia formation and vinculin-stained focal adhesions. UII also provoked a re-localization of UT precoupled to Gαi in filipodia and initiated integrin-stained focal points. Altogether, these findings suggest that UT behaves as a chemotaxic receptor, relaying a signaling switch between directional migration and cell adhesion under gradient or homogeneous concentrations, thereby redefining sequential mechanisms affecting tumor cells during glioma invasion. Taken together, our results allow us to propose a model in order to improve the design of compounds that demonstrate signaling bias for therapies that target specifically the Gi/o signaling pathway.

A proof-of-concept library of pyrrolodiazepinone small molecules was designed based on the Bip-Lys-Tyr motif found in a recently described modulator of the urotensinergic system. Solid-phase synthesis provided 13 analogues, which were tested for their ability to modulate selectively and differentially the potency (EC50) and efficacy (E(max)) of hUII and URP ex vivo in a rat aortic ring bioassay. Notably, at 14 μM, pyrrolodiazepinone R-4a inhibited completely hUII-induced contractions and increased URP-associated vasoconstriction. Pyrrolodiazepinone R-4a represents, to the best of our knowledge, a first-in-class small molecule that exerts a probe-dependent effect on hUII and URP biological activities and proves that UT modulators of the urotensin II receptor (UT) can be rationally designed. The importance of the UT system in the pathogenesis and progression of cardiovascular diseases highlights the utility of pyrrolodiazepinones such as R-4a, which exhibit promising potential as tools for differentiating the respective roles, signaling pathways, and phenotypic outcomes of UII and URP in the UT system.

Urotensin II (UII) exhibits diverse physiological actions including vasoconstriction, locomotor activity, osmoregulation, and immune response via the UII receptor (UTR) in mammals. However, in amphibians the function of the UII-UTR system remains unknown. In the present study, we investigated the potential immune function of UII using leukocytes isolated from the African clawed frog, Xenopus laevis. Stimulation of male frogs with lipopolysaccharide increased mRNA expression of UII and UTR in leukocytes, suggesting that inflammatory stimuli induce activation of the UII-UTR system. Migration assays showed that both UII and UII-related peptide enhanced migration of leukocytes in a dose-dependent manner, and that UII effect was inhibited by the UTR antagonist urantide. Inhibition of Rho kinase with Y-27632 abolished UII-induced migration, suggesting that it depends on the activation of RhoA/Rho kinase. Treatment of isolated leukocytes with UII increased the expression of several cytokine genes including tumor necrosis factor-α, interleukin-1β, and macrophage migration inhibitory factor, and the effects were abolished by urantide. These results suggest that in amphibian leukocytes the UII-UTR system is involved in the activation of leukocyte migration and cytokine gene expression in response to inflammatory stimuli., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The urotensin II receptor (UTR) has long been studied mainly for its involvement in the cardiovascular homeostasis both in health and disease state. Two endogenous ligands activate UTR, i.e. urotensin II (U-II) and urotensin II-related peptide (URP). Extensive expression of the two ligands uncovers the diversified pathophysiological effects mediated by the urotensinergic system such as cardiovascular disorders, smooth muscle cell proliferation, renal disease, diabetes, and tumour growth. As newly reported, U-II and URP have distinct effects on transcriptional activity, cell proliferation, and myocardial contractile activities supporting the idea that U-II and URP interact with UTR in a distinct manner (biased agonism). To shed light on the origin of the divergent activities of the two endogenous ligands, we performed a conformational study on URP by solution NMR in sodium dodecyl sulfate micelle solution and compared the obtained NMR structure of URP with that of hU-II previously determined. Finally, we undertook docking studies between URP, hU-II, and an UT receptor model., (Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.)