Urotensin II receptor deficiency ameliorates ligation-induced carotid intimal hyperplasia partially through the RhoA-YAP1 pathway.

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.

Urantide alleviates atherosclerosis-related liver and kidney injury via the Wnt/ß-catenin signaling pathway in ApoE(-/-) mice.

OBJECTIVE: To investigate the role of urantide in the prevention and treatment of atherosclerosis (AS)-related liver and kidney injury by antagonizing the urotensin II/urotensin receptor (UII/UT) system and regulating the Wnt/ß-catenin signaling pathway. METHODS: Atherosclerotic ApoE-/- mice were treated with 20 mg/kg, 30 mg/kg, and 40 mg/kg urantide for 14 days. RESULTS: When ApoE-/- mice developed AS, significant pathological changes occurred in the liver and kidney, and the UII/UT system in tissue was highly activated; furthermore, the Wnt/ß-catenin signalling pathway was activated, and proteins related to this signalling pathway, such as GSK-3ß, AXIN2, CK­1, and APC, were significantly downregulated. After urantide treatment, the pathological damage to the liver and kidney was effectively improved, the activity of the UII/UT system was effectively inhibited, and the expression of the Wnt/ß-catenin signalling pathway and related proteins was restored. Wnt/ß-catenin signals were mainly localized in the cytoplasm, renal tubules, and interstitium. CONCLUSION: Urantide could improve AS-related liver and kidney injury by antagonizing the UII/UT system, and the improvements in liver and kidney function in atherosclerotic ApoE-/- mice may be related to inhibition of the Wnt/ß-catenin signalling pathway.

Exploration of the urocontrin A scaffold yields new urotensinergic system allosteric modulator and competitive antagonists.

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. [Pep4]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 [Pen2, Pep4]URP as a Gq biased ligand with an insurmountable antagonism in our aortic ring contraction assay.

Urantide prevents CCl4­induced acute liver injury in rats by regulating the MAPK signalling pathway.

A number of drugs and other triggers can cause acute liver injury (ALI) in clinical practice. Therefore, identifying a safe drug for the prevention of liver injury is important. The aim of the present study was to investigate the potential preventive effect and regulatory mechanism of urantide on carbon tetrachloride (CCl4)­induced ALI by investigating the expression of components of the MAPK signalling pathway and the urotensin II (UII)/urotensin receptor (UT) system. Liver oedema and severe fatty degeneration of the cytoplasm were observed in ALI model rats, and the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were found to be significantly increased. Compared with those in the ALI model group, ALT and AST levels and the liver index did not significantly increase in each group given the preventive administration of urantide, and the liver tissue morphology was correspondingly protected. Moreover, the gene and protein expression levels of UII, G protein­coupled receptor (GPR14) and the oxidative stress­sensitive cytokines, α­smooth muscle actin and osteopontin were decreased, indicating that the protein translation process was effectively maintained. However, the expression levels of MAPK signalling pathway­related proteins and genes were decreased. It was found that urantide could effectively block the MAPK signalling pathway by antagonizing the UII/UT system, thus protecting the livers of ALI model rats. Therefore, it was suggested that ALI may be associated with the MAPK signalling pathway, and effective inhibition of the MAPK signalling pathway may be critical in protecting the liver.

Urantide alleviates the symptoms of atherosclerotic rats in vivo and in vitro models through the JAK2/STAT3 signaling pathway.

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.

Urantide decreases hepatic steatosis in rats with experimental atherosclerosis via the MAPK/Erk/JNK pathway.

Hepatic steatosis, an indicator of atherosclerosis (AS), is always accompanied by inflammatory responses and disturbances in lipid metabolism. The present study investigated the protective effect of urantide, a urotensin II (UII) receptor antagonist, on the liver of rats with AS with hepatic steatosis by regulating the MAPK pathway. AS was induced in rats via an intraperitoneal injection of vitamin D3 and the administration of a high­fat diet. Urantide treatment was then administered to the rats. Pathology, liver index, lipid levels and liver function were measured to determine liver injury. The expression levels of UII and G protein­coupled receptor 14 (GPR14) were determined using immunohistochemistry, reverse transcription­quantitative PCR and western blotting. The expression levels of MAPK­related proteins in hepatocytes from each group were quantified using western blotting and immunofluorescence staining. Rats with AS had typical pathological changes associated with AS and hepatic steatosis, which were significantly improved by urantide treatment. Blood lipid levels, body weight, liver index and liver function were recovered in rats with AS after urantide treatment. Urantide downregulated the expression levels of UII and GPR14 in the livers of rats with AS; concurrently, the phosphorylation of Erk1/2 and JNK was significantly decreased. Moreover, no significant changes were observed in the phosphorylation of p38 MAPK in AS rat livers. In conclusion, urantide inhibits the activation of Erk1/2 and JNK by blocking the binding of UII and GPR14, thereby alleviating hepatic steatosis in rats with AS, ultimately restoring lipid metabolism in the liver and alleviating AS lesions.

Effect of urantide on the expression of osteopontin and α-smooth muscle actin in the heart of atherosclerotic rats / 解剖学报

Objective To observe the effect of urantide on the expression of osteopontin (OPN) and α-smooth muscle actin (a-SMA) in the heart tissue of atherosclerosis (AS) rats, and to explore its mechanism of prevention and treatment of myocardial fibrosis injury in rats. Methods Totally 120 3-week-old healthy male Wistar rats in SPF grade were randomly divided into six groups; control group, model group, simvastatin group, urantide (3 days, 7 days, 14 days). HE and Masson trichrome staining were used to observe the morphology of rat heart and the expression of collagen fibers. Immunohistochemistry and Western blotting were used to detect the expression of OPN and α-SMA protein. Results In AS model group, cardiomyocyte hypertrophy or atrophy, a large number of inflammatory cell infiltration and a small amount of foam cells were observed in the heart tissue of rats. The increase of collagen fibers and the expression of OPN and α-SMA protein in cardiac tissue were significantly higher than those in the control group. Compared with the AS model group, after urantide treatment, cardiac injury was significantly improved, and the expression of collagen fiber, OPN and α-SMA protein was decreased. Conclusion Urantide can inhibit the expression of OPN and α-SMA protein in the heart tissue of AS rats to alleviate myocardial fibrosis and play a protective role in the heart tissue of AS rats.

Urantide attenuates myocardial damage in atherosclerotic rats by regulating the MAPK signalling pathway.

OBJECTIVE: To explore the effect of urantide on atherosclerotic myocardial injury by antagonizing the urotensin II/urotensin II receptor (UII/UT) system and regulating the mitogen-activated protein kinase (MAPK) signalling pathway. METHODS: Atherosclerosis (AS) was established in rats by administering a high-fat diet and an intraperitoneal injection of vitamin D3. The effect of treatment with urantide (30 µg/kg), a UII receptor antagonist, for 3, 7, or 14 days on AS-induced myocardial damage was evaluated. RESULTS: The heart of rats with AS exhibited pathological changes suggestive of myocardial injury, and the serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) were significantly increased. Additionally, significant increases in the levels of UII, its receptor (G protein-coupled receptor 14, GPR14), p-P38, p-extracellular signal-regulated kinase (ERK) and p-c-Jun N-terminal kinase (JNK) were observed in the heart. Urantide improved pathological changes in the heart of rats with AS and reduced the serum CK and LDH levels. Additionally, the UII antagonist decreased the increased levels of UII, GPR14, p-P38, p-ERK and p-JNK in the heart. CONCLUSIONS: Urantide alleviates atherosclerotic myocardial injury by inhibiting the UII-GPR14 interaction and regulating the MAPK signalling pathway. We hypothesized that myocardial injury may be associated with the regulation of the MAPK signalling pathway.

The peptide compound urantide regulates collagen metabolism in atherosclerotic rat hearts and inhibits the JAK2/STAT3 pathway.

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 transcription­quantitative PCR and western blot analysis, respectively. Localization of proteins was detected by immunofluorescence. Overexpression of urotensin II (UII) and its receptor, G protein­coupled 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, low­density lipoprotein, high­density 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 (MMP­2), collagen type I/III, and genes and proteins in the JAK2/STAT3 pathway. By contrast, TIMP metallopeptidase inhibitor 2 (TIMP­2) levels were increased. In addition, the MMP­2/TIMP­2 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.

Urotensin receptor antagonist urantide improves atherosclerosis-related kidney injury by inhibiting JAK2/STAT3 signaling pathway in rats.

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.

Urotensin II and urantide exert opposite effects on the cellular components of atherosclerotic plaque in hypercholesterolemic rabbits.

Increasing levels of plasma urotensin II (UII) are positively associated with atherosclerosis. In this study we investigated the role of macrophage-secreted UII in atherosclerosis progression, and evaluated the therapeutic value of urantide, a potent competitive UII receptor antagonist, in atherosclerosis treatment. Macrophage-specific human UII-transgenic rabbits and their nontransgenic littermates were fed a high cholesterol diet for 16 weeks to induce atherosclerosis. Immunohistochemical staining of the cellular components (macrophages and smooth muscle cells) of aortic atherosclerotic lesions revealed a significant increase (52%) in the macrophage-positive area in only male transgenic rabbits compared with that in the nontransgenic littermates. However, both male and female transgenic rabbits showed a significant decrease (45% in males and 31% in females) in the smooth muscle cell-positive area compared with that of their control littermates. The effects of macrophage-secreted UII on the plaque cellular components were independent of plasma lipid level. Meanwhile the wild-type rabbits were continuously subcutaneously infused with urantide (5.4 µg· kg-1· h-1) using osmotic mini-pumps. Infusion of urantide exerted effects opposite to those caused by UII, as it significantly decreased the macrophage-positive area in male wild-type rabbits compared with that of control rabbits. In cultured human umbilical vein endothelial cells, treatment with UII dose-dependently increased the expression of the adhesion molecules VCAM-1 and ICAM-1, and this effect was partially reversed by urantide. The current study provides direct evidence that macrophage-secreted UII plays a key role in atherogenesis. Targeting UII with urantide may promote plaque stability by decreasing macrophage-derived foam cell formation, which is an indicator of unstable plaque.

Polypeptide compound urantide inhibiting expression of type i collagen in rat heart of atherosclerosis / 解剖学报

Objective To observe the effect of the peptide compound urantide on the expression of type I collagen (Col I ) in the heart tissue of rats with atherosclerosis ( As) , and to explore its mechanism of prevention and treatment of heart damage in As rats. Methods Sixty healthy male 3-week-old SPF Wistar rats were selected. The As model was established by intraperitoneal injection of vitamin D3(VD3) to damage the arterial intima and high-fat diet. They were randomly divided into normal group, As model group, simvastatin group and urantide (3 days, 7 days, 14 days) groups. HE staining and Masson trichrome staining were used to observe the morphology and collagen fiber expression of rat hearts. Immunohistochemistry, Western blotting and Real-time PCR were used to detect the expression of Col I protein and gene in rat heart. Results Compared with the normal group, pathological phenomena such As myocardial cell degeneration, intercellular infiltration of a large number of neutrophils, scattered foam cells and hyperemia and hemorrhage were observed in the heart tissues of the As model group. Meanwhile, collagen fibers increased, and the gene and protein expression levels of Col I increased. Compared with the As model group, the cardiac pathological phenomena were effectively alleviated after the treatment with urantide. With the extension of the administration time, the collagen fibers decreased, and the gene and protein expression levels of Col I were gradually down-regulated, especially the effect was the best when the drug was given for 14 days. Conclusion Urantide can inhibit the expression of Col I in As heart to reduce myocardial interstitial damage, and has a protective effect on the heart of As rats.

Urantide improves the structure and function of right ventricle as determined by echocardiography in monocrotaline-induced pulmonary hypertension rat model.

Urotensin II (UII) has been reported to play a key role in pulmonary arterial hypertension (PAH) development. Doppler echocardiography, a noninvasive and simple tool, is recommended for diagnosing PAH. This study was designed to investigate the effect of urantide, a UII receptor antagonist, on the structure and function of the right ventricle in PAH rat models by Doppler echocardiography. A total of 60 male rats were divided into two groups: early- and late-treatment groups. Rats in the urantide and MCT (monocrotaline) subgroups were injected with 10 µg/kg urantide in the urantide group or an equal amount of normal saline in the MCT group 1 week after PAH model construction in the early-treatment group and 4 weeks after the construction in the late-treatment group. Rats in the control group received an equal volume of normal saline solution. PAH-related indexes were measured by echocardiography. PAH rat models exhibited higher right ventricular diastolic diameter and lower time to peak, ejection time, and peak flow velocity of pulmonary artery than controls (P < 0.05). However, compared with the MCT group, all abovementioned indexes were improved in the urantide group (P < 0.05). No significant differences in pulmonary artery diameter and left ventricular ejection fraction were noted among the groups. Compared with the MCT group, systolic pulmonary arterial pressure (SPAP) and mean pulmonary arterial pressure (mPAP) were significantly lower in the urantide group (P < 0.05). SPAP examined by echocardiography was correlated with mPAP by catheterization (P < 0.05). Urantide treatment improved right heart failure parameters in MCT-induced PAH rats, thus providing a potential new strategy for treating PAH.

Urotensin receptors as a new target for CLP induced septic lung injury in mice.

Sepsis is a life-threatening organ dysfunction condition response resulting in acute lung injury. Urotensin II (UII), an endogenous vasoactive peptide, is widely distributed in pulmonary, cardiovascular, central nervous, renal and metabolic systems, and especially in inflammatory regions. This study aimed to investigate whether urotensin II (UII) and UII receptor (UTR) antagonists play a role in the inflammatory response to sepsis-induced lung damage and they are possible therapeutic targets. In the study, 78 male Balb-c mice were used. A cecal ligation and puncture (CLP)-induced polymicrobial sepsis model was applied, and the effects of human urotensin II (agonist) and urantide and palosuran (antagonists) were investigated on lung tissues. Glutathione and malondialdehyde levels and SOD activity of lung tissues were investigated in addition to TNF-α, IL-1ß, IL-6, NF-κB, and UTR mRNA levels. Also, lung sections were histopathologically evaluated. Urantide and palosuran, UII receptor antagonists, decreased proinflammatory cytokines such as TNF-α, IL-1ß, IL-6, NF-κB, and also decreased oxidative stress parameters in lung tissue, which are markers of damage. UTR mRNA expression was increased in septic lungs, and both antagonists significantly decreased the elevated receptor level. Also, histopathological examination showed beneficial effects of both agonists on lung tissue. The results of this study help to understand the inflammatory and therapeutic contribution of the UII/UTR system on sepsis-induced lung damage. We can suggest that UTR receptor antagonists may be evaluated as a potential drug which reduces sepsis-induced lung damage in the future.

Effect of urantide on liver function and histomorphology in atherosclerotic rats / 中国病理生理杂志

AIM:To investigate the effect of urantide on the liver function and histomorphology in the rats with atherosclerosis (AS).METHODS:The AS Wistar rat model was induced by intraperitoneal injection of vitamin D3 (VD3) and feeding with high-fat diet.The rats were randomly divided into normal control group, AS model group, positive medicine group and urantide group.The liver function indexes of the rats were measured by biochemical test, and the pathological changes of the aorta and liver of the rats were observed by hematoxylin-eosin (HE) staining.The mRNA expression of urotensinⅡ (UII) and GPR14 at mRNA and protein levels in rat livers was determined by RT-qPCR and Western blot.RESULTS:The levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , γ-glutamyltransferase (γ-GT) , lactate dehydrogenase (LDH) , total bilirubin (TBIL) , indirect bilirubin (IBIL) and alkaline phosphatase (ALP) in AS model group were significantly increased compared with normal control group (P<0.05).The above indexes in urantide group were remarkably decreased compared with AS model group (P<0.05).No change of the levels of direct bilirubin (DBIL) , total protein (TP) , globulin (GLB) and albumin (ALB) in each group was observed.Urantide postponed hepatocyte fatty degeneration and repaired hepatocyte injury in the AS rats.Compared with normal control group, the mRNA and protein levels of UII and GPR14 in the liver were significantly increased in AS model group (P<0.05).With the prolongation of dosing time, the mRNA and protein levels of UII and GPR14 in the liver were significantly decreased in urantide group compared with AS model group (P<0.05).CONCLUSION:Urantide significantly attenuates the liver damage caused by liver fatty degeneration in AS rats.

Effect of urantide on expression of c-jun n-terminal kinase in thoracic aorta tissue of rats with atherosclerosis and its significance / 吉林大学学报(医学版)

Objective: To investigate the effects of Urantide on the expressions of c-Jun N-terminal kinase (JNK) mRNA and protein in the thoracic aorta tissue of the rats with atherosclerosis (AS) • and to elucidate the molecular mechanism and significance of prevention and treatment of AS. Methods: The AS rat models were established by intraperitoneal injection of Vitamin D combined with high-fat diet and control group was set up at the same time. A total of 150 AS model rats were divided into model group, simvastatin group. IJrantide 3 d group. Urantide 7 d group and Urantide 14 d group ( n= 30). The rats in simvastatin group were adminstrated with simvastatin by gavage for 14 d. and the rats in Urantide groups were injected with Urantide by caudal vein for 3. 7. and 14 d. The serum markers of the rats in various groups were detected by automatic biochemical analyzer; the morphology of rat thoracic aorta tissue was observed by HE staining; the expression levels of JNK mRNA and protein in the rat thoracic aorta tissue were detected by immunohistochemical staining. qRT-PCR and Western blotting methods. Results: Compared with control group, the serum levels of triglyceride (TG). total cholesterol (TC) and low density lipoprotein (LDL) of the rats in model group were increased (P<0. 05). and the level of high-density lipoprotein (HDL) was decreased ( P<.0. 05). The HE staining results showed the formation of bubbling cells in the thoracic aorta tissue, rupture of medullary elastic fibers and calcification of the rats in model group; compared with model group, the pathological symptoms of the thoracic aorta tissue of the rats in simvastatin group and Urantide groups were improved. The immunohistochemistry results showed that the JNK positive particles were weakly expressed in the rat thoracic aorta tissue in control group; the expression intensity of JNK in the rat thoracic aorta tissue in model group was increased ( P<0. 05); compared with model group, the expression intensities of JNK in the rat thoracia aorta tissue in Urantide groups were significantly decreased (P∗C0. 05). The qRT-PCR and Western blotting results showed that the expression levels of JNK mRNA and protein in the rat thoracic aorta tissue in model group were significantly increased ( P

Effects of urantide on serum calcium, blood lipids and indexes of myocardial enzymes in rats with atherosclerosis / 吉林大学学报(医学版)

Objective: To investigate the effect of urantide on the levels of serum calcium, blood lipids and indexes of myocardial enzymes in the rats with atherosclerosis (As), and to clarify its mechanism of prevention and treatment of AS. Methods: A total of 180 Wistar rats were selected and randomly divided into normal control group, AS group, positive drug (simvastatin) group and urantide groups (3, 7 and 14 d group), 30 rats in each group. The rat model of AS was established by feeding on high-fat diet or intraperitoneally injecting vitamin D3 (VDs). The body weights of rats were weighed at three time points: pre-experiment, pre-administration and end of experiment. The levels of Ca", total cholesterol (T O, triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), creatine kinase (CK) and lactic dehydrogenase (LDH) in the serum of the rats in various groups were detected by automatic biochemical analyzer. Results: The body weights of the rats in normal control group were gradually decreased with the prolongation of time; compared with normal control group, the body weights of the rats in AS group at the time point of pre-administration was decreased (P < 0 . 01); compared with AS group, the body weights of the rats in different administration groups were increased (P < 0 . 05 or P< 0. 01). The levels of serum Ca2', TG, TC, LDL, CK and LDH of the rats in AS group were significantly higher than those in normal control group, and the level of HDL was decreased significantly (P < 0 . 01). Compared with AS group, the levels of serum Ca2 , TC, TG, LDL, CK and LDH of the rats in urantide group were significantly decreased (P < 0. 05 or P < 0. 01), while the HDL levels were higher (P < 0. 05 or P < 0. 01). Conclusion: Urantide can prevent and treat AS by down-regulating or up-regulating the levels of serum calcium, blood lipids and indexes of myocardial enzymes in the AS rats.

Effects of urantide on expressions of type IV collagen in thoracic aorta and VSMC of atherosclerotic rats / 吉林大学学报(医学版)

Objective: To investigate the effects of urantide on the expressions of type IV collagen (Col IV) in thoracic aorta and vascular smooth muscle cells (VSMC) in the rats with atherosclerosis (AS), and to clarify its mechanism of prevention and treatment of AS Methods: A total of 180 Wistar rats were randomly divided into normal control group (n=30) and AS model group (n=150). The rat models of AS were established by feeding on high-fat diet or intraperitoneally injecting vitamin Da (VDa). The AS model rats were randomly divided into AS group, fluvestation (Flu) group and urantide group (3, 7, and 14 d groups). The expression of Col IV in thoracic aorta wall of the rats was detected by immunohistochemistry. The levels of hydroxyproline (HYP) in serum and urine of the rats in various groups were measured by ELISA. The VSMC were randomly divided into normal control group, urotensin E (U II 10~smol • L_ 1) group, Flu group and urantide (10~10to 10~" mol • L_ 1) groups. The levels of Col IV in VSMC of the rats in various groups were determined by ELISA. Results: There was a significant difference in the expression levels of Col IV in the irregular plaques of the thoracic aorta of the rats between various groups (F = 3 5 . 0 9, P < 0 . 01). The expression levels of Col IV in thoracic aorta of the rats in AS group were significantly increased compared with normal control group (P < 0 . 01); the intensity and extent of Col IV positive staining in urantide group were lower than those in AS group (P < 0 . 01). There were significant differences in the serum and urine HYP levels between various groups (F = 2 4 . 38, P < 0 . 01; F=26. 72, P < 0 . 01). Compared with normal control group, the serum HYP level of the rats in AS group were significantly increased (P < 0 . 01), and the urine HYP level was significantly decreased (P < 0 . 01). Compared with AS group, the serum HYP levels in urantide groups were significantly decreased (P < 0 . 01) and the urine HYP levels were significantly increased (P < 0. 01), no less than the level in Flu group. The expression levels of Col IV in the culture supernatant of VSMC in the rats in various groups had significantly difference (F = 3 1 . 04, P < 0 . 01). The expression level of Col IV in the culture supernatant of VSMC of the rats in U II group was significantly increased compared with normal control group (P < 0 . 01); the expression levels of Col IV in the culture supernatant of VSMC of the rats in urantide groups were significantly decreased compared with U II group (P < 0 . 05 or P < 0 . 01). Conclusion: Urantide can inhibit the expressions of Col IV in the thoracic aorta and VSMC of the AS rats and alleviate the degree of AS lesions, which provides the experimental evidence for the clinical application of urantide in the treatment of AS.

Opposite actions of urotensin II and relaxin-2 on cellular expression of fibronectin in renal fibrosis: A preliminary experimental study.

Our aim was to evaluate the role of urotensin II, urantide (urotensin II receptor antagonist) and relaxin-2 on the cellular expression of fibronectin as a surrogate marker for renal fibrosis. We employed LLC-PK1 renal tubular epithelial cells and assessed the influence on the fibrotic process of the above-mentioned substances by using anti-fibronectin antibodies in western blot analysis. The addition of urotensin II increased fibronectin expression. Urantide reduced the positivity for fibronectin caused by urotensin II (P<.05). The anti-fibrotic action was more evident for relaxin-2 (P<.01). Also in the model of TGF-ß1-induced fibrosis, urantide and, to a greater extent, relaxin-2 were able to significantly lessen fibronectin expression (respectively, P<.05 and P<.01). In conclusion, relaxin-2 may reduce urotensin II-induced renal fibrosis.

Structure-Activity Study of the Peptides P5U and Urantide by the Development of Analogues Containing Uncoded Amino Acids at Position†9.

Previous modifications of the peptide sequence of human urotensin-II (U-II) led to the identification of two well-known ligands: P5U and urantide. These derivatives are considered to be the most representative agonist and antagonist, respectively, at the human urotensin receptor (UT). Optimization of P5U and urantide was carried out to stabilize specific conformations that may suggest new elements for discriminating agonist versus antagonist activity. We studied novel derivatives containing uncoded amino acids. In particular, the Tyr(9) residue of both P5U and urantide was replaced with nonaromatic hydrophobic bulky residues, as well as conformationally constrained aromatic moieties to generate eight novel derivatives. These analogues further contributed to determining the influence of such residues on binding affinity for and biological activity at UT. One of these eight peptides was also investigated by NMR spectroscopy and docking studies owing to its peculiar conformational properties and mode of interaction with UT. This structure-activity study is aimed at a more thorough examination of the role of tyrosine in modulating the agonism/antagonism of human U-II.