Endothelial urocortin has potent antioxidative properties and is upregulated by inflammatory cytokines and pitavastatin

Possible Correlation between Urocortin 1 (Ucn1) and Immune Parameters in Patients with Endometriosis

The etiology of endometriosis (EMS) has not been clearly elucidated yet, and that is probably the reason why its diagnostic process is frequently long-lasting and inefficient. Nowadays, the non-invasive diagnostic methods of EMS are still being sought. Our study aimed to assess the serum and peritoneal fluid levels of urocortin 1 (Ucn1) in patients with EMS and healthy women. Moreover, considering the immune background of the disease, the association between Ucn1 and several immune parameters was studied in both groups. We found that the serum Ucn1 level was significantly upregulated in women with EMS compared to healthy patients. Moreover, higher serum Ucn1 levels tended to correspond with more advanced stages of the disease (p = 0.031). Receiver operating characteristic (ROC) analysis revealed that based on serum Ucn1 levels, it is possible to distinguish deep infiltrating endometriosis (DIE) from among other EMS types. Together, these results indicate Ucn1 as a possible promising biomarker of EMS: however, not in isolation, but rather to enhance the effectiveness of other diagnostic methods.

Cardioprotective and Vasoprotective Effects of Corticotropin-Releasing Hormone and Urocortins: Receptors and Signaling

Despite the recent progress in research and therapy, cardiovascular diseases are still the most common cause of death worldwide, thus new approaches are still needed. The aim of this review is to highlight the cardioprotective potential of urocortins and corticotropin-releasing hormone (CRH) and their signaling. It has been documented that urocortins and CRH reduce ischemic and reperfusion (I/R) injury, prevent reperfusion ventricular tachycardia and fibrillation, and improve cardiac contractility during reperfusion. Urocortin-induced increase in cardiac tolerance to I/R depends mainly on the activation of corticotropin-releasing hormone receptor-2 (CRHR2) and its downstream pathways including tyrosine kinase Src, protein kinase A and C (PKA, PKCε) and extracellular signal-regulated kinase (ERK1/2). It was discussed the possibility of the involvement of interleukin-6, Janus kinase-2 and signal transducer and activator of transcription 3 (STAT3) and microRNAs in the cardioprotective effect of urocortins. Additionally, phospholipase-A2 inhibition, mitochondrial permeability transition pore (MPT-pore) blockade and suppression of apoptosis are involved in urocortin-elicited cardioprotection. Chronic administration of urocortin-2 prevents the development of postinfarction cardiac remodeling. Urocortin possesses vasoprotective and vasodilator effect; the former is mediated by PKC activation and prevents an impairment of endothelium-dependent coronary vasodilation after I/R in the isolated heart, while the latter includes both cAMP and cGMP signaling and its downstream targets. As CRHR2 is expressed by both cardiomyocytes and vascular endothelial cells. Urocortins mediate both endothelium-dependent and -independent relaxation of coronary arteries.

Urocortinergic system in the epididymis of the normal and cryptorchid dogs

Cryptorchidism is associated with changes in the gonads and the spermatic duct system, which may cause infertility problems. Urocortin (UCN) is a corticotrophin-releasing hormone (CRH)-related peptide, which affects several functions of male genital organs. The aim of the present study was to investigate the expression of UCN and its receptors CRHR1 and CRHR2 using immunohistochemistry, western blotting and real-time reverse transcription polymerase chain reaction in tissues collected from the epididymis of normal and cryptorchid dogs. The lumen of the cryptic epididymal duct was found to be relatively smaller than that of the normal one, and interstitial tissue was abundant in the cryptic epididymis. In addition, only a few spermatids were observed in the lumen of the epididymal duct. Results showed that UCN, CRHR2 and CRHR1 were expressed in tissues collected from normal and cryptic epididymal ducts. Urocortin- and CRHR2-immunoreactivities (IRs) were detected in the principal cells of the caput, corpus and cauda of the normal and cryptic epididymides. CRHR1-IR was detected in vascular smooth muscles and fibromuscular cells surrounding epididymal tubules of the normal and cryptorchid dogs. Expression levels of UCN and CRHR2 mRNA were higher in cryptic epididymal ducts than that in normal epididymal ducts. These results suggest that UCN and its receptors might play a role in regulating the maturation and storage of spermatozoa. These findings indicated that the expression of these proteins could be modulated by the cryptorchidism condition.

Urocortin attenuates myocardial fibrosis in diabetic rats via the Akt/GSK-3β signaling pathway

OBJECTIVE

Urocortin, a novel identified corticotropin-releasing factor-related endocrinal peptide, has been shown to play an essential role in cardioprotection. Until recently, whether urocortin can protect the heart against diabetic cardiomyopathy (DCM) remained unclear. Herein, we evaluated the cardioprotective effect of urocortin on cardiac dysfunction, inflammation, and fibrosis and demonstrated the potential mechanism in a diabetic rat model.

METHODS

Diabetic rats were randomly divided into 4 groups: diabetic control group, urocortin, urocortin + astressin (a selective CRF receptor 2 antagonist) and urocortin + triciribine (an Akt pathway blocker). Cardiac catheterization was performed to evaluate cardiac function. The levels of creatine phosphokinase isoenzyme (CK-MB), plasma brain natriuretic peptide (BNP), myocardial collagen volume fraction (CVF) and left ventricular mass index (LVWI) were measured. Inflammatory factors (transforming growth factor beta 1, TGF-β1; connective tissue growth factor, CTGF) and activation of signaling proteins (Akt, GSK-3β) were also detected using western blot.

RESULTS

DCM was successfully induced by the injection of streptozotocin (STZ) as evidenced by abnormal heart mass and cardiac function as well as the imbalance of extracellular matrix homeostasis. Rats in the DCM group showed increased mRNA and protein levels of LVWI, BNP, CK-MB, CVF, TGF-β1 and CTGF compared to the control group, which were accompanied with diminished phosphorylation of Akt and GSK-3β. Interestingly, myocardial dysfunction, cardiac fibrosis, and inflammation were suppressed by urocortin in the heart of diabetic rats. Moreover, inhibition of phosphorylation of Akt and GSK-3β was also reversed by urocortin. These effects of urocortin were suppressed by astressin. In addition, triciribine partially reduced the effects of urocortin on myocardial dysfunction, inflammation, and cardiac fibrosis.

CONCLUSIONS

These results suggest that urocortin exhibits a therapeutic benefit in the treatment of DCM by attenuating fibrosis and inflammation. Furthermore, inhibition of the Akt/GSK-3β signaling pathway may be partially responsible for these effects.

Urocortin 1 expression and secretion by human umbilical vein endothelial cells: In vitro effects of interleukin 8, interferon γ, lipopolysaccharide, endothelin 1, prostaglandin F-2α, estradiol, progesterone and dexamethasone

Urocortin 1 (Ucn1) is a 40-amino-acid peptide that has vasodilatory activity and displays immunomodulatory and antioxidant properties. Maternal and cord plasma Ucn1 levels are increased in preeclampsia and preterm labor, but the mechanisms of such increase are poorly known. Thus, we investigated Ucn1 localization in human umbilical cord and assessed some potential stimuli to Ucn1 release by human umbilical vein endothelial cells (HUVEC). Human umbilical cords were obtained at uncomplicated term pregnancy (n=11). Ucn1 localization was assessed by immunohistochemistry and quantified. HUVEC were grown in vitro to confluence, then incubated with serial concentrations of interleukin (IL)-8, interferon (INF)-γ, lipopolysaccharide (LPS), endothelin (ET)-1, prostaglandin (PG)F-2α, estradiol, progesterone and dexamethasone and Ucn1 concentrations were measured in the supernatants. Ucn1 was immunolocalized with similar intensity in umbilical cord arteries, vein and Wharton's jelly. Ucn1 mRNA was detected in all HUVEC cultures and Ucn1 peptide was detectable in culture medium from untreated cells at different time points. Incubation with IFN-γ increased Ucn1 secretion in a dose-dependent manner. Treatments with IL-8, LPS, ET-1 and dexamethasone were able to increase three to fourfold Ucn1 release from cultured endothelial cells. In conclusion, umbilical vessels express Ucn1 and may be a contributive source of Ucn1 release into fetal-placental circulation. IL-8, IFN-γ, LPS, ET-1 and dexamethasone promote Ucn1 secretion from cultured HUVEC.

The evaluation of the clinical utility of urocortin 1 and adrenomedullin versus proBNP in systolic heart failure

Objective:

Urocortin 1 (UCN1) has vasodilator, diuretic, and natriuretic effects, and its expression increases in heart failure (HF). Adrenomedullin (ADM) increases cardiac output and lowers blood pressure in healthy men and in patients with heart failure. The aim of the study was to determine UCN1 and ADM levels in patients with HF, to evaluate the relationship of UCN1 and ADM with various clinical parameters, and to assess UCN1 and ADM as diagnostic markers in HF, in comparison with pro-brain natriuretic peptide (pro-BNP).

Methods:

We investigated serum levels of UCN1, ADM, and pro-BNP in 86 consecutive patients with systolic HF [ejection fraction (EF) ≤45%] and 85 healthy controls. Serum UCN1, ADM, and pro-BNP levels were measured with the ELISA method. Transthoracic echocardiography was performed to determine left ventricular EF and pulmonary artery systolic pressure.

Results:

UCN1 and ADM levels were higher in HF patients (446.2±145.7 pg/mL, p<0.001; 87.9±4.2 pg/mL, p<0.001 respectively). UCN1 was positively correlated with pro-BNP (r=0.963, p<0.001), ADM (r=0.915, p<0.001), and NYHA (r=0.879, p<0.001); ADM was positively correlated with pro-BNP (r=0.956, p<0.001) and NYHA (r=0.944, p<0.001). Receiver operating characteristic curves yielded an area under the curve of 1.00 (p<0.001) for UCN1, 1.00 (p<0.001) for ADM, and 0.99 (p<0.001) for pro-BNP in the diagnosis of HF.

Conclusion:

UCN1 and ADM increase with worsening HF and left ventricular dysfunction. They may be used as diagnostic biomarkers in systolic HF, but the incremental value of measuring UCN1 and ADM in patients tested for pro-BNP is questionable.

Urocortin 2 in cardiovascular health and disease

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

Urocortin ameliorates diabetic cardiomyopathy in rats via the Akt/GSK-3β signaling pathway

Urocortin has been shown to exert powerful protective effects on various cardiovascular disease models. However, the role and mechanism of urocortin in protecting against diabetic cardiomyopathy (DCM) has not yet been elucidated. In the present study, the effects of urocortin on cardiac dysfunction, fibrosis, inflammation and the interrelated signaling pathways were investigated in a diabetic rat model. Diabetes mellitus (DM) was induced in the rats by intraperitoneal injection of streptozotocin. The diabetic rats were randomly divided into four groups: Diabetic control, urocortin, urocortin + astressin treatment and urocortin + triciribine treatment groups. All the experiments were conducted at 16 weeks following the induction of DM. The levels of glycosylated hemoglobin (HbA1c), creatine phosphokinase isoenzyme (CK-MB) and plasma brain natriuretic peptide (BNP), as well as the myocardial collagen volume fraction (CVF) and left ventricular mass index (LVWI), were measured. In addition, levels of inflammatory factors, including transforming growth factor (TGF)-β1, connective tissue growth factor (CTGF) and interrelated proteins, such as Akt and glycogen synthase kinase (GSK)-3β, were detected by biochemical analyses. In the diabetic group, the levels of BNP and CK-MB, as well as the mRNA and protein expression levels of TGF-β1 and CTGF, and the LVWI and CVF, were higher compared with the rats in the control group (P<0.05). This was accompanied by decreased Akt and GSK-3β phosphorylation (P<0.05). Notably, urocortin attenuated myocardial dysfunction, cardiac fibrosis and inflammation in the hearts of the diabetic rats. However, urocortin exhibited no effect on the level of HbA1c. In addition, the inhibited phosphorylation of Akt and GSK-3β was restored with urocortin administration. However, all the effects of urocortin were eliminated with treatment of the corticotropin releasing factor receptor 2 antagonist, astressin. Triciribine, an Akt inhibitor, partially eliminated the effects of urocortin on myocardial dysfunction, inflammation and cardiac fibrosis in the hearts of the diabetic rats. These results indicated that urocortin may exhibit great therapeutic potential in the treatment of DCM by attenuating fibrosis and inflammation. Furthermore, the Akt/GSK-3β signaling pathway may be partially involved in mediating these effects.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Antioxidant effects of statins in the management of cardiometabolic disorders

Redox systems are key players in vascular health. A shift in redox homeostasis-that results in an imbalance between reactive oxygen species (ROS) generation and endogenous antioxidant defenses has the potential to create a state of oxidative stress that subsequently plays a role in the pathogenesis of a number of diseases, including those of the cardiovascular and metabolic system. Statins, which are primarily used to reduce the concentration of low-density lipoprotein cholesterol, have also been shown to reduce oxidative stress by modulating redox systems. Studies conducted both in vitro and in vivo support the role of oxidative stress in the development of atherosclerosis and cardiovascular diseases. Oxidative stress may also be responsible for various diabetic complications and the development of fatty liver. Statins reduce oxidative stress by blocking the generation of ROS and reducing the NAD+/NADH ratio. These drugs also have effects on nitric oxide synthase, lipid peroxidation and the adiponectin levels. It is possible that the antioxidant properties of statins contribute to their protective cardiovascular effects, independent of the lipid-lowering actions of these agents. However, possible adverse effects of statins on glucose homeostasis may be related to the redox system. Therefore, studies investigating the modulation of redox signaling by statins are warranted.

Low-density lipoprotein-cholesterol-induced endothelial dysfunction and oxidative stress: the role of statins

SIGNIFICANCE

Cardiovascular diseases (CVD) represent a major public health burden. High low-density lipoprotein (LDL)-cholesterol is a recognized pathogenic factor for atherosclerosis, and its complications and statins represent the most potent and widely used therapeutic approach to prevent and control these disorders.

RECENT ADVANCES

A number of clinical and experimental studies concur to identify endothelial dysfunction as a primary step in the development of atherosclerosis, as well as a risk factor for subsequent clinical events. Oxidant stress resulting from chronic elevation of plasma LDL-cholesterol (LDL-chol) is a major contributor to both endothelial dysfunction and its complications, for example, through alterations of endothelial nitric oxide signaling.

CRITICAL ISSUES

Statin treatment reduces morbidity and mortality of CVD, but increasing evidence questions that this is exclusively through reduction of plasma LDL-chol. The identification of ancillary effects on (cardio)vascular biology, for example, through their modulation of oxidative stress, will not only increase our understanding of their mechanisms of action, with a potential broadening of their indication(s), but also lead to the identification of new molecular targets for future therapeutic developments in CVD.

FUTURE DIRECTIONS

Further characterization of molecular pathways targeted by statins, for example, not directly mediated by changes in plasma lipid concentrations, should enable a more comprehensive approach to the pathogenesis of (cardio)vascular disease, including, for example, epigenetic regulation and fine tuning of cell metabolism.

Pitavastatin subacutely improves endothelial function and reduces inflammatory cytokines and chemokines in patients with hypercholesterolaemia

BACKGROUND

Pitavastatin is a statin with strong pleiotropic effects, but the effects of pitavastatin on endothelial cell function (ECF) and both inflammatory cytokines and chemokines have not been fully investigated.

MATERIAL AND METHODS

We simultaneously measured brachial artery (BA) flow-mediated vasodilatation (FMD) and nitroglycerin-mediated vasodilatation (NMD), as well as plasma biomarkers of inflammatory cytokines and chemokines, in patients with hypercholesterolaemia and other atherosclerotic risk factors who were treated with pitavastatin. Sixty-five hypercholesterolaemic patients (age, 66±11 years) with conventional coronary risk factors were enrolled. BA FMD, BA NMD and serum biomarkers (tumour necrosis factor, interleukin (IL)-6, IL-10, monocyte chemoattractant protein-1, IL-8, P-selectin, E-selectin, soluble intercellular cell adhesion molecule-1 (s-ICAM1)) were measured before and after 4 weeks of treatment with pitavastatin (2 mg/day).

RESULTS

Pitavastatin treatment resulted in an increase from baseline to post-treatment in FMD (3.22±1.72 vs 3.97±2.18%, p<0.05) but not in NMD. Furthermore, pitavastatin treatment led to a decrease from baseline to post-treatment in E-selectin (51±27 vs 46±29 pg/mL, p<0.05) and s-ICAM1 (276±86 vs 258±91 pg/mL, p<0.05). Changes in FMD in response to pitavastatin treatment did not correlate with those of E-selectin or s-ICAM1.

CONCLUSIONS

Pitavastatin treatment resulted in a subacute improvement in ECF and a decrease in chemokine levels. These results suggest that pitavastatin might improve long-term outcomes in patients with atherosclerotic disorders.

Dihydrotestosterone alters urocortin levels in human umbilical vein endothelial cells

Urocortin (UCN1) is a member of corticotrophin-releasing factor (CRF) family, which has been proven to participate in inflammation. Previous work showed that dihydrotestosterone (DHT) could promote the inflammatory process. Little is known about the effect of DHT on UCN1 expression. The aim of our study is to investigate the effects and underlying mechanisms of DHT on endothelial UCN1 expression in the absence and presence of induced inflammation. Therefore, we tested the alterations of endothelial UCN1 expression treated with DHT in the presence or absence of lipopolysaccharide (LPS). Our data showed that DHT alone decreased UCN1 levels, which were attenuated in the presence of the androgen receptor (AR) antagonist flutamide. Conversely, in the presence of LPS, DHT augmented the LPS-induced increase in UCN1 expression, which was, interestingly, not affected by flutamide. When cells were treated with DHT alone, AR was upregulated and translocated into the nuclei, which might repress UCN1 expression via a potential androgen-responsive element found in human CRF family promoter. In the presence of LPS, DHT did not influence AR expression and location while it increased toll-like receptor 4 expression and activation, which was not altered by flutamide. DHT enhanced LPS-induced p38MAPK, ERK1/2, and nuclear factor κB pathway activation, which may contribute to the elevated expression of UCN1. These data suggest that DHT differentially influences UCN1 levels under normal and inflammatory conditions in human umbilical vein endothelial cells, which involves AR-dependent and -independent mechanisms respectively.

Pleiotropic effects of pitavastatin

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are established first line treatments for hypercholesterolaemia. In addition to the direct effects of statins in reducing concentrations of atherogenic low density lipoprotein cholesterol (LDL-C), several studies have indicated that the beneficial effects of statins may be due to some of their cholesterol-independent, multiple (pleiotropic) effects which may differ between different members of the class. Pitavastatin is a novel synthetic lipophilic statin that has a number of pharmacodynamic and pharmacokinetic properties distinct from those of other statins, which may underlie its potential pleiotropic benefits in reducing cardiovascular risk factors. This review examines the principal pleiotropic effects of pitavastatin on endothelial function, vascular inflammation, oxidative stress and thrombosis. The article is based on a systematic literature search carried out in December 2010, together with more recent relevant publications where appropriate. The available data from clinical trials and in vitro and animal studies suggest that pitavastatin is not only effective in reducing LDL-C and triglycerides, but also has a range of other effects. These include increasing high density lipoprotein cholesterol, decreasing markers of platelet activation, improving cardiac, renal and endothelial function, and reducing endothelial stress, lipoprotein oxidation and, ultimately, improving the signs and symptoms of atherosclerosis. It is concluded that the diverse pleiotropic actions of pitavastatin may contribute to reducing cardiovascular morbidity and mortality beyond that achieved through LDL-C reduction.

Regulation and roles of urocortins in the vascular system

Urocortins (Ucns) are members of the corticotropin-releasing factor (CRF) family of peptides. Ucns would have potent effects on the cardiovascular system via the CRF receptor type 2 (CRF(2) receptor). Regulation and roles of each Ucn have been determined in the vascular system. Ucns have more potent vasodilatory effects than CRF. Human umbilical vein endothelial cells (HUVECs) express Ucns1-3 mRNAs, and the receptor, CRF(2a) receptor mRNA. Ucns1-3 mRNA levels are differentially regulated in HUVECs. Differential regulation of Ucns may suggest differential roles of those in HUVECs. Ucn1 and Ucn2 have strong effects on interleukin (IL)-6 gene expression and secretion in rat aortic smooth muscle A7r5 cells. The increase that we observed in IL-6 levels following Ucn treatment of A7r5 cells suggests that smooth muscle cells may be a source of IL-6 secretion under physiological stress conditions. Ucns are important and unique modulators of vascular smooth muscle cells and act directly or indirectly as autocrine and paracrine factors in the vascular system.

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

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

Relevance of urocortins to cardiovascular disease

Acquired cardiovascular diseases such as coronary heart disease, peripheral artery disease and related vascular problems contribute to more than one-third of worldwide morbidity and mortality. In many instances, particularly in the under developed world, cardiovascular diseases are diagnosed at a late stage limiting the scope for improving outcomes. A range of therapies already exist for established cardiovascular disease, although there is significant interest in further understanding disease pathogenesis in order to improve diagnosis and achieve primary and secondary therapeutic goals. The urocortins are a group of recently defined peptide members of the corticotrophin-releasing factor family. Previous pre-clinical work and human association studies suggest that urocortins have potential to exert some beneficial and other detrimental effects on the heart and major blood vessels. More current evidence however favours beneficial effects of urocortins, for example these peptides have been shown to inhibit production of reactive oxygen species and vascular cell apoptosis, and thus may have potential to antagonise the progression of cardiovascular disease. This review summarises published data on the potential role of urocortins in cardiovascular disease.

Regulation of Th1 and Th17 cell differentiation and amelioration of experimental autoimmune encephalomyelitis by natural product compound berberine

Berberine (BBR), an isoquinoline alkaloid derived from plants, is widely used as an anti-inflammatory remedy in traditional Chinese medicine. In this study, we showed that BBR was efficacious in the amelioration of experimental autoimmune encephalomyelitis (EAE) through novel regulatory mechanisms involving pathogenic Th1 and Th17 cells. BBR inhibited differentiation of Th17 cells and, to a lesser degree, Th1 cells through direct actions on the JAK/STAT pathway, whereas it had no effect on the relative number of CD4(+)Foxp3(+) regulatory T cells. In addition, BBR indirectly influenced Th17 and Th1 cell functions through its effect on the expression and function of costimulatory molecules and the production of IL-6, which was attributable to the inhibition of NF-kappaB activity in CD11b(+) APCs. BBR treatment completely abolished the encephalitogenicity of MOG(35-55)-reactive Th17 cells in an adoptive transfer EAE model, and the same treatment significantly inhibited the ability of MOG(35-55)-reactive Th1 cells to induce EAE. This study provides new evidence that natural compounds, such as BBR, are of great value in the search for novel anti-inflammatory agents and therapeutic targets for autoimmune diseases.

Whole genome expression analysis within the angiotensin II-apolipoprotein E deficient mouse model of abdominal aortic aneurysm

BACKGROUND

An animal model commonly used to investigate pathways and potential therapeutic interventions relevant to abdominal aortic aneurysm (AAA) involves subcutaneous infusion of angiotensin II within the apolipoprotein E deficient mouse. The aim of this study was to investigate genes differentially expressed in aneurysms forming within this mouse model in order to assess the relevance of this model to human AAA.

RESULTS

Using microarrays we identified genes relevant to aneurysm formation within apolipoprotein E deficient mice. Firstly we investigated genes differentially expressed in the aneurysm prone segment of the suprarenal aorta in these mice. Secondly we investigated genes that were differentially expressed in the aortas of mice developing aneurysms relative to those that did not develop aneurysms in response to angiotensin II infusion. Our findings suggest that a host of inflammation and extracellular matrix remodelling pathways are upregulated within the aorta in mice developing aneurysms. Kyoto Encyclopedia of Genes and Genome categories enriched in the aortas of mice with aneurysms included cytokine-cytokine receptor interaction, leukocyte transendothelial migration, natural killer cell mediated cytotoxicity and hematopoietic cell lineage. Genes associated with extracellular matrix remodelling, such as a range of matrix metalloproteinases were also differentially expressed in relation to aneurysm formation.

CONCLUSION

This study is the first report describing whole genome expression arrays in the apolipoprotein E deficient mice in relation to aneurysm formation. The findings suggest that the pathways believed to be critical in human AAA are also relevant to aneurysm formation in this mouse model. The findings therefore support the value of this model to investigate interventions and mechanisms of human AAA.

Urocortin: a protective peptide that targets both the myocardium and vasculature

The urocortins are a family of endogenously produced peptide hormones that show great promise as potential drugs for the treatment of heart disease. They can increase contractility and cardiac output without causing changes in mean arterial blood pressure. As expected, the receptor for these peptides is present in cardiomyocytes, and they can bind and protect these cells from simulated ischemia and reperfusion in vitro. The receptor is present, however, in much higher density in the endothelial cells that form a continuous lining of the coronary vasculature. Functionally, the urocortin peptides have been shown to have potent local vasodilatory effects, and may affect other aspects of vascular function. In this review, we will attempt to distinguish the "cardio" from the "vascular" effects of urocortin and its homologues, including the archetypal family member, corticotrophin releasing hormone.

Possible involvement of corticotropin-releasing factor receptor signaling on vascular inflammation

Based on the reported anti-inflammatory and anti-stress responses by corticotropin-releasing factor (CRF) receptor signaling, endogenous CRF receptor agonists, CRF, urocortin (UCN) I and its related peptides, may play protective roles against cardiovascular stresses via the CRF receptor signaling. Therefore, the present study was designed to evaluate the involvement of CRF receptor signaling against vascular inflammatory stress using human aortic endothelial cells (HAECs). In addition, due to the possible involvement of CRF receptor signaling in the effects of statin on endothelial cells, the effects of pitavastatin on the expression of UCN-related peptides in HAECs were also evaluated. HAECs expressed all UCNs, CRF type 1 receptor (CRF-R1), and CRF type 2 (CRF-R2)alpha and CRF-R2beta mRNAs. Real time PCR analysis revealed that UCN I mRNA was down-regulated, whereas UCN II mRNA was up-regulated by tumor necrosis factor (TNF)-alpha. Selective blockade of CRF-R1 resulted in significant increase in TNF-alpha-induced expression of vascular adhesion molecule-1 at mRNA level and E-selectin at mRNA and protein levels. Pitavastatin up-regulated UCN I mRNA without TNF-alpha, but co-incubation with pitavastatin and TNF-alpha resulted in decrease in UCN I mRNA. On the contrary, UCN II, CRF-R1, and CRF-R2 mRNAs were markedly increased by co-incubation of pitavastatin and TNF-alpha. These facts indicate that CRF-R1 signaling may have protective role against TNF-alpha-induced vascular inflammation. In addition, because of up-regulation of CRF-R1 mRNA by pitavastatin with or without TNF-alpha, CRF-R1 may be involved in the vasoprotective effects of pitavastatin.

Urocortin ameliorates diabetic nephropathy in obese db/db mice

BACKGROUND AND PURPOSE

Hyperglycaemia induces overproduction of mitochondrial reactive oxygen species (ROS) in endothelial cells, which is believed to be a major molecular mechanism underlying complications of diabetes, including diabetic nephropathy. Impairment of endothelium-dependent vasodilatation is found in type 2 diabetes. Urocortin is a 40 amino-acid peptide related to the corticotrophin-releasing factor (CRF) family, which suppresses production of ROS in endothelial cells and sustains endothelium-dependent relaxations of rat coronary artery. However, it is not clear if urocortin has any effect on diabetic nephropathy.

EXPERIMENTAL APPROACH

Possible mechanisms underlying the effects of urocortin on diabetic nephropathy were investigated in db/db mice and cultured rat mesangial cells.

KEY RESULTS

Urocortin decreased body weight, plasma levels of advanced glycation end-products, blood urea nitrogen and creatinine levels. However, food intake, plasma insulin and glucose levels remained unaffected. Superoxide dismutase activity was increased markedly, whereas malonaldehyde levels in kidney homogenate and sorbitol concentrations in red blood cells were decreased significantly in urocortin-treated mice. Urocortin significantly decreased glomerular extracellular matrix expansion and accumulation in kidney. Moreover, urocortin inhibited the overexpression of transforming growth factor-beta 1 and connective tissue growth factor in rat mesangial cells induced by 25 mM glucose. All the effects of urocortin, except sorbitol accumulation, were abolished by the non-selective CRF receptor blocker, astressin.

CONCLUSION AND IMPLICATIONS

Urocortin could significantly ameliorate diabetic nephropathy and this effect was mediated via the CRF receptor.

Over-expression of neuropeptide urocortin and its receptors in human allergic nasal mucosa

OBJECTIVES

Urocortin (UCN) is a member of the corticotropin releasing factor (CRF) neuropeptide family. UCN act as locally expressed proinflammatory factor and induce mast cell degranulation, cytokine secretion, and trigger vascular permeability, which are mediated by CRF receptors in peripheral tissues. Considering its functional roles, UCN and its receptors may play a role in the pathogenesis of allergic nasal mucosa. Therefore, we investigated the expression profile and distribution of UCN and CRF receptors in normal and allergic nasal mucosa.

METHODS

Reverse transcriptase-polymerase chain reaction, immunohistochemistry, and Western blotting were applied to the normal and allergic nasal mucosa.

RESULTS

The expression levels of UCN and CRF receptors were increased in allergic nasal mucosa in comparison with normal nasal mucosa. In normal nasal mucosa, UCN and CRF receptors were restricted to the vascular endothelium of submucosal cavernous sinusoids where faint staining was found. However, in allergic nasal mucosa, UCN was expressed in small vessels distributed in lamina propria and the vascular endothelium of cavernous sinusoid located in submucosa. Many scattered positive cells were also found in allergic nasal mucosa, probably UCN-positive leukocytes. CRF receptors were also localized in the vascular endothelium of small vessels and cavernous sinusoid.

CONCLUSIONS

These results indicate that UCN may play a role in the regulation of vascular swelling in normal nasal mucosa. Moreover, in allergic nasal mucosa, increased expression levels of UCN and its receptors may contribute to increased mucosal swelling and vascular permeability, playing an important role in the pathogenesis of allergic rhinitis.

Corticotropin-releasing factor family and its receptors: tumor therapeutic targets?

Urocortin (UCN) and corticotropin-releasing factor (CRF) are members of CRF family. Though CRF is mainly distributed in central nervous system (CNS), UCN has been reported to play biologically diverse roles in several systems such as cardiovascular, respiratory, digestive, reproductive, stress, immunologic system, etc. UCN and CRF bind to two known receptors, CRFR1 and CRFR2, to function. Both CRF receptors are distributed in CNS and periphery tissues, and their expression in cancer tissues has been reported. Now there are many documents indicating UCN/CRF play an important role in the regulation of carcinogenesis. There is also evidence indicating UCN/CRF have anticancer effects via CRFRs. This paper will review the effects of CRF family in cancers.

Urocortin 1 administration from onset of rapid left ventricular pacing represses progression to overt heart failure

Urocortin 1 (Ucn1) may be involved in the pathophysiology of heart failure (HF), but the impact of Ucn1 administration on progression of the disease is unknown. The aim of this study was to investigate the effects of Ucn1 in sheep from the onset of cardiac overload and during the subsequent development of HF. Eight sheep underwent two 4-day periods of HF induction by rapid left ventricular pacing (225 beats/min) in conjunction with continuous infusions of Ucn1 (0.1 microg.kg(-1).h(-1) iv) and a vehicle control (0.9% saline). Compared with control, Ucn1 attenuated the pacing-induced decline in cardiac output (2.43 +/- 0.46 vs. 3.70 +/- 0.89 l/min on day 4, P < 0.01) and increases in left atrial pressure (24.9 +/- 1.0 vs. 11.9 +/- 1.1 mmHg, P < 0.001) and peripheral resistance (38.7 +/- 9.4 vs. 25.2 +/- 6.1 mmHg.l(-1).min, P < 0.001). Ucn1 wholly prevented increases in plasma renin activity (4.02 +/- 1.17 vs. 0.87 +/- 0.1 nmol.l(-1).h(-1), P < 0.001), aldosterone (1,313 +/- 324 vs. 413 +/- 174 pmol/l, P < 0.001), endothelin-1 (3.8 +/- 0.5 vs. 2.0 +/- 0.1 pmol/l, P < 0.001), and vasopressin (10.8 +/- 4.1 vs. 1.8 +/- 0.2 pmol/l, P < 0.05) during pacing alone and blunted the progressive increases in plasma epinephrine (2,132 +/- 697 vs. 1,250 +/- 264 pmol/l, P < 0.05), norepinephrine (3.61 +/- 0.73 vs. 2.07 +/- 0.52 nmol/l, P < 0.05), and atrial (P < 0.05) and brain (P < 0.01) natriuretic peptide levels. Ucn1 administration also maintained urine sodium excretion (0.75 +/- 0.34 vs. 1.59 +/- 0.50 mmol/h on day 4, P < 0.05) and suppressed pacing-induced declines in creatinine clearance (P < 0.05). These findings indicate that Ucn1 treatment from the onset of cardiac overload has the ability to repress the ensuing hemodynamic and renal deterioration and concomitant adverse neurohumoral activation, thereby delaying the development of overt HF. These data strongly support a use for Ucn1 as a therapeutic option early in the course of the disease.

Inhibitory effects of glucocorticoids on urocortin-mediated increases in interleukin-6 gene expression in rat aortic smooth muscle cells

Urocortin (Ucn) 1, Ucn2, and Ucn3 have potent effects on appetite and the cardiovascular system. Endogenous Ucns in combination with CRF receptor type 2beta may have a physiological role in the cardiovascular system. We previously demonstrated that both Ucn1 and Ucn2 increased IL-6 output levels in A7r5 aortic smooth muscle cells. In the present study, we extended observations on stress or hormone-induced changes in IL-6 gene expression in the cardiovascular system, and determined the effects of glucocorticoids on Ucn-mediated increases in IL-6 mRNA levels, protein levels, and gene transcription activity in A7r5 cells. Ucn1, Ucn2, and Ucn3 all increased IL-6 mRNA levels via CRF receptor type 2. Dexamethasone blocked the ability of Ucn1 to increase IL-6 mRNA and protein levels, while it failed to attenuate the Ucns-mediated changes in cyclic AMP (cAMP)-response element binding protein or extracellular signal-related kinases phosphorylation. Dexamethasone also suppressed Ucn1- or cAMP-stimulated IL-6 gene transcription via a glucocorticoid receptor. Together, these findings demonstrate that glucocorticoids suppress IL-6 gene transcription via Ucn-induced cAMP-dependent pathways in A7r5 cells.

Physiology, pharmacology, and therapeutic relevance of urocortins in mammals: ancient CRF paralogs

Urocortins, three paralogs of the stress-related peptide corticotropin-releasing factor (CRF) found in bony fish, amphibians, birds, and mammals, have unique phylogenies, pharmacologies, and tissue distributions. As a result and despite a structural family resemblance, the natural functions of urocortins and CRF in mammalian homeostatic responses differ substantially. Endogenous urocortins are neither simply counterpoints nor mimics of endogenous CRF action. In their own right, urocortins may be clinically relevant molecules in the pathogenesis or management of many conditions, including congestive heart failure, hypertension, gastrointestinal and inflammatory disorders (irritable bowel syndrome, active gastritis, gastroparesis, and rheumatoid arthritis), atopic/allergic disorders (dermatitis, urticaria, and asthma), pregnancy and parturition (preeclampsia, spontaneous abortion, onset, and maintenance of effective labor), major depression and obesity. Safety trials for intravenous urocortin treatment have already begun for the treatment of congestive heart failure. Further understanding the unique functions of urocortin 1, urocortin 2, and urocortin 3 action may uncover other therapeutic opportunities.