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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.

Background/Aims: Urotensin II (UII) and its receptor are highly expressed in the kidney tissue of patients with diabetic nephropathy (DN). The aim of this study is to examine the roles of UII in the induction of endoplasmic reticulum stress (ER stress) and Epithelial-mesenchymal transition (EMT) in DN in vivo and in vitro. Methods: Kidney tissues were collected from patients with DN. C57BL/6 mice and mice with UII receptor knock out were injected with two consecutive doses of streptozotocin to induce diabetes and were sacrificed at 3th week for in vivo study. HK-2 cells in vitro were cultured and treated with UII. Markers of ER stress and EMT, fibronectin and type IV collagen were detected by immunohistochemistry, real time PCR and western blot. Results: We found that the expressions of protein of UII, GRP78, CHOP, ALPHA-SMA, fibronectin and type IV collagen were upregulated while E-cadherin protein was downregulated as shown by immunohistochemistry or western blot analysis in kidney of diabetic mice in comparison to normal control; moreover expressions of GRP78, CHOP, ALPHA-SMA, fibronectin and type IV collagen were inhibited while E-caherin expression was enhanced in kidney in diabetic mice with UII receptor knock out in comparison to C57BL/6 diabetic mice. In HK-2 cells, UII induced upregulation of GRP78, CHOP, ALPHA-SMA, fibroblast-specifc protein 1(FSP-1), fibronectin and type collagen and downregulation of E-cadherin. UII receptor antagonist can block UII-induced ER stress and EMT; moreover, 4-PBA can inhibit the mRNA expression of ALPHA-SMA and FSP1 induced by UII in HK-2 cells. Conclusions: We are the first to verify UII induces ER stress and EMT and increase extracellular matrix production in renal tubular epithelial cell in early diabetic mice. Moreover, UII may induce renal tubular epithelial EMT via triggering ER stress pathway in vitro, which might be the new pathogenic pathway for the development of renal fibrosis in DN.

Hypertensive disorders in pregnancy remain a leading cause of maternal and perinatal mortality and morbidity. We aim to study urotensin II (UII) and its association with the markers of endoplasmic reticulum stress (ERS) in placentas of patients with severe preeclampsia (SPE). Thirty-three patients with hypertensive disorders in pregnancy and twenty-two healthy pregnant women designated as healthy controls were recruited. Expression levels of UII, UII receptor (GPR14) and the markers of ERS in placenta specimens of patients were performed. Plasma and urinary UII levels were measured by radioimmunoassay method. Our study showed that the plasma levels of UII in patients with hypertensive disorders during pregnancy were significantly higher than that of the healthy control group. However, the urinary levels of UII had no difference in two groups. The expression level of mRNA and protein of UII, CCAAT/enhancer-binding protein homologous protein (CHOP) and glucose regulation protein 78 in placentas of SPE was significantly increased. Immunohistochemical analyses show that the expression levels of UII and ERS markers were mainly located in the cytoplasm of placental trophoblastic cells. Moreover, expression level of UII mRNA and protein was positively correlated with that of the markers of ERS. The positive correlation between UII and ERS markers expression level also corresponded with the level of patient's systolic blood pressure and proteinuria. In conclusion, we first verify that expression of UII is associated with ERS in patients with SPE. Our results indicate that UII may trigger ERS in placental trophoblastic cells in patients with preeclampsia.

Aims/Introduction Irisin is a newly identified myokine that can promote energy expenditure. Previous studies showed that circulating urotensin II (UII) levels were increased in diabetes, and UII could inhibit the glucose transport in skeletal muscle in diabetic mice and aggravated insulin resistance. We presumed that irisin levels are associated with UII in diabetic patients. Materials and Methods A total of 71 patients with type 2 diabetes and 40 healthy subjects were recruited. Blood and urinary irisin concentrations were measured by using enzyme-linked immunosorbent assay, and UII concentrations were measured by bioelectrical impedance analysis. Every participant's body composition was analyzed by bioelectrical impedance. Results The serum irisin levels were significantly lower in diabetic patients than that of controls, whereas serum UII levels were significantly higher in diabetic patients than that in that of controls. Serum irisin levels were negatively associated with circulating UII, hemoglobin A1c and the natural logarithm transformation of urinary albumin excretion, whereas serum irisin was positively associated with estimated glomerular filtration rate, and low-density lipoprotein cholesterol and urinary irisin were positively associated with urinary UII. Furthermore, circulating irisin is positively associated with muscle mass, whereas circulating UII is negatively associated with muscle mass in diabetic patients. Hemoglobin A1c and circulating UII are independent determinants of circulating irisin by multiple regression analysis. Conclusions The present results provide the clinical evidence of an association between irisin and UII in diabetic patients. Hemoglobin A1c and circulating UII are independent determinants of circulating irisin. Our results hint that UII and high glucose might inhibit the release of irisin from skeletal muscle in diabetic patients.

Background Granulocyte colony stimulating factor (G-CSF) is a key mediator of neutrophil infiltration and is profibrotic in the liver, lung, and infarcted heart, but its roles in angiotensin II (Ang II)-induced hypertension and cardiac remodeling have not been fully determined. Thus, we sought to investigate the causal relation of G-CSF to neutrophil recruitment and cardiac fibrosis in C57BL/6J mice. Methods Hypertension and cardiac fibrosis were induced in wild-type (WT) mice receiving continuous infusion of Ang II (1,500ng/kg/min). After 7 days, heart sections were stained with hematoxylin and eosin, Masson's trichrome, and immunohistochemistry. The mRNA expression of cytokines was detected by real-time polymerase chain reaction analysis. The protein levels were measured by Western blot analysis. Results After Ang II infusion, myocardial G-CSF expression was significantly elevated in the hearts. Moreover, WT mice exhibited increased blood pressure, marked neutrophil accumulation, proinflammatory cytokine expression, reactive oxygen species production, and cardiac fibrosis after 7 days of Ang II infusion. However, administration of anti-G-CSF neutralizing antibody, but not with control immunoglobulin G, significantly attenuated these effects. In addition, neutralizing G-CSF antibody reversed Ang II-induced activation of ERK1/2, STAT3, and AKT signaling pathways in the hearts. Conclusions This study demonstrates that G-CSF plays a critical role in hypertension and cardiac fibrosis and targeting this cytokine may be a novel therapeutic strategy to ameliorate hypertensive heart disease.

Our previous work reported that endoplasmic reticulum stress (ERS)-mediated apoptosis was activated during vascular calcification (VC). Activating transcription factor 4 (ATF4) is a critical transcription factor in osteoblastogenesis and ERS-induced apoptosis. However, whether ATF4 is involved in ERS-mediated apoptosis contributing to VC remains unclear. In the present study, in vivo VC was induced in rats by administering vitamin D3 plus nicotine. Vascular smooth muscle cell (VSMC) calcification in vitro was induced by incubation in calcifying media containing β-glycerophosphate and CaCl2. ERS inhibitors taurine or 4-phenylbutyric acid attenuated ERS and VSMC apoptosis in calcified rat arteries, reduced calcification and retarded the VSMC contractile phenotype transforming into an osteoblast-like phenotype in vivo. Inhibition of ERS retarded the VSMC phenotypic transition into an osteoblast-like cell phenotype and reduced VSMC calcification and apoptosis in vitro. Interestingly, ATF4 was activated in calcified aortas and calcified VSMCs in vitro. ATF4 knockdown attenuated ERS-induced apoptosis in calcified VSMCs. ATF4 deficiency blocked VSMC calcification and negatively regulated the osteoblast phenotypic transition of VSMCs in vitro. Our results demonstrate that ATF4 was involved at least in part in the process of ERS-mediated apoptosis contributing to VC.

Introduction. Dahl salt-resistant (SR) animal models are similar to peritoneal dialysis patients with fluid volumes overload with normal blood pressure in hemodynamic profiles. We will verify the roles of UII in the regulation of blood pressure in these animal models.Methodology. The Dahl salt-sensitive (SS) and SR rats and UII receptor gene knocked out (KO) mice were placed on a high-salt diet. Renal tissues were performed for the expression of UII in Dahl groups.Results. After high-salt diet for 6 weeks, the systolic blood pressure (SBP) in SR group was significantly lower, accompanied with higher urinary UII levels, higher 24-hour urinary sodium excretion, and higher urinary creatinine clearance in the SR rats in comparison to SS group. The expressions of UII and UT were both upregulated in the kidney tissues of SR group in comparison to SS group (P<0.05). After high-salt diet for 8 weeks, the SBP of the KO group is significantly higher than that of the wild type group.Conclusion. We first demonstrate that renal UII system can play important roles in the regulation of blood pressure in Dahl SR rats which can be highly correlated to its effect on renal tubular sodium absorption.

Intermedin (IMD) plays an important regulatory role in cardiovascular function. We aimed to explore the protein expression of IMD and its receptors, calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs), and the role of endogenous IMD in myocardial ischemia/reperfusion (I/R) injury in rats. The rat model of I/R was created by ligating cardiac left anterior descending artery. Western blot was used to determine protein expression of CRLR and RAMPs, and radioimmunoassay was used to detect IMD content. Compared with control, protein levels of CRLR and RAMPs in both ischemic and nonischemic region were upregulated at different stages of reperfusion. IMD protein content in nonischemic area myocardium also increased. However, IMD protein content in ischemic area downregulated at 3-, 6-, and 12-h reperfusion. In hypoxia/reoxygenation model of neonatal cardiomyocytes, IMD attenuated myocyte injury, and IMD receptor antagonist IMD17-47 aggravated myocyte impairment by blocking endogenous IMD. In conclusion, the downregulation of IMD at early stage of reperfusion might augment myocardium injury.

Aims Abdominal aortic aneurysm (AAA) is characterized by extensive aortic wall matrix degradation that contributes to the remodelling and eventual rupture of the arterial wall. Elastinolytic cathepsin S (Cat S) is highly expressed in human aneurysmal lesions, but whether it contributes to the pathogenesis of AAA remains unknown. Methods and results AAAs were induced in apolipoprotein E (ApoE) and Cat S compound mutant ( Apoe–/–Ctss–/– ) mice and in ApoE-deficient Cat S wild-type littermates ( Apoe–/–Ctss+/+ ) by chronic angiotensin II infusion, and AAA lesions were analysed after 28 days. We found that Cat S expression increased significantly in mouse AAA lesions. The AAA incidence in Apoe–/–Ctss–/– mice was much lower than that in Apoe–/–Ctss+/+ mice (10 vs. 80%). Cat S deficiency significantly reduced external and luminal abdominal aortic diameters, medial elastin fragmentation, and adventitia collagen content. Cat S deficiency reduced aortic lesion expression and the activity of matrix metalloproteinase (MMP)-2, MMP-9, and Cat K, but not the activity of other major cathepsins, such as Cat B and Cat L. Absence of Cat S significantly reduced AAA lesion media smooth muscle cell (SMC) apoptosis, lesion adventitia microvessel content, and inflammatory cell accumulation and proliferation. In vitro studies proved that Cat S helps promote SMC apoptosis, angiogenesis, monocyte and T-cell transmigration, and T-cell proliferation—all of which are essential to AAA pathogenesis. Conclusions These data provide direct evidence that Cat S plays an important role in AAA formation and suggest that Cat S is a new therapeutic target for human AAA.

Objective To examine the effects of exogenously administered intermedin (IMD, adrenomedullin-2) on arterial blood pressure, cardiac function and the cardiovascular IMD receptor system in spontaneously hypertensive rats (SHRs) as well as to investigate the associated mechanisms.

This study compared angiotensin II (Ang II) and angiotensin III (Ang III) for their effects on rat neonatal cardiomyocytes and cardiac fibroblasts in vitro and discussed the possible role of Ang III in the pathogenesis of cardiac remodeling. To do so, protein synthesis, cardiac fibroblast proliferation, collagen synthesis, and secretion in response to treatment with Ang III and Ang II were investigated. Protein synthesis rate was assessed by 3H-Leucine (3H-Leu) incorporation; the content of DNA was defined by 3H-thymidine (3H-TdR) incorporation; and collagen synthesis and secretion were assessed by 3H-proline (3H-Pro) incorporation. In neonatal cardiomyocytes, Ang III stimulated protein synthesis in a concentration-dependent manner, whereas in neonatal cardiac fibroblasts, DNA synthesis as well as collagen synthesis and secretion were increased in a concentration-dependent manner. Treatment with captopril, selective aminopeptidase A (APA) inhibitor (EC33), or selective aminopeptidase N inhibitor (PC18) had no effect on these outcomes. Treatment with losartan significantly decreased the effects of Ang III, except for cardiomyocyte protein synthesis. Compared with Ang II, Ang III could stimulate cardiomyocyte protein synthesis, cardiac fibroblast proliferation, and collagen synthesis and secretion. Furthermore, 10-7 mol/L Ang II but not Ang III significantly increased APA activity in both cardiomyocytes and fibroblasts. All these results show the bioactive effects of Ang III on myocardial cells and suggest that Ang III could be an important independent factor besides Ang II in the regulation of cardiac function and may affect the pathogenesis of cardiac remodeling.

Apelin, the endogenous ligand of the G protein-coupled APJ receptor, is a peptide mediator with emerging regulatory actions in the heart. We aimed to determine whether the endogenous apelin/APJ system is an intrinsic protective pathway in ischemic/reperfusion injury. A Langendorff model of perfused isolated rat hearts and primary cultured myocardial cells from neonatal rats were used. Cardiac function was monitored and apelin/APJ expression was determined by real-time PCR and Western blot analysis. In rats under I/R, cardiac function was significantly decreased as compared with controls, and APJ was over-expressed at both the mRNA and protein levels (by 7-fold and 35%, respectively, both p

Aims/Introduction: Irisin is a newly identified myokine which can promote energy expenditure. Urotensin II (UII) is identified as the most potent mammalian vasoconstrictor to date. Previous studies showed that UII can aggravate insulin resistance while irisin alleviate insulin resistance. Through this study, it is our aim to elucidate if UII can induce insulin resistance and also have an association with the irisin level in hemodialysis (HD) patients. Materials and Methods: One hundred and twenty-eight patients on maintenance hemodialysis treatment and forty healthy subjects were enrolled in this study. Blood irisin concentrations and UII concentrations were measured by ELISA and RIA respectively. The body composition was analyzed by bioelectrical impedance. Results: The serum irisin levels and UII levels were both significantly lower in HD patients in comparison to that of the healthy subjects. The serum irisin levels were lower in HD patients with protein energy wasting than those of the patients without protein energy wasting. The independent determinants of circulating Ln (irisin) (the natural logarithm of irisin) were UII lean body mass and patients with protein energy wasting. Conclusions: Our results are the first to provide the clinical evidence of the association among irisin, UII, and protein energy wasting. Our results hint that UII and protein energy wasting might inhibit the release or synthesis of irisin from skeletal muscles in HD patients.

NOD1 is a member of nucleotide-binding oligomerization domain-like receptors family that participates in many inflammatory processes. Previous studies demonstrated that NOD1 plays an important role in inflammatory cardiovascular diseases. However, its role in myocardial ischemia/reperfusion (I/R) injury remains unknown. The present study investigate whether NOD1 is involved in the pathogenesis of mouse myocardial I/R injury and the underlying mechanisms. Administration of NOD1 ligand (DAP) significantly enhanced myocardial I/R injury, as demonstrated by increased infarct size, the number of TUNEL-positive nuclei, caspase-3 activity, the infiltration of Mac-2- and IL-6-positive cells as compared with untreated heart or cardiomyocytes after I/R injury. In contrast, knockdown of NOD1 by siRNA markedly attenuated mimetic I/R induced cardiomyocyte apoptosis in vitro, indicating that NOD1 enhanced myocardial I/R injury partially through direct heart effects. These effects were partially associated with activation of JNK, p38 MAPK and NF-κB signaling pathways. Taken together, these results provide the first evidence that activation of intracellular sensor NOD1 enhances myocardial I/R injury and may provide novel therapeutic target for ameliorating the ischemic heart diseases.

The main objective of this study is to test the hypothesis that N-methyl-D-aspartate (NMDA) receptors within the rostral ventrolateral medulla (RVLM) are involved in the inhibition of clonidine on the RVLM presympathetic neurons. Totally, 22 presympathetic neurons were recorded in anesthetized and paralyzed rats. The majority of these neurons (n=16 of 22) were significantly inhibited by iontophoretic (30 nA) clonidine, the other 6 neurons were insensitive to clonidine. In seven clonidine-sensitive neurons, iontophoretic clonidine (30 nA) antagonized the neuronal excitation of iontophoretic NMDA receptor agonist NMDA (20 nA). In remaining nine clonidine-sensitive neurons, iontophoretic NMDA receptor antagonist MK801 (60 nA) significantly attenuated the neuronal inhibition of iontophoretic (30 nA) clonidine. In conclusion, these results suggest that NMDA receptors contribute to the inhibition of clonidine on the RVLM presympathetic neurons.

Although it is recognized that imidazoline receptors play an important role in the central regulation of cardiovascular activities, little is known about their role in the caudal ventrolateral medulla. In male Sprague-Dawley rats anesthetized with urethane, we used antagonists of I1-imidazoline receptor or alpha2-adrenoceptor to assess the function of these receptors in the caudal ventrolateral medulla in controlling the cardiovascular effects of clonidine. Unilateral microinjection of clonidine (6 nmol/50 nl) into the caudal ventrolateral medulla significantly (P

ObjectiveAdrenomedullin, a recently discovered peptide with hypotensive effects, has been shown to be elevated in glomerular diseases. In this study, we investigated the relationship between the plasma adrenomedullin and renal tubulointerstitial lesion in patients with mesangial proliferative glomerulonephritis.MethodsTwenty-six patients with a normal renal function, diagnosed histologically with mesangial proliferative glomerulonephritis with (n = 1) or without immunoglobulin A composure (n = 25), were enrolled in this study. Eighteen healthy volunteers were enrolled as controls. Patients were divided into two groups according to the degree of tubulointerstitial lesion. Plasma adrenomedullin level was measured by an adrenomedullin-specific radioimmunoassay.ResultsPlasma adrenomedullin concentrations were higher in patients with mesangial proliferative glomerulonephritis than in healthy volunteers (5.71 × 10−12 ± 0.37 × 10−12 vs 2.12 × 10−12 ± 0.15 ×10−12 mol/L; p

Abdominal aortic aneurysm (AAA) is a fatal disease defined as an abdominal aortic diameter of 3.0 cm or more, where the abdominal aorta exceeds the normal diameter by more than 50%. Histopathological changes of AAA mainly include extracellular matrix (ECM) remodeling at the abdominal aorta wall, but there is lack of specific drugs to treat AAA. Recent studies have reported that lysosomal cathepsins could induce vascular remodeling and AAA formation by regulating vascular inflammation, medial smooth muscle cell apoptosis, neovascularization, and protease expression. Thus, cathepsins are expected to become a new therapeutic target for AAA treatment.

Proliferation and migration of vascular smooth-muscle cells (VSMCs) are essential events in neointimal hyperplasia. Recent findings that active oxygen species induce pro-oncogene expression, and stimulate VSMC DNA synthesis and cell division, suggest that active oxygen species may play an important role in intimal proliferation after arterial injury. To determine how the redox state of the artery was altered by injury, the levels of thiobarbituric-acid-reactive substances (TBARs, markers of lipid oxidation) and glutathione peroxidase (GSH-PX, the enzyme responsible for the production of glutathione, a major intracellular antioxidant) were measured in the rat aorta after balloon injury. There was an inverse relationship between the level of TBARs, which increased significantly to a maximum 17% greater than normal at 10 days after injury (p0.05, n=7), and the activity of GSH-PX, which decreased significantly to a minimum 36.5% less than normal at 10 days after injury (p0.05, n=7). To determine whether maintaining a more reduced vessel environment would inhibit intimal proliferation, L-cysteine was administered by intraperitoneal injection from 3 days before to 14 days after balloon injury. At 14 days after the arterial injury, the aorta was harvested for histological and morphometric measurements of TBARs and GSH-PX. At 7 and 14 days after balloon injury, the aorta was harvested for [3H]thymidine incorporation studies. Efficacy of therapy was demonstrated by a significant decrease in the level of TBARs and an increase in the activity of GSH-PX (p0.05 vs. the control group, n=7). In the L-cysteine group, all parameters of intimal proliferation were significantly reduced compared to the controls, including the intima:media ratio (0.091 vs. 0.253, p0.05); the cross-sectional area of the neointima (0.0563 compared to 0.140 mm2, p0.05), coverage of the internal elastic lamina by the neointima (23.44 compared to 43.27%, p0.05), and [3H]thymidine incorporation (at 7 days 240.58 vs 350.68 cpm/mg tissue, p0.05; at 14 days 181.71 vs. 275.30 cpm/mg tissue, p0.05). These results demonstrate dynamic alterations in the vessel redox state after arterial injury, and suggest that maintaining a more reduced environment (e.g. administration of L-cysteine) will reduce intimal proliferation after arterial injury.

Aim/Introduction Urotensin II (UII) and autophagy have been considered as important components in the pathogenesis of diabetic nephropathy. The present study explores whether UII can regulate autophagy in kidney and its effect in diabetes. Materials and Methods Immunohistochemistry and western blot were conducted on the kidney tissues of diabetic UII receptor (UT) gene knock-out mice, wild type diabetic mice, and normal control mice. For in vitro experiment, HK-2 cells were treated with UII (10-7 mol/L) in the presence or absence of UT antagonist, SB-657510, (10-6 mol/L) or autophagy inducer Rapamycin (10-3 mol/L) for 12 h. Markers for autophagy (LC3-II, p62/SQSTM1) and extracellular matrix (fibronectin, collagen IV) were analyzed. Results In diabetic UT knock-out mice, expression of LC3-II is increased and p62 is reduced in comparison to that of the normal diabetic mice. Fibronectin and collagen IV are down-regulated in diabetic UT knock-out mice when compared to that of the normal diabetic mice. For in vitro cell experiment, UII is shown to inhibit expression LC3-II and increase expression of p62 in comparison to that of the normal control. Treatment with SB-657510 can block UII-induced down-regulation of LC3-II and upregulation of p62 while inhibiting UII-induced upregulation of fibronectin and collagen IV. Adding autophagy inducer Rapamycin also inhibited UII-induced upregulation of fibronectin and collagen IV. Conclusion Our study is the first to show that UII can down-regulate autophagy in kidney while accompanying the increased production of ECM in early diabetes. Our in vitro study also demonstrates that upregulation of autophagy can decrease UII-induced production of ECM in HK-2 cell. This article is protected by copyright. All rights reserved.

Intermedin (IMD) is a newly discovered peptide with increased levels in plasma and cardiac tissue in mice with ischemia/reperfusion. Continuous administration of low dose IMD markedly elevated the mRNA abundance of myocardial BNP in rats. Plasma BNP levels may reflect the severity of degree of coronary stenosis in patients with acute coronary syndrome (ACS). However, the role of circulating IMD in coronary heart disease remains unclear. We aimed to examine the plasma content of IMD and brain natriuretic peptide (BNP) and its clinical significance in patients with ACS. We collected plasma samples from 41 patients with ACS and 31 controls and measured IMD and BNP levels by radioimmunoassay. The severity of coronary artery stenosis for patients with ACS was measured by coronary angiography. Plasma IMD and BNP levels were markedly higher in ACS patients than that in controls (P

Osteogenic differentiation of vascular smooth muscle cells (VSMCs) results in medial artery calcification, which is common in diabetes, but the pathogenesis is poorly understood. We aimed to explore the pathophysiological roles of insulin resistance (IR) on medial artery calcification in rats with 10% fructose in drinking water. After 12 weeks of fructose feeding, rats showed severe IR, with increased levels of fasting blood glucose, serum insulin and oral glucose tolerance test (OGTT). Fructose-fed rats showed aortic calcification, increased aortic calcium deposition and irregular elastic fibers in the medial layer of the vessel wall. Moreover, plasma phosphorus concentration, calcium × phosphorus product and alkaline phosphatase (ALP) activity, and aortic calcium content and ALP activity were significantly increased. Fructose feeding increased mRNA levels of osteopontin, type III sodium-dependent phosphate co-transporter, bone morphogenetic protein-2 and the key transcription factor core binding factor alpha 1 in aortic tissue and downregulated mRNA levels of osteoprotegerin and matrix γ-carboxyglutamic acid protein. Fructose feeding decreased protein levels of smooth-muscle lineage markers and induced severe lipid peroxidation injury. IR induced by high fructose feeding could evoke osteogenic transdifferentiation of VSMCs and promote vascular calcification.

Angiotensin II (Ang II) is an important regulator of cardiac function and injury in hypertension. The novel Ang IV peptide/AT4 receptor system has been implicated in several physiological functions and has some effects opposite to those of Ang II. However, little is known about the role of this system in Ang II-induced cardiac injury. Here we studied the effect of Ang IV on Ang II-induced cardiac dysfunction and injury using isolated rat hearts, neonatal cardiomyocytes and cardiac fibroblasts. We found that Ang IV significantly improved Ang II-induced cardiac dysfunction and injury in the isolated heart in response to ischemia/reperfusion (I/R). Moreover, Ang IV inhibited Ang II-induced cardiac cell apoptosis, cardiomyocyte hypertrophy, and proliferation and collagen synthesis of cardiac fibroblasts; these effects were mediated through the AT4 receptor as confirmed by siRNA knockdown. These findings suggest that Ang IV may have a protective effect on Ang II-induced cardiac injury and dysfunction and may be a novel therapeutic target for hypertensive heart disease.

Objective: Percutaneous coronary intervention (PCI) triggers an acute inflammatory response, while sirolimus is known to have anti-inflammatory properties; the inflammatory system response to PCI after sirolimus-eluting stent placement remains unclear. The purpose of this study is to determine the changes in high sensitive C-reactive protein (hs-CRP) and apelin after PCI procedure and drug-eluting stent implantation in patients with and without reduced left ventricular systolic function. Methods: Forty-eight consecutive patients undergoing PCI at the Beijing Anzhen Hospital between July and September 2006 were recruited. Sirolimus-eluting stents were employed in all patients. Blood samples were drawn immediately before and 24 h after the procedure. Plasma hs-CRP and apelin levels were determined by enzyme immunoassay. Results: Paired t-test revealed a significant increase in both hs-CRP and apelin post-procedure (P=0.006 and P

Urotensin II (UII) is a somatostatin-like peptide recently identified to be involved in metabolic regulation and to play a significant role in diabetes and its complications. In the present study, we investigated the expression of UII and its receptor UT in the soleus muscle of male diabetic KK/upj-AY/J mice (2DM group) and the effects of UII on glucose uptake by the skeletal muscle to explore the role of skeletal muscle-derived UII in the pathogenesis of insulin resistance and diabetes. Radioimmunoassay, RT-PCR, immunohistochemistry and radio-ligand binding assay were used in this study. Compared with C57BL/6J mice (control group), 2DM mice showed increased UII content, by 34.0% in plasma, 15.4% in skeletal muscle tissue and 30.6% in medium containing UII from muscle (all P0.05 or P0.01). UII protein and UT mRNA expression were significantly enhanced in the skeletal muscle of 2DM mice. On [(125)I]UII binding to muscle sarcolemma, UT binding exhibited a saturable single-component characteristic in a specific and time-dependent manner. Scatchard plot analysis showed higher maximal number of specific binding sites (Bmax) in skeletal muscle, by 42.9% (P0.01), and a lower dissociation constant (Kd), by 26.4% (P0.01), in the 2DM group than in controls. On in vitro tissue pre-incubation with UII (10(-9), 10(-8) and 10(-7) mol/L), the insulin-stimulated [(3)H]-2-DG uptake by split soleus muscle was lower, by 9.5%, 33.4% and 39.7% (all P0.01), respectively, than without UII incubation. UII/UT upregulated in skeletal muscle of 2DM mice suggests that UII derived from skeletal muscle might induce the pathogenesis of skeletal muscle insulin resistance as an autocrine factor.

Endothelin-1(1-31) (ET-1(1-31)) is a novel member of the endothelin family, which comprises 31 amino acids and derived from the selective hydrolysis of big ET-1 by chymase. Although ET-1(1-31) has been reported to be involved in biological effects via direct or indirect (converting to ET-1(1-21)) mechanisms, the cardiovascular effects of central ET-1(1-31) are not fully identified. The present study was designed to comparatively investigate the cardiovascular effects of intracerebroventricular (icv) application of ET-1(1-31) or ET-1(1-21) in anesthetized rats. Injection (icv) of ET-1(1-31) (500 pmol) produced a biphasic blood pressure response: an initial increase (from 118+/-8 to 138+/-14 mmHg, P

Endothelin-1 1-31 (ET-1 1-31), a novel member of the endothelin family comprising 31 amino acids and derived from the selective hydrolysis of big ET-1 by chymase, directly activates endothelin receptors or converts to ET-1 1-21 by ET converting enzyme (ECE). The cardiovascular effects of central ET-1 1-31 are not identified. The present study was designed to investigate the cardiovascular actions of ET-1 1-31 within the rostral ventrolateral medulla (RVLM) in anesthetized rats. Bilateral injection of ET-1 1-31 (0.5, 1, and 2 pmol for each side) into the rostral ventrolateral medulla produced an initial pressor and/or a long-lasting hypotensive action but did not affect HR. Unilateral microinjection of 2 and 4 pmol of ET-1 1-31 into the rostral ventrolateral medulla only produced a significant (P0.05) transient increase in blood pressure by an average of 13 and 12 mm Hg, respectively, whereas unilateral microinjection of 8 pmol of ET-1 1-31 produced a sustained fall in blood pressure (from 92 +/- 6 to 69 +/- 8 mm Hg, P0.05). The transient pressor effect of unilaterally injecting ET-1 1-31 (4 pmol) into the rostral ventrolateral medulla was completely abolished by pretreatment with either ETA receptor antagonist BQ123 (83 +/- 2 versus 84 +/- 5 mm Hg, P0.05) or ET converting enzyme inhibitor phosphoramidon (99 +/- 5 versus 99 +/- 7 mm Hg, P0.05) but not ETB receptor antagonist IRL1038 (89 +/- 6 versus 96 +/- 7 mm Hg, P0.05). In addition, prior injection of phosphoramidon also completely abolished the long-lasting hypotension of intra-RVLM ET-1 1-31 (8 pmol) but did not modify the depressor action of intra-RVLM ET-1 1-21 (from 100 +/- 6 to 76 +/- 8 mm Hg, P0.05). In conclusion, the current results suggest that the cardiovascular effects of intra-RVLM ET-1 1-31 might be the result of conversion of ET-1 1-31 to ET-1 1-21 through activation of ETA receptors.

It is known that the caudal ventrolateral medulla (CVLM) plays an important role in controlling blood pressure and mediating the cardiovascular effects of centrally acting antihypertensive drugs such as clonidine. Recently, the effect of clonidine was believed to be related to the functional states of N-methyl-D-aspartate (NMDA) receptors. The present work was designed to observe the interactions between clonidine and NMDA receptor in the CVLM. Unilaterally injected clonidine (6 nmol) into the CVLM not only produced a pressor action, but also effectively (P0.01, n=8) antagonized the decreases in both mean arterial pressure (MAP) (-22.3+/-5.0 to -7.9+/-2.3 mmHg) and heart rate (HR) (-31.9+/-5.9 to -10.3+/-2.7 beats/min) evoked by L-glutamate in the CVLM. Unilaterally injected NMDA receptor antagonist MK801 (200 pmol) into the CVLM significantly increased MAP by 26.5+/-3.7 mmHg and HR by 37.1+/-7.6 beats/min, and completely (P0.01, n=10) abolished the pressor effect (16.1+/-6.6 to 1.5+/-2.8 mmHg) of clonidine in the CVLM. In conclusion, these findings show that NMDA receptors within the CVLM contribute to clonidine-induced action, and suggest that the CVLM plays an important role in the interaction between clonidine and NMDA receptors.

There is ample evidence to show the existence of center I(1)-imidazoline receptors that are involved in the regulation of cardiovascular activities. The purpose of this study was to examine the possible role of I(1)-imidazoline receptors and alpha(2)-adrenoceptors within the caudal ventrolateral medulla (CVLM) in mediating the baroreceptor reflex in anesthetized rats. Unilateral microinjection of idazoxan (2 nmol in 50 nl), a mixed antagonist of I(1)-imidazoline receptors and alpha(2)-adrenoceptors, into the CVLM significantly (P0.01) decreased blood pressure (BP), heart rate (HR), and the firing rate of presympathetic neurons in the rostral ventrolateral medulla (RVLM) by 21+/-6 mmHg, 25+/-5 beats per min and 3.5+/-0.9 spikes/s, respectively. Moreover, unilateral injection of idazoxan into the CVLM significantly (P0.01) reduced the inhibitory responses of the ipsilateral RVLM presympathetic neurons evoked by stimulation of aortic nerve and elevation of BP, and partially inhibited the neuronal cardiac cycle-related rhythm. Depressor responses evoked by aortic nerve stimulation were significantly (P0.01) attenuated 10 and 20 min after bilateral microinjection of idazoxan (2 nmol in 50 nl for each side) into the CVLM (-20+/-4 and -30+/-4 vs. -40+/-1 mmHg). However, injection of yohimbine (500 pmol in 50 nl), a selective alpha(2)-adrenoceptor antagonist, into the CVLM did not affect the resting cardiovascular activities and baroreceptor reflex. It is concluded that the CVLM I(1)-imidazoline receptors are involved in maintenance of tonic cardiovascular activities and transmission of the baroreceptor reflex.