Advances in molecular mechanisms of meiotic arrest and luteinizing hormone-induced meiotic resumption in oocytes / 生理学报

Mammalian oocytes within Graafian follicles are arrested at prophase I of meiosis. C-type natriuretic peptide (NPPC), secreted by mural granulosa cells (MGCs), maintains oocyte meiotic arrest via binding to its cognate receptor natriuretic peptide receptor 2 (NPR2) and producing cyclic guanosine monophosphate (cGMP). NPR2 is most concentrated in the cumulus cells. In addition, cAMP, gap junction, inosine monophosphate dehydrogenase (IMPDH) and other important regulatory factors are also involved in meiotic arrest. Luteinizing hormone (LH) then rapidly decreases cGMP and induces oocyte meiotic resumption. In this paper, advances in the molecular mechanisms of meiotic arrest and LH-induced meiotic resumption were reviewed. This paper may provide new ideas for the prevention, diagnosis and treatment of related reproductive diseases.

C-Type Natriuretic Peptide/Natriuretic Peptide Receptor 2 Is Involved in Cell Proliferation and Testosterone Production in Mouse Leydig Cells

PURPOSE: This study investigated the role of natriuretic peptide receptor 2 (NPR2) on cell proliferation and testosterone secretion in mouse Leydig cells. MATERIALS AND METHODS: Mouse testis of different postnatal stages was isolated to detect the expression C-type natriuretic peptide (CNP) and its receptor NPR2 by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Leydig cells isolated from mouse testis were cultured and treated with shNPR2 lentiviruses or CNP. And then the cyclic guanosine monophosphate production, testosterone secretion, cell proliferation, cell cycle and cell apoptosis in mouse Leydig cells were analyzed by ELISA, RT-qPCR, Cell Counting Kit-8, and flow cytometry. Moreover, the expression of NPR2, cell cycle, apoptosis proliferation and cell cycle related gene were detected by RT-qPCR and Western blot. RESULTS: Knockdown of NPR2 by RNAi resulted in S phase cell cycle arrest, cell apoptosis, and decreased testosterone secretion in mouse Leydig cells. CONCLUSIONS: Our study provides more evidences to better understand the function of CNP/NPR2 pathway in male reproduction, which may help us to treat male infertility.

O NT-ProBNP da admissão versus da alta como preditor prognóstico na insuficiência cardíaca Agudamente Descompensada / NT-ProBNP at Admission Versus NT-ProBNP at discharge as a prognostic predictor in acute decompensated heart failure

Fundamento: Pacientes internados por insuficiência cardíaca (IC) descompensada recebem intensa terapia diurética e vasodilatadora nos primeiros dias, conduta normalmente bem-sucedida na compensação do quadro, permitindo alta hospitalar. No entanto, é comum a recorrência de agravamento nas primeiras semanas após a alta. Objetivo: Avaliar se o principal preditor de recorrência de desfechos em pacientes com IC é o grau de descompensação na admissão ou o estado volêmico obtido após controle clínico. Métodos: coorte prospectiva de pacientes admitidos entre janeiro de 2013 e outubro de 2014, com diagnóstico de IC agudamente descompensada, acompanhados até 60 dias após a alta hospitalar. O critério de inclusão foi aumento da dosagem plasmática do NT-proBNP (> 450 pg/mL para pacientes abaixo de 50 anos ou NT-proBNP > 900 pg/mL para pacientes acima de 50 anos). O desfecho primário foi a combinação de óbito cardiovascular após compensação e reinternação por IC descompensada em 60 dias. Resultados: Foram estudados 90 pacientes, com mediana do NT-proBNP da admissão 3947 pg/mL (IIQ = 2370 pg/mL a 7000 pg/mL), mediana da variação absoluta do NT-proBNP de -1533 pg/mL (IIQ = -3569 pg/mL a 747 pg/mL), e mediana do NT-proBNP da alta de 1946 pg/mL (IIQ = 1000 pg/mL a 3781 pg/mL). A incidência do desfecho combinado foi de 30%, sendo 12,2% de óbitos e 20% de readmissão. A curva ROC do NT-proBNP da admissão e eventos cardiovasculares em 60dias apresentou uma área sob a curva de 0,49 (p = 0,89; IC 95% = 0,36 ­ 0,62). A variação absoluta do NT-proBNP apresentou área sob a curva de 0,65 (p = 0,04; IC 95% =0,51 ­ 0,79) para eventos em 60 dias, e o NT-proBNP da alta apresentou área sob a curva de 0,69 (p = 0,03; IC 95% = 0,58 ­ 0,80). Em análise multivariada, NT-proBNP que precedeu a alta foi preditor do desfecho primário, independente do valor mensurado na admissão e de outros fatores de risco. Conclusão: Diferente do grau de descompensação que motivou a internação, o estado volêmico obtido após compensação da IC se associa a eventos recorrentes. Este achado sugere que, independentemente da gravidade inicial, é a resposta ao tratamento durante o internamento que determina a vulnerabilidade do paciente para nova descompensação

Background: Patients admitted for decompensated heart failure (HF) receive intensive diuretic and vasodilator therapy in the first days. Normally, this is a successful approach that leads to HF compensation and hospital discharge. However, recurrences within the first week of discharge are common. Objective: to evaluate whether the main predictor of recurrent outcomes in patients with HF is the severity of decompensation at admission or patient's blood volume after clinical management. Methods: Prospective, cohort study of patients admitted between January 2013 and October 2014, with diagnosis of acute decompensated HF, who were followed-up for 60 days after discharge. Inclusion criterion was increased plasma NT-proBNP (> 450 pg/mL for patients younger than 50 years or >900pg/mL for patients older than 50 years). Primary outcome was the combination of cardiovascular death with rehospitalization for decompensated HF in 60 days. Results: Ninety patients were studied, with median NT-proBNP at admission of 3,947pg/mL (IQR: 2,370 ­ 7,000 pg/mL), and median NT-proBNP at discharge of 1,946pg/mL (IQR: 1,000 ­ 3,781 pg/mL). The incidence of combined outcome was 30% (12.2% of deaths and 20% of rehospitalization). The area under the ROC curve for NT-proBNP at admission and 60-day cardiovascular events was 0.49 (p = 0.89; 95% CI = 0.36 ­ 0.62). The area under the curve of NT-proBNP absolute variation for 60 day-events was 0.65 (p = 0.04; 95%CI = 0.51 ­ 0.79), and the area under the curve for NT-BNP at discharge was 0.69 (p = 0.03; 95%CI = 0.58 ­ 0.80). In the multivariate analysis, pre-discharge NT-proBNP was a predictor of the primary outcome, independently of the NT-proBNP at admission and other risk factors. Conclusion: Different from the severity of decompensation at hospitalization, blood volume after compensation of HF is associated with recurrent event. This finding suggests that, regardless of initial severity, therapy response during hospitalization is determinant of the risk of recurrent decompensation

Effects of acupuncture on ANP and CNP in adrenal gland and CORT in plasma in rats with chronic emotional stress anxiety / 中国针灸

<p><b>OBJECTIVE</b>To analyze the effects of acupuncture on the level of atrial natriuretic peptide (ANP), C-type natriuretic peptide (CNP) in adrenal gland and the content of corticosterone (CORT) in plasma in rats withchronic emotional stress anxiety, and to explore the partial action mechanism of acupuncture on anxiety disorder.</p><p><b>METHODS</b>Thirty-two healthy Sprague-Dawley (SD) rats, after 7 days of feeding and domestication, were randomly divided into a blank group (10 rats), a model group (11 rats) and an acupuncture group (11 rats). The rats inthe model group and acupuncture group were treated with unpredictable chronic emotional stress (CES) method toestablish the model of anxiety. Rats in the acupuncture group were treated with acupuncture at "Neiguan" (PC 6)and "Shenmen" (HT 7), once every other day, 30 minutes each time. The model establishment and treatment lasted 15 days. Rats in the blank group were treated with identical immobilization but no treatment was given. Theelevated plus maze was used to test the behavioral changes of rats with anxiety; the level of CORT in plasma wasdetected by ELISA, and the expression level of CNP and ANP in adrenal cortex and medulla was detected by immunohistochemical method.</p><p><b>RESULTS</b>(1) The percentage of open-arms time in total time (OT%) in elevated plus maze in the model group was significantly lower than that in the blank group (P<0. 05); the OT% in the acupuncture group was significantly higher than that in the model group (P<0.01). (2) The content of CORT in plasma in the model group was higher than that in the blank group (P<0. 05), while that in the acupuncture group was significantly lower than that in the model group (P<0. 05). (3) The expression of ANP in adrenal medulla and cortex in the model group was lower than that in the blank group (P<0. 01), while the expression of CNP in adrenal medulla and cortex in the model group was higher than that in the blank group (P<0. 01).</p><p><b>CONCLUSION</b>The effects of acupuncture against anxiety are likely to be related to the regulation on the expression of ANP and CNP in adrenal medulla, affecting the release of CORT and inhibition on the activity !f hypothalamic-pituitary-adrenal axis (HPA axis).</p>

Mutações em heterozigose no gene do receptor tipo B dos peptídeos natriuréticos (NPR2) são causa de baixa estatura inicialmente classificada como idiopática / Heterozygous mutations in natriuretic peptide receptor-B gene (NPR2) are cause of short stature initially classified as idiopathic

Nos últimos anos, o sistema do peptídeo natriurético do tipo C (CNP) e seu receptor (NPR-B) foi apontado como um importante regulador do processo de ossificação endocondral. Vários estudos em animais evidenciam o seu papel de estímulo à proliferação e diferenciação de condrócitos e secreção de matriz extracelular. Mutações bialélicas com perda de função do gene do NPR-B (NPR2) levam a uma doença denominada displasia acromesomélica do tipo Maroteaux (AMDM), uma displasia esquelética caracterizada por baixa estatura extrema. Observa-se que familiares de pacientes com AMDM carreadores de mutação no NPR2 têm estatura abaixo da média da população a qual pertencem, sugerindo um papel de mutações em heterozigose do NPR2 como causadoras de baixa estatura idiopática (BEI). Os objetivos deste estudo foram avaliar a presença de mutações no gene NPR2 em um grupo de pacientes com BEI e correlacionar os achados moleculares com o fenótipo dos pacientes e familiares. A região codificadora do gene NPR2 foi sequenciada pelo método de Sanger em 60 pacientes com diagnóstico de BEI. Foram identificadas cinco diferentes variantes alélicas missense em heterozigose no NPR2, cada uma em um único paciente. Essas variantes foram submetidas à análise funcional in vitro para avaliação da atividade da guanililciclase e microscopia confocal para localização intracelular dos receptores NPR-B. As variantes c.226T > C / p.Ser76Pro, c.788G > C / p.Arg263Pro e c.2455C > T / p.Arg819Cys segregam com o fenótipo de baixa estatura dentro das famílias e determinam um prejuízo funcional ao NPR-B. As três variantes geram proteínas que exercem efeito dominante negativo e os receptores NPR-B com as mutações p.Ser76Pro e p.Arg263Pro não se localizam na membrana celular. As variantes c.491C > G / p.Ala164Gly e c.1636A > T / p.Asn546Tyr não segregam com o fenótipo de baixa estatura nas famílias e não se evidenciou um efeito dominante negativo. O escore-Z da altura dos indivíduos carreadores das variantes...

Over the past several years, C-type natriuretic peptide (CNP) and its receptor (NPR-B) system has emerged as an important regulator of endochondral bone growth. Animal models showed a CNP/NPR-B role in promoting chondrocyte proliferation and differentiation and matrix synthesis. Biallelic loss-of-function mutations in NPR-B gene (NPR2) cause acromesomelic dysplasia type Maroteux (AMDM), a skeletal dysplasia with extreme short stature. Relatives of patients with AMDM, heterozygous for NPR2 mutations, were noted to be shorter than expected for their population of origin, suggesting that heterozygous mutations in NPR2 could be a cause of idiopathic short stature (ISS). The objective of this study was to investigate the presence of NPR2 mutations in a group of patients with ISS and to correlate molecular findings with phenotype. The NPR2 coding region was sequenced by Sanger's method in 60 patients with ISS. Five different heterozygous missense variants in NPR2 were identified in five patients. The functional consequences of those variants were established using in vitro cell-based assay to determine guanylate cyclase activity and confocal microscopy to determine intracellular localization of NPR-B. The variants c.226T > C / p.Ser76Pro, c.788G > C / p.Arg263Pro and c.2455C > T / p.Arg819Cys segregated with short stature phenotype and were functionally deleterious. NPR-B receptors with these three variants have a dominantnegative effect and p.Ser76Pro and p.Arg263Pro NPR-B were not localized in the cell membrane. Cosegregation analysis of the variants c.491C > G / p.Ala164Gly and c.1636A > T / p.Asn546Tyr was inconclusive and they did not have a dominant negative effect. Carriers of functionally deleterious variants have a height SD score that ranged from -4.5 to -1.7. One of these patients and two relatives have disproportionate short stature and one has shortened metacarpal. In conclusion, heterozygous mutations in NPR2 gene are cause of short stature in...

Estrogen stimulates cell proliferation and regulates the expression of proteins in C-type natriuretic peptide signaling pathway during chondrogenesis in ATDC5 cells / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of estrogen on cell proliferation and expression of proteins of C-type natriuretic peptide (CNP), natriuretic peptides B receptor (NPR-B) and natriuretic peptides C receptor (NPR-C) in ATDC5 cells during chondrogenesis.</p><p><b>METHOD</b>ATDC5 cells were induced for differentiation with insulin 10 µg/ml (day 0), and were started to be investigated on day 6. They were incubated with: (1) Estradiol (E2) at different concentrations (10(-11)-10(-5) mol/L) for 24 hours (for studying cell proliferation), or for 48 hours (for studying CNP, NPR-B and NPR-C protein expression); (2) E2 (10(-8) mol/L) for 24, 48, 72, 96 and 120 h (for studying cell proliferation), or for 24, 48, 72 and 96 hours (for studying CNP, NPR-B and NPR-C protein expression); (3) E2 (10(-8) mol/L) , and/or ICI 182782 (estrogen receptor antagonist ) (10(-7) mol/L) for 24 hours (for studying cell proliferation). ATDC5 cells proliferation were determined by MTT (OD value). Western-blotting was performed to identify the protein levels of CNP, NPR-B and NPR-C.</p><p><b>RESULT</b>(1) After incubation with E2 (10(-11)-10(-5) mol/L) for 24 h, ATD5 cell number increased with the increasing E2 concentration, peak in E2 concentrations of 10(-9) and 10(-8) mol/L (0.56 ± 0.06 and 0.52 ± 0.02, P < 0.05 and <0.01, respectively) , while significantly decreased in E2 (10(-5) mol/L) (0.30 ± 0.02) compared with DMSO-control (0.38 ± 0.02) (P < 0.05). After incubation with E2 (10(-11)-10(-5) mol/L) for 48 h, the protein level of CNP, NPR-B and NPR-C increased significantly, with the greatest effect seen at a concentration of 10(-10) mol/L E2 for CNP and NPR-B, 10(-9) mol/L E2 for NPR-C (P < 0.05). (2) After incubation with E2 (10(-8) mol/L) for 24 to 96 hours: (1) The cell number in each of the four time points was significantly increased compared with DMSO-control, with the greatest effect in 48 h (0.030 ± 0.003) (P < 0.05 or <0.01, respectively). While the cell number at 120 h was similar to that in DMSO-control. (2) The protein level of CNP increased significantly at 24 h (P < 0.05), seemed to be increased at 48 h and 72 h and decreased at 96 h. Both NPR-B and NPR-C level seemed to be increased at 24 h (P = 0.060 and 0.055, respectively) and seemed to decrease at 48 h, with decreasing significantly at both 72 h and 96 h (P < 0.05). (3) After incubation for 24 h, there was significant difference among the cell number of the four groups (P < 0.05). Cell number of group E2 (0.470 ± 0.032) was increased compared with group (E2+ICI) (0.410 ± 0.018), both being increased compared with group DMSO-control (0.370 ± 0.011, P < 0.05, respectively). There was no difference in cell number between group ICI 182782(0.360 ± 0.035) and group DMSO-control.</p><p><b>CONCLUSION</b>E2 promotes the proliferation of ATDC5 cells i.e. chondrogenesis via estrogen receptor mediated mechanism, in both concentration-dependent and time-dependent manner. E2 (10(-11)-10(-8) mol/L) up-regulates protein expression of CNP, NPR-B and NPR-C of ATDC5 cells during chondrogenesis, and regulate the expression of the three proteins mentioned above positively or negatively at different time point, which implied that estrogen is one of the regulators of CNP signaling pathway.</p>

Regulation of C-type natriuretic peptides and natriuretic peptide receptor-B expression in diabetic rats renal treated by Tongluo Recipe / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of C-type natriuretic peptides (CNP) and natriuretic peptide receptor-B (NPR-B) receptor in diabetic rats renal cortex, and the regulation by Tongluo Recipe (TLR).</p><p><b>METHODS</b>Sixty male SD rats were divided into 3 groups: the normal control group, diabetic model group and diabetic TLR group. Each group was further divided into two subgroups of ten in each, according to 4-week or 12-week observation period. Streptozotocin (STZ)-induced diabetic rats were treated with TLR (1.0 g·kg(-1)·d(-1)) for 4 and 12 weeks, respectively. (1) The essential information was collected for comparing renal mass, serum creatinine and 24 h urine albumen on each group was calculated. (2) CNP mRNA and NPR-B mRNA were detected by realtime-polymerase chain reaction (PCR) on rats renal cortex. (3) Concentration of CNP on renal cortex or serum were analyzed by enzyme-linked immunosorbent assay (ELISA). (4) Pathological evaluation and NPR-B immunostaining for renal tissue were also performed.</p><p><b>RESULTS</b>(1) CNP and NPR-B mRNA levels were detected in each treated or untreated group, with slight elevated in untreated diabetes rats administrated with STZ after 4-week and CNP mRNA level remarkable elevated at 39.21 times higher than normal control group after 12 weeks, but NPR-B mRNA level showed a remarkably down-regulation at 98.07% after 12 weeks. CNP mRNA of TLR-treated group was also elevated after 12-week treatment, but less than untreated group. (2) Concentrations of CNP in renal cortex were obviously increased in treated or untreated diabetes rats, within these groups the treatment of TLR was found more significantly on prompting CNP concentration. Comparing to normal group, serum concentrations of CNP were also increased in treated or untreated diabetic groups, but there was no difference between these diabetic groups. (3) Renal lesions like glomerular volume increased are observed mostly in the relative early stage after 4 weeks. Although TLR treated group had no significant difference in their glomerular volume, the degrees of injury of glomerulus were ameliorated, as well as the NPR-B immunostaining enhanced in glomerulus. Weakly positive immunostaining of NPR-B are observed in glomerulus of normal control, and negative in glomerulus of untreated diabetes rats administrated with STZ after 12 weeks, whereas TLR-treatment groups showed a little enhancement.</p><p><b>CONCLUSION</b>CNP and NPR-B showed different characteristic on renal cortex at different pathological period in diabetes rats, and TLR regulated their expression.</p>

C-Type Natriuretic Peptide as a Surrogate Marker in Variant Angina Pectoris

BACKGROUND AND OBJECTIVES: The purpose of this study was to assess the value of C-type natriuretic peptide (CNP) as a surrogate marker for detection of coronary artery spasm in variant angina pectoris (VAP). SUBJECTS AND METHODS: Sixty-six patients (mean age: 51+/-11 years, M : F=40 : 26) who underwent coronary angiography on suspicion of angina and who were diagnosed with VAP by the acetylcholine-induced spasm provocation test (SPT) were enrolled and divided into a SPT (-) group (n=23) and a SPT (+) group (n=43). Concentrations of CNP and other markers were determined by immunoassay in both groups. RESULTS: Plasma CNP and creatine kinase myoglobin band (CK-MB) concentrations were significantly increased in the SPT (+) group relative to the SPT (-) group (CNP, 5.268+/-1.800 pg/mL vs. 3.342+/-1.150 pg/mL, p=0.002; CK-MB, 2.54+/-1.03 ng/dL vs. 1.86+/-0.96 ng/dL, p=0.019, respectively) while plasma high sensitivity C-reactive protein (hs-CRP) and N-terminal pro-brain natriuretic peptide (NT pro-BNP) concentrations were not significantly different between the SPT (-) group and SPT (+) group (hs-CRP, 2.76+/-4.99 mg/L vs. 3.13+/-4.88 mg/L, p=0.789; NT pro-BNP, 49+/-47 pg/mL vs. 57+/-63 pg/mL, p=0.818, respectively). Plasma CNP concentration was independently associated with the VAP via SPT {odds ratio: 2.014 (95% confidence interval: 1.016-3.992), p=0.045}. A CNP cut-off value of 4.096 pg/mL was found to have a sensitivity of 68.2% and a specificity of 40.0% for predicting the probability of VAP via SPT. CONCLUSION: Increased plasma CNP concentration in patients with VAP may have an impact on the regulation of endothelial function in accordance with the progression of atherosclerosis. Further analysis is warranted to develop clinical applications of this finding.

Role of C-type Natriuretic Peptide in Linear Growth

The natriuretic peptides are a family of three peptides, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP). CNP is produced in the growth plate and acts in a paracrine/autocrine manner and has been found to play an essential role in enchondral bone growth , as demonstrated in rodents and human. Biosynthetic processing of CNP releases a bioinactive amino-terminal propeptide of C-type natriuretic peptide (NTproCNP) and is produced in equimolar amounts with CNP. The level of NTproCNP in plasma reflects the rate of CNP biosynthesis and measured easily using commercial kit by enzyme-linked immunosorbent assay (ELISA) method. Knockout mice for CNP or its cognate receptor (NPR-B) are dwarfed. In human, homozygous loss of functional mutations in the NPR-B gene causes acromesomelic dysplasia, Maroteaux type (OMIM #602875). To clarify the role of CNP/NTproCNP in linear growth in human, some researchers measured plasma NTproCNP levels in healthy children and children with short stature due to various causes. CNP showed the heighest levels after 12 hr of life and with a progressive decline afterwards. It is proved that there is modest but significant correlation between NTproCNP level and IGF-I in healthy children and the timing of peaks in NTproCNP and IGF-I were identical in both sex. This paper will introduce recent advances of researches concerning about the role of CNP/NTproCNP in human growth in children with various conditions and suggest the future direction of this promising study field.

Natriuretic peptide system and cardiovascular disease

The mammalian Natriuretic Peptide [NP] system consists of neuro-hormones, such as atrial natriuretic peptide [ANP], brain natriuretic peptide [BMP], c-type natriuretic peptide [CNP], and the N-Terminal fragment of BMP [NT-pro-BNP]. In response to some cardiovascular derangement the heart [acting as an endocrine organ], brain and other structures secretes natriuretic peptides in an attempt to restore normal circulatory conditions. Their actions are modulated through membrane-bound guanylyl cyclased [GC] receptors. They induce diuresis, natriuresis and vasodilation in the presence of congestive heart failure. These neuro-hormones also play a role in the suppression of neointimal formation after vascular injury. In addition, they act as antifibrotic and antihypertrophic agents preventing cardiac remodeling after myocardial infarction. Further, NP have diagnostic and prognostic role in heart failure, vasoconstriction, left ventricular late remodeling after Ml and others. At present, some drugs such as Nesiritide, NEP inhibitors and vasopeptidase inhibitors were synthetized from NP, to antagonize these cardiovascular derengements. In future, it will be possibile to elaborate some drugs similar to petidase inhibitors and some CNP-like drugs able to reduce many symptoms of cardiovascular derangements without significant side effects

New insights into the role of natriuretic peptides in the regulation of apoptosis in cardiovascular system

Natriuretic peptides NPs are a family of structurally similar but genetically distinct peptides with paracrine and autocrine functions of regulating blood volume, blood pressure, ventricular hypertrophy, pulmonary hypertension, fat metabolism, and long bone growth. There are 3 main natriuretic peptides: atria natriuretic peptides ANP, brain natriuretic peptides BNP and C-type natriuretic peptides CNP. As investigations of the in vivo activities of natriuretic peptides were expanded, evidence suggested that natriuretic peptides might function as regulators of cell proliferation and/or death in a variety of tissues and cell types. Natriuretic peptides are much more frequently observed in cardiovascular system, the present discussion is focus on cell death in cardiovascular system, especially vascular endothelial cells ECs, vascular smooth muscle cells VSMCs, cardiac myocyte

Association of plasma amino-terminal pro-A-, B- and C-type natriuretic peptide levels with NYHA grade and echocardiographic derived parameters of cardiac function in heart failure patients / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the correlation of plasma amino-terminal pro-A-, B- and C-type natriuretic peptide (NT-proANP, NT-proBNP and NT-proCNP) levels with New York Heart Association (NYHA) functional class and echocardiographic derived parameters of cardiac function in heart failure patients.</p><p><b>METHODS</b>Data of NYHA grade, echocardiographic derived parameters of cardiac function, plasma levels of NT-proANP, NT-proBNP and NT-proCNP (measured by enzyme immunoassay method) were obtained in 112 heart failure patients and 44 normal control subjects. The correlation analysis was made between NT-proANP, NT-proBNP, NT-proCNP and NYHA functional class, left atrium diameter (LAD), left ventricular end-diastolic diameter (LVEDD) and left ventricular ejection fraction (LVEF), respectively.</p><p><b>RESULTS</b>The plasma concentrations of NT-proANP, NT-proBNP and NT-proCNP in heart failure patients were significantly higher than in control group (all P<0.05). Correlation analysis revealed a strong correlation between NT-proANP and NT-proBNP (r = 0.790, P = 0.000) and a weak correlation between NT-proCNP and NT-proBNP (r = 0.278, P = 0.003) as well as between NT-proCNP and NT-proANP (r = 0.236, P = 0.012) in heart failure patients. Univariant analysis showed that NT-proANP and NT-proBNP were positively correlated to LAD, LVEDD and negatively correlated to LVEF (all P<0.05) while there was no significant correlation between NT-proCNP and echocardiographic derived parameters of cardiac function in heart failure patients. Multivariate stepwise regression analysis including age, gender, NYHA classification, LAD, LVEDD and LVEF revealed that NYHA classification, LVEF, LAD and age were independent predictors of NT-proANP; while NYHA classification, LVEF and age were independent predictors of NT-proBNP while there was no association among these factors and NT-proCNP.</p><p><b>CONCLUSION</b>In heart failure patients, the plasma concentration of NT-proANP, NT-proBNP and NT-proCNP were significantly increased and NT-proANP, NT-proBNP but not NT-proCNP were significantly correlated to NYHA classification and echocardiographic derived parameters of cardiac function.</p>

Bio-Molecular Markers for Cardiovascular Disease: Significance of Natriuretic Peptides and Adrenomedullin

There are many established and proposed bio-molecular markers for cardiovascular disease, including vasoactive substances, substances related to inflammation and oxidative stress, and substances involved in tissue structure and remodeling. Among these substances, we focused on natriuretic peptides and adrenomedullin (AM) as clinically useful bio-molecular markers in this review. Three natriuretic peptides-atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP)-play various important roles in the cardiovascular system. ANP and BNP are released from the heart and exist primarily as circulating hormones. They participate in the regulation of blood pressure and fluid levels. Plasma levels of ANP and BNP are increased in various pathological conditions such as heart failure, myocardial infarction, and hypertension with cardiac hypertrophy. BNP is now essential as a biochemical marker in managing patients with cardiovascular disease. CNP is mainly produced in vascular endothelium. It contributes to smooth muscle relaxation and growth inhibition as a local hormone, but it is also synthesized in cardiac fibroblasts and inhibits fibroblast proliferation and myocyte growth. However, the significance of plasma CNP levels remains to be elucidated. AM is widely distributed in various organs and tissues, including the cardiovascular system. Not only it is a potent vasodilator peptide, but it also has protective effects against vascular and cardiac cell injury and excessive growth. Plasma AM levels are increased in several cardiovascular diseases, including hypertension, heart failure, myocardial infarction, and atherosclerotic disease, and AM appears to be a predictive and prognostic marker in the setting of cardiovascular disease.

Influence of human C-type natriuretic peptide on vascular endothelial cell proliferation / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of human C-type natriuretic peptide (hCNP) on proliferation of vascular endothelial cells (HUVECs).</p><p><b>METHODS</b>Reconstructed pcDNA3.1 (+)/hCNP was transfected into HUVECs with polyethylenimine and its plasmid expression was examined with RT-PCR, immunohistochemistry and Western blot. MTT method was used to determine the effect of expressed protein on proliferation of HUVECs. pcDNA3.1 (+)/hCNP transfection was used for control.</p><p><b>RESULTS</b>The proliferation of HUVEC 48 h after pcDNA3.1 (+)/hCNP transfection was (0.301 +/- 0.096), which was obviously higher than that with pcDNA3.1 (+) transfection (0.164 +/- 0.012). Reconstructed pcDNA3.1 (+)/hCNP might be expressed in HUVECs effectively and its protein expression was capable of promoting HUVECs proliferation markedly.</p><p><b>CONCLUSION</b>The successive expression of reconstructed pcDNA3.1 (+)/hCNP and the promoting activity of its expressed protein on HUVECs lay the foundation potential therapeutic value of C-type natriuretic peptide.</p>

Lack of circadian change of concentration of C-type natriuretic peptide in rabbit aqueous humor / Ausência de mudança no ritmo circadiano da concentração de peptídeo natriurético tipo C no humor aquoso de coelhos

PURPOSE: To determine whether there is a circadian change of the concentration of C-type natriuretic peptide (CNP) in rabbit aqueous humor. METHODS: Forty-one male white New Zealand rabbits were submitted to a 12 h light and 12 dark lighting schedule; lights on was at 0 h, lights off at 12 h. C-type natriuretic peptide was assayed at 3 light (2 h, 6 h and 10 h) and 3 dark (14,18 and 22 h) times. All groups consisted of four animals but two had more animals to increase the power of tests (6 h, n=12; 22 h, n=13). Dependence between the two eyes was tested by Pearson's correlation. The mean of two eyes was considered for analysis. Differences in concentration in pg/200 ml were evaluated by one-way ANOVA, t test and COSINOR analysis. RESULTS: There were no significant differences between the 6 analyzed groups (one-way ANOVA p=0.157). Pooled into two groups (light and dark), the C-type natriuretic peptide concentration of the light group was lower, 2.626±0.92 pg/200 ml compared with the dark group 3.02±1.16 pg/200 ml but did not reach a significant difference (t test; p=0.23). COSINOR analysis was not statistically significant (R percent=7.72 p=0.209). CONCLUSION: These data demonstrate that the concentration of CNP in aqueous humor did not show a statistically significant circadian change in rabbits entrained to a 12 h light: 12 h dark lighting schedule.

OBJETIVO: Verificar se há mudança na concentração circadiana de peptídeo natriurético tipo C (CNP) no humor aquoso de coelhos. MÉTODOS: Quarenta e um coelhos machos da raça New Zealand foram admitidos numa rotina de 12 horas de luz e 12 de escuridão; luzes eram acesas na hora zero e apagadas na hora 12. O peptídeo natriurético tipo C era medido em três períodos com luz acesa (2, 6 e 10 h) e 3 com luz apagada (14, 18 e 22 h). Todos os grupos tinham 4 animais com exceção de dois períodos em que o n foi incrementado para aumentar o poder dos testes (6 h, n=12; 22 h, n=13). A dependência entre os olhos foi testada por meio da correlação de Pearson. A média dos dois olhos foi usada para a análise. Diferença quanto à concentração média de peptídeo natriurético tipo C em pg/200 ml foi avaliada por meio do teste de one-way ANOVA, teste t e análise de COSINOR. RESULTADOS: Não foi encontrada diferença estatisticamente significante entre os 6 grupos analisados (one-way ANOVA; p=0,157). Reunidos em dois grupos (luz e escuridão), a concentração de peptídeo natriurético tipo C com a luz acesa foi mais baixa (2,626±0,92 pg/200 ml) quando comparada ao grupo com luz apagada (3,02±1,16 pg/200 ml) porém sem alcançar significância estatística (teste de t p=0,23). Análise de COSINOR não foi estatisticamente significante (R por cento=7,72 p=0,209). CONCLUSÃO: Nossos dados demonstraram que a concentração do CNP no humor aquoso de coelhos não mostrou variação circadiana estatisticamente significante quando analisadas num ritmo de luz/escuro 12/12 h.

The broad homeostatic role of natriuretic peptides / O amplo papel homeostático dos peptídeos natriuréticos

A brief non-inclusive review on natriuretic peptides (NP), their receptors, and their main functional properties is presented. The three main NP, atrial (ANP), brain (BNP) and C-type (CNP) are considered. Guanylyl cyclase receptors modulate all the known systemic effects of NP. Clearance receptors determine the metabolic disposal of NP and in this manner regulate their plasma levels and/or local tissue concentrations. Structure-function properties, and homeostatic properties of NP receptors are presented. ANP, which plays a major role in pressure-volume homeostasis, is discussed in relationship to its effects on renal hemodynamic and excretory functions, inhibition of the renin-angiotensin-aldosterone system, vasorelaxant, and third-spacing action. For BNP special attention is directed to its role as a negative modulator of ventricular remodeling, in view of its anti-hypertrophic, anti-fibrotic and anti-inflammatory effects in the heart. The major effect of CNP in promoting vertebral and longitudinal bone growth is briefly addressed. Finally, emphasis is placed on the recent discovery that ANP affects fat metabolism in humans due to its powerful lipolytic action.

Este trabalho apresenta uma breve revisão parcial sobre os peptídeos natriuréticos (NP), seus receptores e suas principais propriedades funcionais. Serão discutidos os três principais NP: atrial (ANP), cerebral (BNP) e tipo-C (CNP). Os receptores guanilil-ciclase modulam todos os efeitos sistêmicos conhecidos dos NP. Receptores de clareamento determinam o catabolismo dos NP e, desta maneira, regulam seus níveis plasmáticos e/ou sua concentração tecidual. As propriedades do tipo estrutura-função e homeostáticas dos receptores de NP são apresentadas. O ANP, que tem um importante papel na homeostase pressão-volume, é discutido em relação aos seus efeitos sobre a hemodinâmica renal e funções de excreção, inibição do sistema renina-angiotensina-aldosterona, vaso-relaxamento e ação no terceiro espaço. Quanto ao BNP, especial atenção é focada no seu papel como um modulador negativo da remodelação ventricular, em vista de seus efeitos anti-hipertróficos, anti-fibróticos e anti-inflamatórios no coração. O principal efeito do CNP em promover crescimento ósseo vertebral e longitudinal é discutido brevemente. Finalmente, enfatiza-se a recente descoberta de que o ANP afeta o metabolismo de gorduras em humanos, devido à sua poderosa ação lipolítica.

Effects of Phosphodiesterase 5 Inhibition with Sildenafil on Atrial Contractile and Secretory Function

Selective inhibition of phosphodiesterase (PDE) 5 opened a new therapeutic approach for cardiovascular disorders. Therefore, the effect of PDE5 inhibition on the cardiac function should thoroughly be defined. The purpose of the present study was to define the effects of sildenafil, a selective inhibitor of PDE5, on the atrial cGMP efflux, atrial dynamics, and the release of atrial natriuretic peptide (ANP). By perfusing rabbit left atria to allow atrial pacing, changes in atrial stroke volume and pulse pressure, transmural extracellular fluid translocation, cGMP efflux, and ANP secretion were measured. SIN-1, an NO donor and soluble (s) guanylyl cyclase (GC) activator, and C-type natriuretic peptide (CNP), an activator of particulate (p) GC activator, were used. Sildenafil increased basal levels of cGMP efflux slightly but not significantly. Sildenafil in a therapeutic dose increased atrial dynamics (for atrial stroke volume, 2.84+/-1.71%, n=12, vs -0.71+/-0.86%, n=21; p<0.05) and decreased ANP release (-9.02+/-3.36%, n=14, vs 1.35+/-3.25%, n=23; p<0.05), however, it had no effect on the SIN-1- or CNP-induced increase of cGMP levels. Furthermore, sildenafil in a therapeutic dose accentuated SIN-1-induced, but not CNP-induced, decrease of atrial pulse pressure and ANP release. These data indicate that PDE5 inhibition with sildenafil has a minor effect on cGMP levels, but has a distinct effect on pGC-cGMP- and sGC-cGMP-induced contractile and secretory function.

Upregulation of Renin-angiotensin, Endothelin and C-type Natriuretic Peptide in Rat Glomerulus with Bilateral Ureteral Obstruction

The present study was designed to investigate the effects renin-angiotensin-aldosterone system (RAAS), endothelin (ET) and local natriuretic peptide (NP) system for glomerulopathy induced in the experimental bilateral ureteral obstructive rats. Sprague-Dawley male rats (200~220 g body weight) were bilaterally obstructed by ligation of the proximal ureters for 24 hours. Control rats were treated in the same ways, except that no ligature was made. The glomeruli were isolated from cortex by graded sieve methods, and the mRNA expressions of local renin-angiotensin system (RAS), aldosterone synthase (CYP11B2), endothelin-1 (ET-1) and NP system were determined by real-time polymerase chain reaction. Following the bilateral ureteral obstruction, the mRNA expressions of renin, angiotensin converting enzyme 1 as well as ET-1 were increased, while that of angiotensin converting enzyme 2 was not changed. The expressions of CYP11B2 and angiotensin II receptors were not changed. C-type natriuretic peptide (CNP) expression was increased, while its receptors (natriuretic peptide receptor-B) were not changed. We suggest that the upregulation of local RAS and ET play a role in the progressive glomerular injury, and that the enhanced CNP activity also plays a compensatory role in obstructive uropathy in the glomerulus.

Los péptidos natricuréticos en insuficiencia cardíaca (Revisión) / The natriuretics peptides in cardiac insuficiente (Review)

El enfoque clínico y fisiopatológico de la insuficiencia cardíaca va variando conforme se conocen nuevos detalles. A inicios del siglo XX su enfoque partía de un exceso de líquidos dentro del organismo que obligaba a los médicos en la eliminación de líquidos y cambios en su distribución a través de torniquetes o sangrías. Ya ha mediados del siglo pasado este sufre un cambio de perspectiva al verse al ICC como un fenómeno de falla de bomba; pero el mayor cambio es el que vivimos actualmente en el cual es vista la ICC como un fenómeno neurohormonal, con participación de hormonas y sus receptores en la génesis fisiopatología de la IC. Es menester de este artículo presentar a la familia de los péptidos natriuréticos atriales y su participación en los eventos fisiopatológicos de la ICC y su estado actual como marcador de severidad de la misma.

Expression of C-type Natriuretic Peptide and Natriuretic Peptide Receptors in the Mouse Submandibular Glands Following Embryonic Development, Postnatal Differentiation and Aging / 대한해부학회지

C-type natriuretic peptide (CNP), a member of natriuretic peptide family, is mainly synthesized in the endothelium and central nervous system. But CNP is also involved in the growth and differentiation of other peripheral organs. Although we have reported the local synthesis and localization of CNP in the adult submandibular glands (SMG), it is not known that the expression and biological activity of CNP following the morphogenesis, differentiation and aging. This study aimed to examine the expression of CNP and its receptors in the developing and differentiating stages of mouse SMG, and the changes of biological activity of its receptors with aging. The SMG, obtained from 14, 16, 18 days-old embryos (E) and 1 day, 2 weeks, 1, 2, 12, and 24 month-old C57BL/6N mouse, were processed for RT-PCR, in situ hybridization, immunohistochemistry and cGMP assay. CNP was strongly expressed in the epithelial clusters of primitive SMG, which was maintained before birth but was markedly decreased after birth. CNP was localized in the intercalated duct and granular convoluted tubules of adult SMG, where NPRC was specifically expressed but NPRB was not. CNP mRNA was gradually decreased from E16 to 2 M but ANP mRNA was opposed. NPRB and NPRC were the same pattern of the expression of CNP but NPRA was weakly expressed. In addition, CNP mRNA was also expressed in the craniofacial tissues such as tooth germs, tongue, premaxilla and bone forming area in which NPRC was specifically expressed but NPRB was not. In the SMG of 2 M, the membrane of duct cells markedly produced cGMP by CNP whereas acini produced cGMP by ANP and BNP rather than CNP. The biological activity of cGMP production of SMG gradually decreased with age. cGMP production was dominant by CNP in SMG of 1M but was by ANP after 2M. These results shows that CNP may play roles both in the morphogenesis and differentiation via NPRC and in the maintenance of duct system via NPRB in the mouse SMG and that the biological activity of its receptors may decreased with aging.