This study aimed to investigate the expression of the natriuretic peptide precursor C coding gene nppc and its role in angiogenesis during embryonic period of the zebrafish. Whole mount in situ hybridization was performed to detect the expression pattern of nppc. nppc specific morpholino and nppc mRNA were injected respectively into the one-cell stage embryo to specifically knock-down and rescue the expression of nppc in Tg (flk1:GFP) and Tg (fli1a:nGFP) transgenic lines. The morphology and endothelial cell number of intersegmental vessel (ISV) were analyzed after imaging using the laser scanning confocal microscope. The results revealed that nppc was expressed in the brain, heart and vasculature of zebrafish larvae at 24 and 48 hours post-fertilization (hpf). Knock-down of nppc affected the development of ISV. Endothelial cell number was reduced after the knock-down of nppc. These results suggest that nppc controls zebrafish angiogenesis by affecting the endothelial cell proliferation and migration.
Animals ; Animals, Genetically Modified ; Cell Movement ; Cell Proliferation ; Endothelial Cells ; physiology ; Gene Knockdown Techniques ; Heart ; physiology ; Larva ; Natriuretic Peptides ; genetics ; physiology ; Neovascularization, Physiologic ; RNA, Messenger ; Zebrafish ; genetics ; physiology ; Zebrafish Proteins ; genetics ; physiology

Angiotensin II (Ang II) is metabolized from N-terminal by aminopeptidases and from C-terminal by Ang converting enzyme (ACE) to generate several truncated angiotensin peptides (Angs). The truncated Angs have different biological effects but it remains unknown whether Ang-(4-8) is an active peptide. The present study was to investigate the effects of Ang-(4-8) on hemodynamics and atrial natriuretic peptide (ANP) secretion using isolated beating rat atria. Atrial stretch caused increases in atrial contractility by 60% and in ANP secretion by 70%. Ang-(4-8) (0.01, 0.1, and 1 µM) suppressed high stretch-induced ANP secretion in a dose-dependent manner. Ang-(4-8) (0.1 µM)-induced suppression of ANP secretion was attenuated by the pretreatment with an antagonist of Ang type 1 receptor (AT₁R) but not by an antagonist of AT₂R or AT₄R. Ang-(4-8)-induced suppression of ANP secretion was attenuated by the pretreatment with inhibitor of phospholipase (PLC), inositol triphosphate (IP₃) receptor, or nonspecific protein kinase C (PKC). The potency of Ang-(4-8) to inhibit ANP secretion was similar to Ang II. However, Ang-(4-8) 10 µM caused an increased mean arterial pressure which was similar to that by 1 nM Ang II. Therefore, we suggest that Ang-(4-8) suppresses high stretch-induced ANP secretion through the AT₁R and PLC/IP₃/PKC pathway. Ang-(4-8) is a biologically active peptide which functions as an inhibition mechanism of ANP secretion and an increment of blood pressure.
Aminopeptidases ; Angiotensin II* ; Angiotensins* ; Animals ; Arterial Pressure ; Atrial Natriuretic Factor* ; Blood Pressure* ; Heart ; Hemodynamics ; Inositol ; Peptides ; Phospholipases ; Protein Kinase C ; Rats* ; Receptor, Angiotensin, Type 1 ; Signal Transduction

In order to improve the expression of recombinant human atrial natriuretic peptide (ANP), a new plasmid (pET28a(+)/ANP₃) containing 3 tandem ANP genes with lysine codon as the interval linker, was constructed. Target gene was transformed into Escherichia coli BL21 (DE3) and induced by IPTG, about 60% of the total-cell-protein was the target protein, His₆-ANP₃. After denaturation and refolding, it was digested by Endoproteinase Lys-C and Carboxypeptidase B (CPB) and then purified by a series of purification processes, about 16 mg purified ANP monomer could be obtained from one liter bacteria broth of shaking culture. Ultimately, the purity of protein was above 90% determined by UPLC and Tricine SDS-PAGE, its molecular weight was 3 080 Da according to LC-MS identification and it was proved to be equivalent to the reference product by ELISA. The use of tandem gene expression can provide a new possible model for the expression of other peptide drugs.
Atrial Natriuretic Factor ; biosynthesis ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; metabolism ; Gene Expression ; Humans ; Metalloendopeptidases ; Peptides ; Plasmids ; genetics ; Recombinant Fusion Proteins ; biosynthesis

Cardiovascular Diseases ; Humans ; Natriuretic Peptides

AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. Previous studies have shown that activation of AMPK results in suppression of cardiac myocyte hypertrophy via inhibition of the p70S6 kinase (p70S6K) and eukaryotic elongation factor-2 (eEF2) signaling pathways. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea, possesses multiple protective effects on the cardiovascular system including cardiac hypertrophy. However, the molecular mechanisms has not been well investigated. In this study, we found that EGCG could significantly reduce natriuretic peptides type A (Nppa), brain natriuretic polypeptide (BNP) mRNA expression and decrease cell surface area in H9C2 cardiomyocytes stimulated with phenylephrine (PE). Moreover, we showed that AMPK is activated in H9C2 cardiomyocytes by EGCG, and AMPK-dependent pathway participates in the inhibitory effects of EGCG on cardiac hypertrophy. Taken together, our findings provide the first evidence that the effect of EGCG against cardiac hypertrophy may be attributed to its activation on AMPK-dependent signaling pathway, suggesting the therapeutic potential of EGCG on the prevention of cardiac remodeling in patients with pressure overload hypertrophy.
AMP-Activated Protein Kinases ; Brain ; Cardiomegaly ; Cardiovascular System ; Energy Metabolism ; Humans ; Hypertrophy* ; Myocytes, Cardiac* ; Natriuretic Peptides ; Phenylephrine ; Phosphotransferases ; RNA, Messenger ; Tea

BACKGROUND/AIMS: Preoperative N-terminal pro-brain natriuretic peptide (NT-proBNP) is a useful predictor of postoperative cardiovascular complications. The present study investigated whether blood NT-proBNP values are suitable for predicting postoperative cardiovascular complications after non-cardiac surgery in elderly patients showing normal left ventricular (LV) function on preoperative echocardiograms. METHODS: This study was performed by analyzing the medical records of elderly patients referred to the cardiology department for the purpose of assessing their cardiac function before orthopedic surgery. Of the patients who underwent echocardiography and NT-proBNP assessment simultaneously, 275 patients aged > or = 70 years and with an LV ejection fraction of > or = 55% were included in the study. RESULTS: Major adverse cardiac and cerebrovascular events (MACCEs) occurred in 33 (12%) of the 275 patients, and the NT-proBNP concentration was higher in patients with complications than in those without complications (1,904.20 +/- 2,300.23 vs. 530.58 +/- 882.27 pg/mL, p < 0.01). The ROC area under the curve was 0.756 (95% confidence interval 0.701-0.805, p < 0.001) with an optimal cutoff of 416.3 pg/mL (69.7% sensitivity, 67.36% specificity). A multivariate analysis showed that a preoperative age of > 80 years (odds ratio, 2.313; p = 0.047) and an increased blood NT-proBNP concentration (odds ratio, 3.189; p = 0.009) were independent risk factors for the prediction of MACCEs. CONCLUSIONS: Although elderly patients scheduled to undergo non-cardiac surgery may show normal LV systolic function on echocardiography, measurement of their preoperative blood NT-proBNP concentration is useful for predicting MACCEs occurring after non-cardiac surgery.
Aged* ; Cardiology ; Echocardiography ; Humans ; Medical Records ; Multivariate Analysis ; Natriuretic Peptides ; Orthopedics* ; Risk Factors

Cardio-renal syndrome (CRS) is a frequent and life-threatening syndrome. It is a disorder of the heart and kidneys in which acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ. Acute kidney injury (AKI) is strongly associated with increased morbidity and mortality in patients with CRS. Early detection of renal dysfunction is not possible using the traditional marker, serum creatinine, and therefore efforts to explore possible biomarkers for early detection of AKI are being made. Apart from predicting AKI, several biomarker studies also identified predictors for poor prognosis such as the need for renal replacement therapy (RRT) or death. It is possible that biomarkers can become risk factors in an improvement of clinical outcomes of CRS. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with renal dysfunction and the treatment for this disease can be modified based on cardiac biomarkers. In addition to natriuretic peptides, which are established cardiac markers, several new biomarkers have been identified and may play important roles in CRS. In this review, we will briefly summarize the literature on novel renal and cardiac biomarkers and discuss their potential roles in the clinical outcome of CRS.
Acute Kidney Injury ; Cardio-Renal Syndrome ; Cardiovascular Diseases ; Creatinine ; Heart ; Heart Failure ; Humans ; Kidney ; Natriuretic Peptides ; Prognosis ; Renal Replacement Therapy ; Risk Factors ; Biomarkers

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.
Animals ; Atrial Natriuretic Factor ; Bone Development ; Bone Diseases, Developmental ; Child ; Enzyme-Linked Immunosorbent Assay ; Growth Plate ; Humans ; Insulin-Like Growth Factor I ; Mice ; Mice, Knockout ; Natriuretic Peptide, Brain ; Natriuretic Peptide, C-Type ; Natriuretic Peptides ; Plasma ; Rodentia

BACKGROUND: Recently, quantitative point-of-care testing (POCT) for cardiac markers using colloidal gold particles was developed in Korea. We evaluated the analytical performance of the HUBI-QUANPRO (Humasis, Korea) assay in comparison with two other assays. METHODS: We evaluated the analytical precision and linearity of HUBI-QUANPRO creatine kinase (CK)-MB, cardiac troponin I (cTnI), and B-type natriuretic peptides (BNP). HUBI-QUANPRO assay was compared with ADVIA Centaur (Siemens, Germany) and Triage (Biosite Diagnostics, USA) assays by using 100 blood samples. In addition, we evaluated the interference of hemoglobin on the HUBI-QUANPRO assay. RESULTS: The coefficients of variation of HUBI-QUANPRO CK-MB, cTnI, and BNP were 7.5-9.7%, 12.0-17.4%, and 14.7-15.7%, respectively. The linearity ranges of HUBI-QUANPRO CK-MB, cTnI, and BNP were 4.7-27.8 ng/mL, 0.76-6.51 ng/mL, and 76.2-762.2 ng/mL, respectively. The comparison study showed no significant difference among them. When 0.5% hemolysis occurred, remarkable hemoglobin interference was found in the three markers resulting in underestimation of the concentrations. CONCLUSIONS: HUBI-QUANPRO CK-MB and BNP showed good analytical performances compared with the other two assays. Hemoglobin interference was noted in the HUBI-QUANPRO assay, especially more in BNP. Although the linearity range of cTnI was narrow, its agreement rate with ADVIA Centaur was good, thus the HUBI-QUANPRO assay could be useful as a quantitative POCT for cardiac markers in the emergency department.
Creatine Kinase ; Emergencies ; Gold Colloid ; Hemoglobins ; Hemolysis ; Korea ; Natriuretic Peptides ; Triage ; Troponin I

3-Iodobenzylguanidine ; Adult ; Aged ; Echocardiography ; Female ; Heart Failure ; diagnosis ; metabolism ; pathology ; Humans ; Male ; Middle Aged ; Myocardial Perfusion Imaging ; methods ; Natriuretic Peptides ; metabolism ; Prognosis ; Prospective Studies