OBJECTIVETo investigate the correlation between pro-B-type natriuretic peptide (NT-proBNP) and heart rate variability (HRV) in patients with diabetes.

METHODSHRV and NT-proBNP levels were assessed in 58 patients with diabetes.The time domain and frequency domain indices and the level of NT-proBNP were compared between patients with normal and abnormal HRV, and the correlation of HRV index and NT-proBNP was analyzed.

RESULTSThe NT-proBNP level was significantly higher in patients with abnormal HRV than in those with normal HRV (320.2±88.3 vs 80.4±25.2 pg/ml, P<0.01).The level of NT-proBNP was negatively correlated with SDNN (r=-0.55, P<0.05), triangle index (r=-0.52, P<0.05), LF (r=-0.62, P<0.01), and VLF (r=-0.56, P<0.05).

CONCLUSIONNT-proBNP level is correlated with HRV, and an increased NT-proBNP indicates cardiac autonomic neuropathy in diabetic patients.

Diabetes Mellitus ; metabolism ; physiopathology ; Heart Rate ; Humans ; Natriuretic Peptide, Brain ; metabolism ; Peptide Fragments ; metabolism

Biomarkers ; Heart Diseases ; diagnosis ; metabolism ; Humans ; Natriuretic Peptide, Brain ; metabolism ; physiology ; Nerve Tissue Proteins ; metabolism ; physiology ; Peptide Fragments ; metabolism ; physiology

Single chain antibody fragment (scFv) is a small molecule composed of a variable region of heavy chain (VH) and a variable region of light chain (VL) of an antibody, and these two chains are connected by a flexible short peptide. scFv is the smallest functional fragment with complete antigen-binding activity, which contains both the antibody-recognizing site and the antigen-binding site. Compared with other antibodies, scFv has the advantages of small molecular weight, strong penetration, low immunogenicity, and easy expression. Currently, the most commonly used display systems for scFv mainly include the phage display system, ribosome display system, mRNA display system, yeast cell surface display system and mammalian cell display system. In recent years, with the development of scFv in the field of medicine, biology, and food safety, they have also attracted much attention in the sectors of biosynthesis and applied research. This review summarizes the advances of scFv display systems in recent years in order to facilitate scFv screening and application.
Animals ; Immunoglobulin Variable Region/genetics* ; Immunoglobulin Fragments/metabolism* ; Single-Chain Antibodies/metabolism* ; Peptide Library ; Mammals/genetics*

Cardiac remodeling is a common pathological manifestation of various end-stage cardiovascular diseases, which leads to myocardial diastolic and systolic dysfunction, low ejection fraction which cannot meet the needs of systemic tissue and organ metabolism, and ultimate progress into heart failure. Excessive activation of the classical renin angiotensin system (RAS), which is the angiotensin-converting enzyme-angiotensin II-type 1 angiotensin II receptor axis (ACE2-Ang II-AT1R axis), plays a key role in the pathological process of cardiac remodeling and heart failure. Angiotensin-converting enzyme 2-angiotensin (1-7)-Mas axis [ACE2-Ang (1-7)-Mas axis] is an endogenous negative regulatory pathway of classical RAS, which can reduce its harmful effects. ACE2 is a monocarboxypeptidase that can hydrolyse Ang II and produce Ang (1-7), which has cardio-protective effects. Ang (1-7), via endogenous receptor Mas, plays the role of vasodilating, anti-proliferation and anti-differentiation, anti-fibrosis, anti-thrombosis and reversing myocardial remodeling. In recent years, with increasingly growing studies on the ACE2-Ang (1-7)-Mas axis, there are more understanding about their metabolic characteristics and mechanism of action. This article describes the role of ACE2 and Ang (1-7) in cardiac remodeling and heart failure and the related mechanisms, and discusses the potential benefits by regulating ACE2 activity and Ang (1-7) levels in clinical and experimental studies, hopefully providing potential therapeutic strategies.
Angiotensin I/metabolism* ; Heart Failure ; Humans ; Peptide Fragments/metabolism* ; Ventricular Remodeling

Animals ; Cells, Cultured ; Gastrointestinal Tract ; metabolism ; Neuroglia ; metabolism ; Neurons ; metabolism ; Peptide Fragments ; metabolism ; Peptides ; metabolism ; Proteins ; metabolism ; Rats

China ; Female ; Heart Failure ; diagnosis ; drug therapy ; metabolism ; Humans ; Male ; Natriuretic Peptide, Brain ; analysis ; Peptide Fragments ; analysis

Myocardial infarction (MI) is the leading cause of death in the developed world. Biomarkers have an essential role in diagnosis, risk stratification, guiding management and clinical decision making in the setting of patients presenting with signs and symptoms of MI. Cardiac troponin (cTn) rose to prominence during the 1990s and has evolved to be the cornerstone for diagnosis of MI. The current criteria for MI diagnosis include a rise and/or fall in cTn with at least one value above the 99th percentile of the upper reference limit. Along with cTn, the natriuretic peptides B-type natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) have an important role in determining prognosis and guiding management. As assays for cTn have been evolved that are capable of reliably detecting smaller and smaller quantities in the blood, a dilemma has emerged as to how to use this new information. Several studies have attempted to answer this question and have shown that these lower concentrations of cTn have important prognostic significance and, more importantly, that intervention in these patients leads to improved clinical outcomes. New algorithms incorporating BNP, NT-proBNP, and more sensitive cTn assays hold promise for more rapid diagnosis or rule-out of MI, allowing for appropriate management steps to be initiated and more efficient and effective utilization of healthcare resources.
Biological Markers/*blood ; Humans ; Myocardial Infarction/*diagnosis/metabolism ; Natriuretic Peptide, Brain/blood ; Peptide Fragments/blood ; Prognosis ; Troponin/blood

The chronic effects of carboxyl-terminal polypeptide of Cardiotrophin-1 (CT-1-CP) on ventricular electrical remodeling were investigated. CT-1-CP, which contains 16 amino acids in sequence of the C-terminal of Cardiotrophin-1, was selected and synthesized, and then administered to Kunming mice (aged 5 weeks) by intraperitoneal injection (500 ng·g⁻¹·day⁻¹) (4 groups, n=10 and female: male=1:1 in each group) for 1, 2, 3 and 4 weeks, respectively. The control group (n=10, female: male=1:1) was injected by physiological saline for 4 weeks. The epicardial monophasic action potential (MAP) was recorded by using a contact-type MAP electrode placed vertically on the left ventricular (LV) epicardium surface, and the electrocardiogram (ECG) signal in lead II was monitored synchronously. ECG intervals (RR, PR, QRS and QT) and the amplitude of MAP (Am), the maximum upstroke velocity (Vmax), as well as action potential durations (APDs) at different repolarization levels (APD30, APD50, APD70, and APD90) of MAP were determined and analyzed in detail. There were no significant differences in RR and P intervals between CT-1-CP-treated groups and control group, but the PR segment and the QRS complex were greater in the former than in the latter (F=2.681 and 5.462 respectively, P<0.05). Though QT interval and the corrected QT interval (QTc) were shorter in CT-1-CP-treated groups than in control group, the QT dispersion (QTd) of them was greater in the latter than in the former (F=3.090, P<0.05) and increased with the time. The ECG monitoring synchronously with the MAP showed that the compression of MAP electrode on the left ventricular epicardium induced performance similar to myocardium ischemia. As compared with those before chest-opening, the PR segment and QT intervals remained basically unchanged in control group, but prolonged significantly in all CT-1-CP-treated groups and the prolongation of QT intervals increased gradually along with the time of exposure to CT-1-CP. The QRS complex had no significant change in control group, one-week and three-week CT-1-CP-treated groups, but prolonged significantly in two-week and four-week CT-1-CP-treated groups. Interestingly, the QTd after chest-opening was significantly greater than that before chest-opening in control group (t=5.242, P<0.01), but decreased along with the time in CT-1-CP-treated groups. The mean MAP amplitude, Vmax and APD were greater in CT-1-CP-treated groups than those in control group, and became more obvious along with the time. The APD in four CT-1-CP-treat groups was prolonged mainly in middle to final repolarization phase. The difference among these groups became significant in middle phase (APD50) (F=6.076, P<0.01) and increased furthermore in late and final phases (APD70: F=10.054; APD90: F=18.691, P<0.01) along with the time of injection of CT-1-CP. The chronic action of CT-1-CP might induce the adapting alteration in cardiac conductivity and ventricular repolarization. The amplitude and the Vmax of the anterior LV epicardial MAP increased obviously, and the APD prolonged mainly in late and final phase of repolarization.
Animals ; Cytokines ; chemistry ; physiology ; Electrocardiography ; Heart Ventricles ; metabolism ; Mice ; Peptide Fragments ; physiology ; Ventricular Function

OBJECTIVETo observe the cellular uptake of beta amyloid protein (Abeta) by cultured human neuroblastoma (SH-SY5Y) cells and the location of Abeta in the subcellular structures.

METHODSThe time course of cellular uptake of Abeta1-42-fluo in the SH-SY5Y cells was observed directly under laser scanning confocal microscope (LSCM). Image analysis was conducted to compare the differences of cellular Abeta uptake after treatment of the cells with different concentrations of extracellular Abeta for 24 h. Multiple immunofluorescence staining was employed to identify the location of Abeta in the subcellular structures.

RESULTSSH-SY5Y cells showed Abeta internalization after incubation with Abeta1-42-fluo (200 nmol/L) for 1 h, and the quantity of Abeta uptake was time-dependent. A higher concentration of extracellular Abeta1-42-fluo resulted in increased Abeta uptake, which differed significantly between the 3 groups with treatment at different concentrations (P<0.01 or 0.05). Immunofluorescence staining revealed a co-localization of part of the Abeta and Lamp-1 (a lysosome marker) in the cytosome.

CONCLUSIONSH-SY5Y cells can clear Abeta through a time- and dose-dependent cellular uptake mechanism. Part of the Abeta uptaken in the cytoplasm is located in the lysosome .

Alzheimer Disease ; metabolism ; Amyloid beta-Peptides ; metabolism ; Cell Line, Tumor ; Humans ; Neuroblastoma ; metabolism ; pathology ; Peptide Fragments ; metabolism

The present study investigated the effect of antiflammin-1 (AF-1) on LPS-induced IL-10 secretion from RAW264.7 cells through uteroglobin-binding protein (UGBP). Cultured RAW264.7 cells, a murine monocyte-macrophage cell line, were divided as following: control group, LPS group (1 µg/mL LPS), AF-1 group (100 μmol/L AF-1), LPS+AF-1 group (2 h of 100 μmol/L AF-1 pretreatment before LPS addition), and LPS+AF-1+anti-UGBP group (30 min of anti-UGBP antibody pretreatment before successive treatments with AF-1 and LPS). IL-10 concentration in the supernatants was detected by ELISA assay, and the level of IL-10 mRNA expression in macrophage was detected by using RT-PCR method. The results showed that AF-1 significantly increased LPS-induced IL-10 secretion in RAW264.7 cells in a dose dependent way, and up-regulated its mRNA level. Anti-UGBP antibody pretreatment attenuated the augmented effect of AF-1 on LPS-induced IL-10 secretion and gene expression. These results suggest that AF-1 promotes LPS-induced IL-10 secretion from macrophages, and this effect is mediated by UGBP.
Animals ; Cell Line ; Gene Expression ; Interleukin-10 ; metabolism ; Lipopolysaccharides ; Macrophages ; metabolism ; Mice ; Peptide Fragments ; metabolism ; RNA, Messenger ; Uteroglobin ; metabolism