assess what China’s health system reform has achieved and what needs to be done over the next decade
View Article and Find Full Text PDFHIP-55 (HPK1-interacting protein of 55 kDa, also named DBNL, SH3P7, and mAbp1) is a multidomain adaptor protein that is critical for organ development and the immune response. Here, we report the coupling of HIP-55 to cell growth control through its 14-3-3-binding phospho-Ser/Thr-sensor sites. Using affinity chromatography, we found HIP-55 formed a complex with 14-3-3 proteins, revealing a new node in phospho-Ser/Thr-mediated signaling networks.
View Article and Find Full Text PDFRationale: During the transition from compensated hypertrophy to heart failure, the signaling between L-type Ca(2+) channels in the cell membrane/T-tubules and ryanodine receptors in the sarcoplasmic reticulum becomes defective, partially because of the decreased expression of a T-tubule-sarcoplasmic reticulum anchoring protein, junctophilin-2. MicroRNA (miR)-24, a junctophilin-2 suppressing miR, is upregulated in hypertrophied and failing cardiomyocytes.
Objective: To test whether miR-24 suppression can protect the structural and functional integrity of L-type Ca(2+) channel-ryanodine receptor signaling in hypertrophied cardiomyocytes.
Rationale: Failing cardiomyocytes exhibit decreased efficiency of excitation-contraction (E-C) coupling. The downregulation of junctophilin-2 (JP2), a protein anchoring the sarcoplasmic reticulum to T-tubules, has been identified as a major mechanism underlying the defective E-C coupling. However, the regulatory mechanism of JP2 remains unknown.
View Article and Find Full Text PDFActa Pharmacol Sin
September 2011
Aim: To study and establish a proteome reference map and regulation network of neonatal rat cardiomyocyte.
Methods: Cultured cardiomyocytes of neonatal rats were used. All proteins expressed in the cardiomyocytes were separated and identified by two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS).
G protein-coupled receptors (GPCRs) activate mitogen-activated protein kinases through a number of distinct pathways in cells. Increasing evidence has suggested that endosomal signaling has an important role in receptor signal transduction. Here we investigated the involvement of endocytosis in α(1A)-adrenergic receptor (α(1A)-AR)-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2).
View Article and Find Full Text PDFMyocardial adrenergic receptors (ARs) play important roles in cardiac hypertrophy. However, the detailed molecular mechanism of AR-mediated cardiac hypertrophy remains elusive to date. To gain full insight into how ARs are involved in the regulation of cardiac hypertrophy, protein expression profiling was performed with comparative proteomics approach on neonatal rat cardiomyocytes.
View Article and Find Full Text PDFZhonghua Yi Shi Za Zhi
September 2009
beta-Adrenergic receptor (beta-AR)-induced cardiac remodeling is closely linked with the re-expression of the atrial natriuretic factor (ANF) gene. However, the exact molecular mechanism of this response remains elusive. Here, we demonstrate that the beta-AR agonist isoproterenol potently evokes the tyrosine phosphorylation of STAT3 and increases its transcriptional activity in an extracellularly regulated kinase 1/2 and glycoprotein (gp)130 signaling-dependent manner in rat cardiomyocytes.
View Article and Find Full Text PDFZhongguo Zhong Xi Yi Jie He Za Zhi
January 2008
Aim: The enhancement of intracellular Ca2+ signaling in response to alpha 1-adrenergic receptor (alpha 1-AR) stimulation is an essential signal transduction event in the regulation of cardiac functions, such as cardiac growth, cardiac contraction, and cardiac adaptation to various situations. The present study was intended to determine the role(s) of the alpha 1-AR subtype(s) in mediating this response.
Methods: We evaluated the effects of subtype-specific agonists and antagonists of the alpha 1- AR on the intracellular Ca2+ signaling of neonatal rat ventricular myocytes using a confocal microscope.
Dynamic nuclear Ca(2+) signals play pivotal roles in diverse cellular functions including gene transcription, cell growth, differentiation, and apoptosis. Here we report a novel nuclear Ca(2+) regulatory mechanism mediated by inositol 1,4,5-trisphosphate receptors (IP(3)Rs) around the nucleus in developing cardiac myocytes. Activation of IP(3)Rs by alpha(1)-adrenergic receptor (alpha(1)AR) stimulation or by IP(3) application (in saponin-permeabilized cells) increases Ca(2+) spark frequency preferentially in the region around the nucleus in neonatal rat ventricular myocytes.
View Article and Find Full Text PDFAim: To investigate the movement of alpha(1A)-adrenergic receptors(alpha(1A)-AR) stimulated by agonist, phenylephrine (PE), and the dynamics of receptor movement in real time in single living cells with millisecond resolution.
Methods: We labeled alpha(1A)-AR using the monoclonal, anti-FLAG (a kind of tag) antibody and Cy3-conjugated goat anti-mouse IgG and recorded the trajectory of their transport process in living HEK293A cells stimulated by agonist, PE, and then analyzed their dynamic properties.
Results: The specific detection of alpha(1A)-AR on the surface of living HEK293A-alpha(1A) cells was achieved.
To test the hypothesis that AMP-activated protein kinase (AMPK) is possibly the downstream signaling molecule of certain subtypes of adrenergic receptor (AR) in the heart, we evaluated AMPK activation mediated by ARs in H9C2 cells, a rat cardiac source cell line, and rat hearts. The AMPK-alpha subunit and the phosphorylation level of Thr(172)-AMPK-alpha subunit were subjected to Western blot analysis. Osmotic minipumps filled with norepinephrine (NE), phenylephrine (PE) or vehicle [0.
View Article and Find Full Text PDFThe heterogeneous motion of alpha(1B)-adrenoceptor (alpha(1B)-AR) was visualized in living cells with BODIPY-labeled antagonist of AR by single molecule fluorescence microscopy at high spatial resolution. The moving trajectory was reconstructed by precise localization (better than 20 nm) with a least-square fit of a two-dimensional Gaussian point spread function to each single spot. Trajectory analysis revealed two apparent groups of movements: directed motion and hindered motion.
View Article and Find Full Text PDFAim: To examine the subcellular distribution of the 3 alpha1-adrenoceptor (alpha1-AR) subtypes and their internalization and trafficking upon agonist stimulation in human embryonic kidney 293A cells.
Methods: Confocal real-time imaging, enzyme linked immunosorbent assay (ELISA) and whole cell [3H]-prazosin binding assay were applied to detect the distribution and localization of the 3 alpha1-AR subtypes.
Results: alpha1A-AR was found both on the cell surface and in the cytoplasm; alpha1BAR, however, was predominantly detected on the cell surface, while alpha1D-AR was detected mainly in the intracellular compartments.
Pressure overload-induced hypertrophy is a key step leading to heart failure. The Ca(2+)-induced Ca(2+) release (CICR) process that governs cardiac contractility is defective in hypertrophy/heart failure, but the molecular mechanisms remain elusive. To examine the intermolecular aspects of CICR during hypertrophy, we utilized loose-patch confocal imaging to visualize the signaling between a single L-type Ca(2+) channel (LCC) and ryanodine receptors (RyRs) in aortic stenosis rat models of compensated (CHT) and decompensated (DHT) hypertrophy.
View Article and Find Full Text PDFBiochem Biophys Res Commun
February 2007
We used the technique of single particle tracking (SPT) with high tempo-spatial resolution to efficiently explore the route and mechanism for the transport of alpha(1A)-adrenergic receptor (alpha(1A)-AR) in real time in living cells. We found that the initial transport of alpha(1A)-AR in cells depended on actin filaments with the velocity of 0.2 microm/s and exhibited discrete 33-nm steps.
View Article and Find Full Text PDFAs we previously reported, cAMP and p38 MAPK instead of protein kinase A were involved in beta-adrenergic receptor (beta-AR)-mediated interleukin-6 (IL-6) production in mouse cardiac fibroblasts. Besides kinases, phosphatases may also be involved in IL-6 gene regulation. To study the role of protein tyrosine phosphatases (PTPs) in beta-AR-mediated IL-6 production, we selected the most widely used PTP inhibitor, phenylarsine oxide (PAO).
View Article and Find Full Text PDFA G-protein-coupled receptor-cell-membrane stationary phase (CMSP) has been prepared by immobilizing cell membranes on the surface of silica, as carrier. The resulting HEK293 alpha1A adrenoceptor cell-membrane stationary phase can be used for rapid on-line chromatographic determination of potential subtype-selective alpha1-adrenoceptor ligand-binding affinities for alpha 1-adrenoceptor subtypes. The objective of the research was to study whether cell lines stably overexpressing subtype receptors could improve the sensitivity and specificity of cell-membrane chromatography (CMC) compared with use of homogenized tissue and cells in primary culture.
View Article and Find Full Text PDF