OBJECTIVETo investigate the effect of 2,3,4',5-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an active component extracted from the root of Polygonum multiflorum, on angiotensin II (Ang II)-induced proliferation of cultured rat vascular smooth muscle cells (VSMCs) and to identify the potential mechanism.

METHODSCell proliferation and cell cycle were determined by cell counting, 5-bromo-2'-deoxyuridine incorporation assay, proliferating cell nuclear antigen protein expression and flow cytometry. Levels of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), mitogenic extracellular kinase 1/2 (MEK1/2) and Src in VSMCs were measured by Western blot. The expression of c-fos, c-jun and c-myc mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Intracellular reactive oxygen species (ROS) was measured by fluorescence assay.

RESULTSTSG significantly inhibited Ang II-induced VSMCs proliferation and arrested cells in the G /S checkpoint (P<0.05 or P<0.01). TSG decreased the levels of phosphorylated ERK1/2, MEK1/2 and Src in VSMCs (P<0.05 or P<0.01). TSG also suppressed c-fos, c-jun and c-myc mRNA expression <0.05 or P<0.01). In addition, the intracellular ROS was reduced by TSG (P<0.01).

CONCLUSIONSTSG inhibited Ang II-induced VSMCs proliferation. Its antiproliferative effect might be associated with down-regulation of intracellular ROS, followed by the suppression of the Src-MEK1/2-ERK1/2 signal pathway, and hence, blocking cell cycle progression.

Angiotensin II ; pharmacology ; Animals ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Glucosides ; pharmacology ; Intracellular Space ; metabolism ; Male ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Phosphorylation ; drug effects ; Proliferating Cell Nuclear Antigen ; metabolism ; Proto-Oncogene Proteins ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Stilbenes ; pharmacology ; Superoxide Dismutase ; metabolism

The accumulation of abnormal protein aggregates is a major characteristic of many neurodegenerative disorders, including Parkinson's disease (PD). The intracytoplasmic deposition of alpha-synuclein aggregates and Lewy bodies, often found in PD and other alpha-synucleinopathies, is thought to be linked to inefficient cellular clearance mechanisms, such as the proteasome and autophagy/lysosome pathways. The accumulation of alpha-synuclein aggregates in neuronal cytoplasm causes numerous autonomous changes in neurons. However, it can also affect the neighboring cells through transcellular transmission of the aggregates. Indeed, a progressive spreading of Lewy pathology among brain regions has been hypothesized from autopsy studies. We tested whether inhibition of the autophagy/lysosome pathway in alpha-synuclein-expressing cells would increase the secretion of alpha-synuclein, subsequently affecting the alpha-synuclein deposition in and viability of neighboring cells. Our results demonstrated that autophagic inhibition, via both pharmacological and genetic methods, led to increased exocytosis of alpha-synuclein. In a mixed culture of alpha-synuclein-expressing donor cells with recipient cells, autophagic inhibition resulted in elevated transcellular alpha-synuclein transmission. This increase in protein transmission coincided with elevated apoptotic cell death in the recipient cells. These results suggest that the inefficient clearance of alpha-synuclein aggregates, which can be caused by reduced autophagic activity, leads to elevated alpha-synuclein exocytosis, thereby promoting alpha-synuclein deposition and cell death in neighboring neurons. This finding provides a potential link between autophagic dysfunction and the progressive spread of Lewy pathology.
Adenine/analogs & derivatives/pharmacology ; Animals ; *Autophagy/drug effects ; Cell Line ; *Exocytosis/drug effects ; Extracellular Space/*metabolism ; Humans ; Mice ; Mice, Knockout ; Microtubule-Associated Proteins/deficiency/metabolism ; Phagosomes/drug effects/metabolism ; Protein Structure, Quaternary ; Protein Transport/drug effects ; alpha-Synuclein/chemistry/*metabolism/secretion/toxicity

Volume transmission (VT) is a widespread mode of intercellular communication that occurs in the extracellular fluid (ECF) and in the cerebrospinal fluid (CSF) of the brain with VT signals moving from source to target cells via energy gradients leading to diffusion and convection (flow). The VT channels are diffuse forming a plexus in the extracellular space, while in wiring transmission (WT) the channels (axons, terminals) are private. The speed is slow (seconds-minutes) in VT while rapid in the millisecond range in WT. The extracellular space is the substrate for VT, which is modulated by the extracellular matrix. Extrasynaptic VT is linked to synaptic transmission and likely often takes place due to incomplete diffusion barriers with the synaptic transmitter reaching extrasynaptic domains of the pre-and post-synaptic membrane of the synapse, the astroglia, and even adjacent synapses. Indications exist for the existence of striatal D2-like receptor-mediated extrasynaptic form of dopamine (DA) VT at the local circuit level in vivo in the human striatum. Synaptic glutamate via extrasynaptic VT can act on extrasynaptic metabotropic glutamate receptors located on the astroglia leading to Ca(2+) mediated astrocytic glutamate release into the extracellular space (ECS). Long distance peptide VT and CSF VT is the major long distance VT with distances more than 1 mm and flow in the CSF. Indications for long distance VT of beta-endorphin and oxytocin are obtained. We propose that monogamy in the female prairie vole may take place through an increase in oxytocin VT, especially in nucleus accumbens. Release of extracellular vesicles containing receptors, proteins, RNAs and mtDNA from cellular networks in the central nervous system (CNS) into the ECF and CSF may be a fundamental communication in the CNS. It represents a special form of volume transmission, the Roamer subtype of VT. It may greatly contribute to dynamic events of synaptic plasticity but also to spread of pathological proteins in protein conformational disorders. VT also occurs in the peripheral nervous system and associated cells. Short and long distance VT may take place in meridian channels via diffusion and flow in the interstitial fluid. Acupuncture can produce VT signals by releasing transmitters and modulators from nerve terminals and mast cells.
Animals ; Cell Communication ; Central Nervous System ; cytology ; Extracellular Space ; metabolism ; Humans ; Synapses ; metabolism

OBJECTIVE: Permeability parameters from dynamic contrast-enhanced MRI (DCE-MRI) and apparent diffusion coefficient (ADC) value on diffusion-weighted imaging (DWI) can be quantitative physiologic metrics for gliomas. The transfer constant (Ktrans) has shown efficacy in grading gliomas. Volume fraction of extravascular extracellular space (ve) has been underutilized to grade gliomas. The purpose of this study was to evaluate ve in its ability to grade gliomas and to assess the correlation with other permeability parameters and ADC values. MATERIALS AND METHODS: A total of 33 patients diagnosed with pathologically-confirmed gliomas were examined by 3 T MRI including DCE-MRI and ADC map. A region of interest analyses for permeability parameters from DCE-MRI and ADC were performed on the enhancing solid portion of the tumors. Permeability parameters form DCE-MRI and ADC between low- and high-grade gliomas; the diagnostic performances of presumptive metrics and correlation among those metrics were statistically analyzed. RESULTS: High-grade gliomas showed higher Ktrans (0.050 vs. 0.010 in median value, p = 0.002) and higher ve (0.170 vs. 0.015 in median value, p = 0.001) than low-grade gliomas. Receiver operating characteristic curve analysis showed significance in both Ktrans and ve for glioma grading. However, there was no significant difference in diagnostic performance between Ktrans and ve. ADC value did not correlate with any of the permeability parameters from DCE-MRI. CONCLUSION: Extravascular extracellular space (ve) appears to be comparable with transfer constant (Ktrans) in differentiating high-grade gliomas from low-grade gliomas. ADC value does not show correlation with any permeability parameters from DCE-MRI.
Adult ; Aged ; Brain Neoplasms/metabolism/*pathology ; Contrast Media/*diagnostic use ; Diffusion Magnetic Resonance Imaging/*methods ; Extracellular Space/metabolism ; Female ; Glioma/metabolism/*pathology ; Humans ; Magnetic Resonance Imaging/methods ; Male ; Middle Aged ; Neoplasm Grading ; Permeability ; ROC Curve ; Sensitivity and Specificity

Long intergenic non-coding RNAs (lincRNAs) have historically been ignored in cancer biology. However, thousands of lincRNAs have been identified in mammals using recently developed genomic tools, including microarray and high-throughput RNA sequencing (RNA-seq). Several of the lincRNAs identified have been well characterized for their functions in carcinogenesis. Here we performed RNA-seq experiments comparing gastric cancer with normal tissues to find differentially expressed transcripts in intergenic regions. By analyzing our own RNA-seq and public microarray data, we identified 31 transcripts, including a known expressed sequence tag, BM742401. BM742401 was downregulated in cancer, and its downregulation was associated with poor survival in gastric cancer patients. Ectopic overexpression of BM742401 inhibited metastasis-related phenotypes and decreased the concentration of extracellular MMP9. These results suggest that BM742401 is a potential lincRNA marker and therapeutic target.
Animals ; DNA, Intergenic/genetics ; Expressed Sequence Tags/*metabolism ; Extracellular Space/metabolism ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Genetic Predisposition to Disease ; Humans ; Male ; Matrix Metalloproteinase 9/metabolism ; Mice ; Mice, Inbred C57BL ; Multivariate Analysis ; Neoplasm Metastasis ; Neoplasm Staging ; Phenotype ; Proportional Hazards Models ; RNA, Long Noncoding/*genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Reproducibility of Results ; Stomach Neoplasms/*genetics/*pathology ; Survival Analysis

OBJECTIVETo investigate the vasodilative effect of paeonol in rat mesenteric artery and the mechanisms responsible for it.

METHODSRats were anaesthetized and sacrificed. The superior mesenteric artery was removed, dissected free of adherent tissue and cut into 2.0 mm long cylindrical segments. Isometric tension of artery rings was recorded by a myograph system in vitro. Concentration-relaxation curves of paeonol (17.8 μ mol/L to 3.16 mmol/L) were recorded on artery rings precontracted by potassium chloride (KCl) and concentration-contraction curves of KCl, 5-hydroxytryptamine (5-HT), noradrenaline (NA) or calcium chloride (CaCl2) were recorded in the presence of paeonol (10(-4.5), 10(-3.8), 10(-3.5) mol/L) respectively. And also, concentration-relaxation curves of paeonol were recorded in the presence of different potassium channel inhibitors and propranolol on rings precontracted with KCl respectively. To investigate the role of intracellular Ca(2+) release from Ca(2+) store, the contraction induced by NA (100 μ mol/L) and CaCl2 (2 mmol/L) in Ca(2+) free medium was observed in the presence of paeonol respectively.

RESULTSPaeonol relaxed artery rings precontracted by KCl in a concentration-dependent manner and the vasodilatation effect was not affected by endothelium denudation. Paeonol significant decreased the maximum contractions (Emax) induced by KCl, CaCl2, NA and 5-HT, as well as Emax induced by NA and CaCl2 in Ca(2+) -free medium, suggesting that paeonol dilated the artery via inhibiting the extracellular Ca(2+) influx mediated by voltage-dependent calcium channel, and receptor-mediated Ca(2+)-influx and release. Moreover, none of glibenclamide, tetraethylammonium, barium chlorded and propranolol affected the paeonol-induced vasodilatation, indicating that the vasodilatation was not contributed to ATP sensitive potassium channel, calcium-activated potassium channel, inwardly rectifying potassium channel, and β-adrenoceptor.

CONCLUSIONPaeonol induces non-endothelium dependent-vasodilatation in rat mesenteric artery via inhibiting voltage-dependent calcium channel-mediated extracellular Ca(2+) influx and receptor-mediated Ca(2+) influx and release.

Acetophenones ; pharmacology ; Adrenergic beta-Antagonists ; pharmacology ; Animals ; Calcium ; metabolism ; Calcium Chloride ; pharmacology ; Endothelium, Vascular ; drug effects ; physiology ; Extracellular Space ; drug effects ; metabolism ; Female ; In Vitro Techniques ; Intracellular Space ; drug effects ; metabolism ; Male ; Mesenteric Arteries ; drug effects ; physiology ; Norepinephrine ; pharmacology ; Potassium Channel Blockers ; pharmacology ; Potassium Chloride ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Serotonin ; pharmacology ; Vasoconstriction ; drug effects ; Vasodilation ; drug effects

Dimerization among the EGFR family of tyrosine kinase receptors leads to allosteric activation of the kinase domains of the partners. Unlike other members in the family, the kinase domain of HER3 lacks key amino acid residues for catalytic activity. As a result, HER3 is suggested to serve as an allosteric activator of other EGFR family members which include EGFR, HER2 and HER4. To study the role of intracellular domains in HER3 dimerization and activation of downstream signaling pathways, we constructed HER3/HER2 chimeric receptors by replacing the HER3 kinase domain (HER3-2-3) or both the kinase domain and the C-terminal tail (HER3-2-2) with the HER2 counterparts and expressed the chimeric receptors in Chinese hamster ovary (CHO) cells. While over expression of the intact human HER3 transformed CHO cells with oncogenic properties such as AKT/ERK activation and increased proliferation and migration, CHO cells expressing the HER3-2-3 chimeric receptor showed significantly reduced HER3/HER2 dimerization and decreased phosphorylation of both AKT and ERK1/2 in the presence of neuregulin-1 (NRG-1). In contrast, CHO cells expressing the HER3-2-2 chimeric receptor resulted in a total loss of downstream AKT activation in response to NRG-1, but maintained partial activation of ERK1/2. The results demonstrate that the intracellular domains play a crucial role in HER3's function as an allosteric activator and its role in downstream signaling.
Amino Acid Sequence ; Animals ; CHO Cells ; Cell Movement ; Cell Proliferation ; Cricetinae ; Cricetulus ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Humans ; Intracellular Space ; enzymology ; MAP Kinase Signaling System ; Models, Molecular ; Molecular Sequence Data ; Phosphatidylinositol 3-Kinases ; metabolism ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Proto-Oncogene Proteins c-akt ; metabolism ; Receptor, ErbB-2 ; chemistry ; Receptor, ErbB-3 ; chemistry ; genetics ; metabolism ; Recombinant Fusion Proteins ; chemistry ; genetics ; metabolism ; Signal Transduction

A new class of RNA regulatory genes known as microRNAs (miRNAs) has been found to introduce a whole new layer of gene regulation in eukaryotes. The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly, but are also detectable outside cells, including in various body fluids (e.g. serum, plasma, saliva, urine and milk). This phenomenon raises questions about the biological function of such extracellular miRNAs. Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles (e.g. exosomes, shedding vesicles and apoptotic bodies) or packaged with RNA-binding proteins (e.g. high-density lipoprotein, Argonaute 2 and nucleophosmin 1). These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes. Furthermore, secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease. Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases. In this review, we summarize what is known about the mechanism of miRNA secretion. In addition, we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs. We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.
Animals ; Diagnosis ; Extracellular Space ; genetics ; Gene Transfer, Horizontal ; Humans ; MicroRNAs ; genetics ; metabolism ; Therapeutics

Corticotrophin-releasing factor (CRF) plays a major role in coordinating stress responses. We aimed to test whether blocking endogenous CRF activity can prevent the stress-induced dilation of intercellular spaces in esophageal mucosa. Eighteen adult male rats were divided into 3 groups: 1) a non-stressed group (the non-stressed group), 2) a saline-pretreated stressed group (the stressed group), 3) and an astressin-pretreated stressed group (the astressin group). Immediately after completing the experiments according to the protocol, distal esophageal segments were obtained. Intercellular space diameters of esophageal mucosa were measured by transmission electron microscopy. Blood was sampled for the measurement of plasma cortisol levels. Mucosal intercellular spaces were significantly greater in the stressed group than in the non-stressed group. Mucosal intercellular spaces of the astressin group were significantly smaller than those of the stressed group. Plasma cortisol levels in the stressed group were significantly higher than in the non-stressed group. Pretreatment with astressin tended to decrease plasma cortisol levels. Acute stress in rats enlarges esophageal intercellular spaces, and this stress-induced alteration appears to be mediated by CRF. Our results suggest that CRF may play a role in the pathophysiology of reflux-induced symptoms or mucosal damage.
Animals ; Corticotropin-Releasing Hormone/*antagonists & inhibitors/metabolism/pharmacology ; Esophagus/anatomy & histology/*drug effects ; Extracellular Space/*drug effects ; Hydrocortisone/blood ; Male ; Mucous Membrane/anatomy & histology/*drug effects ; Neuroprotective Agents/pharmacology ; Peptide Fragments/*pharmacology ; Rats ; Rats, Wistar ; *Stress, Psychological/blood/physiopathology

High-mobility group box 1 (HMGB1) protein has been demonstrated to play an important role in chronic inflammatory diseases including rheumatoid arthritis, and systemic lupus erythematosus. This study investigated the association between extracellular HMGB1 expression and disease activity, and clinical features of Behcet's disease (BD). Extracellular HMGB1 expression in the sera of 42 BD patients was measured and was compared to that of 22 age- and sex-matched healthy controls. HMGB1 expression was significantly increased in BD patients compared to healthy controls (78.70 +/- 20.22 vs 10.79 +/- 1.90 ng/mL, P = 0.002). In addition, HMGB1 expression was significantly elevated in BD patients with intestinal involvement compared to those without (179.61 +/- 67.95 vs 61.89 +/- 19.81 ng/mL, P = 0.04). No significant association was observed between HMGB1 concentration and other clinical manifestations, or disease activity. It is suggested that extracellular HMGB1 may play an important role in the pathogenesis of BD.
Adult ; Aged ; Behcet Syndrome/genetics/*metabolism/pathology ; Extracellular Space/metabolism ; Female ; HMGB1 Protein/genetics/*metabolism ; Humans ; Inflammation ; Intestinal Diseases/blood/genetics ; Male ; Middle Aged ; Young Adult