The aim of the present study was to determine whether tumor necrosis factor (TNF)-α regulates the expression levels of excitatory amino-acid transporters (EAATs) in primary astrocytes and its roles in brain ischemia. Exogenous TNF-α was administered to pure cultured astrocytes and the expression levels of EAAT1, EAAT2 and glial fibrillary acidic protein (GFAP) were evaluated. The results showed that TNF-α at 10 ng/ml enhanced the expression of EAAT2 in a time-dependent manner, while the expression levels of EAAT1 and GFAP did not change.
View Article and Find Full Text PDFElsholtzia splendens (ES) is, rich in flavonoids, used to repair copper contaminated soil in China, which has been reported to benefit cardiovascular systems as folk medicine. However, few direct evidences have been found to clarify the vasorelaxation effect of total flavonoids of ES (TFES). The vasoactive effect of TFES and its underlying mechanisms in rat thoracic aortas were investigated using the organ bath system.
View Article and Find Full Text PDFThe overexpression of P-glycoprotein (P-gp) causes resistance to chemotherapy in human ovarian cancer. However, the underlying mechanism remains unclear. In the present study, we showed that, at membrane-bound protein level, P-gp was 'shared' between human ovarian cancer cells by the intercellular transfer of microvesicles (MVs).
View Article and Find Full Text PDFTo investigate the role of microRNAs in the development of chemoresistance and related epithelial-mesenchymal transition (EMT), we examined the effect of miR-489 in adriamycin (ADM)-resistant human breast cancer cells (MCF-7/ADM). MiR-489 was significantly suppressed in MCF-7/ADM cells compared with chemosensitive parental control MCF-7/WT cells. Forced-expression of miR-489 reversed chemoresistance.
View Article and Find Full Text PDFTreatment of carcinoma commonly fails due to chemoresistance. Studies have shown that endothelial cells acquire resistance via the tumor microenvironment. Microvesicle (MV) shedding from the cell membrane to the microenvironment plays an important role in communication between cells.
View Article and Find Full Text PDFThe use of chemotherapy to treat cancer is effective, but chemoresistance reduces this efficacy. Chemotherapy resistance involves several mechanisms, including the cancer stem cell (CSC) concept. The aim of the present study was to assess whether paclitaxel-resistant epithelial ovarian carcinoma is capable of generating cells with CSC-like properties.
View Article and Find Full Text PDFObjective: To investigate the beneficial effect of bicyclol on rat hearts subjected to ischemia-reperfusion (IR) injuries and its possible mechanism.
Methods: Male Sprague-Dawley rats were intragastrically administered with bicyclol (25, 50 or 100 mg/(kg∙d)) for 3 d. Myocardial IR was produced by occlusion of the coronary artery for 1 h and reperfusion for 3 h.
Biochem Biophys Res Commun
January 2013
The growth and metastasis of tumors depend on angiogenesis. Tumor angiogenesis is initiated by the secretion of growth factors from tumor cells; downstream signals are then triggered in pre-existing blood vessels to sprout a new vascular network. Trichosanthin (TCS) is a type I ribosome-inactivating protein that has anti-tumor activity, but the underlying mechanism remains unclear.
View Article and Find Full Text PDFLuteolin is an antioxidative, antitumor and anti-inflammatory flavone. It has been shown to reduce endothelial dysfunction, but the mechanism is not clear. We set out to explore the effects of luteolin on apoptosis and its mechanism of action in endothelial cells.
View Article and Find Full Text PDFWhile glucose-stimulated insulin secretion depends on Ca(2+) influx through voltage-gated Ca(2+) channels in the cell membrane of the pancreatic β-cell, there is also ample evidence for an important role of intracellular Ca(2+) stores in insulin secretion, particularly in relation to drug stimuli. We report here that thiopental, a common anesthetic agent, triggers insulin secretion from the intact pancreas and primary cultured rat pancreatic β-cells. We investigated the underlying mechanisms by measurements of whole cell K(+) and Ca(2+) currents, membrane potential, cytoplasmic Ca(2+) concentration ([Ca(2+)](i)), and membrane capacitance.
View Article and Find Full Text PDFEthnopharmacological Relevance: Total flavonoids of Flos Chrysanthemi (TFFC) are known to modulate vascular functions, but their effect on endothelial cells injured by oxidative stress is unknown. Our objective was to investigate the vasoprotective effect and mechanism of action of TFFC on rat mesenteric artery exposed to superoxide anions produced by pyrogallol.
Materials And Methods: The vasoprotective effect and mechanism of action of TFFC on primary cultured rat mesenteric arterial endothelial cells and small mesenteric arteries was investigated using small-vessel myography, fluorescent Ca(2+) measurement, fluorescent membrane potential measurement and oxidative fluorescent studies.
Background And Purpose: Transient receptor potential vanilloid 4 (TRPV4) is a Ca(2+) -permeable channel with multiple modes of activation. Apigenin is a plant-derived flavone, which has potential preventive effects on the development of cardiovascular disease. We set out to explore the effects of apigenin on TRPV4 channel activity and its role in vasodilatation.
View Article and Find Full Text PDFThe aim of this study was to determine whether mitochondrial nitric oxide (NO) synthase (NOS) is involved in septic shock myocardial depression. The cecal ligation and puncture (CLP) method was used to induce septic shock. There was a significant depression of hemodynamic parameters recorded in the septic shock stage.
View Article and Find Full Text PDFInterrupted reperfusion reduces ischemia/reperfusion (I/R) injury. This study was designed to determine whether NADPH oxidase participates in the neural protection against global I/R injury after interrupted reperfusion. Mice were randomly divided into five groups: sham (sham-operated), I/R (20-min global I/R), RR (I/R+interrupted reperfusion), Apo (I/R+apocynin administration), and RR+Apo.
View Article and Find Full Text PDFAims: To investigate the role of the mitochondrial Ca(2+)-activated K(+) channel in cardioprotection induced by limb remote ischemic preconditioning.
Main Methods: Male Sprague-Dawley rats (250-300 g) were randomized into control, ischemia/reperfusion (I/R), remote ischemic preconditioning (RPC), NS1619 (a specific mitochondrial Ca(2+)-activated K(+) channel opener), and RPC+paxilline (a specific mitochondrial Ca(2+)-activated K(+) channel inhibitor) groups. RPC was induced by 4 cycles of 5 min of ligation followed by 5 min of reperfusion of the left femoral artery.
Implantation of marrow-derived mesenchymal stem cells (MSCs) is the most promising therapeutic strategy for the treatment of spinal cord injury (SCI), especially because of their potential for clinical application, such as the avoidance of immunologic rejection, their strong secretory properties, and their plasticity for developing into neural cells. However, the recovery from SCI after MSC implantation is minimal due to their limited capacity for the reduction of cystic cavitation, for the axonal regeneration and their uncertain neural plasticity in the spinal cord. We previously pretreated MSCs with all-trans retinoic acid (RA) in vitro.
View Article and Find Full Text PDFThe present study evaluated the potential neuroprotective effect and underlying mechanism of the total flavones extracted from Chrysanthemum morifolium (TFCM) against ischemia/reperfusion (I/R) injury. An animal model of cerebral ischemia was established by occluding the right middle cerebral artery for 90 minutes followed by reperfusion for 22 hours. The neurobehavioral scores, infarct area, and hemispheric edema were evaluated.
View Article and Find Full Text PDFWhile luteolin, a flavone rich in many plants, has some cardiovascular activity, it is not clear whether luteolin has beneficial effects on the vascular endothelial impairment in hyperglycemia/high glucose. Here, we reveal the protective effect of luteolin on endothelium-dependent relaxation in isolated rat aortic rings exposed to high glucose. The thoracic aorta of male Sprague-Dawley rats was rapidly dissected out and the effect of luteolin on the tension of aortic rings pretreated with high glucose (44mM) for 4h was measured in an organ bath system.
View Article and Find Full Text PDFApigenin is shown to have cardiovascular effects, but the effects of apigenin on aortas injured by exogenous oxidants are unknown. The objective of this study was to investigate the effect of apigenin on endothelium-dependent vasorelaxation in isolated rat aortic rings exposed to superoxide anion produced by pyrogallol, and its mechanism. The male Sprague-Dawley rat thoracic aorta was rapidly dissected out and the effect of apigenin on tension of aortic rings pretreated with 500 microM pyrogallol, inducing oxidative stress injury, was measured.
View Article and Find Full Text PDFTo assess its potential neuroprotective effect against ischemia/reperfusion (IR) injury in mice, bicyclol was administered intragastrically once a day for 3 days. After 6h of bicyclol pretreatment on the third day, forebrain ischemia was induced for 1h by bilateral occlusion of the carotid arteries. After different times of reperfusion, the histopathological changes and the levels of mitochondria-generated reactive oxygen species (ROS), malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the cortex and hippocampus were measured.
View Article and Find Full Text PDFAim Of The Study: Based on screening for vasoactive traditional Chinese medicinal herbs, the present study was performed to investigate the vasoactive effects of an ethyl acetate extract from leaves of Morus alba (L.) (ELM) on rat thoracic aorta and the mechanisms underlying these effects.
Materials And Methods: Isolated rat thoracic rings were mounted in an organ bath system and the effects of ELM on their responses were evaluated.
This study was designed (i) to test the hypothesis that the endothelium-derived hyperpolarizing factor (EDHF) component of ACh-induced vasorelaxation and hyperpolarization of smooth muscle cells (SMCs) are impaired following exposure to superoxide anion, and (ii) to further investigate whether luteolin and apigenin induce vasoprotection at the vasoactive concentrations in rat mesenteric artery. Rat mesenteric arterial rings were isolated for isometric force recording and electrophysiological studies. Perfusion pressure of mesenteric arterial bed was measured and visualization of superoxide production was detected with fluorescent dye.
View Article and Find Full Text PDFAlcohol Alcohol
November 2008
Aims: The aim of this study was to investigate the effect of alcohol on rat artery and its underlying mechanism.
Methods: The tension of isolated Sprague-Dawley rat thoracic aortic rings and the pressure of rat mesenteric arterial beds perfused with different concentrations of alcohol (0.1-7.
Oxidative stress is believed to contribute to neuronal damage induced by cerebral ischemia/reperfusion (I/R) injury. The present study was undertaken to evaluate the possible antioxidant neuroprotective effect of genistein against neuronal death in hippocampal CA1 neurons following transient global cerebral ischemia in the rat. Transient global cerebral ischemia was induced in male Sprague-Dawley rats by four-vessel-occlusion for 10min.
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