The aim of this paper was to observe the effect of gambogenic acid on angiogenesis of lung cancer and its preliminary mechanism. After culturing lung adenocarcinoma A549 cells, the conditioned medium was treated with gambogenic acid and then used to culture human umbilical vein endothelial cells (HUVECs) to establish the indirect contact cell co-culture system. A two-dimensional culture model of HUVEC was established with matrigel to observe the effect of gambogenic acid on angiogenesis. DAPI staining was used to observe the morphological changes in HUVEC cells after treatment with gambogenic acid under the fluorescence microscope. Annexin V-FITC/PI staining and flow cytometry analysis were used to determine gambogenic acid's effect on HUVEC cell apoptosis rate. The protein expressions of PI3K, p-PI3K, Akt, p-Akt were measured by Western blot. PTEN-siRNA was transfected into cells, and RT-PCR was used to detect the expression levels of PI3K and Akt genes. Gambogenic acid can significantly inhibit angiogenesis, and its inhibitory effect was dose-dependent. DAPI staining showed apoptotic morphological features of HUVEC cells under fluorescence microscope. Annexin V-FITC/PI staining showed that gambogenic acid induced apoptosis in HUVECs. The results of Western blot showed that the expressions of p-PI3K and p-Akt protein were down-regulated with gambogenic acid, while the expressions of PI3K and Akt protein was insignificant. The results of RT-PCR indicated that the expressions of PI3K and Akt protein were up-regulated by PTEN siRNA. Gambogenic acid can inhibit angiogenesis in lung cancer in vitro, and the mechanism of inhibiting angiogenesis may be related to the PI3K/Akt signaling pathway.
A549 Cells ; Apoptosis ; Coculture Techniques ; Human Umbilical Vein Endothelial Cells ; drug effects ; Humans ; Lung Neoplasms ; drug therapy ; pathology ; Neovascularization, Pathologic ; pathology ; PTEN Phosphohydrolase ; genetics ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Transfection ; Xanthenes ; pharmacology

Hair cells at the base of the cochlea appear to be more susceptible to damage by the aminoglycoside gentamicin than those at the apex. However, the mechanism of base-to-apex gradient ototoxicity by gentamicin remains to be elucidated. We report here that gentamicin caused rodent cochlear hair cell damages in a time- and dose-dependent manner. Hair cells at the basal turn were more vulnerable to gentamicin than those at the apical turn. Gentamicin-conjugated Texas Red (GTTR) uptake was predominant in basal turn hair cells in neonatal rats. Transient receptor potential vanilloid 1 (TRPV1) and 4 (TRPV4) expression was confirmed in the cuticular plate, stereocilia and hair cell body of inner hair cells and outer hair cells. The involvement of TRPV1 and TRPV4 in gentamicin trafficking of hair cells was confirmed by exogenous calcium treatment and TRPV inhibitors, including gadolinium and ruthenium red, which resulted in markedly inhibited GTTR uptake and gentamicin-induced hair cell damage in rodent and zebrafish ototoxic model systems. These results indicate that the cytotoxic vulnerability of cochlear hair cells in the basal turn to gentamicin may depend on effective uptake of the drug, which was, in part, mediated by the TRPV1 and TRPV4 proteins.
Animals ; Cell Death/drug effects ; Cell Polarity/drug effects ; Cell Survival/drug effects ; Dose-Response Relationship, Drug ; Gadolinium/metabolism ; Gentamicins/*metabolism/pharmacology ; Hair Cells, Auditory/drug effects/*metabolism ; Hair Cells, Auditory, Inner/drug effects/metabolism ; Rats ; Rats, Sprague-Dawley ; Ruthenium Red/metabolism ; TRPV Cation Channels/*metabolism ; Time Factors ; Xanthenes/metabolism ; Zebrafish

To investigate the neuroprotective of ligustilide (LIG) against glutamate-induced apoptosis of PC12 cells, cell viability were examined by MTT assay. Flow cytometry was applied to assay cell apoptosis rate. Intracellular calcium concentration was measured by using fluorescent dye Fluo-3/AM. Cytochrome C (Cyt C), Caspase-3, Bax and Bcl-2 protein expression were assayed by western blot. The results showed that glutamate is cytotoxic with an inhibitory concentration 50 (ID50) of 15 mmol · L(-1). Pretreatment with LIG (1, 5, 15 μmol · L(-1)) significantly improved cell viability. The apoptosis rate in glutamate-induced PC12 cells was 13.39%, and decreased in the presence of LIG (1, 5, 15 μmol · L(-1)) by 9.06%, 6.48%, 3.82%, separately. Extracellular accumulation of Ca2+ induced by glutamate were significantly reduced by LIG. The results of western blot manifested that pretreatment LIG could decrease the release of Cyt C from mitochondria, down-regulate Caspase-3 protein expression and up-regulate Bcl-2/Bax ratio, thereby protects PC12 cells from apoptosis. In summary, LIG had protective effect on glutamate-induced apoptosis in PC12 cells through attenuating the increase in intracellular Ca2+ concentration, and inhibiting the release of Cyt C from mitochondria to cytoplasm.
4-Butyrolactone ; analogs & derivatives ; pharmacology ; Aniline Compounds ; Animals ; Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; Calcium ; metabolism ; Caspase 3 ; metabolism ; Cell Survival ; Cytochromes c ; metabolism ; Glutamic Acid ; adverse effects ; Mitochondria ; metabolism ; PC12 Cells ; drug effects ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Xanthenes ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo discuss the mechanism of gambogenic acid (GNA) in inducing the apoptosis of melanoma B16 cells.

METHODThe inhibitory effect of GNA on the proliferation of B16 cells was measured by the methyl thiazolyl tetrazolium (MTT) assay. The effect of GNA on B16 cells was detected by the Hoechst 33258 staining. The transmission electron microscopy was used to observe the ultra-structure changes of B16 cells. The changes in PI3K, p-PI3K, Akt, p-Akt, p-mTOR, PTEN proteins were detected by the Western blotting to discuss the molecular mechanism of GNA in inducing the apoptosis of B16 cells.

RESULTGNA showed a significant inhibitory effect in the growth and proliferation of melanoma B16 cells. The cell viability remarkably decreased with the increase of GNA concentration and the extension of the action time. The results of the Hoechst 33258 staining showed that cells processed with GNA demonstrated apparent apoptotic characteristics. Under the transmission electron microscope, B16 cells, after being treated with GNA, showed obvious morphological changes of apoptosis. The Western blot showed a time-dependent reduction in the p-PI3K and p-Akt protein expressions, with no change in p-PI3K and p-Akt protein expression quantities. The p-mTOR protein expression decreased with the extension of time, where as the PTEN protein expression showed a time-dependent increase.

CONCLUSIONGNA could inhibit the proliferation of melanoma B16 cells and induce their apoptosis within certain time and concentration ranges. Its mechanism in inducing the cell apoptosis may be related to PI3K/Akt/mTOR signaling pathways.

Animals ; Apoptosis ; drug effects ; Blotting, Western ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Melanoma ; metabolism ; pathology ; ultrastructure ; Mice ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; PTEN Phosphohydrolase ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects ; TOR Serine-Threonine Kinases ; metabolism ; Terpenes ; pharmacology ; Xanthenes ; Xanthones ; pharmacology

To explore gambogenic acid (GNA)-induced apoptosis and underlying mechanism in vivo. A549 nude mice xenografts were used as in vivo model to study anticancer effect of GNA by observing tumor growth curve and weight of the tumor. Ultrastructure of A549 cells treated by GNA was observed by TE. Expression of COX-2 and VEGF were detected by immunohistochemistry. TUNEL assay was applied in examining apoptosis index of tumor cells. The tumor isolated from mice treated by GNA (8, 16 mg kg(-1)) took on a slow growth condition compared with control group. The results suggested that weight and volume of the tumor from experimental groups were remarkably decreased compared with control group (P < 0.05). Ultrastructure change of the tumor, such as vacuolization, abnormal distribution of the heterochromosome, volume of the tumor cells, even apoptotic bodies, were observed in GNA-treated group. While no apparent morphological change was observed in the normal group. Typical apoptotic characteristics could be distinctly observed in the mouse treated by GNA for 20 days and apoptosis index in GNA-treated group was significantly higher than model group. Expression of COX-2 and VEGF were significantly down-regulated in GNA-treated groups in comparison with control group (P < 0.01). These results indicate that GNA could affect the development and progression of A549 cells through inducing apoptosis, mediating the expression of VEGF in vascular cells and COX-2 in tumor cells.
Animals ; Antineoplastic Agents, Phytogenic ; therapeutic use ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; metabolism ; Humans ; Immunohistochemistry ; In Situ Nick-End Labeling ; Lung Neoplasms ; drug therapy ; metabolism ; ultrastructure ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microscopy, Electron, Transmission ; Terpenes ; therapeutic use ; Vascular Endothelial Growth Factor A ; metabolism ; Xanthenes ; Xanthones ; therapeutic use ; Xenograft Model Antitumor Assays

BACKGROUNDCa(2+) in the central nervous system plays important roles in brain physiology, including neuronal survival and regeneration in rats with injured facial motoneurons. The present research was to study the modulations of intracellular free Ca(2+) concentrations by cholinergic receptors in rat facial nucleus, and the mechanisms of the modulations.

METHODSThe fluorescence intensity of facial nucleus in Fluo-3 AM loaded acute brainstem slices was detected by applying intracellular free Ca(2+) measurement technique via confocal laser scanning microscope. The changes of fluorescence intensity of facial nucleus indicate the average changes of intracellular free Ca(2+) levels of the neurons.

RESULTSAcetylcholine was effective at increasing the fluorescence intensity of facial nucleus. Muscarine chloride induced a marked increase of fluorescence intensity in a concentration dependent fashion. The enhancement of fluorescence intensity by muscarine chloride was significantly reduced by thapsigargin (depletor of intracellular Ca(2+) store; P < 0.01), rather than Ca(2+) free artifical cerebrospinal fluid or EGTA (free Ca(2+) chelator; P > 0.05). And the increase of fluorescence intensity was also significantly inhibited by pirenzepine (M(1) subtype selective antagonist; P < 0.01) and 4-DAMP (M(3) subtype selective antagonist; P < 0.01). In addition, fluorescence intensity was markedly increased by nicotine. The enhancement of fluorescence intensity by nicotine was significantly reduced by EGTA, nifedipine (L-type voltage-gated Ca(2+) channel blocker), dihydro-beta-erythroidine (alpha4beta2 subtype selective antagonist), and in Ca(2+) free artificial cerebrospinal fluid (P < 0.01), but not in the presence of mibefradil (M-type voltage-gated Ca(2+) channel blocker) or thapsigargin (P > 0.05).

CONCLUSIONSThe data provide the evidence that muscarinic receptors may induce the increase of intracellular free Ca(2+) levels through the Ca(2+) release of intracellular Ca(2+) stores, in a manner related to M(1) and M(3) subtypes of muscarinic receptors in rat facial nucleus. Nicotine may increase intracellular free Ca(2+) concentrations via the influx of extracellular Ca(2+)+ mainly across L-type voltage-gated Ca(2+) channels, in a manner related to the alpha4beta2 subtype of nicotinic receptors.

Acetylcholine ; pharmacology ; Aniline Compounds ; administration & dosage ; Animals ; Brain Stem ; cytology ; drug effects ; metabolism ; Calcium ; metabolism ; Diamines ; pharmacology ; Facial Nerve ; cytology ; Female ; Fluorescent Dyes ; administration & dosage ; In Vitro Techniques ; Male ; Microscopy, Confocal ; Motor Neurons ; drug effects ; metabolism ; Muscarinic Agonists ; pharmacology ; Nicotine ; pharmacology ; Nicotinic Agonists ; pharmacology ; Piperidines ; pharmacology ; Pirenzepine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Cholinergic ; metabolism ; Receptors, Muscarinic ; metabolism ; Receptors, Nicotinic ; metabolism ; Tropicamide ; pharmacology ; Xanthenes ; administration & dosage