1.LC/MS guided approach to discovering nephroprotective substances from Huangkui capsule.
Tingting MA ; Yi WANG ; Xiaoqian CHEN ; Xiaoping ZHAO
Journal of Zhejiang University. Medical sciences 2017;46(1):66-73
To discover the nephroprotective substances from Huangkui capsule.The components of Huangkui capsule were isolated by preparative liquid chromatography, and the active components were screened by LC/MS and identified. The adriamycine-injured HK-2 cells were treated with various active components with different concentrations, and the malonaldehyde (MDA) content, adenosine triphosphate (ATP) level and mitochondrial oxygen consumption rate were measured to verify the protective activity of the compounds.Four active components in Huangkui capsule were identified to exert nephroprotective effects. Fifteen flavanoids from these four components were tentatively identified by LC/MS, and hyperin, myricetin, quercetin, rutin and isoquercetin were confirmed. Hyperin, myricetin quercetin and rutin showed dose-dependent protective effects on injured HK-2 cells. Espacially, hyperin significantly reduced MDA content, quercetin and rutin significantly increased ATP level, and myricetin significantly increased mitochondrial oxygen consumption rate.Hyperin, myricetin, querctein and rutin might be the potential nephroprotective compounds in Huangkui capsule, their effects may be related to the inhibition of lipid peroxidation and the alleviation of mitochondrial damage.
Abelmoschus
;
chemistry
;
drug effects
;
Adenosine Triphosphate
;
metabolism
;
Cell Line, Transformed
;
Chromatography, Liquid
;
Doxorubicin
;
Drugs, Chinese Herbal
;
Epithelial Cells
;
drug effects
;
Flavonoids
;
pharmacology
;
Kidney Diseases
;
chemically induced
;
drug therapy
;
prevention & control
;
Kidney Tubules, Proximal
;
drug effects
;
Lipid Peroxidation
;
drug effects
;
Malondialdehyde
;
metabolism
;
Mass Spectrometry
;
Mitochondria
;
drug effects
;
Oxygen Consumption
;
drug effects
;
Protective Agents
;
chemistry
;
pharmacology
;
Quercetin
;
analogs & derivatives
;
pharmacology
;
Rutin
;
pharmacology
2.Trigeminal purinergic P2X4 receptor involved in experimental occlusal interference-induced hyperalgesia in rat masseter muscle.
Xiaoxiang XU ; Ye CAO ; Tingting DING ; Kaiyuan FU ; Qiufei XIE
Chinese Journal of Stomatology 2016;51(3):176-181
OBJECTIVETo explore the expression of purinergic p2X4 receptor (P2X4R) in trigeminal ganglion of rats after occlusal interference. Investigation of peripheral receptor mechanism of occlusal interference-induced masticatory muscle pain will aid the development of drug intervention against this condition.
METHODSExperimental occlusal interference was established by application of 0.4 mm metal crown to the upper right first molar of male Sprague-Dawley rats. Real-time PCR assay was used to investigate P2X4R mRNA level in trigeminal ganglion in rats with occlusal interference for 3, 7, 10 and 14 days and in control rats without occlusal interference (n=5 in each). Retrograde labelling combining immunofluorescence was performed to evaluate the percentage of P2X4R-positive cells in masseter afferent neurons (n=5 in each group). Graded concentrations of P2XR antagonist TNP-ATP (0.1, 10, 125, 250, 500 μmol/L) or saline (n=5 in each group) was administrated in right masseter and the mechanical sensitivity of bilateral masseters was measured before occlusal interference application, before the injection, and 30 min as well as 60 min after the injection.
RESULTSCompared with control rats (P2X4R mRNA: right side: 1.00±0.26, left side: 0.94± 0.21; percentage of P2X4R-positive masseter afferents: right side: [64.3±6.3]%, left side: [67.7±5.8]%), the level of P2X4R mRNA in bilateral trigeminal ganglia (right side: 5.98±3.56; left side: 5.06±2.88) of rats with occlusal interference for 7 days up-regulated (P<0.01) and the percentage of P2X4R-positive masseter afferent neurons(right side: [81.7±1.5]%; left side: [82.9±2.3]%) increased (P<0.05). Local administration of 10, 125, 250, 500 μmol/L TNP-ATP increased the mechanical withdrawal threshold in masseter 30 min after injection, compared with those before injection (P<0.05).
CONCLUSIONSIncreased expression of trigeminal P2X4R involves in the development of occlusal interference-induced masseter hyperalgesia.
Adenosine Triphosphate ; administration & dosage ; analogs & derivatives ; pharmacology ; Animals ; Dental Occlusion ; Hyperalgesia ; etiology ; Male ; Masseter Muscle ; drug effects ; Masticatory Muscles ; Purinergic P2X Receptor Antagonists ; administration & dosage ; pharmacology ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Receptors, Purinergic P2X4 ; genetics ; metabolism ; Time Factors ; Trigeminal Ganglion ; metabolism
3.ATP-Based Chemotherapy Response Assay in Primary or Recurrent Ovarian and Peritoneal Cancer.
Maria LEE ; Sang Wun KIM ; Eun Ji NAM ; Hanbyoul CHO ; Jae Hoon KIM ; Young Tae KIM ; Sunghoon KIM
Yonsei Medical Journal 2014;55(6):1664-1671
PURPOSE: To investigate chemosensitivity with an adenosine triphosphate-based chemotherapy response assay in patients with epithelial ovarian or peritoneal cancer according to tumor histology, grade, and disease status. MATERIALS AND METHODS: One hundred specimens were collected during primary or secondary debulking from 67 patients with primary ovarian cancer, 24 patients with recurrent ovarian cancer, 5 patients with primary peritoneal cancer, and 4 patients with recurrent peritoneal cancer; samples were collected between August 2006 and June 2009. Tumor cells were isolated and cultured for 48 hours in media containing chemotherapy. The chemosensitivity index (CI) was calculated as 300 minus the sum of the cell death rate at 0.2x, 1x, and 5x drug concentrations, and the CI values were compared. RESULTS: CI values were obtained from 93 of 100 patients. The most active agents against primary disease were ifosfamide and paclitaxel. For primary serous adenocarcinoma, paclitaxel and irinotecan were the most active, followed by ifosfamide. For clear cell carcinoma, ifosfamide was the most active, followed by paclitaxel and irinotecan. Although not statistically significant, the CIs of cisplatin, carboplatin, paclitaxel, and docetaxel decreased as tumor grade increased. In 14 cases of recurrent disease, paclitaxel was the most active, followed by ifosfamide and cisplatin. CONCLUSION: Ifosfamide and paclitaxel were the most active drugs for primary and recurrent disease. Therefore, we recommend further clinical studies to confirm the efficacy of paclitaxel, ifosfamide, and cisplatin combination chemotherapy for recurrent and primary ovarian cancer.
Adenocarcinoma, Clear Cell/*drug therapy/metabolism/pathology
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Adenosine Triphosphate/*metabolism
;
Adult
;
Aged
;
Antineoplastic Combined Chemotherapy Protocols/*therapeutic use
;
Camptothecin/administration & dosage/analogs & derivatives
;
Carboplatin/therapeutic use
;
Cisplatin/administration & dosage
;
Drug Resistance, Neoplasm
;
Drug Screening Assays, Antitumor/methods
;
Female
;
Humans
;
Ifosfamide/administration & dosage
;
Middle Aged
;
Neoplasm Recurrence, Local/*drug therapy
;
Neoplasms, Glandular and Epithelial/*drug therapy/metabolism/pathology
;
Ovarian Neoplasms/*drug therapy/metabolism/pathology
;
Paclitaxel/therapeutic use
;
Peritoneal Neoplasms/*drug therapy/metabolism/pathology
;
Predictive Value of Tests
;
Sensitivity and Specificity
;
Taxoids/administration & dosage
4.Effect of electroacupuncture on the pathomorphology of the sciatic nerve and the sensitization of P2X₃ receptors in the dorsal root ganglion in rats with chronic constrictive injury.
Rui-Dong CHENG ; Wen-Zhan TU ; Wan-Sheng WANG ; En-Mao ZOU ; Fen CAO ; Bo CHENG ; Jie-Zhi WANG ; Yong-Xia JIANG ; Song-He JIANG
Chinese journal of integrative medicine 2013;19(5):374-379
OBJECTIVETo explore the effect of electroacupuncture (EA) on the pathomorphology of the sciatic nerve and the role of P2X3 receptors in EA analgesia.
METHODSThe chronic constriction injury (CCI) model was adopted in this study. A total of 32 rats were randomly divided into four groups: sham CCI, CCI, CCI plus contralateral EA (CCI + conEA) and CCI plus ipsilateral EA (CCI + ipsEA). Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured. EA began at day 7 after the CCI operation and was applied to the Zusanli (ST 36) and Yanglingquan acupoints (GB 34). At day 14, the pathomorphologic changes of the operated sciatic nerve were demonstrated by hematoxylin and eosin staining. In addition, dorsal root ganglion (DRG) neurons isolated from rats were examined by electrophysiological recording to determine if the P2X3 receptor agonists, adenosine 5'-triphosphate disodium (ATP) and α,β-methylen-ATP (α,β-meATP) evoked inward currents.
RESULTSPain thresholds in the CCI group were obviously decreased post CCI surgery (P<0.01). In the EA groups, thermal and mechanical threshold values were increased after the last EA treatment (P<0.05, P<0.01). There was no significant difference in light microscopic examination among the four groups (P>0.05). Current amplitude after application of ATP and α,β-meATP in DRG neurons were much larger in the CCI group compared to those obtained in sham CCI (P<0.05). ATP and α, β-meATP invoked amplitudes in the CCI + EA groups were reduced. There was no signififi cant difference between the CCI + conEA group and the CCI + ipsEA group (P>0.05).
CONCLUSIONEA analgesia may be mediated by decreasing the response of P2X3 receptors to the agonists ATP and α,β-meATP in the DRG of rats with CCI. No pathological changes of the sciatic nerve of rats were observed after EA treatment.
Adenosine Triphosphate ; analogs & derivatives ; pharmacology ; Animals ; Constriction, Pathologic ; Electroacupuncture ; Ganglia, Spinal ; drug effects ; metabolism ; pathology ; Hyperalgesia ; pathology ; Ion Channel Gating ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Reaction Time ; drug effects ; Receptors, Purinergic P2X3 ; metabolism ; Sciatic Nerve ; injuries ; metabolism ; pathology ; Staining and Labeling
5.Application of ATP-tumor chemosensitivity assay in recurrent epithelial ovarian cancer.
Dan ZHAO ; Ling-ying WU ; Xiao-guang LI ; Xiao-bing WANG ; Mo LI ; Yan-fen LI ; Hai-mei TIAN ; Pei-pei SONG ; Jing LIU ; Qing-yun CHANG ; Wei ZHANG
Chinese Journal of Oncology 2010;32(11):855-858
OBJECTIVETo explore the value of adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA) in individualized treatment of recurrent epithelial ovarian cancer (REOC), and to evaluate the correlation between the in vitro chemosensitivity assay and clinical drug sensitivity.
METHODSSixty-nine REOC specimens were tested by ATP-TCA assay retrospectively. The patients were divided into strong sensitive, moderate sensitively and resistant groups according to the ATP-TCA assay results. The clinical results were evaluated according to imaging and serum CA125 analysis. The correlation between in vitro ATP-TCA assay and clinical outcome was statistically analyzed by χ(2) test. The progression free survival (PFS) and overall survival (OS) of each group were analyzed using Kaplan-Meier method.
RESULTSThe results of ATP-TCA assay had significant correlation with clinical outcome. The clinical chemotherapy outcome became better with increased drug sensitivity in vitro (χ(2) = 9.066, P = 0.004). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate for ATP-TCA method to predict the clinical chemotherapy sensitivity of REOC were 87.5%, 45.9%, 58.3%, 80.9% and 65.2%, respectively. The mean PFS of strong sensitive group, moderately sensitive group and resistant group were 187.1 days, 195.0 days and 60.3 days, respectively. The mean OS were 476.7, 335.7 and 237.5 days, respectively, following the start of TCA-directed therapy. The PFS and OS of the two sensitivity groups in vitro were significantly longer than that of the in vitro-resistant group (P < 0.01).
CONCLUSIONThe results of ATP-TCA assay are well correlated with clinical treatment responses. The assay may be an important and useful method for individualized chemotherapy for recurrent ovarian cancer.
Adenosine Triphosphate ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; CA-125 Antigen ; blood ; Carcinoma, Endometrioid ; blood ; drug therapy ; metabolism ; Cystadenocarcinoma, Serous ; blood ; drug therapy ; metabolism ; Deoxycytidine ; administration & dosage ; analogs & derivatives ; Disease-Free Survival ; Doxorubicin ; administration & dosage ; Drug Resistance, Neoplasm ; Drug Screening Assays, Antitumor ; methods ; Etoposide ; administration & dosage ; Female ; Follow-Up Studies ; Humans ; Luminescent Measurements ; Neoplasm Recurrence, Local ; Ovarian Neoplasms ; blood ; drug therapy ; metabolism ; Paclitaxel ; administration & dosage ; Predictive Value of Tests ; Retrospective Studies ; Sensitivity and Specificity ; Survival Rate ; Topotecan ; administration & dosage
6.Pharmacological characteristics of contractile responses regulated by P2Y receptors in circular smooth muscle of the rat gastric body.
Acta Pharmaceutica Sinica 2009;44(5):473-479
This study is to observe the difference in pharmacological characteristics between circular smooth muscles of rat isolated gastric body and gastric fundus, and to investigate the effects of nucleoside and nucleotide on circular smooth muscle of the rat gastric body and the involved receptors. Circular muscle strips of the rat gastric body and gastric fundus were prepared, and contractile responses to agonists were investigated with a technique of drug-receptor interaction in functional system. There was no significant difference between the circular muscle strips of the gastric body and gastric fundus in the responses to KCl, and no difference in EC50 values of contractile responses for 5-HT and His between the two kinds of preparations (P > 0.05). However, Emax values of contractile responses to 5-HT and His [(0.81 +/- 0.26) and (0.88 +/- 0.27) g] in gastric body were significantly smaller than those in gastric fundus [(2.67 +/- 0.61) and (1.90 +/- 0.68) g, P < 0.01], and EC50 value of CCh produced contractile response [(0.45 +/- 0.15) micromol x L(-1)] in gastric body was significantly higher than that in gastric fundus [(0.20 +/- 0.09) micromol x L(-1), P < 0.01]. In precontracted circular muscle strips of the gastric body, ATP (0.1-3000 micromol x L(-1)) produced only a contractile response concentration-dependently, but the same concentration of ATP induced a biphasic response (relaxation followed by a contraction) in precontracted circular muscle strips of the gastric fundus. ATP, UTP, ADP, 2-MeSATP and alpha,beta-MeATP produced contractile responses concentration-dependently in circular muscle strips of the rat gastric body. The EC50 value for 2-MeSATP [(7.2 +/- 5.2) nmol x L(-1)] was about 500 times lower than that for Ach [(3.47 +/- 1.20) micromol x L(-1)]. The rank order of potency for the contraction was 2-MeSATP>ADP>ATP=UTP>alpha,beta-MeATP>adenosine. The contractile responses to ATP and UTP were not significantly affected by phentolamine, propranolol, atropine or tetrodotoxin. In conclusion, there is a significant difference in pharmacological characteristics between the circular smooth muscles of the rat gastric body and gastric fundus and nucleotides might be important mediators responsible for the contraction via a specific P2Y receptor in circular smooth muscle of the rat gastric body.
Adenosine
;
pharmacology
;
Adenosine Diphosphate
;
pharmacology
;
Adenosine Triphosphate
;
analogs & derivatives
;
pharmacology
;
Animals
;
Gastric Fundus
;
drug effects
;
physiology
;
Male
;
Muscle Contraction
;
drug effects
;
Muscle, Smooth
;
drug effects
;
physiology
;
Purinergic P2 Receptor Agonists
;
Rats
;
Rats, Wistar
;
Receptors, Purinergic P2
;
drug effects
;
Stomach
;
drug effects
;
physiology
;
Thionucleotides
;
pharmacology
;
Uridine Triphosphate
;
pharmacology
7.Complete Remission of Unresectable Colon Cancer after Preoperative Chemotherapy Selected by Adenosine Triphosphate-Based Chemotherapy Response Assay.
Jung Wook HUH ; Yoon Ahn PARK ; Eun Joo JUNG ; Kang Young LEE ; Ji Eun KWON ; Seung Kook SOHN
Journal of Korean Medical Science 2008;23(5):916-919
The adenosine triphosphate-based chemotherapy response assay (ATP-CRA) is a chemosensitivity test that offers the potential of selecting cancer treatments based on the responsiveness of individual tumors. We report a case of 47-yr-old male, presented with sigmoid colon cancer with multiple liver and peritoneal metastases, in which there was a complete response for the primary colon cancer after administration of preoperative chemotherapy selected by ATP-CRA. Oxaliplatin was the most sensitive drug based on the ATP-CRA where the specimen obtained by ultrasound- guided percutaneous liver biopsy was used. After twelve cycles of oxaliplatincapecitabine chemotherapy, abdominopelvic computed tomography revealed marked shrinkage of the liver metastases and positron emission tomography showed no uptake of (18)F-fluoro-deoxy-glucose (FDG) either in the liver or peritoneum except localized uptake in the sigmoid colon. The patient underwent an anterior resection and radiofrequency ablation of the liver metastases, which resulted in a macroscopic curative resection of the cancer cells. Histological examination revealed no residual cancer cells in the resected specimen of the sigmoid colon. This result suggested that preoperative chemotherapy chosen by ATP-CRA may be useful for treating advanced colon cancer with unresectable liver and peritoneal metastases.
Adenosine Triphosphate/*metabolism
;
Antineoplastic Agents/*pharmacology
;
Antineoplastic Combined Chemotherapy Protocols/therapeutic use
;
Colonic Neoplasms/*diagnosis/*drug therapy
;
Deoxycytidine/administration & dosage/analogs & derivatives
;
Fluorouracil/administration & dosage/analogs & derivatives
;
Humans
;
Liver Neoplasms/drug therapy/secondary
;
Male
;
Medical Oncology/methods
;
Middle Aged
;
Neoplasm Metastasis
;
Organoplatinum Compounds/administration & dosage
;
Positron-Emission Tomography
;
Remission Induction
;
Treatment Outcome
8.Cross talk between P2 purinergic receptors modulates extracellular ATP-mediated interleukin-10 production in rat microglial cells.
Dong Reoyl SEO ; Soo Yoon KIM ; Kyung You KIM ; Hwan Goo LEE ; Ju Hyun MOON ; Jae Souk LEE ; Se Hoon LEE ; Seung U KIM ; Yong Beom LEE
Experimental & Molecular Medicine 2008;40(1):19-26
Previously we demonstrated that ATP released from LPS-activated microglia induced IL-10 expression in a process involving P2 receptors, in an autocrine fashion. Therefore, in the present study we sought to determine which subtype of P2 receptor was responsible for the modulation of IL-10 expression in ATP-stimulated microglia. We found that the patterns of IL-10 production were dose-dependent (1, 10, 100, 1,000 micrometer) and bell-shaped. The concentrations of ATP, ATP-gammaS, ADP, and ADP-beta S that showed maximal IL-10 release were 100, 10, 100, and 100 micrometer respectively. The rank order of agonist potency for IL-10 production was 2'-3'-O-(4-benzoyl)-benzoyl ATP (BzATP) = dATP > 2-methylthio-ADP (2-meSADP). On the other hand, 2-methylthio-ATP (2-meSATP), alpha,beta-methylene ATP (alpha,beta-meATP), UTP, and UDP did not induce the release of IL-10 from microglia. Further, we obtained evidence of crosstalk between P2 receptors, in a situation where intracellular Ca2+ release and/or cAMP-activated PKA were the main contributors to extracellular ATP-(or ADP)-mediated IL-10 expression, and IL-10 production was down- regulated by either MRS2179 (a P2Y1 antagonist) or 5'-AMPS (a P2Y11 antagonist), indicating that both the P2Y1 and P2Y11 receptors are major receptors involved in IL-10 expression. In addition, we found that inhibition of IL-10 production by high concentrations of ATP-gammaS (100 micrometer) was restored by TNP-ATP (an antagonist of the P2X1, P2X3, and P2X4 receptors), and that IL-10 production by 2-meSADP was restored by 2meSAMP (a P2Y12 receptor antagonist) or pertusis toxin (PTX; a Gi protein inhibitor), indicating that the P2X1, P2X3, P2X4 receptor group, or the P2Y12 receptor, negatively modulate the P2Y11 receptor or the P2Y1 receptor, respectively.
Adenosine Diphosphate/analogs & derivatives/pharmacology
;
Adenosine Triphosphate/analogs & derivatives/*pharmacology
;
Adenylate Cyclase/antagonists & inhibitors
;
Animals
;
Calcium/metabolism
;
Chelating Agents/pharmacology
;
Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors
;
Enzyme Inhibitors/pharmacology
;
Extracellular Space/drug effects/*metabolism
;
Gene Expression Regulation/drug effects
;
Interleukin-10/*biosynthesis
;
Microglia/*drug effects/enzymology/*metabolism
;
RNA, Messenger/genetics/metabolism
;
Rats
;
Rats, Sprague-Dawley
;
Receptor Cross-Talk/*drug effects
;
Receptors, Purinergic P2/agonists/antagonists & inhibitors/genetics/*metabolism
;
Thionucleotides/pharmacology
9.Activation of nicotinic acetylcholine receptor prevents the production of reactive oxygen species in fibrillar beta amyloid peptide (1-42)-stimulated microglia.
Ju Hyun MOON ; Soo Yoon KIM ; Hwan Goo LEE ; Seung U KIM ; Yong Beom LEE
Experimental & Molecular Medicine 2008;40(1):11-18
Recent studies have reported that the "cholinergic anti-inflammatory pathway" regulates peripheral inflammatory responses via alpha7 nicotinic acetylcholine receptors (alpha7 nAChRs) and that acetylcholine and nicotine regulate the expression of proinflammatory mediators such as TNF-alpha and prostaglandin E2 in microglial cultures. In a previous study we showed that ATP released by beta-amyloid-stimulated microglia induced reactive oxygen species (ROS) production, in a process involving the P2X7 receptor (P2X7R), in an autocrine fashion. These observations led us to investigate whether stimulation by nicotine could regulate fibrillar beta amyloid peptide (1-42) (fA beta(1-42))-induced ROS production by modulating ATP efflux-mediated Ca2+ influx through P2X7R. Nicotine inhibited ROS generation in fA beta(1-42)-stimulated microglial cells, and this inhibition was blocked by mecamylamine, a non-selective nAChR antagonist, and a-bungarotoxin, a selective alpha7 nAChR antagonist. Nicotine inhibited NADPH oxidase activation and completely blocked Ca2+ influx in fA beta(1-42)-stimulated microglia. Moreover, ATP release from fA beta(1-42)-stimulated microglia was significantly suppressed by nicotine treatment. In contrast, nicotine did not inhibit 2',3'-O-(4-benzoyl)-benzoyl ATP (BzATP)-induced Ca2+ influx, but inhibited ROS generation in BzATP-stimulated microglia, indicating an inhibitory effect of nicotine on a signaling process downstream of P2X7R. Taken together, these results suggest that the inhibitory effect of nicotine on ROS production in fA beta(1-42)-stimulated microglia is mediated by indirect blockage of ATP release and by directly altering the signaling process downstream from P2X7R.
Adenosine Triphosphate/analogs & derivatives/metabolism/pharmacology
;
Amyloid/*metabolism
;
Amyloid beta-Protein/*pharmacology
;
Animals
;
Calcium/metabolism
;
Enzyme Activation/drug effects
;
Microglia/cytology/*drug effects/enzymology/*metabolism
;
NADPH Oxidase/metabolism
;
Nicotine/pharmacology
;
Nicotinic Antagonists/pharmacology
;
Peptide Fragments/*pharmacology
;
Rats
;
Rats, Sprague-Dawley
;
Reactive Oxygen Species/*metabolism
;
Receptors, Nicotinic/*metabolism
;
Receptors, Purinergic P2/metabolism
10.ATP released from beta-amyloid-stimulated microglia induces reactive oxygen species production in an autocrine fashion.
Soo Yoon KIM ; Ju Hyun MOON ; Hwan Goo LEE ; Seung Up KIM ; Yong Beom LEE
Experimental & Molecular Medicine 2007;39(6):820-827
Present study demonstrated that fibrillar beta-amyloid peptide (fAbeta(1-42)) induced ATP release, which in turn activated NADPH oxidase via the P2X(7) receptor (P2X(7)R). Reactive oxygen species (ROS) production in fAbeta(1-42)-treated microglia appeared to require Ca2+ influx from extracellular sources, because ROS generation was abolished to control levels in the absence of extracellular Ca2+. Considering previous observation of superoxide generation by Ca2+ influx through P2X(7)R in microglia, we hypothesized that ROS production in fAbeta-stimulated microglia might be mediated by ATP released from the microglia. We therefore examined whether fAbeta(1-42)-induced Ca2+ influx was mediated through P2X(7)R activation. In serial experiments, we found that microglial pretreatment with the P2X(7)R antagonists Pyridoxal-phosphate-6-azophenyl-2',4'- disulfonate (100 micrometer) or oxidized ATP (100 micrometer) inhibited fAbeta-induced Ca2+ influx and reduced ROS generation to basal levels. Furthermore, ATP efflux from fAbeta(1-42)-stimulated microglia was observed, and apyrase treatment decreased the generation of ROS. These findings provide conclusive evidence that fAbeta-stimulated ROS generation in microglial cells is regulated by ATP released from the microglia in an autocrine manner.
Adenosine Triphosphate/*metabolism
;
Amyloid beta-Protein/*pharmacology
;
Animals
;
Autocrine Communication/*drug effects/physiology
;
Cells, Cultured
;
Microglia/*drug effects
;
Peptide Fragments/*pharmacology
;
Pyridoxal Phosphate/analogs & derivatives/metabolism
;
Rats
;
Rats, Sprague-Dawley
;
Reactive Oxygen Species/*metabolism
;
Receptors, Purinergic P2/physiology

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