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AIM:To investigate the neuroprotective effect of progesterone against adenosine triphosphate (ATP)-injured human neuroblastoma SH-SY5Y cells.METHODS:The SH-SY5Y cells in the logarithmic phase were divided into different groups according to the progesterone and ATP concentrations.The cell viability was measured by CCK-8 assay.The membrane permeability was detected using fluorescent dye YO-PRO-1.Cytosolic Ca2+ concentration was measured with fluorescent dye Fluo-3/AM.The expression of purinergic P2X7 receptor was assessed by Western blot.RESULTS:The viability of the SH-SY5Y cells was significantly decreased (P ＜ 0.05) and YO-PRO-1 uptake was obviously increased (P ＜ 0.05) in a concentration-dependent manner compared with control group when SH-SY5Y cells were treated with ATP at 1,3,5 and 7 mmol/L for 2 h.The viability reduction of the SH-SY5Y cells induced by ATP was obviously counteracted by treatment with progesterone at 3,10 and 30 nmol/L for 30 min (P ＜ 0.05) as compared with ATP group.YO-PRO-1 fluorescence enhancement induced by ATP in SH-SY5Y cells was significantly reduced (P ＜ 0.05) by progesterone (30 nmol/L) or P2X7 receptor antagonist KN-62 (500 nmol/L) pretreatment for 30 min,and no obvious difference between treatments with progesterone and KN-62 was observed.Cytosolic Ca2+ fluorescence intensity in normal group was a little,but that in ATP group was increased (P ＜ 0.05).Progesterone or KN-62 pretreatment significantly decreased the cytosolic fluorescence intensity of Ca2+ induced by ATP (P ＜ 0.05).However,no obvious difference between treatments with progesterone and KN-62 was found.The expression of P2X7 receptor in ATP group was significantly higher than that in control group (P ＜ 0.05),and progesterone inhibited ATP-induced P2X7 receptor expression (P ＜ 0.05).CONCLUSION:Progesterone inhibits P2X7 receptor expression,membrane pore formation,intracellular Ca2+ increase and cell death induced by ATP,so progesterone may protect SH-SY5Y cells against ATP-induced injuries.
ABSTRACT
AIM:To investigate the neuroprotective effect of progesterone against adenosine triphosphate (ATP)-injured human neuroblastoma SH-SY5Y cells.METHODS:The SH-SY5Y cells in the logarithmic phase were divided into different groups according to the progesterone and ATP concentrations.The cell viability was measured by CCK-8 assay.The membrane permeability was detected using fluorescent dye YO-PRO-1.Cytosolic Ca2+ concentration was measured with fluorescent dye Fluo-3/AM.The expression of purinergic P2X7 receptor was assessed by Western blot.RESULTS:The viability of the SH-SY5Y cells was significantly decreased (P ＜ 0.05) and YO-PRO-1 uptake was obviously increased (P ＜ 0.05) in a concentration-dependent manner compared with control group when SH-SY5Y cells were treated with ATP at 1,3,5 and 7 mmol/L for 2 h.The viability reduction of the SH-SY5Y cells induced by ATP was obviously counteracted by treatment with progesterone at 3,10 and 30 nmol/L for 30 min (P ＜ 0.05) as compared with ATP group.YO-PRO-1 fluorescence enhancement induced by ATP in SH-SY5Y cells was significantly reduced (P ＜ 0.05) by progesterone (30 nmol/L) or P2X7 receptor antagonist KN-62 (500 nmol/L) pretreatment for 30 min,and no obvious difference between treatments with progesterone and KN-62 was observed.Cytosolic Ca2+ fluorescence intensity in normal group was a little,but that in ATP group was increased (P ＜ 0.05).Progesterone or KN-62 pretreatment significantly decreased the cytosolic fluorescence intensity of Ca2+ induced by ATP (P ＜ 0.05).However,no obvious difference between treatments with progesterone and KN-62 was found.The expression of P2X7 receptor in ATP group was significantly higher than that in control group (P ＜ 0.05),and progesterone inhibited ATP-induced P2X7 receptor expression (P ＜ 0.05).CONCLUSION:Progesterone inhibits P2X7 receptor expression,membrane pore formation,intracellular Ca2+ increase and cell death induced by ATP,so progesterone may protect SH-SY5Y cells against ATP-induced injuries.
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Objective To investigate the role of purinergic 2X7 receptor (P2X7R) and its downstream target-NLRP3 inflammasome activation in the process of pancreatic fibrosis in a mouse model of chronic pancreatitis (CP). Methods Forty C57BL/6 mice were randomly divided into normal control group, CP group, P2X7R antagonist oxidized ATP (OxATP) group and brilliant blue G (BBG) group. The chronic pancreatitis model was induced by repeated intraperitoneal injection of the cholecystokinin analogue caerulein with the dose of 50μg/kg for six weeks. Normal saline, OxATP (20μL, 300μmol/L) or BBG (20μL, 10μmol/L) were administered for CP group, OxATP group and BBG group for two weeks after the last caerulein injection. Then all mice were sacrificed and the histopathological changes of the pancreas, especially the fibrotic degrees were evaluated by HE stain, fibrosis score, Sirius red staining and α-SMA immunohistochemical stain. The pancreatic P2X7R, NLRP3 and Caspase-1 expressions were detected by immunohistochemistry respectively to compare the changes between the groups, and explore the role of P2X7R-NLRP3 signaling pathway in pancreatic fibrosis. Results Compared with the normal control group, the scores of pancreatic fibrosis and the expressions of P2X7R, NLRP3 and Caspase-1 in pancreas were significantly increased in CP model group (P<0.05). Compare to CP group, the pancreatic chronic inflammation and the fibrosis indices such as HE fibrosis score, Sirius red staining and α-SMA immunohistochemical stain were ameliorated obviously in OxATP and BBG groups (P<0.05). And expressions of P2X7R, NLRP3 and Caspase-1 in the pancreas were allreduced greatly in both OxATP and BBG groups (P<0.05). Conclusion P2X7R antagonist OxATP and BBG can significantly decrease pancreatic chronic inflammation and fibrosis in the mouse model of CP, which suggests that the blockade of P 2X7R-NLRP3 inflammasome signaling pathway may represent a novel therapeutic strategy for CP and its fibrotic process.
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[ ABSTRACT] AIM:To prove the purinergic signaling mechanism of the neuroprotective action of hydrogen sulfide by observing the effects of sodium hydrosulfide ( NaHS) , a donor of hydrogen sulfide, on the cell viability, intracellular Ca2+concentration ( [ Ca2+] i ) and the change of membrane permeability in the PC12 cells injured by adenosine triphos-phate ( ATP) .METHODS: PC12 cells in logarithmic growth phase were randomly divided into 4 groups.In control group, the cells were cultured without ATP treatment.In ATP group, the cells were treated with ATP after cultured for 24 h.In NaHS+ATP group, the cells were incubated with NaHS for 30 min before treated with ATP, and NaHS always exis-ted in the reaction system.In KN-62+ATP group, the cells were pretreated with KN-62 for 30 min, and the other treat-ments were as the same as those in NaHS+ATP group.The cell viability was assessed by MTT assay.The [ Ca2+] i was detected by Fura-2/AM staining.The membrane permeability was observed by staining with fluorescent dye YO-PRO-1. RESULTS:ATP at concentration of 0.3 mmol/L showed no injury effect on the cells.However, the cell viability was dropped gradually in a dose-dependent manner as the ATP at doses of 1, 3, 5 and 10 mmol/L.The decline of cell viability by ATP was obviously reversed by 200 μmol/L of NaHS in the PC12 cells (P<0.05), but exasperated by 800μmol/L of NaHS (P<0.05).At the same time, ATP evoked the increase in [Ca2+]i in a dose-dependent manner, which was inhib-ited by NaHS ( P<0.05) .Furthermore, the YO-PRO-1 uptake induced by ATP in a dose-dependent and time-dependent manner was also reduced by NaHS ( P<0.05) .CONCLUSION:Hydrogen sulfide has protective effect on the PC12 cells injured by ATP.The mechanism may be related to the reverse of the increased [ Ca2+] i and YO-PRO-1 uptake.
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AIM:To investigate the formation of membrane pore in PC 12 cells induced by exogenous adenosine triphosphate ( ATP) and to identify the key molecular targets .METHODS:PC12 cells were treated with different concen-trations of ATP to establish the injury model .The morphological change was observed under an inverted phase -contrast mi-croscope.The viability of the PC12 cells was measured by CCK-8 assay.Fluorescent dye YO-PRO-1 was used to detect the membrane permeability.The expression of P2X7 receptor and pannexin 1 (Panx1) at mRNA and protein levels was as-sessed by real-time PCR and Western blotting .RESULTS:After exposed to ATP (1 mmol/L, 3 mmol/L and 5 mmol/L) for 3 h, the PC12 cells became edematous , and the number of adherent cells decreased gradually in a dose-dependent man-ner .The cell viabilities in 3 mmol/L ATP group and 5 mmol/L ATP group were significantly decreased compared with con-trol group (P0. 05).The expression of P2X7 receptor at mRNA and protein levels was significantly increased (P0.05) when PC12 cells were exposed to ATP for 3 h.CONCLUSION:Extracellular ATP at high concentration may induce membrane pore formation with the expression and activation of P 2X7 receptor in PC12 cells.