Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the e...Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the effects of TCDD on astrocytes proliferation and underlying molecular mechanism. Methods The cell proliferation was measured by EdU-based proliferation assay and PI staining by flow cytometry. Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of signal transducer and activator of transcription 3(STAT3). Results C6 cells treated with 10 and 50 nmol/L TCDD for 24 h showed significant promotion of the proliferation of. The exposure to TCDD resulted in the upregulation in the expression levels of phosphorylated protein kinase B(p-Akt), phosphorylated STAT3, and cyclin D1 in a dose-and time-dependent manner. The inhibition of Akt expression with LY294002 or STAT3 expression with AG490 abolished the TCDD-induced cyclin D1 upregulation and cell proliferation. Furthermore, LY294002 suppressed the activation of STAT3. Finally, TCDD promoted the translocation of STAT3 from the cytoplasm to the nucleus, and LY294002 treatment blocked this effect. Conclusion TCDD exposure promotes the proliferation of astrocyte cells via the Akt/STAT3/cyclin D1 pathway, leading to astrogliosis.展开更多
Objective Antimony(Sb)has recently been identified as a novel nerve poison,although the cellular and molecular mechanisms underlying its neurotoxicity remain unclear.This study aimed to assess the effects of the nucle...Objective Antimony(Sb)has recently been identified as a novel nerve poison,although the cellular and molecular mechanisms underlying its neurotoxicity remain unclear.This study aimed to assess the effects of the nuclear factor kappa B(NF-κB)signaling pathway on antimony-induced astrocyte activation.Methods Protein expression levels were detected by Western blotting.Immunofluorescence,cytoplasmic and nuclear fractions separation were used to assess the distribution of p65.The expression of protein in brain tissue sections was detected by immunohistochemistry.The levels of mRNAs were detected by Quantitative real-time polymerase chain reaction(qRT-PCR)and reverse transcriptionpolymerase chain reaction(RT-PCR).Results Antimony exposure triggered astrocyte proliferation and increased the expression of two critical protein markers of reactive astrogliosis,inducible nitric oxide synthase(iNOS)and glial fibrillary acidic protein(GFAP),indicating that antimony induced astrocyte activation in vivo and in vitro.Antimony exposure consistently upregulated the expression of inflammatory factors.Moreover,it induced the NF-κB signaling,indicated by increased p65 phosphorylation and translocation to the nucleus.NF-κB inhibition effectively attenuated antimony-induced astrocyte activation.Furthermore,antimony phosphorylated TGF-β-activated kinase 1(TAK1),while TAK1 inhibition alleviated antimonyinduced p65 phosphorylation and subsequent astrocyte activation.Conclusion Antimony activated astrocytes by activating the NF-κB signaling pathway.展开更多
Objective This study aimed to investigate the susceptibility of mice with streptozotocin(STZ)-induced diabetes mellitus(TIDM) to the uptake of pentavalent inorganic arsenic(iAs^V) and the possible molecular mechanism....Objective This study aimed to investigate the susceptibility of mice with streptozotocin(STZ)-induced diabetes mellitus(TIDM) to the uptake of pentavalent inorganic arsenic(iAs^V) and the possible molecular mechanism. Methods TIDM was induced in mice by STZ. TIDM and normal mice were treated with 15.0 mg/kg Na_2HAsO_4·12H_2O by intragastric administration. Then, the concentrations of arsenic in various tissues were measured by atomic fluorescence spectrometry. The gene expression levels of Pit1 and Pit2 were quantified by real-time RT-PCR, and their protein levels were detected by Western blotting in mouse heart, kidney, and liver tissues. Results The concentrations of arsenic in STZ-induced TIDM mouse tissues were higher at 2 h after intragastric administration of Na_2HAsO_4·12H_2O. Compared with the levels in normal mice, PIT1 and PIT2, which play a role in the uptake of iAs^V, were upregulated in the livers and hearts of TIDM mice. PIT1 but not PIT2 was higher in TIDM mouse kidneys. The upregulation of Pit1 and Pit2 expression could be reversed by insulin treatment. Conclusion The increased uptake of iAs^V in TIDM mouse tissues may be associated with increased PIT1 and/or PIT2 expression.展开更多
基金supported by the National Natural Science Foundation of China [No.21477058,81703255]Nantong Jiangsu scientific research project [MS12017014-8]
文摘Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the effects of TCDD on astrocytes proliferation and underlying molecular mechanism. Methods The cell proliferation was measured by EdU-based proliferation assay and PI staining by flow cytometry. Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of signal transducer and activator of transcription 3(STAT3). Results C6 cells treated with 10 and 50 nmol/L TCDD for 24 h showed significant promotion of the proliferation of. The exposure to TCDD resulted in the upregulation in the expression levels of phosphorylated protein kinase B(p-Akt), phosphorylated STAT3, and cyclin D1 in a dose-and time-dependent manner. The inhibition of Akt expression with LY294002 or STAT3 expression with AG490 abolished the TCDD-induced cyclin D1 upregulation and cell proliferation. Furthermore, LY294002 suppressed the activation of STAT3. Finally, TCDD promoted the translocation of STAT3 from the cytoplasm to the nucleus, and LY294002 treatment blocked this effect. Conclusion TCDD exposure promotes the proliferation of astrocyte cells via the Akt/STAT3/cyclin D1 pathway, leading to astrogliosis.
基金supported by the National Natural Science Foundation of China[21477058,81703255]Scientific Research Project of Nantong of Jiangsu[JC2019027,JC2019137]+2 种基金the Qing Lan Project for Excellent Young Key Teachers of Colleges and Universities of Jiangsu Province(2020)the Postgraduate Research&Practice Innovation Program of Jiangsu Province[KYCX20_2854]Large Instruments Open Foundation of Nantong University[KFJN2054]。
文摘Objective Antimony(Sb)has recently been identified as a novel nerve poison,although the cellular and molecular mechanisms underlying its neurotoxicity remain unclear.This study aimed to assess the effects of the nuclear factor kappa B(NF-κB)signaling pathway on antimony-induced astrocyte activation.Methods Protein expression levels were detected by Western blotting.Immunofluorescence,cytoplasmic and nuclear fractions separation were used to assess the distribution of p65.The expression of protein in brain tissue sections was detected by immunohistochemistry.The levels of mRNAs were detected by Quantitative real-time polymerase chain reaction(qRT-PCR)and reverse transcriptionpolymerase chain reaction(RT-PCR).Results Antimony exposure triggered astrocyte proliferation and increased the expression of two critical protein markers of reactive astrogliosis,inducible nitric oxide synthase(iNOS)and glial fibrillary acidic protein(GFAP),indicating that antimony induced astrocyte activation in vivo and in vitro.Antimony exposure consistently upregulated the expression of inflammatory factors.Moreover,it induced the NF-κB signaling,indicated by increased p65 phosphorylation and translocation to the nucleus.NF-κB inhibition effectively attenuated antimony-induced astrocyte activation.Furthermore,antimony phosphorylated TGF-β-activated kinase 1(TAK1),while TAK1 inhibition alleviated antimonyinduced p65 phosphorylation and subsequent astrocyte activation.Conclusion Antimony activated astrocytes by activating the NF-κB signaling pathway.
基金supported by the National Natural Science Foundation of China[grant numbers 21277078,21407082]the Natural Science Foundation of Jiangsu Province[grant numbers BK20140426]+1 种基金the Natural Science Fund Project of Colleges in Jiangsu Province[grant numbers 16KJB330007]the National Undergraduate Innovation Experiment Project[grant numbers 201510304037Z]
文摘Objective This study aimed to investigate the susceptibility of mice with streptozotocin(STZ)-induced diabetes mellitus(TIDM) to the uptake of pentavalent inorganic arsenic(iAs^V) and the possible molecular mechanism. Methods TIDM was induced in mice by STZ. TIDM and normal mice were treated with 15.0 mg/kg Na_2HAsO_4·12H_2O by intragastric administration. Then, the concentrations of arsenic in various tissues were measured by atomic fluorescence spectrometry. The gene expression levels of Pit1 and Pit2 were quantified by real-time RT-PCR, and their protein levels were detected by Western blotting in mouse heart, kidney, and liver tissues. Results The concentrations of arsenic in STZ-induced TIDM mouse tissues were higher at 2 h after intragastric administration of Na_2HAsO_4·12H_2O. Compared with the levels in normal mice, PIT1 and PIT2, which play a role in the uptake of iAs^V, were upregulated in the livers and hearts of TIDM mice. PIT1 but not PIT2 was higher in TIDM mouse kidneys. The upregulation of Pit1 and Pit2 expression could be reversed by insulin treatment. Conclusion The increased uptake of iAs^V in TIDM mouse tissues may be associated with increased PIT1 and/or PIT2 expression.
