Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms...Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed woundhealing assay and Transwell? motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations(10^(-10) and/or 10^(-9) mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mR NA expression of two promigratory genes, including cell division cycle 42(CDC42) and matrix metalloproteinase 2(MMP2)was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor(AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.展开更多
Several cohort studies have reported that dioxin and dioxin-like polychlorinated biphenyls might impair the nervous system and lead to neurological or neurodegenerative diseases in the elder people, but there is limit...Several cohort studies have reported that dioxin and dioxin-like polychlorinated biphenyls might impair the nervous system and lead to neurological or neurodegenerative diseases in the elder people, but there is limited research on the involved mechanism. By using microarray analysis, we figured out the differentially expressed genes between brain samples from SD rats after low-dose（0.1 μg/（kg？bw）） dioxin exposure for six months and controls. To investigate the function changes in the course of dioxin exposure, Gene Ontology（GO） annotation and Kyoto Encyclopedia of Genes and Genomes（KEGG） pathway analysis were performed on the differentially expressed genes. And the changes of several picked genes have been verified by real-time PCR. A total of 145 up-regulated and 64 down-regulated genes were identified. The metabolic processes, interleukin-1 secretion and production were significantly associated with the differentially expressed genes. And the genes regulated by dioxin also clustered to cholinergic synapse and long-term potentiation. Candidate biomarker genes such as egr1, gad2, gabrb3, abca1, ccr5 and pycard may be toxicological targets for dioxin. Furthermore, synaptic plasticity and neuro-immune system may be two principal affected areas by dioxin.展开更多
Dioxin can cause a series of neural toxicological effects. Micro RNAs（mi Rs） play important roles in regulating nervous system function and mediating cellular responses to environmental pollutants, such as dioxin. H...Dioxin can cause a series of neural toxicological effects. Micro RNAs（mi Rs） play important roles in regulating nervous system function and mediating cellular responses to environmental pollutants, such as dioxin. Hsa-mi R-146 b-5 p appears to be involved in neurodegenerative diseases and brain tumors. However, little is known about effects of dioxin on the expression of hsa-mi R-146 b-5 p. We found that the hsa-mi R-146 b-5 p expression and its promoter activity were significantly increased in dioxin treated SK-N-SH cells, a human-derived neuroblastoma cell line. Potential roles of hsa-mi R-146 b-5 p in mediating neural toxicological effects of dioxin may be due to the regulation of certain target genes. We further confirmed that hsa-mi R-146 b-5 p significantly suppressed acetylcholinesterase（ACh E） activity and targeted the3′-untranslated region of the ACh E T subunit, which has been down-regulated in dioxin treated SK-N-SH cells. Functional bioinformatic analysis showed that the known and predicted target genes of hsa-mi R-146 b-5 p were involved in some brain functions or cyto-toxicities related to known dioxin effects, including synapse transmission, in which ACh E may serve as a responsive gene for mediating the effect.展开更多
Aryl hydrocarbon receptor（Ah R）, a ligand-dependent nuclear receptor, is involved in a diverse spectrum of biological and toxicological effects. Due to the lack of three dimensional（3D）crystal or nuclear magnetic ...Aryl hydrocarbon receptor（Ah R）, a ligand-dependent nuclear receptor, is involved in a diverse spectrum of biological and toxicological effects. Due to the lack of three dimensional（3D）crystal or nuclear magnetic resonance structure, the mechanisms of these complex effects of AhR remain to be unclear. Also, commercial monoclonal antibodies（mA bs） against human AhR protein（h Ah R）, as alternative immunological tools, are very limited. Thus, in order to provide more tools for further studies on h Ah R, we prepared two m Abs（1D6 and 4A6） against h Ah R. The two newly generated m Abs specifically bound to amino acids 484–508（located in transcription activation domain） and amino acids 201–215（located in Per-ARNT-Sim domain）of h Ah R, respectively. These epitopes were new as compared with those of commercial m Abs.The m Abs were also characterized by enzyme-linked immunosorbent assay, western blot,immunoprecipitation and indirect immunofluorescence assay in different cell lines. The results showed that the two m Abs could recognize the linearized AhR s in six different human cell lines and a rat hepatoma cell line, as well as the h Ah R with native conformations. We concluded that the newly generated m Abs could be employed in AhR-based bioassays for analysis of environmental contaminants, and held great potential for further revealing the spatial structure of AhR and its biological functions in future studies.展开更多
Extreme high temperatures in the summer have become a global concern,and their risks to the inflammatory system have been largely unknown.Here we appraised the exposure risks of summer heatwaves by comparing the sera ...Extreme high temperatures in the summer have become a global concern,and their risks to the inflammatory system have been largely unknown.Here we appraised the exposure risks of summer heatwaves by comparing the sera cytokine levels in healthy individuals under high and normal temperatures.In addition,we established a cell model with a 1.5°C temperature increase to investigate the regulatory mechanisms of temperature-related cytokines.Our results suggest that elevated temperatures enhance the release of interleukin-6(IL-6)and interleukin-8(IL-8)via the aryl hydrocarbon receptor(AhR)pathway and augment the proinflammatory effects of other factors.This suggests that we may have underestimated the impact of high temperatures on the health of individuals beyond just mortality rates.Moreover,seemingly minor temperature increases of just 1.5℃ can still pose a challenge to cells.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Nos.XDB14030401,XDB14030402)the Natural Science Foundation of China (Nos.21377160,21525730)Tianjin Municipal Science and Technology Commission (No.14JCQNJC11300)
文摘Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed woundhealing assay and Transwell? motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations(10^(-10) and/or 10^(-9) mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mR NA expression of two promigratory genes, including cell division cycle 42(CDC42) and matrix metalloproteinase 2(MMP2)was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor(AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.
基金supported by grants from the Natural Science Foundation of China(Nos.21407171,21377160,21525730)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB14030400)
文摘Several cohort studies have reported that dioxin and dioxin-like polychlorinated biphenyls might impair the nervous system and lead to neurological or neurodegenerative diseases in the elder people, but there is limited research on the involved mechanism. By using microarray analysis, we figured out the differentially expressed genes between brain samples from SD rats after low-dose（0.1 μg/（kg？bw）） dioxin exposure for six months and controls. To investigate the function changes in the course of dioxin exposure, Gene Ontology（GO） annotation and Kyoto Encyclopedia of Genes and Genomes（KEGG） pathway analysis were performed on the differentially expressed genes. And the changes of several picked genes have been verified by real-time PCR. A total of 145 up-regulated and 64 down-regulated genes were identified. The metabolic processes, interleukin-1 secretion and production were significantly associated with the differentially expressed genes. And the genes regulated by dioxin also clustered to cholinergic synapse and long-term potentiation. Candidate biomarker genes such as egr1, gad2, gabrb3, abca1, ccr5 and pycard may be toxicological targets for dioxin. Furthermore, synaptic plasticity and neuro-immune system may be two principal affected areas by dioxin.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB14030401,XDB14030402)the National Natural Science Foundation of China(Nos.21177150,21377160,21525730)
文摘Dioxin can cause a series of neural toxicological effects. Micro RNAs（mi Rs） play important roles in regulating nervous system function and mediating cellular responses to environmental pollutants, such as dioxin. Hsa-mi R-146 b-5 p appears to be involved in neurodegenerative diseases and brain tumors. However, little is known about effects of dioxin on the expression of hsa-mi R-146 b-5 p. We found that the hsa-mi R-146 b-5 p expression and its promoter activity were significantly increased in dioxin treated SK-N-SH cells, a human-derived neuroblastoma cell line. Potential roles of hsa-mi R-146 b-5 p in mediating neural toxicological effects of dioxin may be due to the regulation of certain target genes. We further confirmed that hsa-mi R-146 b-5 p significantly suppressed acetylcholinesterase（ACh E） activity and targeted the3′-untranslated region of the ACh E T subunit, which has been down-regulated in dioxin treated SK-N-SH cells. Functional bioinformatic analysis showed that the known and predicted target genes of hsa-mi R-146 b-5 p were involved in some brain functions or cyto-toxicities related to known dioxin effects, including synapse transmission, in which ACh E may serve as a responsive gene for mediating the effect.
基金supported by the National Natural Science Foundation of China (Nos. 21277168, 21525730)the Strategic Priority Research Program of the Chinese Academy of Sciences (Nos. XDB14030401, XDB14030402)
文摘Aryl hydrocarbon receptor（Ah R）, a ligand-dependent nuclear receptor, is involved in a diverse spectrum of biological and toxicological effects. Due to the lack of three dimensional（3D）crystal or nuclear magnetic resonance structure, the mechanisms of these complex effects of AhR remain to be unclear. Also, commercial monoclonal antibodies（mA bs） against human AhR protein（h Ah R）, as alternative immunological tools, are very limited. Thus, in order to provide more tools for further studies on h Ah R, we prepared two m Abs（1D6 and 4A6） against h Ah R. The two newly generated m Abs specifically bound to amino acids 484–508（located in transcription activation domain） and amino acids 201–215（located in Per-ARNT-Sim domain）of h Ah R, respectively. These epitopes were new as compared with those of commercial m Abs.The m Abs were also characterized by enzyme-linked immunosorbent assay, western blot,immunoprecipitation and indirect immunofluorescence assay in different cell lines. The results showed that the two m Abs could recognize the linearized AhR s in six different human cell lines and a rat hepatoma cell line, as well as the h Ah R with native conformations. We concluded that the newly generated m Abs could be employed in AhR-based bioassays for analysis of environmental contaminants, and held great potential for further revealing the spatial structure of AhR and its biological functions in future studies.
基金supported by the National Natural Science Foundation of China(No.22076216)the National Key Research and Development Program of China(2018YFA0901100)+1 种基金Sanming Project of Medicine in Shenzhen(SZSM201811070)Shenzhen Key Medical Discipline Construction Fund(SZXK067).
文摘Extreme high temperatures in the summer have become a global concern,and their risks to the inflammatory system have been largely unknown.Here we appraised the exposure risks of summer heatwaves by comparing the sera cytokine levels in healthy individuals under high and normal temperatures.In addition,we established a cell model with a 1.5°C temperature increase to investigate the regulatory mechanisms of temperature-related cytokines.Our results suggest that elevated temperatures enhance the release of interleukin-6(IL-6)and interleukin-8(IL-8)via the aryl hydrocarbon receptor(AhR)pathway and augment the proinflammatory effects of other factors.This suggests that we may have underestimated the impact of high temperatures on the health of individuals beyond just mortality rates.Moreover,seemingly minor temperature increases of just 1.5℃ can still pose a challenge to cells.
