Objective To observe the influence of rotenone on the distribution of α-synuclein （ASN） in rat model of Parkinson＇s disease （PD）. Methods Wistar rats were randomly divided into two groups and received 2 mg/kg ro...Objective To observe the influence of rotenone on the distribution of α-synuclein （ASN） in rat model of Parkinson＇s disease （PD）. Methods Wistar rats were randomly divided into two groups and received 2 mg/kg rotenone （s.c.） or sunflower oil （as control group） for about 4 weeks. The hippocampus, substantia nigra and striatum of brain were observed. Hematoxylin and eosin stain were used to observe the Lewy body like inclusion. The expression of tyrosine hydroxylase （TH） or ASN protein was determined by anti-TH or anti-α-synuclein immunohistochemistry, respectively. Results In control rats, ASN protein distributed widely in brain, especially in hippocampus, cortex and striatum. Rotenone obviously increased TH positive neurons and fibers loss in substantia nigra and striatum （P 〈 0.05）. In rotenone treated rats, ASN positive cells increased in global brain but not distributed in an even manner. In substantia nigra, ASN positive stuff was found aggregate in both cytoplasm and nucleus, and some formed spherical inclusion; in striatum, ASN positive neurites end aggregated and agglomerated around neurons; and in hippocampus, few dot-like ASN were aggregated in cell body, and no notable change was found in nucleus. Conclusion In rotenone administrated PD rats, ASN protein aggregated in several brain regions but most obviously in striatum and substantia nigra, and the distribution region of ASN was changed from peri-synapse to the cytoplasm and nucleus of dopaminergic neuron.展开更多
Objective To approach the associated mechanism by which α-synuclein （α-Syn） might regulate the metabolism of dopamine. Methods A DNA fragment, located at --495 to ＋25 of the human tyrosine hydroxylase （TH） gene...Objective To approach the associated mechanism by which α-synuclein （α-Syn） might regulate the metabolism of dopamine. Methods A DNA fragment, located at --495 to ＋25 of the human tyrosine hydroxylase （TH） gene, was amplified by PCR and inserted into the pGL3-Basic luciferase reporter vector. The recombinant plasmid pGL3-THprom was transfected into a dopammergic cell line MES23.5 or a α-Syn over-expressed MES23.5 （named MES23.5/hα-Syn^＋）. The promoter activity was detected by the Dual Luciferase Assay System. Results The luciferase activities in the MES23.5 cells transfected with pGl.,3-Basic, pGL3-THprom, and pGL3-Control vectors were 5.60±0.67, 26.80±4.11, and 32.90±4.75, respectively. On the other hand, the luciferase activity of pGL3-THprom in the MES23.5 （26.80±4.11） was significantly higher than that in the MES23.5/hα-Syn^＋（14.40±0.61） （P〈0.01）. Conclusion These results indicate that the -495 to ＋25 region in the TH gene possesses promoter activity for controlling the gene expression, and that α-Syn may negatively regulate the metabolism of dopamine by affecting the function of TH promoter as a trans-acting factor.展开更多
Objective Intracellular formation of Lewy body （LB） is one of the hallmarks of Parkinson’s disease.The main component of LB is aggregatedα-synuclein,present in the substantia nigra where iron accumulation also occ...Objective Intracellular formation of Lewy body （LB） is one of the hallmarks of Parkinson’s disease.The main component of LB is aggregatedα-synuclein,present in the substantia nigra where iron accumulation also occurs.The present study was aimed to study the relationship between iron andα-synuclein aggregation.Methods SK-N-SH cells were treated with different concentrations of ferric iron for 24 h or 48 h.MTT assay was conducted to determine the cell viability. Thioflavine S staining was used to detectα-synuclein aggregation.Results With the increase of iron concentration,the cell viability decreased significantly.At the concentrations of 5 mmol/L and 10 mmol/L,iron inducedα-synuclein aggregation more severely than at the concentration of 1 mmol/L.Besides,48-h treatment-induced aggregation was more severe than that induced by 24-h treatment,at the corresponding iron concentrations.Conclusion Ferric iron can induceα-synuclein aggregation,which is toxic to the cells,in a dose-and time-dependent way.展开更多
基金supported by the National Nature Science Foundation of China(No.30570627).
文摘Objective To observe the influence of rotenone on the distribution of α-synuclein （ASN） in rat model of Parkinson＇s disease （PD）. Methods Wistar rats were randomly divided into two groups and received 2 mg/kg rotenone （s.c.） or sunflower oil （as control group） for about 4 weeks. The hippocampus, substantia nigra and striatum of brain were observed. Hematoxylin and eosin stain were used to observe the Lewy body like inclusion. The expression of tyrosine hydroxylase （TH） or ASN protein was determined by anti-TH or anti-α-synuclein immunohistochemistry, respectively. Results In control rats, ASN protein distributed widely in brain, especially in hippocampus, cortex and striatum. Rotenone obviously increased TH positive neurons and fibers loss in substantia nigra and striatum （P 〈 0.05）. In rotenone treated rats, ASN positive cells increased in global brain but not distributed in an even manner. In substantia nigra, ASN positive stuff was found aggregate in both cytoplasm and nucleus, and some formed spherical inclusion; in striatum, ASN positive neurites end aggregated and agglomerated around neurons; and in hippocampus, few dot-like ASN were aggregated in cell body, and no notable change was found in nucleus. Conclusion In rotenone administrated PD rats, ASN protein aggregated in several brain regions but most obviously in striatum and substantia nigra, and the distribution region of ASN was changed from peri-synapse to the cytoplasm and nucleus of dopaminergic neuron.
基金This work was supported by the Key Project of National Natural Science Foundation of China （No. 30430280）the National Natural Science Foundation of China （No. 30271437, No.30270482）the Natural Science Foundation of Beijing Municipality （No. 7022011 ）.
文摘Objective To approach the associated mechanism by which α-synuclein （α-Syn） might regulate the metabolism of dopamine. Methods A DNA fragment, located at --495 to ＋25 of the human tyrosine hydroxylase （TH） gene, was amplified by PCR and inserted into the pGL3-Basic luciferase reporter vector. The recombinant plasmid pGL3-THprom was transfected into a dopammergic cell line MES23.5 or a α-Syn over-expressed MES23.5 （named MES23.5/hα-Syn^＋）. The promoter activity was detected by the Dual Luciferase Assay System. Results The luciferase activities in the MES23.5 cells transfected with pGl.,3-Basic, pGL3-THprom, and pGL3-Control vectors were 5.60±0.67, 26.80±4.11, and 32.90±4.75, respectively. On the other hand, the luciferase activity of pGL3-THprom in the MES23.5 （26.80±4.11） was significantly higher than that in the MES23.5/hα-Syn^＋（14.40±0.61） （P〈0.01）. Conclusion These results indicate that the -495 to ＋25 region in the TH gene possesses promoter activity for controlling the gene expression, and that α-Syn may negatively regulate the metabolism of dopamine by affecting the function of TH promoter as a trans-acting factor.
基金supported by the grants from the National Basic Research Development Program of China(No.2006CB500704)the National Natural Science Foundation of China(No.30930036,30870858)the Natural Science Fund for Distinguished Young Scholars of Shandong Province,China(No.JQ200807)
文摘Objective Intracellular formation of Lewy body （LB） is one of the hallmarks of Parkinson’s disease.The main component of LB is aggregatedα-synuclein,present in the substantia nigra where iron accumulation also occurs.The present study was aimed to study the relationship between iron andα-synuclein aggregation.Methods SK-N-SH cells were treated with different concentrations of ferric iron for 24 h or 48 h.MTT assay was conducted to determine the cell viability. Thioflavine S staining was used to detectα-synuclein aggregation.Results With the increase of iron concentration,the cell viability decreased significantly.At the concentrations of 5 mmol/L and 10 mmol/L,iron inducedα-synuclein aggregation more severely than at the concentration of 1 mmol/L.Besides,48-h treatment-induced aggregation was more severe than that induced by 24-h treatment,at the corresponding iron concentrations.Conclusion Ferric iron can induceα-synuclein aggregation,which is toxic to the cells,in a dose-and time-dependent way.
