The dynamic distribution of phosphorylated Histone H3 on Ser10 (phospho-H3) in cells was investigated to determineits function during mitosis. Human breast adenocarcinoma cells MCF-7, and Chinese hamster cells CHO wer...The dynamic distribution of phosphorylated Histone H3 on Ser10 (phospho-H3) in cells was investigated to determineits function during mitosis. Human breast adenocarcinoma cells MCF-7, and Chinese hamster cells CHO were analyzedby indirect immunofluorescence staining with an antibody against phospho-H3. We found that the phosphorylationbegins at early prophase, and spreads throughout the chromosomes at late prophase. At metaphase, most of the phospho-H3 aggregates at the end of the condensed entity of chromosomes at equatorial plate. During anaphase and telophase,the fluorescent signal of phospho-H3 is detached from chromosomes into cytoplasm. At early anaphase, phospho-H3shows ladder bands between two sets of separated chromosome, and forms “sandwich-like structure” when the chro-mosomes condensed. With the cleavage progressing, the “ladders” of the histone contract into a bigger bright dot. Thenthe histone aggregates and some of compacted microtubules in the midbody region are composed into a “bar-like”complex to separate daughter cells. The daughter cells seal their plasma membrane along with the ends of the “bar”,inside which locates microtubules and modified histones, to finish the cytokinesis and keep the “bar complex” out of thecells. The specific distribution and kinetics of phospho-H3 in cytoplasm suggest that the modified histones may takepart in the formation of midbody and play a crucial role in cytokinesis.展开更多
Objective: To investigate the effects of lithium on cognitive function and metabolism of Amyloid-beta Protein Precursor (APP) and tau phosphorylation in rats chronically exposed to aluminum. Methods: Twenty-four chron...Objective: To investigate the effects of lithium on cognitive function and metabolism of Amyloid-beta Protein Precursor (APP) and tau phosphorylation in rats chronically exposed to aluminum. Methods: Twenty-four chronically aluminum-exposed rats were randomly divided into 2 groups: a lithium-treatment group and a non-treatment group (n=12 per group). Lithium chloride was administered to the lithium-treatment group via gastric gavage daily for 6 weeks (200 mg/kg·d LiCl), while the non-treatment group was administered the same volume of sodium chloride by the same means. An additional control group (n=12) received no intervention. Memory function was evaluated by the Morris water maze test. Aβ was measured by immunohistochemical staining, while total APP, phosphorylated-tau protein, CDK5 and PP2A were determined by Western Blotting. Results: (1) Compared to the non-treatment group, the lithium-treatment group had a significantly shorter mean escape latency and a lower proportion of random navigation pattern in the spatial probe test (P<0.05). After the platform was taken away, the rats in the lithium-treatment group crossed the platform quadrant significantly more and stayed longer in the platform quadrant than those in the non-treatment group (P<0.05). (2) The number of Aβ positive neurons in the hippocampus and cortex was significantly less in the lithium-treatment group than in the non-treatment group (P<0.05), but the content of APP was not different between groups (P=0.730). (3) Phosphorylation of tau protein decreased significantly in the lithium-treatment group than that in the non-treatment group (P<0.05). The content of CDK5 in the lithium-treatment group was significantly less than that in the non-treatment group in the cortex and hippocampus, while there was no difference in the content of PP2A between the 2 groups. The expression of CDK5 was significantly correlated with phosphorylated tau (r=0.871, P=0.024) in the lithium-treatment group. Conclusion: Lithium may improve memory function in rats chronically exposed to aluminum by decreasing both the production of Aβ and tau phosphorylation, with the latter results from inhibiting expression of CDK5.展开更多
文摘目的:探究小鼠颞叶癫痫慢性发作期蛋白质功能和信号通路的改变。方法:(1)制备小鼠卡英酸颞叶癫痫模型,行为学达到Racine分级4分判定为造模成功。28 d后,取对照组和实验组小鼠海马组织进行磷酸化蛋白组学实验;(2)选取检出密度大于106的数据进行统计分析;(3)利用GO(Gene Ontology)数据库、KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库和STRING数据库对磷酸化蛋白组学数据进行统计分析;(4)结合文献对组学结果进行分析。结果:(1)质谱共检测出12 697个蛋白质磷酸化位点,其中159个位点变化差异具有统计学意义(P<0.05);(2)在蛋白质功能层面,磷酸化水平显著性变化的蛋白质的分子功能主要是结合(39.5%)和催化活性(35.7%),这些蛋白质参与细胞交流(20.8%)、初级代谢和含磷酸盐化合物代谢等生化过程;(3)在信号通路层面,这些蛋白质参与10条信号转导通路,包括谷氨酸能突触信号通路、Ras信号通路、长时程增强信号通路等;(4)在蛋白质相互作用层面,这些蛋白质形成以Grin1和Dlg3为核心,以Arhgef 2、Arhgap33和Tiam1为核心与以Spnb1/3/4、Add3和Ank2为核心的蛋白质相互作用网;(5)磷酸化蛋白组学数据显示,Grin1、Arhgef2、Arhgap33、Tiam1、Sptbn1/2/4和Ank2等磷酸化水平在癫痫慢性发作期显著升高。结论:磷酸化蛋白组学的结果从蛋白质功能、信号通路和蛋白质相互作用3个层面阐明了小鼠颞叶癫痫慢性发作期海马体蛋白质的变化,验证了磷酸化蛋白组学研究的可靠性,并提示多巴胺功能和Kir3.1钾通道功能可能与癫痫发生相关。
文摘The dynamic distribution of phosphorylated Histone H3 on Ser10 (phospho-H3) in cells was investigated to determineits function during mitosis. Human breast adenocarcinoma cells MCF-7, and Chinese hamster cells CHO were analyzedby indirect immunofluorescence staining with an antibody against phospho-H3. We found that the phosphorylationbegins at early prophase, and spreads throughout the chromosomes at late prophase. At metaphase, most of the phospho-H3 aggregates at the end of the condensed entity of chromosomes at equatorial plate. During anaphase and telophase,the fluorescent signal of phospho-H3 is detached from chromosomes into cytoplasm. At early anaphase, phospho-H3shows ladder bands between two sets of separated chromosome, and forms “sandwich-like structure” when the chro-mosomes condensed. With the cleavage progressing, the “ladders” of the histone contract into a bigger bright dot. Thenthe histone aggregates and some of compacted microtubules in the midbody region are composed into a “bar-like”complex to separate daughter cells. The daughter cells seal their plasma membrane along with the ends of the “bar”,inside which locates microtubules and modified histones, to finish the cytokinesis and keep the “bar complex” out of thecells. The specific distribution and kinetics of phospho-H3 in cytoplasm suggest that the modified histones may takepart in the formation of midbody and play a crucial role in cytokinesis.
文摘Objective: To investigate the effects of lithium on cognitive function and metabolism of Amyloid-beta Protein Precursor (APP) and tau phosphorylation in rats chronically exposed to aluminum. Methods: Twenty-four chronically aluminum-exposed rats were randomly divided into 2 groups: a lithium-treatment group and a non-treatment group (n=12 per group). Lithium chloride was administered to the lithium-treatment group via gastric gavage daily for 6 weeks (200 mg/kg·d LiCl), while the non-treatment group was administered the same volume of sodium chloride by the same means. An additional control group (n=12) received no intervention. Memory function was evaluated by the Morris water maze test. Aβ was measured by immunohistochemical staining, while total APP, phosphorylated-tau protein, CDK5 and PP2A were determined by Western Blotting. Results: (1) Compared to the non-treatment group, the lithium-treatment group had a significantly shorter mean escape latency and a lower proportion of random navigation pattern in the spatial probe test (P<0.05). After the platform was taken away, the rats in the lithium-treatment group crossed the platform quadrant significantly more and stayed longer in the platform quadrant than those in the non-treatment group (P<0.05). (2) The number of Aβ positive neurons in the hippocampus and cortex was significantly less in the lithium-treatment group than in the non-treatment group (P<0.05), but the content of APP was not different between groups (P=0.730). (3) Phosphorylation of tau protein decreased significantly in the lithium-treatment group than that in the non-treatment group (P<0.05). The content of CDK5 in the lithium-treatment group was significantly less than that in the non-treatment group in the cortex and hippocampus, while there was no difference in the content of PP2A between the 2 groups. The expression of CDK5 was significantly correlated with phosphorylated tau (r=0.871, P=0.024) in the lithium-treatment group. Conclusion: Lithium may improve memory function in rats chronically exposed to aluminum by decreasing both the production of Aβ and tau phosphorylation, with the latter results from inhibiting expression of CDK5.
