K562细胞株增殖分化相关转录因子研究进展

K562细胞作为体外研究白血病细胞增殖与分化的良好模型,其转录因子及作用机制研究是一关键的环节.本文就其中GATA、STAT、Sp家族等在K562细胞增殖分化中的作用及其相关进展作一综述.     

Interactions and Tradeoffs Between Cell Recruitment,Proliferation, and Differentiation Affect CNS Regeneration

Regeneration of central nervous system (CNS) lesions requires movement of progenitor cells and production of their differentiated progeny. Although damage to the CNS clearly promotes these two processes, the interplay between these complex events and how it affects a response remains elusive. Here, we use spatial stochastic modeling to show that tradeoffs arise between production and recruitment during regeneration. Proper spatial control of cell cycle timing can mitigate these tradeoffs, maximizing recruitment, improving infiltration into the lesion, and reducing wasteful production outside of it. Feedback regulation of cell lineage dynamics alone however leads to spatial defects in cell recruitment, suggesting a novel, to our knowledge, hypothesis for the aggregation of cells to the periphery of a lesion in multiple sclerosis. Interestingly, stronger chemotaxis does not correct this aggregation and instead, substantial random cell motions near the site of the lesion are required to improve CNS regeneration.     

Interactions and Tradeoffs Between Cell Recruitment,Proliferation, and Differentiation Affect CNS Regeneration

Regeneration of central nervous system (CNS) lesions requires movement of progenitor cells and production of their differentiated progeny. Although damage to the CNS clearly promotes these two processes, the interplay between these complex events and how it affects a response remains elusive. Here, we use spatial stochastic modeling to show that tradeoffs arise between production and recruitment during regeneration. Proper spatial control of cell cycle timing can mitigate these tradeoffs, maximizing recruitment, improving infiltration into the lesion, and reducing wasteful production outside of it. Feedback regulation of cell lineage dynamics alone however leads to spatial defects in cell recruitment, suggesting a novel, to our knowledge, hypothesis for the aggregation of cells to the periphery of a lesion in multiple sclerosis. Interestingly, stronger chemotaxis does not correct this aggregation and instead, substantial random cell motions near the site of the lesion are required to improve CNS regeneration.     

microRNA-194模拟物对成骨肉瘤细胞系SOSP_9607生物学特性的影响

目的：观察miR-194模拟物对于成骨肉瘤细胞系SOSP_9607细胞增殖、周期和凋亡的影响。方法：四甲基偶氮唑蓝（MTT）法绘制细胞生长曲线,流式细胞仪测定细胞凋亡和周期。将SOSP_9607细胞分为对照组和实验组,对照组分为阴性对照和正常细胞对照组。实验组采用miR-194模拟物（hsa-miR-194mimics）转染成骨肉瘤细胞系SOSP_9607,增强SOSP_9607细胞内miR-194的活性。结果：与对照组比较,实验组细胞的增殖能力明显下降。实验组凋亡率（10.1±0.22）%与阴性对照组凋亡率（3.3±0.19）%相比明显增高（P〈0.01）。与对照组比较,实验组细胞周期G0/G1细胞比例显著增加,G2/M期细胞比例显著减少,S期细胞比例显著减少（P〈0.01）。结论：通过转染miR-194模拟物增强SOSP_9607细胞中miR-194的活性对SOSP_9607细胞的增殖和凋亡造成显著影响。     

Genome Duplication and Gene Loss Affect the Evolution of Heat Shock Transcription Factor Genes in Legumes

Whole-genome duplication events (polyploidy events) and gene loss events have played important roles in the evolution of legumes. Here we show that the vast majority of Hsf gene duplications resulted from whole genome duplication events rather than tandem duplication, and significant differences in gene retention exist between species. By searching for intraspecies gene colinearity (microsynteny) and dating the age distributions of duplicated genes, we found that genome duplications accounted for 42 of 46 Hsf-containing segments in Glycine max, while paired segments were rarely identified in Lotus japonicas, Medicago truncatula and Cajanus cajan. However, by comparing interspecies microsynteny, we determined that the great majority of Hsf-containing segments in Lotus japonicas, Medicago truncatula and Cajanus cajan show extensive conservation with the duplicated regions of Glycine max. These segments formed 17 groups of orthologous segments. These results suggest that these regions shared ancient genome duplication with Hsf genes in Glycine max, but more than half of the copies of these genes were lost. On the other hand, the Glycine max Hsf gene family retained approximately 75% and 84% of duplicated genes produced from the ancient genome duplication and recent Glycine-specific genome duplication, respectively. Continuous purifying selection has played a key role in the maintenance of Hsf genes in Glycine max. Expression analysis of the Hsf genes in Lotus japonicus revealed their putative involvement in multiple tissue-/developmental stages and responses to various abiotic stimuli. This study traces the evolution of Hsf genes in legume species and demonstrates that the rates of gene gain and loss are far from equilibrium in different species.     

转录因子CREB对细胞周期调控机制的研究进展

细胞周期是一个复杂而精细的调节过程,有许多蛋白参与。其cyclin、CDK、CKI是细胞周期调控的内源性分子,三者在细胞周期中相互协调并与细胞信号转导通路之间形成复杂的调控网络。cAMP应答元件结合蛋白(cAMP response element binding protein,CREB)作为细胞核内调控因子,通过自身磷酸化实现调节功能,改变cyclin、CDK和CKI的转录,从而调控细胞周期。该文就近年来CREB对细胞周期调控的研究进展作一综述。     

核转录因子Foxp3在小鼠黑色素瘤细胞中的表达

目的:检测小鼠黑色素瘤细胞中核转录因子Foxp3的表达。方法:用TRIzol试剂提取小鼠黑色素瘤细胞RNA,通过实时荧光定量PCR检测小鼠黑色素瘤细胞中Foxp3 mRNA的表达,通过Western印迹和流式细胞术检测小鼠黑色素瘤细胞中Foxp3蛋白的表达,通过免疫荧光检测小鼠黑色素瘤细胞中Foxp3分子的表达。结果:在小鼠黑色素瘤细胞中存在Foxp3的mRNA转录和分子表达,免疫荧光显示Foxp3定位于黑色素瘤细胞的胞核及核周部位。结论:证实了小鼠黑色素瘤细胞表达Foxp3,将为临床黑色素瘤的免疫治疗提供新的靶标和治疗策略。     

Comprehensive Molecular Profiling Identifies FOXM1 as a Key Transcription Factor for Meningioma Proliferation

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