Dimethylations of histone H3 lysine 9 and lysine 27 are important epigenetic marks associated with transcription repression. Here, we identified KIAA1718 （KDM7A） as a novel histone demethylase specific for these two...Dimethylations of histone H3 lysine 9 and lysine 27 are important epigenetic marks associated with transcription repression. Here, we identified KIAA1718 （KDM7A） as a novel histone demethylase specific for these two repressing marks. Using mouse embryonic stem cells, we demonstrated that KIAA1718 expression increased at the early phase of neural differentiation. Knockdown of the gene blocked neural differentiation and the effect was rescued by the wild-type human gene, and not by a catalytically inactive mutant. In addition, overexpression of KIAA1718 accelerated neural differentiation. We provide the evidence that the pro-neural differentiation effect of KDM7A is mediated through direct transcriptional activation of FGF4, a signal molecule implicated in neural differentiation. Thus, our study identified a dual-specificity histone demethylase that regulates neural differentiation through FGF4.展开更多
In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice, the sustenance of their pluripotency and normal karyotype depend on the feeder layer ...In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice, the sustenance of their pluripotency and normal karyotype depend on the feeder layer of mouse embryonic fibroblasts (MEF). Compared with the feeder layer of MEF cells, medium conditioned by Buffalo rat liver cells (BRL-CM) is able to maintain pluripotency and karyo-typic normality of ES cells only in short term cell propagation. Besides, ES cells grown in BRL-CM are also capable of aggregation with 8-cell embryos of Swiss strain and develop into germ line chimaeras. Modification to the method of aggregating ES cells with early embryos by making a hole in agar layer on the top of MEF feeder cells was shown to be more convenient and efficient than the conventional microdrop method.展开更多
AIM： To investigate a dual labeling technique, which would enable real-time monitoring of transplanted em- bryonic stem cell （ESC） kinetics, as well as long-term tracking. METHODS： Liver damage was induced in C57/...AIM： To investigate a dual labeling technique, which would enable real-time monitoring of transplanted em- bryonic stem cell （ESC） kinetics, as well as long-term tracking. METHODS： Liver damage was induced in C57/BL6 male mice （n = 40） by acetaminophen （APAP） 300 mg/kg administered intraperitoneally. Green fluores- cence protein （GFP） positive C57/BL6 mouse ESCs were stained with the near-infrared fluorescent lipophilic tracer 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbo- cyanine iodide （DiR） immediately before transplantationinto the spleen. Each of the animals in the cell therapy group （n = 20） received 5 x 106 ESCs 4 h following treatment with APAP. The control group （n = 20） re- ceived the vehicle only. The distribution and dynamics of the cells were monitored in real-time with the IVIS lumina-2 at 30 rain post transplantation, then at 3, 12, 24, 48 and 72 h, and after one and 2 wk. Immunohisto- chemical examination of liver tissue was used to identify expression of GFP and albumin. Plasma alanine amino- transferase （ALT） was measured as an indication of liver damage.RESULTS： DiR-stained ESCs were easily tracked with the IVIS using the indocyanine green filter due to its high background passband with minimal background autofluorescence. The transplanted cells were confined inside the spleen at 30 min post-transplantation, gradu- ally moved into the splenic vein, and were detectable in parts of the liver at the 3 h time-point. Within 24 h of transplantation, homing of almost 90% of cells was confirmed in the liver. On day three, however, the DiR signal started to fade out, and ex vivo IVIS imaging of different organs allowed signal detection at time-points when the signal could not be detected by in vivo imag- ing, and confirmed that the highest photon emission was in the liver （P 〈 0.0001）. At 2 wk, the DiRsignal was no longer detectable in vivo; however, immuno- histochemistry analysis of constitutively-expressed GFP was used to provide an insight into the distr展开更多
Although Activin/Nodal signaling regulates pluripotency of human embryonic stem （ES） cells, how this signaling acts in mouse ES cells remains largely unclear. To investigate this, we confirmed that mouse ES cells po...Although Activin/Nodal signaling regulates pluripotency of human embryonic stem （ES） cells, how this signaling acts in mouse ES cells remains largely unclear. To investigate this, we confirmed that mouse ES cells possess active Smad2-mediated Activin/Nodal signaling and found that Smad2-mediated Activin/Nodal signaling is dispensable for self-renewal maintenance but is required for proper differentiation toward the mesendoderm lineage. To gain insights into the underlying mechanisms, Smad2-associated genes were identified by genome-wide chromatin immu- noprecipitation-chip analysis. The results showed that there is a transcriptional correlation between Smad2 binding and Activin/Nodal signaling modulation, and that the development-related genes were enriched among the Smad2- bound targets. We further identified Tapbp as a key player in mesendoderm differentiation of mouse ES cells acting downstream of the Activin/Nodal-Smad2 pathway. Taken together, our findings suggest that Smad2-mediated Activin/Nodal signaling orchestrates mesendoderm lineage commitment of mouse ES cells through direct modulation of corresponding developmental regulator expression.展开更多
In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a ne...In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a neural fate. Previous studies have shown that the neural conversion of mouse ES cells includes both the participation of neural-specific transcription factors and the regulation of epigenetic modifications. However, the intracellular mechanism underlying this intrinsic transition still re- mains to be further elucidated. Herein, we describe a long intergenic non-coding RNA, LincRNA1230, which participates in the regulation of the neural lineage specification of mouse ES cells. The ectopic forced expression of LincRNAI230 dramatically inhibited mouse ES cells from adopting a neural cell fate, while LincRNA1230 knockdown promoted the conversion of mouse ES cells towards neural progenitors. Mechanistic studies have shown that LincRNA1230 inhibits the activation of early neural genes, such as Pax6 and Soxl, through the modulation of bivalent modifications （tri-methylation of histone3 lysine4 and his- tone3 lysine27） at the promoters of these genes. The interaction of LincRNA1230 with Wdr5 blocked the localization of Wdr5 at the promoters of early neural genes, thereby inhibiting the enrichment of H3K4me3 modifications at these loci. Collectively, these findings revealed a crucial role for LincRNA1230 in the regulation of the neural differentiation of mouse ES cells.展开更多
基金Supplementary information is linked to the online version of the paper on the Cell Research website.Acknowledgments We thank Anning Lin （The University of Chicago） for the critical reading of the paper, members in the Chen lab for technical help, the cell biology and molecular biology core facilities for confocal study and Q-PCR, and Shanghai Biochip Co Ltd. for microarray analysis. The H3K27me2 antibody was kindly provided by Li Tang （Fudan University） and Thomas Jenuwein （Research Institute of Molecular Pathology, The Vienna Biocenter）. This work was supported by the National Basic Research Program of China （2007CB957900, 2006CB943902, 2007CB947101, 2008KR0695, 2009CB941100, 2005CB522704）, the Chinese Academy of Sciences （KSCX2-YW-R-04）, the National Natural Science Foundation of China （90919026, 30870538,30623003, 30721065, 30830034, 90919046）, the Shanghai Pujiang Program （0757S11361）, the Shanghai Key Project of Basic Science Research （06DJ14001, 06DZ22032, 08DJ1400501）, and the Council of Shanghai Municipal Government for Science and Technology （088014199）.
文摘Dimethylations of histone H3 lysine 9 and lysine 27 are important epigenetic marks associated with transcription repression. Here, we identified KIAA1718 （KDM7A） as a novel histone demethylase specific for these two repressing marks. Using mouse embryonic stem cells, we demonstrated that KIAA1718 expression increased at the early phase of neural differentiation. Knockdown of the gene blocked neural differentiation and the effect was rescued by the wild-type human gene, and not by a catalytically inactive mutant. In addition, overexpression of KIAA1718 accelerated neural differentiation. We provide the evidence that the pro-neural differentiation effect of KDM7A is mediated through direct transcriptional activation of FGF4, a signal molecule implicated in neural differentiation. Thus, our study identified a dual-specificity histone demethylase that regulates neural differentiation through FGF4.
文摘In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice, the sustenance of their pluripotency and normal karyotype depend on the feeder layer of mouse embryonic fibroblasts (MEF). Compared with the feeder layer of MEF cells, medium conditioned by Buffalo rat liver cells (BRL-CM) is able to maintain pluripotency and karyo-typic normality of ES cells only in short term cell propagation. Besides, ES cells grown in BRL-CM are also capable of aggregation with 8-cell embryos of Swiss strain and develop into germ line chimaeras. Modification to the method of aggregating ES cells with early embryos by making a hole in agar layer on the top of MEF feeder cells was shown to be more convenient and efficient than the conventional microdrop method.
基金Supported by Citadel Capital Scholarship Foundation,EgyptDr. Leslie Borthwick/Ms. Anita Holme,Charitable Research Fund East and North Herts NHS TrusHertfordshire,United Kingdom
文摘AIM： To investigate a dual labeling technique, which would enable real-time monitoring of transplanted em- bryonic stem cell （ESC） kinetics, as well as long-term tracking. METHODS： Liver damage was induced in C57/BL6 male mice （n = 40） by acetaminophen （APAP） 300 mg/kg administered intraperitoneally. Green fluores- cence protein （GFP） positive C57/BL6 mouse ESCs were stained with the near-infrared fluorescent lipophilic tracer 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbo- cyanine iodide （DiR） immediately before transplantationinto the spleen. Each of the animals in the cell therapy group （n = 20） received 5 x 106 ESCs 4 h following treatment with APAP. The control group （n = 20） re- ceived the vehicle only. The distribution and dynamics of the cells were monitored in real-time with the IVIS lumina-2 at 30 rain post transplantation, then at 3, 12, 24, 48 and 72 h, and after one and 2 wk. Immunohisto- chemical examination of liver tissue was used to identify expression of GFP and albumin. Plasma alanine amino- transferase （ALT） was measured as an indication of liver damage.RESULTS： DiR-stained ESCs were easily tracked with the IVIS using the indocyanine green filter due to its high background passband with minimal background autofluorescence. The transplanted cells were confined inside the spleen at 30 min post-transplantation, gradu- ally moved into the splenic vein, and were detectable in parts of the liver at the 3 h time-point. Within 24 h of transplantation, homing of almost 90% of cells was confirmed in the liver. On day three, however, the DiR signal started to fade out, and ex vivo IVIS imaging of different organs allowed signal detection at time-points when the signal could not be detected by in vivo imag- ing, and confirmed that the highest photon emission was in the liver （P 〈 0.0001）. At 2 wk, the DiRsignal was no longer detectable in vivo; however, immuno- histochemistry analysis of constitutively-expressed GFP was used to provide an insight into the distr
基金Acknowledgments We thank Gaoyang Zhu for technical assistance. This work was supported by grants from the National Natural Science Foundation of China （30930050, 30921004）, the 973 Program （2006CB943401, 2010CB833706） to YGC, and grants from the China National Science Foundation （Grant # 30890033, 30588001 and 30620120433）, Chinese Ministry of Science and Technology（Grant # 2006CB910700） to JDH.
文摘Although Activin/Nodal signaling regulates pluripotency of human embryonic stem （ES） cells, how this signaling acts in mouse ES cells remains largely unclear. To investigate this, we confirmed that mouse ES cells possess active Smad2-mediated Activin/Nodal signaling and found that Smad2-mediated Activin/Nodal signaling is dispensable for self-renewal maintenance but is required for proper differentiation toward the mesendoderm lineage. To gain insights into the underlying mechanisms, Smad2-associated genes were identified by genome-wide chromatin immu- noprecipitation-chip analysis. The results showed that there is a transcriptional correlation between Smad2 binding and Activin/Nodal signaling modulation, and that the development-related genes were enriched among the Smad2- bound targets. We further identified Tapbp as a key player in mesendoderm differentiation of mouse ES cells acting downstream of the Activin/Nodal-Smad2 pathway. Taken together, our findings suggest that Smad2-mediated Activin/Nodal signaling orchestrates mesendoderm lineage commitment of mouse ES cells through direct modulation of corresponding developmental regulator expression.
基金supported by National Natural Science Foundation of China (81530042, 31571529, 31210103905, 31571519, 31571390, 31371510, 31301208, 31471250, 31401257)the Ministry of Science and Technology (2012CB966603, 2013CB967600, 2013CB967401)+2 种基金Science and Technology Commission of Shanghai Municipality (15JC1403200, 15JC1403201)Shanghai Rising-Star Program (14QA1403900)the Fundamental Research Funds for the Central Universities (2000219099)
文摘In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a neural fate. Previous studies have shown that the neural conversion of mouse ES cells includes both the participation of neural-specific transcription factors and the regulation of epigenetic modifications. However, the intracellular mechanism underlying this intrinsic transition still re- mains to be further elucidated. Herein, we describe a long intergenic non-coding RNA, LincRNA1230, which participates in the regulation of the neural lineage specification of mouse ES cells. The ectopic forced expression of LincRNAI230 dramatically inhibited mouse ES cells from adopting a neural cell fate, while LincRNA1230 knockdown promoted the conversion of mouse ES cells towards neural progenitors. Mechanistic studies have shown that LincRNA1230 inhibits the activation of early neural genes, such as Pax6 and Soxl, through the modulation of bivalent modifications （tri-methylation of histone3 lysine4 and his- tone3 lysine27） at the promoters of these genes. The interaction of LincRNA1230 with Wdr5 blocked the localization of Wdr5 at the promoters of early neural genes, thereby inhibiting the enrichment of H3K4me3 modifications at these loci. Collectively, these findings revealed a crucial role for LincRNA1230 in the regulation of the neural differentiation of mouse ES cells.
