Epigenetic analysis of human embryonic carcinoma cells during retinoic acid-induced neural differentiation

2010 ◽  
Vol 88 (3) ◽  
pp. 527-538 ◽  
Author(s):  
Maryam Shahhoseini ◽  
Adeleh Taei ◽  
Narges Zare Mehrjardi ◽  
Ghasem Hosseini Salekdeh ◽  
Hossein Baharvand

Differentiation of stem cells from a pluripotent to a committed state involves global changes in genome expression patterns, critically determined by chromatin structure and interactions of chromatin-binding proteins. The dynamics of chromatin structure are tightly regulated by multiple epigenetic mechanisms such as histone modifications and the incorporation of histone variants. In the current work, we induced neural differentiation of a human embryonal carcinoma stem cell line, NTERA2/NT2, by retinoic acid (RA) treatment, primarily according to two different methods of adherent cell culture (rosette formation) and suspension cell culture (EB formation) conditions, and histone modifications and variations were compared through these processes. Western blot analysis of histone extracts showed significant changes in the acetylation and methylation patterns of histone H3, and expression level of the histone variant H2A.Z, after RA treatment in both protocols. Using chromatin immunoprecipitation (ChIP) coupled with real-time PCR, it was shown that these epigenetic changes occurred on the regulatory regions of 4 marker genes (Oct4, Nanog, Nestin, and Pax6) in a culture condition dependent manner. This report demonstrates the dynamic interplay of histone modification and variation in regulating the gene expression profile, during stem cell differentiation and under different culture conditions.

2015 ◽  
Vol 35 (10) ◽  
pp. 1700-1711 ◽  
Author(s):  
Fenfang Chen ◽  
Xia Lin ◽  
Pinglong Xu ◽  
Zhengmao Zhang ◽  
Yanzhen Chen ◽  
...  

Bone morphogenetic proteins (BMPs) play vital roles in regulating stem cell maintenance and differentiation. BMPs can induce osteogenesis and inhibit myogenesis of mesenchymal stem cells. Canonical BMP signaling is stringently controlled through reversible phosphorylation and nucleocytoplasmic shuttling of Smad1, Smad5, and Smad8 (Smad1/5/8). However, how the nuclear export of Smad1/5/8 is regulated remains unclear. Here we report that the Ran-binding protein RanBP3L acts as a nuclear export factor for Smad1/5/8. RanBP3L directly recognizes dephosphorylated Smad1/5/8 and mediates their nuclear export in a Ran-dependent manner. Increased expression of RanBP3L blocks BMP-induced osteogenesis of mouse bone marrow-derived mesenchymal stem cells and promotes myogenic induction of C2C12 mouse myoblasts, whereas depletion of RanBP3L expression enhances BMP-dependent stem cell differentiation activity and transcriptional responses. In conclusion, our results demonstrate that RanBP3L, as a nuclear exporter for BMP-specific Smads, plays a critical role in terminating BMP signaling and regulating mesenchymal stem cell differentiation.


2003 ◽  
Vol 81 (3) ◽  
pp. 131-140 ◽  
Author(s):  
John D Lewis ◽  
D Wade Abbott ◽  
Juan Ausió

The process of meiosis reduces a diploid cell to four haploid gametes and is accompanied by extensive recombination. Thus, the dynamics of chromatin during meiosis are significantly different than in mitotic cells. As spermatogenesis progresses, there is a widespread reorganization of the haploid genome followed by extensive DNA compaction. It has become increasingly clear that the dynamic composition of chromatin plays a critical role in the activities of enzymes and processes that act upon it. Therefore, an analysis of the role of histone variants and modifications in these processes may shed light upon the mechanisms involved and the control of chromatin structure in general. Histone variants such as histone H3.3, H2AX, and macroH2A appear to play key roles in the various stages of spermiogenesis, in addition to the specifically modulated acetylation of histone H4 (acH4), ubiquitination of histones H2A and H2B (uH2A, uH2B), and phosphorylation of histone H3 (H3p). This review will examine recent discoveries concerning the role of histone modifications and variants during meiosis and spermatogenesis.Key words: histone variants, histone modifications, chromatin structure, meiosis.


2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Chi Huu Nguyen ◽  
Katharina Bauer ◽  
Hubert Hackl ◽  
Angela Schlerka ◽  
Elisabeth Koller ◽  
...  

AbstractEcotropic virus integration site 1 (EVI1), whose overexpression characterizes a particularly aggressive subtype of acute myeloid leukemia (AML), enhanced anti-leukemic activities of all-trans retinoic acid (atRA) in cell lines and patient samples. However, the drivers of leukemia formation, therapy resistance, and relapse are leukemic stem cells (LSCs), whose properties were hardly reflected in these experimental setups. The present study was designed to address the effects of, and interactions between, EVI1 and retinoids in AML LSCs. We report that Evi1 reduced the maturation of leukemic cells and promoted the abundance, quiescence, and activity of LSCs in an MLL-AF9-driven mouse model of AML. atRA further augmented these effects in an Evi1 dependent manner. EVI1 also strongly enhanced atRA regulated gene transcription in LSC enriched cells. One of their jointly regulated targets, Notch4, was an important mediator of their effects on leukemic stemness. In vitro exposure of leukemic cells to a pan-RAR antagonist caused effects opposite to those of atRA. In vivo antagonist treatment delayed leukemogenesis and reduced LSC abundance, quiescence, and activity in Evi1high AML. Key results were confirmed in human myeloid cell lines retaining some stem cell characteristics as well as in primary human AML samples. In summary, our study is the first to report the importance of EVI1 for key properties of AML LSCs. Furthermore, it shows that atRA enhances, and a pan-RAR antagonist counteracts, the effects of EVI1 on AML stemness, thus raising the possibility of using RAR antagonists in the therapy of EVI1high AML.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Sujeong Jang ◽  
Jong-Seong Park ◽  
Han-Seong Jeong

Stem cells are a powerful resource for cell-based transplantation therapies, but understanding of stem cell differentiation at the molecular level is not clear yet. We hypothesized that the Wnt pathway controls stem cell maintenance and neural differentiation. We have characterized the transcriptional expression of Wnt during the neural differentiation of hADSCs. After neural induction, the expressions of Wnt2, Wnt4, and Wnt11 were decreased, but the expression of Wnt5a was increased compared with primary hADSCs in RT-PCR analysis. In addition, the expression levels of most Fzds and LRP5/6 ligand were decreased, but not Fzd3 and Fzd5. Furthermore, Dvl1 and RYK expression levels were downregulated in NI-hADSCs. There were no changes in the expression of ß-catenin and GSK3ß. Interestingly, Wnt5a expression was highly increased in NI-hADSCs by real time RT-PCR analysis and western blot. Wnt5a level was upregulated after neural differentiation and Wnt3, Dvl2, and Naked1 levels were downregulated. Finally, we found that the JNK expression was increased after neural induction and ERK level was decreased. Thus, this study shows for the first time how a single Wnt5a ligand can activate the neural differentiation pathway through the activation of Wnt5a/JNK pathway by binding Fzd3 and Fzd5 and directing Axin/GSK-3ß in hADSCs.


Stem Cells ◽  
2014 ◽  
Vol 32 (6) ◽  
pp. 1451-1458 ◽  
Author(s):  
Bilal N. Sheikh ◽  
Natalie L. Downer ◽  
Andrew J. Kueh ◽  
Tim Thomas ◽  
Anne K. Voss

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