Lsd1 restricts the number of germline stem cells by regulating multiple targets in escort cells.
Lsd1 restricts the number of germline stem cells by regulating multiple targets in escort cells.
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DOI：
10.1371/journal.pgen.1004200
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发表时间：
2014-03
期刊：
影响因子：
4.5
通讯作者：
Buszczak M
中科院分区：
文献类型：
--
作者：
Eliazer S;Palacios V;Wang Z;Kollipara RK;Kittler R;Buszczak M
称为生态位的特殊微环境通过控制干细胞自我更新和干细胞子细胞分化之间的平衡来调节组织稳态。然而，控制体内生态位的形成、大小和信号传导的机制仍然知之甚少。果蝇护送细胞中高度保守的组蛋白去甲基化酶 Lsd1 的缺失会导致帽细胞生态位外的 BMP 信号传导增加以及生殖系干细胞 (GSC) 表型的扩大。在这里，我们提供的证据表明，Lsd1 的缺失还会导致护送细胞形态的逐渐变化及其最终死亡。为了更好地表征 Lsd1 在卵巢内不同细胞群中的功能，我们进行了染色质免疫沉淀结合大规模平行测序 (ChIP-seq)。该分析表明，Lsd1 与护卫细胞中数量惊人的有限位点相关，而与帽细胞中的位点较少且通常不同。这些发现表明 Lsd1 表现出高度选择性的结合，这在很大程度上取决于特定的细胞环境。 Lsd1 不直接靶向护卫细胞中的 dpp 位点。相反，Lsd1 调节 engrailed 的表达并破坏 engrailed 及其假定的下游靶标 hedgehog 抑制 Lsd1 突变体表型。有趣的是，engrailed 的过度表达（而非刺猬）会导致 GSC 细胞的扩增，其标志是 BMP 信号传导的扩增。其他潜在的直接 Lsd1 靶基因的敲除（与 BMP 信号传导没有明显关联）也会部分抑制 Lsd1 突变表型。这些结果表明，Lsd1 通过调节不同的基因组来限制 GSC 样细胞的数量，并提供进一步的证据，表明在发育和成年期必须仔细控制护航细胞功能，以确保适当的种系分化。控制体内生态位的形成、大小和信号输出的机制仍然知之甚少。对果蝇生殖干细胞 (GSC) 的研究表明，染色质编程极大地影响这些细胞及其后代的行为。先前的研究表明，高度保守的组蛋白去甲基化酶 Lsd1 的缺失会导致异位生态位信号传导和 GSC 表型扩展。为了确定 Lsd1 的直接调控靶标，我们采用染色质免疫沉淀结合大规模平行测序 (ChIP-seq)，使用 GSC 生态位内外的特定细胞群。这些实验表明，Lsd1 与特定细胞群内的一百多个基因组位点表现出高度富集的结合。此外，其中一些直接靶标的错误调节导致了 Lsd1 突变体中观察到的干细胞表型的扩大。这些结果提供了关于 Lsd1 如何直接限制 GSC 微环境大小的见解，并建立了一个理解和探索体内干细胞生态位内外染色质编程的平台。
Specialized microenvironments called niches regulate tissue homeostasis by controlling the balance between stem cell self-renewal and the differentiation of stem cell daughters. However the mechanisms that govern the formation, size and signaling of in vivo niches remain poorly understood. Loss of the highly conserved histone demethylase Lsd1 in Drosophila escort cells results in increased BMP signaling outside the cap cell niche and an expanded germline stem cell (GSC) phenotype. Here we present evidence that loss of Lsd1 also results in gradual changes in escort cell morphology and their eventual death. To better characterize the function of Lsd1 in different cell populations within the ovary, we performed Chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq). This analysis shows that Lsd1 associates with a surprisingly limited number of sites in escort cells and fewer, and often, different sites in cap cells. These findings indicate that Lsd1 exhibits highly selective binding that depends greatly on specific cellular contexts. Lsd1 does not directly target the dpp locus in escort cells. Instead, Lsd1 regulates engrailed expression and disruption of engrailed and its putative downstream target hedgehog suppress the Lsd1 mutant phenotype. Interestingly, over-expression of engrailed, but not hedgehog, results in an expansion of GSC cells, marked by the expansion of BMP signaling. Knockdown of other potential direct Lsd1 target genes, not obviously linked to BMP signaling, also partially suppresses the Lsd1 mutant phenotype. These results suggest that Lsd1 restricts the number of GSC-like cells by regulating a diverse group of genes and provide further evidence that escort cell function must be carefully controlled during development and adulthood to ensure proper germline differentiation. The mechanisms that govern the formation, size and signaling output of in vivo niches remain poorly understood. Studies of Drosophila germline stem cells (GSCs) have suggested that chromatin programming greatly influences the behavior of these cells and their progeny. Previous work has shown that loss of the highly conserved histone demethylase Lsd1 results in ectopic niche signaling and an expanded GSC phenotype. To determine direct regulatory targets of Lsd1, we employed chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq) using specific cell populations inside and outside of the GSC niche. These experiments revealed that Lsd1 exhibits highly enriched binding to over one hundred genomic sites within a specific cell population. Furthermore, mis-regulation of some of these direct targets contributes to the expanded stem cell phenotype observed in Lsd1 mutants. These results provide insights into how Lsd1 directly restricts the size of the GSC microenvironment and establish a platform for understanding and exploring chromatin programming inside and outside an in vivo stem cell niche.
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DOI：
10.1073/pnas.0809144106
发表时间：
2009-01-27
影响因子：
11.1
作者：
Hsu, Hwei-Jan;Drummond-Barbosa, Daniela
通讯作者：
Drummond-Barbosa, Daniela
影响因子：
64.5
作者：
LEE, JJ;VONKESSLER, DP;BEACHY, PA
通讯作者：
BEACHY, PA
DOI：
10.1073/pnas.78.2.1095
发表时间：
1981-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
KORNBERG, T
通讯作者：
KORNBERG, T
影响因子：
16
作者：
Heinz S;Benner C;Spann N;Bertolino E;Lin YC;Laslo P;Cheng JX;Murre C;Singh H;Glass CK
通讯作者：
Glass CK
模因套件：用于发现和搜索的工具。
影响因子：
14.9
作者：
Bailey TL;Boden M;Buske FA;Frith M;Grant CE;Clementi L;Ren J;Li WW;Noble WS
通讯作者：
Noble WS