An iterative genetic and dynamical modelling approach identifies novel features of the gene regulatory network underlying melanocyte development.
An iterative genetic and dynamical modelling approach identifies novel features of the gene regulatory network underlying melanocyte development.
复制标题
DOI：
10.1371/journal.pgen.1002265
复制
发表时间：
2011-09
期刊：
影响因子：
4.5
通讯作者：
Kelsh RN
中科院分区：
文献类型：
--
作者：
Greenhill ER;Rocco A;Vibert L;Nikaido M;Kelsh RN
从多能前体产生稳定分化的细胞类型的机制是理解正常发育的关键，并对癌症治疗和干细胞的治疗用途具有影响。色素细胞是神经嵴干细胞的主要衍生物，也是我们理解细胞分化遗传学的关键模型细胞类型。已经确定了几个驱动黑素细胞命运特化的因素，包括黑素细胞发育的转录因子和主调节因子Mitf和Wnt信号传导以及驱动mitf表达的多能性和命运特化因子Sox 10。虽然这些因素共同驱动多能神经嵴细胞成为特定的成黑素细胞，但稳定黑素细胞分化的机制仍不清楚。此外，关于Sox10是否在黑素细胞分化中具有持续作用存在争议。在这里，我们使用斑马鱼在体内探索基因调控网络（GRN）的黑素细胞的规范和分化。我们使用一个迭代的过程中的数学建模和实验观察系统地探索我们所定义的核心黑素细胞GRN。我们表明，Sox10是不需要进行分化和表达下调分化细胞中，响应Mitfa和Hdac1。出乎意料的是，我们发现Sox10抑制黑素细胞分化基因的Mitf依赖性表达。我们的系统生物学方法使我们能够预测黑素细胞GRN的两个新特征，然后我们通过实验验证。具体而言，我们表明，维持mitfa表达是Mitfa依赖性的，并确定Sox9b作为提供一个Mitfa独立的输入黑素细胞分化。我们的数据支持我们以前的建议，Sox10的功能只是短暂的调节mitfa，不能负责长期维持mitfa的表达，事实上，Sox10可能会减缓斑马鱼胚胎中的黑素细胞分化。更一般地说，这种理解黑素细胞分化的新方法为这种和其他细胞类型的分化的系统建模提供了基础。在多细胞生物体中，一个基因组用于制造许多不同的细胞类型。这就需要所有这些基因的活性被配置成多个不同的、稳定的活性状态，每个状态对应于组织的不同细胞类型特征之一。分化细胞类型的稳定活性状态与多能干细胞的不同和瞬时状态特征形成对比。我们对这些状态的关键特征知之甚少，这些状态调节干细胞向稳定分化的转变。在这里，我们研究这个问题的黑素细胞，一个遗传特征良好的细胞类型，使用动态数学建模和实验操作相结合。在人类中，黑素细胞状态的破坏导致先天性和退行性色素性疾病，而它们的不稳定可能是引发黑色素瘤的重要因素。我们的工作预测，验证，并确定了几个新的功能，斑马鱼黑素细胞的基因调控网络，包括一个稳定的分化状态。我们的研究证明了这种系统生物学方法在理解分化细胞状态的遗传基础方面的实用性。
The mechanisms generating stably differentiated cell-types from multipotent precursors are key to understanding normal development and have implications for treatment of cancer and the therapeutic use of stem cells. Pigment cells are a major derivative of neural crest stem cells and a key model cell-type for our understanding of the genetics of cell differentiation. Several factors driving melanocyte fate specification have been identified, including the transcription factor and master regulator of melanocyte development, Mitf, and Wnt signalling and the multipotency and fate specification factor, Sox10, which drive mitf expression. While these factors together drive multipotent neural crest cells to become specified melanoblasts, the mechanisms stabilising melanocyte differentiation remain unclear. Furthermore, there is controversy over whether Sox10 has an ongoing role in melanocyte differentiation. Here we use zebrafish to explore in vivo the gene regulatory network (GRN) underlying melanocyte specification and differentiation. We use an iterative process of mathematical modelling and experimental observation to explore methodically the core melanocyte GRN we have defined. We show that Sox10 is not required for ongoing differentiation and expression is downregulated in differentiating cells, in response to Mitfa and Hdac1. Unexpectedly, we find that Sox10 represses Mitf-dependent expression of melanocyte differentiation genes. Our systems biology approach allowed us to predict two novel features of the melanocyte GRN, which we then validate experimentally. Specifically, we show that maintenance of mitfa expression is Mitfa-dependent, and identify Sox9b as providing an Mitfa-independent input to melanocyte differentiation. Our data supports our previous suggestion that Sox10 only functions transiently in regulation of mitfa and cannot be responsible for long-term maintenance of mitfa expression; indeed, Sox10 is likely to slow melanocyte differentiation in the zebrafish embryo. More generally, this novel approach to understanding melanocyte differentiation provides a basis for systematic modelling of differentiation in this and other cell-types. In a multicellular organism, one genome is used to make numerous different cell-types. This must require the activity of all these genes to be configured into multiple distinct and stable active states, each corresponding to one of the different cell-types characteristic of a tissue. The stable active states of differentiated cell-types contrast with the different, and transient, states characteristic of multipotent stem cells. We know little of the key features of these states that regulate the switch of a stem cell to stable differentiation. Here we examine this issue in the melanocyte, a genetically well-characterised cell-type, using a combination of dynamic mathematical modelling and experimental manipulation. In humans, disruption of the melanocyte state results in congenital and degenerative pigmentary diseases, whereas their destabilisation is likely to be an important factor in initiating melanoma. Our work predicts, validates, and identifies several novel features to the gene regulatory network of the zebrafish melanocyte, including one stabilising the differentiated state. Our study demonstrates the utility of this systems biology approach to understanding the genetic basis for differentiated cell states.
登录
查看更多内容
影响因子：
4.3
作者：
Cronin JC;Wunderlich J;Loftus SK;Prickett TD;Wei X;Ridd K;Vemula S;Burrell AS;Agrawal NS;Lin JC;Banister CE;Buckhaults P;Rosenberg SA;Bastian BC;Pavan WJ;Samuels Y
通讯作者：
Samuels Y
影响因子：
2.7
作者：
Chiang, EFL;Pai, CI;Chung, BC
通讯作者：
Chung, BC
影响因子：
3.5
作者：
Bondurand, N;Pingault, V;Goossens, M
通讯作者：
Goossens, M
影响因子：
4.6
作者：
Barrallo-Gimeno, A;Holzschuh, J;Knapik, EW
通讯作者：
Knapik, EW
影响因子：
2.7
作者：
Ignatius, Myron S.;Moose, Holly E.;Henion, Paul D.
通讯作者：
Henion, Paul D.