Generation of Isogenic D4Z4 Contracted and Noncontracted Immortal Muscle Cell Clones from a Mosaic Patient A Cellular Model for FSHD
Generation of Isogenic D4Z4 Contracted and Noncontracted Immortal Muscle Cell Clones from a Mosaic Patient A Cellular Model for FSHD
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DOI：
10.1016/j.ajpath.2012.07.007
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发表时间：
2012-10-01
影响因子：
6
通讯作者：
van der Maarel, Silvere M.
中科院分区：
文献类型：
--
作者：
Krom, Yvonne D.;Dumonceaux, Julie;van der Maarel, Silvere M.
在大多数情况下，面肩肱骨肌营养不良症（FSHD）是由4q亚端粒D4Z4重复的收缩引起的。这种收缩与局部染色质去浓缩和DUX4逆转录基因的抑制有关。其复杂的遗传和表观遗传原因以及疾病严重程度的高度临床变异性使FSHD发病机制的研究复杂化。一个经过验证的细胞模型绕过了相当大的异质性，将有助于FSHD的机制和治疗研究。利用新发FSHD中D4Z4重复收缩的体细胞嵌合发生率高的特点，我们建立了一个嵌合患者的克隆肌源性细胞模型。除了D4Z4重复序列的大小不同，个体克隆在基因上是相同的，要么是正常的，要么是FSHD的大小。这些克隆保留了它们的肌原性特征，D4Z4收缩克隆与非收缩克隆的不同之处在于在散发性细胞核中DUX4的表达爆发，表明这种爆发样现象是一种基因座固有的特征。因此，在D4Z4收缩克隆中可以观察到DUX4表达的下游效应，如DUX4靶基因的差异表达。我们还展示了他们参与免疫缺陷小鼠的体内再生，进一步扩大了这些克隆在机制和治疗研究中的潜力。这些细胞系将有助于两两比较，以确定fshd特异性差异，并有望为高通量药物筛选创造新的机会。（中华病理学杂志，2012,18:1387-1401;http://dx.doi.org/10.1016/j.ajpath.2012.07.007）
In most cases facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of the D4Z4 repeat in the 4q subtelomere. This contraction is associated with local chromatin decondensation and derepression of the DUX4 retrogene. Its complex genetic and epigenetic cause and high clinical variability in disease severity complicate investigations on the pathogenic mechanism underlying FSHD. A validated cellular model bypassing the considerable heterogeneity would facilitate mechanistic and therapeutic studies of FSHD. Taking advantage of the high incidence of somatic mosaicism for D4Z4 repeat contraction in de novo FSHD, we have established a clonal myogenic cell model from a mosaic patient. Individual clones are genetically identical except for the size of the D4Z4 repeat array, being either normal or FSHD sized. These clones retain their myogenic characteristics, and D4Z4 contracted clones differ from the noncontracted clones by the bursts of expression of DUX4 in sporadic nuclei, showing that this burst-like phenomenon is a locus-intrinsic feature. Consequently, downstream effects of DUX4 expression can be observed in D4Z4 contracted clones, like differential expression of DUX4 target genes. We also show their participation to in vivo regeneration with immunodeficient mice, further expanding the potential of these clones for mechanistic and therapeutic studies. These cell lines will facilitate pairwise comparisons to identify FSHD-specific differences and are expected to create new opportunities for high-throughput drug screens. (Am J Pathol 2012, 181: 1387-1401; http://dx.doi.org/10.1016/j.ajpath.2012.07.007)