Methylation alterations of WT1 and homeobox genes in inflamed muscle biopsy samples from patients with untreated juvenile dermatomyositis suggest self-renewal capacity.
Methylation alterations of WT1 and homeobox genes in inflamed muscle biopsy samples from patients with untreated juvenile dermatomyositis suggest self-renewal capacity.
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DOI：
10.1002/art.34573
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发表时间：
2012-10
影响因子：
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通讯作者：
Min Wang;Hehuang Xie;S. Shrestha;S. Sredni;Gabrielle Morgan;L. Pachman
中科院分区：
文献类型：
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作者：
Min Wang;Hehuang Xie;S. Shrestha;S. Sredni;Gabrielle Morgan;L. Pachman
目的探讨幼年型皮肌炎（DM）和其他特发性炎性肌病（IIMs）患儿炎症肌肉中甲基化改变的作用。方法：磁共振成像指导的诊断性肌肉活检采集了20名青少年DM儿童的样本，用于全基因组DNA甲基化分析，并采集了4名健康对照的肌肉活检样本。亚硫酸氢盐处理后焦磷酸测序证实了青少年DM和其他IIM的甲基化状态。免疫组化确定的定位和表达水平的WT 1。结果比较青少年DM和正常对照肌肉的全基因组DNA甲基化谱，发现27个基因在组间存在显著的甲基化差异。这些基因富含转录因子和/或细胞周期调节因子，与未治疗疾病的持续时间无关。其中有六个同源异型盒基因; ALX 4，HOXC 11，HOXD 3和HOXD 4是低甲基化的，而EMX 2和HOXB 1是高甲基化的。青年DM组WT 1甲基化水平明显降低（Δβ =-0.41，P < 0.001）。来自56名青少年DM患者的样本中的亚硫酸氢盐焦磷酸测序验证证实了这些基因的甲基化改变。在幼年型多发性肌炎（n = 5）和其他IIM（n = 9）中观察到类似的甲基化改变。与其他结果一致，幼年DM肌肉中WT 1蛋白表达增加，平均阳性率为11.6%，而正常肌肉中未检测到（P < 0.001）。结论这些结果表明，儿童青少年DM和IIMs的受影响的肌肉有能力被修复，同源框和WT 1基因的表观遗传标记，以促进这一修复过程，潜在的治疗干预的新途径。
OBJECTIVE To determine the effect of methylation alteration in inflamed muscles from children with juvenile dermatomyositis (DM) and other idiopathic inflammatory myopathies (IIMs). METHODS Magnetic resonance imaging-directed diagnostic muscle biopsies yielded samples from 20 children with juvenile DM, which were used for genome-wide DNA methylation profiling, as were muscle biopsy samples from 4 healthy controls. Bisulfite treatment followed by pyrosequencing confirmed methylation status in juvenile DM and other IIMs. Immunohistochemistry defined localization and expression levels of WT1. RESULTS Comparison of genome-wide DNA methylation profiling between juvenile DM muscle and normal control muscle revealed 27 genes with a significant methylation difference between the groups. These genes were enriched with transcription factors and/or cell cycle regulators and were unrelated to duration of untreated disease. Six homeobox genes were among them; ALX4, HOXC11, HOXD3, and HOXD4 were hypomethylated, while EMX2 and HOXB1 were hypermethylated. WT1 was significantly hypomethylated in juvenile DM (Δβ = -0.41, P < 0.001). Bisulfite pyrosequencing verification in samples from 56 patients with juvenile DM confirmed the methylation alterations of these genes. Similar methylation alterations were observed in juvenile polymyositis (n = 5) and other IIMs (n = 9). Concordant with the other findings, WT1 protein was increased in juvenile DM muscle, with average positive staining of 11.6%, but was undetectable in normal muscle (P < 0.001). CONCLUSION These results suggest that affected muscles of children with juvenile DM and IIMs have the capacity to be repaired, and that homeobox and WT1 genes are epigenetically marked to facilitate this repair process, potentially suggesting new avenues of therapeutic intervention.