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Methylation alterations of WT1 and homeobox genes in inflamed muscle biopsy samples from patients with untreated juvenile dermatomyositis suggest self-renewal capacity.

ABSTRACT: To determine the effect of methylation alteration in inflamed muscles from children with juvenile dermatomyositis (DM) and other idiopathic inflammatory myopathies (IIMs).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.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 (?? = -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).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.

SUBMITTER: Wang M

PROVIDER: S-EPMC3462248 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature

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Methylation alterations of WT1 and homeobox genes in inflamed muscle biopsy samples from patients with untreated juvenile dermatomyositis suggest self-renewal capacity.

Wang Min M Xie Hehuang H Shrestha Sheela S Sredni Simone S Morgan Gabrielle A GA Pachman Lauren M LM

Arthritis and rheumatism 20121001 10

<h4>Objective</h4>To determine the effect of methylation alteration in inflamed muscles from children with juvenile dermatomyositis (DM) and other idiopathic inflammatory myopathies (IIMs).<h4>Methods</h4>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 methylatio ...[more]

PMID: 22674142

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Project description:Background :To evaluate the impact of the duration of chronic inflammation on gene expression in skeletal muscle biopsies (MBx) from untreated children with juvenile dermatomyositis (JDM) and identify genes and biological processes associated with the disease progression, expression profiling data from 16 girls with active symptoms of JDM greater or equal to 2 months were compared with 3 girls with active symptoms less than 2 months. Results: Seventy-nine genes were differentially expressed between the groups with long or short duration of untreated disease. Genes involved in immune responses and vasculature remodeling were expressed at a higher level in muscle biopsies from children with greater or equal to 2 months of symptoms, while genes involved in stress responses and protein turnover were expressed at a lower level. Among the 79 genes, expression of 9 genes showed a significant linear regression relationship with the duration of untreated disease. Five differentially expressed genes--HLA-DQA1, smooth muscle myosin heavy chain, clustering, plexin D1 and tenomodulin--were verified by quantitative RT-PCR. The chronic inflammation of longer disease duration was also associated with increased DC-LAMP+ and BDCA2+ mature dendritic cells, identified by immunohistochemistry. Conclusions: We conclude that chronic inflammation alters the gene expression patterns in muscle of untreated children with JDM. Symptoms lasting greater or equal to 2 months were associated with dendritic cell maturation and anti-angiogenic vascular remodelling, directly contributing to disease pathophysiology. Experiment Overall Design: After obtaining informed consent, 23 girls with definite JDM were enrolled in this study prior to obtaining the MRI directed diagnostic muscle biopsy. All 23 JDM samples and 4 healthy age- and sex-matched controls were expression profiled and for first gene filtering. Only profiling data from untreated patients (19 profiles) were then analyzed statistically. Experiment Overall Design: disease duration : less than 2 months: YJD-JDM-2UA-s2,YJD-JDM-1UA-s2,YJD-JDM-16UA-s2 Experiment Overall Design: disease duration : more than 2 months:YJD-JDM-30UA-s2,YJD-JDM-19UA-s2,YJD-JDM-5UA-s2,YJD-JDM-21UA-s2,YJD-JDM-18UA-s2,YJD-JDM-3UA-s2,YJD-JDM-23UA-s2,YJD-JDM-9UA-S2,YJD-JDM-12UA-s2,YJD-JDM-14UA-s2,YJD-JDM-25UA-s2,YJD-JDM-8UA-s2,YJD-JDM-15UA-s2,YJD-JDM-13UA-s2,YJD-JDM-10UA-S2,YJD-JDM-6UA-s2.

Project description:ObjectiveJuvenile dermatomyositis (DM) is a rare and severe autoimmune condition characterized by rash and proximal muscle weakness. While some patients respond to standard treatment, others do not. This study was carried out to investigate whether histopathologic findings and myositis-specific autoantibodies (MSAs) have prognostic significance in juvenile DM.MethodsMuscle biopsy samples (n = 101) from patients in the UK Juvenile Dermatomyositis Cohort and Biomarker Study were stained, analyzed, and scored for severity of histopathologic features. In addition, autoantibodies were measured in the serum or plasma of patients (n = 90) and longitudinal clinical data were collected (median duration of follow-up 4.9 years). Long-term treatment status (on or off medication over time) was modeled using generalized estimating equations.ResultsMuscle biopsy scores differed according to MSA subgroup. When the effects of MSA subgroup were accounted for, increased severity of muscle histopathologic features was predictive of an increased risk of remaining on treatment over time: for the global pathology score (histopathologist's visual analog scale [hVAS] score), 1.48-fold higher odds (95% confidence interval [95% CI] 1.12-1.96; P = 0.0058), and for the total biopsy score (determined with the standardized score tool), 1.10-fold higher odds (95% CI 1.01-1.21; P = 0.038). A protective effect was identified in patients with anti-Mi-2 autoantibodies, in whom the odds of remaining on treatment were 7.06-fold lower (95% CI 1.41-35.36; P = 0.018) despite muscle biopsy scores indicating more severe disease. In patients with anti-nuclear matrix protein 2 autoantibodies, anti-transcription intermediary factor 1γ autoantibodies, or no detectable autoantibody, increased histopathologic severity alone, without adjustment for the effect of MSA subtype, was predictive of the risk of remaining on treatment: for the hVAS global pathology score, 1.61-fold higher odds (95% CI 1.16-2.22; P = 0.004), and for the total biopsy score, 1.13-fold higher odds (95% CI 1.03-1.24; P = 0.013).ConclusionHistopathologic severity, in combination with MSA subtype, is predictive of the risk of remaining on treatment in patients with juvenile DM and may be useful for discussing probable treatment length with parents and patients. Understanding these associations may identify patients at greater risk of severe disease.

Dataset Information

Methylation alterations of WT1 and homeobox genes in inflamed muscle biopsy samples from patients with untreated juvenile dermatomyositis suggest self-renewal capacity.

Publications

Methylation alterations of WT1 and homeobox genes in inflamed muscle biopsy samples from patients with untreated juvenile dermatomyositis suggest self-renewal capacity.

Similar Datasets

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