TY - JOUR
T1 - Expanded [CCTG]n repetitions are not associated with abnormal methylation at the CNBP locus in myotonic dystrophy type 2 (DM2) patients
AU - Santoro, Massimo
AU - Fontana, Luana
AU - Maiorca, Francesca
AU - Centofanti, Federica
AU - Massa, Roberto
AU - Silvestri, Gabriella
AU - Novelli, Giuseppe
AU - Botta, Annalisa
PY - 2018
Y1 - 2018
N2 - Myotonic Dystrophy type 2 (DM2) is a multisystemic disorder associated with an expanded [CCTG]n repeat in intron 1 of the CNBP gene. Epigenetic modifications have been reported in many repeat expansion disorders, including myotonic dystrophy type 1 (DM1), either as a mechanism to explain somatic repeat instability or transcriptional alterations in disease genes. The purpose of our work was to determine the effect of DM2 mutation on the methylation status of CpG islands localized in the 5â² promoter region and in the 3â² end of the [CCTG]n expansion of the CNBP gene. By bisulfite pyrosequencing, we characterized the methylation profile of two different CpG islands within these regions, either in whole blood and skeletal muscle tissues of DM2 patients (n = 72 and n = 7, respectively) and controls (n = 50 and n = 7, respectively). Moreover, we compared the relative mRNA transcript levels of CNBP gene in leukocytes and in skeletal muscle tissues from controls and DM2 patients. We found that CpG sites located in the promoter region showed hypomethylation, whereas CpG sites at 3â² end of the CCTG array are hypermethylated. Statistical analyses did not demonstrate any significant differences in the methylation profile between DM2 patients and controls in both tissues analyzed. According to the methylation analysis, CNBP gene expression levels are not significantly altered in DM2 patients. These results show that [CCTG]n repeat expansion, differently from the DM1 mutation, does not influence the methylation status of the CNBP gene and suggest that other molecular mechanisms are involved in the pathogenesis of DM2.
AB - Myotonic Dystrophy type 2 (DM2) is a multisystemic disorder associated with an expanded [CCTG]n repeat in intron 1 of the CNBP gene. Epigenetic modifications have been reported in many repeat expansion disorders, including myotonic dystrophy type 1 (DM1), either as a mechanism to explain somatic repeat instability or transcriptional alterations in disease genes. The purpose of our work was to determine the effect of DM2 mutation on the methylation status of CpG islands localized in the 5â² promoter region and in the 3â² end of the [CCTG]n expansion of the CNBP gene. By bisulfite pyrosequencing, we characterized the methylation profile of two different CpG islands within these regions, either in whole blood and skeletal muscle tissues of DM2 patients (n = 72 and n = 7, respectively) and controls (n = 50 and n = 7, respectively). Moreover, we compared the relative mRNA transcript levels of CNBP gene in leukocytes and in skeletal muscle tissues from controls and DM2 patients. We found that CpG sites located in the promoter region showed hypomethylation, whereas CpG sites at 3â² end of the CCTG array are hypermethylated. Statistical analyses did not demonstrate any significant differences in the methylation profile between DM2 patients and controls in both tissues analyzed. According to the methylation analysis, CNBP gene expression levels are not significantly altered in DM2 patients. These results show that [CCTG]n repeat expansion, differently from the DM1 mutation, does not influence the methylation status of the CNBP gene and suggest that other molecular mechanisms are involved in the pathogenesis of DM2.
KW - Bisulfite pyrosequencing
KW - CNBP expression
KW - Methylation
KW - Molecular Biology
KW - Molecular Medicine
KW - Myotonic dystrophy type 2
KW - Bisulfite pyrosequencing
KW - CNBP expression
KW - Methylation
KW - Molecular Biology
KW - Molecular Medicine
KW - Myotonic dystrophy type 2
UR - http://hdl.handle.net/10807/112425
UR - http://www.elsevier.com/locate/bbadis
U2 - 10.1016/j.bbadis.2017.12.037
DO - 10.1016/j.bbadis.2017.12.037
M3 - Article
SN - 0925-4439
VL - 1864
SP - 917
EP - 924
JO - BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR BASIS OF DISEASE
JF - BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR BASIS OF DISEASE
ER -