Disrupted microRNA expression caused by Mecp2 loss in a mouse model of Rett syndrome.
MicroRNAs (miRNAs) are short non-coding RNA molecules that regulate post-transcriptional gene expression. They influence a wide range of physiological functions, including neuronal processes, and are regulated by various mechanisms, such as DNA methylation. This epigenetic mark is recognized by transcriptional regulators such as the methyl CpG binding protein Mecp2. Rett syndrome is a complex neurological disorder that has been associated with mutations in the gene coding for Mecp2. Thus, we examined the possible miRNA misregulation caused by Mecp2 absence in a mouse model of Rett syndrome. Using miRNA expression microarrays, we observed that the brain of Rett syndrome mice undergoes a disruption of the expression profiles of miRNAs. Among the significantly altered miRNAs (26%, 65 of 245), overall downregulation of these transcripts was the most common feature (71%), whilst the remaining 30% were upregulated. Further validation by quantitative RT-PCR demonstrated that the most commonly disrupted miRNAs were miR-146a, miR-146b, miR-130, miR-122a, miR-342 and miR-409 (downregulated), and miR-29b, miR329, miR-199b, miR-382, miR-296, miR-221 and miR-92 (upregulated). Most importantly, transfection of miR-146a in a neuroblastoma cell line caused the downregulation of IL-1 receptor-associated kinase 1 (Irak1) levels, suggesting that the identified defect of miR-146a in Rett syndrome mice brains might be responsible for the observed upregulation of Irak1 in this model of the human disease. Overall, we provide another level of molecular deregulation occurring in Rett syndrome that might be useful for understanding the disease and for designing targeted therapies.
Urdinguio
Rocio G
RG
Cancer Epigenetics and Biology Program (PEBC); Bellvitge Biomedical Research Institute, L’Hospitalet, Barcelona, Catalonia, Spain.
Fernandez
Agustin F
AF
Lopez-Nieva
Pilar
P
Rossi
Simona
S
Huertas
Dori
D
Kulis
Marta
M
Liu
Chang-Gong
CG
Croce
Carlo M
CM
Calin
George A
GA
Esteller
Manel
M
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D004195:Disease Models, Animal; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics; D008297:Male; D051783:Methyl-CpG-Binding Protein 2 / Q000172:deficiency* / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D012323:RNA Processing, Post-Transcriptional; D015518:Rett Syndrome / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; C497393:Mecp2 protein, mouse; D051783:Methyl-CpG-Binding Protein 2; D035683:MicroRNAs; C534190:Mirn146 microRNA, mouse; D053592:Interleukin-1 Receptor-Associated Kinases; C507769:Irak1 protein, mouse