Adult neural function requires MeCP2.

Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Science (Impact Factor: 31.48). 06/2011; 333(6039):186. DOI: 10.1126/science.1206593
Source: PubMed

ABSTRACT Rett syndrome (RTT) is a postnatal neurological disorder caused by mutations in MECP2, encoding the epigenetic regulator methyl-CpG-binding protein 2 (MeCP2). The onset of RTT symptoms during early life together with findings suggesting neurodevelopmental abnormalities in RTT and mouse models of RTT raised the question of whether maintaining MeCP2 function exclusively during early life might protect against disease. We show by using an inducible model of RTT that deletion of Mecp2 in adult mice recapitulates the germline knock-out phenotype, underscoring the ongoing role of MeCP2 in adult neurological function. Moreover, unlike the effects of other epigenetic instructions programmed during early life, the effects of early MeCP2 function are lost soon after its deletion. These findings suggest that therapies for RTT must be maintained throughout life.

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    ABSTRACT: Males are predominantly affected by autism spectrum disorders (ASD) with a prevalence ratio of 5:1. However, the underlying pathological mechanisms governing the male preponderance of ASD remain unclear. Recent studies suggested that epigenetic aberrations may cause synaptic dysfunctions, which might be related to the pathophysiology of ASD. In this study, we used rat offspring prenatally exposed to valproic acid (VPA) as an animal model of ASD. We found male-selective abnormalities in the kinetic profile of the excitatory glutamatergic synaptic protein expressions linked to N-methyl-D-aspartate receptor (NMDAR), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and metabotropic glutamate receptor 5 (mGluR5) pathways in the prefrontal cortex of the VPA-exposed offspring at postnatal weeks 1, 2, and 4. Furthermore, VPA exposure showed a male-specific attenuation of the methyl-CpG-binding protein 2 (MeCP2) expressions both in the prefrontal cortex of offspring and in the gender-isolated neural progenitor cells (NPCs). In the gender-isolated NPCs culture, higher concentration of VPA induced an increased glutamatergic synaptic development along with decreased MeCP2 expression in both genders suggesting the role of MeCP2 in the modulation of synaptic development. In the small interfering RNA (siRNA) knock-down study, 50 pmol of Mecp2 siRNA inhibited the MeCP2 expression in male- but not in female-derived NPCs with concomitant induction of postsynaptic proteins such as PSD95. Taken together, we suggest that the male-inclined reduction of MeCP2 expression is involved in the abnormal development of glutamatergic synapse and male preponderance in the VPA animal models of ASD.
    Molecular Neurobiology 11/2014; DOI:10.1007/s12035-014-8987-z · 5.29 Impact Factor
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    PLoS ONE 12/2014; 9(12):e115444. DOI:10.1371/journal.pone.0115444 · 3.53 Impact Factor
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    ABSTRACT: Rett syndrome (RTT) is a genetic disorder characterized by a range of features including cognitive impairment, gait abnormalities and a reduction in purposeful hand skills. Mice harbouring knockout mutations in the Mecp2 gene display many RTT-like characteristics and are central to efforts to find novel therapies for the disorder. As hand stereotypies and gait abnormalities constitute major diagnostic criteria in RTT, it is clear that motor and gait-related phenotypes will be of importance in assessing preclinical therapeutic outcomes. We therefore aimed to assess gait properties over the prodromal phase in a functional knockout mouse model of RTT. In male Mecp2 knockout mice, we observed alterations in stride, coordination and balance parameters at 4 weeks of age, before the onset of other overt phenotypic changes as revealed by observational scoring. These data suggest that gait measures may be used as a robust and early marker of MeCP2-dysfunction in future preclinical therapeutic studies.
    PLoS ONE 11/2014; 9(11):e112889. DOI:10.1371/journal.pone.0112889 · 3.53 Impact Factor


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