4,325 research outputs found
Providence College Faculty Author Series 2012-2013: Dr. Adrian Weimer
Full text linkDr. Adrian Weimer (History, Providence College) discusses her new book Martyrs\u27 Mirror: Persecution and Holiness in Early New England and the cultural importance of martyrdom within Colonial America
Providence College Faculty Author Series 2012-2013: Dr. Adrian Weimer
No full textDr. Adrian Weimer (History, Providence College) discusses her new book Martyrs\u27 Mirror: Persecution and Holiness in Early New England and the cultural importance of martyrdom within Colonial America
Adrian Matejka, 34th Annual ODU Literary Festival
No full textAdrian Matejka is the author of The Devil’s Garden and Mixology, which was a winner of the 2008 National Poetry Series. He is the recipient of two Illinois Arts Council Literary Awards and fellowships from Cave Canem and the Lannan Foundation. His work has been featured in American Poetry Review, The Best American Poetry 2010, and Ploughshares, among other journals and anthologies. He teaches at Southern Illinois University Edwardsville
The molecular basis of variable phenotypic severity among common missense mutations causing Rett syndrome
Full text linkRett syndrome is caused by mutations in the X-linked MECP2 gene, which encodes a chromosomal protein that binds to methylated DNA. Mouse models mirror the human disorder and therefore allow investigation of phenotypes at a molecular level. We describe an Mecp2 allelic series representing the three most common missense Rett syndrome (RTT) mutations, including first reports of Mecp2[R133C] and Mecp2[T158M] knock-in mice, in addition to Mecp2[R306C] mutant mice. Together these three alleles comprise ∼25% of all RTT mutations in humans, but they vary significantly in average severity. This spectrum is mimicked in the mouse models; R133C being least severe, T158M most severe and R306C of intermediate severity. Both R133C and T158M mutations cause compound phenotypes at the molecular level, combining compromised DNA binding with reduced stability, the destabilizing effect of T158M being more severe. Our findings contradict the hypothesis that the R133C mutation exclusively abolishes binding to hydroxymethylated DNA, as interactions with DNA containing methyl-CG, methyl-CA and hydroxymethyl-CA are all reduced in vivo. We find that MeCP2[T158M] is significantly less stable than MeCP2[R133C], which may account for the divergent clinical impact of the mutations. Overall, this allelic series recapitulates human RTT severity, reveals compound molecular aetiologies and provides a valuable resource in the search for personalized therapeutic interventions.</p
Book Review: Bird Migration: A General Survey
No full textBook Review: Bird Migration: A General Survey (2nd edn)Book Author: P. Berthold.Oxford Ornithology Series, Oxford University Press, Oxford. 2001.Pp. 253. Price £27.50. ISBN 0 19 850786 0 (hardback); 019 850787 9 (paperback
The second report of the Seychelles Bird Records Committee
No full textVolume: 8Start Page: 23End Page: 2
Human neuronal LUHMES cell line as a model system for studying Rett syndrome
Full text linkRett syndrome (RTT) is a severe neurological disorder that affects approximately 1:10000
girls. Classical RTT is defined by a developmental regression phase and subsequent
stabilisation of diagnostic criteria, which include partial or complete loss of spoken
language, dyspraxic gait and stereotypic hand movements such as hand mouthing. RTT is a
monogenic disorder, with the majority of cases being due to loss-of-function mutations in
MeCP2 (methyl-CpG binding protein 2). Due to this clear genotype-phenotype link multiple
RTT mouse models have been used to elucidate the molecular details, and consequent
neuropathogenesis, of this complex neurological disease, as well as for the development of
potential therapeutics for RTT. However, as the molecular details become clearer, the need
for a simpler model system becomes evident. Human induced pluripotent stem cells
(hiPSCs) generated from RTT patient fibroblasts are an option; however the handling of
these cells is laborious, time-consuming and expensive and they often differentiate into a
heterogeneous population of cells. To explore an alternative human model system I have
been genetically engineering and experimenting with the human dopaminergic LUHMES
cell line. LUHMES cells are an immortalised pre-neuronal cell line derived from an 8-week
old, female foetus and can readily be differentiated into a homogeneous population of
mature, electrically active neurons in just one week. In this thesis I have assessed the
phenotypic properties of the wild-type cell line, demonstrated the ease of genetic
manipulation of LUHMES cells by CRISPR/Cas9 approaches, generated seven mutant
MECP2 LUHMES cell lines and explored the potential of protein therapy as a therapeutic
approach for RTT. The LUHMES cell line proves to be extremely easy to handle and robust
and has yielded novel molecular insights into the function of MeCP2 in human neurons. In
particular, MeCP2-null cells show a striking relationship between the level of gene body
methylation and the extent of transcriptional upregulation when compared to wild-type
neurons. In contrast neurons that express a form of MeCP2 that can bind to DNA but cannot
recruit a transcriptional corepressor complex (the R306C mutant) do not exhibit substantial
gene expression alterations, yet do display a consistent decrease in total RNA amount. This
decrease in total RNA is recapitulated in MeCP2-null LUHMES-derived neurons and in
brain regions from MeCP2-R306C mice. The requirement for functional DNA binding for
normal gene-body methylation dependent gene repression is demonstrated by assessing
LUHMES cells that overexpress MeCP2-R111G, a protein that cannot bind to DNA.
Furthermore, overexpression of the MeCP2-R306C protein highlights the importance of
NCoR binding for normal gene repression, but also demonstrates that MeCP2-R306C protein
retains some gene repression activity. Thinking more broadly, this cell line also has
applications as a model system for a variety of other neurological disorders; as a simplified
model system to elucidate molecular and neurological phenotypes, and as a relevant human system that can be cultured in a high-throughput manner for testing therapeutic strategies
Performing the archive: following in the footsteps
Full text linkUsing documentation of Mike Pearson's performance 'Bubbling Tom', Deirdre Heddon attempts to step into his shoes and re-perform it
Towards a CRISPR-mediated therapy for Rett Syndrome
Full text linkRett syndrome (RTT) is a severe neurological disorder which is caused by
mutations in the X-linked gene MECP2 (methyl-CpG binding protein 2). RTT-like symptoms can be reversed in Mecp2-null mice by restoring MeCP2
expression, which suggests that the disorder may be curable. Based on this,
there has been a major focus on developing therapeutic strategies which can
restore MeCP2 levels. However, MeCP2 overexpression also leads to
neurological dysfunction, and so achieving safe but effective MeCP2 levels is
a significant challenge for conventional gene therapy approaches.
Most RTT-causing mutations affect two discrete domains which are necessary
and sufficient for MeCP2 function. However, some RTT-causing mutations
affect the region C-terminal to these domains. These include the missense
mutation P322L and a group of C-terminal deletions which account for
approximately 10% of RTT cases. These mutations cause RTT due to a
dramatic reduction in MeCP2 protein levels. Since mouse models lacking the
C-terminus of MeCP2 express normal levels of MeCP2 and do not have RTT-like symptoms, we hypothesised that removal of the mutant C-terminus would
restore MeCP2 protein levels and alleviate RTT-like symptoms.
This work investigates the potential of using CRISPR (clustered regularly
interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9)
to restore protein levels of P322L and the most prevalent C-terminal deletion.
Guide RNAs can be designed which target Cas9 to the mutant allele, where it
introduces a double-stranded break in the DNA. Since endogenous repair of
CRISPR/Cas9-induced lesions often generates frameshift-causing mutations,
we predicted that most repair products would generate stable C-terminally
truncated MeCP2. The advantages of this approach are that MECP2 remains
under the control of its regulatory elements, circumventing any issues with
gene dosage, and that cutting by transient expression of CRISPR/Cas9
components should provide permanent correction.
Using cell culture models I have demonstrated that CRISPR/Cas9 targeting of
P322L and a C-terminal deletion predominantly generates repair products with
increased protein levels. The stage is therefore set to determine whether
CRISPR/Cas9 targeting in vivo also increases MeCP2 protein levels in mouse
models of RTT, and whether this is sufficient to alleviate RTT-like symptoms.
The promising results in cell culture suggest that there is potential to translate
these findings into a therapy for RTT patients
- …
