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result(s) for
"Moerman, Don"
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eEF2K inhibition blocks Aβ42 neurotoxicity by promoting an NRF2 antioxidant response
by
Somasekharan, Syam Prakash
,
Bhanshali, Forum
,
Delaidelli, Alberto
in
Alzheimer Disease - enzymology
,
Alzheimer Disease - therapy
,
Amyloid beta-Peptides - genetics
2017
Soluble oligomers of amyloid-β (Aβ) impair synaptic plasticity, perturb neuronal energy homeostasis, and are implicated in Alzheimer’s disease (AD) pathogenesis. Therefore, significant efforts in AD drug discovery research aim to prevent the formation of Aβ oligomers or block their neurotoxicity. The eukaryotic elongation factor-2 kinase (eEF2K) plays a critical role in synaptic plasticity, and couples neurotransmission to local dendritic mRNA translation. Recent evidence indicates that Aβ oligomers activate neuronal eEF2K, suggesting a potential link to Aβ induced synaptic dysfunction. However, a detailed understanding of the role of eEF2K in AD pathogenesis, and therapeutic potential of eEF2K inhibition in AD, remain to be determined. Here, we show that eEF2K activity is increased in postmortem AD patient cortex and hippocampus, and in the hippocampus of aged transgenic AD mice. Furthermore, eEF2K inhibition using pharmacological or genetic approaches prevented the toxic effects of Aβ42 oligomers on neuronal viability and dendrite formation in vitro. We also report that eEF2K inhibition promotes the nuclear factor erythroid 2-related factor (NRF2) antioxidant response in neuronal cells, which was crucial for the beneficial effects of eEF2K inhibition in neurons exposed to Aβ42 oligomers. Accordingly, NRF2 knockdown or overexpression of the NRF2 inhibitor, Kelch-Like ECH-Associated Protein-1 (Keap1), significantly attenuated the neuroprotection associated with eEF2K inhibition. Finally, genetic deletion of the eEF2K ortholog
efk
-
1
reduced oxidative stress, and improved chemotaxis and serotonin sensitivity in
C. elegans
expressing human Aβ42 in neurons. Taken together, these findings highlight the potential utility of eEF2K inhibition to reduce Aβ-mediated oxidative stress in AD.
Journal Article
A Strategy To Isolate Modifiers of Caenorhabditis elegans Lethal Mutations: Investigating the Endoderm Specifying Ability of the Intestinal Differentiation GATA Factor ELT-2
2018
The ELT-2 GATA factor normally functions in differentiation of the C. elegans endoderm, downstream of endoderm specification. We have previously shown that, if ELT-2 is expressed sufficiently early, it is also able to specify the endoderm and to replace all other members of the core GATA-factor transcriptional cascade (END-1, END-3, ELT-7). However, such rescue requires multiple copies (and presumably overexpression) of the end-1p::elt-2 cDNA transgene; a single copy of the transgene does not rescue. We have made this observation the basis of a genetic screen to search for genetic modifiers that allow a single copy of the end-1p::elt-2 cDNA transgene to rescue the lethality of the end-1 end-3 double mutant. We performed this screen on a strain that has a single copy insertion of the transgene in an end-1 end-3 background. These animals are kept alive by virtue of an extrachromosomal array containing multiple copies of the rescuing transgene; the extrachromosomal array also contains a toxin under heat shock control to counterselect for mutagenized survivors that have been able to lose the rescuing array. A screen of ∼14,000 mutagenized haploid genomes produced 17 independent surviving strains. Whole genome sequencing was performed to identify genes that incurred independent mutations in more than one surviving strain. The C. elegans gene tasp-1 was mutated in four independent strains. tasp-1 encodes the C. elegans homolog of Taspase, a threonine-aspartic acid protease that has been found, in both mammals and insects, to cleave several proteins involved in transcription, in particular MLL1/trithorax and TFIIA. A second gene, pqn-82, was mutated in two independent strains and encodes a glutamine-asparagine rich protein. tasp-1 and pqn-82 were verified as loss-of-function modifiers of the end-1p::elt-2 transgene by RNAi and by CRISPR/Cas9-induced mutations. In both cases, gene loss leads to modest increases in the level of ELT-2 protein in the early endoderm although ELT-2 levels do not strictly correlate with rescue. We suggest that tasp-1 and pqn-82 represent a class of genes acting in the early embryo to modulate levels of critical transcription factors or to modulate the responsiveness of critical target genes. The screen’s design, rescuing lethality with an extrachromosomal transgene followed by counterselection, has a background survival rate of <10−4 without mutagenesis and should be readily adapted to the general problem of identifying suppressors of C. elegans lethal mutations.
Journal Article
eEF2K inhibition blocks A beta 42 neurotoxicity by promoting an NRF2 antioxidant response
2017
Soluble oligomers of amyloid- beta (A beta ) impair synaptic plasticity, perturb neuronal energy homeostasis, and are implicated in Alzheimer's disease (AD) pathogenesis. Therefore, significant efforts in AD drug discovery research aim to prevent the formation of A beta oligomers or block their neurotoxicity. The eukaryotic elongation factor-2 kinase (eEF2K) plays a critical role in synaptic plasticity, and couples neurotransmission to local dendritic mRNA translation. Recent evidence indicates that A beta oligomers activate neuronal eEF2K, suggesting a potential link to A beta induced synaptic dysfunction. However, a detailed understanding of the role of eEF2K in AD pathogenesis, and therapeutic potential of eEF2K inhibition in AD, remain to be determined. Here, we show that eEF2K activity is increased in postmortem AD patient cortex and hippocampus, and in the hippocampus of aged transgenic AD mice. Furthermore, eEF2K inhibition using pharmacological or genetic approaches prevented the toxic effects of A beta 42 oligomers on neuronal viability and dendrite formation in vitro. We also report that eEF2K inhibition promotes the nuclear factor erythroid 2-related factor (NRF2) antioxidant response in neuronal cells, which was crucial for the beneficial effects of eEF2K inhibition in neurons exposed to A beta 42 oligomers. Accordingly, NRF2 knockdown or overexpression of the NRF2 inhibitor, Kelch-Like ECH-Associated Protein-1 (Keap1), significantly attenuated the neuroprotection associated with eEF2K inhibition. Finally, genetic deletion of the eEF2K ortholog efk-1 reduced oxidative stress, and improved chemotaxis and serotonin sensitivity in C. elegans expressing human A beta 42 in neurons. Taken together, these findings highlight the potential utility of eEF2K inhibition to reduce A beta -mediated oxidative stress in AD.
Journal Article
Prepublication data sharing
by
Cooke, Robert M
,
El Emam, Khaled
,
Gunter, Chris
in
Access to Information
,
Cooperative Behavior
,
Guidelines as Topic
2009
At a time when advances in DNA sequencing technologies mean that many more laboratories can produce massive data sets, and when an ever-growing number of fields (beyond genome sequencing) are grappling with their own datasharing policies, a Data Release Workshop was convened in Toronto in May 2009 by Genome Canada and other funding agencies. In Toronto, attendees endorsed the value of rapid prepublication data release for large reference data sets in biology and medicine that have broad utility and agreed that prepublication data release should go beyond genomics and proteomics studies to other data sets - including chemical structure, metabolomic and RNA interference data sets, and to annotated clinical resources (cohorts, tissue banks and case-control studies).
Journal Article
eEF2K inhibition blocks Abeta42 neurotoxicity by promoting an NRF2 antioxidant response
by
Somasekharan, Syam Prakash
,
Bhanshali, Forum
,
Hayden, Michael R
in
Advertising executives
,
Alzheimer's disease
,
Amyloidosis
2017
Soluble oligomers of amyloid-[beta] (A[beta]) impair synaptic plasticity, perturb neuronal energy homeostasis, and are implicated in Alzheimer's disease (AD) pathogenesis. Therefore, significant efforts in AD drug discovery research aim to prevent the formation of A[beta] oligomers or block their neurotoxicity. The eukaryotic elongation factor-2 kinase (eEF2K) plays a critical role in synaptic plasticity, and couples neurotransmission to local dendritic mRNA translation. Recent evidence indicates that A[beta] oligomers activate neuronal eEF2K, suggesting a potential link to A[beta] induced synaptic dysfunction. However, a detailed understanding of the role of eEF2K in AD pathogenesis, and therapeutic potential of eEF2K inhibition in AD, remain to be determined. Here, we show that eEF2K activity is increased in postmortem AD patient cortex and hippocampus, and in the hippocampus of aged transgenic AD mice. Furthermore, eEF2K inhibition using pharmacological or genetic approaches prevented the toxic effects of A[beta]42 oligomers on neuronal viability and dendrite formation in vitro. We also report that eEF2K inhibition promotes the nuclear factor erythroid 2-related factor (NRF2) antioxidant response in neuronal cells, which was crucial for the beneficial effects of eEF2K inhibition in neurons exposed to A[beta]42 oligomers. Accordingly, NRF2 knockdown or overexpression of the NRF2 inhibitor, Kelch-Like ECH-Associated Protein-1 (Keap1), significantly attenuated the neuroprotection associated with eEF2K inhibition. Finally, genetic deletion of the eEF2K ortholog efk-1 reduced oxidative stress, and improved chemotaxis and serotonin sensitivity in C. elegans expressing human A[beta]42 in neurons. Taken together, these findings highlight the potential utility of eEF2K inhibition to reduce A[beta]-mediated oxidative stress in AD.
Journal Article
Quality of life and patient satisfaction after one-stage implant-based breast reconstruction with an acellular dermal matrix versus two-stage breast reconstruction (BRIOS): primary outcome of a randomised, controlled trial
by
Bouman, Mark-Bram
,
Young-Afat, Danny Aschwin
,
Twisk, Johannes Wilhelmus Rembertus
in
Acellular Dermis
,
Adult
,
Breast
2018
There is increasing interest in the use of acellular dermal matrices (ADMs) in implant-based breast reconstruction (IBBR). Suggested advantages are that ADMs facilitate one-stage IBBR and improve aesthetic outcomes. We compared immediate one-stage ADM-assisted IBBR with two-stage IBBR (current standard of care). Our previously reported secondary endpoint showed that one-stage ADM-assisted IBBR was associated with significantly more adverse outcomes. Here, we present the primary endpoint results aiming to assess whether one-stage IBBR with ADM provides higher patient-reported quality of life (QOL) compared with two-stage IBBR.
This multicentre, open-label, randomised controlled trial (BRIOS study) was done in eight hospitals in the Netherlands. We recruited women aged older than 18 years with breast carcinoma or a genetic predisposition who intended to undergo skin-sparing mastectomy and immediate IBBR. Participants were randomly assigned to undergo one-stage IBBR with ADM (Strattice, LifeCell, Branchburg, NJ, USA) or two-stage IBBR. Randomisation was stratified by centre and indication for surgery (oncological or prophylactic) in blocks of ten participants. The primary endpoint was patient-reported QOL, as measured with the BREAST-Q (ie, health-related QOL scales and satisfaction scales), in the modified intention-to-treat population. The study follow-up is complete. This study is registered with the Netherlands Trial Register, number NTR5446.
Between April 14, 2013, and May 29, 2015, we enrolled 142 women, of whom 69 were randomly assigned to receive one-stage ADM-assisted IBBR and 73 to receive two-stage IBBR. After exclusions, the modified intention-to-treat population comprised 60 patients in the one-stage group and 61 patients in the two-stage group. Of these, 48 women (mean follow-up 17·0 months [SD 7·8]) in the one-stage group and 44 women (17·2 months [SD 6·7]) in the two-stage group completed the BREAST-Q at least 1 year after implant placement. We found no significant differences in postoperative patient-reported QOL domains, including physical wellbeing (one-stage mean 78·0 [SD 14·1] vs two-stage 79·3 [12·2], p=0·60), psychosocial wellbeing (72·6 [17·3] vs 72·8 [19·6], p=0·95), and sexual wellbeing (58·0 [17·0] vs 57·1 [19·5], p=0·82), or in the patient-reported satisfaction domains: satisfaction with breasts (63·4 [15·8] vs 60·3 [15·4], p=0·35) and satisfaction with outcome (72·8 [19·1] vs 67·8 [16·3], p=0·19).
Taken together with our previously published findings, one-stage IBBR with ADM does not yield superior results in terms of patient-reported QOL compared with two-stage IBBR. Risks for adverse outcomes were significantly higher in the one-stage ADM group. Use of ADM for one-stage IBBM should be considered on a case-by-case basis.
Pink Ribbon, Nuts-Ohra, and LifeCell.
Journal Article