3,118 research outputs found
Girls Count: A Global Investment & Action Agenda
Explains how girls' welfare affects overall economic and social outcomes. Outlines steps to disaggregate health, education, and other data by age and gender; invest strategically in girls' programs; and ensure equitable benefits for girls in all sectors
Automobile Insurance--Assignment, Subrogation and the Real Party in Interest Statute in Missouri
Regulation of Neuronal Survival and Death by E2F-Dependent Gene Repression and Derepression
AbstractNeuronal death induced by a variety of means requires participation of the E2F family of transcription factors. Here, we show that E2F acts as a gene silencer in neurons and that repression of E2F-responsive genes is required for neuronal survival. Moreover, neuronal death evoked by DNA damaging agents or trophic factor withdrawal is characterized by derepression of E2F-responsive genes. Such derepression, rather than direct E2F-promoted gene activation, is required for death. Among the genes that are derepressed in neurons subjected to DNA damage or trophic factor withdrawal are the transcription factors B- and C-myb. Overexpression of B- and C-myb is sufficient to evoke neuronal death. These findings support a model in which E2F-dependent gene repression and derepression play pivotal roles in neuronal survival and death, respectively
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Dominant-negative ATF5 rapidly depletes survivin in tumor cells.
Survivin (BIRC5, product of the BIRC5 gene) is highly expressed in many tumor types and has been widely identified as a potential target for cancer therapy. However, effective anti-survivin drugs remain to be developed. Here we report that both vector-delivered and cell-penetrating dominant-negative (dn) forms of the transcription factor ATF5 that promote selective death of cancer cells in vitro and in vivo cause survivin depletion in tumor cell lines of varying origins. dn-ATF5 decreases levels of both survivin mRNA and protein. The depletion of survivin protein appears to be driven at least in part by enhanced proteasomal turnover and depletion of the deubiquitinase USP9X. Survivin loss is rapid and precedes the onset of cell death triggered by dn-ATF5. Although survivin downregulation is sufficient to drive tumor cell death, survivin over-expression does not rescue cancer cells from dn-ATF5-promoted apoptosis. This indicates that dn-ATF5 kills malignant cells by multiple mechanisms that include, but are not limited to, survivin depletion. Cell-penetrating forms of dn-ATF5 are currently being developed for potential therapeutic use and the present findings suggest that they may pose an advantage over treatments that target only survivin
Manipulation and Study of Gene Expression in Neurotoxin- Treated Neuronal PC12 and SH-SY5Y Cells for In Vitro Studies of Parkinson’s Disease
Neuronal PC12 and SH-SY5Y cells are highly suitable in vitro models for study of the neurodegenerative mechanisms occurring in Parkinson’s disease (PD). Differentiated PC12 and SH-SY5Y cells bear many similarities to the neuronal populations affected in PD, and they provide a convenient source of large amounts of homogeneous material for biochemical and molecular downstream applications. In the present review, we describe how to differentiate PC12 and SH-SY5Y cells into neuron-like cells and provide protocols for their transfection with plasmids and infection with viral particles to manipulate gene expression. We also describe how to treat neuronal PC12 and SH-SY5Y cells with the classical PD neurotoxins 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-pyridinium ion (MPP+). Finally, we give detailed methods for several downstream applications useful for the analysis of cell death pathways in PD
The influence of snow depth and hardness on winter habitat selection by caribou on the southwest coast of Newfoundland
LaPoile Herd caribou winter in the coastal margin of their range in southwestern Newfoundland. Reduced snow depths near the coast (0-20 km inland), as a result of moderated winter temperatures and low elevations, appear to provide more favourable foraging conditions than do areas further inland. In the latter areas greatly increased snow depth and hardness combine to create very extreme winter conditions and these areas are avoided by caribou throughout the winter period
Isolation and Culture of Post-Natal Mouse Cerebellar Granule Neuron Progenitor Cells and Neurons
The cerebellar cortex is a well described structure that provides unique opportunities for studying neuronal properties and development1,2. Of the cerebellar neuronal types (granule cells, Purkinje cells and inhibitory interneurons), granule neurons are by far the most numerous and are the most abundant type of neurons in the mammalian brain. In rodents, cerebellar granule neurons are generated during the first two post-natal weeks from progenitor cells in the outermost layer of the cerebellar cortex, the external granule layer (EGL). The protocol presented here describes techniques to enrich and culture granule neurons and their progenitor cells from post-natal mouse cerebellum. We will describe procedures to obtain cultures of increasing purity3,4, which can be used to study the differentiation of proliferating progenitor cells into granule neurons5,6. Once the progenitor cells differentiate, the cultures also provide a homogenous population of granule neurons for experimental manipulation and characterization of phenomena such as synaptogenesis, glutamate receptor function7, interaction with other purified cerebellar cells8,9 or cell death7
Regression/eradication of gliomas in mice by a systemically-deliverable ATF5 dominant-negative peptide.
Malignant gliomas have poor prognosis and urgently require new therapies. Activating Transcription Factor 5 (ATF5) is highly expressed in gliomas, and interference with its expression/function precipitates targeted glioma cell apoptosis in vitro and in vivo. We designed a novel deliverable truncated-dominant-negative (d/n) form of ATF5 fused to a cell-penetrating domain (Pen-d/n-ATF5-RP) that can be intraperitoneally/subcutaneously administered to mice harboring malignant gliomas generated; (1) by PDGF-B/sh-p53 retroviral transformation of endogenous neural progenitor cells; and (2) by human U87-MG xenografts. In vitro Pen-d/n-ATF5-RP entered into glioma cells and triggered massive apoptosis. In vivo, subcutaneously-administered Pen-d/n-ATF5-RP passed the blood brain barrier, entered normal brain and tumor cells, and then caused rapid selective tumor cell death. MRI verified elimination of retrovirus-induced gliomas within 8-21 days. Histopathology revealed growth-suppression of intracerebral human U87-MG cells xenografts. For endogenous PDGF-B gliomas, there was no recurrence or mortality at 6-12 months versus 66% mortality in controls at 6 months. Necropsy and liver-kidney blood enzyme analysis revealed no adverse effects on brain or other tissues. Our findings thus identify Pen-d/n-ATF5-RP as a potential therapy for malignant gliomas
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