Post-natal knockout of prion protein alters hippocampal CA1 properties, but does not result in neurodegeneration

Mallucci, Giovanna R.; Ratté, Stéphanie; Asante, Emmanuel A.; Linehan, Jacqueline M.; Gowland, Ian; Jefferys, John G. R.; Collinge, John

doi:10.1093/emboj/21.3.202

Cited by 342 publications

(295 citation statements)

References 51 publications

(100 reference statements)

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“…Consistent with our observations in the PRNP −/− cattle, Prnp −/− mice with exclusive disruption on the Prnp ORF remained healthy 2,3 and showed only slightly abnormal phenotypes, such as altered synaptic function 29,30 and sleep-wake circadian rhythms 31,32 . However, the phenotype in the synaptic function appears to be normal in other murine genetic backgrounds 33 .We have monitored sleep-wake activity in the knockout cattle, along with age-, sex-and breed-matched wild-type controls, at frequent intervals throughout the day and night for one week, but did not observe any obvious alterations.…”

supporting

confidence: 89%

Production of cattle lacking prion protein

et al. 2006

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Prion diseases are caused by propagation of misfolded forms of the normal cellular prion protein PrP C , such as PrP BSE in bovine spongiform encephalopathy (BSE) in cattle and PrP CJD in Creutzfeldt-Jakob disease (CJD) in humans 1 . Disruption of PrP C expression in mice, a species that does not naturally contract prion diseases, results in no apparent developmental abnormalities [2][3][4][5] . However, the impact of ablating PrP C function in natural host species of prion diseases is unknown. Here we report the generation and characterization of PrP C -deficient cattle produced by a sequential gene-targeting system 6 . At over 20 months of age, the cattle are clinically, physiologically, histopathologically, immunologically and reproductively normal. Brain tissue homogenates are resistant to prion propagation in vitro as assessed by protein misfolding cyclic amplification 7 . PrP C -deficient cattle may be a useful model for prion research and could provide industrial bovine products free of prion proteins.To generate PrP C -deficient (PRNP −/− ) cattle, we transfected a male Holstein primary fetal fibroblast line 6594 with first and second knockout (KO) vectors (pBPrP(H)KOneo and pBPrP (H)KOpuro vectors) 6 to sequentially disrupt the two alleles of PRNP. PRNP −/− fetal cell lines were established at 40-60 d of gestation and three of the PRNP −/− fetal cell lines (5211, 5232 and 4296) were recloned to produce calves (Table 1 and Fig. 1a). To verify that the calves possess the PRNP −/− genotype, we collected ear biopsies and established fibroblast cell lines for genotyping. Genotyping was done by genomic PCR specific to each gene targeting event 6 (primer pairs: neoF7 × neoR7 and puroF14 × puroR14, Fig. 1b COMPETING INTERESTS STATEMENTThe authors declare competing financial interests (see the Nature Biotechnology website for details).Reprints and permissions information is available online at http://npg.nature.com/reprintsandpermissions/ NIH Public Access Fig. 1c) and confirmed the disruption of PRNP-specific mRNA expression in PRNP −/− calves. For protein expression analysis, we performed PrP-specific western blot analyses on fibroblasts (Fig. 1d), peripheral blood lymphocytes (Fig. 1e) and brain stem (Fig. 1f) from wild-type and PRNP −/− calves using the mouse anti-bovine PrP monoclonal antibody F89. We detected PrP-specific bands in the wild-type calves, whereas no reaction was observed in PRNP −/− calves and negative control mouse fibroblasts. These data clearly demonstrate that the PRNP gene is functionally inactivated in the PRNP −/− calves.PRNP −/− cattle were monitored for growth and general health status from birth to 20 months of age. Mean birth weight was 46 kg and average daily gain was 0.91 kg/d to 10 months. Both values were in the normal range for Holstein bulls. Serum chemistry was evaluated at 6 months of age and compared with published reference ranges. All the values for PRNP −/− calves (n = 12) were well within the reference range (Supplementary Table 1) and obvious abnormalities w...

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confidence: 89%

Production of cattle lacking prion protein

et al. 2006

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“…The data support the development of generic proteostatic approaches 22,28 to therapy-fine-tuning protein synthesis-in prion, and perhaps other neurodegenerative disorders involving protein misfolding. [7][8][9][10] . For all analyses n 5 3 mice unless otherwise stated.…”

Section: Research Lettermentioning

confidence: 99%

“…We examined hippocampi from prion-infected tg37 mice used in our previous experiments [7][8][9][10] , in which the time course of impairment and recovery are clearly defined. Hemizygous tg37 mice express mouse PrP at approximately three times wild-type levels and succumb to Rocky Mountain Laboratory (RML) prion infection within 12 weeks post infection (w.p.i.)…”

mentioning

confidence: 99%

“…Hemizygous tg37 mice express mouse PrP at approximately three times wild-type levels and succumb to Rocky Mountain Laboratory (RML) prion infection within 12 weeks post infection (w.p.i.) 10 . They first develop behavioural signs with decreased burrowing activity at approximately 9 w.p.i., after reduction in hippocampal synaptic transmission and first neuropathological changes 7,8 .…”

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confidence: 99%

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Sustained translational repression by eIF2α-P mediates prion neurodegeneration

Moreno

Radford

Peretti

et al. 2012

Nature

553

617

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The mechanisms leading to neuronal death in neurodegenerative disease are poorly understood. Many of these disorders, including Alzheimer's, Parkinson's and prion diseases, are associated with the accumulation of misfolded disease-specific proteins. The unfolded protein response is a protective cellular mechanism triggered by rising levels of misfolded proteins. One arm of this pathway results in the transient shutdown of protein translation, through phosphorylation of the a-subunit of eukaryotic translation initiation factor, eIF2. Activation of the unfolded protein response and/or increased eIF2a-P levels are seen in patients with Alzheimer's, Parkinson's and prion diseases 1-4 , but how this links to neurodegeneration is unknown. Here we show that accumulation of prion protein during prion replication causes persistent translational repression of global protein synthesis by eIF2a-P, associated with synaptic failure and neuronal loss in prion-diseased mice. Further, we show that promoting translational recovery in hippocampi of prion-infected mice is neuroprotective. Overexpression of GADD34, a specific eIF2a-P phosphatase, as well as reduction of levels of prion protein by lentivirally mediated RNA interference, reduced eIF2a-P levels. As a result, both approaches restored vital translation rates during prion disease, rescuing synaptic deficits and neuronal loss, thereby significantly increasing survival. In contrast, salubrinal, an inhibitor of eIF2a-P dephosphorylation 5 , increased eIF2a-P levels, exacerbating neurotoxicity and significantly reducing survival in priondiseased mice. Given the prevalence of protein misfolding and activation of the unfolded protein response in several neurodegenerative diseases, our results suggest that manipulation of common pathways such as translational control, rather than disease-specific approaches, may lead to new therapies preventing synaptic failure and neuronal loss across the spectrum of these disorders.Neurodegenerative diseases pose an ever-increasing challenge for society and health care systems worldwide, but their molecular pathogenesis is still largely unknown and no curative treatments exist. Alzheimer's (AD), Parkinson's (PD) and prion diseases are separate clinical and pathological conditions, but it is likely they share common mechanisms leading to neuronal death. Mice with prion disease show misfolded prion protein (PrP) accumulation and develop extensive neurodegeneration (with profound neurological deficits), in contrast to mouse models of AD or PD, in which neuronal loss is rare. Uniquely therefore, prion-infected mice allow access to mechanisms linking protein misfolding with neuronal death. Prion replication involves the conversion of cellular PrP, PrP C , to its misfolded, aggregating conformer, PrP Sc , a process leading ultimately to neurodegeneration 6 . We have previously shown rescue of neuronal loss and reversal of early cognitive and morphological changes in prion-infected mice by depleting PrP in neurons, preventing prion replication and ab...

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“…Recent studies indicate that these mice also show increased susceptibility to glutamate excitotoxicity (Khosravani et al, 2008a;Rangel et al, 2007;Walz et al, 1999;Walz et al, 2002) as a result of changes in the expression of glutamate receptor subunits (Khosravani et al, 2008a;Lledo et al, 1996;Rangel et al, 2007). More recently, a conditional knockout of PrP c has been generated (Mallucci et al, 2002). These mice do not show the behavioral alterations of infected mice unless PrP aggregates are formed (Mallucci et al, 2003;Mallucci et al, 2007).…”

Section: Prnp-deficient Micementioning

confidence: 99%