8 research outputs found
Immunotherapy Targeting Pathological Tau Conformers in a Tangle Mouse Model Reduces Brain Pathology with Associated Functional Improvements
Immunotherapies for various neurodegenerative diseases have recently emerged as a promising approach for clearing pathological protein conformers in these disorders. This type of treatment has not been assessed in models that develop neuronal tau aggregates as observed in frontotemporal dementia and Alzheimer's disease. Here, we present that active immunization with a phosphorylated tau epitope, in P301L tangle model mice, reduces aggregated tau in the brain and slows progression of the tangle-related behavioral phenotype. Females had more tau pathology than males but were also more receptive to the immunotherapy. The tau antibodies generated in these animals recognized pathological tau on brain sections. Performance on behavioral assays that require extensive motor coordination correlated with tau pathology in corresponding brain areas, and antibody levels against the immunogen correlated inversely with tau pathology. Interestingly, age-dependent autoantibodies that recognized recombinant tau protein but not the immunogen were detected in the P301L mice. To confirm that anti-tau antibodies could enter the brain and bind to pathological tau, FITC-tagged antibodies purified from a P301L mouse, with a high antibody titer against the immunogen, were injected into the carotid artery of P301L mice. These antibodies were subsequently detected within the brain and colocalized with PHF1 and MC1 antibodies that recognize pathological tau. Currently, no treatment is available for clearing tau aggregates. Our present findings may lead to a novel therapy targeting one of the major hallmarks of Alzheimer's disease and frontotemporal dementia
Soluble forms of tau are toxic in Alzheimer's disease
Accumulation of neurofibrillary tangles (NFT), intracellular inclusions of fibrillar forms of tau, is a hallmark of Alzheimer Disease. NFT have been considered causative of neuronal death, however, recent evidence challenges this idea. Other species of tau, such as soluble misfolded, hyperphosphorylated, and mislocalized forms, are now being implicated as toxic. Here we review the data supporting soluble tau as toxic to neurons and synapses in the brain and the implications of these data for development of therapeutic strategies for Alzheimerâs disease and other tauopathies
Immunotherapy targeting pathological tau conformers in a tangle mouse model reduces brain pathology with associated functional improvements
Immunotherapies for various neurodegenerative diseases have recently emerged as a promising approach for clearing pathological protein conformers in these disorders. This type of treatment has not been assessed in models that develop neuronal tau aggregates as observed in frontotemporal dementia and Alzheimer's disease. Here, we present that active immunization with a phosphorylated tau epitope, in P301L tangle model mice, reduces aggregated tau in the brain and slows progression of the tangle-related behavioral phenotype. Females had more tau pathology than males but were also more receptive to the immunotherapy. The tau antibodies generated in these animals recognized pathological tau on brain sections. Performance on behavioral assays that require extensive motor coordination correlated with tau pathology in corresponding brain areas, and antibody levels against the immunogen correlated inversely with tau pathology. Interestingly, age-dependent autoantibodies that recognized recombinant tau protein but not the immunogen were detected in the P301L mice. To confirm that anti-tau antibodies could enter the brain and bind to pathological tau, FITC-tagged antibodies purified from a P301L mouse, with a high antibody titer against the immunogen, were injected into the carotid artery of P301L mice. These antibodies were subsequently detected within the brain and colocalized with PHF1 and MC1 antibodies that recognize pathological tau. Currently, no treatment is available for clearing tau aggregates. Our present findings may lead to a novel therapy targeting one of the major hallmarks of Alzheimer's disease and frontotemporal dementia
Alpha-synuclein deficiency in the C57BL/6JOlaHsd strain does not modify disease progression in the ME7-model of prion disease
We previously detailed how intrahippocampal inoculation of C57BL/6J mice with murine modified scrapie (ME7) leads to chronic neurodegeneration (Cunningham C, Deacon R, Wells H, Boche D, Waters S, Diniz CP, Scott H, Rawlins JN, Perry VH (2003) Eur J Neurosci 17:2147â2155.). Our characterization of the ME7-model is based on inoculation of this murine modified scrapie agent into C57BL/6J mice from Harlan laboratories. This agent in the C57BL/6J host generates a disease that spans a 24-week time course. The hippocampal pathology shows progressive misfolded prion (PrPSc) deposition, astrogliosis and leads to behavioural dysfunction underpinned by the early synaptic loss that precedes neuronal death. The Harlan C57BL/6J, although widely used as a wild type mouse, are a sub-strain harbouring a spontaneous deletion of ?-synuclein with the full description C57BL/6JOlaHsd. Recently ?-synuclein has been shown to ameliorate the synaptic loss in a mouse model lacking the synaptic chaperone CSP-?. This opens a potential confound of the ME7-model, particularly with respect to the signature synaptic loss that underpin the physiological and behavioural dysfunction. To investigate if this strain-selective loss of a candidate disease modifier impacts on signature ME7 pathology, we compared cohorts of C57BL/6JOlaHsd (?-synuclein negative) with the founder strain from Charles Rivers (C57BL/6JCrl, ?-synuclein positive). There were subtle changes in behaviour when comparing control animals from the two sub-strains indicating potentially significant consequences for studies assuming neurobiogical identity of both strains. However, there was no evidence that the absence of ?-synuclein modifies disease. Indeed, accumulation of PrPSc, synaptic loss and the behavioural dysfunction associated with the ME7-agent was the same in both genetic backgrounds. Our data suggest that ?-synuclein deficiency does not contribute to the compartment specific processes that give rise to prion disease mediated synaptotoxicity and neurodegeneration
Apolipoprotein E (apoE) uptake and distribution in mammalian cell lines is dependent upon source of apoE and can be monitored in living cells
As part of investigations of the cellular uptake of apolipoprotein E (apoE) relevant to Alzheimer's disease we have found that different preparations of apoE are handled differently by cells expressing the LDL-receptor. Comparing recombinant, cellular and native apoE, complexed with different preparations of lipid we find that only cellular and native apoE enter a vesicular compartment. Some, but not all of these apoE containing vesicles are lysosomes. In order to further examine the intracellular fate of apoE we demonstrate that apoE-Enhanced green fluorescent protein chimeric protein can be taken up from medium by recipient cells and tracked within these cells for extended periods
Why would some migrants choose to engage in degrading work?
This paper develops a model of voluntary migration into degrading work. The essence of the model is a tension between two âbads:â that which arises from being relatively deprived at home, and that which arises from engaging in humiliating work away from home. Balancing between these two âbadsâ can give rise to an explicit, voluntary choice to engage in humiliating work. The paper identifies conditions under which a migrant will choose to engage in degrading work rather than being forced into it, to work abroad as a prostitute, say, rather than on a farm. The paper delineates the possible equilibria and finds that greater relative deprivation will make it more likely that the equilibrium outcome will be âengagement in prostitution.â It is shown that under well specified conditions, every individual will work as a prostitute, yet every individual would be better off working on a farm. Put differently, when specific conditions are satisfied, there is a possibility of a âcoordination failure:â if individuals believe that everyone else will choose to be a prostitute, this belief will be self-fulfilling. In this case, all the individuals choose to engage in prostitution, which renders each of them worse off. The paper discusses various policy implications. It is shown that a policy intervention (a crackdown on migrantsâ engagement in prostitution), if implemented strictly, can increase everyoneâs welfare, but when the policy is implemented loosely, cracking down on prostitution will only reduce individualsâ welfare without reducing their engagement in prostitution.Migrants, Relative deprivation, Degrading work, Humiliation, Multiple equilibria, Welfare assessment, Policy implications, Labor and Human Capital, Political Economy, F22, J24, J81,