Modelling the Pan-European Economic Burden of Alzheimer's Disease.

Background: Recent advances open the opportunity of altering the course of Alzheimer's disease (AD) through lifestyle-based modifications and novel therapies. Ensuring that society is investing limited budgets in the interventions that have the greatest potential to generate tangible impact will require tools to guide policymakers. Objectives: To build on previous studies to develop an economic model that estimates the societal burden of AD and evaluates the potential impact of novel interventions in six large European countries. Design: AD progression was modelled using a published Markov structure with a 40-year time horizon to estimate lifetime costs and life years in a cohort aged 65 years and above diagnosed with mild cognitive impairment due to AD (MCI-AD) in 2020. Demographic projections were utilized to estimate the prevalence of MCI-AD up to 2100, total corresponding costs and life years. The model allows a comparison of costs associated with the introduction of a hypothetical new disease-modifying therapy that slows disease progression between MCI-AD and all AD-Dementia stages as well as a 'delayed onset' scenario where disease progression is halted at the MCI-AD stage, potentially occurring, for example, through lifestyle-based modifications. Results: The 2022 present value of total lifetime costs for this cohort moving through all disease stages is ~€1.2T. Approximately 80% of the present value of lifetime costs in our model are driven by informal care and non-medical direct costs. Our model suggests that a 25% and 50% reduction in disease progression compared to natural history could translate into a present value of cost savings of €33.7B and €72.7B. Halting MCI-AD progression for 3 years with no therapeutic effect thereafter resulted in a present value cost savings of €84.7B in savings. Conclusions: Our data further suggest that early intervention via disease-modifying therapies or lifestyle-based modifications in AD could result in cost savings for society. Additionally, our findings reinforce the importance of accounting for the full value of innovative interventions, management and care paradigms, including their potential impact on direct, indirect and intangible costs impacting patients, their care partners and health and social care systems.

Grafted neural progenitors migrate and form neurons after experimental traumatic brain injury.

PURPOSE: Neural stem and progenitor cells (NSPC) generate neurons and glia, a feature that makes them attractive for cell replacement therapies. However, efforts to transplant neural progenitors in animal models of brain injury typically result in high cell mortality and poor neuronal differentiation. METHODS: In an attempt to improve the outcome for grafted NSPC after controlled cortical impact we transplanted Enhanced Green Fluorescent Protein (EGFP)-positive NSPC into the contra lateral ventricle of mice one week after injury. RESULTS: Grafted EGFP-NSPC readily migrated to the injured hemisphere where we analyzed the proportion of progenitors and differentiated progeny at different time points. Transplantation directly into the injured parenchyma, resulted in few brains with detectable EGFP-NSPC. On the contrary, in more than 90% of the mice that received a transplant into the lateral ventricle detectable EGFP-positive cells were found. The cells were integrated into the lateral ventricle wall of the un-injured hemisphere, throughout the corpus callosum, and in the cortical perilesional area. At one-week post transplantation, grafted cells that had migrated to the perilesion area mainly expressed markers of neural progenitors and neurons, while in the corpus callosum and the ventricular lining, grafted cells with a glial fate were more abundant. After 3 months, grafted cells in the perilesion area were less abundant whereas cells that had migrated to the walls of the third- and lateral- ventricle of the injured hemisphere were still detectable, suggesting that the injury site remained a hostile environment. CONCLUSION: Transplantation to the lateral ventricle, presumably for being a neurogenic region, provides a favorable environment improving the outcome for grafted NSPC both in term of their appearance at the cortical site of injury, and their acquisition of neural markers.

Nuclear receptor binding protein 2 is induced during neural progenitor differentiation and affects cell survival.

We previously identified nuclear receptor binding protein 2 (NRBP2) in a screen for genes induced by differentiation of neural stem/progenitor cells. Here we show that during embryonic mouse brain development NRBP2 was expressed in the walls of the third and fourth ventricles, and in the hippocampus. In the adult brain, Purkinje cells of the cerebellum and neurons in the CA3 region of the hippocampus were main sites of NRBP2 expression. Analysis of a pediatric medulloblastoma showed that clusters of NRBP2 positive tumor cells co-expressed neurofilament, but not GFAP. Thus, NRBP2 was associated with neuronal differentiation both in normal and malignant brain tissue. We report that NRBP2 is a 55-60 kDa protein with mainly cytoplasmic location. In vitro, NRBP2 protein levels increased as neural stem/progenitor cells differentiated, and its down regulation by siRNA rendered neural progenitor cells more vulnerable to apoptosis. NRBP2 has no previously assigned function and our studies suggest a role for NRBP2 in neural progenitor cell survival.

Enhanced neuronal differentiation in a three-dimensional collagen-hyaluronan matrix.

Efficient 3D cell systems for neuronal induction are needed for future use in tissue regeneration. In this study, we have characterized the ability of neural stem/progenitor cells (NS/PC) to survive, proliferate, and differentiate in a collagen type I-hyaluronan scaffold. Embryonic, postnatal, and adult NS/PC were seeded in the present 3D scaffold and cultured in medium containing epidermal growth factor and fibroblast growth factor-2, a condition that stimulates NS/PC proliferation. Progenitor cells from the embryonic brain had the highest proliferation rate, and adult cells the lowest, indicating a difference in mitogenic responsiveness. NS/PC from postnatal stages down-regulated nestin expression more rapidly than both embryonic and adult NS/PC, indicating a faster differentiation process. After 6 days of differentiation in the 3D scaffold, NS/PC from the postnatal brain had generated up to 70% neurons, compared with 14% in 2D. NS/PC from other ages gave rise to approximately the same proportion of neurons in 3D as in 2D (9-26% depending on the source for NS/PC). In the postnatal NS/PC cultures, the majority of betaIII-tubulin-positive cells expressed glutamate, gamma-aminobutyric acid, and synapsin I after 11 days of differentiation, indicating differentiation to mature neurons. Here we report that postnatal NS/PC survive, proliferate, and efficiently form synapsin I-positive neurons in a biocompatible hydrogel.

Tumor suppressor gene BRCA-1 is expressed by embryonic and adult neural stem cells and involved in cell proliferation.

BRCA-1 is a tumor suppressor gene that plays a role in DNA repair and cellular growth control. Here we show that BRCA-1 mRNA is expressed by embryonic rat brain and is localized to the neuroepithelium containing neuronal precursor cells. The expression of BRCA-1 decreases during rat brain development, but BRCA-1 is expressed postnatally by proliferating neuronal precursor cells in the developing cerebellum. Neural stem cells (NSC) prepared from embryonic rat brain and cultured in the presence of epidermal growth factor were positive for BRCA-1. Induction of NSC differentiation resulted in down-regulation of BRCA-1 expression as shown by RNA and protein analyses. In addition to embryonic cells, BRCA-1 is also present in NSC prepared from adult rat brain. In adult rats, BRCA1 was expressed by cells in the walls of brain ventricles and in choroid plexus. The results show that BRCA-1 is present in embryonic and adult rat NSC and that the expression is linked to NSC proliferation.