The amyloid hypothesis of Alzheimer's disease (AD) suggests that soluble amyloid β (Aβ) is an initiator of a cascade of events eventually leading to neurodegeneration. Recently, we reported that Aβ deranged Ca(2+) homeostasis specifically in hippocampal astrocytes by targeting key elements of Ca(2+) signaling, such as mGluR5 and IP3 R1. In the present study, we dissect a cascade of signaling events by which Aβ deregulates glial Ca(2+) : (i) 100 nM Aβ leads to an increase in cytosolic calcium after 4-6 h of treatment; (ii) mGluR5 is increased after 24 h of treatment; (iii) this increase is blocked by inhibitors of calcineurin (CaN) and NF-kB. Furthermore, we show that Aβ treatment of glial cells leads to de-phosphorylation of Bcl10 and an increased CaN-Bcl10 interaction. Last, mGluR5 staining is augmented in hippocampal astrocytes of AD patients in proximity of Aβ plaques and co-localizes with nuclear accumulation of the p65 NF-kB subunit and increased staining of CaNAα. Taken together our data suggest that nanomolar [Aβ] deregulates Ca(2+) homeostasis via CaN and its downstream target NF-kB, possibly via the cross-talk of Bcl10 in hippocampal astrocytes.
The most accredited (and fashionable) hypothesis of the pathogenesis of Alzheimer Disease (AD) sees accumulation of β-amyloid protein in the brain (in both soluble and insoluble forms) as a leading mechanism of neurotoxicity. How β-amyloid triggers the neurodegenerative disorder is at present unclear, but growing evidence suggests that a deregulation of Ca(2+) homeostasis and deficient Ca(2+) signalling may represent a fundamental pathogenic factor. Given that symptoms of AD are most likely linked to synaptic dysfunction (at the early stages) followed by neuronal loss (at later and terminal phases of the disease), the effects of β-amyloid have been mainly studied in neurones. Yet, it must be acknowledged that neuroglial cells, including astrocytes, contribute to pathological progression of most (if not all) neurological diseases. Here, we review the literature pertaining to changes in Ca(2+) signalling in astrocytes exposed to exogenous β-amyloid or in astrocytes from transgenic Alzheimer disease animals models, characterized by endogenous β-amyloidosis. Accumulated experimental data indicate deregulation of Ca(2+) homeostasis and signalling in astrocytes in AD, which should be given full pathogenetic consideration. Further studies are warranted to comprehend the role of deficient astroglial Ca(2+) signalling in the disease progression.
Background Advanced therapy medicinal products (ATMPs) represent an important cornerstone for innovation in healthcare. However, uncertainty on the value, the high average cost per patient and their one-shot nature has raised a debate on their assessment and appraisal process for pricing and reimbursement (P&R) purposes. This debate led experts providing for recommendations on this topic. Our primary objective is to investigate the ATMPs P&R process in the main five European countries and to understand if this process is consistent with published P&R expert recommendations. We also investigated the current ATMP pipelines to understand if future ATMPs will create challenges for their P&R process. Methods P&R framework for ATMPs in the European Major five (EU5) countries was investigated through a literature search on PubMed, institutional websites of National Health Authorities and grey literature. The ATMPs pipeline database was populated from a clinical trial database (clinicaltrials.gov), relying on inclusion and exclusion criteria retrieved from the literature. Results Reimbursement status of ATMPs is different across the EU5 countries, with the exception of CAR-Ts which are reimbursed in all countries. Standard P&R process in place for other medicinal products is extended to ATMPs, with the exception of some cases in Germany. List prices, where available, are high and, tend to be aligned across countries. Outcome-based Managed Entry Agreements (MEAs) have been extensively used for ATMPs. Extra-funds for hospitals managing ATMPs were provided only in Germany and, as additional fund per episode, in France. The accreditation process of hospitals for ATMPs management was in most countries managed by the national authorities. As far as ATMPs pipeline is concerned, ATMPs in development are mostly targeting non-rare diseases. Conclusions Expert recommendations for ATMPs P&R were partially applied: the role of outcome-based MEAs has increased and the selection process of the centres authorized to use these treatments has been enhanced; additional funding for ATMPs management to accredited centres has not been completely considered and annuity payment and broader perspective in cost considerations are far from being put in place. These recommendations should be considered for future P&R negotiations to pursue rational resource allocation and deal with budget constraints.
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