Jonathan R. Moll

Amyloid beta modulation of neuronal network activity in vitro.

In vitro assays offer a means of screening potential therapeutics and accelerating the drug development process. Here, we utilized neuronal cultures on planar microelectrode arrays (MEA) as a functional assay to assess the neurotoxicity of amyloid-β 1-42 (Aβ42), a biomolecule implicated in the Alzheimer׳s disease (AD). In this approach, neurons harvested from embryonic mice were seeded on the substrate-integrated microelectrode arrays. The cultured neurons form a spontaneously active network, and the spiking activity as a functional endpoint could be detected via the MEA. Aβ42 oligomer, but not monomer, significantly reduced network spike rate. In addition, we demonstrated that the ionotropic glutamate receptors, NMDA and AMPA/kainate, play a role in the effects of Aβ42 on neuronal activity in vitro. To examine the utility of the MEA-based assay for AD drug discovery, we tested two model therapeutics for AD, methylene blue (MB) and memantine. Our results show an almost full recovery in the activity within 24h after administration of Aβ42 in the cultures pre-treated with either MB or memantine. Our findings suggest that cultured neuronal networks may be a useful platform in screening potential therapeutics for Aβ induced changes in neurological function.

In vivo and ex vivo imaging of amyloid-β cascade aggregates with a Pronucleon™ peptide.

Accumulation of amyloid-β (Aβ) cascade aggregates is considered a hallmark of Alzheimers disease (AD). Current dogma holds that the appearance of Aβ oligomers and larger aggregates occur many years prior to plaque formation associated with the advanced and irreparable neurocognitive decline characteristic of AD. This premise is the impetus to identify these Aβ precursor structures prior to advanced plaque development. The Pronucleon™ technology platform is comprised of a novel series of engineered peptides that provide a unique readout when associated with beta-rich fiber and oligomeric Aβ. This technology has been applied to Ex Vivo tissue sections and In Vivo mouse models of AD to determine the potential utility of these synthetic peptides as potential imaging agents. In Ex Vivo studies, the Pronucleon™ peptide binds plaque like structures in brain sections obtained from transgenic mice overexpressing hAPP with both the human Swedish and London Aβ mutations. In Vivo, Pronucleon™ peptide administered peripherally can localize to the brain and label plaques throughout the brain in transgenic mice. Taken together, the data suggest that Pronucleon™ could provide a new imaging tool for Aβ cascade elements that precede advanced plaque and fibril formation, thereby advancing early diagnosis and treatment opportunities.

Specific detection of soluble amyloid beta oligomers using conformationally dynamic pronucleon™ peptides

Background: In MMST test the attention, calculation and working memory are being tested by making the patients count from 100 down 7 by 7. Alternatively by testing them to spell the ‘WORLD’ backward. The aim of this study is to compare the two methods for finding the relation of age, sex and education on the total MMST score. Methods: The subjects were chosen among dementia patients coming from 9 centers (TAC-Turquaz Alzheimer Study Group) which had come to be examined for for the first time. Fourhundred fortynine subjects (165 male, 284 female) older than 55 years were analyzed whose MMSE scores are in between 10 to 24. All the participants answered the questions of MMST and the evaluation are made over total score of 30. The subjects were asked to count 100 down 7 by 7 and also to spell the word ‘World’ backwards. Results: The mean MMSE score is 22.2664.76 in spelling the word ‘‘WORLD’’ backwards, the mean MMSE score is 18.964.29 in counting 100 down 7 by 7. We found statisticaly significant set as p1⁄40.0001 between two tests, there is a negative correlation between the age and the test scores (p1⁄40.001, r1⁄40.168) were established, We found also there is no affect of gender on the test scores (p>0.05). Conclusions: While making the clinical diagnosis, standardized alternative tests according to age and education give out more precise information.