Nipun Chopra

Amyloid-beta protein clearance and degradation (ABCD) pathways and their role in Alzheimer's disease.

Amyloid-β proteins (Aβ) of 42 (Aβ42) and 40 aa (Aβ40) accumulate as senile plaques (SP) and cerebrovascular amyloid protein deposits that are defining diagnostic features of Alzheimers disease (AD). A number of rare mutations linked to familial AD (FAD) on the Aβ precursor protein (APP), Presenilin-1 (PS1), Presenilin- 2 (PS2), Adamalysin10, and other genetic risk factors for sporadic AD such as the ε4 allele of Apolipoprotein E (ApoE-ε4) foster the accumulation of Aβ and also induce the entire spectrum of pathology associated with the disease. Aβ accumulation is therefore a key pathological event and a prime target for the prevention and treatment of AD. APP is sequentially processed by β-site APP cleaving enzyme (BACE1) and γ-secretase, a multisubunit PS1/PS2-containing integral membrane protease, to generate Aβ. Although Aβ accumulates in all forms of AD, the only pathways known to be affected in FAD increase Aβ production by APP gene duplication or via base substitutions on APP and γ-secretase subunits PS1 and PS2 that either specifically increase the yield of the longer Aβ42 or both Aβ40 and Aβ42. However, the vast majority of AD patients accumulate Aβ without these known mutations. This led to proposals that impairment of Aβ degradation or clearance may play a key role in AD pathogenesis. Several candidate enzymes, including Insulin-degrading enzyme (IDE), Neprilysin (NEP), Endothelin-converting enzyme (ECE), Angiotensin converting enzyme (ACE), Plasmin, and Matrix metalloproteinases (MMPs) have been identified and some have even been successfully evaluated in animal models. Several studies also have demonstrated the capacity of γ-secretase inhibitors to paradoxically increase the yield of Aβ and we have recently established that the mechanism is by skirting Aβ degradation. This review outlines major cellular pathways of Aβ degradation to provide a basis for future efforts to fully characterize the panel of pathways responsible for Aβ turnover.

Human primary mixed brain cultures: preparation, differentiation, characterization and application to neuroscience research

BackgroundCulturing primary cortical neurons is an essential neuroscience technique. However, most cultures are derived from rodent brains and standard protocols for human brain cultures are sparse. Herein, we describe preparation, maintenance and major characteristics of a primary human mixed brain culture, including neurons, obtained from legally aborted fetal brain tissue. This approach employs standard materials and techniques used in the preparation of rodent neuron cultures, with critical modifications.ResultsThis culture has distinct differences from rodent cultures. Specifically, a significant numbers of cells in the human culture are derived from progenitor cells, and the yield and survival of the cells grossly depend on the presence of bFGF. In the presence of bFGF, this culture can be maintained for an extended period. Abundant productions of amyloid-β, tau and proteins make this a powerful model for Alzheimers research. The culture also produces glia and different sub-types of neurons.ConclusionWe provide a well-characterized methodology for human mixed brain cultures useful to test therapeutic agents under various conditions, and to carry forward mechanistic and translational studies for several brain disorders.

CONSTITUTIVE IN VIVO OVEREXPRESSION OF MIR146A AND MIR200B INDEPENDENTLY MODULATES LEVELS OF ALZHEIMER'S DISEASE (AD)- RELATED PROTEINS IN THE MOUSE HIPPOCAMPUS AND CEREBRAL CORTEX

P3-061 CONSTITUTIVE IN VIVO OVEREXPRESSION OF MIR146A AND MIR200B INDEPENDENTLY MODULATES LEVELS OFALZHEIMER’S DISEASE (AD)RELATED PROTEINS IN THE MOUSE HIPPOCAMPUS AND CEREBRAL CORTEX Debomoy K. Lahiri, Nipun Chopra, Bryan Maloney, Nigel H. Greig, Subrata Chakrabarti, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer Disease Center, Indianapolis, IN, USA; Indiana University School of Medicine, Indianapolis, IN, USA; Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, USA; Department of Pathology and Laboratory Medicine, London, ON, Canada. Contact e-mail: dlahiri@ iupui.edu

SP1-MODULATING COMPOUNDS AS A NOVEL DRUG TARGET FOR ALZHEIMER'S DISEASE (AD)

ethnography being observation. Person centred principles were used to guide the research process as well as inclusionary consent method (Dewing 2007). Guided reflective practice was the cornerstone of the inquiry. Results: Care staff gained insight into the drivers behind resident’s interactions when observations were discussed and reflected upon. Residents were found to have more agency in influencing their direct environment than previously thought possible. Conclusions: The results indicate there is strong potential for PIECE-dem to be used by practitioners to gain understanding of how the person with advanced dementia is experiencing their care environment, exercising agency, and how they can be appropriately supported.