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Biology subjects

Gentry, E.

Publications and source records attributed to Gentry, E..

2 recordsLinked to original sources

Network-Level Characterization of Spontaneous Calcium Activity in an In-Vitro Alzheimer's Disease Model

The neurodegenerative disorder Alzheimers disease (AD) is widely known for biomarkers such as amyloid beta plaques and tauopathy, as well as functional differences in memory and cognitive ability. Despite this devastating functional impact, a large body of work only focuses on molecular biomarkers of AD. In this study, we investigate collective neural dynamics in vitro and assess how network-level properties differ between a well-established model of familial AD (FAD) and a newly developed in vitro accelerated model (acAD). The new model system reliably develops the key structural characteristics of AD in three weeks, but its calcium dynamics had not been characterized previously. Spontaneous network dynamics influences information processing as part of the internal network state. Here we measure this spontaneous activity of a network of hundreds of cells in each field of view. We find that the FAD model has a larger fraction of hyperactive cells, while the acAD model displays similar characteristics to healthy cells. Additionally, the FAD model has altered cooperation between cells, losing a proportion of highly correlated cellular activities, both for fast and slow coupling among cells. The acAD model is again consistent with healthy networks. Since the acAD model does not show the same spontaneous network dysfunction seen in FAD, it can enable measurements of changes in learning and memory associated with the plasticity, rather than the structure of the internal network state.

biophysics↗

Development of an Accelerated Cellular Model for Alzheimer's Disease

Alzheimers Disease (AD) is a leading cause of dementia characterized by amyloid plaques and neurofibrillary tangles, and its pathogenesis remains unclear. Current cellular models for AD often require several months to exhibit phenotypic features due to the lack of an aging environment in vitro. Lamin A is a key component of the nuclear lamina. And progerin, a truncated protein resulting from specific lamin A mutations, causes Hutchinson-Gilford Progeria Syndrome (HGPS), a disease that prematurely ages individuals. Studies have reported that lamin A expression is induced in the brains of AD patients, and overlapping cellular phenotypes have been observed between HGPS and AD cells. In this study, we investigated the effects of exogenous progerin expression on neural progenitor cells carrying familial AD mutations (FAD). Within three to four weeks of differentiation, these cells exhibited robust AD phenotypes, including increased tau phosphorylation, amyloid plaque accumulation, and an elevated A{beta}42 to A{beta}40 ratio. Additionally, progerin expression significantly increased AD cellular phenotypes such as cell death and cell cycle re-entry. Our results suggest that progerin expression could be used to create an accelerated model for AD development and drug screening. Significance StatementAlzheimers Disease (AD) contributes to most dementia, while its mechanism is still under investigation. One of the challenges for studying AD is the model issue, including the genetic divergence of animals and human, and the rejuvenation of induced pluripotent stem cells (iPSCs). Progerin is a mutant lamin A found in the accelerated aging disease progeria. There are a lot of molecular similarities between Alzheimers Disease (AD) and progeria. Here, we developed an accelerated 2D/3D cell model system for AD by ectopically expressing progerin in a previously characterized AD cell model carrying familial AD (FAD) mutations. Our study showed that progerin addition could accelerate AD phenotypical progression, including tau phosphorylation and formation of {beta}-amyloid plaques.

cell biology↗