Journal of Proteomics & Bioinformatics
Open Access
ISSN: 0974-276X
ISSN: 0974-276X
Grace E Stutzmann
The Chicago Medical School - Rosalind Franklin University, USA
Scientific Tracks Abstracts: J Proteomics Bioinform
Statement of the Problem: A shared aspect among many neurodegenerative disorders is a limited understanding of cellular disease mechanisms. In our research, we have found that dysregulated calcium channels play a central and early role in driving diseases such as Alzheimerâ??s, Huntingtonâ??s and brain injury. Specifically, defects in intracellular calcium stores within the endoplasmic reticulum (ER) and their resident release channels such as the ryanodine receptor (RyR) are upstream of the major disease features such as protein aggregates and synaptic deficits. By focusing upon the proximal calcium channelopathy, rather than later-stage features, significant advances in understanding disease etiology may be made. Methodology & Theoretical Orientation: Whole cell patch clamp electrophysiology combined with 2-photon calcium imaging are used to record signaling from hippocampal neurons in acute brain slices from mouse models of Alzheimerâ??s disease (AD) and human neurons transformed from AD patients. Immunoassays and qRT PCR probe protein and transcript levels in mouse and human neurons. Findings: In early stage AD mice, RyR-evoked calcium signals are significantly greater than non-transgenic controls, while calcium signaling though voltage-gated channels and NMDA receptors are not different. Similar observations were made in human neurons from AD patients. Additionally, RyR 2 message is increased in both the mouse and human AD neurons. Pharmacologically normalizing RyR-calcium release restores RyR 2 levels in mice, as well as reduces many of the AD features including beta amyloid, hyperphosphorylated tau and synaptic loss. Conclusion & Significance: Dysregulated ER calcium channel functioning is an early feature of AD in mouse models and human samples and likely initiates a pathogenic cascade in the proximal disease stages. Because of the multiple and essential roles of calcium signaling in neurons, alterations in RyR-channel properties can generate multiple downstream maladaptive effects such as those seen in neurodegenerative disorders. Recent Publications 1. Goussakov I, Miller M and Stutzmann G E (2010) NMDA-mediated Ca2+ influx drives ryanodine receptor activation in dendrites of young Alzheimer's disease mice. Journal of Neuroscience 30(36):12128-37. 2. Bruno A, Huang J, Bennett D A, Marr R, Hastings M L and Stutzmann G E (2011) Altered ryanodine receptor expression in mild cognitive impairment and Alzheimerâ??s Disease. Neurobiology of Aging 33(5): 1001.e1-6. 3. Chakroborty S, Kim J, Schneider C, Jacobson C, Molgó J and Stutzmann G E (2012) Early pre- and postsynaptic calcium signaling abnormalities mask underlying synaptic depression in presymptomatic Alzheimer's disease mice. Journal of Neuroscience 32(24):8341-53. 4. Chakroborty S, Briggs C, Miller M B, Goussakov I, Schneider C, Kim J, Wicks J, Richardson J, Conklin V, Cameransi B and Stutzmann G E (2012) Stabilizing ER calcium channel function as an early prevention strategy for Alzheimerâ??s disease. PLoS One 7(12):e52056. 5. Lacampagne A, Liu X, Reiken S, Bussiere R, Meli A C, Lauritzen I, Teich A F, Zalk R, Saint N, Arancio O, Bauer C, Duprat F, Briggs C A, Chakroborty S, Stutzmann G E, Shelanski M L, Checler F, Chami M and Marks A R (2017) Posttranslational remodeling of ryanodine receptor induces calcium leak leading to Alzheimerâ??s disease-like pathologies and cognitive deficits. Acta Neuropathologica 134(5):749-767.