This proposal brings together a unique multidisciplinary team of leading experts in alcohol studies and real time dynamic fluorescence imaging of cells and subcellular structures in intact tissues, high resolution electron tomography, sophisticated molecular biology and computational biology to address a fundamental question of how a deregulation of local interactions between organelles can result in global cell dysfunction, tissue damage and disease. The study addresses the regulation of the mitochondria-endoplasmic reticulum (ER)/sarcoplasmic reticulum (SR) interface and its relationship to localized Ca2+ signaling, formation of reactive oxygen species (ROS) and ER stress. The central hypothesis to be tested is that chronic alcohol exposure causes impaired ER/SR-mitochondrial structural and functional coupling and thereby increases the susceptibility to cell injury in liver and skeletal muscle. Our group has developed methods to manipulate the ER/SR-mitochondrial interface and has shown that this has consequences for localized Ca2+ signaling.
Our first aim i s to further develop these new experimental tools to be able a) to manipulate and measure the ER/SR-mitochondrial interface, b) to monitor the impact of controlled mitochondrial localization on local [Ca2+] signals and local ROS formation and c) to assess ER/SR stress responses in real time at the single cell level. This will help us analyze the relationship between ER/SR stress and changes in localized Ca2+ and ROS signaling. We will then test the concept that the effect of chronic alcohol exposure on ER/SR-mitochondrial interactions leads to impairments in ER/SR-mitochondrial structure, calcium signaling and induces ER/SR- mitochondrial stress responses in the liver and skeletal muscle. Finally, we will determine whether the alterations in ER-mitochondrial morphology and function contribute to alcohol-induced metabolic dysfunction and cell injury in vivo. With these approaches, we can answer fundamental questions about the subcellular organization of the ER-mitochondrial network and its disruption by ethanol. These studies will shed new light on the mechanisms by which alcohol abuse can cause tissue damage and will provide unique opportunities for the development of innovative treatment strategies.

Public Health Relevance

Chronic alcoholism is associated with ER stress and mitochondrial dysfunction and changes in ER and mitochondrial morphology in multiple tissues. The ER/SR-mitochondrial junctions are important for the function and structure of both ER/SR and mitochondria and are envisioned as a target and an important mediator of the alcohol's effect on liver and skeletal muscle injury. A multidisciplinary approach utilizing expertise in alcohol studies and real time dynamic fluorescence imaging of cells and subcellular structures in intact tissues, high resolution electron tomography, sophisticated molecular biology and computational biology will help to address a fundamental question of how a deregulation of local interactions between organelles can result in global cell dysfunction, tissue damage and disease.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
High Impact Research and Research Infrastructure Programs (RC2)
Project #
5RC2AA019416-02
Application #
7942067
Study Section
Special Emphasis Panel (ZAA1-GG (02))
Program Officer
Orosz, Andras
Project Start
2009-09-30
Project End
2012-08-31
Budget Start
2010-09-01
Budget End
2012-08-31
Support Year
2
Fiscal Year
2010
Total Cost
$982,941
Indirect Cost
Name
Thomas Jefferson University
Department
Pathology
Type
Schools of Medicine
DUNS #
053284659
City
Philadelphia
State
PA
Country
United States
Zip Code
19107
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Eisner, Verónica; Csordás, György; Hajnóczky, György (2013) Interactions between sarco-endoplasmic reticulum and mitochondria in cardiac and skeletal muscle - pivotal roles in Ca²? and reactive oxygen species signaling. J Cell Sci 126:2965-78
Csordas, Gyorgy; Varnai, Peter; Golenar, Tunde et al. (2012) Calcium transport across the inner mitochondrial membrane: molecular mechanisms and pharmacology. Mol Cell Endocrinol 353:109-13
Garcia-Perez, Cecilia; Schneider, Timothy G; Hajnoczky, Gyorgy et al. (2011) Alignment of sarcoplasmic reticulum-mitochondrial junctions with mitochondrial contact points. Am J Physiol Heart Circ Physiol 301:H1907-15
Csordás, György; Várnai, Péter; Golenár, Tünde et al. (2010) Imaging interorganelle contacts and local calcium dynamics at the ER-mitochondrial interface. Mol Cell 39:121-32