Cell death by apoptosis is recognized as a major component of ischemia/reperfusion (I/R) injury. Activation of cell death pathways during I/R leads to loss of terminally differentiated cardiac myocytes, thus contributing to the development of heart failure. The Bcl-2 family proteins play an important role in regulating the mitochondrial pathway of apoptosis in the myocardium. BnipS is a pro-apoptotic member of the Bcl-2 family and is localized primarily to the mitochondria in myocardial cells. Overexpression of BnipS leads to mitochondrial dysfunction and cell death in various cell types, including neonatal cardiac myocytes. Elevated levels of BnipS protein have been reported in vivo in animal models of acute ischemia and heart failure. We have found that BnipS is expressed at substantially in the adult myocardium and our preliminary data indicate that BnipS plays a significant role in l/R-mediated cell death by activation of the mitochondrial pathway. Moreover, we have found that overexpression of BnipS causes extensive fragmentation of the mitochondrial network along with upregulation of autophagy, and that BnipS is subjected to proteolysis in cells subjected to hypoxia or simulated I/R. (8). In this proposal, we will explore the hypothesis that BnipS functions as a redox sensor that is activated by increased oxidative stress during I/R, leading to mitochondrial dysfunction and subsequent cell death. This hypothesis will be explored with the following specific aims: 1. Investigate the role of BnipS as a mitochondrial sensor of oxidative stress 2. Define the molecular mechanism(s) by which BnipS mediates mitochondrial fragmentation 3. Elucidate the role of autophagy in BnipS-mediated cell death 4. Characterize the role of BnipS proteolysis in response to I/R Our long-term goal is to understand the pathways that contribute to I/R injury and the results from this proposal will provide new insights into the pathways of apoptosis and their regulation in the heart. Further understanding of how BnipS functions in the heart has the potential to identify new therapeutic targets to treat or prevent heart disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
3R01HL087023-03S1
Application #
7887470
Study Section
Myocardial Ischemia and Metabolism Study Section (MIM)
Program Officer
Schwartz, Lisa
Project Start
2007-07-19
Project End
2009-09-30
Budget Start
2009-07-01
Budget End
2009-09-30
Support Year
3
Fiscal Year
2009
Total Cost
$13,322
Indirect Cost
Name
San Diego State University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
073371346
City
San Diego
State
CA
Country
United States
Zip Code
92182
Shires, Sarah E; Gustafsson, Åsa B (2018) Regulating Renewable Energy: Connecting AMPK?2 to PINK1/Parkin-Mediated Mitophagy in the Heart. Circ Res 122:649-651
Woodall, Benjamin P; Gustafsson, Åsa B (2018) Mesenchymal Stem Cell-Mediated Autophagy Inhibition. Circ Res 123:518-520
Lampert, Mark A; Gustafsson, Åsa B (2018) Balancing Autophagy for a Healthy Heart. Curr Opin Physiol 1:21-26
Shires, Sarah E; Kitsis, Richard N; Gustafsson, Åsa B (2017) Beyond Mitophagy: The Diversity and Complexity of Parkin Function. Circ Res 120:1234-1236
Hammerling, Babette C; Najor, Rita H; Cortez, Melissa Q et al. (2017) A Rab5 endosomal pathway mediates Parkin-dependent mitochondrial clearance. Nat Commun 8:14050
Zhong, Zhenyu; Umemura, Atsushi; Sanchez-Lopez, Elsa et al. (2016) NF-?B Restricts Inflammasome Activation via Elimination of Damaged Mitochondria. Cell 164:896-910
Leon, Leonardo J; Gustafsson, Åsa B (2016) Staying young at heart: autophagy and adaptation to cardiac aging. J Mol Cell Cardiol 95:78-85
Shirakabe, Akihiro; Fritzky, Luke; Saito, Toshiro et al. (2016) Evaluating mitochondrial autophagy in the mouse heart. J Mol Cell Cardiol 92:134-9
Kubli, Dieter A; Gustafsson, Åsa B (2015) Unbreak my heart: targeting mitochondrial autophagy in diabetic cardiomyopathy. Antioxid Redox Signal 22:1527-44
Lee, Youngil; Kubli, Dieter A; Hanna, Rita A et al. (2015) Cellular redox status determines sensitivity to BNIP3-mediated cell death in cardiac myocytes. Am J Physiol Cell Physiol 308:C983-92

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