There is growing evidence that loss of mitochondrial function is closely associated with the development of various human maladies such as cardiovascular disease, cancer, and diabetes. However, the precise role of mitochondrial dysfunction in the pathogenesis of these diseases is not completely understood. Normal functioning of mitochondria relies on maintaining the inner membrane potential to drive oxidative phosphorylation and redox balance. Thus, examining the effects of controlled, reversible, induction of mitochondrial depolarization and membrane permeability (MMP) on downstream processes will lead to critical information that helps to reveal the mechanisms responsible for mitochondria-induced cell dysfunction. Currently, the only methods available to manipulate MMP are to use chemicals to uncouple the mitochondria or to induce permeability transition pore opening. However, pharmacological approaches often cause unknown side effects and lack the ability to probe spatiotemporal domains. A new approach capable of precisely controlling mitochondria would be a major methodological advance for the field. The primary goal of this exploratory project is to apply advanced molecular and optical techniques to develop a novel optogenetic-based tool for controllable mitochondrial manipulation with light. Particularly, a heterologous light-gated rhodopsin protein, namely channelrhodopsin 2 (ChR2), will be targeted to and expressed on the inner mitochondrial membrane (IMM) of mammalian cells. The responses of cells expressing mitochondrial ChR2 to light illumination will be examined. Based on our preliminary data, we hypothesize that ChR2 can be functionally expressed on IMM with properties similar to that on the plasma membrane, allowing precise optical manipulation of mitochondrial membrane potential and permeability. The hypothesis will be tested in the experiments of the following Specific Aims: (i) develop and characterize novel cell line models expressing optimal level, mitochondrially-targeted ChR2; and (ii) examine the light-induced mitochondrial depolarization and understand the differential (e.g. cytoprotective or proapoptotic) effect of MMP on cell function using the innovative optogenetic approach. Successful completion of the proposed studies will not only lead to novel, new generation optogenetic-based research tools, but also allow us to gain critical insights into the mechanisms by which a change of MMP differentially regulates the downstream intracellular processes, causing either beneficial or deleterious influences on cells and organs. It will also act as a foundation for future studies to develop targeted treatments for diseases involving mitochondrial dysfunction.

Public Health Relevance

Loss of mitochondrial function has been implicated in a variety of human maladies such as cardiovascular disease, cancer, and diabetes. It is therefore critically important to work toward a complete understanding of how the defects of mitochondria cause cell and even organ dysfunction so that effective targeted therapies can be developed. This project is highly relevant to public health, as it will provide (i) a novel tool allowing precse and remote control of mitochondria using visible (blue) light, and (ii) proof-of-concept evidence for the potential application of optogenetic-based therapeutical strategies for the treatment of diseases involving mitochondrial dysfunction.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21HL127599-02
Application #
9251315
Study Section
Myocardial Ischemia and Metabolism Study Section (MIM)
Program Officer
Luo, James
Project Start
2016-04-01
Project End
2018-03-31
Budget Start
2017-04-01
Budget End
2018-03-31
Support Year
2
Fiscal Year
2017
Total Cost
$183,370
Indirect Cost
$53,955
Name
University of Alabama Birmingham
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
063690705
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Zhao, Meng; Fan, Chengming; Ernst, Patrick J et al. (2018) Y-27632 Preconditioning Enhances Transplantation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes in Myocardial Infarction Mice. Cardiovasc Res :
Ou, Jianfa; Si, Yingnan; Goh, KahYong et al. (2018) Bioprocess development of antibody-drug conjugate production for cancer treatment. PLoS One 13:e0206246
Yang, Kevin; Long, Qinqiang; Saja, Kamalamma et al. (2017) Knockout of the ATPase inhibitory factor 1 protects the heart from pressure overload-induced cardiac hypertrophy. Sci Rep 7:10501
Xu, Ningning; Ma, Chao; Ou, Jianfa et al. (2017) Comparative Proteomic Analysis of Three Chinese Hamster Ovary (CHO) Host Cells. Biochem Eng J 124:122-129
Li, Qince; Ni, Rong Ruby; Hong, Huixian et al. (2017) Electrophysiological Properties and Viability of Neonatal Rat Ventricular Myocyte Cultures with Inducible ChR2 Expression. Sci Rep 7:1531
Zhang, Fang; Gannon, Mary; Chen, Yunjia et al. (2017) The amyloid precursor protein modulates ?2A-adrenergic receptor endocytosis and signaling through disrupting arrestin 3 recruitment. FASEB J 31:4434-4446
Zhou, Lufang; Xu, Ningning; Sun, Yan et al. (2014) Targeted biopharmaceuticals for cancer treatment. Cancer Lett 352:145-51