In the proposed studies, we aim to develop and validate technology to allow for high-throughput assays of inhibitors and inducers of mitochondrial depolarization, the point of no return for apoptosis. As apoptosis is a key unregulated pathway in tumor progression, its study and ultimately control is of paramount important in cancer biology. Preliminary studies by some of us have shown a correlation between patient cancer progression-free survival rate and the response of mitochondria (depolarization of the inner membrane, permeabilization of the outer membrane) to pro-apoptotic BH3 peptides in digitonin permeabilized patient primary tumor cells. We also have shown that the patients whose mitochondria are more easily depolarized with BH3 peptides respond better to chemotherapy. In proof of concept work, we demonstrated an on-chip nanofluidic technology that was able to trap individual, living mitochondria isolated from cell and tissues, and to interrogate the membrane potential using potential sensitive fluorescence probes of these individual mitochondria in response various chemical environments, including substrates and inhibitors of the electron transport chain, as well as calcium challenges which resulted in mitochondrial flickering and depolarization. In addition, our initial work demonstrated in preliminary studies the electrical sensing of the opening and closing of individual ion channels in lipid bilayers using nanotube electrodes. In the proposed studies we will develop and validate this technology to sense the opening and closing of individual ion channels in mitoplasts and mitochondria, study their statistics and timing, and to develop a platform to enable, ultimately, high throughput assays of the electrophysiology of the mitochondrial electron transport chain and membrane depolarization at the single ion channel level. The technology will be transformative in three ways: First, it will validate a qualitatively new assay for study of apoptosis. Deregulation of apoptosis is well known as one of 6 hallmarks of cancer, however, methods to study mitochondrial depolarization have been lacking. Second, it will allow for a qualitatively new way to study electrophysiology at the single ion channel level. This will allow unprecedented studies of timing, location, and statistics of the mitochondrial membrane flickering and depolarization. Finally, the overall technology will enable new studies of mitochondrial metabolism. Cancer metabolism is one of the 2 new hallmarks added last year to cancer, and this instrumentation will enable the understanding of one important component of metabolic flux (namely, membrane potential). Because our high throughput technology will enable assays of thousands of individual mitochondria from small numbers of cells (even a single cell), it will enable an advance in instrumentation to study the interrelationships between metabolism, stem cells, and cancer biology.

Public Health Relevance

This project develops techniques to study programmed cell death and its regulation by proteins and molecules. Because regulating this is important to understand cell growth and proliferation, it may aid to understand how this process goes wrong in cancer (uncontrolled cell growth and proliferation), and eventually enable new therapies to treat cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Exploratory/Developmental Grants Phase II (R33)
Project #
1R33CA182384-01A1
Application #
8811041
Study Section
Special Emphasis Panel (ZCA1-SRLB-Q (O2))
Program Officer
Knowlton, John R
Project Start
2015-02-01
Project End
2018-01-31
Budget Start
2015-02-01
Budget End
2016-01-31
Support Year
1
Fiscal Year
2015
Total Cost
$412,541
Indirect Cost
$62,739
Name
University of California Irvine
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92697
Singh, Larry N; Crowston, Jonathan G; Lopez Sanchez, M Isabel G et al. (2018) Mitochondrial DNA Variation and Disease Susceptibility in Primary Open-Angle Glaucoma. Invest Ophthalmol Vis Sci 59:4598-4602
Pei, Liming; Wallace, Douglas C (2018) Mitochondrial Etiology of Neuropsychiatric Disorders. Biol Psychiatry 83:722-730
Weisz, Eliana D; Towheed, Atif; Monyak, Rachel E et al. (2018) Loss of Drosophila FMRP leads to alterations in energy metabolism and mitochondrial function. Hum Mol Genet 27:95-106
Zand, Katayoun; Pham, Ted D A; Li, Jinfeng et al. (2017) Resistive flow sensing of vital mitochondria with nanoelectrodes. Mitochondrion 37:8-16
Burke, Peter J (2017) Mitochondria, Bioenergetics and Apoptosis in Cancer. Trends Cancer 3:857-870
Morrow, Ryan M; Picard, Martin; Derbeneva, Olga et al. (2017) Mitochondrial energy deficiency leads to hyperproliferation of skeletal muscle mitochondria and enhanced insulin sensitivity. Proc Natl Acad Sci U S A 114:2705-2710
Wallace, Douglas C (2017) A Mitochondrial Etiology of Neuropsychiatric Disorders. JAMA Psychiatry 74:863-864
Zhou, Weiwei; Burke, Peter J (2017) Versatile Bottom-Up Synthesis of Tethered Bilayer Lipid Membranes on Nanoelectronic Biosensor Devices. ACS Appl Mater Interfaces 9:14618-14632
Angelin, Alessia; Gil-de-Gómez, Luis; Dahiya, Satinder et al. (2017) Foxp3 Reprograms T Cell Metabolism to Function in Low-Glucose, High-Lactate Environments. Cell Metab 25:1282-1293.e7
Pham, Ted D; Pham, Phi Q; Li, Jinfeng et al. (2016) Cristae remodeling causes acidification detected by integrated graphene sensor during mitochondrial outer membrane permeabilization. Sci Rep 6:35907

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