Isolation of subcellular components, such as mitochondria, is of significant importance for the elucidation of their biological function by proteomic and metabolomic methods. Anomalies of mitochondrial physiology have been implicated in a range of disorders, including stroke, heart disease, diabetes, obesity and ageing. Mitochondria are increasingly popular targets in modern studies. In addition to their importance as potential drug targets, functional mitochondrial isolates could be crucial in high-throughput drug screening. Pressure Cycling Technology (PCT) uses controlled hydrostatic pressure pulses to disrupt membranes and release cellular components. The feasibility experiments in Phase I, demonstrated that alternating pressure can be used to disrupt parts of the cellular structure while leaving others intact. These selective effects of PCT are based on the target's reaction to rapid changes in pressure. It has been shown that fine tuning of PCT parameters can be used to isolate subcellular structures with a level of control and reproducibility that is superior to that of traditional methods. Subcellular proteomic profiling can be complementary to studies that often focus on intact cells or whole cell lysates. By reducing the complexity of intact cells or tissues, the isolation, fractionation and concentration of subcellular components according to their cellular localization can be very useful in the quest for low abundance protein biomarkers. This Phase II SBIR project is designed to develop a robust platform technology that will facilitate the isolation of intact and biologically functional subcellular components for biomarker research, diagnostics and drug discovery. Our initial effort will be placed in a development of the advanced PCT sample preparation system for on-demand isolation of intact mitochondria from cultured cells and tissues. Functional mitochondria as well as other organelles of significance will be extracted using this system. Optimization studies of PCT methods will be carried out to maximize yield and integrity of mitochondria from a set of clinically relevant tissue types - liver, lung, brain, heart, skeletal muscle and adipose tissue. It is anticipated that, once the cells are ruptured by PCT, subcellular components in additional to mitochondria, such as nuclei or membrane fractions, may be isolated efficiently by slight modification of the protocols optimized for mitochondrial extraction. Furthermore, A PCT-based sub-mitochondrial fractionation methods will be studied for the enrichment of low abundance proteins localized in specific mitochondrial compartments. Efforts will include hardware improvement, new designs of sample-specific containers, validations of protocols, and examinations of extracted products using a number of representative downstream applications. At the conclusion of this project, we aim to offer a commercial platform, validated protocols and kits for isolations of intact mitochondria from animal tissues, and optimization protocols that users may employ for extracting human postsurgical samples and biopsies in future clinical proteomic diagnostics.
| Gross, Vera S; Greenberg, Heather K; Baranov, Sergei V et al. (2011) Isolation of functional mitochondria from rat kidney and skeletal muscle without manual homogenization. Anal Biochem 418:213-23 |
| Gross, Vera; Lazarev, Alexander; Lawrence, Nathan et al. (2008) Isolation of mitochondria from cell cultures by PCT for proteomic analysis. Biotechniques 45:99-100 |
