All ETDs from UAB

Advisory Committee Chair

Victor M Darley-Usmar

Advisory Committee Members

Scott Ballinger

Yabing Chen

Louis J Dell’Italia

C Roger White

James George

Document Type

Dissertation

Date of Award

2015

Degree Name by School

Doctor of Philosophy (PhD) Heersink School of Medicine

Abstract

The increasing prevalence of metabolic syndrome, diabetes, atherosclerosis, and many other diseases only recently associated with aberrant metabolism, have led to a de-mand for clinical assays to determine a patient’s mitochondrial health. With the rapidly growing interest in personalized medicine, such an assay would ideally be able to capture the metabolic changes associated with oxidative stress, inflammation, and therapy of a patient in a swift and non-invasive manner. Short of tissue biopsies, this burgeoning field of Translational Bioenergetics has had minimal success in obtaining sufficient human cells and the means to assess them both accurately and swiftly. The purpose of this study was to develop a method to assess the bioenergetic health of patients from a routine, non-invasive collection of whole blood. Isolation of blood cells in a manner amenable to bio-energetic analysis was necessary and methods were developed which utilized density gradient and magnetic cell sorting with nutrient rich buffers to collect pure and viable leukocytes and platelets from freshly drawn whole blood. Bioenergetic profiles were ob-tained using sequential injection of mitochondrial inhibitors on an extracellular flux ana-lyzer. These studies revealed distinct and adaptable metabolic programs in healthy donor monocytes, neutrophils, lymphocytes, and platelets. The Bioenergetic Health Index was developed to condense the major features of the bioenergetic profile in to a single, unit-less number that could readily identify bioenergetic dysfunction. To validate the potential of these cells as bioenergetic biomarkers, monocytes showed significant bioenergetic dysfunction in the inflammatory and oxidative environment observed in the pericardial space following cardiac surgery. Furthermore, this extracellular flux technology was able to measure the oxygen consumption through NADPH oxidase to generate superoxide and hydrogen peroxide in monocytes and neutrophils. Interestingly, the oxidative burst of neutrophils was observed to modulate the mitochondrial and glycolytic function of lym-phocytes, preventing them engaging a metabolic program essential for their immune ef-fector functions. In this thesis, we investigate the unique interactions and metabolic pro-grams of monocytes, neutrophils, lymphocytes, and platelets, and demonstrate their utility in translational bioenergetics and as bioenergetic biomarkers in health and disease.

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