Mitochondrial networking in human blood cells with application in acute care illnesses.

Mitochondria are dynamic organelles that adapt in response to environmental stresses or mutations. Dynamic processes involving mitochondria include their locomotion within cells and fusion and fission events in which mitochondrial join together or split apart. Various imaging strategies have been utilized to track mitochondrial dynamics. One common limitation of most of the methods available is that the time required to perform the technique and analyze the results prohibits application to clinical diagnosis and therapy. We recently demonstrated "whole-cell" mitochondrial analysis in a two-dimensional fashion with fluorescence microscopy. Our developed technique allows evaluation of whole-cell mitochondrial networking, including assessment of mitochondrial motility and rates of fission and fusion events using human blood cells (peripheral blood mononuclear cells (PBMCs)) on a clinically relevant timescale. We demonstrate this methodology in a cohort of healthy subjects as well as a cohort of hospitalized subjects having sepsis, an acute care illness. As there is increasing use of human blood cells as a proxy of organ mitochondrial function with respiration in various disease states, the addition of mitochondrial dynamics will now allow for more thorough clinical evaluation of mitochondrial networking in human disease with potential exploration of therapeutics.