NF-kB and Chromatin Changes in Human Sepsis
The proposal continues our objective to elucidate the molecular events that control acute systemic inflammation, a highly lethal process. In the previous grant cycle, we discovered a Toll like receptor (TLR) - driven, temportally-defined, epigenetic program in innate immunity macrophages and neutrophis, which directs the course of acute systemic inflammation. This process modifies chromatin structure to repress or activate distinct functional sets of genes, thus generating distinct phenotypic phases. Others and we have shown that bioenergy shifts also occur in innate immunity cells during acute systemic inflammation. This application develops the unified concept that modifications in bioenergetics integrate with epigenetics to direct the phase shifts of acute inflammation. We propose two specific aims: Aim 1) To define the connections between bio-energy and epigenetics. We will use a cell model that reproduces TLR4-dependent phase shifts to: a) delineate gene-specific chromatin modifications; b) determine protein-protein interactions; c) assess metabolic profiles by mass spectroscopy; and c) translate our concept to human normal and sepsis blood leukocytes. Aim 2) To test effects of modifying bio-energy and epigenetic shift on clinical outcomes. We will us a murine model of sepsis to: a) define bio-energy and epigenetic phase shifts, using biochemical and genetic methods to analyze plasma and isolated leukocytes from spleen, peritoneum, and bone marrow; and b) use pharmacologic and genetic approaches to determine whether modifying to adaptive phase alters microvascular inflammation and survival. Our result will broadly impact the field of inflammation by providing new insight on how acute inflammation is orchestrated, and inform novel therapies.