Single-Cell NF-κB Dynamics for Modeling TNF-Αlpha Signaling Circuits

NF-κB transcription factors are composed of homodimers or heterodimers. There are 5 subunits in the NF-κB family, including p50, p52, p65(RelA), RelB, and c-Rel, respectively. NF-κB activity can be induced by a variety of stimuli, including ultraviolet irradiation, cytokines, free radicals, oxidized low density lipoprotein (LDL), and bacterial or viral antigens. Incorrect regulation of NF-kB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection, and improper immune development. A recent study reveals that binding of TNF-α to TNF-R activates transcription of its target genes. In addition, after stimulation with TNF-α, NF-kB activation results in oscillations in nuclear NF-kB and target gene expression can be regulated by negative feedback loops. The project will present single-cell NF-kB dynamics for modeling TNF-α signaling circuits using nano-biomedical technologies. In addition, we will propose high-throughput quantitative measurements with single-cell resolution in understanding how biological systems operate, and present novel design of micro-scale surface enhanced Raman spectroscopy (SERS) system to probe biological circuits inside a living cell due to the presence of TNF-α stimulation. This project will primarily focus on three specific aims, and we will outline them briefly: Aim 1: Construction of a novel study design for single-cell NF-kB biological circuits; Aim 2: Mathematical analysis of the NF-kB pathway regulation controlled by interlinked negative feedback loops, and Aim 3: Investigate the relationships between NF-kB and p53 oscillator pathways. We anticipate the proposed approach based on nano-biomedical technologies, together with the platform at single-cell level could be applied to build a methodology for probing oscillations in transcription factor dynamics at the cellular level and provide practical strategy to answer how cells can distinguish the pathways from inflammation, cell apoptosis and necrosis based on NF-kB transcription factor.