Open AccessPhysiological levels of TNFα stimulation induce stochastic dynamics of NF-κB responses in single living cells
Author(s) -
David A. Turner,
Pawel Paszek,
Dan J. Woodcock,
David E. Nelson,
Caroline A. Horton,
Yunjiao Wang,
David G. Spiller,
D.A.J. Rand,
Mike White,
Claire V. Harper
Publication year - 2010
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.069641
Subject(s) - biology , tumor necrosis factor alpha , stimulation , microbiology and biotechnology , cytokine , nfkb1 , inflammation , nf κb , biophysics , signal transduction , immunology , neuroscience , transcription factor , biochemistry , gene
Nuclear factor kappa B (NF-kappaB) signalling is activated by cellular stress and inflammation and regulates cytokine expression. We applied single-cell imaging to investigate dynamic responses to different doses of tumour necrosis factor alpha (TNFalpha). Lower doses activated fewer cells and those responding showed an increasingly variable delay in the initial NF-kappaB nuclear translocation and associated IkappaBalpha degradation. Robust 100 minute nuclear:cytoplasmic NF-kappaB oscillations were observed over a wide range of TNFalpha concentrations. The result is supported by computational analyses, which identified a limit cycle in the system with a stable 100 minute period over a range of stimuli, and indicated no co-operativity in the pathway activation. These results suggest that a stochastic threshold controls functional all-or-nothing responses in individual cells. Deterministic and stochastic models simulated the experimentally observed activation threshold and gave rise to new predictions about the structure of the system and open the way for better mechanistic understanding of physiological TNFalpha activation of inflammatory responses in cells and tissues.