Time-varying stimuli that prolong IKK activation promote nuclear remodeling and mechanistic switching of NF-κB dynamics

Nat Commun. 2025 Aug 8;16(1):7329. doi: 10.1038/s41467-025-62837-0.

Abstract

Temporal properties of molecules within signaling networks, such as sub-cellular changes in protein abundance, encode information that mediate cellular responses to stimuli. How dynamic signals relay and process information is a critical gap in understanding cellular behaviors. In this work, we investigate transmission of information about changing extracellular cytokine concentrations from receptor-level supramolecular assemblies of IKK kinases downstream to the NF-κB transcription factor. In a custom robot-controlled microfluidic cell culture, we simultaneously measure input-output encoding of IKK-NF-κB in dual fluorescent-reporter cells. When compared with single cytokine pulses, dose-conserving pulse trains prolong IKK assemblies and lead to disproportionately enhanced retention of nuclear NF-κB. Using particle swarm optimization, we demonstrate that a mechanistic model does not recapitulate this emergent property. By contrast, invoking mechanisms for NF-κB-dependent chromatin remodeling to the model recapitulates experiments, showing how temporal dosing that prolongs IKK assemblies facilitates switching to permissive chromatin that sequesters nuclear NF-κB. Remarkably, using simulations to resolve single-cell receptor data accurately predicts same-cell NF-κB time courses for more than 80% of our single cell trajectories. Our data and simulations therefore suggest that cell-to-cell heterogeneity in cytokine responses are predominantly due to mechanisms at the level receptor-associated protein complexes.

MeSH terms

  • Cell Nucleus* / metabolism
  • Chromatin Assembly and Disassembly*
  • Cytokines / metabolism
  • Humans
  • I-kappa B Kinase* / genetics
  • I-kappa B Kinase* / metabolism
  • Models, Biological
  • NF-kappa B* / genetics
  • NF-kappa B* / metabolism
  • Signal Transduction
  • Time Factors

Substances

  • NF-kappa B
  • I-kappa B Kinase
  • Cytokines