Temporal dynamics of a CSF1R signaling gene regulatory network involved in epilepsy

PLoS Comput Biol. 2021 Apr 5;17(4):e1008854. doi: 10.1371/journal.pcbi.1008854. eCollection 2021 Apr.

Abstract

Colony Stimulating Factor 1 Receptor (CSF1R) is a potential target for anti-epileptic drugs. However, inhibition of CSF1R is not well tolerated by patients, thereby prompting the need for alternative targets. To develop a framework for identification of such alternatives, we here develop a mathematical model of a pro-inflammatory gene regulatory network (GRN) involved in epilepsy and centered around CSF1R. This GRN comprises validated transcriptional and post-transcriptional regulations involving STAT1, STAT3, NFκB, IL6R, CSF3R, IRF8, PU1, C/EBPα, TNFR1, CSF1 and CSF1R. The model was calibrated on mRNA levels of all GRN components in lipopolysaccharide (LPS)-treated mouse microglial BV-2 cells, and allowed to predict that STAT1 and STAT3 have the strongest impact on the expression of the other GRN components. Microglial BV-2 cells were selected because, the modules from which the GRN was deduced are enriched for microglial marker genes. The function of STAT1 and STAT3 in the GRN was experimentally validated in BV-2 cells. Further, in silico analysis of the GRN dynamics predicted that a pro-inflammatory stimulus can induce irreversible bistability whereby the expression level of GRN components occurs as two distinct states. The irreversibility of the switch may enforce the need for chronic inhibition of the CSF1R GRN in order to achieve therapeutic benefit. The cell-to-cell heterogeneity driven by the bistability may cause variable therapeutic response. In conclusion, our modeling approach uncovered a GRN controlling CSF1R that is predominantly regulated by STAT1 and STAT3. Irreversible inflammation-induced bistability and cell-to-cell heterogeneity of the GRN provide a theoretical foundation to the need for chronic GRN control and the limited potential for disease modification via inhibition of CSF1R.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Epilepsy / genetics*
  • Gene Regulatory Networks*
  • Mice
  • Models, Biological*
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / genetics*
  • STAT1 Transcription Factor / metabolism
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction / genetics*

Substances

  • Csf1r protein, mouse
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor
  • STAT1 Transcription Factor
  • STAT3 Transcription Factor

Grants and funding

The work of FPL was supported by the D.G. Higher Education and Scientific Research of the French Community of Belgium (Action de Recherche Concertée 15/20-065). UCB-Pharma (http://www.ucb.com) financially supported the research project by funding 70% of the human and laboratory resources required. Authors from UCB staff have taken part in the study design, data analysis and manuscript preparation.