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Updated: Nov 4, 2025
Microglia as a Surrogate Biosensor to Determine Nanoparticle Neurotoxicity
Published on: October 25, 2016
PapRIV, a BV-2 microglial cell activating quorum sensing peptide
Yorick Janssens1, Nathan Debunne1, Anton De Spiegeleer1,2,3
1Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
Abstract:
Quorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood-brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.
Insights
Bacterial quorum sensing peptides (QSPs) like PapRIV can cross the gut-brain barrier. This peptide activates microglia, suggesting a role in gut-brain communication and neuroinflammation.
Area of Science:
- Microbiology
- Neuroscience
- Immunology
Background:
- Quorum sensing peptides (QSPs) are bacterial signaling molecules with potential host effects.
- The gut-brain axis links gut microbiota to microglial function.
- Microglia play a crucial role in brain immunity and function.
Purpose of the Study:
- To investigate the microglial activating properties of the QSP PapRIV from Bacillus cereus.
- To determine if PapRIV can cross the gastro-intestinal tract and blood-brain barrier.
- To explore PapRIV's role in gut-brain interactions.
Main Methods:
- In vitro studies using BV-2 microglia cells and Caco-2 cell models.
- In vivo assessment of peptide presence in mouse plasma.
- Analysis of cytokine (IL-6, TNFα) and ROS expression.
- NF-κB pathway activation assessment.
- Metabolite identification in serum.
Main Results:
- PapRIV demonstrated in vitro activation of BV-2 microglia cells.
- PapRIV successfully crossed the Caco-2 cell model and was detected in mouse plasma, indicating BBB penetration.
- PapRIV induced IL-6, TNFα, and ROS expression in a NF-κB dependent manner.
- A major active metabolite of PapRIV was identified in serum.
Conclusions:
- PapRIV can traverse the gastro-intestinal tract and blood-brain barrier.
- PapRIV exhibits microglia-activating properties in vitro.
- These findings suggest a potential role for PapRIV in modulating gut-brain axis communication and neuroinflammation.
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