Periodic Report Summary 2 - DANGER ATP (Regulation of inflammatory response by extracellular ATP and P2X7 receptor signalling: through and beyond the inflammasome.)
Adenosine triphosphate (ATP) is the molecule in charge to transport the chemical energy of the cell and maintain cellular metabolism. When a tissue is damaged, its cells release their intracellular content, and when ATP reaches high extracellular concentration, it signals to immune cells to alert danger. DangerATP is a project that seeks to understand how extracellular ATP is controlled and modulates the inflammatory response beyond tissue injury and cell death, ultimately depicting how the purinergic receptor for extracellular ATP in macrophages signals through and beyond inflammasome activation. To date (half-way through its funding), DangerATP has generated the following major results:
- During infection and sterile danger, we have detected how extracellular ATP is produced and regulated by using leading tools for the visualization of ATP by bioluminescence recording. The presence of extracellular ATP does not always correlate with tissue injury, but it could be regulated by several channels on the plasma membrane of macrophages. Different triggers, pathogenic and sterile, uses different pathways for ATP release and this ATP was important to establish a complete immune response.
- In parallel, we have been also characterizing how extracellular danger ATP activates a key pro-inflammatory pathway, the NLRP3 inflammasome, by using a pioneering bioluminescence resonance energy transfer technique. Currently, we are exploring the exact mechanisms by which NLRP3 activates, and how different small molecules could interfere this activation, in order to understand the mechanism of action of future anti-inflammatory drugs.
- After macrophage ATP stimulation, not only NLRP3 inflammasome is activated, but other parallel pathways are initiated. We have advance our understanding of these pathways by characterizing the major proteins released from macrophages after ATP stimulation. We have discovered that not only pro-inflammatory mediators are produced, but also, we have found that anti-inflammatory molecules are released from macrophages after ATP stimulation. Therefore, dangerous ATP could be also involved in the resolution of the inflammation. How these pathways signals and regulate the initiation and resolution of the inflammation is currently our focus.
- During infection and sterile danger, we have detected how extracellular ATP is produced and regulated by using leading tools for the visualization of ATP by bioluminescence recording. The presence of extracellular ATP does not always correlate with tissue injury, but it could be regulated by several channels on the plasma membrane of macrophages. Different triggers, pathogenic and sterile, uses different pathways for ATP release and this ATP was important to establish a complete immune response.
- In parallel, we have been also characterizing how extracellular danger ATP activates a key pro-inflammatory pathway, the NLRP3 inflammasome, by using a pioneering bioluminescence resonance energy transfer technique. Currently, we are exploring the exact mechanisms by which NLRP3 activates, and how different small molecules could interfere this activation, in order to understand the mechanism of action of future anti-inflammatory drugs.
- After macrophage ATP stimulation, not only NLRP3 inflammasome is activated, but other parallel pathways are initiated. We have advance our understanding of these pathways by characterizing the major proteins released from macrophages after ATP stimulation. We have discovered that not only pro-inflammatory mediators are produced, but also, we have found that anti-inflammatory molecules are released from macrophages after ATP stimulation. Therefore, dangerous ATP could be also involved in the resolution of the inflammation. How these pathways signals and regulate the initiation and resolution of the inflammation is currently our focus.