Related Experiment Video
Updated: Jun 1, 2026
Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages
Published on: May 21, 2018
Defect in mevalonate pathway induces pyroptosis in Raw 264.7 murine monocytes
Annalisa Marcuzzi1, Elisa Piscianz, Martina Girardelli
1Medical Genetic Service, Institute for Maternal and Child Health "Burlo Garofolo", Trieste, Italy. marcuzzi@burlo.trieste.it
Abstract:
The inhibition of mevalonate pathway by the aminobisphosphonate alendronate (ALD) has been previously associated with an augmented lipopolysaccharide-induced interleukin-1beta (IL-1β) secretion in monocytes, as demonstrated in an auto-inflammatory disease known as mevalonate kinase deficiency (MKD). In this study we investigated the effect of ALD + LPS on monocyte cell line (Raw 264.7) death. ALD strongly augmented LPS-induced programmed cell death (PCD) as well as IL-1β secretion in Raw murine monocytes, whereas necrosis was rather unaffected. ALD + LPS induced caspase-3 activation. Inhibition of IL-1β stimulation partially restored cell viability. These findings suggest that the inhibition of mevalonate pathway, together with a bacterial stimulus, induce a PCD partly sustained by the caspase-3-related apoptosis and partly by caspase-1-associated pyroptosis. The involvement of pyroptosis is a novel hit in our cell model and opens discussions about its role in inflammatory cells with chemical or genetic inhibition of mevalonate pathway.
Insights
Alendronate combined with lipopolysaccharide significantly increases programmed cell death in monocytes, partly via apoptosis and pyroptosis. This suggests a novel role for pyroptosis in inflammatory responses when the mevalonate pathway is inhibited.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Alendronate (ALD) inhibits the mevalonate pathway.
- This inhibition is linked to increased interleukin-1beta (IL-1β) secretion in monocytes, observed in mevalonate kinase deficiency (MKD).
Purpose of the Study:
- To investigate the combined effects of alendronate (ALD) and lipopolysaccharide (LPS) on monocyte cell death.
- To elucidate the mechanisms underlying ALD + LPS-induced cell death in Raw 264.7 monocytes.
Main Methods:
- Utilized Raw 264.7 murine monocyte cell line.
- Administered alendronate (ALD) and lipopolysaccharide (LPS) to monocytes.
- Assessed programmed cell death (PCD), necrosis, IL-1β secretion, and caspase-3 activation.
Main Results:
- ALD significantly augmented LPS-induced programmed cell death (PCD) and IL-1β secretion.
- Necrosis was largely unaffected by ALD + LPS treatment.
- Caspase-3 activation was observed, and inhibiting IL-1β partially restored cell viability.
Conclusions:
- Mevalonate pathway inhibition plus a bacterial stimulus (LPS) induces PCD in monocytes.
- This PCD is mediated by both caspase-3-dependent apoptosis and caspase-1-dependent pyroptosis.
- The involvement of pyroptosis represents a novel finding, suggesting its role in inflammatory cells with inhibited mevalonate pathways.
