Caspase-1 modulates incisional sensitization and inflammation.

Area of Science:

• Pain research
• Inflammation biology
• Molecular mechanisms of nociception

Background:

• Surgical injury triggers inflammatory mediators, leading to hyperalgesia and pain.
• Interleukin-1β (IL-1β) is crucial in this process, but its regulation post-incision is unclear.
• Caspase-1 cleaves pro-IL-1β into its active form, suggesting its role in incisional pain.

Purpose of the Study:

• To investigate the role of caspase-1 in regulating incisional interleukin-1β levels.
• To determine if caspase-1 inhibition can reduce postsurgical nociceptive sensitization and inflammation.
• To explore the therapeutic potential of targeting caspase-1 for pain management.

Main Methods:

• Utilized a mouse hind paw incisional model.
• Administered selective caspase-1 inhibitors (Ac-YVAD-CMK, VRTXSD727).
• Assessed nociceptive sensitization, edema, warmth, cytokine levels, and caspase-1 expression via enzyme activity assays and confocal microscopy.

Main Results:

• Caspase-1 activity significantly increased in skin near surgical wounds.
• Caspase-1 inhibition markedly reduced mechanical allodynia and thermal hyperalgesia, providing analgesia.
• Inhibition also decreased wound-associated edema, warmth, and levels of IL-1β, macrophage-inflammatory protein 1α, and prostaglandin E2.

Conclusions:

• Caspase-1 inhibition effectively reduces postsurgical sensitization and inflammation.
• The mechanism is likely dependent on the caspase-1/interleukin-1β pathway.
• Targeting caspase-1 presents a promising strategy for managing postsurgical pain.