S. aureus drives itch and scratch-induced skin damage through a V8 protease-PAR1 axis

Area of Science:

• Microbiology
• Neuroscience
• Dermatology

Background:

• The skin barrier is exposed to microbes, but their role in itch is unclear.
• Staphylococcus aureus is linked to itchy skin conditions.
• Pruriceptor sensory neurons detect and transmit itch signals.

Purpose of the Study:

• To investigate the role of microbes, specifically Staphylococcus aureus, in generating itch.
• To identify the bacterial factors responsible for S. aureus-induced itch.
• To explore therapeutic strategies targeting the identified mechanism.

Main Methods:

• Epicutaneous exposure of mice to S. aureus.
• Testing isogenic bacterial mutants lacking specific virulence factors.
• Assessing itch behavior and scratch-induced skin damage.
• Investigating the cleavage of proteinase-activated receptor 1 (PAR1) by V8 protease.
• Utilizing genetic deficiency, siRNA knockdown, and pharmacological blockade of PAR1.

Main Results:

• S. aureus exposure induced significant itch and skin damage.
• The S. aureus serine protease V8 was identified as a key mediator of itch and alloknesis.
• V8 protease cleaves PAR1 on both mouse and human sensory neurons.
• Inhibition of PAR1 reduced itch and skin damage caused by V8 and S. aureus.

Conclusions:

• Staphylococcus aureus directly activates sensory neurons to cause itch.
• The V8 protease-V8-PAR1 signaling pathway is a critical mechanism for S. aureus-induced itch.
• Targeting the V8-PAR1 interaction offers a potential therapeutic approach for treating itch associated with S. aureus.