Effects of Overload on Imiquimod-Induced Psoriasis Model Mice: A Basic Experimental Study.

Area of Science:

• Immunology
• Dermatology
• Exercise Physiology

Background:

• Psoriasis is a chronic inflammatory skin disease linked to arthritis and enthesitis.
• Key inflammatory cytokines include interleukin-17 (IL-17), IL-23, and tumor necrosis factor-alpha (TNF-α).
• Gamma delta (γδ) T cells contribute to inflammation by producing IL-17 and TNF-α, but the role of mechanical stress is unclear.

Purpose of the Study:

• To investigate the impact of strenuous exercise on the pathology of imiquimod (IMQ)-induced psoriasis in a mouse model.
• To elucidate the mechanisms linking mechanical stress, inflammation, and psoriasis development.

Main Methods:

• Mice with IMQ-induced psoriasis were subjected to treadmill running (strenuous exercise) or kept sedentary.
• Skin, thymus, and shoulder tissues were analyzed for inflammatory markers (IL-17, IL-23, TNF-α, MMP-13) and cell infiltration (γδ T cells).
• Serum cytokine levels were measured to assess systemic inflammation.

Main Results:

• Strenuous exercise significantly increased γδ T cell infiltration and IL-17/IL-23 expression in the skin.
• Exercise enhanced γδ T cell development and IL-17 expression in the thymus.
• Elevated serum levels of TNF-α and IL-17 were observed, alongside exercise-induced entheseal changes like angiogenesis and increased TNF-α/MMP-13 expression.

Conclusions:

• Strenuous exercise exacerbates the pathological features of IMQ-induced psoriasis in mice.
• Physical stress can worsen both skin and entheseal inflammation in psoriasis models.