Monocyte adhesion to fibronectin in psoriasis

Area of Science:

• Immunology
• Dermatology
• Cell Biology

Background:

• Mononuclear cells (MNC) differentiate into macrophages after extravasation, involving chemotaxis and adhesion to extracellular matrix proteins.
• Endothelial adhesion and chemotaxis are altered in psoriasis, but MNC adhesion to extracellular matrix proteins remains unstudied.
• Transforming growth factor-beta (TGF-beta) abnormally regulates MNC adhesion to endothelial cells in psoriasis.

Purpose of the Study:

• To investigate the role of substance P in regulating monocyte adhesion to fibronectin in psoriasis.
• To test the hypothesis that substance P influences monocyte-fibronectin interactions in psoriatic individuals.

Main Methods:

• Monocytes were isolated from 16 healthy controls and 11 psoriatic patients using gradient centrifugation.
• Monocyte adhesion to fibronectin was assessed using fibronectin-coated microtiter plates.
• Adherent cell numbers were quantified by measuring hexosaminidase activity.

Main Results:

• No significant differences in basal or substance P-stimulated monocyte adhesion were found between normal and psoriatic individuals.
• A subset of psoriatic patients showed a response to substance P.
• This in vitro response correlated with unstable psoriasis linked to stressful life events.

Conclusions:

• Monocyte priming by fibronectin or substance P is not critical in the pathogenesis of stable, chronic psoriasis.
• Substance P may play a role in the development of new lesions in some patients with unstable psoriasis.
• The findings suggest a potential link between substance P, monocyte behavior, and the exacerbation of psoriasis in specific patient subgroups.