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Contribution of myeloperoxidase and inducible nitric oxide synthase to pathogenesis of psoriasis
Nursel Dilek1, Aziz Ramazan Dilek2, Yakup Taşkın3
1Dermatology Department, Recep Tayyip Erdoğan University, Medical Faculty Hospital, Rize, Turkey.
Introduction:
Histological changes of psoriasis include invasion of neutrophils into the epidermis and formation of Munro abscesses in the epidermis. Neutrophils are the predominant white blood cells in circulation when stimulated; they discharge the abundant myeloperoxidase (MPO) enzyme that uses hydrogen peroxide to oxidize chloride for killing ingested bacteria.
Aim:
To investigate the contribution of neutrophils to the pathogenesis of psoriasis at the blood and tissue levels through inducible nitric oxide synthase (iNOS) and MPO.
Material And Methods:
A total of 50 adult patients with a chronic plaque form of psoriasis and 25 healthy controls were enrolled to this study. Serum MPO and iNOS levels were measured using ELISA method. Two biopsy specimens were taken in each patient from the center of the lesion and uninvolved skin. Immunohistochemistry was performed for MPO and iNOS on both normal and psoriasis vulgaris biopsies.
Results:
While a significant difference between serum myeloperoxidase levels were detected, a similar statistical difference between participants in the serum iNOS levels was not found. In immunohistochemistry, intensely stained leukocytes with MPO and intensely staining with iNOS in psoriatic skin was observed.
Conclusions:
Neutrophils in psoriasis lesions are actively producing MPO and this indirectly triggers the synthesis of iNOS. Targeting of MPO or synthesis of MPO in the lesion area may contribute to development of a new treatment option.
Insights
Neutrophils in psoriasis lesions produce myeloperoxidase (MPO), which indirectly triggers inducible nitric oxide synthase (iNOS). Targeting MPO may offer a new psoriasis treatment.
Area of Science:
- Dermatology
- Immunology
- Pathophysiology
Background:
- Psoriasis involves neutrophil infiltration and Munro's abscesses.
- Neutrophils release myeloperoxidase (MPO) for bacterial killing.
Purpose of the Study:
- Investigate neutrophil involvement in psoriasis pathogenesis.
- Analyze myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) at blood and tissue levels.
Main Methods:
- Studied 50 psoriasis patients and 25 healthy controls.
- Measured serum MPO and iNOS via ELISA.
- Performed immunohistochemistry for MPO and iNOS on skin biopsies.
Main Results:
- Serum MPO levels differed significantly between groups.
- Serum iNOS levels showed no significant statistical difference.
- Immunohistochemistry revealed intense MPO and iNOS staining in psoriatic skin leukocytes.
Conclusions:
- Neutrophils in psoriatic lesions actively produce MPO, indirectly inducing iNOS synthesis.
- Targeting MPO or its synthesis presents a potential therapeutic strategy for psoriasis.
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