Alarmine und ihre Bedeutung für entzündliche Hauterkrankungen

Zusammenfassung

Körpereigene antimikrobielle Peptide (AMP) bilden einen Schutzfilm auf unserer Haut und schützen sie vor bakteriellen und viralen Infektionen. Neben ihrer Funktion in der Infektabwehr initiieren und koordinieren AMPs zudem die kutane Immunantwort und sind als sogenannte „Alarmine” ein wesentlicher Bestandteil des angeborenen Abwehrsystems. Entzündliche Hautkrankheiten, die mit einer Barrierestörung assoziiert sind, wie das atopische Ekzem, Psoriasis oder Rosazea, sind gekennzeichnet durch eine Fehlregulation des AMP Cathelicidin. Während bei der Rosazea eine fehlerhafte Proteinspaltung von Cathelicidin vorliegt, wird beim atopischen Ekzem eine verminderte Produktion diskutiert. Bei Psoriasis wiederum ist Cathelicidin erhöht und möglicherweise an einer Autoimmunreaktion beteiligt. Durch Eingriffe in die Expression von Cathelicidin und anderer AMP bietet sich vielleicht ein neuartiger therapeutischer Ansatz dieser Erkrankungen. Die Cathelicidinproduktion wird in der Haut über den Vitamin D3-Signalweg reguliert, was neue Therapiemöglichkeiten für entzündliche und infektiöse Hautkrankheiten eröffnen könnte. Bis dahin ist die Untersuchung der Regulationsmechanismen der AMPs Gegenstand intensiver dermatologischer Grundlagenforschung.

Abstract

Our skin is constantly exposed to potentially harmful microorganisms. As effectors of innate immunity antimicrobial peptides (AMP) protect the skin from bacterial or viral infections. Furthermore, these peptides are an essential part of the host's immune system as they initiate and coordinate immune reactions. Hence, the term „alarmins” has been coined to designate AMPs. Inflammatory skin diseases such as atopic eczema, rosacea and psoriasis are characterized by dysfunction or dysregulation of antimicrobial peptides. In rosacea, cathelicidin peptide processing is abnormal, whereas in atopic eczema the induction of cathelicidin may be diminished. In psoriasis cathelicidin expression is upregulated and may be involved in an autoimmune cascade. Pharmacological regulation of AMP expression could be a novel therapeutic strategy to ameliorate inflammation and hence the burden of these inflammatory diseases. Therefore, an in-depth understanding of molecular mechanisms underlying AMP regulation is needed and current subject of dermatological research.

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