IL-1b Drives Inflammatory Responses to Propionibacterium acnes In Vitro and In Vivo. M. Kistowska, et al. Department of Dermatology, University Hospital, Zürich, Switzerland. Journal of Investigative Dermatology, 2014, 134, 677–685.
Acne Vulgaris is a common skin condition which affects to some degree almost everyone during teenage years but it can persist especially in females – so that 10% of women aged 40 still have it.
Main forms include retentional (comedones) and inflammatory (papules and pustules) types although both can coexist.
There are many ways which can explain inflammatory lesions, but the presence of Propionibacterium Acnes (PA) is one of them
Inflammatory Acne Vulgaris presents as papules and pustules and these are the most common lesions in women with acne persisting after the age of 25 – often there are few comedones (blackheads and whiteheads)
Indeed, in this group Acne Vulgar is hard to treat and effective oral treatments (such as isotretinoin) need to be used with caution due to the pregnancy risk.
In this study, the authors introduce a mechanism that regulates inflammatory responses to PA :
–IL-1b mRNA and the active processed form of IL-1b are abundant in inflammatory acne lesions.
–PA activates the NLRP3-inflammasome protein pathway in histiocytes (macrophages). This triggers inflammation (innate response) in the following ways:
-IL-1b is processed and secretion that is dependent on phagocytosis (IL-1β is synthesized as a precursor form protein only after stimulation, in contrast to IL-1α. )
-reactive oxygen species (ROS) synthesis,
-cellular potassium (K) leakage into the cytoplasm
In mice Il-1b and the NLRP3-inflammasome are needed to induce PA-induced inflammation
A targeted therapeutical agent could be an interesting way to treat Acne Vulgaris(inflammatory type).
Article selection: Prof Dr Jean-Hilaire Saurat – dermatologist. Geneva, Switzerland