Abstract
The skin barrier is broadly composed of two elements—a physical barrier mostly localised in the epidermis, and an immune barrier localised in both the dermis and epidermis. These two systems interact cooperatively to maintain skin homeostasis and overall human health. However, if dysregulated, several skin diseases may arise. Psoriasis is one of the most prevalent skin diseases associated with disrupted barrier function. It is characterised by the formation of psoriatic lesions, the aberrant differentiation and proliferation of keratinocytes, and excessive inflammation. In this review, we summarize recent discoveries in disease pathogenesis, including the contribution of keratinocytes, immune cells, genetic and environmental factors, and how they advance current and future treatments.
Highlights
A number of different cytokines and chemokines may be released to compel the infiltration of inflammatory cells, such as neutrophils, monocytes, plasmacytoid dendritic cells and effector T cells from blood vessels
Several studies have found AQP3 expression is down-regulated in psoriatic lesions and is abnormally localised to the keratinocyte cytoplasm, which may contribute to skin barrier disruption and dehydration in psoriasis [59,60,61]
Keratinocytes treated with interferon (IFN)-γ can induce the differentiation of naïve T cells into T helper (Th) 1 and Th17 subtypes, in the absence of professional antigen presenting cells [88]
Summary
TJ proteins consist of a complex network of intra and extracellular proteins, including occludin, cingulin, zonula occludens (ZO), claudins and junctional adhesion molecule-A [3] They can become dysregulated in response to radiation, infection, and inflammatory processes [4]. Other skin resident immune cells include innate lymphoid cells (ILCs), mast cells, and γδ T cells [8], which are crucial in initiating inflammatory cytokine responses. A number of different cytokines and chemokines may be released to compel the infiltration of inflammatory cells, such as neutrophils, monocytes, plasmacytoid dendritic cells (pDCs) and effector T cells (effT) from blood vessels They remove the invaded pathogens and clear cell debris. Dysregulation can contribute to many inflammatory skin disorders, including psoriasis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
