Role of Antimicrobial Peptides in Skin Barrier Repair in Individuals with Atopic Dermatitis

Abstract

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that exhibits a complex interplay of skin barrier disruption and immune dysregulation. Patients with AD are susceptible to cutaneous infections that may progress to complications, including staphylococcal septicemia. Although most studies have focused on filaggrin mutations, the physical barrier and antimicrobial barrier also play critical roles in the pathogenesis of AD. Within the physical barrier, the stratum corneum and tight junctions play the most important roles. The tight junction barrier is involved in the pathogenesis of AD, as structural and functional defects in tight junctions not only disrupt the physical barrier but also contribute to immunological impairments. Furthermore, antimicrobial peptides, such as LL-37, human b-defensins, and S100A7, improve tight junction barrier function. Recent studies elucidating the pathogenesis of AD have led to the development of barrier repair therapy for skin barrier defects in patients with this disease. This review analyzes the association between skin barrier disruption in patients with AD and antimicrobial peptides to determine the effect of these peptides on skin barrier repair and to consider employing antimicrobial peptides in barrier repair strategies as an additional approach for AD management.

Detection of Antimicrobial Peptides in Stratum Corneum by Mass Spectrometry

“…Through their antimicrobial and immunomodulatory effects AMPs are important players of skin homeostasis. By suppressing/preventing the invasion of potential pathogens, some AMPs are considered as markers reflecting the defensive status of the skin [ 1 , 7 , 21 , 23 , 40 , 41 ]. Additionally, as cohesive forces gradually increase with depth, the AMPs that can be retrieved by a tape stripping approach frequently applied for superficial skin sampling might be of highest relevance [ 30 ].…”

“…Samples collected with tape stripping method provide suitable material for the identification of SC-specific proteins [ 27 ]. In this way, hBDs, LL-37, RNase 7, S100A7, DCD proteins have been identified in the SC samples of healthy and inflamed skin [ 1 , 2 , 14 , 20 , 22 , 24 , 25 ].…”

“…The human skin provides an interface between our body and the external environment acting not only as a physical barrier but also as antimicrobial and immune barriers [ 1 , 2 , 3 , 4 ]. Skin components, such as keratinocytes, mast cells, sebocytes, neutrophil granulocytes and sweat glands synthesize small, usually 12–50 amino acid long proteins that belong to the family of antimicrobial and immunomodulatory proteins (AMPs) providing a prompt response against potentially pathogenic agents [ 5 ].…”

“…The investigation of the skin’s AMP profile may have both diagnostic and predictive value. AMPs could serve as markers for assessing the stage and severity of certain skin diseases, such as LL-37 and hBD4 in atopic dermatitis (AD), S100A7 in psoriasis vulgaris (Ps) and kallikrein 5 in papulopustular rosacea (PPR) [ 1 , 7 , 14 , 22 , 23 ]. During our work we aimed to develop a novel method to establish the AMP profile of the stratum corneum that would represent all examined conditions of the skin, under both healthy and diseased state.…”

Immunomodulatory Properties of Host Defence Peptides in Skin Wound Healing

“…Atopic dermatitis (eczema) is another pathological skin condition [109]. Unlike the psoriasis which is characterised by elevated levels of innate immunity peptides, in atopic dermatitis, host defence peptide levels are not abundant and together with skin dryness make affected areas prone to infections [110].…”