The Extracellular Matrix in Skin Inflammation and Infection

Abstract

The extracellular matrix (ECM) is an integral component of all organs and plays a pivotal role in tissue homeostasis and repair. While the ECM was long thought to mostly have passive functions by providing physical stability to tissues, detailed characterization of its physical structure and biochemical properties have uncovered an unprecedented broad spectrum of functions. It is now clear that the ECM not only comprises the essential building block of tissues but also actively supports and maintains the dynamic interplay between tissue compartments as well as embedded resident and recruited inflammatory cells in response to pathologic stimuli. On the other hand, certain pathogens such as bacteria and viruses have evolved strategies that exploit ECM structures for infection of cells and tissues, and mutations in ECM proteins can give rise to a variety of genetic conditions. Here, we review the composition, structure and function of the ECM in cutaneous homeostasis, inflammatory skin diseases such as psoriasis and atopic dermatitis as well as infections as a paradigm for understanding its wider role in human health.

In Vitro and Clinical Evaluation of Cannabigerol (CBG) Produced via Yeast Biosynthesis: A Cannabinoid with a Broad Range of Anti-Inflammatory and Skin Health-Boosting Properties

“…Collagens are essential scaffold proteins that promote skin smoothness and elasticity, but as we age their expression levels (collagen I and type III) decline [15]. Moreover, collagen IV is essential for basement membrane stability and is a key ECM protein [16]. Analysis of these key ECM genes suggests that CBG provides more significant anti-aging benefits to skin than CBD.…”

Characterization of Collagen I Fiber Thickness, Density, and Orientation in the Human Skin In Vivo Using Second-Harmonic Generation Imaging

“…The SAAID describes the ratio of the autofluorescence (AF) signal intensity, indicative for elastin, to the SHG signal intensity, indicative for collagen I [9], according to Equation (1). SAAID = (SHG − AF)/(SHG + AF).…”

“…In addition, 28 different subtypes of collagen can be found throughout the human body as structural components of, among others, tendons, cartilage, and skin, but also bones and teeth. The main collagens in the human skin are type I, III, XII, and XIV collagen [1]. In human skin, collagens of types I and III are mainly found in scaffolding structures [2,3] and are synthesized by fibroblasts [4,5].…”

Keratins as an Inflammation Trigger Point in Epidermolysis Bullosa Simplex

“…TLRs mediate the link between the appearance of pathogen-associated molecular patterns, which are often associated with injury, and the transcriptional activation of the NF-kB pathway and MAPK activation (Figure 6). DAMPs from external infections, injury, or endogenous alarm molecules, which might be the alternative form of fibronectin (FN-EDA) in the ECM or the products of laminin degradation, are recognized by TLRs [151]. The propagation of sterile inflammation occurs in response to extracellular Hsp70 (eHsp70) acting via TLR2 and TLR4, which are expressed on KCs, among others [152].…”