Fatty acid transporters in skin development, function and disease

Abstract

Fatty acids in the epidermis can be incorporated into complex lipids or exist in a free form, and they are crucial to proper functions of the epidermis and its appendages, such as sebaceous glands. Epidermal fatty acids can be synthesized de novo by keratinocytes or taken up from extracutaneous sources in a process that likely involves protein transporters. Several proteins that are expressed in the epidermis have been proposed to facilitate the uptake of long-chain fatty acids (LCFA) in mammalian cells, including fatty acid translocase/CD36, fatty acid binding protein, and fatty acid transport protein (FATP)/very long-chain acyl-CoA synthetase. In this review, we will discuss the mechanisms by which these candidate transporters facilitate the uptake of fatty acids. We will then discuss the clinical implications of defects in these transporters and relevant animal models, including the FATP4 animal models and ichthyosis prematurity syndrome, a congenital ichthyosis caused by FATP4 deficiency. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier.

<b>Immunohistochemical localization of fatty acid transporters and MCT1 in the sebaceous glands of mouse </b><b>skin </b>

“…We confirmed the membrane-bound expression in the mouse sebaceous glands and further clarified a unique localization of CD36 different from that of MCT1 in meibomian and preputial glands: CD36 was expressed in the more mature glandular cells, while MCT1 was weak in those cells. Analyses of CD36-deficient mice and humans did not show any apparent skin abnormalities (9). In accordance, our mouse model with genetic deletion of CD36 did not affect the essential expression of MCT1 or fatty acid binding proteins in the sebaceous glands.…”

“…Several transporters and binding proteins for fatty acids regulate the production of the sebum. The main molecules for the uptake and transfer of long-chain fatty acids may be the membrane bound transporter CD36, E-FABP (epidermal-fatty acid binding protein), and FATP (fatty acid transport protein)-4; the latter two are cytoplasmic fatty acid binding proteins (9). Recently, we reported the selective expression of MCT1 in the sebaceous glands including the meibomian gland and preputial gland.…”

Olive by-products: Challenge application in cosmetic industry

“…Squalene/␤-sitosterol Softener (Viola and Viola, 2009) Oleuropein ↓ Increase in skin thickness and reduction elasticity induced by long term exposure to UVB ↓Tumors growth in exposed skin Skin protecting, anti-aging, anti-inflammatory, antimicrobial, antiviral ↑Proteasome activity ↓ Intracellular levels of ROS (Andreadou et al, 2006;Japon-Lujan et al, 2006;Katsiki et al, 2007;Khalil et al, 2015;Kimura and Sumiyoshi, 2009;Omar, 2010b;Ziogas et al, 2010) Hydroxytyrosol Antimicrobial activity Anti-inflammatory properties (El and Karakaya, 2009) Cellulose, pectic polysaccharides, hemicellulosic polymers ↑ Physical and structural properties of hydration ↑ Oil holding capacity (Elleuch et al, 2011;Rodriguez-Gutierrez et al, 2014) Stone Skin exfoliation (Cosmoliva, 2014;RedFlower, 2014) Fatty acids ↓ Permeability barrier (blocks for complex lipids in sebum produced by sebaceous glands) Signaling keratinocytes to regulate epidermal homeostase Acidification of stratum corneum ↑ Hydratation ↑ Softness ↑ Elasticity ↑ Protective barrier (Lin and Khnykin, 2014;van Smeden et al, 2014) Mineral content ↑ Hydratation ↑ Stiffness Controlling pH (Roberts et al, 2007;Wang et al, 2015) In several studies, it has been demonstrated that HT has antioxidant and antimicrobial effects (Bisignano et al, 1999), representing 92% of the total phenols of final extracts (de Leonardis et al, 2008), with cytotoxic effects and anti-inflammatory properties (El and Karakaya, 2009). A linear relationship between oleuropein content and antioxidant capacity of the extracts from leaves has been previously reported (Conde et al, 2009).…”

“…Specifically in skin, incorporated into complex lipids or in a free form, they are crucial to proper functions of epidermis and sebaceous glands (Lin and Khnykin, 2014). According to Lin and Khnykin (2014) FA have multiple functions in the epidermis: permeability barrier; blocks for complex lipids in sebum produced by sebaceous glands; signaling keratinocytes to regulate epidermal homeostasis; and, finally, promote the acidification of the stratum corneum.…”

Secreted Acb1 Contributes to the Yeast-to-Hypha Transition in Cryptococcus neoformans

“…Among higher eukaryotes, there are multiple copies of Acbp-encoding genes in one genome, and these proteins differ in size and subcellular localization (28)(29)(30)(31)(32)(33)(34). Nonetheless, all Acbps are conserved in the acyl-CoA-binding domain (34).…”