Thin-layer chromatographic analyses of lipids in different layers of porcine epidermis and oral epithelium

Squier, Christopher A.; Wertz, Philip W.; Cox, Patrick

doi:10.1016/0003-9969(91)90017-o

Cited by 31 publications

(13 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In porcine epidermis, this b-glucosidase activity is active at acidic pH [45], and the activity in epidermis and palatal epithelium exceeded that in non-keratinized oral epithelium [46]. Thus, the relative inactivity of b-glucosidase in non-keratinized epithelium is consistent not only with the persistence of GlcCer species to the epithelial surface [47,48], but also with less-stringent barrier in non-keratinized oral epithelium [49].…”

Section: Enzymatic Processing Of Glucosylceramide and Sphingomyelin Imentioning

confidence: 75%

Epidermal sphingolipids: Metabolism, function, and roles in skin disorders

2006

View full text Add to dashboard Cite

Mammalian epidermis produces and delivers large quantities of glucosylceramide and sphingomyelin precursors to stratum corneum extracellular domains, where they are hydrolyzed to corresponding ceramide species. This cycle of lipid precursor formation and subsequent hydrolysis represents a mechanism that protects the epidermis against potentially harmful effects of ceramide accumulation within nucleated cell layers. Prominent skin disorders, such as psoriasis and atopic dermatitis, have diminished epidermal ceramide levels, reflecting altered sphingolipid metabolism, that may contribute to disease severity/ progression. Enzymatic processes in the hydrolysis of glucosylceramide and sphingomyelin, and the roles of sphingolipids in skin diseases, are the focus of this review. Keywords: ABCA12; Barrier; Ceramide; Dermis; Epidermis; Gaucher; Glucocerebrosidase; Glucosylceramides; Ichthyosis; Niemann-Pick; Prosaposin; Saposins; Sphingolipid; Sphingomyelin; Sphingomyelinase; Stratum corneum Sphingolipids in the structure and function of mammalian epidermisMammalian skin is composed of two distinct layers divided by a basement membrane zone: (1) the underlying dermis containing primarily fibroblasts embedded in an acellular collagen/elastin matrix that accounts for the majority of skin thickness; and (2) the overlying epidermis, responsible for formation and maintenance of the skin barrier to both desiccation and penetration of xenobiotics. The function of this barrier resides primarily in the extracellular lipid domains between the outermost, enucleated cells, called corneocytes, of the stratum corneum (SC). Mammalian SC contains extensive quantities of lipids, localized to these extracellular domains (interstices), comprised of nearly equimolar quantities of ceramides (Cer), cholesterol, and free fatty acids, a ratio that is imperative for normal organization into the lamellar membrane structures primarily responsible for epidermal barrier homeostasis [1,2]. Cer species comprise approximately half of the total intercellular lipid content by weight, and are critical for these lamellar membrane structures [3,4]. The specific roles for Cer in epidermal function have been revealed in studies with both normal and diseased human skin, as well as animal models and model membranes in vitro [5,6]. For example, the Cer content is altered in patients with both atopic dermatitis [7][8][9] and psoriasis [10,11] (discussed further below). Likewise, cholesterol as well as both essential and non-essential free fatty acids play separate, critical roles in epidermal barrier homeostasis.Given that human SC contains at least nine major Cer fractions (see Fig. 1), many of which are unique to the epidermis, including omega(x)-hydroxylated and x-acylated forms, as well as x-hydroxy-Cer species that are covalently attached via the x-hydroxyl of the N-acyl fatty acid to cornified envelope proteins of the enucleate stratum corneum cells (i.e., corneocytes), the metabolism of these unique sphingolipids is of significant interest. It is ...

show abstract

Section: Enzymatic Processing Of Glucosylceramide and Sphingomyelin Imentioning

confidence: 75%

Epidermal sphingolipids: Metabolism, function, and roles in skin disorders

2006

View full text Add to dashboard Cite

show abstract

“…In epidermis, lipids accumulate with increasing cellular differentiation (40,41). Much of the accumulating lipid is packaged in the form of small membranous organelles known as lamellar granules (42)(43)(44)(45)(46).…”

Section: Composition Of Lipids At the Skin Surfacementioning

confidence: 99%

“…The hydrolytic enzymes act on the phospholipids to produce ceramide from sphingomyelin and glucosylceramides and a mixture of saturated fatty acids and monounsaturated cholesterol esters from the phosphoglycerides. Ceramides, cholesterol, and free fatty acids are the principal lipids of the stratum corneum (40,41,47,48).…”

Section: Composition Of Lipids At the Skin Surfacementioning

confidence: 99%

Thematic Review Series: Skin Lipids. Antimicrobial lipids at the skin surface

Drake

Brogden

Dawson

et al. 2008

Journal of Lipid Research

272

222

View full text Add to dashboard Cite

The skin surface represents our interface with the external environment, and as such, is our first line of defense against microbial colonization and infection. Lipids at the skin surface are thought to underlie at least part of an antimicrobial barrier. Some of these lipids are synthesized in the epidermis and are carried to the surface as cells differentiate, whereas others are secreted onto the surface from the sebaceous glands. One such group, free sphingoid bases, are known to have broad antimicrobial activity, and our previous studies demonstrate their presence at the skin surface. Free sphingoid bases may be generated by enzymatic hydrolysis of epidermal ceramides. In addition, our preliminary results demonstrate potent antibacterial activity associated with two specific fatty acids derived from sebaceous triglycerides. Most remarkably, one of these fatty acids (sapienic acid, C16:1#6), in combination with a low concentration of ethanol, is very effective against methicillin-resistant Staphylococcus aureus (MRSA). In fact, this combination was far more effective than mupirocin with or without ethanol. Mupirocin is a "gold standard" for activity against MRSA.

show abstract

“…The cell membrane of outer cell layers of non-keratinized epithelia contains lipids as phospholipids, cholesterol sulphate, ceramide, glucosphingolipid and glycosylceramides which act as a barrier to hydrophilic molecules [27,28]. However, the presence of lipids and cytokeratins in the superficial keratinocytes of the non-keratinized epithelia is much less marked than in the keratinized ones, making the lining mucosa much more permeable, especially to water and hydrophilic molecules, and so more suitable for systemic drug delivery.…”

Section: Oral Mucosa: Histology Physiology and Permeability Featuresmentioning

confidence: 99%

Mucoadhesive Polymers for Oral Transmucosal Drug Delivery: A Review

Bagán¹,

Paderni²,

Termine³

et al. 2012

CPD

View full text Add to dashboard Cite

Abstract:The oral mucosa offers an interesting site for the application of dosage forms that release drugs within/throughout the oral mucosa, by assuring a high drug bioavailability for topic and systemic effects. However, the relative permeability of the oral mucosa and the washing effect related to the oral fluids and mechanical stresses must be considered in the formulation of oral dosage forms. Since a sustained drug release can be guaranteed only if dosage forms remain in contact with the oral site of absorption/application for a prolonged time, the development of mucoadhesive dosage forms is mandatory. The mucoadhesion is a complex phenomenon and the mucoadhesive bond consists of two different parts, the mucoadhesive polymers and the mucous substrate. In addition to factors related to the oral mucosa and oral environment features, the physical-chemical characteristics of mucoadhesive polymers must be also considered as factors influencing the mucoadhesive bonds. While it is not possible to modify the mucosal features or it is possible to modify or inhibit only in part certain mucosal processes, the knowledge of polymer properties influencing mucoadhesive bonds allows to modify or to control these properties in developing increasingly effective mucoadhesive systems. The aims of this review are to discuss the several mechanisms and factors behind the phenomenon of mucoadhesion with particular reference to the features of the oral environment, oral mucosa, and polymeric compounds influencing mucoadhesion process. Finally, a brief mention to the main mucoadhesive dosage forms designed for oral transmucosal drug delivery is made.

show abstract

Thin-layer chromatographic analyses of lipids in different layers of porcine epidermis and oral epithelium

Cited by 31 publications

References 27 publications

Epidermal sphingolipids: Metabolism, function, and roles in skin disorders

Epidermal sphingolipids: Metabolism, function, and roles in skin disorders

Thematic Review Series: Skin Lipids. Antimicrobial lipids at the skin surface

Mucoadhesive Polymers for Oral Transmucosal Drug Delivery: A Review

Contact Info

Product

Resources

About