BACKGROUND: The efficiency of lipid extraction by different kinds of solvents from stratum corneum may vary. OBJECTIVE: To assess the efficiency of lipid extraction by several solvents from the stratum corneum, the total lipids weights were measured by an electronic microbalance, and lipids compositions of a stratum corneum were analyzed by thin layer chromatography(TLC) after pretreatment of several solvents, respectively. METHODS: Stratum corneums separated fro circumcised prepuce were pretreated with acetone, petroleum ether, or distillecl water for 10 minutes. Lipids of stratum corneum were extracted with methanol chlorofonn-H,O mixture(4: 2: 1.6, v/v, Bligh Dyer solvent). Lipids weights were weighed, and the ratio of lipid weight and wet weight of stratum corneum were measured. TLC was performed and lipids compositions were quantitated by photodensitometer. Lipids extraction in viva was performed on both forearms. After two times stripping with sellotape, lipids were extrected with the solvents using cup method. These were dried and lipids weights were weighed. RESULTS: The efficiency of lipid extraction from the stratum corneum of circumcised prepuce were acetone, petroleum e1 her, and distilled water in decreasing order. All groups were similar in the compositions of the stratum corneum lipids except for those of cholesterol esters and sphingolipids. The efficiency of lipid extraction from in vivo skin were ranked in order from petroleurn ether, acetone, down to distilled water. The efficiency of lipid extraction of petroleum ether and acetone were higher than that of distilled water. CONCLUSION: The efficiency of lipid extraction is influenced by the kinds of solvents as well as the materials and the methods of extraction.
Acetone ; Cholesterol Esters ; Ether ; Forearm ; Methanol ; Petroleum ; Skin ; Solvents* ; Sphingolipids ; Water ; Weights and Measures

Stratum corneum lipids, which are enriched in sphingolipids, free fatty acids, and cholesterol, are required for epidermal barrier function. When the epidermal permeability barrier is perturbed, the transepidermal water loss returns to normal by 24-48 hours in parallel with the reappearance of stratum corneum lipids, derived from secreted lamellar bodis and accelerated lipid synthesis. Recent evidence shows that topical application of individual lipids interferes with barrier recovery while complete mixtures of cholesterol, fatty acids, and ceramides facilitate recovery after barrier disrupton. Metabolic imbalances and perturbed barrier function can be either the cause or the consequences of the pathobiology of scaling disease. Many skin diseases relating cornification and dryness are indeed related to abnormality of one or several combinations of lipids. Recently the cytokines which have changed during barrier recovery seem to be important in understanding of epidermal lipid homeostasis as well as barrier recovery.
Ceramides ; Cholesterol ; Cytokines ; Fatty Acids ; Fatty Acids, Nonesterified ; Homeostasis* ; Permeability ; Skin Diseases ; Sphingolipids ; Water

BACKGROUND: Ceramides are the main lipid component of the stratum corneum and are a structurally heterogeneous and complex group of sphingolipids of which sphingoid bases are the basic structural constituents. Altered levels of sphingoid bases have been reported in skin conditions that involve dryness and barrier disruption, including atopic dermatitis. OBJECTIVE: The purpose of this study was to investigate the altered levels of sphingoid bases in psoriatic epidermis and their relationship with the clinical severity of the psoriasis. METHODS: Samples from the lesional and non-lesional epidermis were obtained from eight psoriasis patients. Levels of sphingosine and sphinganine were analyzed by high-performance liquid chromatography. The expression of ceramide synthase and ceramidase proteins, which are related to sphingosine and sphinganine metabolism, were measured using Western blot analysis. RESULTS: Levels of sphingosine and sphinganine in the lesional epidermis were significantly higher than those in the non-lesional epidermis. Although there was no altered ceramide synthase and ceramidase, there was a highly significant positive correlation between the % change of ceramidase, the degradative enzyme of ceramide into sphingosine, and the Psoriasis Area Severity Index (PASI) score. CONCLUSION: The levels of sphingosine and sphinganine were significantly increased in psoriatic epidermis and the % change of ceramidase was positively correlated with the clinical severity of psoriasis.
Blotting, Western ; Ceramidases ; Ceramides ; Chromatography, Liquid ; Epidermis ; Humans ; Oxidoreductases ; Proteins ; Psoriasis ; Skin ; Sphingolipids ; Sphingosine

BACKGROUND: Ceramides are the main lipid component of the stratum corneum and are a structurally heterogeneous and complex group of sphingolipids of which sphingoid bases are the basic structural constituents. Altered levels of sphingoid bases have been reported in skin conditions that involve dryness and barrier disruption, including atopic dermatitis. OBJECTIVE: The purpose of this study was to investigate the altered levels of sphingoid bases in psoriatic epidermis and their relationship with the clinical severity of the psoriasis. METHODS: Samples from the lesional and non-lesional epidermis were obtained from eight psoriasis patients. Levels of sphingosine and sphinganine were analyzed by high-performance liquid chromatography. The expression of ceramide synthase and ceramidase proteins, which are related to sphingosine and sphinganine metabolism, were measured using Western blot analysis. RESULTS: Levels of sphingosine and sphinganine in the lesional epidermis were significantly higher than those in the non-lesional epidermis. Although there was no altered ceramide synthase and ceramidase, there was a highly significant positive correlation between the % change of ceramidase, the degradative enzyme of ceramide into sphingosine, and the Psoriasis Area Severity Index (PASI) score. CONCLUSION: The levels of sphingosine and sphinganine were significantly increased in psoriatic epidermis and the % change of ceramidase was positively correlated with the clinical severity of psoriasis.
Blotting, Western ; Ceramidases ; Ceramides ; Chromatography, Liquid ; Epidermis ; Humans ; Oxidoreductases ; Proteins ; Psoriasis ; Skin ; Sphingolipids ; Sphingosine

Animals ; Apoptosis ; physiology ; Cellular Senescence ; physiology ; Humans ; Neoplasms ; pathology ; Sphingolipids ; chemistry ; metabolism ; physiology

The present study investigated the effect of emodin on the serum metabolite profiles in the chronic constriction injury(CCI) model by non-target metabolomics and explored its analgesic mechanism. Twenty-four Sprague Dawley(SD) rats were randomly divided into a sham group(S), a CCI group(C), and an emodin group(E). The rats in the emodin group were taken emodin via gavage once a day for fifteen days(50 mg·kg~(-1)) on the first day after the CCI surgery. Mechanical withdrawal threshold(MWT) and thermal withdrawal threshold(TWL) in each group were performed before the CCI surgery and 3,7, 11, and 15 days after surgery. After 15 days, blood samples were collected from the abdominal aorta. The differential metabolites were screened out by non-target metabolomics and analyzed with Kyoto Encyclopedia of Genes and Genomes(KEGG) and ingenuity pathway analysis(IPA). From the third day after CCI surgery, the MWT and TWL values were reduced significantly in both CCI group and emodin group, compared with the sham group(P<0.01). At 15 days post-surgery, the MWT and TWL values in emodin group increased significantly compared with the CCI group(P<0.05). As revealed by non-target metabolomics, 72 differential serum metabolites were screened out from the C-S comparison, including 41 up-regulated and 31 down-regulated ones, while 26 differential serum metabolites from E-C comparison, including 10 up-regulated and 16 down-regulated ones. KEGG analysis showed that the differential metabolites in E-C comparison were enriched in the signaling pathways, such as sphingolipid metabolism, arginine biosynthesis, glycerophospholipid metabolism, and tryptophan metabolism. IPA showed that the differential metabolites were mainly involved in the lipid metabolism-molecular transport-small molecule biochemistry network. In conclusion, emodin can exert an analgesic role via regulating sphingolipid metabolism and arginine biosynthesis.
Analgesics/pharmacology* ; Animals ; Arginine ; Emodin/pharmacology* ; Neuralgia/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sphingolipids

Ceramides (Cer) comprise the major constituent of sphingolipids in the epidermis and are known to play diverse roles in the outermost layers of the skin including water retention and provision of a physical barrier. In addition, they can be hydrolyzed into free sphingoid bases such as C18 sphingosine (SO) and C18 sphinganine (SA) or can be further metabolized to C18 So-1-phosphate (S1P) and C18 Sa-1-phosphate (Sa1P) in keratinocytes. The significance of ceramide metabolites emerged from studies reporting altered levels of SO and SA in skin disorders and the role of S1P and Sa1P as signaling lipids. However, the overall metabolism of sphingoid bases and their phosphates during keratinocyte differentiation remains not fully understood. Therefore, in this study, we analyzed these Cer metabolites in the process of keratinocyte differentiation. Three distinct keratinocyte differentiation stages were prepared using 0.07 mM calcium (Ca2+) (proliferation stage), 1.2 mM Ca2+ (early differentiation stage) in serum-free medium, or serum-containing medium with vitamin C (50 microL/mL) (late differentiation stage). Serum-containing medium was also used to determine whether vitamin C increases the concentrations of sphingoid bases and their phosphates. The production of sphingoid bases and their phosphates after hydrolysis by alkaline phosphatase was determined using high-performance liquid chromatography. Compared to cells treated with 0.07 mM Ca2+, levels of SO, SA, S1P, and SA1P were not altered after treatment with 1.2 mM Ca2+. However, in keratinocytes cultured in serum-containing medium with vitamin C, levels of SO, SA, S1P, and SA1P were dramatically higher than those in 0.07- and 1.2-mM Ca2+-treated cells; however, compared to serum-containing medium alone, vitamin C did not significantly enhance their production. Taken together, we demonstrate that late differentiation induced by vitamin C and serum was accompanied by dramatic increases in the concentration of sphingoid bases and their phosphates, although vitamin C alone had no effect on their production.
Alkaline Phosphatase ; Ascorbic Acid ; Calcium ; Ceramides ; Chromatography, Liquid ; Epidermis ; Hydrolysis ; Keratinocytes ; Phosphates ; Retention (Psychology) ; Skin ; Sphingolipids ; Sphingosine ; Vitamins ; Water

Inflammatory skin diseases such as atopic dermatitis (AD) and rosacea were complicated by barrier abrogation and deficiency in innate immunity. The first defender of epidermal innate immune response is the antimicrobial peptides (AMPs) that exhibit a broad-spectrum antimicrobial activity against multiple pathogens, including Gram-positive and Gram-negative bacteria, viruses, and fungi. The deficiency of these AMPs in the skin of AD fails to protect our body against virulent pathogen infections. In contrast to AD where there is a suppression of AMPs, rosacea is characterized by overexpression of cathelicidin antimicrobial peptide (CAMP), the products of which result in chronic epidermal inflammation. In this regard, AMP generation that is controlled by a key ceramide metabolite S1P-dependent mechanism could be considered as alternate therapeutic approaches to treat these skin disorders, i.e., Increased S1P levels strongly stimulated the CAMP expression which elevated the antimicrobial activity against multiple pathogens resulting the improved AD patient skin.
Dermatitis, Atopic* ; Endoplasmic Reticulum Stress ; Fungi ; Gram-Negative Bacteria ; Humans ; Immunity, Innate ; Inflammation ; Peptides* ; Rosacea ; Skin ; Skin Diseases ; Sphingolipids*

Fatty acids (FAs) are highly diverse in terms of carbon (C) chain-length and number of double bonds. FAs with C>20 are called very long-chain fatty acids (VLCFAs). VLCFAs are found not only as constituents of cellular lipids such as sphingolipids and glycerophospholipids but also as precursors of lipid mediators. Our understanding on the function of VLCFAs is growing in parallel with the identification of enzymes involved in VLCFA synthesis or degradation. A variety of inherited diseases, such as ichthyosis, macular degeneration, myopathy, mental retardation, and demyelination, are caused by mutations in the genes encoding VLCFA metabolizing enzymes. In this review, we describe mammalian VLCFAs by highlighting their tissue distribution and metabolic pathways, and we discuss responsible genes and enzymes with reference to their roles in pathophysiology.
Carbon ; Demyelinating Diseases ; Fatty Acids* ; Glycerophospholipids ; Ichthyosis ; Intellectual Disability ; Macular Degeneration ; Metabolic Networks and Pathways ; Metabolism* ; Muscular Diseases ; Sphingolipids ; Tissue Distribution

Sphingolipids, especially ceramide and S1P, are structural components of biological membranes and bioactive molecules which participate in diverse cellular activities such as cell division, differentiation, gene expression and apoptosis. Emerging evidence demonstrates the role of sphingolipids in hepatocellular death, which contributes to the progression of several liver diseases including ischaemia-reperfusion liver injury, steatohepatitis or hepatocarcinogenesis. Furthermore, some data indicate that the accumulation of some sphingolipids contributes to the hepatic dysfunctions. Hence, understanding of sphingolipid may open up a novel therapeutic avenue to liver diseases. This review focuses on the progress in the sphingolipid metabolic pathway with a focus on hepatic diseases and drugs targeting the sphingolipid pathway.
Apoptosis ; Ceramides ; metabolism ; Fatty Liver ; metabolism ; physiopathology ; Humans ; Liver Diseases ; metabolism ; physiopathology ; Lysophospholipids ; metabolism ; Reperfusion Injury ; metabolism ; physiopathology ; Sphingolipids ; metabolism ; Sphingosine ; analogs & derivatives ; metabolism