Fermentative production of tetraacetyl phytosphingosine: a review / 生物工程学报

Tetraacetyl phytosphingosine (TAPS) is an excellent raw material for natural skin care products. Its deacetylation leads to the production of phytosphingosine, which can be further used for synthesizing the moisturizing skin care product ceramide. For this reason, TAPS is widely used in the skin care oriented cosmetics industry. The unconventional yeast Wickerhamomyces ciferrii is the only known microorganism that can naturally secrete TAPS, and it has become the host for the industrial production of TAPS. This review firstly introduces the discovery, functions of TAPS, and the metabolic pathway for TAPS biosynthesis is further introduced. Subsequently, the strategies for increasing the TAPS yield of W. ciferrii, including haploid screening, mutagenesis breeding and metabolic engineering, are summarized. In addition, the prospects of TAPS biomanufacturing by W. ciferrii are discussed in light of the current progresses, challenges, and trends in this field. Finally, guidelines for engineering W. ciferrii cell factory using synthetic biology tools for TAPS production are also presented.

Novel Pathogenic Mutation of PNPLA1 Identified in Autosomal Recessive Congenital Ichthyosis: A Case Report / 中国医学科学杂志(英文版)

Autosomal recessive congenital ichthyosis (ARCI) is characterized by being born as collodion babies, hyperkeratosis, and skin scaling. We described a collodion baby at birth with mild ectropion, eclabium, and syndactyly. Whole exome sequencing showed a compound heterozygous variant c.[56C>A], p.(Ser19X) and c.[100G>A], p.(Ala34Thr) in the PNPLA1 gene [NM_001145717; exon 1]. The protein encoded by PNPLA1 acts as a unique transacylase that specifically transfers linoleic acid from triglyceride to ω-hydroxy fatty acid in ceramide, thus giving rise to ω-O-acylceramide, a particular class of sphingolipids that is essential for skin barrier function. The variant was located in the patatin core domain of PNPLA1 and resulted in a truncated protein which could disrupt the function of the protein. This case report highlights a novel compound heterozygous mutation in PNPLA1 identified in a Chinese child.

Sphingolipid Mediators of Myocardial Pathology

Cardiomyopathy is the leading cause of mortality worldwide. While the causes of cardiomyopathy continue to be elucidated, current evidence suggests that aberrant bioactive lipid signaling plays a crucial role as a component of cardiac pathophysiology. Sphingolipids have been implicated in the pathophysiology of cardiovascular disease, as they regulate numerous cellular processes that occur in primary and secondary cardiomyopathies. Experimental evidence gathered over the last few decades from both in vitro and in vivo model systems indicates that inhibitors of sphingolipid synthesis attenuate a variety of cardiomyopathic symptoms. In this review, we focus on various cardiomyopathies in which sphingolipids have been implicated and the potential therapeutic benefits that could be gained by targeting sphingolipid metabolism.

Ceramides: Nutrient Signals that Drive Hepatosteatosis

Ceramides are minor components of the hepatic lipidome that have major effects on liver function. These products of lipid and protein metabolism accumulate when the energy needs of the hepatocyte have been met and its storage capacity is full, such that free fatty acids start to couple to the sphingoid backbone rather than the glycerol moiety that is the scaffold for glycerolipids (e.g., triglycerides) or the carnitine moiety that shunts them into mitochondria. As ceramides accrue, they initiate actions that protect cells from acute increases in detergent-like fatty acids; for example, they alter cellular substrate preference from glucose to lipids and they enhance triglyceride storage. When prolonged, these ceramide actions cause insulin resistance and hepatic steatosis, 2 of the underlying drivers of cardiometabolic diseases. Herein the author discusses the mechanisms linking ceramides to the development of insulin resistance, hepatosteatosis and resultant cardiometabolic disorders.

Genetic Architecture of Circulating Very-Long-Chain (C24:0 and C22:0) Ceramide Concentrations

OBJECTIVE: Total ceramide concentrations are linked with increased insulin resistance and cardiac dysfunction. However, recent studies have demonstrated that plasma concentrations of specific very-long-chain fatty ceramides (C24:0 and C22:0) are associated with a reduced incidence of coronary heart disease and all-cause mortality. We hypothesized that specific genetic loci are associated with plasma C22:0 and C24:0 concentrations.METHODS: Heritability and genome-wide association studies of plasma C24:0 and C22:0 ceramide concentrations were performed among 2,217 participants in the Framingham Heart Study Offspring Cohort, adjusting for cardiovascular risk factor covariates and cardiovascular drug treatment.RESULTS: The multivariable-adjusted heritability for C22:0 and C24:0 ceramides was 0.42 (standard error [SE], 0.07; p=1.8E-9) and 0.25 (SE, 0.08; p=0.00025), respectively. Nineteen single nucleotide polymorphisms (SNPs), all on chromosome 20, significantly associated with C22:0 concentrations; the closest gene to these variants was SPTLC3. The lead SNP (rs4814175) significantly associated with 3% lower plasma C22:0 concentrations (p=2.83E-11). Nine SNPs, all on chromosome 20 and close to SPTLC3, were significantly associated with C24:0 ceramide concentrations. All 9 were also significantly related to plasma C22:0 levels. The lead SNP (rs168622) was significantly associated with 10% lower plasma C24:0 ceramide concentrations (p=9.94E-09).CONCLUSION: SNPs near the SPTLC3 gene, which encodes serine palmitoyltransferase long chain base subunit 3 (SPTLC3; part of the enzyme that catalyzes the rate-limiting step of de novo sphingolipid synthesis) were associated with plasma C22:0 and C24:0 ceramide concentrations. These results are biologically plausible and suggest that SPTLC3 may be a potential therapeutic target for C24:0 and C22:0 ceramide modulation.

Enrichment of Short-Chain Ceramides and Free Fatty Acids in the Skin Epidermis, Liver, and Kidneys of db/db Mice, a Type 2 Diabetes Mellitus Model

Patients with diabetes mellitus (DM) often suffer from diverse skin disorders, which might be attributable to skin barrier dysfunction. To explore the role of lipid alterations in the epidermis in DM skin disorders, we quantitated 49 lipids (34 ceramides, 14 free fatty acids (FFAs), and cholesterol) in the skin epidermis, liver, and kidneys of db/db mice, a Type 2 DM model, using UPLC-MS/MS. The expression of genes involved in lipid synthesis was also evaluated. With the full establishment of hyperglycemia at the age of 20 weeks, remarkable lipid enrichment was noted in the skin of the db/db mice, especially at the epidermis and subcutaneous fat bed. Prominent increases in the ceramides and FFAs (>3 fold) with short or medium chains (

Soft coral Cespitularia stolonifera: New cytotoxic ceramides and gastroprotective activity / 中国天然药物

In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol (1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol (2), 24-methylcholesta-5, 24(28)-diene-3β-acetate (3), 4-methyl-24-methylcholesta-22-ene-3-ol (4), and cholesterol, was isolated and characterized from CHCl/MeOH extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate (1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NMR, HRESI-MS, and GC-MS, in addition of chemical methods. (-)-Alloaromadendren, ledane, (1)-alloaromadendren oxide, isoaromadendrene epoxide and (-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides (1) and (1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids (2) and (3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The CHCl/MeOH extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.

Recent advances in study of sphingolipids on liver diseases / 药学学报

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.

Simultaneous quantitative analysis of different ceramide species in cells by high-performance liquid chromatography-tandem mass spectrometry / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish a high-performance liquid chromatography-tandem mass spectrometry (HPLC-ESI-MS) method for simultaneous quantitative analysis of different ceramide species in cells.</p><p><b>METHODS</b>The analysis was performed on an Agilent 1290 HPLC system with a ZORBAX Eclipse XDB-C8 (150.0 mm × 2.1 mm, 3.5 μL) column and a temperature of 35 ℃. Methanol with 1 mmol/L ammonium formate and 0.2% formic acid was used as mobile phase A and 100% methanol was used as mobile phase B. And the ceramides were separated by gradient elution at a flow rate of 0.3 mL/min. Electrospray ionization (ESI) with multiple reaction monitoring (MRM) was used in the analysis.</p><p><b>RESULTS</b>Four ceramide species all had a good linear response in the determination ranges (R² ≥ 0.9987). The average recoveries (n = 9) were 99.1%,99.9%,100.5% and 98.2% with RSDs of 5.6%, 5.1%, 4.7% and 5.5%, respectively. In addition, the levels of ceramides in FL cells were relatively stable, while the C24-ceramide had the highest level.</p><p><b>CONCLUSION</b>The HPLC-ESI-MS method for simultaneous analysis of ceramides has high accuracy, reproducibility and linearity, which may be used for quantification of ceramide species in cells.</p>

Effects of Artesunate on hepatic fibrosis and its mechanism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of Artesunate(Art) on the LX-2 cell.</p><p><b>METHODS</b>The cultured hepatic stellate cells were divided into control group and Art-treated groups with 250,350,450 µmol/L. The rate of cellular proliferation was detected by MIT assay, the content of ceramide (Cer)was determined by HPLC method, the content of hydroxyproline (Hyp) was determined by enzyme digestion method, the expressions of PPAR-γ, p53 and Caspase 3 were detected by Western blot.</p><p><b>RESULTS</b>Compared with control group, IX-2 treated with Art were inhibited in a concentration-dependent manner(P < 0.01). Art could significantly increase the content of cerarnide in LX-2 ( P <0.01), and the content of Hyp was significantly decreased (P <0.05, P <0.01). The expressions of PPAR-γ, p53 and Caspase 3 were increased compared with that of control group(P < 0.01).</p><p><b>CONCLUSION</b>Artesunate could inhibit the proliferation and induce apoptosis of hepatic stellate cells through upregulating ceramide.</p>

Induction of a Hardening Phenomenon and Quantitative Changes of Ceramides in Stratum Corneum

BACKGROUND: Hardening phenomenon of human skin after repeated exposure to the irritants is well-known, but the precise mechanism remains elusive. OBJECTIVE: To modify the previous experimental model of hardening phenomenon by repeated applications of two different concentrations of sodium lauryl sulfate (SLS) solutions to Korean healthy volunteers and to investigate the quantitative changes of ceramides in stratum corneum before and after chronic repeated irritation. METHODS: Eight hundred microliters of distilled water containing 0.1% and 2% SLS was applied for 10 minutes on the forearm of 41 healthy volunteers for 3 weeks. After an intervening 3-week rest, 24-hour patch tests with 1% SLS were conducted on previously irritated sites. Transepidermal water loss (TEWL), erythema index and quantity of ceramide were measured in the stratum corneum before and after irritation. RESULTS: TEWL values on the sites preirritated with 2% SLS were lower than those with 0.1% SLS. Hardening phenomenon occurred in 24 volunteers at day 44. The changes in ceramide levels were not significantly higher in the hardened skin than in the non-hardened skin. CONCLUSION: Repetitive stimulation with a higher concentration of SLS can more easily trigger skin hardening.

Definition, Pathogenesis, and Natural Progress of Non-alcoholic Fatty Liver Disease / 임상당뇨병

Non-alcoholic fatty liver disease (NAFLD) is emerging as a world-wide health problem and is currently recognized as a hepatic manifestation of metabolic syndrome. It is an umbrella term to describe a wide range of diseases from simple steatosis to non-alcoholic hepatosteatosis (NASH) and NSAH-related liver cirrhosis. NAFLD is mainly associated with insulin resistance which allows increased free fatty acid (FFA) flux to the liver by increasing lipolysis from adipose tissue, triggering macrophage/immune activation, decreasing skeletal muscle glucose uptake, and increasing de novo lipogenesis. Increased FFA pool in the liver, in turn, increases lipotoxic intermediates, such as ceramides, diacylglycerols, and lysophosphatidylcholines, which are responsible for mitochondrial dysfunction and endoplasmic reticulum stress, resulting in inflammation of the liver. When inflammation is severe enough to affect stellate cells, hepatic fibrosis can be induced.

Mechanisms of aging and programmed death of erythrocytes / 中国实验血液学杂志

Erythrocytes lack nuclei and mitochondria, critical elements in the machinery of nucleated cell apoptosis. However, most recently, it became obvious that erythrocytes may undergo programmed aging, as well as suicidal death. The term eryptosis has been coined to describe the suicidal erythrocyte death. Eryptosis is triggered mainly by increased cytosolic Ca(2+) activity, in turn, Ca(2+) activates Ca(2+)-sensitive K(+) channels, scramblase, calpain and other proteases, respectively. A series of molecular events of erythrocyte programmed death induced. The cascade reaction of related molecules and finally lead to cell clearance. There is evidence suggesting that erythrocytes aging and death process are regulated tightly and there are many molecular participants and signaling pathways involved in aging and death process of erythrocytes. Erythrocytes have already been used as a model for aging study, and the knowledge about mechanisms involved in eryptosis may provide an important clue to understand the mechanisms involved in suicidal death of nucleated cells. In this review the factors influencing programmed death of erythrocytes, the role of Ca(2+) and ceramide in programmed death of erythrocytes, the role of blebbing in process of erythrocyte aging, the antigens of erythrocyte aging and so on are summarized.

Ceramides and terpenoids from Russula austrodelica Singer / Ceramidas y terpenoides desde Russula austrodelica Singer

A mixture of ceramides and known terpenes, was obtained from the fruiting bodies of Russula austrodelica. The structures were determined from chemical and spectroscopic evidence. R. austrodelica is a mycorrhizal fungus that grow in the Nothophagus forests of southern Chile. This is the first report of the isolation of ceramides in Chilean mushrooms.

Una mezcla de ceramidas y de terpenos conocidos, se obtuvo de los cuerpos fructíferos de Russula austrodelica. Las estructuras fueron determinadas a partir de evidencias químicas y espectroscópicas. R. austrodelica es un hongo micorrícico que crecen en los bosques de Nothophagus del sur de Chile. Este es el primer informe del aislamiento de ceramidas en hongos chilenos.

Clinical use of a ceramide-based moisturizer for treating dogs with atopic dermatitis

In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms.

Inflammasomes, multi-cellular protein complex in myeloid cells, induce several metabolic diseases via interleukin-1beta maturation / 동물의과학연구지

Inflammation mainly mediated by innate immune cells as the first line of host defense against pathogens is an acute response that limits tissue damage and eliminates pathogens in the body. In triggering inflammation, several pattern recognition receptors work together; membrane-associated Toll-like receptors, c-type lectin receptors, retinoic acid-inducible gene-like helicase receptors, absent in melanoma-like receptors, and cytosolic nucleotide-binding domain and leucine-rich repeat receptors. Among them, inflammasome is a newly trigger of inflammation in response to exogenous and endogenous stimuli and its activation leads to the assembly of multiprotein platforms composed of NLRP3 (NOD-like receptor family, pyrin domain containing 3), ASC (apoptosis associated speck-like protein containing a CARD), and procaspase 1. Thus, the activated inflammasome activates caspase 1, resulting in processing and secretion of interleukin (IL)-1beta. Recent emerging data suggest that dysregulated metabolites, i.e., amyloids, ceramides, and cholesterol crystals, have been classified as inflammasome activators. In addition, IL-1beta may play a critical role in the pathogenesis of chronic inflammation-induced disorders such as Alzheimer's diseases, type 2 diabetes, and atheriosclerosis. This review introduces the basic concept of inflammasome activation and auto-inflammatory diseases. In addition, it discusses the updated signaling models of inflammasome activation that link metabolic dysfunction in order to outline future therapeutic approaches to inflammasome-mediating diseases.

Atopic dermatitis and skin barrier dysfunction

Atopic dermatitis is a chronic relapsing eczematous dermatosis, which usually starts in childhood, and various causes are intricately associated with the development of the disease. Recently, various abnormalities in barrier function have been identified as the cause of atopic dermatitis. Loss-of-function mutation of filaggrin, a significant constituent of skin barrier, has been revealed as a cause for atopic dermatitis, and factors like enhanced protease activity, and decreased synthesis of the lipid lamellae especially ceramides also plays an important role in barrier dysfunction. Not only these genetic causes but also environmental factors are associated in barrier dysfunction, such as soap or detergents which increases skin pH, or proteases of dust mites or cockroaches which enhances epidermal barrier breakdown. Lately, skin barrier dysfunction is also thought to play an important role in the early stage of other allergic diseases such as asthma. Therefore, comprehension of the function of skin barrier can provide help in understanding various allergic diseases.

Altered Levels of Sphingosine and Sphinganine in Psoriatic Epidermis

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.

Altered Levels of Sphingosine and Sphinganine in Psoriatic Epidermis

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.