Therapeutic Strategy for Fabry Disease by Intravenous Administration of Adeno-Associated Virus 9 in a Symptomatic Mouse Model.

Fabry disease (FD) is an inherited lysosomal storage disease caused by deficiency of α-galactosidase A (α-Gal A), an enzyme that hydrolyzes glycosphingolipids in lysosome. Accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3) in tissues, induces cellular dysfunction leading to multi-organ disorder. Gene therapy is a promising strategy that can overcome these problems, and virus vectors such as adeno-associated virus (AAV) have been used for study on gene therapy. We used human Gb3 synthetase-transgenic (TgG3S)/α-Gal A knockout (GLAko) mice. TgG3S/GLAko mice have elevated Gb3 accumulation in the major organs compared with GLAko mice, which have been widely used as a model for FD. At the age of 6 weeks, male TgG3S/GLAko were injected with 2 × 1012 vector genome AAV9 vectors containing human α-Gal A cDNA. Eight weeks after intravenous injection of AAV, α-Gal A enzymatic activity was elevated in the plasma, heart, and liver of TgG3S/GLAko mice to levels corresponding to 224%, 293%, and 105% of wild-type, respectively. Gb3 amount 8 weeks after AAV injection in the heart and liver of this group was successfully reduced to levels corresponding to 16% and 3% of untreated TgG3S/GLAko mice. Although the brain and kidney of AAV9-treated TgG3S/GLAko mice showed no significant increases in α-Gal A activity, Gb3 amount was smaller than untreated littermates (48% and 44%, respectively). In this study, systemic AAV administration did not show significant extension of the lifespan of TgG3S/GLAko mice compared with the untreated littermates. The timing of AAV injection, capsid choice, administration route, and injection volume may be important to achieve sufficient expression of α-Gal A in the whole body for the amelioration of lifespan.

Diterpenoid DGA induces apoptosis via endoplasmic reticulum stress caused by changes in glycosphingolipid composition and inhibition of STAT3 in glioma cells.

Glioma is one of the most common malignant primary brain tumors, with poor prognosis and high recurrence. There are currently few drugs approved for brain tumors; thus, it is necessary to develop new effective drugs. Natural diterpenoids have important biological activities, including antiinflammatory, antioxidative, and antitumor effects. In this study, 7α,14ß-dihydroxy-ent-kaur-17-dimethylamino-3,15-dione (DGA), a diterpenoid compound modified from glaucocalyxin A, inhibited the proliferation of many tumor cells, especially glioma. Flow cytometry analysis showed that DGA induced apoptosis in glioma cells. DGA also inhibited xenograft tumors in nude mice. It affected the expression of ceramide synthases (CerS) in glioma cells; CerS1 decreased, and CerS2 and CerS5 increased, resulting in a change in the composition of glycosphingolipids containing varying acyl chain lengths. In glioma cells treated with DGA, the gene transcription of activating transcription factor 4 (ATF4), X-box binding protein-1 (XBP1), and C/EBP-homologous protein (CHOP) in unfolded protein response pathways was upregulated. Meanwhile, the ratio of proapoptotic protein Bcl-2-associated X protein (BAX) to antiapoptotic protein B-cell lymphoma 2 (Bcl-2) also increased. This suggested that an imbalance of glycosphingolipids caused by DGA induced severe endoplasmic reticulum stress and triggered cell apoptosis. Moreover, Western blotting showed DGA inhibited the signal transducers and activators of transcription 3 (STAT3) signaling pathway by reducing the phosphorylation of STAT3 and its upstream kinases, which also promoted the apoptosis of glioma cells. Together, these results explored the anticancer activities of DGA and highlighted it as a potential candidate for treating glioma.

miRNA Expression Associated with HbF in Saudi Sickle Cell Anemia.

Background and Objectives: Sickle cell anemia (SCA) is a hereditary monogenic disease due to a single ß-globin gene mutation that codes for the production of sickle hemoglobin. Its phenotype is modulated by fetal hemoglobin (HbF), a product of γ-globin genes. Exploring the molecules that regulate γ-globin genes at both transcriptional and translational levels, including microRNA (miRNA), might help identify alternative therapeutic targets. Materials and Methods: Using next-generation sequencing we identified pre-miRNAs and mature miRNA expression signatures associated with different HbF levels in patients homozygous for the sickle hemoglobin gene. The involvement of identified miRNAs in potential SCD-related pathways was investigated with the DIANA TOOL and miRWalk 2.0 database. Results: miR-184 were most highly upregulated in reticulocytes. miR-3609 and miR-483-5p were most highly downregulated in sickle cell anemia with high HbF. miR-370-3p that regulates LIN28A, and miR-451a which is effective in modulating α- and ß- globin levels were also significantly upregulated. miRNA targeted gene pathway interaction identified BCL7A, BCL2L1, LIN28A, KLF6, GATA6, solute carrier family genes and ZNF genes associated with erythropoiesis, cell cycle regulation, glycosphingolipid biosynthesis, cAMP, cGMP-PKG, mTOR, MAPK and PI3K-AKT signaling pathways and cancer pathways. Conclusions: miRNA signatures and their target genes identified novel miRNAs that could regulate fetal hemoglobin production and might be exploited therapeutically.

[Neuronal glycolipids regulate glial cell division negatively during development and following a lesion]. / Glicolipidos neuronales regulan negativamente la division glial durante el desarrollo y tras una lesion.

Glial cells in the central nervous system of adult mammals outnumber neurons 10-fold. Their number remains stationary throughout adulthood, controlled by the concomitant presence of mitogens and mitogen inhibitors. The most abundant inhibitor, neurostatin, is ganglioside GD1b O-acetylated on hydroxyl 9 of its outermost sialic acid. Neurostatin inhibited the proliferation of primary microglia and astroblasts in culture (cytostatic) as well as both rodent and human glioma cells (cytotoxic) at nanomolar concentrations. At those concentrations neurostatin had no effect on non-glial lineage cells or differentiated glia. Neurostatin shows direct antimitotic activity on tumoral cells, interfering with multiple signals regulating cell cycle progression. But it also promotes indirectly total destruction of experimental rat brain glioma, presumably by making it visible to the host immune system and activating CD4+ and CD8+ lymphocytes. Neurostatin could be a new anti-inflammatory agent, with multiple convergent direct and indirect actions on glioma growth, a pathology without satisfactory clinical treatment. Neurostatin is produced by neurons but its expression is up-regulated by neuron-astrocyte contact. The action of neurostatin could be mediated by a number of receptor proteins, including integrins, Toll-like receptors and siglecs.

TITLE: Glicolipidos neuronales regulan negativamente la division glial durante el desarrollo y tras una lesion.En el sistema nervioso central de los mamiferos, las celulas gliales superan diez veces en numero a las neuronas. Su numero permanente estacionario durante la edad adulta, controlado por la presencia simultanea de mitogenos gliales e inhibidores de esos mitogenos. El inhibidor mas abundante, la neurostatina, es el gangliosido GD1b O-acetilado en el grupo 9 del acido sialico mas externo. La neurostatina y los oligosacaridos sinteticos inhiben la proliferacion de astroblastos en cultivo primario (citostaticos) y de celulas de gliomas (citotoxicos), tanto de roedores como de humanos, en concentracion nanomolar. A esas concentraciones, la neurostatina no tuvo efecto sobre celulas de linaje no glial ni sobre glia madura. La neurostatina y sus analogos mostraron actividad antimitotica directa sobre las celulas tumorales, interfiriendo con la progresion del ciclo celular en multiples sitios, pero tambien actuaron indirectamente, haciendo visibles las celulas tumorales al sistema inmune del huesped y activando linfocitos CD4+ y CD8+. Analogos de neurostatina podrian generar nuevos farmacos antiinflamatorios, con multiples acciones directas e indirectas contra el crecimiento de gliomas, una patologia todavia sin tratamiento clinico satisfactorio. La neurostatina es producida por las neuronas, pero el contacto de estas con astrocitos estimula notablemente su expresion. La accion de la neurostatina puede estar mediada por numerosas proteinas receptoras, incluyendo integrinas, siglecs y receptores Toll-like.

Structure-activity relationship studies of novel glycosphingolipids that stimulate natural killer T-cells.

KRN7000, an anticancer drug candidate developed by Kirin Brewery Co. in 1995, is an α-galactosyl ceramide. It is a ligand making a complex with CD1d protein, and it stimulates invariant natural killer T (NKT) cells, which are one of the lineages of immunocytes. NKT cells activated by recognition of the CD1d/KRN7000 complex with its invariant T-cell receptor (TCR) can induce both protective and regulatory immune responses. To determine the recognition and activation mechanisms of NKT cells and to develop drug candidates more effective than KRN7000, a large number of analogs of KRN7000 have been synthesized. Some of them show potent bioactivities and have the potential of being utilized as therapeutic agents. In this review, structure-activity relationship studies of novel glycolipids which stimulate NKT cells efficiently are summarized.

Dipeptidyl peptidase IV, aminopeptidase N and DPIV/APN-like proteases in cerebral ischemia.

BACKGROUND: Cerebral inflammation is a hallmark of neuronal degeneration. Dipeptidyl peptidase IV, aminopeptidase N as well as the dipeptidyl peptidases II, 8 and 9 and cytosolic alanyl-aminopeptidase are involved in the regulation of autoimmunity and inflammation. We studied the expression, localisation and activity patterns of these proteases after endothelin-induced occlusion of the middle cerebral artery in rats, a model of transient and unilateral cerebral ischemia. METHODS: Male Sprague-Dawley rats were used. RT-PCR, immunohistochemistry and protease activity assays were performed at different time points, lasting from 2 h to 7 days after cerebral ischemia. The effect of protease inhibitors on ischemia-dependent infarct volumes was quantified 7 days post middle cerebral artery occlusion. Statistical analysis was conducted using the t-test. RESULTS: Qualitative RT-PCR revealed these proteases in ipsilateral and contralateral cortices. Dipeptidyl peptidase II and aminopeptidase N were up-regulated ipsilaterally from 6 h to 7 days post ischemia, whereas dipeptidyl peptidase 9 and cytosolic alanyl-aminopeptidase were transiently down-regulated at day 3. Dipeptidyl peptidase 8 and aminopeptidase N immunoreactivities were detected in cortical neurons of the contralateral hemisphere. At the same time point, dipeptidyl peptidase IV, 8 and aminopeptidase N were identified in activated microglia and macrophages in the ipsilateral cortex. Seven days post artery occlusion, dipeptidyl peptidase IV immunoreactivity was found in the perikarya of surviving cortical neurons of the ipsilateral hemisphere, whereas their nuclei were dipeptidyl peptidase 8- and amino peptidase N-positive. At the same time point, dipeptidyl peptidase IV, 8 and aminopeptidase N were targeted in astroglial cells. Total dipeptidyl peptidase IV, 8 and 9 activities remained constant in both hemispheres until day 3 post experimental ischemia, but were increased (+165%) in the ipsilateral cortex at day 7. In parallel, aminopeptidase N and cytosolic alanyl-aminopeptidase activities remained unchanged. CONCLUSIONS: Distinct expression, localization and activity patterns of proline- and alanine-specific proteases indicate their involvement in ischemia-triggered inflammation and neurodegeneration. Consistently, IPC1755, a non-selective protease inhibitor, revealed a significant reduction of cortical lesions after transient cerebral ischemia and may suggest dipeptidyl peptidase IV, aminopeptidase N and proteases with similar substrate specificity as potentially therapy-relevant targets.

Aglycon of rhizochalin from the Rhizochalina incrustata induces apoptosis via activation of AMP-activated protein kinase in HT-29 colon cancer cells.

Rhizochalin is a two-headed sphingolipid-like compound isolated from the sponge Rhizochalina incrustata. It has been reported that rhizocalin and its derivates have a chemopreventive and chemotherapeutic effect. However, the molecular mechanism of these effects is not understood. Here, we demonstrate that aglycon of rhizochalin (AglRhz) from the Rhizochalina incrustata induces AMP-activated protein kinase (AMPK) phosphorylation, and thereby inhibits mammalian target of rapamycin (mTOR)-p70S6 kinase-extracellular signal-regulated kinase (ERK) signaling and activator protein 1 (AP-1) activity via phosphorylation of Raptor in HT-29 cells. In addition, AglRhz induced activation of caspase-3 and poly(ADP-ribose) polymerase (PARP), and DNA fragmentation in HT-29 cells, leads to induction of apoptosis as well as suppression of tumorigenicity of HT-29 cells. Notably, AglRhz inhibits insulin-like growth factor (IGF)-1-induced AP-1 activity and cell transformation in JB6 Cl41 cells. Overall, our findings identify AMPK as an important target protein for mediating the anti-tumor properties of AglRhz in HT-29 colon cancer cells and have important implication for sponges, the most important marine source, in colon cancer.

Inhibition of reactive gliosis attenuates excitotoxicity-mediated death of retinal ganglion cells.

Reactive gliosis is a hallmark of many retinal neurodegenerative conditions, including glaucoma. Although a majority of studies to date have concentrated on reactive gliosis in the optic nerve head, very few studies have been initiated to investigate the role of reactive gliosis in the retina. We have previously shown that reactive glial cells synthesize elevated levels of proteases, and these proteases, in turn, promote the death of retinal ganglion cells (RGCs). In this investigation, we have used two glial toxins to inhibit reactive gliosis and have evaluated their effect on protease-mediated death of RGCs. Kainic acid was injected into the vitreous humor of C57BL/6 mice to induce reactive gliosis and death of RGCs. C57BL/6 mice were also treated with glial toxins, alpha-aminoadipic acid (AAA) or Neurostatin, along with KA. Reactive gliosis was assessed by immunostaining of retinal cross sections and retinal flat-mounts with glial fibrillary acidic protein (GFAP) and vimentin antibodies. Apoptotic cell death was assessed by TUNEL assays. Loss of RGCs was determined by immunostaining of flat-mounted retinas with Brn3a antibodies. Proteolytic activities of matrix metalloproteinase-9 (MMP-9), tissue plasminogen activator (tPA), and urokinase plasminogen activator (uPA) were assessed by zymography assays. GFAP-immunoreactivity indicated that KA induced reactive gliosis in both retinal astrocytes and in Muller cells. AAA alone or in combination with KA decreased GFAP and vimentin-immunoreactivity in Mϋller cells, but not in astrocytes. In addition AAA failed to decrease KA-mediated protease levels and apoptotic death of RGCs. In contrast, Neurostatin either alone or in combination with KA, decreased reactive gliosis in both astrocytes and Mϋller cells. Furthermore, Neurostatin decreased protease levels and prevented apoptotic death of RGCs. Our findings, for the first time, indicate that inhibition of reactive gliosis decreases protease levels in the retina, prevents apoptotic death of retinal neurons, and provides substantial neuroprotection.

Neurostatin blocks glioma cell cycle progression by inhibiting EGFR activation.

The high frequency and malignancy of human glioblastomas has stimulated the search for potential therapeutic approaches. The control of the glioma cell proliferation in response to mitogenic signals is one of the most promising antitumoral strategies, and the main target of several therapies. Neurostatin, an O-acetylated derivative of the ganglioside GD1b, has potent antiproliferative activity over the in vitro and in vivo growth of glioma cells. The mechanism of its antitumoral action is the focus of the present study. Using a combined in vitro-in vivo approach, we observed that neurostatin arrested glioma proliferation by inhibiting the expression of cell cycle promoters (i.e. cyclins and CDKs) and promoting the expression of cell cycle inhibitors (i.e. p21 and p27). Neurostatin inhibits epidermal growth factor receptor (EGFR) signaling pathways, blocking the activation of the main promitogenic MAPKs and PI3K pathways. Neurostatin action not only interferes in the cell cycle progression, but also in the protection from apoptosis, and the generation of angiogenic and invasive responses. The antitumoral actions described here point to neurostatin as a novel and promising chemotherapeutic agent for glioma treatment.

Actualización en el tratamiento de la enfermedad de Fabry: conceptos fisiopatológicos / Update on the treatment of Fabry’s disease: pathophysiological concepts

Introducción. La enfermedad de Fabry es la resultante de la deficiencia de alfa-galactosidasa A lisosomal, lo que genera un depósito excesivo de glucoesfingolípidos en células endoteliales, musculares lisas de los vasos, podocitos, neuronas, etc. Los síntomas se inician en la niñez, con dolor neuropático, para progresar a la insuficiencia renal, cardíaca y accidentes cerebrovasculares desde la tercera década de vida. Desarrollo. Esta revisión presenta los cambios en los conceptos fisiopatológicos que se han adquirido después de nueve años de inicio de la terapia de reemplazo enzimático. La sustitución enzimática muestra utilidad cuanto más temprano se inicie, lo que lleva a revisar los criterios para su uso en los pacientes. Por otro lado, se evalúa la necesidad de tratamientos concomitantes basándose en la fisiopatología de la enfermedad. Conclusión. Se debe evaluar el uso conjunto de terapia de reemplazo enzimático, antiproteinúricos, estatinas y ácido acetilsalicílico como tratamiento inicial en todos los pacientes con enfermedad de Fabry (AU)

Introduction. Fabry’s disease is a consequence of the deficiency of lysosomal alpha-galactosidase A, which gives rise to excessive depositing of glycosphingolipids in endothelial cells, smooth muscle cells in vessels, podocytes, neurons, etc. The symptoms begin in childhood, with neuropathic pain, and progress towards kidney and heart failure, as well as cerebrovascular accidents from the third decade of life onwards. Development. This review presents the changes in the pathophysiological concepts that have been acquired in the nine years since enzyme replacement therapy started to be employed. The earlier enzyme replacement is started, the more effective it is, which thereby calls for a review of the criteria for its use in patients. Furthermore, the need for concomitant treatments is also evaluated based on the pathophysiology of the disease. Conclusions. The joint use of enzyme replacement therapy, antiproteinuric drugs, statins and acetylsalicylic acid must be evaluated as initial treatment in all patients with Fabry’s disease (AU)

[Structure and biological activity of glycosphingolipids from starfish and feather stars].

Glycosphingolipids (GSLs) are contained in a various cell membranes and have recently been implicated in many physiologic functions. They are classified based on their sugar moieties into ceramides, cerebrosides, sulfatides, ceramide-oligohexosides, globosides, and gangliosides. A number of GSLs have been obtained from marine invertebrates such as echinoderms, poriferans, and mollusks and have unique biological activities. During the course of our search for biologically active GSLs from echinoderms, we conducted the isolation and structural elucidation of GSLs from starfish and feather stars and found numerous GSLs, some of which have unique structures. In particular, gangliosides from feather stars were unique in that the sialic acids bind to inositol-phosphoceramide. We also found that the GSLs from starfish and feather stars possess neuritogenic activity toward the rat pheochromocytoma cell line PC12, antihyperglycemic effects against type 2 diabetic BKS. Cg-m+/+Leprdb/J (db/db) mice, and antiosteoporosis effects toward the osteoporosis model mice (OVX mice). These biological activities are thought to be related to dementia, osteoporosis, and diabetes, which are becoming social problems, and are expected to become the seeds of preventive or therapeutic drugs for these illness.

beta-Glycosphingolipids as immune modulators.

beta-Glycosphingolipids have emerged as a family of potential ligands for natural killer T (NKT)-regulatory lymphocytes. This subset of regulatory lymphocytes has been implicated in the regulation of autoimmune processes. The major histocompatibility complex (MHC) Class I-like CD1d glycoprotein is a member of the CD1 family of antigen-presenting molecules and is responsible for selection of NKT cells. beta-Glycolipids have been shown to alter immune responses in the opposing settings of autoimmune diseases or cancer. In this review, we discuss the potential use of beta-glycoshpingolipids for NKT-based immunotherapy.

Beta-glycosphingolipids-mediated lipid raft alteration is associated with redistribution of NKT cells and increased intrahepatic CD8+ T lymphocyte trapping.

The aim of this study was to determine the effect of beta-glycosphingolipids on intra-hepatic natural killer T (NKT) lymphocyte regulatory function and on lymphocyte trapping via alteration of cell membrane lipid rafts. Immune-mediated colitis was induced by intracolonic instillation of trinitrobenzene sulfonic acid. Mice were treated with beta-lactosylceramide (LC), beta-glucosylceramide (GC), beta-galactosylceramide, ceramide, or a combination of both GC and LC (IGL), or solvent alone. Lipid rafts were investigated by fluorescence-activated cell sorting analysis of ganglioside-GM1 and fluorescence microscopy of structure. Administration of beta-glycosphingolipids resulted in an increased intrahepatic/peripheral NKT ratio, increased intrahepatic CD8+ lymphocyte trapping, decreased serum interferon-gamma (IFN-gamma) levels and decreased serum IFN-gamma/interleukin-10 ratio. Administration of GC, LC, or IGL significantly altered the levels of GM1, a key marker of lipid rafts, on NKT regulatory lymphocytes. The immune modulatory effect of beta-glycosphingolipids was associated with increased survival and significant alleviation of colitis as determined by improvement in both the macroscopic and microscopic scores. In conclusion, administration of beta-glycosphingolipids increased NKT regulatory lymphocyte redistribution and intrahepatic CD8(+) T lymphocyte trapping, resulting in alleviation of immune-mediated colitis. The effects of these naturally occurring compounds were associated with modification of the T lymphocyte lipid raft structure, which is a site for immune modulation.

Therapeutic potential of selectin antagonists in psoriasis.

Psoriasis is a systemic chronic inflammatory disorder. One of the major characteristics is an excess of infiltration of inflammatory cells, mainly lymphocytes, into the skin. Because the adhesion family of selectins is suggested to play a relevant role in this process, selectins have emerged as an interesting target for drug discovery and development in psoriasis. Different strategies targeting selectins have been described. This review discusses these approaches and summarises the current development of selectin antagonists for the treatment of psoriasis. An expert opinion will give the authors' personal opinion about selectin antagonism in psoriasis and which approach might be preferable.

Vaccination of BALB/c mice with Leishmania donovani derived lipophosphoglycan does not conver cross-protection to L. major infections.

OBJECTIVE: To determine whether Leishmania donovani-derived lipophosphoglycan (LPG) can confer cross-protection to L. major in susceptible BALB/c mice model. METHODS: BALB/c mice were immunised with a total dose of 30 microg of LPG plus 150 microl of mycobacterium bovis Bacille Calmette guerin (BCG) and later challenged with virulent L. Major parasites. RESULTS: This study demonstrated an activation of both the humoral as well as cell-mediated response to LPG mixed with BCG which correlated with resistance against the disease. However, immunised mice were not protected compared to their PBS controls. CONCLUSION: Though L. donovani infections have been shown to confer cross-protection to L. major this may not be true for purified antigens.

Effect of a lipid-rich emollient containing ceramide 3 in experimentally induced skin barrier dysfunction.

In the present study we compared the effect of a ceramide 3-containing emollient (Locobase(R) Repair) with a control emollient (vaselinum album/cremor lanette ana) and untreated damaged skin using clinical, bioengineering and immunohistochemical methods in two different models of experimentally induced skin barrier dysfunction. In model A (n = 13) skin barrier dysfunction was inflicted at three investigation sites by tape stripping. In model B (n = 13) the volunteers were patch tested at three investigation sites with sodium dodecyl sulphate (0.2%) for 4 h a day for 4 consecutive days. The investigation sites were treated once a day with the above-mentioned agents. Irritant reaction was assessed daily by erythema scoring and measurements of transepidermal water loss (TEWL). After 5D, punch biopsies were taken from all sites. Immunohistochemical assessment was carried out with respect to epidermal proliferation, epidermal differentiation and Langerhans cells. Tape stripping resulted in an erythematous reaction and an increase of TEWL associated with up-regulation of cycling cells, involucrin and expression of cytokeratin 16. At day 4, ceramide 3-containing emollient significantly decreased (p < 0.03) the erythema score, TEWL and cycling cells in comparison with the untreated site. Repetitive exposure to SDS induced a variable degree of erythema, gradual increase of TEWL, an increase of cycling cells, and up-regulation of involucrin, E-FABP and SKALP. The treatment with the control emollient significantly prevented erythema, increase of TEWL and cycling cells at day 4 compared to the untreated site. In summary, the present study demonstrated that both tested emollients improve skin barrier in different conditions compared to the untreated skin. There is some indication that formulations containing skin-related lipids might be of benefit in barrier disruption following tape stripping. Different models and clinical trials are needed to establish the usefulness in specific conditions of emollients containing skin-related lipids.

Evaluation of efficacy of a skin lipid mixture in patients with irritant contact dermatitis, allergic contact dermatitis or atopic dermatitis: a multicenter study.

Disturbances of skin barrier function occur in several skin diseases, e.g., atopic dermatitis (AD), irritant/allergic contact dermatitis (ICD, ACD). Skin barrier damage triggers the production of cytokines that stimulate lipogenesis which may also cause inflammatory processes. The aim of this study was to evaluate the efficacy of a topical skin lipid mixture in the treatment of ICD, ACD and AD. 580 consecutive patients suffering from ICD, ACD or AD were treated with a skin lipid mixture containing ceramide-3 and patented nanoparticles. Patients received the lipid mixture alone or in combination with topical corticosteroids until clearance or for 8 weeks. Both treatment groups statistically improved all parameters considered at week 4 and 8 as compared to baseline. Between the 2 treatment groups, there was a statistically significant difference in favour of combined therapy for (ICD, ACD, AD, respectively): erythema, pruritus and overall disease severity; erythema and pruritus; erythema, pruritus, fissuring and overall disease severity. No statistically significant difference was found for (ICD, ACD, AD, respectively): dryness, scaling and fissuring; scaling, fissuring and overall disease severity; dryness and scaling. Between the 2 ACD treatment groups, there was a statistically significant difference in favour of the skin lipid mixture for dryness. In conclusion, the study shows that balanced lipid mixtures are effective in improving barrier properties and the clinical condition of the skin in contact dermatitis.

Colonic cell proliferation and aberrant crypt foci formation are inhibited by dairy glycosphingolipids in 1, 2-dimethylhydrazine-treated CF1 mice.

Dietary sphingomyelin (SM) inhibits early stages of colon cancer (appearance of aberrant crypt foci, ACF) and decreases the proportion of adenocarcinomas vs. adenomas in 1,2-dimethylhydrazine (DMH)-treated CF1 mice. To elucidate the structural specificity of this inhibition, the effects of the other major sphingolipids in milk (glycosphingolipids) were determined. Glucosylceramide (GluCer), lactosylceramide (LacCer) and ganglioside G(D3) were fed individually to DMH-treated (six doses of 30 mg/kg body weight) female CF1 mice at 0.025 or 0.1 g/100 g of the diet for 4 wk. All reduced the number of ACF by > 40% (P < 0.001), which is comparable to the reduction by SM in earlier studies. Immunohistochemical analysis of the colons revealed that sphingolipid feeding also reduced proliferation, with the most profound effect (up to 80%; P < 0.001) in the upper half of the crypts. Since the bioactive backbones of the glycosphingolipids (i.e., ceramide and other metabolites) are the likely mediators of these effects, the susceptibility of these complex sphingolipids to digestion in the colon was examined by incubating 500 microgram of each sphingolipid with colonic segments from mice and analysis of substrate disappearance and product formation by tandem mass spectrometry. All of the sphingolipids (including SM) disappeared over time with a substantial portion appearing as ceramide. Partially hydrolyzed intermediates (such as GluCer from LacCer or G(D3)) were not detected, which suggests that the cleavage involves colonic (or microflora) endoglycosidases. In summary, consumption of dairy SM and glycosphingolipids suppresses colonic cell proliferation and ACF formation in DMH-treated mice; hence, many categories of sphingolipids affect these key events in colon carcinogenesis.

Glycosphingolipid antigens and cancer therapy.

Specific types of glycosphingolipid (GSL), which are chemically detectable in normal cells, are more highly expressed in tumors. The high level of expression on the surfaces of tumor cells causes an antibody response to these GSLs, which can therefore be described as tumor-associated antigens. Some of these GSLs have been shown to be adhesion molecules involved in tumor cell metastasis, and to be modulators of signal transduction controlling tumor cell growth and motility. Tumor-associated GSL antigens have been used in the development of antitumor vaccines. GSLs and sphingolipids involved in adhesion and signaling are therefore targets for cancer therapy.