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1.
J Oleo Sci ; 69(10): 1307-1315, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32908096

RESUMO

Ceramide, an intercellular lipid of the stratum corneum, plays an essential role in making the skin barrier. One problem with the use of medical adhesive tape or sheets for skin is that their repeated attachment and detachment may cause some damage to the skin. An attempt has been made to eliminate this problem by mixing ceramide into the adhesive of sheets, and has delivered excellent clinical results. This study aimed to investigate whether ceramide is transferred from the adhesive with added ceramide to the skin. An adhesive sheet was prepared by adding synthetic ceramide (CER) to UV-curable acrylic adhesive gel. After affixing the adhesive sheet to human skin for a certain period, it was peeled off and cut perpendicular to the adhesive surface. Synchrotron micro-infrared spectroscopy of the sectioned samples showed that the ceramide concentration in the gel sheet decreases as the application time to human skin increases. This is thought to be due to the release of CER from the gel sheet.


Assuntos
Adesivos , Ceramidas/administração & dosagem , Ceramidas/metabolismo , Liberação Controlada de Fármacos , Absorção Cutânea , Pele/metabolismo , Fita Cirúrgica , Ceramidas/análise , Géis , Humanos , Espectrofotometria Infravermelho
2.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(3): 279-282, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32981286

RESUMO

Objective: To investigate the effects of ceramide pathway on the inhibition of artesunate (Art) to hepatic fibrosis.Methods: LX-2 cells were divided into control group, Art treated group with 350 µmol/L, fumonisin B1 (FB1) treated group with 6 µmol/L, and Co-administration group of artesunate 350 µmol/L and fumonisin B1 6 µmol/L. There were 7 compound holes in each group. After 24 hours of treatment, the cells and supernatant were collected and detected. The expressions of homo sapiens longevity assurance homologue 2 (LASS2), peroxisome proliferators-activated receptors-γ (PPAR-γ) and Caspase-3 were evaluated by Western blot, the content of ceramide was evaluated by HPLC-FLD method, MTT assay was adopted to measure the rate of proliferation of LX-2 cells. The content of hydroxyproline was determined by digestive method. Results: Compared with the control group, the expression of ceramide synthase protein and the ceramide content were increased significantly, the proliferation of LX-2 cells was inhibited significantly, the expressions of PPAR-γ and Caspase-3 protein were up-regulated and the secretion of hydroxyproline was inhibited in Art treated group (P<0.05). In FB1 treated group, the protein expression of ceramide synthase and the ceramide content were decreased significantly, the proliferation of LX-2 cells was increased significantly, the expressions of PPAR-γ and Caspase-3 protein were down-regulated, and the secretion of hydroxyproline was increased (P<0.05). Compared with the Art alone group, the combination of the two drugs could significantly reduce the effects of Art on the expression of ceramide synthase protein and the increase of ceramide content, and attenuate the effects of Art on the cell proliferation , PPAR-γ, Caspase-3 protein expression and hydroxyproline level of LX-2 cells (P<0.05). Conclusion: Artesunate could inhibit hepatic fibrosis by increasing the content of ceramide through the ceramide synthase-ceramide pathway.


Assuntos
Artesunato , Ceramidas , Cirrose Hepática , Oxirredutases , Artesunato/farmacologia , Proliferação de Células/efeitos dos fármacos , Ceramidas/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/enzimologia , Cirrose Hepática/prevenção & controle , Oxirredutases/metabolismo
3.
Adv Exp Med Biol ; 1274: 101-135, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894509

RESUMO

Intensive research in the field of sphingolipids has revealed diverse roles in cell biological responses and human health and disease. This immense molecular family is primarily represented by the bioactive molecules ceramide, sphingosine, and sphingosine 1-phosphate (S1P). The flux of sphingolipid metabolism at both the subcellular and extracellular levels provides multiple opportunities for pharmacological intervention. The caveat is that perturbation of any single node of this highly regulated flux may have effects that propagate throughout the metabolic network in a dramatic and sometimes unexpected manner. Beginning with S1P, the receptors for which have thus far been the most clinically tractable pharmacological targets, this review will describe recent advances in therapeutic modulators targeting sphingolipids, their chaperones, transporters, and metabolic enzymes.


Assuntos
Redes e Vias Metabólicas/efeitos dos fármacos , Modelos Biológicos , Terapia de Alvo Molecular , Esfingolipídeos/metabolismo , Ceramidas/metabolismo , Humanos , Lisofosfolipídeos/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo
4.
Nat Commun ; 11(1): 4279, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855410

RESUMO

Plasma and tumor caveolin-1 (Cav-1) are linked with disease progression in prostate cancer. Here we report that metabolomic profiling of longitudinal plasmas from a prospective cohort of 491 active surveillance (AS) participants indicates prominent elevations in plasma sphingolipids in AS progressors that, together with plasma Cav-1, yield a prognostic signature for disease progression. Mechanistic studies of the underlying tumor supportive onco-metabolism reveal coordinated activities through which Cav-1 enables rewiring of cancer cell lipid metabolism towards a program of 1) exogenous sphingolipid scavenging independent of cholesterol, 2) increased cancer cell catabolism of sphingomyelins to ceramide derivatives and 3) altered ceramide metabolism that results in increased glycosphingolipid synthesis and efflux of Cav-1-sphingolipid particles containing mitochondrial proteins and lipids. We also demonstrate, using a prostate cancer syngeneic RM-9 mouse model and established cell lines, that this Cav-1-sphingolipid program evidences a metabolic vulnerability that is targetable to induce lethal mitophagy as an anti-tumor therapy.


Assuntos
Caveolina 1/metabolismo , Neoplasias da Próstata/metabolismo , Esfingolipídeos/metabolismo , Idoso , Animais , Caveolina 1/sangue , Caveolina 1/genética , Linhagem Celular Tumoral , Ceramidas/metabolismo , Intervalo Livre de Doença , Regulação Neoplásica da Expressão Gênica , Glicoesfingolipídeos/biossíntese , Humanos , Lipídeos/sangue , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Pirrolidinas/farmacologia , Esfingomielinas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Am J Pathol ; 190(10): 2018-2028, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32679228

RESUMO

Studies of lysosome associated protein transmembrane 4B (LAPTM4B) have mainly focused on the 35-kDa isoform and its association with poor prognosis in cancers. Here, by employing a novel monoclonal antibody, the authors found that the 24-kDa LAPTM4B isoform predominated in most, both healthy and malignant, human cells and tissues studied. LAPTM4B-24 lacks the extreme N-terminus and, contrary to LAPTM4B-35, failed to promote cell migration. The endogenous LAPTM4B-24 protein was subject to rapid turnover with a t1/2 of approximately 1 hour. The protein was degraded by both lysosomal and proteasomal pathways, and its levels were increased by the availability of nutrients and lysosomal ceramide. These findings underscore the pathophysiological relevance of the LAPTM4B-24 isoform and identify it as a dynamically regulated effector in lysosomal nutrient signaling.


Assuntos
Movimento Celular/fisiologia , Ceramidas/metabolismo , Lisossomos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Oncogênicas/metabolismo , Humanos , Isoformas de Proteínas/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo
6.
Exp Parasitol ; 217: 107948, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32698076

RESUMO

Immunomodulation is an emerging concept to combat infection in recent years. Immunomodulators like arabinosylated-lipoarabinomannan (Ara-LAM) and glycyrrhizic-acid (GA) possess anti-leishmanial property, whereas sodium-antimony-gluconate (SAG) is still considered as the first choice for chemotherapy against leishmaniasis. During infection, invasion of Leishmania donovani needs the potential requirement of Ca2+, which is further responsible for apoptosis in intracellular amastigotes. However, suppression of elevated intracellular calcium by the activation of plasma-membrane-calcium-ATPase (PMCA4) facilitates survival of L. donovani in the host. In the present study, SAG, Ara-LAM, and GA were found to evoke significant increase in intracellular Ca2+ in L. donovani infected macrophages by inhibiting PMCA4. Moreover, PMCA4 inhibition by TFP or PMCA4 siRNA elevated the level of PKCß, whereas calcium-independent upregulation of PKCζ remained unchanged in infected macrophages. Furthermore, application of immunomodulators in infected macrophages resulted in down-regulation of PKCζ, conversion of anti-inflammatory to pro-inflammatory cytokines and inhibition of PMCA4. Plasma membrane-associated ceramide which is known to be elevated during leishmaniasis, triggered upregulation of PMCA4 via PKCζ activation. Interestingly, immunomodulators attenuated ceramide generation, which resulted into reduced PKCζ activation leading to the decreased PMCA expression in infected macrophages. Therefore, our study elucidated the efficacy of SAG, Ara-LAM, and GA in the reduction of parasite burden in macrophages by suppressing PMCA activation through inhibition of ceramide mediated upregulation of PKCζ.


Assuntos
Antiprotozoários/uso terapêutico , ATPases Transportadoras de Cálcio/sangue , Membrana Celular/enzimologia , Fatores Imunológicos/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Animais , Gluconato de Antimônio e Sódio/farmacologia , Gluconato de Antimônio e Sódio/uso terapêutico , Antiprotozoários/farmacologia , Cálcio/metabolismo , ATPases Transportadoras de Cálcio/efeitos dos fármacos , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Ceramidas/metabolismo , Meios de Cultura Livres de Soro , Densitometria , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/uso terapêutico , Imipramina/farmacologia , Immunoblotting , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/uso terapêutico , Macrófagos/fisiologia , Camundongos , RNA de Protozoário/genética , RNA de Protozoário/isolamento & purificação , RNA Interferente Pequeno/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Reversa , Transfecção
7.
Nat Commun ; 11(1): 2471, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424203

RESUMO

Gut microbes are linked to host metabolism, but specific mechanisms remain to be uncovered. Ceramides, a type of sphingolipid (SL), have been implicated in the development of a range of metabolic disorders from insulin resistance (IR) to hepatic steatosis. SLs are obtained from the diet and generated by de novo synthesis in mammalian tissues. Another potential, but unexplored, source of mammalian SLs is production by Bacteroidetes, the dominant phylum of the gut microbiome. Genomes of Bacteroides spp. and their relatives encode serine palmitoyltransfease (SPT), allowing them to produce SLs. Here, we explore the contribution of SL-production by gut Bacteroides to host SL homeostasis. In human cell culture, bacterial SLs are processed by host SL-metabolic pathways. In mouse models, Bacteroides-derived lipids transfer to host epithelial tissue and the hepatic portal vein. Administration of B. thetaiotaomicron to mice, but not an SPT-deficient strain, reduces de novo SL production and increases liver ceramides. These results indicate that gut-derived bacterial SLs affect host lipid metabolism.


Assuntos
Bacteroides/fisiologia , Ceramidas/metabolismo , Microbioma Gastrointestinal , Redes e Vias Metabólicas , Esfingolipídeos/metabolismo , Animais , Células CACO-2 , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Vida Livre de Germes , Humanos , Resistência à Insulina , Mucosa Intestinal/microbiologia , Fígado/metabolismo , Redes e Vias Metabólicas/genética , Camundongos , Mutação/genética , Serina C-Palmitoiltransferase/deficiência , Serina C-Palmitoiltransferase/genética , Serina C-Palmitoiltransferase/metabolismo
8.
Mol Cells ; 43(5): 419-430, 2020 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-32392908

RESUMO

The liver is an important organ in the regulation of glucose and lipid metabolism. It is responsible for systemic energy homeostasis. When energy need exceeds the storage capacity in the liver, fatty acids are shunted into nonoxidative sphingolipid biosynthesis, which increases the level of cellular ceramides. Accumulation of ceramides alters substrate utilization from glucose to lipids, activates triglyceride storage, and results in the development of both insulin resistance and hepatosteatosis, increasing the likelihood of major metabolic diseases. Another sphingolipid metabolite, sphingosine 1-phosphate (S1P) is a bioactive signaling molecule that acts via S1P-specific G protein coupled receptors. It regulates many cellular and physiological events. Since an increase in plasma S1P is associated with obesity, it seems reasonable that recent studies have provided evidence that S1P is linked to lipid pathophysiology, including hepatosteatosis and fibrosis. Herein, we review recent findings on ceramides and S1P in obesity-mediated liver diseases and the therapeutic potential of these sphingolipid metabolites.


Assuntos
Ceramidas/metabolismo , Hepatopatias/metabolismo , Fígado/metabolismo , Lisofosfolipídeos/metabolismo , Obesidade/metabolismo , Esfingosina/análogos & derivados , Animais , Homeostase , Humanos , Resistência à Insulina , Metabolismo dos Lipídeos , Fígado/patologia , Esfingosina/metabolismo
9.
Cancer Res ; 80(12): 2651-2662, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32291318

RESUMO

Ceramide-induced endothelial cell apoptosis boosts intestinal stem cell radiosensitivity. However, the molecular connection between these two cellular compartments has not been clearly elucidated. Here we report that ceramide and its related enzyme acid sphingomyelinase (ASM) are secreted by irradiated endothelial cells and act as bystander factors to enhance the radiotoxicity of intestinal epithelium. Ceramide and the two isoforms of ASM were acutely secreted in the blood serum of wild-type mice after 15 Gy radiation dose, inducing a gastrointestinal syndrome. Interestingly, serum ceramide was not enhanced in irradiated ASMKO mice, which are unable to develop intestinal failure injury. Because ASM/ceramide were secreted by primary endothelial cells, their contribution was studied in intestinal epithelium dysfunction using coculture of primary endothelial cells and intestinal T84 cells. Adding exogenous ASM or ceramide enhanced epithelial cell growth arrest and death. Conversely, blocking their secretion by endothelial cells using genetic, pharmacologic, or immunologic approaches abolished intestinal T84 cell radiosensitivity. Use of enteroid models revealed ASM and ceramide-mediated deleterious mode-of-action: when ceramide reduced the number of intestinal crypt-forming enteroids without affecting their structure, ASM induced a significant decrease of enteroid growth without affecting their number. Identification of specific and different roles for ceramide and ASM secreted by irradiated endothelial cells opens new perspectives in the understanding of intestinal epithelial dysfunction after radiation and defines a new class of potential therapeutic radiomitigators. SIGNIFICANCE: This study identifies secreted ASM and ceramide as paracrine factors enhancing intestinal epithelial dysfunction, revealing a previously unknown class of mediators of radiosensitivity.


Assuntos
Ceramidas/metabolismo , Células Endoteliais/metabolismo , Mucosa Intestinal/patologia , Lesões por Radiação/patologia , Esfingomielina Fosfodiesterase/metabolismo , Animais , Efeito Espectador/efeitos da radiação , Células Cultivadas , Ceramidas/sangue , Técnicas de Cocultura , Desipramina/farmacologia , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/efeitos da radiação , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Células Epiteliais/efeitos da radiação , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos da radiação , Masculino , Camundongos , Camundongos Knockout , Comunicação Parácrina/genética , Comunicação Parácrina/efeitos da radiação , Cultura Primária de Células , RNA Interferente Pequeno/metabolismo , Lesões por Radiação/sangue , Lesões por Radiação/etiologia , Lesões por Radiação/prevenção & controle , Tolerância a Radiação/efeitos dos fármacos , Tolerância a Radiação/genética , Esfingomielina Fosfodiesterase/antagonistas & inibidores , Esfingomielina Fosfodiesterase/sangue , Esfingomielina Fosfodiesterase/genética
10.
J Pharmacol Exp Ther ; 373(3): 476-487, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32273303

RESUMO

Zona pellucida binding protein 2 (Zpbp2) and ORMDL sphingolipid biosynthesis regulator 3 (Ormdl3), mapped downstream of Zpbp2, were identified as two genes associated with airway hyper-responsiveness (AHR). Ormdl3 gene product has been shown to regulate the biosynthesis of ceramides. Allergic asthma was shown to be associated with an imbalance between very-long-chain ceramides (VLCCs) and long-chain ceramides (LCCs). We hypothesized that Fenretinide can prevent the allergic asthma-induced augmentation of Ormdl3 gene expression, normalize aberrant levels of VLCCs and LCCs, and treat allergic asthma symptoms. We induced allergic asthma by house dust mite (HDM) in A/J WT mice and Zpbp2 KO mice expressing lower levels of Ormdl3 mRNA than WT. We investigated the effect of a novel formulation of Fenretinide, LAU-7b, on the AHR, inflammatory cell infiltration, mucus production, IgE levels, and ceramide levels. Although lower Ormdl3 expression, which was observed in Zpbp2 KO mice, was associated with lower AHR, allergic Zpbp2 KO mice were not protected from inflammatory cell infiltration, mucus accumulation, or aberrant levels of VLCCs and LCCs induced by HDM. LAU-7b treatment protects both the Zpbp2 KO and WT mice. The treatment significantly lowers the gene expression of Ormdl3, normalizes the VLCCs and LCCs, and corrects all the other phenotypes associated with allergic asthma after HDM challenge, except the elevated levels of IgE. LAU-7b treatment prevents the augmentation of Ormdl3 expression and ceramide imbalance induced by HDM challenge and protects both WT and Zpbp2 KO mice against allergic asthma symptoms. SIGNIFICANCE STATEMENT: Compared with A/J WT mice, KO mice with Zpbp2 gene deletion have lower AHR and lower levels of Ormdl3 expression. The novel oral clinical formulation of Fenretinide (LAU-7b) effectively lowers the AHR and protects against inflammatory cell infiltration and mucus accumulation induced by house dust mite in both Zpbp2 KO and WT A/J mice. LAU-7b prevents Ormdl3 overexpression in WT allergic mice and corrects the aberrant levels of very-long-chain and long-chain ceramides in both WT and Zpbp2 KO allergic mice.


Assuntos
Asma/tratamento farmacológico , Asma/metabolismo , Ceramidas/metabolismo , Regulação para Baixo/efeitos dos fármacos , Fenretinida/farmacologia , Proteínas de Membrana/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Expressão Gênica/efeitos dos fármacos , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Knockout , Hipersensibilidade Respiratória/tratamento farmacológico , Hipersensibilidade Respiratória/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-32144130

RESUMO

INTRODUCTION: Gestational diabetes mellitus (GDM), a common pregnancy disorder, increases the risk of fetal overgrowth and later metabolic morbidity in the offspring. The placenta likely mediates these sequelae, but the exact mechanisms remain elusive. Mitochondrial dynamics refers to the joining and division of these organelles, in attempts to maintain cellular homeostasis in stress conditions or alterations in oxygen and fuel availability. These remodeling processes are critical to optimize mitochondrial function, and their disturbances characterize diabetes and obesity. METHODS AND RESULTS: Herein we show that placental mitochondrial dynamics are tilted toward fusion in GDM, as evidenced by transmission electron microscopy and changes in the expression of key mechanochemical enzymes such as OPA1 and active phosphorylated DRP1. In vitro experiments using choriocarcinoma JEG-3 cells demonstrated that increased exposure to insulin, which typifies GDM, promotes mitochondrial fusion. As placental ceramide induces mitochondrial fission in pre-eclampsia, we also examined ceramide content in GDM and control placentae and observed a reduction in placental ceramide enrichment in GDM, likely due to an insulin-dependent increase in ceramide-degrading ASAH1 expression. CONCLUSIONS: Placental mitochondrial fusion is enhanced in GDM, possibly as a compensatory response to maternal and fetal metabolic derangements. Alterations in placental insulin exposure and sphingolipid metabolism are among potential contributing factors. Overall, our results suggest that GDM has profound impacts on placental mitochondrial dynamics and metabolism, with plausible implications for the short-term and long-term health of the offspring.


Assuntos
Diabetes Gestacional/fisiopatologia , Dinâmica Mitocondrial , Placenta/fisiopatologia , Linhagem Celular , Ceramidas/metabolismo , Diabetes Gestacional/metabolismo , Feminino , Homeostase , Humanos , Insulina/administração & dosagem , Insulina/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Mitocôndrias/ultraestrutura , Proteínas Mitocondriais/metabolismo , Placenta/metabolismo , Placenta/ultraestrutura , Gravidez
12.
Artigo em Inglês | MEDLINE | ID: mdl-32112978

RESUMO

Ceramide kinase (CerK) phosphorylates ceramide to ceramide-1-phosphate (C1P), a bioactive sphingolipid. Since the mechanisms responsible for regulating the proliferation and migration/metastasis of cancer cells by the CerK/C1P pathway remain unclear, we conducted the present study. The knockdown of CerK in A549 lung and MCF-7 breast cancer cells (shCerK cells) increased the formation of lamellipodia, which are membrane protrusions coupled with cell migration. Mouse embryonic fibroblasts prepared from CerK-null mice also showed an enhanced formation of lamellipodia. The overexpression of CerK inhibited lamellipodium formation in A549 cells. The knockdown of CerK increased the number of cells having lamellipodia with Rac1 and the levels of active Rac1-GTP form, whereas the overexpression of CerK decreased them. CerK was located in lamellipodia after the epidermal growth factor treatment, indicating that CerK functioned there to inhibit Rac1. The migration of A549 cells was negatively regulated by CerK. An intravenous injection of A549-shCerK cells into nude mice resulted in markedly stronger metastatic responses in the lungs than an injection of control cells. The in vitro growth of A549 cells and in vivo expansion after the injection into mouse flanks were not affected by the CerK knockdown. These results suggest that the activation of CerK/C1P pathway has inhibitory roles on lamellipodium formation, migration, and metastasis of A549 lung cancer cells.


Assuntos
Neoplasias Pulmonares/patologia , Metástase Neoplásica/patologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Pseudópodes/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Células A549 , Animais , Movimento Celular , Ceramidas/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Células MCF-7 , Masculino , Camundongos , Invasividade Neoplásica/patologia , Fosfotransferases (Aceptor do Grupo Álcool)/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto
13.
PLoS One ; 15(3): e0230499, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32187230

RESUMO

Glycosphingolipids (GSLs) hexosylceramides and lactosylceramides are elevated in lupus mice and human patients with nephritis. Whereas other renal diseases characterized by increased GSL levels are thought to be a result of upregulated GSL synthesis, our results suggest elevated hexosylceramides and lactosylceramides in lupus nephritis is a result of increased catabolism of ganglioside GM3 due to significantly increased neuraminidase (NEU) activity. Thus, we hypothesized GM3 would be decreased in lupus nephritis kidneys and blocking NEU activity would reduce GSLs and improve disease in lupus mice. Female MRL/lpr lupus mice were treated with water or the NEU inhibitor oseltamivir phosphate at the onset of proteinuria to block GSL catabolism. Age-matched (non-nephritic) female MRL/MpJ lupus mice served as controls. Renal GM3 levels were significantly higher in the nephritic MRL/lpr water-treated mice compared to non-nephritic MRL/MpJ mice, despite significantly increased renal NEU activity. Blocking GSL catabolism increased, rather than decreased, renal and urine GSL levels and disease was not significantly impacted. A pilot study treating MRL/lpr females with GlcCer synthase inhibitor Genz-667161 to block GSL synthesis resulted in a strong significant negative correlation between Genz-667161 dose and renal GSL hexosylceramide and GM3 levels. Splenomegaly was negatively correlated and serum IgG levels were marginally correlated with increasing Genz-667161 dose. These results suggest accumulation of renal GM3 may be due to dysregulation of one or more of the GSL ganglioside pathways and inhibiting GSL synthesis, but not catabolism, may be a therapeutic approach for treating lupus nephritis.


Assuntos
Glicoesfingolipídeos/metabolismo , Nefrite Lúpica/tratamento farmacológico , Nefrite Lúpica/metabolismo , Animais , Ceramidas/metabolismo , Feminino , Gangliosídeo G(M3)/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Lactosilceramidas/metabolismo , Camundongos , Camundongos Endogâmicos MRL lpr , Neuraminidase/metabolismo , Oseltamivir/análogos & derivados , Oseltamivir/uso terapêutico , Ácidos Fosforosos/uso terapêutico , Projetos Piloto , Proteinúria/tratamento farmacológico , Proteinúria/metabolismo
14.
Am J Pathol ; 190(6): 1211-1223, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32194052

RESUMO

Lysosomal acid ceramidase (Ac) has been shown to be critical for ceramide hydrolysis and regulation of lysosome function and cellular homeostasis. In the present study, we generated a knockout mouse strain (Asah1fl/fl/PodoCre) with a podocyte-specific deletion of the α subunit (main catalytic subunit) of Ac. Although no significant morphologic changes in glomeruli were observed in these mice under light microscope, severe proteinuria and albuminuria were found in these podocyte-specific knockout mice compared with control genotype littermates. Transmission electron microscopic analysis showed that podocytes of the knockout mice had distinctive foot process effacement and microvillus formation. These functional and morphologic changes indicate the development of nephrotic syndrome in mice bearing the Asah1 podocyte-specific gene deletion. Ceramide accumulation determined by liquid chromatography-tandem mass spectrometry was demonstrated in isolated glomeruli of Asah1fl/fl/PodoCre mice compared with their littermates. By crossbreeding Asah1fl/fl/PodoCre mice with Smpd1-/- mice, we also produced a double knockout strain, Smpd1-/-/Asah1fl/fl/PodoCre, that also lacks Smpd1, the acid sphingomyelinase that hydrolyzes sphingomyelin to ceramide. These mice exhibited significantly lower levels of glomerular ceramide with decreased podocyte injury compared with Asah1fl/fl/PodoCre mice. These results strongly suggest that lysosomal Ac in podocytes is essential for the maintenance of the structural and functional integrity of podocytes.


Assuntos
Ceramidase Ácida/genética , Ceramidas/metabolismo , Glomérulos Renais/metabolismo , Síndrome Nefrótica/metabolismo , Podócitos/metabolismo , Ceramidase Ácida/metabolismo , Animais , Glomérulos Renais/patologia , Glomérulos Renais/ultraestrutura , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Síndrome Nefrótica/genética , Síndrome Nefrótica/patologia , Podócitos/patologia , Podócitos/ultraestrutura
15.
Animal ; 14(S1): s165-s175, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32024571

RESUMO

Coordinated changes in energy metabolism develop to support gestation and lactation in the periparturient dairy cow. Maternal physiology involves the partitioning of nutrients (i.e. glucose, amino acids and fatty acids (FA)) for fetal growth and milk synthesis. However, the inability of the dairy cow to successfully adapt to a productive lactation may trigger metabolic stress characterized by uncontrolled adipose tissue lipolysis and reduced insulin sensitivity. A consequence is lipotoxicity and hepatic triglyceride deposition that favors the development of fatty liver disease (FLD) and ketosis. This review describes contemporary perspectives pertaining to FA surfeit and complex lipid metabolism in the transition dairy cow. The role of saturated and unsaturated FA as bioactive signaling molecules capable of modulating insulin secretion and sensitivity is explored. Moreover, the metabolic fate of FA as influenced by mitochondrial function is considered. This includes the influence of inadequate mitochondrial oxidation on acylcarnitine status and the use of FA for lipid mediator synthesis. Lipid mediators, including the sphingolipid ceramide and diacylglycerol, are evaluated considering their established ability to inhibit insulin signaling and glucose transport in non-ruminant diabetics. The mechanisms of FLD in the transition cow are revisited with attention centered on glycerophospholipid phosphatidylcholine and triglyceride secretion. The relationship between oxidative stress and oxylipids within the context of insulin antagonism, hepatic steatosis and inflammation is also reviewed. Lastly, peripartal hormonal involvement or lack thereof of adipokines (i.e. leptin, adiponectin) and hepatokines (i.e. fibroblast growth factor-21) is described. Similarities and differences in ruminant and non-ruminant physiology are routinely showcased. Unraveling the lipidome of the dairy cow has generated breakthroughs in our understanding of periparturient lipid biology. Therapeutic approaches that target FA and complex lipid metabolism holds promise to enhance cow health, well-being and productive lifespan.


Assuntos
Bovinos/fisiologia , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos , Leite/metabolismo , Transdução de Sinais , Animais , Carnitina/análogos & derivados , Carnitina/metabolismo , Ceramidas/metabolismo , Metabolismo Energético , Feminino , Glucose/metabolismo , Glicerofosfolipídeos/metabolismo , Insulina/metabolismo , Resistência à Insulina , Lactação , Lipólise , Fígado/metabolismo , Mitocôndrias/metabolismo , Esfingolipídeos/metabolismo , Triglicerídeos/metabolismo
16.
Nat Rev Endocrinol ; 16(4): 224-233, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32060415

RESUMO

Ceramide accumulation is a hallmark in the manifestation of numerous obesity-related diseases, such as type 2 diabetes mellitus and atherosclerosis. Until the early 2000s, ceramides were viewed as a homogenous class of sphingolipids. However, it has now become clear that ceramides exert fundamentally different effects depending on the specific fatty acyl chain lengths, which are integrated into ceramides by a group of enzymes known as dihydroceramide synthases. In addition, alterations in ceramide synthesis, trafficking and metabolism in specific cellular compartments exert distinct consequences on metabolic homeostasis. Here, we examine the emerging concept of how the intracellular localization of ceramides with distinct acyl chain lengths can regulate glucose metabolism, thus emphasizing their potential as targets in the development of novel and specific therapies for obesity and obesity-associated diseases.


Assuntos
Ceramidas/metabolismo , Doenças Metabólicas/metabolismo , Animais , Glucose/metabolismo , Humanos , Esfingolipídeos/metabolismo
17.
Life Sci ; 245: 117352, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32006527

RESUMO

AIMS: The depot-specific differences in lipidome of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) reflect heterogeneity of white adipose tissue (WAT), which plays a central role in its distinct response to outside stimuli. However, the detailed lipidome of depot-specific WAT is largely unknown, especially the minor constitutes including phospholipid and sphingolipid. MATERIALS AND METHODS: To investigate this field, we applied a high-coverage targeted lipidomics approach of VAT and SAT in male C57BL/6J mice to compare the basal level of their lipid profiles. Applying microarray and quantitative real-time polymerase chain reaction, we analyzed the transcriptome of twodepot-specific WAT and verified the differences in individual genes. KEY FINDINGS: In total, 342 lipid species from 19 lipid classes were identified. Our results showed the composition of TAG and FFA were different in length of chain and saturation. Interestingly, low abundance phospholipid, sphingolipid and cardiolipin were significantly higher in SAT. Lipid correlation network analysis vindicated that TAG and phospholipid formed distinct subnet and had more connections with other lipid species. Enriched ontology analysis of gene screened from LIPID MAPS and microarray suggested the differences were mainly involved in lipid metabolism, insulin resistance and inflammatory response. SIGNIFICANCE: Our comprehensive lipidomics and transcriptomics analyses revealed differences in lipid composition and lipid metabolism of two depot-specific WAT, which would offer new insights into the investigation of heterogeneity of visceral and subcutaneous white adipose tissue.


Assuntos
Tecido Adiposo Branco/metabolismo , Gordura Intra-Abdominal/metabolismo , Lipidômica , Gordura Subcutânea/metabolismo , Transcriptoma , Tecido Adiposo Branco/química , Animais , Cardiolipinas/análise , Cardiolipinas/metabolismo , Ceramidas/análise , Ceramidas/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Glicerídeos/análise , Glicerídeos/metabolismo , Gordura Intra-Abdominal/química , Metabolismo dos Lipídeos , Lipídeos/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosfolipídeos/análise , Fosfolipídeos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Gordura Subcutânea/química
18.
Int J Mol Sci ; 21(3)2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32028642

RESUMO

Human epidermis is positioned at the interface with the external environment, protecting our bodies against external challenges, including air pollutants. Emerging evidence suggests that diesel particulate extract (DPE), a major component of air pollution, leads to impairment of diverse cellular functions in keratinocytes (KC). In this study, we investigated the cellular mechanism underlying DPE-induced KC apoptosis. We first addressed cell death occurring in KC exposed to DPE, paralleled by increased activation of NADPH oxidases (NOXs) and subsequent ROS generation. Blockade of NOX activation with a specific inhibitor attenuated the expected DPE-induced KC apoptosis. In contrast, pre-treatment with a specific inhibitor of reactive oxygen species (ROS) generation did not reverse DPE/NOX-mediated increase in KC apoptosis. We next noted that NOX-mediated KC apoptosis is mainly attributable to neutral sphingomyelinase (SMase)-mediated stimulation of ceramides, which is a well-known pro-apoptotic lipid. Moreover, we found that inhibition of NOX activation significantly attenuated DPE-mediated increase in the ratio of ceramide to its key metabolite sphingosine-1-phosphate (S1P), an important determinant of cell fate. Together, these results suggest that activation of neutral SMase serves as a key downstream signal for the DPE/NOX activation-mediated alteration in ceramide and S1P productions, and subsequent KC apoptosis.


Assuntos
Apoptose , Óleos Combustíveis/toxicidade , Queratinócitos/patologia , NADPH Oxidases/metabolismo , Petróleo/toxicidade , Esfingomielina Fosfodiesterase/metabolismo , Ceramidas/metabolismo , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Lisofosfolipídeos/metabolismo , NADPH Oxidases/genética , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Esfingomielina Fosfodiesterase/genética , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Emissões de Veículos/toxicidade
19.
Int J Mol Sci ; 21(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033121

RESUMO

Bioactive sphingolipids are emerging as key regulators of vascular function and homeostasis. While most of the clinical studies have been devoted to profile circulating sphingolipids in maternal plasma, little is known about the role of the sphingolipid at the feto-placental vasculature, which is in direct contact with the offspring circulation. Our study aims to compare the sphingolipid profile of normal with preeclamptic (PE) placental chorionic arteries and isolated endothelial cells, with the goal of unveiling potential underlying pathomechanisms in the vasculature. Dihydrosphingosine and sphingomyelin (SM) concentrations (C16:0-, C18:0-, and C24:0- sphingomyelin) were significantly increased in chorionic arteries of preeclamptic placentas, whereas total ceramide, although showing a downward trend, were not statistically different. Moreover, RNA and immunofluorescence analysis showed impaired sphingosine-1-phosphate (S1P) synthesis and signaling in PE vessels. Our data reveal that the exposure to a deranged maternal intrauterine environment during PE alters the sphingolipid signature and gene expression on the fetal side of the placental vasculature. This pathological remodeling consists in increased serine palmitoyltransferase (SPT) activity and SM accrual in PE chorionic arteries, with concomitance impairment endothelial S1P signaling in the endothelium of these vessels. The increase of endothelial S1P phosphatase, lyase and S1PR2, and blunted S1PR1 expression support the onset of the pathological phenotype in chorionic arteries.


Assuntos
Feto/metabolismo , Troca Materno-Fetal/fisiologia , Placenta/metabolismo , Circulação Placentária/fisiologia , Pré-Eclâmpsia/metabolismo , Esfingolipídeos/metabolismo , Artérias/metabolismo , Artérias/fisiopatologia , Ceramidas/metabolismo , Córion/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/fisiologia , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Feto/fisiopatologia , Expressão Gênica/fisiologia , Humanos , Lisofosfolipídeos/metabolismo , Placenta/fisiologia , Pré-Eclâmpsia/fisiopatologia , Gravidez , Transdução de Sinais/fisiologia , Esfingomielinas/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo
20.
Clin Sci (Lond) ; 134(5): 439-458, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32091078

RESUMO

Sphingolipids have been implicated in the etiology of atherosclerosis. The commonly used sphingolipid inhibitors, myriocin (a ceramide inhibitor) and d-PDMP (d-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol, a glycosphingolipid inhibitor), have shown therapeutic potential but their efficacy and their underlying mechanisms remain unclear. Here, apolipoprotein E-deficient (apoE-/-) mice were fed a high-fat diet (HFD) and treated with a control, myriocin, d-PDMP, or atorvastatin for 12 weeks. We analyzed the effects of these drugs on the size and detailed composition of atherosclerotic plaques. Molecular biological approaches were used to explore how the inhibitors affect lipid metabolism and foam-cell formation. Treatment with myriocin or d-PDMP led to smaller and less vulnerable atherosclerotic lesions and was almost as effective as atorvastatin. Sphingolipid inhibitors down-regulated the expression of monocyte chemotactic protein 1 (MCP-1) and its receptor chemoattractant cytokine receptor 2 (CCR2), which play a key role in monocyte recruitment. They also decreased pro-inflammatory Ly-6chigh monocytes and influenced the uptake of modified LDL by down-regulating the expression of cluster of differentiation 36 (CD36) and lectin-like oxidized LDL (ox-LDL) receptor-1 (LOX-1). The inhibitors exhibited the advantage of maintaining normal glucose homeostasis compared with atorvastatin. These findings reveal for the first time that the modulation of sphingolipid synthesis can effectively alleviate atherosclerosis progression by preventing lipid uptake and reducing inflammatory responses in the arterial walls.


Assuntos
Apolipoproteínas E/deficiência , Aterosclerose/prevenção & controle , Ácidos Graxos Monoinsaturados/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Morfolinas/farmacologia , Vasculite/prevenção & controle , Animais , Anticolesterolemiantes/farmacologia , Apolipoproteínas E/genética , Aterosclerose/metabolismo , Atorvastatina/farmacologia , Transporte Biológico/efeitos dos fármacos , Ceramidas/antagonistas & inibidores , Ceramidas/metabolismo , Glicoesfingolipídeos/antagonistas & inibidores , Glicoesfingolipídeos/metabolismo , Imunossupressores/farmacologia , Lipídeos/sangue , Lipídeos/farmacocinética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Placa Aterosclerótica/prevenção & controle , Vasculite/metabolismo
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