Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphing...Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphingolipids and their metabolic enzymes are associated with a variety of human diseases.Moreover,blood sphingolipids can also be used as biomarkers for disease diagnosis.This review summarizes the biosynthesis,metabolism,and pathological roles of sphingolipids,with emphasis on the biosynthesis of ceramide,the precursor for the biosynthesis of complex sphingolipids with different fatty acyl chains.The possibility of using sphingolipids for disease prediction,diagnosis,and treatment is also discussed.Targeting endogenous ceramides and complex sphingolipids along with their specific fatty acyl chain to promote future drug development will also be discussed.展开更多
A set of three sphingolipids, N-2′-hydroxyplmitoyl-1-O-β-D-glucopyranosyl-9-methyl-4E, 8E-sphingadiene （A）, N-2′-hydroxyl-3′E-octadecenoyl-1-O-β-D-glucopyranosyl-9-methyl-4E, 8E-sphingediene （B） and N-palmito...A set of three sphingolipids, N-2′-hydroxyplmitoyl-1-O-β-D-glucopyranosyl-9-methyl-4E, 8E-sphingadiene （A）, N-2′-hydroxyl-3′E-octadecenoyl-1-O-β-D-glucopyranosyl-9-methyl-4E, 8E-sphingediene （B） and N-palmitoyldihydrosphingosine （C）, were isolated from two marine-derived mangrove endophytic fungal strains （strains No. 1924 and 3893） from the South China Sea. Their structures were elucidated by 2D NMR and FABMS methods. It is the first time that these sphingolipids were separated and obtained from marine-derived mangrove endophytic fungus from the South China Sea.展开更多
Objective:Cholangiocarcinoma(CCA)is a rare but highly malignant hepatobiliary cancer with a very poor prognosis and limited treatment options.CCA is commonly associated with chronic cholestasis and significantly eleva...Objective:Cholangiocarcinoma(CCA)is a rare but highly malignant hepatobiliary cancer with a very poor prognosis and limited treatment options.CCA is commonly associated with chronic cholestasis and significantly elevated levels of primary and conjugated bile acids(CBAs),which are correlated with bile duct obstruction.展开更多
The sphingolipid metabolites ceramide,sphingosine,and sphingosine-1-phosphate(S1P) and its enzyme sphingosine kinase(SphK) play an important role in the regulation of cell proliferation,survival,inflammation,and cell ...The sphingolipid metabolites ceramide,sphingosine,and sphingosine-1-phosphate(S1P) and its enzyme sphingosine kinase(SphK) play an important role in the regulation of cell proliferation,survival,inflammation,and cell death.Ceramide and sphingosine usually inhibit proliferation and promote apoptosis,while its metabolite S1P phosphorylated by SphK stimulates growth and suppresses apoptosis.Because these metabolites are interconvertible,it has been proposed that it is not the absolute amounts of these metabolites but rather their relative levels that determine cell fate.The relevance of this "sphingolipid rheostat" and its role in regulating cell fate has been borne out by work in many labs using many different cell types and experimental manipulations.A central finding of these studies is that SphK is a critical regulator of the sphingolipid rheostat,as it not only produces the pro-growth,anti-apoptotic messenger S1P,but also decreases levels of pro-apoptotic ceramide and sphingosine.Activation of bioactive sphingolipid S1P signaling has emerged as a critical protective pathway in response to acute ischemic injury in both cardiac and cerebrovascular disease,and these observations have considerable relevance for future potential therapeutic targets.展开更多
Synapses are key structures involved in transmitting information in the nervous system,and their functions rely on the regulation of various lipids.Lipids play important roles in synapse formation,neurotransmitter rel...Synapses are key structures involved in transmitting information in the nervous system,and their functions rely on the regulation of various lipids.Lipids play important roles in synapse formation,neurotransmitter release,and signal transmission,and dysregulation of lipid metabolism is closely associated with various neurodegenerative diseases.The complex roles of lipids in synaptic function and neurological diseases have recently garnered increasing attention,but their specific mechanisms remain to be fully understood.This review aims to explore how lipids regulate synaptic activity in the central nervous system,focusing on their roles in synapse formation,neurotransmitter release,and signal transmission.Additionally,it discusses the mechanisms by which glial cells modulate synaptic function through lipid regulation.This review shows that within the central nervous system,lipids are essential components of the cell membrane bilayer,playing critical roles in synaptic structure and function.They regulate presynaptic vesicular trafficking,postsynaptic signaling pathways,and glial-neuronal interactions.Cholesterol maintains membrane fluidity and promotes the formation of lipid rafts.Glycerophospholipids contribute to the structural integrity of synaptic membranes and are involved in the release of synaptic vesicles.Sphingolipids interact with synaptic receptors through various mechanisms to regulate their activity and are also involved in cellular processes such as inflammation and apoptosis.Fatty acids are vital for energy metabolism and the synthesis of signaling molecules.Abnormalities in lipid metabolism may lead to impairments in synaptic function,affecting information transmission between neurons and the overall health of the nervous system.Therapeutic strategies targeting lipid metabolism,particularly through cholesterol modulation,show promise for treating these conditions.In neurodegenerative diseases such as Alzheimer’s disease,Parkinson disease,and amyotrophic lateral sclerosis,dysregulation of lipid metabolism is closely linked to synaptic dysfunction.Therefore,lipids are not only key molecules in neural regeneration and synaptic repair but may also contribute to neurodegenerative pathology when metabolic dysregulation occurs.Further research is needed to elucidate the specific mechanisms linking lipid metabolism to synaptic dysfunction and to develop targeted lipid therapies for neurological diseases.展开更多
Sphingolipids are not only a pivotal component of membranes but also act as bioactive molecules.Cotton fiber is one of the longest plant cells and sphingolipids are closely associated with the development of cotton fi...Sphingolipids are not only a pivotal component of membranes but also act as bioactive molecules.Cotton fiber is one of the longest plant cells and sphingolipids are closely associated with the development of cotton fiber cells.However,their function in cotton fiber cell development and its action mechanism is unclear.Through cotton genetic transformation and chemistry biological approach,we identified the function and action mechanism of the glucosylceramide synthase gene GhGCS1 and its product glucosylceramide(GluCer)in cotton fiber growth.GhGCS1 was preferentially expressed at the stage of fiber elongation and localized in the endoplasmic reticulum.Overexpression of GhGCS1 promoted GluCer synthesis and fiber elongation,which was consistent with the exogenous application of GluCer(FA-C22)(containing very long-acyl-chain fatty acid)to cotton fiber in ovule culture system in vitro.Contrarily,suppressing GhGCS1 expression inhibited GluCer synthesis and fiber elongation,which was similar as the exogenous application of GluCer synthesis inhibitor,PDMP.Transcriptome analysis revealed that the fiber elongation regulated by GhGCS1 was associated with brassinosteroid(BR)synthesis and signaling related gene expression.Meanwhile,we detected the BL content of control and transgenic fiber cells.The BL content significantly increased and decreased in up-and down-regulated transgenic fibers when compared with control fibers,respectively.Furthermore,we found that PDMP treatment blocked BR synthesis and signal transduction,while exogenous application of GluCer could enhance BR synthesis and signaling.Overall,our results revealed that GhGCS1 and GluCer regulated cotton fiber elongation by influencing BR synthesis and signaling.Our study shed a novel insight on regulatory mechanism of cotton fiber elongation and provides theoretical support,genetic resources and novel transgenic materials for improvement of crop quality.展开更多
Background Hepatic ischemia-reperfusion （I/R） injury occurs in many clinical procedures. The molecular mechanisms responsible for hepatic I/R injury however remain unknown. Sphingolipids, in particular ceramide, pla...Background Hepatic ischemia-reperfusion （I/R） injury occurs in many clinical procedures. The molecular mechanisms responsible for hepatic I/R injury however remain unknown. Sphingolipids, in particular ceramide, play a role in stress and death receptor-induced hepatocellular death, contributing to the progression of several liver diseases including liver I/R injury. In order to further define the role of sphingolipids in hepatic I/R, systemic analysis of sphingolipids after reperfusion is necessary. Methods We investigated the lipidomic changes of sphingolipids in a rat model of warm hepatic I/R injury, by delayed extraction matrix-assisted laser desorption ionization time-of-flight mass spectrometry （DE MALDI-TOF-MS）. Results The total amounts of ceramide and sphingomyelin and the intensity of most kinds of sphingolipids, mainly sphingomyelin, significantly increased at 1 hour after reperfusion （P 〈0.05） and reached peaks at 6 hours after reperfusion （P 〈0.01） compared to controls. Six new forms of ceramide and sphingomyelins appeared 6 hours after reperfusion, they were （m/z） 537.8, 555.7, 567.7, 583.8, 683.5 and 731.4 respectively. A ceramide-monohexoside （m/z） 804.4 （CMH（d18：1C22：1＋Na）＋） also increased after reperfusion and correlated with extent of liver injury after reperfursion. Conclusions Three main forms of sphingolipids, ceramide, sphingomyelin and ceramide-monohexoside, are related to hepatic I/R injury and provide a new perspective in understanding the mechanisms responsible for hepatic I/R injury.展开更多
A novel normal-phase UPLC-QToF MS method was developed for sphingolipids analysis,which was then applied to separate and identify seven classes of sphingolipids in plasma.The time-consuming of this novel method was mu...A novel normal-phase UPLC-QToF MS method was developed for sphingolipids analysis,which was then applied to separate and identify seven classes of sphingolipids in plasma.The time-consuming of this novel method was much shorter than previous 2D LC–MS method,while the sensitivity,repeatability and resolution for sphingolipids analysis were better or comparable.Besides,the differences of lipids in human plasma among diabetes mellitus patients,diabetes mellitus associated with atherosclerosis patients and control subjects were also compared.Finally,12 sphingolipids species were identified as the amounts of which in diabetes mellitus associated with atherosclerosis patients were significantly higher than them in diabetes mellitus patients(VIP>1.0,p value<0.05,fold change>1.5).As the isomers of GalCs and GluCs were successfully separated,it was found that five GluCs,rather than GalCs,were included in these 12 potential biomarkers.These results suggest the need to separate GalCs from GluCs,and also indicated that there may be some extra activation pathways of diabetes mellitus associated with atherosclerosis,different from the atherosclerosis pathway and the diabetes mellitus pathway,causing cardiovascular disease.展开更多
The Elongator complex is conserved in a wide range of species and plays crucial roles in diverse cellular processes.We have previously shown that the Elongator protein PoElp3 was involved in the asexual development,pa...The Elongator complex is conserved in a wide range of species and plays crucial roles in diverse cellular processes.We have previously shown that the Elongator protein PoElp3 was involved in the asexual development,pathogenicity,and autophagy of the rice blast fungus.In this study,we further revealed that PoElp3 functions via tRNA-mediated protein integrity.Phenotypic analyses revealed that overexpression of two of the tRNAs,tK(UUU)and tQ(UUG)could rescue the defects inΔPoelp3 strain.TMT-based proteomic and transcriptional analyses demonstrated that 386 proteins were down-regulated inΔPoelp3 strain compared with wild type strain Guy11,in a transcription-independent manner.Codon usage assays revealed an enrichment of Glutamine CAA-biased mRNA in the 386 proteins compared with the 70-15 genome.In addition to those reported previously,we also found that PoErp9,a sphingolipid C9-methyltransferase,was down-regulated in theΔPoelp3strain.Through an ILV2-specific integration of PoERP9-GFP into the wild type andΔPoelp3 strain,we were able to show that PoErp9 was positively regulated by PoElp3 translationally but not transcriptionally.Functional analyses revealed that PoErp9 was involved in the fungal growth,conidial development,pathogenicity,and TORrelated autophagy homeostasis in Pyricularia oryzae.Taken together,our results suggested that PoElp3 acts through the tRNA-mediated translational efficiency to regulate asexual development,pathogenicity,sphingolipid metabolism,and autophagy in the rice blast fungus.展开更多
Myalgic encephalomyelitis/chronic fatigue syndrome-an insidious disease:The recent COVID-19 pandemic has brought substantial attention to the overlapping symptoms between long COVID and myalgic encephalomyelitis/chron...Myalgic encephalomyelitis/chronic fatigue syndrome-an insidious disease:The recent COVID-19 pandemic has brought substantial attention to the overlapping symptoms between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome(ME/CFS),a chronic and poorly understood neurological disorder(Shankar et al.,2024).展开更多
Prenatal overweight/obesity(OW/OB)can alter colostrum lipid patterns,thereby affecting the lipid metabolism and even the cognitive and healthy development of infants.However,studies on changes in colostrum lipids in t...Prenatal overweight/obesity(OW/OB)can alter colostrum lipid patterns,thereby affecting the lipid metabolism and even the cognitive and healthy development of infants.However,studies on changes in colostrum lipids in the context of OW/OB are limited,particularly for glycerides and polar lipids.Therefore,this study investigated the infl uence of maternal prenatal weight on colostrum in lipid subclasses and molecular species.The concentration of triacylglycerols(TAGs)in the colostrum of the OW/OB group(35894.43 mg/L)was higher than that of the normal weight(NW)group(26639.20 mg/L),suggesting that colostrum from OW/OB mothers could provide more energy to their infants.Further analysis of the fatty acid composition of TAGs revealed that elevated maternal body weight enhanced the concentration of TAGs containing saturated or n-6 fatty acids and shortened the carbon number of TAGs.Docosahexaenoic acid(DHA)/arachidonic acid(AA)/choline-containing lipids,such as DHA-containing TAGs,AA/DHA-containing phosphatidylethanolamine,and choline-containing phospholipids,were present in higher levels in the colostrum of OW/OB mothers than NW mothers.However,the concentrations of palmitic acid-containing TAGs,linoleic acid-containing TAGs,dihomo-γ-linolenic acid-containing TAGs,and polar lipids and the ratio of TAGs containing n-6 fatty acid/n-3 fatty acid were signifi cantly higher in the colostrum of OW/OB mothers than in that of NW mothers.The fatty acid composition and sphingoid bases of sphingolipids were also altered due to elevated body weight.In conclusion,OW/OB affects colostrum lipids with respect to composition,concentration,and percentage.Although the colostrum of healthy OW/OB mothers can provide suffi cient DHA/AA/choline-containing lipids to their infants,normalization of body weight and fat reserves should be considered as a strategy for highquality human milk lipids.展开更多
BACKGROUND Hyperuricemia(HUA)is a public health concern that needs to be solved urgently.The lyophilized powder of Poecilobdella manillensis has been shown to significantly alleviate HUA;however,its underlying metabol...BACKGROUND Hyperuricemia(HUA)is a public health concern that needs to be solved urgently.The lyophilized powder of Poecilobdella manillensis has been shown to significantly alleviate HUA;however,its underlying metabolic regulation remains unclear.AIM To explore the underlying mechanisms of Poecilobdella manillensis in HUA based on modulation of the gut microbiota and host metabolism.METHODS A mouse model of rapid HUA was established using a high-purine diet and potassium oxonate injections.The mice received oral drugs or saline.Additionally,16S rRNA sequencing and ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry-based untargeted metabolomics were performed to identify changes in the microbiome and host metabolome,respectively.The levels of uric acid transporters and epithelial tight junction proteins in the renal and intestinal tissues were analyzed using an enzyme-linked immunosorbent assay.RESULTS The protein extract of Poecilobdella manillensis lyophilized powder(49 mg/kg)showed an enhanced anti-trioxypurine ability than that of allopurinol(5 mg/kg)(P<0.05).A total of nine bacterial genera were identified to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder,which included the genera of Prevotella,Delftia,Dialister,Akkermansia,Lactococcus,Escherichia_Shigella,Enterococcus,and Bacteroides.Furthermore,22 metabolites in the serum were found to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder,which correlated to the Kyoto Encyclopedia of Genes and Genomes pathways of cysteine and methionine metabolism,sphingolipid metabolism,galactose metabolism,and phenylalanine,tyrosine,and tryptophan biosynthesis.Correlation analysis found that changes in the gut microbiota were significantly related to these metabolites.CONCLUSION The proteins in Poecilobdella manillensis powder were effective for HUA.Mechanistically,they are associated with improvements in gut microbiota dysbiosis and the regulation of sphingolipid and galactose metabolism.展开更多
Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune ...Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune response,and drug sensitivity.Methods:Data were obtained from The Cancer Genome Atlas(TCGA)-Hepatocellular Carcinoma(LIHC)and Gene Expression Omnibus(GEO,GSE14520 datasets).47 sphingolipid metabolism genes were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database.After classifying HCC samples using the Non-negative Matrix Factorization(NMF)clustering method,differentially expressed genes were screened.Then,8 risk genes were obtained by univariate analysis,survival random forest reduction and lasso analysis.The expression of 8 risk genes was verified in vitro.Results:8 risk genes were used to construct the Sphingolipid score model.High-Sphingolipid score predicted poor prognosis of HCC patients.Sphingolipid score was associated with immune checkpoints(IL-1B,TLR4,TGFB1,and IL-10),immune cells(Th2,Treg,MDSC,Neutrophil,Fibroblasts and macrophage),and MAPK Cascade.In the High-Sphingolipid score group,a significantly higher proportion of patients with TP53(p53)mutations was significantly higher(56%).Furthermore,patients with a high-Sphingolipid score were predicted to have a higher sensitivity to chemotherapy drugs.In vitro validation showed that compared with normal liver cells LX-2,TRIM47,and S100A9 significantly increased in liver cancer cells Hep G2,MHCC-97H,and Hep3B2.1-7,while SLC1A7,LPCAT1,and CFHR4 significantly decreased.Silencing TRIM47 reduced the proliferation and promoted apoptosis.The levels of ceramide synthesis-related indexes(CERS1,CERS6,CERS5,and SPTLC2)increased,and the ACER3 related to catalytic hydrolysis decreased.Conclusion:We constructed a sphingolipid metabolism-related prognostic signature(Sphingolipid score)based on 8 risk genes.TRIM47 may affect the development of liver cancer by regulating the relevant indicators of ceramide synthesis and catalytic hydrolysis.展开更多
Traditional Chinese medicine has a long and illustrious history,and with the development of modern science and technology,the research and application of traditional Chinese medicines have continued to progress signif...Traditional Chinese medicine has a long and illustrious history,and with the development of modern science and technology,the research and application of traditional Chinese medicines have continued to progress significantly.Many traditional Chinese medicinal herbs have undergone scientific validation,reinvi-gorating with new life and vitality,and contributing unique strengths to the advancement of human health.Recently,the discovery that leech total protein extracted from Poecilobdella manillensis lyophilized powder reduces blood uric acid(UA)levels by inhibiting the activity of xanthine oxidase to decrease UA synthesis and promotes UA excretion by regulating different UA transporters in the kidney and intestine has undoubtedly injected new vitality and hope into this field of research.The purpose of this editorial is to comment on this study,explore its strengths and weaknesses,and there is a hope to treat a range of metabolic-related syndromes,including hyperuricemia,by targeting the gut microbiota.展开更多
Non-alcoholic fatty liver disease(NAFLD)is one of the fastest-growing diseases,and its global prevalence is estimated to increase>50%by 2030.NAFLD is comorbid with metabolic syndrome,obesity,type 2 diabetes,and ins...Non-alcoholic fatty liver disease(NAFLD)is one of the fastest-growing diseases,and its global prevalence is estimated to increase>50%by 2030.NAFLD is comorbid with metabolic syndrome,obesity,type 2 diabetes,and insulin resistance.Despite extensive research efforts,there are no pharmacologic or biological therapeutics for the treatment of NAFLD.Bile acids and sphingolipids are well-characterized signaling molecules.Over the last few decades,researchers have uncovered potential mechanisms by which bile acids and sphingolipids regulate hepatic lipid metabolism.Dysregulation of bile acid and sphingolipid metabolism has been linked to steatosis,inflammation,and fibrosis in patients with NAFLD.This clinical observation has been recapitulated in animal models,which are well-accepted by experts in the hepatology field.Recent transcriptomic and lipidomic studies also show that sphingolipids are important players in the pathogenesis of NAFLD.Moreover,the identification of bile acids as activators of sphingolipid-mediated signaling pathways established a novel theory for bile acid and sphingolipid biology.In this review,we summarize the recent advances in the understanding of bile acid and sphingolipid-mediated signaling pathways as potential contributors to NAFLD.A better understanding of the pathologic effects mediated by bile acids and sphingolipids will facilitate the development of new diagnostic and therapeutic strategies for NAFLD.展开更多
Sphingolipids have been suggested to act as second messengers for an array of cellular signaling activities in plant cells, including stress responses and programmed cell death （PCD）. However, the mechanisms underpi...Sphingolipids have been suggested to act as second messengers for an array of cellular signaling activities in plant cells, including stress responses and programmed cell death （PCD）. However, the mechanisms underpinning these processes are not well understood. Here, we report that an Arabidopsis mutant, fumonisin B1 r_esistant11-1 （/br11-1）, which fails to generate reactive oxygen intermediates （ROIs）, is incapable of initiating PCD when the mutant is challenged by fumonisin B l （FB0, a specific inhibitor of ceramide synthase. Molecular analysis indicated that FBR11 encodes a long-chain base 1 （LCB 1） subunit of serine palmitoyltransferase （SPT）, which catalyzes the first rate-limiting step of de novo sphingolipid synthesis. Mass spectrometric analysis of the sphingolipid concentrations revealed that whereas the fbr11-1 mutation did not affect basal levels of sphingoid bases, the mutant showed attenuated formation of sphingoid bases in response to FBl. By a direct feeding experiment, we show that the free sphingoid bases dihydrosphingosine, phytosphingosine and sphingosine efficiently induce ROI generation followed by cell death. Conversely, ROI generation and cell death induced by dihydrosphingosine were specifically blocked by its phosphorylated form dihydrosphingosine- 1-phosphate in a dosedependent manner, suggesting that the maintenance of homeostasis between a free sphingoid base and its phosphorylated derivative is critical to determining the cell fate. Because alterations of the sphingolipid level occur prior to the ROI production, we propose that the free sphingoid bases are involved in the control of PCD in Arabidopsis, presumably through the regulation of the ROI level upon receiving different developmental or environmental cues.展开更多
Lipid dysmetabolism is one of the main features of diabetes mellitus and manifests by dyslipidemia as well as the ectopic accumulation of lipids in various tissues and organs,including the kidney.Research suggests tha...Lipid dysmetabolism is one of the main features of diabetes mellitus and manifests by dyslipidemia as well as the ectopic accumulation of lipids in various tissues and organs,including the kidney.Research suggests that impaired cholesterol metabolism,increased lipid uptake or synthesis,increased fatty acid oxidation,lipid droplet accumulation and an imbalance in biologically active sphingolipids(such as ceramide,ceramide-1-phosphate and sphingosine-1-phosphate)contribute to the development of diabetic kidney disease(DKD).Currently,the literature suggests that both quality and quantity of lipids are associated with DKD and contribute to increased reactive oxygen species production,oxidative stress,inflammation,or cell death.Therefore,control of renal lipid dysmetabolism is a very important therapeutic goal,which needs to be archived.This article will review some of the recent advances leading to a better understanding of the mechanisms of dyslipidemia and the role of particular lipids and sphingolipids in DKD.展开更多
Sphingosine-1-phosphate (S1P) is a bioactive sphingo-lipid that has been implicated in regulation of a number of cancer cell malignant behaviors, including cell proliferation, survival, chemotherapeutic resistance and...Sphingosine-1-phosphate (S1P) is a bioactive sphingo-lipid that has been implicated in regulation of a number of cancer cell malignant behaviors, including cell proliferation, survival, chemotherapeutic resistance and angiogenesis. However, the effects of S1P on cancer cell migration, invasion and metastasis, are perhaps its most complex, due to the fact that, depending upon the S1P receptors that mediate its responses and the crosstalk with other signaling pathways, S1P can either positively or negatively regulate invasion. This review summarizes the effects of S1P on cancer cell invasion and the mechanisms by which it affects this important aspect of cancer cell behavior.展开更多
Balanced sphingolipid signaling is important for the maintenance of homeostasis. Sphingolipids were demonstrated to function as structural components, second messengers, and regulators of cell growth and survival in n...Balanced sphingolipid signaling is important for the maintenance of homeostasis. Sphingolipids were demonstrated to function as structural components, second messengers, and regulators of cell growth and survival in normal and disease-affected tissues. Particularly, sphingosine kinase 1 (SphK1) and its product sphingosine-1-phosphate (S1P) operate as mediators and facilitators of proliferation-linked signaling. Unlimited proliferation (selfrenewal) within the regulated environment is a hallmark of progenitor/stem cells that was recently associated with the S1P signaling network in vasculature, nervous,muscular, and immune systems. S1P was shown to regulate progenitor-related characteristics in normal and cancerstemcells(CSCs) viaG-protein coupled receptorsS1Pn(n=1 to 5). The SphK/S1P axis is crucially involved in the regulation of embryonic development of vasculature and the nervous system, hematopoietic stem cell migration, regeneration of skeletal muscle, and development of multiple sclerosis. The ratio of the S1P receptor expression, localization, and specific S1P receptoractivated downstream effectors influenced the rate of selfrenewal and should be further explored as regeneration related targets. Considering malignant transformation,it is essential to control the level of self-renewal capacity.Proliferation of the progenitor cell should be synchronized with differentiation to provide healthy lifelong function of blood, immune systems, and replacement of damaged ordead cells. The differentiation-related role of SphK/S1P remains poorly assessed. A few pioneering investigations exploredpharmacologicaltoolsthattargetsphingolipid signaling and can potentially confine and direct self-renewal towards normal differentiation. Further investigation is required to test the role of the SphK/S1P axis in regulation of self-renewal and differentiation.展开更多
The genetic variants of orosomucoid-like protein 3(ORMDL3)gene are associated with highly significant increases in the number of human rhinovirus(HRV)-induced wheezing episodes in children.Recent investigations have b...The genetic variants of orosomucoid-like protein 3(ORMDL3)gene are associated with highly significant increases in the number of human rhinovirus(HRV)-induced wheezing episodes in children.Recent investigations have been focused on the mechanisms of ORMDL3 in rhinovirus infection for asthma and asthma exacerbations.ORMDL3 not only regulates major human rhinovirus receptor intercellular adhesion molecule 1 expression,but also plays pivotal roles in viral infection through metabolisms of ceramide and sphingosine-1-phosphate,endoplasmic reticulum(ER)stress,ER-Golgi interface and glycolysis.Research on the roles of ORMDL3 in HRV infection will lead us to identify new biomarkers and novel therapeutic targets in childhood asthma and viral induced asthma exacerbations.展开更多
基金supported by grants from National Key R&D Program of China(2018YFA0506900,2018YFA0800901)the National Natural Science Foundation of China(NSFC92057202)the Chinese Academy of Sciences(XDB39050900).
文摘Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphingolipids and their metabolic enzymes are associated with a variety of human diseases.Moreover,blood sphingolipids can also be used as biomarkers for disease diagnosis.This review summarizes the biosynthesis,metabolism,and pathological roles of sphingolipids,with emphasis on the biosynthesis of ceramide,the precursor for the biosynthesis of complex sphingolipids with different fatty acyl chains.The possibility of using sphingolipids for disease prediction,diagnosis,and treatment is also discussed.Targeting endogenous ceramides and complex sphingolipids along with their specific fatty acyl chain to promote future drug development will also be discussed.
基金the National ＂863＂ Program of China （No. 2001AA624010）the Guangdong Provincial Natural Science Foundation of China （No. 04300674）+1 种基金 the Guangdong Provincial Science and Technology Program Foundation of China （No.2004B30101017） the Foshan City Foundation for the Development of Science and Technology （No. 2005081871）.
文摘A set of three sphingolipids, N-2′-hydroxyplmitoyl-1-O-β-D-glucopyranosyl-9-methyl-4E, 8E-sphingadiene （A）, N-2′-hydroxyl-3′E-octadecenoyl-1-O-β-D-glucopyranosyl-9-methyl-4E, 8E-sphingediene （B） and N-palmitoyldihydrosphingosine （C）, were isolated from two marine-derived mangrove endophytic fungal strains （strains No. 1924 and 3893） from the South China Sea. Their structures were elucidated by 2D NMR and FABMS methods. It is the first time that these sphingolipids were separated and obtained from marine-derived mangrove endophytic fungus from the South China Sea.
文摘Objective:Cholangiocarcinoma(CCA)is a rare but highly malignant hepatobiliary cancer with a very poor prognosis and limited treatment options.CCA is commonly associated with chronic cholestasis and significantly elevated levels of primary and conjugated bile acids(CBAs),which are correlated with bile duct obstruction.
基金Supported by Grants from the National Institutes of Health (NS40516,to Yenari MA)the Veteran's Merit Award(Yenari MA)+3 种基金the Uehara Foundation(2013 Research Fellowship,to Kawabori M)the National Heart,Lung,and Blood Institute/NHLBI(1P01 HL 68738 and R01 HL 090606 to Karliner JS)Grants to Yenari MA and Karliner JS were administered by the Northern California Institute for Research and Educationsupported by resources of the Veterans Affairs Medical Center, San Francisco,California
文摘The sphingolipid metabolites ceramide,sphingosine,and sphingosine-1-phosphate(S1P) and its enzyme sphingosine kinase(SphK) play an important role in the regulation of cell proliferation,survival,inflammation,and cell death.Ceramide and sphingosine usually inhibit proliferation and promote apoptosis,while its metabolite S1P phosphorylated by SphK stimulates growth and suppresses apoptosis.Because these metabolites are interconvertible,it has been proposed that it is not the absolute amounts of these metabolites but rather their relative levels that determine cell fate.The relevance of this "sphingolipid rheostat" and its role in regulating cell fate has been borne out by work in many labs using many different cell types and experimental manipulations.A central finding of these studies is that SphK is a critical regulator of the sphingolipid rheostat,as it not only produces the pro-growth,anti-apoptotic messenger S1P,but also decreases levels of pro-apoptotic ceramide and sphingosine.Activation of bioactive sphingolipid S1P signaling has emerged as a critical protective pathway in response to acute ischemic injury in both cardiac and cerebrovascular disease,and these observations have considerable relevance for future potential therapeutic targets.
基金supported by the National Natural Science Foundation of China,No.82201568(to QQ)Capital’s Funds for Health Improvement and Research,No.2024-2-1031(to QQ)Beijing Nova Program,No.20240484566(to QQ).
文摘Synapses are key structures involved in transmitting information in the nervous system,and their functions rely on the regulation of various lipids.Lipids play important roles in synapse formation,neurotransmitter release,and signal transmission,and dysregulation of lipid metabolism is closely associated with various neurodegenerative diseases.The complex roles of lipids in synaptic function and neurological diseases have recently garnered increasing attention,but their specific mechanisms remain to be fully understood.This review aims to explore how lipids regulate synaptic activity in the central nervous system,focusing on their roles in synapse formation,neurotransmitter release,and signal transmission.Additionally,it discusses the mechanisms by which glial cells modulate synaptic function through lipid regulation.This review shows that within the central nervous system,lipids are essential components of the cell membrane bilayer,playing critical roles in synaptic structure and function.They regulate presynaptic vesicular trafficking,postsynaptic signaling pathways,and glial-neuronal interactions.Cholesterol maintains membrane fluidity and promotes the formation of lipid rafts.Glycerophospholipids contribute to the structural integrity of synaptic membranes and are involved in the release of synaptic vesicles.Sphingolipids interact with synaptic receptors through various mechanisms to regulate their activity and are also involved in cellular processes such as inflammation and apoptosis.Fatty acids are vital for energy metabolism and the synthesis of signaling molecules.Abnormalities in lipid metabolism may lead to impairments in synaptic function,affecting information transmission between neurons and the overall health of the nervous system.Therapeutic strategies targeting lipid metabolism,particularly through cholesterol modulation,show promise for treating these conditions.In neurodegenerative diseases such as Alzheimer’s disease,Parkinson disease,and amyotrophic lateral sclerosis,dysregulation of lipid metabolism is closely linked to synaptic dysfunction.Therefore,lipids are not only key molecules in neural regeneration and synaptic repair but may also contribute to neurodegenerative pathology when metabolic dysregulation occurs.Further research is needed to elucidate the specific mechanisms linking lipid metabolism to synaptic dysfunction and to develop targeted lipid therapies for neurological diseases.
基金funded by the National Natural Science Foundation of China(32372114,31971984)the Special Fund for Youth Team of the Southwest Universities(SWU-XJPY202306)+1 种基金the Chongqing Graduate Scientific Research Innovation Project(CYS23239)the Genetically Modified Organisms Breeding Major Project of China(2018ZX0800921B)。
文摘Sphingolipids are not only a pivotal component of membranes but also act as bioactive molecules.Cotton fiber is one of the longest plant cells and sphingolipids are closely associated with the development of cotton fiber cells.However,their function in cotton fiber cell development and its action mechanism is unclear.Through cotton genetic transformation and chemistry biological approach,we identified the function and action mechanism of the glucosylceramide synthase gene GhGCS1 and its product glucosylceramide(GluCer)in cotton fiber growth.GhGCS1 was preferentially expressed at the stage of fiber elongation and localized in the endoplasmic reticulum.Overexpression of GhGCS1 promoted GluCer synthesis and fiber elongation,which was consistent with the exogenous application of GluCer(FA-C22)(containing very long-acyl-chain fatty acid)to cotton fiber in ovule culture system in vitro.Contrarily,suppressing GhGCS1 expression inhibited GluCer synthesis and fiber elongation,which was similar as the exogenous application of GluCer synthesis inhibitor,PDMP.Transcriptome analysis revealed that the fiber elongation regulated by GhGCS1 was associated with brassinosteroid(BR)synthesis and signaling related gene expression.Meanwhile,we detected the BL content of control and transgenic fiber cells.The BL content significantly increased and decreased in up-and down-regulated transgenic fibers when compared with control fibers,respectively.Furthermore,we found that PDMP treatment blocked BR synthesis and signal transduction,while exogenous application of GluCer could enhance BR synthesis and signaling.Overall,our results revealed that GhGCS1 and GluCer regulated cotton fiber elongation by influencing BR synthesis and signaling.Our study shed a novel insight on regulatory mechanism of cotton fiber elongation and provides theoretical support,genetic resources and novel transgenic materials for improvement of crop quality.
基金This work was supported partly by grants from the National Natural Science Foundation of China （No. 30772054 and No. 30672071）.
文摘Background Hepatic ischemia-reperfusion （I/R） injury occurs in many clinical procedures. The molecular mechanisms responsible for hepatic I/R injury however remain unknown. Sphingolipids, in particular ceramide, play a role in stress and death receptor-induced hepatocellular death, contributing to the progression of several liver diseases including liver I/R injury. In order to further define the role of sphingolipids in hepatic I/R, systemic analysis of sphingolipids after reperfusion is necessary. Methods We investigated the lipidomic changes of sphingolipids in a rat model of warm hepatic I/R injury, by delayed extraction matrix-assisted laser desorption ionization time-of-flight mass spectrometry （DE MALDI-TOF-MS）. Results The total amounts of ceramide and sphingomyelin and the intensity of most kinds of sphingolipids, mainly sphingomyelin, significantly increased at 1 hour after reperfusion （P 〈0.05） and reached peaks at 6 hours after reperfusion （P 〈0.01） compared to controls. Six new forms of ceramide and sphingomyelins appeared 6 hours after reperfusion, they were （m/z） 537.8, 555.7, 567.7, 583.8, 683.5 and 731.4 respectively. A ceramide-monohexoside （m/z） 804.4 （CMH（d18：1C22：1＋Na）＋） also increased after reperfusion and correlated with extent of liver injury after reperfursion. Conclusions Three main forms of sphingolipids, ceramide, sphingomyelin and ceramide-monohexoside, are related to hepatic I/R injury and provide a new perspective in understanding the mechanisms responsible for hepatic I/R injury.
基金the National Key R&D Program of China(2017YFC0906800)National Natural Science Foundation of China(Grant nos.21527809 and 21175005).
文摘A novel normal-phase UPLC-QToF MS method was developed for sphingolipids analysis,which was then applied to separate and identify seven classes of sphingolipids in plasma.The time-consuming of this novel method was much shorter than previous 2D LC–MS method,while the sensitivity,repeatability and resolution for sphingolipids analysis were better or comparable.Besides,the differences of lipids in human plasma among diabetes mellitus patients,diabetes mellitus associated with atherosclerosis patients and control subjects were also compared.Finally,12 sphingolipids species were identified as the amounts of which in diabetes mellitus associated with atherosclerosis patients were significantly higher than them in diabetes mellitus patients(VIP>1.0,p value<0.05,fold change>1.5).As the isomers of GalCs and GluCs were successfully separated,it was found that five GluCs,rather than GalCs,were included in these 12 potential biomarkers.These results suggest the need to separate GalCs from GluCs,and also indicated that there may be some extra activation pathways of diabetes mellitus associated with atherosclerosis,different from the atherosclerosis pathway and the diabetes mellitus pathway,causing cardiovascular disease.
基金supported by National Natural Science Foundation of China(32172365 and 32272513)the Central Guidance on Local Science and Technology Development Fund of Fujian Province,China(2022L3088)the Innovative Research Funding of Fujian Agriculture and Forestry University,China(CXZX2020153D)。
文摘The Elongator complex is conserved in a wide range of species and plays crucial roles in diverse cellular processes.We have previously shown that the Elongator protein PoElp3 was involved in the asexual development,pathogenicity,and autophagy of the rice blast fungus.In this study,we further revealed that PoElp3 functions via tRNA-mediated protein integrity.Phenotypic analyses revealed that overexpression of two of the tRNAs,tK(UUU)and tQ(UUG)could rescue the defects inΔPoelp3 strain.TMT-based proteomic and transcriptional analyses demonstrated that 386 proteins were down-regulated inΔPoelp3 strain compared with wild type strain Guy11,in a transcription-independent manner.Codon usage assays revealed an enrichment of Glutamine CAA-biased mRNA in the 386 proteins compared with the 70-15 genome.In addition to those reported previously,we also found that PoErp9,a sphingolipid C9-methyltransferase,was down-regulated in theΔPoelp3strain.Through an ILV2-specific integration of PoERP9-GFP into the wild type andΔPoelp3 strain,we were able to show that PoErp9 was positively regulated by PoElp3 translationally but not transcriptionally.Functional analyses revealed that PoErp9 was involved in the fungal growth,conidial development,pathogenicity,and TORrelated autophagy homeostasis in Pyricularia oryzae.Taken together,our results suggested that PoElp3 acts through the tRNA-mediated translational efficiency to regulate asexual development,pathogenicity,sphingolipid metabolism,and autophagy in the rice blast fungus.
基金supported by the Judith Jane Mason and Harold Stannett Williams Memorial Foundation National Medical Program(#Mason2210)to JX。
文摘Myalgic encephalomyelitis/chronic fatigue syndrome-an insidious disease:The recent COVID-19 pandemic has brought substantial attention to the overlapping symptoms between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome(ME/CFS),a chronic and poorly understood neurological disorder(Shankar et al.,2024).
基金supported by the Guangxi Science and Technology Project (AD20297088)the National Natural Science Foundation of China (32272316)the Beijing Innovation Team of Livestock Industry Technology System (BAIC05-2022)
文摘Prenatal overweight/obesity(OW/OB)can alter colostrum lipid patterns,thereby affecting the lipid metabolism and even the cognitive and healthy development of infants.However,studies on changes in colostrum lipids in the context of OW/OB are limited,particularly for glycerides and polar lipids.Therefore,this study investigated the infl uence of maternal prenatal weight on colostrum in lipid subclasses and molecular species.The concentration of triacylglycerols(TAGs)in the colostrum of the OW/OB group(35894.43 mg/L)was higher than that of the normal weight(NW)group(26639.20 mg/L),suggesting that colostrum from OW/OB mothers could provide more energy to their infants.Further analysis of the fatty acid composition of TAGs revealed that elevated maternal body weight enhanced the concentration of TAGs containing saturated or n-6 fatty acids and shortened the carbon number of TAGs.Docosahexaenoic acid(DHA)/arachidonic acid(AA)/choline-containing lipids,such as DHA-containing TAGs,AA/DHA-containing phosphatidylethanolamine,and choline-containing phospholipids,were present in higher levels in the colostrum of OW/OB mothers than NW mothers.However,the concentrations of palmitic acid-containing TAGs,linoleic acid-containing TAGs,dihomo-γ-linolenic acid-containing TAGs,and polar lipids and the ratio of TAGs containing n-6 fatty acid/n-3 fatty acid were signifi cantly higher in the colostrum of OW/OB mothers than in that of NW mothers.The fatty acid composition and sphingoid bases of sphingolipids were also altered due to elevated body weight.In conclusion,OW/OB affects colostrum lipids with respect to composition,concentration,and percentage.Although the colostrum of healthy OW/OB mothers can provide suffi cient DHA/AA/choline-containing lipids to their infants,normalization of body weight and fat reserves should be considered as a strategy for highquality human milk lipids.
基金Supported by National Natural Science Foundation of China,No.82160843.
文摘BACKGROUND Hyperuricemia(HUA)is a public health concern that needs to be solved urgently.The lyophilized powder of Poecilobdella manillensis has been shown to significantly alleviate HUA;however,its underlying metabolic regulation remains unclear.AIM To explore the underlying mechanisms of Poecilobdella manillensis in HUA based on modulation of the gut microbiota and host metabolism.METHODS A mouse model of rapid HUA was established using a high-purine diet and potassium oxonate injections.The mice received oral drugs or saline.Additionally,16S rRNA sequencing and ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry-based untargeted metabolomics were performed to identify changes in the microbiome and host metabolome,respectively.The levels of uric acid transporters and epithelial tight junction proteins in the renal and intestinal tissues were analyzed using an enzyme-linked immunosorbent assay.RESULTS The protein extract of Poecilobdella manillensis lyophilized powder(49 mg/kg)showed an enhanced anti-trioxypurine ability than that of allopurinol(5 mg/kg)(P<0.05).A total of nine bacterial genera were identified to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder,which included the genera of Prevotella,Delftia,Dialister,Akkermansia,Lactococcus,Escherichia_Shigella,Enterococcus,and Bacteroides.Furthermore,22 metabolites in the serum were found to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder,which correlated to the Kyoto Encyclopedia of Genes and Genomes pathways of cysteine and methionine metabolism,sphingolipid metabolism,galactose metabolism,and phenylalanine,tyrosine,and tryptophan biosynthesis.Correlation analysis found that changes in the gut microbiota were significantly related to these metabolites.CONCLUSION The proteins in Poecilobdella manillensis powder were effective for HUA.Mechanistically,they are associated with improvements in gut microbiota dysbiosis and the regulation of sphingolipid and galactose metabolism.
基金The work was supported by funds from The Science and Technology Project of Hangzhou City(Agriculture and Social Development,No.2016007)&(Agriculture and Social Development,No.20201231Y131)&(Social Development,No.20140633B57)The Science and Technology Project of Yuhang District,Hangzhou City(Nos.2017002&2014003)+2 种基金The Health Science and Technology Project of Hangzhou City(No.2015B32)Zhejiang Provincial Natural Science Foundation of China under Grant(No.LTGY23H160006)The Health Science and Technology Project of Zhejiang Province(No.2023XY009).
文摘Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune response,and drug sensitivity.Methods:Data were obtained from The Cancer Genome Atlas(TCGA)-Hepatocellular Carcinoma(LIHC)and Gene Expression Omnibus(GEO,GSE14520 datasets).47 sphingolipid metabolism genes were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database.After classifying HCC samples using the Non-negative Matrix Factorization(NMF)clustering method,differentially expressed genes were screened.Then,8 risk genes were obtained by univariate analysis,survival random forest reduction and lasso analysis.The expression of 8 risk genes was verified in vitro.Results:8 risk genes were used to construct the Sphingolipid score model.High-Sphingolipid score predicted poor prognosis of HCC patients.Sphingolipid score was associated with immune checkpoints(IL-1B,TLR4,TGFB1,and IL-10),immune cells(Th2,Treg,MDSC,Neutrophil,Fibroblasts and macrophage),and MAPK Cascade.In the High-Sphingolipid score group,a significantly higher proportion of patients with TP53(p53)mutations was significantly higher(56%).Furthermore,patients with a high-Sphingolipid score were predicted to have a higher sensitivity to chemotherapy drugs.In vitro validation showed that compared with normal liver cells LX-2,TRIM47,and S100A9 significantly increased in liver cancer cells Hep G2,MHCC-97H,and Hep3B2.1-7,while SLC1A7,LPCAT1,and CFHR4 significantly decreased.Silencing TRIM47 reduced the proliferation and promoted apoptosis.The levels of ceramide synthesis-related indexes(CERS1,CERS6,CERS5,and SPTLC2)increased,and the ACER3 related to catalytic hydrolysis decreased.Conclusion:We constructed a sphingolipid metabolism-related prognostic signature(Sphingolipid score)based on 8 risk genes.TRIM47 may affect the development of liver cancer by regulating the relevant indicators of ceramide synthesis and catalytic hydrolysis.
文摘Traditional Chinese medicine has a long and illustrious history,and with the development of modern science and technology,the research and application of traditional Chinese medicines have continued to progress significantly.Many traditional Chinese medicinal herbs have undergone scientific validation,reinvi-gorating with new life and vitality,and contributing unique strengths to the advancement of human health.Recently,the discovery that leech total protein extracted from Poecilobdella manillensis lyophilized powder reduces blood uric acid(UA)levels by inhibiting the activity of xanthine oxidase to decrease UA synthesis and promotes UA excretion by regulating different UA transporters in the kidney and intestine has undoubtedly injected new vitality and hope into this field of research.The purpose of this editorial is to comment on this study,explore its strengths and weaknesses,and there is a hope to treat a range of metabolic-related syndromes,including hyperuricemia,by targeting the gut microbiota.
基金supported by Department of Veteran Affairs Merit Award(No.I01BX004033)Research Career Scientist Award(No.IK6BX0094477)National Institutes of Health Grant(Nos.R01 DK104893,R01DK-057543,and R21 AA026629-01)。
文摘Non-alcoholic fatty liver disease(NAFLD)is one of the fastest-growing diseases,and its global prevalence is estimated to increase>50%by 2030.NAFLD is comorbid with metabolic syndrome,obesity,type 2 diabetes,and insulin resistance.Despite extensive research efforts,there are no pharmacologic or biological therapeutics for the treatment of NAFLD.Bile acids and sphingolipids are well-characterized signaling molecules.Over the last few decades,researchers have uncovered potential mechanisms by which bile acids and sphingolipids regulate hepatic lipid metabolism.Dysregulation of bile acid and sphingolipid metabolism has been linked to steatosis,inflammation,and fibrosis in patients with NAFLD.This clinical observation has been recapitulated in animal models,which are well-accepted by experts in the hepatology field.Recent transcriptomic and lipidomic studies also show that sphingolipids are important players in the pathogenesis of NAFLD.Moreover,the identification of bile acids as activators of sphingolipid-mediated signaling pathways established a novel theory for bile acid and sphingolipid biology.In this review,we summarize the recent advances in the understanding of bile acid and sphingolipid-mediated signaling pathways as potential contributors to NAFLD.A better understanding of the pathologic effects mediated by bile acids and sphingolipids will facilitate the development of new diagnostic and therapeutic strategies for NAFLD.
基金Acknowledgments We would like to thank the Arabidopsis Biological Resources Center （Ohio State University, USA） for providing seeds and Dr Teresa Dunn （Uniformed Services University of the Health Sciences, USA） for providing yeast strains. We are grateful to Drs Weicai Yang, Yongbiao Xue （Institute of Genetics and Developmental Biology, Chinese Academy of Sciences） and De Ye （China Agriculture University） for critical reading of the manuscript. This work was supported by grants from the National Natural Science Foundation of China （30330360, 30125025 and 30221002） and the Chinese Academy of Sciences to Jianru Zuo.
文摘Sphingolipids have been suggested to act as second messengers for an array of cellular signaling activities in plant cells, including stress responses and programmed cell death （PCD）. However, the mechanisms underpinning these processes are not well understood. Here, we report that an Arabidopsis mutant, fumonisin B1 r_esistant11-1 （/br11-1）, which fails to generate reactive oxygen intermediates （ROIs）, is incapable of initiating PCD when the mutant is challenged by fumonisin B l （FB0, a specific inhibitor of ceramide synthase. Molecular analysis indicated that FBR11 encodes a long-chain base 1 （LCB 1） subunit of serine palmitoyltransferase （SPT）, which catalyzes the first rate-limiting step of de novo sphingolipid synthesis. Mass spectrometric analysis of the sphingolipid concentrations revealed that whereas the fbr11-1 mutation did not affect basal levels of sphingoid bases, the mutant showed attenuated formation of sphingoid bases in response to FBl. By a direct feeding experiment, we show that the free sphingoid bases dihydrosphingosine, phytosphingosine and sphingosine efficiently induce ROI generation followed by cell death. Conversely, ROI generation and cell death induced by dihydrosphingosine were specifically blocked by its phosphorylated form dihydrosphingosine- 1-phosphate in a dosedependent manner, suggesting that the maintenance of homeostasis between a free sphingoid base and its phosphorylated derivative is critical to determining the cell fate. Because alterations of the sphingolipid level occur prior to the ROI production, we propose that the free sphingoid bases are involved in the control of PCD in Arabidopsis, presumably through the regulation of the ROI level upon receiving different developmental or environmental cues.
基金the National Institute of Health(Research in Dr.Alessia Fornoni’s laboratory),No.R01DK117599,No.R01DK104753,No.R01CA227493,No.U54DK083912,No.UM1DK100846,and No.U01DK116101the Miami Clinical Translational Science Institute,No.UL1TR000460and the Chernowitz Medical Research Foundation(Mitrofanova A and Burke G),No.GR016291.
文摘Lipid dysmetabolism is one of the main features of diabetes mellitus and manifests by dyslipidemia as well as the ectopic accumulation of lipids in various tissues and organs,including the kidney.Research suggests that impaired cholesterol metabolism,increased lipid uptake or synthesis,increased fatty acid oxidation,lipid droplet accumulation and an imbalance in biologically active sphingolipids(such as ceramide,ceramide-1-phosphate and sphingosine-1-phosphate)contribute to the development of diabetic kidney disease(DKD).Currently,the literature suggests that both quality and quantity of lipids are associated with DKD and contribute to increased reactive oxygen species production,oxidative stress,inflammation,or cell death.Therefore,control of renal lipid dysmetabolism is a very important therapeutic goal,which needs to be archived.This article will review some of the recent advances leading to a better understanding of the mechanisms of dyslipidemia and the role of particular lipids and sphingolipids in DKD.
基金Supported by R21 CA124685 from the National Cancer InstituteR01 NS41517 from the National Institute of Neurological Disorders and Stroke
文摘Sphingosine-1-phosphate (S1P) is a bioactive sphingo-lipid that has been implicated in regulation of a number of cancer cell malignant behaviors, including cell proliferation, survival, chemotherapeutic resistance and angiogenesis. However, the effects of S1P on cancer cell migration, invasion and metastasis, are perhaps its most complex, due to the fact that, depending upon the S1P receptors that mediate its responses and the crosstalk with other signaling pathways, S1P can either positively or negatively regulate invasion. This review summarizes the effects of S1P on cancer cell invasion and the mechanisms by which it affects this important aspect of cancer cell behavior.
文摘Balanced sphingolipid signaling is important for the maintenance of homeostasis. Sphingolipids were demonstrated to function as structural components, second messengers, and regulators of cell growth and survival in normal and disease-affected tissues. Particularly, sphingosine kinase 1 (SphK1) and its product sphingosine-1-phosphate (S1P) operate as mediators and facilitators of proliferation-linked signaling. Unlimited proliferation (selfrenewal) within the regulated environment is a hallmark of progenitor/stem cells that was recently associated with the S1P signaling network in vasculature, nervous,muscular, and immune systems. S1P was shown to regulate progenitor-related characteristics in normal and cancerstemcells(CSCs) viaG-protein coupled receptorsS1Pn(n=1 to 5). The SphK/S1P axis is crucially involved in the regulation of embryonic development of vasculature and the nervous system, hematopoietic stem cell migration, regeneration of skeletal muscle, and development of multiple sclerosis. The ratio of the S1P receptor expression, localization, and specific S1P receptoractivated downstream effectors influenced the rate of selfrenewal and should be further explored as regeneration related targets. Considering malignant transformation,it is essential to control the level of self-renewal capacity.Proliferation of the progenitor cell should be synchronized with differentiation to provide healthy lifelong function of blood, immune systems, and replacement of damaged ordead cells. The differentiation-related role of SphK/S1P remains poorly assessed. A few pioneering investigations exploredpharmacologicaltoolsthattargetsphingolipid signaling and can potentially confine and direct self-renewal towards normal differentiation. Further investigation is required to test the role of the SphK/S1P axis in regulation of self-renewal and differentiation.
文摘The genetic variants of orosomucoid-like protein 3(ORMDL3)gene are associated with highly significant increases in the number of human rhinovirus(HRV)-induced wheezing episodes in children.Recent investigations have been focused on the mechanisms of ORMDL3 in rhinovirus infection for asthma and asthma exacerbations.ORMDL3 not only regulates major human rhinovirus receptor intercellular adhesion molecule 1 expression,but also plays pivotal roles in viral infection through metabolisms of ceramide and sphingosine-1-phosphate,endoplasmic reticulum(ER)stress,ER-Golgi interface and glycolysis.Research on the roles of ORMDL3 in HRV infection will lead us to identify new biomarkers and novel therapeutic targets in childhood asthma and viral induced asthma exacerbations.
