Two new ceramides,(2S,3S,4R)-2-N-[(2 R)-2 -hydroxypentacosanoylamino]-nonacosane-1,3,4-triol(1) and(2S,3S,4R,8E)-2- N-[(2 R)-2 -hydroxytetracosanoylamino]-8-eicosylene-1,3,4-triol(2) have been isolated from the stems ...Two new ceramides,(2S,3S,4R)-2-N-[(2 R)-2 -hydroxypentacosanoylamino]-nonacosane-1,3,4-triol(1) and(2S,3S,4R,8E)-2- N-[(2 R)-2 -hydroxytetracosanoylamino]-8-eicosylene-1,3,4-triol(2) have been isolated from the stems of Piper betle L.collected from Baoshan city of Yunnan Province in China.Their structures were determined by spectroscopic and chemical methods.展开更多
A new ceramide and its glycoside were isolated from the flower of Albizia julibrissin. Their structures were established as (25,35,4R,8E)-2-[(2'R)-hydroxyhexadecanoylamino]-8-tetra-cosene-l,3,4-triol(I)and 1-O-β-...A new ceramide and its glycoside were isolated from the flower of Albizia julibrissin. Their structures were established as (25,35,4R,8E)-2-[(2'R)-hydroxyhexadecanoylamino]-8-tetra-cosene-l,3,4-triol(I)and 1-O-β-D-glucopyranosy1-(2S,3S,4R,8E)-2-[(2'R)-hydroxy-hexade-canoylamino]-8-tetracosene-1,3,4-triol (II) on the basis of chemical and spectroscopic studies.展开更多
In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol(1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol(2), 24-methylchol...In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol(1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol(2), 24-methylcholesta-5, 24(28)-diene-3β-acetate(3), 4-methyl-24-methylcholesta- 22-ene-3-ol(4), and cholesterol, was isolated and characterized from CH2Cl2/Me OH extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate(1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NMR, HRESI-MS, and GC-MS, in addition of chemical methods.(-)-Alloaromadendren, ledane,(1)-alloaromadendren oxide, isoaromadendrene epoxide and(-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides(1) and(1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids(2) and(3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The CH_2Cl_2/MeOH extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.展开更多
BACKGROUND Bile acids play an important role in the amelioration of type 2 diabetes following duodenal-jejunal bypass(DJB).Serum bile acids are elevated postoperatively.However,the clinical relevance is not known.Bile...BACKGROUND Bile acids play an important role in the amelioration of type 2 diabetes following duodenal-jejunal bypass(DJB).Serum bile acids are elevated postoperatively.However,the clinical relevance is not known.Bile acids in the peripheral circulation reflect the amount of bile acids in the gut.Therefore,a further investigation of luminal bile acids following DJB is of great significance.AIM To investigate changes of luminal bile acids following DJB.METHODS Salicylhydroxamic acid(SHAM),DJB,and DJB with oral chenodeoxycholic acid(CDCA)supplementation were performed in a high-fat-diet/streptozotocininduced diabetic rat model.Body weight,energy intake,oral glucose tolerance test,luminal bile acids,serum ceramides and intestinal ceramide synthesis were analyzed at week 12 postoperatively.RESULTS Compared to SHAM,DJB achieved rapid and durable improvement in glucose tolerance and led to increased total luminal bile acid concentrations with preferentially increased proportion of farnesoid X receptor(FXR)-inhibitory bile acids within the common limb.Intestinal ceramide synthesis was repressed with decreased serum ceramides,and this phenomenon could be partially antagonized by luminal supplementation of FXR activating bile acid CDCA.CONCLUSION DJB significantly changes luminal bile acid composition with increased proportion FXR-inhibitory bile acids and reduces serum ceramide levels.There observations suggest a novel mechanism of bile acids in metabolic regulation after DJB.展开更多
A recent study published by Zhang et al.1 in Nature suggested that the endogenous ceramide receptors cysteinyl leukotriene receptor 2(CYSLTR2)and the pyrimidinergic receptor P2Y6(P2Y6R)are potential novel targets for ...A recent study published by Zhang et al.1 in Nature suggested that the endogenous ceramide receptors cysteinyl leukotriene receptor 2(CYSLTR2)and the pyrimidinergic receptor P2Y6(P2Y6R)are potential novel targets for the treatment of athero-sclerosis and related cardiovascular conditions beyond main-stream cholesterol control strategies.This new finding paves the way for another milestone in the emerging innovative search for novel atherosclerosis therapies.展开更多
Ceramides,formed by the dehydration of long-chain fatty acids with phytosphingosine and its derivatives,are widely used in skincare,cosmetics,and pharmaceuticals.Due to the exceedingly low concentration of phytos-phin...Ceramides,formed by the dehydration of long-chain fatty acids with phytosphingosine and its derivatives,are widely used in skincare,cosmetics,and pharmaceuticals.Due to the exceedingly low concentration of phytos-phingosine in plant seeds,relying on the extraction method is highly challenging.Currently,the primary method for obtaining phytosphingosine is the deacetylation of tetraacetyl phytosphingosine(TAPS)derived from fermentation.Wickerhamomyces ciferrii,an unconventional yeast from the pods of Dipteryx odorata,is the only known microorganism capable of naturally secreting TAPS,which is of great industrial value.In recent years,research and applications focused on modifying W.ciferrii for TAPS overproduction have increased rapidly.This review first describes the discovery history,applications,microbial synthesis pathway of TAPS.Research progress in using haploid breeding,mutagenesis breeding,and metabolic engineering to improve TAPS pro-duction is then summarized.In addition,the future prospects of TAPS production using the W.ciferrii platform are discussed in light of the current progress,challenges,and trends in this field.Finally,guidelines for future researches are also emphasized.展开更多
Background:Previously,dihydroceramide(d18:0/24:0)(dhCer(d18:0/24:0))was reported to be a potential biomarker for acute-onchronic liver failure(ACLF)prognosis.In this study,we further explored the role of dhCer(d18:0/2...Background:Previously,dihydroceramide(d18:0/24:0)(dhCer(d18:0/24:0))was reported to be a potential biomarker for acute-onchronic liver failure(ACLF)prognosis.In this study,we further explored the role of dhCer(d18:0/24:0)in the progression of ACLF to validate the biomarker using ACLF rat model.Methods:ACLF rats were sacrificed at 4 and 8 h post-D-galactosamine(D-gal)/lipopolysaccharide(LPS)administration to investigate the liver biochemical markers,prothrombin time and liver histopathology.Change in dhCer and other sphingolipids levels were investigated by high-performance liquid chromatography coupled to tandem mass spectrometry(HPLC-MS/MS).Rats were treated with N-(4-hydroxyphenyl)retinamide(4-HPR)to examine the mortality rate and its role in improving ACLF.Results:LPS/D-gal administration resulted in significant elevation in alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels.Prothrombin time was prolonged and histopathological examination showed abnormality.HPLC-MS/MS results showed total dhCer levels in ACLF group(64.10±8.90 pmol/100 mL,64.22±6.78 pmol/100 mL for 4 and 8 h,respectively)were decreased significantly compared with control group(121.61±23.09 pmol/100 mL)(P<0.05).In particular,dhCer(d18:0/24:0),dhCer(d18:0/20:0),and dhCer(d18:0/22:0)levels were decreased.Treatment with 4-HPR significantly increased the levels of dhCers,including dhCer(d18:0/24:0)compared with ACLF group,for the level of dhCer(d18:0/24:0)in 4-HPR group was 20.10±8.60 pmol/100 mL and the level of dhCer(d18:0/24:0)in ACLF group was 9.74±2.99 pmol/100 mL(P<0.05).This was associated with reduced mortality rate and prolonged survival time.The ALT and AST in 4-HPR group were significantly decreased compared with ACLF group.The prothrombin time of 4-HPR group(41.49 s)was significantly lower than the prothrombin time of ACLF group(57.96 s)(P<0.05).4-HPR also decreased plasma ammonia levels slightly,as the plasma ammonia levels in 4-HPR group and ACLF group were 207.37±60.43,209.15±60.43 mmol/L,respectively.Further,4-HPR treatment improved histopathological parameters.Conclusions:DhCer,especially dhCer(d18:0/24:0),is involved in the progression of ACLF.Increasing the levels of dhCer can reduce the mortality rate of ACLF rats and alleviate liver injury.展开更多
Two new ceramides were isolated from the 95% EtOH extract of traditional Chinese medicinal plant Isatis indigotica. Their structures were elucidated as 1-O-β-D-glucopyranosyl-(2S, 3R)-N-(2'-hydroxypentacosanoyl)-...Two new ceramides were isolated from the 95% EtOH extract of traditional Chinese medicinal plant Isatis indigotica. Their structures were elucidated as 1-O-β-D-glucopyranosyl-(2S, 3R)-N-(2'-hydroxypentacosanoyl)-octadeca-11E-sphingenine (1) and 1-O-β-D-glucopyranosyl-(2S,3R)-N-(2'-hydroxyhe xacosanoyl)-octadeca-11E-sphingenine (2) on the basis of spectroscopic data. Their cytotoxic effects were evaluated by using MTT method.展开更多
Background Cognitive decline in Alzheimer’s disease(AD)is associated with hyperphosphorylated tau(pTau)propagation between neurons along synaptically connected networks,in part via extracellular vesicles(EVs).EV biog...Background Cognitive decline in Alzheimer’s disease(AD)is associated with hyperphosphorylated tau(pTau)propagation between neurons along synaptically connected networks,in part via extracellular vesicles(EVs).EV biogenesis is triggered by ceramide enrichment at the plasma membrane from neutral sphingomyelinase2(nSMase2)-mediated cleavage of sphingomyelin.We report,for the first time,that human tau expression elevates brain ceramides and nSMase2 activity.Methods To determine the therapeutic benefit of inhibiting this elevation,we evaluated PDDC,the first potent,selective,orally bioavailable,and brain-penetrable nSMase2 inhibitor in the transgenic PS19 AD mouse model.Additionally,we directly evaluated the effect of PDDC on tau propagation in a mouse model where an adeno-associated virus(AAV)encoding P301L/S320F double mutant human tau was stereotaxically-injected unilaterally into the hippocampus.The contralateral transfer of the double mutant human tau to the dentate gyrus was monitored.We examined ceramide levels,histopathological changes,and pTau content within EVs isolated from the mouse plasma.Results Similar to human AD,the PS19 mice exhibited increased brain ceramide levels and nSMase2 activity;both were completely normalized by PDDC treatment.The PS19 mice also exhibited elevated tau immunostaining,thinning of hippocampal neuronal cell layers,increased mossy fiber synaptophysin immunostaining,and glial activation,all of which were pathologic features of human AD.PDDC treatment reduced these changes.The plasma of PDDC-treated PS19 mice had reduced levels of neuronal-and microglial-derived EVs,the former carrying lower pTau levels,compared to untreated mice.In the tau propagation model,PDDC normalized the tau-induced increase in brain ceramides and significantly reduced the amount of tau propagation to the contralateral side.Conclusions PDDC is a first-in-class therapeutic candidate that normalizes elevated brain ceramides and nSMase2 activity,leading to the slowing of tau spread in AD mice.展开更多
Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of whic...Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of which are insensitive or cumbersome. This paper described methods utilizing thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) followed by evaporative light scattering detection (ELSD) to detect ceramide directly in cell extracts without derivatization, which was proved to be efficient and reproducible. Five kinds of ceramides were used as standards. Both TLC and normal-phase HPLC/ELSD results indicate that yeast contains several kinds of ceramides.展开更多
This study used non-invasive evaluation methods measured six skin physiological parameters of the lower lip in 180 subjects,including moisture content,transepidermal water loss(TEWL),smoothness(SESM),scaliness of the ...This study used non-invasive evaluation methods measured six skin physiological parameters of the lower lip in 180 subjects,including moisture content,transepidermal water loss(TEWL),smoothness(SESM),scaliness of the skin(SESC),wrinkles(SEW),and red area of the lip skin,and compared the effects of 6 groups of lip balms(no-additive group,marine oligosaccharides group,ceramides group,glycyrrhizinic acid group,allantoin group,and mixed group;30 each)on the skin physiological parameters of dry,flaking,and cracked lip subjects.The results showed that the lip mositure content of the subjects in the marine oligosaccharide group,glycyrrhetinic acid group,and allantoin group increased significantly by 44.40%,42.84%and 58.08%after 7 days of lip balm(P<0.05).The TEWL in the ceramide group and the allantoin group was significantly reduced by 21.83%and 24.72%,respectively,after 7 days of lip paste use(P<0.05).The lip skin smoothness values of subjects in the glycyrrhizic acid group and the allantoin group were significantly reduced by 18.76%and 14.97%,respectively,after 28 days of lip balm application(P<0.05).The lip skin scaling indices of subjects in the marine oligosaccharide group,the ceramides group,and the allantoin group were significantly reduced by 33.77%,42.69%,and 38.07%,respectively,after 28 days of lip balm application(P<0.05).The wrinkle parameters of the lip skin of the subjects in the marine oligosaccharide,glycyrrhizinic acid and allantoin groups were significantly reduced by 23.06%,23.29%and 25.98%,respectively,after 28 days of lip balm application(P<0.05).And the area of the red zone of the lip skin of the subjects in the allantoin group was significantly reduced by 4.27%,after 28 days of lip balm application(P<0.05).Combining the effects of the four active ingredients on the secretion of hyaluronic acid(moisturizing effect)and inflammatory factor(IL-6)in HSF cells,it suggests that marine oligosaccharides and allantoin have a perfect impact on enhancing the water content of the skin on the lips of the subjects,and further improve the symptoms of flaking and wrinkles on the lips of the subjects.The ceramide and allantoin can repair the skin barrier well and have a good effect on the chapped and flaky lips of the subjects.After 28 days of using lip balm,the water content of lips in the mixed group increased,the skin barrier was repaired and became smoother,and the wrinkles,scale index,and red zone value were reduced,which could well relieve chronic lip inflammation and lay a foundation for developing lip products for the treatment of chronic cheilitis.展开更多
Alzheimer's disease(AD),a progressive dementia,is one of the most common neurodegenerative diseases.Clinical trial results of amyloid-β(Aβ)and tau regulators based on the pretext of straightforward amyloid and t...Alzheimer's disease(AD),a progressive dementia,is one of the most common neurodegenerative diseases.Clinical trial results of amyloid-β(Aβ)and tau regulators based on the pretext of straightforward amyloid and tau immunotherapy were disappointing.There are currently no effective strategies for slowing the progression of AD.Herein,we spotlight the dysregulation of lipid metabolism,particularly the elevation of ceramides(Cers),as a critical yet underexplored facet of AD pathogenesis.Our study delineates the role of Cers in promoting microglial pyroptosis,a form of programmed cell death distinct from apoptosis and necroptosis,characterized by cellular swelling,and membrane rupture mediated by the NLRP3 inflammasome pathway.Utilizing both in vivo experiments with amyloid precursor protein(APP)/presenilin 1(PS1)transgenic mice and in vitro assays with BV-2 microglial cells,we investigate the activation of microglial pyroptosis by Cers and its inhibition by icariin(ICA),a flavonoid with known antioxidant and anti-inflammatory properties.Our findings reveal a significant increase in Cers levels and pyroptosis markers(NOD-like receptor family,pyrin domain containing 3(NLRP3),apoptosis-associated speck-like protein containing a caspase recruitment domain,caspase-1,gasdermin D(GSDMD),and interleukin-18(IL-18))in the brains of AD model mice,indicating a direct involvement of Cers in AD pathology through the induction of microglial pyroptosis.Conversely,ICA treatment effectively reduces these pyroptotic markers and Cer levels,thereby attenuating microglial pyroptosis and suggesting a novel therapeutic mechanism of action against AD.This study not only advances our understanding of the pathogenic role of Cers in AD but also introduces ICA as a promising candidate for AD therapy,capable of mitigating neuroinflammation and pyroptosis through the cyclooxygenase-2(COX-2)-NLRP3 inflammasome-gasdermin D(GSDMD)axis.Our results pave the way for further exploration of Cer metabolism disorders in neurodegenerative diseases and highlight the therapeutic potential of targeting microglial pyroptosis in AD.展开更多
Microglia,the resident monocyte of the central nervous system,play a crucial role in the response to spinal cord injury.However,the precise mechanism remains unclear.To investigate the molecular mechanisms by which mi...Microglia,the resident monocyte of the central nervous system,play a crucial role in the response to spinal cord injury.However,the precise mechanism remains unclear.To investigate the molecular mechanisms by which microglia regulate the neuroinflammatory response to spinal cord injury,we performed single-cell RNA sequencing dataset analysis,focusing on changes in microglial subpopulations.We found that the MG1 subpopulation emerged in the acute/subacute phase of spinal cord injury and expressed genes related to cell pyroptosis,sphingomyelin metabolism,and neuroinflammation at high levels.Subsequently,we established a mouse model of contusive injury and performed intrathecal injection of siRNA and molecular inhibitors to validate the role of ceramide synthase 5 in the neuroinflammatory responses and pyroptosis after spinal cord injury.Finally,we established a PC12-BV2 cell co-culture system and found that ceramide synthase 5 and pyroptosis-associated proteins were highly expressed to induce the apoptosis of neuron cells.Inhibiting ceramide synthase 5 expression in a mouse model of spinal cord injury effectively reduced pyroptosis.Furthermore,ceramide synthase 5-induced pyroptosis was dependent on activation of the NLRP3 signaling pathway.Inhibiting ceramide synthase 5 expression in microglia in vivo reduced neuronal apoptosis and promoted recovery of neurological function.Pla2g7 formed a“bridge”between sphingolipid metabolism and ceramide synthase 5-mediated cell death by inhibiting the NLRP3 signaling pathway.Collectively,these findings suggest that inhibiting ceramide synthase 5 expression in microglia after spinal cord injury effectively suppressed microglial pyroptosis mediated by NLRP3,thereby exerting neuroprotective effects.展开更多
Metabolic diseases have emerged as a leading cause of mortality from non-communicable diseases,posing a significant global public health challenge.Al-though the association between ceramides(Cers)and metabolic disease...Metabolic diseases have emerged as a leading cause of mortality from non-communicable diseases,posing a significant global public health challenge.Al-though the association between ceramides(Cers)and metabolic diseases is well-established,the role of the acid sphingomyelinase(ASMase)/Cer pathway in these diseases remains underexplored.This review synthesizes recent research on the biological functions,regulatory mechanisms,and targeted therapies related to the ASMase/Cer pathway in metabolic conditions,including obesity,diabetes,non-alcoholic fatty liver disease,and cardiovascular disease.The effects of the ASMase/Cer pathway on metabolic disease-related indicators,such as glycolipid metabolism,insulin resistance,inflammation,and mitochondrial homeostasis are elucidated.Moreover,this article discusses the therapeutic strategies using ASMase/Cer inhibitors for inverse prevention and treatment of these metabolic diseases in light of the possible efficacy of blockade of the ASMase/Cer pathway in arresting the progression of metabolic diseases.These insights offered herein should provide insight into the contribution of the ASMase/Cer pathway to metabolic diseases and offer tools to develop therapeutic interventions for such pathologies and their severe complications.展开更多
Non-alcoholic fatty liver disease(NAFLD),the most common chronic liver disorder in Western countries,comprises steatosis to nonalcoholic steatohepatitis(NASH),with the latter having the potential to progress to cirrho...Non-alcoholic fatty liver disease(NAFLD),the most common chronic liver disorder in Western countries,comprises steatosis to nonalcoholic steatohepatitis(NASH),with the latter having the potential to progress to cirrhosis.The transition from isolated steatosis to NASH is still poorly understood,but lipidomics approach revealed that the hepatic lipidome is extensively altered in the setting of steatosis and steatohepatitis and these alterations correlate with disease progression.Recent data suggest that both quantity and quality of the accumulated lipids are involved in pathogenesis of NAFLD.Changes in glycerophospholipid,sphingolipid,and fatty acid composition have been described in both liver biopsies and plasma of patients with NAFLD,implicating that specific lipid species are involved in oxidative stress,inflammation,and cell death.In this article,we summarize the findings of main human lipidomics studies in NAFLD and delineate the currently available information on the pathogenetic role of each lipid class in lipotoxicity and disease progression.展开更多
The nucleus-initiated augmentation of ER membrane is reflected in a coordinated synthesis and intercalation of the explicit proteins and lipids required for the replacement, repair and function of the cell and its org...The nucleus-initiated augmentation of ER membrane is reflected in a coordinated synthesis and intercalation of the explicit proteins and lipids required for the replacement, repair and function of the cell and its organelles. The direct connection between nucleus and the membranes containing labeled sphingosine (SphN) and ceramide (Cer) was affirmed by determining synthetic activity of serine palmitoyltransferase (SPT). The SPT and the newly synthesized serine-labeled lipid products were identified in the Outer- and Inner-Nuclear Membrane (ONM, INM) and ER. The pulse-chase experiments disclosed that the incorporation of radiolabeled lipids into both nuclear membranes declined upon their simultaneous increase in Endoplasmic Reticulum (ER). These results, and prior findings regarding metabolic transfer of nuclear membrane phosphoinositides to the outer leaflet of ER [Slomiany and Slomiany, Health, 2011, 3, 187-199], allowed us to reason that INM and ONM are not distinct entities, but uninterrupted continuum facing nucleosol and then cytosol when protracted into segment known as ER. Consequently, the identification of SPT and its products in the inner leaflet of nuclear and ER microsomes lent credence to the luminal presence of Cer in Golgi, luminal synthesis of glycosphingolipids (GSphLs), sphingomyelin (SM), and their delivery to the outer leaflet of apical and basolateral cell membrane, respectively. The findings presented in this communication provide further support to our concept that the factual intercalation of proteins and lipids into the cell membranes can only take place during their simultaneous synthesis that is guided by the nuclear and cytosolic processes enacted in nuclear-ER membrane continuum. At the nuclear stage, the signal-specific genes expression promotes active synthesis and intercalation of lipids into the organelles’ customized membrane that is protracted and articulated in ER in form of transport vesicles.展开更多
Ceramides are a class of lipid molecules widely distributed in eukaryotic cells in small amount. To investigate the possibility of ceramide production by yeast, a yeast strain Yarrowia lipolitica was grown under diffe...Ceramides are a class of lipid molecules widely distributed in eukaryotic cells in small amount. To investigate the possibility of ceramide production by yeast, a yeast strain Yarrowia lipolitica was grown under different conditions including changing carbon/nitrogen ratio, and serine concentration, dissolved oxygen and presence of ethanol. It was found that increased dissolved oxygen supply increased the ceramide content in the yeast 2.5 fold of its normal control level. Ethanol treatment could also enhance ceramide accumulation by 3.3 fold compared with the control although the cell growth was negatively affected. Cellular redox potential was shown to affect ceramide accumulation by the yeast. This was possibly related to the cellular reactive oxygen species presented in the yeast.展开更多
OBJECTIVE:To explore the mechanism of the Chinese medicine Cigu Xiaozhi prescription(慈菇消脂方,CGXZ)in the treatment of the non-alcoholic fatty liver disease(NAFLD)by detoxification and phlegm-reducing,the effect of ...OBJECTIVE:To explore the mechanism of the Chinese medicine Cigu Xiaozhi prescription(慈菇消脂方,CGXZ)in the treatment of the non-alcoholic fatty liver disease(NAFLD)by detoxification and phlegm-reducing,the effect of CGXZ prescription on ceramide-mediated lipid apoptosis in Hep G2 cells with NAFLD.METHODS:The experiment was randomly divided into 6groups:normal control group,model group,CGXZ prescription medicated serum high,medium,and low dose groups,and pioglitazone positive control group.Using 500μmol/L free fatty acid(FFA)mixture to induce Hep G2 cells to establish NAFLD cell model,respectively,with 2%,4%,and 6%concentration of CGXZ prescription medicated serum intervention for 24 h.The changes in organelles and lipid droplet accumulation were observed under the electron microscope.Furthermore,Td T-mediated d UTP Nick-End Labeling method was used to assay hepatocyte apoptosis;Biochemical determination of glutamic-pyruvic transaminase,glutamic oxalacetic transaminase,triglycerides,and FFA levels in Hep G2cells;the content of ceramide was determined by highperformance thin-layer chromatography.Finally,Western Blot and quantitative real-time polymerase chain reaction(q RT-PCR)were used to determine the protein and gene expression levels,such as inducible nitric oxide synthase(i NOS),nuclear factorκB(NF-κB),B cell lymphoma 2(Bcl-2)and Bcl-2-associated X(Bax).RESULTS:Under the electron microscope,the cells in the model group showed moderate-to-severe steatosis,and apoptotic bodies could be seen.The model group had greater improvements in the apoptosis rate(P<0.01),and the levels of ceramide C2 and FFA in the cytoplasm(P<0.01)than the normal control group.The protein expressions of NF-κB,i NOS,and Bax were significantly up-regulated(P<0.05),while the Bcl-2 had no significant change(P>0.05).Compared with the model group,the levels of ceramide C2 and FFA(P<0.01),the protein expressions of NF-κB,i NOS,and Bax(P<0.05)in the CGXZ prescription treatment group and pioglitazone positive control group were significantly decreased;Only the Bcl-2 protein was significantly up-regulated in the high-dose Chinese medicine group(P<0.05).The downregulation of Bax m RNA expression in each Chinese medicine treatment group was significantly better than in the pioglitazone positive control group(P<0.01).CONCLUSIONS:The CGXZ prescription,formulated with the method of detoxification and phlegm,can inhibit lipoapoptosis in the NAFLD cell model by downregulating the levels of ceramide C2 and FFA,which may be achieved by regulating ceramide/i NOS/NF-κB signaling pathway.展开更多
A new triterpenoid saponin, namely pomatoside A (3) 13beta, 28-epoxy-16-oleananone-3-O-[alpha-L-rhamnopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->4)-O-beta-D-glucopyranosyl-(1 -->6)-O-beta-D-glucopyranos...A new triterpenoid saponin, namely pomatoside A (3) 13beta, 28-epoxy-16-oleananone-3-O-[alpha-L-rhamnopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->4)-O-beta-D-glucopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->2)]-beta-D-glucopyranoside, together with twelve known compounds, was isolated for the first time from Pomatosace filicula Maxim., a monotypic endemic plant, grown in the Qinghai-Xizang Plateau of China. Their structures were elucidated by spectroscopic analyses and chemical methods, especially 2D-NMR.展开更多
A new ceramide, (2S,3S,4R, 10E)-2-[(2'R)-2'-hydroxytetracosanoyl amino]-10-octadecene-1, 3,4-triol (1), together with twelve known compounds, cerebroside A, cerebroside B, cerebroside D, cytochalasin D, epoxyc...A new ceramide, (2S,3S,4R, 10E)-2-[(2'R)-2'-hydroxytetracosanoyl amino]-10-octadecene-1, 3,4-triol (1), together with twelve known compounds, cerebroside A, cerebroside B, cerebroside D, cytochalasin D, epoxycytochalasin D, cytochalasin C, loganin, cerevisterol, ergosta-7,22-dien-3beta, 5alpha, 6alpha-triol, ergosta-4,6,8(14),22-tetraen-3-one, ergosterol peroxide and ergosta-5,7,22-trien-3-ol, was isolated from ethyl acetate fraction of Engleromyces goetzei P. Henn. The structure of new ceramide (1) was elucidated by spectral data and chemical method, especially by 2D-NMR techniques. All of the compounds except cytochalasin D were first obtained from this fungus.展开更多
基金supported by the Key Project of Chinese Ministry of Education(No.209116)
文摘Two new ceramides,(2S,3S,4R)-2-N-[(2 R)-2 -hydroxypentacosanoylamino]-nonacosane-1,3,4-triol(1) and(2S,3S,4R,8E)-2- N-[(2 R)-2 -hydroxytetracosanoylamino]-8-eicosylene-1,3,4-triol(2) have been isolated from the stems of Piper betle L.collected from Baoshan city of Yunnan Province in China.Their structures were determined by spectroscopic and chemical methods.
文摘A new ceramide and its glycoside were isolated from the flower of Albizia julibrissin. Their structures were established as (25,35,4R,8E)-2-[(2'R)-hydroxyhexadecanoylamino]-8-tetra-cosene-l,3,4-triol(I)and 1-O-β-D-glucopyranosy1-(2S,3S,4R,8E)-2-[(2'R)-hydroxy-hexade-canoylamino]-8-tetracosene-1,3,4-triol (II) on the basis of chemical and spectroscopic studies.
基金supported by the Science and Technology Development Fund(STDF)(No.6554)
文摘In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol(1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol(2), 24-methylcholesta-5, 24(28)-diene-3β-acetate(3), 4-methyl-24-methylcholesta- 22-ene-3-ol(4), and cholesterol, was isolated and characterized from CH2Cl2/Me OH extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate(1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NMR, HRESI-MS, and GC-MS, in addition of chemical methods.(-)-Alloaromadendren, ledane,(1)-alloaromadendren oxide, isoaromadendrene epoxide and(-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides(1) and(1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids(2) and(3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The CH_2Cl_2/MeOH extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.
文摘BACKGROUND Bile acids play an important role in the amelioration of type 2 diabetes following duodenal-jejunal bypass(DJB).Serum bile acids are elevated postoperatively.However,the clinical relevance is not known.Bile acids in the peripheral circulation reflect the amount of bile acids in the gut.Therefore,a further investigation of luminal bile acids following DJB is of great significance.AIM To investigate changes of luminal bile acids following DJB.METHODS Salicylhydroxamic acid(SHAM),DJB,and DJB with oral chenodeoxycholic acid(CDCA)supplementation were performed in a high-fat-diet/streptozotocininduced diabetic rat model.Body weight,energy intake,oral glucose tolerance test,luminal bile acids,serum ceramides and intestinal ceramide synthesis were analyzed at week 12 postoperatively.RESULTS Compared to SHAM,DJB achieved rapid and durable improvement in glucose tolerance and led to increased total luminal bile acid concentrations with preferentially increased proportion of farnesoid X receptor(FXR)-inhibitory bile acids within the common limb.Intestinal ceramide synthesis was repressed with decreased serum ceramides,and this phenomenon could be partially antagonized by luminal supplementation of FXR activating bile acid CDCA.CONCLUSION DJB significantly changes luminal bile acid composition with increased proportion FXR-inhibitory bile acids and reduces serum ceramide levels.There observations suggest a novel mechanism of bile acids in metabolic regulation after DJB.
基金financial support from the Sino-German Centre(GZ919,M-0679)the Sichuan Science and Technology Program(2024JDHJ0043,2025YFHZ0121)。
文摘A recent study published by Zhang et al.1 in Nature suggested that the endogenous ceramide receptors cysteinyl leukotriene receptor 2(CYSLTR2)and the pyrimidinergic receptor P2Y6(P2Y6R)are potential novel targets for the treatment of athero-sclerosis and related cardiovascular conditions beyond main-stream cholesterol control strategies.This new finding paves the way for another milestone in the emerging innovative search for novel atherosclerosis therapies.
基金supported by the National Natural Science Foundation of China(22178173)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20231119)+3 种基金the China Postdoctoral Science Foundation(2024M751420)the Jiangsu Agricultural Science and Technology Independent Innovation Fund Project(CX(22)3015)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(XTC2204)the Newton Advanced Fellowships(NAF\R1\201187).
文摘Ceramides,formed by the dehydration of long-chain fatty acids with phytosphingosine and its derivatives,are widely used in skincare,cosmetics,and pharmaceuticals.Due to the exceedingly low concentration of phytos-phingosine in plant seeds,relying on the extraction method is highly challenging.Currently,the primary method for obtaining phytosphingosine is the deacetylation of tetraacetyl phytosphingosine(TAPS)derived from fermentation.Wickerhamomyces ciferrii,an unconventional yeast from the pods of Dipteryx odorata,is the only known microorganism capable of naturally secreting TAPS,which is of great industrial value.In recent years,research and applications focused on modifying W.ciferrii for TAPS overproduction have increased rapidly.This review first describes the discovery history,applications,microbial synthesis pathway of TAPS.Research progress in using haploid breeding,mutagenesis breeding,and metabolic engineering to improve TAPS pro-duction is then summarized.In addition,the future prospects of TAPS production using the W.ciferrii platform are discussed in light of the current progress,challenges,and trends in this field.Finally,guidelines for future researches are also emphasized.
基金This work was supported by the National Natural Science Foundation of China(No.81573487)the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2017-12M-1-013)the Drug Innovation Major Project(No.2018ZX09711001-003-011).
文摘Background:Previously,dihydroceramide(d18:0/24:0)(dhCer(d18:0/24:0))was reported to be a potential biomarker for acute-onchronic liver failure(ACLF)prognosis.In this study,we further explored the role of dhCer(d18:0/24:0)in the progression of ACLF to validate the biomarker using ACLF rat model.Methods:ACLF rats were sacrificed at 4 and 8 h post-D-galactosamine(D-gal)/lipopolysaccharide(LPS)administration to investigate the liver biochemical markers,prothrombin time and liver histopathology.Change in dhCer and other sphingolipids levels were investigated by high-performance liquid chromatography coupled to tandem mass spectrometry(HPLC-MS/MS).Rats were treated with N-(4-hydroxyphenyl)retinamide(4-HPR)to examine the mortality rate and its role in improving ACLF.Results:LPS/D-gal administration resulted in significant elevation in alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels.Prothrombin time was prolonged and histopathological examination showed abnormality.HPLC-MS/MS results showed total dhCer levels in ACLF group(64.10±8.90 pmol/100 mL,64.22±6.78 pmol/100 mL for 4 and 8 h,respectively)were decreased significantly compared with control group(121.61±23.09 pmol/100 mL)(P<0.05).In particular,dhCer(d18:0/24:0),dhCer(d18:0/20:0),and dhCer(d18:0/22:0)levels were decreased.Treatment with 4-HPR significantly increased the levels of dhCers,including dhCer(d18:0/24:0)compared with ACLF group,for the level of dhCer(d18:0/24:0)in 4-HPR group was 20.10±8.60 pmol/100 mL and the level of dhCer(d18:0/24:0)in ACLF group was 9.74±2.99 pmol/100 mL(P<0.05).This was associated with reduced mortality rate and prolonged survival time.The ALT and AST in 4-HPR group were significantly decreased compared with ACLF group.The prothrombin time of 4-HPR group(41.49 s)was significantly lower than the prothrombin time of ACLF group(57.96 s)(P<0.05).4-HPR also decreased plasma ammonia levels slightly,as the plasma ammonia levels in 4-HPR group and ACLF group were 207.37±60.43,209.15±60.43 mmol/L,respectively.Further,4-HPR treatment improved histopathological parameters.Conclusions:DhCer,especially dhCer(d18:0/24:0),is involved in the progression of ACLF.Increasing the levels of dhCer can reduce the mortality rate of ACLF rats and alleviate liver injury.
文摘Two new ceramides were isolated from the 95% EtOH extract of traditional Chinese medicinal plant Isatis indigotica. Their structures were elucidated as 1-O-β-D-glucopyranosyl-(2S, 3R)-N-(2'-hydroxypentacosanoyl)-octadeca-11E-sphingenine (1) and 1-O-β-D-glucopyranosyl-(2S,3R)-N-(2'-hydroxyhe xacosanoyl)-octadeca-11E-sphingenine (2) on the basis of spectroscopic data. Their cytotoxic effects were evaluated by using MTT method.
基金supported by the National Institute of Health Grants R01 AG059799(to BSS),R01AG057420 and R01MH131219(to NJH),P30 MH075673(to NJH and BSS)a grant from the Tau Consortium and Alzheimer’s Association(T-PEP-18-579974C,to BSS)a grant from the Richman Family Precision Medicine Center of Excellence in Alzheimer’s disease(to BSS and DK).KC and TRJ were Funded by NIH R25GM109441(Hopkins PREP).
文摘Background Cognitive decline in Alzheimer’s disease(AD)is associated with hyperphosphorylated tau(pTau)propagation between neurons along synaptically connected networks,in part via extracellular vesicles(EVs).EV biogenesis is triggered by ceramide enrichment at the plasma membrane from neutral sphingomyelinase2(nSMase2)-mediated cleavage of sphingomyelin.We report,for the first time,that human tau expression elevates brain ceramides and nSMase2 activity.Methods To determine the therapeutic benefit of inhibiting this elevation,we evaluated PDDC,the first potent,selective,orally bioavailable,and brain-penetrable nSMase2 inhibitor in the transgenic PS19 AD mouse model.Additionally,we directly evaluated the effect of PDDC on tau propagation in a mouse model where an adeno-associated virus(AAV)encoding P301L/S320F double mutant human tau was stereotaxically-injected unilaterally into the hippocampus.The contralateral transfer of the double mutant human tau to the dentate gyrus was monitored.We examined ceramide levels,histopathological changes,and pTau content within EVs isolated from the mouse plasma.Results Similar to human AD,the PS19 mice exhibited increased brain ceramide levels and nSMase2 activity;both were completely normalized by PDDC treatment.The PS19 mice also exhibited elevated tau immunostaining,thinning of hippocampal neuronal cell layers,increased mossy fiber synaptophysin immunostaining,and glial activation,all of which were pathologic features of human AD.PDDC treatment reduced these changes.The plasma of PDDC-treated PS19 mice had reduced levels of neuronal-and microglial-derived EVs,the former carrying lower pTau levels,compared to untreated mice.In the tau propagation model,PDDC normalized the tau-induced increase in brain ceramides and significantly reduced the amount of tau propagation to the contralateral side.Conclusions PDDC is a first-in-class therapeutic candidate that normalizes elevated brain ceramides and nSMase2 activity,leading to the slowing of tau spread in AD mice.
文摘Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of which are insensitive or cumbersome. This paper described methods utilizing thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) followed by evaporative light scattering detection (ELSD) to detect ceramide directly in cell extracts without derivatization, which was proved to be efficient and reproducible. Five kinds of ceramides were used as standards. Both TLC and normal-phase HPLC/ELSD results indicate that yeast contains several kinds of ceramides.
文摘This study used non-invasive evaluation methods measured six skin physiological parameters of the lower lip in 180 subjects,including moisture content,transepidermal water loss(TEWL),smoothness(SESM),scaliness of the skin(SESC),wrinkles(SEW),and red area of the lip skin,and compared the effects of 6 groups of lip balms(no-additive group,marine oligosaccharides group,ceramides group,glycyrrhizinic acid group,allantoin group,and mixed group;30 each)on the skin physiological parameters of dry,flaking,and cracked lip subjects.The results showed that the lip mositure content of the subjects in the marine oligosaccharide group,glycyrrhetinic acid group,and allantoin group increased significantly by 44.40%,42.84%and 58.08%after 7 days of lip balm(P<0.05).The TEWL in the ceramide group and the allantoin group was significantly reduced by 21.83%and 24.72%,respectively,after 7 days of lip paste use(P<0.05).The lip skin smoothness values of subjects in the glycyrrhizic acid group and the allantoin group were significantly reduced by 18.76%and 14.97%,respectively,after 28 days of lip balm application(P<0.05).The lip skin scaling indices of subjects in the marine oligosaccharide group,the ceramides group,and the allantoin group were significantly reduced by 33.77%,42.69%,and 38.07%,respectively,after 28 days of lip balm application(P<0.05).The wrinkle parameters of the lip skin of the subjects in the marine oligosaccharide,glycyrrhizinic acid and allantoin groups were significantly reduced by 23.06%,23.29%and 25.98%,respectively,after 28 days of lip balm application(P<0.05).And the area of the red zone of the lip skin of the subjects in the allantoin group was significantly reduced by 4.27%,after 28 days of lip balm application(P<0.05).Combining the effects of the four active ingredients on the secretion of hyaluronic acid(moisturizing effect)and inflammatory factor(IL-6)in HSF cells,it suggests that marine oligosaccharides and allantoin have a perfect impact on enhancing the water content of the skin on the lips of the subjects,and further improve the symptoms of flaking and wrinkles on the lips of the subjects.The ceramide and allantoin can repair the skin barrier well and have a good effect on the chapped and flaky lips of the subjects.After 28 days of using lip balm,the water content of lips in the mixed group increased,the skin barrier was repaired and became smoother,and the wrinkles,scale index,and red zone value were reduced,which could well relieve chronic lip inflammation and lay a foundation for developing lip products for the treatment of chronic cheilitis.
基金supported by the National Natural Science Foundation of China(Grant No.:82374552)Hunan Provincial Natural Science Foundation of China for Distinguished Young Scholars(Grant No.:2024JJ2086)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(Grant No.:2022RC1220)Support Plan for High-level Health and Medical Talents in Hunan Province,China.
文摘Alzheimer's disease(AD),a progressive dementia,is one of the most common neurodegenerative diseases.Clinical trial results of amyloid-β(Aβ)and tau regulators based on the pretext of straightforward amyloid and tau immunotherapy were disappointing.There are currently no effective strategies for slowing the progression of AD.Herein,we spotlight the dysregulation of lipid metabolism,particularly the elevation of ceramides(Cers),as a critical yet underexplored facet of AD pathogenesis.Our study delineates the role of Cers in promoting microglial pyroptosis,a form of programmed cell death distinct from apoptosis and necroptosis,characterized by cellular swelling,and membrane rupture mediated by the NLRP3 inflammasome pathway.Utilizing both in vivo experiments with amyloid precursor protein(APP)/presenilin 1(PS1)transgenic mice and in vitro assays with BV-2 microglial cells,we investigate the activation of microglial pyroptosis by Cers and its inhibition by icariin(ICA),a flavonoid with known antioxidant and anti-inflammatory properties.Our findings reveal a significant increase in Cers levels and pyroptosis markers(NOD-like receptor family,pyrin domain containing 3(NLRP3),apoptosis-associated speck-like protein containing a caspase recruitment domain,caspase-1,gasdermin D(GSDMD),and interleukin-18(IL-18))in the brains of AD model mice,indicating a direct involvement of Cers in AD pathology through the induction of microglial pyroptosis.Conversely,ICA treatment effectively reduces these pyroptotic markers and Cer levels,thereby attenuating microglial pyroptosis and suggesting a novel therapeutic mechanism of action against AD.This study not only advances our understanding of the pathogenic role of Cers in AD but also introduces ICA as a promising candidate for AD therapy,capable of mitigating neuroinflammation and pyroptosis through the cyclooxygenase-2(COX-2)-NLRP3 inflammasome-gasdermin D(GSDMD)axis.Our results pave the way for further exploration of Cer metabolism disorders in neurodegenerative diseases and highlight the therapeutic potential of targeting microglial pyroptosis in AD.
基金supported by grants from the National Key Research and Development Program of China,No.2017YFA0105400(to LR)the Key Research and Development Program of Guangdong Province,No.2019B020236002(to LR)the National Natural Science Foundation of China,Nos.81972111(to LZ),81772349(to BL).
文摘Microglia,the resident monocyte of the central nervous system,play a crucial role in the response to spinal cord injury.However,the precise mechanism remains unclear.To investigate the molecular mechanisms by which microglia regulate the neuroinflammatory response to spinal cord injury,we performed single-cell RNA sequencing dataset analysis,focusing on changes in microglial subpopulations.We found that the MG1 subpopulation emerged in the acute/subacute phase of spinal cord injury and expressed genes related to cell pyroptosis,sphingomyelin metabolism,and neuroinflammation at high levels.Subsequently,we established a mouse model of contusive injury and performed intrathecal injection of siRNA and molecular inhibitors to validate the role of ceramide synthase 5 in the neuroinflammatory responses and pyroptosis after spinal cord injury.Finally,we established a PC12-BV2 cell co-culture system and found that ceramide synthase 5 and pyroptosis-associated proteins were highly expressed to induce the apoptosis of neuron cells.Inhibiting ceramide synthase 5 expression in a mouse model of spinal cord injury effectively reduced pyroptosis.Furthermore,ceramide synthase 5-induced pyroptosis was dependent on activation of the NLRP3 signaling pathway.Inhibiting ceramide synthase 5 expression in microglia in vivo reduced neuronal apoptosis and promoted recovery of neurological function.Pla2g7 formed a“bridge”between sphingolipid metabolism and ceramide synthase 5-mediated cell death by inhibiting the NLRP3 signaling pathway.Collectively,these findings suggest that inhibiting ceramide synthase 5 expression in microglia after spinal cord injury effectively suppressed microglial pyroptosis mediated by NLRP3,thereby exerting neuroprotective effects.
基金Supported by Ganzhou City’s“Light of the Soviet Area”Talent Project,No.GZSQZG202301009。
文摘Metabolic diseases have emerged as a leading cause of mortality from non-communicable diseases,posing a significant global public health challenge.Al-though the association between ceramides(Cers)and metabolic diseases is well-established,the role of the acid sphingomyelinase(ASMase)/Cer pathway in these diseases remains underexplored.This review synthesizes recent research on the biological functions,regulatory mechanisms,and targeted therapies related to the ASMase/Cer pathway in metabolic conditions,including obesity,diabetes,non-alcoholic fatty liver disease,and cardiovascular disease.The effects of the ASMase/Cer pathway on metabolic disease-related indicators,such as glycolipid metabolism,insulin resistance,inflammation,and mitochondrial homeostasis are elucidated.Moreover,this article discusses the therapeutic strategies using ASMase/Cer inhibitors for inverse prevention and treatment of these metabolic diseases in light of the possible efficacy of blockade of the ASMase/Cer pathway in arresting the progression of metabolic diseases.These insights offered herein should provide insight into the contribution of the ASMase/Cer pathway to metabolic diseases and offer tools to develop therapeutic interventions for such pathologies and their severe complications.
文摘Non-alcoholic fatty liver disease(NAFLD),the most common chronic liver disorder in Western countries,comprises steatosis to nonalcoholic steatohepatitis(NASH),with the latter having the potential to progress to cirrhosis.The transition from isolated steatosis to NASH is still poorly understood,but lipidomics approach revealed that the hepatic lipidome is extensively altered in the setting of steatosis and steatohepatitis and these alterations correlate with disease progression.Recent data suggest that both quantity and quality of the accumulated lipids are involved in pathogenesis of NAFLD.Changes in glycerophospholipid,sphingolipid,and fatty acid composition have been described in both liver biopsies and plasma of patients with NAFLD,implicating that specific lipid species are involved in oxidative stress,inflammation,and cell death.In this article,we summarize the findings of main human lipidomics studies in NAFLD and delineate the currently available information on the pathogenetic role of each lipid class in lipotoxicity and disease progression.
文摘The nucleus-initiated augmentation of ER membrane is reflected in a coordinated synthesis and intercalation of the explicit proteins and lipids required for the replacement, repair and function of the cell and its organelles. The direct connection between nucleus and the membranes containing labeled sphingosine (SphN) and ceramide (Cer) was affirmed by determining synthetic activity of serine palmitoyltransferase (SPT). The SPT and the newly synthesized serine-labeled lipid products were identified in the Outer- and Inner-Nuclear Membrane (ONM, INM) and ER. The pulse-chase experiments disclosed that the incorporation of radiolabeled lipids into both nuclear membranes declined upon their simultaneous increase in Endoplasmic Reticulum (ER). These results, and prior findings regarding metabolic transfer of nuclear membrane phosphoinositides to the outer leaflet of ER [Slomiany and Slomiany, Health, 2011, 3, 187-199], allowed us to reason that INM and ONM are not distinct entities, but uninterrupted continuum facing nucleosol and then cytosol when protracted into segment known as ER. Consequently, the identification of SPT and its products in the inner leaflet of nuclear and ER microsomes lent credence to the luminal presence of Cer in Golgi, luminal synthesis of glycosphingolipids (GSphLs), sphingomyelin (SM), and their delivery to the outer leaflet of apical and basolateral cell membrane, respectively. The findings presented in this communication provide further support to our concept that the factual intercalation of proteins and lipids into the cell membranes can only take place during their simultaneous synthesis that is guided by the nuclear and cytosolic processes enacted in nuclear-ER membrane continuum. At the nuclear stage, the signal-specific genes expression promotes active synthesis and intercalation of lipids into the organelles’ customized membrane that is protracted and articulated in ER in form of transport vesicles.
文摘Ceramides are a class of lipid molecules widely distributed in eukaryotic cells in small amount. To investigate the possibility of ceramide production by yeast, a yeast strain Yarrowia lipolitica was grown under different conditions including changing carbon/nitrogen ratio, and serine concentration, dissolved oxygen and presence of ethanol. It was found that increased dissolved oxygen supply increased the ceramide content in the yeast 2.5 fold of its normal control level. Ethanol treatment could also enhance ceramide accumulation by 3.3 fold compared with the control although the cell growth was negatively affected. Cellular redox potential was shown to affect ceramide accumulation by the yeast. This was possibly related to the cellular reactive oxygen species presented in the yeast.
基金Natural Science Foundation-funded Project:the Interaction of mi RNAs and Hh Signaling Pathway in NASH Related Liver Fibrosis and the Intervention of Sagittaria Xiaozhi Pill(No.81860821)Toxin and Eliminating Phlegm Intervention Ceramide and Induced iNOS Nonalcoholic Fatty Liver Disease Fat Research of Apoptosis Signaling(No.81460710)。
文摘OBJECTIVE:To explore the mechanism of the Chinese medicine Cigu Xiaozhi prescription(慈菇消脂方,CGXZ)in the treatment of the non-alcoholic fatty liver disease(NAFLD)by detoxification and phlegm-reducing,the effect of CGXZ prescription on ceramide-mediated lipid apoptosis in Hep G2 cells with NAFLD.METHODS:The experiment was randomly divided into 6groups:normal control group,model group,CGXZ prescription medicated serum high,medium,and low dose groups,and pioglitazone positive control group.Using 500μmol/L free fatty acid(FFA)mixture to induce Hep G2 cells to establish NAFLD cell model,respectively,with 2%,4%,and 6%concentration of CGXZ prescription medicated serum intervention for 24 h.The changes in organelles and lipid droplet accumulation were observed under the electron microscope.Furthermore,Td T-mediated d UTP Nick-End Labeling method was used to assay hepatocyte apoptosis;Biochemical determination of glutamic-pyruvic transaminase,glutamic oxalacetic transaminase,triglycerides,and FFA levels in Hep G2cells;the content of ceramide was determined by highperformance thin-layer chromatography.Finally,Western Blot and quantitative real-time polymerase chain reaction(q RT-PCR)were used to determine the protein and gene expression levels,such as inducible nitric oxide synthase(i NOS),nuclear factorκB(NF-κB),B cell lymphoma 2(Bcl-2)and Bcl-2-associated X(Bax).RESULTS:Under the electron microscope,the cells in the model group showed moderate-to-severe steatosis,and apoptotic bodies could be seen.The model group had greater improvements in the apoptosis rate(P<0.01),and the levels of ceramide C2 and FFA in the cytoplasm(P<0.01)than the normal control group.The protein expressions of NF-κB,i NOS,and Bax were significantly up-regulated(P<0.05),while the Bcl-2 had no significant change(P>0.05).Compared with the model group,the levels of ceramide C2 and FFA(P<0.01),the protein expressions of NF-κB,i NOS,and Bax(P<0.05)in the CGXZ prescription treatment group and pioglitazone positive control group were significantly decreased;Only the Bcl-2 protein was significantly up-regulated in the high-dose Chinese medicine group(P<0.05).The downregulation of Bax m RNA expression in each Chinese medicine treatment group was significantly better than in the pioglitazone positive control group(P<0.01).CONCLUSIONS:The CGXZ prescription,formulated with the method of detoxification and phlegm,can inhibit lipoapoptosis in the NAFLD cell model by downregulating the levels of ceramide C2 and FFA,which may be achieved by regulating ceramide/i NOS/NF-κB signaling pathway.
文摘A new triterpenoid saponin, namely pomatoside A (3) 13beta, 28-epoxy-16-oleananone-3-O-[alpha-L-rhamnopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->4)-O-beta-D-glucopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->2)]-beta-D-glucopyranoside, together with twelve known compounds, was isolated for the first time from Pomatosace filicula Maxim., a monotypic endemic plant, grown in the Qinghai-Xizang Plateau of China. Their structures were elucidated by spectroscopic analyses and chemical methods, especially 2D-NMR.
文摘A new ceramide, (2S,3S,4R, 10E)-2-[(2'R)-2'-hydroxytetracosanoyl amino]-10-octadecene-1, 3,4-triol (1), together with twelve known compounds, cerebroside A, cerebroside B, cerebroside D, cytochalasin D, epoxycytochalasin D, cytochalasin C, loganin, cerevisterol, ergosta-7,22-dien-3beta, 5alpha, 6alpha-triol, ergosta-4,6,8(14),22-tetraen-3-one, ergosterol peroxide and ergosta-5,7,22-trien-3-ol, was isolated from ethyl acetate fraction of Engleromyces goetzei P. Henn. The structure of new ceramide (1) was elucidated by spectral data and chemical method, especially by 2D-NMR techniques. All of the compounds except cytochalasin D were first obtained from this fungus.
