Physical stresses such as high temperature or hyper- osmosis are known causes of intracellular ceramide (Cer) accumulation in mammalian epithelial cells;these stresses also result in the activation of the biosy- nthes...Physical stresses such as high temperature or hyper- osmosis are known causes of intracellular ceramide (Cer) accumulation in mammalian epithelial cells;these stresses also result in the activation of the biosy- ntheses of glucosylceramide (GlcCer) or galactosyl- ceramide via ceramide glycosylation. We confirmed that intracellular Cer and GlcCer increased in mouse fibroblast Mop 8 cells under conditions of heat stress. When molecular species of Cer, GlcCer and sphingo- myelin (SM) were analyzed by matrix assisted laser desorption ionization time of flight mass spectrome- try (MALDI-TOF MS), the molecular ion peaks of Cer (d18:1 - C16:0, Na+) and Cer (d18:1 - C22:0, Na+) increased under heat stress compared with those of Cer (d18:1 - C24:1, Na+) and Cer (d18:1 - C24:0, Na+). GlcCer and SM demonstrated the wide spectra of fatty acyl chains compared with that of Cer. The ratio of GlcCer consisted of hydroxy fatty acid to that con- sisted of non-hydroxy fatty acid increased 2-5-fold in heat stressed cells. Cer metabolism-related genes, se- rine palmitoyltransferase (Spt), ceramide synthase-1, -2, -4, -5 and -6 (CerS1, -2, -4, -5 and -6), neutral sphingomyelinase-1 and -2 (nSMase1 and nS-Mase2), sphingomyelin synthase-1 (SgmS1), and ceramide glu- cosyltransferase (GlcT), were activated after 16 h un- der heat stress at 42?C. Activation of Sg-mS1 and GlcT genes played a role as Cer scavengers in the decrease of intracellular Cer levels. Activation of Cer- S5 and/or CerS6 gene may contribute to the accu- mulation of Cer species of (d18:1 - C16:0) under heat stress.展开更多
Glycosphingolipid (GSL) metabolism is involved in various physiological processes, including all major cell signaling pathways, and its dysregulation is linked to some diseases. The four-phosphate adaptor protein FAPP...Glycosphingolipid (GSL) metabolism is involved in various physiological processes, including all major cell signaling pathways, and its dysregulation is linked to some diseases. The four-phosphate adaptor protein FAPP2-mediated glucosylceramide (GlcCer) transport for complex GSL synthesis has been studied extensively. However, the molecular machinery of FAPP2 as a GlcCer-transferring protein remains poorly defined. Here, we identify a Golgi-resident protein, acyl-coenzyme A binding domain containing 3 (ACBD3), as an interacting partner of FAPP2. We find that ACBD3 knockdown leads to dramatic Golgi fragmentation, which subsequently causes FAPP2 dispersal throughout the cytoplasm and a decreased localization at trans-Golgi network. The further quantitative Upidomic analysis indicates that ACBD3 knockdown triggers abnormal sphingolipid metabolism. Interestingly, the expression of siRNA-resistant full-length ACBD3 can rescue these defects caused by ACBD3 knockdown. These data reveal critical roles for ACBD3 in maintaining the integrity of Golgi morphology and cellular sphingolipid homeostasis and establish the importance of the integrated Golgi complex for the transfer of GlcCer and complex GSL synthesis.展开更多
Background Glucosylceramide synthase （GCS） can reduce ceramide levels and help cells escape ceramide-induced apoptosis, thus leading to multidrug resistance （MDR）. However, its expression and clinical significance...Background Glucosylceramide synthase （GCS） can reduce ceramide levels and help cells escape ceramide-induced apoptosis, thus leading to multidrug resistance （MDR）. However, its expression and clinical significance in thyroid neoplasms still remain unclear. We aimed to elucidate the expression of GCS and explore its correlation with the clinicopathological characteristics in papillary thyroid carcinomas （PTCs）. Methods We retrospectively investigated GCS protein expression level in tissue specimens obtained from 108 consecutive PTC patients by immunohistochemistry and Western blotting. Results GCS was weakly positive or negative in normal follicular cells, but it was frequently overexpressed in PTC cells. GCS overexpression was associated with primary tumor size, local infiltration, lymph node metastasis, and local recurrence, but not associated with gender, age, pathological variants, tumor multifocality, tumor stage or distant metastasis. Western blotting also showed that GCS protein levels were much higher in PTCs＇ tissues than in normal thyroid tissues. Conclusion GCS was upregulated in PTCs and might be an independent factor affecting prognosis.展开更多
Background Glucosylceramide synthase （GCS）,an enzyme responsible for ceramide glycosylation,plays an important role in multidrug resistance （MDR） in some tumors in vitro; however,its expression and clinicopatholog...Background Glucosylceramide synthase （GCS）,an enzyme responsible for ceramide glycosylation,plays an important role in multidrug resistance （MDR） in some tumors in vitro; however,its expression and clinicopathological significance in non-small cell lung cancer （NSCLC） remains unclear.Methods We evaluated GCS expression in 116 paired tumor and adjacent non-cancerous tissues and 50 frozen tissues from patients with NSCLC using immunohistochemistry and western blotting,and explored the correlation between GCS and NSCLC clinicopathological characteristics and prognosis.We observed the association between GCS and the MDR proteins P-glycoprotein （P-gp） and lung resistance-related protein （LRP） to determine the link between GCS and MDR at the histological level.Results GCS expression was significantly upregulated in NSCLC tumors compared with non-cancerous tissue.There was high GCS expression in 75/116 tumor specimens （64.7％） and 16/116 non-cancerous specimens （13.8％）.High GCS expression was significantly associated with poor differentiation （P=0.01）,lymph node metastasis （P=0.004）,recurrence/ distant metastasis （P=0.006）,and chemotherapy resistance （P=0.025）.Multivariate analysis demonstrated that GCS immunopositivity was an independent risk factor for survival （P=0.018）.P-gp was expressed in 80/116 tumors （69.0％） and in 12/116 non-cancerous tissue specimens （10.3％; P=0.001）; LRP was expressed in 85/116 tumors （73.3％） and 19/116 non-cancerous tissue specimens （16.4％; P=0.001）.Importantly,the results demonstrated that increased GCS expression in NSCLC cancer specimens correlated with increased expression of P-gp and LRP,molecules known to stimulate cancer cell MDR （r=0.612 and 0.503,P=0.01 and 0.035,respectively）.Conclusion GCS upregulation might contribute to the development of NSCLC and could be a useful prognostic indicator and chemoresistance predictor for NSCLC patients.展开更多
Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylc...Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylceramide (GC), and epidermal growth factor (EGF). Spongy sheets were categorized into the following groups: Group I (HA/PGA), Group II (HA/PGA + VC), Group III (HA/PGA + GC), Group IV (HA/PGA + VC, GC), Group V (HA/PGA + EGF), Group VI (HA/PGA + VC, EGF), Group VII (HA/PGA + GC, EGF), and Group VIII (HA/PGA + VC, GC, EGF). In the first experiment, we examined fibroblast proliferation in conditioned medium that had been prepared by immersing each spongy sheet in a conventional culture medium. EGF-incorporating spongy sheets (Groups V-VIII) enhanced fibroblast proliferation more than EGF-free spongy sheets (Groups I-IV). In the second experiment, cytokine production by fibroblasts was evaluated using a wound surface model. This involved elevation of fibroblasts-incorporating collagen gel sheets to the air-liquid interface, on which a spongy sheet (Groups I, IV, V and VIII) was placed and cultured for 1 week. EGF-incorporating spongy sheets (Groups V and VIII) enhanced the production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by fibroblasts more than EGF-free spongy sheets (Groups I and IV). The effect of these four types of spongy sheet on wounds was investigated in animal experiments. Chemical peel was performed by contacting 50% trichloroacetic acid (TCA) on the dorsal region of mice, after which a spongy sheet was placed, and the wound condition was then observed in a two-week period. Angiogenesis was facilitated to a greater degree in Group VIII compared with Groups I, IV and V. This finding indicates that Group VIII spongy sheet is a promising aid for skin recovery after chemical peel.展开更多
The present paper is in the same time an overview of the literature concerning the alterations of lipids in the stratum corneum(SC) of atopic dogs and a review of data based on our publications. Knowing the importance...The present paper is in the same time an overview of the literature concerning the alterations of lipids in the stratum corneum(SC) of atopic dogs and a review of data based on our publications. Knowing the importance of the SC barrier function for against pathogens in atopic dermatitis, we show for the first time a detailed biochemical analysis of lipids corresponding to the same amount of proteins in the successive layers of canine SC taken using tape stripping and their specificity as compared to humans. Also we show new results concerning the changes in the composition for proteinbound ceramides, and for the other lipids in involved and non-involved skin areas in atopic dogs. We show how a topical or oral treatment can restore the SC lipid composition and reconstruct the barrier integrity by upregulating the biosynthesis of protein-bound ceramides.展开更多
Compared to proteins and RNAs, functional specificities associated with structural variations in fatty acids and lipids have been greatly underexplored. This review describes how our lab naively started to work on lip...Compared to proteins and RNAs, functional specificities associated with structural variations in fatty acids and lipids have been greatly underexplored. This review describes how our lab naively started to work on lipids 14 years ago, and how we have gradually overcome obstacles to address some interesting biological questions by combining genetics with biochemical methods on the nematode Caenorhabditis elegans. Our studies have revealed lipid variants and their metabolic pathways, in specific tissues, impact development and behaviors by regulating specific signaling events. The review also discusses the general research approach, style of lab management, and funding mechanisms that have facilitated the frequent research direction changes in the lab, including the journey into the lipid field.展开更多
文摘Physical stresses such as high temperature or hyper- osmosis are known causes of intracellular ceramide (Cer) accumulation in mammalian epithelial cells;these stresses also result in the activation of the biosy- ntheses of glucosylceramide (GlcCer) or galactosyl- ceramide via ceramide glycosylation. We confirmed that intracellular Cer and GlcCer increased in mouse fibroblast Mop 8 cells under conditions of heat stress. When molecular species of Cer, GlcCer and sphingo- myelin (SM) were analyzed by matrix assisted laser desorption ionization time of flight mass spectrome- try (MALDI-TOF MS), the molecular ion peaks of Cer (d18:1 - C16:0, Na+) and Cer (d18:1 - C22:0, Na+) increased under heat stress compared with those of Cer (d18:1 - C24:1, Na+) and Cer (d18:1 - C24:0, Na+). GlcCer and SM demonstrated the wide spectra of fatty acyl chains compared with that of Cer. The ratio of GlcCer consisted of hydroxy fatty acid to that con- sisted of non-hydroxy fatty acid increased 2-5-fold in heat stressed cells. Cer metabolism-related genes, se- rine palmitoyltransferase (Spt), ceramide synthase-1, -2, -4, -5 and -6 (CerS1, -2, -4, -5 and -6), neutral sphingomyelinase-1 and -2 (nSMase1 and nS-Mase2), sphingomyelin synthase-1 (SgmS1), and ceramide glu- cosyltransferase (GlcT), were activated after 16 h un- der heat stress at 42?C. Activation of Sg-mS1 and GlcT genes played a role as Cer scavengers in the decrease of intracellular Cer levels. Activation of Cer- S5 and/or CerS6 gene may contribute to the accu- mulation of Cer species of (d18:1 - C16:0) under heat stress.
基金the National Natural Science Foundation of China (31271517 and 31271518)State Key Laboratory of Molecular Developmental Biology+1 种基金ZHYX (2017zhyx29) of Scientific Research Foundation of the Institute for Translational Medicine of Anhui ProvinceBSKY (XJ201123) of Anhui Medical University.
文摘Glycosphingolipid (GSL) metabolism is involved in various physiological processes, including all major cell signaling pathways, and its dysregulation is linked to some diseases. The four-phosphate adaptor protein FAPP2-mediated glucosylceramide (GlcCer) transport for complex GSL synthesis has been studied extensively. However, the molecular machinery of FAPP2 as a GlcCer-transferring protein remains poorly defined. Here, we identify a Golgi-resident protein, acyl-coenzyme A binding domain containing 3 (ACBD3), as an interacting partner of FAPP2. We find that ACBD3 knockdown leads to dramatic Golgi fragmentation, which subsequently causes FAPP2 dispersal throughout the cytoplasm and a decreased localization at trans-Golgi network. The further quantitative Upidomic analysis indicates that ACBD3 knockdown triggers abnormal sphingolipid metabolism. Interestingly, the expression of siRNA-resistant full-length ACBD3 can rescue these defects caused by ACBD3 knockdown. These data reveal critical roles for ACBD3 in maintaining the integrity of Golgi morphology and cellular sphingolipid homeostasis and establish the importance of the integrated Golgi complex for the transfer of GlcCer and complex GSL synthesis.
文摘Background Glucosylceramide synthase （GCS） can reduce ceramide levels and help cells escape ceramide-induced apoptosis, thus leading to multidrug resistance （MDR）. However, its expression and clinical significance in thyroid neoplasms still remain unclear. We aimed to elucidate the expression of GCS and explore its correlation with the clinicopathological characteristics in papillary thyroid carcinomas （PTCs）. Methods We retrospectively investigated GCS protein expression level in tissue specimens obtained from 108 consecutive PTC patients by immunohistochemistry and Western blotting. Results GCS was weakly positive or negative in normal follicular cells, but it was frequently overexpressed in PTC cells. GCS overexpression was associated with primary tumor size, local infiltration, lymph node metastasis, and local recurrence, but not associated with gender, age, pathological variants, tumor multifocality, tumor stage or distant metastasis. Western blotting also showed that GCS protein levels were much higher in PTCs＇ tissues than in normal thyroid tissues. Conclusion GCS was upregulated in PTCs and might be an independent factor affecting prognosis.
文摘Background Glucosylceramide synthase （GCS）,an enzyme responsible for ceramide glycosylation,plays an important role in multidrug resistance （MDR） in some tumors in vitro; however,its expression and clinicopathological significance in non-small cell lung cancer （NSCLC） remains unclear.Methods We evaluated GCS expression in 116 paired tumor and adjacent non-cancerous tissues and 50 frozen tissues from patients with NSCLC using immunohistochemistry and western blotting,and explored the correlation between GCS and NSCLC clinicopathological characteristics and prognosis.We observed the association between GCS and the MDR proteins P-glycoprotein （P-gp） and lung resistance-related protein （LRP） to determine the link between GCS and MDR at the histological level.Results GCS expression was significantly upregulated in NSCLC tumors compared with non-cancerous tissue.There was high GCS expression in 75/116 tumor specimens （64.7％） and 16/116 non-cancerous specimens （13.8％）.High GCS expression was significantly associated with poor differentiation （P=0.01）,lymph node metastasis （P=0.004）,recurrence/ distant metastasis （P=0.006）,and chemotherapy resistance （P=0.025）.Multivariate analysis demonstrated that GCS immunopositivity was an independent risk factor for survival （P=0.018）.P-gp was expressed in 80/116 tumors （69.0％） and in 12/116 non-cancerous tissue specimens （10.3％; P=0.001）; LRP was expressed in 85/116 tumors （73.3％） and 19/116 non-cancerous tissue specimens （16.4％; P=0.001）.Importantly,the results demonstrated that increased GCS expression in NSCLC cancer specimens correlated with increased expression of P-gp and LRP,molecules known to stimulate cancer cell MDR （r=0.612 and 0.503,P=0.01 and 0.035,respectively）.Conclusion GCS upregulation might contribute to the development of NSCLC and could be a useful prognostic indicator and chemoresistance predictor for NSCLC patients.
文摘Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylceramide (GC), and epidermal growth factor (EGF). Spongy sheets were categorized into the following groups: Group I (HA/PGA), Group II (HA/PGA + VC), Group III (HA/PGA + GC), Group IV (HA/PGA + VC, GC), Group V (HA/PGA + EGF), Group VI (HA/PGA + VC, EGF), Group VII (HA/PGA + GC, EGF), and Group VIII (HA/PGA + VC, GC, EGF). In the first experiment, we examined fibroblast proliferation in conditioned medium that had been prepared by immersing each spongy sheet in a conventional culture medium. EGF-incorporating spongy sheets (Groups V-VIII) enhanced fibroblast proliferation more than EGF-free spongy sheets (Groups I-IV). In the second experiment, cytokine production by fibroblasts was evaluated using a wound surface model. This involved elevation of fibroblasts-incorporating collagen gel sheets to the air-liquid interface, on which a spongy sheet (Groups I, IV, V and VIII) was placed and cultured for 1 week. EGF-incorporating spongy sheets (Groups V and VIII) enhanced the production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by fibroblasts more than EGF-free spongy sheets (Groups I and IV). The effect of these four types of spongy sheet on wounds was investigated in animal experiments. Chemical peel was performed by contacting 50% trichloroacetic acid (TCA) on the dorsal region of mice, after which a spongy sheet was placed, and the wound condition was then observed in a two-week period. Angiogenesis was facilitated to a greater degree in Group VIII compared with Groups I, IV and V. This finding indicates that Group VIII spongy sheet is a promising aid for skin recovery after chemical peel.
文摘The present paper is in the same time an overview of the literature concerning the alterations of lipids in the stratum corneum(SC) of atopic dogs and a review of data based on our publications. Knowing the importance of the SC barrier function for against pathogens in atopic dermatitis, we show for the first time a detailed biochemical analysis of lipids corresponding to the same amount of proteins in the successive layers of canine SC taken using tape stripping and their specificity as compared to humans. Also we show new results concerning the changes in the composition for proteinbound ceramides, and for the other lipids in involved and non-involved skin areas in atopic dogs. We show how a topical or oral treatment can restore the SC lipid composition and reconstruct the barrier integrity by upregulating the biosynthesis of protein-bound ceramides.
基金supported by Howard Hughes Medical Institute and National Institute of Health
文摘Compared to proteins and RNAs, functional specificities associated with structural variations in fatty acids and lipids have been greatly underexplored. This review describes how our lab naively started to work on lipids 14 years ago, and how we have gradually overcome obstacles to address some interesting biological questions by combining genetics with biochemical methods on the nematode Caenorhabditis elegans. Our studies have revealed lipid variants and their metabolic pathways, in specific tissues, impact development and behaviors by regulating specific signaling events. The review also discusses the general research approach, style of lab management, and funding mechanisms that have facilitated the frequent research direction changes in the lab, including the journey into the lipid field.
