1
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Vti1a/b support distinct aspects of TGN and cis-/medial Golgi organization. Sci Rep 2022; 12:20870. [PMID: 36460703 PMCID: PMC9718741 DOI: 10.1038/s41598-022-25331-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
Retrograde trafficking towards the trans-Golgi network (TGN) is important for dense core vesicle (DCV) biogenesis. Here, we used Vti1a/b deficient neurons to study the impact of disturbed retrograde trafficking on Golgi organization and cargo sorting. In Vti1a/b deficient neurons, staining intensity of cis-/medial Golgi proteins (e.g., GM130 and giantin) was increased, while the intensity of two recycling TGN proteins, TGN38 and TMEM87A, was decreased and the TGN-resident protein Golgin97 was normal. Levels and localization of DCV cargo markers, LAMP1 and KDEL were also altered. This phenotype was not caused by reduced Golgi size or absence of a TGN compartment. The phenotype was partially phenocopied by disturbing sphingolipid homeostasis, but was not rescued by overexpression of sphingomyelin synthases or the sphingolipid synthesis inhibitor myriocin. We conclude that Vti1a/b are important for distinct aspects of TGN and cis-/medial Golgi organization. Our data underline the importance of retrograde trafficking for Golgi organization, DCV cargo sorting and the distribution of proteins of the regulated secretory pathway.
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2
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Lambert-Smith IA, Saunders DN, Yerbury JJ. Progress in biophysics and molecular biology proteostasis impairment and ALS. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 174:3-27. [PMID: 35716729 DOI: 10.1016/j.pbiomolbio.2022.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 05/19/2022] [Accepted: 06/09/2022] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neurodegenerative disease that results from the loss of both upper and lower motor neurons. It is the most common motor neuron disease and currently has no effective treatment. There is mounting evidence to suggest that disturbances in proteostasis play a significant role in ALS pathogenesis. Proteostasis is the maintenance of the proteome at the right level, conformation and location to allow a cell to perform its intended function. In this review, we present a thorough synthesis of the literature that provides evidence that genetic mutations associated with ALS cause imbalance to a proteome that is vulnerable to such pressure due to its metastable nature. We propose that the mechanism underlying motor neuron death caused by defects in mRNA metabolism and protein degradation pathways converges on proteostasis dysfunction. We propose that the proteostasis network may provide an effective target for therapeutic development in ALS.
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Affiliation(s)
- Isabella A Lambert-Smith
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Darren N Saunders
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Justin J Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.
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3
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Vos M, Dulovic-Mahlow M, Mandik F, Frese L, Kanana Y, Haissatou Diaw S, Depperschmidt J, Böhm C, Rohr J, Lohnau T, König IR, Klein C. Ceramide accumulation induces mitophagy and impairs β-oxidation in PINK1 deficiency. Proc Natl Acad Sci U S A 2021; 118:e2025347118. [PMID: 34686591 PMCID: PMC8639384 DOI: 10.1073/pnas.2025347118] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2021] [Indexed: 11/18/2022] Open
Abstract
Energy production via the mitochondrial electron transport chain (ETC) and mitophagy are two important processes affected in Parkinson's disease (PD). Interestingly, PINK1, mutations of which cause early-onset PD, plays a key role in both processes, suggesting that these two mechanisms are connected. However, the converging link of both pathways currently remains enigmatic. Recent findings demonstrated that lipid aggregation, along with defective mitochondria, is present in postmortem brains of PD patients. In addition, an increasing body of evidence shows that sphingolipids, including ceramide, are altered in PD, supporting the importance of lipids in the pathophysiology of PD. Here, we identified ceramide to play a crucial role in PINK1-related PD that was previously linked almost exclusively to mitochondrial dysfunction. We found ceramide to accumulate in mitochondria and to negatively affect mitochondrial function, most notably the ETC. Lowering ceramide levels improved mitochondrial phenotypes in pink1-mutant flies and PINK1-deficient patient-derived fibroblasts, showing that the effects of ceramide are evolutionarily conserved. In addition, ceramide accumulation provoked ceramide-induced mitophagy upon PINK1 deficiency. As a result of the ceramide accumulation, β-oxidation in PINK1 mutants was decreased, which was rescued by lowering ceramide levels. Furthermore, stimulation of β-oxidation was sufficient to rescue PINK1-deficient phenotypes. In conclusion, we discovered a cellular mechanism resulting from PD-causing loss of PINK1 and found a protective role of β-oxidation in ETC dysfunction, thus linking lipids and mitochondria in the pathophysiology of PINK1-related PD. Furthermore, our data nominate β-oxidation and ceramide as therapeutic targets for PD.
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Affiliation(s)
- Melissa Vos
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany;
| | | | - Frida Mandik
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany
| | - Lisa Frese
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany
| | - Yuliia Kanana
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany
| | | | | | - Claudia Böhm
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany
| | - Jonas Rohr
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany
| | - Thora Lohnau
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany
| | - Inke R König
- Institut für Medizinische Biometrie und Statistik, University of Luebeck, 23562 Luebeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Luebeck, 23562 Luebeck, Germany;
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4
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Sun Y, Liu Y, Ma X, Hu H. The Influence of Cell Cycle Regulation on Chemotherapy. Int J Mol Sci 2021; 22:6923. [PMID: 34203270 PMCID: PMC8267727 DOI: 10.3390/ijms22136923] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/14/2022] Open
Abstract
Cell cycle regulation is orchestrated by a complex network of interactions between proteins, enzymes, cytokines, and cell cycle signaling pathways, and is vital for cell proliferation, growth, and repair. The occurrence, development, and metastasis of tumors are closely related to the cell cycle. Cell cycle regulation can be synergistic with chemotherapy in two aspects: inhibition or promotion. The sensitivity of tumor cells to chemotherapeutic drugs can be improved with the cooperation of cell cycle regulation strategies. This review presented the mechanism of the commonly used chemotherapeutic drugs and the effect of the cell cycle on tumorigenesis and development, and the interaction between chemotherapy and cell cycle regulation in cancer treatment was briefly introduced. The current collaborative strategies of chemotherapy and cell cycle regulation are discussed in detail. Finally, we outline the challenges and perspectives about the improvement of combination strategies for cancer therapy.
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Affiliation(s)
- Ying Sun
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China; (Y.S.); (Y.L.)
| | - Yang Liu
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China; (Y.S.); (Y.L.)
| | - Xiaoli Ma
- Qingdao Institute of Measurement Technology, Qingdao 266000, China;
| | - Hao Hu
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China; (Y.S.); (Y.L.)
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5
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Gonzalez-Riano C, León-Espinosa G, Regalado-Reyes M, García A, DeFelipe J, Barbas C. Metabolomic Study of Hibernating Syrian Hamster Brains: In Search of Neuroprotective Agents. J Proteome Res 2019; 18:1175-1190. [DOI: 10.1021/acs.jproteome.8b00816] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Gonzalo León-Espinosa
- Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Campus Montegancedo, 28223 Pozuelo de Alarcón, Madrid, Spain
- Instituto Cajal (CSIC), Avenida Doctor Arce 37, 28002 Madrid, Spain
| | - Mamen Regalado-Reyes
- Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Campus Montegancedo, 28223 Pozuelo de Alarcón, Madrid, Spain
| | | | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Campus Montegancedo, 28223 Pozuelo de Alarcón, Madrid, Spain
- Instituto Cajal (CSIC), Avenida Doctor Arce 37, 28002 Madrid, Spain
- CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Calle de Valderrebollo, 5, 28031 Madrid, Spain
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6
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Activation of neutral sphingomyelinase 2 by starvation induces cell-protective autophagy via an increase in Golgi-localized ceramide. Cell Death Dis 2018; 9:670. [PMID: 29867196 PMCID: PMC5986760 DOI: 10.1038/s41419-018-0709-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/18/2018] [Accepted: 05/02/2018] [Indexed: 12/19/2022]
Abstract
Autophagy is essential for optimal cell function and survival, and the entire process accompanies membrane dynamics. Ceramides are produced by different enzymes at different cellular membrane sites and mediate differential signaling. However, it remains unclear which ceramide-producing pathways/enzymes participate in autophagy regulation under physiological conditions such as nutrient starvation, and what the underlying mechanisms are. In this study, we demonstrate that among ceramide-producing enzymes, neutral sphingomyelinase 2 (nSMase2) plays a key role in autophagy during nutrient starvation. nSMase2 was rapidly and stably activated upon starvation, and the enzymatic reaction in the Golgi apparatus facilitated autophagy through the activation of p38 MAPK and inhibition of mTOR. Moreover, nSMase2 played a protective role against cellular damage depending on autophagy. These findings suggest that nSMase2 is a novel regulator of autophagy and provide evidence that Golgi-localized ceramides participate in cytoprotective autophagy against starvation.
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7
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D'Angelo G, Moorthi S, Luberto C. Role and Function of Sphingomyelin Biosynthesis in the Development of Cancer. Adv Cancer Res 2018; 140:61-96. [PMID: 30060817 DOI: 10.1016/bs.acr.2018.04.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sphingomyelin (SM) biosynthesis represents a complex, finely regulated process, mostly occurring in vertebrates. It is intimately linked to lipid transport and it is ultimately carried out by two enzymes, SM synthase 1 and 2, selectively localized in the Golgi and plasma membrane. In the course of the SM biosynthetic reaction, various lipids are metabolized. Because these lipids have both structural and signaling functions, the SM biosynthetic process has the potential to affect diverse important cellular processes (such as cell proliferation, cell survival, and migration). Thus defects in SM biosynthesis might directly or indirectly impact the normal physiology of the cell and eventually of the organism. In this chapter, we will focus on evidence supporting a role for SM biosynthesis in specific cellular functions and how its dysregulation can affect neoplastic transformation.
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Affiliation(s)
- Giovanni D'Angelo
- Institute of Protein Biochemistry, National Research Council of Italy, Naples, Italy
| | - Sitapriya Moorthi
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, United States
| | - Chiara Luberto
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, United States
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8
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Duran JM, Campelo F, van Galen J, Sachsenheimer T, Sot J, Egorov MV, Rentero C, Enrich C, Polishchuk RS, Goñi FM, Brügger B, Wieland F, Malhotra V. Sphingomyelin organization is required for vesicle biogenesis at the Golgi complex. EMBO J 2012. [PMID: 23178595 DOI: 10.1038/emboj.2012.317] [Citation(s) in RCA: 231] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Sphingomyelin and cholesterol can assemble into domains and segregate from other lipids in the membranes. These domains are reported to function as platforms for protein transport and signalling. Do similar domains exist in the Golgi membranes and are they required for protein secretion? We tested this hypothesis by using D-ceramide-C6 to manipulate lipid homeostasis of the Golgi membranes. Lipidomics of the Golgi membranes isolated from D-ceramide-C6-treated HeLa cells revealed an increase in the levels of C6-sphingomyelin, C6-glucosylceramide, and diacylglycerol. D-ceramide-C6 treatment in HeLa cells inhibited transport carrier formation at the Golgi membranes without affecting the fusion of incoming carriers. The defect in protein secretion as a result of D-ceramide-C6 treatment was alleviated by knockdown of the sphingomyelin synthases 1 and 2. C6-sphingomyelin prevented liquid-ordered domain formation in giant unilamellar vesicles and reduced the lipid order in the Golgi membranes of HeLa cells. These findings highlight the importance of a regulated production and organization of sphingomyelin in the biogenesis of transport carriers at the Golgi membranes.
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Affiliation(s)
- Juan M Duran
- Cell and Developmental Biology Programme, Centre for Genomic Regulation, Barcelona, Spain
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9
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Wang G, Dinkins M, He Q, Zhu G, Poirier C, Campbell A, Mayer-Proschel M, Bieberich E. Astrocytes secrete exosomes enriched with proapoptotic ceramide and prostate apoptosis response 4 (PAR-4): potential mechanism of apoptosis induction in Alzheimer disease (AD). J Biol Chem 2012; 287:21384-95. [PMID: 22532571 DOI: 10.1074/jbc.m112.340513] [Citation(s) in RCA: 280] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Amyloid protein is well known to induce neuronal cell death, whereas only little is known about its effect on astrocytes. We found that amyloid peptides activated caspase 3 and induced apoptosis in primary cultured astrocytes, which was prevented by caspase 3 inhibition. Apoptosis was also prevented by shRNA-mediated down-regulation of PAR-4, a protein sensitizing cells to the sphingolipid ceramide. Consistent with a potentially proapoptotic effect of PAR-4 and ceramide, astrocytes surrounding amyloid plaques in brain sections of the 5xFAD mouse (and Alzheimer disease patient brain) showed caspase 3 activation and were apoptotic when co-expressing PAR-4 and ceramide. Apoptosis was not observed in astrocytes with deficient neutral sphingomyelinase 2 (nSMase2), indicating that ceramide generated by nSMase2 is critical for amyloid-induced apoptosis. Antibodies against PAR-4 and ceramide prevented amyloid-induced apoptosis in vitro and in vivo, suggesting that apoptosis was mediated by exogenous PAR-4 and ceramide, potentially associated with secreted lipid vesicles. This was confirmed by the analysis of lipid vesicles from conditioned medium showing that amyloid peptide induced the secretion of PAR-4 and C18 ceramide-enriched exosomes. Exosomes were not secreted by nSMase2-deficient astrocytes, indicating that ceramide generated by nSMase2 is critical for exosome secretion. Consistent with the ceramide composition in amyloid-induced exosomes, exogenously added C18 ceramide restored PAR-4-containing exosome secretion in nSMase2-deficient astrocytes. Moreover, isolated PAR-4/ceramide-enriched exosomes were taken up by astrocytes and induced apoptosis in the absence of amyloid peptide. Taken together, we report a novel mechanism of apoptosis induction by PAR-4/ceramide-enriched exosomes, which may critically contribute to Alzheimer disease.
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Affiliation(s)
- Guanghu Wang
- Program in Developmental Neurobiology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Georgia Health Sciences University, Augusta, Georgia 30912, USA
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10
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Gusain A, Hatcher JF, Adibhatla RM, Wesley UV, Dempsey RJ. Anti-proliferative effects of tricyclodecan-9-yl-xanthogenate (D609) involve ceramide and cell cycle inhibition. Mol Neurobiol 2012; 45:455-64. [PMID: 22415444 DOI: 10.1007/s12035-012-8254-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/01/2012] [Indexed: 12/14/2022]
Abstract
Tricyclodecan-9-yl-xanthogenate (D609) inhibits phosphatidylcholine (PC)-phospholipase C (PLC) and/or sphingomyelin (SM) synthase (SMS). Inhibiting SMS can increase ceramide levels, which can inhibit cell proliferation. Here, we examined how individual inflammatory and glia cell proliferation is altered by D609. Treatment with 100-μM D609 significantly attenuated the proliferation of RAW 264.7 macrophages, N9 and BV-2 microglia, and DITNC(1) astrocytes, without affecting cell viability. D609 significantly inhibited BrdU incorporation in BV-2 microglia and caused accumulation of cells in G(1) phase with decreased number of cells in the S phase. D609 treatment for 2 h significantly increased ceramide levels in BV-2 microglia, which, following a media change, returned to control levels 22 h later. This suggests that the effect of D609 may be mediated, at least in part, through ceramide increase via SMS inhibition. Western blots demonstrated that 2-h treatment of BV-2 microglia with D609 increased expression of the cyclin-dependent kinase (Cdk) inhibitor p21 and down-regulated phospho-retinoblastoma (Rb), both of which returned to basal levels 22 h after removal of D609. Exogenous C8-ceramide also inhibited BV-2 microglia proliferation without loss of viability and decreased BrdU incorporation, supporting the involvement of ceramide in D609-mediated cell cycle arrest. Our current data suggest that D609 may offer benefit after stroke (Adibhatla and Hatcher, Mol Neurobiol 41:206-217, 2010) through ceramide-mediated cell cycle arrest, thus restricting glial cell proliferation.
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Affiliation(s)
- Anchal Gusain
- Department of Neurological Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792, USA
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11
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Melser S, Molino D, Batailler B, Peypelut M, Laloi M, Wattelet-Boyer V, Bellec Y, Faure JD, Moreau P. Links between lipid homeostasis, organelle morphodynamics and protein trafficking in eukaryotic and plant secretory pathways. PLANT CELL REPORTS 2011; 30:177-193. [PMID: 21120657 DOI: 10.1007/s00299-010-0954-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 11/15/2010] [Indexed: 05/30/2023]
Abstract
The role of lipids as molecular actors of protein transport and organelle morphology in plant cells has progressed over the last years through pharmacological and genetic investigations. The manuscript is reviewing the roles of various lipid families in membrane dynamics and trafficking in eukaryotic cells, and summarizes some of the related physicochemical properties of the lipids involved. The article also focuses on the specific requirements of the sphingolipid glucosylceramide (GlcCer) in Golgi morphology and protein transport through the plant secretory pathway. The use of a specific inhibitor of plant glucosylceramide synthase and selected Arabidopsis thaliana RNAi lines stably expressing several markers of the plant secretory pathway, establishes specific steps sensitive to GlcCer biosynthesis. Collectively, data of the literature demonstrate the existence of links between protein trafficking, organelle morphology, and lipid metabolism/homeostasis in eukaryotic cells including plant cells.
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Affiliation(s)
- Su Melser
- Laboratoire de Biogenèse Membranaire, UMR 5200 Université Bordeaux 2-CNRS, Université Bordeaux 2, case 92, 146 rue Léo-Saignat, 33076 Bordeaux, France.
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12
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La Rosa S, Vigetti D, Placidi C, Finzi G, Uccella S, Clerici M, Bartolini B, Carnevali I, Losa M, Capella C. Localization of carboxyl ester lipase in human pituitary gland and pituitary adenomas. J Histochem Cytochem 2010; 58:881-9. [PMID: 20566755 DOI: 10.1369/jhc.2010.956169] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Carboxyl ester lipase (CEL) is an enzyme that hydrolyzes a wide variety of lipid substrates, including ceramides, which are known to show inhibitory regulation of pituitary hormone secretion in experimental models. Because no studies on CEL expression in human pituitary and pituitary adenomas have been reported in the literature, we investigated CEL expression in 10 normal pituitary glands and 86 well-characterized pituitary adenomas [12 FSH/LH cell, 17 α-subunit/null cell, 6 TSH cell, 21 ACTH cell, 11 prolactin (PRL) cell, and 19 GH cell adenomas] using IHC, immunoelectron microscopy, Western blotting, and quantitative RT-PCR. In normal adenohypophysis, CEL was localized in GH, ACTH, and TSH cells. In adenomas, it was mainly found in functioning GH, ACTH, and TSH tumors, whereas its expression was poor in the corresponding silent adenomas and was lacking in FSH/LH cell, null cell, and PRL cell adenomas. Ultrastructurally, CEL was localized in secretory granules close to their membranes. This is the first study demonstrating CEL expression in normal human pituitary glands and in functioning GH, ACTH, and TSH adenomas. Considering that CEL hydrolyzes ceramides, inactivating their inhibitory function on pituitary hormone secretion, our findings suggest a possible role of CEL in the regulation of hormone secretion in both normal and adenomatous pituitary cells.
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Affiliation(s)
- Stefano La Rosa
- Department of Pathology, Ospedale di Circolo, Varese, Italy.
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13
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Furt F, Moreau P. Importance of lipid metabolism for intracellular and mitochondrial membrane fusion/fission processes. Int J Biochem Cell Biol 2009; 41:1828-36. [PMID: 19703652 DOI: 10.1016/j.biocel.2009.02.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 02/06/2009] [Accepted: 02/10/2009] [Indexed: 10/21/2022]
Abstract
Mitochondria move along cytoskeletal tracks, fuse and divide. These dynamic features have been shown to be critical for several mitochondrial functions in cell viability and cell death. After a rapid recall of the proteic machineries that are known to be involved, the review will focus on lipids, other key molecular actors of membrane dynamics. A summary of the current knowledge on lipids and their implication in various cellular membrane fusion/fission processes will be first presented. The review will then report what has been discovered or can be expected on the role of the different families of lipids in mitochondrial membrane fusion and fission processes.
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Affiliation(s)
- Fabienne Furt
- Membrane Biogenesis Laboratory, UMR 5200, University of Bordeaux II-CNRS, France
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14
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Fugmann T, Hausser A, Schöffler P, Schmid S, Pfizenmaier K, Olayioye MA. Regulation of secretory transport by protein kinase D-mediated phosphorylation of the ceramide transfer protein. ACTA ACUST UNITED AC 2007; 178:15-22. [PMID: 17591919 PMCID: PMC2064413 DOI: 10.1083/jcb.200612017] [Citation(s) in RCA: 320] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein kinase D (PKD) has been identified as a crucial regulator of secretory transport at the trans-Golgi network (TGN). Recruitment and activation of PKD at the TGN is mediated by the lipid diacylglycerol, a pool of which is generated by sphingomyelin synthase from ceramide and phosphatidylcholine. The nonvesicular transfer of ceramide from the endoplasmic reticulum to the Golgi complex is mediated by the lipid transfer protein CERT (ceramide transport). In this study, we identify CERT as a novel in vivo PKD substrate. Phosphorylation on serine 132 by PKD decreases the affinity of CERT toward its lipid target phosphatidylinositol 4-phosphate at Golgi membranes and reduces ceramide transfer activity, identifying PKD as a regulator of lipid homeostasis. We also show that CERT, in turn, is critical for PKD activation and PKD-dependent protein cargo transport to the plasma membrane. Thus, the interdependence of PKD and CERT is key to the maintenance of Golgi membrane integrity and secretory transport.
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Affiliation(s)
- Tim Fugmann
- University of Stuttgart, Institute of Cell Biology and Immunology, 70569 Stuttgart, Germany
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15
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Moreau P. Lipids: architects and regulators of membrane dynamics and trafficking. PLANT SIGNALING & BEHAVIOR 2007; 2:157-159. [PMID: 19704742 PMCID: PMC2634043 DOI: 10.4161/psb.2.3.3686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 12/07/2006] [Indexed: 05/28/2023]
Abstract
We have recently shown that an inhibition of sterol synthesis by fenpropimorph leads to an accumulation of sterol precursors, hydroxypalmitic acid-containing glucosylceramides and detergent resistant membranes in the Golgi bodies instead of the plasma membrane, suggesting that the individual molecules or the microdomains were blocked in the Golgi. These results and others from several eukaryotic models link lipid metabolism with membrane morphodynamics that are involved in membrane trafficking. Focus has been expanded to other lipid families, and numerous evidences are given showing lipids and lipid-modifying enzymes as key regulators of membrane homeostasis which can strongly regulate membrane morphodynamics and therefore trafficking. Beside protein-based machineries, lipid-based machineries are also shown as crucial regulatory forces involved in protein transport and sorting.
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16
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Brumeanu TD, Preda-Pais A, Stoica C, Bona C, Casares S. Differential partitioning and trafficking of GM gangliosides and cholesterol-rich lipid rafts in thymic and splenic CD4 T cells. Mol Immunol 2007; 44:530-40. [PMID: 16597465 DOI: 10.1016/j.molimm.2006.02.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 01/06/2006] [Accepted: 02/14/2006] [Indexed: 01/25/2023]
Abstract
The GM gangliosides and cholesterol components of plasma membrane lipid rafts play an important role in the recruitment and signaling of protein receptors in eukaryotic cells. Herein, we have analyzed at the single-cell level the partitioning and intracellular trafficking of GM gangliosides and cholesterol in quiescent (CD4+CD69-) and CD3-activated (CD4+CD69+) thymic and splenic T cells. First, regardless the gender and the quiescent or activated status of T cells, the GM and cholesterol content in cytosol and plasma membrane as well as the expression levels of GM synthase, Sphingomyelin phosphodiestarase 2 and HMG Co-A reductase genes involved in GM and cholesterol synthesis were constantly lower in CD4 thymocytes than in CD4 splenocytes. Second, we detected variations in the balance between GM and cholesterol in plasma membrane depending on aging, and found that deprivation of cellular cholesterol does not necessarily affect the GM content in both quiescent CD4 thymocytes and splenocytes. Third, CD3 stimulation up-regulated the GM and little if any the cholesterol content in both thymic and splenic CD4 T cells, suggesting a cross talk between the CD3 signaling and GM but not cholesterol biosynthesis pathway. Fourth, partitioning and trafficking of GM to the plasma membrane depended on the transport of ceramide precursors from endoplasmic reticulum to Golgi network, as well as on the synthesis, glycosylation and vesicular assembly in trans-Golgi, and less on the cytoskeleton architecture in both quiescent and activated CD4 thymic and splenic T cells. Together, these findings suggest that the differential partitioning and intracellular trafficking of GM and cholesterol in thymic and splenic CD4 T cells may account for the stage of functional maturation.
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Affiliation(s)
- Teodor-D Brumeanu
- Department of Medicine, Division of Immunology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA.
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Hui DY, Howles PN. Molecular mechanisms of cholesterol absorption and transport in the intestine. Semin Cell Dev Biol 2005; 16:183-92. [PMID: 15797829 DOI: 10.1016/j.semcdb.2005.01.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many enzymes and transport proteins participate in cholesterol absorption. This review summarizes recent results on several proteins that are important for each step of the cholesterol absorption pathway, including the important roles of: (i) pancreatic triglyceride lipase (PTL), carboxyl ester lipase (CEL), and ileal bile acid transporter in determining the rate of cholesterol absorption; (ii) ATP binding cassette (ABC) transporters and the Niemann-Pick C-1 like-1 (NPC1L1) protein as intestinal membrane gatekeepers for cholesterol efflux and influx; and (iii) intracellular membrane vesicles and transport proteins in lipid trafficking through intracellular compartments prior to lipoprotein assembly and secretion to plasma circulation.
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Affiliation(s)
- David Y Hui
- Department of Pathology, University of Cincinnati Genome Research Institute, Cincinnati, OH 45237-0507, USA.
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Hui DY, Howles PN. Carboxyl ester lipase: structure-function relationship and physiological role in lipoprotein metabolism and atherosclerosis. J Lipid Res 2002; 43:2017-30. [PMID: 12454261 DOI: 10.1194/jlr.r200013-jlr200] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Carboxyl ester lipase (CEL), previously named cholesterol esterase or bile salt-stimulated (or dependent) lipase, is a lipolytic enzyme capable of hydrolyzing cholesteryl esters, tri-, di-, and mono-acylglycerols, phospholipids, lysophospholipids, and ceramide. The active site catalytic triad of serine-histidine-aspartate is centrally located within the enzyme structure and is partially covered by a surface loop. The carboxyl terminus of the protein regulates enzymatic activity by forming hydrogen bonds with the surface loop to partially shield the active site. Bile salt binding to the loop domain frees the active site for accessibility by water-insoluble substrates. CEL is synthesized primarily in the pancreas and lactating mammary gland, but the enzyme is also expressed in liver, macrophages, and in the vessel wall. In the gastrointestinal tract, CEL serves as a compensatory protein to other lipolytic enzymes for complete digestion and absorption of lipid nutrients. Importantly, CEL also participates in chylomicron assembly and secretion, in a mechanism mediated through its ceramide hydrolytic activity. Cell culture studies suggest a role for CEL in lipoprotein metabolism and oxidized LDL-induced atherosclerosis. Thus, this enzyme, which has a wide substrate reactivity and diffuse anatomic distribution, may have multiple functions in lipid and lipoprotein metabolism, and atherosclerosis.
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Affiliation(s)
- David Y Hui
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Elyaman W, Yardin C, Hugon J. Involvement of glycogen synthase kinase-3beta and tau phosphorylation in neuronal Golgi disassembly. J Neurochem 2002; 81:870-80. [PMID: 12065646 DOI: 10.1046/j.1471-4159.2002.00838.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The dissociation of the neuronal Golgi complex is a classical feature observed in neurodegenerative disorders including Alzheimer's disease. The goal of this study is to determine if the phosphorylation of tau protein is involved in neuronal Golgi disassembly. Primary cortical cultures were exposed to two Golgi toxins, brefeldin A (BFA) or nordihydroguaiaretic acid (NDGA). Immunocytochemical studies using the anti58 k antibody revealed that Golgi disassembly started in exposed neurons a few minutes after treatment. BFA and NDGA induced a rapid and transient increase in tau phosphorylation in a site-specific manner on immunoblots. In addition, the increase in tau phosphorylation directly correlated with a transient dissociation of tau from the cytoskeleton and a decrease of the acetylated tubulin. Furthermore, the activity of glycogen synthase kinase-3beta (GSK-3beta) increased transiently, as demonstrated by the kinase activity assay and by immunoblottings of serine-9 and tyrosine-216 phosphorylated of GSK-3beta. A decrease of the Akt phosphorylated form was also shown. The increase in tau phosphorylation was inhibited by the GSK-3beta inhibitor, lithium. Finally, morphometric studies showed that lithium partially blocked the Golgi disassembly caused by BFA or NDGA. Together these findings indicate that GSK-3beta activity and tau phosphorylation state are involved in the maintenance of the neuronal Golgi organization.
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Affiliation(s)
- Wassim Elyaman
- Department of Anatomy, Faculty of Medicine, the University of Hong Kong, 21 Sassoon Road, Hong Kong, SAR
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20
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Ogretmen B, Pettus BJ, Rossi MJ, Wood R, Usta J, Szulc Z, Bielawska A, Obeid LM, Hannun YA. Biochemical mechanisms of the generation of endogenous long chain ceramide in response to exogenous short chain ceramide in the A549 human lung adenocarcinoma cell line. Role for endogenous ceramide in mediating the action of exogenous ceramide. J Biol Chem 2002; 277:12960-9. [PMID: 11815611 DOI: 10.1074/jbc.m110699200] [Citation(s) in RCA: 335] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Treatment of A549 cells with C(6)-ceramide resulted in a significant increase in the endogenous long chain ceramide levels, which was inhibited by fumonisin B1 (FB1), and not by myriocin (MYR). The biochemical mechanisms of generation of endogenous ceramide were investigated using A549 cells treated with selectively labeled C(6)-ceramides, [sphingosine-3-(3)H]d-erythro-, and N-[N-hexanoyl-1-(14)C]d-erythro-C(6)-ceramide. The results demonstrated that (3)H label was incorporated into newly synthesized long chain ceramides, which was inhibited by FB1 and not by MYR. Interestingly, the (14)C label was not incorporated into long chain ceramides. Taken together, these results show that generation of endogenous ceramide in response to C(6)-ceramide is due to recycling of the sphingosine backbone of C(6)-ceramide via deacylation/reacylation and not due to the elongation of its fatty acid moiety. Moreover, the generation of endogenous long chain ceramide in response to C(6)-ceramide was completely blocked by brefeldin A, which causes Golgi disassembly, suggesting a role for the Golgi in the metabolism of ceramide. In addition, the generation of endogenous ceramide in response to short chain exogenous ceramide was induced by d-erythro- but not l-erythro-C(6)-ceramide, demonstrating the stereospecificity of this process. Interestingly, several key downstream biological activities of ceramide, such as growth inhibition, cell cycle arrest, and modulation of telomerase activity were induced by d-erythro-C(6)-ceramide, and not l-erythro-C(6)-ceramide (and inhibited by FB1) in A549 cells, suggesting a role for endogenous long chain ceramide in the regulation of these responses.
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Affiliation(s)
- Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.
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21
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Kirby RJ, Zheng S, Tso P, Howles PN, Hui DY. Bile salt-stimulated carboxyl ester lipase influences lipoprotein assembly and secretion in intestine: a process mediated via ceramide hydrolysis. J Biol Chem 2002; 277:4104-9. [PMID: 11733511 DOI: 10.1074/jbc.m107549200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bile salt-stimulated carboxyl ester lipase (CEL), also called cholesterol esterase, is one of the major proteins secreted by the pancreas. The physiological role of CEL was originally thought to be its mediation of dietary cholesterol absorption. However, recent studies showed no difference between wild type and CEL knockout mice in the total amount of cholesterol absorbed in a single meal. The current study tests the hypothesis that CEL in the intestinal lumen may influence the type of lipoproteins produced. A lipid emulsion containing 4 mm phospholipid, 13.33 mm [(3)H]triolein, and 2.6 mm [(14)C]cholesterol in 19 mm taurocholate was infused into the duodenum of lymph fistula CEL(+/+) and CEL(-/-) mice at a rate of 0.3 ml/h. Results showed no difference between CEL(+/+) and CEL(-/-) mice in the rate of cholesterol and triglyceride transport from the intestinal lumen to the lymph. However, CEL(-/-) mice produced predominantly smaller lipoproteins, whereas the CEL(+/+) mice produced primarily large chylomicrons and very low density lipoprotein. The proximal intestine of CEL(-/-) mice was also found to possess significantly less ceramide hydrolytic activity than that present in CEL(+/+) mice. By using Caco2 cells grown on Transwell membranes as a model, sphingomyelinase treatment inhibited the secretion of larger chylomicron-like lipoproteins without affecting total cholesterol secretion. In contrast, the addition of CEL to the apical medium increased the amount of large lipoproteins produced and alleviated the inhibition induced by sphingomyelinase. Taken together, this study identified a novel and physiologically significant role for CEL, namely the promotion of large chylomicron production in the intestine. The mechanism appears to be mediated through CEL hydrolysis of ceramide generated during the lipid absorption process.
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Affiliation(s)
- R Jason Kirby
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
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Nakamura M, Kuroiwa N, Kono Y, Takatsuki A. Glucosylceramide synthesis inhibitors block pharmacologically induced dispersal of the Golgi and anterograde membrane flow from the endoplasmic reticulum: implication of sphingolipid metabolism in maintenance of the Golgi architecture and anterograde membrane flow. Biosci Biotechnol Biochem 2001; 65:1369-78. [PMID: 11471737 DOI: 10.1271/bbb.65.1369] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
PDMP (D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol) and PPMP (D,L-threo-1-phenyl-2-hexadecanoylamino-3-morpholino-1-propanol), inhibitors of glucosylceramide synthesis, blocked brefeldin A (BFA)- and nordihydroguaiaretic acid-induced dispersal of the Golgi and trans Golgi network, and Golgi-derived vesicles were retained in the juxtanuclear region. PDMP and PPMP did not stabilize microtubules but blocked nocodazole-induced extensive fragmentation and dispersal of the Golgi, and large Golgi vesicles were retained in the juxtanuclear region. PPMP is a stronger inhibitor of glucosylceramide synthesis than PDMP, but PDMP showed a stronger activity against BFA-induced retrograde membrane flow. However, PPMP showed a stronger activity for Golgi disruption and inhibition of anterograde trafficking from the endoplasmic reticulum, and rebuilding of the Golgi architecture. Cumulatively, these results suggest that sphingolipid metabolism is implicated in maintenance of the Golgi architecture and anterograde membrane flow from the endoplasmic reticulum but not in Golgi dispersal induced by BFA.
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Affiliation(s)
- M Nakamura
- Animal and Cellular Systems Laboratory, RIKEN The Institute of Physical and Chemical Research, Saitama, Japan
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