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Kitamura K, Saito K, Homma T, Fuyuki A, Onouchi S, Saito S. Prosaposin/Saposin Expression in the Developing Rat Olfactory and Vomeronasal Epithelia. J Dev Biol 2024; 12:29. [PMID: 39585030 PMCID: PMC11587001 DOI: 10.3390/jdb12040029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2024] [Revised: 10/15/2024] [Accepted: 11/04/2024] [Indexed: 11/26/2024] Open
Abstract
Prosaposin is a glycoprotein widely conserved in vertebrates, and it acts as a precursor for saposins that accelerate hydrolysis in lysosomes or acts as a neurotrophic factor without being processed into saposins. Neurogenesis in the olfactory neuroepithelia, including the olfactory epithelium (OE) and the vomeronasal epithelium (VNE), is known to occur throughout an animal's life, and mature olfactory neurons (ORNs) and vomeronasal receptor neurons (VRNs) have recently been revealed to express prosaposin in the adult olfactory organ. In this study, the expression of prosaposin in the rat olfactory organ during postnatal development was examined. In the OE, prosaposin immunoreactivity was observed in mature ORNs labeled using olfactory marker protein (OMP) from postnatal day (P) 0. Immature ORNs showed no prosaposin immunoreactivity throughout the examined period. In the VNE, OMP-positive VRNs were mainly observed in the basal region of the VNE on P10 and showed an adult-like distribution from P20. On the other hand, prosaposin immunoreactivity was observed in VRNs from P0, suggesting that not only mature VRNs but also immature VRNs express prosaposin. This study raises the possibility that prosaposin is required for the normal development of the olfactory organ and has different roles in the OE and the VNE.
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Affiliation(s)
- Kai Kitamura
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; (K.K.); (T.H.); (A.F.); (S.O.)
| | - Kyoko Saito
- Gifu Prefectural Chuo Livestock Hygiene Service Center, 1-1 Yanagido, Gifu 501-1112, Japan;
| | - Takeshi Homma
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; (K.K.); (T.H.); (A.F.); (S.O.)
| | - Aimi Fuyuki
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; (K.K.); (T.H.); (A.F.); (S.O.)
| | - Sawa Onouchi
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; (K.K.); (T.H.); (A.F.); (S.O.)
| | - Shouichiro Saito
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; (K.K.); (T.H.); (A.F.); (S.O.)
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2
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Breitwieser GE, Cippitelli A, Wang Y, Pelletier O, Dershem R, Wei J, Toll L, Fakhoury B, Brunori G, Metpally R, Carey DJ, Robishaw J. Rare GPR37L1 Variants Reveal Potential Association between GPR37L1 and Disorders of Anxiety and Migraine. J Neurosci 2024; 44:e1226232024. [PMID: 38569927 PMCID: PMC11089846 DOI: 10.1523/jneurosci.1226-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 04/05/2024] Open
Abstract
GPR37L1 is an orphan receptor that couples through heterotrimeric G-proteins to regulate physiological functions. Since its role in humans is not fully defined, we used an unbiased computational approach to assess the clinical significance of rare G-protein-coupled receptor 37-like 1 (GPR37L1) genetic variants found among 51,289 whole-exome sequences from the DiscovEHR cohort. Rare GPR37L1 coding variants were binned according to predicted pathogenicity and analyzed by sequence kernel association testing to reveal significant associations with disease diagnostic codes for epilepsy and migraine, among others. Since associations do not prove causality, rare GPR37L1 variants were functionally analyzed in SK-N-MC cells to evaluate potential signaling differences and pathogenicity. Notably, receptor variants exhibited varying abilities to reduce cAMP levels, activate mitogen-activated protein kinase (MAPK) signaling, and/or upregulate receptor expression in response to the agonist prosaptide (TX14(A)), as compared with the wild-type receptor. In addition to signaling changes, knock-out (KO) of GPR37L1 or expression of certain rare variants altered cellular cholesterol levels, which were also acutely regulated by administration of the agonist TX14(A) via activation of the MAPK pathway. Finally, to simulate the impact of rare nonsense variants found in the large patient cohort, a KO mouse line lacking Gpr37l1 was generated. Although KO animals did not recapitulate an acute migraine phenotype, the loss of this receptor produced sex-specific changes in anxiety-related disorders often seen in chronic migraineurs. Collectively, these observations define the existence of rare GPR37L1 variants associated with neuropsychiatric conditions in the human population and identify the signaling changes contributing to pathological processes.
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Affiliation(s)
- Gerda E Breitwieser
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Andrea Cippitelli
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Yingcai Wang
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Oliver Pelletier
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Ridge Dershem
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Jianning Wei
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Lawrence Toll
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Bianca Fakhoury
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Gloria Brunori
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | | | - David J Carey
- Geisinger, Weis Center for Research, Danville, Pennsylvania
| | - Janet Robishaw
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
- College of Veterinary Medicine, University of Florida, Gainesville, Florida
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3
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Cabasso O, Kuppuramalingam A, Lelieveld L, Van der Lienden M, Boot R, Aerts JM, Horowitz M. Animal Models for the Study of Gaucher Disease. Int J Mol Sci 2023; 24:16035. [PMID: 38003227 PMCID: PMC10671165 DOI: 10.3390/ijms242216035] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/26/2023] Open
Abstract
In Gaucher disease (GD), a relatively common sphingolipidosis, the mutant lysosomal enzyme acid β-glucocerebrosidase (GCase), encoded by the GBA1 gene, fails to properly hydrolyze the sphingolipid glucosylceramide (GlcCer) in lysosomes, particularly of tissue macrophages. As a result, GlcCer accumulates, which, to a certain extent, is converted to its deacylated form, glucosylsphingosine (GlcSph), by lysosomal acid ceramidase. The inability of mutant GCase to degrade GlcSph further promotes its accumulation. The amount of mutant GCase in lysosomes depends on the amount of mutant ER enzyme that shuttles to them. In the case of many mutant GCase forms, the enzyme is largely misfolded in the ER. Only a fraction correctly folds and is subsequently trafficked to the lysosomes, while the rest of the misfolded mutant GCase protein undergoes ER-associated degradation (ERAD). The retention of misfolded mutant GCase in the ER induces ER stress, which evokes a stress response known as the unfolded protein response (UPR). GD is remarkably heterogeneous in clinical manifestation, including the variant without CNS involvement (type 1), and acute and subacute neuronopathic variants (types 2 and 3). The present review discusses animal models developed to study the molecular and cellular mechanisms underlying GD.
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Affiliation(s)
- Or Cabasso
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel; (O.C.); (A.K.)
| | - Aparna Kuppuramalingam
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel; (O.C.); (A.K.)
| | - Lindsey Lelieveld
- Leiden Institute of Chemistry, Leiden University, 9502 Leiden, The Netherlands; (L.L.); (M.V.d.L.); (R.B.)
| | - Martijn Van der Lienden
- Leiden Institute of Chemistry, Leiden University, 9502 Leiden, The Netherlands; (L.L.); (M.V.d.L.); (R.B.)
| | - Rolf Boot
- Leiden Institute of Chemistry, Leiden University, 9502 Leiden, The Netherlands; (L.L.); (M.V.d.L.); (R.B.)
| | - Johannes M. Aerts
- Leiden Institute of Chemistry, Leiden University, 9502 Leiden, The Netherlands; (L.L.); (M.V.d.L.); (R.B.)
| | - Mia Horowitz
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel; (O.C.); (A.K.)
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4
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He Y, Kaya I, Shariatgorji R, Lundkvist J, Wahlberg LU, Nilsson A, Mamula D, Kehr J, Zareba-Paslawska J, Biverstål H, Chergui K, Zhang X, Andren PE, Svenningsson P. Prosaposin maintains lipid homeostasis in dopamine neurons and counteracts experimental parkinsonism in rodents. Nat Commun 2023; 14:5804. [PMID: 37726325 PMCID: PMC10509278 DOI: 10.1038/s41467-023-41539-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 09/08/2023] [Indexed: 09/21/2023] Open
Abstract
Prosaposin (PSAP) modulates glycosphingolipid metabolism and variants have been linked to Parkinson's disease (PD). Here, we find altered PSAP levels in the plasma, CSF and post-mortem brain of PD patients. Altered plasma and CSF PSAP levels correlate with PD-related motor impairments. Dopaminergic PSAP-deficient (cPSAPDAT) mice display hypolocomotion and depression/anxiety-like symptoms with mildly impaired dopaminergic neurotransmission, while serotonergic PSAP-deficient (cPSAPSERT) mice behave normally. Spatial lipidomics revealed an accumulation of highly unsaturated and shortened lipids and reduction of sphingolipids throughout the brains of cPSAPDAT mice. The overexpression of α-synuclein via AAV lead to more severe dopaminergic degeneration and higher p-Ser129 α-synuclein levels in cPSAPDAT mice compared to WT mice. Overexpression of PSAP via AAV and encapsulated cell biodelivery protected against 6-OHDA and α-synuclein toxicity in wild-type rodents. Thus, these findings suggest PSAP may maintain dopaminergic lipid homeostasis, which is dysregulated in PD, and counteract experimental parkinsonism.
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Affiliation(s)
- Yachao He
- Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Ibrahim Kaya
- Department of Pharmaceutical Biosciences, Medical Mass Spectrometry Imaging, Uppsala University, Uppsala, Sweden
| | - Reza Shariatgorji
- Department of Pharmaceutical Biosciences, Medical Mass Spectrometry Imaging, Uppsala University, Uppsala, Sweden
- Science for Life Laboratory, Spatial Mass Spectrometry, Uppsala University, Uppsala, Sweden
| | - Johan Lundkvist
- Division of Neurogeriatrics, Department of Neurobiology, Care Science and Society, Karolinska Institutet, Stockholm, Sweden
- Sinfonia Biotherapeutics AB, Huddinge, Sweden
| | - Lars U Wahlberg
- Division of Neurogeriatrics, Department of Neurobiology, Care Science and Society, Karolinska Institutet, Stockholm, Sweden
| | - Anna Nilsson
- Department of Pharmaceutical Biosciences, Medical Mass Spectrometry Imaging, Uppsala University, Uppsala, Sweden
- Science for Life Laboratory, Spatial Mass Spectrometry, Uppsala University, Uppsala, Sweden
| | - Dejan Mamula
- Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Jan Kehr
- Section of Pharmacological Neurochemistry, Department of Physiology and Pharmacology, Karolinska Institute, Solna, Sweden
| | - Justyna Zareba-Paslawska
- Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Henrik Biverstål
- Sinfonia Biotherapeutics AB, Huddinge, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Karima Chergui
- Laboratory of Molecular Neurophysiology, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Xiaoqun Zhang
- Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Per E Andren
- Department of Pharmaceutical Biosciences, Medical Mass Spectrometry Imaging, Uppsala University, Uppsala, Sweden
- Science for Life Laboratory, Spatial Mass Spectrometry, Uppsala University, Uppsala, Sweden
| | - Per Svenningsson
- Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
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5
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Breitwieser GE, Cippitelli A, Wang Y, Pelletier O, Dershem R, Wei J, Toll L, Fakhoury B, Brunori G, Metpally R, Carey DJ, Robishaw J. Rare GPR37L1 variants reveal potential roles in anxiety and migraine disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.05.547546. [PMID: 37461723 PMCID: PMC10349990 DOI: 10.1101/2023.07.05.547546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
GPR37L1 is an orphan receptor that couples through heterotrimeric G-proteins to regulate physiological functions. Since its role in humans is not fully defined, we used an unbiased computational approach to assess the clinical significance of rare GPR37L1 genetic variants found among 51,289 whole exome sequences from the DiscovEHR cohort. Briefly, rare GPR37L1 coding variants were binned according to predicted pathogenicity, and analyzed by Sequence Kernel Association testing to reveal significant associations with disease diagnostic codes for epilepsy and migraine, among others. Since associations do not prove causality, rare GPR37L1 variants were then functionally analyzed in SK-N-MC cells to evaluate potential signaling differences and pathogenicity. Notably, receptor variants exhibited varying abilities to reduce cAMP levels, activate MAPK signaling, and/or upregulate receptor expression in response to the agonist prosaptide (TX14(A)), as compared to the wild-type receptor. In addition to signaling changes, knockout of GPR37L1 or expression of certain rare variants altered cellular cholesterol levels, which were also acutely regulated by administration of the agonist TX14(A) via activation of the MAPK pathway. Finally, to simulate the impact of rare nonsense variants found in the large patient cohort, a knockout (KO) mouse line lacking Gpr37L1 was generated, revealing loss of this receptor produced sex-specific changes implicated in migraine-related disorders. Collectively, these observations define the existence of rare GPR37L1 variants in the human population that are associated with neuropsychiatric conditions and identify the underlying signaling changes that are implicated in the in vivo actions of this receptor in pathological processes leading to anxiety and migraine. SIGNIFICANCE STATEMENT G-protein coupled receptors (GPCRs) represent a diverse group of membrane receptors that contribute to a wide range of diseases and serve as effective drug targets. However, a number of these receptors have no identified ligands or functions, i.e., orphan receptors. Over the past decade, advances have been made, but there is a need for identifying new strategies to reveal their roles in health and disease. Our results highlight the utility of rare variant analyses of orphan receptors for identifying human disease associations, coupled with functional analyses in relevant cellular and animal systems, to ultimately reveal their roles as novel drug targets for treatment of neurological disorders that lack wide-spread efficacy.
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6
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Zhang T, Alonzo I, Stubben C, Geng Y, Herdman C, Chandler N, Doane KP, Pluimer BR, Trauger SA, Peterson RT. A zebrafish model of combined saposin deficiency identifies acid sphingomyelinase as a potential therapeutic target. Dis Model Mech 2023; 16:dmm049995. [PMID: 37183607 PMCID: PMC10320721 DOI: 10.1242/dmm.049995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 04/26/2023] [Indexed: 05/16/2023] Open
Abstract
Sphingolipidoses are a subcategory of lysosomal storage diseases (LSDs) caused by mutations in enzymes of the sphingolipid catabolic pathway. Like many LSDs, neurological involvement in sphingolipidoses leads to early mortality with limited treatment options. Given the role of myelin loss as a major contributor toward LSD-associated neurodegeneration, we investigated the pathways contributing to demyelination in a CRISPR-Cas9-generated zebrafish model of combined saposin (psap) deficiency. psap knockout (KO) zebrafish recapitulated major LSD pathologies, including reduced lifespan, reduced lipid storage, impaired locomotion and severe myelin loss; loss of myelin basic protein a (mbpa) mRNA was progressive, with no changes in additional markers of oligodendrocyte differentiation. Brain transcriptomics revealed dysregulated mTORC1 signaling and elevated neuroinflammation, where increased proinflammatory cytokine expression preceded and mTORC1 signaling changes followed mbpa loss. We examined pharmacological and genetic rescue strategies via water tank administration of the multiple sclerosis drug monomethylfumarate (MMF), and crossing the psap KO line into an acid sphingomyelinase (smpd1) deficiency model. smpd1 mutagenesis, but not MMF treatment, prolonged lifespan in psap KO zebrafish, highlighting the modulation of acid sphingomyelinase activity as a potential path toward sphingolipidosis treatment.
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Affiliation(s)
- Tejia Zhang
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Ivy Alonzo
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Chris Stubben
- Bioinformatic Analysis Shared Resource, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Yijie Geng
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Chelsea Herdman
- Department of Neurobiology and Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Nancy Chandler
- Electron Microscopy Core Laboratory, University of Utah, Salt Lake City, UT 84112, USA
| | - Kim P. Doane
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Brock R. Pluimer
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Sunia A. Trauger
- Harvard Center for Mass Spectrometry, Harvard University, Cambridge, MA 02138, USA
| | - Randall T. Peterson
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
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7
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Kitamura K, Homma T, Sohel MSH, Fuyuki A, Miyawaki S, Onouchi S, Saito S. Expression patterns of prosaposin and its receptors, G protein-coupled receptor (GPR) 37 and GPR37L1, in the mouse olfactory organ. Tissue Cell 2023; 82:102093. [PMID: 37075680 DOI: 10.1016/j.tice.2023.102093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/24/2023] [Accepted: 04/14/2023] [Indexed: 04/21/2023]
Abstract
Prosaposin is a glycoprotein conserved widely in vertebrates, because it is a precursor for saposins that are required for normal lysosomal function and thus for autophagy, and acts as a neurotrophic factor. Most tetrapods possess two kinds of olfactory neuroepithelia, namely, the olfactory epithelium (OE) and the vomeronasal epithelium (VNE). This study examined the expression patterns of prosaposin and its candidate receptors, G protein-coupled receptor (GPR) 37 and GPR37L1, in mouse OE and VNE by immunofluorescence and in situ hybridization. Prosaposin immunoreactivity was observed in the olfactory receptor neurons, vomeronasal receptor neurons, Bowman's gland (BG), and Jacobson's gland (JG). Prosaposin expression was mainly observed in mature neurons. Prosaposin mRNA expression was observed not only in these cells but also in the apical region of the VNE. GPR37 and GPR37L1 immunoreactivities were found only in the BG and/or the JG. Prosaposin was suggested to secrete and facilitate the autophagic activities of the neurons and modulate the mucus secretion in mouse olfactory organ.
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Affiliation(s)
- Kai Kitamura
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Takeshi Homma
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Japan
| | - Md Shahriar Hasan Sohel
- Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Japan
| | - Aimi Fuyuki
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Shingo Miyawaki
- Laboratory of Veterinary Surgery, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Sawa Onouchi
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan; Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Japan
| | - Shouichiro Saito
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan; Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Japan.
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8
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Kojima R, Zurbruegg M, Li T, Paslawski W, Zhang X, Svenningsson P. Prosaposin Reduces α-Synuclein in Cells and Saposin C Dislodges it from Glucosylceramide-enriched Lipid Membranes. J Mol Neurosci 2022; 72:2313-2325. [PMID: 36152140 PMCID: PMC9726671 DOI: 10.1007/s12031-022-02066-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/10/2022] [Indexed: 01/18/2023]
Abstract
Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder affecting over 1% of the 65 + age population. Saposin C, a lysosomal protein required for the normal activity of glucocerebrosidase (GCase), may serve as a disease modifier in PD. Saposin C is cleaved from its precursor, Prosaposin (PSAP), which is secreted as an uncleaved protein and exerts neuroprotective effects. In this study, we aim to elucidate the neuroprotective roles of PSAP and saposin C in PD by evaluating their effects on α-synuclein accumulation in human neuroblastoma cells. Stable overexpression of PSAP reduced monomeric α-synuclein levels in SH-SY5Y cells, while PSAP knockdown by small interfering RNA led to the opposite effect, and those effects were independent of GCase activity. Autophagy flux was decreased by stable PSAP overexpression. Furthermore, a flow-through assay revealed that recombinant saposin C was able to detach α-synuclein from artificial glucosylceramide-enriched lipid membranes at the lysosomal pH. Taken together, our findings provide further evidence that PSAP and saposin C as key proteins involved in α-synuclein clearance by dislodging it from lipid membranes.
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Affiliation(s)
- Rika Kojima
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Mark Zurbruegg
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Tianyi Li
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Wojciech Paslawski
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Xiaoqun Zhang
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Per Svenningsson
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76, Stockholm, Sweden.
- Basic and Clinical Neuroscience, King's College London, London, UK.
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9
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Shibuya Y, Kumar KK, Mader MMD, Yoo Y, Ayala LA, Zhou M, Mohr MA, Neumayer G, Kumar I, Yamamoto R, Marcoux P, Liou B, Bennett FC, Nakauchi H, Sun Y, Chen X, Heppner FL, Wyss-Coray T, Südhof TC, Wernig M. Treatment of a genetic brain disease by CNS-wide microglia replacement. Sci Transl Med 2022; 14:eabl9945. [PMID: 35294256 PMCID: PMC9618306 DOI: 10.1126/scitranslmed.abl9945] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hematopoietic cell transplantation after myeloablative conditioning has been used to treat various genetic metabolic syndromes but is largely ineffective in diseases affecting the brain presumably due to poor and variable myeloid cell incorporation into the central nervous system. Here, we developed and characterized a near-complete and homogeneous replacement of microglia with bone marrow cells in mice without the need for genetic manipulation of donor or host. The high chimerism resulted from a competitive advantage of scarce donor cells during microglia repopulation rather than enhanced recruitment from the periphery. Hematopoietic stem cells, but not immediate myeloid or monocyte progenitor cells, contained full microglia replacement potency equivalent to whole bone marrow. To explore its therapeutic potential, we applied microglia replacement to a mouse model for Prosaposin deficiency, which is characterized by a progressive neurodegeneration phenotype. We found a reduction of cerebellar neurodegeneration and gliosis in treated brains, improvement of motor and balance impairment, and life span extension even with treatment started in young adulthood. This proof-of-concept study suggests that efficient microglia replacement may have therapeutic efficacy for a variety of neurological diseases.
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Affiliation(s)
- Yohei Shibuya
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kevin K Kumar
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA,These authors contributed equally
| | - Marius Marc-Daniel Mader
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,These authors contributed equally
| | - Yongjin Yoo
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,These authors contributed equally
| | - Luis Angel Ayala
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mu Zhou
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | - Gernot Neumayer
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ishan Kumar
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ryo Yamamoto
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Paul Marcoux
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Benjamin Liou
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - F Chris Bennett
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hiromitsu Nakauchi
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA,Division of Stem Cell Therapy, Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Ying Sun
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Xiaoke Chen
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Frank L. Heppner
- Department of Neuropathology, Cluster of Excellence, NeuroCure, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany,Department of Neuropathology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany,Cluster of Excellence, NeuroCure, Charitéplatz 1, 10117 Berlin, Germany,Berlin Institute of Health (BIH), 10117 Berlin, Germany,German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA,Veterans Administration Palo Alto Healthcare System, Palo Alto, CA 94304, USA
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA,Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marius Wernig
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA,Lead Contact,Correspondence:
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10
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Kongmanas K, Saewu A, Kiattiburut W, Baker MA, Faull KF, Burger D, Tanphaichitr N. Accumulation of Seminolipid in Sertoli Cells Is Associated with Increased Levels of Reactive Oxygen Species and Male Subfertility: Studies in Aging Arsa Null Male Mice. Antioxidants (Basel) 2021; 10:antiox10060912. [PMID: 34199863 PMCID: PMC8227610 DOI: 10.3390/antiox10060912] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 12/31/2022] Open
Abstract
Seminolipid (also known as sulfogalactosylglycerolipid-SGG), present selectively in male germ cells, plays important roles in spermatogenesis and sperm–egg interaction. The proper degradation of SGG in apoptotic germ cells is also as important. Sertoli cells first phagocytose apoptotic germ cells, then Sertoli lysosomal arylsulfatase A (ARSA) desulfates SGG, the first step of SGG degradation. We have reported that aging male Arsa−/− mice become subfertile with SGG accumulation in Sertoli cell lysosomes, typical of a lysosomal storage disorder (LSD). Since reactive oxygen species (ROS) levels are increased in other glycolipid-accumulated LSDs, we quantified ROS in Arsa−/− Sertoli cells. Our analyses indicated increases in superoxide and H2O2 in Arsa−/− Sertoli cells with elevated apoptosis rates, relative to WT counterparts. Excess H2O2 from Arsa−/− Sertoli cells could travel into testicular germ cells (TGCs) to induce ROS production. Our results indeed indicated higher superoxide levels in Arsa−/− TGCs, compared with WT TGCs. Increased ROS levels in Arsa−/− Sertoli cells and TGCs likely caused the decrease in spermatogenesis and increased the abnormal sperm population in aging Arsa−/− mice, including the 50% decrease in sperm SGG with egg binding ability. In summary, our study indicated that increased ROS production was the mechanism through which subfertility manifested following SGG accumulation in Sertoli cells.
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Affiliation(s)
- Kessiri Kongmanas
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; (K.K.); (A.S.); (W.K.); (D.B.)
- Department of Biochemistry, Microbiology, Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Division of Dengue Hemorrhagic Fever Research/Siriraj Center of Research Excellence in Dengue and Emerging Pathogens, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Metabolomics and Phenomics Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Arpornrad Saewu
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; (K.K.); (A.S.); (W.K.); (D.B.)
| | - Wongsakorn Kiattiburut
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; (K.K.); (A.S.); (W.K.); (D.B.)
| | - Mark A Baker
- Department of Biological Science, University of Newcastle, Callaghan, NSW 2308, Australia;
| | - Kym F Faull
- Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, CA 90024, USA;
| | - Dylan Burger
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; (K.K.); (A.S.); (W.K.); (D.B.)
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Nongnuj Tanphaichitr
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; (K.K.); (A.S.); (W.K.); (D.B.)
- Department of Biochemistry, Microbiology, Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Department of Obstetrics & Gynecology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8L6, Canada
- Correspondence: ; Tel.: +1-(613)-737-8899 (ext. 72793); Fax: +1-(613)-739-6968
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11
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Grabowski GA, Antommaria AHM, Kolodny EH, Mistry PK. Gaucher disease: Basic and translational science needs for more complete therapy and management. Mol Genet Metab 2021; 132:59-75. [PMID: 33419694 PMCID: PMC8809485 DOI: 10.1016/j.ymgme.2020.12.291] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/15/2020] [Accepted: 12/18/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Gregory A Grabowski
- Department of Pediatrics, University of Cincinnati College of Medicine, United States of America; Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, United States of America; Division of Human Genetics, Cincinnati Children's Research Foundation, Cincinnati, OH, United States of America.
| | - Armand H M Antommaria
- Department of Pediatrics, University of Cincinnati College of Medicine, United States of America; Lee Ault Carter Chair of Pediatric Ethics, Cincinnati Children's Research Foundation, Cincinnati, OH, United States of America.
| | - Edwin H Kolodny
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States of America.
| | - Pramod K Mistry
- Departments of Medicine and Pediatrics, Yale School of Medicine, New Haven, CT, United States of America.
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12
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Choi KM, Hwang SD, Joo MS, Hwang JY, Kwon MG, Jeong JM, Seo JS, Lee JH, Lee HC, Park CI. Two short antimicrobial peptides derived from prosaposin-like proteins in the starry flounder (Platichthys stellatus). FISH & SHELLFISH IMMUNOLOGY 2020; 105:95-103. [PMID: 32619625 DOI: 10.1016/j.fsi.2020.05.075] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/12/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
Prosaposin (PSAP) is a precursor of saposin (SAP), which is present in lysosomal and secreted proteins. PSAP is a member of the SAP-like protein families, which comprise multifunctional proteins. In particular, their antimicrobial activity has been reported. We identified PSAP-like (PsPSAPL) sequences from starry flounder and analysed their expression and antimicrobial activity based on cDNA and amino acid sequences. PsPSAPL showed conservation of three saposin B type domains at high levels, and PsPSAPL mRNA was relatively abundantly distributed in the brain and gills of healthy starry founders. PsPSAPL mRNA showed significant expression changes in response to viral haemorrhagic septicaemia virus and Streptococcus parauberis. Synthetic peptides (PsPSAPL-1 and -2), prepared based on amino acid sequences, were used to confirm as well as analyse the antimicrobial activity against bacteria and parasites. Consequently, PsPSAPL-1 and -2 were found to significantly inhibit the growth of various bacteria and kill the Miamiensis avidus. In addition, bacterial biofilm formation was significantly inhibited. Safety was also confirmed by analysing cell haemolysis. These results indicate the immunological function of PsPSAP and the potential antimicrobial activity of the AMPs PsPSAPL-1 and -2.
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Affiliation(s)
- Kwang-Min Choi
- Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea
| | - Seong Don Hwang
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Min-Soo Joo
- Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea
| | - Jee Youn Hwang
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Mun-Gyeong Kwon
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Ji-Min Jeong
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Jung Soo Seo
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Ji Hoon Lee
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Hee-Chung Lee
- Aquatic Animal Disease Control Center, National Institute of Fisheries Science (NIFS), 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 46083, Republic of Korea
| | - Chan-Il Park
- Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea.
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13
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Codognoto VM, Yamada PH, Schmith RA, Rydygier de Ruediger F, de Paula Freitas-Dell'Aqua C, de Souza FF, Brochine S, do Carmo LM, Vieira AF, Oba E. Cross comparison of seminal plasma proteins from cattle and buffalo (Bubalus bubalis). Reprod Domest Anim 2019; 55:81-92. [PMID: 31733131 DOI: 10.1111/rda.13589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/25/2019] [Accepted: 11/13/2019] [Indexed: 11/27/2022]
Abstract
The objective of this study was to evaluate seminal plasma proteins from cattle and buffalo (Bubalus bubalis), to identify differences between related species. Sixteen buffaloes and 16 cattle between 30 and 60 months of age were used. Semen collection was performed by electroejaculation, followed by macroscopic and microscopic subjective analyses. After analysis, the samples were centrifuged at 800 g for 10 min, and the supernatant (seminal plasma) was recentrifuged at 10,000 g for 30 min at 4°C. The total protein concentration was determined by the Bradford method, and the proteins were digested in solution for mass spectrometry (nLC-MS/MS). Multivariate statistical analysis was used to evaluate the proteomics results by non-hierarchical clustering the considering exponentially modified protein abundance index (emPAI). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used for clustering. Proteomics identified 78 proteins, and multivariate analysis showed 4 that were over-expressed in buffaloes (cystatin C, prosaposin, peptide YY and keratin type II cytoskeletal 5) and 9 in cattle (spermadhesin-1, seminal plasma protein PDC-109, ribonuclease 4, metalloproteinase inhibitor 2, acrosin inhibitor 1, seminal ribonuclease, C-type natriuretic peptide, angiogenin-1 and osteopontin). Among the proteins identified in seminal plasma, the C-type natriuretic peptide and metalloproteinase inhibitors were described for the first time in buffaloes. Some protease inhibitors were found over-expressed in buffaloes, and important proteins in seminal plasma of cattle were not identified or were found at lower expression levels in buffaloes, which can contribute to reproductive performance in this species.
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Affiliation(s)
- Viviane Maria Codognoto
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Paulo Henrique Yamada
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Rúbia Alves Schmith
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Felipe Rydygier de Ruediger
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Camila de Paula Freitas-Dell'Aqua
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Fabiana Ferreira de Souza
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Suzane Brochine
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Lucas Monteiro do Carmo
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Andressa Filaz Vieira
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
| | - Eunice Oba
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu, Brazil
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14
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Codognoto VM, Yamada PH, Schmith RA, de Ruediger FR, Scott C, de Faria Lainetti P, Brochine S, de Paula Freitas-Dell'Aqua C, de Souza FF, Oba E. Functional insights into the role of seminal plasma proteins on sperm motility of buffalo. Anim Reprod Sci 2018; 195:251-258. [PMID: 29884323 DOI: 10.1016/j.anireprosci.2018.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/24/2018] [Accepted: 06/01/2018] [Indexed: 12/29/2022]
Abstract
The objective of the present study was to describe the proteins from the seminal plasma of buffalo and correlate these proteins with sperm motility. Ejaculates from sixteen Murrah buffalo were used. Semen collection was performed by electroejaculation, and the ejaculate was evaluated by macroscopic (volume) and microscopic analysis (subjective motility and vigor, as well as sperm concentration). After the analysis, the samples were centrifuged (800g for 10 min and 10,000 for 30 min at 4 °C), and the supernatant (seminal plasma) was used to determine total protein concentration by the Bradford method. Based on total protein concentration, an aliquot (50 μg) was taken to conduct protein in-solution digestion for nano-LC-ESI-Q-TOF mass spectrometry analysis. Samples were divided into two groups, minimal (little sperm motility) and greater (typical sperm motility), based on non-hierarchical clustering considering motility and emPAI protein value. The data were analyzed by multivariate statistical analysis using principal component analysis (PCA) and partial analysis of minimum squares discrimination (PLS-DA). Forty-eight proteins were detected in the seminal plasma, and fifteen were common to two groups. There were six proteins that were significantly different between the groups. The main functions of proteins in seminal plasma were catalytic and binding activity. Spermadhesin protein, ribonuclease, 14-3-3 protein zeta/delta and acrosin inhibitor were in greater amounts in seminal plasma from the group with greater sperm motility; prosaposin and peptide YY were in greater amounts in the group with little sperm motility. The proteins detected in the greater motility group were correlated with sperm protection, including protection against oxidative stress, lipid peroxidation, protease inhibition and prevention of premature capacitation and acrosome reaction. In the group with little sperm motility, one of the identified proteins is considered to be an antifertility factor, whereas the function of other identified protein is not definitive. Results from the present study add to the knowledge base about the molecular processes related with sperm motility, and these findings can be used for determining potential markers of semen quality.
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Affiliation(s)
- Viviane Maria Codognoto
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil.
| | - Paulo Henrique Yamada
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Rúbia Alves Schmith
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Felipe Rydygier de Ruediger
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Caroline Scott
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Patrícia de Faria Lainetti
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Suzane Brochine
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Camila de Paula Freitas-Dell'Aqua
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Fabiana Ferreira de Souza
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
| | - Eunice Oba
- São Paulo State University (UNESP), School of Veterinary Medicine and Animal Science, Department of Animal Reproduction and Veterinary Radiology, Botucatu, Brazil
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15
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Zhou X, Sullivan PM, Sun L, Hu F. The interaction between progranulin and prosaposin is mediated by granulins and the linker region between saposin B and C. J Neurochem 2017. [PMID: 28640985 DOI: 10.1111/jnc.14110] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The frontotemporal lobar degeneration (FTLD) protein progranulin (PGRN) is essential for proper lysosomal function. PGRN localizes in the lysosomal compartment within the cell. Prosaposin (PSAP), the precursor of lysosomal saposin activators (saposin A, B, C, D), physically interacts with PGRN. Previously, we have shown that PGRN and PSAP facilitate each other's lysosomal trafficking. Here, we report that the interaction between PSAP and PGRN requires the linker region of saposin B and C (BC linker). PSAP protein with the BC linker mutated, fails to interact with PGRN and deliver PGRN to lysosomes in the biosynthetic and endocytic pathways. On the other hand, PGRN interacts with PSAP through multiple granulin motifs. Granulin D and E bind to PSAP with similar affinity as full-length PGRN. Read the Editorial Comment for this article on page 154.
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Affiliation(s)
- Xiaolai Zhou
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
| | - Peter M Sullivan
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
| | - Lirong Sun
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
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16
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Impaired prosaposin lysosomal trafficking in frontotemporal lobar degeneration due to progranulin mutations. Nat Commun 2017; 8:15277. [PMID: 28541286 PMCID: PMC5477518 DOI: 10.1038/ncomms15277] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 03/15/2017] [Indexed: 01/01/2023] Open
Abstract
Haploinsufficiency of progranulin (PGRN) due to mutations in the granulin (GRN) gene causes frontotemporal lobar degeneration (FTLD), and complete loss of PGRN leads to a lysosomal storage disorder, neuronal ceroid lipofuscinosis (NCL). Accumulating evidence suggests that PGRN is essential for proper lysosomal function, but the precise mechanisms involved are not known. Here, we show that PGRN facilitates neuronal uptake and lysosomal delivery of prosaposin (PSAP), the precursor of saposin peptides that are essential for lysosomal glycosphingolipid degradation. We found reduced levels of PSAP in neurons both in mice deficient in PGRN and in human samples from FTLD patients due to GRN mutations. Furthermore, mice with reduced PSAP expression demonstrated FTLD-like pathology and behavioural changes. Thus, our data demonstrate a role of PGRN in PSAP lysosomal trafficking and suggest that impaired lysosomal trafficking of PSAP is an underlying disease mechanism for NCL and FTLD due to GRN mutations. Mutations in the granulin gene are associated with frontotemporal lobe dementia (FTLD) and a lysosomal storage disease. The authors show that reduced progranulin levels leads to impaired neuronal uptake and lysosomal delivery of prosaposin, and that decreased prosaposin expression in mice leads to FTLD-like behaviour.
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17
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Sellin J, Schulze H, Paradis M, Gosejacob D, Papan C, Shevchenko A, Psathaki OE, Paululat A, Thielisch M, Sandhoff K, Hoch M. Characterization of Drosophila Saposin-related mutants as a model for lysosomal sphingolipid storage diseases. Dis Model Mech 2017; 10:737-750. [PMID: 28389479 PMCID: PMC5483003 DOI: 10.1242/dmm.027953] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 04/04/2017] [Indexed: 11/20/2022] Open
Abstract
Sphingolipidoses are inherited diseases belonging to the class of lysosomal storage diseases (LSDs), which are characterized by the accumulation of indigestible material in the lysosome caused by specific defects in the lysosomal degradation machinery. While some LSDs can be efficiently treated by enzyme replacement therapy (ERT), this is not possible if the nervous system is affected due to the presence of the blood-brain barrier. Sphingolipidoses in particular often present as severe, untreatable forms of LSDs with massive sphingolipid and membrane accumulation in lysosomes, neurodegeneration and very short life expectancy. The digestion of intralumenal membranes within lysosomes is facilitated by lysosomal sphingolipid activator proteins (saposins), which are cleaved from a prosaposin precursor. Prosaposin mutations cause some of the severest forms of sphingolipidoses, and are associated with perinatal lethality in mice, hampering studies on disease progression. We identify the Drosophila prosaposin orthologue Saposin-related (Sap-r) as a key regulator of lysosomal lipid homeostasis in the fly. Its mutation leads to a typical spingolipidosis phenotype with an enlarged endolysosomal compartment and sphingolipid accumulation as shown by mass spectrometry and thin layer chromatography. Sap-r mutants show reduced viability with ∼50% survival to adulthood, allowing us to study progressive neurodegeneration and analyze their lipid profile in young and aged flies. Additionally, we observe a defect in sterol homeostasis with local sterol depletion at the plasma membrane. Furthermore, we find that autophagy is increased, resulting in the accumulation of mitochondria in lysosomes, concomitant with increased oxidative stress. Together, we establish Drosophila Sap-r mutants as a lysosomal storage disease model suitable for studying the age-dependent progression of lysosomal dysfunction associated with lipid accumulation and the resulting pathological signaling events.
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Affiliation(s)
- Julia Sellin
- LIMES-Institute, Program Unit Development & Genetics, Laboratory for Molecular Developmental Biology, University of Bonn, Carl-Troll-Strasse 31, 53115 Bonn, Germany
| | - Heike Schulze
- LIMES-Institute, Program Unit Membrane Biology & Lipid Biochemistry, c/o Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Marie Paradis
- LIMES-Institute, Program Unit Development & Genetics, Laboratory for Molecular Developmental Biology, University of Bonn, Carl-Troll-Strasse 31, 53115 Bonn, Germany
| | - Dominic Gosejacob
- LIMES-Institute, Program Unit Development & Genetics, Laboratory for Molecular Developmental Biology, University of Bonn, Carl-Troll-Strasse 31, 53115 Bonn, Germany
| | - Cyrus Papan
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Andrej Shevchenko
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Olympia Ekaterina Psathaki
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
| | - Achim Paululat
- University of Osnabrück, Biology, EM unit, Barbarastraße 11, 49076 Osnabrueck, Germany
| | - Melanie Thielisch
- LIMES-Institute, Program Unit Development & Genetics, Laboratory for Molecular Developmental Biology, University of Bonn, Carl-Troll-Strasse 31, 53115 Bonn, Germany
| | - Konrad Sandhoff
- LIMES-Institute, Program Unit Membrane Biology & Lipid Biochemistry, c/o Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Michael Hoch
- LIMES-Institute, Program Unit Development & Genetics, Laboratory for Molecular Developmental Biology, University of Bonn, Carl-Troll-Strasse 31, 53115 Bonn, Germany
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18
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Zhou X, Sun L, Bastos de Oliveira F, Qi X, Brown WJ, Smolka MB, Sun Y, Hu F. Prosaposin facilitates sortilin-independent lysosomal trafficking of progranulin. J Cell Biol 2015; 210:991-1002. [PMID: 26370502 PMCID: PMC4576858 DOI: 10.1083/jcb.201502029] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Prosaposin directly interacts with progranulin and facilitates progranulin lysosomal trafficking via the trafficking receptors M6PR and LRP1, independent of the previously identified progranulin trafficking pathway mediated by sortilin. Mutations in the progranulin (PGRN) gene have been linked to two distinct neurodegenerative diseases, frontotemporal lobar degeneration (FTLD) and neuronal ceroid lipofuscinosis (NCL). Accumulating evidence suggests a critical role of PGRN in lysosomes. However, how PGRN is trafficked to lysosomes is still not clear. Here we report a novel pathway for lysosomal delivery of PGRN. We found that prosaposin (PSAP) interacts with PGRN and facilitates its lysosomal targeting in both biosynthetic and endocytic pathways via the cation-independent mannose 6-phosphate receptor and low density lipoprotein receptor-related protein 1. PSAP deficiency in mice leads to severe PGRN trafficking defects and a drastic increase in serum PGRN levels. We further showed that this PSAP pathway is independent of, but complementary to, the previously identified PGRN lysosomal trafficking mediated by sortilin. Collectively, our results provide new understanding on PGRN trafficking and shed light on the molecular mechanisms behind FTLD and NCL caused by PGRN mutations.
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Affiliation(s)
- Xiaolai Zhou
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Lirong Sun
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853 Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Francisco Bastos de Oliveira
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Xiaoyang Qi
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45229
| | - William J Brown
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Ying Sun
- Division of Human Genetics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
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Lecht S, Gerstenhaber JA, Stabler CT, Pimton P, Karamil S, Marcinkiewicz C, Schulman ES, Lelkes PI. Heterogeneous Mixed-Lineage Differentiation of Mouse Embryonic Stem Cells Induced by Conditioned Media from A549 Cells. Stem Cells Dev 2014; 23:1923-36. [DOI: 10.1089/scd.2014.0042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Shimon Lecht
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Jonathan A. Gerstenhaber
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Collin T. Stabler
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Pimchanok Pimton
- Department of Biology, School of Science, Walailak University, Thammarat, Thailand
| | - Seda Karamil
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Cezary Marcinkiewicz
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Edward S. Schulman
- Division of Pulmonary, Critical Care and Sleep Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Peter I. Lelkes
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
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20
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Xu Z, Shan F, Shan F, Meng C, Zhou X, Zhang X, Chen X, Jiao X. Generation and application of a 293 cell line stably expressing bovine interferon-gamma. Protein Expr Purif 2014; 99:131-7. [PMID: 24794970 DOI: 10.1016/j.pep.2014.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/13/2014] [Accepted: 04/22/2014] [Indexed: 10/25/2022]
Abstract
A stable mammalian cell line expressing highly active bovine interferon-gamma (BoIFN-γ) was generated using Flp recombinase-mediated integration. This recombinant 293 cell line (B1) efficiently secreted FLAG-tagged BoIFN-γ protein into the culture supernatant, as determined by ELISA and Western blot. The recombinant BoIFN-γ exhibited high anti-viral activity, suggesting that the 293 cells expressed BoIFN-γ that structurally and biologically resembled the natural protein. Two monoclonal antibodies (mAbs) with high affinity for the 293 cell-expressed BoIFN-γ were identified using this cell line, and these mAbs can be used for the development of diagnostic kits. Thus, this work demonstrates the successful generation of a 293 cell line that produces large quantities of highly active BoIFN-γ and demonstrates its potential application in the research of bovine infectious diseases.
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Affiliation(s)
- Zhengzhong Xu
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Fengli Shan
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Fa Shan
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Chuang Meng
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Sciences, University of Connecticut, Storrs, CT 06269, USA
| | - Xiaoming Zhang
- Unit of Innate Defense and Immune Modulation, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiang Chen
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China.
| | - Xinan Jiao
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China.
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21
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Saito S, Saito K, Nabeka H, Shimokawa T, Kobayashi N, Matsuda S. Differential expression of the alternatively spliced forms of prosaposin mRNAs in rat choroid plexus. Cell Tissue Res 2014; 356:231-42. [PMID: 24414178 DOI: 10.1007/s00441-013-1773-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 11/14/2013] [Indexed: 02/02/2023]
Abstract
Prosaposin has two distinct profiles. One is a precursor form that is processed into saposins thus promoting lysosomal sphingolipid hydrolase function, whereas the other is an intact form that is not processed into saposins but is abundant in certain tissues and secretory fluids, including the cerebrospinal fluid. In rats, alternative splicing in the prosaposin gene generates mRNAs with and without a 9-base insertion (Pro+9 and Pro+0 mRNAs, respectively). Pro+9 mRNA is reported to be preferentially expressed in tissues in which the intact form of prosaposin dominates, whereas Pro+0 mRNA is preferentially expressed in tissues in which the precursor dominates. The expression patterns of Pro+9 and Pro+0 mRNAs in the rat choroid plexus are examined in the present study. The specificities of 36-mer oligonucleotide probes used to detect the 9-base insertion by in situ hybridization were demonstrated by dot-blot hybridization. Next, these probes were used for in situ hybridization, which showed predominant expression of Pro+0 mRNA and weak expression of Pro+9 mRNA in the choroid plexus. These expression patterns were confirmed by reverse transcription plus the polymerase chain reaction with AlwI restriction enzyme treatment. Expression of the intact form of prosaposin in the choroid plexus was assessed by Western blotting and immunohistochemistry. Because the choroid plexus is responsible for the generation of cerebrospinal fluid containing the intact form of prosaposin, the present study raises the possibility that Pro+0 mRNA is related to the intact form in the choroid plexus and that the alternatively spliced forms of mRNAs do not simply correspond to the precursor and intact forms of prosaposin.
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Affiliation(s)
- Shouichiro Saito
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Yanagido, Gifu, 501-1128, Japan,
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22
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Sun Y, Zamzow M, Ran H, Zhang W, Quinn B, Barnes S, Witte DP, Setchell KDR, Williams MT, Vorhees CV, Grabowski GA. Tissue-specific effects of saposin A and saposin B on glycosphingolipid degradation in mutant mice. Hum Mol Genet 2013; 22:2435-50. [PMID: 23446636 DOI: 10.1093/hmg/ddt096] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Individual saposin A (A-/-) and saposin B (B-/-)-deficient mice show unique phenotypes caused by insufficient degradation of myelin-related glycosphingolipids (GSLs): galactosylceramide and galactosylsphingosine and sulfatide, respectively. To gain insight into the interrelated functions of saposins A and B, combined saposin AB-deficient mice (AB-/-) were created by knock-in point mutations into the saposins A and B domains on the prosaposin locus. Saposin A and B proteins were undetectable in AB-/- mice, whereas prosaposin, saposin C and saposin D were expressed near wild-type (WT) levels. AB-/- mice developed neuromotor deterioration at >61 days and exhibited abnormal locomotor activity and enhanced tremor. AB-/- mice (~96 days) lived longer than A-/- mice (~85 days), but shorter than B-/- mice (~644 days). Storage materials were observed in Schwann cells and neuronal processes by electron microscopy. Accumulation of p62 and increased levels of LC3-II were detected in the brainstem suggesting altered autophagy. GSL analyses by (liquid chromatography) LC/MS identified substantial increases in lactosylceramide in AB-/- mouse livers. Sulfatide accumulated, but galactosylceramide remained at WT levels, in the AB-/- mouse brains and kidneys. Brain galactosylsphingosine in AB-/- mice was ~68% of that in A-/- mice. These findings indicate that combined saposins A and B deficiencies attenuated GalCer-β-galactosylceramidase and GM1-β-galactosidase functions in the degradation of lactosylceramide preferentially in the liver. Blocking sulfatide degradation from the saposin B deficiency diminished galactosylceramide accumulation in the brain and kidney and galctosylsphingosine in the brain. These analyses of AB-/- mice continue to delineate the tissue differential interactions of saposins in GSL metabolism.
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Affiliation(s)
- Ying Sun
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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23
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Bereman MS, Tomazela DM, Heins HS, Simonato M, Cogo PE, Hamvas A, Patterson BW, Cole FS, MacCoss MJ. A method to determine the kinetics of multiple proteins in human infants with respiratory distress syndrome. Anal Bioanal Chem 2012; 403:2397-402. [PMID: 22526637 PMCID: PMC3694176 DOI: 10.1007/s00216-012-5953-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 03/02/2012] [Accepted: 03/14/2012] [Indexed: 12/18/2022]
Abstract
We report a method to measure in vivo turnover of four proteins from sequential tracheal aspirates obtained from human newborn infants with respiratory distress syndrome using targeted proteomics. We detected enrichment for all targeted proteins approximately 3 h from the start of infusion of [5,5,5-(2)H(3)] leucine, secretion times that varied from 1.2 to 2.5 h, and half lives that ranged between 10 and 21 h. Complement factor B, a component of the alternative pathway of complement activation, had an approximately twofold-longer half-life than the other three proteins. In addition, the kinetics of mature and carboxy-terminal tryptic peptides from the same protein (surfactant protein B) were not statistically different (p = 0.49).
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Affiliation(s)
- Michael S Bereman
- Department of Genome Sciences, University of Washington, Seattle, WA 98195-5502, USA.
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24
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Nakken B, Varga T, Szatmari I, Szeles L, Gyongyosi A, Illarionov PA, Dezso B, Gogolak P, Rajnavolgyi E, Nagy L. Peroxisome Proliferator-Activated Receptor γ-Regulated Cathepsin D Is Required for Lipid Antigen Presentation by Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 2011; 187:240-7. [DOI: 10.4049/jimmunol.1002421] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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25
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Xu Q, Nomura T, Ikeda M, Ohta M, Kameyama KI, Konishi M, Wu D, Inumaru S, Murakami K. Stability of recombinant bovine interferon-γ antiviral activity in the absence of stabilizing additives. Microbiol Immunol 2011; 55:595-8. [PMID: 21545512 DOI: 10.1111/j.1348-0421.2011.00349.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The stability of recombinant bovine interferon-γ (rbIFN-γ) produced by a baculovirus expression system was investigated under different storage conditions: freezing-thawing and storage for 30 days at temperatures of -80, 4, 25, and 37°C. Antiviral activity was not significantly decreased by freeze-thawing at least five times. Furthermore, although not statistically different, antiviral activity gradually decreased as temperature increased. These findings suggest that rbIFN-γ possesses high thermal and freeze-thaw stability.
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Affiliation(s)
- Qingyuan Xu
- Harbin Veterinary Research Institute, 427 Maduan Street, Harbin 150001, China
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Yoneshige A, Suzuki K, Suzuki K, Matsuda J. A mutation in the saposin C domain of the sphingolipid activator protein (Prosaposin) gene causes neurodegenerative disease in mice. J Neurosci Res 2010; 88:2118-34. [PMID: 20175216 DOI: 10.1002/jnr.22371] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Saposins A, B, C, and D are small amphiphatic glycoproteins that are encoded in tandem within a precursor protein (prosaposin, PSAP), and are required for in vivo degradation of sphingolipids. Humans with saposin C deficiency exhibit the clinical presentation of Gaucher-like disease. We generated two types of saposin C mutant mice, one carrying a homozygous missense mutation (C384S) in the saposin C domain of prosaposin (Sap-C(-/-)) and the other carrying the compound heterozygous mutation with a second null Psap allele (Psap(-/C384S)). During early life stages, both Sap-C(-/-) and Psap(-/C384S) mice grew normally; however, they developed progressive motor and behavioral deficits after 3 months of age and the majority of affected mice could scarcely move by about 15 months. They showed no signs of hepatosplenomegaly throughout their lives. No accumulation of glucosylceramide and glucosylsphingosine was detected in the brain or liver of both Sap-C(-/-) and Psap(-/C384S) mice. Neuropathological analyses revealed patterned loss of cerebellar Purkinje cells, widespread axonal spheroids filled with membrane-derived concentric or lamellar electron-dense bodies, and lipofuscin-like deposition in the neurons. Soap-bubble-like inclusion bodies were detected in the trigeminal ganglion cells and the vascular endothelial cells. Compound heterozygous Psap(-/C384S) mice showed qualitatively identical but faster progression of the neurological phenotypes than Sap-C(-/-) mice. These results suggest the in vivo role of saposin C in axonal membrane homeostasis, the disruption of which leads to neurodegeneration in lysosomal storage disease.
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Affiliation(s)
- Azusa Yoneshige
- Institute of Glycoscience, Tokai University, Hiratsuka, Kanagawa, Japan
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27
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Lu K, Zhao G, Lu H, Zhao S, Song Y, Qi X, Hou Y. Toll-like receptor 4 can recognize SapC-DOPS to stimulate macrophages to express several cytokines. Inflamm Res 2010; 60:153-61. [PMID: 20853174 DOI: 10.1007/s00011-010-0249-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 07/20/2010] [Accepted: 09/06/2010] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE AND DESIGN SapC-DOPS is a newly combined compound consisting of saposin C and dioleoylphosphatidylserine (DOPS). Our recent study showed that SapC-DOPS exhibits anti-tumor activity. However, SapC-DOPS has recognition elements of Toll-like receptor (TLR) 2 and TLR4; therefore, we want to know whether SapC-DOPS can induce abnormal immunoreaction via identification TLRs. METHODS We investigated the capacity of SapC-DOPS to induce cytokines in vivo and in vitro and analyzed the involvement of TLR and NF-kB in these cytokines production. RESULTS SapC-DOPS could activate the cytokine production by peripheral macrophages, enhance the expressions of TLR4 and stimulate the NF-κB nuclear translocation. PDTC, an NF-κB inhibitor, could decrease the SapC-DOPS inducible TNF-α and IL-1β production. CONCLUSIONS SapC-DOPS was similar to LPS in the immune response and may induce the production of cytokines in macrophages via the TLR4 signaling pathway and, at least in part, the alteration of the NF-κB pathway.
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Affiliation(s)
- Kaihua Lu
- Immunology and Reproductive Biology Lab of Medical School and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, People's Republic of China
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Xu YH, Barnes S, Sun Y, Grabowski GA. Multi-system disorders of glycosphingolipid and ganglioside metabolism. J Lipid Res 2010; 51:1643-75. [PMID: 20211931 DOI: 10.1194/jlr.r003996] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Glycosphingolipids (GSLs) and gangliosides are a group of bioactive glycolipids that include cerebrosides, globosides, and gangliosides. These lipids play major roles in signal transduction, cell adhesion, modulating growth factor/hormone receptor, antigen recognition, and protein trafficking. Specific genetic defects in lysosomal hydrolases disrupt normal GSL and ganglioside metabolism leading to their excess accumulation in cellular compartments, particularly in the lysosome, i.e., lysosomal storage diseases (LSDs). The storage diseases of GSLs and gangliosides affect all organ systems, but the central nervous system (CNS) is primarily involved in many. Current treatments can attenuate the visceral disease, but the management of CNS involvement remains an unmet medical need. Early interventions that alter the CNS disease have shown promise in delaying neurologic involvement in several CNS LSDs. Consequently, effective treatment for such devastating inherited diseases requires an understanding of the early developmental and pathological mechanisms of GSL and ganglioside flux (synthesis and degradation) that underlie the CNS diseases. These are the focus of this review.
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Affiliation(s)
- You-Hai Xu
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229-3039, USA
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29
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Sun Y, Liou B, Ran H, Skelton MR, Williams MT, Vorhees CV, Kitatani K, Hannun YA, Witte DP, Xu YH, Grabowski GA. Neuronopathic Gaucher disease in the mouse: viable combined selective saposin C deficiency and mutant glucocerebrosidase (V394L) mice with glucosylsphingosine and glucosylceramide accumulation and progressive neurological deficits. Hum Mol Genet 2010; 19:1088-97. [PMID: 20047948 PMCID: PMC2830832 DOI: 10.1093/hmg/ddp580] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Gaucher disease is caused by defective acid β-glucosidase (GCase) function. Saposin C is a lysosomal protein needed for optimal GCase activity. To test the in vivo effects of saposin C on GCase, saposin C deficient mice (C−/−) were backcrossed to point mutated GCase (V394L/V394L) mice. The resultant mice (4L;C*) began to exhibit CNS abnormalities ∼30 days: first as hindlimb paresis, then progressive tremor and ataxia. Death occurred ∼48 days due to neurological deficits. Axonal degeneration was evident in brain stem, spinal cord and white matter of cerebellum accompanied by increasing infiltration of the brain stem, cortex and thalamus by CD68 positive microglial cells and activation of astrocytes. Electron microscopy showed inclusion bodies in neuronal processes and degenerating cells. Accumulation of p62 and Lamp2 were prominent in the brain suggesting the impairment of autophagosome/lysosome function. This phenotype was different from either V394L/V394L or C−/− alone. Relative to V394L/V394L mice, 4L;C* mice had diminished GCase protein and activity. Marked increases (20- to 30-fold) of glucosylsphingosine (GS) and moderate elevation (1.5- to 3-fold) of glucosylceramide (GC) were in 4L;C* brains. Visceral tissues had increases of GS and GC, but no storage cells were found. Neuronal cells in thick hippocampal slices from 4L;C* mice had significantly attenuated long-term potentiation, presumably resulting from substrate accumulation. The 4L;C* mouse mimics the CNS phenotype and biochemistry of some type 3 (neuronopathic) variants of Gaucher disease and is a unique model suitable for testing pharmacological chaperone and substrate reduction therapies, and investigating the mechanisms of neuronopathic Gaucher disease.
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Affiliation(s)
- Ying Sun
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229-3039, USA
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30
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Sun Y, Ran H, Zamzow M, Kitatani K, Skelton MR, Williams MT, Vorhees CV, Witte DP, Hannun YA, Grabowski GA. Specific saposin C deficiency: CNS impairment and acid beta-glucosidase effects in the mouse. Hum Mol Genet 2009; 19:634-47. [PMID: 20015957 PMCID: PMC2807372 DOI: 10.1093/hmg/ddp531] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Saposins A, B, C and D are derived from a common precursor, prosaposin (psap). The few patients with saposin C deficiency develop a Gaucher disease-like central nervous system (CNS) phenotype attributed to diminished glucosylceramide (GC) cleavage activity by acid β-glucosidase (GCase). The in vivo effects of saposin C were examined by creating mice with selective absence of saposin C (C−/−) using a knock-in point mutation (cysteine-to-proline) in exon 11 of the psap gene. In C−/− mice, prosaposin and saposins A, B and D proteins were present at near wild-type levels, but the saposin C protein was absent. By 1 year, the C−/− mice exhibited weakness of the hind limbs and progressive ataxia. Decreased neuromotor activity and impaired hippocampal long-term potentiation were evident. Foamy storage cells were observed in dorsal root ganglion and there was progressive loss of cerebellar Purkinje cells and atrophy of cerebellar granule cells. Ultrastructural analyses revealed inclusions in axonal processes in the spinal cord, sciatic nerve and brain, but no excess of multivesicular bodies. Activated microglial cells and astrocytes were present in thalamus, brain stem, cerebellum and spinal cord, indicating regional pro-inflammatory responses. No storage cells were found in visceral organs of these mice. The absence of saposin C led to moderate increases in GC and lactosylceramide (LacCer) and their deacylated analogues. These results support the view that saposin C has multiple roles in glycosphingolipid (GSL) catabolism as well as a prominent function in CNS and axonal integrity independent of its role as an optimizer/stabilizer of GCase.
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Affiliation(s)
- Ying Sun
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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31
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Kolter T, Sandhoff K. Lysosomal degradation of membrane lipids. FEBS Lett 2009; 584:1700-12. [PMID: 19836391 DOI: 10.1016/j.febslet.2009.10.021] [Citation(s) in RCA: 211] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 10/09/2009] [Indexed: 01/05/2023]
Abstract
The constitutive degradation of membrane components takes place in the acidic compartments of a cell, the endosomes and lysosomes. Sites of lipid degradation are intralysosomal membranes that are formed in endosomes, where the lipid composition is adjusted for degradation. Cholesterol is sorted out of the inner membranes, their content in bis(monoacylglycero)phosphate increases, and, most likely, sphingomyelin is degraded to ceramide. Together with endosomal and lysosomal lipid-binding proteins, the Niemann-Pick disease, type C2-protein, the GM2-activator, and the saposins sap-A, -B, -C, and -D, a suitable membrane lipid composition is required for degradation of complex lipids by hydrolytic enzymes.
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Affiliation(s)
- Thomas Kolter
- LiMES - Life and Medical Sciences Institute, Membrane Biology and Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, University of Bonn, Bonn, Germany
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32
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Exploration of senescence-associated genes by differential display reverse transcription polymerase chain reaction: Prosaposin as a novel senescence-associated gene. Arch Pharm Res 2009; 32:737-45. [DOI: 10.1007/s12272-009-1513-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2009] [Revised: 03/27/2009] [Accepted: 03/27/2009] [Indexed: 11/26/2022]
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Kacher Y, Brumshtein B, Boldin-Adamsky S, Toker L, Shainskaya A, Silman I, Sussman JL, Futerman AH. Acid beta-glucosidase: insights from structural analysis and relevance to Gaucher disease therapy. Biol Chem 2008; 389:1361-9. [PMID: 18783340 DOI: 10.1515/bc.2008.163] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In mammalian cells, glucosylceramide (GlcCer), the simplest glycosphingolipid, is hydrolyzed by the lysosomal enzyme acid beta-glucosidase (GlcCerase). In the human metabolic disorder Gaucher disease, GlcCerase activity is significantly decreased owing to one of approximately 200 mutations in the GlcCerase gene. The most common therapy for Gaucher disease is enzyme replacement therapy (ERT), in which patients are given intravenous injections of recombinant human GlcCerase; the Genzyme product Cerezyme has been used clinically for more than 15 years and is administered to approximately 4000 patients worldwide. Here we review the crystal structure of Cerezyme and other recombinant forms of GlcCerase, as well as of their complexes with covalent and non-covalent inhibitors. We also discuss the stability of Cerezyme, which can be altered by modification of its N-glycan chains with possible implications for improved ERT in Gaucher disease.
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Affiliation(s)
- Yaacov Kacher
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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34
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Abstract
Although a minor constituent by weight, surfactant protein B (SP-B) plays a major role in surfactant function. It is the unique structure of SP-B that promotes permeabilization, cross-linking, mixing, and fusion of phospholipids, facilitating the proper structure and function of pulmonary surfactant as well as contributing to the formation of lamellar bodies. SP-B production is a complex process within alveolar type 2 cells and is under hormonal and developmental control. Understanding the posttranslational events in the maturation of SP-B may provide new insight into the process of lamellar body formation and into the pathophysiology of pulmonary disorders associated with surfactant abnormalities.
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Affiliation(s)
- Susan Guttentag
- Department of Pediatrics, Division of Neonatology, The University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4318, USA
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35
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Sun Y, Witte DP, Ran H, Zamzow M, Barnes S, Cheng H, Han X, Williams MT, Skelton MR, Vorhees CV, Grabowski GA. Neurological deficits and glycosphingolipid accumulation in saposin B deficient mice. Hum Mol Genet 2008; 17:2345-56. [PMID: 18480170 PMCID: PMC2465797 DOI: 10.1093/hmg/ddn135] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Accepted: 04/21/2008] [Indexed: 12/18/2022] Open
Abstract
Saposin B derives from the multi-functional precursor, prosaposin, and functions as an activity enhancer for several glycosphingolipid (GSL) hydrolases. Mutations in saposin B present in humans with phenotypes resembling metachromatic leukodystrophy. To gain insight into saposin B's physiological functions, a specific deficiency was created in mice by a knock-in mutation of an essential cysteine in exon 7 of the prosaposin locus. No saposin B protein was detected in the homozygotes (B-/-) mice, whereas prosaposin, and saposins A, C and D were at normal levels. B-/- mice exhibited slowly progressive neuromotor deterioration and minor head tremor by 15 months. Excess hydroxy and non-hydroxy fatty acid sulfatide levels were present in brain and kidney. Alcian blue positive (sulfatide) storage cells were found in the brain, spinal cord and kidney. Ultrastructural analyses showed lamellar inclusion material in the kidney, sciatic nerve, brain and spinal cord tissues. Lactosylceramide (LacCer) and globotriaosylceramide (TriCer) were increased in various tissues of B-/- mice supporting the in vivo role of saposin B in the degradation of these lipids. CD68 positive microglial cells and activated GFAP positive astrocytes showed a proinflammatory response in the brains of B-/- mice. These findings delineate the roles of saposin B for the in vivo degradation of several GSLs and its primary function in maintenance of CNS function. B-/- provide a useful model for understanding the contributions of this saposin to GSL metabolism and homeostasis.
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Affiliation(s)
- Ying Sun
- Division of Human Genetics
- Department of Pediatrics
| | - David P. Witte
- Division of Pediatric Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pathology, University of Cincinnati College of Medicine, Cincinnati, OH 45229-3039, USA
| | | | | | | | - Hua Cheng
- Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Xianlin Han
- Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
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CHU ZHENGTAO, SUN YING, KUAN CHIAYI, GRABOWSKI GREGORYA, QI XIAOYANG. Saposin C: Neuronal Effect and CNS Delivery by Liposomes. Ann N Y Acad Sci 2008. [DOI: 10.1111/j.1749-6632.2005.tb00031.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
BACKGROUND The therapy of the lysosomal storage diseases (LSDs) was developed by supplying adequate amounts of the needed enzyme to affected individuals. This approach in Gaucher disease provided a prototype for the basic and clinical sciences, and the economic foundation for other ultra-orphan diseases. OBJECTIVE Using the success of enzyme therapy for Gaucher disease, the challenges are highlighted for alternative bioproduction systems, and substrate reduction and molecular chaperone approaches for treatment of Gaucher disease and other ultra-orphan diseases. METHODS Literature review provided insight into the current status of enzyme therapies for LSDs, the proposed mechanisms of alternative approaches to therapy, and the obstacles in a competitive marketplace for treatment of ultra-rare diseases. RESULTS/CONCLUSIONS These developments are placed in the contexts of finding rare patients with LSDs, their marked phenotypic spectrum, potential markets, and new orphan drug costs. The confluence of these challenges has led to a competitive environment with the potential for multiple, alternative, expensive treatments for orphan diseases.
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Affiliation(s)
- Gregory A Grabowski
- University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, The Division of Human Genetics, Department of Pediatrics, Cincinnati, Ohio 45229-3039, USA.
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38
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Yuan W, Qi X, Tsang P, Kang SJ, Illarionov PA, Besra GS, Gumperz J, Cresswell P. Saposin B is the dominant saposin that facilitates lipid binding to human CD1d molecules. Proc Natl Acad Sci U S A 2007; 104:5551-6. [PMID: 17372201 PMCID: PMC1838443 DOI: 10.1073/pnas.0700617104] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Indexed: 12/11/2022] Open
Abstract
CD1d molecules bind lipid antigens in the endocytic pathway, and access to the pathway is important for the development of CD1d-restricted natural killer T (NKT) cells. Saposins, derived from a common precursor, prosaposin, are small, heat-stable lysosomal glycoproteins required for lysosomal degradation of sphingolipids. Expression of prosaposin is required for efficient lipid binding and recognition of human CD1d molecules by NKT cells. Despite high sequence homology among the four saposins, they have different specificities for lipid substrates and different mechanisms of action. To determine the saposins involved in promoting lipid binding to CD1d, we expressed prosaposin deletion mutants lacking individual saposins in prosaposin-negative, CD1d-positive cells. No individual saposin proved to be absolutely essential, but the absence of saposin B resulted in the lowest recognition of alpha-galactosylceramide by NKT cells. When recombinant exogenous saposins were added to the prosaposin-negative cells, saposin B was the most efficient in restoring CD1d recognition. Saposin B was also the most efficient in mediating alpha-galactosylceramide binding to recombinant plate-bound CD1d and facilitating NKT cell activation. Saposin B could also mediate lipid binding to soluble CD1d molecules in a T cell-independent assay. The optimal pH for saposin B-mediated lipid binding to CD1d, pH 6, is higher than that of lysosomes, suggesting that saposin B may facilitate lipid binding to CD1d molecules throughout the endocytic pathway.
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Affiliation(s)
- Weiming Yuan
- *Department of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8011
| | - Xiaoyang Qi
- Division and Program in Human Genetics, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229
| | - Pansy Tsang
- *Department of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8011
| | - Suk-Jo Kang
- *Department of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8011
| | - Petr A. Illarionov
- Department of Microbial Physiology and Chemistry, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom; and
| | - Gurdyal S. Besra
- Department of Microbial Physiology and Chemistry, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom; and
| | - Jenny Gumperz
- Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, 1300 University Avenue, Madison, WI 53706
| | - Peter Cresswell
- *Department of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8011
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Sun Y, Witte DP, Zamzow M, Ran H, Quinn B, Matsuda J, Grabowski GA. Combined saposin C and D deficiencies in mice lead to a neuronopathic phenotype, glucosylceramide and α-hydroxy ceramide accumulation, and altered prosaposin trafficking. Hum Mol Genet 2007; 16:957-71. [PMID: 17353235 DOI: 10.1093/hmg/ddm040] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Saposins (A, B, C and D) are approximately 80 amino acid stimulators of glycosphingolipid (GSL) hydrolases that derive from a single precursor, prosaposin. In both humans and mice, prosaposin/saposin deficiencies lead to severe neurological deficits. The CD-/- mice with saposin C and D combined deficiencies were produced by introducing genomic point mutations into a critical cysteine in each of these saposins. These mice develop a severe neurological phenotype with ataxia, kyphotic posturing and hind limb paralysis. Relative to prosaposin null mice ( approximately 30 days), CD-/- mice had an extended life span ( approximately 56 days). Loss of Purkinje cells was evident after 6 weeks, and storage bodies were present in neurons of the spinal cord, brain and dorsal root ganglion. Electron microscopy showed well-myelinated fibers and axonal inclusions in the brain and sciatic nerve. Marked accumulations of glucosylceramides and alpha-hydroxy ceramides were present in brain and kidney. Minor storage of lactosylceramide (LacCer) was observed when compared with tissues from the prosaposin null mice, suggesting a compensation in LacCer degradation by saposin B for the saposin C deficiency. Skin fibroblasts and tissues from CD-/- mice showed an increase of intracellular prosaposin, impaired prosaposin secretion, deficiencies of saposins C and D and decreases in saposins A and B. In addition, the deficiency of saposin C in CD-/- mice resulted in cellular decreases of acid beta-glucosidase activity and protein. This CD null mouse model provides a tool to explore the in vivo functional interactions of saposins in GSL metabolism and lysosomal storage diseases, and prosaposin's physiological effects.
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Affiliation(s)
- Ying Sun
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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40
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Akil O, Chang J, Hiel H, Kong JH, Yi E, Glowatzki E, Lustig LR. Progressive deafness and altered cochlear innervation in knock-out mice lacking prosaposin. J Neurosci 2007; 26:13076-88. [PMID: 17167097 PMCID: PMC6674959 DOI: 10.1523/jneurosci.3746-06.2006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
After a yeast two-hybrid screen identified prosaposin as a potential interacting protein with the nicotinic acetylcholine receptor (nAChR) subunit alpha10, studies were performed to characterize prosaposin in the normal rodent inner ear. Prosaposin demonstrates diffuse organ of Corti expression at birth, with gradual localization to the inner hair cells (IHCs) and its supporting cells, inner pillar cells, and synaptic region of the outer hair cells (OHCs) and Deiters' cells (DCs) by postnatal day 21 (P21). Microdissected OHC and DC quantitative reverse transcriptase-PCR and immunohistology localizes prosaposin mRNA to DCs and OHCs, and protein predominantly to the apex of the DCs. Subsequent studies in a prosaposin knock-out (KO) (-/-) mouse showed intact but slightly reduced hearing through P19, but deafness by P25 and reduced distortion product otoacoustic emissions from P15 onward. Beginning at P12, the prosaposin KO mice showed histologic organ of Corti changes including cellular hypertrophy in the region of the IHC and greater epithelial ridge, a loss of OHCs from cochlear apex, and vacuolization of OHCs. Immunofluorescence revealed exuberant overgrowth of auditory afferent neurites in the region of the IHCs and proliferation of auditory efferent neurites in the region of the tunnel of Corti. IHC recordings from these KO mice showed normal I-V curves and responses to applied acetylcholine. Together, these results suggest that prosaposin helps maintain normal innervation patterns to the organ of Corti. Furthermore, prosaposin's overlapping developmental expression pattern and binding capacity toward the nAChR alpha10 suggest that alpha10 may also play a role in this function.
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MESH Headings
- Acoustic Stimulation/methods
- Animals
- Animals, Newborn
- Cochlea/embryology
- Cochlea/innervation
- Cochlea/metabolism
- Cochlea/ultrastructure
- Deafness/genetics
- Deafness/metabolism
- Deafness/physiopathology
- Gene Expression Regulation, Developmental
- Hair Cells, Auditory/metabolism
- Hair Cells, Auditory/ultrastructure
- Hair Cells, Auditory, Inner/embryology
- Hair Cells, Auditory, Inner/metabolism
- Hair Cells, Auditory, Outer/embryology
- Hair Cells, Auditory, Outer/metabolism
- Mice
- Mice, Knockout
- Organ of Corti/metabolism
- Organ of Corti/ultrastructure
- Rats
- Rats, Sprague-Dawley
- Saposins/deficiency
- Saposins/genetics
- Saposins/physiology
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Affiliation(s)
- Omar Akil
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, California 94143-0449
| | - Jolie Chang
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, California 94143-0449
| | - Hakim Hiel
- Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, and
| | - Jee-Hyun Kong
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Eunyoung Yi
- Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, and
| | - Elisabeth Glowatzki
- Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, and
| | - Lawrence R. Lustig
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, California 94143-0449
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41
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Ahtiainen L, Luiro K, Kauppi M, Tyynelä J, Kopra O, Jalanko A. Palmitoyl protein thioesterase 1 (PPT1) deficiency causes endocytic defects connected to abnormal saposin processing. Exp Cell Res 2006; 312:1540-53. [PMID: 16542649 DOI: 10.1016/j.yexcr.2006.01.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 01/17/2006] [Accepted: 01/18/2006] [Indexed: 11/16/2022]
Abstract
Infantile neuronal ceroid lipofuscinosis (INCL) is a severe neurodegenerative disorder of the childhood caused by mutations in the gene encoding palmitoyl protein thioesterase 1 (PPT1). PPT1 localizes to late endosomes/lysosomes of non-neuronal cells and in neurons also to presynaptic areas. PPT1-deficiency causes massive death of cortical neurons and most tissues show an accumulation of saposins A and D. We have here studied endocytic pathways, saposin localization and processing in PPT1-deficient fibroblasts to elucidate the cellular defects resulting in accumulation of specific saposins. We show that PPT1-deficiency causes a defect in fluid-phase and receptor-mediated endocytosis, whereas marker uptake and recycling endocytosis remain intact. Furthermore, we show that saposins A and D are more abundant and relocalized in PPT-deficient fibroblasts and mouse primary neurons. Metabolic labeling and immunoprecipitation analyses revealed hypersecretion and abnormal processing of prosaposin, implying that the accumulation of saposins may result from endocytic defects. We show for the first time a connection between saposin storage and a defect in the endocytic pathway of INCL cells. These data provide new insights into the metabolism of PPT1-deficient cells and offer a basis for further studies on cellular processes causing neuronal death in INCL and other neurodegenerative diseases.
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Affiliation(s)
- Laura Ahtiainen
- National Public Health Institute, Department of Molecular Medicine, Biomedicum Helsinki, P.O. Box 104, 00251 Helsinki, Finland
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42
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Abstract
An athymic mouse-derived immature T-cell clone, N-9F, was not maintained by interleukin-2 alone but required another soluble factor, contained in concanavalin A-stimulated rat splenocyte culture supernatant, namely T cell growth factor (TCGF), for its proliferation. An N-9F-proliferation factor (NPF) was isolated in a pure form from TCGF. N-9F cells and immature thymocytes proliferated in the presence of N-9F at 10(-12)-10(-9)M in a dose-dependent manner, but adult thymocytes were not stimulated by NPF. NPF increased DNA synthesis of N-9F. NPF increased CD4 and CD8 double negative, single positive and double positive thymocytes in fetal thymus organ culture. A hamster anti-NPF antiserum possessing the capacity to neutralize N-9F proliferation activity of NPF neutralized the increasing effect of NPF on immature thymocytes. All effects of NPF was inhibited by mAb QR6.6 to recognize a 100 kDa surface molecule of N-9F. The amino-terminal 20 amino acid sequence of NPF was identified and identical to that of rat saposin A. The apparent molecular weight of NPF, 16000, was comparable to that of saposin A. A Hitrap-mouse recombinant His-tag-saposin A antibody column bound NPF, pulled down the NPF activity in TCGF, and the antibody recognized a 16kDa molecule in western-blotting of TCGF. Thus, NPF in TCGF was a saposin A-like protein possessing the capacity for growth and differentiation of immature thymocytes. The physiological significance of NPF in the growth and differentiation of immature thymocytes was discussed in view of the characteristic distributions of NPF and the molecule recognized by its mAb QR6.6 in fetal thymi.
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Affiliation(s)
- Yasuhiro Kohama
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita City, Japan.
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43
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Kiss RS, Ma Z, Nakada-Tsukui K, Brugnera E, Vassiliou G, McBride HM, Ravichandran KS, Marcel YL. The lipoprotein receptor-related protein-1 (LRP) adapter protein GULP mediates trafficking of the LRP ligand prosaposin, leading to sphingolipid and free cholesterol accumulation in late endosomes and impaired efflux. J Biol Chem 2006; 281:12081-92. [PMID: 16497666 DOI: 10.1074/jbc.m600621200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
One of the conserved functional pathways linked to engulfment of apoptotic corpses involves two membrane proteins low density lipoprotein receptor-related protein-1 (LRP) and ABCA1 and the LRP adapter protein GULP. Because LRP and ABCA1 play roles in cellular lipid trafficking and efflux, here we addressed whether the third member, the LRP adapter protein GULP, also affects cellular lipid transport. Several lines of evidence show that overexpression of GULP causes glycosphingolipid and free cholesterol accumulation in the late endosome/lysosome compartment that is accompanied by down-regulation of ABCA1 and decreased efflux. Conversely, knockdown of endogenous GULP expression promoted cholesterol flux through the late endosomes and up-regulation of ABCA1, even in the context of a disease state such as Niemann-Pick Type C disease. Mechanistically, we were able to show that trafficking of the LRP ligands alpha2-macroglobulin and prosaposin, a protein cofactor necessary for glycosphingolipid degradation, are impaired in cells expressing full-length GULP protein, resulting in glycosphingolipid and free cholesterol accumulation in the late endosome/lysosome compartment. On the other hand, knockdown of endogenous GULP results in enhanced targeting of prosaposin and enhanced clearance of glycosphingolipids and cholesterol from the late endosomes. Taken together, these data reveal that GULP/LRP/ABCA1 represents a triad of molecules involved in engulfment and cellular lipid homeostasis.
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Affiliation(s)
- Robert S Kiss
- Lipoprotein and Atherosclerosis Research Group, Department of Pathology and Laboratory Medicine, University of Ottawa Heart Institute, Ottawa K1Y 4W7, Canada
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44
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Sun Y, Quinn B, Witte DP, Grabowski GA. Gaucher disease mouse models: point mutations at the acid beta-glucosidase locus combined with low-level prosaposin expression lead to disease variants. J Lipid Res 2005; 46:2102-13. [PMID: 16061944 DOI: 10.1194/jlr.m500202-jlr200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gaucher disease is a common lysosomal storage disease caused by a defect of acid beta-glucosidase (GCase). The optimal in vitro hydrolase activity of GCase requires saposin C, an activator protein that derives from a precursor, prosaposin. To develop additional models of Gaucher disease and to test in vivo effects of saposin deficiencies, mice expressing low levels (4--45% of wild type) of prosaposin and saposins (PS-NA) were backcrossed into mice with specific point mutations (V394L/V394L or D409H/D409H) of GCase. The resultant mice were designated 4L/PS-NA and 9H/PS-NA, respectively. In contrast to PS-NA mice, the 4L/PS-NA and 9H/PS-NA mice displayed large numbers of engorged macrophages and nearly exclusive glucosylceramide (GC) accumulation in the liver, lung, spleen, thymus, and brain. Electron microscopy of the storage cells showed the characteristic tubular storage material of Gaucher cells. Compared with V394L/V394L mice, 4L/PS-NA mice that expressed 4--6% of wild-type prosaposin levels had approximately 25--75% decreases in GCase activity and protein in liver, spleen, and fibroblasts. These results imply that reduced saposin levels increased the instability of V394L or D409H GCases and that these additional decreases led to large accumulations of GC in all tissues. These models mimic a more severe Gaucher disease phenotype and could be useful for therapeutic intervention studies.
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Affiliation(s)
- Ying Sun
- Division and Program in Human Genetics, Children's Hospital Research Foundation, Cincinnati, OH 45229-3039, USA
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45
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Gopalakrishnan M, Grosch HW, Locatelli-Hoops S, Werth N, Smolenová E, Nettersheim M, Sandhoff K, Hasilik A. Purified recombinant human prosaposin forms oligomers that bind procathepsin D and affect its autoactivation. Biochem J 2005; 383:507-15. [PMID: 15255780 PMCID: PMC1133744 DOI: 10.1042/bj20040175] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Before delivery to endosomes, portions of proCD (procathepsin D) and proSAP (prosaposin) are assembled into complexes. We demonstrate that such complexes are also present in secretions of cultured cells. To study the formation and properties of the complexes, we purified proCD and proSAP from culture media of Spodoptera frugiperda cells that were infected with baculoviruses bearing the respective cDNAs. The biological activity of proCD was demonstrated by its pH-dependent autoactivation to pseudocathepsin D and that of proSAP was demonstrated by feeding to saposin-deficient cultured cells that corrected the storage of radioactive glycolipids. In gel filtration, proSAP behaved as an oligomer and proCD as a monomer. ProSAP altered the elution of proCD such that the latter was shifted into proSAP-containing fractions. ProSAP did not change the elution of mature cathepsin D. Using surface plasmon resonance and an immobilized biotinylated proCD, binding of proSAP was demonstrated under neutral and weakly acidic conditions. At pH 6.8, specific binding appeared to involve more than one binding site on a proSAP oligomer. The dissociation of the first site was characterized by a K(D1) of 5.8+/-2.9x10(-8) M(-1) (calculated for the monomer). ProSAP stimulated the autoactivation of proCD and also the activity of pseudocathepsin D. Concomitant with the activation, proSAP behaved as a substrate yielding tri- and disaposins and smaller fragments. Our results demonstrate that proSAP forms oligomers that are capable of binding proCD spontaneously and independent of the mammalian type N-glycosylation but not capable of binding mature cathepsin D. In addition to binding proSAP, proCD behaves as an autoactivable and processing enzyme and its binding partner as an activator and substrate.
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Affiliation(s)
| | - Hans-Wilhelm Grosch
- *Institute of Physiological Chemistry, Philipps-University Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany
| | - Silvia Locatelli-Hoops
- †The Kekulé Institute for Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany
| | - Norbert Werth
- †The Kekulé Institute for Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany
| | - Eva Smolenová
- *Institute of Physiological Chemistry, Philipps-University Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany
| | - Michael Nettersheim
- †The Kekulé Institute for Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany
| | - Konrad Sandhoff
- †The Kekulé Institute for Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany
| | - Andrej Hasilik
- *Institute of Physiological Chemistry, Philipps-University Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany
- To whom correspondence should be addressed (email )
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46
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Cohen T, Auerbach W, Ravid L, Bodennec J, Fein A, Futerman AH, Joyner AL, Horowitz M. The exon 8-containing prosaposin gene splice variant is dispensable for mouse development, lysosomal function, and secretion. Mol Cell Biol 2005; 25:2431-40. [PMID: 15743835 PMCID: PMC1061615 DOI: 10.1128/mcb.25.6.2431-2440.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prosaposin is a multifunctional protein with diverse functions. Intracellularly, prosaposin is a precursor of four sphingolipid activator proteins, saposins A to D, which are required for hydrolysis of sphingolipids by several lysosomal exohydrolases. Secreted prosaposin has been implicated as a neurotrophic, myelinotrophic, and myotrophic factor as well as a spermatogenic factor. It has also been implicated in fertilization. The human and the mouse prosaposin gene has a 9-bp exon (exon 8) that is alternatively spliced, resulting in an isoform with three extra amino acids, Gln-Asp-Gln, within the saposin B domain. Alternative splicing in the prosaposin gene is conserved from fish to humans, tissue specific, and regulated in the brain during development and nerve regeneration-degeneration processes. To elucidate the physiological role of alternative splicing, we have generated a mouse lacking exon 8 by homologous recombination. The exon 8 prosaposin mutant mice are healthy and fertile with no obvious phenotype. No changes were detected in prosaposin secretion or in accumulation and metabolism of gangliosides, sulfatides, neutral glycosphingolipids, neutral phospholipids, other neutral lipids, and ceramide. These data strongly indicate that the prosaposin variant containing the exon 8-encoded three amino acids is dispensable for normal mouse development and fertility as well as for prosaposin secretion and its lysosomal function, at least in the presence of the prosaposin variant missing the exon 8-encoded three amino acids.
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Affiliation(s)
- Tsadok Cohen
- Department of Cell Research and Immunology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
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47
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Unuma K, Chen J, Saito S, Kobayashi N, Sato K, Saito K, Wakisaka H, Mominoki K, Sano A, Matsuda S. Changes in expression of prosaposin in the rat facial nerve nucleus after facial nerve transection. Neurosci Res 2005; 52:220-7. [PMID: 15927723 DOI: 10.1016/j.neures.2005.03.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 03/05/2005] [Accepted: 03/18/2005] [Indexed: 11/30/2022]
Abstract
Prosaposin is the precursor of saposins A, B, C and D, which are activators of sphingolipid hydrolases. In addition, unprocessed prosaposin functions as a neurotrophic factor in the central and peripheral nervous systems by acting to prevent neuronal apoptosis, to elongate neurites and to facilitate myelination. In this study, the expression pattern of prosaposin in the facial nerve nucleus after facial nerve transection was examined by immunohistochemistry and in situ hybridization. Prosaposin immunoreactivity in the neurons on the operated side facial nerve nucleus showed a biphasic pattern: it was significantly increased on day 3 after transection, decreased dramatically on day 7, started to increase gradually on day 14 and reached another peak on day 21 after transection. Significant increases in the levels of prosaposin mRNA were identified in the neurons on the operated side, suggesting that prosaposin was synthesized vigorously by the neurons themselves in the case of facial nerve transection. The diverse changes in prosaposin immunoreactivity during the process of facial nerve regeneration may reflect the diverse neurotrophic activities of prosaposin in facial motoneurons.
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Affiliation(s)
- Kana Unuma
- Division of Anatomy and Embryology, Department of Integrated Basic Medical Science, Ehime University School of Medicine, Shitsukawa, Toon-shi, Ehime 791-0295, Japan
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48
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Soler-García AA, Maitra R, Kumar V, Ise T, Nagata S, Beers R, Bera TK, Pastan I. The PATE gene is expressed in the accessory tissues of the human male genital tract and encodes a secreted sperm-associated protein. Reproduction 2005; 129:515-24. [PMID: 15798027 DOI: 10.1530/rep.1.00576] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ThePATEgene is expressed in prostate and testis. To determine if PATE is expressed in other accessory tissues of the male genital tract, RT-PCR of the epididymis and seminal vesicle was performed. PATE mRNA was highly expressed in the epididymis and seminal vesicle.In situhybridization of the testis showed PATE mRNA is strongly expressed in the spermatogonia. ThePATEgene encodes a 14-kDa protein with a predicted signal sequence and a cleavage site between residues G21 and S22. To determine if PATE is a secreted protein, 293T cells were transfected with a pcDNA-PATE-myc-His plasmid and protein immunoprecipitated with anti-myc monoclonal antibody. Western blot analysis showed the presence of PATE-myc-His protein was in the medium and the cell lysate. Confocal microscopy demonstrated that PATE-myc-His protein is found in the endoplasmic reticulum. The polyclonal antibody SOL-1 was generated by immunization of rabbits with recombinant PATE protein expressed and purified fromEscherichia coli.Western blots were performed on extracts of prostate, testis, seminal vesicle and ejaculated spermatozoa, but PATE protein was only detected in the spermatozoa. Immunostaining of sperm smears revealed that PATE is located in a band-like pattern in the sperm head. Our data indicate that PATE is made by various sexual accessory tissues and secreted into the semen where it becomes associated with sperm, suggesting that PATE is a novel sperm-associated protein with a possible role in mammalian sperm maturation.
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Affiliation(s)
- Angel A Soler-García
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4264, USA
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Wei YD, Lee SJ, Lee KS, Gui ZZ, Yoon HJ, Kim I, Je YH, Guo X, Sohn HD, Jin BR. N-glycosylation is necessary for enzymatic activity of a beetle (Apriona germari) cellulase. Biochem Biophys Res Commun 2005; 329:331-6. [PMID: 15721311 DOI: 10.1016/j.bbrc.2005.01.131] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Indexed: 01/07/2023]
Abstract
We previously reported that the beta-1,4-endoglucanase (EGase) belonging to glycoside hydrolase family 45 cloned from the mulberry longicorn beetle, Apriona germari (Ag-EGase I), is composed of 237 amino acid residues and has a potential N-glycosylation site at 97-100 amino acid residues (NSTF). We here describe the N-glycosylation and its role for enzymatic activity of the Ag-EGase I. The N-glycosylation of Ag-EGase I was revealed by the treatment of tunicamycin to the recombinant virus-infected insect Sf9 cells and by endoglycosidase F to the purified recombinant Ag-EGase I, demonstrating that the carbohydrate moieties are not necessary for secretion but essential for Ag-EGase I enzyme activity. To further elucidate the functional role of the N-glycosylation in Ag-EGase I, we have assayed the cellulase enzyme activity in Thr99Gln mutant. Lack of N-glycosylation in Ag-EGase I showed no substantial enzyme activity. This result demonstrates that N-glycosylation at site 97-100 amino acid residues (NSTF) is essential for enzyme activity.
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Affiliation(s)
- Ya Dong Wei
- Department of Applied Biotechnology, College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea
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Chu Z, Witte DP, Qi X. Saposin C-LBPA interaction in late-endosomes/lysosomes. Exp Cell Res 2005; 303:300-7. [PMID: 15652344 DOI: 10.1016/j.yexcr.2004.09.029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Revised: 09/12/2004] [Accepted: 09/30/2004] [Indexed: 11/27/2022]
Abstract
Acidic phospholipids and saposins associations are involved in the degradation process of glycosphingolipids/sphingolipids in late endosomes/lysosomes. In this report, we showed the colocalization of saposin C and lysobisphosphatidic acid (LBPA) in human fibroblasts by using cytoimmunofluorescence analysis. This colocalization pattern was not seen with other saposins. Large numbers of saposins A, B, and D illustrated the staining patterns that differ from LBPA. In addition, ingested anti-LBPA antibody altered the location of saposin C in human wild-type fibroblasts. In vitro assays demonstrated that saposin C at nM concentrations induced membrane fusion of LBPA containing phospholipid vesicles. Under the same condition, other saposins had no fusion induction on these vesicles. These results suggested a specific interaction between saposin C and LBPA. Total saposin-deficient fibroblasts showed a massive accumulation of multivesicular bodies (MVBs) by electron microscopic analysis. No significant increase of MVBs was found in saposins A and B deficient cells. Interestingly, the accumulated MVBs were significantly reduced by loading saposin C alone into the total saposin-deficient cells. Therefore, we propose that saposin C-LBPA interaction plays a role in the regulation of MVB formation in cells.
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Affiliation(s)
- Zhengtao Chu
- Division and Program in Human Genetics, Children's Hospital Research Foundation, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
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