Acid and neutral sphingomyelinases: roles and mechanisms of regulation

2004 ◽  
Vol 82 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Norma Marchesini ◽  
Yusuf A Hannun
Keyword(s):  
Nitric Oxide ◽  
Molecular Mechanisms ◽  
Caveolin 1 ◽  
Niemann Pick Disease ◽  
Extracellular Stimuli ◽  
Niemann Pick ◽  
Hydrolysis Of ◽  
Pick Disease

Ceramide, an emerging bioactive lipid and second messenger, is mainly generated by hydrolysis of sphingomyelin through the action of sphingomyelinases. At least two sphingomyelinases, neutral and acid sphingo myelinases, are activated in response to many extracellular stimuli. Despite extensive studies, the precise cellular function of each of these sphingomyelinases in sphingomyelin turnover and in the regulation of ceramide-mediated responses is not well understood. Therefore, it is essential to elucidate the factors and mechanisms that control the activation of acid and neutral sphingomyelinases to understand their the roles in cell regulation. This review will focus on the molecular mechanisms that regulate these enzymes in vivo and in vitro, especially the roles of oxidants (glu ta thi one, peroxide, nitric oxide), proteins (saposin, caveolin 1, caspases), and lipids (diacylglycerol, arachidonic acid, and ceramide).Key words: sphingomyelinase, ceramide, apoptosis, Niemann-Pick disease, FAN (factor associated with N-SMase activation).

Optical non-invasive detection of Niemann-Pick disease in vitro and in vivo

2017 ◽  
Vol 120 (1-2) ◽  
pp. S71
Author(s):  
Prakrit V. Jena ◽  
Thomas V. Galassi ◽  
Daniel Roxbury ◽  
Robert E. Schwartz ◽  
Frederick R. Maxfield ◽  
...  
Keyword(s):  
Non Invasive ◽  
Niemann Pick Disease ◽  
Niemann Pick ◽  
Pick Disease

scholarly journals In Vitro and In Vivo Evaluation of 6-O-α-Maltosyl-β-Cyclodextrin as a Potential Therapeutic Agent Against Niemann-Pick Disease Type C

2019 ◽  
Vol 20 (5) ◽  
pp. 1152 ◽  
Author(s):  
Nushrat Yasmin ◽  
Yoichi Ishitsuka ◽  
Madoka Fukaura ◽  
Yusei Yamada ◽  
Shuichi Nakahara ◽  
...  
Keyword(s):  
Free Cholesterol ◽  
Disease Type ◽  
Cholesterol Trafficking ◽  
Niemann Pick Disease ◽  
Type C ◽  
Niemann Pick ◽  
Deficient Mice ◽  
Pick Disease

Niemann-Pick disease Type C (NPC) is a rare lysosomal storage disease characterized by the dysfunction of intracellular cholesterol trafficking with progressive neurodegeneration and hepatomegaly. We evaluated the potential of 6-O-α-maltosyl-β-cyclodextrin (G2-β-CD) as a drug candidate against NPC. The physicochemical properties of G2-β-CD as an injectable agent were assessed, and molecular interactions between G2-β-CD and free cholesterol were studied by solubility analysis and two-dimensional proton nuclear magnetic resonance spectroscopy. The efficacy of G2-β-CD against NPC was evaluated using Npc1 deficient Chinese hamster ovary (CHO) cells and Npc1 deficient mice. G2-β-CD in aqueous solution showed relatively low viscosity and surface activity; characteristics suitable for developing injectable formulations. G2-β-CD formed higher-order inclusion complexes with free cholesterol. G2-β-CD attenuated dysfunction of intercellular cholesterol trafficking and lysosome volume in Npc1 deficient CHO cells in a concentration dependent manner. Weekly subcutaneous injections of G2-β-CD (2.9 mmol/kg) ameliorated abnormal cholesterol metabolism, hepatocytomegaly, and elevated serum transaminases in Npc1 deficient mice. In addition, a single cerebroventricular injection of G2-β-CD (21.4 μmol/kg) prevented Purkinje cell loss in the cerebellum, body weight loss, and motor dysfunction in Npc1 deficient mice. In summary, G2-β-CD possesses characteristics favorable for injectable formulations and has therapeutic potential against in vitro and in vivo NPC models.

scholarly journals Effect of Maltosyl-Beta-cyclodextrin on in vitro and in vivo models of Niemann-Pick disease type C

2018 ◽  
Vol WCP2018 (0) ◽  
pp. PO3-8-13
Author(s):  
Nushrat Yasmin ◽  
Yoichi Ishitsuka ◽  
Yusei Yamada ◽  
Madoka Fukaura ◽  
Shuichi Nakahara ◽  
...  
Keyword(s):  
Disease Type ◽  
In Vivo Models ◽  
Beta Cyclodextrin ◽  
Niemann Pick Disease ◽  
Type C ◽  
Niemann Pick ◽  
Pick Disease

scholarly journals Elucidating the mechanism of cyclodextrins in the treatment of Niemann-Pick Disease Type C using crosslinked 2-hydroxypropyl-β-cyclodextrin

2020 ◽  
Author(s):  
Dario Carradori ◽  
Hsintsung Chen ◽  
Beat Werner ◽  
Aagam Shah ◽  
Chiara Leonardi ◽  
...  
Keyword(s):  
Clinical Investigation ◽  
Disease Type ◽  
Niemann Pick Disease ◽  
Type C ◽  
High Doses ◽  
Niemann Pick ◽  
Stable Forms ◽  
Pick Disease

AbstractNiemann-Pick Disease Type C (NPC) is a severe neurovisceral disorder that is pathophysiologically characterized by intracellular transport abnormalities leading to cytoplasmic accumulation of lipids such as cholesterol and multiple sphingolipids, including sphingosine. The compound 2-hydroxypropyl-β-cyclodextrin (HPβCD) is a compound with high cholesterol complexation capacity and is currently under clinical investigation for the treatment of NPC. However, due to its short blood half-life, high doses are required to produce a therapeutic effect. It has been reported in mice that HPβCD’s circulation time and efficacy can be improved by increasing its size via polymerization, but the biodegradable nature of these systems did not allow the contribution of the macromolecule to the activity to be determined. In this work, stable forms of polymerized HPβCD were generated (via epichlorohydrin crosslinking) to investigate their in vitro mechanisms of action and in vivo effects. Crosslinked CDs (8-312 kDa) displayed a 10-fold greater complexation capacity towards cholesterol than monomeric HPβCD but were taken up by cells to a lower extent (in a size-dependent fashion), resulting in an overall comparable in vitro effect on intracellular cholesterol accumulation that was dependent on cholesterol complexation. When tested in vivo, the crosslinked 19.3 kDa HPβCD exhibited a longer terminal half-life than the monomeric HPβCD. However, it did not increase the life span of Npc1 mice, possibly due to reduced organ penetration and brain diffusion consequence of its large molecular weight. This could be circumvented by the application of magnetic resonance imaging-guided low intensity-pulsed focused ultrasound (MRIg-FUS), which increased the brain penetration of the CD. In conclusion, stable forms of polymerized HPβCD constitute valuable tools to elucidate CDs’ mechanism of action. Moreover, the use of MRIg-FUS to maximize CDs tissue penetration warrants further investigation, as it may be key to harnessing CDs full therapeutic potential in the treatment of NPC.Graphical abstractThe 2-hydroxypropyl-β-cyclodextrin (HPβCD) is a well-established pharmaceutical excipient that can complex cholesterol and is currently under clinical investigation to treat Niemann-Pick Disease Type C (NPC). However, high doses of the drug are needed to achieve a therapeutic effect. Using stable and long circulating crosslinked HPβCDs, this study attempts to further understand the mechanisms behind CDs’ activity.

Alveolar lipoproteinosis in an acid sphingomyelinase-deficient mouse model of Niemann-Pick disease

2003 ◽  
Vol 284 (3) ◽  
pp. L518-L525 ◽  
Author(s):  
Machiko Ikegami ◽  
Rajwinder Dhami ◽  
Edward H. Schuchman
Keyword(s):  
Alveolar Macrophages ◽  
Pulmonary Inflammation ◽  
Acid Sphingomyelinase ◽  
Deficient Mouse ◽  
Niemann Pick Disease ◽  
Surfactant Inhibition ◽  
Niemann Pick ◽  
Surfactant Composition ◽  
Pick Disease

Types A and B Niemann-Pick disease (NPD) are lipid storage disorders caused by the deficient activity of acid sphingomyelinase (ASM). In humans, NPD is associated with the dysfunction of numerous organs including the lung. Gene targeting of the ASM gene in transgenic mice produced an animal model with features typical of NPD, including pulmonary inflammation. To assess mechanisms by which ASM perturbed lung function, we studied lung morphology, surfactant content, and metabolism in ASM-deficient mice in vivo. Pulmonary inflammation, with increased cellular infiltrates and the accumulation of alveolar material, was associated with alterations in surfactant content. Saturated phosphatidylcholine (SatPC) content was increased twofold, and sphingomyelin content was increased 5.5-fold in lungs of the ASM knockout (ASMKO) mice. Additional sphingomyelin enhanced the sensitivity of surfactant inhibition by plasma proteins. Clearance of SatPC from the lungs of ASMKO mice was decreased. Catabolism of SatPC by alveolar macrophages from the ASMKO mouse was significantly decreased, likely accounting for decreased pulmonary SatPC in vivo. In summary, ASM is required for normal surfactant catabolism by alveolar macrophages in vivo. Alterations in surfactant composition, including increased sphingomyelin content, contributed to the abnormal surfactant function observed in the ASM-deficient mouse.

scholarly journals Human iNSC-derived brain organoid model of lysosomal storage disorder in Niemann–Pick disease type C

2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Seung-Eun Lee ◽  
Nari Shin ◽  
Myung Geun Kook ◽  
Dasom Kong ◽  
Nam Gyo Kim ◽  
...  
Keyword(s):  
Stem Cells ◽  
Lysosomal Storage Disorder ◽  
Disease Type ◽  
Lysosomal Storage ◽  
Niemann Pick Disease ◽  
Type C ◽  
Storage Disorder ◽  
Niemann Pick ◽  
Pick Disease

AbstractRecent studies on developing three-dimensional (3D) brain organoids from stem cells have allowed the generation of in vitro models of neural disease and have enabled the screening of drugs because these organoids mimic the complexity of neural tissue. Niemann-Pick disease, type C (NPC) is a neurodegenerative lysosomal storage disorder caused by mutations in the NPC1 or NPC2. The pathological features underlying NPC are characterized by the abnormal accumulation of cholesterol in acidic compartments, including late endosomes and lysosomes. Due to the inaccessibility of brain tissues from human NPC patients, we developed NPC brain organoids with induced neural stem cells from NPC patient-derived fibroblasts. NPC organoids exhibit significantly reduced size and proliferative ability, which are accompanied by accumulation of cholesterol, impairment in neuronal differentiation, and autophagic flux and dysfunction of lysosomes; therefore, NPC organoids can recapitulate the main phenotypes of NPC patients. Furthermore, these pathological phenotypes observed in NPC organoids were reversed by treatment with valproic acid and HPBCD, which are known to be an effective treatment for several neurodegenerative diseases. Our data present patient-specific phenotypes in 3D organoid-based models of NPC and highlight the application of this model to drug screening in vitro.

Spermatozoa from mice deficient in Niemann-Pick disease type C2 (NPC2) protein have defective cholesterol content and reduced in vitro fertilising ability

2014 ◽  
Vol 26 (4) ◽  
pp. 609 ◽  
Author(s):  
Dolores Busso ◽  
María José Oñate-Alvarado ◽  
Elisa Balboa ◽  
Juan Castro ◽  
Carlos Lizama ◽  
...  
Keyword(s):  
Cholesterol Content ◽  
Disease Type ◽  
Wild Type ◽  
Cholesterol Levels ◽  
Niemann Pick Disease ◽  
Epididymal Maturation ◽  
Sperm Membrane ◽  
Niemann Pick ◽  
Pick Disease

The cholesterol content of the sperm membrane is regulated during both maturation in the epididymis and capacitation in the female tract, two processes required for the spermatozoa to acquire their fertilising ability. Because Niemann-Pick disease, type C2 (NPC2) protein is one of the most abundant components of the epididymal fluid and contains a functional cholesterol-binding site that can transfer cholesterol between membranes, it has been suggested for years that NPC2 could be involved in the regulation of cholesterol levels in spermatozoa during epididymal maturation. In the present study, western blot and immunohistochemistry analyses demonstrated significant levels of NPC2 in the mouse epididymal epithelium. Epididymal spermatozoa obtained from NPC2–/– mice were morphologically normal and had normal motility parameters, but had a reduced cholesterol content compared with that of wild-type (WT) spermatozoa, as determined by both biochemical and by flow cytometry analyses. These results suggest that NPC2 could be involved in regulating cholesterol levels in spermatozoa during epididymal maturation. To understand the relevance of epididymal NPC2 for sperm function, the ability of spermatozoa to undergo events influenced by epididymal maturation, such as capacitation and fertilisation, were compared between WT and NPC2–/– mice. Capacitated NPC2–/– spermatozoa exhibited defective tyrosine phosphorylation patterns and a reduced ability to fertilise cumulus–oocyte complexes compared with WT spermatozoa, supporting the relevance of mouse epididymal NPC2 for male fertility.

scholarly journals TIE2 Associates with Caveolae and Regulates Caveolin-1 To Promote Their Nuclear Translocation

2017 ◽  
Vol 37 (21) ◽  
Author(s):  
Mohammad B. Hossain ◽  
Rehnuma Shifat ◽  
Jingyi Li ◽  
Xuemei Luo ◽  
Kenneth R. Hess ◽  
...  
Keyword(s):  
Dna Repair ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Subcellular Fractionation ◽  
Tyrosine Kinase Receptor ◽  
Histone H4 ◽  
Small Interfering Rnas ◽  
Caveolin 1

ABSTRACT DNA repair pathways are aberrant in cancer, enabling tumor cells to survive standard therapies—chemotherapy and radiotherapy. Our group previously reported that, upon irradiation, the membrane-bound tyrosine kinase receptor TIE2 translocates into the nucleus and phosphorylates histone H4 at Tyr51, recruiting ABL1 to the DNA repair complexes that participate in the nonhomologous end-joining pathway. However, no specific molecular mechanisms of TIE2 endocytosis have been reported. Here, we show that irradiation or ligand-induced TIE2 trafficking is dependent on caveolin-1, the main component of caveolae. Subcellular fractionation and confocal microscopy demonstrated TIE2/caveolin-1 complexes in the nucleus, and using inhibitor or small interfering RNAs (siRNAs) against caveolin-1 or Tie2 inhibited their trafficking. TIE2 was found in caveolae and directly phosphorylated caveolin-1 at Tyr14 in vitro and in vivo. This modification regulated the generation of TIE2/caveolin-1 complexes and was essential for TIE2/caveolin-1 nuclear translocation. Our data further demonstrate that the combination of TIE2 and caveolin-1 inhibitors resulted in significant radiosensitization of malignant glioma cells, which will guide the development of combinatorial treatment with radiotherapy for patients with glioblastoma.

scholarly journals C-Reactive Protein Adversely Alters the Protein–Protein Interaction of the Endothelial Isoform of Nitric Oxide Synthase

2010 ◽  
Vol 56 (8) ◽  
pp. 1345-1348 ◽  
Author(s):  
Simona Valleggi ◽  
Sridevi Devaraj ◽  
Mohan R Dasu ◽  
Ishwarlal Jialal
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Protein Interactions ◽  
Heat Shock Protein 90 ◽  
C Reactive Protein ◽  
Caveolin 1 ◽  
Reactive Protein ◽  
Oxide Synthase

BACKGROUND C-reactive protein (CRP) inhibits the activity of the endothelial isoform of nitric oxide synthase (eNOS) via uncoupling of the enzyme both in vitro and in vivo. eNOS activity appears to be related in part to its interaction with other cellular proteins, including heat shock protein 90 (Hsp90), caveolin-1, and porin. In this study, we examined the effect of CRP treatment of human aortic endothelial cells (HAECs) on eNOS interaction with caveolin-1, Hsp90, and porin. METHODS We incubated HAECs with CRP (0, 12.5, and 25 mg/L) for 1, 6, or 24 h and assessed the interaction of these proteins with eNOS by immunoprecipitation and western blotting. RESULTS CRP treatment (12.5 and 25 mg/L) of HAECs for 24 h significantly increased eNOS binding to caveolin-1 (40% and 54% increase, respectively; P < 0.05) and decreased binding to Hsp90 (33% and 66% decrease, respectively; P < 0.05). CRP (25 mg/L) also significantly decreased the binding of porin to eNOS (11% decrease, P < 0.05). Similar results were seen when HAECs were treated with CRP for 6 h. CONCLUSIONS These negative protein–protein interactions of eNOS were able to partly explain the CRP-induced decreases in the activity of this critical enzyme, which caused endothelial dysfunction.

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