gw-4869 and Disease-Models--Animal

Inflammatory cytokines in the tumor microenvironment (TME) contribute to tumor growth, proliferation, and invasion, and tumor-derived extracellular vesicles (EVs) act as critical "messengers" of communication in the tumor microenvironment. The effects of EVs derived from oral squamous cell carcinoma (OSCC) cells on tumor progression and the inflammatory microenvironment are still unclear. Our study aims to investigate the role of OSCC-derived EVs in tumor progression, the imbalanced TME, and immunosuppression and their effect on the IL-17A-induced signaling pathway.. EVs were isolated from the supernatant of a mouse OSCC cell line, SCC7. The effects of SCC7-EVs and the EV release-specific inhibitor GW4869 on the proliferation and migration of SCC7 cells were investigated in vitro by using CCK-8 and scratch wound healing assays. RT-qPCR and ELISA were performed to examine the alterations in cytokine levels. Then, a mouse xenograft model of OSCC was established by submucosal injection of SCC7 cells with or without SCC7-EV and GW4869 treatment. The effects of GW4869 and SCC7-EVs on xenograft tumor proliferation and invasion were investigated by tumor volume determination and histopathological examination. ELISA was used to investigate the changes in serum cytokine levels. Immunohistochemistry was adopted to analyze the alterations in the levels of inflammatory cytokines, immune factors, and crucial molecules in the IL-17A signaling pathway.. SCC7-derived EVs increased the supernatant and serum levels of IL-17A, IL-10, IL-1β, and PD-L1, while GW4869 decreased those of TNF-α and IFN-γ. SCC7-EV treatment significantly increased xenograft tumor growth and invasion in mice but resulted in little liquefactive necrosis in tumors. However, GW4869 treatment significantly inhibited xenograft tumor growth but resulted in more liquefactive necrosis. SCC7-derived EVs decreased the expression level of PTPN2, suppressing the immune responses of CD8 + T cells in vivo. Moreover, SCC7-EV treatment significantly enhanced the tumor expression levels of crucial molecules in the IL-17A pathway, including IL-17A, TRAF6 and c-FOS, whereas GW4869 treatment significantly reduced those levels in tumor tissues.. Our results indicated that OSCC-derived EVs can promote tumor progression by altering the TME, causing an inflammatory cytokine imbalance, inducing immunosuppression, and contributing to overactivation of the IL-17A-induced signaling pathway. Our study might provide novel insights into the role of OSCC-derived EVs in tumor biological behavior and immune dysregulation.

Topics: Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Cytokines; Disease Models, Animal; Extracellular Vesicles; Head and Neck Neoplasms; Humans; Interleukin-17; Mice; Mouth Neoplasms; Necrosis; Protein Tyrosine Phosphatase, Non-Receptor Type 2; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Tumor Microenvironment

Our study is aimed at investigating the mechanism by which electroacupuncture (EA) promoted nerve regeneration by regulating the release of exosomes and exosome-mediated miRNA-21 (miR-21) transmission. Furthermore, the effects of Schwann cells- (SC-) derived exosomes on the overexpression of miR-21 for the treatment of PNI were investigated.. A sciatic nerve injury model of rat was constructed, and the expression of miR-21 in serum exosomes and damaged local nerves was detected using RT-qPCR after EA treatment. The exosomes were identified under a transmission electron microscope and using western blotting analysis. Then, the exosome release inhibitor, GW4869, and the miR-21-5p-sponge used for the knockdown of miR-21 were used to clarify the effects of exosomal miR-21 on nerve regeneration promoted by EA. The nerve conduction velocity recovery rate, sciatic nerve function index, and wet weight ratio of gastrocnemius muscle were determined to evaluate sciatic nerve function recovery. SC proliferation and the level of neurotrophic factors were assessed using immunofluorescence staining, and the expression levels of SPRY2 and miR-21 were detected using RT-qPCR analysis. Subsequently, the transmission of exosomal miR-21 from SC to the axon was verified. We found that EA inhibited the release of serum exosomal miR-21 in a PNI model of rats during the early stage of PNI, while it promoted its release during later stages. EA enhanced the accumulation of miR-21 in the injured nerve and effectively promoted the recovery of nerve function after PNI. The treatment effect of EA was attenuated when the release of circulating exosomes was inhibited or when miR-21 was downregulated in local injury tissue via the miR-21-5p-sponge. Normal exosomes secreted by SC exhibited the ability to promote the recovery of nerve function, while the overexpression of miR-21 enhanced the effects of the exosomes. In addition, exosomal miR-21 secreted by SC could promote neurite outgrowth. Our results demonstrated the mechanism of EA on PNI from the perspective of exosome-mediated miR-21 transport and provided a theoretical basis for the use of exosomal miR-21 as a novel strategy for the treatment of PNI.

Topics: Aniline Compounds; Animals; Benzylidene Compounds; Cell Line, Transformed; Disease Models, Animal; Electroacupuncture; Exosomes; Gene Expression; Gene Expression Regulation; Gene Knockdown Techniques; Male; MicroRNAs; Nerve Regeneration; Nerve Tissue Proteins; Peripheral Nerve Injuries; Rats; Rats, Wistar; Recovery of Function; Schwann Cells; Sciatic Nerve; Signal Transduction; Transfection

Extracellular vesicles (EVs) curb important biological functions. We previously disclosed that ischemia-reperfusion (IR) induces increased release of EVs (IR-EVs) in the heart. However, the role of IR-EVs in IR pathological process remains poorly understood. Here we found that adoptive transfer of IR-EVs aggravated IR induced heart injury, and EV inhibition by GW4869 reduced the IR injury. Our in vivo and in vitro investigations substantiated that IR-EVs facilitated M1-like polarization of macrophages with increased expression of proinflammatory cytokines. Further, we disclosed the miRNA profile in cardiac EVs and confirmed the enrichment of miRNAs, such as miR-155-5p in IR-EVs compared to EVs from the sham heart (S-EVs). In particular, IR-EVs transferred miR-155-5p to macrophages and enhanced the inflammatory response through activating JAK2/STAT1 pathway. Interestingly, IR-EVs not only boosted the local inflammation in the heart, but even triggered systemic inflammation in distant organs. Taken together, we newly identify an IR-EVs-miR-155-5p

Topics: Aniline Compounds; Animals; Benzylidene Compounds; Cytokines; Disease Models, Animal; Extracellular Vesicles; Heart Injuries; Inflammation; Janus Kinase 2; Macrophages; Male; Mice; Mice, Inbred C57BL; MicroRNAs; Microscopy, Confocal; Myocardial Ischemia; Myocardial Reperfusion Injury; Signal Transduction; STAT1 Transcription Factor

Exosome is a novel tool with an essential role in cell communication. However, its role in the pathogenesis of sepsis-induced acute lung injury is currently unknown. Here, we first found that lipopolysaccharide (LPS) could up-regulate the expression of pro-inflammatory cytokines and promote exosomes release in the murine alveolar macrophage cell line (MHs cells). Moreover, we found MHs cells derived exosomes also maintain the pro-inflammatory effect after LPS stimulation. Treating with hydrochloride hydrate (GW4869) could dose-dependently downregulated the release of exosomes and inhibited the upregulation of inflammatory cytokines in MHs cells with LPS treatment. Also, we further identified GW4869 administration induced the remission of histopathologic changes, the reduction of pro-inflammatory cytokines in lung tissue, and inhibit serum exosomes release. These results indicate that the downregulation of exosome release by GW4869 might protect lung tissue from LPS induced injury through the suppression of excessive inflammatory responses, suggesting its potential therapeutic effects on sepsis-induced acute lung injury.

Topics: Acute Lung Injury; Aniline Compounds; Animals; Benzylidene Compounds; Cytokines; Disease Models, Animal; Exosomes; Inflammation; Lipopolysaccharides; Macrophages; Male; Mice; Mice, Inbred C57BL; Sepsis

Crohn's disease (CD) is an intestinal immune-dysfunctional disease. Extracellular vesicles (EVs) are membrane-enclosed particles full of functional molecules, e.g., nuclear acids. Recently, EVs have been shown to participate in the development of CD by realizing intercellular communication among intestinal cells. However, the role of EVs carrying double-strand DNA (dsDNA) shed from sites of intestinal inflammation in CD has not been investigated. Here we isolated EVs from the plasma or colon lavage of murine colitis and CD patients. The level of exosomal dsDNA, including mtDNA and nDNA, significantly increased in murine colitis and active human CD, and was positively correlated with the disease activity. Moreover, the activation of the STING pathway was verified in CD. EVs from the plasma of active human CD triggered STING activation in macrophages in vitro. EVs from LPS-damaged colon epithelial cells were also shown to raise inflammation in macrophages via activating the STING pathway, but the effect disappeared after the removal of exosomal dsDNA. These findings were further confirmed in STING-deficient mice and macrophages. STING deficiency significantly ameliorated colitis. Besides, potential therapeutic effects of GW4869, an inhibitor of EVs release were assessed. The application of GW4869 successfully ameliorated murine colitis by inhibiting STING activation. In conclusion, exosomal dsDNA was found to promote intestinal inflammation via activating the STING pathway in macrophages and act as a potential mechanistic biomarker and therapeutic target of CD.

Topics: Aniline Compounds; Animals; Benzylidene Compounds; Colitis; Crohn Disease; Disease Models, Animal; DNA; Endocytosis; Enterocytes; Extracellular Vesicles; Humans; Inflammation; Macrophages; Membrane Proteins; Mice, Knockout; Models, Biological; Phosphorylation; Signal Transduction

Background Epidemiological studies have suggested an association between

Topics: Adolescent; Adult; Aniline Compounds; Animals; Anti-Bacterial Agents; Antigens, Bacterial; Bacterial Proteins; Benzylidene Compounds; Brachial Artery; Case-Control Studies; Cell Line; Cell Movement; Cell Proliferation; China; Disease Models, Animal; Endothelial Cells; Endothelium, Vascular; Exosomes; Female; Gastrointestinal Agents; Helicobacter Infections; Helicobacter pylori; Host-Pathogen Interactions; Humans; Male; Mice, Inbred C57BL; Missouri; Neovascularization, Physiologic; Vasodilation; Young Adult

Topics: Adipogenesis; Aniline Compounds; Animals; Base Sequence; Benzylidene Compounds; Cell Proliferation; Disease Models, Animal; Down-Regulation; Exosomes; Femur Head Necrosis; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Mesenchymal Stem Cells; MicroRNAs; Neovascularization, Physiologic; Osteoblasts; Osteogenesis; Rabbits; Signal Transduction; Up-Regulation; Wound Healing

Cardiovascular diseases are risk factors for dementia, but the mechanisms remain elusive. Here, we report that myocardial infarction (MI) generated by the ligation of the left coronary artery (LCA) could lead to increased miR-1 levels in the hippocampus and blood with neuronal microtubule damage and decreased TPPP/p25 protein expression in the hippocampus. These changes could be prevented by a knockdown of miR-1 using hippocampal stereotaxic injections of anti-miR-1 oligonucleotide fragments carried by a lentivirus vector (lenti-pre-AMO-miR-1). TPPP/p25 protein was downregulated by miR-1 overexpression, upregulated by miR-1 inhibition, and unchanged by binding-site mutations or miR-masks, indicating that the TPPP/p25 gene was a potential target for miR-1. Additionally, the pharmacological inhibition of sphingomyelinase by GW4869 to inhibit exosome generation in the heart significantly attenuated the increased miR-1 levels in the hippocampi of transgenic (Tg) and MI mice. Collectively, the present study demonstrates that MI could directly lead to neuronal microtubule damage independent of MI-induced chronic brain hypoperfusion but involving the overexpression of miR-1 in the hippocampus that was transported by exosomes from infarcted hearts. This study reveals a novel insight into the molecular mechanisms of heart-to-brain communication at the miRNA level.

Topics: Analysis of Variance; Aniline Compounds; Animals; Benzylidene Compounds; Cells, Cultured; Coculture Techniques; Disease Models, Animal; Exosomes; Genetic Vectors; Hippocampus; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; MicroRNAs; Microtubules; Myocardial Infarction; Myocytes, Cardiac; Nerve Tissue Proteins; Neurons; Phosphotransferases; Rats; Rats, Sprague-Dawley; Transfection

Atherosclerosis is a chronic multifactorial and inflammatory disease of large and medium arteries and the leading cause of cardiovascular diseases worldwide. The aim of this study was to investigate whether and how the nSMase2 (type 2-neutral sphingomyelinase), a key enzyme of sphingolipid metabolism, may contribute to the development of atherosclerotic lesions.. The role of nSMase2 in atherosclerosis was investigated in. The genetic deficiency or inhibition of nSMase2 strongly decreases the development of atherosclerotic lesions in

Topics: Aniline Compounds; Animals; Anti-Inflammatory Agents; Aorta; Aortic Diseases; Atherosclerosis; Benzylidene Compounds; Disease Models, Animal; Endothelial Cells; Enzyme Inhibitors; Inflammation; Inflammation Mediators; Macrophages, Peritoneal; Male; Mice; Mice, Inbred C57BL; Mice, Knockout, ApoE; NF-E2-Related Factor 2; Plaque, Atherosclerotic; RAW 264.7 Cells; Signal Transduction; Sphingomyelin Phosphodiesterase

Progression of multiple myeloma (MM) is largely dependent on the bone marrow (BM) microenvironment wherein communication through different factors including extracellular vesicles takes place. This cross-talk not only leads to drug resistance but also to the development of osteolysis. Targeting vesicle secretion could therefore simultaneously ameliorate drug response and bone disease. In this paper, we examined the effects of MM exosomes on different aspects of osteolysis using the 5TGM1 murine model. We found that 5TGM1 sEVs, or 'exosomes', not only enhanced osteoclast activity, they also blocked osteoblast differentiation and functionality in vitro. Mechanistically, we could demonstrate that transfer of DKK-1 led to a reduction in Runx2, Osterix, and Collagen 1A1 in osteoblasts. In vivo, we uncovered that 5TGM1 exosomes could induce osteolysis in a similar pattern as the MM cells themselves. Blocking exosome secretion using the sphingomyelinase inhibitor GW4869 not only increased cortical bone volume, but also it sensitized the myeloma cells to bortezomib, leading to a strong anti-tumor response when GW4869 and bortezomib were combined. Altogether, our results indicate an important role for exosomes in the BM microenvironment and suggest a novel therapeutic target for anti-myeloma therapy.

Topics: Aniline Compounds; Animals; Antineoplastic Agents; Apoptosis; Benzylidene Compounds; Biomarkers; Bone Diseases; Bone Resorption; Bortezomib; Cell Line, Tumor; Cell Transformation, Neoplastic; Disease Models, Animal; Exosomes; Extracellular Vesicles; Female; Humans; Mice; Multiple Myeloma; Osteoblasts; Osteoclasts; Osteolysis; Standard of Care; Tumor Burden; Wnt Signaling Pathway

The p75 neurotrophin receptor (p75

Topics: Analgesics; Aniline Compounds; Animals; Antibodies; Benzylidene Compounds; Carbazoles; Disease Models, Animal; Enzyme Inhibitors; Hot Temperature; Hyperalgesia; Indole Alkaloids; Male; Nerve Growth Factor; Nerve Tissue Proteins; Protein Kinase C; Rats, Sprague-Dawley; Receptor, trkA; Receptors, Growth Factor; Receptors, Nerve Growth Factor; Sphingosine; Touch; TRPV Cation Channels

Cytoplasmic TDP-43 aggregation is a pathological hallmark of amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Here we investigated the role of exosomes in the secretion and propagation of TDP-43 aggregates. TDP-43 was detected in secreted exosomes from Neuro2a cells and primary neurons but not from astrocytes or microglia. Evidence is presented that protein aggregation and autophagy inhibition are factors that promote exosomal secretion of TDP-43. We also report that levels of exosomal TDP-43 full length and C-terminal fragment species are upregulated in human amyotrophic lateral sclerosis brains. Exposure of Neuro2a cells to exosomes from amyotrophic lateral sclerosis brain, but not from control brain, caused cytoplasmic redistribution of TDP-43, suggesting that secreted exosomes might contribute to propagation of TDP-43 proteinopathy. Yet, inhibition of exosome secretion by inactivation of neutral sphingomyelinase 2 with GW4869 or by silencing RAB27A provoked formation of TDP-43 aggregates in Neuro2a cells. Moreover, administration of GW4869 exacerbated the disease phenotypes of transgenic mice expressing human TDP-43

Topics: Aniline Compounds; Animals; Behavior, Animal; Benzylidene Compounds; Cell Line; Disease Models, Animal; DNA-Binding Proteins; Exosomes; Humans; Mice; Mice, Transgenic; Sphingomyelin Phosphodiesterase; TDP-43 Proteinopathies

We present evidence here that exosomes stimulate aggregation of amyloid beta (Aβ)1-42 in vitro and in vivo and interfere with uptake of Aβ by primary cultured astrocytes and microglia in vitro. Exosome secretion is prevented by the inhibition of neutral sphingomyelinase 2 (nSMase2), a key regulatory enzyme generating ceramide from sphingomyelin, with GW4869. Using the 5XFAD mouse, we show that intraperitoneal injection of GW4869 reduces the levels of brain and serum exosomes, brain ceramide, and Aβ1-42 plaque load. Reduction of total Aβ1-42 as well as number of plaques in brain sections was significantly greater (40% reduction) in male than female mice. Our results suggest that GW4869 reduces amyloid plaque formation in vivo by preventing exosome secretion and identifies nSMase2 as a potential drug target in AD by interfering with exosome secretion.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Aniline Compounds; Animals; Astrocytes; Benzylidene Compounds; Brain; Cells, Cultured; Ceramides; Disease Models, Animal; Exosomes; Female; Male; Mice, Inbred C57BL; Microglia; Molecular Targeted Therapy; Peptide Fragments; Plaque, Amyloid; Protein Aggregation, Pathological; Sphingomyelin Phosphodiesterase

The CADUCEUS trial of cardiosphere-derived cells (CDCs) has shown that it may be possible to regenerate injured heart muscle previously thought to be permanently scarred. The mechanisms of benefit are known to be indirect, but the mediators have yet to be identified. Here we pinpoint exosomes secreted by human CDCs as critical agents of regeneration and cardioprotection. CDC exosomes inhibit apoptosis and promote proliferation of cardiomyocytes, while enhancing angiogenesis. Injection of exosomes into injured mouse hearts recapitulates the regenerative and functional effects produced by CDC transplantation, whereas inhibition of exosome production by CDCs blocks those benefits. CDC exosomes contain a distinctive complement of microRNAs, with particular enrichment of miR-146a. Selective administration of a miR-146a mimic reproduces some (but not all) of the benefits of CDC exosomes. The findings identify exosomes as key mediators of CDC-induced regeneration, while highlighting the potential utility of exosomes as cell-free therapeutic candidates.

Topics: Albumins; Aniline Compounds; Animals; Benzylidene Compounds; Cell Differentiation; Cell Proliferation; Cell- and Tissue-Based Therapy; Cells, Cultured; Disease Models, Animal; Exosomes; Fibroblasts; Human Umbilical Vein Endothelial Cells; Humans; Mice; Mice, Knockout; Mice, SCID; MicroRNAs; Myocardial Infarction; Myocytes, Cardiac; Neovascularization, Physiologic; Polyesters; Rats; Rats, Sprague-Dawley; Regeneration

Endoplasmic reticulum (ER) stress and excessive nitric oxide production via induction of inducible nitric oxide synthase (NOS2) have been implicated in the pathogenesis of neuronal retinal cell death in ocular hypertension. Neutral sphingomyelinase (N-SMase)/ceramide pathway can regulate NOS2 expression, hence this study determined the role of selective neutral sphingomyelinase (N-SMase) inhibition on retinal NOS2 levels, ER stress, apoptosis and visual evoked potentials (VEPs) in a rat model of elevated intraocular pressure (EIOP). NOS2 expression and retinal protein nitration were significantly greater in EIOP and significantly decreased with N-SMase inhibition. A significant increase was observed in retinal ER stress markers pPERK, CHOP and GRP78 in EIOP, which were not significantly altered by N-SMase inhibition. Retinal TUNEL staining showed increased apoptosis in all EIOP groups; however N-SMase inhibition significantly decreased the percent of apoptotic cells in EIOP. Caspase-3, -8 and -9 activities were significantly increased in EIOP and returned to baseline levels following N-SMase inhibition. Latencies of all VEP components were significantly prolonged in EIOP and shortened following N-SMase inhibition. Data confirm the role of nitrative injury in EIOP and highlight the protective effect of N-SMase inhibition in EIOP via down-regulation of NOS2 levels and nitrative stress.

Topics: Aniline Compounds; Animals; Apoptosis; Benzylidene Compounds; Blotting, Western; Caspases; Disease Models, Animal; Endoplasmic Reticulum Stress; Evoked Potentials, Visual; Glaucoma; Immunohistochemistry; In Situ Nick-End Labeling; Intraocular Pressure; Male; Nitric Oxide Synthase Type II; Random Allocation; Rats, Wistar; Retina; Sphingomyelin Phosphodiesterase; Up-Regulation

Outcomes for organ transplantation are constantly improving because of advances in organ preservation, surgical techniques, immune clinical monitoring, and immunosuppressive treatment preventing acute transplant rejection. However, chronic rejection including transplant vasculopathy still limits long-term patient survival. Transplant vasculopathy is characterized by progressive neointimal hyperplasia leading to arterial stenosis and ischemic failure of the allograft. This work sought to decipher the manner in which the humoral immune response, mimicked by W6/32 anti-HLA antibody, contributes to transplant vasculopathy.. Studies were performed in vitro on cultured human smooth muscle cells, ex vivo on human arterial segments, and in vivo in a model consisting of human arterial segments grafted into severe combined immunodeficiency/beige mice injected weekly with anti-HLA antibodies. We report that anti-HLA antibodies are mitogenic for smooth muscle cells through a signaling mechanism implicating matrix metalloproteinases (MMPs) (membrane type 1 MMP and MMP2) and neutral sphingomyelinase-2. This mitogenic signaling and subsequent DNA synthesis are blocked in smooth muscle cells silenced for MMP2 or for neutral sphingomyelinase-2 by small interfering RNAs, in smooth muscle cells transfected with a vector coding for a dominant-negative form of membrane type 1 MMP, and after treatment by pharmacological inhibitors of MMPs (Ro28-2653) or neutral sphingomyelinase-2 (GW4869). In vivo, Ro28-2653 and GW4869 reduced the intimal thickening induced by anti-HLA antibodies in human mesenteric arteries grafted into severe combined immunodeficiency/beige mice.. These data highlight a crucial role for MMP2 and neutral sphingomyelinase-2 in vasculopathy triggered by a humoral immune response and open new perspectives for preventing transplant vasculopathy with the use of MMP and neutral sphingomyelinase inhibitors, in addition to conventional immunosuppression.

Topics: Aniline Compounds; Animals; Antibodies, Anti-Idiotypic; Arteries; Benzylidene Compounds; Cells, Cultured; Constriction, Pathologic; Disease Models, Animal; HLA Antigens; Humans; Hyperplasia; In Vitro Techniques; Matrix Metalloproteinase 14; Matrix Metalloproteinase 2; Matrix Metalloproteinase Inhibitors; Mice; Mice, SCID; Models, Animal; Muscle, Smooth, Vascular; Neointima; Piperazines; Pyrimidines; RNA, Small Interfering; Sphingomyelin Phosphodiesterase; Vascular Diseases; Vascular Grafting

The sphingolipid ceramide is a bioactive signaling lipid that is thought to play important roles in modulating synaptic activity, in part by regulating the function of excitatory postsynaptic receptors. However, the molecular mechanisms by which ceramide exerts its effects on synaptic activity remain largely unknown. We recently demonstrated that a rapid generation of ceramide by neutral sphingomyelinase-2 (nSMase2; also known as "sphingomyelin phosphodiesterase-3") played a key role in modulating excitatory postsynaptic currents by controlling the insertion and clustering of NMDA receptors (Wheeler et al. [2009] J. Neurochem. 109:1237-1249). We now demonstrate that nSMase2 plays a role in memory. Inhibition of nSMase2 impaired spatial and episodic-like memory in mice. At the molecular level, inhibition of nSMase2 decreased ceramide, increased PSD-95, increased the number of AMPA receptors, and altered the subunit composition of NMDA receptors. Our study identifies nSMase2 as an important component for efficient memory formation and underscores the importance of ceramide in regulating synaptic events related to learning and memory.

Topics: Analysis of Variance; Aniline Compounds; Animals; Benzylidene Compounds; Brain; Ceramides; Disease Models, Animal; Enzyme Inhibitors; Mass Spectrometry; Maze Learning; Memory Disorders; Mice; Mice, Knockout; Space Perception; Sphingolipids; Sphingomyelin Phosphodiesterase