| 1. |
- Annelies, Nonneman, et al.
(författare)
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Astrocyte-derived Jagged-1 mitigates deleterious Notch signaling in amyotrophic lateral sclerosis
- 2018
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Ingår i: Neurobiology of Disease. - : Academic Press. - 0969-9961 .- 1095-953X. ; 119, s. 26-40
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Tidskriftsartikel (refereegranskat)abstract
- Amyotrophic lateral sclerosis (ALS) is a late-onset devastating degenerative disease mainly affecting motor neurons. Motor neuron degeneration is accompanied and aggravated by oligodendroglial pathology and the presence of reactive astrocytes and microglia. We studied the role of the Notch signaling pathway in ALS, as it is implicated in several processes that may contribute to this disease, including axonal retraction, microgliosis, astrocytosis, oligodendrocyte precursor cell proliferation and differentiation, and cell death. We observed abnormal activation of the Notch signaling pathway in the spinal cord of SOD1(G93A) mice, a well-established model for ALS, as well as in the spinal cord of patients with sporadic ALS (sALS). This increased activation was particularly evident in reactive GFAP-positive astrocytes. In addition, one of the main Notch ligands, Jagged-1, was ectopically expressed in reactive astrocytes in spinal cord from ALS mice and patients, but absent in resting astrocytes. Astrocyte-specific inactivation of Jagged-1 in presymptomatic SOD1(G93A) mice further exacerbated the activation of the Notch signaling pathway and aggravated the course of the disease in these animals without affecting disease onset. These data suggest that aberrant Notch signaling activation contributes to the pathogenesis of ALS, both in sALS patients and SOD1(G93A) mice, and that it is mitigated in part by the upregulation of astrocytic Jagged-1.
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| 2. |
- Damenti, Martina, et al.
(författare)
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STED and parallelized RESOLFT optical nanoscopy of the tubular endoplasmic reticulum and its mitochondrial contacts in neuronal cells
- 2021
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961 .- 1095-953X. ; 155
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Tidskriftsartikel (refereegranskat)abstract
- The classic view of organelle cell biology is undergoing a constant revision fueled by the new insights unraveled by fluorescence nanoscopy, which enable sensitive, faster and gentler observation of specific proteins in situ. The endoplasmic reticulum (ER) is one of the most challenging structure to capture due the rapid and constant restructuring of fine sheets and tubules across the full 3D cell volume. Here we apply STED and parallelized 2D and 3D RESOLFT live imaging to uncover the tubular ER organization in the fine processes of neuronal cells with focus on mitochondria-ER contacts, which recently gained medical attention due to their role in neurodegeneration. Multi-color STED nanoscopy enables the simultaneous visualization of small transversal ER tubules crossing and constricting mitochondria all along axons and dendrites. Parallelized RESOLFT allows for dynamic studies of multiple contact sites within seconds and minutes with prolonged time-lapse imaging at similar to 50 nm spatial resolution. When operated in 3D super resolution mode it enables a new isotropic visualization of such contacts extending our understanding of the three-dimensional architecture of these packed structures in axons and dendrites.
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| 3. |
- Kankaanpää, Jari, et al.
(författare)
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Cerebrospinal fluid antibodies to oxidized LDL are increased in Alzheimer's disease.
- 2009
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961 .- 1095-953X. ; 33:3, s. 467-72
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Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein oxidation may play an important role in the pathogenesis of Alzheimer's Disease (AD), and therefore, we investigated cerebrospinal fluid (CSF) antibodies to oxidized low-density lipoprotein (OxLDL) in patients with AD and other neurodegenerative dementias. IgM and IgG antibody titers to OxLDL were measured in 50 CSF samples and 11 plasma samples using chemiluminescent ELISA. All CSF samples contained IgG antibodies, and also most IgM, binding to OxLDL. CSF antibodies to OxLDL were not related to CSF protein or albumin concentrations or plasma antibodies to OxLDL. Competition immunoassay for specificity demonstrated that about 50% of the CSF IgG binding to OxLDL was inhibited by soluble OxLDL. CSF IgG antibodies to OxLDL were significantly increased in AD patients compared to controls and to patients with frontotemporal lobar degeneration. The role of these antibodies in CSF is unknown and further investigations are needed.
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| 4. |
- Ruiz-Riquelme, A., et al.
(författare)
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Larger aggregates of mutant seipin in Celia's Encephalopathy, a new protein misfolding neurodegenerative disease
- 2015
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Ingår i: Neurobiology of Disease. - : Elsevier. - 0969-9961 .- 1095-953X. ; 83, s. 44-53
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Tidskriftsartikel (refereegranskat)abstract
- Celia's Encephalopathy (MIM #. 615924) is a recently discovered fatal neurodegenerative syndrome associated with a new BSCL2 mutation (c.985C>T) that results in an aberrant isoform of seipin (Celia seipin). This mutation is lethal in both homozygosity and compounded heterozygosity with a lipodystrophic BSCL2 mutation, resulting in a progressive encephalopathy with fatal outcomes at ages 6-8. Strikingly, heterozygous carriers are asymptomatic, conflicting with the gain of toxic function attributed to this mutation. Here we report new key insights about the molecular pathogenic mechanism of this new syndrome. Intranuclear inclusions containing mutant seipin were found in brain tissue from a homozygous patient suggesting a pathogenic mechanism similar to other neurodegenerative diseases featuring brain accumulation of aggregated, misfolded proteins. Sucrose gradient distribution showed that mutant seipin forms much larger aggregates as compared with wild type (wt) seipin, indicating an impaired oligomerization. On the other hand, the interaction between wt and Celia seipin confirmed by coimmunoprecipitation (CoIP) assays, together with the identification of mixed oligomers in sucrose gradient fractionation experiments can explain the lack of symptoms in heterozygous carriers. We propose that the increased aggregation and subsequent impaired oligomerization of Celia seipin leads to cell death. In heterozygous carriers, wt seipin might prevent the damage caused by mutant seipin through its sequestration into harmless mixed oligomers.
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| 5. |
- Takenaga, Keizo, et al.
(författare)
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Modified expression of Mts1/S100A4 protein in C6 glioma cells or surrounding astrocytes affects migration of tumor cells in vitro and in vivo
- 2007
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961 .- 1095-953X. ; 25:3, s. 455-463
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Tidskriftsartikel (refereegranskat)abstract
- The calcium-binding Mtsl/S100A4 protein plays an important role in motility and metastatic activity of tumor cells. Recently we showed that Mts1/S100A4 is expressed in white matter astrocytes and influences their migration in vitro and in vivo. Here, we have investigated the role of Mts1/S100A4 expression in C6 glioma cells or surrounding astrocytes for migration ofC6 cells on astrocytes, using short interference (si) RNA to silence Mtsl/S100A4 expression. We find that in vitro, the migration of Mts1/S100A4 expressing and silenced C6 cells on astrocytes is predominantly dependent on the expression of Mts1/S100A4 in astrocytes, i.e. C6 cells preferably migrate on Mts1/S100A4-silenced astrocytes. In vivo, Mtsl/S100A4-positive C6 cells preferably migrate in white matter. In contrast Mts1/S100A4-silenced C6 cells avoid white matter and migrate in gray matter and meninges. Thus, the migration pattern ofC6 cells is affected by their intrinsic Mtsl/S100A4 expression as well as Mtsl/S100A4 expression in astrocytes. To investigate if Mts1/S100A4 has a significant role on brain tumor progression, we made quantitative RT-PCR analysis for the expression of S100A4/Mtsl in various grades of astrocytic tumors. Our data showed that high-grade glioblastomas express higher amount of S100A4/Mtsl than low-grade astrocytic tumors.
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