WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Access type: Open accessAuthor: search.filters.author.Seyrantepe, Volkan

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Now showing 1 - 10 of 23
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Imbalance in Redox Homeostasis Is Associated With Neurodegeneration in the Murine Model of Tay-Sachs Disease
    (Springer, 2025) Basirli, Hande; Ates, Nurselin; Seyrantepe, Volkan
    BackgroundTay-Sachs disease is a neurodegenerative disorder characterized by a build-up of GM2 ganglioside in the brain, which results in progressive central nervous system dysfunction. Our group recently generated Hexa-/-Neu3-/- mice, a murine model with neuropathological abnormalities similar to the infantile form of Tay-Sachs disease. Previously, we reported progressive neurodegeneration with neuronal loss in the brain sections of Hexa-/-Neu3-/- mice. However, the relationship between the severity of neurodegeneration and the imbalance in redox homeostasis was not yet clarified in Hexa-/-Neu3-/- mice. Here, we evaluated whether neurodegeneration is associated with oxidative stress in the tissues and cells of Hexa-/-Neu3-/- mice and neuroglia cells from Tay-Sachs patients.Methods and resultsCell death and oxidative stress-related markers were evaluated in four brain regions and fibroblasts of 5-month-old WT, Hexa-/-, Neu3-/-, and Hexa-/-Neu3-/- mice and human neuroglia cells using Western blot, RT-PCR, and immunohistochemistry analyses. We further analyzed oxidative stress levels in the samples using flow cytometry analyses. We discovered neuronal death, alterations in intracellular ROS levels, and damaging effects of oxidative stress, especially in the cerebellum and fibroblasts of Hexa-/-Neu3-/- mice.ConclusionsOur results showed that alteration in redox homeostasis might be related to neurodegeneration in the murine model of Tay-Sachs Disease. These findings suggest that targeting the altered redox balance and increased oxidative stress might be a rational therapeutic approach for alleviating neurodegeneration and treating Tay-Sachs disease.
  • Conference Object
    Treatment With Recombinant Human Lysosomal Sshexosaminidase Reduces Gm2 Accumulation in Tay-Sachs Disease Cells
    (Academic Press inc Elsevier Science, 2024) Inci, Orhan Kerim; Leal, Andres F.; Ates, Nurselin; Suarez, Diego; Espejo, Angela J.; Almeciga-Diaz, Carlos Javier; Seyrantepe, Volkan
    [No Abstract Available]
  • Review
    Citation - WoS: 7
    Gangliosides as Therapeutic Targets for Neurodegenerative Diseases
    (Hindawi Ltd, 2024) Inci, Orhan Kerim; Basirli, Hande; Can, Melike; Yanbul, Selman; Seyrantepe, Volkan
    Gangliosides, sialic acid-containing glycosphingolipids, are abundant in cell membranes and primarily involved in controlling cell signaling and cell communication. The altered ganglioside pattern has been demonstrated in several neurodegenerative diseases, characterized during early-onset or infancy, emphasizing the significance of gangliosides in the brain. Enzymes required for the biosynthesis of gangliosides are linked to several devastating neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), hereditary spastic paraplegia (HSP). In this review, we summarized not only the critical roles of biosynthetic enzymes and their inhibitors in ganglioside metabolism but also the efficacy of treatment strategies of ganglioside to address their significance in those diseases.
  • Conference Object
  • Review
    Citation - WoS: 6
    Citation - Scopus: 8
    Molecular Trojan Horses for Treating Lysosomal Storage Diseases
    (Academic Press, 2023) Leal, Andres Felipe; Rintz, Estera; Çelik, Betül; Ago, Yasuhiko; León, Daniel; İnci, Orhan Kerim; Seyrantepe, Volkan
    Lysosomal storage diseases (LSDs) are caused by monogenic mutations in genes encoding for proteins related to the lysosomal function. Lysosome plays critical roles in molecule degradation and cell signaling through interplay with many other cell organelles, such as mitochondria, endoplasmic reticulum, and peroxisomes. Even though several strategies (i.e., protein replacement and gene therapy) have been attempted for LSDs with promising results, there are still some challenges when hard-to-treat tissues such as bone (i.e., cartilages, ligaments, meniscus, etc.), the central nervous system (mostly neurons), and the eye (i.e., cornea, retina) are affected. Consistently, searching for novel strategies to reach those tissues remains a priority. Molecular Trojan Horses have been well-recognized as a potential alternative in several pathological scenarios for drug delivery, including LSDs. Even though molecular Trojan Horses refer to genetically engineered proteins to overcome the blood-brain barrier, such strategy can be extended to strategies able to transport and deliver drugs to specific tissues or cells using cell-penetrating peptides, monoclonal antibodies, vesicles, extracellular vesicles, and patient-derived cells. Only some of those platforms have been attempted in LSDs. In this paper, we review the most recent efforts to develop molecular Trojan Horses and discuss how this strategy could be implemented to enhance the current efficacy of strategies such as protein replacement and gene therapy in the context of LSDs. © 2023
  • Conference Object
    Elimination of the B4galnt1 Gene Normalizes Lifespan and Prevents Pathology in Tay-Sachs Disease Mice
    (Elsevier, 2023) Seyrantepe, Volkan
    Tay-Sachs disease is a neurodegenerative lysosomal storage disorder caused by mutations in the Hexa gene, which encodes the alpha subunit of lysosomal ß-hexaminidase A (HEXA). HEXA is responsible for the conversion of GM2 to GM3, therefore the deficiency leads to the accumulation of GM2 in the lysosomes, neurodegeneration, and eventual death. Currently, there is no efficient therapy for the disease yet.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Autophagic Flux Is Impaired in the Brain Tissue of Tay-Sachs Disease Mouse Model
    (Public Library of Science, 2023) Şengül, Tuğçe; Can, Melike; Ateş, Nurselin; Seyrantepe, Volkan
    Tay-Sachs disease is a lethal lysosomal storage disorder caused by mutations in the HexA gene encoding the α subunit of the lysosomal β-hexosaminidase enzyme (HEXA). Abnormal GM2 ganglioside accumulation causes progressive deterioration in the central nervous system in Tay-Sachs patients. Hexa-/-mouse model failed to display abnormal phenotype. Recently, our group generated Hexa-/-Neu3-/-mouse showed severe neuropathological indications similar to Tay-Sachs patients. Despite excessive GM2 ganglioside accumulation in the brain and visceral organs, the regulation of autophagy has not been clarified yet in the Tay-Sachs disease mouse model. Therefore, we investigated distinct steps of autophagic flux using markers including LC3 and p62 in four different brain regions from the Hexa-/-Neu3-/-mice model of Tay-Sachs disease. Our data revealed accumulated autophagosomes and autophagolysosomes indicating impairment in autophagic flux in the brain. We suggest that autophagy might be a new therapeutic target for the treatment of devastating Tay-Sachs disease. © 2023 Sengul et al.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Analysis of Brain Lipids in the Early-Onset Tay–sachs Disease Mouse Model With the Combined Deficiency of Β-Hexosaminidase a and Neuraminidase 3
    (Frontiers Media S.A., 2022) Can, Melike; Şengül, Tuğçe; Akyıldız Demir, Seçil; İnci, Orhan K.; Basırlı, Hatice Hande; Seyrantepe, Volkan
    Tay–Sachs disease is an autosomal recessively inherited lysosomal storage disease that results from loss-of-function mutations in the HEXA gene coding βhexosaminidase A. HEXA gene deficiency affects the central nervous system owing to GM2 ganglioside accumulation in lysosomes resulting in progressive neurodegeneration in patients. We recently generated a novel mice model with a combined deficiency of βhexosaminidase A and neuraminidase 3 (Hexa−/−Neu3−/−) that mimics both the neuropathological and clinical abnormalities of early-onset Tay–Sachs disease. Here, we aimed to explore the secondary accumulation of lipids in the brain of Hexa−/ −Neu3−/− mice.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Sialidase Neu4 Deficiency Is Associated With Neuroinflammation in Mice
    (Springer, 2021) Timur, Zehra Kevser; İnci, Orhan Kerim; Akyıldız Demir, Seçil; Seyrantepe, Volkan
    Sialidases catalyze the removal of sialic acid residues from glycoproteins, oligosaccharides, and sialylated glycolipids. Sialidase Neu4 is in the lysosome and has broad substrate specificity. Previously generated Neu4-/- mice were viable, fertile and lacked gross morphological abnormalities, but displayed a marked vacuolization and lysosomal storage in lung and spleen cells. In addition, we showed that there is an increased level of GD1a ganglioside and a markedly decreased level of GM1 ganglioside in the brain of Neu4-/- mice. In this study, we further explored whether sialidase Neu4 deficiency causes neuroinflammation. We demostrated that elevated level of GD1a and GT1b is associated with an increased level of LAMP1-positive lysosomal vesicles and Tunel-positive neurons correlated with alterations in the expression of cytokines and chemokines in adult Neu4-/- mice. Astrogliosis and microgliosis were also significantly enhanced in the hippocampus, and cerebellum. These changes in brain immunity were accompanied by motor impairment in these mice. Our results indicate that sialidase Neu4 is a novel mediator of an inflammatory response in the mouse brain due to the altered catabolism of gangliosides.
  • Article
    Citation - WoS: 37
    Citation - Scopus: 40
    Gm2 Ganglioside Accumulation Causes Neuroinflammation and Behavioral Alterations in a Mouse Model of Early Onset Tay-Sachs Disease
    (BioMed Central Ltd., 2020) Akyıldız Demir, Seçil; Timur, Zehra Kevser; Ateş, Nurselin; Martinez, Luis Alarcon; Seyrantepe, Volkan
    Background Tay-Sachs disease (TSD), a type of GM2-gangliosidosis, is a progressive neurodegenerative lysosomal storage disorder caused by mutations in the alpha subunit of the lysosomal beta-hexosaminidase enzyme. This disease is characterized by excessive accumulation of GM2 ganglioside, predominantly in the central nervous system. Although Tay-Sachs patients appear normal at birth, the progressive accumulation of undegraded GM2 gangliosides in neurons leads to death. Recently, an early onset Tay-Sachs disease mouse model, with genotypeHexa-/-Neu3-/-, was generated. Progressive accumulation of GM2 led to premature death of the double KO mice. Importantly, this double-deficient mouse model displays typical features of Tay-Sachs patients, such as cytoplasmic vacuolization of nerve cells, deterioration of Purkinje cells, neuronal death, deceleration in movement, ataxia, and tremors. GM2-gangliosidosis is characterized by acute neurodegeneration preceded by activated microglia expansion, macrophage, and astrocyte activation, along with the production of inflammatory mediators. However, the mechanism of disease progression inHexa-/-Neu3-/-mice, relevant to neuroinflammation is poorly understood. Method In this study, we investigated the onset and progression of neuroinflammatory changes in the cortex, cerebellum, and retina ofHexa-/-Neu3-/-mice and control littermates by using a combination of molecular genetics and immunochemical procedures. Results We found elevated levels of pro-inflammatory cytokine and chemokine transcripts, such as Ccl2, Ccl3, Ccl4, and Cxcl10 and also extensive microglial and astrocyte activation and proliferation, accompanied by peripheral blood mononuclear cell infiltration in the vicinity of neurons and oligodendrocytes. Behavioral tests demonstrated a high level of anxiety, and age-dependent loss in both spatial learning and fear memory inHexa-/-Neu3-/-mice compared with that in the controls. Conclusion Altogether, our data suggest thatHexa-/-Neu3-/-mice display a phenotype similar to Tay-Sachs patients suffering from chronic neuroinflammation triggered by GM2 accumulation. Furthermore, our work contributes to better understanding of the neuropathology in a mouse model of early onset Tay-Sachs disease.