398 research outputs found
Mesenchymal Stem Cells in a Transgenic Mouse Model of Multiple System Atrophy: Immunomodulation and Neuroprotection
Mesenchymal stem cells (MSC) are currently strong candidates for cell-based therapies. They are well known for their differentiation potential and immunoregulatory properties and have been proven to be potentially effective in the treatment of a large variety of diseases, including neurodegenerative disorders. Currently there is no treatment that provides consistent long-term benefits for patients with multiple system atrophy (MSA), a fatal late onset α-synucleinopathy. Principally neuroprotective or regenerative strategies, including cell-based therapies, represent a powerful approach for treating MSA. In this study we investigated the efficacy of intravenously applied MSCs in terms of behavioural improvement, neuroprotection and modulation of neuroinflammation in the (PLP)-αsynuclein (αSYN) MSA model.MSCs were intravenously applied in aged (PLP)-αSYN transgenic mice. Behavioural analyses, defining fine motor coordination and balance capabilities as well as stride length analysis, were performed to measure behavioural outcome. Neuroprotection was assessed by quantifying TH neurons in the substantia nigra pars compacta (SNc). MSC treatment on neuroinflammation was analysed by cytokine measurements (IL-1α, IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, GM-CSF, INFγ, MCP-1, TGF-β1, TNF-α) in brain lysates together with immunohistochemistry for T-cells and microglia. Four weeks post MSC treatment we observed neuroprotection in the SNc, as well as downregulation of cytokines involved in neuroinflammation. However, there was no behavioural improvement after MSC application.To our knowledge this is the first experimental approach of MSC treatment in a transgenic MSA mouse model. Our data suggest that intravenously infused MSCs have a potent effect on immunomodulation and neuroprotection. Our data warrant further studies to elucidate the efficacy of systemically administered MSCs in transgenic MSA models
Systemic proteasome inhibition triggers neurodegeneration in a transgenic mouse model expressing human α-synuclein under oligodendrocyte promoter: implications for multiple system atrophy
Multiple system atrophy (MSA) is a progressive late onset neurodegenerative α-synucleinopathy with unclear pathogenesis. Recent genetic and pathological studies support a central role of α-synuclein (αSYN) in MSA pathogenesis. Oligodendroglial cytoplasmic inclusions of fibrillar αSYN and dysfunction of the ubiquitin–proteasome system are suggestive of proteolytic stress in this disorder. To address the possible pathogenic role of oligodendroglial αSYN accumulation and proteolytic failure in MSA we applied systemic proteasome inhibition (PSI) in transgenic mice with oligodendroglial human αSYN expression and determined the presence of MSA-like neurodegeneration in this model as compared to wild-type mice. PSI induced open field motor disability in transgenic αSYN mice but not in wild-type mice. The motor phenotype corresponded to progressive and selective neuronal loss in the striatonigral and olivopontocerebellar systems of PSI-treated transgenic αSYN mice. In contrast no neurodegeneration was detected in PSI-treated wild-type controls. PSI treatment of transgenic αSYN mice was associated with significant ultrastructural alterations including accumulation of fibrillar human αSYN in the cytoplasm of oligodendroglia, which resulted in myelin disruption and demyelination characterized by increased g-ratio. The oligodendroglial and myelin pathology was accompanied by axonal degeneration evidenced by signs of mitochondrial stress and dysfunctional axonal transport in the affected neurites. In summary, we provide new evidence supporting a primary role of proteolytic failure and suggesting a neurodegenerative pathomechanism related to disturbed oligodendroglial/myelin trophic support in the pathogenesis of MSA
Influence of Antioxidant SkQ1 on Accumulation of Mitochondrial DNA Deletions in the Hippocampus of Senescence-Accelerated OXYS Rats
Human and animal aging is associated with gradual decline of cognitive functions (especially learning ability and memory) and increased risk of development of neurodegenerative diseases 596 Abbreviations: bp, base pairs; mtDNA, mitochondrial DNA; ∆mtDNA, deletion in mitochondrial DNA; ∆mtDNA 4834 , 4834-bp mitochondrial DNA deletion; ROS, reactive oxygen species; SkQ1, antioxidant 10-(6′-plastoquinonyl)decyltriphenylphosphonium. * To whom correspondence should be addressed. Abstract-Reduction of efficiency of oxidative phosphorylation associated with aging and the development of neurodegenerative diseases including Alzheimer's disease is thought to be linked to the accumulation of deletions in mitochondrial DNA (∆mtDNA), which are seen as a marker of oxidative damage. Recently, we have shown that mitochondria-targeted antioxidant SkQ1 (10-(6′-plastoquinonyl)decyltriphenylphosphonium) can slow the development of signs of Alzheimer's disease in senescence-accelerated OXYS rats. The purpose of this study was to explore the relationship between the development of neurodegenerative changes in the brain of OXYS rats and changes in the amount of mtDNA and the 4834-bp mitochondrial DNA deletion (∆mtDNA 4834 ) as well as the effect of SkQ1. We studied the relative amount of mtDNA and ∆mtDNA 4834 in the hippocampus of OXYS and Wistar (control) rats at ages of 1, 2, 6, 10, and 20 days and 3, 6, and 24 months. During the period crucial for manifestation of the signs of accelerated aging of OXYS rats (from 1.5 to 3 months of age), we evaluated the effects of administration of SkQ1 (250 nmol/kg) and vitamin E (670 mmol/kg, reference treatment) on the amount of mtDNA and ∆mtDNA 4834 and on the formation of the behavioral feature of accelerated senescence in OXYS rats -passive type of behavior in the open field test. In OXYS rats, the level of ∆mtDNA 4834 in the hippocampus is increased compared to the Wistar rats, especially at the stage of completion of brain development in the postnatal period. This level remains elevated not only at the stages preceding the manifestation of the signs of accelerated brain aging and the development of pathological changes linked to Alzheimer's disease, but also during their progression. However, at age of 24 months, there were no detectable differences between the two strains. SkQ1 treatment reduced the level of ∆mtDNA 4834 in the hippocampus of Wistar and OXYS rats and slowed the formation of passive behavior in OXYS rats. These results support the possible use of SkQ1 for prophylaxis of brain aging. Influence of Antioxidant SkQ1 o
Changes in the transcriptome of the prefrontal cortex of OXYS rats as the signs of Alzheimer’s disease development
Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease. It produces atrophic changes in the brain, which cause dementia. The incidence of AD is increasing with increasing life expectancy and gradual aging of the population in developed countries. There are no effective prophylactic interventions because of insufficient understanding of the AD pathogenesis and the absence of adequate experimental models. Recently, we showed that senescence-accelerated OXYS rats represent a promising model of AD; in these rats, accelerated aging of the brain is accompanied by the typical signs of AD: degenerative alterations and death of neurons, a decrease in synaptic density, mitochondrial dysfunction, hyperphosphorylation of the tau protein, an increased level of amyloid β (Aβ1–42), and the formation of amyloid plaques. To elucidate how these signs develop, we used a nextgeneration RNA sequencing technique (RNA-Seq) to study the prefrontal-cortex transcriptome of OXYS rats during the manifestation of AD signs (at an age of 5 months) and during their active progression (at an age of 18 months), using age-matched Wistar rats (parental strain) as controls. At the age of 5 months, there were significant differences between OXYS and Wistar rats (p < 0.01) in the mRNA expression of more than 900 genes (> 2000 genes at the age of 18 months) in the prefrontal cortex. Most of these genes were related to neuronal plasticity, protein phosphorylation, Са2+ homeostasis, hypoxia, immune processes, and apoptosis. Between the ages of 5 and 18 months, there were changes in the expression of 499 genes in Wistar rats and changes in the expression of 5500 genes in OXYS rats. Only 333 genes were common between these sets. This finding points to differences in the mechanisms and rates of age-related changes in the brain between normal aging and the period of development of AD-specific neurodegenerative processes
Dwarf Copper-Gold Porphyry Deposits of the Buchim-Damjan-Borov Dol Ore District, Republic of Macedonia (FYROM)
The metallogenic aspects, tectonic setting, magmatism, structure, and composition of Au-and Ag-bearing porphyry copper deposits in the Buchim-Damjan-Borov Dol ore district and their genetic features are considered and compared with earlier published data. Special attention is paid to supergene gold in heavy concentrate halos of the Borov Dol deposit. The total Cu reserves of the deposits discussed in this paper do not exceed 150 kt. The Buchim deposit likely is the world's smallest deposit of this type currently involved in mining. A comprehensive study of these dwarf porphyry copper deposits is undertaken to answer questions on the conditions of their formation. How do they differ from formation conditions of giant deposits
Ameliorative effects of the flavonoid fustin in a rat model of trinitrobenzensulfonic acid-induced colitis
Trinitrobenzene sulfonic acid (TNBS)-induced colitis is a widely used animal model that mimics the signs and symptoms of inflammatory bowel disease. Fustin is a flavonoid found in Cotinus coggygria. The aim of the present study was to investigate the effect of fustin isolated from Cotinus coggygria heartwood in a rat model of TNBS-induced colitis. In this experiment, 30 male Wistar rats were used, allocated to three groups: Control, TNBS and TNBS+F10. Colitis was induced by rectal application of TNBS. After the induction of colitis, fustin at a dose of 10 mg/kg was administered orally to TNBS+F10 group in the course of 8 days. Severity of colitis, oxidative stress and inflammation were assessed by macroscopic, histopathological, immunohistochemical and biochemical analyses. Rats from TNBS group demonstrated severe colonic damage. Fustin treatment ameliorated most of the macroscopic and some of the histopathological indices of colonic damage, and restored the activity of the endogenous antioxidant superoxide dismutase in tissue homogenate but did not affect the signs of inflammation measured by the activity of alkaline phosphatase in serum and tissue homogenate, as well as the expression of NF-kB in the colon. In conclusion, the ameliorative effects of fustin in the experimental TNBS-induced colitis might be the result of its antioxidant properties.International Conference: Kliment's Days 2023 - 60 years Faculty of Biology 09/11/2023 - 11/11/2023 Sofia, Bulgari
Level structure of 69Se
15 págs.; 9 figs.; 5 tabs. ; PACS number(s): 23.20.Lv, 21.10.Re, 27.50.1e, 21.60.2nExcited levels in 69Se have been studied using the 40Ca(32S,2pn)69Se reaction at 95- and 105-MeV beam energy, γ rays have been detected with the EUROBALL spectrometer operated in conjunction with the neutron wall and the charged-particle detector array EUCLIDES. New level sequences with positive and negative parities have been identified from n-γγ and n-γγγ coincidences. Spins have been assigned to many of the levels on the basis of angular distribution and directional correlation measurements. Excitation energies of the positive-parity yrast band and the branching ratios of its decay are compared with the predictions of the rigid triaxial rotor plus particle model. ©2004 The American Physical SocietyA. J. acknowledges financial support from the Deutsche Forschungsgemeinshaft (DPG)
within the Heisenberg program. This work was supported
by BMBF under Contract Nos. 06 OK 958 and 06 GÖ 951
and the EUROVIV Contract No. HPRI-CT-1999-000783.Peer Reviewe
Native gold of the porphyry copper mineralization in the Borov Dol deposit (Republic of Macedonia)
Marine biodiversity and ecosystem function relationships: The potential for practical monitoring applications
Abstract
There is an increasing demand for environmental assessments of the marine environment to include ecosystem function. However, existing schemes are predominantly based on taxonomic (i.e. structural) measures of biodiversity. Biodiversity and Ecosystem Function (BEF) relationships are suggested to provide a mechanism for converting taxonomic information into surrogates of ecosystem function. This review assesses the evidence for marine BEF relationships and their potential to be used in practical monitoring applications (i.e. operationalized).
Five key requirements were identified for the practical application of BEF relationships: 1) a complete understanding of strength, direction and prevalence of marine BEF relationships, 2) an understanding of which biological components are influential within specific BEF relationships, 3) the biodiversity of the selected biological components can be measured easily, 4) the ecological mechanisms that are the most important for generating marine BEF relationships, i.e. identity effects or complementarity, are known and 5) the proportion of the overall functional variance is explained by biodiversity, and hence BEF relationships, has been established.
Numerous positive and some negative BEF relationships were found within the literature, although many reproduced poorly the natural species richness, trophic structures or multiple functions of real ecosystems (requirement 1). Null relationships were also reported. The consistency of the positive and negative relationships was often low that compromised the ability to generalize BEF relationships and confident application of BEF within marine monitoring. Equally, some biological components and functions have received little or no investigation.
Expert judgement was used to attribute biological components using spatial extent, presence and functional rate criteria (requirement 2). This approach highlighted the main biological components contributing the most to specific ecosystem functions, and that many of the particularly influential components were found to have received the least amount of research attention.
The need for biodiversity to be measureable (requirement 3) is possible for most biological components although difficult within the functionally important microbes. Identity effects underpinned most marine BEF relationships (requirement 4). As such, processes that translated structural biodiversity measures into functional diversity were found to generate better BEF relationships.
The analysis of the contribution made by biodiversity, over abiotic influences, to the total expression of a particular ecosystem function was rarely measured or considered (requirement 5). Hence it is not possible to determine the overall importance of BEF relationships within the total ecosystem functioning observed. In the few studies where abiotic factors had been considered, it was clear that these modified BEF relationships and have their own direct influence on functional rate.
Based on the five requirements, the information required for immediate ‘operationalization’ of BEF relationships within marine functional monitoring is lacking. However, the concept of BEF inclusion within practical monitoring applications, supported by ecological modelling, shows promise for providing surrogate indicators of functioning
УЛЬТРАСТРУКТУРА СИНАПСОВ В ГИППОКАМПЕ КРЫС В ПРОЦЕССЕ СТАРЕНИЯ
The aim of the study was to examine age-related changes in the ultrastructure of synapses in the CA1 region of the hippocampus of Wistar rats and premature aging OXYS rats.To assess changes of the sinaptoarhitectonics photographed on 15 randomly chosen fields of view of the pyramidal layer of the CA1 region of the hippocampus with five slices at a standard magnification of 10000. It was determined the amount of mineral contacts (size of the field of view is 50 μm2) and calculated numerical density of synapses per 100 μm2. The number of contacts with asymmetric and symmetric organization sistemasubsidiaries units, perforated, hypertrophic contacts are counted.The study showed that there are significant differences in the ultrastructural organization of the synapses between the lines, already 4 months old. The numerical density of snaps in this age group OXYS rats was significantly higher than that of Wistar. Ultrastructure of synapses in the CA1 region of the hippocampus of rats at the age of 18 months more bulupodadan pathological essentiaompetencies processes and membrane prematurely senescent rats in contrast to the control line. The numerical indicator of protect contents 18-month-old rats OXYS was significantly lower than in Wistar.Identified interstrain differences in the degree of changes of synapses can testify in favor of a different sensitivity to oxidative stress in rats investigated lines.Цель исследования – изучить возрастные изменения ультраструктуры синапсов СА1-региона гиппокампа крыс линии Wistar и преждевременно стареющих крыс линии OXYS.Материал и методы. Для оценки изменений синаптоархитектоники фотографировали по 15 случайно выбранных полей зрения пирамидного слоя СА1-региона гиппокампа с пяти срезов при стандартном увеличении 10 000. Определяли количество межнейрональных контактов (площадь поля зрения – 50 мкм2) и высчитывали численную плотность синапсов на 100 мкм2. Подсчитывали количество определенных контактов с асимметричной и симметричной организацией системы субсинаптических единиц, перфорированные, гипертрофированные контакты. Подразделяли синапсы по протяженности активной зоны контакта.Результаты. Проведенное исследование показало, что существенные различия в ультраструктурной организации синапсов между линиями наблюдаются уже в 4-месячном возрасте. Численная плотность синапсов в этой возрастной группе у крыс OXYS была значимо выше, чем у Wistar. Ультраструктура синапсов СА1-региона гиппокампа крыс в возрасте 18 мес в большей степени была подвержена патологическим изменениям пресинаптических отростков и мембраны у преждевременно стареющих крыс в отличии от линии контроля. Показатель численной плотности контактов 18-месячных крыс OXYS был значимо ниже, чем у линии Wistar. Выявленные межлинейные различия по степени изменений синапсов могут свидетельствовать в пользу разной чувствительности к окислительному стрессу крыс исследуемых линий
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