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Wyszukujesz frazę "amyloid-β" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Molecular mechanisms initiating amyloid β-fibril formation in Alzheimers disease
Autorzy:
Kirkitadze, Marina
Kowalska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1041422.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
protein aggregation
fibrillogenesis
Alzheimer's disease
neurotoxicity
amyloid-β
APP mutations
Opis:
The deposition of aggregated amyloid β-protein (Aβ) in the human brain is a major lesion in Alzheimer' disease (AD). The process of Aβ fibril formation is associated with a cascade of neuropathogenic events that induces brain neurodegeneration leading to the cognitive and behavioral decline characteristic of AD. Although a detailed knowledge of Aβ assembly is crucial for the development of new therapeutic approaches, our understanding of the molecular mechanisms underlying the initiation of Aβ fibril formation remains very incomplete. The genetic defects responsible for familial AD influence fibrillogenesis. In a majority of familial cases determined by amyloid precursor protein (APP) and presenilin (PS) mutations, a significant overproduction of Aβ and an increase in the Aβ42/Aβ40 ratio are observed. Recently, it was shown that the two main alloforms of Aβ have distinct biological activity and behaviour at the earliest stage of assembly. In vitro studies demonstrated that Aβ42 monomers, but not Aβ40, form initial and minimal structures (pentamer/hexamer units called paranuclei) that can oligomerize to larger forms. It is now apparent that Aβ oligomers and protofibrils are more neurotoxic than mature Aβ fibrils or amyloid plaques. The neurotoxicity of the prefibrillar aggregates appears to result from their ability to impair fundamental cellular processes by interacting with the cellular membrane, causing oxidative stress and increasing free Ca^(2+)that eventually lead to apoptotic cell death.
Źródło:
Acta Biochimica Polonica; 2005, 52, 2; 417-423
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola metali w rozwoju choroby Alzheimera i Parkinsona
The role of metals in development Alzheimer's and Parkinson's diseases
Autorzy:
Żygowska, Justyna
Szymańska, Aneta
Powiązania:
https://bibliotekanauki.pl/articles/2057913.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
choroba neurodegeneracyjna
jony metali
β-amyloid
białka amyloidogenne
choroba Alzheimera
choroba Parkinsona
neurodegenerative diseases
amyloidogenic proteins
amyloid β
metal ions
Alzheimer's disease
Parkinson disease
Opis:
Neurodegenerative diseases are the consequence of progressive brain degeneration caused by the death of nerve cells. Many factors that influence the neurodegeneration development are still not fully known. A lot of studies indicate the contribution of metal ions in this process. Copper, zinc, and iron are trace elements essential for proper functioning of the body. They are part of many enzymes participating in the transmission of the nerve signals, electrons transport, neurotransmitters and nucleic acids synthesis, and oxygen storage. Disorder of metals homeostasis leads to the development of severe diseases and nervous system degenerations. An excess of copper and iron ions causes a significant increase in cellular oxidative stress. Metals catalyze the reactions of free radicals formation that destroy proteins, lipids, and nucleic acids. High concentration of copper and iron ions were found in the deposits of amyloidogenic proteins. Amyloid β (Alzheimer disease) and α synuclein (Parkinson disease) have ions binding chain structures. The metal-protein interaction increases oligomerization speed in vitro. A lot of evidence suggests that the disorder of Cu, Zn and Fe homeostasis accelerates the progress of brain neurodegeneration. Human organism contains many metals, which are not needed for the proper functioning of the body, e.g. aluminum. Al binds to nucleic acids causing an increase in cellular oxidative stress and initiating proteins oligomerization. The presence of aluminum is also considered to be disadvantageous for the nervous system. The lack of medicines for neurodegenerative diseases forces us to search for new therapies. The development of degenerations could be slowed down by chelators of toxic metals, but first, these diseases must be better understood. Adverse effects of high concentration of metal ions on brain functioning are not fully known. This knowledge is necessary to find effective drugs.
Źródło:
Wiadomości Chemiczne; 2022, 76, 1-2; 1-25
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Circular dichroism and aggregation studies of amyloid β (11-8) fragment and its variants.
Autorzy:
Juszczyk, Paulina
Kołodziejczyk, Aleksandra
Grzonka, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/1041423.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
secondary structure studies
thioflavine T assay
aggregation studies.
Alzheimer's disease
amyloid β
circular dichroism (CD)
Opis:
Aggregation of Aβ peptides is a seminal event in Alzheimer's disease. Detailed understanding of Aβ assembly would facilitate the targeting and design of fibrillogenesis inhibitors. Here comparative conformational and aggregation studies using CD spectroscopy and thioflavine T fluorescence assay are presented. As a model peptide, the 11-28 fragment of Aβ was used. This model peptide is known to contain the core region responsible for Aβ aggregation. The structural and aggregational behaviour of the peptide was compared with the properties of its variants corresponding to natural, clinically relevant mutants at positions 21-23 (A21G, E22K, E22G, E22Q and D23N). In HFIP (hexafluoro-2-propanol), a strong α-helix inducer, the CD spectra revealed an unexpectedly high amount of β-sheet conformation. The aggregation process of Aβ(11-28) variants provoked by water addition to HFIP was found to be consistent with a model of an α-helix-containing intermediate. The aggregation propensity of all Aβ(11-28) variants was also compared and discussed.
Źródło:
Acta Biochimica Polonica; 2005, 52, 2; 425-431
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Targeting BACE with small inhibitory nucleic acids - a future for Alzheimers disease therapy?
Autorzy:
Nawrot, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/1043280.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
β-amyloid peptide
deoxyribozymes
small interfering RNAs
hammerhead ribozymes
Alzheimer's disease
β-secretase
Opis:
β-Secretase, a β-site amyloid precursor protein (APP) cleaving enzyme (BACE), participates in the secretion of β-amyloid peptides (Aβ), the major components of the toxic amyloid plaques found in the brains of patients with Alzheimer's disease (AD). According to the amyloid hypothesis, accumulation of Aβ is the primary influence driving AD pathogenesis. Lowering of Aβ secretion can be achieved by decreasing BACE activity rather than by down-regulation of the APP substrate protein. Therefore, β-secretase is a primary target for anti-amyloid therapeutic drug design. Several approaches have been undertaken to find an effective inhibitor of human β-secretase activity, mostly in the field of peptidomimetic, non-cleavable substrate analogues. This review describes strategies targeting BACE mRNA recognition and its down-regulation based on the antisense action of small inhibitory nucleic acids (siNAs). These include antisense oligonucleotides, catalytic nucleic acids - ribozymes and deoxyribozymes - as well as small interfering RNAs (siRNAs). While antisense oligonucleotides were first used to identify an aspartyl protease with β-secretase activity, all the strategies now demonstrate that siNAs are able to inhibit BACE gene expression in a sequence-specific manner, measured both at the level of its mRNA and at the level of protein. Moreover, knock-down of BACE reduces the intra- and extracellular population of Aβ40 and Aβ42 peptides. An anti-amyloid effect of siNAs is observed in a wide spectrum of cell lines as well as in primary cortical neurons. Thus targeting BACE with small inhibitory nucleic acids may be beneficial for the treatment of Alzheimer's disease and for future drug design.
Źródło:
Acta Biochimica Polonica; 2004, 51, 2; 431-444
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Alzheimers disease: Its origin at the membrane, evidence and questions.
Autorzy:
Buchet, Rene
Pikuła, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/1044315.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
β-amyloid precursor protein
membrane proteases
Alzheimer's disease
lipid composition
membrane microdomains
Opis:
Numerous results on membrane lipid composition from different regions of autopsied Alzheimer's disease brains in comparison with corresponding fractions isolated from control brains revealed significant differences in serine- and ethanolamine-containing glycerophospholipid as well as in glycosphingolipid content. Changes in membrane lipid composition are frequently accompanied by alterations in membrane fluidity, hydrophobic mismatch, lipid signaling pathways, transient formation and disappearance of lipid microdomains, changes in membrane permeability to cations and variations of other membrane properties. In this review we focus on possible implications of altered membrane composition on β-amyloid precursor protein (APP) and on proteolysis of APP leading eventually to the formation of neurotoxic β-amyloid (Aβ) peptides, the major proteinaceous component of extracellular senile plaques, directly involved in Alzheimer's disease pathogenesis.
Źródło:
Acta Biochimica Polonica; 2000, 47, 3; 725-733
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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