Search results for "Protein"
showing 10 items of 21431 documents
Curcumin-like compounds designed to modify amyloid beta peptide aggregation patterns
2017
International audience; Curcumin is a natural polyphenol able to bind the amyloid beta peptide, which is related to Alzheimer's disease, and modify its self-assembly pathway. This paper focuses on a multi-disciplinary study that starts from the design of curcumin-like compounds with the key chemical features required for inhibiting amyloid beta aggregation, and reports the effects of these compounds on the in vitro aggregation of amyloid beta peptides. Chemoinformatic screening was performed through the calculation of molecular descriptors that were able to highlight the drug-like profile, followed by docking studies with an amyloid beta peptide fibril. The computational design underlined t…
The Blood-Brain Barrier in Alzheimer’s Disease
2020
The accumulation of neurotoxic amyloid-beta (Aβ) in the brain is one of the characteristic hallmarks of Alzheimer's disease (AD). Aβ-peptide brain homeostasis is governed by its production and various clearance mechanisms. The blood-brain barrier provides a large surface area for influx and efflux mechanisms into and out of the brain. Different transporters and receptors have been implicated to play crucial roles in Aβ clearance from brain. Besides Aβ transport, the blood-brain barrier tightly regulates the brain's microenvironment; however, vascular alterations have been shown in patients with AD. Here, we summarize how the blood-brain barrier changes during aging and in disease and focus …
Trifluoroethanol modulates α-synuclein amyloid-like aggregate formation, stability and dissolution
2016
The conversion of proteins into amyloid fibrils and other amyloid-like aggregates is closely connected to the onset of a series of age-related pathologies. Upon changes in environmental conditions, amyloid-like aggregates may also undergo disassembly into oligomeric aggregates, the latter being recognized as key effectors in toxicity. This indicates new possible routes for in vivo accumulation of toxic species. In the light of the recognized implication of α-Synuclein (αSN) in Parkinson's disease, we present an experimental study on supramolecular assembly of αSN with a focus on stability and disassembly paths of such supramolecular aggregate species. Using spectroscopic techniques, two-pho…
Hsp60, amateur chaperone in amyloid-beta fibrillogenesis
2016
BACKGROUND: Molecular chaperones are a very special class of proteins that play essential roles in many cellular processes like folding, targeting and transport of proteins. Moreover, recent evidence indicates that chaperones can act as potentially strong suppressor agents in Alzheimer's disease (AD). Indeed, in vitro experiments demonstrate that several chaperones are able to significantly slow down or suppress aggregation of Aβ peptide and in vivo studies reveal that treatment with specific chaperones or their overexpression can ameliorate some distinct pathological signs characterizing AD. METHODS: Here we investigate using a biophysical approach (fluorescence, circular dichroism (CD), t…
Beyond Amyloid - Widening the View on Alzheimer's Disease
2017
For 25 years, the amyloid cascade hypothesis, based on the finding that mutations in the amyloid precursor protein are closely linked to familial forms of Alzheimer's disease (AD), dominated the research on this disease. Recent failures of clinical anti-amyloidogenic trials, however, substantially support the reasoning (i) that the pathomechanisms that trigger familial AD, namely the generation, aggregation, and deposition of amyloid beta, cannot necessarily be extrapolated to sporadic cases and (ii) that amyloid beta represents a prominent histopathological feature in AD but not its exclusive causative factor. In autumn 2016, the Volkswagen Foundation hosted the Herrenhausen Symposium ‘Bey…
Middle Pleistocene protein sequences from the rhinoceros genus Stephanorhinus and the phylogeny of extant and extinct Middle/Late Pleistocene Rhinoce…
2017
BackgroundAncient protein sequences are increasingly used to elucidate the phylogenetic relationships between extinct and extant mammalian taxa. Here, we apply these recent developments to Middle Pleistocene bone specimens of the rhinoceros genusStephanorhinus. No biomolecular sequence data is currently available for this genus, leaving phylogenetic hypotheses on its evolutionary relationships to extant and extinct rhinoceroses untested. Furthermore, recent phylogenies based on Rhinocerotidae (partial or complete) mitochondrial DNA sequences differ in the placement of the Sumatran rhinoceros (Dicerorhinus sumatrensis). Therefore, studies utilising ancient protein sequences from Middle Pleis…
The Role of Osteoprotegerin and Its Ligands in Vascular Function
2019
International audience; The superfamily of tumor necrosis factor (TNF) receptors includes osteoprotegerin (OPG) and its ligands, which are receptor activators of nuclear factor kappa-B ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). The OPG/RANKL/RANK system plays an active role in pathological angiogenesis and inflammation as well as cell survival. It has been demonstrated that there is crosstalk between endothelial cells and osteoblasts during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. This OPG/RANKL/RANK/TRAIL system acts on specific cell surface receptors, which are then able to transmit their signals to other intracellular comp…
Role of Regular Physical Activity in Neuroprotection against Acute Ischemia
2020
One of the major obstacles that prevents an effective therapeutic intervention against ischemic stroke is the lack of neuroprotective agents able to reduce neuronal damage; this results in frequent evolution towards a long-term disability with limited alternatives available to aid in recovery. Nevertheless, various treatment options have shown clinical efficacy. Neurotrophins such as brain-derived neurotrophic factor (BDNF), widely produced throughout the brain, but also in distant tissues such as the muscle, have demonstrated regenerative properties with the potential to restore damaged neural tissue. Neurotrophins play a significant role in both protection and recovery of function followi…
Crosstalk between angiotensin and the nonamyloidogenic pathway of Alzheimer's amyloid precursor protein.
2017
The association between hypertension and an increased risk for Alzheimer's disease (AD) and dementia is well established. Many data suggest that modulation of the renin-angiotensin system may be meaningful for the prevention and therapy of neurodegenerative disorders, in particular AD. Proteolytic cleavage of the amyloid precursor protein (APP) by α-secretase precludes formation of neurotoxic Aβ peptides and is expected to counteract the development of AD. An established approach for the up-regulation of α-secretase cleavage is the activation of G protein-coupled receptors (GPCRs). Therefore, our study aimed to analyze whether stimulation of angiotensin AT1 or AT2 receptors stably expressed…
Renin-Angiotensin System Inhibition in Cardiovascular Patients at the Time of COVID19: Much Ado for Nothing? A Statement of Activity from the Directo…
2020
Cardiovascular diseases, in particular hypertension, as well as the cardiovascular treatment with Renin-Angiotensin System inhibitors such as Angiotensin Converting Enzyme (ACE) inhibitors and Angiotensin Receptor Blockers (ARBs), are claimed once again as mechanisms of Severe Acute Respiratory Syndrome (SARS) during the COVID-19 outbreak due to Cov-2 epidemics. In vitro studies are available to support the eventual role of ACE inhibitors and ARBs in both the promotion and antagonism of the disease. The available literature, indeed, presents contrasting results, all concentrated in experimental models. Evidence in humans is lacking that those mechanisms are actually occurring in the present…