Accelerated Extracellular Nucleotide Metabolism in Brain Microvascular Endothelial Cells in Experimental Hypercholesterolemia.

Hypercholesterolemia affects the neurovascular unit, including the cerebral blood vessel endothelium. Operation of this system, especially in the context of energy metabolism, is controlled by extracellular concentration of purines, regulated by ecto-enzymes, such as e-NTPDase-1/CD39, ecto-5'-NT/CD73, and eADA. We hypothesize that hypercholesterolemia, via modulation of the activity of nucleotide metabolism-regulating ecto-enzymes, deteriorates glycolytic efficiency and energy metabolism of endothelial cells, which may potentially contribute to development of neurodegenerative processes.

The extent of damage to the blood-brain barrier in the hypercholesterolemic LDLR/Apo E double knockout mice depends on the animal's age, duration of pathology and brain area.

One of the effects of hypercholesterolemia (Hch) exerted on the central nervous system (CNS) is damage to the blood-brain barrier (BBB). Increased permeability of BBB results from structural changes in the vascular wall, loss of the tight junctions and barrier function, as well as alterations in the concentration of proteins located in the layers of the vascular wall. These changes occur in the course of metabolic and neurodegenerative diseases.

Transient cerebral ischemia induces the neuroglial proliferative activity and the potential to redirect neuroglial differentiation.

Brain injury triggers a complex response involving morphological changes, cellular proliferation, and differentiation of newly formed neuroglial subpopulations. These processes have been extensively studied in animal stroke models with permanent large vessel occlusion. However, less is known about neuroglial response after transient cerebral ischemia.

Identification of N-linked glycans as specific mediators of neuronal uptake of acetylated α-Synuclein.

Cell-to-cell transmission of toxic forms of α-Synuclein (αS) is thought to underlie disease progression in Parkinson disease. αS in humans is constitutively N-terminally acetylated (αSacetyl), although the impact of this modification is relatively unexplored. Here, we report that αSacetyl is more effective at inducing intracellular aggregation in primary neurons than unmodified αS (αSun).

Targeting the Intrinsically Disordered Proteome Using Small-Molecule Ligands.

Intrinsically disordered proteins (IDPs) and regions (IDRs) make up a significant part of the proteome and facilitate a wide range of physiological and pathological functions that are only beginning to be understood. As such, they are highly attractive targets for drug development and bioengineering. However, their inability to adopt well-defined structures provides significant obstacles for developing ligands that regulate their behaviors.

Proteasome inhibitors against amelanotic melanoma.

The incidence of malignant melanoma, the most aggressive skin cancer, is increasing constantly. Despite new targeted therapies, the prognosis for patients with metastatic disease remains poor. Thus, there is a need for new combinational treatments, and antineoplastic agents potentially valuable in this approach are inhibitors of the ubiquitin-proteasome system (UPS).

Noncovalent inhibitors of human 20S and 26S proteasome based on trypsin inhibitor SFTI-1.

Sunflower trypsin inhibitor (SFTI-1) is recognized as an attractive scaffold to designed potent inhibitors of various proteases. We have recently found that its analogues inhibit noncovalently both human and yeast 20S proteasomes. Here, a set of novel and more potent in vitro inhibitors is presented.

Foldamer-mediated manipulation of a pre-amyloid toxin.

Disordered proteins, such as those central to Alzheimer's and Parkinson's, are particularly intractable for structure-targeted therapeutic design. Here we demonstrate the capacity of a synthetic foldamer to capture structure in a disease relevant peptide. Oligoquinoline amides have a defined fold with a solvent-excluded core that is independent of its outwardly projected, derivatizable moieties.

Morphological Changes within the Rat Lateral Ventricle after the Administration of Proteasome Inhibitors.

The broad variety of substances that inhibit the action of the ubiquitin-proteasome system (UPS)-known as proteasome inhibitors-have been used extensively in previous studies, and they are currently frequently proposed as a novel form of cancer treatment and as a protective factor in intracerebral hemorrhage treatment. The experimental data on the safest route of proteasome inhibitor administration, their associated side effects, and the possible ways of minimizing these effects have recently become a very important topic. The aim of our present study was to determine the effects of administering of MG-132, lactacystin and epoxomicin, compounds belonging to three different classes of proteasome inhibitors, on the ependymal walls of the lateral ventricle.

Age related skeletal muscle atrophy and upregulation of autophagy in dogs.

Sarcopenia, the age related loss of muscle mass and strength, is a multifactorial condition that occurs in a variety of species and represents a major healthcare concern for older adults in human medicine. In veterinary medicine, skeletal muscle atrophy is often observed in dogs as they reach old age, but the process is not well understood. Autophagy is a mechanism for degradation and recycling of cellular constituents and is potentially involved in sarcopenia.

Tobacco smoking alters the number of oral epithelial cells with apoptotic features.

Tobacco smoking is a global problem associated with the occurrence of many systemic diseases and tumors. Oral cavity tumors are common tobacco-related cancers, and of all the anatomical structures that are exposed to the effects of smoking, the oral cavity remains the least-explored area. Changes that occur in the biology of oral epithelial keratinocytes under the influence of the components of tobacco smoke often go unnoticed, if they are asymptomatic.

Nigrostriatal pathway degeneration in rats after intraperitoneal administration of proteasome inhibitor MG-132.

The proteins' ubiquitination and their further degradation by proteasomes are crucial for cell cycle regulation, transcription and DNA replication, inflammatory response, and apoptosis. Proteasome inhibitors have recently become considered as a promising method in cancer and inflammatory disease therapy. In this study, utilizing the rat model, we try to establish the influence of proteasome inhibitor MG-132: (1) on the basis of spontaneous and evoked locomotor activity and (2) on the condition of nigrostriatal projections eight weeks after MG-132 intraperitoneal administration.

Crosstalk between autophagy and proteasome protein degradation systems: possible implications for cancer therapy.

The Ubiquitin-Proteasomes System (UPS) and autophagy, two main intracellular protein degradation pathways within the eukaryotic cells which were originally regarded as rather independent, seem to be very closely related. Proteasome inhibitors, including the multipathway inhibitor bortezomib, are drawing increased attention for their therapeutic potential in the treatment of chronic inflammation and cancer, especially tumours with a high degree of malignancy. The over-activation of autophagy induces cell death and may act as a powerful tumour-suppressing mechanism.

Correlation between dopaminergic phenotype and expression of calretinin in the midbrain nuclei of the opossum (Monodelphis domestica): an immunohistological study.

We investigated distribution and morphology of neurons of the midbrain nuclei: the ventral tegmental area (VTA), substantia nigra (SN) and periaqueductal gray (PAG) of the adult grey short-tailed opossums that were double immunolabeled for the presence of calretinin (CR) and/or tyrosine hydroxylase (TH). The majority of TH-immunopositive neurons and fibers were located in the VTA, SN, and only scarce population of small neurons expressing TH was present in the PAG. In the SN 80 percent of TH-expressing neurons had large cell bodies, and only a small fraction had small perikarya.

Transcription factor Pax6 is expressed by astroglia after transient brain ischemia in the rat model.

Reactive astrogliosis is regarded as an universal astrocytic response to different kinds of lesions, concerned with glial fibrillary acidic protein (GFAP) up-regulation, cellular hypertrophy and proliferation. The origin of reactive and proliferating cells in the adult brain is still disputable. Persistent progenitors as well as de-differentiating adult cells of various glial lineages are regarded as possible candidates.

Expression of the calcium-binding proteins in the central, medial and cortical nuclei of the rabbit amygdaloid complex during postnatal development.

Calbindin-D28k (CB), parvalbumin (PV) and calretinin (CR) are calcium-binding proteins (CaBPs) considered to be markers for certain subpopulations of neurons in the central nervous system. The aim of this study was to describe the pattern of distribution of CB-, PV- and CR-immunoreactive elements in the rabbit corticomedial amygdaloid complex during the postnatal period. The time course of changes in CaBPs expression during maturation of the selected nuclei indicates their diversity.

Variations in popliteal fossa venous anatomy: implications for diagnosis of deep-vein thrombosis.

Background: To retrospectively review the bilateral venous system within the popliteal fossa to evaluate the types of variations and their frequency seen in venous anatomy.

Materials And Methods: During routine dissection of formalin-fixed cadavers, a retrospective review of 32 bilateral (64 limbs) lower limbs obtained from adult donors was performed. Deep veins present in the popliteal fossa were evaluated according to predetermined criteria for the presence of duplication of vessels and interindividual variations in venous anatomy.

Vortex-induced amyloid superstructures of insulin and its component A and B chains.

Insulin is an amyloid-forming polypeptide built of two disulfide-linked chains (A and B), both themselves amyloidogenic. An interesting property of insulin is that agitation strongly influences the course of its aggregation, resulting in characteristic chiral superstructures of amyloid fibrils. Here, we investigate the self-assembly of these superstructures by comparing the quiescent and vortex-assisted aggregation of insulin and its individual A and B chains in the presence or absence of reducing agent tris(2-carboxyethyl)phosphine (TCEP).

Cross-seeding of fibrils from two types of insulin induces new amyloid strains.

The irreversibility and autocatalytic character of amyloidogenesis and the polymorphism of amyloid fibrils underlie the phenomenon of self-propagating strains, wherein the mother seed, rather than the seeding environment, determines the properties of daughter fibrils. Here we study the formation of amyloid fibrils from bovine insulin and the recombinant Lys(B31)-Arg(B32) human insulin analog. The two polypeptides are similar enough to cross-seed but, upon spontaneous aggregation, form amyloid fibrils with distinct spectral features in the infrared amide I' band region.

An FT-IR study on packing defects in mixed β-aggregates of poly(L-glutamic acid) and poly(D-glutamic acid): a high-pressure rescue from a kinetic trap.

Under favorable conditions of pH and temperature, poly(L-glutamic acid) (PLGA) adopts different types of secondary and quaternary structures, which include spiral assemblies of amyloid-like fibrils. Heating of acidified solutions of PLGA (or PDGA) triggers formation of β(2)-type aggregates with morphological and tinctorial properties typical for amyloid fibrils. In contrast to regular antiparallel β-sheet (β(1)), the amide I' vibrational band of β(2)-fibrils is unusually red-shifted below 1600 cm(-1), which has been attributed to bifurcated hydrogen bonds coupling C═O and N-D groups of the main chains to glutamic acid side chains.

Spiral superstructures of amyloid-like fibrils of polyglutamic acid: an infrared absorption and vibrational circular dichroism study.

Amyloid fibrils, which are often associated with certain degenerative disorders, reveal a number of intriguing spectral properties. However, the relationship between the structure of fibrils and their optical traits remains poorly understood. Poly(L-glutamic) acid is a model polypeptide shown recently to form amyloid-like fibrils with an atypical infrared amide I' band at 1595 cm(-1), which has been attributed to the presence of bifurcated hydrogen bonds coupling C═O and N-D groups of the main chains to glutamate side chains.

A methodology to establish a database to study gene environment interactions for childhood asthma.

Background: Gene-environment interactions are likely to explain some of the heterogeneity in childhood asthma. Here, we describe the methodology and experiences in establishing a database for childhood asthma designed to study gene-environment interactions (PAGES--Paediatric Asthma Gene Environment Study).

Methods: Children with asthma and under the care of a respiratory paediatrician are being recruited from 15 hospitals between 2008 and 2011.

Insulin amyloid superstructures as templates for surface enhanced Raman scattering.

Nanostructuring of noble metal surfaces with biomorphic and biological templates facilitates a variety of applications of surface enhanced Raman scattering (SERS). Here we show that the newly reported insulin amyloid superstructures may be employed as stable nanoscaffolds for metallic Au films providing an effective substrate for SERS on covalently bound molecules of 4-mercaptobenzoic acid (4-MBA). The vortex-aligned insulin fibrils are capable of templating nanopatterns in sputtered Au layers without overlapping the SERS spectra of 4-MBA with vibrational bands stemming from the protein.