Long-term, super-resolution imaging of amyloid structures using transient amyloid binding microscopy

Amyloid fibrils and tangles are signatures of Alzheimer disease, but nanometer-sized aggregation intermediates are hypothesized to be the structures most toxic to neurons. The structures of these oligomers are too small to be resolved by conventional light microscopy. We have developed a simple and versatile method, called transient amyloid binding (TAB), to image amyloid structures with nanoscale resolution using amyloidophilic dyes, such as Thioflavin T, without the need for covalent labeling or immunostaining of the amyloid protein. Transient binding of ThT molecules to amyloid structures over time generates photon bursts that are used to localize single fluorophores with nanometer precision. Continuous replenishment of fluorophores from the surrounding solution minimizes photobleaching, allowing us to visualize a single amyloid structure for hours to days. We show that TAB microscopy can image both the oligomeric and fibrillar stages of amyloid-β aggregation. We also demonstrate that TAB microscopy can image the structural remodeling of amyloid fibrils by epi-gallocatechin gallate. Finally, we utilize TAB imaging to observe the non-linear growth of amyloid fibrils

Super‐Resolution Imaging of Amyloid Structures over Extended Times by Using Transient Binding of Single Thioflavin T Molecules

Oligomeric amyloid structures are crucial therapeutic targets in Alzheimer\u27s and other amyloid diseases. However, these oligomers are too small to be resolved by standard light microscopy. We have developed a simple and versatile tool to image amyloid structures by using thioflavin T without the need for covalent labeling or immunostaining. The dynamic binding of single dye molecules generates photon bursts that are used for fluorophore localization on a nanometer scale. Thus, photobleaching cannot degrade image quality, allowing for extended observation times. Super‐resolution transient amyloid binding microscopy promises to directly image native amyloid by using standard probes and record amyloid dynamics over minutes to days. We imaged amyloid fibrils from multiple polypeptides, oligomeric, and fibrillar structures formed during different stages of amyloid‐β aggregation, as well as the structural remodeling of amyloid‐β fibrils by the compound epi‐gallocatechin gallate

Wind Power Forecasting Error Distributions: An International Comparison

Wind power forecasting is essential for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that may occur is a critical factor for system operation functions, such as the setting of operating reserve levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations.QC 20130116Elektra 36141: Korttidsplanering av vatten-värmekraftsystem vid stora mängder vindkraft: System-perspektive

FOXP3-positive cell infiltration in the chorionic villi is increased in the placenta accreta and decreased in the placental abruption

Objectives: Growing data suggest a role of Treg cells in placentation. The aim of the study was to evaluate Treg cells (FOXP3-positive cells) placental bed infiltration in patients with placenta accrete syndrome (PAS) and patients who experienced placental abruption. Material and methods: The study group included 13 patients with PAS and the control group consisted of 66 women who had caesarean (CD) delivery of whom, 44 patients with elective caesarean (EC) delivery, and 22 patients with urgent caesarean (UC) delivery due to placental abruption. FOXP3 cell infiltration was assessed by means of immunohistochemistry in placental chorionic villous (CV) and in the decidua (D) and cumulatively in the placental bed (PB). Results: We observed significant difference in the degree of FOXP3-positive cell CV infiltration between studied groups (p = 0.04). FOXP3-positive cells were the most commonly observed in PAS patients, while, they were the least frequently presented in patients after UC. The immunoreactivity for FOXP3-positive cells in CV were as follows: PAS 5 (38%), urgent CS 1 (5%) and elective CS 8 (18%) subjects. We found no difference in the presence of FOXP3-positive cells in the D (p = 0.35) and in the PB (p = 0.23) of analyzed groups.  FOXP3-cell infiltration was not related with patient age, BMI, gestational age and neonatal birth weight. Conclusions: Our study provides further evidence that abnormal invasive placentation is an associated disturbance of the maternal immune response. Accordingly, we have theorized that alteration of the FOXP3-positive Treg cell infiltration into the placental bed allows trophoblast cell invasion

Functional specialization of calreticulin domains

Calreticulin is a Ca2+-binding chaperone in the endoplasmic reticulum (ER), and calreticulin gene knockout is embryonic lethal. Here, we used calreticulin-deficient mouse embryonic fibroblasts to examine the function of calreticulin as a regulator of Ca2+ homeostasis. In cells without calreticulin, the ER has a lower capacity for Ca2+ storage, although the free ER luminal Ca2+ concentration is unchanged. Calreticulin-deficient cells show inhibited Ca2+ release in response to bradykinin, yet they release Ca2+ upon direct activation with the inositol 1,4,5-trisphosphate (InsP3). These cells fail to produce a measurable level of InsP3 upon stimulation with bradykinin, likely because the binding of bradykinin to its cell surface receptor is impaired. Bradykinin binding and bradykinin-induced Ca2+ release are both restored by expression of full-length calreticulin and the N + P domain of the protein. Expression of the P + C domain of calreticulin does not affect bradykinin-induced Ca2+ release but restores the ER Ca2+ storage capacity. Our results indicate that calreticulin may play a role in folding of the bradykinin receptor, which affects its ability to initiate InsP3-dependent Ca2+ release in calreticulin-deficient cells. We concluded that the C domain of calreticulin plays a role in Ca2+ storage and that the N domain may participate in its chaperone functions

Rocznik Lubuski (t. 31, cz.1): Muzea i ochrona dziedzictwa kulturowego na Środkowym Nadodrzu

Muzea i Ochrona Dziedzictwa Kulturowego na Środkowym Nadodrzu

Regulation of the Actin Cytoskeleton by an Interaction of IQGAP Related Protein GAPA with Filamin and Cortexillin I

Filamin and Cortexillin are F-actin crosslinking proteins in Dictyostelium discoideum allowing actin filaments to form three-dimensional networks. GAPA, an IQGAP related protein, is required for cytokinesis and localizes to the cleavage furrow during cytokinesis. Here we describe a novel interaction with Filamin which is required for cytokinesis and regulation of the F-actin content. The interaction occurs through the actin binding domain of Filamin and the GRD domain of GAPA. A similar interaction takes place with Cortexillin I. We further report that Filamin associates with Rac1a implying that filamin might act as a scaffold for small GTPases. Filamin and activated Rac associate with GAPA to regulate actin remodelling. Overexpression of filamin and GAPA in the various strains suggests that GAPA regulates the actin cytoskeleton through interaction with Filamin and that it controls cytokinesis through association with Filamin and Cortexillin

Expression of the chemokine receptor CCR5 in psoriasis and results of a randomized placebo controlled trial with a CCR5 inhibitor

Several reports have indicated that the chemokine receptor CCR5 and its ligands, especially CCL5 (formerly known as RANTES), may play a role in the pathogenesis of psoriasis. The purpose of this investigation was to examine the expression of CCR5 and its ligands in chronic plaque psoriasis and to evaluate the clinical and immunohistochemical effect of a CCR5 receptor inhibitor. Immunohistochemical analysis showed low but significant increased total numbers of CCR5 positive cells in epidermis and dermis of lesional skin in comparison to non-lesional skin. However, relative expression of CCR5 proportional to the cells observed revealed that the difference between lesional and non-lesional skin was only statistically significant in the epidermis for CD3 positive cells and in the dermis for CD68 positive cells. Quantification of mRNA by reverse transcriptase-polymerase chain reaction only showed an increased expression of CCL5 (RANTES) in lesional skin. A randomized placebo-controlled clinical trial in 32 psoriasis patients revealed no significant clinical effect and no changes at the immunohistochemical level comparing patients treated with placebo or a CCR5 inhibitor SCH351125. We conclude that although CCR5 expression is increased in psoriatic lesions, this receptor does not play a crucial role in the pathogenesis of psoriasis

Stau Search in IceCube

The tau lepton’s supersymmetric partner, the stau, appears in some models as the next-to-lightest supersymmetric particle. Their deacy process into the lightest superpartner is usually suppressed by supersymmetry breaking, which makes it a long-lived particle. In this scenario, its signature is a long, minimally ionizing track when traveling through the IceCube detector. Independent of their primary energy, the stau tracks appear like low-energy muons in the detector. A potential signal of staus would thus be an excess over muon tracks induced by atmospheric muon neutrinos. Our analysis focuses on the region around the horizon as here the ratio between stau signal and atmospheric background is largest. We will present the first sensitivity to constrain the stau mass using IceCube and demonstrate the potential of this analysis with future improvements