Direct visualization of domain wall pinning in sub-100 nm 3D magnetic nanowires with cross-sectional curvature.

The study of 3D magnetic nanostructures has uncovered rich phenomena including the stabilization of topological spin textures using nanoscale curvature, controlled spin-wave emission, and novel ground states enabled by collective frustrated interactions. From a technological perspective, 3D nanostructures offer routes to ultrahigh density data storage, massive interconnectivity within neuromorphic devices, as well as mechanical induction of stem cell differentiation. However, the fabrication of 3D nanomagnetic systems with feature sizes down to 10 nm poses a significant challenge.

Efficient and economic protein labeling for NMR in mammalian expression systems: Application to a preT-cell and T-cell receptor protein.

Protein nuclear magnetic resonance (NMR) spectroscopy relies on the ability to isotopically label polypeptides, which is achieved through heterologous expression in various host organisms. Most commonly, Escherichia coli is employed by leveraging isotopically substituted ammonium and glucose to uniformly label proteins with N and C, respectively. Moreover, E.

Probing the Conformational Space of the Cannabinoid Receptor 2 and a Systematic Investigation of DNP-Enhanced MAS NMR Spectroscopy of Proteins in Detergent Micelles.

Tremendous progress has been made in determining the structures of G-protein coupled receptors (GPCR) and their complexes in recent years. However, understanding activation and signaling in GPCRs is still challenging due to the role of protein dynamics in these processes. Here, we show how dynamic nuclear polarization (DNP)-enhanced magic angle spinning nuclear magnetic resonance in combination with a unique pair labeling approach can be used to study the conformational ensemble at specific sites of the cannabinoid receptor 2.

Observation of Coherent Spin Waves in a Three-Dimensional Artificial Spin Ice Structure.

Harnessing high-frequency spin dynamics in three-dimensional (3D) nanostructures may lead to paradigm-shifting, next-generation devices including high density spintronics and neuromorphic systems. Despite remarkable progress in fabrication, the measurement and interpretation of spin dynamics in complex 3D structures remain exceptionally challenging. Here, we take a first step and measure coherent spin waves within a 3D artificial spin ice (ASI) structure using Brillouin light scattering.

Thermostability of a recombinant G protein-coupled receptor expressed at high level in mammalian cell culture.

Rational design of pharmaceutical drugs targeting integral membrane G protein-coupled receptors (GPCR) requires thorough understanding of ligand binding and mechanism of activation through high resolution structural studies of purified proteins. Due to inherent conformational flexibility of GPCR, stabilization of these proteins solubilized from cell membranes into detergents is a challenging task. Here, we take advantage of naturally occurring post-translational modifications for stabilization of purified GPCR in detergent micelles.

Harnessing Multi-Photon Absorption to Produce Three-Dimensional Magnetic Structures at the Nanoscale.

Three-dimensional nanostructured magnetic materials have recently been the topic of intense interest since they provide access to a host of new physical phenomena. Examples include new spin textures that exhibit topological protection, magnetochiral effects and novel ultrafast magnetic phenomena such as the spin-Cherenkov effect. Two-photon lithography is a powerful methodology that is capable of realising 3D polymer nanostructures on the scale of 100 nm.

Site Selective Antibody-Oligonucleotide Conjugation via Microbial Transglutaminase.

Nucleic Acid Therapeutics (NATs), including siRNAs and AntiSense Oligonucleotides (ASOs), have great potential to drug the undruggable genome. Targeting siRNAs and ASOs to specific cell types of interest has driven dramatic improvement in efficacy and reduction in toxicity. Indeed, conjugation of tris-GalNAc to siRNAs and ASOs has shown clinical efficacy in targeting diseases driven by liver hepatocytes.

Induction of RNAi Responses by Short Left-Handed Hairpin RNAi Triggers.

Small double-stranded, left-handed hairpin (LHP) RNAs containing a 5'-guide-loop-passenger-3' structure induce RNAi responses by a poorly understood mechanism. To explore LHPs, we synthesized fully 2'-modified LHP RNAs targeting multiple genes and found all to induce robust RNAi responses. Deletion of the loop and nucleotides at the 5'-end of the equivalent passenger strand resulted in a smaller LHP that still induced strong RNAi responses.

Efficient delivery of RNAi prodrugs containing reversible charge-neutralizing phosphotriester backbone modifications.

RNA interference (RNAi) has great potential to treat human disease. However, in vivo delivery of short interfering RNAs (siRNAs), which are negatively charged double-stranded RNA macromolecules, remains a major hurdle. Current siRNA delivery has begun to move away from large lipid and synthetic nanoparticles to more defined molecular conjugates.

Protein transduction domain delivery of therapeutic macromolecules.

Owing to their unprecedented selectivity, specific activity and potential for 1000+ fold amplification of signal, macromolecules, such as peptides, catalytic protein domains, complete proteins, and oligonucleotides, offer great potential as therapeutic molecules. However, therapeutic use of macromolecules is limited by their poor penetration in tissues and their inability to cross the cellular membrane. The discovery of small cationic peptides that cross the membrane, called Protein Transduction Domains (PTDs) or Cell Penetrating Peptides (CPPs), in the late 1980s opened the door to cellular delivery of large, bioactive molecules.

Epithelial p38alpha controls immune cell recruitment in the colonic mucosa.

Intestinal epithelial cells (IECs) compose the first barrier against microorganisms in the gastrointestinal tract. Although the NF-kappaB pathway in IECs was recently shown to be essential for epithelial integrity and intestinal immune homeostasis, the roles of other inflammatory signaling pathways in immune responses in IECs are still largely unknown. Here we show that p38alpha in IECs is critical for chemokine expression, subsequent immune cell recruitment into the intestinal mucosa, and clearance of the infected pathogen.

Arginine deficiency augments inflammatory mediator production by airway epithelial cells in vitro.

Background: Previously we showed that reduced availability of the essential amino acid tryptophan per se attenuates post-transcriptional control of interleukin (IL)-6 and IL-8 leading to hyperresponsive production of these inflammatory mediators by airway epithelial cells. Availability of the non-essential amino acid arginine in the inflamed airway mucosa of patients with asthma is reduced markedly, but it is not known whether this can also lead to an exaggerated production of IL-6 and IL-8.

Methods: IL-6 and IL-8 were determined by ELISA in culture supernatants of NCI-H292 airway epithelial-like cells and normal bronchial epithelial (NHBE) cells that were exposed to TNF-alpha, LPS or no stimulus, in medium with or without arginine.

RISC-target interaction: cleavage and translational suppression.

Small RNA molecules have been known and utilized to suppress gene expression for more than a decade. The discovery that these small RNA molecules are endogenously expressed in many organisms and have a critical role in controlling gene expression has led to the arising of a whole new field of research. Termed small interfering RNA (siRNA) or microRNA (miRNA) these approximately 22 nt RNA molecules have the capability to suppress gene expression through various mechanisms once they are incorporated in the multi-protein RNA-Induced Silencing Complex (RISC) and interact with their target mRNA.

TNF-alpha stimulation inhibits siRNA-mediated RNA interference through a mechanism involving poly-(A) tail stabilization.

The control of mRNA stability is a complex biological process that involves numerous factors, including microRNA (miRNA) and short interfering RNA (siRNA). Here, we show that short interfering RNA (siRNA) and microRNA share some similarities in their response to cellular stress. miR16 expedites the degradation of mRNAs containing AU-rich elements (ARE) in their 3' untranslated region (UTR).

Cytoskeletal architecture differentially controls post-transcriptional processing of IL-6 and IL-8 mRNA in airway epithelial-like cells.

Airway epithelial cells are critically dependent on an intact cytoskeleton for innate defense functions. There are various pathophysiological conditions that affect the cytoskeletal architecture. We studied the effect of cytoskeletal distortion in polarized airway epithelial-like NCI-H292 cells on inflammatory gene expression, exemplified by interleukin(IL)-6 and IL-8.

E1A expression dysregulates IL-8 production and suppresses IL-6 production by lung epithelial cells.

Background: The adenoviral protein E1A has been proposed to play a role in the pathophysiology of COPD, in particular by increasing IL-8 gene transcription of lung epithelial cells in response to cigarette smoke-constituents such as LPS. As IL-8 production is also under tight post-transcriptional control, we planned to study whether E1A affected IL-8 production post-transcriptionally. The production of IL-6 by E1A-positive cells had not been addressed and was studied in parallel.

Interleukin-17 induces hyperresponsive interleukin-8 and interleukin-6 production to tumor necrosis factor-alpha in structural lung cells.

Lung epithelial cells contribute to local inflammation by the production of pro-inflammatory mediators like interleukin (IL)-8 and IL-6. Although their production depends on gene transcription, previous studies showed that post-transcriptional mechanisms modulate IL-8 and IL-6 production. Human lung epithelial cells turn from normoresponsive into hyperresponsive IL-8- and IL-6-producing cells when their IL-8 and IL-6 mRNA degradation is reduced.

Exaggerated IL-8 and IL-6 responses to TNF-alpha by parainfluenza virus type 4-infected NCI-H292 cells.

Respiratory viruses induce and potentiate airway inflammation, which is related to the induction of proinflammatory mediators such as interleukin (IL)-8 and IL-6. Here we report on mechanisms implicated in IL-8 and IL-6 production by airway epithelium-like NCI-H292 cells exposed to parainfluenza virus type 4a (PIV-4). PIV-4 readily infected NCI-H292 cells as reflected by intracellular PIV-4 antigen expression.

Ingrowth of aorta wall into stent grafts impregnated with basic fibroblast growth factor: a porcine in vivo study of blood vessel prosthesis healing.

Objective: Endovascular aneurysm repair is an alternative treatment of abdominal aortic aneurysm. The procedure is less invasive, and morbidity and most probably mortality are reduced. However, some problems, such as endoleakage, are yet to be resolved.

Ingrowth of aorta vascular cells into basic fibroblast growth factor-impregnated vascular prosthesis material: a porcine and human in vitro study on blood vessel prosthesis healing.

Objective: One of the most life-threatening vascular diseases is rupture of an abdominal aneurysm. The conventional treatment is based on surgical reconstruction. An alternative treatment is endovascular aneurysm repair (EVAR).