Hydrothermal Synthesis of Monoclinic VO Microparticles without Use of Hazardous Reagents: A Key Role for the W-Dopant.

Monoclinic vanadium dioxide (VO (M)) is a promising material for various applications ranging from sensing to signature management and smart windows. Most applications rely on its reversible structural phase transition to rutile VO (VO (R)), which is accompanied by a metal-to-insulator transition. Bottom-up hydrothermal synthesis has proven to yield high quality monoclinic VO but requires toxic and highly reactive reducing agents that cannot be used outside of a research lab.

Safe targeting of T cell acute lymphoblastic leukemia by pathology-specific NOTCH inhibition.

Given the high frequency of activating mutations in T cell acute lymphoblastic leukemia (T-ALL), inhibition of the γ-secretase complex remains an attractive target to prevent ligand-independent release of the cytoplasmic tail and oncogenic NOTCH1 signaling. However, four different γ-secretase complexes exist, and available inhibitors block all complexes equally. As a result, these cause severe "on-target" gastrointestinal tract, skin, and thymus toxicity, limiting their therapeutic application.

The anti-malarial drug chloroquine sensitizes oncogenic NOTCH1 driven human T-ALL to γ-secretase inhibition.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive cancer arising from T-cell progenitors. Although current treatments, including chemotherapy and glucocorticoids, have significantly improved survival, T-ALL remains a fatal disease and new treatment options are needed. Since more than 60% of T-ALL cases bear oncogenic NOTCH1 mutations, small molecule inhibitors of NOTCH1 signalling; γ-secretase inhibitors (GSI), are being actively investigated for the treatment of T-ALL.

Restricted Location of PSEN2/γ-Secretase Determines Substrate Specificity and Generates an Intracellular Aβ Pool.

γ-Secretases are a family of intramembrane-cleaving proteases involved in various signaling pathways and diseases, including Alzheimer's disease (AD). Cells co-express differing γ-secretase complexes, including two homologous presenilins (PSENs). We examined the significance of this heterogeneity and identified a unique motif in PSEN2 that directs this γ-secretase to late endosomes/lysosomes via a phosphorylation-dependent interaction with the AP-1 adaptor complex.

NOTCH blockade combined with radiation therapy and temozolomide prolongs survival of orthotopic glioblastoma.

Glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults. The current standard of care includes surgery followed by radiotherapy (RT) and chemotherapy with temozolomide (TMZ). Treatment often fails due to the radiation resistance and intrinsic or acquired TMZ resistance of a small percentage of cells with stem cell-like behavior (CSC).

Insights into Autoregulation of Notch3 from Structural and Functional Studies of Its Negative Regulatory Region.

Notch receptors are transmembrane proteins that undergo activating proteolysis in response to ligand stimulation. A negative regulatory region (NRR) maintains receptor quiescence by preventing protease cleavage prior to ligand binding. We report here the X-ray structure of the NRR of autoinhibited human Notch3, and compare it with the Notch1 and Notch2 NRRs.

Human NOTCH2 Is Resistant to Ligand-independent Activation by Metalloprotease Adam17.

Cell surface receptors of the NOTCH family of proteins are activated by ligand induced intramembrane proteolysis. Unfolding of the extracellular negative regulatory region (NRR), enabling successive proteolysis by the enzymes Adam10 and γ-secretase, is rate-limiting in NOTCH activation. Mutations in the NOTCH1 NRR are associated with ligand-independent activation and frequently found in human T-cell malignancies.

Susceptibility allele-specific loss of miR-1324-mediated silencing of the INO80B chromatin-assembly complex gene in pre-eclampsia.

In humans, the elucidation of the genetics underlying multifactorial diseases such as pre-eclampsia remains complex. Given the current day availability of genome-wide linkage- and expression data pools, we applied pathway-guided genome-wide meta-analysis guided by the premise that the functional network underlying these multifactorial syndromes is under selective genetic pressure. This approach drastically reduced the genomic region of interest, i.

Regulated proteolysis of NOTCH2 and NOTCH3 receptors by ADAM10 and presenilins.

In mammals, there are four NOTCH receptors and five Delta-Jagged-type ligands regulating many aspects of embryonic development and adult tissue homeostasis. NOTCH proteins are type I transmembrane receptors that interact with ligands on adjacent cells and are activated by regulated intramembrane proteolysis (RIP). The activation mechanism of NOTCH1 receptors upon ligand binding is well understood and requires cleavage by ADAM10 metalloproteases prior to intramembranous cleavage by γ-secretase.

High NOTCH activity induces radiation resistance in non small cell lung cancer.

Background And Purpose: Patients with advanced NSCLC have survival rates <15%. The NOTCH pathway plays an important role during lung development and physiology but is often deregulated in lung cancer, making it a potential therapeutic target. We investigated NOTCH signaling in NSCLC and hypothesized that high NOTCH activity contributes to radiation resistance.

Synaptic PI(3,4,5)P3 is required for Syntaxin1A clustering and neurotransmitter release.

PI(3,4,5)P3 is a low-abundance lipid thought to play a role in the regulation of synaptic activity; however, the mechanism remains obscure. We have constructed novel split Venus-based probes and used superresolution imaging to localize PI(3,4,5)P3 at Drosophila larval neuromuscular synapses. We find the lipid in membrane domains at neurotransmitter release sites, where it concentrates with Syntaxin1A, a protein essential for vesicle fusion.

E-Cadherin loss associated with EMT promotes radioresistance in human tumor cells.

Background And Purpose: Hypoxia is a hallmark of solid cancers and associated with metastases and treatment failure. During tumor progression epithelial cells often acquire mesenchymal features, a phenomenon known as epithelial-to-mesenchymal transition (EMT). Intratumoral hypoxia has been linked to EMT induction.

WASP is activated by phosphatidylinositol-4,5-bisphosphate to restrict synapse growth in a pathway parallel to bone morphogenetic protein signaling.

Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P(2)] is a membrane lipid involved in several signaling pathways. However, the role of this lipid in the regulation of synapse growth is ill-defined. Here we identify PI(4,5)P(2) as a gatekeeper of neuromuscular junction (NMJ) size.

Neurons generated from APP/APLP1/APLP2 triple knockout embryonic stem cells behave normally in vitro and in vivo: lack of evidence for a cell autonomous role of the amyloid precursor protein in neuronal differentiation.

Alzheimer's disease amyloid precursor protein (APP) has been implicated in many neurobiologic processes, but supporting evidence remains indirect. Studies are confounded by the existence of two partially redundant APP homologues, APLP1 and APLP2. APP/APLP1/APLP2 triple knockout (APP tKO) mice display cobblestone lissencephaly and are perinatally lethal.

Tweek, an evolutionarily conserved protein, is required for synaptic vesicle recycling.

Synaptic vesicle endocytosis is critical for maintaining synaptic communication during intense stimulation. Here we describe Tweek, a conserved protein that is required for synaptic vesicle recycling. tweek mutants show reduced FM1-43 uptake, cannot maintain release during intense stimulation, and harbor larger than normal synaptic vesicles, implicating it in vesicle recycling at the synapse.

Inactivation of clathrin heavy chain inhibits synaptic recycling but allows bulk membrane uptake.

Synaptic vesicle reformation depends on clathrin, an abundant protein that polymerizes around newly forming vesicles. However, how clathrin is involved in synaptic recycling in vivo remains unresolved. We test clathrin function during synaptic endocytosis using clathrin heavy chain (chc) mutants combined with chc photoinactivation to circumvent early embryonic lethality associated with chc mutations in multicellular organisms.

Dynamic development of the calyx of Held synapse.

The calyx of Held is probably the largest synaptic terminal in the brain, forming a unique one-to-one connection in the auditory ventral brainstem. During early development, calyces have many collaterals, whose function is unknown. Using electrophysiological recordings and fast-calcium imaging in brain slices, we demonstrate that these collaterals are involved in synaptic transmission.

Dynamics of the readily releasable pool during post-tetanic potentiation in the rat calyx of Held synapse.

The size of the readily releasable pool (RRP) of vesicles was measured in control conditions and during post-tetanic potentiation (PTP) in a large glutamatergic terminal called the calyx of Held. We measured excitatory postsynaptic currents evoked by a high frequency train of action potentials in slices of 4-11-day-old rats. After a tetanus the cumulative release during such a train was enlarged by approximately 50%, indicating that the size of the RRP was increased.

An increase in calcium influx contributes to post-tetanic potentiation at the rat calyx of Held synapse.

We studied the contribution of a change in presynaptic calcium influx to posttetanic potentiation (PTP) in the calyx of Held synapse, an axosomatic synapse in the auditory brain stem. We made whole cell patch-clamp recordings of a principal cell after loading of the presynaptic terminal with a calcium dye. After induction of PTP by a high-frequency train of afferent stimuli, the Fluo-4 fluorescence transients evoked by an action potential became on average 15 +/- 4% larger (n = 7).

Post-tetanic potentiation in the rat calyx of Held synapse.

We studied synaptic plasticity in the calyx of Held synapse, an axosomatic synapse in the auditory brainstem, by making whole-cell patch clamp recordings of the principal cells innervated by the calyces in a slice preparation of 7- to 10-day-old rats. A 5 min 20 Hz stimulus train increased the amplitude of excitatory postsynaptic currents (EPSCs) on average more than twofold. The amplitude of the synaptic currents took several minutes to return to control values.

Monitoring agonist-induced phospholipase C activation in live cells by fluorescence resonance energy transfer.

Agonist-induced intracellular Ca(2+) signals following phospholipase C (PLC) activation display a variety of patterns, including transient, sustained, and oscillatory behavior. These Ca(2+) changes have been well characterized, but detailed kinetic analyses of PLC activation in single living cells is lacking, due to the absence of suitable indicators for use in vivo. Recently, green fluorescent protein-tagged pleckstrin homology domains have been employed to monitor PLC activation in single cells, based on (confocal) imaging of their fluorescence translocation from the membrane to the cytosol that occurs upon hydrolysis of phosphatidylinositol bisphosphate.

Locating femoral graft placement from lateral radiographs in anterior cruciate ligament reconstruction: a comparison of 3 methods of measuring radiographic images.

Graft positioning in anterior cruciate ligament (ACL) reconstruction is usually documented from lateral postoperative radiographs. The purpose of this study was to compare 3 measurement methods for femoral graft placement in 50 patients with ACL reconstruction. Intraoperative radiographic images were obtained and divided into 2 groups.