Thiyl radicals are co-products of dinitrosyl iron complex (DNIC) formation.

Thiyl radicals are detected by EPR as co-products of dinitrosyl iron complex (DNIC) formation. In demonstrating that DNIC formation generates RS˙ in a NO rich environment, these results provide a novel route for S-nitroso thiol formation

Dynamics of Dinitrosyl Iron Complex (DNIC) Formation with Low Molecular Weight Thiols.

Dinitrosyl iron complexes (DNICs) are ubiquitous in mammalian cells and tissues producing nitric oxide (NO) and have been argued to play key physiological and pathological roles. Nonetheless, the mechanism and dynamics of DNIC formation in aqueous media remain only partially understood. Here, we report a stopped-flow kinetics and density functional theory (DFT) investigation of the reaction of NO with ferrous ions and the low molecular weight thiols glutathione (GSH) and cysteine (CysSH) as well as the peptides WCGPC and WCGPY to produce DNICs in pH 7.4 aqueous media. With each thiol, a two-stage reaction pattern is observed. The first stage involves several rapidly established pre-equilibria leading to a ferrous intermediate concluded to have the composition FeII(NO)(RS)2(H2O)x (C). In the second stage, C undergoes rate-limiting, unimolecular autoreduction to give thiyl radical (RS•) plus the mononitrosyl Fe(I) complex FeI(NO)(RS)(H2O)x following the reactivity order of CysSH > WCGPC > WCGPY > GSH. Time course simulations using the experimentally determined kinetics parameters demonstrate that, at a NO flux characteristic of inflammation, DNICs will be rapidly formed from intracellular levels of ferrous iron and thiols. Furthermore, the proposed mechanism offers a novel pathway for S-nitroso thiol (RSNO) formation in a biological environment

Evidence for glutamate as a neuroglial transmitter within sensory ganglia

This study examines key elements of glutamatergic transmission within sensory ganglia of the rat. We show that the soma of primary sensory neurons release glutamate when depolarized. Using acute dissociated mixed neuronal/glia cultures of dorsal root ganglia (DRG) or trigeminal ganglia and a colorimetric assay, we show that when glutamate uptake by satellite glial cells (SGCs) is inhibited, KCl stimulation leads to simultaneous increase of glutamate in the culture medium. With calcium imaging we see that the soma of primary sensory neurons and SGCs respond to AMPA, NMDA, kainate and mGluR agonists, and selective antagonists block this response. Using whole cell patch-clamp technique, inward currents were recorded from small diameter (<30 µm) DRG neurons from intact DRGs (ex-vivo whole ganglion preparation) in response to local application of the above glutamate receptor agonists. Following a chronic constriction injury (CCI) of either the inferior orbital nerve or the sciatic nerve, glutamate expression increases in the trigeminal ganglia and DRG respectively. This increase occurs in neurons of all diameters and is present in the somata of neurons with injured axons as well as in somata of neighboring uninjured neurons. These data provides additional evidence that glutamate can be released within the sensory ganglion, and that the somata of primary sensory neurons as well as SGCs express functional glutamate receptors at their surface. These findings, together with our previous gene knockdown data, suggest that glutamatergic transmission within the ganglion could impact nociceptive thresholdpublished_or_final_versio

Temporomandibular joint inflammation activates glial and immune cells in both the trigeminal ganglia and in the spinal trigeminal nucleus

<p>Abstract</p> <p>Background</p> <p>Glial cells have been shown to directly participate to the genesis and maintenance of chronic pain in both the sensory ganglia and the central nervous system (CNS). Indeed, glial cell activation has been reported in both the dorsal root ganglia and the spinal cord following injury or inflammation of the sciatic nerve, but no data are currently available in animal models of trigeminal sensitization. Therefore, in the present study, we evaluated glial cell activation in the trigeminal-spinal system following injection of the Complete Freund's Adjuvant (CFA) into the temporomandibular joint, which generates inflammatory pain and trigeminal hypersensitivity.</p> <p>Results</p> <p>CFA-injected animals showed ipsilateral mechanical allodynia and temporomandibular joint edema, accompanied in the trigeminal ganglion by a strong increase in the number of GFAP-positive satellite glial cells encircling neurons and by the activation of resident macrophages. Seventy-two hours after CFA injection, activated microglial cells were observed in the ipsilateral trigeminal subnucleus caudalis and in the cervical dorsal horn, with a significant up-regulation of Iba1 immunoreactivity, but no signs of reactive astrogliosis were detected in the same areas. Since the purinergic system has been implicated in the activation of microglial cells during neuropathic pain, we have also evaluated the expression of the microglial-specific P2Y₁₂receptor subtype. No upregulation of this receptor was detected following induction of TMJ inflammation, suggesting that any possible role of P2Y₁₂in this paradigm of inflammatory pain does not involve changes in receptor expression.</p> <p>Conclusions</p> <p>Our data indicate that specific glial cell populations become activated in both the trigeminal ganglia and the CNS following induction of temporomandibular joint inflammation, and suggest that they might represent innovative targets for controlling pain during trigeminal nerve sensitization.</p

Measuring Low-Order Aberrations in a Segmented Telescope

The in-focus PSF optimizer (IPO) is an algorithm for use in monitoring and controlling the alignment of the segments of a segmented-mirror astronomical telescope. IPO is so named because it computes wave-front aberrations of the telescope from digitized pointspread functions (PSFs) measured in infocus images. Inasmuch as distant astronomical objects that behave optically as point sources can typically be seen in almost any astronomical image, the main benefit afforded by IPO may be to enable maintenance of mirror-segment alignments without detracting from valuable scientific-observation time. IPO evolved from prescription-retrieval type algorithms. Prescription retrieval uses in-focus and out-of-focus PSFs to infer the state of an imaging optical system. The state, in this context, refers to the positions, orientations, and low-order figure errors of the optical elements in the system. Both prescription- retrieval and IPO use an iterative, nonlinear, least-squares optimizer to compute the optimal state parameters such that a digital computer-generated model image matches the digitized image acquired from the real system. The difference between IPO and prescription- retrieval algorithms is that IPO is specifically designed to utilize infocus images only. Although the restriction to in-focus images limits IPO to calculating only the lowest-order wave front aberrations, it also causes the resulting computation to take much less time because fewer degrees of freedom are included in the optimization process. In the prescription retrieval software developed at JPL, the model images are generated using the ray-trace/physical optics program, MACOS. IPO, on the other hand, uses a linear sensitivity matrix to compute the exit-pupil wave front from the system parameters; the wave front is then converted into a complex pupil field, which is then propagated to the image plane via a fast Fourier transform. This approach is computationally faster and requires less computer memory than is needed for prescription retrieval

Advanced Biopolymer-Based Nanocomposites and Hybrid Materials

The exploitation of naturally occurring polymers to engineer advanced nanocomposites and hybrid materials is the focus of increasing scientific activity, explained by growing environmental concerns and interest in the peculiar features and multiple functionalities of these macromolecules. Natural polymers, such as polysaccharides and proteins, present a remarkable potential for the design of all kinds of materials for application in a multitude of domains. This Special Issue collected the work of scientists on the current developments in the field of multifunctional biopolymer-based nanocomposites and hybrid materials with a particular emphasis on their production methodologies, properties, and prominent applications. Thus, materials related to bio-based nanocomposites and hybrid materials manufactured with different partners, namely natural polymers, bioactive compounds, and inorganic nanoparticles, are reported in the Special Issue Advanced Biopolymer-Based Nanocomposites and Hybrid Materials

High and Low Molecular Weight Fluorescein Isothiocyanate (FITC)–Dextrans to Assess Blood-Brain Barrier Disruption: Technical Considerations

This note is to report how histological preparation techniques influence the extravasation pattern of the different molecular sizes of fluorescein isothiocyanate (FITC)–dextrans, typically used as markers for blood-brain barrier leakage. By using appropriate preparation methods, false negative results can be minimized. Wistar rats underwent a 2-h middle cerebral artery occlusion and magnetic resonance imaging. After the last imaging scan, Evans blue and FITC–dextrans of 4, 40, and 70 kDa molecular weight were injected. Different histological preparation methods were used. Sites of blood-brain barrier leakage were analyzed by fluorescence microscopy. Extravasation of Evans blue and high molecular FITC–dextrans (40 and 70 kDa) in the infarcted region could be detected with all preparation methods used. If exposed directly to saline, the signal intensity of these FITC–dextrans decreased. Extravasation of the 4-kDa low molecular weight FITC–dextran could only be detected using freshly frozen tissue sections. Preparations involving paraformaldehyde and sucrose resulted in the 4-kDa FITC–dextran dissolving in these reactants and being washed out, giving the false negative result of no extravasation. FITC–dextrans represent a valuable tool to characterize altered blood-brain barrier permeability in animal models. Diffusion and washout of low molecular weight FITC–dextran can be avoided by direct immobilization through immediate freezing of the tissue. This pitfall needs to be known to avoid the false impression that there was no extravasation of low molecular weight FITC–dextrans

Lipidomics Reveals Early Metabolic Changes in Subjects with Schizophrenia: Effects of Atypical Antipsychotics

There is a critical need for mapping early metabolic changes in schizophrenia to capture failures in regulation of biochemical pathways and networks. This information could provide valuable insights about disease mechanisms, trajectory of disease progression, and diagnostic biomarkers. We used a lipidomics platform to measure individual lipid species in 20 drug-naïve patients with a first episode of schizophrenia (FE group), 20 patients with chronic schizophrenia that had not adhered to prescribed medications (RE group), and 29 race-matched control subjects without schizophrenia. Lipid metabolic profiles were evaluated and compared between study groups and within groups before and after treatment with atypical antipsychotics, risperidone and aripiprazole. Finally, we mapped lipid profiles to n3 and n6 fatty acid synthesis pathways to elucidate which enzymes might be affected by disease and treatment. Compared to controls, the FE group showed significant down-regulation of several n3 polyunsaturated fatty acids (PUFAs), including 20:5n3, 22:5n3, and 22:6n3 within the phosphatidylcholine and phosphatidylethanolamine lipid classes. Differences between FE and controls were only observed in the n3 class PUFAs; no differences where noted in n6 class PUFAs. The RE group was not significantly different from controls, although some compositional differences within PUFAs were noted. Drug treatment was able to correct the aberrant PUFA levels noted in FE patients, but changes in re patients were not corrective. Treatment caused increases in both n3 and n6 class lipids. These results supported the hypothesis that phospholipid n3 fatty acid deficits are present early in the course of schizophrenia and tend not to persist throughout its course. These changes in lipid metabolism could indicate a metabolic vulnerability in patients with schizophrenia that occurs early in development of the disease. © 2013 McEvoy et al

Increased Expression in Dorsolateral Prefrontal Cortex of CAPON in Schizophrenia and Bipolar Disorder

BACKGROUND: We have previously reported linkage of markers on chromosome 1q22 to schizophrenia, a finding supported by several independent studies. Within this linkage region, we have identified significant linkage disequilibrium between schizophrenia and markers within the gene for carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase (CAPON). Prior sequencing of the ten exons of CAPON failed to reveal a coding mutation associated with illness. METHODS AND FINDINGS: We screened a human fetal brain cDNA library and identified a new isoform of CAPON that consists of the terminal two exons of the gene, and verified the expression of the predicted corresponding protein in human dorsolateral prefrontal cortex (DLPFC). We examined the expression levels of both the ten-exon CAPON transcript and this new isoform in postmortem brain samples from the Stanley Array Collection. Quantitative real-time PCR analysis of RNA from the DLPFC in 105 individuals (35 with schizophrenia, 35 with bipolar disorder, and 35 psychiatrically normal controls) revealed significantly (p < 0.005) increased expression of the new isoform in both schizophrenia and bipolar disorder. Furthermore, this increased expression was significantly associated (p < 0.05) with genotype at three single-nucleotide polymorphisms previously identified as being in linkage disequilibrium with schizophrenia. CONCLUSION: Based on the known interactions between CAPON, neuronal nitric oxide synthase (nNOS), and proteins associated with the N-methyl-D-aspartate receptor (NMDAR) complex, overexpression of either CAPON isoform would be expected to disrupt the association between nNOS and the NMDAR, leading to changes consistent with the NMDAR hypofunctioning hypothesis of schizophrenia. This study adds support to a role of CAPON in schizophrenia, produces new evidence implicating this gene in the etiology of bipolar disorder, and suggests a possible mechanism of action of CAPON in psychiatric illness

Hax1 regulates neutrophil adhesion and motility through RhoA

Loss of Hax1, which is associated with a severe congenital neutropenia syndrome, impairs neutrophil uropod detachment and directed migration