Long Noncoding RNAs in Host-Pathogen Interactions.

Long noncoding RNAs (lncRNAs) are key molecules that regulate gene expression in a variety of organisms. LncRNAs can drive different transcriptional and post-transcriptional events that impact cellular functions. Recent studies have identified many lncRNAs associated with immune cell development and activation; however, an understanding of their functional role in host immunity to infection is just emerging. Here, we provide a detailed and updated review of the functional roles of lncRNAs in regulating mammalian immune responses during host-pathogen interactions, because these functions may be either beneficial or detrimental to the host. With increased mechanistic insight into the roles of lncRNAs, it may be possible to design and/or improve lncRNA-based therapies to treat a variety of infectious and inflammatory diseases.

Research on the Methods and Algorithms Improving the Measurements Precision and Market Competitive Advantages of Fiber Optic Current Sensors.

An electromagnetic instrument transformer is a common device used to measure large current values in high-voltage electrical networks; it has been in use for more than a century. However, the optical current transformer, a promising technology also known as a fiber optic current sensor (FOCS), offers increased safety and ease of operation, as well as the absence of errors caused by the magnetic circuit of legacy transformers. Although the FOCS scheme is well known and has been actively developed for over a quarter century, it has certain disadvantages that limit its use. This paper describes the authors' efforts to solve these problems in order to make FOCS technology competitive and widely adopted. We upgraded the FOCS optical circuit, expanded the frequency band of the captured current signal, and reduced the solution's cost. We designed new signal processing algorithms to compensate for errors caused by internal factors in the measurement circuit, as well as those caused by environmental influences. We developed an FOCS computer model based on the Jones matrix formalism to enhance the experimental debugging. It allowed us to define the requirements for elements of the optical circuit and its production accuracy.

Temporal Derivative Distribution Repair (TDDR): A motion correction method for fNIRS.

Functional near-infrared spectroscopy (fNIRS) is an optical neuroimaging technique of growing interest as a tool for investigation of cortical activity. Due to the on-head placement of optodes, artifacts arising from head motion are relatively less severe than for functional magnetic resonance imaging (fMRI). However, it is still necessary to remove motion artifacts. We present a novel motion correction procedure based on robust regression, which effectively removes baseline shift and spike artifacts without the need for any user-supplied parameters. Our simulations show that this method yields better activation detection performance than 5 other current motion correction methods. In our empirical validation on a working memory task in a sample of children 7-15 years, our method produced stronger and more extensive activation than any of the other methods tested. The new motion correction method enhances the viability of fNIRS as a functional neuroimaging modality for use in populations not amenable to fMRI.

E3 ubiquitin ligases Pellinos as regulators of pattern recognition receptor signaling and immune responses.

Pellinos are a family of E3 ubiquitin ligases discovered for their role in catalyzing K63-linked polyubiquitination of Pelle, an interleukin-1 (IL-1) receptor-associated kinase homolog in the Drosophila Toll pathway. Subsequent studies have revealed the central and non-redundant roles of mammalian Pellino-1, Pellino-2, and Pelino-3 in signaling pathways emanating from IL-1 receptors, Toll-like receptors, NOD-like receptors, T- and B-cell receptors. While Pellinos ability to interact with many signaling intermediates suggested their scaffolding roles, recent findings in mice expressing ligase-inactive Pellinos demonstrated the importance of Pellino ubiquitin ligase activity. Cell-specific functions of Pellinos have emerged, e.g. Pellino-1 being a negative regulator in T lymphocytes and a positive regulator in myeloid cells, and details of molecular regulation of receptor signaling by various members of the Pellino family have been revealed. In this review, we summarize current information about Pellino-mediated regulation of signaling by pattern recognition receptors, T-cell and B-cell receptors and tumor necrosis factor receptors, and discuss Pellinos roles in sepsis and infectious diseases, as well as in autoimmune, inflammatory, and allergic disorders. We also provide our perspective on the potential of targeting Pellinos with peptide- or small molecule-based drug compounds as a new therapeutic approach for septic shock and autoimmune pathologies.

The R753Q polymorphism in Toll-like receptor 2 (TLR2) attenuates innate immune responses to mycobacteria and impairs MyD88 adapter recruitment to TLR2.

Toll-like receptor 2 (TLR2) plays a critical role in host defenses against mycobacterial infections. The R753Q TLR2 polymorphism has been associated with increased incidence of tuberculosis and infections with non-tuberculous mycobacteria in human populations, but the mechanisms by which this polymorphism affects TLR2 signaling are unclear. In this study, we determined the impact of the R753Q TLR2 polymorphism on macrophage sensing of Mycobacterium smegmatis Upon infection with M. smegmatis, macrophages from knock-in mice harboring R753Q TLR2 expressed lower levels of TNF-α, IL-1ß, IL-6, and IL-10 compared with cells from WT mice, but both R753Q TLR2- and WT-derived macrophages exhibited comparable bacterial burdens. The decreased cytokine responses in R753Q TLR2-expressing macrophages were accompanied by impaired phosphorylation of IL-1R-associated kinase 1 (IRAK-1), p38, ERK1/2 MAPKs, and p65 NF-κB, suggesting that the R753Q TLR2 polymorphism alters the functions of the myeloid differentiation primary response protein 88 (MyD88)-IRAK-dependent signaling axis. Supporting this notion, HEK293 cells stably transfected with YFP-tagged R753Q TLR2 displayed reduced recruitment of MyD88 to TLR2, decreased NF-κB activation, and impaired IL-8 expression upon exposure to M. smegmatis Collectively, our results indicate that the R753Q polymorphism alters TLR2 signaling competence, leading to impaired MyD88-TLR2 assembly, reduced phosphorylation of IRAK-1, diminished activation of MAPKs and NF-κB, and deficient induction of cytokines in macrophages infected with M. smegmatis.

Deficiency in IRAK4 activity attenuates manifestations of murine Lupus.

Interleukin-1 receptor-associated kinase (IRAK) 4 mediates host defense against infections. As an active kinase, IRAK4 elicits full spectra of myeloid differentiation primary response protein (MyD) 88-dependent responses, while kinase-inactive IRAK4 induces a subset of cytokines and negative regulators whose expression is not regulated by mRNA stability. IRAK4 kinase activity is critical for resistance against Streptococcus pneumoniae, but its involvement in autoimmunity is incompletely understood. In this study, we determined the role of IRAK4 kinase activity in murine lupus. Lupus development in BXSB mice expressing the Y chromosome autoimmunity accelerator (Yaa) increased basal and Toll-like receptor (TLR) 4/7-induced phosphorylation of mitogen-activated protein kinases, p65 nuclear factor-κB (NF-κB), enhanced tumor necrosis factor (TNF)-α and C-C motif chemokine ligand (CCL) 5 gene expression in splenic macrophages, but decreased levels of Toll-interacting protein and IRAK-M, without affecting IRAK4 or IRAK1 expression. Mice harboring kinase-inactive IRAK4 on the lupus-prone Yaa background manifested blunted TLR signaling in macrophages and reduced glomerulonephritis, splenomegaly, serum anti-nuclear antibodies, numbers of splenic macrophages, total and TNF-α+ dendritic cells, activated T- and B-lymphocytes, and lower TNF-α expression in macrophages compared with lupus-prone mice with functional IRAK4. Thus, IRAK4 kinase activity contributes to murine lupus and could represent a new therapeutic target.

Signal detection algorithms for interferometric sensors with harmonic phase modulation: distortion analysis and suppression.

In the current paper, distortions in digital demodulation schemes with harmonic phase modulation for interferometric optical sensors are considered. In particular, the influence of target signal variations on phase demodulation errors is theoretically evaluated. An analytical expression describing the phase error magnitude dependence on the first derivative and mean value of the measured signal and amplitude of the phase modulation in the case of a simple 4-point demodulation algorithm is derived. After that, an approach for synthesizing algorithms with suppressed sensitivity to target signal variations is developed. Based on this approach, a novel 4+1 demodulation algorithm is proposed. It is shown analytically that the demodulation error of the new 4+1 algorithm is proportional to the second derivative of the target signal, and therefore, is typically several orders of magnitude smaller than in the case of the 4-point algorithm. The correspondence between analytical expressions and real phase errors induced by target signal variations is verified by means of numeric simulation.

Pellino-1 Positively Regulates Toll-like Receptor (TLR) 2 and TLR4 Signaling and Is Suppressed upon Induction of Endotoxin Tolerance.

Endotoxin tolerance reprograms Toll-like receptor (TLR) 4-mediated macrophage responses by attenuating induction of proinflammatory cytokines while retaining expression of anti-inflammatory and antimicrobial mediators. We previously demonstrated deficient TLR4-induced activation of IL-1 receptor-associated kinase (IRAK) 4, IRAK1, and TANK-binding kinase (TBK) 1 as critical hallmarks of endotoxin tolerance, but mechanisms remain unclear. In this study, we examined the role of the E3 ubiquitin ligase Pellino-1 in endotoxin tolerance and TLR signaling. LPS stimulation increased Pellino-1 mRNA and protein expression in macrophages from mice injected with saline and in medium-pretreated human monocytes, THP-1, and MonoMac-6 cells, whereas endotoxin tolerization abrogated LPS inducibility of Pellino-1. Overexpression of Pellino-1 in 293/TLR2 and 293/TLR4/MD2 cells enhanced TLR2- and TLR4-induced nuclear factor κB (NF-κB) and expression of IL-8 mRNA, whereas Pellino-1 knockdown reduced these responses. Pellino-1 ablation in THP-1 cells impaired induction of myeloid differentiation primary response protein (MyD88), and Toll-IL-1R domain-containing adapter inducing IFN-ß (TRIF)-dependent cytokine genes in response to TLR4 and TLR2 agonists and heat-killed Escherichia coli and Staphylococcus aureus, whereas only weakly affecting phagocytosis of heat-killed bacteria. Co-expressed Pellino-1 potentiated NF-κB activation driven by transfected MyD88, TRIF, IRAK1, TBK1, TGF-ß-activated kinase (TAK) 1, and TNFR-associated factor 6, whereas not affecting p65-induced responses. Mechanistically, Pellino-1 increased LPS-driven K63-linked polyubiquitination of IRAK1, TBK1, TAK1, and phosphorylation of TBK1 and IFN regulatory factor 3. These results reveal a novel mechanism by which endotoxin tolerance re-programs TLR4 signaling via suppression of Pellino-1, a positive regulator of MyD88- and TRIF-dependent signaling that promotes K63-linked polyubiquitination of IRAK1, TBK1, and TAK1.

Does the resting state connectivity have hemispheric asymmetry? A near-infrared spectroscopy study.

Near-infrared spectroscopy (NIRS) is a novel technology for low-cost noninvasive brain imaging suitable for use in virtually all subject and patient populations. Numerous studies of brain functional connectivity using fMRI, and recently NIRS, suggest new tools for the assessment of cognitive functions during task performance and the resting state (RS). We analyzed functional connectivity and its possible hemispheric asymmetry measuring coherence of optical signals at low frequencies (0.01-0.1 Hz) in the prefrontal cortex in 13 right-handed (RH) and 2 left-handed (LH) healthy subjects at rest (4-8 min) using a continuous-wave NIRS instrument CW5 (TechEn, Milford, MA). Two optical probes were placed bilaterally over the inferior frontal gyrus (IFG) and the middle frontal gyrus (MFG) using anatomical landmarks of the 10-20 system. As a result, 28 optical channels (14 for each hemisphere) were recorded for changes in oxygenated (HbO) and de-oxygenated (HbR) hemoglobin. Global physiological signals (respiratory and cardiac) were removed using Principal and Independent Component Analyses. Inter-channel coherences for HbO and HbR signals were calculated using Morlet wavelets along with correlation coefficients. Connectivity matrices showed specific patterns of connectivity which was higher within each anatomical region (IFG and MFG) and between hemispheres (e.g., left IFG<->right IFG) than between IFG and MFG in the same hemisphere. Laterality indexes were calculated as t-values for the 'left>right' comparisons of intrinsic connectivity within each regional group of channels in each subject. Regardless of handedness, the group average laterality indexes were negative thus revealing significantly higher connectivity in the right hemisphere in the majority of RH subjects and in both LH subjects. The analysis of Granger causality between hemispheres has also shown a greater flow of information from the right to the left hemisphere which may point to an important role of the right hemisphere in the resting state. These data encourage further exploration of the NIRS connectivity and its application for the analysis of hemispheric relationships within the functional architecture of the brain.

The Asp299Gly polymorphism alters TLR4 signaling by interfering with recruitment of MyD88 and TRIF.

Asp(299)Gly (D299G) and, to a lesser extent, Thr(399)Ile (T399I) TLR4 polymorphisms have been associated with gram-negative sepsis and other infectious diseases, but the mechanisms by which they affect TLR4 signaling are unclear. In this study, we determined the impact of the D299G and T399I polymorphisms on TLR4 expression, interactions with myeloid differentiation factor 2 (MD2), LPS binding, and LPS-mediated activation of the MyD88- and Toll/IL-1R resistance domain-containing adapter inducing IFN-ß (TRIF) signaling pathways. Complementation of human embryonic kidney 293/CD14/MD2 transfectants with wild-type (WT) or mutant yellow fluorescent protein-tagged TLR4 variants revealed comparable total TLR4 expression, TLR4-MD2 interactions, and LPS binding. FACS analyses with anti-TLR4 Ab showed only minimal changes in the cell-surface levels of the D299G TLR4. Cells transfected with D299G TLR4 exhibited impaired LPS-induced phosphorylation of p38 and TANK-binding kinase 1, activation of NF-κB and IFN regulatory factor 3, and induction of IL-8 and IFN-ß mRNA, whereas T399I TLR4 did not cause statistically significant inhibition. In contrast to WT TLR4, expression of the D299G mutants in TLR4(-/-) mouse macrophages failed to elicit LPS-mediated induction of TNF-α and IFN-ß mRNA. Coimmunoprecipitation revealed diminished LPS-driven interaction of MyD88 and TRIF with the D299G TLR4 species, in contrast to robust adapter recruitment exhibited by WT TLR4. Thus, the D299G polymorphism compromises recruitment of MyD88 and TRIF to TLR4 without affecting TLR4 expression, TLR4-MD2 interaction, or LPS binding, suggesting that it interferes with TLR4 dimerization and assembly of intracellular docking platforms for adapter recruitment.

The detection of absence seizures using cross-frequency coupling analysis with a deep learning network.

High frequency oscillations are important novel biomarkers of epileptogenic tissue. The interaction of oscillations across different time scales is revealed as cross-frequency coupling (CFC) representing a high-order structure in the functional organization of brain rhythms. New artificial intelligence methods such as deep learning neural networks can provide powerful tools for automated analysis of EEG. Here we present a Stacked Sparse Autoencoder (SSAE) trained to recognize absence seizure activity based on the cross-frequency patterns within scalp EEG. We used EEG records from the Temple University Hospital database. Absence seizures (n = 94) from 12 patients were taken into analysis along with segments of background activity. Half of the records were selected randomly for network training and the second half were used for testing. Power-to-power coupling was calculated between all frequencies 2-120 Hz pairwise using the EEGLAB toolbox. The resulting CFC matrices were used as training or testing inputs to the autoencoder. The trained network was able to recognize background and seizure segments (not used in training) with a sensitivity of 96.3%, specificity of 99.8% and overall accuracy of 98.5%. Our results provide evidence that the SSAE neural networks can be used for automated detection of absence seizures within scalp EEG.

R753Q polymorphism inhibits Toll-like receptor (TLR) 2 tyrosine phosphorylation, dimerization with TLR6, and recruitment of myeloid differentiation primary response protein 88.

The R753Q polymorphism in the Toll-IL-1 receptor domain of Toll-like receptor 2 (TLR2) has been linked to increased incidence of tuberculosis and other infectious diseases, but the mechanisms by which it affects TLR2 functions are unclear. Here, we studied the impact of the R753Q polymorphism on TLR2 expression, hetero-dimerization with TLR6, tyrosine phosphorylation, and recruitment of myeloid differentiation primary response protein (MyD) 88 and MyD88 adapter-like (Mal). Complementation of HEK293 cells with transfected WT or R753Q TLR2 revealed their comparable total levels and only minimal changes in cell surface expression of the mutant species. Notably, even a 100-fold increase in amounts of transfected R753Q TLR2 versus WT variant did not overcome the compromised ability of the mutant TLR2 to activate nuclear factor κB (NF-κB), indicating that a minimal decrease in cell surface levels of the R753Q TLR2 cannot account for the signaling deficiency. Molecular modeling studies suggested that the R753Q mutation changes the electrostatic potential of the DD loop and results in a discrete movement of the residues critical for protein-protein interactions. Confirming these predictions, biochemical assays demonstrated that R753Q TLR2 exhibits deficient agonist-induced tyrosine phosphorylation, hetero-dimerization with TLR6, and recruitment of Mal and MyD88. These proximal signaling deficiencies correlated with impaired capacities of the R753Q TLR2 to mediate p38 phosphorylation, NF-κB activation, and induction of IL-8 mRNA in transfected HEK293 cells challenged with inactivated Mycobacterium tuberculosis or mycobacterial components. Thus, the R753Q polymorphism renders TLR2 signaling-incompetent by impairing its tyrosine phosphorylation, dimerization with TLR6, and recruitment of Mal and MyD88.

Capturing dynamic patterns of task-based functional connectivity with EEG.

A new approach to trace the dynamic patterns of task-based functional connectivity, by combining signal segmentation, dynamic time warping (DTW), and Quality Threshold (QT) clustering techniques, is presented. Electroencephalography (EEG) signals of 5 healthy subjects were recorded as they performed an auditory oddball and a visual modified oddball tasks. To capture the dynamic patterns of functional connectivity during the execution of each task, EEG signals are segmented into durations that correspond to the temporal windows of previously well-studied event-related potentials (ERPs). For each temporal window, DTW is employed to measure the functional similarities among channels. Unlike commonly used temporal similarity measures, such as cross correlation, DTW compares time series by taking into consideration that their alignment properties may vary in time. QT clustering analysis is then used to automatically identify the functionally connected regions in each temporal window. For each task, the proposed approach was able to establish a unique sequence of dynamic pattern (observed in all 5 subjects) for brain functional connectivity.

Pathogenic Old World arenaviruses inhibit TLR2/Mal-dependent proinflammatory cytokines in vitro.

Lymphocytic choriomeningitis virus (LCMV), the prototype arenavirus, and Lassa virus (LASV), the causative agent of Lassa fever (LF), have extensive strain diversity and significant variations in pathogenicity for humans and experimental animals. The WE strain of LCMV (LCMV-WE), but not the Armstrong (Arm) strain, induces a fatal LF-like disease in rhesus macaques. We also demonstrated that LASV infection of human macrophages and endothelial cells resulted in reduced levels of proinflammatory cytokines. Here we have shown that cells infected with LASV or with LCMV-WE suppressed Toll-like receptor 2 (TLR2)-dependent proinflammatory cytokine responses. The persisting isolate LCMV clone 13 (CL13) also failed to stimulate interleukin-6 (IL-6) in macrophages. In contrast, nonpathogenic Mopeia virus, which is a genetic relative of LASV and LCMV-Arm induced robust responses that were TLR2/Mal dependent, required virus replication, and were enhanced by CD14. Superinfection experiments demonstrated that the WE strain of LCMV inhibited the Arm-mediated IL-8 response during the early stage of infection. In cells transfected with the NF-κB-luciferase reporter, infection with LCMV-Arm resulted in the induction of NF-κB, but cells infected with LCMV-WE and CL13 did not. These results suggest that pathogenic arenaviruses suppress NF-κB-mediated proinflammatory cytokine responses in infected cells.

Endotoxin tolerance impairs IL-1 receptor-associated kinase (IRAK) 4 and TGF-beta-activated kinase 1 activation, K63-linked polyubiquitination and assembly of IRAK1, TNF receptor-associated factor 6, and IkappaB kinase gamma and increases A20 expression.

Endotoxin tolerance reprograms Toll-like receptor 4 responses by impairing LPS-elicited production of pro-inflammatory cytokines without inhibiting expression of anti-inflammatory or anti-microbial mediators. In septic patients, Toll-like receptor tolerance is thought to underlie decreased pro-inflammatory cytokine expression in response to LPS and increased incidence of microbial infections. The impact of endotoxin tolerance on recruitment, post-translational modifications and signalosome assembly of IL-1 receptor-associated kinase (IRAK) 4, IRAK1, TNF receptor-associated factor (TRAF) 6, TGF-ß-activated kinase (TAK) 1, and IκB kinase (IKK) γ is largely unknown. We report that endotoxin tolerization of THP1 cells and human monocytes impairs LPS-mediated receptor recruitment and activation of IRAK4, ablates K63-linked polyubiquitination of IRAK1 and TRAF6, compromises assembly of IRAK1-TRAF6 and IRAK1-IKKγ platforms, and inhibits TAK1 activation. Deficiencies in these signaling events in LPS-tolerant cells coincided with increased expression of A20, an essential deubiquitination enzyme, and sustained A20-IRAK1 associations. Overexpression of A20 inhibited LPS-induced activation of NF-κB and ablated NF-κB reporter activation driven by ectopic expression of MyD88, IRAK1, IRAK2, TRAF6, and TAK1/TAB1, while not affecting the responses induced by IKKß and p65. A20 shRNA knockdown abolished LPS tolerization of THP1 cells, mechanistically linking A20 and endotoxin tolerance. Thus, deficient LPS-induced activation of IRAK4 and TAK1, K63-linked polyubiquitination of IRAK1 and TRAF6, and disrupted IRAK1-TRAF6 and IRAK1-IKKγ assembly associated with increased A20 expression and A20-IRAK1 interactions are new determinants of endotoxin tolerance.

Assessment of Cognitive Reserve using Near Infrared Spectroscopy.

Cognitive reserve (CR) is the ability to preserve cognitive functions in the presence of brain pathology. In the context of Alzheimer's disease (AD), patients with higher CR show better cognitive performance relative to brain damage therefore higher CR reduces the risk of dementia. There is a strong need to develop a neurophysiological biomarker of CR given the growing interest in understanding protective brain mechanisms in AD. FMRI studies indicate that frontoparietal network plays an important role in cognitive reserve. We calculated intraregional functional connectivity of lateral prefrontal cortex (FC LPFC) using functional near infrared spectroscopy (fNIRS) in the resting state of 13 healthy individuals who were also assessed for IQ and motoric skills (the Purdue Pegboard test, PPT). FC LPFC was found to positively correlate with IQ (a proxy measure of cognitive reserve) while showing a lack of or negative correlation with the PPT scores. The results demonstrate that the cost-effective, noninvasive and widely applicable fNIRS technology can be used to evaluate cognitive reserve in individuals at risk for and patients with AD with possible numerous applications in the context of healthy aging and other age-related cognitive disorders.

Motor engagement relates to accurate perception of phonemes and audiovisual words, but not auditory words.

A longstanding debate has surrounded the role of the motor system in speech perception, but progress in this area has been limited by tasks that only examine isolated syllables and conflate decision-making with perception. Using an adaptive task that temporally isolates perception from decision-making, we examined an EEG signature of motor activity (sensorimotor µ/beta suppression) during the perception of auditory phonemes, auditory words, audiovisual words, and environmental sounds while holding difficulty constant at two levels (Easy/Hard). Results revealed left-lateralized sensorimotor µ/beta suppression that was related to perception of speech but not environmental sounds. Audiovisual word and phoneme stimuli showed enhanced left sensorimotor µ/beta suppression for correct relative to incorrect trials, while auditory word stimuli showed enhanced suppression for incorrect trials. Our results demonstrate that motor involvement in perception is left-lateralized, is specific to speech stimuli, and it not simply the result of domain-general processes. These results provide evidence for an interactive network for speech perception in which dorsal stream motor areas are dynamically engaged during the perception of speech depending on the characteristics of the speech signal. Crucially, this motor engagement has different effects on the perceptual outcome depending on the lexicality and modality of the speech stimulus.

A mouse model of human TLR4 D299G/T399I SNPs reveals mechanisms of altered LPS and pathogen responses.

Two cosegregating single-nucleotide polymorphisms (SNPs) in human TLR4, an A896G transition at SNP rs4986790 (D299G) and a C1196T transition at SNP rs4986791 (T399I), have been associated with LPS hyporesponsiveness and differential susceptibility to many infectious or inflammatory diseases. However, many studies failed to confirm these associations, and transfection experiments resulted in conflicting conclusions about the impact of these SNPs on TLR4 signaling. Using advanced protein modeling from crystallographic data of human and murine TLR4, we identified homologous substitutions of these SNPs in murine Tlr4, engineered a knock-in strain expressing the D298G and N397I TLR4 SNPs homozygously, and characterized in vivo and in vitro responses to TLR4 ligands and infections in which TLR4 is implicated. Our data provide new insights into cellular and molecular mechanisms by which these SNPs decrease the TLR4 signaling efficiency and offer an experimental approach to confirm or refute human data possibly confounded by variables unrelated to the direct effects of the SNPs on TLR4 functionality.

Distinct mutations in IRAK-4 confer hyporesponsiveness to lipopolysaccharide and interleukin-1 in a patient with recurrent bacterial infections.

We identified previously a patient with recurrent bacterial infections who failed to respond to gram-negative LPS in vivo, and whose leukocytes were profoundly hyporesponsive to LPS and IL-1 in vitro. We now demonstrate that this patient also exhibits deficient responses in a skin blister model of aseptic inflammation. A lack of IL-18 responsiveness, coupled with diminished LPS and/or IL-1-induced nuclear factor-kappaB and activator protein-1 translocation, p38 phosphorylation, gene expression, and dysregulated IL-1R-associated kinase (IRAK)-1 activity in vitro support the hypothesis that the defect lies within the signaling pathway common to toll-like receptor 4, IL-1R, and IL-18R. This patient expresses a "compound heterozygous" genotype, with a point mutation (C877T in cDNA) and a two-nucleotide, AC deletion (620-621del in cDNA) encoded by distinct alleles of the IRAK-4 gene (GenBank/EMBL/DDBJ accession nos. AF445802 and AY186092). Both mutations encode proteins with an intact death domain, but a truncated kinase domain, thereby precluding expression of full-length IRAK-4 (i.e., a recessive phenotype). When overexpressed in HEK293T cells, neither truncated form augmented endogenous IRAK-1 kinase activity, and both inhibited endogenous IRAK-1 activity modestly. Thus, IRAK-4 is pivotal in the development of a normal inflammatory response initiated by bacterial or nonbacterial insults.

Possible therapeutic effects of transcutaneous electrical stimulation via concentric ring electrodes.

Even with the latest advancements in antiepileptic drugs (AEDs) there are still many persons whose seizures are not controlled. There are also side effects reported associated with the AEDs. Electrical stimulation of the brain has shown promise toward controlling seizures. However, most brain stimulation techniques involve invasive procedures to implant electrodes and electronic stimulators. There are no conclusive descriptions of where to place the implanted electrodes to control seizures. Noninvasive electrical stimulation does not require the risks of implantation, and the electrodes can be moved easily as needed to determine where they may be the most effective in reducing seizure activity. Herein we review the progress of our group in the development of noninvasive electrical stimulation via concentric ring electrodes to control seizures in rats induced by penicillin G, pilocarpine, and pentylenetetrazole (PTZ).