Trafficking patterns of NMDA and GABA_A receptors in a Mg²⁺-free cultured hippocampal neuron model of status epilepticus

Cho, Y.J.,Kim, H.,Kim, W.J.,Chung, S.,Kim, Y.H.,Cho, I.,Lee, B.I.,Heo, K. Elsevier Science Publishers, Biomedical Division 2017 Epilepsy research Vol.136 No.-

An altered pattern of receptor trafficking is one of the pathophysiologic mechanisms of status epilepticus (SE). The gradual internalization of GABA<SUB>A</SUB> receptors (GABARs) occurs in both in vitro and in vivo models of SE and is thought to be a cause of decreased GABAergic inhibition. Unlike GABARs, little is known about alterations in NMDA receptor (NMDAR) trafficking during SE, even though increased activity of NMDARs is indispensable for the induction and maintenance of SE. Therefore, we aimed to simultaneously investigate the changes in the trafficking patterns of GABARs and NMDARs in an in vitro cultured hippocampal neuron model of SE. For induction of epileptiform discharges, hippocampal neurons were exposed to external medium without Mg<SUP>2+</SUP>. Biotinylation assay and immunofluorescence staining for GABAR β2,3 and NMDAR NR1 subunits were performed to quantify and visualize surface GABARs and NMDARs, respectively. The frequency of spontaneous action potentials increased more than 4-fold after Mg<SUP>2+</SUP>-free induction. The level of surface GABARs decreased over time after Mg<SUP>2+</SUP>-free induction, dropping to approximately 50% of control levels an hour after Mg<SUP>2+</SUP>-free induction. By contrast, the trafficking of NMDARs to the surface was enhanced after a slight time lag, increasing by 30% of control levels an hour after Mg<SUP>2+</SUP>-free induction. Our data showed the changes of both NMDAR and GABAR trafficking during prolonged SE induced by a Mg<SUP>2+</SUP>-free extracellular environment and confirmed that this in vitro SE model is suitable for examining alterations in the receptor trafficking pattern by prolonged seizure activity. These results suggest that targeting of surface NMDAR could be a promising method in controlling benzodiazepine-resistant SE.

The effect of transcranial direct current stimulation on auditory hallucination in patients with schizophrenia

Lee, Tae Young,Lee, Junhee,Kim, Minah,Kwon, Jun Soo ELSEVIER SCIENCE DIVISION 2018 Schizophrenia Research Vol.192 No.-

Different alterations in brain functional networks according to direct and indirect topological connections in patients with schizophrenia

Park, Chang-hyun,Lee, Seungyup,Kim, Taewon,Won, Wang Yeon,Lee, Kyoung-Uk ELSEVIER SCIENCE DIVISION 2017 Schizophrenia Research Vol.188 No.-

<P><B>Abstract</B></P> <P>Schizophrenia displays connectivity deficits in the brain, but the literature has shown inconsistent findings about alterations in global efficiency of brain functional networks. We supposed that such inconsistency at the whole brain level may be due to a mixture of different portions of global efficiency at sub-brain levels. Accordingly, we considered measuring portions of global efficiency in two aspects: spatial portions by considering sub-brain networks and topological portions by considering contributions to global efficiency according to direct and indirect topological connections. We proposed adjacency and indirect adjacency as new network parameters attributable to direct and indirect topological connections, respectively, and applied them to graph-theoretical analysis of brain functional networks constructed from resting state fMRI data of 22 patients with schizophrenia and 22 healthy controls. Group differences in the network parameters were observed not for whole brain and hemispheric networks, but for regional networks. Alterations in adjacency and indirect adjacency were in opposite directions, such that adjacency increased, but indirect adjacency decreased in patients with schizophrenia. Furthermore, over connections in frontal and parietal regions, increased adjacency was associated with more severe negative symptoms, while decreased adjacency was associated with more severe positive symptoms of schizophrenia. This finding indicates that connectivity deficits associated with positive and negative symptoms of schizophrenia may involve topologically different paths in the brain. In patients with schizophrenia, although changes in global efficiency may not be clearly shown, different alterations in brain functional networks according to direct and indirect topological connections could be revealed at the regional level.</P>

Shared co-expression networks in frontal cortex of the normal aged brain and schizophrenia

Kim, Sanghyeon,Jo, Yousang,Webster, Maree J.,Lee, Doheon ELSEVIER SCIENCE DIVISION 2019 Schizophrenia Research Vol.204 No.-

<P><B>Abstract</B></P> <P>Previous studies on the brain of people with schizophrenia have identified structural changes and gene expression changes, suggesting that brain aging maybe accelerated in people with schizophrenia. To better characterize gene expression profiles in schizophrenia and in the aged population we constructed co-expression networks using RNA-Seq data from frontal cortex. The first data set analysed was from 62 subjects with schizophrenia and 51 unaffected controls ranging in age from 19 to 63 years. The second separate data set was from normal control individuals ranging in age from 29 to 106 years. In the first data set, we found two co-expression modules significantly associated with schizophrenia. One was a downregulated co-expression module enriched for neuron function related genes and the other was an upregulated immune/inflammation-related module. In the second data set of normal individuals, we found seven co-expression modules significantly correlated with age. A comparison of the co-expression modules from the two data sets revealed a significant consensus in nodes associated with schizophrenia and those associated with normal aging. The results indicate that a co-expression module related to neuronal function is downregulated and an immune/inflammation related co-expression module is upregulated, and associated with cells of the blood vessels, in both schizophrenia and in normal aging. This finding adds further support to the hypothesis that there may be accelerated brain aging in schizophrenia.</P>

Multiplex real-time polymerase chain reaction for the differential detection of porcine circovirus 2 and 3

Kim, H.R.,Park, Y.R.,Lim, D.R.,Park, M.J.,Park, J.Y.,Kim, S.H.,Lee, K.K.,Lyoo, Y.S.,Park, C.K. ELSEVIER SCIENCE DIVISION 2017 JOURNAL OF VIROLOGICAL METHODS Vol.250 No.-

A multiplex quantitative real-time polymerase chain reaction (mqPCR) assay was developed for the rapid and differential detection of porcine circovirus 2 (PCV2) and PCV3. Each of the capsid genes of PCV2 and PCV3 were amplified using specific primers and probe sets, while no other porcine pathogen genes were detected. Limit of detection of the assay was below 50 copies of the target genes of PCV2 and PCV3, and was comparable to that of previously described methods The assay showed high repeatability and reproducibility, with coefficients of intra-assay and inter-assay variation of less than 4.0%. Clinical evaluation using tissue samples from a domestic pig farm showed that PCV2 and PCV3 co-circulated at the farm. Moreover, singular infection rates of PCV2 or PCV3 were 21.7% (10/46) or 6.5% (¾6), respectively, while the co-infection rate of PCV3 with PCV2 was 28.3% (1¾6). PCV3 DNA was detected by the mqPCR in respiratory diseased piglet tissue samples and aborted fetal tissue samples, suggesting that PCV3 infection is associated with porcine respiratory disease and reproductive failure in the pig farm. This mqPCR method is a rapid and reliable differential diagnostic tool for the monitoring and surveillance of PCV2 and PCV3 in the field.

Intracellular pathogens go extreme: genome evolution in the Rickettsiales

Darby, A.C.,Cho, N.H.,Fuxelius, H.H.,Westberg, J.,Andersson, S.G.E. Elsevier Science Publishers (Biomedical Division) 2007 Trends in genetics Vol.23 No.10

The Rickettsiales, a genetically diverse group of the α-Proteobacteria, include major mammalian pathogens, such as the agents of epidemic typhus, scrub typhus, ehrlichioses and heartwater disease. Sequenced genomes of this bacterial order have provided exciting insights into reductive genome evolution, antigenic variation and host cell manipulation. Recent results suggest that human pathogens emerged relatively late in the evolution of the Rickettsiales. Surprisingly, there is no association between pathogenicity and the acquisition of novel virulence genes. Here, we explore the genomic differences between members of the Rickettsiales and ask what are the changes that enable infectious agents to emerge from seemingly harmless bacteria.

An improved reverse transcription loop-mediated isothermal amplification assay for sensitive and specific detection of serotype O foot-and-mouth disease virus

Lim, Da-Rae,Kim, Hye-Ryung,Park, Min-Ji,Chae, Ha-Gyeong,Ku, Bok-Kyung,Nah, Jin-Ju,Ryoo, So-Yoon,Wee, Sung-Hwan,Park, Yu-Ri,Jeon, Hyo-Sung,Kim, Ji-Jeong,Jeon, Bo-Young,Lee, Hyeong-Woo,Yeo, Sang-Geon,Pa ELSEVIER SCIENCE DIVISION 2018 JOURNAL OF VIROLOGICAL METHODS Vol.260 No.-

<P><B>Abstract</B></P> <P>A sensitive and specific swarm primer-based reverse transcription loop-mediated isothermal amplification (sRT-LAMP) assay for the detection of serotype O foot-and-mouth disease virus (FMDV) was developed and evaluated. The assay specifically amplified the <I>VP3</I> gene of serotype O FMDV, but did not amplify the <I>VP3</I> gene of other serotype FMDVs or any other viruses. The limit of detection of the assay was 10<SUP>2</SUP> TCID<SUB>50</SUB>/mL or 10<SUP>3</SUP> RNA copies/μL, which is 100 times lower than that of the RT-LAMP assay without swarm primers. The new assay is 10 times more sensitive than reverse transcription-polymerase chain reaction (RT-PCR) and is comparable to the sensitivity of real time RT-PCR (qRT-PCR). Evaluation of the assay using different serotypes of FMDV strains showed 100% agreement with the RT-PCR results. The previously reported serotype O FMDV-specific RT-LAMP assay did not detect 20 out of 22 strains of serotype O FMDVs, probably due to multiple mismatches between the primer and template sequences, showing that it is not suitable for detecting the serotype O FMDVs circulating in Pool 1 region countries, including Korea. In contrast, the developed sRT-LAMP assay with improved primers can rapidly and accurately diagnose serotype O FMDVs circulating in Pool 1 region countries and will be a useful alternative to RT-PCR and qRT-PCR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A swarm primer-applied RT-LAMP assay was developed for the detection of serotype O FMDV. </LI> <LI> The assay was 10 times more sensitive than RT-PCR and comparable to the sensitivity of qRT-PCR. </LI> <LI> The swarm primer RT-LAMP assay showed 100% agreement with conventional RT-PCR. </LI> </UL> </P>

Development of rapid and highly sensitive detection of Bean common mosaic necrosis virus in leguminous crops using loop-mediated isothermal amplification assay

Lee, S.,Kim, H.,Lee, J.Y.,Rho, J.Y. ELSEVIER SCIENCE DIVISION 2017 JOURNAL OF VIROLOGICAL METHODS Vol.249 No.-

Bean common mosaic necrosis virus (BCMNV) is a plant pathogenic virus that can infect leguminous crops such as kidney beans, sunn hemp, red beans, and mung beans. BCMNV has not been reported in Korea and is classified as a quarantine plant virus. Currently, the standard diagnostic method for diagnosis of BCMNV is reverse transcription (RT)-nested PCR system. However a more rapid monitoring system is needed to enable the testing of more samples. The use of highly efficient loop-mediated isothermal amplification (LAMP) assay for its detection has not yet been reported, and development of LAMP for detecting BCMNV in this study. In addition, confirmation of LAMP amplification can be achieved using restriction enzyme Mse I (T/TAA). The developed technique could be used for more rapid, specific and sensitive monitoring of BCMNV in leguminous crops than conventional nested RT-PCR.

The effect of tDCS on auditory hallucination and P50 sensory gating in patients with schizophrenia: A pilot study

Kim, Minah,Yoon, Youngwoo Bryan,Lee, Tak Hyung,Lee, Tae Young,Kwon, Jun Soo ELSEVIER SCIENCE DIVISION 2018 Schizophrenia Research Vol.192 No.-

Increased diffusivity in gray matter in recent onset schizophrenia is associated with clinical symptoms and social cognition

Lee, J.S.,Kim, C.Y.,Joo, Y.H.,Newell, D.,Bouix, S.,Shenton, M.E.,Kubicki, M. ELSEVIER SCIENCE DIVISION 2016 Schizophrenia Research Vol.176 No.2

Introduction: Diffusion weighted MRI (dMRI) is a method sensitive to pathological changes affecting tissue microstructure. Most dMRI studies in schizophrenia, however, have focused solely on white matter. There is a possibility, however, that subtle changes in diffusivity exist in gray matter (GM). Accordingly, we investigated diffusivity in GM in patients with recent onset schizophrenia. Methods: We enrolled 45 patients and 21 age and sex-matched healthy controls. All subjects were evaluated using the short form of the Wechsler Adult Intelligence Scale, the Positive and Negative Syndrome Scale (PANSS), and the video based social cognition scale. DMRI and T1W images were acquired on a 3 Tesla magnet, and mean Fractional Anisotropy (FA), Trace (TR) and volume were calculated for each of the 68 cortical GM Regions of Interest parcellated using FreeSurfer. Results: There was no significant difference of FA and GM volume between groups after Bonferroni correction. For the dMRI measures, however, patients evinced increased TR in the left bank of the superior temporal sulcus, the right inferior parietal, the right inferior temporal, and the right middle temporal gyri. In addition, higher TR in the right middle temporal gyrus and the right inferior temporal gyrus, respectively, was associated with decreased social function and higher PANSS score in patients with schizophrenia. Conclusion: This study demonstrates high sensitivity of dMRI to subtle pathology in GM in recent onset schizophrenia, as well as an association between increased diffusivity in temporal GM regions and abnormalities in social cognition and exacerbation of psychiatric symptoms.