S1P₁ Regulates M1/M2 Polarization toward Brain Injury after Transient Focal Cerebral Ischemia

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 (S1P₁) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between S1P₁ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of S1P₁ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether S1P₁ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing S1P₁ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing S1P₁ activity with AUY954 administration inhibited M1-polarizatioin-relevant NF-κB activation in post-ischemic brain. Particularly, NF-κB activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through S1P₁ in post-ischemic brain mainly occurred in activated microglia. Suppressing S1P₁ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that S1P₁ could also influence M2 polarization in post-ischemic brain. Finally, suppressing S1P₁ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following S1P₁ activation. Overall, these results revealed S1P₁-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.

The Protective Factors of Suicide Probability in Religious Male High School Students

PURPOSE: This study was conducted to identify the protective factors that influence suicide probability in religious male high school students. METHODS: The data was collected from Nov. 5 to Dec. 10, 2009. Data were collected by self-report questionnaire from 255 students selected from 2 religious male high schools in B city. The instruments for this study were the Suicide Probability Scale for Adolescence (SPS-A), Inventory Parents Peer Attachment-Revision (IPPA-R), Spiritual Well-being Scale (SWBS), and Ego-identity Scale. The data were analyzed using t-test, one-way ANOVA, Scheffe test, Pearson correlation coefficients and stepwise multiple regression with the SPSS 14.0 program. RESULTS: The protective factors of suicide probability in religious male high school students were identified as existential spiritual well-being (beta= -.46, p<.001), self-identity (beta= -.30, p<.001), and mother attachment (beta= -.21, p<.001). These three factors explained 61.5% of the variance in suicide probability. CONCLUSIONS: The results suggest that improvement in spirituality, ego-identity, and mother attachment for religious male high school students is important to reduce the probability of suicide.

Prediction of Exposure to 1763MHz Radiofrequency Radiation Using Support Vector Machine Algorithm in Jurkat Cell Model System

We have investigated biological responses to radiofrequency (RF) radiation in in vitro and in vivo models. By measuring the levels of heat shock proteins as well as the activation of mitogen activated protein kinases (MAPKs), we could not detect any differences upon RF exposure. In this study, we used more sensitive method to find the molecular responses to RF radiation. Jurkat, human T-Iymphocyte cells were exposed to 1763 MHz RF radiation at an average specific absorption rate (SAR) of 10 W/kg for one hour and harvested immediately (R0) or after five hours (R5). From the profiles of 30,000 genes, we selected 68 differentially expressed genes among sham (S), R0 and R5 groups using a random-variance F-test. Especially 45 annotated genes were related to metabolism, apoptosis or transcription regulation. Based on support vector machine (SVM) algorithm, we designed prediction model using 68 genes to discriminate three groups. Our prediction model could predict the target class of 19 among 20 examples exactly (95% accuracy). From these data, we could select the 68 biomarkers to predict the RF radiation exposure with high accuracy, which might need to be validated in in vivo models.

Characterization of E. coli-induced Genes in Bombyx mori Fatbody using Expressed Sequence Tags Analysis

To accelerate the molecular analysis of specifically induced antibacterial peptide against pathogen (E. coli), cDNA library prepared from the larvae fatbody of Bombyx mori was examined by the expressed sequence tag (EST) analysis. In a total of 722 clones, 653 clones were unique genes. Of 653 unique genes, 43.2% (282/653 ESTs) was identified as characterized genes, 38.1% (249/653 ESTs) as uncharacterized genes, and 18.7% (122/653 ESTs) as novel ESTs. According to the functional categorization of the characterized genes, 36.2% (102/282 ESTs) was antibacterial proteins. The highest expressed peptides, 78.4% of all the expressed antibacterial proteins (80/102 ESTs), belonged to the cecropin family. The antibacterial effect of selected clones representing novel ESTs based on a phylogenetic analysis was examined against various bacterial strains. None of the clones showed significant inhibitory effect to the bacteria tested. These results suggested that most of the novel molecules induced by E. coli may not act as immune-induced antibacterial peptides in the fatbody.

Genomic organization and expression of parkin in Drosophila melanogaster

We report here the isolation, characterization on genomic structure and expression of the D. melanogaster homolog of human parkin. The 2,122 bp parkin gene sequence contains six exons that form a 1,449 bp transcript encoding a protein of 482 amino acids. 151 bp of 5' and 112 bp of 3' untranslated regions were identified by a combination of 5'-RACE/primer extension and 3'-RACE, respectively. The 5' UTR contains three transcription initiation sites. Neither a classical TATA nor a CAAT box was found in the putative promoter sequence. However, binding sites for AhR-Arnt, AP4, NF1 and GATA transcription factors were identified. Transient transfection analysis of the 5' UTR confirmed its promoter activity in HEK 293 cells and SH-SY5Y neuronal cells using a dual luciferase reporting system. The amino acid sequence of D. melanogaster Parkin exhibits 42%, 43% and 43% identity to that of human, mouse and rat, respectively, representing a 54 kDa protein band via western blot analysis. It shows a high degree of conservation in the Ubiquitin-like domain at the N-terminus (34%), the In-Between RING finger domains (IBR, 65-69%), and the RING finger domains at the C-terminus (56-57%). The expression pattern of D. melanogaster parkin varies during the developmental stages, with the highest expression in the adult stage as measured by competitive RT-PCR. From immunostainings of the embryo, D. melanogaster parkin was expressed slightly higher in the central nervous system (brain and nerve cord) during the late embryonic stage.