Gender Differences in Aggression-related Responses on EEG and ECG

Gender differences in aggression viewed from an evolutionary and sociocultural perspective have traditionally explained why men engage in more direct and physical aggression, and women engage in more indirect and relational aggression. However, psychological and behavioral studies offer inconsistent support for this theory due to personal or social factors, and little is known about the gender-based neurobiological mechanisms of aggression. This study investigates gender differences in aggression through an analysis of electroencephalography (EEG) and electrocardiography (ECG) based neurobiological responses to commonly encountered stimuli, as well as psychological approaches in healthy Korean youth. Our results from self-reports indicate that overall aggression indices, including physical and reactive/overt aggression, were stronger in men. This agrees with the results of previous studies. Furthermore, our study reveals prominent gender-related patterns in γ signals from the right ventrolateral frontal cortex and changes in heart rate through stimulation by aggressive videos. In particular, gender differences in EEG and ECG responses were observed in response to different scenes, as simple aversion and situation-dependent aggression, respectively. In addition, we discovered decisive gender-distinct EEG signals during stimulation of the situation-dependent aggression regions within the right ventromedial prefrontal and ventrolateral frontal regions. Our findings provide evidence of a psychological propensity for aggression and neurobiological mechanisms of oscillation underlying gender differences in aggression. Further studies of oscillatory responses to aggression and provocation will expand the objective understanding of the different emotional worlds between men and women.

Neurogenic potentials of human amniotic fluid-derived stem cells according to expression levels of stem cell markers and ingredients of induction medium

PURPOSE: We investigated the neurogenic potentials of amniotic fluid-derived stem cells (AFSCs) according to the expression levels of stem cell markers and ingredients in the neural induction media. MATERIALS AND METHODS: Four samples of AFSCs with different levels of Oct-4 and c-kit expression were differentiated neurally, using three kinds of induction media containing retinoic acid (RA) and/or a mixture of 3-isobutyl-1-methylxanthine/indomethacin/insulin (neuromix), and examined by immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) for their expression of neurospecific markers. RESULTS: The cells in neuromix-containing media displayed small nuclei and long processes that were characteristic of neural cells. RT-PCR analysis revealed that the number of neural markers showing upregulation was greater in cells cultured in the neuromix-containing media than in those cultured in RA-only medium. Neurospecific gene expression was also higher in Oct-4 and c-kit double-positive cells than in c-kit-low or -negative cells. CONCLUSION: The stem cell marker c-kit (rather than Oct-4) and the ingredient neuromix (rather than RA) exert greater effects on neurogenesis of AFSCs.

Cell Death and Immunity

Dying cells interact with living cells and release molecules that can signal to immune system. Based on the morphology of the dying cells, there are three types of cell death, which are apoptotic cell death (Type I), autophagic cell death (Type II) and necrotic cell death (Type III). The immune response is different according to the pathway of cell death as apoptosis or necrosis regulates immune response via caspase activation or cytokine secretion, respectively. Here, we discuss the different modes of cell death and the nature of the immune response elicited by the released molecules from the cell death.

Introduction of the CIITA gene into tumor cells produces exosomes with enhanced anti-tumor effects

Exosomes are small membrane vesicles secreted from various types of cells. Tumor-derived exosomes contain MHC class I molecules and tumor-specific antigens, receiving attention as a potential cancer vaccine. For induction of efficient anti-tumor immunity, CD4+ helper T cells are required, which recognize appropriate MHC class II-peptide complexes. In this study, we have established an MHC class II molecule-expressing B16F1 murine melanoma cell line (B16F1-CIITA) by transduction of the CIITA (Class II transactivator) gene. Exosomes from B16-CII cells (CIITA-Exo) contained a high amount of MHC class II as well as a tumor antigen TRP2. When loaded on dendritic cells (DCs), CIITA-Exo induced the increased expression of MHC class II molecules and CD86 than the exosomes from the parental cells (Exo). In vitro assays using co-culture of immunized splenocytes and exosome-loaded DCs demonstrated that CIITA-Exo enhanced the splenocyte proliferation and IL-2 secretion. Consistently, compared to B16-Exo, CIITA-Exo induced the increased mRNA levels of inflammatory cytokines such as TNF-alpha, chemokine receptor CCR7 and the production of Th1-polarizing cytokine IL-12. A tumor preventive model showed that CIITA-Exo significantly inhibited tumor growth in a dose-dependent manner. Ex vivo assays using immunized mice demonstrated that CIITA-Exo induced a higher amount of Th1-polarized immune responses such as Th1-type IgG2a antibodies and IFN-gamma cytokine as well as TRP2-specific CD8+ T cells. A tumor therapeutic model delayed effects of tumor growth by CIITA-Exo. These findings indicate that CIITA-Exo are more efficient as compared to parental Exo to induce anti-tumor immune responses, suggesting a potential role of MHC class II-containing tumor exosomes as an efficient cancer vaccine.

Characteristics of amniotic fluid derived stem cells with trisomy 21 / 대한산부인과학회지

OBJECTIVE: To assess molecular markers of amniotic fluid derived stem cells (AFSCs) in aspects of increased neurological deficit in Down syndrome. METHODS: Amniotic fluid samples through amniocentesis for prenatal diagnosis from four mid trimester pregnancies; by routine chromosomal analysis, two of them were trisomy 21 (Down syndrome) and others were normal, were selected after informed consent. Cells from two-stage culture protocol were assayed; morphology through phase contrast microscopy, chromosomal analysis, reverse transcriptase-polymerase chain reaction and Western blot analysis. RESULTS: AFSCs were highly proliferative in subcultures and most of them were mononuclear, fibroblast-like, fusiform cells. There were also a few ovoid cells. The chromosomal analysis of amniotic fluid stem cells was identical to that of amniotic fluid cells. Two of four samples were 47,XX,+21, others were 46,XX. Of the proteins related to Down syndrome, the expression of S100beta were increased in AFSCs of Down syndrome, COL6A1 (Collagen IV, alpha 1) was down-regulated in them and insulin like growth factor binding protein-1 was expressed in all AFSCs. Stem cell markers were expressed heterogeneously. Oct4 (POU5F1), nanog, and SOX2 (sex determining region Y) were expressed in both groups. But c-Kit was not expressed in AFSCs of Down syndrome. The neural cell marker, neuron specific enolase was detected in both groups. Other neural cell markers, microtubule associated protein 2, glial fibrillary acidic protein were undetectable in ASFCs of Down syndrome. Bcl-2 gene family proteins related with apoptosis were assayed. The expression of Bcl-XL was increased in Down syndrome more than in normal pregnancy. Bcl-2 and BID were expressed in all AFSCs and Bax was down-regulated in Down syndrome. CONCLUSION: AFSCs are an excellent choice for many future tissue engineering strategies and cell based therapies. Analysis of molecular features of AFSCs from normal and Down syndrome will provide the basis of further experimental study.

Characterization and differentiation into adipocytes of mesenchymal stem cells (MSCs) from human adipose tissue and amniotic fluid / 대한산부인과학회지

OBJECTIVE: Mesenchymal stem cells (MSCs) are potentially very useful for regenerative and reparative medicine as well as therapeutic possibilities. The aim of this study is to examine the ability of ADSCs and AFSCs to be phenotypically and functionally differentiated into adipocyte and to determine the appropriate stem cell source and conditions for efficient adipocyte regeneration. METHODS: Adipogenic differentiation was induced by culturing confluent ADSCs and AFSCs in adipogenic medium for 2~4 weeks. During the differentiation inducing period, we evaluated the successful adipogenesis by performing immunocytochemistry and RT-PCR to detect the lipid producibility and several adipogenic gene expressions including lipoprotein lipase (LPL), peroxisome proliferator-activated receptor gamma2 (PPAR gamma2) and adiponectin. RESULTS: ADSCs and AFSCs are expanded easily in vitro and exhibited a fibroblast-like morphology as previously known in MSCs from bone marrow and a commercial source. Flow cytometric analysis showed that ADSCs and AFSCs expressed several CD marker antigens similar to those observed on bone marrow-derived MSCs. Adipogenic induction of ADSCs and AFSCs resulted in the extended cell morphology, intracellular staining of an established lipid dye Oil Red O, and expression of adipocyte-specific genes. CONCLUSION: Both ADSCs and AFSCs successfully differentiate in vitro into adipogenic cells in the presence of the lineage-specific induction factors although ADSC showed the greater capability. Therefore, the results suggest that ADSCs and AFSCs may be an excellent choice for many future tissue engineering strategies and cell-based therapies.

Comparative Uptake of Tc-99m Sestamibi and Tc-99m Tetrofosmin in Cancer Cells and Tissue Expressing P-Glycoprotein or Multidrug Resistance Associated Protein / 대한핵의학회잡지

PURPOSE: 99mTc-sestamibi (MIBI) and 99mTc-tetrofosmin have been used as substrates for P-glycoprotein (Pgp) and multidrug resistance associated protein (MRP), which are closely associated with multidrug resistance of the tumors. To understand different handling of radiotracers in cancer cell lines expressing Pgp and MRP, we compared cellular uptakes of 99mTc-MIBI and 99mTc-tetrofosmin. The effects of cyclosporin A (CsA), well-known multidrug resistant reversing agent, on the uptake of both tracers were also compared. MATERIALS AND METHODS: HCT15/CL02 human colorectal cancer cells for Pgp expressing cells, and human non-small cell lung cancer A549 cells for MRP expressing cells, were used for in vitro and in vivo studies. RT-PCR, western blot analysis and immunohistochemistry were used for detection of Pgp and MRP. MDR-reversal effect with CsA was evaluated at different drug concentrations after incubation with MIBI or tetrofosmin. Radioactivities of supernatant and pellet were measured with gamma well counter. Tumoral uptake of the tracers were measured from tumor bearing nude mice treated with or without CsA. RESULTS: RT-PCR, western blot analysis of the cells and immunochemical staining revealed selective expression of Pgp and MRP for HCT15/CL02 and A549 cells, respectively. There were no significant difference in cellular uptakes of both tracers in HCT15/CL02 cells, but MIBI uptake was slightly higher than that of tetrofosmin in A549 cells. Co-incubation with CsA resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Uptake of MIBI or tetrofosmin in HCT15/CL02 cells was increased by 10- and 2.4-fold, and by 7.5 and 6.3-fold in A549 cells, respectively. Percentage increase of MIBI was higher than that of tetrofosmin with CsA for both cells (p< 0.05). In vivo biodistribution study showed that MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively increased by the time, up to 240 min with CsA. But increases in tumoral uptake were not significantly different between MIBI and tetrofosmin for both tumors. CONCLUSION: MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators in vitro, but these differences were not evident in vivo tumoral uptake. Both MIBI and tetrofosmin seem to be suitable tracers for imaging Pgp- and MRP-mediated drug resistance in tumors.