Predictors for runaway behavior in adolescents in South Korea: national data from a comprehensive survey of adolescents.

Background: Runaway behavior is reported to impede the growth, mental health development, and social adjustment of adolescents. Exposure to harmful media causes problematic behaviors in adolescents, sometimes inducing them to run away from home. Methods: This study examined the factors influencing adolescents' runaway behavior. Utilizing the data of 11,354 adolescents from the Survey of Media Usage and Harmful Environment among Adolescents, a hierarchical logistic regression analysis was conducted using the SPSS 24.0 program. Results: The significant predictors of runaway behavior were the grade of the adolescent, deviant behaviors (drinking, smoking), autonomous control ability, relationship with family, and harmful media (p < 0.001). This regression model explained 13.1% of the variance in runaway behavior. A significant outcome of this study is that harmful media was identified as one of the factors affecting adolescents' runaway behavior. Adjusted OR and 95% CI of harmful media was 1.23 (1.10-1.38). Conclusion: This study showed that individual, family, social factors, and harmful media influence adolescents' runaway behavior. The results emphasize the importance of health teachers and the need for early intervention programs, for the identification and prevention of risk factors for adolescents' runaway behavior.

Predictors for Sexual Intercourse Experience among Runaway Female At-Risk Adolescents.

This study attempted to provide basic data for creating a program to help promote safe sexual behavior among runaway female at-risk adolescents by identifying factors related to the sexual experiences. This study conducted a logistic regression analysis using data regarding 182 female at-risk adolescents, which were sourced from the 2016 survey of Korean adolescents' contact with media usage and harmful environment. This study showed that adolescents' age, smoking, and harmful environments are associated with the occurrence of sexual activity among at-risk female adolescents. One significant outcome of this study was the identification of harmful environmental factors and their impact on sexual behavior. Since smoking and sex-related problems among adolescents can act as risk factors for adult sexual health in the future, schools should institute direct and indirect channels for assessing sex-related problems among runaway female at-risk adolescents and establishing proactive and preventive measures for promoting their sexual health. In addition, a social cooperation system should be established in order to assess, and mediate within, the environments around schools in order to minimize adolescents' exposure to harmful environments.

Predictors of Runaway Behavior Among At-Risk Youth.

This study examines the factors influencing runaway experiences among at-risk youth. Using the data of 1,743 at-risk youth from the 2016 survey of Korean adolescents' contact with media usage and harmful environment, a logistic regression analysis was conducted. This study shows that factors associated with the adolescents' experiences of family relationships, violence victimization, and harmful environment influence the occurrence of runaway behavior in at-risk adolescents. A significant outcome of this study is the identification of a harmful environment as a factor affecting runaway behavior. The factors identified need to be considered in the development of prevention programs targeting runway behavior among at-risk youth. School nurses are uniquely positioned to review and revise educational strategies to raise adolescents' awareness regarding the effects of harmful environments and to promote violence prevention. This framework provides school nurses with systematic methods for early identification and management of risk factors among at-risk youth runway behavior.

Deficiency of glutathione peroxidase-1 and catalase attenuated diet-induced obesity and associated metabolic disorders.

AIMS: Oxidative stress has been considered to contribute to the development of obesity-related metabolic disorders including insulin resistance. To the contrary, deficiency of an anti-oxidizing enzyme, glutathione peroxidase (GPx)-1, was reported to enhance insulin signaling, suggesting that oxidative stress may inhibit the development of type 2 diabetes. However, the beneficial effects of the absence of GPx-1 in metabolic homeostasis, including body weight control, have not yet been clearly manifested. To clarify the relationship between oxidative stress and obesity-related metabolic disorders, we investigated another mouse deficient with both GPx-1 and catalase (Cat). METHODS: C57BL/6J wild-type and GPx-1-/- × Cat-/- mice were fed with a high-fat diet (60% fat) or a normal chow diet for 16 weeks and were investigated for metabolic and histological studies. RESULTS: Body weight gain was significantly reduced, and glucose metabolism as well as hepatic steatosis was obviously improved in the GPx-1-/- × Cat-/- mice. The serum levels of insulin and total cholesterol were also significantly lowered. For the underlying mechanism, inflammation was attenuated and expression of markers for fat browning was enhanced in the visceral white adipose tissues. CONCLUSIONS: Oxidative stress due to deficiency of GPx-1 and Cat may improve obesity-related metabolic disorders through attenuation of inflammation and fat browning.

Attenuation of collagen-induced arthritis by hyperbaric oxygen therapy through altering immune balance in favor of regulatory T cells.

Hyperbaric oxygen (HBO2) therapy is currently used for the treatment of chronic wounds, radiation-induced soft tissue necrosis, several oxygen-deficiency conditions and decompression sickness. In addition to the current indications, much empirical and experimental data suggest that HBO2 therapy may benefit autoimmune diseases by suppressing immunity, but the underlying mechanism is not well understood. Therefore, in the present study, we investigated whether HBO2 prevents the development of collagen-induced arthritis (CIA) in association with alteration of the immune balance between pro-inflammatory Th17 and anti-inflammatory regulatory T cells (Tregs). Arthritis was induced in DBA/1 mice by intradermal injection of type II collagen. Animals received either no treatment or 90 minutes of HBO2 (100% oxygen, at 2.0 ATA) daily beginning three days prior to the injection and were monitored for the development of arthritis. Six weeks later, joint tissues and spleens were analyzed for the alteration of immune balance between Th17 and Tregs by immunohistochemistry (IHC) or Western blot. Injection of collagen-induced extensive arthritis and extramedullary hematopoiesis in the spleens. Meanwhile, joint swelling and inflammatory tissue damages as well as extramedullary hematopoiesis were significantly less severe in the mice treated with HBO2. Both IHC and Western blot showed a decrease of FOXP3 and an increase of pSTAT3 expressions in the joints and spleens of the mice injected with collagen. This suggested that the systemic immune balance was biased toward Th17 cells, which was reversed by HBO2 therapy. These results suggested acute CIA associated with an immune balance favoring Th17 was attenuated by HBO2 in parallel with restoration of the immune balance to favor Tregs.

Exogenous Hydrogen Peroxide Induces Lipid Raft-Mediated STAT-6 Activation in T Cells.

BACKGROUND/AIMS: CD4+ T cells are a critical component of the adaptive immune response. While the mechanisms controlling the differentiation of the Th1, Th17, and regulatory T cell subsets from naïve CD4+ T cells are well described, the factors that induce Th2 differentiation are still largely unknown. METHODS: The effects of treatment with exogenous H2O2 on STAT-6 phosphorylation and activation in T cells were examined by immunoblotting, immunofluorescence and gel shift assay. Anti-CD3 antibody and methyl-ß-cyclodextrin were utilized to induce lipid raft assembly and to investigate the involvement of lipid rafts, respectively. RESULTS: Jurkat and EL-4 T cells that were exposed to H2O2 showed rapid and strong STAT-6 phosphorylation, and the extent of STAT-6 phosphorylation was enhanced by co-treatment with anti-CD3 antibody. The effect of H2O2 on STAT-6 phosphorylation and translocation was inhibited by disruption of lipid rafts. STAT-6 activation in response to H2O2 treatment regulated IL-4 gene expression, and this response was strengthened by treatment with anti-CD3. CONCLUSION: Our results indicate that reactive oxygen species such as H2O2 can act on upstream and initiating factors for activation of STAT-6 in T cells and contribute to formation of a positive feedback loop between STAT-6 and IL-4 in the Th2 differentiation process.

Hyperoxygenation attenuated a murine model of atopic dermatitis through raising skin level of ROS.

Atopic dermatitis (AD) is a chronic inflammatory skin disease resulting from excessive stimulation of immune cells. Traditionally, reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases, but several opposing observations suggest the protective role of ROS in inflammatory disease. Recently, we demonstrated ROS prevented imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function. Thus, we hypothesized AD might also be attenuated in elevated levels of ROS through tissue hyperoxygenation, such as by hyperbaric oxygen therapy (HBOT) or applying an oxygen-carrying chemical, perfluorodecalin (PFD). Elevated levels of ROS in the skin have been demonstrated directly by staining with dihydroethidum as well as indirectly by immunohistochemistry (IHC) for indoleamine 2,3-dioxygenase (IDO). A murine model of AD was developed by repeated application of a chemical irritant (1% 2,4-dinitrochlorobenzene) and house dust mite (Dermatophagoide farinae) extract on one ear of BALB/c mice. The results showed treatment with HBOT or PFD significantly attenuated AD, comparably with 0.1% prednicarbate without any signs of side effects, such as telangiectasia. The expressions of interleukin-17A and interferon-γ were also decreased in the AD lesions by treatment with HBOT or PFD. Enhanced expression of IDO and reduced level of hypoxia-inducible factor-1α, in association with increased frequency of FoxP3+ regulatory T cells in the AD lesions, might be involved in the underlying mechanism of oxygen therapy. Taken together, it was suggested that tissue hyperoxygenation, by HBOT or treatment with PFD, might attenuate AD through enhancing skin ROS level.

Immune enhancing effects of Echinacea purpurea root extract by reducing regulatory T cell number and function.

Echinacea purpurea preparations (EPs) have been traditionally used for the treatment of various infections and also for wound healing. Accumulating evidence suggests their immunostimulatory effects. Regulatory T cells (Tregs) are known to play a key role in immune regulation in vivo. However, there have been no reports so far on the effects of EP on the frequency or function of Tregs in vivo. Therefore, in the present study, we investigated the quantitative and functional changes in Tregs by in vivo administration with EP. The frequencies of CD4+FoxP3+ and CD4+CD25+ Tregs in the spleens of BALB/c mice administered with EP for 3 weeks were investigated by flow cytometry. The suppressive function of CD4CD25+ Tregs in association with the proliferative activity of CD4+CD25 effector T cells (Teffs) and the feeder function of CD4 antigen-presenting cells (APCs) were analyzed by carboxyfluorescein succinimidyl ester-dilution assay. The results showed a lowered frequency of CD4+FoxP3+ and CD4+CD25+ Tregs and attenuated suppressive function of CD4+CD25+ Tregs, while the feeder function of APCs was enhanced in the EP-administered mice. On the other hand, the proliferative activity of Teffs was not significantly different in the EP-administered mice. The results suggest that decreased number and function of Tregs, in association with the enhanced feeder function of APCs, may contribute to the enhancement of immune function by EP.

Attenuation of experimental colitis in glutathione peroxidase 1 and catalase double knockout mice through enhancing regulatory T cell function.

Reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases including inflammatory bowel diseases (IBD). Meanwhile, several studies suggested the protective role of ROS in immune-mediated inflammatory diseases, and it was recently reported that dextran sodium sulfate (DSS)-induced colitis was attenuated in mice with an elevated level of ROS due to deficiency of peroxiredoxin II. Regulatory T cells (Tregs) are critical in the prevention of IBD and Treg function was reported to be closely associated with ROS level, but it has been investigated only in lowered levels of ROS so far. In the present study, in order to clarify the relationship between ROS level and Treg function, and their role in the pathogenesis of IBD, we investigated mice with an elevated level of ROS due to deficiency of both glutathione peroxidase (GPx)-1 and catalase (Cat) for the susceptibility of DSS-induced colitis in association with Treg function. The results showed that DSS-induced colitis was attenuated and Tregs were hyperfunctional in GPx1-/- × Cat-/- mice. In vivo administration of N-acetylcysteine (NAC) aggravated DSS-induced colitis and decreased Treg function to the level comparable to WT mice. Attenuated Th17 cell differentiation from naïve CD4+ cells as well as impaired production of IL-6 and IL-17A by splenocytes upon stimulation suggested anti-inflammatory tendency of GPx1-/- × Cat-/- mice. Suppression of Stat3 activation in association with enhancement of indoleamine 2,3-dioxygenase and FoxP3 expression might be involved in the immunosuppressive mechanism of GPx1-/- × Cat-/- mice. Taken together, it is implied that ROS level is critical in the regulation of Treg function, and IBD may be attenuated in appropriately elevated levels of ROS.

Reactive oxygen species prevent imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function.

Psoriasis is a chronic inflammatory skin disease resulting from immune dysregulation. Regulatory T cells (Tregs) are important in the prevention of psoriasis. Traditionally, reactive oxygen species (ROS) are known to be implicated in the progression of inflammatory diseases, including psoriasis, but many recent studies suggested the protective role of ROS in immune-mediated diseases. In particular, severe cases of psoriasis vulgaris have been reported to be successfully treated by hyperbaric oxygen therapy (HBOT), which raises tissue level of ROS. Also it was reported that Treg function was closely associated with ROS level. However, it has been only investigated in lowered levels of ROS so far. Thus, in this study, to clarify the relationship between ROS level and Treg function, as well as their role in the pathogenesis of psoriasis, we investigated imiquimod-induced psoriatic dermatitis (PD) in association with Treg function both in elevated and lowered levels of ROS by using knockout mice, such as glutathione peroxidase-1(-/-) and neutrophil cytosolic factor-1(-/-) mice, as well as by using HBOT or chemicals, such as 2,3-dimethoxy-1,4-naphthoquinone and N-acetylcysteine. The results consistently showed Tregs were hyperfunctional in elevated levels of ROS, whereas hypofunctional in lowered levels of ROS. In addition, imiquimod-induced PD was attenuated in elevated levels of ROS, whereas aggravated in lowered levels of ROS. For the molecular mechanism that may link ROS level and Treg function, we investigated the expression of an immunoregulatory enzyme, indoleamine 2,3-dioxygenase (IDO) which is induced by ROS, in PD lesions. Taken together, it was implied that appropriately elevated levels of ROS might prevent psoriasis through enhancing IDO expression and Treg function.

Functional changes in regulatory T cells during an experimental infection with sparganum (plerocercofid of Spirometra mansoni).

Regulatory T (Treg) cells are important in the regulation of immune response, but the exact regulation of Treg-cell function in vivo is still not well known. In the present study, we investigated the functional activity of CD4(+) CD25(+) Treg cells as well as the frequency and number of CD4(+) CD25(+) FoxP3(+) Treg cells in the spleens of experimentally infected mice with a tissue-migrating parasite, sparganum (plerocercoid of Spirometra mansoni) for 3 weeks. The results demonstrated fluctuations in the Treg-cell function during the parasite infection, being up-regulated at day 3, down-regulated until day 14, and thereafter up-regulated again at day 21. We also investigated the cytokine-producing capability of the splenocytes to study the pattern of immune response of the mice to the parasite. The results showed decreased capabilities of interleukin-2 (IL-2), interferon-γ (IFN-γ) and IL-17α production, whereas IL-4-producing and IL-10-producing capabilities were increased along with the parasitic infection. Meanwhile, IL-6-producing capability was increased to reach a peak at week 2, and thereafter was decreased to the baseline level. As a regulatory mechanism, we found that Treg-cell function was attenuated in the presence of the crude extracts of sparganum, but was enhanced in the presence of the excretory-secretory products, suggesting that sparganum products were involved in the triggering and regulation of immune response in the acute and chronic phases, respectively. Results show that Treg cells are central in the immune homeostasis in vivo that is maintained by host-parasite interactions during the parasitic infection.

CD4⁺CD25⁺ regulatory T cells from MRL/lpr mice were functionally more active in vitro but did not prevent spontaneous as well as adriamycin-induced nephropathy in vivo.

OBJECTIVE: The frequency and function of Tregs are important in the pathogenesis of SLE. Nonetheless, the function of Tregs is still controversial in SLE patients and lupus mouse models. In the present study, we investigated the suppressive function of Tregs from MRL/lpr mice in vitro and in vivo by using an alternative quantitative assay. METHODS: We assessed the suppressive function of CD4(+)CD25(+) Tregs, the proliferative activity of CD4(+)CD25(-) effector T cells (Teffs) and the feeder activity of CD11c(+) dendritic cells (DCs), isolated from the spleens of MRL/lpr mice and wild-type (WT) MRL/+ mice, by carboxyfluorescein diacetate succinimidyl ester dilution assay stimulated with two distinct types of signals, weak and strong. In order to assess the protective function of Tregs from an immune-mediated disease in vivo, we induced renal damage by injecting adriamycin (ADN) into the mice. RESULTS: The in vitro assay showed enhanced suppressive activity of Tregs and feeder activity of DCs, but far less proliferative activity of Teffs from MRL/lpr mice, compared with those from the WT mice. The in vivo study showed more severe ADN-induced nephropathy in MRL/lpr mice than in the WT mice, while mild interstitial nephritis had already begun spontaneously by 16 weeks in MRL/lpr mice. CONCLUSION: It was suggested that Tregs from MRL/lpr mice were functionally competent and intrinsically more active in vitro, but they were not capable of preventing the ADN-induced as well as the spontaneously developing nephropathy in vivo.

Somatic mutations of the KEAP1 gene in common solid cancers.

AIMS: KEAP1 inhibits nuclear factor erythroid 2-related factor 2 (NRF2)-induced cytoprotection, and is considered to be a candidate tumour suppressor. Somatic mutation of NRF2 has been analysed in a wide variety of human cancers, whereas somatic mutation of KEAP1 has been reported only in lung and gall bladder cancers. The aim of our study was to investigate whether KEAP1 mutations are widespread in human cancers. METHODS AND RESULTS: We analysed 499 cancer tissues from lung, breast, colon, stomach, liver, larynx and prostate, and leukaemias, by single-strand conformation polymorphism analysis. We detected somatic mutations of KEAP1 in gastric (11.1%), hepatocellular (8.9%), colorectal (7.8%), lung (4.6%), breast (2.0%) and prostate (1.3%) carcinomas. Allelic losses of the KEAP1 locus were identified in 42.9% of cancers with KEAP1 mutations, but no NRF2 mutations were detected in these cancers. The NRF2-activated cytoprotective proteins (NAD(P)H dehydrogenase quinone 1 and glutamine-cysteine ligase catalytic subunit) were expressed in all of the cancers with KEAP1 mutations. CONCLUSIONS: Our data show that KEAP1 mutations occur widely in solid cancers, irrespective of histological type. Biallelic inactivation of KEAP1 and increased levels of cytoprotective proteins in the cancers suggest that KEAP1 mutations might protect cancer cells from oxidative insults and play a role in the development of solid cancers.

Immune dysregulation in chronic stress: a quantitative and functional assessment of regulatory T cells.

OBJECTIVE: Chronic stress is closely related to immune dysfunction. Immune parameters have been analyzed in many ways in humans and animals under chronic stress. Recently, it has been proved that FoxP3+ regulatory T cells (Tregs) play a key role in immune regulation in vivo. However, it has not yet been elucidated how Tregs respond to chronic stress in vivo. Therefore, in the present study, we investigated the frequency of and functional changes in Tregs from mice under chronic stress. METHODS: Spleen cells were separated from C57/BL6 mice that had been exposed to immobilization stress for 3 weeks. The frequencies of FoxP3+ and CD4+ CD25+ cells were analyzed by flow cytometry. CD4+CD25- cells (effector T cells, Teffs), CD4+CD25+ cells (Tregs) and CD4- cells (antigen-presenting cells, APCs) were separated for the functional assessment of the proliferative activity of Teffs, the suppressive activity of Tregs and the feeder activity of APCs. RESULTS: The results showed that chronic immobilization stress significantly increased the frequencies of CD4+CD25+ and CD4+FoxP3+ cells. Chronic immobilization stress also enhanced the suppressive function of CD4+ CD25+ Tregs. On the other hand, the proliferative activity of Teffs and the feeder activity of APCs were decreased in the mice under chronic immobilization stress. CONCLUSION: Taken together, it is suggested that increased number and function of Tregs may actively contribute to the immune dysfunction in chronic immobilization stress, synergizing with the decreased function of Teffs and APCs.

Anti-cancer activity and mechanistic features of a NK cell activating molecule.

Natural cytotoxicity receptors (NCRs) are major activating receptors involved in NK cytotoxicity. NCR expression varies with the activation state of NK cells, and the expression level correlates with NK cells' natural cytotoxicity. In this study, we found that Gö6983, a PKC inhibitor, induced a remarkable increase of NCR expression on primary NK cells, but other PKC inhibitors and NK cell stimulators such as IL-2 and PMA, did not. Gö6983 increased the expression of NCR in a time- and concentration-dependent manner. Furthermore, Gö6983 strongly upregulated the surface expression of death ligands FasL and TRAIL, but not cytotoxic molecules perforin and granzyme B. Unlike two other NK stimulating molecules, IL-2, and PMA, Gö6983 did not induce NK cell proliferation. Up-regulation of NCRs and death ligands on NK cells by Gö6983 resulted in a significant enhancement of NK cytotoxicity against various cancer cell lines. Most importantly, administration of Gö6983 effectively inhibited pulmonary tumor metastasis in mice in a dose-dependent manner. These results suggest that Gö6983 functions as an NK cell activating molecule (NKAM); this NKAM is a novel anti-cancer and anti-metastasis drug candidate because it enhances NK cytotoxicity against cancer cells in vivo as well as in vitro.

Amino-acid sequence motifs for PKC-mediated membrane trafficking of the inhibitory killer Ig-like receptor.

Activation-induced upregulation of inhibitory killer Ig-like receptor (KIR) is regulated by protein kinase Cs (PKCs). Conventional PKCs increase KIR expression on the post-transcriptional level by increasing the recycling of surface molecules and endoplasmic reticulum (ER)-Golgi processing. PKCdelta plays a role in the secretion of cytoplasmic KIR through lytic granules. In this study, we identified amino acid sequence motifs associated with PKC-mediated KIR membrane trafficking by systematic mutagenesis. Mutations of Y(398) and HLWC(364) completely inhibited the PMA-induced increase of KIR molecules at surface as well as total protein levels, indicating that these are associated with ER-Golgi processing and sorting to plasma membrane through lytic granules. Mutations of Y-based motif, including Y(398), acidic region (PE(394)), dileucine motif-like region (IL(423)) and PKC-phosphorylatable S(415) caused a blockade of surface KIR endocytosis after PKC stimulation. Mutation of T(145) caused an accumulation of mutant proteins in late endosomes and lysosomes after PKC activation, suggesting that T(145) might be related to the recovery of endocytosed KIR to the surface membrane. We also demonstrated that PKCs could directly phosphorylate the KIR cytoplasmic tail by means of western blot and in vitro kinase assay, implying that phosphorylation status of KIR cytoplasmic tail can direct the fate of surface KIR molecules. Taken together, various sequence motifs are implicated in the PKC-mediated post-transcriptional upregulation of KIR, and each of these motifs work in different steps after PKC activation.