Longitudinal associations between traditional and cyberbullying victimization and depressive symptoms among young Chinese: A mediation analysis.

BACKGROUND: The impacts of bullying victimization on psychological health are long-lasting. However, the longitudinal mediating processes of the association between being bullied (traditionally and in a cyber context) and depressive symptoms of Chinese youth remain underexplored, including across the sexes. OBJECTIVE: This study investigated the longitudinal association between bullying victimization and depressive symptoms, including the mediating effects of physical health, healthy lifestyles, sleep quality, and academic achievements. Different pathways from traditional bullying and cyberbullying victimization regarding depressive symptoms were also explored, with a comparison across the sexes. PARTICIPANTS AND SETTING: Data were obtained from the China Education Panel Survey, and ninth graders aged approximately 15 years constituted the baseline cohort. METHODS: The baseline data and longitudinal data at two- and five-year follow-ups, respectively, were evaluated to estimate structural equation models. RESULTS: Baseline traditional bullying and cyberbullying victimization significantly predicted subsequent depressive symptoms at both follow-ups (P < 0.001). Being bullied also predicted worse healthy lifestyles, poorer sleep quality, and lower academic achievements (P < 0.05), all significantly correlated with the development of depressive symptoms (P < 0.001) regarding both bullying victimizations. Physical health was the mediator of the traditional bullying victimization-depressive symptoms linkage (P < 0.05). Female victims have a relatively higher risk of depression versus male victims, with different mediating pathways from victimization to depressive symptoms. CONCLUSIONS: Our findings strengthen the evidence of a longitudinal association between bullying victimization and depressive symptoms, provide new explanations for mechanisms of mediation, and highlight the importance of long-term comprehensive mental health interventions for victims of bullying.

MiR-103 regulates the angiogenesis of ischemic stroke rats by targeting vascular endothelial growth factor (VEGF).

OBJECTIVES: To investigate the effect of miR-103 on the angiogenesis of ischemic stroke rats via targeting vascular endothelial growth factor (VEGF) at the molecular level. MATERIALS AND METHODS: Rat models had received the middle cerebral artery occlusion (MCAO) or sham operation before grouping, and cell models of oxygen-glucose deprivation (OGD) were performed. FITC-dextran, matrigel, and Trans-well assays were used to evaluate the vascular density, tube formation, and cell migration respectively. The expression levels of miR-103 and VEGF were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Dual-luciferase assay was used for analyzing the targeting relationship between miR-103 and VEGF. RESULTS: We found the reduced miR-103 in rats after MCAO. Down-regulating miR-103 with the miR-103 inhibitor enhanced VEGF, ameliorated the neurological scores, decreased infarct volume, and increased vascular density in rats after MCAO. Besides, in OGD human umbilical vein endothelial cells (HUVECs), inhibition of miR-103 could promote the increase of tube length and the migration of cells. Additionally, we found that miR-103 could directly target VEGF and thereby lead to the down-expression of VEGF. Meanwhile, si-VEGF could reverse the effect of miR-103 inhibitor on angiogenesis in rats subjected to MCAO. CONCLUSION: Inhibition of miR-103 could promote ischemic stroke angiogenesis and reduce infarction volume via enhancing VEGF, which provides a new target for the clinical treatment of ischemic stroke.