Exploring the role of neuronal-enriched extracellular vesicle miR-93 and interoception in major depressive disorder.

Major depressive disorder (MDD) is associated with interoceptive processing dysfunctions, but the molecular mechanisms underlying this dysfunction are poorly understood. This study combined brain Neuronal-Enriched Extracellular Vesicle (NEEV) technology and serum markers of inflammation and metabolism with Functional Magnetic Resonance Imaging (fMRI) to identify the contribution of gene regulatory pathways, in particular micro-RNA (miR) 93, to interoceptive dysfunction in MDD. Individuals with MDD (n = 44) and healthy comparisons (HC; n = 35) provided blood samples and completed an interoceptive attention task during fMRI. EVs were separated from plasma using a precipitation method. NEEVs were enriched by magnetic streptavidin bead immunocapture utilizing a neural adhesion marker (CD171) biotinylated antibody. NEEV specificities were confirmed by ow cytometry, western blot, particle size analyzer, and transmission electron microscopy. NEEV small RNAs were purified and sequenced. Results showed that: (1) MDD exhibited lower NEEV miR-93 expression than HC; (2) within MDD but not HC, those individuals with the lowest NEEV miR-93 expression had the highest serum concentrations of interleukin (IL)-1 receptor antagonist, IL-6, tumor necrosis factor, and leptin; and (3) within HC but not MDD, those participants with the highest miR-93 expression showed the strongest bilateral dorsal mid-insula activation. Since miR-93 is regulated by stress and affects epigenetic modulation by chromatin reorganization, these results suggest that healthy individuals but not MDD participants show an adaptive epigenetic regulation of insular function during interoceptive processing. Future investigations will need to delineate how specific internal and external environmental conditions contribute to miR-93 expression in MDD and what molecular mechanisms alter brain responsivity to body-relevant signals.

The effect of a mindfulness-based stress intervention on neurobiological and symptom measures in adolescents with early life stress: a randomized feasibility study.

BACKGROUND: Early life stress (ELS) has been linked to poor mental and physical health outcomes in adolescence and adulthood. Mindfulness reduces symptoms of depression and anxiety and improves cognitive and social outcomes in both youth and adults. However, little is known whether mindfulness can mitigate against the adverse neurobiological and psychological effects of ELS. This study aimed to examine the feasibility of conducting a group mindfulness intervention in adolescents with ELS and provide preliminary indication of potential effects on stress-related biomarkers and mental health symptoms. METHODS: Forty adolescents were randomized to receive either eight sessions of Mindfulness-Based Stress Reduction for Teens in group format (MBSR-T; n = 21) or Treatment as Usual Control group (CTRL; n = 17). Outcomes were assessed at baseline and follow-up and included measures associated with neurobiological functioning (immune and endocrine biomarkers) and self-reported mental health (depressive) symptoms. Linear mixed effects models were used to assess the effects of group and time on these outcome measures. RESULTS: Sixteen of the 21 adolescents completed the intervention, attending an average of 6.5 sessions. The model examining cortisol responses to stress induction revealed medium effects trending toward significance (Cohen's d = .56) for anticipatory cortisol levels in the MBSR-T relative to CTRL groups. No significant effects were found in models examining C-reactive protein or interleukin 6 inflammatory markers. The model examining depressive symptoms revealed a medium effect for symptom reduction (Cohen's d = .69) in the MBSR-T relative to CTRL groups. CONCLUSIONS: This study demonstrated feasibility of conducting a group-based MBSR-T intervention for adolescents with ELS. There was some evidence for efficacy on a symptom level with potential subtle changes on a biological level. Future larger studies are needed to determine the efficacy of group-based mindfulness interventions in this population. TRIAL REGISTRATION: Identifier # NCT03633903 , registered 16/08/2018.

Electronic Nicotine Delivery Systems and Serum Folate: A Case Study.

INTRODUCTION: In 2018, the US Surgeon General declared youth electronic nicotine delivery systems (ENDS) use as an epidemic. Combustible cigarettes have been shown to adversely affect folate status; however, no study to date has explored how ENDS impact folate status. METHODS: In this case study, a white 18-year-old woman was followed for a 1-month period as part of a larger study. During her participation in the study, a self-report of dietary folate consumption and use of alcohol, tobacco, and other drugs (ATOD) was collected. Each week, dried blood spots were collected to assess red blood cell (RBC) and serum folate. RESULTS: During the first 2 weeks of the study, she used ENDS and her serum folate values were depleted in the ranges of 1.91 to 4.39 µg/L. During the third week, when no ENDS were used, her serum folate value was measured at 29.44 µg/L. When ENDS use resumed during the fourth week, her serum folate value fell to 7.50 µg/L. CONCLUSIONS: This relationship suggests the need for additional studies on ENDS use and serum folate status, particularly among adolescent women who already have the lowest folate status nationally.