Chemical Imaging of RNA-Tau Amyloid Fibrils at the Nanoscale Using Tip-Enhanced Raman Spectroscopy

In the presence of cofactors, tau protein can form amyloid deposits in the brain which are implicated in many neurodegenerative disorders. Heparin, lipids, and RNA are used to recreate tau aggregates in vitro from recombinant protein. However, the mechanism of interaction of these cofactors and the interactions between cofactors and tau are poorly understood. Herein, we use tip-enhanced Raman spectroscopy (TERS) to visualize the spatial distribution of adenine, protein secondary structure, and amino acids (arginine, lysine and histidine) in single polyadenosine (polyA)-induced tau fibrils with nanoscale spatial resolution (<10-20 nm). Based on reference unenhanced and surface-enhanced Raman spectra, we show that the polyA anionic cofactor is incorporated in the fibril structure and seems to be superficial to the β-sheet core, but nonetheless enveloped within the random-coiled fuzzy coat. TERS images also prove the colocalization of positively charged arginine, lysine, and histidine amino acids and negatively charged polyA, which constitutes an important step forward to better comprehend the action of RNA cofactors in the mechanism of formation of toxic tau fibrils. TERS appears as a powerful technique for the identification of cofactors in individual tau fibrils and their mode of interaction.

An interactive video increasing French students' mental health literacy: a mixed-methods randomized controlled pilot study

Mental health literacy (MHL) is a determinant of psychological well-being in young people. A randomized controlled design was used to evaluate the appreciation and effectiveness of an interactive video on French University students' MHL (knowledge about depression and suicidal behavior, mental health help-seeking behaviors, stigma and misconceptions about mental health). At the baseline, all participants (n = 101) completed a questionnaire including several scales on MHL. One month after, participants were randomly assigned to two homogeneous groups (intervention, n = 50 or control, n = 51) and again completed the questionnaire on MHL. Through a mixed-methods approach, semi-structured interviews were also conducted with the intervention group to collect information on the appreciation of the interactive video. Quantitative data indicated that MHL scores increased or remained stable in the intervention group. Comparison with the control group and multivariate logistic regression models did not show statistically significant differences, due to the small sample of the study. According to qualitative data, users appreciated the content and the format of the intervention. It was suggested that the video could be disseminated in other University campuses in France and internationally to promote MHL among students.