A protocol for isolation and culturing of mouse primary postmitotic photoreceptors and isolation of extracellular vesicles.

Here, we present a protocol for isolating and culturing mouse photoreceptors in a minimal, chemically defined medium free from serum. We describe steps for retina dissection, enzymatic dissociation, photoreceptor enrichment, cell culture, extracellular vesicles (EVs) enrichment, and EV ultrastructural analysis. This protocol, which has been verified for cultured cells derived from multiple murine strains, allows for the study of several aspects of photoreceptor biology, including EV isolation and nanotube formation. For complete details on the use and execution of this protocol, please refer to Kalargyrou et al. (2021).1.

Antioxidant and lipid supplementation improve the development of photoreceptor outer segments in pluripotent stem cell-derived retinal organoids.

The generation of retinal organoids from human pluripotent stem cells (hPSC) is now a well-established process that in part recapitulates retinal development. However, hPSC-derived photoreceptors that exhibit well-organized outer segment structures have yet to be observed. To facilitate improved inherited retinal disease modeling, we determined conditions that would support outer segment development in maturing hPSC-derived photoreceptors. We established that the use of antioxidants and BSA-bound fatty acids promotes the formation of membranous outer segment-like structures. Using new protocols for hPSC-derived retinal organoid culture, we demonstrated improved outer segment formation for both rod and cone photoreceptors, including organized stacked discs. Using these enhanced conditions to generate iPSC-derived retinal organoids from patients with X-linked retinitis pigmentosa, we established robust cellular phenotypes that could be ameliorated following adeno-associated viral vector-mediated gene augmentation. These findings should aid both disease modeling and the development of therapeutic approaches for the treatment of photoreceptor disorders.

Monitoring eating and activity: Links with disordered eating, compulsive exercise, and general wellbeing among young adults.

OBJECTIVE: To explore the relationships between the use of food intake and activity monitoring tools with compulsive exercise, eating psychopathology, and psychological wellbeing. METHOD: Participants (N = 352; mean age 21.90 years) indicated their use of activity and food intake monitoring tools, and completed the Compulsive Exercise Test (CET), Eating Disorders Examination Questionnaire (EDE-Q), and the Warwick Edinburgh Mental Wellbeing Scale (WEMWBS). RESULTS: Users of monitoring tools reported significantly higher CET and EDE-Q scores than nonusers. Positive associations were detected between the frequency of activity monitoring tool use with CET and EDE-Q scores. Participants who reported using monitoring tools primarily to manage weight and shape reported higher levels of eating and compulsive exercise psychopathology than those who reported using tools to improve health and fitness. DISCUSSION: Features of compulsive exercise and eating psychopathology are elevated among users of food intake and activity monitoring tools; and particularly among those who report using the tools for weight and shape purposes. Longitudinal and experimental research is needed to further our understanding of these observed associations, and specifically to explore the prospective relationships between monitoring tool use, eating psychopathology, and compulsive exercise.