Amyloid ß (Aß) peptide directly activates amylin-3 receptor subtype by triggering multiple intracellular signaling pathways.

The two age-prevalent diseases Alzheimer disease and type 2 diabetes mellitus share many common features including the deposition of amyloidogenic proteins, amyloid ß protein (Aß) and amylin (islet amyloid polypeptide), respectively. Recent evidence suggests that both Aß and amylin may express their effects through the amylin receptor, although the precise mechanisms for this interaction at a cellular level are unknown. Here, we studied this by generating HEK293 cells with stable expression of an isoform of the amylin receptor family, amylin receptor-3 (AMY3). Aß1-42 and human amylin (hAmylin) increase cytosolic cAMP and Ca(2+), trigger multiple pathways involving the signal transduction mediators protein kinase A, MAPK, Akt, and cFos. Aß1-42 and hAmylin also induce cell death during exposure for 24-48 h at low micromolar concentrations. In the presence of hAmylin, Aß1-42 effects on HEK293-AMY3-expressing cells are occluded, suggesting a shared mechanism of action between the two peptides. Amylin receptor antagonist AC253 blocks increases in intracellular Ca(2+), activation of protein kinase A, MAPK, Akt, cFos, and cell death, which occur upon AMY3 activation with hAmylin, Aß1-42, or their co-application. Our data suggest that AMY3 plays an important role by serving as a receptor target for actions Aß and thus may represent a novel therapeutic target for development of compounds to treat neurodegenerative conditions such as Alzheimer disease.

Pediatric Chronic Tracheostomy Care: An Evaluation of an Innovative Competency-Based Education Program for Community Health Care Providers.

Objective: To evaluate the immediate and sustained knowledge retention and sense of self-efficacy of homecare nurses following completion of a standardized competency-based tracheostomy education course. Safe discharge of children requiring tracheostomy with or without ventilation relies on the competence of homecare nurses. Study Design: Pragmatic, randomized controlled trial of 44 homecare nurses. Participants were randomized into the intervention group (n = 21), which received the tracheostomy course, or the control group (n = 23), which received an enterostomy and vascular access course. Multiple-choice question (MCQ) knowledge assessments and self-efficacy questionnaires were administered to both groups pre-course and post-course at 6 week, 3 month, 6 month, and 12 month follow-ups. Results: Twenty participants in the intervention group and 19 in the control group were included. Four withdrew from the study and two crossed over from the control into the intervention arm. The change in mean self-efficacy scores (total score = 100) was significantly higher in the intervention group than in the control group at 6 weeks (intervention (mean ± SD): 18.6 ± 14.5; control: 6.6 ± 20.4; p = 0.04) and 3 months (intervention: 19.6 ± 14.2; control: 5.2 ± 17.0; p = 0.007), and trended higher at 6 months (intervention: 18.0 ± 14.5; control: 6.9 ± 24.1; p = 0.1). The change in mean MCQ assessment scores (total score = 20) trended higher in the intervention group than in the control group at 6 weeks (intervention (mean ± SD): 1.8 ± 2.2; control: 1.6, ± 2.9; p = 0.8). Conclusions: Homecare nurses who attended the tracheostomy course demonstrated a higher sense of self-efficacy at long-term follow-up. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT04559932.