Basic Science and Pathogenesis

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Alzheimer's disease (AD) is the leading cause of dementia, characterized by neurofibrillary tangles and amyloid plaques.
• Familial AD (FAD), an early-onset form, is caused by mutations in APP, PS1, or PS2 genes.
• Previous studies indicate altered autophagy pathways in FAD fibroblasts.

Purpose of the Study:

• To investigate macroautophagy and chaperone-mediated autophagy (CMA) in fibroblasts from familial Alzheimer's disease (FAD) patients.
• To assess potential dysregulation of autophagy and CMA pathways in FAD.

Main Methods:

• Fibroblasts from FAD patients and healthy controls were cultured and analyzed.
• Western blotting was employed to characterize macroautophagy and CMA markers.
• Autophagic activity and flux were measured using Cyto-ID assay and Premo™ Autophagy Tandem Sensor, with autophagy induced by fasting and chloroquine.

Main Results:

• FAD fibroblasts exhibited increased autophagy activity (elevated LC3 expression) despite very low autophagy flux.
• Chaperone-mediated autophagy (CMA) markers, LAMP2a and Hsc70, were found to be downregulated in FAD cells.
• Significant variations in autophagy activity were observed between FAD and healthy control cells.

Conclusions:

• Autophagy activity and CMA markers are dysregulated in fibroblasts from FAD patients compared to healthy individuals.
• These findings in peripheral cells suggest potential for novel biomarkers and therapeutic targets for FAD.
• The study highlights the utility of FAD fibroblasts for drug testing and early diagnostic strategies.