A cell-penetrable mini-chaperone extends the lifespan of Caenorhabditis elegans and alleviates β amyloid-induced toxicity

Abstract

Purpose : A peptide chaperone representing the active site region of the αA-crystallin chaperone has potential therapeutic value in diseases involving protein aggregation, oxidative stress, and apoptosis. The goal of this study is to explore the therapeutic potentials of a modified αA-crystallin peptide chaperone having cell-penetrable property using the Caenorhabditis elegans as the model system.

Methods : Cell-penetrable mini-chaperones (CPMCs) and scrambled peptide controls were obtained from Genscript. C. elegans strains used in the study were from CGC, University of Minnesota, MN, USA. The chaperone-like activity of the peptides was tested in vitro using aggregating alcohol dehydrogenase and citrate synthase as substrates. The entry of peptides into worms was confirmed by fluorescence microscopy using FITC labeled peptides. The effect of peptides on the worm lifespan was tested at 20^oC employing wild-type (N2) worms grown on nematode growth media (2 ml) and fed with 50 μg peptide along with E. coli OP50 food source. The response of peptide-treated worms against thermal-induced stress was observed at 35^oC using wild-type (N2) and α-synuclein expressing NL5901 strain. The ability of the CPMCs to attenuate beta-amyloid aggregation-induced paralysis and survival was tested in CL4176 strain expressing β-amyloid peptide.

Results : The CPMCs showed enhanced chaperone-like activity when compared to mini-chaperones without the cell-penetrating sequence. CPMC peptide treatment augments the survival of worms by 23% without affecting their feeding behavior and reproductive health. Wild-type worms (N2) pre-treated with the CPMC peptide (50 µg) for 4h at 20^oC and then subjected to thermal stress (35^oC) showed increased (84%) thermotolerance. C. elegans fed with scrambled peptide control did not improve the worm lifespan and thermotolerance. CPMCs readily entered cells and protected worms against chemical-induced oxidative stress. CPMC-treatment delays β-amyloid induced paralysis and extend survival (16%) under temperature up-shift (15-25^oC).

Conclusions : Our findings indicate the beneficial and therapeutic potential of αA-crystallin based CPMCs against aging and age-related proteinopathies. The outcome of the present study can be extended to future investigation to gain mechanistic insights into the impending role of CPMCs.

This is a 2020 ARVO Annual Meeting abstract.