Visualization of aging-associated chromatin alterations with an engineered TALE system

Area of Science:

• Molecular Biology
• Genomics
• Cell Biology

Background:

• Accurate visualization of specific genomic loci in live cells is crucial for studying dynamic chromatin changes during processes like cellular aging.
• Existing precision genomic imaging techniques are limited by the lack of specific fluorescent probes with high signal-to-noise contrast.
• Conventional transcription activator-like effectors (TALEs) often form protein aggregates, hindering their utility in imaging.

Purpose of the Study:

• To develop an improved TALE-based genomic imaging method with enhanced specificity and signal-to-noise ratio.
• To investigate aging-associated genomic alterations in live cells using the novel imaging technique.
• To identify novel molecular markers for human aging.

Main Methods:

• Screening and development of thioredoxin-fused TALEs (TTALEs) to prevent protein aggregation.
• High-quality live-cell imaging of various genomic loci using TTALEs.
• Observation and analysis of epigenetic alterations at telomeres and centromeres in human and mouse premature aging models.

Main Results:

• Fusion of thioredoxin with TALEs effectively prevented aggregate formation, enabling robust genomic imaging.
• TTALEs facilitated high-quality imaging of diverse genomic loci.
• Aging-associated epigenetic alterations were observed at telomeres and centromeres in premature aging models.
• Attrition of ribosomal DNA repeats was identified as a molecular marker for human aging.

Conclusions:

• Thioredoxin-fused TALEs (TTALEs) provide a simple, robust, and effective method for precise chromatin dynamics monitoring in vitro and in vivo.
• This advanced imaging approach overcomes limitations of previous methods, offering improved specificity and signal-to-noise contrast.
• The identification of ribosomal DNA repeat attrition offers a new molecular marker for understanding and potentially tracking human aging.