Compartment-specific eccDNA patterns reveal senescence associated biomarkers in hUC-MSCs

Area of Science:

• Stem Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Therapeutic applications of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are hindered by replicative senescence during in vitro expansion.
• Understanding the molecular mechanisms underlying hUC-MSC senescence is crucial for optimizing their clinical utility.

Purpose of the Study:

• To investigate the dynamics of extrachromosomal circular DNA (eccDNA) in different cellular compartments during hUC-MSC aging.
• To explore the potential of eccDNA as a biomarker for monitoring hUC-MSC senescence.

Main Methods:

• Establishment of a long-term passaging model for hUC-MSCs to induce and study senescence.
• Integrated transcriptomic and eccDNA profiling of cell pellets (CP), cell culture media (CM), and extracellular vesicles (EVs) at sequential timepoints.
• Validation of senescence-associated phenotypes.

Main Results:

• eccDNA abundance in CP remained stable, while CM and EVs showed increased eccDNA loads compared to CP during senescence.
• CM- and EVs-derived eccDNAs exhibited distinct size distribution patterns compared to CP-derived eccDNAs.
• Compartment-specific eccDNA dynamics correlated with the activation of growth-regulatory gene expression, and recurrent eccDNA species harbored senescence-associated genes.

Conclusions:

• eccDNA exhibits distinct compartment-specific dynamics during hUC-MSC aging.
• eccDNA profiles in CM and EVs may serve as potential biomarkers for senescence monitoring.
• These findings provide insights into mitigating senescence-related limitations for hUC-MSC-based therapies.