Quantifying Senescence-Associated Phenotypes in Primary Multipotent Mesenchymal Stromal Cell Cultures

Area of Science:

• Cellular and Molecular Biology
• Gerontology
• Regenerative Medicine

Background:

• Cellular senescence acts as a tumor suppressor mechanism by halting the proliferation of potentially cancerous cells.
• Senescent cells accumulate with age, and their excessive presence can impair tissue function and contribute to age-related diseases.
• Multipotent mesenchymal stromal cells (MSCs), vital for cell-based therapies, are susceptible to senescence, impacting their therapeutic potential and role in aging.

Purpose of the Study:

• To provide strategies for the molecular characterization and validation of senescence in MSCs.
• To understand the clinical relevance of MSC senescence in human aging and age-related diseases.
• To identify reliable markers for selecting competent MSCs for therapeutic applications and targeting senescent MSCs.

Main Methods:

• Measuring senescence-associated β-galactosidase (SA-βgal) activity.
• Assessing cell cycle arrest.
• Detecting persistent DNA damage response (DDR) signaling.
• Analyzing the senescence-associated secretory phenotype (SASP).

Main Results:

• No single hallmark is sufficient for identifying senescent MSCs due to the complexity of the senescence phenotype.
• A combination of key hallmarks, including SA-βgal activity, cell cycle arrest, DDR signaling, and SASP, is necessary for robust validation.
• This approach aids in distinguishing functional MSCs from senescent ones.

Conclusions:

• Accurate identification of senescent MSCs is critical for both understanding aging processes and optimizing cell-based therapies.
• Targeting senescent MSCs may offer a novel therapeutic strategy for age-related diseases.
• Validated MSC senescence markers are essential for ensuring the efficacy and safety of MSC-based regenerative medicine.