Induction, regulation and roles of neural adhesion molecule L1CAM in cellular senescence

Area of Science:

• Cellular senescence
• Aging research
• Biomarker discovery

Background:

• Senescent cells (SC) accumulate with age and contribute to aging-associated diseases.
• Targeting SC with senolytic therapies may promote organismal rejuvenation.
• Identifying specific markers on SC is crucial for effective targeting.

Purpose of the Study:

• To identify novel cell-surface proteins differentially expressed on human senescent cells.
• To investigate the regulation and functional role of identified markers in senescence.

Main Methods:

• Comparative proteomic analysis of replicatively senescent human fibroblasts.
• Validation of protein expression changes in various senescence models (chemical, radiation, genetic).
• Investigation of signaling pathways (TGFbeta, RAS/MAPK) and metabolic influences on marker expression.

Main Results:

• Identified 78 enriched and 73 underrepresented proteins on senescent cells.
• Discovered L1CAM (normally restricted to neural system and kidneys) is induced in specific senescence types.
• L1CAM induction is linked to p16INK4a, TGFbeta signaling, and metabolic pathways, but not Ras-induced senescence.
• Senescent cells with increased L1CAM expression exhibit enhanced adhesion and migration.

Conclusions:

• L1CAM is a novel, dynamically regulated marker associated with cellular senescence.
• Senescence development involves intricate regulation by cell growth, metabolism, and signaling pathways.
• Findings provide mechanistic insights into senescence and potential targets for future senolytic strategies.