Cellular senescence is the irreversible cell cycle arrest in response to various types of stress. Although the plasma membrane and its composition are significantly affected by cellular senescence, detailed studies on the physical properties of the plasma membrane have shown inconclusive results. In this study, we utilized both ensemble and single-molecule fluorescence imaging to investigate how membrane properties, such as fluidity, hydrophobicity, and ganglioside GM1 level are affected by cellular senescence. The diffusion coefficient of lipid probes, as well as the type of diffusion determined by an exponent α, which is the slope of the log-log plot of mean squared displacement as a function of time lag, were analyzed. We found that the number of molecules with a lower diffusion coefficient increased as cells became senescent. The changes in the population with a lower diffusion coefficient, observed after methyl-β-cyclodextrin treatment, and the increase in ceramide levels, detected using a ceramide-specific antibody, suggest that ceramide-rich lipid rafts were enhanced in senescent cells. Our results emphasize the importance of membrane properties in cellular senescence and might serve as a base for in-depth studies to determine how such domains facilitate the signaling pathway specific to cellular senescence.
Bibliographical noteFunding Information:
We thank Dr. Seong Ho Kim for his assistance at the beginning of the project. This work was supported by the National Research Foundation of Korea (NRF) Grant (2021R1A2C2008897 and 2019K1A4A7A02102530) and the KIST Grant (2E31092).
© 2021 American Chemical Society
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry