TOKYO – Researchers at Tokyo Metropolitan University have developed a new method to distinguish “aged” human cells from younger ones using electric fields. Current methods for identifying these “senescent” cells rely on biochemical “labels,” which can be difficult to apply and can alter the cells, hindering research. The new method is label-free and less damaging, and the team plans to adapt it for use with other cell types.

Cellular aging is the foundation of the aging process. As we age, “senescent” cells accumulate, losing function and releasing inflammatory compounds. These cells are implicated in aging-related conditions such as arterial hardening,Alzheimer’s disease,and type 2 diabetes.

Understanding how senescent cells impact our physiology is crucial for developing treatments. This begins with accurately identifying senescent cells. Existing methods involve selective “labeling,” such as attaching fluorescent molecules to compounds present in aged cells. This process is time-consuming, complex, and can alter the cells being studied.

to overcome these limitations, a team led by Assistant Professor Ippei Yagi from Tokyo Metropolitan University has created a new approach. instead of chemical labels, they expose cells to an alternating electric field, causing a slight charge rearrangement. When the electric field is non-uniform,the cell migrates back and forth between electrodes. the cell’s motion changes significantly with the field’s frequency, at a value called the cutoff frequency. This method, frequency-modulated dielectrophoresis (FM-DEP), characterizes cell type by measuring this cutoff frequency.

The team studied human dermal fibroblasts, a key component of skin connective tissue. They found a important difference in cutoff frequencies between senescent and younger cells. These differences arise from changes in the lipid molecules that make up the cell membrane. FM-DEP is fast, easy to use, and label-free.

The new method is a valuable tool for aging research and has potential applications in regenerative medicine and drug screening. The team aims to extend FM-DEP to other cell types, creating a versatile cell identification method.

This research was supported by JSPS KAKENHI Grant Numbers JP23K28453 and JP23KK0260.

Understanding Cellular Senescence