The aging is defined as the decline of the function of tissue and organisms, and has led to many human diseases, including cancer and neurodegenerative diseases. Although people have generally recognized that the depletion of stem cells is a sign of aging, few people have observed the cell activity of tissue stem cells during aging in a complete micro -ring. To a large extent, people still do not know how tissue stem cells are split, relocated, and perished during aging. Due to these basic cell behaviors, the current understanding of tissue autologous cell aging is obtained by indirect measurement of the number and function of autologous cells. Therefore, our understanding of stem cell depletion is mainly limited to the lack of cell division and self -renewal, which is usually caused by DNA damage and cell aging.
In the basic characteristics of tissue stem cells, the static state is known. It plays an important role in the maintenance of stem cells by restricting the number of stem cell division and reducing the pressure of cells. Although the loss of static stomach is proven to cause losses of the potential of stem cell proliferation in the way of cells, when the stem cells lose their static state, their activities have not been visualized. In addition, people do not know whether the loss of stem cells will be independent of cell split control and affect the integrity of stem cell areas. Finally, in the process of aging, the split rate of stem cells usually decreases; how to affect aging for a long time is still an open issue.
Recently, researchers took hair follicle stem cells as an example to conduct research on this issue. They found that among the elderly mice, epithelial cells fled from the stem cell area of the hair follicles (HF) to the leather, resulting in miniaturization of the hair follicles.
Single cell RNA-SEQ and seatering enzymes and chromosome sequencing (ATAC-SEQ) show that the expression of cell adhesion and extracellular matrix genes in elderly hair follicles stem cells is adjusted by FOXC1 and NFATC1. The lack of FOXC1 and NFATC1 reproduces the miniaturization of the hair follicles and leads to hair loss.
In addition, living imaging captures the migration of a single epithelial cell from stem cell interval and the disintegration of hair follicles.
In short, this study revealed that the activity of the unknown epithelial cells that has so far escaped its micro -environment is a mechanism of reduced stem cells and tissue degeneration. The identification of homeless epithelial cells in elderly tissue provides a new perspective for understanding of disease -related diseases.
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Chi zhang al. Escape of hair follicle stics causes sthaustion during aging. Nature aging (2021).