Extracellular proteoglycan decorin maintains human hair follicle stem cells

Abstract

Hair follicle stem cells (HFSC) are localized in the bulge region of the hair follicle and play a role in producing hair. Recently, it has been shown that the number of HFSC decreases with age, which is thought to be a cause of senile alopecia. Therefore, maintaining HFSC may be key for the prevention of age‐related hair loss, but the regulatory mechanisms of HFSC and the effects of aging on them are largely unknown. In general, stem cells are known to require regulatory factors in the pericellular microenvironment, termed the stem cell niche, to maintain their cell function. In this study, we focused on the extracellular matrix proteoglycan decorin (DCN) as a candidate factor for maintaining the human HFSC niche. Gene expression analysis showed that DCN was highly expressed in the bulge region. We observed decreases in DCN expression as well as the number of KRT15‐positive HFSC with age. In vitro experiments with human plucked hair‐derived HFSC revealed that HFSC lost their undifferentiated state with increasing passages, and prior to this change a decrease in DCN expression was observed. Furthermore, knockdown of DCN promoted HFSC differentiation. In contrast, when HFSC were cultured on DCN‐coated plates, they showed an even more undifferentiated state. From these results, as a novel mechanism for maintaining HFSC, it was suggested that DCN functions as a stem cell niche component, and that the deficit of HFSC maintenance caused by a reduction in DCN expression could be a cause of age‐related hair loss.

Genome-wide detection of RNA editing events during the hair follicles cycle of Tianzhu white yak

“…HFs stem cells decide hair regrowth and its maintenance relies on the specific niche. It is known the number of HFs stem cells decreases with age, as HFs stem cell niche component, DCN has been suggested as a candidate factor that is related to age-regulated hair loss [ 54 ]. The development of epithelial cells is essential for hair morphogenesis, Desmocollin-2 ( DSC2 ) has been demonstrated plays a vital role in regulating epithelial morphogenesis [ 55 ].…”

Telomere Dynamics and Telomerase in the Biology of Hair Follicles and their Stem Cells as a Model for Aging Research

“…It remains to be explored whether alterations in TL in HF ESCs in distinct HF regions and/or their progeny in the outer root sheath and hair matrix are associated with human hair diseases. These include not only chemotherapy-or radiotherapy-induced alopecia but also cicatricial (scarring) alopecia, androgenetic alopecia (AGA), telogen effluvium, and long-standing cases of alopecia areata (Gao et al, 2019;Miyachi et al, 2018;Trüeb and Tobin, 2010;Yoshida et al, 2011) (Figure 2).…”

Development and Maintenance of Epidermal Stem Cells in Skin Adnexa

“…Laminin 332, as a component of the basal lamina, allows anchoring COL17A1 + SCs in a bulge; the anchorage is crucial for the maintenance of HFSCs [47]. The bulge region is also enriched with the proteoglycan decorin [48] that can bind TGF-β1 and interact with EGFR. The upper bulb SCs produce another extracellular matrix (ECM) molecule, EGFL6, that is released by upper bulge cells together with BDNF and is required for the sensitive innervation and the organisation of lanceolate mechanosensory complexes.…”