Aiko Sada

• Ph.D
• Professor at Kyushu University

The interfollicular epidermis regenerates from heterogeneous basal skin cell populations that divide at different rates. It has previously been presumed that infrequently dividing basal cells known as label-retaining cells (LRCs) are stem cells, whereas non-LRCs are short-lived progenitors. Here we employ the H2B-GFP pulse-chase system in adult mou...

Delayed wound healing and reduced barrier function with an increased risk of cancer are characteristics of aged skin and one possible mechanism is misregulation or dysfunction of epidermal stem cells during aging. Recent studies have identified heterogeneous stem cell populations within the mouse interfollicular epidermis that are defined by territ...

Aging in the epidermis is marked by a gradual decline in barrier function, impaired wound healing, hair loss, and an increased risk of cancer. This could be due to age‐related changes in the properties of epidermal stem cells and defective interactions with their microenvironment. Currently, no biochemical tools are available to detect and evaluate...

Adult tissues contain label-retaining cells (LRCs) which are relatively slow-cycling and considered to represent a property of tissue stem cells (SCs). In the ocular surface epithelium, LRCs are present in the limbus and conjunctival fornix; however, the character of these LRCs remains unclear due to lack of appropriate molecular markers. Using thr...

Epithelial stem cells exhibit heterogeneity, with distinct stem cell populations occupying specific tissue regions. The human skin displays a characteristic undulating structure at the epidermal-dermal junction, which supports mechanical strength and influences the spatial organization of epithelial stem cells. Unlike human skin, mouse skin lacks t...

Tissue stem cells (SCs) divide infrequently as a protective mechanism against internal and external stresses associated with aging. Here, we demonstrate that slow- and fast-cycling SCs in the mouse skin epidermis undergo distinct aging processes. Two years of lineage tracing reveals that Dlx1+ slow-cycling clones expand into the fast-cycling SC ter...

Tissue stem cells divide infrequently as a protective mechanism against internal and external stresses associated with aging. Here, we demonstrate that slow- and fast-cycling interfollicular epidermal stem cells in mouse skin undergo distinct aging processes. Two years of lineage tracing reveals that Dlx1+ slow-cycling clones expanded into the fast...

The maladaptive remodeling of vessel walls with neointima formation is a common feature of proliferative vascular diseases. It has been proposed that neointima formation is caused by the dedifferentiation of mature smooth muscle cells (SMCs). Recent evidence suggests that adventitial cells also participate in neointima formation; however, their cel...

Stem cell (SC) proliferation and differentiation organize tissue homeostasis. However, how SCs regulate coordinate tissue scaling in dynamic organs remain unknown. Here, we delineate SC regulations in dynamic skin. We found that interfollicular epidermal SCs (IFESCs) shape basal epidermal proliferating clusters (EPCs) in expanding abdominal epiderm...

Adult tissues contain label-retaining cell (LRC)s, which are relatively slow-cycling and considered to represent a unique property of tissue stem cell (SC)s. In the ocular surface epithelium, LRCs are detected in the limbus, a boundary between cornea and conjunctiva, and the fornix of the conjunctiva; however, the character of LRCs and identity of...

Epigenetic mechanisms controlling adult mammalian stem cell (SC) dynamics might be critical for tissue regeneration but are poorly understood. Mouse skin and hair follicle SCs (HFSCs) display reduced histone H3 K4me3, K9me3, and K27me3 methylation levels (hypomethylation) preceding hair growth. Chemical inhibition of relevant histone demethylases i...

Aging in the skin epidermis is marked by a gradual decline in barrier function, impaired wound healing and an increased risk of cancer. This could be due to an age-related change in the property of epidermal stem cells or defective interactions with its microenvironment and/or other cell types in the skin. There have been conflicting reports for ag...

Ectopic calcification occurs during development of chronic kidney disease and has a negative impact on long-term prognosis. The precise molecular mechanism and prevention strategies, however, are not established. Fibulin-7 (Fbln7) is a matricellular protein structurally similar to elastogenic short fibulins, shown to bind dental mesenchymal cells a...

In many adult tissues, homeostasis relies on self-renewing stem cells that are primed for differentiation. The reconciliation mechanisms of these characteristics remain a fundamental question in stem cell biology. We propose that regulation at the post-transcriptional level is essential for homeostasis in murine spermatogonial stem cells (SSCs). He...

Stem cells can self-renew and differentiate over extended periods of time. Understanding how stem cells acquire their fates is a central question in stem cell biology. Early work in Drosophila germ line and neuroblast showed that fate choice is achieved by strict asymmetric divisions that can generate each time one stem and one differentiated cell....

Stem cells are maintained by both stem cell-extrinsic niche signals and stem cell-intrinsic factors. During murine spermatogenesis, glial cell line-derived neurotrophic factor (GDNF) signal emanated from Sertoli cells and germ cell-intrinsic factor NANOS2 represent key regulators for the maintenance of spermatogonial stem cells. However, it remains...

The regulation of gene expression via a 3' untranslated region (UTR) plays essential roles in the discrimination of the germ cell lineage from somatic cells during embryogenesis. This is fundamental to the continuation of a species. Mouse NANOS3 is an essential protein required for the germ cell maintenance and is specifically expressed in these ce...

Maintaining Germline Stem Cells Spermatogonial stem cell pools in postnatal testes have to be maintained to continuously generate spermatozoa. It has been difficult to identify these stem cells in vivo, because of their small numbers and lack of appropriate molecular markers, but now Sada et al. (p. 1394 ) show that the RNA-binding protein NANOS2 i...

Spermatogonial stem cells (SSCs) reside in undifferentiated type-A spermatogonia and contribute to continuous spermatogenesis by maintaining the balance between self-renewal and differentiation, thereby meeting the biological demand in the testis. Spermatogonia have to date been characterized principally through their morphology, but we herein repo...

The expression of C/EBPalpha, which may govern transcription of mature hepatocyte marker genes, was suppressed in periportal hepatoblasts in mouse liver development, leading to biliary cell differentiation. This study was undertaken to analyze how inactivation of the Cebpa gene affects biliary cell differentiation and gene expression of the regulat...