Publications by authors named "Koh-ei Toyoshima"

Biological rhythms are involved in almost all types of biological processes, not only physiological processes but also morphogenesis. Currently, how periodic morphological patterns of tissues/organs in multicellular organisms form is not fully understood. Here, using mouse zigzag hair, which has 3 bends, we found that a change in the combination of hair progenitors and their micro-niche and subsequent bend formation occur every three days.

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In mammals, organ induction occurs only during embryonic development except for hair follicles (HFs). However, HF-resident epithelial stem cells (HFSCs), which are responsible for repetitive HF regeneration, are not fully characterized. Here, we establish in vitro culture systems that are capable of controlling the ability of HFSCs to regenerate HFs.

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Organ systems play essential roles in the physiological functions required for homeostasis. A 3D integumentary organ system (3D-IOS) comprises the skin and skin appendages such as hair follicles and sebaceous glands. This protocol describes how to induce the differentiation of murine induced pluripotent stem (iPS) cells into a 3D-IOS.

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Skin tissues, in particular the epidermis, are severely affected by zinc deficiency. However, the zinc-mediated mechanisms that maintain the cells that form the epidermis have not been established. Here, we report that the zinc transporter ZIP10 is highly expressed in the outer root sheath of hair follicles and plays critical roles in epidermal development.

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Hair follicles develop from the ectoderm in embryos and cyclically regenerate using proper spatiotemporal signaling molecules, which are conserved in organogenesis during adulthood. Previously, we demonstrated that bioengineered hair follicle germs could regenerate functional hair follicles via a three-dimensional cell manipulation technique, which we named the "organ germ method ." We could also regulate the type of hair follicle and pigmentation with correct structures by rearranging the source of the cells.

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Hair follicle morphogenesis is first induced by epithelial-mesenchymal interactions in the developing embryo. In the hair follicle, various stem-cell populations are maintained in specialized niches to promote repetitive hair follicle-morphogenesis, which is observed in the variable lower region of the hair follicle as a postnatal hair cycle. In contrast, the genesis of most organs is induced only once during embryogenesis.

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The integumentary organ system is a complex system that plays important roles in waterproofing, cushioning, protecting deeper tissues, excreting waste, and thermoregulation. We developed a novel in vivo transplantation model designated as a clustering-dependent embryoid body transplantation method and generated a bioengineered three-dimensional (3D) integumentary organ system, including appendage organs such as hair follicles and sebaceous glands, from induced pluripotent stem cells. This bioengineered 3D integumentary organ system was fully functional following transplantation into nude mice and could be properly connected to surrounding host tissues, such as the epidermis, arrector pili muscles, and nerve fibers, without tumorigenesis.

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Purpose: The aim of this study was to compare saliva flow and protein composition induced using five basic taste stimulations between natural and bioengineered salivary glands.

Materials And Methods: We developed a mouse saliva secretion model using taste stimulation and analyzed the saliva secretion from natural and bioengineered salivary glands using an assay. The protein components and alpha-amylase in the natural and bioengineered saliva were analyzed by gel electrophoresis and Western blotting.

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Organ regenerative therapy aims to reproduce fully functional organs to replace organs that have been lost or damaged as a result of disease, injury, or aging. For the fully functional regeneration of ectodermal organs, a concept has been proposed in which a bioengineered organ is developed by reproducing the embryonic processes of organogenesis. Here, we show that a bioengineered hair follicle germ, which was reconstituted with embryonic skin-derived epithelial and mesenchymal cells and ectopically transplanted, was able to develop histologically correct hair follicles.

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Organ replacement regenerative therapy is purported to enable the replacement of organs damaged by disease, injury or aging in the foreseeable future. Here we demonstrate fully functional hair organ regeneration via the intracutaneous transplantation of a bioengineered pelage and vibrissa follicle germ. The pelage and vibrissae are reconstituted with embryonic skin-derived cells and adult vibrissa stem cell region-derived cells, respectively.

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The autologous transplantation of hair follicles that have been separated into single follicular units is an accepted treatment for androgenetic alopecia. Recent studies demonstrate that the multiple stem cell populations and surrounding cutaneous tissues coordinately regulate the hair follicle functions and skin homeostasis. Therefore, the critical issues for consideration regarding functional hair restoration therapy are reproduction the correct connectivity and cooperation with host cutaneous tissues, including the arrector pili muscle (APM) and nerve system.

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Female pattern hair loss (FPHL) is frequently referred to as female androgenetic alopecia (FAGA). However, the role of androgen in this type of hair loss remains uncertain. We previously reported greater therapeutic efficacy of finasteride in Japanese male androgenetic alopecia (MAGA) patients in cases where the CAG repeats of the androgen receptor (AR) gene were short.

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We previously showed that cultured rat dermal papilla cells (DPCs) retain their hair-inducing capacity on afollicular epidermal cell (EPCs). Here, we examined the hair growth-inducing capacity of differently subcultured DPCs by transplanting them, along with rat EPCs, onto the backs of nude mice (graft chamber assay). DPCs at passage (p) 6 (DPCs(p6) or, more generally, low-passage DPCs) induced hair formation.

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