Blank Spots in the Map of Human Skin: The Challenge for Xenotransplantation

This review discusses the patterns and regulatory mechanisms of keratin expression in various biological conditions and reports no new experimental results.

This study indicates that innate lymphoid cells-type 1 may provoke alopecia areata by disrupting hair follicle immune privilege and inducing characteristic lesions, challenging the view that alopecia areata is purely an autoantigen-dependent, T cell-driven condition.

This review discusses factors affecting wound-induced hair neogenesis in mice and reports no new results; it aims to facilitate meaningful comparisons of experiments across different laboratories.

This review covers the structure, development, cycle, and molecular regulation of hair follicles but does not report new results, aiming to offer insights for addressing hair follicle-related diseases.

This study found that CD26+ fibroblasts are crucial for effective extracellular matrix production and achieving rapid epidermal and dermal homeostasis in human tissue-engineered skin substitutes transplanted onto rodents.

This study examined aging hair follicle stem cells in mice and found that inflammation reduction in dermal white adipose tissue can stimulate regenerative behavior, highlighting its role in hair follicle aging.

This study demonstrates that dermal white adipose tissue regulates human hair growth and pigmentation through hepatocyte growth factor secretion, highlighting potential therapeutic targets for hair-related disorders.

This review discusses how inflammation influences hair follicle stem cell activities like wound healing and follicle cycling and suggests a potential link between inflammation, stem cell activation, and programmed cell death.

In this study, researchers found that extrafollicular progenitors marked by Hic1 are the main contributors to reparative fibroblasts in wound repair, with potential to modulate healing outcomes through genetic and pharmacological interventions.

This study found that in mice, dermal adipocytes initiate inflammation and aid repair after skin injury by releasing lipids, suggesting a role in managing inflammatory diseases and impaired wound healing.

This review discusses the role of the immune niche in hair follicle regeneration and its impact on different forms of alopecia, highlighting research gaps and potential therapeutic strategies.

This study explored the complex roles of niche cells in regulating hair follicle stem cells, identifying specific cell functions such as signaling, sensing, and relaying messages, which could provide insights into treating hair loss conditions like androgenetic alopecia and alopecia areata.

This study found that mature dermal adipocytes have high plasticity, undergoing dedifferentiation and redifferentiation, which plays a significant role in hair cycling and wound healing.

This review discusses dermal cell heterogeneity in wound healing and scar formation, highlighting the varied roles of different fibroblasts and the potential of skin substitutes without presenting new clinical results.

This study found that Lgr5 and Lgr6 stem cells both activated wound-healing genes, but only Lgr5 stem cells changed their identity to contribute to new skin formation during wound repair.

In this study, iNKT10 cells were found to play a significant role in preventing and treating alopecia areata in a humanized mouse model, suggesting these cells could have potential in managing related autoimmune disorders.

Two main types of fibroblasts with unique functions and additional subtypes were identified in human skin.

This study identified at least four distinct fibroblast populations in adult human skin, each with unique functional properties, suggesting potential therapeutic applications for wound healing and fibrosis-related diseases.

This review discusses the limitations of animal models, particularly mice, in accurately predicting human skin wound healing outcomes and emphasizes understanding species-specific differences in skin characteristics for better translation to clinical settings.

This study found that hair follicles in mice and humans can convert wound-related myofibroblasts into adipocytes, suggesting a potential pathway to reduce scar formation by activating BMP signaling.

This study observed that applying JAK-STAT pathway inhibitors to mouse and human skin led to rapid hair growth by inducing the anagen phase of hair follicles.

This article presents a comprehensive guide for classifying human hair follicle cycle stages in vivo using scalp xenografts on immunocompromised mice, offering valuable resources for researchers in the field.

This review revisits the mechanisms of wound induced hair follicle neogenesis in mice and concludes that the process involves canonical WNT signaling activated by Fgf9 from γδ T cells, but more research is needed to fully understand its cellular bases.

This study developed a humanized scalp model in mice which demonstrated that transplanted cultured human hair follicle dermal cells contributed to the restoration of damaged hair follicles.

This study found that aging mice experience slower and more fragmented hair cycle waves, but transplanting aged skin to a young host can partially restore hair cycling, implicating extracellular factors.

This review summarizes the anatomical and physiological aspects of human hair and its clinical significance, but does not report new research findings.

This study found that skin fibroblasts in mice arise from two distinct lineages which contribute differently to dermal structure and repair, impacting hair follicle formation during wound healing.

This study found that altering cell culture conditions to form three-dimensional papilla spheroids can restore the ability of human dermal papilla cells to induce hair growth in adult skin.

This study found that fibroblast growth factor 9, initially secreted by γδ T cells, plays a key role in modulating hair follicle regeneration in mice after skin wounds.

This study found that grafting split-thickness human skin onto nude mice produces scars that mimic hypertrophic scar characteristics in humans, offering a useful model for studying scar formation and treatments.

This study developed an animal model that recreates alopecia areata by injecting healthy human skin grafts in immunocompromised mice with peripheral blood mononuclear cells enriched for NKG2D+ and CD56+ cells.

This study found that intradermal adipocyte lineage cells in mice are necessary and sufficient to activate follicular stem cells, highlighting their role in regulating skin stem cell activity.

This study found that when human hair follicles were grafted onto mice, they progressed through dystrophic stages and returned to normal growth, with stem cells aiding in recovery.

In this study, serum from patients with alopecia areata or universalis did not affect hair growth in transplanted scalp skin grafts on nude mice, despite increased deposition of immunoreactants.