A Neuroendocrinological Perspective on Human Hair Follicle Pigmentation

This article reviews the impact of H2O2-redox homeostasis on hair follicle pigmentation via tyrosinase and associated mechanisms, discussing primarily findings from murine models without providing new clinical results for humans.

This article discusses the development and research applications of human hair follicle organ culture techniques, highlighting its potential to explore biological processes beyond dermatology.

This review discusses the pathogenesis and challenges in treating primary cicatricial alopecia, highlighting the need to understand immune protection collapse in hair follicle stem cells; it reports no new clinical results.

This article discusses mouse genetic studies to explore factors influencing melanogenesis, highlighting pH and cysteine's roles, and proposes a hypothesis for human hair color diversity; it reports no new results.

This study found that thyroid hormones T3 and T4 enhance keratin 15 promoter activity and stimulate CD200 expression in epithelial stem cells from human scalp hair follicles, affecting their growth and differentiation.

This review discusses prolactin production and regulation in human skin and hair follicles, highlighting its potential broader implications but reports no new empirical results.

This study reported that patients with alopecia areata have reduced expression of the melanocortin receptor MC2R in their scalp tissues compared to normal scalp, indicating potential involvement in the condition's pathophysiology.

This study identified key genetic regions associated with alopecia areata, highlighting both acquired and innate immune involvement, with a novel link to the upregulation of ULBP ligands in autoimmune disease.

This paper argues that the cycling hair follicle serves as a valuable model for systems biology research, highlighting its potential for translational medicine.

Oestrogen and thyrotropin-releasing hormone affect prolactin and its receptor in human skin and hair, suggesting new treatment options for related conditions.

This study found that normal human epidermis expresses TSH and may be an indirect target of TSH signaling, with expression regulated by endocrine controls of the hypothalamic-pituitary-thyroid axis.

This study demonstrates that stem cells from human foreskins, which lack hair follicles, can differentiate into melanocytes and migrate to the epidermis, potentially altering our understanding of pigmentation disorders.

This study found that prolactin is a key regulator of keratin expression in human hair follicles, enhancing specific keratin types and influencing epithelial stem cell-associated keratins.

This review explores the complex relationship between thyroid hormones and skin, discussing potential mechanisms and known interactions but reports no new clinical results, emphasizing the need for further research.

This study found that ionizing irradiation significantly inhibits proliferation and induces apoptosis in human hair follicle keratinocytes, suggesting its potential as a preclinical assay system for testing radioprotectants.

This study found that thyrotropin-releasing hormone (TRH) acts as a potent stimulator of hair growth in human scalp hair follicles, promoting elongation and prolonging the anagen phase.

This study reported that GFP labeling driven by the K15 promoter enables visualization and selection of stem cells in adult human scalp hair follicles for further analysis and manipulation.

This study introduced a new classification system for distinguishing between anagen VI and early catagen stages in human hair follicle organ culture, using it to confirm eflornithine's ability to induce premature catagen.

This study found a decreased number of follicular melanocytes in patients with alopecia areata, though it remains unclear if this decrease is due to autoimmune attack or rapid hair cycling.

This research highlights that psychological stress can adversely affect hair growth in mice, implicating potential pathways that may be relevant in understanding stress-induced hair growth inhibition in humans.

This study found that hydrogen peroxide accumulation and reduced methionine sulfoxide repair play a significant role in the oxidative damage linked to senile hair graying.

This review summarizes fundamental concepts and recent advancements in hair follicle biology, including insights from mouse models into broader molecular and cellular processes relevant to regeneration and development.

In this study, UVB irradiation of organ-cultured human anagen hair follicles in vitro reduced hair elongation and increased cell death, affecting hair growth and regulatory processes.

Thyroid-stimulating hormone affects hair follicles but doesn't change hair growth or color.

This study presents a novel in vitro assay using human folliculoid microspheres to research hair growth, which may facilitate preclinical testing of hair growth-modulatory agents.

In this study, T3 and T4 were found to directly influence human hair follicles in vitro, enhancing keratinocyte proliferation, prolonging the hair growth phase, and affecting pigmentation.

This review discusses the protective effects and mechanisms of melatonin in skin and suggests potential therapeutic applications in cutaneous medicine, reporting no new clinical findings.

This review explores the potential (neuro-)endocrine influences on hair follicle epithelial stem cell biology and emphasizes the need for more systematic research, but it provides no new empirical results.

In this study, researchers found that substance P triggered premature catagen development and immune changes in human scalp hair follicles, providing a possible biological link between stress and hair loss conditions like telogen effluvium and alopecia areata.

This study suggests that melatonin plays a role in hair follicle function by modulating growth and pigmentation, and it may act as a protective agent in active hair growth phases.

This study found that organ-cultured human scalp hair follicles can mimic chemotherapy-induced damage in vivo and serve as a model to explore molecular targets and protective agents for hair follicle preservation.

This review examines the interplay of genetics and neuroimmunology in alopecia areata, highlighting its potential to inform broader autoimmunity research, but reports no new findings.

This study observed that antisense oligonucleotides targeting FGFR-1 increased cellular activity in hair follicle cultures from mice, suggesting potential clinical utility for treating baldness.

This article discusses the influence of estrogens on hair follicle growth and metabolism, suggesting a significant role alongside androgens in hair growth control but reports no new clinical results.

This review discusses the brain-skin connection, the skin's role in stress response, and highlights unmet challenges in understanding stress-induced skin inflammation but reports no new experimental findings.

This study found that oxidative stress in hair follicle melanocytes contributes to premature aging and apoptosis, providing insights into graying as a model for studying aging and testing antiaging therapies.

The study found that prolactin expressed in human scalp hair follicles acts as an autocrine modulator, inhibiting hair growth and promoting hair follicle regression, which may contribute to hair loss in hyper-prolactinemia patients.

This study reports that human hair follicle stem cells express different surface markers than mouse stem cells, facilitating their isolation and potentially aiding in the development of cell-based skin treatments.

This study provides evidence that psychoemotional stress inhibits hair growth in mice by affecting the brain-hair follicle axis, with specific neuropeptides and treatments modulating this effect.

This study indicates that stress in mice recruits specific neuroimmunoendocrine elements, leading to neurogenic skin inflammation that inhibits hair growth and highlights the skin's role in stress response research.

This review discusses how the CRH/POMC systems may regulate human hair follicle pigmentation and highlights the concept of "self-similarity" in melanocortin systems at both local and systemic levels, without presenting new experimental results.

This study found that hair follicles in both mice and humans may serve as an important site for melatonin synthesis and signaling, potentially influencing hair cycle regulation by modulating keratinocyte apoptosis.

This study defines classification criteria for hair follicle dystrophy using a mouse model of chemotherapy-induced alopecia, providing tools for standardized hair damage assessment.

This study found that human scalp hair follicles can respond to corticotropin releasing hormone stimulation similarly to the classical HPA axis, including up-regulating cortisol production and activating neuroendocrine feedback loops.

This study found that premature hair loss due to stress does not occur in NK-1 receptor knockout or mast cell deficient mice, suggesting a key role for neurokinin substance P and mast cell interaction in stress-related hair follicle changes.

This review discusses the cutaneous serotoninergic/melatoninergic system's potential role in skin function and resilience against environmental and internal stresses, but does not report new experimental findings.

This article reviews follicular melanogenesis, detailing how melanin synthesis and its regulation in hair follicles depend on a complex interplay of cellular and molecular mechanisms, but reports no new clinical findings.

This study found that psychoemotional stress disrupts hair growth in mice by terminating anagen and suggests a potential pathway for pharmacological management of stress-related hair loss in humans.

This study found that thyroid-stimulating hormone receptors are functionally expressed in various skin cells, implying potential physiological and pathological roles in skin, especially in conditions like autoimmune diseases.

In this study, different types of catagen in the C57BL/6 mouse model exhibited varying effects on hair follicle melanocytes and melanin distribution, with spontaneous and dexamethasone-induced catagen showing pigment incontinence, while cyclophosphamide-induced catagen retained dendritic melanocytes but increased ectopic melanin.

This article examines the terminal to vellus transition in androgenetic alopecia through cellular and developmental mechanisms, discussing challenges and knowledge gaps without presenting new clinical findings.

This study found that the switch-off of melanogenesis during the hair cycle in C57 BL-6 mice is a gradual and stochastic process starting in mid anagen VI, with specific biochemical markers indicating the transition to catagen.

This article presents two cases of alopecia areata occurring simultaneously in a married couple, suggesting a potential psychosocial factor like stress rather than genetic causation.

This study found that murine skin is a target for melatonin bioregulation, as melatonin affected DNA synthesis and tyrosinase activity in skin organ culture.

This review discusses the role of intrinsic skin signals, rather than serum signals, in regulating melanin synthesis and hair pigmentation, but reports no new experimental data.

This study successfully grew and maintained human hair follicles in vitro, noting that TGF-β1 negatively affects growth, while EGF replicates hair-removal effects seen in animals.

This study found HLA and beta 2-microglobulin antigens in various skin structures, with specific localization patterns in keratinocytes and hair follicle components, but not in eccrine or apocrine glands.