The Peripheral Clock Regulates Human Pigmentation

This article discusses the role of human hair follicles in neuroendocrinology and suggests potential new therapeutic targets by examining how neuromediators influence hair growth, pigmentation, and stem cell biology in organ cultures.

This review examines the molecular mechanisms of the circadian clock and its effects on cardiovascular functions, proposing a novel non-invasive method using hair follicle cells to assess circadian regulation in humans, but reports no new clinical results.

This study found that peripheral clock genes, particularly BMAL1 and Period1, modulate human hair follicle cycling, suggesting their potential as therapeutic targets for affecting hair growth.

This review discusses the role of oxidative stress in hair greying and suggests that understanding melanocyte susceptibility at different follicular locations may help develop therapies for preventing and reversing the process; it reports no new experimental results.

This study discovered that the circadian clock influences hair follicle regeneration, making hair grow faster in the morning and causing more radiation-induced hair loss in the morning compared to the evening.

This study reports that melanocytes form a defined photoresponsive network in the skin that reads environmental light cycles and may influence the sleep-waking cycle similar to the pineal gland.

In this study, silencing P-cadherin in human scalp hair follicles reduced melanogenesis and associated protein expression, suggesting P-cadherin is crucial for normal hair pigmentation via GSK3β-mediated Wnt signaling.

This study found that the circadian clock in mouse skin regulates cell proliferation and affects sensitivity to UVB-induced DNA damage, with potential implications for understanding human skin cancer risk.

This study found that activation of cannabinoid 1 receptors in human scalp hair follicles may limit excessive mast cell activation and maturation, suggesting a potential therapeutic strategy for managing MC-dependent skin diseases.

This review discusses the identification and characteristics of melanocyte stem cells, emphasizing their role in hair pigmentation, greying, and skin repigmentation, but reports no new research findings.

This study suggests that the susceptibility of hair follicle melanocytes to oxidative stress as they age may be key in the graying of hair due to reduced catalase expression and activity.

This article discusses the role of neurohormones and neuropeptides in hair follicle pigmentation and outlines promising neuroendocrinological strategies to address greying and damage, but reports no new clinical results.

This article discusses the challenges in hair follicle pigmentation research compared to epidermal melanocytes and highlights the limitations of relying on mouse models, but reports no new experimental findings.

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

This study found that circadian clock genes are involved in regulating the hair growth cycle, suggesting a connection between daily rhythms and the longer hair follicle cycling process.

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 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.

This study introduced a novel in vitro assay for tracking melanosome transfer between melanocytes and keratinocytes, facilitating the quantification of melanin transfer and supporting the role of filopodia as a conduit.

This review discusses the protective and stress-buffering roles of melatonin in skin functions and structures but does not present new clinical findings.

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 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.

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 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 observed that melanogenesis in human hair follicles is linked to anagen phases, with melanocyte activity and enzyme expression being region-specific to the nascent bulb.

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 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 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.