Signaling Pathways in Hair Aging

In this study, estetrol (E4) treatment was associated with increased hair growth in ex vivo human hair follicles, suggesting its potential as a treatment for hair loss disorders.

This review outlines the potential of using human pluripotent stem cells for hair follicle bioengineering, detailing current HF morphogenesis and cycling knowledge, various cell sources, and strategies using iPSCs, while discussing the challenges and prospects for therapeutic use in addressing hair loss.

This study reports that baricitinib was more effective than placebo in promoting hair growth in adults with severe alopecia areata after 36 weeks of treatment in clinical trials.

This comprehensive review analyzes androgenetic alopecia treatments, discussing the mechanisms, costs, efficacy, and safety of FDA-approved drugs like minoxidil and finasteride, as well as newer non-FDA-approved options that have shown effectiveness across various studies.

This study found that IL-1α promotes hair follicle regeneration and stem cell activation in an age-dependent manner by modulating inflammatory cells and oxidative stress in mice.

This review discusses the hormonal impact on hair growth and the relationship between endocrine disorders and hair changes, reporting no new clinical results.

This review discusses regenerative medicine approaches for treating alopecia, including mesenchymal stem cell therapies and platelet-rich plasma, but reports no new clinical results, emphasizing the need for further study.

This review discusses the potential of secretome derived from stem cells for treating alopecia areata and reports no new clinical results; the authors suggest the need for further human trials.

This study found that control of Demodex mite colonization in mice required skin ILC2s and IL-13, highlighting their role in maintaining HF integrity and limiting mite overgrowth.

This article reviews the aging process of sebaceous glands, highlighting the role of intrinsic and extrinsic factors on their degradation and reporting no new clinical findings.

This study found that PBX1 overexpression reduces hair follicle-derived mesenchymal stem cell senescence and apoptosis by interacting with SIRT1 and PARP1, highlighting a potential mechanism for addressing aging-related diseases.

This study describes a protocol for generating hair-bearing skin organoids from human pluripotent stem cells, achieving full complexity resembling fetal skin tissue by day 130 in vitro.

This review analyzed 17 recent clinical trials on platelet-rich plasma for androgenetic alopecia but reports no new clinical results; the authors seek a consensus on optimal PRP use.

In this study, Cyanidin 3-O-arabinoside was found to protect against DHT-induced dermal papilla cell senescence and mitochondrial dysfunction in androgenetic alopecia, restoring hair growth in mouse models.

This review found that topical finasteride has similar efficacy to oral finasteride in treating male and female pattern hair loss, with fewer systemic side effects, mainly causing localized scalp reactions like irritation and erythema.

This study found that androgen receptor signaling is linked to blood vessel regression in the dermal papilla of balding scalp, contributing to hair follicle miniaturization in androgenetic alopecia.

This study found that intrinsic reactive oxygen species drive the hair follicle cycle progression through DNA damage and repair, apoptosis, and macrophage polarization, influencing hair loss and regeneration dynamics in mice.

This review discusses the composition, activation, and regulation of the JAK/STAT pathway and highlights its role and inhibitors in various diseases, but reports no new experimental results.

Aging causes hair loss and graying due to stem cell decline and changes in cell behavior and communication.

This study found that PBX1 overexpression reduces hair follicle-derived mesenchymal stem cell senescence and apoptosis by alleviating ROS-mediated DNA damage, rather than enhancing DNA repair.

This review discusses the current state of research on skin organoids, highlighting their potential for replicating complex skin structures and comparing recent studies on stem cell microenvironments.

This study found that FDA-approved low-level light/laser therapy devices significantly increased hair density in individuals with pattern hair loss compared to sham devices.

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 suggests that the herbal formulation Phyllotex™ may promote hair growth in androgenetic alopecia by enhancing cell proliferation and reducing oxidative stress and TGF-β1 expression in vitro.

This review examines the life cycle, biomarkers, and functions of hair follicle stem cells, emphasizing their role in hair loss therapy and other skin and hair disorders, but reports no new clinical results.

This study reported that while topical minoxidil exhibits hair regrowth in androgenetic alopecia, oral minoxidil 5 mg/day was more effective than topical forms after six months, with low doses also potentially effective for women and other hair loss types.

This study found that Argan press cake extracts stimulated hair growth and reduced inflammation and oxidative stress in human hair follicle dermal papilla cells, suggesting potential for anti-hair loss drug development.

In this mouse study, UVA and UVB exposure led to hair follicle miniaturization, graying, and prolonged hair cycle duration, associated with changes in stem cells and increased Wnt signaling activity.

In this study, increased corticosterone from chronic stress prolonged hair follicle stem cell quiescence in mice, inhibiting regeneration, but restoring Gas6 expression overcame this inhibition.

This review discusses the role of telomere length dynamics in hair follicle biology and reports no new clinical findings, emphasizing the need for further research in humans.

This review indicates that low-level laser therapy may stimulate hair growth in both men and women with androgenetic alopecia, showing similar efficacy to minoxidil in some studies, but requires more robust evidence.

This review discusses the potential of platelet-rich plasma applications in regenerative medicine and explores recent progress and challenges in translating non-clinical PRP findings into human treatments, but reports no new clinical results.

This study suggests that the novel "After Minoxidil" spray improved styling ease and reduced greasiness in patients using topical minoxidil, which may enhance compliance and treatment efficacy.

This study found that sympathetic nerves and arrector pili muscles form a niche that modulates hair follicle stem cell activity, revealing their role in hair follicle regeneration.

This review discusses the role of Wnt/β-catenin signaling in hair follicle regeneration and highlights recent progress in developing hair loss treatments targeting this pathway, but reports no new clinical results.

Scientists created human skin with hair from stem cells, which could help treat hair loss and skin conditions.

This review discusses age-related changes in scalp skin and their potential effects on hair follicle aging, but reports no new clinical results, calling for further investigation.

In this study, DHT was observed to have varying effects on hair follicle growth and related protein expression depending on concentration, with the Wnt/β-catenin pathway potentially playing a significant role.

Stress can cause hair to turn gray by depleting stem cells.

In this review, researchers highlight preclinical and clinical studies on stem cell-based therapies for hair loss, noting promising early findings but indicating that further robust clinical research is necessary to better understand their effectiveness, safety, and mechanisms.

This study reported that inhibiting the JAK-STAT pathway with baricitinib restored cellular homeostasis, delayed senescence, and reduced proinflammatory markers in Hutchinson-Gilford progeria syndrome cell models.

This study found that telomere shortening disrupts BMP/pSmad/P63 signaling, leading to skin atrophy via Follistatin up-regulation, and suggests potential therapeutic targets.

This study found that lymphatic vessels in mice are important for hair follicle development and organization, as their depletion blocks hair growth.

In this study, researchers found that alkylating chemotherapy causes hair follicle stem cells to lose their regenerative ability by initially triggering proliferation followed by apoptosis, leading to permanent regeneration loss.

This study found that PBX1 enhances the proliferation and reprogramming of hair follicle mesenchymal stem cells by activating the AKT/GSK3β signaling pathway, promoting NANOG expression, and inhibiting apoptosis.

This abstract reports that topical minoxidil is currently the only FDA-approved treatment for pattern hair loss in both men and women.

This review discusses the role of cholesterol homeostasis in hair follicle biology and its potential connections to various hair disorders, but it reports no new findings.

This review explores the hair follicle microbiome's interaction with the immune system, discussing its potential clinical implications for scalp health and disease but reports no new clinical results.

This study found that Oncostatin M, via JAK-STAT5 signaling, keeps hair follicle stem cells inactive, and its removal leads to hair growth initiation in mice.

This laboratory study found that activated platelet‐rich plasma supernatant enhanced hair growth signaling pathways in cultured human dermal papilla cells, suggesting potential for treating androgenic alopecia.

This review discusses the use of platelet-rich plasma as a treatment for androgenetic alopecia and highlights the need for standardized protocols, reporting no new clinical results.

In this study, a high-fat, high-cholesterol diet in atherosclerotic mice led to skin inflammation and hair problems, which could be reversed by inhibiting glycosphingolipid synthesis.

This review finds preliminary evidence suggesting that topical finasteride may significantly reduce hair loss and increase hair counts in treating androgenetic alopecia, with a promising safety profile.

This study found that prostaglandin D2 promotes androgen receptor and AKT signaling in human dermal papilla cells through the DP2 receptor, potentially contributing to androgenetic alopecia.

This review examines current understanding of hair graying and suggests it may be caused by depletion of melanocyte stem cells due to genotoxic stress or dysfunctional melanocytes from oxidative stress.

This review discusses the molecular mechanisms of androgens and androgen receptors in skin disorders, particularly androgenetic alopecia, and reports no new clinical results; it highlights potential areas for future treatment development.

This article discusses the use of platelet-rich plasma as a supportive treatment for hair loss, emphasizing its potential to enhance hair follicle health and patient satisfaction, but reports no new clinical results.

This review synthesizes recent findings on the hair follicle stem cell niche and its complex interactions, exploring potential pathways for developing new hair growth therapies; it reports no new clinical results.

This study found that the transcription factor Gata6 plays a crucial role in adult mouse hair follicle regeneration by promoting the renewal and preventing DNA damage of rapidly proliferating progenitor cells.

This research found that Foxc1 transcription factor and COL17A1 are critical in regulating quiescence and hair thinning in hair follicle stem cells, with aging-related DNA damage leading to hair loss.

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 study observed that baricitinib treatment led to significant improvement in a patient's alopecia areata symptoms and suggests further clinical trials to explore its potential as a treatment.

This study found that macrophages near hair follicles contribute to the activation of skin epithelial stem cells in mice, suggesting a novel role for macrophages in regulating hair growth.

This study found that smoking, obesity, and family history are significant risk factors for premature hair graying in young men.

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 study suggests that a hair follicle enzyme assay may predict response to minoxidil treatment for androgenetic alopecia with high sensitivity and specificity in a preliminary analysis.

This review examines misconceptions and gaps in the understanding of androgenic alopecia (AGA) etiopathogenesis, offering new perspectives but no new experimental results.

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.

The researchers reported that reactive oxygen species regulate the stress-induced SP-Mast cell pathway, which might support using antioxidants to treat stress-related hair loss.

This study reveals an antagonistic competition between BMP and Wnt signaling within stem cells, influencing their fate towards hair germ characteristics based on the BMP/Wnt activity ratio.

This study found that estrogen can cause reversible suppression of the hair cycle by inducing premature catagen and maintaining the telogen phase without damaging the hair follicle stem cell niche or the signature gene expressions of dermal papilla cells.

PGD2 stops hair growth and is higher in bald men with AGA.

This article examines the evidence regarding finasteride's sexual side effects and offers recommendations for patient counseling but reports no new clinical findings.

This study found that hair follicles undergo significant molecular changes with age, notably a decline in keratins and keratin-associated proteins, which may contribute to age-related hair alterations.

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 review discusses the potential role of oxidative stress in hair graying and age-related alopecia, emphasizing the need for new strategies to counteract these effects, but reports no new results.

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 review discusses factors affecting hair aging and the current pharmacological treatments for androgenetic alopecia, mentioning topical minoxidil and oral finasteride, but does not present new clinical findings.

This article reviews the stages and regulation of the hair cycle, highlighting molecular regulators involved, but it does not present new research findings.

This review summarizes the major events and regulators of the hair cycle in mammals but reports no new experimental results; it emphasizes the complex regulation of stem cell activation and differentiation during hair growth.

This article reviews factors influencing hair aging and available treatments like minoxidil and finasteride for androgenetic alopecia but reports no new clinical results.

This review discusses the development, regulation, and aging of the human hair follicle pigmentary system and suggests potential for reversing hair graying by manipulating follicle melanocytes in vitro, but reports no clinical results.

Minoxidil can cause skin allergy; use alternative solvents or treatments if allergic.

This review discusses common hair loss conditions and explores how advancements in hair follicle biology might lead to more effective treatments but reports no new results.

This review discusses the potential for mood stabilizers, antidepressants, and some antipsychotic and antianxiety drugs to induce alopecia and reports no clinical results.

In this study, lipid peroxides were found to induce apoptosis in hair follicle cells and advance the catagen phase in mice, suggesting a potential mechanism for alopecia development.

Finasteride treats enlarged prostate and may help with baldness, but effects on sexual function and male fetuses are unclear.

Minoxidil effectively treats severe hypertension but may cause side effects, so careful monitoring is needed.