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The Journal of Investigative Dermatology Sep 2023Because hair follicles (HFs) are highly sensitive to ionizing radiation, radiotherapy-induced alopecia (RIA) is a core adverse effect of oncological radiotherapy. Yet,... (Review)
Review
Because hair follicles (HFs) are highly sensitive to ionizing radiation, radiotherapy-induced alopecia (RIA) is a core adverse effect of oncological radiotherapy. Yet, effective RIA-preventive therapy is unavailable because the underlying pathobiology remains underinvestigated. Aiming to revitalize interest in pathomechanism-tailored RIA management, we describe the clinical RIA spectrum (transient, persistent, progressive alopecia) and our current understanding of RIA pathobiology as an excellent model for studying principles of human organ and stem cell repair, regeneration, and loss. We explain that HFs respond to radiotherapy through two distinct pathways (dystrophic anagen or catagen) and why this makes RIA management so challenging. We discuss the responses of different HF cell populations and extrafollicular cells to radiation, their roles in HF repair and regeneration, and how they might contribute to HF miniaturization or even loss in persistent RIA. Finally, we highlight the potential of targeting p53-, Wnt-, mTOR-, prostaglandin E-, FGF7-, peroxisome proliferator-activated receptor-γ-, and melatonin-associated pathways in future RIA management.
Topics: Humans; Hair Follicle; Alopecia; Drug-Related Side Effects and Adverse Reactions; Stem Cells
PubMed: 37294241
DOI: 10.1016/j.jid.2023.02.041 -
Clinica Chimica Acta; International... Jul 2023Androgenetic alopecia (AGA) is treated by 5α-reductase inhibitors (5ARI) such as finasteride and dutasteride, which are widely used as therapeutic agents. However,...
BACKGROUND
Androgenetic alopecia (AGA) is treated by 5α-reductase inhibitors (5ARI) such as finasteride and dutasteride, which are widely used as therapeutic agents. However, their pharmacokinetics in target organs (scalp and hair follicles) have not yet been investigated.
PURPOSE
To confirm the effective action of finasteride and dutasteride in the hair follicle tissues, we developed a method to measure these concentrations in hair.
RESULTS
Compared to the non-detection (N.D.) group, the dihydrotestosterone (DHT) concentrations decreased significantly in both the finasteride and dutasteride groups. The dutasteride group showed significantly lower DHT concentrations among all groups.
CONCLUSIONS
Measurement of finasteride, dutasteride, and DHT concentrations in hair would aid in evaluating the drug pharmacokinetics and its therapeutic effects on AGA patients.
Topics: Humans; Finasteride; Dutasteride; Dihydrotestosterone; Alopecia; Hair
PubMed: 37385468
DOI: 10.1016/j.cca.2023.117456 -
Cutis Apr 2022
Topics: Alopecia; Cicatrix; Dermatitis; Hair; Humans
PubMed: 35659847
DOI: 10.12788/cutis.0490 -
The Journal of Family Practice Apr 2022THE PRESENTATION A Early central centrifugal cicatricial alopecia with a small central patch of hair loss in a 45-year-old Black woman. B Late central centrifugal...
THE PRESENTATION A Early central centrifugal cicatricial alopecia with a small central patch of hair loss in a 45-year-old Black woman. B Late central centrifugal cicatricial alopecia with a large central patch of hair loss in a 43-year-old Black woman.
Topics: Adult; Black or African American; Alopecia; Black People; Cicatrix; Female; Humans; Middle Aged
PubMed: 35561242
DOI: 10.12788/jfp.0388 -
Stem Cells and Development Jan 2024The health of hair is directly related to people's health and appearance. Hair has key physiological functions, including skin protection and temperature regulation.... (Review)
Review
The health of hair is directly related to people's health and appearance. Hair has key physiological functions, including skin protection and temperature regulation. Hair follicle (HF) is a vital mini-organ that directly impacts hair growth. Besides, various signaling pathways and molecules regulate the growth cycle transition of HFs. Hair and its regeneration studies have attracted much interest in recent years with the increasing rate of alopecia. Mesenchymal stem cells (MSCs), as pluripotent stem cells, can differentiate into fat, bone, and cartilage and stimulate regeneration and immunological regulation. MSCs have been widely employed to treat various clinical diseases, such as bone and cartilage injury, nerve injury, and lung injury. Besides, MSCs can be used for treatment of hair diseases due to their regenerative and immunomodulatory abilities. This review aimed to assess MSCs' treatment for alopecia, pertinent signaling pathways, and new material for hair regeneration in the last 5 years.
Topics: Humans; Hair; Hair Follicle; Alopecia; Mesenchymal Stem Cells; Signal Transduction
PubMed: 37847179
DOI: 10.1089/scd.2023.0156 -
American Family Physician Feb 2017
Topics: Alopecia; Diagnosis, Differential; Humans; Male; Military Personnel; Nails; Young Adult
PubMed: 28145665
DOI: No ID Found -
JCI Insight Dec 2023Hair loss is a debilitating condition associated with the depletion of dermal papilla cells (DPCs), which can be replenished by dermal sheath cells (DSCs). Hence,...
Hair loss is a debilitating condition associated with the depletion of dermal papilla cells (DPCs), which can be replenished by dermal sheath cells (DSCs). Hence, strategies aimed at increasing the populations of DPCs and DSCs hold promise for the treatment of hair loss. In this study, we demonstrated in mice that introduced exogenous DPCs and DSCs (hair follicle mesenchymal stem cells) could effectively migrate and integrate into the dermal papilla and dermal sheath niches, leading to enhanced hair growth and prolonged anagen phases. However, the homing rates of DPCs and DSCs were influenced by various factors, including recipient mouse depilation, cell passage number, cell dose, and immune rejection. Through in vitro and in vivo experiments, we also discovered that the CXCL13/CXCR5 pathway mediated the homing of DPCs and DSCs into hair follicle niches. This study underscores the potential of cell-based therapies for hair loss by targeted delivery of DPCs and DSCs to their respective niches and sheds light on the intriguing concept that isolated mesenchymal stem cells can home back to their original niche microenvironment.
Topics: Mice; Animals; Hair Follicle; Cells, Cultured; Alopecia; Cell- and Tissue-Based Therapy; Mesenchymal Stem Cells
PubMed: 37917167
DOI: 10.1172/jci.insight.173549 -
Cutis Dec 2023Telogen effluvium (TE) is a common clinical consequence of medication-related alopecia. The inciting cause of TE may be difficult to identify due to delays in clinically... (Review)
Review
Telogen effluvium (TE) is a common clinical consequence of medication-related alopecia. The inciting cause of TE may be difficult to identify due to delays in clinically apparent hair loss. Because medication-induced TE is a nonscarring alopecia that typically is reversible, appropriate management requires identification of the underlying triggering medication and cessation of it, if possible. In part 1 of this series, we review the existing literature on medication-induced TE with a focus on systemic retinoids, antifungal agents, and psychotropic medications.
Topics: Humans; Alopecia Areata; Alopecia
PubMed: 38290075
DOI: 10.12788/cutis.0910 -
Expert Opinion on Drug Discovery Mar 2015Hair loss or alopecia affects the majority of the population at some time in their life, and increasingly, sufferers are demanding treatment. Three main types of... (Review)
Review
INTRODUCTION
Hair loss or alopecia affects the majority of the population at some time in their life, and increasingly, sufferers are demanding treatment. Three main types of alopecia (androgenic [AGA], areata [AA] and chemotherapy-induced [CIA]) are very different, and have their own laboratory models and separate drug-discovery efforts.
AREAS COVERED
In this article, the authors review the biology of hair, hair follicle (HF) cycling, stem cells and signaling pathways. AGA, due to dihydrotesterone, is treated by 5-α reductase inhibitors, androgen receptor blockers and ATP-sensitive potassium channel-openers. AA, which involves attack by CD8(+)NK group 2D-positive (NKG2D(+)) T cells, is treated with immunosuppressives, biologics and JAK inhibitors. Meanwhile, CIA is treated by apoptosis inhibitors, cytokines and topical immunotherapy.
EXPERT OPINION
The desire to treat alopecia with an easy topical preparation is expected to grow with time, particularly with an increasing aging population. The discovery of epidermal stem cells in the HF has given new life to the search for a cure for baldness. Drug discovery efforts are being increasingly centered on these stem cells, boosting the hair cycle and reversing miniaturization of HF. Better understanding of the molecular mechanisms underlying the immune attack in AA will yield new drugs. New discoveries in HF neogenesis and low-level light therapy will undoubtedly have a role to play.
Topics: Administration, Topical; Alopecia; Animals; Drug Discovery; Hair; Hair Follicle; Humans; Immunotherapy; Pharmaceutical Preparations; Stem Cells
PubMed: 25662177
DOI: 10.1517/17460441.2015.1009892 -
Cutis Apr 2019Hair loss can be distressing for patients regardless of race, gender, or age. There are unique nuances when diagnosing, treating, and understanding the hair care... (Review)
Review
Hair loss can be distressing for patients regardless of race, gender, or age. There are unique nuances when diagnosing, treating, and understanding the hair care practices of black patients. Treatment regimens are largely anecdotal for some of the most common types of alopecia affecting those with skin of color. The key to treatment compliance is setting expectations at the beginning of the hair loss investigation journey and developing a partnership with the patient. The treatments and diagnoses discussed herein are not a comprehensive list but represent some of the more common conditions and initial approaches to treatment.
Topics: Black or African American; Alopecia; Humans
PubMed: 31116819
DOI: No ID Found