Complex changes in the apoptotic and cell differentiation programs during initiation of the hair follicle response to chemotherapy

Preservation solution protects isolated hair micrografts by inhibiting apoptosis of hair bulb

AIMS

To investigate the effectiveness of histidine-tryptophan-ketoglutarate (HTK) solution compared to Ringer's (RS) solution for preserving isolated hair follicles (HFs), focusing on structural integrity, cell viability, apoptosis prevention, and identifying the mechanisms of cell death during the preservation period.

MATERIALS AND METHODS

Isolated human HFs were preserved in HTK or RS solution for periods ranging from 2 to 12 h. Morphological changes were assessed using H&E staining and transmission electron microscopy (TEM). Cell viability, proliferation, and apoptosis were evaluated through Ki-67/TUNEL staining, live/dead cell staining, and immunofluorescence. Quantitative real-time PCR and Western blot analysis were conducted to examine apoptosis-related gene expression, and qPCR array analyses were performed to determine the pathways involved in HF apoptosis.

KEY FINDINGS

HTK solution preserved the structure of HFs more effectively than RS, maintaining collagen organization, preventing intercellular edema, and sustaining cell membrane integrity. HFs preserved in HTK solution exhibited significantly higher viability and proliferation rates, with a reduced rate of apoptosis compared to RS. Gene expression profiling indicated that HTK group inhibited the activation of the TNF signaling pathway and mitochondrial dysfunction, which were associated with apoptosis in RS-preserved HFs.

SIGNIFICANCE

This study demonstrates that HTK solution is more effective than RS solution for HF preservation, particularly in extended storage settings required for large-scale hair transplantation. By inhibiting apoptosis pathways and preserving cellular integrity, HTK solution may enhance the success and outcomes of hair transplant procedures, providing insights into optimizing micrograft preservation and reducing ischemia-hypoxia injury in isolated HFs.

Discovery of petroleum ether extract of eclipta targeting p53/Fas pathway for the treatment of chemotherapy-induced alopecia: Network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Ecliptea herba, a traditional Chinese herbal medicine for hair loss, was first recorded in the Tang Dynasty's 'Qian Jin Yue Ling', of which the active ingredients and mechanisms of action in the treatment of chemotherapy-induced hair loss remain poorly investigated.

AIM OF THE STUDY

To investigate the effects of the petroleum ether extract of Eclipta (PEE) on alopecia and follicle damage and elucidate its potential therapeutic mechanisms using the integration of network pharmacology, bioinformatics, and experimental validation.

MATERIALS AND METHODS

UPLC-MS was used to analyse the chemical composition of PEE. A network pharmacology approach was employed to establish the 'components-targets-pathways' network of PEE to explore potential therapeutic pathways and targets. Molecular docking was used for validation, and the mechanism of PEE in treating chemotherapy-induced alopecia (CIA) was elucidated using in vitro and in vivo on CIA models.

RESULTS

UPLC-MS analysis of PEE revealed 185 components, while network pharmacology and molecular docking analyses revealed potential active compounds and their target molecules, suggesting the involvement of core genes, such as TP53, ESR1, AKT1, IL6, TNF, and EGFR. The key components included wedelolactone, dimethyl-wedelolactone, luteoloside, linarin, and hispidulin. In vivo, PEE promoted hair growth, restored the number of hair follicles, and reduced follicle apoptosis. Conversely, in vitro, PEE enhanced cell viability, reduced apoptosis, and protected HaCaT cells from damage induced by 4-hydroperoxycyclophosphamide (4-HC).

CONCLUSIONS

PEE alleviated hair follicle damage in CIA mice by inhibiting the P53/Fas pathway, which may be associated with inhibiting hair follicle cell apoptosis. This study provides a novel therapeutic strategy for treating cyclophosphamide-induced hair loss.

Novel Synergistic Approach for Bioactive Macromolecules: Evaluating the Efficacy of Goat Placenta Extract in PEGylated Liposomes and Microspicules for Chemotherapy-Induced Hair Loss

Chemotherapy-induced hair loss is a distressing side effect of cancer treatment, and medical interventions are often needed to address this problem. The objectives of this study were to evaluate the bioactivity of goat placenta (GP) extract on both normal and chemotherapy-induced hair cells and to develop PEGylated liposomes (PL) and microspicule (MS) formulations for promoting hair growth in patients with chemotherapy-induced hair loss. The bioactivities of GP extract on human follicle dermal papilla (HFDP) cells and cells damaged by chemotherapy were assessed. GP extract was incorporated into PLs and MS gel (PL-MS) and then investigated in vitro skin permeation and in vivo studies on the scalps of patients with chemotherapy-induced hair loss. GP extract stimulated HFDP cell proliferation in both normal and cisplatin-damaged cells. PL nanovesicles and MS gel worked synergistically to deliver macromolecular proteins into the skin and hair follicles. The application of GP extract-loaded PL-MS to the scalps of chemotherapy-treated patients for 12 weeks significantly enhanced the hair growth rate, without causing skin irritation. In conclusion, GP extract promoted the proliferation of hair cells damaged by chemotherapy, when this extract, combined with PL-MS, effectively delivered bioactive macromolecules across the skin and hair follicles, resulting in successful regrowth of hair post-chemotherapy.

Colicin N Mediates Apoptosis and Suppresses Integrin-Modulated Survival in Human Lung Cancer Cells

The inherent limitations, including serious side-effects and drug resistance, of current chemotherapies necessitate the search for alternative treatments especially for lung cancer. Herein, the anticancer activity of colicin N, bacteria-produced antibiotic peptide, was investigated in various human lung cancer cells. After 24 h of treatment, colicin N at 5-15 µM selectively caused cytotoxicity detected by MTT assay in human lung cancer H460, H292 and H23 cells with no noticeable cell death in human dermal papilla DPCs cells. Flow cytometry analysis of annexin V-FITC/propidium iodide indicated that colicin N primarily induced apoptosis in human lung cancer cells. The activation of extrinsic apoptosis evidenced with the reduction of c-FLIP and caspase-8, as well as the modulation of intrinsic apoptosis signaling proteins including Bax and Mcl-1 were observed via Western blot analysis in lung cancer cells cultured with colicin N (10-15 µM) for 12 h. Moreover, 5-15 µM of colicin N down-regulated the expression of activated Akt (p-Akt) and its upstream survival molecules, integrin β1 and αV in human lung cancer cells. Taken together, colicin N exhibits selective anticancer activity associated with suppression of integrin-modulated survival which potentiate the development of a novel therapy with high safety profile for treatment of human lung cancer.

CDK4/6 inhibition mitigates stem cell damage in a novel model for taxane-induced alopecia

Taxanes are a leading cause of severe and often permanent chemotherapy‐induced alopecia. As the underlying pathobiology of taxane chemotherapy‐induced alopecia remains poorly understood, we investigated how paclitaxel and docetaxel damage human scalp hair follicles in a clinically relevant ex vivo organ culture model. Paclitaxel and docetaxel induced massive mitotic defects and apoptosis in transit amplifying hair matrix keratinocytes and within epithelial stem/progenitor cell‐rich outer root sheath compartments, including within Keratin 15+ cell populations, thus implicating direct damage to stem/progenitor cells as an explanation for the severity and permanence of taxane chemotherapy‐induced alopecia. Moreover, by administering the CDK4/6 inhibitor palbociclib, we show that transit amplifying and stem/progenitor cells can be protected from paclitaxel cytotoxicity through G1 arrest, without premature catagen induction and additional hair follicle damage. Thus, the current study elucidates the pathobiology of taxane chemotherapy‐induced alopecia, highlights the paramount importance of epithelial stem/progenitor cell‐protective therapy in taxane‐based oncotherapy, and provides preclinical proof‐of‐principle in a healthy human (mini‐) organ that G1 arrest therapy can limit taxane‐induced tissue damage.

Chemotherapy-Induced Hair Loss: The Use of Biomarkers for Predicting Alopecic Severity and Treatment Efficacy

Damage to hair follicles following exposure to toxic chemotherapeutics can cause substantial hair loss, commonly known as chemotherapy-induced alopecia (CIA). Preventive therapies remain limited; however, recent advances in the use of scalp cooling technologies have proved successful in preventing or reducing hair loss in some patients. Further improvements in scalp cooling efficacy and/or development of novel treatments to prevent chemotherapy-induced hair loss are required. To achieve this, post-chemotherapy assessment of hair follicle damage markers, with and without scalp cooling, would provide invaluable mechanistic and prognostic information. At present, the availability of such data is extremely limited. This article describes the potential utility of a combination of biomarkers in assessing drug-induced alopecia and the protective potential of existing or new treatments. A greater understanding of the precise mechanisms of anti-CIA therapies through biomarker analysis would enhance the rationale, use, and development of such treatments.

How chemotherapy and radiotherapy damage the tissue: Comparative biology lessons from feather and hair models

Chemotherapy and radiotherapy are common modalities for cancer treatment. While targeting rapidly growing cancer cells, they also damage normal tissues and cause adverse effects. From the initial insult such as DNA double-strand break, production of reactive oxygen species (ROS) and a general stress response, there are complex regulatory mechanisms that control the actual tissue damage process. Besides apoptosis, a range of outcomes for the damaged cells are possible including cell cycle arrest, senescence, mitotic catastrophe, and inflammatory responses and fibrosis at the tissue level. Feather and hair are among the most actively proliferating (mini-)organs and are highly susceptible to both chemotherapy and radiotherapy damage, thus provide excellent, experimentally tractable model systems for dissecting how normal tissues respond to such injuries. Taking a comparative biology approach to investigate this has turned out to be particularly productive. Started in chicken feather and then extended to murine hair follicles, it was revealed that in addition to p53-mediated apoptosis, several other previously overlooked mechanisms are involved. Specifically, Shh, Wnt, mTOR, cytokine signalling and ROS-mediated degradation of adherens junctions have been implicated in the damage and/or reparative regeneration process. Moreover, we show here that inflammatory responses, which can be prominent upon histological examination of chemo- or radiotherapy-damaged hair follicle, may not be essential for the hair loss phenotype. These studies point to fundamental, evolutionarily conserved mechanisms in controlling tissue responses in vivo, and suggest novel strategies for the prevention and management of adverse effects that arise from chemo- or radiotherapy.

Modeling Chemotherapy-Induced Hair Loss: From Experimental Propositions toward Clinical Reality

Chemotherapy-induced hair loss is one of the most devastating side effects of cancer treatment. To study the effects of chemotherapeutic agents on the hair follicle, a number of experimental models have been proposed. Yoon et al. report that transplantation of human scalp hair follicles onto chemotherapy-treated immunodeficient mice serves as an excellent in vivo model for chemotherapy-induced hair loss. Yoon et al. demonstrate that (i) the response of human hair follicles grafted onto immunodeficient mice to cyclophosphamide resembles the key features of the chemotherapy-induced hair loss seen in patients with cancer and (ii) this human in vivo model for chemotherapy-induced hair loss is closer to clinical reality than to any earlier models. Undoubtedly, this model will serve as a valuable tool for analyses of the mechanisms that underlie this devastating side effect of anti-cancer therapy.

Development of a Model for Chemotherapy-Induced Alopecia: Profiling of Histological Changes in Human Hair Follicles after Chemotherapy

Optimized research models are required to further understand the pathogenesis and prophylaxis of chemotherapy-induced alopecia. Our aim was to develop a mouse model for chemotherapy-induced alopecia by follicular unit transplantation of human hair follicles onto immunodeficient mice. Twenty-two weeks after transplantation, a single dose of cyclophosphamide (Cph) was administered to mice in the Cph100 (100 mg/kg) and Cph150 (150 mg/kg) groups. On day 6, hair follicles showed dystrophic changes, with swollen dermal papilla and ectopic melanin clumping in the hair bulb. In addition, upregulated expression of apoptotic regulators [P53, Fas/Fas-ligand, tumor necrosis factor-related apoptosis-inducing ligand/tumor necrosis factor-related apoptosis-inducing ligand receptor (TRAIL/TRAIL receptor), and Bax], increased apoptotic matrix keratinocytes, downregulated Ki67 expression, and decreased melanogenic protein in the hair bulb were noted in both groups. After 12 treatment days, hair follicles in Cph100 mice appeared to diminish dystrophic changes. In contrast, hair follicles of Cph150 mice prematurely entered a dystrophic catagen phase after 9 treatment days, and immunofluorescence staining for Ki67 and melanogenic protein expressions was barely visible. Two hair follicle damage response pathways were observed in this model, namely dystrophic anagen (Cph100) and catagen (Cph150) pathways. Our model might be useful for further understanding the impact of chemotherapy on human hair follicles.

A Guide to Studying Human Hair Follicle Cycling In Vivo

Hair follicles (HFs) undergo lifelong cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Given that HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. Although available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. In this article, we present such a guide, which uses objective, well-defined, and reproducible criteria, and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in suboptimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field.

Protective effect of Korean Red Ginseng against chemotherapeutic drug-induced premature catagen development assessed with human hair follicle organ culture model

Background

Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects for patients undergoing chemotherapy. This study evaluated the protective effect of Korean Red Ginseng (KRG) on CIA in a well-established in vitro human hair follicle organ culture model as it occurs in vivo.

Methods

We examined whether KRG can prevent premature hair follicle dystrophy in a human hair follicle organ culture model during treatment with a key cyclophosphamide metabolite, 4-hydroperoxycyclophosphamide (4-HC).

Results

4-HC inhibited human hair growth, induced premature catagen development, and inhibited proliferation and stimulated apoptosis of hair matrix keratinocytes. In addition, 4-HC increased p53 and Bax protein expression and decreased Bcl2 protein expression. Pretreatment with KRG protected against 4-HC-induced hair growth inhibition and premature catagen development. KRG also suppressed 4-HC-induced inhibition of matrix keratinocyte proliferation and stimulation of matrix keratinocyte apoptosis. Moreover, KRG restored 4-HC-induced p53 and Bax/Bcl2 expression.

Conclusion

Overall, our results indicate that KRG may protect against 4-HC-induced premature catagen development through modulation of p53 and Bax/Bcl2 expression.