scholarly journals Splenic melanosis during normal murine C57BL/6 hair cycle and after chemotherapy.

2013 ◽  
Vol 60 (3) ◽  
Author(s):  
Dominika Michalczyk-Wetula ◽  
Aleksander Salwiński ◽  
Małgorzata Popik ◽  
Monika Jakubowska ◽  
Przemysław M Płonka
Keyword(s):  
Body Weight ◽  
Side Effects ◽  
Hair Follicle ◽  
Cancer Chemotherapy ◽  
Hair Loss ◽  
Murine Model ◽  
Hair Follicles ◽  
Hair Cycle ◽  
Normal Hair ◽  
Hematoxylin And Eosin

Cancer chemotherapy is associated with serious side effects, including temporary hair loss and impairment of pigmentation. We suspect that ectopic melanin deposition occurring due to chemotherapy may add to these effects worsening the already unpleasant symptoms. We associated the ectopic occurrence of follicular melanin after chemotherapy with splenic melanosis - an interesting example of extradermal melanin localization - and we expected an increase in splenic melanin deposition after chemotherapy. Using the C57BL/6 murine model of synchronized hair cycle induced by depilation, we visualized splenic melanin by means of several histological and histochemical protocols of staining: hematoxylin and eosin, May-Grünwald-Giemsa and Fontana-Masson. Unexpectedly, the splenic deposition of melanin decreased due to application of cyclophosphamide (i.p. 120 mg/ kg body weight on day 9 post depilation). The drop was abrupt and lasted for at least 5 days (day 13-18 post depilation), as compared with normal hair cycle. Moreover, in mice with normal, depilation-induced hair cycle we observed a similar drop shortly before entering catagen (day 15 post depilation), followed by a slow and partial increase in splenic melanization up to day 27 post depilation in both groups. We conclude that cyclophosphamide negatively affects splenic melanization and/or extradermal transfer of ectopic melanin from the dystrophic hair follicles, but the most powerful down-regulator of splenic melanosis is normal and dystrophic catagen - the phase of hair follicle involution and re-modelling.

scholarly journals Secreted Frizzled-related protein 4 inhibits the regeneration of hair follicles

PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6153 ◽  
Author(s):  
Haiying Guo ◽  
Yizhan Xing ◽  
Fang Deng ◽  
Ke Yang ◽  
Yuhong Li
Keyword(s):  
Hair Follicle ◽  
Hair Follicles ◽  
Hair Cycle ◽  
Related Protein ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Potential Therapeutic Application ◽  
Hematoxylin And Eosin ◽  
Hair Follicle Growth ◽  
Treated Hair

Secreted Frizzled-related Protein 4 (sFRP4) belongs to Wnt inhibitors. Previously, we reported that sFRP4 inhibited the differentiation of melanocyte. Here, by using of immunostaining, we showed that sFRP4 is expressed in both human and mouse hair follicles, especially in the outer root sheath and inner root sheath. To reveal the role of sFRP4 in hair follicle growth and hair cycle, we induced synchronized hair cycle in the dorsal skin of mice by depilation, and injected sFRP4 intradermally into the skin. By hematoxylin and eosin staining, we found that the regeneration of hair follicles was inhibited by sFRP4. However, the structure of hair follicles remained complete. Compared with phosphate buffer saline-treated hair follicles, the sFRP4-treated hair follicles still had the same expression pattern of keratins. Our findings reveal that sFRP4 inhibits but not blocks the regeneration of hair follicles, and supply a potential therapeutic application to treat hair follicle regeneration disorders.

scholarly journals Localisation and regulation of cholesterol transporters in the human hair follicle: mapping changes across the hair cycle

2021 ◽  
Author(s):  
Megan A. Palmer ◽  
Eleanor Smart ◽  
Iain S. Haslam
Keyword(s):  
Hair Follicle ◽  
Human Hair ◽  
Vital Role ◽  
Transport Proteins ◽  
Hair Follicles ◽  
Regulatory Control ◽  
Cholesterol Transport ◽  
Hair Cycle ◽  
Human Hair Follicle

AbstractCholesterol has long been suspected of influencing hair biology, with dysregulated homeostasis implicated in several disorders of hair growth and cycling. Cholesterol transport proteins play a vital role in the control of cellular cholesterol levels and compartmentalisation. This research aimed to determine the cellular localisation, transport capability and regulatory control of cholesterol transport proteins across the hair cycle. Immunofluorescence microscopy in human hair follicle sections revealed differential expression of ATP-binding cassette (ABC) transporters across the hair cycle. Cholesterol transporter expression (ABCA1, ABCG1, ABCA5 and SCARB1) reduced as hair follicles transitioned from growth to regression. Staining for free cholesterol (filipin) revealed prominent cholesterol striations within the basement membrane of the hair bulb. Liver X receptor agonism demonstrated active regulation of ABCA1 and ABCG1, but not ABCA5 or SCARB1 in human hair follicles and primary keratinocytes. These results demonstrate the capacity of human hair follicles for cholesterol transport and trafficking. Future studies examining the role of cholesterol transport across the hair cycle may shed light on the role of lipid homeostasis in human hair disorders.

scholarly journals Dermal exosomes containing miR-218-5p promote hair regeneration by regulating β-catenin signaling

2020 ◽  
Vol 6 (30) ◽  
pp. eaba1685 ◽  
Author(s):  
Shiqi Hu ◽  
Zhenhua Li ◽  
Halle Lutz ◽  
Ke Huang ◽  
Teng Su ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Hair Growth ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Hair Cycle ◽  
Paracrine Signaling ◽  
Hair Regrowth ◽  
Study Results ◽  
Anagen Phase ◽  
Hair Follicle Cycle

The progression in the hair follicle cycle from the telogen to the anagen phase is the key to regulating hair regrowth. Dermal papilla (DP) cells support hair growth and regulate the hair cycle. However, they gradually lose key inductive properties upon culture. DP cells can partially restore their capacity to promote hair regrowth after being subjected to spheroid culture. In this study, results revealed that DP spheroids are effective at inducing the progression of the hair follicle cycle from telogen to anagen compared with just DP cell or minoxidil treatment. Because of the importance of paracrine signaling in this process, secretome and exosomes were isolated from DP cell culture, and their therapeutic efficacies were investigated. We demonstrated that miR-218-5p was notably up-regulated in DP spheroid–derived exosomes. Western blot and immunofluorescence imaging were used to demonstrate that DP spheroid–derived exosomes up-regulated β-catenin, promoting the development of hair follicles.

scholarly journals Epithelium-Mesenchyme Interactions Control the Activity of Peroxisome Proliferator-Activated Receptor β/δ during Hair Follicle Development

2005 ◽  
Vol 25 (5) ◽  
pp. 1696-1712 ◽  
Author(s):  
Nicolas Di-Poï ◽  
Chuan Young Ng ◽  
Nguan Soon Tan ◽  
Zhongzhou Yang ◽  
Brian A. Hemmings ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Hair Follicles ◽  
Peroxisome Proliferator ◽  
Follicle Development ◽  
Paracrine Factor ◽  
Peroxisome Proliferator Activated Receptor ◽  
Proliferation And Apoptosis ◽  
Normal Hair ◽  
Hair Follicle Development

ABSTRACT Hair follicle morphogenesis depends on a delicate balance between cell proliferation and apoptosis, which involves epithelium-mesenchyme interactions. We show that peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) and Akt1 are highly expressed in follicular keratinocytes throughout hair follicle development. Interestingly, PPARβ/δ- and Akt1-deficient mice exhibit similar retardation of postnatal hair follicle morphogenesis, particularly at the hair peg stage, revealing a new important function for both factors in the growth of early hair follicles. We demonstrate that a time-regulated activation of the PPARβ/δ protein in follicular keratinocytes involves the up-regulation of the cyclooxygenase 2 enzyme by a mesenchymal paracrine factor, the hepatocyte growth factor. Subsequent PPARβ/δ-mediated temporal activation of the antiapoptotic Akt1 pathway in vivo protects keratinocytes from hair pegs against apoptosis, which is required for normal hair follicle development. Together, these results demonstrate that epithelium-mesenchyme interactions in the skin regulate the activity of PPARβ/δ during hair follicle development via the control of ligand production and provide important new insights into the molecular biology of hair growth.

scholarly journals Early Stages ofwe/we wal/walMouse Hair Morphogenesis: Light and Fluorescent Microscopy of the Whole-Mount Epidermis

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Alexandra Rippa ◽  
Olga Leonova ◽  
Vladimir Popenko ◽  
Andrey Vasiliev ◽  
Vasily Terskikh ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Hair Loss ◽  
Early Stage ◽  
Fluorescent Microscopy ◽  
Adult Life ◽  
Hair Follicles ◽  
Whole Mount ◽  
Interfollicular Epidermis ◽  
Embryonic Morphogenesis ◽  
Hair Morphogenesis

In adult skin, hair follicles cyclically self-renew in a manner that recapitulates embryonic hair follicle morphogenesis. The most common pathology of hair in adults is alopecia, which is hair loss to different extent. There are a number of murine models of alopecia including spontaneous mutations. In the present study, we worked with double homozygouswe/we wal/walmice which demonstrate symptoms closely resembling human alopecia. Using whole-mount preparations of epidermis of E18.5 embryos we show that hair follicle defects can be revealed as early as during embryonic morphogenesis in these mutants. The number of hair follicles was reduced almost 1.5-fold in mutant skin. The shape of the early stage small follicles was altered in mutant animals as compared to control ones. Additionally, follicles of mutant embryos were wider at the point of conjunction with interfollicular epidermis. We believe that the mutant mice studied represent a fascinating model to address the problem of hair loss. We demonstrated alterations in the morphogenesis of embryonic hair follicle inwe/we wal/waldouble homozygous mice developing alopecia postnatally. We suppose that incorrect morphogenesis of hair follicles during embryogenesis is closely related to alopecia in the adult life. Unveiling the mechanisms involved in altered embryogenesis may elucidate the pathogenesis of alopecia.

Effects of Finasteride on Apoptosis and Regulation of the Human Hair Cycle

2002 ◽  
Vol 6 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Marty E. Sawaya ◽  
Ulrike Blume-Peytavi ◽  
Diane L. Mullins ◽  
Bernard P. Nusbaum ◽  
David Whiting ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Human Hair ◽  
Time Course ◽  
Central Element ◽  
Constitutive Expression ◽  
Hair Follicles ◽  
Dermal Fibroblasts ◽  
Follicle Cells ◽  
Hair Cycle ◽  
Cellular Expression

Background: A number of studies have provided evidence that apoptosis is a central element in the regulation of hair follicle regression. In androgenetic alopecia (AGA), the exact location and control of key players in the apoptotic pathways remains obscure. Objective: In the present study, we used a panel of antibodies and investigated the spatial and cellular pattern of expression of caspases and inhibitors of apoptosis (IAPs), such as XIAP and FLIP, in men with normal scalp and in men with AGA before and after 6 months of treatment with 1 mg oral finasteride treatment. Methods and Results: Constitutive expression of caspases-1, −3, −8, and −9 and XIAP was detected predominantly within the isthmic and infundibular hair follicle area, basilar layer of the epidermis, and eccrine and sebaceous glands. AGA-affected tissues showed an increase in caspase (−1, −3, −6, −9) immunoreactivity with a concomitant decrease in XIAP staining. After 6 months of finasteride treatment, both caspases and XIAP were similar to levels exhibited by normal subjects. Immunoblot analysis was performed to determine antibody specificity and cellular expression of caspases. Purified populations of keratinocytes, melanocytes, dermal papilla, and dermal fibroblasts derived from human hair follicles were cultured in vitro and treated with 0.5 μm staurosporin. Time-course experiments revealed that processing of caspase-3 is a principal event during apoptosis of these hair cell types. Conclusion: These data suggest that alterations in levels of caspases and IAPs regulate hair follicle homeostasis. Moreover, finasteride appears to influence caspase and XIAP expression in hair follicle cells thus signaling anagen, active growth in the hair cycle.

scholarly journals Discovery of a novel murine keratin 6 (K6) isoform explains the absence of hair and nail defects in mice deficient for K6a and K6b

2001 ◽  
Vol 154 (3) ◽  
pp. 619-630 ◽  
Author(s):  
Sonja M. Wojcik ◽  
Mary A. Longley ◽  
Dennis R. Roop
Keyword(s):  
Hair Follicle ◽  
Embryonic Stem ◽  
Constitutive Expression ◽  
Hair Follicles ◽  
Stem Cell Technology ◽  
Keratin Gene ◽  
Dorsal Tongue ◽  
Normal Hair ◽  
B Mice ◽  
Keratin 6

The murine genome is known to have two keratin 6 (K6) genes, mouse K6 (MK6)a and MK6b. These genes display a complex expression pattern with constitutive expression in the epithelia of oral mucosa, hair follicles, and nail beds. We generated mice deficient for both genes through embryonic stem cell technology. The majority of MK6a/b−/− mice die of starvation within the first two weeks of life. This is due to a localized disintegration of the dorsal tongue epithelium, which results in the build up of a plaque of cell debris that severely impairs feeding. However, ∼25% of MK6a/b−/− mice survive to adulthood. Remarkably, the surviving MK6a/b−/− mice have normal hair and nails. To our surprise, we discovered MK6 staining both in the hair follicle and the nail bed of MK6a/b−/− mice, indicating the presence of a third MK6 gene. We cloned this previously unknown murine keratin gene and found it to be highly homologous to human K6hf, which is expressed in hair follicles. We therefore termed this gene MK6 hair follicle (MK6hf). The presence of MK6hf in the MK6a/b−/− follicles and nails offers an explanation for the absence of hair and nail defects in MK6a/b−/− animals.

scholarly journals What Can Complex Dietary Supplements Do for Hair Loss and How Can It Be Validly Measured—A Review

2020 ◽  
Vol 10 (14) ◽  
pp. 4996
Author(s):  
Nicole Braun ◽  
Ulrike Heinrich
Keyword(s):  
Hair Follicle ◽  
Dietary Supplements ◽  
Hair Loss ◽  
Hair Growth ◽  
Hair Cycle ◽  
Active Growth ◽  
Widespread Occurrence ◽  
Non Invasive ◽  
Anagen Phase

Hair plays a major role in perception within a society. It provides information about gender, age, health, and social status. It is therefore not surprising that those affected are exposed to great suffering due to the widespread occurrence of hair loss. As a result, the demand for new products to remedy this problem is not diminishing. Hair grows in cycles, and a hair follicle goes through several phases called the hair cycle. The active growth phase (anagen phase) lasts 2–6 years. In this state a hair follicle shows a growth of about 1 cm per month. In order to improve the existing hair status, hair should be kept in the active anagen phase as long as possible, or the transition to anagen should be stimulated. A number of reviews already describe the influence of individual active ingredients on hair growth. However, the following review describes existing studies of complex dietary supplements with their experimental weaknesses and strengths and their influence on hair loss. Also, for the determination of hair loss, it is important to use a valid method with high acceptance by the test persons. In this context, the TrichoScale® is a validated and non-invasive tool for quantifying hair loss/hair growth. Thus, it is an ideal measuring instrument to objectively quantify the effectiveness of a hair loss treatment.

The effect of melatonin treatment on fur maturation period and hair follicle cycle in growing chinchillas

2002 ◽  
Vol 75 (1) ◽  
pp. 49-55 ◽  
Author(s):  
J. Lanszki ◽  
D. Allain ◽  
R.-G. Thébault ◽  
Zs. Szendrö
Keyword(s):  
Hair Follicle ◽  
Activity Cycle ◽  
Hair Follicles ◽  
Control Group ◽  
Melatonin Treatment ◽  
Maturation Period ◽  
Continuous Release ◽  
Melatonin Administration ◽  
Normal Hair ◽  
Hair Follicle Cycle

AbstractThe effect of melatonin treatment on fur maturation period and hair follicle cycle in 4-month-old male and female chinchillas, kept under conditions of natural photoperiod, was studied. The animals were treated with continuous-release implants of melatonin (18 mg, group M, no. = 56), while no treatment was given to the control (group C, no. = 69). The effect on hair follicle activity cycle under conditions of normal hair growth (no. = 8) and after defleecing (no. = 8) and on number of hair fibres per follicle bundle (no. = 27) were measured by taking skin samples for histological examination once a month. The age at fur priming was reduced by 31 days (P < 0001) in the melatonin-treated chinchillas. When moulting began during the short-day period, the fur reached maturity 13 days (P < 005) sooner than when the moult began during the long-day period. Melatonin administration proved to be effective in these two periods. Melatonin treatment led to hair follicle activity decreasing at a faster rate, and the differences between treated and control groups from day 60 were significant (P < 005). The primary and secondary hair follicles reached the telogen phase 30 days earlier. Due to melatonin administration more fibres per follicle bundle were observed on the matured pelt (P < 005). At 4 months of age, following the removal of hair by defleecing, the growth of the first adult hair was studied without the presence of young-age hairs. No influence of defleecing as opposed to normal hair development on age at fur maturation or on the number of fibres per hair follicle bundle was observed. Within groups M and C the number of fibres per hair follicle bundle proved to be independent of age at first fur priming. No substantial differences between the groups were observed with respect to either body weight or pelt length at the time of pelting. According to these results, melatonin administration is effective in shortening the coat maturation period in growing chinchillas and causing corresponding changes in the hair follicle cycle.

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