Use of γ-Glutamyl Transpeptidase Activity as a Marker of Hair Cycle and Anagen Induction in Mouse Hair Follicles

1994 ◽  
Vol 103 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Thomas T. Kawabe ◽  
Allen E. Buhl ◽  
Marc F. Kubicek ◽  
Garland A. Johnson
Keyword(s):  
Hair Follicles ◽  
Hair Cycle ◽  
Glutamyl Transpeptidase ◽  
Anagen Induction

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.

Expression of ΔNLef1 in mouse epidermis results in differentiation of hair follicles into squamous epidermal cysts and formation of skin tumours

Development ◽  
2002 ◽  
Vol 129 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Catherin Niemann ◽  
David M. Owens ◽  
Jörg Hülsken ◽  
Walter Birchmeier ◽  
Fiona M. Watt
Keyword(s):  
Sonic Hedgehog ◽  
Hair Follicles ◽  
Hair Cycle ◽  
Mouse Epidermis ◽  
Sonic Hedgehog Pathway ◽  
Skin Tumours ◽  
Adult Mice ◽  
Tumour Formation ◽  
Interfollicular Epidermis ◽  
Skin Abnormalities

To examine the consequences of repressing β-catenin/Lef1 signalling in mouse epidermis, we expressed a ΔNLef1 transgene, which lacks the β-catenin binding site, under the control of the keratin 14 promoter. No skin abnormalities were detected before the first postnatal hair cycle. However, from 6 weeks of age, mice underwent progressive hair loss which correlated with the development of dermal cysts. The cysts were derived from the base of the hair follicles and expressed morphological and molecular markers of interfollicular epidermis. Adult mice developed spontaneous skin tumours, most of which exhibited sebaceous differentiation, which could be indicative of an origin in the upper part of the hair follicle. The transgene continued to be expressed in the tumours and β-catenin signalling was still inhibited, as evidenced by absence of cyclin D1 expression. However, patched mRNA expression was upregulated, suggesting that the sonic hedgehog pathway might play a role in tumour formation. Based on our results and previous data on the consequences of activating β-catenin/Lef1 signalling in postnatal keratinocytes, we conclude that the level of β-catenin signalling determines whether keratinocytes differentiate into hair or interfollicular epidermis, and that perturbation of the pathway by overexpression of ΔNLef1 can lead to skin tumour formation.

scholarly journals Inhibition of Rab27a and Rab27b Has Opposite Effects on the Regulation of Hair Cycle and Hair Growth

2020 ◽  
Vol 21 (16) ◽  
pp. 5672
Author(s):  
Kyung-Eun Ku ◽  
Nahyun Choi ◽  
Jong-Hyuk Sung
Keyword(s):  
Hair Growth ◽  
Expression Patterns ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Hair Cycle ◽  
Outer Root Sheath ◽  
Dermal Papilla Cells ◽  
Root Sheath ◽  
Culture Models

Rab27a/b are known to play an important role in the transport of melanosomes, with their knockout causing silvery gray hair. However, the relationship between Rab27a/b and hair growth is not well known. To evaluate the role of Rab27a/b in hair cycle, we investigated the expression of Rab27a/b during hair cycling and human outer root sheath (hORS) cells. The expression of Rab27a in ORS cells was mainly detected at the anagen, whereas expression of Rab27b in ORS, and epidermal cells was strongly expressed at the telogen. Additionally, Rab27a/b were expressed in the Golgi of hORS cells. To evaluate the role of Rab27a/b in hair growth, telogen-to-anagen transition animal and vibrissae hair follicles (HFs) organ culture models were assayed using Rab27a/b siRNAs. The knockdown of Rab27a or Rab27b suppressed or promoted hair growth, respectively. These results were also confirmed in human dermal papilla cells (hDPCs) and hORS cells, showing the opposite mitogenic effects. Moreover, Rab27b knockdown increased the expression levels of various growth factors in the hDPCs and hORS cells. Overall, the opposite temporal expression patterns during hair cycling and roles for hair growth of Rab27a/b suggested that Rab27a/b might regulate the hair cycle. Therefore, our study may provide a novel solution for the development of hair loss treatment by regulating Rab27a/b levels.

scholarly journals Vitamin A Metabolism During Refractory Telogen

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 109-109
Author(s):  
Damla Hovland ◽  
Liye Suo ◽  
Natalia Kedishvili ◽  
John Sundberg ◽  
Helen Everts
Keyword(s):  
Vitamin A ◽  
Hair Follicles ◽  
Dietary Vitamin ◽  
Hair Cycle ◽  
Retinol Dehydrogenase ◽  
Vitamin A Metabolism ◽  
Funding Sources ◽  
Morphogenetic Protein ◽  
Bmp4 Expression ◽  
Complete Set

Abstract Objectives Hair follicles cycle through periods of growth (anagen), regression (catagen) and rest (telogen). Telogen is further divided into refractory and competent telogen based on the expression of bone morphogenetic protein 4 (BMP4). Previously, the expression of a complete set of proteins involved in retinoic acid (RA) synthesis and signaling localized to the hair follicle and changed throughout the hair cycle. In addition, excess dietary vitamin A arrested the hair cycle in telogen; while retinol dehydrogenases short-chain dehydrogenase/reductase family 16C members 5 and 6 (Sdr16c5−/−/Sdr16c6−/−) double null mice had an accelerated the hair cycle. The purpose of this study was to further define these changes in the hair cycle. Methods The localization of RA synthesis proteins SDR16C5, retinol dehydrogenase 10 (RDH10), retinal dehydrogenase 2 (ALDH1A2), cellular RA binding protein 2 (CRABP2), RA degradation enzyme cytochrome p450 26B1 (CYP26B1), and BMP4 was examined in telogen hair follicles in female C57BL/6 J mice by immunohistochemistry. Immunohistochemistry with an antibody against BMP4 was also used to mark refractory telogen in the previous dietary vitamin A study. Results All proteins localized to BMP4 positive refractory telogen hair follicles. SDR16C5 and ALDH1A2 were also seen in BMP4 negative competent telogen hair follicles, but at a lower level. RDH10 was expressed in both BMP4 negative and positive hair follicles at similar levels. BMP4 expression was also used to distinguish refractory from competent telogen in C57BL/6 J mice fed different levels of vitamin A. Both low and excess dietary vitamin A resulted a greater percentage of hair follicles in refractory telogen in different studies. Conclusions In conclusion, RA synthesis and signaling may be stronger in refractory telogen and contribute to the inhibition of the hair cycle. Funding Sources NIH/NIAMS, Internal funding.

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 Plakoglobin Suppresses Epithelial Proliferation and Hair Growth in Vivo

2000 ◽  
Vol 149 (2) ◽  
pp. 503-520 ◽  
Author(s):  
Emmanuelle Charpentier ◽  
Robert M. Lavker ◽  
Elizabeth Acquista ◽  
Pamela Cowin
Keyword(s):  
Hair Growth ◽  
Cultured Cells ◽  
Hair Follicles ◽  
Tumor Formation ◽  
Hair Cycle ◽  
Epithelial Proliferation ◽  
Desmosomal Cadherins ◽  
Hair Follicle Cycle

Plakoglobin regulates cell adhesion by providing a modulatable connection between both classical and desmosomal cadherins and their respective cytoskeletal linker proteins. Both plakoglobin and the related protein β-catenin are posttranscriptionally upregulated in response to Wnt-1 in cultured cells. Upregulation of β-catenin has been implicated in potentiating hyperproliferation and tumor formation. To investigate the role of plakoglobin in these functions we expressed a full-length (PG) and an NH2-terminally truncated form of plakoglobin (ΔN80PG) in mouse epidermis and hair follicles, tissues which undergo continuous and easily observed postnatal renewal and remodeling. Expression of these constructs results in stunted hair growth, a phenotype that has also been observed in transgenic mice expressing Wnt3 and Dvl2 (Millar et al. 1999). Hair follicles from PG and ΔN80PG mice show premature termination of the growth phase (anagen) of the hair cycle, an event that is regulated in part by FGF5 (Hebert et al. 1994). The proliferative rate of the epidermal cells was reduced and apoptotic changes, which are associated with entry into the regressive phase of the hair follicle cycle (catagen), occurred earlier than usual.

Morphological changes associated with the growth cycle of vibrissal follicles in the rat

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 597-607
Author(s):  
R. D. Young ◽  
R. F. Oliver
Keyword(s):  
Morphological Changes ◽  
Dermal Papilla ◽  
Growth Cycle ◽  
Hair Follicles ◽  
Transitional Period ◽  
Hair Cycle ◽  
Hair Bulb ◽  
No Formation ◽  
The Matrix ◽  
Small Aggregation

Morphological changes which occur in the growth cycle of the rat vibrissal follicle during the transitional period between consecutive anagen phases are described. In contrast with pelage hair follicles, there is no shortening of the follicle, no formation of a papilla ‘rest’ and no close synchrony between club differentiation and follicle regression. Telogen is therefore considered to occur after loss of the matrix of the hair bulb and maximal diminution of the dermal papilla to a small aggregation of cells. These differences are discussed in relation to current nomenclature of the hair cycle and the function of the vibrissal follicle.

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.

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