scholarly journals HISTOLOGY AND CYTOCHEMISTRY OF HUMAN SKIN

1957 ◽  
Vol 3 (3) ◽  
pp. 343-348 ◽  
Author(s):  
William Montagna
Keyword(s):  
Enzyme Activity ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Outer Root Sheath ◽  
Moderate Amount ◽  
Strong Concentration ◽  
Apocrine Glands ◽  
Root Sheath ◽  
Secretory Coil

1. Various amounts of ß-glucuronidase activity may be found in all of the cutaneous appendages. 2. In the epidermis, the basal layer and the Malpighian layer contain a moderate amount of it, but a band of cells, including the stratum granulosum and the cells immediately above it, is rich in ß-glucuronidase. 3. The cells of the duct of eccrine sweat glands have moderately strong enzyme activity, but those in the secretory coil are strongly reactive; small and large reactive granules are crowded in the reactive cytoplasm. 4. The cells of the secretory coil of the apocrine glands contain more ß-glucuronidase than any other cutaneous appendage. 5. In the sebaceous glands, a very strong concentration of enzyme activity is found in the undifferentiated peripheral cells, a smaller amount of it is found in the differentiating cells. 6. In active hair follicles, the largest amount of ß-glucuronidase is found in the outer root sheath and in the bulb. In the outer sheath, the strongest concentration is found around the level of the keratogenous zone of the cortex. The dermal papilla is strongly reactive. In quiescent hair follicles, the outer root sheath has a moderate amount of enzyme concentration, but the dermal papilla is unreactive. 7. In the dermis, the fibroblasts in the papillary layer, the smooth muscle cells of the arrectores pilorum and the tunica media of arteries, and the fat cells all exhibit enzyme activity. Mast cells show a great concentration of ß-glucuronidase.

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 Migration of Melanoblasts into the Developing Murine Hair Follicle Is Accompanied by Transient c-Kit Expression

2002 ◽  
Vol 50 (6) ◽  
pp. 751-766 ◽  
Author(s):  
Eva M. J. Peters ◽  
Desmond J. Tobin ◽  
Natasha Botchkareva ◽  
Marcus Maurer ◽  
Ralf Paus
Keyword(s):  
Stem Cell ◽  
Hair Follicle ◽  
Stem Cell Factor ◽  
Mouse Skin ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Cell Populations ◽  
Outer Root Sheath ◽  
Hair Bulb ◽  
Root Sheath

Disruption of the c-Kit/stem cell factor (SCF) signaling pathway interferes with the survival, migration, and differentiation of melanocytes during generation of the hair follicle pigmentary unit. We examined c-Kit, SCF, and S100 (a marker for precursor melanocytic cells) expression, as well as melanoblast/melanocyte ultrastructure, in perinatal C57BL/6 mouse skin. Before the onset of hair bulb melanogenesis (i.e., stages 0–4 of hair follicle morphogenesis), strong c-Kit immunoreactivity (IR) was seen in selected non-mela-nogenic cells in the developing hair placode and hair plug. Many of these cells were S100-IR and were ultrastructurally identified as melanoblasts with migratory appearance. During the subsequent stages (5 and 6), increasingly dendritic c-Kit-IR cells successively invaded the hair bulb, while S100-IR gradually disappeared from these cells. Towards the completion of hair follicle morphogenesis (stages 7 and 8), several distinct follicular melanocytic cell populations could be defined and consisted broadly of (a) undifferentiated, non-pigmented c-Kit-negative melanoblasts in the outer root sheath and bulge and (b) highly differentiated melanocytes adjacent to the hair follicle dermal papilla above Auber's line. Widespread epithelial SCF-IR was seen throughout hair follicle morphogenesis. These findings suggest that melanoblasts express c-Kit as a prerequisite for migration into the SCF-supplying hair follicle epithelium. In addition, differentiated c-Kit-IR melanocytes target the bulb, while non-c-Kit-IR melanoblasts invade the outer root sheath and bulge in fully developed hair follicles.

scholarly journals Regulation of prolactin receptor expression in ovine skin in relation to circulating prolactin and wool follicle growth status

2002 ◽  
Vol 172 (3) ◽  
pp. 605-614 ◽  
Author(s):  
AJ Nixon ◽  
CA Ford ◽  
JE Wildermoth ◽  
AJ Craven ◽  
MG Ashby ◽  
...  
Keyword(s):  
In Situ Hybridisation ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Receptor Expression ◽  
Ribonuclease Protection Assay ◽  
Plasma Prolactin ◽  
Follicle Growth ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Wool Follicle

Seasonal patterns of hair growth are governed, at least in part, by levels of prolactin in circulation, and although receptors for prolactin (PRLR) have been demonstrated in hair follicles, little is known of their regulation in relation to follicular cycles. In this study, a photoperiod-generated increase in prolactin was used to induce a wool follicle cycle during which changes in PRLR expression in sheep skin were determined by ribonuclease protection assay and in situ hybridisation. mRNA for prolactin and both isoforms of PRLR were also detected in skin by reverse transcription and polymerase chain reaction. As circulating prolactin began to rise from low levels, PRLR mRNA in the skin initially fell. These changes immediately preceded the catagen (regressive) phase of the hair cycle. Further increase in prolactin resulted in up-regulation of PRLR during telogen (dormancy), particularly in the epithelial hair germ, to reach a peak during proanagen (reactivation). In anagen (when follicle growth was fully re-established), PRLR mRNA returned to levels similar to those observed before the induced cycle. Hence, this longer term rise and fall of PRLR expression followed that of plasma prolactin concentration with a lag of 12-14 days. PRLR mRNA was most abundant in the dermal papilla, outer root sheath, hair germ, skin glands and epidermis. Location of PRLR in the dermal papilla and outer root sheath indicates action of prolactin on the growth-controlling centres within wool follicles. These cycle-related patterns of PRLR expression suggest dynamic regulation of PRLR by prolactin, thereby modulating hormonal responsiveness of seasonally growing hair follicles.

scholarly journals HISTOLOGY AND CYTOCHEMISTRY OF HUMAN SKIN

1955 ◽  
Vol 1 (1) ◽  
pp. 13-16 ◽  
Author(s):  
William Montagna
Keyword(s):  
Enzyme Activity ◽  
Stratum Corneum ◽  
Esterase Activity ◽  
Hair Follicles ◽  
Sweat Glands ◽  
Stratum Granulosum ◽  
Apocrine Glands ◽  
Dark Cells ◽  
Outer Sheath ◽  
Eccrine Sweat Glands

1. In the epidermis non-specific esterase activity outlines a strongly reactive band between the stratum granulosum and the stratum corneum. In the epidermis of the palm, there is no such esterase-rich band. 2. The outer sheath of active hair follicles has strong enzyme activity. The degenerating hair bulb in catagen follicles is very strongly reactive, and clusters of cells around the hair club in quiescent follicles are rich in enzyme activity. 3. Strong enzyme activity is found in young sebaceous cells, while decaying sebaceous cells and newly formed sebum are unreactive. Old sebum, however, is very intensely reactive. 4. Only the "dark" cells of eccrine sweat glands show a reaction; the "clear" cells are negative. 5. The cells of axillary apocrine glands abound in enzyme.

scholarly journals The Glypican-1/HGF/C-Met and Glypican-1/VEGF/VEGFR2 Ternary Complexes Regulate Hair Follicle Angiogenesis

2021 ◽  
Vol 9 ◽  
Author(s):  
Charlie Colin-Pierre ◽  
Nicolas Berthélémy ◽  
Nicolas Belloy ◽  
Louis Danoux ◽  
Vincent Bardey ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Dermal Papilla ◽  
Human Keratinocytes ◽  
Hair Follicles ◽  
Microvascular Endothelial Cell ◽  
Outer Root Sheath ◽  
Dermal Papilla Cells ◽  
Root Sheath ◽  
Microvascular Endothelial

The hair renewal involves changes in the morphology of the hair follicle and its micro-vascularization. In alopecia, the hair cycle is accelerated, resulting in the formation of thinner and shorter hair. In addition, alopecia is associated with a decrease in the micro-vascularization of the hair follicles. In this study, the role of glypicans (GPCs) was analyzed in the regulation of the angiogenesis of human dermal microvascular endothelial cells (HDMEC). The analysis of glypican gene expression showed that GPC1 is the major glypican expressed by human keratinocytes of outer root sheath (KORS), human hair follicle dermal papilla cells (HHFDPC) and HDMEC. KORS were demonstrated to secrete VEGF and HGF. The HDMEC pseudotube formation was induced by KORS conditioned media (KORSCM). It was totally abrogated after GPC1 siRNA transfection of HDMEC. Moreover, when cleaved by phospholipase C (PLC), GPC1 promotes the proliferation of HDMEC. Finally, GPC1 was shown to interact directly with VEGFR2 or c-Met to regulate angiogenesis induced by the activation of these receptors. Altogether, these results showed that GPC1 is a key regulator of microvascular endothelial cell angiogenesis induced by VEGF and HGF secreted by KORS. Thus, GPC1 might constitute an interesting target to tackle alopecia in dermatology research.

Distribution of prolactin receptor immunoreactivity in ovine skin and changes during the wool follicle growth cycle

1997 ◽  
Vol 155 (2) ◽  
pp. 265-275 ◽  
Author(s):  
VJ Choy ◽  
AJ Nixon ◽  
AJ Pearson
Keyword(s):  
Monoclonal Antibody ◽  
Receptor Gene ◽  
Prolactin Receptor ◽  
Dermal Papilla ◽  
Growth Cycle ◽  
Sweat Glands ◽  
Follicle Growth ◽  
Outer Root Sheath ◽  
Rnase Protection ◽  
Root Sheath

Prolactin is believed to mediate seasonal cues entraining seasonal reproductive and hair follicle growth cycles. Prolactin receptor binding activity and prolactin receptor gene expression in mammalian skin have recently been described. In this report, prolactin receptor immunoreactivity is identified in sheep skin using a monoclonal antibody against the rat liver prolactin receptor. Western blotting analysis of microsomal membrane proteins from skin showed major bands corresponding to molecular weights of 87 and 71 kDa and minor bands at 101 and 21 kDa. RNase protection analysis revealed the presence of mRNA species coding for long and short forms of the prolactin receptor. Formalin-fixed sections, exposed to the monoclonal antibody and stained by an immunogold method, revealed prolactin receptor-immunoreactivity in the dermal papilla, germinal matrix, outer root sheath, lower regions of the inner root sheath and connective tissue sheath of wool follicles. Staining was absent from keratinised cell populations. In all samples, the interfollicular epidermis, sebaceous and sweat glands were positively stained. The distribution of prolactin receptor is described in both growing and inactive wool follicles and related to postulated cycle-specific actions of circulating prolactin in the control of seasonal fibre growth.

scholarly journals Requirement of zinc transporter ZIP10 for epidermal development: Implication of the ZIP10–p63 axis in epithelial homeostasis

2017 ◽  
Vol 114 (46) ◽  
pp. 12243-12248 ◽  
Author(s):  
Bum-Ho Bin ◽  
Jinhyuk Bhin ◽  
Mikiro Takaishi ◽  
Koh-ei Toyoshima ◽  
Saeko Kawamata ◽  
...  
Keyword(s):  
Progenitor Cell ◽  
Hair Follicles ◽  
Zinc Transporter ◽  
Outer Root Sheath ◽  
Epithelial Homeostasis ◽  
Cell Proliferation And Differentiation ◽  
Root Sheath ◽  
Signaling Axis ◽  
Progenitor Cell Proliferation ◽  
Epidermal Development

Skin tissues, in particular the epidermis, are severely affected by zinc deficiency. However, the zinc-mediated mechanisms that maintain the cells that form the epidermis have not been established. Here, we report that the zinc transporter ZIP10 is highly expressed in the outer root sheath of hair follicles and plays critical roles in epidermal development. We found that ZIP10 marked epidermal progenitor cell subsets and that ablating Zip10 caused significant epidermal hypoplasia accompanied by down-regulation of the transactivation of p63, a master regulator of epidermal progenitor cell proliferation and differentiation. Both ZIP10 and p63 are significantly increased during epidermal development, in which ZIP10-mediated zinc influx promotes p63 transactivation. Collectively, these results indicate that ZIP10 plays important roles in epidermal development via, at least in part, the ZIP10–zinc–p63 signaling axis, thereby highlighting the physiological significance of zinc regulation in the maintenance of skin epidermis.

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