Communication compartments in hair follicles and their implication in differentiative control

Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 389-393 ◽  
Author(s):  
E. Kam ◽  
M.B. Hodgins

Observations on hair follicles presented in this paper show that boundaries to junctional communication are formed between groups of cells following different pathways of differentiation. The patterns of junctional communication in the bulbs of rat vibrissa follicles and human hair follicles were studied by microinjection of the fluorescent tracer dye Lucifer Yellow CH. Dye spread was extensive between undifferentiated cells of the hair bulb matrix but communication boundaries were found between groups of morphologically distinct cells. For example, boundaries to dye spread were observed between undifferentiated matrix cells and cells in the early stage of differentiation into the inner root sheath, between Huxley's and Henle's layers in the early inner root sheath and between cells of the cuticle and cortex of the hair. Dye did not spread between epithelial cells of the hair bulb and mesenchymal cells of the connective tissue sheath or dermal papilla. The patterns of dye spread became more complex (increased boundary formation and subcompartmentation) as differentiation progressed in higher regions of the hair bulb. The observed communication can be related to previous ultrastructural studies by others on the distribution of gap junctions in the wool follicle. These results show that junctional communication, with its consequent intercellular spread of small ions and molecules, is associated with uniformity of expression and behaviour within cell populations and that interruption of communication through the formation of boundaries and communication compartments is temporally and spatially related to the production of subpopulations of cells committed to the expression of different phenotypes.

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Zhenyu Wu ◽  
Yanli Zhu ◽  
Hongli Liu ◽  
Gongyan Liu ◽  
Fuchang Li

Abstract Wnt signaling plays an important role in the growth and development of hair follicles (HFs). Among the signaling molecules, Wnt10b was shown to promote the differentiation of primary skin epithelial cells toward the hair shaft and inner root sheath of the HF cells in mice in vitro. Whisker HFs were isolated from Rex rabbits and cultured in vitro to measure hair shaft growth. Meanwhile, dermal papilla cells (DPCs) were isolated and cultured in vitro. Treatment with AdWnt10b or the Wnt/β-Catenin Pathway inhibitor, XAV939, assessed the DPCs proliferation by CCK-8 assay. And the cell cycle was also analyzed by flow cytometry. We found that Wnt10b could promote elongation of the hair shaft, whereas XAV-939 treatment could eliminated this phenomenon. AdWnt10b treatment promoted the proliferation and induced G1/S transition of DPCs. AdWnt10b stimulation up-regulated β-Catenin protein in DPCs. Inhibition of Wnt/β-Catenin signaling by XAV-939 could decreased the basal and Wnt10b-enhanced proliferation of DPCs. And could also suppress the cell cycle progression in DPCs. In summary, our study demonstrates that Wnt10b could promote HFs growth and proliferation of DPCs via the Wnt/β-Catenin signaling pathway in Rex rabbits.


2002 ◽  
Vol 50 (6) ◽  
pp. 751-766 ◽  
Author(s):  
Eva M. J. Peters ◽  
Desmond J. Tobin ◽  
Natasha Botchkareva ◽  
Marcus Maurer ◽  
Ralf Paus

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.


2020 ◽  
Vol 21 (16) ◽  
pp. 5672
Author(s):  
Kyung-Eun Ku ◽  
Nahyun Choi ◽  
Jong-Hyuk Sung

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.


1994 ◽  
Vol 45 (4) ◽  
pp. 769 ◽  
Author(s):  
SA Holle ◽  
PM Harris ◽  
AS Davies ◽  
MJ Birtles

Effects of selection for high fleeceweight in the New Zealand Romney sheep were investigated in relation to the morphology of individual follicles and changes in the germinative cell population of the follicle bulb. Two-year-old Romney rams, 10 from each of two selection lines (Massey University fleeceweight-selected (FWT) and control (CLT) flock), were run together on pasture for a period from June to early December. At three times during this observation period (June, August and November) skin samples were taken from their midside flanks after local injection of bromodeoxyuridine (BrdU), to assess proliferation of bulb cells and several dimensional measurements of the follicle bulb and dermal papilla. FWT sheep had larger follicle dimensions than CLT sheep during winter and summer, with a greater number of proliferating bulb cells. Both flocks showed a seasonal change in follicle size, with a decline during winter, but the size of the dermal papilla was less affected than the germinative tissue area. Measurements of proliferation density (number of proliferating cells per area/volume of bulb tissue) suggest that changes in proliferation density do not contribute to flock differences in fleece production. However, during summer, FWT showed a 40% advantage over CLT sheep in hourly cell production based on data from three dimensional follicle bulb extrapolation. The different genotypes showed variations in width, as well as area of cortex and inner root sheath (IRS), measured across the top of the dermal papilla. The expression of these differences was further enhanced through seasonal influences, suggesting that there is an interaction between genetic/flock influences and seasonal influences on cell distribution to cortex and inner root sheath.


2018 ◽  
Vol 67 (2) ◽  
pp. 85-97 ◽  
Author(s):  
Didier Pin ◽  
Valérie Pendaries ◽  
Sokhna Keita Alassane ◽  
Carine Froment ◽  
Nicolas Amalric ◽  
...  

Filaggrin (FLG) and corneodesmosin (CDSN) are two key proteins of the human epidermis. FLG loss-of-function mutations are the strongest genetic risk factors for human atopic dermatitis. Studies of the epidermal distribution of canine FLG and CDSN are limited. Our aim was to better characterize the distribution of FLG and CDSN in canine skin. Using immunohistochemistry on beagle skin, we screened a series of monoclonal antibodies (mAbs) specific for human FLG and CDSN. The cross-reactive mAbs were further used using immunoelectron microscopy and Western blotting. The structure of canine CDSN and FLG was determined using publicly available databases. In the epidermis, four anti-FLG mAbs stained keratohyalin granules in the granular keratinocytes and corneocyte matrix of the lower cornified layer. In urea-extracts of dog epidermis, several bands corresponding to proFLG and FLG monomers were detected. One anti-CDSN mAb stained the cytoplasm of granular keratinocytes and cells of both the inner root sheath and medulla of hair follicles. Dog CDSN was located in lamellar bodies, in the extracellular parts of desmosomes and in corneodesmosomes. A protein of 52 kDa was immunodetected. Genomic DNA analysis revealed that the amino acid sequence and structure of canine and human CDSN were highly similar.


2019 ◽  
Vol 67 (7) ◽  
pp. 495-509
Author(s):  
Naoko Kanno ◽  
Saishu Yoshida ◽  
Takako Kato ◽  
Yukio Kato

Neuronatin ( Nnat) is expressed in the pituitary, pancreas, and other tissues; however, the function of NNAT is still unclear. Recent studies have demonstrated that NNAT is localized in the sex-determining region Y-box 2-positive stem/progenitor cells in the developing rat pituitary primordium and is downregulated during differentiation into mature hormone-producing cells. Moreover, NNAT is widely localized in subcellular organelles, excluding the Golgi. Here, we further evaluated NNAT-positive cells and intracellular localization in embryonic and postnatal rat tissues such as the pancreas, tongue, whisker hair follicle, and testis. Immunohistochemistry revealed that NNAT was localized in undifferentiated cells (i.e., epithelial basal cells and basement cells in the papillae of the tongue and round and elongated spermatids of the testis) as well as in differentiated cells (insulin-positive cells and exocrine cells of the pancreas, taste receptor cells of the fungiform papilla, the inner root sheath of whisker hair follicles, and spermatozoa). In addition, NNAT exhibited novel intracellular localization in acrosomes in the spermatozoa. Because the endoplasmic reticulum (ER) is excluded from spermatozoa and sarco/ER Ca2+-ATPase isoform 2 (SERCA2) is absent from the inner root sheath, these findings suggested that NNAT localization in the ER and its interaction with SERCA2 are cell- or tissue-specific properties.


Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 597-607
Author(s):  
R. D. Young ◽  
R. F. Oliver

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.


2001 ◽  
Vol 145 (4) ◽  
pp. 558-568 ◽  
Author(s):  
R.M. Porter ◽  
L.D. Corden ◽  
D.P. Lunny ◽  
F.J.D. Smith ◽  
E.B. Lane ◽  
...  

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