scholarly journals Probing keratinocyte and differentiation specificity of the human K5 promoter in vitro and in transgenic mice.

1993 ◽  
Vol 13 (6) ◽  
pp. 3176-3190 ◽  
Author(s):  
C Byrne ◽  
E Fuchs
Keyword(s):  
Transgenic Mice ◽  
Transcription Initiation ◽  
Gene Segment ◽  
Hair Follicles ◽  
Cell Type ◽  
Outer Root Sheath ◽  
Specific Expression ◽  
Root Sheath ◽  
Stratified Epithelia

Keratins K5 and K14 form the extensive intermediate filament network of mitotically active basal cells in all stratified epithelia. We have explored the regulatory mechanisms governing cell-type-specific and differentiation stage-specific expression of the human K5 gene in transiently transfected keratinocytes in vitro and in transgenic mice in vivo. Six thousand base pairs of 5' upstream K5 sequence directed proper basal cell-specific expression in all stratified epithelia. Surprisingly, as few as 90 bp of the K5 promoter still directed expression to stratified epithelia, with expression predominantly in epidermis, hair follicles, and tongue. Despite keratinocyte-preferred expression, the truncated K5 promoter displayed departures from basal to suprabasal expression in epidermis and from outer root sheath to inner root sheath expression in the follicle, with some regional variations in expression as well. To begin to elucidate the molecular controls underlying the keratinocyte specificity of the truncated promoter, we examined protein-DNA interactions within this region. A number of keratinocyte nuclear proteins bind to a K5 gene segment extending from -90 to +32 bp and are functionally involved in transcriptional regulation in vitro. Interestingly, several of these factors are common to both the K5 and K14 promoters, although they appear to be distinct from those previously implicated in keratinocyte specificity. Mutagenesis studies indicate that factors binding in the vicinity of the TATA box and transcription initiation are responsible for the cell type specificity of the truncated K5 promoter.

Probing keratinocyte and differentiation specificity of the human K5 promoter in vitro and in transgenic mice

1993 ◽  
Vol 13 (6) ◽  
pp. 3176-3190
Author(s):  
C Byrne ◽  
E Fuchs
Keyword(s):  
Transgenic Mice ◽  
Transcription Initiation ◽  
Gene Segment ◽  
Hair Follicles ◽  
Cell Type ◽  
Outer Root Sheath ◽  
Specific Expression ◽  
Root Sheath ◽  
Stratified Epithelia

Keratins K5 and K14 form the extensive intermediate filament network of mitotically active basal cells in all stratified epithelia. We have explored the regulatory mechanisms governing cell-type-specific and differentiation stage-specific expression of the human K5 gene in transiently transfected keratinocytes in vitro and in transgenic mice in vivo. Six thousand base pairs of 5' upstream K5 sequence directed proper basal cell-specific expression in all stratified epithelia. Surprisingly, as few as 90 bp of the K5 promoter still directed expression to stratified epithelia, with expression predominantly in epidermis, hair follicles, and tongue. Despite keratinocyte-preferred expression, the truncated K5 promoter displayed departures from basal to suprabasal expression in epidermis and from outer root sheath to inner root sheath expression in the follicle, with some regional variations in expression as well. To begin to elucidate the molecular controls underlying the keratinocyte specificity of the truncated promoter, we examined protein-DNA interactions within this region. A number of keratinocyte nuclear proteins bind to a K5 gene segment extending from -90 to +32 bp and are functionally involved in transcriptional regulation in vitro. Interestingly, several of these factors are common to both the K5 and K14 promoters, although they appear to be distinct from those previously implicated in keratinocyte specificity. Mutagenesis studies indicate that factors binding in the vicinity of the TATA box and transcription initiation are responsible for the cell type specificity of the truncated K5 promoter.

Effect of Minoxidil Sulfate on the Growth of Human Anagen Hair Follicles Grown in Collagen Gels, and on the Colony Growth of Human Cultured Outer Root Sheath Cells in vitro.

1992 ◽  
Vol 54 (4) ◽  
pp. 727-732 ◽  
Author(s):  
Naoyuki UCHIDA ◽  
Takesi FUJIE ◽  
Seiji ARASE ◽  
Yosiroh NINOMIYA ◽  
Hideki NAKANISI ◽  
...  
Keyword(s):  
Colony Growth ◽  
Hair Follicles ◽  
Collagen Gels ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Anagen Hair ◽  
Outer Root Sheath Cells ◽  
Sheath Cells

scholarly journals Integrin-linked kinase is required for epidermal and hair follicle morphogenesis

2007 ◽  
Vol 177 (3) ◽  
pp. 501-513 ◽  
Author(s):  
Katrin Lorenz ◽  
Carsten Grashoff ◽  
Robert Torka ◽  
Takao Sakai ◽  
Lutz Langbein ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Leading Edge ◽  
Hair Shaft ◽  
Hair Follicles ◽  
Membrane Dynamics ◽  
Epidermal Keratinocytes ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Integrin Linked Kinase

Integrin-linked kinase (ILK) links integrins to the actin cytoskeleton and is believed to phosphorylate several target proteins. We report that a keratinocyte-restricted deletion of the ILK gene leads to epidermal defects and hair loss. ILK-deficient epidermal keratinocytes exhibited a pronounced integrin-mediated adhesion defect leading to epidermal detachment and blister formation, disruption of the epidermal–dermal basement membrane, and the translocation of proliferating, integrin-expressing keratinocytes to suprabasal epidermal cell layers. The mutant hair follicles were capable of producing hair shaft and inner root sheath cells and contained stem cells and generated proliferating progenitor cells, which were impaired in their downward migration and hence accumulated in the outer root sheath and failed to replenish the hair matrix. In vitro studies with primary ILK-deficient keratinocytes attributed the migration defect to a reduced migration velocity and an impaired stabilization of the leading-edge lamellipodia, which compromised directional and persistent migration. We conclude that ILK plays important roles for epidermis and hair follicle morphogenesis by modulating integrin-mediated adhesion, actin reorganization, and plasma membrane dynamics in keratinocytes.

scholarly journals Epidermal Growth Factor Promotes Proliferation and Migration of Follicular Outer Root Sheath Cells via Wnt/β-Catenin Signaling

2016 ◽  
Vol 39 (1) ◽  
pp. 360-370 ◽  
Author(s):  
Haihua Zhang ◽  
Weixiao Nan ◽  
Shiyong Wang ◽  
Tietao Zhang ◽  
Huazhe Si ◽  
...  
Keyword(s):  
Egf Receptor ◽  
Nuclear Translocation ◽  
Hair Follicles ◽  
Regulatory Genes ◽  
Outer Root Sheath ◽  
Daily Growth ◽  
Root Sheath ◽  
And Migration ◽  
Proliferation And Migration

Background/Aims: To investigate the effect and molecular mechanism of EGF on the growth and migration of hair follicle outer root sheath (ORS) cells. Methods: Intact anagen hair follicles were isolated from mink skin and cultured with EGF in vitro to measure ORS daily growth. Meanwhile, purified primary ORS cells were treated or transfected with EGF, and their proliferation and migration were assessed by MTT assay and transwell assay, respectively. The signaling pathway downstream of EGF was characterized by using the Wnt/β-catenin signaling inhibitor, XAV-939. Results: EGF of 2-20 ng/ml, not higher or lower, promoted the growth of follicular ORS in vitro. EGF treatment or overexpression promoted the proliferation and migration of ORS cells. Moreover, EGF stimulation induced nuclear translocation of β-catenin, and upregulated the expression of Wnt10b, β-catenin, EGF receptor and SOX9. Inhibition of Wnt/β-catenin signaling by XAV-939 significantly reduced the basal and EGF-enhanced proliferation and migration of ORS cells. In addition, a number of follicle-regulatory genes, such as Survivin, Msx2 and SGK3, were upregulated by EGF in the ORS cells, which was also inhibited by XAV-939. Conclusion: EGF promotes the proliferation and migration of ORS cells and modulates the expression of several follicle-regulatory genes via Wnt/β-catenin signaling.

Expression and role of E- and P-cadherin adhesion molecules in embryonic histogenesis. II. Skin morphogenesis

Development ◽  
1989 ◽  
Vol 105 (2) ◽  
pp. 271-277 ◽  
Author(s):  
Y. Hirai ◽  
A. Nose ◽  
S. Kobayashi ◽  
M. Takeichi
Keyword(s):  
Hair Follicles ◽  
Homogeneous Distribution ◽  
Upper Lip ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Skin Morphogenesis ◽  
Dermal Cells ◽  
E Cadherin

Expression and the role of E- and P-cadherin in the histogenesis of the surface epidermis and hair follicles were examined using the upper lip skin of the mouse. P-cadherin is expressed exclusively in the proliferating region of these tissues, that is in the germinative layer of the surface epidermis, the outer root sheath and the hair matrix. E-cadherin is coexpressed in these layers but this molecule was also detected in non-proliferating regions such as the intermediate layer of the surface epidermis and the immature regions of the inner root sheath. Neither P- nor E-cadherin was detected in fully keratinized layers such as the horny layer of the surface epidermis, the outermost layer of the outer root sheath and the mature hair fibres. These two cadherins were not detected in dermal cells. We cultured pieces of the upper lip skin in vitro in the absence or presence of a monoclonal antibody to E-cadherin (ECCD-1) or to P-cadherin (PCD-1). In control cultures, skin morphogenesis normally occurred in a pattern whereby the hair follicles grew and dermal cells were condensed to form the dermal sheath. A mixture of ECCD-1 and PCD-1, however, induced abnormal morphogenesis in the skin in several respects. (1) The cuboidal or columnar arrangement of basal epithelial cells was distorted. (2) Hair follicles were deformed. (3) Condensation of dermal cells was suppressed, causing a homogeneous distribution of these cells. These results suggest that cadherins present in epidermal cells are involved not only in maintaining the arrangement of these cells but also in inducing dermal condensation.

scholarly journals Culturing of Melanocytes from the Equine Hair Follicle Outer Root Sheath

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 177
Author(s):  
Hanluo Li ◽  
Jule Kristin Michler ◽  
Alexander Bartella ◽  
Anna Katharina Sander ◽  
Sebastian Gaus ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Hair Follicles ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Human Melanocytes ◽  
Experimental Base ◽  
Typical Morphology ◽  
Insight Into ◽  
Study Offer

Hair follicles harbor a heterogeneous regenerative cell pool and represent a putative low-to-non-invasively available source of stem cells. We previously reported a technology for culturing human melanocytes from the hair follicle outer root sheath (ORS) for autologous pigmentation of tissue engineered skin equivalents. This study translated the ORS technology to horses. We de-veloped a culture of equine melanocytes from the ORS (eMORS) from equine forelock hair follicles cultured by means of an analogue human hair follicle-based in vitro methodology. The procedure was adjusted to equine physiology by addition of equine serum to the culture medium. The hair follicles were isolated by macerating forelock skin rests, enzymatically digested and subjected to air-medium-interface cultivation method. The procedure resulted in differentiated equine melanocytes, which exhibited typical morphology, presence of melanosomes, expression of cytoskeleton proteins vimentin, α-SMA, Sox2, S100ß and tyrosinase as well as tyrosinase activity followed by production of melanin. According to all assessed parameters, eMORS could be ranked as partially melanotic melanocytes. The results of the study offer an experimental base for further insight into hair follicle biology in equine and for comparative studies of hair follicles across different species.

Identification of upstream and intragenic regulatory elements that confer cell-type-restricted and differentiation-specific expression on the muscle creatine kinase gene

1988 ◽  
Vol 8 (7) ◽  
pp. 2896-2909 ◽  
Author(s):  
E A Sternberg ◽  
G Spizz ◽  
W M Perry ◽  
D Vizard ◽  
T Weil ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Regulatory Element ◽  
Simian Virus 40 ◽  
Muscle Cells ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Simian Virus ◽  
Cell Type ◽  
Specific Expression ◽  
Developing Muscle

Terminal differentiation of skeletal myoblasts is accompanied by induction of a series of tissue-specific gene products, which includes the muscle isoenzyme of creatine kinase (MCK). To begin to define the sequences and signals involved in MCK regulation in developing muscle cells, the mouse MCK gene has been isolated. Sequence analysis of 4,147 bases of DNA surrounding the transcription initiation site revealed several interesting structural features, some of which are common to other muscle-specific genes and to cellular and viral enhancers. To test for sequences required for regulated expression, a region upstream of the MCK gene from -4800 to +1 base pairs, relative to the transcription initiation site, was linked to the coding sequences of the bacterial chloramphenicol acetyltransferase (CAT) gene. Introduction of this MCK-CAT fusion gene into C2 muscle cells resulted in high-level expression of CAT activity in differentiated myotubes and no detectable expression in proliferating undifferentiated myoblasts or in nonmyogenic cell lines. Deletion mutagenesis of sequences between -4800 and the transcription start site showed that the region between -1351 and -1050 was sufficient to confer cell type-specific and developmentally regulated expression on the MCK promoter. This upstream regulatory element functioned independently of position, orientation, or distance from the promoter and therefore exhibited the properties of a classical enhancer. This upstream enhancer also was able to confer muscle-specific regulation on the simian virus 40 promoter, although it exhibited a 3- to 5-fold preference for its own promoter. In contrast to the cell type- and differentiation-specific expression of the upstream enhancer, the MCK promoter was able to function in myoblasts and myotubes and in nonmyogenic cell lines when combined with the simian virus 40 enhancer. An additional positive regulatory element was identified within the first intron of the MCK gene. Like the upstream enhancer, this intragenic element functioned independently of position, orientation, and distance with respect to the MCK promoter and was active in differentiated myotubes but not in myoblasts. These results demonstrate that expression of the MCK gene in developing muscle cells is controlled by complex interactions among multiple upstream and intragenic regulatory elements that are functional only in the appropriate cellular context.

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