scholarly journals Defining BMP functions in the hair follicle by conditional ablation of BMP receptor IA

2003 ◽  
Vol 163 (3) ◽  
pp. 609-623 ◽  
Author(s):  
Krzysztof Kobielak ◽  
H. Amalia Pasolli ◽  
Laura Alonso ◽  
Lisa Polak ◽  
Elaine Fuchs
Keyword(s):  
Hair Follicle ◽  
Progenitor Cells ◽  
Gene Targeting ◽  
Transcriptional Activation ◽  
Hair Shaft ◽  
Bmp Receptor ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Conditional Gene Targeting ◽  
Sequential Inhibition

Using conditional gene targeting in mice, we show that BMP receptor IA is essential for the differentiation of progenitor cells of the inner root sheath and hair shaft. Without BMPRIA activation, GATA-3 is down-regulated and its regulated control of IRS differentiation is compromised. In contrast, Lef1 is up-regulated, but its regulated control of hair differentiation is still blocked, and BMPRIA-null follicles fail to activate Lef1/β-catenin–regulated genes, including keratin genes. Wnt-mediated transcriptional activation can be restored by transfecting BMPRIA-null keratinocytes with a constitutively activated β-catenin. This places the block downstream from Lef1 expression but upstream from β-catenin stabilization. Because mice lacking the BMP inhibitor Noggin fail to express Lef1, our findings support a model, whereby a sequential inhibition and then activation of BMPRIA is necessary to define a band of hair progenitor cells, which possess enough Lef1 and stabilized β-catenin to activate the hair specific keratin genes and generate the hair shaft.

scholarly journals The expression of desmosomal and corneodesmosomal antigens shows specific variations during the terminal differentiation of epidermis and hair follicle epithelia.

1992 ◽  
Vol 40 (9) ◽  
pp. 1329-1337 ◽  
Author(s):  
V Mils ◽  
C Vincent ◽  
F Croute ◽  
G Serre
Keyword(s):  
Monoclonal Antibodies ◽  
Hair Follicle ◽  
Hair Shaft ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Anagen Hair ◽  
Differentiation Pathways ◽  
Junctional Structure ◽  
Three Components

Using five monoclonal antibodies (MAb), we studied by indirect immunofluorescence the desmosomes and a junctional structure specific to cornified layers, the corneodesmosome, in normal and plantar epidermis and in the various sheaths of the anagen hair follicle. The monoclonal antibodies DP1&2.2-15, PG5.1, and DG3.10, specific for desmoplakins I/II, plakoglobin, and desmoglein I, respectively, were used to study the desmosome antigens, and G36-19 and G20-21 to study the corneodesmosome antigens. The distribution and sequence of expression of the five antigens allowed the nine epithelial differentiation pathways studied to be merged into four distinct families: non-plantar epidermis, characterized by the absence of desmosome and corneodesmosome antigens in the stratum corneum; the outer root sheath of the hair follicle, which behaves like the viable layers of the epidermis with regard to the desmosome antigens but does not express the corneodesmosome antigens; plantar epidermis and the three components of the inner root sheath in which the corneodesmosome antigens are present up to the desquamating layer; and the three components of the hair shaft, which are characterized by the absence of expression of both the desmosome and the corneodesmosome antigens in its mature portion.

A Selectable Biomarker in Hair Follicle Cycles – Cathepsins: A Preliminary Study in Murine

2021 ◽  
pp. 1-7
Author(s):  
Jingzhu Bai ◽  
Zijian Gong ◽  
Qingfang Xu ◽  
Haiyan Chen ◽  
Qiaoping Chen ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Hair Cycle ◽  
Biological Factors ◽  
Outer Root Sheath ◽  
Physiological Processes ◽  
Intervention Measures ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Preliminary Study ◽  
Paraffin Method

<b><i>Background/Objective:</i></b> Hair cycle is regulated by many biological factors. Cathepsins are involved in various physiological processes in human skin. Here, we investigated the cathepsin expression and distribution changes in follicular growth cycles for better understanding the hair cycles and to explore new intervention measures. <b><i>Methods:</i></b> The 24 mice (C57BL/6, female, 7-week old) were selected and removed the back hair via rosin/paraffin method. At Day 8, Day 20, and Day 25, biopsy on post-plucking area was done. Immunohistochemical staining, Western blot, and Q-PCR were used to test the cathepsin B/D/L/E. <b><i>Results:</i></b> In anagen, cathepsins (B, D, L, and E) were distributed in the hair follicle matrix, inner hair root sheath, and hair. In catagen, cathepsins were mainly observed in un-apoptosis inner root sheath and outer root sheath. Expression of cathepsins B-mRNA and L-mRNA was decreased from anagen and catagen to telogen. Cathepsin D-mRNA was increased in catagen and then decreased in telogen. Cathepsin E-mRNA was decreased in catagen and slightly increased in telogen. <b><i>Conclusions:</i></b> The distribution and expression of cathepsins B, D, L, and E in hair follicle changed with hair growth process which indicated that cathepsins might act as selectable biomarkers of hair cycle in different stages.

scholarly journals THE ELECTRON MICROSCOPY OF THE HUMAN HAIR FOLLICLE

1957 ◽  
Vol 3 (2) ◽  
pp. 223-230 ◽  
Author(s):  
M. S. C. Birbeck ◽  
E. H. Mercer
Keyword(s):  
Hair Follicle ◽  
Cross Sections ◽  
Plasma Membranes ◽  
Membrane Complex ◽  
Outer Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Cell Layers ◽  
Adhesive Contacts ◽  
Similar Complex

1. The three cylinders of cells, each one cell thick, which together constitute the inner root sheath, arise from the peripheral portions of the undifferentiated matrix. These cells, like the hair cuticle, are stabilised by the spread of adhesive contacts between their plasma membranes which occurs in the mid-bulb and upper bulb of the hair follicle. 2. The characteristic intracellular product of all three cell layers is trichohyaline. This substance is formed in the first place as amorphous droplets which subsequently transform into a birefringent form. 3. This transformation, involving the formation of a birefringent product from an amorphous precursor, is in contrast to the formation in the cortex of keratin which originates in a fibrous form. 4. Trichohyaline appears first and transforms first in the cells of Henle which are nearest the outer sheath and the dermal supply vessels. This transformation occurs at the level of the neck of the follicle. Synthesis and transformation in the cells of Huxley and the sheath cuticle lag behind the similar events in the cells of Henle. The transformation does not begin until the lower prekeratinous zone in the Huxley and cuticle cells. 5. The amorpous-fibrous transformation occurs rapidly cell by cell and involves the conversion of all the trichohyaline droplets. In longitudinal sections the birefringent modification can be seen extending from the droplets in both directions parallel to the axis of the hair. In cross-sections the images of the transformed material are difficult to interpret. They may be seen as sections of corrugated sheets (∼100 A thick) or condensed fibrils ∼100 A in width. 6. At the same time that the trichohyaline transforms, the spacing between the cell membranes increases and a dark deposit appears centrally between them. This membrane complex, and the similar complex of the hair cuticle cells described in Part 2, may be specialised formations whose purpose is to hold the hardened cells together.

Synthesis of porcine pCLCA2 protein during late differentiation of keratinocytes of epidermis and hair follicle inner root sheath

2012 ◽  
Vol 350 (3) ◽  
pp. 445-453 ◽  
Author(s):  
Stephanie Plog ◽  
Lars Mundhenk ◽  
Lutz Langbein ◽  
Achim D. Gruber
Keyword(s):  
Hair Follicle ◽  
Root Sheath ◽  
Inner Root Sheath

scholarly journals 889 Trpv3 gain-of-function mutation impairs differentiation of hair follicle inner root sheath

2019 ◽  
Vol 139 (5) ◽  
pp. S154
Author(s):  
Z. Song ◽  
X. Chen ◽  
Q. Zhao ◽  
Z. Lin ◽  
S. Yang ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Gain Of Function ◽  
Root Sheath ◽  
Inner Root Sheath

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.

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