scholarly journals Association of basonuclin with ability of keratinocytes to multiply and with absence of terminal differentiation.

1994 ◽  
Vol 126 (2) ◽  
pp. 495-506 ◽  
Author(s):  
H Tseng ◽  
H Green

Basonuclin is a protein possessing three pairs of zinc fingers and a nuclear localization signal. Expression of the gene is largely confined to keratinocytes of stratified squamous epithelia and hair follicles. In the epidermis and in stratified epidermal cultures, basonuclin is present in the nuclei of cells in or close to the basal layer but not in the nuclei of cells in more superficial layers. The Ki-67 protein, a nuclear marker for any stage of the multiplication cycle is present in only a subclass of basonuclin-containing cells. In cultured keratinocytes, the disappearance of basonuclin mRNA is associated with loss of colony-forming ability and the appearance of mRNA for involucrin, a protein characteristic of terminal differentiation. In hair follicles, the largest reservoir of basonuclin-containing cells is the outer root sheath, which contains precursors of differentiated cells of the hair shaft and of the epidermis. Basonuclin is not a cell cycle marker but is likely instead to be a regulatory molecular whose presence in the keratinocyte is linked to the maintenance of proliferative capacity and prevention of terminal differentiation.

2007 ◽  
Vol 177 (3) ◽  
pp. 501-513 ◽  
Author(s):  
Katrin Lorenz ◽  
Carsten Grashoff ◽  
Robert Torka ◽  
Takao Sakai ◽  
Lutz Langbein ◽  
...  

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.


Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2798
Author(s):  
Yanyu He ◽  
Xiu Liu ◽  
Jie De ◽  
Saihong Kang ◽  
John S. Munday

This experiment compared secondary hair follicles (SFs) in Tibetan cashmere goats from two different steppes that were at different altitudes and had different temperatures. Twenty-four 2-year-old goats were studied. Twelve goats were from Rikaze in Tibet which is at an altitude of above 5000 m with an average temperature of 0 °C. The other 12 studied goats were from Huan County of Gansu Province which is around 2000 m above sea level with an average temperature of 9.2 °C. The structural features of SFs were assessed using light microscopy and transmission electron microscopy. The presence of HIF-1a, HIF-2a, HIF-3a, HSP27, and HOXC13 proteins was studied using immunohistochemistry and immunofluorescence. Light and electron microscopy revealed that the SFs of the Tibetan cashmere goats that lived in the Rikaze Steppe were in the proanagen stage in May. However, the SFs of the goats from the lower warmer Huan County were in the anagen stage at the same time. Immunohistochemistry revealed intense immunostaining for HIF-1a protein in the inner root sheath (IRS) and hair shaft (HS); immunostaining against HIF-2a in the outer root sheath (ORS) and IRS; HIF-3a protein immunostaining in the ORS; HSP27 immunostaining in the ORS, IRS, and HS; and HOXC13 immunostaining in the ORS and HS. HIF-1a protein expression in the IRS and HS was higher than the expression in the ORS (p < 0.05) while the expression of HIF-2a protein was higher in the ORS and IRS than the HS (p < 0.05). The expression of HIF-3a protein was higher in the ORS than in the IRS (p < 0.05). Expression of HOXC13 protein was higher in the ORS than in the IRS and HS (p < 0.05). Immunostaining of HIF-1a, HIF-2a, and HSP27 protein was significantly higher in SFs from cashmere goats from Rikaze than in goats from Huan (p < 0.05). In contrast, HOX13 protein immunostaining was significantly higher in cashmere goats from Huan than from Rikaze (p < 0.05). Significant differences were observed in the SFs of cashmere goats from two locations that differ in altitude and temperature. This suggests the differences in the secondary hair follicles could be due to the hypoxia and lower temperatures experienced by the goats in Rikaze. These results are useful in understanding how altitude and temperature influence SF development. Hair produced by the SFs are used for down fiber. Therefore, understanding of the factors that influence SF development will allow the production and harvest of these valuable fibers to be maximized.


1965 ◽  
Vol 13 (8) ◽  
pp. 668-676 ◽  
Author(s):  
MICHAEL J. C. IM

The activities of the following dehydrogenase systems were demonstrated in the skin of the rhesus monkey ( Macaca mulatta): succinic, malic, isocitric (DPN and TPN), lactic, α-glycerophosphate, glucose 6-phosphate, 6-phosphogluconate, β-hydroxybutyric and glutamic dehydrogenase. Strong dehydrogenase activity in general is restricted to metabolically active sites such as the basal layer of the epidermis, the outer root sheath of the hair follicles, the hair matrix and bulb, the clear cells of the eccrine sweat glands and the basal cells of the sweat glands. The myelinated fibers of Meissner corpuscles and the inner bulb of the Pacinian corpuscles in the palms and soles abound in all of the dehydrogenases. The enzymes are also abundant in the arrectores pilorum muscles, the endothelium of the arterioles, the fibroblasts and mast cells.


Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 639-651 ◽  
Author(s):  
B. Risek ◽  
F.G. Klier ◽  
N.B. Gilula

The expression of four different gap junction gene products (alpha 1, beta 1, beta 2, and beta 3) has been analysed during rat skin development and the hair growth cycle. Both alpha 1 (Cx43) and beta 2 (Cx26) connexins were coexpressed in the undifferentiated epidermis. A specific, developmentally regulated elimination of beta 2 expression was observed in the periderm at E16. Coinciding with the differentiation of the epidermis, differential expression of alpha 1 and beta 2 connexins was observed in the newly formed epidermal layers. alpha 1 connexin was expressed in the basal and spinous layers, while beta 2 was confined to the differentiated spinous and granular layers. Large gap junctions were present in the basal layer, while small gap junctions, associated with many desmosomes, were typical for the differentiated layers. Although the distribution pattern for alpha 1 and beta 2 expression remained the same in the neonatal and postnatal epidermis, the RNA and protein levels decreased markedly following birth. Hair follicle development was marked by expression of alpha 1 connexin in hair germs at E16. Following beta 2 detection at E20, the expression increased for both alpha 1 and beta 2 in developing follicles. A cell-type-specific expression was detected in the outer root sheath, in the matrix, in the matrix-derived cells (inner root sheath, cortex and medulla) and in the dermal papilla. In addition, alpha 1 was specifically expressed in the arrector pili muscle, while sebocytes expressed both alpha 1 and beta 3 (Cx31) connexin. beta 1 connexin (Cx32) was not detected at any stage analysed. The results indicate that multiple gap junction genes contribute to epidermal and follicular morphogenesis. Moreover, based on the utilization of gap junctions in all living cells of the surface epidermis, it appears that the epidermis may behave as a large communication compartment that may be coupled functionally to epidermal appendages (hair follicles and sebaceous glands) via gap junctional pathways.


Author(s):  
Yong Li ◽  
Hui Guo ◽  
Youbao Zhong ◽  
Xiaofen Hu

The aim was to investigate distribution characteristics of melanocytes in Taihe Silky Fowl’s skin by Lillie’s and DOPA staining methods and transmission electron microscopy. According to the present results, mature melanocytes were mainly located in basal layer of epidermis and hair follicle bulbs, whereas the amelanotic melanocytes were in the outer root sheath of hair follicles. In various partial skins, maturity levels of melanocytes generally were as: claw skin>rear skin>dorsal skin>abdominal skin>wattle skin>cockscomb skin. In mature melanocytes, melanosomes were divided into stage I, II, III and IV, and mostly belonged to stage IV. To conclude, melanocytes in hairy skin more easily reached mature status than in meaty skin and the melanocytes in dorsal skin matured faster than in abdominal skin as well. Furthermore, the melanin migration was subjected to the strict control of melanocytes, but had nothing to do with keratinocytes.


1996 ◽  
Vol 8 (7) ◽  
pp. 1089 ◽  
Author(s):  
N Nishimura ◽  
GR Cam ◽  
H Nishimura ◽  
C Tohyama ◽  
Y Saitoh ◽  
...  

The distribution of metallothionein (MT) and MT mRNAs was examined in hair (wool) follicles, where high levels of cell proliferation are found and where the resulting cells provide a temporal record of differentiation events. MT was found in the cytoplasm and some nuclei of follicle bulb cells of the proliferative zone, outer root sheath cells and in basal layer cells of sebaceous glands and sweat glands. The population of 5-bromo-2'-deoxyuridine (BrdU)+ cells in these tissues overlapped, but were not completely coincident with the distribution of MT staining. MT mRNA expression in hair (wool) follicles was assessed by in situ hybridization with four gene-specific sheep MT (sMT) isoforms. Intense signals were obtained with the sMT-Ib probe in follicle bulb cells from the proliferative zone to the keratogenous zone. Signals from the sMT-Ia probe were present in the same cells, but were much weaker. No signals were detected using the sMT-Ic and sMT-II gene-specific probes. The findings suggest that: (1) MT is important in cell proliferation and/or cell differentiation in the hair follicle bulb; (2) MT translation is inhibited during cell differentiation and migration; and (3) tissue-specific expression of uncharacterized sMT isoforms is likely.


2009 ◽  
Vol 84 (2) ◽  
pp. 1183-1188 ◽  
Author(s):  
Henoch S. Hong ◽  
Johanna M. Eberhard ◽  
Phillip Keudel ◽  
Benjamin A. Bollmann ◽  
Matthias Ballmaier ◽  
...  

ABSTRACT HIV-1 infection is characterized by loss of CD56dim CD16+ NK cells and increased terminal differentiation on various lymphocyte subsets. We identified a decrease of CD57− and CD57dim cells but not of CD57bright cells on CD56dim CD16+ NK cells in chronic HIV infection. Increasing CD57 expression was strongly associated with increasing frequencies of killer immunoglobulin-like receptors (KIRs) and granzyme B-expressing cells but decreasing percentages of cells expressing CD27+, HLA-DR+, Ki-67+, and CD107a. Our data indicate that HIV leads to a decline of less-differentiated cells and suggest that CD57 is a useful marker for terminal differentiation on NK cells.


2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Omer Alici ◽  
Musa Kemal Keles ◽  
Alper Kurt

Proliferating trichilemmal tumors (PTTs) are neoplasms derived from the outer root sheath of the hair follicle. These tumors, which commonly affect the scalp of elderly women, rarely demonstrate malignant transformation. Although invasion of the tumors into neighboring tissues and being accompanied with anaplasia and necrosis are accepted as findings of malignancy, histological features may not always be sufficient to identify these tumors. The clinical behavior of the tumor may be incompatible with its histological characteristics. Squamous-cell carcinoma should certainly be considered in differential diagnosis because of its similarity in morphological appearance with PTT. Immunostaining for CD34, P53, and Ki-67 is a useful adjuvant diagnostic method that can be used in differential diagnosis aside from morphological findings. In this study, we aimed to present the case of a 52-year-old female patient with clinicopathological features. We reported a low-grade malignant proliferating trichilemmal tumor in this patient and detected no relapse or metastasis in a 24-month period of follow-up.


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