scholarly journals A STUDY OF THE ULTRASTRUCTURAL LOCALIZATION OF HAIR KERATIN SYNTHESIS UTILIZING ELECTRON MICROSCOPIC AUTORADIOGRAPHY IN A MAGNETIC FIELD

1964 ◽  
Vol 21 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Takashi Nakai
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Ultrastructural Localization ◽  
Hair Follicles ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Anagen Hair ◽  
Cellular Components

The sites of the incorporation of labeled cystine into keratinizing structures were studied in electron microscopic autoradiographs. The tracer used was cystine labeled with S35 emitting long-range ionizing particles. During exposure for 1 to 2 months, according to our method of electron microscopic autoradiography, emulsion-coated specimens were exposed to a static magnetic field which appeared to result in a marked increase in the number of reacted silver grains. In young Swiss mice receiving intraperitoneal injections at 1, 3, and 6 hours before biopsy, conventional autoradiography demonstrated that S35-cystine was intensely localized in the keratogenous zone of anagen hair follicles, and that the radioactivity there increased in intensity progressively with time while the radioactivity in the hair bulb always remained very low. Our observations with electron microscopic autoradiography in a magnetic field appeared to indicate that at 3 and 6 hours after injection the S35-cystine was directly and specifically incorporated into tonofibrils in the hair cortex and into amorphous keratin granules of the hair cuticle layer, possibly without any particular concentration of this substance in the other cellular components. There seemed to be an appreciable concentration of cystine in tonofibrils of the cuticle of the inner root sheath. However, trichohyalin granules in the hair medulla and inner root sheath failed to show any evidence of cystine concentration. The improved sensitivity of the electron microscopic autoradiography with S35-cystine appeared to be partly due to the application of a static magnetic field. However, the reason for this could not be explained theoretically.

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
Keyword(s):  
Lucifer Yellow ◽  
Early Stage ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Hair Dye ◽  
Hair Bulb ◽  
Ultrastructural Studies ◽  
Junctional Communication ◽  
Root Sheath ◽  
Inner Root Sheath

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.

scholarly journals Wnt10b promotes hair follicles growth and dermal papilla cells proliferation via Wnt/β-Catenin signaling pathway in Rex rabbits

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Zhenyu Wu ◽  
Yanli Zhu ◽  
Hongli Liu ◽  
Gongyan Liu ◽  
Fuchang Li
Keyword(s):  
Cell Cycle ◽  
Signaling Pathway ◽  
Cell Cycle Progression ◽  
Dermal Papilla ◽  
Hair Shaft ◽  
Hair Follicles ◽  
Dermal Papilla Cells ◽  
Root Sheath ◽  
Inner Root Sheath

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.

scholarly journals Refined Immunochemical Characterization in Healthy Dog Skin of the Epidermal Cornification Proteins, Filaggrin, and Corneodesmosin

2018 ◽  
Vol 67 (2) ◽  
pp. 85-97 ◽  
Author(s):  
Didier Pin ◽  
Valérie Pendaries ◽  
Sokhna Keita Alassane ◽  
Carine Froment ◽  
Nicolas Amalric ◽  
...  
Keyword(s):  
Risk Factors ◽  
Genetic Risk ◽  
Genomic Dna ◽  
Dna Analysis ◽  
Hair Follicles ◽  
Loss Of Function ◽  
Lamellar Bodies ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Cornified Layer

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.

scholarly journals Characteristic Localization of Neuronatin in Rat Testis, Hair Follicle, Tongue, and Pancreas

2019 ◽  
Vol 67 (7) ◽  
pp. 495-509
Author(s):  
Naoko Kanno ◽  
Saishu Yoshida ◽  
Takako Kato ◽  
Yukio Kato
Keyword(s):  
Hair Follicle ◽  
Intracellular Localization ◽  
Taste Receptor ◽  
Hair Follicles ◽  
Rat Tissues ◽  
Basal Cells ◽  
Fungiform Papilla ◽  
Differentiated Cells ◽  
Root Sheath ◽  
Inner Root Sheath

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.

Ultrastructural localization of drug binding sites

1978 ◽  
Vol 36 (2) ◽  
pp. 52-53
Author(s):  
S.F. Hoff ◽  
A.J. Macinnis
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Phosphotungstic Acid ◽  
Ultrastructural Localization ◽  
Drug Binding ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Drug Binding Site ◽  
Drug Binding Sites ◽  
Conventional Electron Microscopy

The need for a high resolution morphological method of identifying drug binding sites has been mentioned by several authors. Electron microscopic autoradiography may identify statisically an organelle as a drug binding site, but in practice has proven unreliable. This is primarily due to the tissue preparatory procedures used in conventional electron microscopy, which denature proteins and extract many proteins and lipid components from the tissue. As the drug binding sites are denatured and/or extracted, drugs are displaced from their “receptors.” Then the drugs are either extracted or attached to an anomolous binding site created by the preparatory procedure. Sjöstrand's minimal denaturation technique is based on a sound physical-chemical rationale and was modified slightly to accommodate the drug localization procedure used in this study.It was found after many experiments that phosphotungstic acid (PTA) at pH7 had the highest specificity for the drugs used in this study and the lowest affinity for biological structures.

Incorporation of tritiated cytochalasin B into ectodermal explants of the amphibian gastrula

Development ◽  
1976 ◽  
Vol 36 (1) ◽  
pp. 209-223
Author(s):  
M. M. Perry ◽  
G. G. Selman ◽  
J. Jacob
Keyword(s):  
Cytochalasin B ◽  
Superficial Layer ◽  
Electron Microscopic ◽  
Cytoplasmic Matrix ◽  
Electron Microscopic Autoradiography ◽  
Triturus Alpestris ◽  
Cell Fractions ◽  
Cellular Components ◽  
Silver Grains ◽  
Compact Spheres

Ectodermal explants from gastrulae of Triturus alpestris were exposed to tritiated cytochalasin B (5 and 10µg/ml) for ½–2½ h. The flat explants failed to heal into compact spheres and the component cells gradually rounded up. Radioactivity in the fixed and sectioned material was analysed by light and electron microscopic autoradiography. Silver grains were found predominantly over the yolk platelets, but were also scattered over other cellular components. Areas containing pigment granules or the feltwork material, present in the apices of dissociating cells of the superficial layer, exhibited higher activity than areas containing mitochondria or cytoplasmic matrix. Lipid droplets and nuclei showed comparatively little activity. The results are discussed in relation to previous findings on the uptake of tritiated cytochalasin D by cell fractions.

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