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Hoober JK, Eggink LL. The Discovery and Function of Filaggrin. Int J Mol Sci 2022; 23:ijms23031455. [PMID: 35163390 PMCID: PMC8835998 DOI: 10.3390/ijms23031455] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/17/2022] [Accepted: 01/26/2022] [Indexed: 12/11/2022] Open
Abstract
Keratohyalin granules were discovered in the mid-19th century in cells that terminally differentiate to form the outer, cornified layer of the epidermis. The first indications of the composition of these structures emerged in the 1960s from a histochemical stain for histidine, followed by radioautographic evidence of a high incidence of histidine incorporation into newly synthesized proteins in cells containing the granules. Research during the next three decades revealed the structure and function of a major protein in these granules, which was initially called the ‘histidine-rich protein’. Steinert and Dale named the protein ‘filaggrin’ in 1981 because of its ability to aggregate keratin intermediate filaments. The human gene for the precursor, ‘profilaggrin,’ was reported in 1991 to encode 10, 11 or 12 nearly identical repeats. Remarkably, the mouse and rat genes encode up to 20 repeats. The lifetime of filaggrin is the time required for keratinocytes in the granular layer to move into the inner cornified layer. During this transition, filaggrin facilitates the collapse of corneocytes into ‘building blocks’ that become an impermeable surface barrier. The subsequent degradation of filaggrin is as remarkable as its synthesis, and the end-products aid in maintaining moisture in the cornified layer. It was apparent that ichthyosis vulgaris and atopic dermatitis were associated with the absence of this protein. McLean’s team in 2006 identified the cause of these diseases by discovering loss-of-function mutations in the profilaggrin gene, which led to dysfunction of the surface barrier. This story illustrates the complexity in maintaining a healthy, functional epidermis.
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Cracking the Skin Barrier: Liquid-Liquid Phase Separation Shines under the Skin. JID INNOVATIONS 2021; 1:100036. [PMID: 34909733 PMCID: PMC8659386 DOI: 10.1016/j.xjidi.2021.100036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 06/07/2021] [Accepted: 06/18/2021] [Indexed: 12/25/2022] Open
Abstract
Central to forming and sustaining the skin’s barrier, epidermal keratinocytes (KCs) fluxing to the skin surface undergo a rapid and enigmatic transformation into flat, enucleated squames. At the crux of this transformation are intracellular keratohyalin granules (KGs) that suddenly disappear as terminally differentiating KCs transition to the cornified skin surface. Defects in KGs have long been linked to skin barrier disorders. Through the biophysical lens of liquid-liquid phase separation (LLPS), these enigmatic KGs recently emerged as liquid-like membraneless organelles whose assembly and subsequent pH-triggered disassembly drive squame formation. To stimulate future efforts toward cracking the complex process of skin barrier formation, in this review, we integrate the key concepts and foundational work spanning the fields of LLPS and epidermal biology. We review the current progress in the skin and discuss implications in the broader context of membraneless organelles across stratifying epithelia. The discovery of environmentally sensitive LLPS dynamics in the skin points to new avenues for dissecting the skin barrier and for addressing skin barrier disorders. We argue that skin and its appendages offer outstanding models to uncover LLPS-driven mechanisms in tissue biology.
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Key Words
- 3D, three-dimensional
- AD, atopic dermatitis
- CE, cornified envelope
- EDC, epidermal differentiation complex
- ER, endoplasmic reticulum
- IDP, intrinsically-disordered protein
- KC, keratinocyte
- KG, keratohyalin granule
- LCST, lower critical solution temperature
- LLPS, liquid-liquid phase separation
- PTM, post-translational modification
- TG, trichohyalin granule
- UCST, upper critical solution temperature
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Gibbs NK. l-Histidine Supplementation in Adults and Young Children with Atopic Dermatitis (Eczema). J Nutr 2020; 150:2576S-2579S. [PMID: 33000160 DOI: 10.1093/jn/nxaa200] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/31/2020] [Accepted: 06/22/2020] [Indexed: 01/03/2023] Open
Abstract
Atopic dermatitis (AD) is an incurable, inflammatory skin condition that is prevalent (∼20%) in young children. There is an unmet clinical need, particularly in children, for safe interventions that target the etiology of the disease. Deficiencies in the skin barrier protein, filaggrin (FLG) have been identified as major predisposing factors in AD. In mammals, l-histidine is rapidly incorporated into epidermal FLG and subsequent FLG proteolysis releases l-histidine as an important natural moisturizing factor (NMF). It has therefore been hypothesized that l-histidine supplementation would be a safe approach to augment both FLG and the NMF, enhance skin barrier function, and reduce AD severity. In a clinical pilot study, adult subjects (n = 24) with AD took either a placebo or 4 g oral l-histidine daily for 8 wk. Unlike the placebo, l-histidine reduced AD (34% reduction in SCORing Atopic Dermatitis scores; P < 0.003) after 4 wk. Nine and 8 adverse events (AEs), and 1 and 0 severe AEs were recorded in the l-histidine or placebo groups, respectively, with no AE being causally related to l-histidine ingestion. A survey of adults (n = 98) taking 4 g l-histidine daily reiterated a lack of causal AEs and also reported a 33% reduction in topical corticosteroid use. A placebo-controlled, clinical pilot study conducted in young children with AD (n = 49; mean age 3.5 y) taking 0.8 g l-histidine daily, showed that eczema area and severity index scores were reduced by 49% (P < 0.02) at 12 wk, whereas a placebo had no effect. The children taking l-histidine had 50 minor AEs (compared with 39 on placebo), with 78% considered as "not," 18% "unlikely," and 4% "possibly" related to l-histidine ingestion. These studies indicate that at the levels reported, oral l-histidine supplementation is well tolerated and has potential as a safe intervention for long-term use in the management of AD in all age groups.
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Affiliation(s)
- Neil K Gibbs
- Dermatological Sciences, University of Manchester, Manchester, UK; and Curapel, Stuart House, Chepstow, UK
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Tan SP, Brown SB, Griffiths CE, Weller RB, Gibbs NK. Feeding filaggrin: effects of l-histidine supplementation in atopic dermatitis. Clin Cosmet Investig Dermatol 2017; 10:403-411. [PMID: 29042806 PMCID: PMC5634381 DOI: 10.2147/ccid.s146760] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Atopic dermatitis (AD), also known as eczema, is one of the most common chronic skin conditions worldwide, affecting up to 16% of children and 10% of adults. It is incurable and has significant psychosocial and economic impacts on the affected individuals. AD etiology has been linked to deficiencies in the skin barrier protein, filaggrin. In mammalian skin, l-histidine is rapidly incorporated into filaggrin. Subsequent filaggrin proteolysis releases l-histidine as an important natural moisturizing factor (NMF). In vitro studies were conducted to investigate the influence of l-histidine on filaggrin processing and barrier function in human skin-equivalent models. Our further aim was to examine the effects of daily oral l-histidine supplementation on disease severity in adult AD patients. We conducted a randomized, double-blind, placebo-controlled, crossover, nutritional supplementation pilot study to explore the effects of oral l-histidine in adult AD patients (n=24). In vitro studies demonstrated that l-histidine significantly increased both filaggrin formation and skin barrier function (P<0.01, respectively). Data from the clinical study indicated that once daily oral l-histidine significantly reduced (P<0.003) AD disease severity by 34% (physician assessment using the SCORingAD tool) and 39% (patient self-assessment using the Patient Oriented Eczema Measure tool) after 4 weeks of treatment. No improvement was noted with the placebo (P>0.32). The clinical effect of oral l-histidine in AD was similar to that of mid-potency topical corticosteroids and combined with its safety profile suggests that it may be a safe, nonsteroidal approach suitable for long-term use in skin conditions that are associated with filaggrin deficits such as AD.
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Affiliation(s)
- Siao Pei Tan
- MRC Centre for Inflammation Research.,Department of Dermatology, The University of Edinburgh, Edinburgh
| | - Simon B Brown
- MRC Centre for Inflammation Research.,Department of Dermatology, The University of Edinburgh, Edinburgh
| | - Christopher Em Griffiths
- Dermatology Centre, Division of Musculoskeletal and Dermatological Sciences, Salford Royal NHS Foundation Trust, University of Manchester, Manchester
| | - Richard B Weller
- MRC Centre for Inflammation Research.,Department of Dermatology, The University of Edinburgh, Edinburgh
| | - Neil K Gibbs
- Dermatology Centre, Division of Musculoskeletal and Dermatological Sciences, Salford Royal NHS Foundation Trust, University of Manchester, Manchester.,Curapel, Life Sciences Hub Wales, Cardiff, UK
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Han STR, Haberkamp M, Flynn GL. Epidermal Kinetics and Skin Condition: I. Stripping Technique for Quantitating Stratum Corneum Turnover in Hairless Mouse Skin. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/15569528909062958] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
The study describes the vertical distribution of free amino acids in the porcine epidermis as compared to the human integument, using a micro-determination TLC method based on the reaction of amino acids with dansyl chloride. This microanalytical approach demonstrated 22 free amino acids, with the relatively largest amounts being present for acidic amino acids and their amides. It was obvious that the relative amounts of certain amino acids (alanine, proline, valine, glutamine, histidine, glycine, threonine) decreased, whereas acidic amino acids (glutamic acid, aspartic acid) increased from the stratum basale up to the stratum corneum. This distributional pattern could be verified for the dorsal and lateral body regions of the pig breeds used, and for man. The results obtained are discussed in view of the development of epidermal keratinization.
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Affiliation(s)
- W Meyer
- Institut für Zoologie, Tierärztliche Hochschule Hannover, F.R.G
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Biologic Structure and Function: Perspectives on Morphologic Approaches to the Study of the Granular Layer Keratinocyte. J Invest Dermatol 1989. [DOI: 10.1038/jid.1989.36] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Holbrook KA. Biologic structure and function: perspectives on morphologic approaches to the study of the granular layer keratinocyte. J Invest Dermatol 1989; 92:84S-104S. [PMID: 2467953 DOI: 10.1111/1523-1747.ep13075079] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- K A Holbrook
- Department of Biological Structure, University of Washington School of Medicine, Seattle 98195
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Potten CS, Saffhill R, Maibach HI. Measurement of the transit time for cells through the epidermis and stratum corneum of the mouse and guinea-pig. CELL AND TISSUE KINETICS 1987; 20:461-72. [PMID: 3450396 DOI: 10.1111/j.1365-2184.1987.tb01355.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A new approach to determine the transit time through the epidermis is presented, involving a gentle washing of the skin surface to collect the loosely attached surface corneocytes. This, it is believed, will be less likely to stimulate the system than tape-stripping or scraping. Radioactively labelled thymidine and iododeoxyuridine have been used to label cells in the basal layer and various labelled amino acids (glycine, cystine and methionine) have been used to label the metabolically viable cell layers (up to and including the granular layer). The resulting changes in surface radioactivity levels have been interpreted to provide a basal to surface transit time of 8-9.5 days for hairless and haired mouse epidermis and about 13.5 days for guinea-pigs. The basal to granular layer transit time, which probably includes some basal layer residence time, is about 4.5 days in the mouse and 8 days in the guinea-pig. The granular to surface time in mice is about 5 days. The results also suggest that when nuclear and cytoplasmic organelles are degraded in the granular layer, material is released that can diffuse rapidly through the stratum corneum to the surface. Some of this can be shown by chromatography to be thymidine. Hence, the stratum corneum is previous to molecules such as nucleosides. This rapid diffusion outwards through the skin can also be detected shortly after injecting [125I]-iododeoxyuridine.
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Affiliation(s)
- C S Potten
- Paterson Laboratories, Christie Hospital, Holt Radium Institute, Withington, Manchester, U.K
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Sybert VP, Dale BA, Holbrook KA. Ichthyosis vulgaris: identification of a defect in synthesis of filaggrin correlated with an absence of keratohyaline granules. J Invest Dermatol 1985; 84:191-4. [PMID: 2579164 DOI: 10.1111/1523-1747.ep12264813] [Citation(s) in RCA: 242] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ichthyosis vulgaris is an autosomal dominant disorder of keratinization characterized histologically by absent or reduced keratohyaline granules in the epidermis and mild hyperkeratosis. The basic defect in ichthyosis vulgaris is unknown. We have tested for the presence of filaggrin and its precursor, profilaggrin, in the epidermis of affected and unaffected individuals from 2 families with ichthyosis vulgaris and correlated its presence and relative quantity with ultrastructure findings in the same individuals. Filaggrin was present on stained sodium dodecyl sulfate gels and immunoblots of epidermal proteins from controls and unaffected family members. It was absent from the more severely affected individuals in each family and reduced in intensity in the less severely affected family members. Immunohistology in controls showed localization of filaggrin-related protein in the stratum corneum and within the granular layer. In contrast, tissue from affected individuals showed little or no reaction. Electron microscopic studies showed that keratohyaline granules were absent in 3 severely affected individuals, and reduced in number in the others. The relative amount of keratohyalin by electron microscopy correlated with the amount of filaggrin detectable on immunoblots. The stratum corneum was thicker than in normals but showed the typical "keratin pattern" staining suggesting that filaggrin is not essential for keratin filament aggregation and may have another function in vivo. We have demonstrated that the structural proteins, profilaggrin and filaggrin, are reduced or absent in 5 patients from 2 pedigrees with ichthyosis vulgaris. This biochemical abnormality correlates with the morphologic reduction in the amount of keratohyalin, and with the clinical severity of the disorder.
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Resing KA, Walsh KA, Dale BA. Identification of two intermediates during processing of profilaggrin to filaggrin in neonatal mouse epidermis. J Cell Biol 1984; 99:1372-8. [PMID: 6480697 PMCID: PMC2113300 DOI: 10.1083/jcb.99.4.1372] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A major event in the keratinization of epidermis is the production of the histidine-rich protein filaggrin (26,000 mol wt) from its high molecular weight (greater than 350,000) phosphorylated precursor (profilaggrin). We have identified two nonphosphorylated intermediates (60,000 and 90,000 mol wt) in NaSCN extracts of epidermis from C57/Bl6 mice by in vivo pulse-chase studies. Results of peptide mapping using a two-dimensional technique suggest that these intermediates consist of either two or three copies of filaggrin domains. Each of the intermediates has been purified. The ratios of amino acids in the purified components are unusual and essentially identical. The data are discussed in terms of a precursor containing tandem repeats of similar domains. In vivo pulse-chase experiments demonstrate that the processing of the high molecular weight phosphorylated precursor involves dephosphorylation and proteolytic steps through three-domain and two-domain intermediates to filaggrin. These processing steps appear to occur as the cell goes through the transition cell stage to form a cornified cell.
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Fukuyama K, Meceira J, Tuffanelli DL, Epstein WL. An immunohistochemical study of nuclear proteins in differentiating epidermal cells. Anat Rec (Hoboken) 1984; 208:357-64. [PMID: 6202170 DOI: 10.1002/ar.1092080306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Both DNA and RNA disappear from the nucleus during differentiation of granular cells into cornified cells but the fate of nuclear proteins remains unknown. We investigated localization of nuclear proteins in rat epidermis by light and electron microscopic immunoperoxidase techniques. As a probe, three sera that reacted, respectively, with the nucleoplasm, nucleolus, and nuclear envelope of basal cells of rat epidermis were used. In granular cells both the antinucleoplasm serum and antinucleolus serum increased intensity of the nuclear staining, but they reacted also with ribosomes, filaments, and periphery of keratohyalin granules in the cytoplasm. The staining appeared diffusely in cornified cells and identification of nuclear components became impossible. In contrast, the antinuclear envelope serum stained only the nuclear outline in granular cells and continued to stain the nuclear contour in cornified cells of the fourth and fifth proximal cell layers. The antigenic components surrounded amorphous but not filamentous materials in cornified cells. These findings suggest that some nuclear proteins become immunologically indistinguishable from cytoplasmic protein. However, the nuclear envelope protein maintains its localization even after nucleic acids are lost and the nuclear space is detectable in cornified cells by use of autoantibody directed to this protein(s).
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Abstract
Disturbances in the process of normal cornification leading to pathologic scaling provide the pathophysiologic basis for the ichthyoses. These disturbances may result from either abnormalities in protein metabolism (keratinization) (i.e., the "bricks") or in lipid metabolism (i.e., the "mortar") (Fig. 1). The evidence linking the various ichthyoses to defects in protein or lipid metabolism have been reviewed. It is likely that future advances will lead not only to a more complete understanding of the pathogenesis of these disorders, but also will shed significant light on the normal stratum corneum functions of barrier formation and desquamation, as well as lead the way to more rational and effective therapies. In recent years, prenatal diagnosis has been successfully performed in several of the ichthyoses. It is likely that improvements in our ability to prenatally diagnose those disorders will advance hand-in-hand with further progress in unraveling their underlying causes.
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Brysk MM, Snider JM, Smith EB. Separation of newborn rat epidermal cells on discontinuous isokinetic gradients of PERCOLL. J Invest Dermatol 1981; 77:205-9. [PMID: 6268711 DOI: 10.1111/1523-1747.ep12479888] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A one-step procedure has been developed for the separation of epidermal cells using PERCOLL (a new colloidal silica medium of low viscosity, osmolarity, and toxicity) for density gradient centrifugation. Newborn rat epidermal cells were dispersed with trypsin-EDTA and separated into 4 fractions in discontinuous isokinetic gradients. The cell fractions were characterized by their appearance in photomicrographs and their distribution by number and size. Preferential incorporation of 3H-thymidine and 14C-glycine, by basal and granular cells respectively, confirmed the identification of cell types. The basal cells, which were collected in the densest fraction (1.090), were the most homogeneous population with a mean diameter between 7-8 mum and showed 98% viability. The granular cells predominated in the least dense fraction (1.023). The intermediate fractions contained spinous cells admixed with the other cell types.
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Dale BA, Vadlamudi B, DeLap LW, Bernstein IA. Similarities between stratum corneum basic protein and histidine-rich protein II from newborn rat epidermis. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 668:98-106. [PMID: 6165394 DOI: 10.1016/0005-2795(81)90153-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The stratum corneum basic protein and histidine-rich protein II were each isolated from newborn rat epidermis and compared by biochemical and immunologic methods. The proteins were indistinguishable by immunodiffusion using antiserum elicited to either protein. The migration of the proteins on SDS-polyacrylamide gel electrophoresis was identical giving a molecular weight of 49 000. These proteins, which have similar but unusual amino acid compositions, give very similar tryptic peptide maps. Both proteins aggregate with keratin filaments to form macrofibrils. These results suggest that histidine-rich protein II and stratum corneum basic protein are the same protein. We suggest that this protein be called histidine-rich basic protein.
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Abstract
Cells of the inner layers of the epidermis contain small keratins (46-58K), whereas the cells of the outer layers contain large keratins (63-67K) in addition to small ones. The changes in keratin composition that take place within each cell during the course of its terminal differentiation result largely from changes in synthesis. Cultured epidermal cells resemble cells of the inner layers of the epidermis in synthesizing only small keratins. The cultured cells possess translatable mRNA only for small keratins, whereas mRNA extracted from whole epidermis can be translated into both large and small keratins. As no synthesis takes place in the outermost layer of the epidermis (stratum corneum), the keratins of this layer must be synthesized earlier, but in some cases they then become smaller: this presumably occurs by post-translational processing of the molecules during the final stages of differentiation. Stratified squamous epithelia of internal organs do not form a typical stratum corneum and do not make the large keratins characteristic of epidermis. Their keratins are also different from those of cultured keratinocytes, implying that they have embarked on an alternate route of terminal keratin synthesis.
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Ball R, Walker G, Bernstein I. Histidine-rich proteins as molecular markers of epidermal differentiation. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)30348-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Baratz RS, Farbman AI, Telser A. Developmental changes in the protein profile of cornifying lingual epithelium. J Invest Dermatol 1977; 68:277-84. [PMID: 67156 DOI: 10.1111/1523-1747.ep12494219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Epithelia from the tongue dorsum of 14- to 21-day embryos, 21-day embryos, 3-week-old, and adult rats were separated from their connective tissues by incubation in balanced salt solution containing EDTA. Aliquots from total extracts of these tissues were electrophoresed on sodium dodecyl sulfate-polyacrylamide gels. Scans of gels stained with fast green (FG) revealed more than 20 peaks. Ten major peaks ranging from apparent molecular weights (MW) of 120,000 to 14,000 daltons comprised about 70% of the total protein on each gel. This report focuses primarily on two pairs of peaks, arbitrarily numbered 2 and 3 (MWs 71,000 and 69,000) and 9 and 10 (MWs 17,500 and 14,000). Peaks 9 and 10 predominated in the 15-day embryos where they comprised about 30% of the total protein. As development proceeded, there was a gradual shift in the protein profile in favor of peaks 2 and 3 until on the 20th day the relative amounts of these peaks reached a maximum and peaks 9 and 10 decreased in relative amounts. The protein profile on the 20th fetal day resembled that of the 3-week-old rats and the adults. The rise in the relative amounts of peaks 2 and 3 coincided with the morphologic appearance of large numbers of tonofilaments and the onset of cornification. When the gel was stained by a procedure specific for sulfhydryl groups, peaks 9 and 10 were especially reactive after the 18th day; plainmetric analysis revealed that these had twice the relative affinity for this stain than for FG whereas other peaks had equal or less affinity. The incorporation of [3H]cystine into peaks 9 and 10 was relatively greater than into the other proteins.
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Brysk MM, Gray RH, Bernstein IA. Tonofilament protein from newborn rat epidermis. Isolation, localization, and biosynthesis of marker of epidermal differentiation. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(18)71875-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Ohshima Y. AUTORADIOGRAPHIC STUDY ON THE UPTAKE OF 3H-AMINO ACIDS BY NORMAL AND PATHOLOGICAL HUMAN EPIDERMIS. J Dermatol 1976. [DOI: 10.1111/j.1346-8138.1976.tb00981.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yoshio Ohshima
- Department of Dermatology; Kyoto Prefectural University of Medicine; Kamikyo-ku Kyoto Japan
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Abstract
The mammalian epidermis is organized into layers of structurally different cells--the basal, spinous, granular and cornified layers--which represent steps in the differentiative process that terminates in cornification and desquamation. Investigation of the molecular mechanisms that control this ordered sequence of events provides clues to the etiology of certain epidermal pathologies. DNA synthesis and mitosis are normally restricted to the basal layer. Several substances have been implicated in the mitotic control of epidermal cells, the loss of mitotic activity being the first major step in normal keratinization. Investigations performed in this laboratory indicate that isolated differentiated nuclei can replicate their DNA which they are inhibited from doing in situ. Addition of a high speed supernate from homogenized differentiated cells inhibited this synthetic activity in vitro suggesting the existence of a cytoplasmic inhibitor of DNA synthesis. It is not known whether mitotic inhibition in differentiated epidermal cells is a function of the inhibition of DNA replication. Contrary to previous assumptions, recent experimental evidence clearly indicates that, unlike DNA synthesis, RNA synthesis occurs in differentiated cells. Correlated with this synthetic activity is the observation that a protein rich in histidine is specifically formed in the granular cells. This protein appears to be a component of the keratohyalin granules which fill the cells of the granular layer. Investigations were conducted in this laboratory to determine whether control of the synthesis of this protein occurs at the level of translation or transcription. Translation, in vitro, of mRNA obtained from isolated populations of each epidermal cell type suggested that control of protein synthesis in the differentiating epidermis is transcriptional, i.e. only in the granular cell is there an mRNA for the histidine-rich protein. Transcription, in vitro, of chormatin isolated from the separated cell populations produced RNA with a ratio of cytidine to uracil consistent with the predicted mRNA for this protein thus providing additional support for the hypothesis that epidermal differentiation is controlled at the level of 'gene-readout'.
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Pruniéras M, Delescluse C, Regnier M. The culture of skin. A review of theories and experimental methods. J Invest Dermatol 1976; 67:58-65. [PMID: 180188 DOI: 10.1111/1523-1747.ep12512483] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Two main criticisms can be leveled against the standard methods of skin culture: they are poorly quantifiable and the cultured cell populations are heterogeneous. A new technique based mainly on enzymatic dissociation allows specific cell types to be extracted from the skin before cultivation. In this way, separate cultures of epidermal keratinocytes and dermal fibroblasts can be obtained from the same piece of skin. These purified systems have been used to study the kinetics of epidermal cell growth and to quantify the effect of various chemically defined substances on the growth and differentiation of keratinocytes. With further refinements in technique, purified populations of melanocytes can be extracted. The co-culture of pigmented melanocytes with albino keratinocytes has been proposed as a model to study pigment donation in vitro. The usual organ culture technique, including the use of large explants of skin immersed in the culture fluid, has been modified to show that adult human skin partially regenerates in vitro and that mitotic activity goes on for months in the regenerated epidermis. The use of nucleic acid hybridization techniques, combined with skin cell cultures from human tumors, opens new avenues of research on human cancer.
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Boisson MC, Gianelly AA, Ruben MP, Randall FJ, Bloom AA. Epithelial changes incident to tooth movement: a radio-autographic analysis. J Periodontol 1976; 47:335-41. [PMID: 1064721 DOI: 10.1902/jop.1976.47.6.335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Delecluse C, Fukuyama K, Epstein WL. Dibutyryl cyclic AMP-induced differentiation of epidermal cells in tissue culture. J Invest Dermatol 1976; 66:8-13. [PMID: 54395 DOI: 10.1111/1523-1747.ep12477975] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Histochemical and biochemical techniques have been used to compare the effects of dibutyryl cyclic AMP on epidermal cells and dermal cells in primary tissue culture. Rhodamin B staining showed only scattered positive cells in nontreated epidermal cells and a few contaminating keratinizing cell foci in both nontreated and treated dermal cell cultures. In contrast, treated epidermal cells stained strongly and had many keratinizing cell foci. A significant increase in histidine, cystine, and arginine incorporation was noted in epidermal cells treated with dibutyryl cyclic AMP as compared to untreated epidermal cells and to dermal cell cultures both treated and untreated. Dibutyryl cyclic AMP had no significant effect on leucine and phenylalanine incorporation. These results seem to suggest that the intracellular level of cyclic AMP not only controls the synthesis of DNA by epidermal cells in culture but also induces the process of differentiation toward keratinization.
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Freinkel RK, Wier KA. Changing patterns of incorporation of (14C)histidine and (3H)leucine into epidermal proteins during differentiation of fetal rat skin. J Invest Dermatol 1975; 65:482-7. [PMID: 1194713 DOI: 10.1111/1523-1747.ep12610193] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Synthesis of epidermal proteins has been assessed during epidermal differentiation in fetal rat skin by studies of the simultaneous incorporation of [14C]histidine (H) and [3H]leucine (L) in vitro. Relative incorporation of the two amino acids into epidermal proteins was assessed in terms of H/L ratios and absolute rates of incorporation related to DNA content. Biochemical parameters were correlated with morphologic development. An increase in incorporation of both amino acids accompanied stratification and development of granular and cornified layers between 18 days of gestation and 3 to 5 days postpartum. Relatively greater incorporation of histidine after development of mature granular cells and stratum corneum was reflected in increasing H/L ratios. These results correlated with negative Pauly staining of the initial fetal keratohyaline granules at day 18 and positive staining of mature granules at subsequent stages of development. H/L ratios appear to represent a sensitive marker for differential protein synthesis during differentiation in whole epidermis. The results suggest that biosynthesis of histidine-rich protein is associated with production of mature keratohyaline granules during fetal development.
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Fukuyama K, Epstein WL. Heterogenous proteins in keratohyaline granules studied by quantitative autoradiography. J Invest Dermatol 1975; 65:113-17. [PMID: 1151106 DOI: 10.1111/1523-1747.ep12598080] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Electron microscopic autoradiography with [3H]histidine, [3H]cystine, I13H]arginine, and [3H]proline was used to study protein synthesis in keratohyaline granules of newborn rats. All 3H-amino acids were incorporated into proteins in the granular cells, and the radioactive proteins appeared in the keratohyaline granules. However, the amount of radioactivity associated with the granules and the pattern of ultrastructural localization of the radioactive proteins differed considerably for each 3H-amino acid. "Histidine-labeled" protein was located mainly in the matrix portion of keratohyaline granules whereas "cystine-labeled" protein accumulated in the dense homogenous deposits. "Arginine-labeled" protein was distributed more diffusely in the organelles of granular cells, but that associated with keratohyaline granules seemed to localize mostly with "histidine-labeled" protein and partly with "cystine-labeled" protein. Large amounts of "proline-labeled" protein were also present in other areas of the cytoplasm than keratohyaline granules. This protein localized in the dense homogeneous deposits, but it seemed to turn over more rapidly than "cystine-labeled" protein, an indication that the dense homogenous deposits consist of at least two different polypeptide chains, one of which contains higher cystine and the other higher proline.
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Bernstein IA, Kaman RL, Malinoff H, Sachs L, Gray RH. Translation of polysomal messenger RNA during epidermal differentiation. J Invest Dermatol 1975; 65:102-6. [PMID: 1151105 DOI: 10.1111/1523-1747.ep12598067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Translation in vitro of messenger RNA obtained from preparations of active polysomes isolated from the epidermal basal, spinous, and granular cells of the newborn rat has provided evidence that in the context of differentiation in this tissue, control of protein synthesis is exerted at the level of transcription. The data supporting this hypothesis are reviewed.
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Ugel AR. Bovine keratohyalin: anatomical, histochemical, ultrastructural, immunologic, and biochemical studies. J Invest Dermatol 1975; 65:118-26. [PMID: 50383 DOI: 10.1111/1523-1747.ep12598085] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Salt extraction studies showed that keratohyalin (KH) could be solubilized and extracted from fresh bovine hoof epidermis. The solubility of KH varied in relation to the molarity of the salt solution used for extraction. Using this information, the extracted KH was aggregated in vitro by dialyzing the high salt extract against distilled water. Histochemical, ultrastructural, and immunologic studies of the resultant particles or macroaggregates showed that the latter had the same properties and immunogenicity as the KH granule in situ and produced antibodies against it. Fractionation of the macroaggregates by polyacrylamide gel electrophoresis demonstrated that the macroaggregates were compsed of sets of 20 polymers whose subunits or monomers had a molecular weight of 16,900. Amino acid analyses showed that the macroaggregates and the various fractionated polymers were similar and that the protein ahd 116 amino acid residues. Serine, arginine, glycine, glutamic acid, and histidine constituted 78% of all residues, and serine alone represented 27%. The molecular weight by amino acid analyses was 16,150 after correction for the 8% ribonucleic acid which appears to be complexed to the protein.
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Fukuyama K, Epstein WL. A comparative autoradiographic study of keratogyalin granules containing cystine and histidine. JOURNAL OF ULTRASTRUCTURE RESEARCH 1975; 51:314-25. [PMID: 166197 DOI: 10.1016/s0022-5320(75)80096-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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34
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Rowden G. Ultrastructural studies of keratinized epithelia of the mouse. III. Determination of the volumes of nuclei and cytoplasm of cells in murine epidermis. J Invest Dermatol 1975; 64:1-3. [PMID: 1110303 DOI: 10.1111/1523-1747.ep12540840] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Simple morphometric analyses were applied to mouse epidermal specimens prepared for electrom microscopy. Mean values were obtained for the dimensions of cells and nuclei in basal, suprabasal, and granular layers. These measurements were applied to simplified models representing the shapes of cells in the three strata. A fourfold increase in cytoplasmic volume was observed as cells passed from the basal to granular layers. During this transition, the nuclear volume did not decrease significantly.
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Tezuka T, Freedberg IM. Epidermal structural proteins. III. Isolation and purification of histidine-rich protein of the newborn rat. J Invest Dermatol 1974; 63:402-6. [PMID: 4436598 DOI: 10.1111/1523-1747.ep12676567] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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36
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Debov SS, Mikhailov IN, Vinogradova EV. Electron-microscopic characteristics of the dynamics of thymidine-H3 and uridine-H3 in the mouse epidermis. Bull Exp Biol Med 1974. [DOI: 10.1007/bf00796675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Sibrack LA, Gray RH, Bernstein IA. Localization of the histidine-rich protein in keratohyalin: a morphologic and macromolecular marker in epidermal differentiation. J Invest Dermatol 1974; 62:394-405. [PMID: 4820683 DOI: 10.1111/1523-1747.ep12701654] [Citation(s) in RCA: 87] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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38
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Baden HP, Roth SI, Goldsmith LA, Baden SB, Lee LD. Keratohyalin protein in disorders of keratinization. J Invest Dermatol 1974; 62:411-4. [PMID: 4132224 DOI: 10.1111/1523-1747.ep12701666] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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39
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MacCallum DK, Han SS. An electron microscopic autoradiographic study of proline incorporation by mouse lingual epithelium. ZEITSCHRIFT FUR ZELLFORSCHUNG UND MIKROSKOPISCHE ANATOMIE (VIENNA, AUSTRIA : 1948) 1974; 147:479-90. [PMID: 4407657 DOI: 10.1007/bf00307250] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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40
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Baden H, Sviokla S, Roth I. The structural protein of reptilian scales. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1974; 187:287-94. [PMID: 4813419 DOI: 10.1002/jez.1401870212] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Susi FR. Synthesis and fate of glycoprotein in rat oral mucosa 3 as observed by light electron microscopic radioautography with L-fucose-H. ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1973; 36:148-54. [PMID: 4514519 DOI: 10.1016/0030-4220(73)90277-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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44
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Stern IB, Sekeri-Pataryas KH. The uptake of 14C-leucine and 14C-histidine by cell suspensions of isolated strata of neonatal rat epidermis. J Invest Dermatol 1972; 59:251-9. [PMID: 5055188 DOI: 10.1111/1523-1747.ep12627274] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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46
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48
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Vaughan FL, Bernstein IA. Studies of proliferative capabilities in isolated epidermal basal and differentiated cells. J Invest Dermatol 1971; 56:454-66. [PMID: 4931581 DOI: 10.1111/1523-1747.ep12261386] [Citation(s) in RCA: 48] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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49
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Sugawara K, Bernstein IA. Biosynthesis, in vitro, of "histidine-protein"--a biochemical marker in epidermal differentiation. BIOCHIMICA ET BIOPHYSICA ACTA 1971; 238:129-38. [PMID: 4325154 DOI: 10.1016/0005-2787(71)90016-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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50
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Moore JT, Karasek MA. Isolation and properties of a germinative and a non-germinative cell population from postembryonic mouse, rabbit, and human epidermis. J Invest Dermatol 1971; 56:318-24. [PMID: 5556520 DOI: 10.1111/1523-1747.ep12261079] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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