scholarly journals The role of cathepsin E in terminal differentiation of keratinocytes

2011 ◽  
Vol 392 (6) ◽  
Author(s):  
Tomoyo Kawakubo ◽  
Atsushi Yasukochi ◽  
Kuniaki Okamoto ◽  
Yoshiko Okamoto ◽  
Seiji Nakamura ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Primary Cultures ◽  
Terminal Differentiation ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Marker Genes ◽  
Differentiation Markers ◽  
Cathepsin E

Abstract Cathepsin E (CatE) is predominantly expressed in the rapidly regenerating gastric mucosal cells and epidermal keratinocytes, in addition to the immune system cells. However, the role of CatE in these cells remains unclear. Here we report a crucial role of CatE in keratinocyte terminal differentiation. CatE deficiency in mice induces abnormal keratinocyte differentiation in the epidermis and hair follicle, characterized by the significant expansion of corium and the reduction of subcutaneous tissue and hair follicle. In a model of skin papillomas formed in three different genotypes of syngeneic mice, CatE deficiency results in significantly reduced expression and altered localization of the keratinocyte differentiation induced proteins, keratin 1 and loricrin. Involvement of CatE in the regulation of the expression of epidermal differentiation specific proteins was corroborated by in vitro studies with primary cultures of keratinocytes from the three different genotypes of mice. In wild-type keratinocytes after differentiation inducing stimuli, the CatE expression profile was compatible to those of the terminal differentiation marker genes tested. Overexpression of CatE in mice enhances the keratinocyte terminal differentiation process, whereas CatE deficiency results in delayed differentiation accompanying the reduced expression or the ectopic localization of the differentiation markers. Our findings suggest that in keratinocytes CatE is functionally linked to the expression of terminal differentiation markers, thereby regulating epidermis formation and homeostasis.

Terminal differentiation in keratinocytes involves positive as well as negative regulation by retinoic acid receptors and retinoid X receptors at retinoid response elements

1992 ◽  
Vol 12 (11) ◽  
pp. 4862-4871
Author(s):  
B J Aneskievich ◽  
E Fuchs
Keyword(s):  
Retinoic Acid ◽  
Terminal Differentiation ◽  
Cell Types ◽  
Epidermal Differentiation ◽  
Retinoic Acid Receptors ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Retinoid X Receptors ◽  
Response Elements ◽  
X Receptors

Terminal differentiation of epidermal keratinocytes is inhibited by 1 microM retinoic acid, a concentration which induces differentiation in a number of cell types, including F9 teratocarcinoma cells. The molecular basis for these opposing retinoid responses is unknown, although retinoic acid receptors (RARs) and retinoid X receptors (RXRs) have been detected in both cell types. When F9 cells are stably transfected with a truncated RAR alpha lacking the E/F domain necessary for ligand binding and RAR/RXR dimerization, action at retinoid response elements is suppressed and cells produce a retinoic acid-resistant phenotype; i.e., they are blocked in differentiation (A. S. Espeseth, S. P. Murphy, and E. Linney, Genes Dev. 3:1647-1656, 1989). If retinoid receptors influence epidermal differentiation only in a negative fashion, then suppression of transactivation at retinoid response elements would be expected to enhance, rather than block, keratinocyte differentiation. In this study, we show that surprisingly, even though constitutive expression of an analogous truncated RAR gamma in keratinocytes specifically suppressed transactivation at retinoid response elements, keratinocytes were blocked, rather than enhanced, in their ability to undergo morphological and biochemical features of differentiation. These findings demonstrate a direct and hitherto unrecognized role for RARs and RXRs in positively as well as negatively regulating epidermal differentiation. Additionally, our studies extend those of Espeseth et al. (Genes Dev. 3:1647-1656, 1989), indicating a novel RAR function independent of the E/F domain.

scholarly journals A non-canonical lysosome biogenesis pathway generates Golgi-associated lysosomes during epidermal differentiation

2018 ◽  
Author(s):  
Sarmistha Mahanty ◽  
Shruthi Shirur Dakappa ◽  
Rezwan Shariff ◽  
Saloni Patel ◽  
Mruthyunjaya Mathapathi Swamy ◽  
...  
Keyword(s):  
Cellular Differentiation ◽  
Brefeldin A ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Differentiation Markers ◽  
Human Epidermal Keratinocytes ◽  
Lysosome Biogenesis ◽  
Proteome Changes ◽  
And Function

AbstractKeratinocytes maintain epidermis integrity and function including physical and antimicrobial barrier through cellular differentiation. This process is predicted to be controlled by calcium ion gradient and nutritional stress. Keratinocytes undergo proteome changes during differentiation, which enhances the intracellular organelle digestion to sustain the stress conditions. However, the molecular mechanism between epidermal differentiation and organelle homeostasis is poorly understood. Here, we used primary neonatal human epidermal keratinocytes to study the link between cellular differentiation, signaling pathways and organelle turnover. Upon addition of calcium chloride (2 mM) to the culture medium, keratinocytes increased their cell size and the expression of differentiation markers. Moreover, differentiated keratinocytes showed enhanced lysosome biogenesis that was dependent on ATF6-arm of UPR signaling but independent of mTOR-MiT/TFE transcription factors. Furthermore, chemical inhibition of mTOR has increased keratinocyte differentiation and relocalized the MiT/TFE TFs to the lysosome membranes, indicating that autophagy activation promotes the epidermal differentiation. Interestingly, differentiation of keratinocytes resulted in dispersal of fragmented Golgi and lysosomes, and the later organelles showed colocalization with Golgi-tethering proteins, suggesting that these lysosomes possibly originated from Golgi, hence named as Golgi-associated lysosomes (GALs). Consistent to this prediction, inhibition of Golgi function using brefeldin A completely abolished the formation of GALs and the keratinocyte differentiation. Thus, ER stress regulates the biogenesis of GALs, which maintains keratinocyte differentiation and epidermal homeostasis.

scholarly journals Single-cell transcriptomics defines keratinocyte differentiation in avian scutate scales

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Julia Lachner ◽  
Florian Ehrlich ◽  
Matthias Wielscher ◽  
Matthias Farlik ◽  
Marcela Hermann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Terminal Differentiation ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Scale Type ◽  
Epidermal Differentiation Complex ◽  
Evolutionarily Conserved ◽  
Beta Proteins

AbstractThe growth of skin appendages, such as hair, feathers and scales, depends on terminal differentiation of epidermal keratinocytes. Here, we investigated keratinocyte differentiation in avian scutate scales. Cells were isolated from the skin on the legs of 1-day old chicks and subjected to single-cell transcriptomics. We identified two distinct populations of differentiated keratinocytes. The first population was characterized by mRNAs encoding cysteine-rich keratins and corneous beta-proteins (CBPs), also known as beta-keratins, of the scale type, indicating that these cells form hard scales. The second population of differentiated keratinocytes contained mRNAs encoding cysteine-poor keratins and keratinocyte-type CBPs, suggesting that these cells form the soft interscale epidermis. We raised an antibody against keratin 9-like cysteine-rich 2 (KRT9LC2), which is encoded by an mRNA enriched in the first keratinocyte population. Immunostaining confirmed expression of KRT9LC2 in the suprabasal epidermal layers of scutate scales but not in interscale epidermis. Keratinocyte differentiation in chicken leg skin resembled that in human skin with regard to the transcriptional upregulation of epidermal differentiation complex genes and genes involved in lipid metabolism and transport. In conclusion, this study defines gene expression programs that build scutate scales and interscale epidermis of birds and reveals evolutionarily conserved keratinocyte differentiation genes.

scholarly journals Contributions of Nitric Oxide to AHR-Ligand-Mediated Keratinocyte Differentiation

2020 ◽  
Vol 21 (16) ◽  
pp. 5680
Author(s):  
Carrie Hayes Sutter ◽  
Haley M. Rainwater ◽  
Thomas R. Sutter
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cell ◽  
Cell Fate ◽  
Terminal Differentiation ◽  
Metabolic Reprogramming ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Nitric Oxide Signaling ◽  
Selective Ligand

Activation of the aryl hydrocarbon receptor (AHR) in normal human epidermal keratinocytes (NHEKs) accelerates keratinocyte terminal differentiation through metabolic reprogramming and reactive oxygen species (ROS) production. Of the three NOS isoforms, NOS3 is significantly increased at both the RNA and protein levels by exposure to the very potent and selective ligand of the AHR, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Inhibition of NOS with the chemical N-nitro-l-arginine methyl ester (l-NAME) reversed TCDD-induced cornified envelope formation, an endpoint of terminal differentiation, as well as the expression of filaggrin (FLG), a marker of differentiation. Conversely, exposure to the NO-donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP), increased the number of cornified envelopes above control levels and augmented the levels of cornified envelopes formed in response to TCDD treatment and increased the expression of FLG. This indicates that nitric oxide signaling can increase keratinocyte differentiation and that it is involved in the AHR-mediated acceleration of differentiation. As the nitrosylation of cysteines is a mechanism by which NO affects the structure and functions of proteins, the S-nitrosylation biotin switch technique was used to measure protein S-nitrosylation. Activation of the AHR increased the S-nitrosylation of two detected proteins of about 72 and 20 kD in size. These results provide new insights into the role of NO and protein nitrosylation in the process of epithelial cell differentiation, suggesting a role of NOS in metabolic reprogramming and the regulation of epithelial cell fate.

scholarly journals Terminal differentiation in keratinocytes involves positive as well as negative regulation by retinoic acid receptors and retinoid X receptors at retinoid response elements.

1992 ◽  
Vol 12 (11) ◽  
pp. 4862-4871 ◽  
Author(s):  
B J Aneskievich ◽  
E Fuchs
Keyword(s):  
Retinoic Acid ◽  
Terminal Differentiation ◽  
Cell Types ◽  
Epidermal Differentiation ◽  
Retinoic Acid Receptors ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Retinoid X Receptors ◽  
Response Elements ◽  
X Receptors

Terminal differentiation of epidermal keratinocytes is inhibited by 1 microM retinoic acid, a concentration which induces differentiation in a number of cell types, including F9 teratocarcinoma cells. The molecular basis for these opposing retinoid responses is unknown, although retinoic acid receptors (RARs) and retinoid X receptors (RXRs) have been detected in both cell types. When F9 cells are stably transfected with a truncated RAR alpha lacking the E/F domain necessary for ligand binding and RAR/RXR dimerization, action at retinoid response elements is suppressed and cells produce a retinoic acid-resistant phenotype; i.e., they are blocked in differentiation (A. S. Espeseth, S. P. Murphy, and E. Linney, Genes Dev. 3:1647-1656, 1989). If retinoid receptors influence epidermal differentiation only in a negative fashion, then suppression of transactivation at retinoid response elements would be expected to enhance, rather than block, keratinocyte differentiation. In this study, we show that surprisingly, even though constitutive expression of an analogous truncated RAR gamma in keratinocytes specifically suppressed transactivation at retinoid response elements, keratinocytes were blocked, rather than enhanced, in their ability to undergo morphological and biochemical features of differentiation. These findings demonstrate a direct and hitherto unrecognized role for RARs and RXRs in positively as well as negatively regulating epidermal differentiation. Additionally, our studies extend those of Espeseth et al. (Genes Dev. 3:1647-1656, 1989), indicating a novel RAR function independent of the E/F domain.

scholarly journals Pyridoxine Stimulates Filaggrin Production in Human Epidermal Keratinocytes

2021 ◽  
Author(s):  
Miyuki Fujishiro ◽  
Shoichi Yahagi ◽  
Shota Takemi ◽  
Takafumi Sakai ◽  
ichiro sakata
Keyword(s):  
Pyridoxal Phosphate ◽  
Seborrheic Dermatitis ◽  
Epidermal Differentiation ◽  
Disulfonic Acid ◽  
Epidermal Keratinocytes ◽  
Marker Genes ◽  
Dependent Manner ◽  
Human Epidermal Keratinocytes ◽  
Concentration Dependent Manner ◽  
Protein Levels

Abstract Pyridoxine (PN), one of the vitamers of vitamin B6, plays an important role in the maintenance of epidermal function and is used to treat acne and rough skin. Clinical studies have revealed that PN deficiency causes skin problems such as seborrheic dermatitis and stomatitis. However, the detailed effects of PN and its mechanism of action in epidermal function are poorly understood. In this study, we examined the effects of PN on epidermal function in normal human epidermal keratinocytes and found that PN specifically causes an increase in the expression of profilaggrin mRNA, among marker genes of terminal epidermal differentiation. In addition, PN treatment caused an increase in the production of filaggrin protein in a concentration-dependent manner. Treatment with P2x purinoceptor antagonists, namely, pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid) tetrasodium salt hydrate and TNP-ATP hydrate, induced an increase in the filaggrin protein levels. Moreover, we showed that elevated filaggrin production induced upon PN treatment was suppressed by ATP (known as P2x purinoceptor agonist). This study is the first to report that PN causes an increase in filaggrin transcription and production, and these results suggest that PN-induced filaggrin production may be a useful target as a daily care component in atopic dermatitis, wherein filaggrin levels are specifically reduced.

Inhibition of cadherin function differentially affects markers of terminal differentiation in cultured human keratinocytes

1999 ◽  
Vol 112 (24) ◽  
pp. 4569-4579
Author(s):  
M.D. Hines ◽  
H.C. Jin ◽  
M.J. Wheelock ◽  
P.J. Jensen
Keyword(s):  
Terminal Differentiation ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Differentiation Markers ◽  
Protein Levels ◽  
Surface Molecules ◽  
Transglutaminase 1 ◽  
Differentiation Marker ◽  
E Cadherin

Cadherin function is required for normal keratinocyte intercellular adhesion and stratification. In the present study, we have investigated whether cadherin-cadherin interactions may also modulate keratinocyte differentiation, as evidenced by alterations in the levels of several differentiation markers. Confluent keratinocyte cultures, propagated in low Ca(2+) medium in which cadherins are not active, were pre-incubated with antibodies that block the function of E-cadherin and/or P-cadherin; Ca(2+)was then elevated to 1 mM to activate the cadherins and induce differentiation. In control cultures (incubated with no antibody or with antibodies to other cell surface molecules), Ca(2+) elevation induced an increase in type 1 transglutaminase, profilaggrin, and loricrin, as measured by western blotting and in agreement with previous results. However, the concurrent addition of antibodies against both E- and P-cadherin prevented this increase in transglutaminase 1 protein. Incubation with either antibody alone had no consistent effect. Profilaggrin and loricrin, which are later markers of keratinocyte differentiation, responded differently from transglutaminase 1 to addition of antibodies. In the presence of anti-E-cadherin antibody, both loricrin and profilaggrin levels were dramatically enhanced compared to the high Ca(2+) control cells, while addition of antibody to P-cadherin slightly attenuated the Ca(2+)-induced increase. In the presence of both antibodies, loricrin and profilaggrin protein levels were intermediate between those observed in the presence of either antibody alone. The expression of involucrin, however, was unaffected by addition of antibodies. In addition, effects of the anti-cadherin antibodies were not secondary to alterations in proliferation or programmed cell death, as determined by several independent assays of these processes. Thus, the consequences of cadherin inhibition depend upon both the particular cadherin and the differentiation marker under study. Taken together, these data suggest that E-cadherin and P-cadherin contribute to the orderly progression of terminal differentiation in the epidermis in multiple ways.

scholarly journals Identification of Novel Keratinocyte Differentiation Modulating Compounds by High-Throughput Screening

2006 ◽  
Vol 11 (8) ◽  
pp. 977-984 ◽  
Author(s):  
Masaru Honma ◽  
Mark Stubbs ◽  
Ian Collins ◽  
Paul Workman ◽  
Wynne Aherne ◽  
...  
Keyword(s):  
Protein Kinase ◽  
High Throughput ◽  
High Throughput Screening ◽  
Histone Deacetylase Inhibitors ◽  
Terminal Differentiation ◽  
Mek Inhibitor ◽  
Keratinocyte Differentiation ◽  
Immunofluorescent Staining ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes

The authors have designed high-throughput screens to identify compounds that promote or inhibit terminal differentiation of primary human epidermal keratinocytes. Eleven known inhibitors of signaling pathways and approximately 4000 compounds of diverse structure were screened using an In-Cell Western system based on immunofluorescent staining of the terminal differentiation marker, involucrin. Staurosporine, a nonspecific protein kinase C inhibitor, and H89, a protein kinase A inhibitor, promoted expression of involucrin. Conversely, U0126, a MEK inhibitor, and SAHA or SBHA, 2 histone deacetylase inhibitors, reduced the expression of involucrin during calcium-induced stratification. In addition, the authors found 1 novel compound that induced keratinocyte differentiation and 2 novel compounds that were inhibitory to calcium-induced differentiation. The differentiation-inducing compound also inhibited growth of a human squamous cell carcinoma line by stimulating both differentiation and apoptosis. Because the compound affected the tumor cells at a lower concentration than primary keratinocytes, it may have potential as an antitumor therapy.

scholarly journals The potency of the fs260 connexin43 mutant to impair keratinocyte differentiation is distinct from other disease-linked connexin43 mutants

2010 ◽  
Vol 429 (3) ◽  
pp. 473-483 ◽  
Author(s):  
Jared M. Churko ◽  
Stephanie Langlois ◽  
Xinyue Pan ◽  
Qing Shao ◽  
Dale W. Laird
Keyword(s):  
Endoplasmic Reticulum ◽  
Skin Disease ◽  
Disease Burden ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Additive Effects ◽  
Wild Type ◽  
Organotypic Cultures ◽  
Oculodentodigital Dysplasia

Although there are currently 62 mutants of Cx43 (connexin43) that can cause ODDD (oculodentodigital dysplasia), only two mutants have also been reported to cause palmar plantar hyperkeratosis. To determine how mutants of Cx43 can lead to this skin disease, REKs (rat epidermal keratinocytes) were engineered to express an ODDD-associated Cx43 mutant always linked to skin disease (fs260), an ODDD-linked Cx43 mutant which has been reported to sometimes cause skin disease (fs230), Cx43 mutants which cause ODDD only (G21R, G138R), a mouse Cx43 mutant linked to ODDD (G60S), a non-disease-linked truncated Cx43 mutant that is trapped in the endoplasmic reticulum (Δ244*) or full-length Cx43. When grown in organotypic cultures, of all the mutants investigated, only the fs260-expressing REKs consistently developed a thinner stratum corneum and expressed lower levels of Cx43, Cx26 and loricrin in comparison with REKs overexpressing wild-type Cx43. REKs expressing the fs260 mutant also developed a larger organotypic vital layer after acetone-induced injury and exhibited characteristics of parakeratosis. Collectively, our results suggest that the increased skin disease burden exhibited in ODDD patients harbouring the fs260 mutant is probably due to multiple additive effects cause by the mutant during epidermal differentiation.

scholarly journals Ligand Targeting of EphA2 Enhances Keratinocyte Adhesion and Differentiation via Desmoglein 1

2010 ◽  
Vol 21 (22) ◽  
pp. 3902-3914 ◽  
Author(s):  
Samantha Lin ◽  
Kristin Gordon ◽  
Nihal Kaplan ◽  
Spiro Getsios
Keyword(s):  
Epidermal Cell ◽  
Mapk Pathway ◽  
Primary Cultures ◽  
Basal Layer ◽  
Receptor Activation ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Adjacent Cell

EphA2 is a receptor tyrosine kinase that is engaged and activated by membrane-linked ephrin-A ligands residing on adjacent cell surfaces. Ligand targeting of EphA2 has been implicated in epithelial growth regulation by inhibiting the extracellular signal-regulated kinase 1/2 (Erk1/2)-mitogen activated protein kinase (MAPK) pathway. Although contact-dependent EphA2 activation was required for dampening Erk1/2-MAPK signaling after a calcium switch in primary human epidermal keratinocytes, the loss of this receptor did not prevent exit from the cell cycle. Incubating keratinocytes with a soluble ephrin-A1-Fc peptide mimetic to target EphA2 further increased receptor activation leading to its down-regulation. Moreover, soluble ligand targeting of EphA2 restricted the lateral expansion of epidermal cell colonies without limiting proliferation in these primary cultures. Rather, ephrin-A1-Fc peptide treatment promoted epidermal cell colony compaction and stratification in a manner that was associated with increased keratinocyte differentiation. The ligand-dependent increase in keratinocyte adhesion and differentiation relied largely upon the up-regulation of desmoglein 1, a desmosomal cadherin that maintains the integrity and differentiated state of suprabasal keratinocytes in the epidermis. These data suggest that keratinocytes expressing EphA2 in the basal layer may respond to ephrin-A1–based cues from their neighbors to facilitate entry into a terminal differentiation pathway.

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