Human keratinocytes migrate to the negative pole in direct current electric fields comparable to those measured in mammalian wounds

1996 ◽  
Vol 109 (1) ◽  
pp. 199-207 ◽  
Author(s):  
K.Y. Nishimura ◽  
R.R. Isseroff ◽  
R. Nuccitelli
Keyword(s):  
Electric Fields ◽  
Human Keratinocytes ◽  
Voltage Gradient ◽  
Primary Human Keratinocytes ◽  
Directed Movement ◽  
Average Cell ◽  
Negative Pole ◽  
Mammalian Skin ◽  
Dc Electric Fields

Previous measurements of the lateral electric fields near skin wounds in guinea pigs have detected DC fields between 100–200 mV/mm near the edge of the wound. We have studied the translocation response of motile primary human keratinocytes migrating on a collagen substrate while exposed to similar physiological DC electric fields. We find that keratinocytes migrate randomly on collagen in fields of 5 mV/mm or less, but in larger fields they migrate towards the negative pole of the field, exhibiting galvanotaxis. Since these cells have an average cell length of 50 microns, this implies that they are able to detect a voltage gradient as low as 0.5 mV along their length. This cath-odally-directed movement exhibits increased directedness with increasing field strengths between 10 and 100 mV/mm. We observe a maximally directed response at 100 mV/mm with half of the cells responding to the field within 14 minutes. The average speed of migration tended to be greater in fields above 50 mV/mm than in smaller fields. We conclude that human keratinocytes migrate towards the negative pole in DC electric fields that are of the same magnitude as measured in vivo near wounds in mammalian skin.

scholarly journals β4 Integrin and Epidermal Growth Factor Coordinately Regulate Electric Field-mediated Directional Migration via Rac1

2006 ◽  
Vol 17 (11) ◽  
pp. 4925-4935 ◽  
Author(s):  
Christine E. Pullar ◽  
Brian S. Baier ◽  
Yoshinobu Kariya ◽  
Alan J. Russell ◽  
Basil A.J. Horst ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Ligand Binding ◽  
Electric Fields ◽  
Human Keratinocytes ◽  
Primary Human Keratinocytes ◽  
Directional Migration ◽  
Epidermal Growth ◽  
Β4 Integrin

Endogenous DC electric fields (EF) are present during embryogenesis and are generated in vivo upon wounding, providing guidance cues for directional cell migration (galvanotaxis) required in these processes. To understand the role of beta (β)4 integrin in directional migration, the migratory paths of either primary human keratinocytes (NHK), β4 integrin-null human keratinocytes (β4−), or those in which β4 integrin was reexpressed (β4+), were tracked during exposure to EFs of physiological magnitude (100 mV/mm). Although the expression of β4 integrin had no effect on the rate of cell movement, it was essential for directional (cathodal) migration in the absence of epidermal growth factor (EGF). The addition of EGF potentiated the directional response, suggesting that at least two distinct but synergistic signaling pathways coordinate galvanotaxis. Expression of either a ligand binding–defective β4 (β4+AD) or β4 with a truncated cytoplasmic tail (β4+CT) resulted in loss of directionality in the absence of EGF, whereas inhibition of Rac1 blinded the cells to the EF even in the presence of EGF. In summary, both the β4 integrin ligand–binding and cytoplasmic domains together with EGF were required for the synergistic activation of a Rac-dependent signaling pathway that was essential for keratinocyte directional migration in response to a galvanotactic stimulus.

scholarly journals Inhibition of Calcineurin/NFAT Signaling Blocks Oncogenic H-Ras Induced Autophagy in Primary Human Keratinocytes

2021 ◽  
Vol 9 ◽  
Author(s):  
Shuangshuang Wang ◽  
Hua Qian ◽  
Liwei Zhang ◽  
Panpan Liu ◽  
Dexuan Zhuang ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Human Keratinocytes ◽  
Primary Human Keratinocytes ◽  
Activated T Cells ◽  
Ras Pathway ◽  
Ras Family ◽  
Interfering Rna

Mutations of H-Ras, a member of the RAS family, are preferentially found in cutaneous squamous cell carcinomas (SCCs). H-Ras has been reported to induce autophagy, which plays an essential role in tissue homeostasis in multiple types of cancer cells and in fibroblasts, however, the potential role of H-Ras in regulating autophagy in human keratinocytes has not been reported. In this study, we found that the stable expression of the G12V mutant of H-RAS (H-RasG12V) induced autophagy in human keratinocytes, and interestingly, the induction of autophagy was strongly blocked by inhibiting the calcineurin/nuclear factor of activated T cells (NFAT) pathway with either a calcineurin inhibitor (Cyclosporin A) or a NFAT inhibitor (VIVIT), or by the small interfering RNA (siRNA) mediated knockdown of calcineurin B1 or NFATc1 in vitro, as well as in vivo. To characterize the role of the calcineurin/NFAT pathway in H-Ras induced autophagy, we found that H-RasG12V promoted the nuclear translocation of NFATc1, an indication of the activation of the calcineurin/NFAT pathway, in human keratinocytes. However, activation of NFATc1 either by the forced expression of NFATc1 or by treatment with phenformin, an AMPK activator, did not increase the formation of autophagy in human keratinocytes. Further study revealed that inhibiting the calcineurin/NFAT pathway actually suppressed H-Ras expression in H-RasG12V overexpressing cells. Finally, chromatin immunoprecipitation (ChIP) assays showed that NFATc1 potentially binds the promoter region of H-Ras and the binding efficiency was significantly enhanced by the overexpression of H-RasG12V, which was abolished by treatment with the calcineurin/NFAT pathway inhibitors cyclosporine A (CsA) or VIVIT. Taking these data together, the present study demonstrates that the calcineurin/NFAT signaling pathway controls H-Ras expression and interacts with the H-Ras pathway, involving the regulation of H-Ras induced autophagy in human keratinocytes.

scholarly journals A protein phosphatase network controls the temporal and spatial dynamics of differentiation commitment in human epidermis

2017 ◽  
Author(s):  
Ajay Mishra ◽  
Angela Oliveira Pisco ◽  
Benedicte Oules ◽  
Tony Ly ◽  
Kifayathullah Liakath-Ali ◽  
...  
Keyword(s):  
Stem Cell ◽  
Terminal Differentiation ◽  
Human Keratinocytes ◽  
Cell Renewal ◽  
Stable States ◽  
Primary Human Keratinocytes ◽  
Network Modelling ◽  
Epidermal Homeostasis

AbstractEpidermal homeostasis depends on a balance between stem cell renewal and terminal differentiation1,2. While progress has been made in characterising the stem and differentiated cell compartments3, the transition between the two cell states, termed commitment4, is poorly understood. Here we characterise commitment by integrating transcriptomic and proteomic data from disaggregated primary human keratinocytes held in suspension for up to 12h. We have previously shown that commitment begins at approximately 4h and differentiation is initiated by 8h5. We find that cell detachment induces a network of protein phosphatases. The pro-commitment phosphatases – including DUSP6, PPTC7, PTPN1, PTPN13 and PPP3CA – promote terminal differentiation by negatively regulating ERK MAPK and positively regulating key API transcription factors. Their activity is antagonised by concomitant upregulation of the anti-commitment phosphatase DUSP10. The phosphatases form a dynamic network of transient positive and negative interactions, with DUSP6 predominating at commitment. Boolean network modelling identifies a mandatory switch between two stable states (stem cell and differentiated cell) via an unstable (committed) state. In addition phosphatase expression is spatially regulated relative to the location of stem cells, both in vivo and in response to topographical cues in vitro. We conclude that an auto-regulatory phosphatase network maintains epidermal homeostasis by controlling the onset and duration of commitment.

scholarly journals Platelet-Released Growth Factors Induce Differentiation of Primary Keratinocytes

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Andreas Bayer ◽  
Mersedeh Tohidnezhad ◽  
Justus Lammel ◽  
Sebastian Lippross ◽  
Peter Behrendt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Factors ◽  
Terminal Differentiation ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Dependent Manner ◽  
Primary Human Keratinocytes ◽  
Transglutaminase 1 ◽  
Keratin 1

Autologous thrombocyte concentrate lysates, for example, platelet-released growth factors, (PRGFs) or their clinically related formulations (e.g., Vivostat PRF®) came recently into the physicians’ focus as they revealed promising effects in regenerative and reparative medicine such as the support of healing of chronic wounds. To elucidate the underlying mechanisms, we analyzed the influence of PRGF and Vivostat PRF on human keratinocyte differentiation in vitro and on epidermal differentiation status of skin wounds in vivo. Therefore, we investigated the expression of early (keratin 1 and keratin 10) and late (transglutaminase-1 and involucrin) differentiation markers. PRGF treatment of primary human keratinocytes decreased keratin 1 and keratin 10 gene expression but induced involucrin and transglutaminase-1 gene expression in an epidermal growth factor receptor- (EGFR-) dependent manner. In concordance with these results, microscopic analyses revealed that PRGF-treated human keratinocytes displayed morphological features typical of keratinocytes undergoing terminal differentiation. In vivo treatment of artificial human wounds with Vivostat PRF revealed a significant induction of involucrin and transglutaminase-1 gene expression. Together, our results indicate that PRGF and Vivostat PRF induce terminal differentiation of primary human keratinocytes. This potential mechanism may contribute to the observed beneficial effects in the treatment of hard-to-heal wounds with autologous thrombocyte concentrate lysates in vivo.

scholarly journals Differential Efficacy of Novel Antiviral Substances in 3D and Monolayer Cell Culture

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1294
Author(s):  
Robert Koban ◽  
Markus Neumann ◽  
Philipp P. Nelson ◽  
Heinz Ellerbrok
Keyword(s):  
Cell Culture ◽  
Antiviral Activity ◽  
Virus Replication ◽  
3D Culture ◽  
Human Keratinocytes ◽  
Infection Model ◽  
Cowpox Virus ◽  
Primary Human Keratinocytes

Repurposing of approved drugs that target host functions also important for virus replication promises to overcome the shortage of antiviral therapeutics. Mostly, virus biology including initial screening of antivirals is studied in conventional monolayer cells. The biology of these cells differs considerably from infected tissues. 3D culture models with characteristics of human tissues may reflect more realistically the in vivo events during infection. We screened first, second, and third generation epidermal growth factor receptor (EGFR)-inhibitors with different modes of action and the EGFR-blocking monoclonal antibody cetuximab in a 3D cell culture infection model with primary human keratinocytes and cowpox virus (CPXV) for antiviral activity. Antiviral activity of erlotinib and osimertinib was nearly unaffected by the cultivation method similar to the virus-directed antivirals tecovirimat and cidofovir. In contrast, the host-directed inhibitors afatinib and cetuximab were approx. 100-fold more efficient against CPXV in the 3D infection model, similar to previous results with gefitinib. In summary, inhibition of EGFR-signaling downregulates virus replication comparable to established virus-directed antivirals. However, in contrast to virus-directed inhibitors, in vitro efficacy of host-directed antivirals might be seriously affected by cell cultivation. Results obtained for afatinib and cetuximab suggest that screening of such drugs in standard monolayer culture might underestimate their potential as antivirals.

scholarly journals In Vitro Expansion of Keratinocytes on Human Dermal Fibroblast-Derived Matrix Retains Their Stem-Like Characteristics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chee-Wai Wong ◽  
Catherine F. LeGrand ◽  
Beverley F. Kinnear ◽  
Radoslaw M. Sobota ◽  
Rajkumar Ramalingam ◽  
...  
Keyword(s):  
Dermal Fibroblast ◽  
Human Keratinocytes ◽  
Dermal Fibroblasts ◽  
Collagen I ◽  
Matrix Composition ◽  
Major Influence ◽  
Primary Human Keratinocytes ◽  
Matrix Deposition

AbstractThe long-term expansion of keratinocytes under conditions that avoid xenogeneic components (i.e. animal serum- and feeder cell-free) generally causes diminished proliferation and increased terminal differentiation. Here we present a culture system free of xenogeneic components that retains the self-renewal capacity of primary human keratinocytes. In vivo the extracellular matrix (ECM) of the tissue microenvironment has a major influence on a cell’s fate. We used ECM from human dermal fibroblasts, cultured under macromolecular crowding conditions to facilitate matrix deposition and organisation, in a xenogeneic-free keratinocyte expansion protocol. Phospholipase A2 decellularisation produced ECM whose components resembled the core matrix composition of natural dermis by proteome analyses. Keratinocytes proliferated rapidly on these matrices, retained their small size, expressed p63, lacked keratin 10 and rarely expressed keratin 16. The colony forming efficiency of these keratinocytes was enhanced over that of keratinocytes grown on collagen I, indicating that dermal fibroblast-derived matrices maintain the in vitro expansion of keratinocytes in a stem-like state. Keratinocyte sheets formed on such matrices were multi-layered with superior strength and stability compared to the single-layered sheets formed on collagen I. Thus, keratinocytes expanded using our xenogeneic-free protocol retained a stem-like state, but when triggered by confluence and calcium concentration, they stratified to produce epidermal sheets with a potential clinical use.

scholarly journals Modulation of intracellular calcium levels inhibits secretion of collagenase 1 by migrating keratinocytes.

1997 ◽  
Vol 8 (5) ◽  
pp. 811-824 ◽  
Author(s):  
B D Sudbeck ◽  
B K Pilcher ◽  
A P Pentland ◽  
W C Parks
Keyword(s):  
Intracellular Calcium ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Mrna Levels ◽  
Basal Cells ◽  
Primary Human Keratinocytes ◽  
Protein Levels ◽  
Differentiated Cells ◽  
Keratin 14

Calcium concentration influences keratinocyte differentiation, and, following injury, keratinocytes move through an environment of changing calcium levels. Because these migrating cells in wounds invariably express collagenase 1, we assessed if modulation of calcium levels regulates collagenase 1 production by primary human keratinocytes. Accurately reflecting the confined spatial pattern of enzyme production seen in vivo, collagenase 1 mRNA was expressed only by keratinocytes migrating from foci of differentiated cells. Treatment with calcium ionophores A23187 or thapsigargin markedly inhibited the basal and phorbol 12-myristate 13-acetate-(PMA) stimulated accumulation of keratinocyte collagenase 1 in the medium but did not affect collagenase 1 production by control or PMA-treated fibroblasts. A23187-mediated inhibition of collagenase 1 protein was not associated with a decrease in mRNA levels but rather was controlled by a selective and reversible block of enzyme secretion. This block in secretion was likely not due to altered protein folding as the proenzyme within A23187-treated cells remained capable of autolytic activation upon treatment with p-aminophenylmercuric acetate. In contrast, 92-kDa gelatinase mRNA and secreted protein levels were coordinately reduced by A23187. Keratin 14 expression, a basal keratinocyte marker, was reduced with PMA treatment, but A23187 did not affect keratin 14 expression. In human wounds, both basal and suprabasal keratinocytes at the migrating front of epidermis stained for keratin 14, but only the basal cells expressed collagenase 1. These data suggest that collagenase 1 production is not necessarily linked with expression of basal cell markers and that modulation of intracellular calcium levels can block secretion of collagenase 1 by keratinocytes which have moved away from the stratum basalis and from their natural substrate.

scholarly journals Embryonic fibroblast motility and orientation can be influenced by physiological electric fields.

1984 ◽  
Vol 98 (1) ◽  
pp. 296-307 ◽  
Author(s):  
C A Erickson ◽  
R Nuccitelli
Keyword(s):  
Field Strength ◽  
Electric Fields ◽  
Threshold Field ◽  
Voltage Gradient ◽  
Ion Currents ◽  
Embryonic Cells ◽  
Field Lines ◽  
Epithelial Layers ◽  
Embryonic Fibroblast

Epithelial layers in developing embryos are known to drive ion currents through themselves that will, in turn, generate small electric fields within the embryo. We hypothesized that the movement of migratory embryonic cells might be guided by such fields, and report here that embryonic quail somite fibroblast motility can be strongly influenced by small DC electric fields. These cells responded to such fields in three ways: (a) The cells migrated towards the cathodal end of the field by extending lamellipodia in that direction. The threshold field strength for this galvanotaxis was between 1 and 10 mV/mm when the cells were cultured in plasma. (b) The cells oriented their long axes perpendicular to the field lines. The threshold field strength for this response for a 90-min interval in the field was 150 mV/mm in F12 medium and between 50 and 100 mV/mm in plasma. (c) The cells elongated under the influence of field strengths of 400 mV/mm and greater. These fibroblasts were therefore able to detect a voltage gradient at least as low as 0.2 mV across their width. Electric fields of at least 10-fold larger in magnitude than this threshold field have been detected in vivo in at least one vertebrate thus far, so we believe that these field effects encompass a physiological range.

scholarly journals Expression of membrane type 1 matrix metalloproteinase in papillomavirus-positive cells: role of the human papillomavirus (HPV) 16 and HPV8 E7 gene products

2005 ◽  
Vol 86 (5) ◽  
pp. 1291-1296 ◽  
Author(s):  
Sigrun Smola-Hess ◽  
Jenny Pahne ◽  
Cornelia Mauch ◽  
Paola Zigrino ◽  
Hans Smola ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Cellular Proliferation ◽  
Human Keratinocytes ◽  
Hpv Infection ◽  
Host Cells ◽  
Primary Human Keratinocytes ◽  
E7 Gene ◽  
Membrane Type

Matrix metalloproteinases (MMPs) degrade extracellular matrix. They are involved in cellular proliferation, migration, angiogenesis, invasion and metastasis. MT-1 MMP, a membrane-bound MMP, is expressed in carcinomas of the uterine cervix in vivo. This type of cancer is associated with human papillomavirus (HPV) infection. Here it was shown that keratinocytes transformed with HPV16 or HPV18 in vitro, and HPV-positive cervical carcinoma cell lines, constitutively expressed MT-1 MMP. Expression of the E7 protein from the mucosal and cutaneous high-risk types HPV16 and HPV8, but not from the cutaneous low-risk type HPV1, was sufficient to induce MT-1 MMP expression in primary human keratinocytes and HaCaT cells. As a consequence, MMP-2 was activated. MT-1 MMP expression might play a role in the HPV life cycle by promoting proliferation of host cells and might contribute to their invasive phenotype during malignant progression.

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