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

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ajay Mishra ◽  
Bénédicte Oulès ◽  
Angela Oliveira Pisco ◽  
Tony Ly ◽  
Kifayathullah Liakath-Ali ◽  
...  
Keyword(s):  
Spatial Dynamics ◽  
Dynamic Network ◽  
Human Keratinocytes ◽  
Cell Renewal ◽  
Stable States ◽  
Primary Human Keratinocytes ◽  
Network Modelling ◽  
Epidermal Homeostasis

Epidermal homeostasis depends on a balance between stem cell renewal and terminal differentiation. The transition between the two cell states, termed commitment, is poorly understood. Here, we characterise commitment by integrating transcriptomic and proteomic data from disaggregated primary human keratinocytes held in suspension to induce differentiation. Cell detachment induces several protein phosphatases, five of which - DUSP6, PPTC7, PTPN1, PTPN13 and PPP3CA – promote differentiation by negatively regulating ERK MAPK and positively regulating AP1 transcription factors. Conversely, DUSP10 expression antagonises commitment. The phosphatases form a dynamic network of transient positive and negative interactions that change over time, with DUSP6 predominating at commitment. Boolean network modelling identifies a mandatory switch between two stable states (stem and differentiated) via an unstable (committed) state. Phosphatase expression is also spatially regulated in vivo and in vitro. We conclude that an auto-regulatory phosphatase network maintains epidermal homeostasis by controlling the onset and duration of commitment.

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):  
Spatial Dynamics ◽  
Human Keratinocytes ◽  
Cell Renewal ◽  
Primary Human Keratinocytes ◽  
Network Modelling ◽  
Proteomic Data ◽  
Stem Cell Renewal ◽  
Epidermal Homeostasis

AbstractEpidermal homeostasis depends on a balance between stem cell renewal and terminal differentiation. The transition between the two cell states, termed commitment, 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 to induce differentiation. We find that cell detachment induces a network of protein phosphatases. The pro-commitment phosphatases – including DUSP6, PPTC7, PTPN1, PTPN13 and PPP3CA – promote differentiation by negatively regulating ERK MAPK and positively regulating AP1 transcription factors. Their activity is antagonised by concomitant upregulation of DUSP10. Boolean network modelling of phosphatase interactions identifies commitment as an inherently unstable biological switch between the stem and differentiated cell states. Furthermore, phosphatase expression is spatially regulated both in vivo and in vitro. We conclude that an auto-regulatory phosphatase network maintains epidermal homeostasis by controlling the onset and duration of commitment.

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 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 Remodeling the Human Adult Stem Cell Niche for Regenerative Medicine Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Silvana Bardelli ◽  
Marco Moccetti
Keyword(s):  
Stem Cell ◽  
Regenerative Medicine ◽  
Translational Medicine ◽  
Process Development ◽  
Therapeutic Potential ◽  
Adult Stem Cell ◽  
Cell Renewal ◽  
Stem Cell Niches

The interactions between stem cells and their surrounding microenvironment are pivotal to determine tissue homeostasis and stem cell renewal or differentiation and regenerationin vivo. Ever since they were postulated in 1978, stem cell niches have been identified and characterized in many germline and adult tissues. Comprehensive studies over the last decades helped to clarify the critical components of stem cell niches that include cellular, extracellular, biochemical, molecular, and physical regulators. This knowledge has direct impact on their inherent regenerative potential. Clinical applications demand readily available cell sources that, under controlled conditions, provide a specific therapeutic function. Thus, translational medicine aims at optimizingin vitroorin vivothe various components and complex architecture of the niche to exploit its therapeutic potential. Accordingly, the objective is to recreate the natural niche microenvironment during cell therapy process development and closely comply with the requests of regulatory authorities. In this paper, we review the most recent advances of translational medicine approaches that target the adult stem cell natural niche microenvironment for regenerative medicine applications.

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.

Sign in / Sign up

Export Citation Format

Share Document