scholarly journals Addressing differentiation in live human keratinocytes by assessment of membrane packing order

2020 ◽  
Author(s):  
Danuta Gutowska-Owsiak ◽  
Christian Eggeling ◽  
Graham S Ogg ◽  
Jorge Bernardino de la Serna
Keyword(s):  
Stratum Corneum ◽  
Single Cell ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Dead Cell ◽  
Differentiation Markers ◽  
Complex Processes ◽  
Impermeable Barrier ◽  
Therapeutic Development ◽  
Polarity Sensitive

Differentiation of keratinocytes is critical for epidermal stratification and formation of a protective stratum corneum. It involves a series of complex processes leading through gradual changes in characteristics and functions of keratinocytes up to their programmed cell death via cornification. The stratum corneum is an impermeable barrier, comprised of dead cell remnants (corneocytes) embedded within lipid matrix. Corneocyte membranes are comprised of specialized lipids linked to late differentiation proteins, contributing to the formation of a highly stiff and mechanically strengthen layer. To date, the assessment of the progression of keratinocyte differentiation is only possible by determination of specific differentiation markers, e.g. by using proteomics-based approaches. Unfortunately, this requires fixation or cell lysis, and currently there is no robust methodology available to study differentiation in living cells, neither at a single cell, nor in high throughput. Here, we explore a new live-cell based approaches for screening differentiation advancement in keratinocytes, in a “calcium switch” model. We employ a polarity-sensitive dye, Laurdan, and Laurdan general polarization function (GP) as a reporter of the degree of membrane lateral packing order or condensation, as an adequate marker of differentiation. We show that the assay is straightforward and can be conducted either on a single cell level using confocal spectral imaging or on the ensemble level using a fluorescence plate reader. Such systematic quantification may become useful for understanding mechanisms of keratinocyte differentiation, such as the role of membrane inhomogeneities in stiffness, and for future therapeutic development.

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 Phosphoprotein Phosphatase 1 Is Required for Extracellular Calcium-Induced Keratinocyte Differentiation

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chandrama Shrestha ◽  
Yuanyuan Tang ◽  
Hong Fan ◽  
Lusha Li ◽  
Qin Zeng ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Second Messengers ◽  
Human Keratinocytes ◽  
Extracellular Calcium ◽  
Keratinocyte Differentiation ◽  
Differentiation Markers ◽  
Calcium Stimulation ◽  
E Cadherin

Extracellular calcium is a major regulator of keratinocyte differentiation in vitro and appears to play that role in vivo, but the mechanism is unclear. We have previously demonstrated that, following calcium stimulation, PIP5K1αis recruited by the E-cadherin-β-catenin complex to the plasma membrane where it provides the substrate PIP2 for both PI3K and PLC-γ1. This signaling pathway is critical for calcium-induced generation of second messengers including IP3 and intracellular calcium and keratinocyte differentiation. In this study, we explored the upstream regulatory mechanism by which calcium activates PIP5K1αand the role of this activation in calcium-induced keratinocyte differentiation. We found that treatment of human keratinocytes in culture with calcium resulted in an increase in serine dephosphorylation and PIP5K1αactivation. PP1 knockdown blocked extracellular calcium-induced increase in serine dephosphorylation and activity of PIP5K1αand induction of keratinocyte differentiation markers. Knockdown of PLC-γ1, the downstream effector of PIP5K1α, blocked upstream dephosphorylation and PIP5K1αactivation induced by calcium. Coimmunoprecipitation revealed calcium induced recruitment of PP1 to the E-cadherin-catenin-PIP5K1αcomplex in the plasma membrane. These results indicate that PP1 is recruited to the extracellular calcium-dependent E-cadherin-catenin-PIP5K1αcomplex in the plasma membrane to activate PIP5K1α, which is required for PLC-γ1 activation leading to keratinocyte differentiation.

scholarly journals Phosphatidylinositol-4-phosphate 5-kinase 1α Mediates Extracellular Calcium-induced Keratinocyte Differentiation

2009 ◽  
Vol 20 (6) ◽  
pp. 1695-1704 ◽  
Author(s):  
Zhongjian Xie ◽  
Sandra M. Chang ◽  
Sally D. Pennypacker ◽  
Er-Yuan Liao ◽  
Daniel D. Bikle
Keyword(s):  
Plasma Membrane ◽  
Second Messengers ◽  
Human Keratinocytes ◽  
Extracellular Calcium ◽  
Keratinocyte Differentiation ◽  
Activity Levels ◽  
Differentiation Markers ◽  
Resultant Increase ◽  
Phosphatidylinositol 4 ◽  
E Cadherin

Extracellular calcium (Cao) is a major regulator of keratinocyte differentiation, but the mechanism is unclear. Phosphatidylinositol-4-phosphate 5-kinase 1α (PIP5K1α) is critical in synthesizing phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. In this study, we sought to determine whether PIP5K1α plays a role in mediating the ability of Cao to induce keratinocyte differentiation. We found that treatment of human keratinocytes in culture with Cao resulted in increased PIP5K1α level and activity, as well as PI(4,5)P2 level, binding of phosphatidylinositol 3,4,5-triphosphate [PI(3,4,5)P3] to and activation of phospholipase C-γ1 (PLC-γ1), with the resultant increase in inositol 1,4,5-trisphosphate (IP3) and intracellular calcium (Cai). Knockdown of PIP5K1α in human keratinocytes blocked Cao-induced increases in the binding of PI(3,4,5)P3 to PLC-γ1; PLC-γ1 activity; levels of PI(4,5)P2, IP3, and Cai; and induction of keratinocyte differentiation markers. Coimmunoprecipitation and confocal studies revealed that Cao stimulated PIP5K1α recruitment to the E-cadherin–catenin complex in the plasma membrane. Knockdown of E-cadherin or β-catenin blocked Cao-induced activation of PIP5K1α. These results indicate that after Cao stimulation PIP5K1α is recruited by the E-cadherin–catenin complex to the plasma membrane where it provides the substrate PI(4,5)P2 for both PI3K and PLC-γ1. This signaling pathway is critical for Cao-induced generation of the second messengers IP3 and Cai and keratinocyte differentiation.

scholarly journals 2-APB arrests human keratinocyte proliferation and inhibits cutaneous squamous cell carcinomain vitro

2018 ◽  
Author(s):  
Aislyn M. Nelson ◽  
Yalda Moayedi ◽  
Sophie A. Greenberg ◽  
Marlon E. Ruiz ◽  
Uffe B. Jensen ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Risk ◽  
Cell Lines ◽  
Squamous Cell ◽  
Transient Receptor Potential ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Differentiation Markers ◽  
Keratinocyte Proliferation ◽  
Human Keratinocyte

AbstractBackgroundThe epidermis is a stratified epithelium whose differentiation program is triggered in part by calcium. Dysregulation of keratinocyte differentiation may lead to non-melanoma skin cancers, including cutaneous squamous cell carcinoma (cSCC). The compound 2-aminoethoxydiphenyl borate (2-APB) modulates calcium signaling by altering activity of calcium-permeable channels of the transient receptor potential (TRP) and ORAI families, and is therefore poised to govern signaling pathways that control the balance of keratinocyte proliferation and differentiation.ObjectiveWe sought to determine whether 2-APB alters differentiation of normal human keratinocytes and progression of human cSCCs modelsin vitro.MethodsPrimary human keratinocyte cultures were treated with 2-APB and levels of proliferation (EdU incorporation) and differentiation markers [quantitative PCR (qPCR)] were assessed. Human cSCC biopsies and cell lines were analyzed for TRP and ORAI gene expression via qPCR. cSCC cell lines were cultured in organtypic cultures and analyzed for growth and invasiveness after 2-APB or vehicle treatment.ResultsCulturing human keratinocytes with 2-APB arrested cell proliferation, triggered differentiation-gene expression and altered epidermal stratification, indicating that 2-APB application is sufficient to promote differentiation. In human organotypic cSCC cultures, 2-APB attenuated tumor growth and invasiveness. Finally, expression of a panel of 2-APB-targeted ion channels (TRPV3, TRPV1, TRPC1, OraI1, OraI2 and OraI3) was dysregulated in high-risk cSCC biopsies.ConclusionsCollectively, these findings identify 2-APB as a potential therapeutic for high-risk cSCCs.

scholarly journals Microfluidic Based Physical Approaches towards Single-Cell Intracellular Delivery and Analysis

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 631
Author(s):  
Kiran Kaladharan ◽  
Ashish Kumar ◽  
Pallavi Gupta ◽  
Kavitha Illath ◽  
Tuhin Subhra Santra ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Biology ◽  
Transfection Efficiency ◽  
Intracellular Delivery ◽  
Diagnostic Tools ◽  
Delivery Methods ◽  
Physical Methods ◽  
Cell Measurement ◽  
Therapeutic Development ◽  
Single Living

The ability to deliver foreign molecules into a single living cell with high transfection efficiency and high cell viability is of great interest in cell biology for applications in therapeutic development, diagnostics, and drug delivery towards personalized medicine. Various physical delivery methods have long demonstrated the ability to deliver cargo molecules directly to the cytoplasm or nucleus and the mechanisms underlying most of the approaches have been extensively investigated. However, most of these techniques are bulk approaches that are cell-specific and have low throughput delivery. In comparison to bulk measurements, single-cell measurement technologies can provide a better understanding of the interactions among molecules, organelles, cells, and the microenvironment, which can aid in the development of therapeutics and diagnostic tools. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great interest. In recent years, single-cell technologies have become increasingly robust and accessible, although limitations exist. This review article aims to cover various microfluidic-based physical methods for single-cell intracellular delivery such as electroporation, mechanoporation, microinjection, sonoporation, optoporation, magnetoporation, and thermoporation and their analysis. The mechanisms of various physical methods, their applications, limitations, and prospects are also elaborated.

scholarly journals Eucalyptus citriodora extract regulates cutaneous homeostasis including immune dysregulation and skin barrier dysfunction via the modulation of peroxisome proliferator-activated receptor-delta (PPAR-delata) pathway

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Akihiro Aioi ◽  
Takuhiro Yamada
Keyword(s):  
Mrna Expression ◽  
Skin Barrier ◽  
Immune Dysregulation ◽  
Keratinocyte Differentiation ◽  
Hacat Cells ◽  
Skin Disorders ◽  
Eucalyptus Citriodora ◽  
Barrier Dysfunction ◽  
Differentiation Markers ◽  
Transfected Cells

Perturbation of cutaneous homeostasis including immune dysregulation and skin barrier dysfunction evokes skin disorders. In this study, we examined the effect of Eucalyptus citriodora (Euc-c) extract on cytokine production, cell proliferation and cell differentiation in HaCaT cells to elucidate its influence on cutaneous homeostasis. Euc-c suppressed significantly LPS-induced IL-6 and TNF-a-induced IL-8 production from HaCaT cells. Conversely IL-1ra production was significantly enhanced by Euc-c. The expressions of IVL, CERS3 and CERS4, keratinocyte differentiation markers, were upregulated to 3.1, 2.8 and 2.7-fold respectively by Euc-c treatment, compared to the control, while the proliferation was downregulated. The lipid contents in Euc-c-treated cells tended to increase, compared with non-treated cells. To explore the underlying mechanism of these effect, we next performed siRNA experiments against PPAR-b/d. Euc-c enhanced PPAR-b/d mRNA expression to 3.25-fold, while PPAR-b/d mRNA expression in transfected cells was suppressed. The expressions of IVL, CERS3 and CERS4 in transfected cells were suppressed to 1.48, 0.82 and 0.72-fold respectively, concomitant with suppression of PPAR-b/d mRNA expression. These results indicated that Euc-c exerts anti-inflammatory effects and regulates keratinocyte differentiation via the modulation of PPAR-b/d pathway. Therefore, the application of Euc-c is expected to exert beneficial effect on skin disorders evoked by perturbation of skin homeostasis.Key words: Eucalyptus citriodora, PPAR-b/d, inflammation, barrier function, cutaneous homeostasis

The hSkn-1a POU transcription factor enhances epidermal stratification by promoting keratinocyte proliferation

2001 ◽  
Vol 114 (10) ◽  
pp. 1913-1923 ◽  
Author(s):  
J. Hildesheim ◽  
U. Kuhn ◽  
C.L. Yee ◽  
R.A. Foster ◽  
K.B. Yancey ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Human Keratinocytes ◽  
Dominant Negative ◽  
Keratinocyte Differentiation ◽  
Transactivation Domain ◽  
Hacat Keratinocytes ◽  
Primary Human Keratinocytes ◽  
Keratinocyte Proliferation ◽  
Proliferation And Differentiation ◽  
Epidermal Homeostasis

Skn-1a is a POU transcription factor that is primarily expressed in the epidermis and is known to modulate the expression of several genes associated with keratinocyte differentiation. However, the formation of a stratified epidermis requires a carefully controlled balance between keratinocyte proliferation and differentiation, and a role for Skn-1a in this process has not been previously demonstrated. Here, our results show, surprisingly, that human Skn-1a contributes to epidermal stratification by primarily promoting keratinocyte proliferation and secondarily by enhancing the subsequent keratinocyte differentiation. In organotypic raft cultures of both primary human keratinocytes and immortalized HaCaT keratinocytes, human Skn-1a expression is associated with increased keratinocyte proliferation and re-epithelialization of the dermal substrates, resulting in increased numbers of keratinocytes available for the differentiation process. In these same raft cultures, human Skn-1a expression enhances the phenotypic changes of keratinocyte differentiation and the upregulated expression of keratinocyte differentiation genes. Conversely, expression of a dominant negative human Skn-1a transcription factor lacking the C-terminal transactivation domain blocks keratinocytes from proliferating and stratifying. Keratinocyte stratification is dependent on a precise balance between keratinocyte proliferation and differentiation, and our results suggest that human Skn-1a has an important role in maintaining epidermal homeostasis by promoting keratinocyte proliferation.

Single cell analysis of bradykinin-induced calcium response in human keratinocytes

1991 ◽  
Vol 2 (3) ◽  
pp. 226
Author(s):  
Y. Sato ◽  
H. Takagi ◽  
M. Seishima ◽  
S. Mori ◽  
Y. Nozawa
Keyword(s):  
Single Cell ◽  
Single Cell Analysis ◽  
Human Keratinocytes ◽  
Cell Analysis ◽  
Calcium Response

scholarly journals Noncanonical NOTCH Signaling Limits Self-Renewal of Human Epithelial and Induced Pluripotent Stem Cells through ROCK Activation

2013 ◽  
Vol 33 (22) ◽  
pp. 4434-4447 ◽  
Author(s):  
Takashi Yugawa ◽  
Koichiro Nishino ◽  
Shin-ichi Ohno ◽  
Tomomi Nakahara ◽  
Masatoshi Fujita ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Human Keratinocytes ◽  
Small Gtpase ◽  
Keratinocyte Differentiation ◽  
Growth Defect ◽  
Self Renewal ◽  
Induced Pluripotent

NOTCH plays essential roles in cell fate specification during embryonic development and in adult tissue maintenance. In keratinocytes, it is a key inducer of differentiation. ROCK, an effector of the small GTPase Rho, is also implicated in keratinocyte differentiation, and its inhibition efficiently potentiates immortalization of human keratinocytes and greatly improves survival of dissociated human pluripotent stem cells. However, the molecular basis for ROCK activation is not fully established in these contexts. Here we provide evidence that intracellular forms of NOTCH1 trigger the immediate activation of ROCK1 independent of its transcriptional activity, promoting differentiation and resulting in decreased clonogenicity of normal human keratinocytes. Knockdown of NOTCH1 abrogated ROCK1 activation and conferred sustained clonogenicity upon differentiation stimuli. Treatment with a ROCK inhibitor, Y-27632, or ROCK1 silencing substantially rescued the growth defect induced by activated NOTCH1. Furthermore, we revealed that impaired self-renewal of human induced pluripotent stem cells upon dissociation is, at least in part, attributable to NOTCH-dependent ROCK activation. Thus, the present study unveils a novel NOTCH-ROCK pathway critical for cellular differentiation and loss of self-renewal capacity in a subset of immature cells.

scholarly journals Human epidermal stem cell differentiation is modulated by specific lipid subspecies

2020 ◽  
Vol 117 (36) ◽  
pp. 22173-22182
Author(s):  
Matteo Vietri Rudan ◽  
Ajay Mishra ◽  
Christian Klose ◽  
Ulrike S. Eggert ◽  
Fiona M. Watt
Keyword(s):  
Stem Cell ◽  
Stem Cell Differentiation ◽  
Human Keratinocytes ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Fatty Acid Transport ◽  
Epidermal Stem Cell ◽  
Primary Human Keratinocytes ◽  
Induced Differentiation ◽  
Lipid Species

While the lipids of the outer layers of mammalian epidermis and their contribution to barrier formation have been extensively described, the role of individual lipid species in the onset of keratinocyte differentiation remains unknown. A lipidomic analysis of primary human keratinocytes revealed accumulation of numerous lipid species during suspension-induced differentiation. A small interfering RNA screen of 258 lipid-modifying enzymes identified two genes that on knockdown induced epidermal differentiation:ELOVL1, encoding elongation of very long-chain fatty acids protein 1, andSLC27A1, encoding fatty acid transport protein 1. By intersecting lipidomic datasets from suspension-induced differentiation and knockdown keratinocytes, we pinpointed candidate bioactive lipid subspecies as differentiation regulators. Several of these—ceramides and glucosylceramides—induced differentiation when added to primary keratinocytes in culture. Our results reveal the potential of lipid subspecies to regulate exit from the epidermal stem cell compartment.

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