PROTEIN EXPRESSION PATTERNS OF RADIATION-TRANSFORMED HUMAN EPIDERMAL KERATINOCYTES

Author(s):  
S. PRASAD ◽  
A. DRITSCHILO ◽  
J.S. RHIM ◽  
P. WORLAND ◽  
P.J. THRAVES
2015 ◽  
Vol 20 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Mohamed A. Adly ◽  
Hanan A. Assaf ◽  
Shaima’a F. Abdel-Rady ◽  
Nagwa Sayed Ahmed ◽  
Mahmoud Rezk Abdelwahed Hussein

Background: Vitiligo is an idiopathic skin disease, characterized by circumscribed white macules or patches on the skin due to loss of the functional melanocytes. Glial cell line–derived neurotrophic factor (GDNF) and its cognate receptor (GFRα-1) are distal members of the transforming growth factor-β superfamily. GDNF, produced by the basal cell keratinocytes, is involved in the migration and differentiation of the melanocytes from the neural crest to the epidermis. This study examines the hypothesis that expression of GDNF protein and its cognate receptor GFRα-1 protein is altered in vitiliginous skin. Patients and Methods: To test our hypothesis, we examined the expression patterns of these proteins in vitiliginous and corresponding healthy (control) skin biopsies (20 specimens each) using immunoperoxidase staining techniques. Results: We found variations between the vitiliginous skin and healthy skin. In healthy skin, the expression of GDNF and GFRα-1 proteins was strong (basal cell keratinocytes and melanocytes), moderate (spinous layer), and weak (granular cell layer). In contrast, weak expression of GDNF protein was observed in all epidermal layers of vitiliginous skin. GFRα-1 protein expression was strong (basal cell keratinocytes and melanocytes), moderate (spinous layer), and weak (granular cell layer). In both healthy skin and vitiliginous skin, the expression of GDNF and GFRα-1 proteins was strong in the adnexal structures. Conclusions: We report, for the first time, decreased expression of GDNF proteins in the epidermal keratinocytes of vitiliginous skin. Our findings suggest possible pathogenetic roles for these proteins in the development of vitiligo. The clinical ramifications of these observations mandate further investigations.


2018 ◽  
Vol 19 (10) ◽  
pp. 3072 ◽  
Author(s):  
Andrzej Slominski ◽  
Tae-Kang Kim ◽  
Zorica Janjetovic ◽  
Anna Brożyna ◽  
Michal Żmijewski ◽  
...  

A novel pathway of vitamin D activation by CYP11A has previously been elucidated. To define the mechanism of action of its major dihydroxy-products, we tested the divergence and overlap between the gene expression profiles of human epidermal keratinocytes treated with either CYP11A1-derived 20,23(OH)2D3 or classical 1,25(OH)2D3. Both secosteroids have significant chemical similarity with the only differences being the positions of the hydroxyl groups. mRNA was isolated and examined by microarray analysis using Illumina’s HumanWG-6 chip/arrays and subsequent bioinformatics analyses. Marked differences in the up- and downregulated genes were observed between 1,25(OH)2D3- and 20,23(OH)2D3-treated cells. Hierarchical clustering identified both distinct, opposite and common (overlapping) gene expression patterns. CYP24A1 was a common gene strongly activated by both compounds, a finding confirmed by qPCR. Ingenuity pathway analysis identified VDR/RXR signaling as the top canonical pathway induced by 1,25(OH)2D3. In contrast, the top canonical pathway induced by 20,23(OH)2D3 was AhR, with VDR/RXR being the second nuclear receptor signaling pathway identified. QPCR analyses validated the former finding by revealing that 20,23(OH)2D3 stimulated CYP1A1 and CYP1B1 gene expression, effects located downstream of AhR. Similar stimulation was observed with 20(OH)D3, the precursor to 20,23(OH)2D3, as well as with its downstream metabolite, 17,20,23(OH)3D3. Using a Human AhR Reporter Assay System we showed marked activation of AhR activity by 20,23(OH)2D3, with weaker stimulation by 20(OH)D3. Finally, molecular modeling using an AhR LBD model predicted vitamin D3 hydroxyderivatives to be good ligands for this receptor. Thus, our microarray, qPCR, functional studies and molecular modeling indicate that AhR is the major receptor target for 20,23(OH)2D3, opening an exciting area of investigation on the interaction of different vitamin D3-hydroxyderivatives with AhR and the subsequent downstream activation of signal transduction pathways in a cell-type-dependent manner.


2020 ◽  
Vol 40 (1) ◽  
pp. 113-123
Author(s):  
SJ Kim ◽  
X Zhang ◽  
SB Cho ◽  
CH Kim ◽  
HC Park ◽  
...  

Objectives: Uremic pruritus is common in patients with chronic kidney disease (CKD). The retention of uremic solutes is thought to be associated with uremic pruritus. Meanwhile, activation of protease-activated receptor-2 (PAR-2) has been suggested to play an important role in pruritus. The present study was performed to investigate the effects of uremic solutes on the expression of PAR-2 in the skin. Methods: Indoxyl sulfate (IS), p-cresol (PC), and uremic sera from CKD patients were used to stimulate PAR-2 expression in normal human epidermal keratinocytes (NHEKs). Also, NHEKs were additionally pretreated with soybean trypsin inhibitor to evaluate its inhibitory effect on PAR-2 expression. Patterns of cutaneous PAR-2 expression were investigated in skin samples from five CKD patients and CKD mice. Results: In NHEKs, IS, PC, and sera from CKD patients significantly induced PAR-2 mRNA and protein expression. Soybean trypsin inhibitor significantly decreased PAR-2 mRNA and protein expression in NHEKs treated with IS, PC, and CKD sera. NHEKs treated with IS and PC exhibited significant increases in protease activity. Skin from both CKD patients and mice exhibited marked upregulation of PAR-2 expression compared to control skin. Conclusions: Results from the present study suggest that uremic solutes either directly or indirectly affect PAR-2 expression in the skin of CKD subjects, potentially playing an important role in the pathogenesis of uremic pruritus.


2021 ◽  
Vol 22 (19) ◽  
pp. 10810
Author(s):  
Dema Ali ◽  
Dana Alhattab ◽  
Hanan Jafar ◽  
Malak Alzubide ◽  
Nour Sharar ◽  
...  

The stemness in keratinocyte stem cells (KSCs) is determined by their gene expression patterns. KSCs are crucial in maintaining epidermal homeostasis and wound repair and are widely used candidates for therapeutic applications. Although several studies have reported their positive identifiers, unique biomarkers for KSCs remain elusive. Here, we aim to identify potential candidate stem cell markers. Human epidermal keratinocytes (HEKs) from neonatal foreskin tissues were isolated and cultured. Single-cell clonal analysis identified and characterized three types of cells: KSCs (holoclones), transient amplifying cells (TACs; meroclones), and differentiated cells (DSCs; paraclones). The clonogenic potential of KSCs demonstrated the highest proliferation potential of KSCs, followed by TACs and DSCs, respectively. Whole-transcriptome analysis using microarray technology unraveled the molecular signatures of these cells. These results were validated by quantitative real-time polymerase chain reaction and flow cytometry analysis. A total of 301 signature upregulated and 149 downregulated differentially expressed genes (DEGs) were identified in the KSCs, compared to TACs and DSCs. Furthermore, DEG analyses revealed new sets of genes related to cell proliferation, cell adhesion, surface makers, and regulatory factors. In conclusion, this study provides a useful source of information for the identification of potential SC-specific candidate markers.


Author(s):  
John C. Bierman ◽  
Timothy Laughlin ◽  
Makio Tamura ◽  
Ben C. Hulette ◽  
Catherine E. Mack ◽  
...  

Daily exposure of skin to environmental stressors leads to molecular and morphological changes ascribed as premature aging. These stressors include solar radiation, industrial pollution, fossil fuel and carbon emissions, which cause cellular damage that induces an inflammatory response in skin. Several inflammatory components are known to be involved in triggering the senescence-associated secretory phenotype (SASP) which is known to accelerate aging. It is hypothesized that preventing induction of inflammation by environmental stressors can prevent premature aging. Since it is known that nicotinamide (Nam) has anti-inflammatory properties, we tested whether Nam can inhibit environmental stressor-induced inflammation. Exposure of keratinocytes to UVB, urban dust, diesel exhaust, and cigarette smoke extract stimulated production of the inflammatory mediators PGE2, IL-6, and IL-8 and induced gene expression patterns associated with apoptosis, DNA repair, and cell cycle control. In all cases, Nam treatment significantly inhibited these stress-induced responses. Nam also reduced IL-8 levels stimulated by the combination of topically applied particulate matter (PM2.5) and UV exposure in 3D skin equivalents. Under 5% 02 conditions that more closely mimic physiological 02 levels, Nam had a heightened inhibitory effect on UVB-induced PGE2 levels in keratinocytes. In a UV-challenge study, treatment with Nam reduced skin surface IL-1RA/IL-1 inflammatory biomarkers and erythema that were induced by solar simulated radiation. These findings provide a body of evidence that Nam can mitigate in part the skin’s inflammatory response elicited by exposure to environmental stressors. This supports the potential that Nam can inhibit premature aging and help maintain skin’s functionality and appearance.


Author(s):  
A. R. Crooker ◽  
M. C. Myers ◽  
T. L. Beard ◽  
E. S. Graham

Cell culture systems have become increasingly popular as a means of screening toxic agents and studying toxic mechanisms of drugs and other chemicals at the cellular and subcellular levels. These in vitro tests can be conducted rapidly in a broad range of relevant mammalian culture systems; a variety of biological and biochemical cytotoxicity endpoints can be examined. The following study utilized human keratinocytes to evaluate the relative cytotoxicities of nitrofurazone (NF) and silver sulfadiazine (SS), the active ingredients of FURACIN(R) Topical Cream and SILVADENE(R) Cream, respectively. These compounds are anti-infectives used in the treatment of burn patients. Cell ultrastructure and elemental composition were utilized as cytotoxicity endpoints.Normal Human Epidermal Keratinocytes (HK) were prepared from the EpiPackTM culture system (Clonetics Corporation, Boulder, CO). For scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cells were seeded on sterile 35 mm Falcon plastic dishes; for elemental microanalysis, cells were plated on polished pyrolytic carbon discs (E. Fullam, Latham, NY) placed in the culture dishes.


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