scholarly journals Keratins as an Inflammation Trigger Point in Epidermolysis Bullosa Simplex

2021 ◽  
Vol 22 (22) ◽  
pp. 12446
Author(s):  
Nadezhda A. Evtushenko ◽  
Arkadii K. Beilin ◽  
Anastasiya V. Kosykh ◽  
Ekaterina A. Vorotelyak ◽  
Nadya G. Gurskaya
Keyword(s):  
Er Stress ◽  
Epidermolysis Bullosa ◽  
Trigger Point ◽  
Basal Layer ◽  
Sterile Inflammation ◽  
Global Changes ◽  
Epidermolysis Bullosa Simplex ◽  
Molecular Pattern ◽  
Signaling Activation ◽  
Cellular Pathology

Epidermolysis bullosa simplex (EBS) is a group of inherited keratinopathies that, in most cases, arise due to mutations in keratins and lead to intraepidermal ruptures. The cellular pathology of most EBS subtypes is associated with the fragility of the intermediate filament network, cytolysis of the basal layer of the epidermis, or attenuation of hemidesmosomal/desmosomal components. Mutations in keratins 5/14 or in other genes that encode associated proteins induce structural disarrangements of different strengths depending on their locations in the genes. Keratin aggregates display impaired dynamics of assembly and diminished solubility and appear to be the trigger for endoplasmic reticulum (ER) stress upon being phosphorylated by MAPKs. Global changes in cellular signaling mainly occur in cases of severe dominant EBS mutations. The spectrum of changes initiated by phosphorylation includes the inhibition of proteasome degradation, TNF-α signaling activation, deregulated proliferation, abnormal cell migration, and impaired adherence of keratinocytes. ER stress also leads to the release of proinflammatory danger-associated molecular pattern (DAMP) molecules, which enhance avalanche-like inflammation. Many instances of positive feedback in the course of cellular stress and the development of sterile inflammation led to systemic chronic inflammation in EBS. This highlights the role of keratin in the maintenance of epidermal and immune homeostasis.

scholarly journals A function for keratins and a common thread among different types of epidermolysis bullosa simplex diseases.

1991 ◽  
Vol 115 (6) ◽  
pp. 1661-1674 ◽  
Author(s):  
P A Coulombe ◽  
M E Hutton ◽  
R Vassar ◽  
E Fuchs
Keyword(s):  
Transgenic Mice ◽  
Basal Cell ◽  
Epidermolysis Bullosa ◽  
Single Gene ◽  
Basal Layer ◽  
Structural Function ◽  
Epidermolysis Bullosa Simplex ◽  
Physical Trauma ◽  
Keratin Filament ◽  
Filament Network

Previously we demonstrated that transgenic mice expressing a mutant keratin in the basal layer of their stratified squamous epithelia exhibited a phenotype bearing resemblance to a subclass (Dowling Meara) of a heterogeneous group of human skin disorders known as epidermolysis bullosa simplex (EBS) (Vassar, R., P. A. Coulombe, L. Degenstein, K. Albers, E. Fuchs. 1991. Cell. 64:365-380.). The extent to which subtypes of EBS diseases might be genetically related is unknown, although they all exhibit skin blistering as a consequence of basal cell cytolysis. We have now examined transgenic mice expressing a range of keratin mutants which perturb keratin filament assembly to varying degrees. We have generated phenotypes which include most subtypes of EBS, demonstrating for the first time that at least in mice, these diseases can be generated by different mutations within a single gene. A strong correlation existed between the severity of the disease and the extent to which the keratin filament network was disrupted, implicating perturbations in keratin networks as an essential component of these diseases. Some keratin mutants elicited subtle perturbations, with no signs of the tonofilament clumping typical of Dowling-Meara EBS and our previous transgenic mice. Importantly, basal cell cytolysis still occurred, thereby uncoupling cytolysis from the generation of large, insoluble cytoplasmic protein aggregates. Moreover, cell rupture occurred in a narrowly defined subnuclear zone, and seemed to involve three factors: (a) filament perturbation, (b) the columnar shape of the basal cell, and (c) physical trauma. This work provides the best evidence to date for a structural function of a cytoplasmic intermediate filament network, namely to impart mechanical integrity to the cell in the context of its tissue.

scholarly journals Role of Jagged1-mediated Notch Signaling Activation in the Differentiation and Stratification of the Human Limbal Epithelium

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1945
Author(s):  
Sheyla González ◽  
Maximilian Halabi ◽  
David Ju ◽  
Matthew Tsai ◽  
Sophie X. Deng
Keyword(s):  
Notch Signaling ◽  
Progenitor Cell ◽  
Basal Layer ◽  
Notch Signaling Pathway ◽  
Basal Cells ◽  
Proliferation Markers ◽  
Limbal Epithelium ◽  
Asymmetric Divisions ◽  
Signaling Activation

The Notch signaling pathway plays a key role in proliferation and differentiation. We investigated the effect of Jagged 1 (Jag1)-mediated Notch signaling activation in the human limbal stem/progenitor cell (LSC) population and the stratification of the limbal epithelium in vitro. After Notch signaling activation, there was a reduction in the amount of the stem/progenitor cell population, epithelial stratification, and expression of proliferation markers. There was also an increase of the corneal epithelial differentiation. In the presence of Jag1, asymmetric divisions were decreased, and the expression pattern of the polarity protein Par3, normally present at the apical-lateral membrane of basal cells, was dispersed in the cells. We propose a mechanism in which Notch activation by Jag1 decreases p63 expression at the basal layer, which in turn reduces stratification by decreasing the number of asymmetric divisions and increases differentiation.

scholarly journals Gastrostomy for infants with severe epidermolysis bullosa simplex in neonatal intensive care

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
M. Marro ◽  
S. De Smet ◽  
D. Caldari ◽  
C. Lambe ◽  
S. Leclerc-Mercier ◽  
...  
Keyword(s):  
Intensive Care ◽  
Epidermolysis Bullosa ◽  
Neonatal Intensive Care ◽  
Nutrition Support ◽  
Epidermolysis Bullosa Simplex ◽  
Withdrawal Time ◽  
Multicentric Study ◽  
Nasogastric Tubes ◽  
Mucosal Involvement ◽  
Enteral Nutrition Support

Abstract Introduction Severe epidermolysis bullosa simplex (EBS sev) is a rare genodermatosis characterized by congenital generalized blistering and mucosal involvement. Increased needs and decreased intake quickly lead to nutritional imbalance. Enteral nutrition support is proposed, but classical nasogastric tubes are not well tolerated in these patients and gastrostomy is preferred. Objective and methods To report the experience with EBS sev in neonatal units of French reference centers for gastrostomy. In this retrospective multicentric study, we included all patients with EBS sev who had gastrostomy placement before age 9 months during neonatal care hospitalization. Results Nine infants (5 males/4 females) with severe skin and mucosal involvement were included. A gastrostomy was decided, at an early age (mean 3.7 months, range 1.4 to 8 months) in infants with mean weight 4426 g (range 3500 to 6000 g). Techniques used were endoscopy with the pull technique for 5 infants and surgery under general anesthesia for 4. Main complications were local but resolved after treatment. All infants gained weight after gastrostomy. The mean withdrawal time (n = 7) for the gastrostomy was 35.8 months (range 10.5 months to 6.5 years). Seven children had persistent oral disorders. Conclusions Gastrostomy in infants with EBS sev can be necessary in neonatal intensive care units. Both surgical and endoscopic pull techniques seem efficient, with good tolerance.

A recurrent keratin 14 mutation in Dowling-Meara epidermolysis bullosa simplex

1999 ◽  
Vol 141 (4) ◽  
pp. 747-748 ◽  
Author(s):  
Sasaki ◽  
Shimizu ◽  
Akiyama ◽  
Hiraoka ◽  
Takizawa ◽  
...  
Keyword(s):  
Epidermolysis Bullosa ◽  
Epidermolysis Bullosa Simplex ◽  
Keratin 14
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