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Preclinical validation of PKC412 as a therapy candidate for epidermolysis bullosa simplex across multiple keratin
Henriette Jopp1, Alexander Kraft2, Bernd Hoffmann3
1Division of Cell and Developmental Biology, Institute of Biology, Leipzig University, Leipzig, Germany.
Background:
Epidermolysis bullosa simplex (EBS) is a hereditary skin fragility disorder caused by missense pathogenic variants in KRT5 or KRT14. These variants trigger the collapse of the cytoskeleton into cytoplasmic protein aggregates, rendering the epidermis highly susceptible to mechanical stress, leading to intraepidermal blistering and the loss of intercellular cohesion. No molecular therapies for EBS currently exist.
Objectives:
To characterize keratin 5 (K5) or keratin 14 (K14) mutant keratinocytes from patients with EBS in response to PKC412 treatment in monolayer culture and epidermal equivalents, to clarify the potential of PKC412 as a drug repurposing therapy approach in EBS.
Methods:
We conducted a comprehensive characterization of K5 and K14 mutant keratinocytes in response to PKC412, examining its effects on proliferation, wound closure and apoptosis. Additionally, we evaluated the improvement of intercellular cohesion through stretch assays, epithelial sheet assays and assessment of desmosomal organization. Finally, we investigated the efficacy of PKC412 application both in skin explants and EBS-derived epidermal equivalent cultures.
Results:
We found that PKC412 is effective in various keratinocytes carrying pathogenic variants associated with localized, generalized or intermediate forms of EBS. PKC412 enhanced intercellular adhesion both in immortalized healthy and EBS keratinocytes, as well as healthy primary keratinocytes, and under stretch conditions. Immunoblot analyses revealed a concentration-dependent reduction in desmoplakin phosphorylation, which remained stable over the course of 3 days at the sites investigated. Additionally, application of PKC412 in epidermal equivalent cultures restored desmoplakin distribution in the epidermal basal layer.
Conclusions:
PKC412 markedly enhanced intercellular cohesion and stress resilience in patient-derived EBS keratinocytes, both in monolayer and three-dimensional culture systems. These findings highlight PKC412 as a promising therapeutic candidate for the treatment of EBS.
Insights
PKC412 significantly improved skin cell adhesion and resilience in Epidermolysis Bullosa Simplex (EBS) models. This suggests PKC412 is a promising therapeutic candidate for treating EBS, a rare genetic skin disorder.
Area of Science:
- Dermatology and Genetic Skin Disorders
- Molecular Biology and Cell Signaling
- Drug Repurposing and Translational Medicine
Background:
- Epidermolysis Bullosa Simplex (EBS) is a severe inherited skin fragility disorder.
- Caused by mutations in KRT5 or KRT14 genes, leading to epidermal blistering and loss of cohesion.
- Currently, no effective molecular therapies exist for EBS.
Purpose of the Study:
- To investigate the therapeutic potential of PKC412 for Epidermolysis Bullosa Simplex (EBS).
- To characterize the effects of PKC412 on keratin 5 (K5) and keratin 14 (K14) mutant keratinocytes.
- To evaluate PKC412 as a potential drug repurposing strategy for EBS.
Main Methods:
- Comprehensive characterization of K5/K14 mutant keratinocytes with PKC412 treatment.
- Assessed proliferation, wound closure, and apoptosis.
- Evaluated intercellular cohesion using stretch assays, epithelial sheet assays, and desmosomal organization analysis.
- Tested PKC412 efficacy in skin explants and epidermal equivalent cultures.
Main Results:
- PKC412 demonstrated efficacy across various EBS keratinocyte types.
- Enhanced intercellular adhesion in healthy and EBS keratinocytes, even under mechanical stress.
- Reduced desmoplakin phosphorylation and restored its distribution in epidermal basal layers.
- PKC412 improved stress resilience and cohesion in patient-derived EBS keratinocytes.
Conclusions:
- PKC412 significantly enhances intercellular cohesion and stress resilience in EBS keratinocytes.
- Demonstrated efficacy in both monolayer and 3D culture systems.
- PKC412 emerges as a promising therapeutic candidate for Epidermolysis Bullosa Simplex treatment.
