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Projekt Druckansicht

Dystrophe Epidermolysis bullosa: quantitative Proteom Untersuchungen zur Aufklärung molekularer Mechanismen

Fachliche Zuordnung Dermatologie
Biochemie
Förderung Förderung von 2012 bis 2020
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 219062131
 
Erstellungsjahr 2020

Zusammenfassung der Projektergebnisse

Dystrophic epidermolysis bullosa (DEB) is manifested by chronically fragile skin that becomes heavily fibrotic at exposed sites and establishes a microenvironment supportive of progression of metastatic cutaneous squamous cell carcinomas (cSCCs). DEB is caused by deficiency of the extracellular protein collagen VII, which assembles into large anchoring fibrils that are critical for firm epidermal-dermal cohesion. The genotype to phenotype correlation in DEB is weak, with affected individuals with the same mutation combinations showing disparate phenotypes. This indicates that factors outside the status of collagen VII heavily influence disease presentation and progression. Knowledge of such factors and mechanisms can be therapeutically exploited to provide symptom relief and decrease the severity of the disease. The aim of this collaborative project was to generate new knowledge about the molecular mechanisms dysregulated in DEB by identifying hitherto unknown proteins and genes involved in disease pathogenesis and phenotypic variability. We focused our work on cell-cell crosstalk, perturbed signal transduction and the role of inflammation in disease progression. By using complementary approaches from global to targeted analyses, in vitro as well as in vivo, our aim was to better understand clinical phenotypes in DEB and to link these phenotypes to molecular pathways, thus to establish an important prerequisite for the design of novel, causal molecular therapies. Using primary cells, we shed light onto dysregulated molecular mechanism in DEB, focusing on TGF-β signaling. Primary DEB keratinocytes facilitated fibrosis in DEB. Loss of collagen VII had extra- and intracellular consequences, resulting in keratinocyte-supported inflammatory processes and tissue destabilization. Mechanistic analysis of DEB fibroblasts demonstrated that latent TGF-β activation in DEB occurred through several mechanisms, including thrombospondin-1, RGD-binding integrins, matrix metalloproteinases and reactive oxygen species, which acted in concert, in a self-perpetuating feedback loop to progress fibrosis. We also identified several links between loss of collagen VII and altered immunity. Microenvironmental alterations increased bacterial challenges in DEB skin. Importantly, we identified collagen VII as member of the lymphoid extracellular matrix, its loss leading to an intrinsic innate immune dysfunction and perturbed defense against bacteria. Finally, we performed a detailed analysis of disease progression in DEB using a mouse model and highlighted that targeting of inflammatory immunity and stimulation of the renin-angiotensin system might be novel therapeutic approaches for treatment of injury- and inflammationinduced fibrosis.

Projektbezogene Publikationen (Auswahl)

 
 

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