Mechanistic interrogation of mutation-independent disease modulators of RDEB identifies the small leucine-rich proteoglycan PRELP as a TGF-beta antagonist and inhibitor of fibrosis Articles uri icon

publication date

  • June 2022

start page

  • 189

end page

  • 206

volume

  • 111

International Standard Serial Number (ISSN)

  • 0945-053X

Electronic International Standard Serial Number (EISSN)

  • 1569-1802

abstract

  • Recessive dystrophic epidermolysis bullosa (RDEB) is a genetic extracellular matrix disease caused by deficiency in type VII collagen (Col VII). The disease manifests with devastating mucocutaneous fragility leading to progressive fibrosis and metastatic squamous cell carcinomas. Although Col VII abundance is considered the main predictor of symptom course, previous studies have revealed the existence of mutation-independent mechanisms that control disease progression. Here, to investigate and validate new molecular modifiers of wound healing and fibrosis in a natural human setting, and toward development of disease-modulating treatment of RDEB, we performed gene expression profiling of primary fibroblast from RDEB siblings with marked phenotypic variations, despite having equal COL7A1 genotype. Gene enrichment analysis suggested that severe RDEB was associated with enhanced response to TGFB stimulus, oxidoreductase activity, and cell contraction. Consistently, we found an increased response to TGFB, higher levels of basal and induced reactive oxygen species (ROS), and greater contractile ability in collagen lattices in RDEB fibroblasts (RDEBFs) from donors with severe RDEB vs mild RDEB. Treatment with antioxidants allowed a reduction of the pro-fibrotic and contractile phenotype. Importantly, our analyses revealed higher expression and deposition in skin of the relatively uncharacterized small leucine-rich extracellular proteoglycan PRELP/prolargin associated with milder RDEB manifestations. Mechanistic investigations showed that PRELP effectively attenuated fibroblasts' response to TGFB stimulus and cell contractile capacity. Moreover, PRELP overexpression in RDEBFs enhanced RDEB keratinocyte attachment to fibroblast-derived extracellular matrix in the absence of Col VII. Our results highlight the clinical relevance of pro-oxidant status and hyper-responsiveness to TGFB in RDEB severity and progression. Of note, our study also reveals PRELP as a novel and natural TGFB antagonist with a likely dermo-epidermal pro-adhesive capacity.

subjects

  • Biology and Biomedicine
  • Robotics and Industrial Informatics

keywords

  • extracellular matrix disease; recessive dystrophic epidermolysis bullosa; fibrosis; oxidative stress; tgf-ß; prelp