miR-29 Regulates Type VII Collagen in Recessive Dystrophic Epidermolysis Bullosa.
Recessive dystrophic epidermolysis bullosa (RDEB) is a complex inherited skin disorder caused by loss-of-function mutations in the COL7A1 gene. For an effective treatment of this disorder to be realized, both a thorough understanding of the regulation of COL7A1 and an understanding of the underlying nature of the complications of RDEB are needed. Currently, both posttranscriptional regulation of COL7A1 and the underlying causes of fibrosis in RDEB patients are poorly understood. Here, we describe a mechanism of regulation, to our knowledge previously unknown, by which micro RNA-29 (miR-29) regulates COL7A1 in a complex network: both directly through targeting its 3' untranslated region at two distinct seed regions and indirectly through targeting an essential transcription factor required for basal COL7A1 expression, SP1. In turn, miR-29 itself is regulated by SP1 activity and transforming growth factor-β signaling. RDEB mice express high levels of transforming growth factor-β and significantly lower miR-29 compared with wild-type cohorts. The sustained decrease in miR-29 in RDEB skin leads to an increase of miR-29 target genes expressed in the skin, including profibrotic extracellular matrix collagens. Collectively, we identify miR-29 as an important factor in both regulating COL7A1 and inhibiting transforming growth factor-β-mediated fibrosis.
Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, Minnesota, USA.
Michael
M
Vanden Oever
Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, Minnesota, USA.
Daniel
D
Muldoon
Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, Minnesota, USA.
Wendy
W
Mathews
Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, Minnesota, USA.
Ron
R
McElmurry
Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, Minnesota, USA; Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA. Electronic address: tolar003@umn.edu.
Jakub
J
Tolar
D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D024143:Collagen Type VII / Q000235:genetics*; D016108:Epidermolysis Bullosa Dystrophica / Q000235:genetics*; D005355:Fibrosis; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism*
C569053:COL7A1 protein, human; C583886:Col7a1 protein, mouse; D024143:Collagen Type VII; C547014:MIRN29 microRNA, mouse; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D016329:Sp1 Transcription Factor; D016212:Transforming Growth Factor beta