Probes for TGF-β

Abstract

RATIONALE:

Given the paucity of effective treatments for Idiopathic Pulmonary Fibrosis (IPF), new insights into the deleterious mechanisms controlling lung fibroblast activation, the key cell type driving the fibrogenic process, are essential to develop new therapeutic strategies. Transforming growth factor β (TGF-β) is the main pro-fibrotic factor, but its inhibition is associated with severe side effects due to its pleiotropic role.

OBJECTIVES:

We hypothesized that downstream non-coding effectors of TGF-β in fibroblasts may represent new effective therapeutic targets whose modulation may be well-tolerated.

METHODS:

We investigated the whole non-coding fraction of TGF-β-stimulated lung fibroblast transcriptome to identify new genomic determinants of lung fibroblast differentiation into myofibroblast. Differential expression of the long non-coding RNA DNM3OS and its associated miRNAs was validated in a murine model of pulmonary fibrosis and in IPF tissue samples. Distinct and complementary antisense oligonucleotide-based strategies aiming at interfering with DNM3OS were used to elucidate the role of DNM3OS and its associated miRNAs in IPF pathogenesis.

MEASUREMENTS AND MAIN RESULTS:

We identified DNM3OS as a fibroblast-specific critical downstream effector of TGF-β-induced lung myofibroblast activation. Mechanistically, DNM3OS regulates this process in trans by giving rise to three distinct profibrotic mature miRNAs (i.e. miR-199a-5p/3p and miR-214-3p), which influence both SMAD and non-SMAD components of TGF-β signaling in a multifaceted way. In vivo, we showed that interfering with DNM3OS function not only prevents lung fibrosis but also improves established pulmonary fibrosis.

CONCLUSION:

Pharmacological approaches aiming at interfering with DNM3OS may represent new effective therapeutic strategies in IPF.