Pathological extracellular matrix suppresses microRNA-29 at the level of microRNA processing in Idiopathic Pulmonary Fibrosis

Loading...
Thumbnail Image

Persistent link to this item

Statistics
View Statistics

Journal Title

Journal ISSN

Volume Title

Title

Pathological extracellular matrix suppresses microRNA-29 at the level of microRNA processing in Idiopathic Pulmonary Fibrosis

Published Date

2015-06

Publisher

Type

Thesis or Dissertation

Abstract

Introduction: Idiopathic Pulmonary Fibrosis (IPF) is a lethal lung disorder that kills 40,000 Americans each year. It is characterized by pathological accumulation of activated myofibroblasts and extracellular matrix (ECM) which compromises gas exchange leading to death by asphyxiation. The IPF lung is an order of magnitude stiffer than normal. When primary human lung fibroblasts are cultured on IPF decellularized lung tissue (IPF-ECM), translational repression of ECM genes is disabled due to down-regulation of microRNA-29 (miR-29); however, the molecular mechanism is undefined. Stiffness drives fibroblast-to-myofibroblast differentiation; and stiffness has been shown to mediate microRNA expression. We therefore hypothesized that IPF-ECM decreases miR-29 due to increased matrix stiffness. Methodology: We cultured primary human lung fibroblasts on polyacrylamide hydrogels corresponding to physiological or IPF stiffness, or on Control- or IPF-ECM; and quantified precursor or mature miR-29 (Q-PCR). On hydrogels and decellularized ECM, we defined microRNA processing activity using a luciferase based construct. Results: IPF-ECM caused decreased mature miR-29 and increased precursor miR-29. In contrast, stiffness increased mature miR-29, and decreased precursor miR-29. MicroRNA processing activity was increased by both IPF-ECM and stiffness. Conclusion: On hydrogels simulating pathological stiffness, a stiffness sensor provides a physiological negative feedback signal to increase miR-29, which in turn represses connective tissue synthesis. IPF-ECM mediates decreased miR-29, overriding what should be a negative feedback response to stiffness. Both IPF-ECM and pathological stiffness increases microRNA processing activity, which suggests primary microRNA is converted to precursor microRNA and that IPF-ECM deregulates microRNA processing at the level of post-microprocessor complex. Thus, our data is the first to identify corruption of microRNA processing by the IPF fibrotic matrix itself as one mechanism for sustained connective tissue production in IPF.

Keywords

Description

University of Minnesota Ph.D. dissertation. June 2015. Major: Microbiology, Immunology and Cancer Biology. Advisor: Kaylee Schwertfeger. 1 computer file (PDF); vi, 65 pages.

Related to

Replaces

License

Collections

Series/Report Number

Funding information

Isbn identifier

Doi identifier

Previously Published Citation

Other identifiers

Suggested citation

Herrera, Jeremy. (2015). Pathological extracellular matrix suppresses microRNA-29 at the level of microRNA processing in Idiopathic Pulmonary Fibrosis. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/174855.

Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.