Matrisome Properties of Scaffolds Direct Fibroblasts in Idiopathic Pulmonary Fibrosis.

Linda Elowsson Rendin,Göran Dellgren,Leif Bjermer,Anna Löfdahl,Anna-Karin Larsson-Callerfelt,Emma Åhrman,Martin Silverborn,Catharina Müller,Gunilla Westergren-Thorsson,Thomas Notermans,Xiao-Hong Zhou,Anders Malmström,Johan Malmström,Oskar Rosmark,Barbora Michaliková,Hanna Isaksson

doi:10.3390/ijms20164013

Abstract

In idiopathic pulmonary fibrosis (IPF) structural properties of the extracellular matrix (ECM) are altered and influence cellular responses through cell-matrix interactions. Scaffolds (decellularized tissue) derived from subpleural healthy and IPF lungs were examined regarding biomechanical properties and ECM composition of proteins (the matrisome). Scaffolds were repopulated with healthy fibroblasts cultured under static stretch with heavy isotope amino acids (SILAC), to examine newly synthesized proteins over time. IPF scaffolds were characterized by increased tissue density, stiffness, ultimate force, and differential expressions of matrisome proteins compared to healthy scaffolds. Collagens, proteoglycans, and ECM glycoproteins were increased in IPF scaffolds, however while specific basement membrane (BM) proteins such as laminins and collagen IV were decreased, nidogen-2 was also increased. Findings were confirmed with histology, clearly showing a disorganized BM. Fibroblasts produced scaffold-specific proteins mimicking preexisting scaffold composition, where 11 out of 20 BM proteins were differentially expressed, along with increased periostin and proteoglycans production. We demonstrate how matrisome changes affect fibroblast activity using novel approaches to study temporal differences, where IPF scaffolds support a disorganized BM and upregulation of disease-associated proteins. These matrix-directed cellular responses emphasize the IPF matrisome and specifically the BM components as important factors for disease progression.

Highlights

In idiopathic pulmonary fibrosis (IPF) the biomechanics and composition of the extracellular matrix (ECM) are altered causing a pathological phenotype associated with increased tissue stiffness and disorganized structures of the lung [1]
Slcui. 2n0g19,t2i0s,sxuFeORbPyEERRoRsEmVIaEWrk et al [13], double stranded DNA (dsDNA) content was efficiently remov3 eodf 2f8ollowing decellularization showing only 1.5% residual dsDNA per mg tissue in IPF derived scaffolds
At further examination of heavy labeled proteins, we identified that the synthesis of tenascin and periostin was significantly altered in repopulated IPF scaffolds, matrix components that have been associated with the progression of IPF [25,26]

Summary

Introduction

In idiopathic pulmonary fibrosis (IPF) the biomechanics and composition of the extracellular matrix (ECM) are altered causing a pathological phenotype associated with increased tissue stiffness and disorganized structures of the lung [1]. In comparison to other cell culture systems, decellularized tissue (scaffolds) comprise a unique ex vivo system that more closely mimics the original intricate 3D milieu of the lung. Through this ex vivo model a better understanding of unknown key cellular mechanisms can be obtained in order to understand which ECM properties drive the formation of fibrotic tissue and which role the ECM of IPF scaffolds has in disease progression. In IPF, fibroblasts demonstrate an increased cellular stiffness, perhaps functioning as a positive feedback loop contributing to the formation of a non-compliant stiff lung tissue [18]

Objectives

Methods

Results

Conclusion