Matrix Derived Extracellular Vesicles and MicroRNA Differ in Profile Between Healthy and COPD Lung Extracellular Matrix

Cell-derived extracellular vesicles (EVs) are vital components of normal physiological processes and have been implicated in a large variety of pathologies, including cancers and lung diseases. EVs are membrane bound vesicles produced by all human cells and are involved in intercellular communication by transporting proteins and genetic elements through the extracellular space to neighboring cells. As such, there is increasing interest in the biological function of EV cargo. In particular, microRNAs (miRNAs) are small (18-25 nucleotide) non-coding RNA fragments that are incorporated into EVs and have a significant role in cell biology through post-translational regulation of gene expression. EVs are classically isolated from biological fluids, such as the bloodstream, urine, and bronchoalveolar lavage fluid (BALF) of the lung. However, recent studies have shown that EVs are also embedded in the extracellular matrix (ECM) and ECM-associated EVs contain miRNAs that impact cell behavior. While abnormalities in EVs and miRNA cargo have been implicated in a variety of lung diseases, such as chronic obstruction pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), EVs have never been isolated from lung ECM. Here, we utilize decellularized human lungs from patients with normal (i.e. no history of lung dysfunction or smoking) or COPD lungs. Decellularized lungs were liquid nitrogen milled to form lung ECM powder from four patients with normal lungs (n=4) or COPD lungs (n=4). Lung ECM powders were enzymatically digested to derive a soluble fraction of lung ECM, and subsequently, total RNA was isolated and analyzed by bioanalzyer. Interestingly, preliminary results show that over 80% of the RNA isolated from both normal and diseased lung ECM was miRNA, and diseased lung ECM contained an increased amount of miRNA. Critically, this work provides the first example that miRNA can be isolated from lung ECM and ECM-associated miRNA differs in diseased conditions