Lats2-Underexpressing Bone Marrow-Derived Mesenchymal Stem Cells Ameliorate LPS-Induced Acute Lung Injury in Mice

Liang Dong,Lang Li

doi:10.1155/2019/4851431

Abstract

The pathophysiology of the acute lung injury (ALI) is characterized by the damage of alveolar epithelial cells, which can be repaired by exogenous bone marrow-derived mesenchymal stem cells (BMSCs). However, the migration and differentiation abilities of BMSCs are not sufficient for the purpose, and a new approach that could strengthen the repair effects of BMSCs in ALI still needs to be clarified. We have previously proved that in vitro large tumor suppressor kinase 2- (Lats2-) underexpressing BMSCs may enhance their tissue repair effects in ALI; thus, in the present study, we tried to explore whether Lats2-underexpressing BMSCs could rescue lipopolysaccharide- (LPS-) induced ALI in vivo. BMSCs from C57BL/6 mice transfected with Lats2-interfering lentivirus vector or lentivirus blank controls were transplanted intratracheally into LPS-induced ALI mice. The retention and differentiation of BMSCs in the lung were evaluated by in vivo imaging, immunofluorescence staining, and Western blotting. The lung edema and permeability were assessed by lung wet weight/body weight ratio (LWW/BW) and measurements of proteins in bronchoalveolar lavage fluid (BALF) using ELISA. Acute lung inflammation was measured by the cytokines in the lung homogenate and BALF using RT-qPCR and ELISA, respectively. Lung injury was evaluated by HE staining and lung injury scoring. Pulmonary fibrosis was evaluated by Picrosirius red staining, immunohistochemistry for α-SMA and TGF-β1, and hydroxyproline assay and RT-qPCR for Col1α1 and Col3α1. Lats2-mediated inhibition of the Hippo pathway increased the retention of BMSCs and their differentiation toward type II alveolar epithelial cells in the lung. Furthermore, Lats2-underexpressing BMSCs improved lung edema, permeability of the lung epithelium, and lung inflammation. Finally, Lats2-underexpressing BMSCs alleviated lung injury and early pulmonary fibrosis. Our studies suggest that underexpression of Lats2 could further enhance the repair effects of BMSCs against epithelial impair and the therapeutic potential of BMSCs in ALI mice.

Highlights

The pathophysiological hallmark of acute lung injury (ALI) is the disruption of alveolar epithelial cells, leading to increased permeability of blood–air barrier and noncardiogenic lung edema [1]
In our previous in vitro study, large tumor suppressor kinase 2- (Lats2-)underexpressing bone marrow-derived mesenchymal stem cells (BMSCs) derived from C57BL/6 mice were constructed successfully, and we found that large tumor suppressor kinase 2 (Lats2)-mediated inhibition of the Hippo pathway in vitro enhances the migration of bone marrow-derived mesenchymal stem cells (MSCs) (BMSCs) to injured lung tissue, promotes the differentiation of BMSCs into type II alveolar epithelial (ATII) cells, and confers resistance to H2O2induced oxidative stress [11]
Immunofluorescence staining and ex vivo near infrared region (NIR) imaging were performed on the lungs from ALI+MSC-shcontrol and ALI+MSC-shLats2 mice at 3, 7, and 14 days after LPS challenge to track the intrapulmonary BMSCs

Summary

Introduction

The pathophysiological hallmark of acute lung injury (ALI) is the disruption of alveolar epithelial cells, leading to increased permeability of blood–air barrier and noncardiogenic lung edema [1]. Stem-cell-based repair of damaged alveolar epithelium will be a promising cure for patients with ALI [3]. Because of their properties of multipotency and immunoregulation, mesenchymal stem cells (MSCs) are ideal seed cells for cellbased therapy in ALI [4]. Recent animal and human studies reported that exogenous MSCs could migrate to ALI lung tissue and repair alveolar epithelial injury [5, 6]. The therapeutic effects remain limited due to the low engraftment and differentiation rates of MSCs in the lung tissue of ALI models [7, 8]. Clarifying the mechanisms that promote the differentiation, migration, and antioxidative activities of MSC may optimize the MSC-mediated therapeutic effects in ALI [9, 10]

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