Adult Rat Bone Marrow-Derived Stem Cells Promote Late Fetal Type II Cell Differentiation in a Co-Culture Model

Abstract

Bronchopulmonary dysplasia develops in preterm infants due to a combination of lung immaturity and lung injury. Cultured pluripotent bone marrow stem cells (BMSC) are known to reduce injury and induce repair in adult and in immature lungs, possibly through paracrine secretion of soluble factors. The paracrine relationship between BMSC and primary fetal lung epithelial type II cells is unknown. We determined the effects of BMSC on type II cell and fibroblast behavior using an in vitro co-culture model. Rat BMSC were isolated and co-cultured with primary fetal E21 rat type II cells or lung fibroblasts in a Transwell® system without direct cell contact. Effects of BMSC conditioned media (CM) on type II cell and fibroblast proliferation and on type II cell surfactant phospholipid (DSPC) synthesis and mRNA expression of surfactant proteins B and C (sftpb and sftpc) were studied. We also determined the effect of fibroblast and type II cell CM on BMSC proliferation and surface marker expression. Co-culture with BMSC significantly decreased type II cell and fibroblast proliferation to 72.5% and 83.7% of controls, respectively. Type II cell DSPC synthesis was significantly increased by 21% and sftpb and sftpc mRNA expressions were significantly induced (2.1 fold and 2.4 fold, respectively). BMSC proliferation was significantly reduced during the co-culture. Flow cytometry confirmed that BMSC retained the expression of undifferentiated stem cell markers despite their exposure to fetal lung cell CM. We conclude that BMSC induce fetal type II cell differentiation through paracrine release of soluble factors. These studies provide clues for how BMSC may act in promoting alveolar repair following injury.

Human Decidua-Derived Mesenchymal Stem Cells Differentiate into Functional Alveolar Type II-Like Cells that Synthesize and Secrete Pulmonary Surfactant Complexes

“…We speculate that the pneumocyte-like phenotype of ATII-LCs could progress further to full differentiation upon immersion into a more complete lung environment, either in the tissue in vivo or in more elaborated cell culture models that could incorporate features like the presence of an air-liquid interface. In this sense, Transwell devices have been reported as successful for lung differentiation by other groups [24] , [26] , and it could provide additional signaling to improve full differentiation of ATII-LCs.…”

“…Clinically, administration of MSCs from different origins into animal models of lung injury has been demonstrated by a number of authors to be a valuable therapeutic tool [24] , [26] , [63] – [68] . We have recently reported that DMSCs could be useful for future clinical applications [33] , [69] .…”

“…In the latest years, stem cells have been extensively investigated as a potential source of alveolar epithelial cells [13] . Murine [14] – [21] and human [20] , [22] , [23] embryonic stem cells, adult bone marrow-derived stem cells from rat [24] and human [25] , [26] as well as human stem cells derived from amniotic fluid [27] , amnion [28] or umbilical cord blood [29] have been derivated into cells with phenotypical features consistent with ATII cells. We have previously described a population of mesenchymal stem cells (MSCs) isolated from human extraembryonic membranes termed Decidua-derived Mesenchymal Stem Cells (DMSCs) with the capacity of differentiation into ATII-like cells [30] .…”

Hyperoxia-induced bronchopulmonary dysplasia: better models for better therapies

“…Table 2 shows an overview of the different types of models as well as sources from which cells and tissue are commonly derived. These include 2D cultured cells or 3D-organotypic lung co-cultures as well as ex vivo anatomical scaffolds or models derived from live tissue or 3D-printed using biomimetic materials ( Sucre et al, 2020 ; Montigaud et al, 2019 ; Möbius et al, 2018 ; Jiang et al, 2018 ; Leeman et al, 2019 ; Montemurro et al, 2006 ; Sucre et al, 2018 ; Knoll et al, 2013 ). Fetal primary epithelial cells isolated from human or rodent lung tissues can be cultured together with lung-derived fibroblasts or MSCs to study the effect of hyperoxia regarding the expression of transcription factors associated with pulmonary development.…”

“…In summary, in vitro models meet the need to reduce the use of animals in research, and provide an easily accessible platform in which to dissect the currently less understood molecular consequences of hyperoxia and to screen candidate therapeutics for treatment of BPD ( Wu et al, 2018 ; Leeman et al, 2019 ; Knoll et al, 2013 ). Knowledge gained from these customizable models will allow investigators to manipulate developmental pathways within the lung, in order to improve clinical outcomes associated with BPD.…”