PAI-1 regulates AT2-mediated re-alveolarization and ion permeability

Gibran Ali; Mo Zhang; Jianjun Chang; Runzhen Zhao; Yang Jin; Jiwang Zhang; Hong-Long Ji

doi:10.1186/s13287-023-03414-4

PAI-1 regulates AT2-mediated re-alveolarization and ion permeability

Stem Cell Res Ther. 2023 Jul 27;14(1):185. doi: 10.1186/s13287-023-03414-4.

Authors

Gibran Ali^#¹, Mo Zhang^#^{1

2}, Jianjun Chang¹, Runzhen Zhao^{1

3}, Yang Jin⁴, Jiwang Zhang⁵, Hong-Long Ji^{6

7}

Affiliations

¹ Department of Cellular and Molecular Biology, Texas Lung Injury Institute, University of Texas at Tyler Health Science Center, Tyler, TX, USA.
² Xinxiang Medical University, Xinxiang, Henan, China.
³ Department of Surgery, Burn and Shock Trauma Research Institute, Loyola University Chicago, 2160 S 1St Avenue, Maywood, IL, 60153, USA.
⁴ Division of Pulmonary and Critical Care Medicine, Department of Medicine, Boston University, Boston, MA, USA.
⁵ Department of Cancer Biology, Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University Medical Center, Maywood, IL, USA.
⁶ Department of Cellular and Molecular Biology, Texas Lung Injury Institute, University of Texas at Tyler Health Science Center, Tyler, TX, USA. hji@luc.edu.
⁷ Department of Surgery, Burn and Shock Trauma Research Institute, Loyola University Chicago, 2160 S 1St Avenue, Maywood, IL, 60153, USA. hji@luc.edu.

^# Contributed equally.

Abstract

Background: Acute lung injury is characterized by overwhelmingly elevated PAI-1 in both lung edema fluid and the circulating system. The role of increased PAI-1, encoded by Serpine1 gene, in the regeneration of injured lung epithelium has not been understood completely. This study aimed to investigate the role of Serpine1 in the regulation of alveolar type 2 epithelial cell (AT2) fate in a humanized mouse line carrying diseased mutants (Serpine1^Tg).

Methods: Wild-type (wt) and Serpine1^Tg AT2 cells were either cultured as monolayers or 3D alveolospheres. Colony-forming assay and total surface area of organoids were analyzed. AT1 and AT2 cells in organoids were counted by immunohistochemistry and fluorescence-activated cell sorting (FACS). To test the potential effects of elevated PAI-1 on the permeability in the epithelial monolayers, we digitized the biophysical properties of polarized AT2 monolayers grown at the air-liquid interface.

Results: A significant reduction in total AT2 cells harvested in Serpine1^Tg mice was observed compared with wt controls. AT2 cells harvested from Serpine1^Tg mice reduced significantly over the wt controls. Spheroids formed by Serpine1^Tg AT2 cells were lesser than wt control. Similarly, the corresponding surface area, a readout of re-alveolarization of injured epithelium, was markedly reduced in Serpine1^Tg organoids. FACS analysis revealed a significant suppression in the number of AT2 cells, in particular, the CD44⁺ subpopulation, in Serpine1^Tg organoids. A lesser ratio of AT1:AT2 cells in Serpine1^Tg organoids was observed compared with wt cultures. There was a significant increase in transepithelial resistance but not amiloride inhibition.

Conclusions: Our study suggests elevated PAI-1 in injured lungs downregulates alveolar epithelial regeneration by reducing the AT2 self-renewal, particularly in the CD44⁺ cells.

Keywords: Differentiation; Organoids; Proliferation; Re-alveolarization; Serpine1.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Alveolar Epithelial Cells*
Animals
Cells, Cultured
Lung
Mice
Permeability
Plasminogen Activator Inhibitor 1* / genetics
Plasminogen Activator Inhibitor 1* / metabolism

Substances

Plasminogen Activator Inhibitor 1

Grants and funding

R01 HL134828/HL/NHLBI NIH HHS/United States