Fibrinolytic niche is required for alveolar type 2 cell-mediated alveologenesis via a uPA-A6-CD44⁺-ENaC signal cascade

Gibran Ali^#¹, Mo Zhang^#^{1

2}, Runzhen Zhao^#¹, Krishan G Jain¹, Jianjun Chang^{1

3}, Satoshi Komatsu¹, Beiyun Zhou^{4

5

6

7}, Jiurong Liang⁸, Michael A Matthay^{9

10}, Hong-Long Ji^{11

12}

Affiliations

¹ Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX, USA.
² Institute of Lung and Molecular Therapy, Xinxiang Medical University, Xinxiang, Henan, China.
³ Institute of Health Sciences, China Medical University, Shenyang, Liaoning, China.
⁴ Division of Pulmonary, Critical Care and Sleep Medicine, University of Southern California, Los Angeles, CA, USA.
⁵ Hastings Center for Pulmonary Research, University of Southern California, Los Angeles, CA, USA.
⁶ Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA.
⁷ Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
⁸ Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
⁹ Department of Medicine and Anesthesia, University of California San Francisco, San Francisco, CA, USA.
¹⁰ Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA.
¹¹ Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX, USA. James.Ji@uthct.edu.
¹² Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, TX, USA. James.Ji@uthct.edu.

^# Contributed equally.

PMID: 33640905
PMCID: PMC7910758
DOI: 10.1038/s41392-021-00511-9

Fibrinolytic niche is required for alveolar type 2 cell-mediated alveologenesis via a uPA-A6-CD44⁺-ENaC signal cascade

Gibran Ali et al. Signal Transduct Target Ther. 2021.

. 2021 Feb 27;6(1):97.

doi: 10.1038/s41392-021-00511-9.

Authors

Affiliations

¹ Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX, USA.
² Institute of Lung and Molecular Therapy, Xinxiang Medical University, Xinxiang, Henan, China.
³ Institute of Health Sciences, China Medical University, Shenyang, Liaoning, China.
⁴ Division of Pulmonary, Critical Care and Sleep Medicine, University of Southern California, Los Angeles, CA, USA.
⁵ Hastings Center for Pulmonary Research, University of Southern California, Los Angeles, CA, USA.
⁶ Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA.
⁷ Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
⁸ Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
⁹ Department of Medicine and Anesthesia, University of California San Francisco, San Francisco, CA, USA.
¹⁰ Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA.
¹¹ Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX, USA. James.Ji@uthct.edu.
¹² Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, TX, USA. James.Ji@uthct.edu.

^# Contributed equally.

PMID: 33640905
PMCID: PMC7910758
DOI: 10.1038/s41392-021-00511-9

No abstract available

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Conflict of interest statement

The authors declare no competing interests.

Figures

**Fig. 1**
a Quantification of AT2 cells in influenza-infected mouse lungs 5 days post infection. n = 10 sections from 3 different mice per group. Yield of AT2 cells from *Plau*^−/− and wt control mice. (n = 15 mice/genotype). b Colony formation observed and analyzed from day 4 to day 12 post seeding. Colony number and colony forming efficiency (CFE) on day 8 of the cultures. (n = 16 wells per set of experiments and repeated with 6 pairs of mice). c Representative images of organoid sections stained with the H & E procedure for wt and *Plau*^−/− group. Stacked confocal images of wt and *Plau*^−/− organoids. AT1 and AT2 cells were identified and counted as pdpn-positive (red) and sftpc-positive (green) cells, respectively (n = 16 organoids per group from three separate experiments). Confocal images and FACS analysis of polarized AT2 monolayers (n = 19 transwells per group from three separate experiments). d A Click-iT EdU assay kit was used to identify AT2 cells with active DNA synthesis on day 7 of the monolayer cultures (n = 16 per group from 6 separate preparations). Stacked organoid images of DAPI for nuclei (left), EdU (middle), and merged (right) in wt and *Plau*^−/− organoids (n = 25 for each group from 6 separate preparations). e Representative short-circuit current (Isc) in the presence and absence of bath Na⁺ ions. The bath solution was replaced with Na⁺ free medium as indicated by arrows, summarized Isc level, Isc traces in the presence of accumulating amiloride added to the apical compartment, dotted and dashed lines are generated by fitting raw data points with the Hill equation to compute IC₅₀ value for amiloride (130 ± 2.5 μM for wt and 108 ± 14.9 μM for *Plau*^−/− cells), transepithelial resistance of AT2 monolayers measured with a chopstick meter (n = 15 monolayers from 3 different cell preparations). f Effects of the A6 peptide and CD44 receptor on the formation of organoids and AT2 lineage in organoids. (n = 16 transwells/group from 6 independent experiments). Colony number on day 8 of the cultures. (n = 16 wells per set of experiments and repeated with 6 pairs of mice). FlowJo analyzed FACS results. Wt AT2 cells were treated with blocking antibody against CD44 receptor, and *Plau*^−/− cells were incubated with A6 peptide. Pdpn and EpCAM are biomarkers for AT1 and AT2 cells, respectively. (n = 12 transwells for each group from 6 independent experiments). g Comparison of the number of EpCAM⁺CD44⁺ AT2 cells between wt and *Plau*^−/− mice. n = 7 mice/genotype. Number of organoids per transwell for CD44⁺ and CD44⁻ AT2 cells. n = 18 for each group from four independent experiments. Statistical comparison of FACS data for AT1 and AT2 cells in organoids grown from CD44⁺ and CD44^– subpopulations. n = 12 transwells per group from three independent experiments. h Summary of the uPA-A6-CD44⁺-ENaC cascade in regulating the fate of AT2 cells critical for re-alveologenesis. Scale bar, 50 and 100 µm. Data are means ± sem and analyzed with the Student’s t test, pair signed rank test, and one-way ANOVA followed by Tukey post hoc analysis in NS, not significant, *P ≤ 0.05, **P ≤ 0.01, and ***P ≤ 0.001 compared with wt controls

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References

1. Zhao R, et al. Proliferative regulation of alveolar epithelial type 2 progenitor cells by human Scnn1d gene. Theranostics. 2019;9:8155–8170. doi: 10.7150/thno.37023. - DOI - PMC - PubMed
1. Jiang D, et al. Regulation of lung injury and repair by Toll-like receptors and hyaluronan. Nat. Med. 2005;11:1173–1179. doi: 10.1038/nm1315. - DOI - PubMed
1. Zhao R, et al. Plasmin improves blood-gas barrier function in oedematous lungs by cleaving epithelial sodium channels. Br. J. Pharm. 2020;177:3091–3106. doi: 10.1111/bph.15038. - DOI - PMC - PubMed
1. Bohnert BN, et al. Urokinase-type plasminogen activator (uPA) is not essential for epithelial sodium channel (ENaC)-mediated sodium retention in experimental nephrotic syndrome. Acta Physiol. 2019;227:e13286. doi: 10.1111/apha.13286. - DOI - PubMed
1. Ji HL, et al. Proteolytic regulation of epithelial sodium channels by urokinase plasminogen activator: cutting edge and cleavage sites. J. Biol. Chem. 2015;290:5241–5255. doi: 10.1074/jbc.M114.623496. - DOI - PMC - PubMed

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Fibrinolytic niche is required for alveolar type 2 cell-mediated alveologenesis via a uPA-A6-CD44⁺-ENaC signal cascade

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Fibrinolytic niche is required for alveolar type 2 cell-mediated alveologenesis via a uPA-A6-CD44⁺-ENaC signal cascade

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