Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jul 22:11:1598.
doi: 10.3389/fimmu.2020.01598. eCollection 2020.

Epithelial-Mesenchymal Transition in Asthma Airway Remodeling Is Regulated by the IL-33/CD146 Axis

Zhixiao Sun  1 , Ningfei Ji  1 , Qiyun Ma  1 , Ranran Zhu  1 , Zhongqi Chen  1 , Zhengxia Wang  1 , Yan Qian  1 , Chaojie Wu  1 , Fan Hu  2 , Mao Huang  1 , Mingshun Zhang  3
Affiliations

Epithelial-Mesenchymal Transition in Asthma Airway Remodeling Is Regulated by the IL-33/CD146 Axis

Zhixiao Sun et al. Front Immunol. .

Abstract

Epithelial-mesenchymal transition (EMT) is essential in asthma airway remodeling. IL-33 from epithelial cells is involved in pulmonary fibrosis. CD146 has been extensively explored in cancer-associated EMT. Whether IL-33 regulates CD146 in the EMT process associated with asthma airway remodeling is still largely unknown. We hypothesized that EMT in airway remodeling was regulated by the IL-33/CD146 axis. House dust mite (HDM) extract increased the expression of IL-33 and CD146 in epithelial cells. Increased expression of CD146 in HDM-treated epithelial cells could be blocked with an ST2-neutralizing antibody. Moreover, HDM-induced EMT was dependent on the CD146 and TGF-β/SMAD-3 signaling pathways. IL-33 deficiency decreased CD146 expression and alleviated asthma severity. Similarly, CD146 deficiency mitigated EMT and airway remodeling in a murine model of chronic allergic airway inflammation. Furthermore, CD146 expression was significantly elevated in asthma patients. We concluded that IL-33 from HDM extract-treated alveolar epithelial cells stimulated CD146 expression, promoting EMT in airway remodeling in chronic allergic inflammation.

Keywords: CD146; IL-33; allergy; asthma; epithelial-mesenchymal transition.

PubMed Disclaimer

Figures

Figure 1
Figure 1
HDM promoted CD146 expression in alveolar epithelial cells. (A) CD146 mRNA in HDM-treated MLE-12 cells was measured by qRT-PCR. (B) Western blot analysis of CD146 expression in MLE-12 cells treated with HDM extract (100 μg/ml). (C) The level of SPD in primary alveolar epithelial cells was measured by immunofluorescence. Ab(+): stained with anti-SPD antibody; Ab(–): stained with isotype antibody (D) Western blot analysis of CD146 expression in primary alveolar epithelial cells treated with HDM extract (100 μg/ml). *P < 0.05; **P < 0.01;***P < 0.001.
Figure 2
Figure 2
HDM promoted CD146 expression in alveolar epithelial cells via IL-33/ST2 signaling. (A) Western blot analysis of IL-33 expression in MLE-12 cells treated with HDM extract (100 μg/ml). (B) ELISA analysis of IL-33 levels in the cell culture supernatant of MLE-12 cells treated with HDM extract (100 μg/ml). (C) ELISA analysis of IL-33 levels in the cell lysates of MLE-12 cells treated with Derp1 (extracted HDM without LPS). (D) ELISA analysis of IL-33 levels in the cell culture supernatant of MLE-12 cells treated with Derp1 (extracted HDM without LPS). (E) Western blot analysis of CD146 expression in MLE-12 cells treated with IL-33 for 24 h. (F) Western blot analysis of CD146 expression in A549 cells treated with IL-33 for 24 h. (G) Western blot analysis of CD146 expression in MLE-12 cells treated with HDM extract (100 μg/ml) with or without an ST2-neutralizing antibody (5 μg/ml). *P < 0.05; **P < 0.01; ***P < 0.001.
Figure 3
Figure 3
CD146 expression in alveolar epithelial cells was dependent on p65. (A) Western blot analysis of MyD88 expression in MLE-12 cells treated with HDM extract (100 μg/ml). (B) Western blot analysis of NF-κB p65 expression in MLE-12 cells treated with HDM extract (100 μg/ml). (C) Western blot analysis of MAPK expression in MLE-12 cells treated with HDM extract (100 μg/ml). (D) Western blot analysis of CD146 expression in MLE-12 cells treated with HDM extract (100 μg/ml) and a p65 inhibitor (BAY, 10 μm) for 24 h. (E) Western blot analysis of CD146 expression in MLE-12 cells treated with HDM extract and a p38 inhibitor (SB203580, 10 μm) for 24 h. *P < 0.05.
Figure 4
Figure 4
HDM promoted EMT in alveolar epithelial cells. (A) Western blot analysis of E-cadherin and N-cadherin expression in MLE-12 cells treated with HDM extract (100 μg/ml). (B) Immunofluorescence analysis of E-cadherin expression in MLE-12 cells treated with HDM extract (100 μg/ml) for 24 h. (C) Immunofluorescence analysis of N-cadherin expression in MLE-12 cells treated with HDM extract (100 μg/ml) for 24 h. (D) Western blot analysis of fibronectin and α-SMA expression in MLE-12 cells treated with HDM extract (100 μg/ml). *P < 0.05.
Figure 5
Figure 5
HDM promoted EMT in alveolar epithelial cells via CD146. (A) Western blot analysis of CD146 and E-cadherin expression in MLE-12 cells treated with a CD146 expression plasmid (CD146 open reading frame, CD146 ORF) or blank vehicle (Blk vector). (B) Western blot analysis of CD146 and E-cadherin expression in MLE-12 cells treated with a CD146 siRNA plasmid and HDM extract (100 μg/ml). (C) Western blot analysis of E-cadherin expression in MLE-12 cells treated with HDM extract (100 μg/ml) and an ST2-neutralizing antibody (5 μg/ml). *P < 0.05.
Figure 6
Figure 6
TGF-β and SMAD3 played dominant roles in HDM-treated alveolar epithelial cell EMT. (A) Western blot analysis of TGF-β expression in MLE-12 cells treated with HDM extract (100 μg/ml). (B) Western blot analysis of STAT3 expression in MLE-12 cells treated with HDM extract (100 μg/ml). (C) Western blot analysis of SMAD3 expression in MLE-12 cells treated with HDM extract. (D) Western blot analysis of E-cadherin expression in MLE-12 cells treated with HDM extract (100 μg/ml) and a SMAD3 inhibitor (SIS3, 10 μm) for 24 h. *P < 0.05; **P < 0.01;***P < 0.001.
Figure 7
Figure 7
IL-33 played an important role in a mouse model of asthma. (A) Flow chart showing the chronic asthma model (5 days/week for 5 weeks). (B) Lung resistance in mice was measured with the FinePointe RC System. (C,D) The numbers of total cells, eosinophils, neutrophils, and lymphocytes in BALF were quantified. (E) Representative images of lung sections stained with H&E. (F) ELISA analysis of total IgE levels in sera. (G) ELISA analysis of IL-4, IL-5, IL-13, and IFN-γ levels in the supernatants of lung homogenates. *P < 0.05; **P < 0.01; ***P < 0.001; #P > 0.1.
Figure 8
Figure 8
IL-33 was essential for CD146 expression and EMT in a mouse model of asthma. (A) ELISA analysis of collagen-I levels in the lung homogenates of mice. (B) Representative images of lung sections stained with PAS. (C) Representative images of lung sections stained with Sirius red. (D) Western blot analysis of CD146 and E-cadherin expression in lung tissues. (E) Representative images of immunohistochemical analysis of E-cadherin expression in lung tissues. *P < 0.05; **P < 0.01; ***P < 0.001.
Figure 9
Figure 9
CD146 deficiency mitigated disease severity in a mouse model of asthma. (A) Lung resistance in mice was measured with the FinePointe RC System. (B) Representative images of lung sections stained with H&E. (C) ELISA analysis of total IgE levels in sera. (D) ELISA analysis of IL-4, IL-5, IL-13, and IFN-γ levels in the supernatants of lung homogenates. (E) ELISA analysis of IL-33 levels in the supernatants of lung homogenates. *P < 0.05; **P < 0.01; ***P < 0.001; #P >0.05.
Figure 10
Figure 10
CD146 deficiency decreased EMT in a mouse model of asthma. (A) ELISA analysis of collagen-I levels in the supernatants of lung homogenates of WT mice and CD146 KO mice. (B,C) Representative images of PAS- or Sirius red-stained lung sections from WT mice and CD146 KO mice. (D) Western blot analysis of E-cadherin expression in lung tissues from WT mice and CD146 KO mice. (E) Representative images of immunohistochemical analysis of E-cadherin expression in lung tissues from WT mice and CD146 KO mice. *P < 0.05; **P < 0.01; ***P < 0.001.
Figure 11
Figure 11
Soluble CD146 was elevated in the plasma of asthma patients. The level of soluble CD146 in the plasma of asthmatic patients and healthy people was measured by ELISA. ***P < 0.001.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Mims JW. Asthma: definitions and pathophysiology. Int Forum Allergy Rhinol. (2015) 5(Suppl. 1):S2–6. 10.1002/alr.21609 - DOI - PubMed
    1. Al-Muhsen S, Johnson JR, Hamid Q. Remodeling in asthma. J Allergy Clin Immunol. (2011) 128:451–62. 10.1016/j.jaci.2011.04.047 - DOI - PubMed
    1. Rout-Pitt N, Farrow N, Parsons D, Donnelley M. Epithelial mesenchymal transition (EMT): a universal process in lung diseases with implications for cystic fibrosis pathophysiology. Respir Res. (2018) 19:136. 10.1186/s12931-018-0834-8 - DOI - PMC - PubMed
    1. Hackett TL, Warner SM, Stefanowicz D, Shaheen F, Pechkovsky DV, Murray LA, et al. . Induction of epithelial-mesenchymal transition in primary airway epithelial cells from patients with asthma by transforming growth factor-beta1. Am J Respir Crit Care Med. (2009) 180:122–33. 10.1164/rccm.200811-1730OC - DOI - PubMed
    1. Yang ZC, Qu ZH, Yi MJ, Shan YC, Ran N, Xu L, et al. . MiR-448-5p inhibits TGF-beta1-induced epithelial-mesenchymal transition and pulmonary fibrosis by targeting Six1 in asthma. J Cell Physiol. (2019) 234:8804–14. 10.1002/jcp.27540 - DOI - PubMed

Publication types

MeSH terms