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
. 2016 Jul 6:22:2357-62.
doi: 10.12659/msm.896390.

Thymic Stromal Lymphopoietin Promotes Fibrosis and Activates Mitogen-Activated Protein Kinases in MRC-5 Cells

Li Li  1 , Su Tang  2 , Xiaodong Tang  3
Affiliations

Thymic Stromal Lymphopoietin Promotes Fibrosis and Activates Mitogen-Activated Protein Kinases in MRC-5 Cells

Li Li et al. Med Sci Monit. .

Abstract

BACKGROUND Acute lung injury (ALI) is a life-threatening hypoxemic respiratory disorder with high incidence and mortality. ALI usually manifests as widespread inflammation and lung fibrosis with the accumulation of pro-inflammatory and pro-fibrotic factors and collagen. Thymic stromal lymphopoietin (TSLP) has a significant role in regulation of inflammation but little is known about its roles in lung fibrosis or ALI. This study aimed to define the role and possible regulatory mechanism of TSLP in lung fibrosis. MATERIAL AND METHODS We cultured human lung fibroblast MRC-5 cells and overexpressed or inhibited TSLP by the vector or small interfering RNA transfection. Then, the pro-fibrotic factors skeletal muscle actin alpha (α-SMA) and collagen I, and the 4 mitogen-activated protein kinases (MAPKs) - MAPK7, p38, extracellular signal-regulated kinase 1 (ERK1), and c-Jun N-terminal kinase 1 (JNK1) - were detected by Western blot. RESULTS Results showed that TSLP promoted the production of α-SMA and collagen I (P<0.001), suggesting that it can accelerate MRC-5 cell fibrosis. It also activated the expression of MAPK7, p-p38, p-ERK1, and p-JNK1, but the total MAPK7, p-38, ERK1, and JNK1 protein levels were mostly unchanged, indicating the activated MAPK pathways that might contribute to the promotion of cell fibrosis. CONCLUSIONS This study shows the pro-fibrotic role of TSLP in MRC-5 cells, suggesting TSLP is a potential therapeutic target for treating lung fibrosis in ALI. It possibly functions via activating MAPKs. These findings add to our understanding of the mechanism of fibrosis.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Transfection induces the overexpression and inhibition of TSLP. (A) TSLP mRNA level was up-regulated in the TSLP group, and down-regulated in the si-TSLP group. (B) TSLP protein level was up-regulated in the TSLP group and down-regulated in the si-TSLP group. TSLP levels in the si-Control group were almost unchanged. GAPDH and β-actin were used as the endogenous references for qPCR and Western blot, respectively. *** P<0.001. TSLP – thymic stromal lymphopoietin. Control – cells without transfection. si-Control – cells transfected with the control siRNA. TSLP – cells transfected with TSLP overexpression vector. si-TSLP – cells transfected with TSLP-specific siRNA.
Figure 2
Figure 2
α-SMA and collagen I were up-regulated by TSLP. (A) Western blot and the corresponding histogram indicate α-SMA was promoted by TSLP overexpression and inhibited by si-TSLP. (B) Western blot and the corresponding histogram indicate Collagen I was promoted by TSLP overexpression and inhibited by si-TSLP. β-actin was used as the endogenous reference for Western blot. *** P<0.001. TSLP – thymic stromal lymphopoietin. Control – cells without transfection. si-Control – cells transfected with the control siRNA. TSLP – cells transfected with TSLP overexpression vector. si-TSLP – cells transfected with TSLP-specific siRNA. α-SMA – skeletal muscle actin alpha.
Figure 3
Figure 3
Major MAPKs were activated by TSLP. (A) Western blot shows protein levels of MAPK7, p-ERK1, p-p38, and p-JNK1 were up-regulated by TSLP overexpression and down-regulated by si-TSLP. ERK1, p-38, and JNK1 levels remained unchanged. (B) Histogram indicates the band density of MAPK7. (C–E) Histograms indicate the band densities of p-ERK1, p-p38, or p-JNK1 compared to those of ERK1, p38, or JNK1. β-actin was used as the endogenous reference for Western blot. * P<0.05. *** P<0.001. TSLP – thymic stromal lymphopoietin. Control – cells without transfection. si-Control – cells transfected with the control siRNA. TSLP – cells transfected with TSLP overexpression vector. si-TSLP – cells transfected with TSLP-specific siRNA. MAPK7 – mitogen-activated protein kinase 7. ERK1 – extracellular signal-regulated kinase 1. p38 – mitogen-activated protein kinase 14. JNK1 – c-Jun N-terminal kinase 1.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Toy P, Popovsky MA, Abraham E, et al. Transfusion-related acute lung injury: Definition and review. Critical Care Medicine. 2005;33:721–26. - PubMed
    1. Erickson SE, Martin GS, Davis JL, et al. Recent trends in acute lung injury mortality: 1996–2005. Crit Care Med. 2009;37:1574–79. - PMC - PubMed
    1. Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med. 2005;353:1685–93. - PubMed
    1. Stringer KA, Serkova NJ, Karnovsky A, et al. Metabolic consequences of sepsis-induced acute lung injury revealed by plasma (1)H-nuclear magnetic resonance quantitative metabolomics and computational analysis. Am J Physiol Lung Cell Mol Physiol. 2011;300:L4–11. - PMC - PubMed
    1. Marik PE, Corwin HL. Acute lung injury following blood transfusion: expanding the definition. Crit Care Med. 2008;36:3080–84. - PubMed

MeSH terms

Substances