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Activated Wnt signaling induces myofibroblast differentiation of mesenchymal stem cells, contributing to pulmonary fibrosis.

Sun Z, Wang C, Shi C, Sun F, Xu X, Qian W, Nie S, Han X - Int. J. Mol. Med. (2014)

Bottom Line: Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis.The in vitro study results demonstrated that activation of the Wnt/β-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1.Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.

View Article: PubMed Central - PubMed

Affiliation: Immunology and Reproductive Biology Laboratory, Medical School of Nanjing University, Nanjing, Jiangsu 210093, P.R. China.

ABSTRACT
Acute lung injury may lead to fibrogenesis. However, no treatment is currently available. This study was conducted to determine the effects of bone marrow-derived mesenchymal stem cells (MSCs) in a model of HCl-induced acute lung injury in Sprague-Dawley (SD) rats. Stromal cell-derived factor (SDF)-1 and its receptor CXC chemokine receptor (CXCR)4 have been shown to participate in mobilizing MSCs. Adenovirus carrying the CXCR4 gene was used to transfect MSCs in order to increase the engraftment numbers of MSCs at injured sites. Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis. The results showed that engraftment of MSCs almost differentiated into myofibroblasts, but rarely differentiated into lung epithelial cells. Additionally, it was demonstrated that activated canonical Wnt/β-catenin signaling in injured lung tissue regulated the myofibroblast differentiation of MSCs in vivo. The in vitro study results demonstrated that activation of the Wnt/β-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1. Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.

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Related in: MedlinePlus

Immunofluorescent staining and flow cytometric analysis was used to detect the engraftment of mesenchymal stem cells (MSCs) (white arrows, green fluorescent cells, GFP+ cells) in lung tissue. (A) Immunofluorescent staining detected the engraftment of MSCs. No GFP+ cells (MSCs) are detectable in the control lung tissue, while the expression of stromal cell-derived factor (SDF)-1 (red) is very low. GFP+ cells are detectable in acute lung injury (ALI)+MSC-CXC chemokine receptor (CXCR)4 and ALI+MSC-GFP groups. More GFP+ cells were identified at SDF-1-expressed sites in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP group. Scale bar, 50 μm. (B) Flow cytometric analysis for the engraftment ratio of MSCs in lung tissue. MSCs transfected with Ad-CXCR4 or GFP reporter gene (Ad-GFP) were termed GFP+ cells. Flow cytometry was used to analyze the GFP+ cells in lung cell populations subsequent to MSC administration into lung, as shown in the right area. The SDF-1/CXCR4 axis promotes MSCs to engraft into injured lung tissue. (a) Control group with GFP+ cell injection; (b) MSCs transfected with Ad-GFP is used as positive control; (c) MSC-CXCR4 cells injection in ALI lung on day 7 post-transplantation; (d) MSC-GFP cells injection in ALI lung on day 7 post-transplantation; (e) MSC-CXCR4 cells injection in ALI lung on day 14 post-transplantation; (f) MSC-GFP cells injection in ALI lung on day 14 post-transplantation. More GFP+ cells were detected in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP and control groups.
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f3-ijmm-33-05-1097: Immunofluorescent staining and flow cytometric analysis was used to detect the engraftment of mesenchymal stem cells (MSCs) (white arrows, green fluorescent cells, GFP+ cells) in lung tissue. (A) Immunofluorescent staining detected the engraftment of MSCs. No GFP+ cells (MSCs) are detectable in the control lung tissue, while the expression of stromal cell-derived factor (SDF)-1 (red) is very low. GFP+ cells are detectable in acute lung injury (ALI)+MSC-CXC chemokine receptor (CXCR)4 and ALI+MSC-GFP groups. More GFP+ cells were identified at SDF-1-expressed sites in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP group. Scale bar, 50 μm. (B) Flow cytometric analysis for the engraftment ratio of MSCs in lung tissue. MSCs transfected with Ad-CXCR4 or GFP reporter gene (Ad-GFP) were termed GFP+ cells. Flow cytometry was used to analyze the GFP+ cells in lung cell populations subsequent to MSC administration into lung, as shown in the right area. The SDF-1/CXCR4 axis promotes MSCs to engraft into injured lung tissue. (a) Control group with GFP+ cell injection; (b) MSCs transfected with Ad-GFP is used as positive control; (c) MSC-CXCR4 cells injection in ALI lung on day 7 post-transplantation; (d) MSC-GFP cells injection in ALI lung on day 7 post-transplantation; (e) MSC-CXCR4 cells injection in ALI lung on day 14 post-transplantation; (f) MSC-GFP cells injection in ALI lung on day 14 post-transplantation. More GFP+ cells were detected in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP and control groups.

Mentions: To assess the engraftment ratio of MSCs at injury sites, we measured the subpopulation of GFP+ cells in lung tissue. Immunofluorescence staining was used to detect the engraftment sites of MSCs (GFP+ cells) in lung tissue. The results showed that MSCs engrafted the injury sites that expressed SDF-1 at a high level (Fig. 3A). More GFP+ cells were identified in SDF-1-expressed sites of the ALI+MSC-CXCR4 group compared to the ALI+MSC-GFP group. Flow cytometry was used to analyze the SDF-1-expressed sites to confirm the role of the SDF-1/CXCR4 axis in the migration of MSCs. Following transplantation of the MSCs for 7 days, ~12% GFP+ cells in the cell population were identified in the ALI+MSC-CXCR4 group; however, only ~2% GFP+ cells were identified in the ALI+MSC-GFP group (Fig. 3B). The results demonstrated that a high expression of SDF-1 at the injury sites and CXCR4 overexpression in MSCs improved the migration of MSCs into injury sites. These results indicated that the SDF-1/CXCR4 chemotactic axis is crucial in regulating the migration of MSCs. For long-term transplantation, GFP+ cells in the cell population showed a similar time-dependent decrease. Following transplantation of the MSCs for 14 days, ~10% GFP+ cells were identified at the injury sites in the ALI+MSC-CXCR4 group. Engraftment of MSCs in the lung marked effects on the fibrosis or reparation of injured lung tissue.


Activated Wnt signaling induces myofibroblast differentiation of mesenchymal stem cells, contributing to pulmonary fibrosis.

Sun Z, Wang C, Shi C, Sun F, Xu X, Qian W, Nie S, Han X - Int. J. Mol. Med. (2014)

Immunofluorescent staining and flow cytometric analysis was used to detect the engraftment of mesenchymal stem cells (MSCs) (white arrows, green fluorescent cells, GFP+ cells) in lung tissue. (A) Immunofluorescent staining detected the engraftment of MSCs. No GFP+ cells (MSCs) are detectable in the control lung tissue, while the expression of stromal cell-derived factor (SDF)-1 (red) is very low. GFP+ cells are detectable in acute lung injury (ALI)+MSC-CXC chemokine receptor (CXCR)4 and ALI+MSC-GFP groups. More GFP+ cells were identified at SDF-1-expressed sites in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP group. Scale bar, 50 μm. (B) Flow cytometric analysis for the engraftment ratio of MSCs in lung tissue. MSCs transfected with Ad-CXCR4 or GFP reporter gene (Ad-GFP) were termed GFP+ cells. Flow cytometry was used to analyze the GFP+ cells in lung cell populations subsequent to MSC administration into lung, as shown in the right area. The SDF-1/CXCR4 axis promotes MSCs to engraft into injured lung tissue. (a) Control group with GFP+ cell injection; (b) MSCs transfected with Ad-GFP is used as positive control; (c) MSC-CXCR4 cells injection in ALI lung on day 7 post-transplantation; (d) MSC-GFP cells injection in ALI lung on day 7 post-transplantation; (e) MSC-CXCR4 cells injection in ALI lung on day 14 post-transplantation; (f) MSC-GFP cells injection in ALI lung on day 14 post-transplantation. More GFP+ cells were detected in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP and control groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

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f3-ijmm-33-05-1097: Immunofluorescent staining and flow cytometric analysis was used to detect the engraftment of mesenchymal stem cells (MSCs) (white arrows, green fluorescent cells, GFP+ cells) in lung tissue. (A) Immunofluorescent staining detected the engraftment of MSCs. No GFP+ cells (MSCs) are detectable in the control lung tissue, while the expression of stromal cell-derived factor (SDF)-1 (red) is very low. GFP+ cells are detectable in acute lung injury (ALI)+MSC-CXC chemokine receptor (CXCR)4 and ALI+MSC-GFP groups. More GFP+ cells were identified at SDF-1-expressed sites in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP group. Scale bar, 50 μm. (B) Flow cytometric analysis for the engraftment ratio of MSCs in lung tissue. MSCs transfected with Ad-CXCR4 or GFP reporter gene (Ad-GFP) were termed GFP+ cells. Flow cytometry was used to analyze the GFP+ cells in lung cell populations subsequent to MSC administration into lung, as shown in the right area. The SDF-1/CXCR4 axis promotes MSCs to engraft into injured lung tissue. (a) Control group with GFP+ cell injection; (b) MSCs transfected with Ad-GFP is used as positive control; (c) MSC-CXCR4 cells injection in ALI lung on day 7 post-transplantation; (d) MSC-GFP cells injection in ALI lung on day 7 post-transplantation; (e) MSC-CXCR4 cells injection in ALI lung on day 14 post-transplantation; (f) MSC-GFP cells injection in ALI lung on day 14 post-transplantation. More GFP+ cells were detected in the ALI+MSC-CXCR4 group compared with the ALI+MSC-GFP and control groups.
Mentions: To assess the engraftment ratio of MSCs at injury sites, we measured the subpopulation of GFP+ cells in lung tissue. Immunofluorescence staining was used to detect the engraftment sites of MSCs (GFP+ cells) in lung tissue. The results showed that MSCs engrafted the injury sites that expressed SDF-1 at a high level (Fig. 3A). More GFP+ cells were identified in SDF-1-expressed sites of the ALI+MSC-CXCR4 group compared to the ALI+MSC-GFP group. Flow cytometry was used to analyze the SDF-1-expressed sites to confirm the role of the SDF-1/CXCR4 axis in the migration of MSCs. Following transplantation of the MSCs for 7 days, ~12% GFP+ cells in the cell population were identified in the ALI+MSC-CXCR4 group; however, only ~2% GFP+ cells were identified in the ALI+MSC-GFP group (Fig. 3B). The results demonstrated that a high expression of SDF-1 at the injury sites and CXCR4 overexpression in MSCs improved the migration of MSCs into injury sites. These results indicated that the SDF-1/CXCR4 chemotactic axis is crucial in regulating the migration of MSCs. For long-term transplantation, GFP+ cells in the cell population showed a similar time-dependent decrease. Following transplantation of the MSCs for 14 days, ~10% GFP+ cells were identified at the injury sites in the ALI+MSC-CXCR4 group. Engraftment of MSCs in the lung marked effects on the fibrosis or reparation of injured lung tissue.

Bottom Line: Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis.The in vitro study results demonstrated that activation of the Wnt/β-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1.Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.

View Article: PubMed Central - PubMed

Affiliation: Immunology and Reproductive Biology Laboratory, Medical School of Nanjing University, Nanjing, Jiangsu 210093, P.R. China.

ABSTRACT
Acute lung injury may lead to fibrogenesis. However, no treatment is currently available. This study was conducted to determine the effects of bone marrow-derived mesenchymal stem cells (MSCs) in a model of HCl-induced acute lung injury in Sprague-Dawley (SD) rats. Stromal cell-derived factor (SDF)-1 and its receptor CXC chemokine receptor (CXCR)4 have been shown to participate in mobilizing MSCs. Adenovirus carrying the CXCR4 gene was used to transfect MSCs in order to increase the engraftment numbers of MSCs at injured sites. Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis. The results showed that engraftment of MSCs almost differentiated into myofibroblasts, but rarely differentiated into lung epithelial cells. Additionally, it was demonstrated that activated canonical Wnt/β-catenin signaling in injured lung tissue regulated the myofibroblast differentiation of MSCs in vivo. The in vitro study results demonstrated that activation of the Wnt/β-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1. Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.

Show MeSH
Related in: MedlinePlus