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Bleomycin-Treated Chimeric Thy1-Deficient Mice with Thy1-Deficient Myofibroblasts and Thy-Positive Lymphocytes Resolve Inflammation without Affecting the Fibrotic Response.

Cohen PY, Breuer R, Zisman P, Wallach-Dayan SB - Mediators Inflamm. (2015)

Bottom Line: Using gene chip analysis, we detected that myofibroblast Thy1 crosslinking mediates downregulation of genes promoting cell proliferation, survival, and differentiation, and reduces production of extracellular matrix (ECM) components, while concurrently mediating the upregulation of genes known to foster inflammation and immunological functions.Lung myofibroblasts downregulate Thy1 expression to increase their proliferation but to diminish the in vivo inflammatory milieu.Inflammation is not essential for evolution of fibrosis as was previously stated.

View Article: PubMed Central - PubMed

Affiliation: Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel.

ABSTRACT
Lung fibrosis is characterized by abnormal accumulation of fibroblasts in the interstitium of the alveolar space. Two populations of myofibroblasts, distinguished by Thy1 expression, are detected in human and murine lungs. Accumulation of Thy1-negative (Thy1(-)) myofibroblasts was shown in the lungs of humans with idiopathic pulmonary fibrosis (IPF) and of bleomycin-treated mice. We aimed to identify genetic changes in lung myofibroblasts following Thy1 crosslinking and assess the impact of specific lung myofibroblast Thy1-deficiency, in vivo, in bleomycin-injured mouse lungs. Thy1 increased in mouse lung lymphocytes following bleomycin injury but decreased in myofibroblasts when fibrosis was at the highest point (14 days), as assessed by immunohistochemistry. Using gene chip analysis, we detected that myofibroblast Thy1 crosslinking mediates downregulation of genes promoting cell proliferation, survival, and differentiation, and reduces production of extracellular matrix (ECM) components, while concurrently mediating the upregulation of genes known to foster inflammation and immunological functions. Chimeric Thy1-deficient mice with Thy1(+) lymphocytes and Thy1(-) myofibroblasts showed fibrosis similar to wild-type mice and an increased number of CD4/CD25 regulatory T cells, with a concomitant decrease in inflammation. Lung myofibroblasts downregulate Thy1 expression to increase their proliferation but to diminish the in vivo inflammatory milieu. Inflammation is not essential for evolution of fibrosis as was previously stated.

No MeSH data available.


Related in: MedlinePlus

Assessment of the T cell population following bleomycin intratracheal instillation (IT) in wild-type mice (WT) (control) with Thy1+ lymphocytes and Thy1+ myofibroblasts, and chimeric Thy1-deficient mice with Thy1+ lymphocytes and Thy1− myofibroblasts. Chimeric Thy1-deficient mice were created by total body irradiation (750 rad) of Thy1-deficient mice, followed by transplantation with WT Thy1+ lymphoid cells. For comparison, wild-type (WT) mice were irradiated and had adoptive transfer with Thy1+ (WT) lymphoid cells. (A1 and A2) Immunofluorescence of CD4+/CD25+, and (B1 and B2) CD8 staining of mouse lung sections 14 d following IT bleomycin in chimeric Thy1-deficient mice (empty bars) and control WT mice (grey bars). N 6 = 5 WT and 8 chimeric Thy1-deficient. (A1) Nomarski microscopy pictures of CD4/CD25 (yellow) (∗P < 0.05), and (B1) CD8 (green) staining are presented. (A2 and B2) 10 fields of every immunofluorescence slide were digitized and semiquantitatively analyzed using the Ariol system. The relative staining ratio represents the ratio between numbers of stained and unstained cells in a certain analyzed are. The results were similar in 2 different experiments.
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fig4: Assessment of the T cell population following bleomycin intratracheal instillation (IT) in wild-type mice (WT) (control) with Thy1+ lymphocytes and Thy1+ myofibroblasts, and chimeric Thy1-deficient mice with Thy1+ lymphocytes and Thy1− myofibroblasts. Chimeric Thy1-deficient mice were created by total body irradiation (750 rad) of Thy1-deficient mice, followed by transplantation with WT Thy1+ lymphoid cells. For comparison, wild-type (WT) mice were irradiated and had adoptive transfer with Thy1+ (WT) lymphoid cells. (A1 and A2) Immunofluorescence of CD4+/CD25+, and (B1 and B2) CD8 staining of mouse lung sections 14 d following IT bleomycin in chimeric Thy1-deficient mice (empty bars) and control WT mice (grey bars). N 6 = 5 WT and 8 chimeric Thy1-deficient. (A1) Nomarski microscopy pictures of CD4/CD25 (yellow) (∗P < 0.05), and (B1) CD8 (green) staining are presented. (A2 and B2) 10 fields of every immunofluorescence slide were digitized and semiquantitatively analyzed using the Ariol system. The relative staining ratio represents the ratio between numbers of stained and unstained cells in a certain analyzed are. The results were similar in 2 different experiments.

Mentions: Having shown decreased inflammation in the lungs of chimeric Thy1-deficient mice compared to WT mice, we determined the differences in the inflammatory cell mileux of their lungs. We stained lung sections with anti-CD8 (cytotoxic cells) and costained them with anti-CD4 and anti-CD25 mAbs (T regulatory cells). A much larger number of CD4+/CD25+ lymphocytes were detected in chimeric Thy1-deficient mice when compared to WT mice (Figures 4(A1) and 4(A2)); however, there were a comparable number of CD8 cells in WT and Thy1-deficient mice (Figures 4(B1) and 4(B2)).


Bleomycin-Treated Chimeric Thy1-Deficient Mice with Thy1-Deficient Myofibroblasts and Thy-Positive Lymphocytes Resolve Inflammation without Affecting the Fibrotic Response.

Cohen PY, Breuer R, Zisman P, Wallach-Dayan SB - Mediators Inflamm. (2015)

Assessment of the T cell population following bleomycin intratracheal instillation (IT) in wild-type mice (WT) (control) with Thy1+ lymphocytes and Thy1+ myofibroblasts, and chimeric Thy1-deficient mice with Thy1+ lymphocytes and Thy1− myofibroblasts. Chimeric Thy1-deficient mice were created by total body irradiation (750 rad) of Thy1-deficient mice, followed by transplantation with WT Thy1+ lymphoid cells. For comparison, wild-type (WT) mice were irradiated and had adoptive transfer with Thy1+ (WT) lymphoid cells. (A1 and A2) Immunofluorescence of CD4+/CD25+, and (B1 and B2) CD8 staining of mouse lung sections 14 d following IT bleomycin in chimeric Thy1-deficient mice (empty bars) and control WT mice (grey bars). N 6 = 5 WT and 8 chimeric Thy1-deficient. (A1) Nomarski microscopy pictures of CD4/CD25 (yellow) (∗P < 0.05), and (B1) CD8 (green) staining are presented. (A2 and B2) 10 fields of every immunofluorescence slide were digitized and semiquantitatively analyzed using the Ariol system. The relative staining ratio represents the ratio between numbers of stained and unstained cells in a certain analyzed are. The results were similar in 2 different experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4537759&req=5

fig4: Assessment of the T cell population following bleomycin intratracheal instillation (IT) in wild-type mice (WT) (control) with Thy1+ lymphocytes and Thy1+ myofibroblasts, and chimeric Thy1-deficient mice with Thy1+ lymphocytes and Thy1− myofibroblasts. Chimeric Thy1-deficient mice were created by total body irradiation (750 rad) of Thy1-deficient mice, followed by transplantation with WT Thy1+ lymphoid cells. For comparison, wild-type (WT) mice were irradiated and had adoptive transfer with Thy1+ (WT) lymphoid cells. (A1 and A2) Immunofluorescence of CD4+/CD25+, and (B1 and B2) CD8 staining of mouse lung sections 14 d following IT bleomycin in chimeric Thy1-deficient mice (empty bars) and control WT mice (grey bars). N 6 = 5 WT and 8 chimeric Thy1-deficient. (A1) Nomarski microscopy pictures of CD4/CD25 (yellow) (∗P < 0.05), and (B1) CD8 (green) staining are presented. (A2 and B2) 10 fields of every immunofluorescence slide were digitized and semiquantitatively analyzed using the Ariol system. The relative staining ratio represents the ratio between numbers of stained and unstained cells in a certain analyzed are. The results were similar in 2 different experiments.
Mentions: Having shown decreased inflammation in the lungs of chimeric Thy1-deficient mice compared to WT mice, we determined the differences in the inflammatory cell mileux of their lungs. We stained lung sections with anti-CD8 (cytotoxic cells) and costained them with anti-CD4 and anti-CD25 mAbs (T regulatory cells). A much larger number of CD4+/CD25+ lymphocytes were detected in chimeric Thy1-deficient mice when compared to WT mice (Figures 4(A1) and 4(A2)); however, there were a comparable number of CD8 cells in WT and Thy1-deficient mice (Figures 4(B1) and 4(B2)).

Bottom Line: Using gene chip analysis, we detected that myofibroblast Thy1 crosslinking mediates downregulation of genes promoting cell proliferation, survival, and differentiation, and reduces production of extracellular matrix (ECM) components, while concurrently mediating the upregulation of genes known to foster inflammation and immunological functions.Lung myofibroblasts downregulate Thy1 expression to increase their proliferation but to diminish the in vivo inflammatory milieu.Inflammation is not essential for evolution of fibrosis as was previously stated.

View Article: PubMed Central - PubMed

Affiliation: Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel.

ABSTRACT
Lung fibrosis is characterized by abnormal accumulation of fibroblasts in the interstitium of the alveolar space. Two populations of myofibroblasts, distinguished by Thy1 expression, are detected in human and murine lungs. Accumulation of Thy1-negative (Thy1(-)) myofibroblasts was shown in the lungs of humans with idiopathic pulmonary fibrosis (IPF) and of bleomycin-treated mice. We aimed to identify genetic changes in lung myofibroblasts following Thy1 crosslinking and assess the impact of specific lung myofibroblast Thy1-deficiency, in vivo, in bleomycin-injured mouse lungs. Thy1 increased in mouse lung lymphocytes following bleomycin injury but decreased in myofibroblasts when fibrosis was at the highest point (14 days), as assessed by immunohistochemistry. Using gene chip analysis, we detected that myofibroblast Thy1 crosslinking mediates downregulation of genes promoting cell proliferation, survival, and differentiation, and reduces production of extracellular matrix (ECM) components, while concurrently mediating the upregulation of genes known to foster inflammation and immunological functions. Chimeric Thy1-deficient mice with Thy1(+) lymphocytes and Thy1(-) myofibroblasts showed fibrosis similar to wild-type mice and an increased number of CD4/CD25 regulatory T cells, with a concomitant decrease in inflammation. Lung myofibroblasts downregulate Thy1 expression to increase their proliferation but to diminish the in vivo inflammatory milieu. Inflammation is not essential for evolution of fibrosis as was previously stated.

No MeSH data available.


Related in: MedlinePlus