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Atopic dermatitis-like disease and associated lethal myeloproliferative disorder arise from loss of Notch signaling in the murine skin.

Dumortier A, Durham AD, Di Piazza M, Vauclair S, Koch U, Ferrand G, Ferrero I, Demehri S, Song LL, Farr AG, Leonard WJ, Kopan R, Miele L, Hohl D, Finke D, Radtke F - PLoS ONE (2010)

Bottom Line: The AD-like associated inflammation is accompanied by a myeloproliferative disorder (MPD) characterized by an increase in immature myeloid populations in the bone marrow and spleen.Genetic studies demontrated that G-CSF mediates the MPD as well as changes in the bone marrow microenvironment leading to osteopenia.Our data demonstrate a critical role for Notch in repressing TSLP production in keratinocytes, thereby maintaining integrity of the skin and the hematopoietic system.

View Article: PubMed Central - PubMed

Affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL SV ISREC), Lausanne, Switzerland.

ABSTRACT

Background: The Notch pathway is essential for proper epidermal differentiation during embryonic skin development. Moreover, skin specific loss of Notch signaling in the embryo results in skin barrier defects accompanied by a B-lymphoproliferative disease. However, much less is known about the consequences of loss of Notch signaling after birth.

Methodology and principal findings: To study the function of Notch signaling in the skin of adult mice, we made use of a series of conditional gene targeted mice that allow inactivation of several components of the Notch signaling pathway specifically in the skin. We demonstrate that skin-specific inactivation of Notch1 and Notch2 simultaneously, or RBP-J, induces the development of a severe form of atopic dermatitis (AD), characterized by acanthosis, spongiosis and hyperkeratosis, as well as a massive dermal infiltration of eosinophils and mast cells. Likewise, patients suffering from AD, but not psoriasis or lichen planus, have a marked reduction of Notch receptor expression in the skin. Loss of Notch in keratinocytes induces the production of thymic stromal lymphopoietin (TSLP), a cytokine deeply implicated in the pathogenesis of AD. The AD-like associated inflammation is accompanied by a myeloproliferative disorder (MPD) characterized by an increase in immature myeloid populations in the bone marrow and spleen. Transplantation studies revealed that the MPD is cell non-autonomous and caused by dramatic microenvironmental alterations. Genetic studies demontrated that G-CSF mediates the MPD as well as changes in the bone marrow microenvironment leading to osteopenia.

Significance: Our data demonstrate a critical role for Notch in repressing TSLP production in keratinocytes, thereby maintaining integrity of the skin and the hematopoietic system.

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Related in: MedlinePlus

G-CSF is responsible for the cell non-autonomous development of the TSLP-induced MPD.(A) EPLM cultures on ST-2 cells in presence of IL-7, or increasing concentrations of rmTSLP showing an increase in B cell numbers, but no increase of myeloid cells. The experiment was performed twice, and each cytokine concentration was analyzed as triplicates. (B) Southern blot analysis of genomic DNA from scraped epidermis from control (Ctrl), RBP-JK5, and RBP-JK5G-CSF+/− mice showing the floxed and the recombined (Recomb) alleles of the RBP-J gene. Recombination efficiency is similar for the two mutant mouse strains. Representative blot for n = 3 mice of each genotype, three individual experiments. (C) HE staining on skin (two upper panels) and spleen (bottom panels) sections from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice. Macroscopy of the spleens in inserts (n = 5 mice per sample group from two individual experiments). (D) Serum G-CSF and TSLP levels in control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice (* = p value<0.02). The bar diagrams represent mean values ± SD (n = 5 per sample group of mice from two individual experiments). Representative flow cytometric analysis of myeloid and B cells of the spleen (E) and the bone marrow (F) from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice stained for CD11b and Gr1, or CD21 and CD23 (gated on B220+ splenic B cells), or B220 and CD43 within the BM compartment (n = 5 per sample group from two individual experiments). [Scale bars: 50 µm].
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pone-0009258-g006: G-CSF is responsible for the cell non-autonomous development of the TSLP-induced MPD.(A) EPLM cultures on ST-2 cells in presence of IL-7, or increasing concentrations of rmTSLP showing an increase in B cell numbers, but no increase of myeloid cells. The experiment was performed twice, and each cytokine concentration was analyzed as triplicates. (B) Southern blot analysis of genomic DNA from scraped epidermis from control (Ctrl), RBP-JK5, and RBP-JK5G-CSF+/− mice showing the floxed and the recombined (Recomb) alleles of the RBP-J gene. Recombination efficiency is similar for the two mutant mouse strains. Representative blot for n = 3 mice of each genotype, three individual experiments. (C) HE staining on skin (two upper panels) and spleen (bottom panels) sections from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice. Macroscopy of the spleens in inserts (n = 5 mice per sample group from two individual experiments). (D) Serum G-CSF and TSLP levels in control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice (* = p value<0.02). The bar diagrams represent mean values ± SD (n = 5 per sample group of mice from two individual experiments). Representative flow cytometric analysis of myeloid and B cells of the spleen (E) and the bone marrow (F) from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice stained for CD11b and Gr1, or CD21 and CD23 (gated on B220+ splenic B cells), or B220 and CD43 within the BM compartment (n = 5 per sample group from two individual experiments). [Scale bars: 50 µm].

Mentions: As TSLP is mostly known to influence and/or promote B cell development [31], [32], [33], it is not clear how it can induce a MPD. To determine whether TSLP functions in a direct manner to cause the MPD in N1N2K5 mice, we investigated the influence of TSLP on hematopoietic differentiation. WT early BM progenitors with lymphoid and myeloid potential (EPLM: CD117+B220int/+CD93+CD19-CD3-NK1.1-) [34] were cultured on stromal ST-2 cells in the presence of IL-7, an essential cytokine to promote B cell development, or with increasing concentrations of recombinant murine TSLP. BM progenitors cultured with TSLP (0.5-50 ng/ml) showed a developmental skew towards the B cell lineage, implying that TSLP can substitute for IL-7 and thus favors B cell development, which is in agreement with previous reports [31], [32], [33]. Even high concentrations of TSLP in the culture medium did not lead to an expansion of myeloid cells (Figure 6A) suggesting that TSLP cannot enhance proliferation or differentiation of immature progenitors into the myeloid lineage in a cell autonomous manner.


Atopic dermatitis-like disease and associated lethal myeloproliferative disorder arise from loss of Notch signaling in the murine skin.

Dumortier A, Durham AD, Di Piazza M, Vauclair S, Koch U, Ferrand G, Ferrero I, Demehri S, Song LL, Farr AG, Leonard WJ, Kopan R, Miele L, Hohl D, Finke D, Radtke F - PLoS ONE (2010)

G-CSF is responsible for the cell non-autonomous development of the TSLP-induced MPD.(A) EPLM cultures on ST-2 cells in presence of IL-7, or increasing concentrations of rmTSLP showing an increase in B cell numbers, but no increase of myeloid cells. The experiment was performed twice, and each cytokine concentration was analyzed as triplicates. (B) Southern blot analysis of genomic DNA from scraped epidermis from control (Ctrl), RBP-JK5, and RBP-JK5G-CSF+/− mice showing the floxed and the recombined (Recomb) alleles of the RBP-J gene. Recombination efficiency is similar for the two mutant mouse strains. Representative blot for n = 3 mice of each genotype, three individual experiments. (C) HE staining on skin (two upper panels) and spleen (bottom panels) sections from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice. Macroscopy of the spleens in inserts (n = 5 mice per sample group from two individual experiments). (D) Serum G-CSF and TSLP levels in control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice (* = p value<0.02). The bar diagrams represent mean values ± SD (n = 5 per sample group of mice from two individual experiments). Representative flow cytometric analysis of myeloid and B cells of the spleen (E) and the bone marrow (F) from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice stained for CD11b and Gr1, or CD21 and CD23 (gated on B220+ splenic B cells), or B220 and CD43 within the BM compartment (n = 5 per sample group from two individual experiments). [Scale bars: 50 µm].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2823782&req=5

pone-0009258-g006: G-CSF is responsible for the cell non-autonomous development of the TSLP-induced MPD.(A) EPLM cultures on ST-2 cells in presence of IL-7, or increasing concentrations of rmTSLP showing an increase in B cell numbers, but no increase of myeloid cells. The experiment was performed twice, and each cytokine concentration was analyzed as triplicates. (B) Southern blot analysis of genomic DNA from scraped epidermis from control (Ctrl), RBP-JK5, and RBP-JK5G-CSF+/− mice showing the floxed and the recombined (Recomb) alleles of the RBP-J gene. Recombination efficiency is similar for the two mutant mouse strains. Representative blot for n = 3 mice of each genotype, three individual experiments. (C) HE staining on skin (two upper panels) and spleen (bottom panels) sections from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice. Macroscopy of the spleens in inserts (n = 5 mice per sample group from two individual experiments). (D) Serum G-CSF and TSLP levels in control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice (* = p value<0.02). The bar diagrams represent mean values ± SD (n = 5 per sample group of mice from two individual experiments). Representative flow cytometric analysis of myeloid and B cells of the spleen (E) and the bone marrow (F) from control (Ctrl), RBP-JK5 and RBP-JK5/G-CSF+/− mice stained for CD11b and Gr1, or CD21 and CD23 (gated on B220+ splenic B cells), or B220 and CD43 within the BM compartment (n = 5 per sample group from two individual experiments). [Scale bars: 50 µm].
Mentions: As TSLP is mostly known to influence and/or promote B cell development [31], [32], [33], it is not clear how it can induce a MPD. To determine whether TSLP functions in a direct manner to cause the MPD in N1N2K5 mice, we investigated the influence of TSLP on hematopoietic differentiation. WT early BM progenitors with lymphoid and myeloid potential (EPLM: CD117+B220int/+CD93+CD19-CD3-NK1.1-) [34] were cultured on stromal ST-2 cells in the presence of IL-7, an essential cytokine to promote B cell development, or with increasing concentrations of recombinant murine TSLP. BM progenitors cultured with TSLP (0.5-50 ng/ml) showed a developmental skew towards the B cell lineage, implying that TSLP can substitute for IL-7 and thus favors B cell development, which is in agreement with previous reports [31], [32], [33]. Even high concentrations of TSLP in the culture medium did not lead to an expansion of myeloid cells (Figure 6A) suggesting that TSLP cannot enhance proliferation or differentiation of immature progenitors into the myeloid lineage in a cell autonomous manner.

Bottom Line: The AD-like associated inflammation is accompanied by a myeloproliferative disorder (MPD) characterized by an increase in immature myeloid populations in the bone marrow and spleen.Genetic studies demontrated that G-CSF mediates the MPD as well as changes in the bone marrow microenvironment leading to osteopenia.Our data demonstrate a critical role for Notch in repressing TSLP production in keratinocytes, thereby maintaining integrity of the skin and the hematopoietic system.

View Article: PubMed Central - PubMed

Affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL SV ISREC), Lausanne, Switzerland.

ABSTRACT

Background: The Notch pathway is essential for proper epidermal differentiation during embryonic skin development. Moreover, skin specific loss of Notch signaling in the embryo results in skin barrier defects accompanied by a B-lymphoproliferative disease. However, much less is known about the consequences of loss of Notch signaling after birth.

Methodology and principal findings: To study the function of Notch signaling in the skin of adult mice, we made use of a series of conditional gene targeted mice that allow inactivation of several components of the Notch signaling pathway specifically in the skin. We demonstrate that skin-specific inactivation of Notch1 and Notch2 simultaneously, or RBP-J, induces the development of a severe form of atopic dermatitis (AD), characterized by acanthosis, spongiosis and hyperkeratosis, as well as a massive dermal infiltration of eosinophils and mast cells. Likewise, patients suffering from AD, but not psoriasis or lichen planus, have a marked reduction of Notch receptor expression in the skin. Loss of Notch in keratinocytes induces the production of thymic stromal lymphopoietin (TSLP), a cytokine deeply implicated in the pathogenesis of AD. The AD-like associated inflammation is accompanied by a myeloproliferative disorder (MPD) characterized by an increase in immature myeloid populations in the bone marrow and spleen. Transplantation studies revealed that the MPD is cell non-autonomous and caused by dramatic microenvironmental alterations. Genetic studies demontrated that G-CSF mediates the MPD as well as changes in the bone marrow microenvironment leading to osteopenia.

Significance: Our data demonstrate a critical role for Notch in repressing TSLP production in keratinocytes, thereby maintaining integrity of the skin and the hematopoietic system.

Show MeSH
Related in: MedlinePlus