Limits...
Superficial dsg2 expression limits epidermal blister formation mediated by pemphigus foliaceus antibodies and exfoliative toxins.

Brennan D, Hu Y, Medhat W, Dowling A, Mahoney MG - Dermatol Res Pract (2010)

Bottom Line: Cell-cell adhesion mediated by desmosomes is crucial for maintaining proper epidermal structure and function, as evidenced by several severe and potentially fatal skin disorders involving impairment of desmosomal proteins.We showed that ectopic expression of Dsg2 reduced the extent of blister formation in response to both ETA and PF Ig.Collectively, our data support the role for Dsg2 in cell adhesion and suggest that ectopic superficial expression of Dsg2 can increase membrane preservation of Dsg1 and limit epidermal blister formation mediated by PF antibodies and exfoliative toxins.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.

ABSTRACT
Cell-cell adhesion mediated by desmosomes is crucial for maintaining proper epidermal structure and function, as evidenced by several severe and potentially fatal skin disorders involving impairment of desmosomal proteins. Pemphigus foliaceus (PF) and staphylococcal scalded skin syndrome (SSSS) are subcorneal blistering diseases resulting from loss of function of the desmosomal cadherin, desmoglein 1 (Dsg1). To further study the pathomechanism of these diseases and to assess the adhesive properties of Dsg2, we employed a recently established transgenic (Tg) mouse model expressing Dsg2 in the superficial epidermis. Neonatal Tg and wild type (WT) mice were injected with purified ETA or PF Ig. We showed that ectopic expression of Dsg2 reduced the extent of blister formation in response to both ETA and PF Ig. In response to PF Ig, we observed either a dramatic loss or a reorganization of Dsg1-alpha, Dsg1-beta, and, to a lesser extent, Dsg1-gamma, in WT mice. The Inv-Dsg2 Tg mice showed enhanced retention of Dsg1 at the cell-cell border. Collectively, our data support the role for Dsg2 in cell adhesion and suggest that ectopic superficial expression of Dsg2 can increase membrane preservation of Dsg1 and limit epidermal blister formation mediated by PF antibodies and exfoliative toxins.

No MeSH data available.


Related in: MedlinePlus

Superficial expression of Dsg2 reduces disruption of Dsg1 in response to PF Ig. Newborn WT and Dsg2 Tg mice were injected subcutaneously with PF Ig, and, 18 hours later, back skin samples were frozen in OCT or were fixed in formalin and embedded in paraffin for immunostaining. (a) Direct immunostaining for human Ig (hIg, left panels), showing localization of human antibodies to the epidermis after PF Ig passive transfer. The same tissue was immunostained with Flag antibodies, demonstrating the presence of Dsg2-Flag in the Tg, but not WT, skin (middle panels). Double labeling for the human Ig (red) and the Flag tag (green) is shown (right panels). Staining of human Ig was considerably more intact at the cell-cell border in the Tg skin, particularly in the superficial epidermis, where Dsg2 was expressed. Thus, superficial Dsg2 retains PF Ig at the cell-cell borders. (b) Lesional and nonlesional back skin sections were then immunostained with antibodies AP61, AP498, and Ab15, which were raised against the extracellular domain of Dsg1-α, Dsg1-β, and Dsg1-γ, respectively. DAPI (blue) was used as a nuclear stain. Arrows demarcate site of blister cleavage (lesional skin). In WT mice, treatment with PF Ig dramatically disrupted cell-cell border staining of Dsg1-α and Dsg1-β but not Dsg1-γ (left panels). Superficial expression of Dsg2 reduced the extent of Dsg1 perturbation (internalization and degradation). There was no significantly observable difference between lesional and non-lesional epidermis.
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fig5: Superficial expression of Dsg2 reduces disruption of Dsg1 in response to PF Ig. Newborn WT and Dsg2 Tg mice were injected subcutaneously with PF Ig, and, 18 hours later, back skin samples were frozen in OCT or were fixed in formalin and embedded in paraffin for immunostaining. (a) Direct immunostaining for human Ig (hIg, left panels), showing localization of human antibodies to the epidermis after PF Ig passive transfer. The same tissue was immunostained with Flag antibodies, demonstrating the presence of Dsg2-Flag in the Tg, but not WT, skin (middle panels). Double labeling for the human Ig (red) and the Flag tag (green) is shown (right panels). Staining of human Ig was considerably more intact at the cell-cell border in the Tg skin, particularly in the superficial epidermis, where Dsg2 was expressed. Thus, superficial Dsg2 retains PF Ig at the cell-cell borders. (b) Lesional and nonlesional back skin sections were then immunostained with antibodies AP61, AP498, and Ab15, which were raised against the extracellular domain of Dsg1-α, Dsg1-β, and Dsg1-γ, respectively. DAPI (blue) was used as a nuclear stain. Arrows demarcate site of blister cleavage (lesional skin). In WT mice, treatment with PF Ig dramatically disrupted cell-cell border staining of Dsg1-α and Dsg1-β but not Dsg1-γ (left panels). Superficial expression of Dsg2 reduced the extent of Dsg1 perturbation (internalization and degradation). There was no significantly observable difference between lesional and non-lesional epidermis.

Mentions: Next, we wanted to evaluate whether or not superficial expression of Dsg2 had an effect on Dsg1 fate and localization in response to PF Ig. We first confirmed, by direct immunostaining, the presence of human antibodies in the skin of mice treated with PF Ig (Figure 5(a), left panels). The human Ig was detected in the epidermis of both WT and Tg skin. In WT skin, staining for human antibodies was diffuse and was disrupted by some cytoplasmic staining. Interestingly, in the Tg epidermis, the staining for human antibodies was clearly at the cell-cell borders, suggesting, perhaps, the presence of more intact desmosomes (Figure 5(a), lower left panel). We also immunostained the same tissues for Dsg2-Flag to demonstrate that Tg, but not WT, mice expressed the Dsg2-Flag transgene (Figure 5(a), middle panels). Double labeling (Figure 5(a), right panels) showed colocalization (yellow) of Dsg2 (green) and human Ig (red) at the cell-cell border in the superficial epidermis (lower right panel).


Superficial dsg2 expression limits epidermal blister formation mediated by pemphigus foliaceus antibodies and exfoliative toxins.

Brennan D, Hu Y, Medhat W, Dowling A, Mahoney MG - Dermatol Res Pract (2010)

Superficial expression of Dsg2 reduces disruption of Dsg1 in response to PF Ig. Newborn WT and Dsg2 Tg mice were injected subcutaneously with PF Ig, and, 18 hours later, back skin samples were frozen in OCT or were fixed in formalin and embedded in paraffin for immunostaining. (a) Direct immunostaining for human Ig (hIg, left panels), showing localization of human antibodies to the epidermis after PF Ig passive transfer. The same tissue was immunostained with Flag antibodies, demonstrating the presence of Dsg2-Flag in the Tg, but not WT, skin (middle panels). Double labeling for the human Ig (red) and the Flag tag (green) is shown (right panels). Staining of human Ig was considerably more intact at the cell-cell border in the Tg skin, particularly in the superficial epidermis, where Dsg2 was expressed. Thus, superficial Dsg2 retains PF Ig at the cell-cell borders. (b) Lesional and nonlesional back skin sections were then immunostained with antibodies AP61, AP498, and Ab15, which were raised against the extracellular domain of Dsg1-α, Dsg1-β, and Dsg1-γ, respectively. DAPI (blue) was used as a nuclear stain. Arrows demarcate site of blister cleavage (lesional skin). In WT mice, treatment with PF Ig dramatically disrupted cell-cell border staining of Dsg1-α and Dsg1-β but not Dsg1-γ (left panels). Superficial expression of Dsg2 reduced the extent of Dsg1 perturbation (internalization and degradation). There was no significantly observable difference between lesional and non-lesional epidermis.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig5: Superficial expression of Dsg2 reduces disruption of Dsg1 in response to PF Ig. Newborn WT and Dsg2 Tg mice were injected subcutaneously with PF Ig, and, 18 hours later, back skin samples were frozen in OCT or were fixed in formalin and embedded in paraffin for immunostaining. (a) Direct immunostaining for human Ig (hIg, left panels), showing localization of human antibodies to the epidermis after PF Ig passive transfer. The same tissue was immunostained with Flag antibodies, demonstrating the presence of Dsg2-Flag in the Tg, but not WT, skin (middle panels). Double labeling for the human Ig (red) and the Flag tag (green) is shown (right panels). Staining of human Ig was considerably more intact at the cell-cell border in the Tg skin, particularly in the superficial epidermis, where Dsg2 was expressed. Thus, superficial Dsg2 retains PF Ig at the cell-cell borders. (b) Lesional and nonlesional back skin sections were then immunostained with antibodies AP61, AP498, and Ab15, which were raised against the extracellular domain of Dsg1-α, Dsg1-β, and Dsg1-γ, respectively. DAPI (blue) was used as a nuclear stain. Arrows demarcate site of blister cleavage (lesional skin). In WT mice, treatment with PF Ig dramatically disrupted cell-cell border staining of Dsg1-α and Dsg1-β but not Dsg1-γ (left panels). Superficial expression of Dsg2 reduced the extent of Dsg1 perturbation (internalization and degradation). There was no significantly observable difference between lesional and non-lesional epidermis.
Mentions: Next, we wanted to evaluate whether or not superficial expression of Dsg2 had an effect on Dsg1 fate and localization in response to PF Ig. We first confirmed, by direct immunostaining, the presence of human antibodies in the skin of mice treated with PF Ig (Figure 5(a), left panels). The human Ig was detected in the epidermis of both WT and Tg skin. In WT skin, staining for human antibodies was diffuse and was disrupted by some cytoplasmic staining. Interestingly, in the Tg epidermis, the staining for human antibodies was clearly at the cell-cell borders, suggesting, perhaps, the presence of more intact desmosomes (Figure 5(a), lower left panel). We also immunostained the same tissues for Dsg2-Flag to demonstrate that Tg, but not WT, mice expressed the Dsg2-Flag transgene (Figure 5(a), middle panels). Double labeling (Figure 5(a), right panels) showed colocalization (yellow) of Dsg2 (green) and human Ig (red) at the cell-cell border in the superficial epidermis (lower right panel).

Bottom Line: Cell-cell adhesion mediated by desmosomes is crucial for maintaining proper epidermal structure and function, as evidenced by several severe and potentially fatal skin disorders involving impairment of desmosomal proteins.We showed that ectopic expression of Dsg2 reduced the extent of blister formation in response to both ETA and PF Ig.Collectively, our data support the role for Dsg2 in cell adhesion and suggest that ectopic superficial expression of Dsg2 can increase membrane preservation of Dsg1 and limit epidermal blister formation mediated by PF antibodies and exfoliative toxins.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.

ABSTRACT
Cell-cell adhesion mediated by desmosomes is crucial for maintaining proper epidermal structure and function, as evidenced by several severe and potentially fatal skin disorders involving impairment of desmosomal proteins. Pemphigus foliaceus (PF) and staphylococcal scalded skin syndrome (SSSS) are subcorneal blistering diseases resulting from loss of function of the desmosomal cadherin, desmoglein 1 (Dsg1). To further study the pathomechanism of these diseases and to assess the adhesive properties of Dsg2, we employed a recently established transgenic (Tg) mouse model expressing Dsg2 in the superficial epidermis. Neonatal Tg and wild type (WT) mice were injected with purified ETA or PF Ig. We showed that ectopic expression of Dsg2 reduced the extent of blister formation in response to both ETA and PF Ig. In response to PF Ig, we observed either a dramatic loss or a reorganization of Dsg1-alpha, Dsg1-beta, and, to a lesser extent, Dsg1-gamma, in WT mice. The Inv-Dsg2 Tg mice showed enhanced retention of Dsg1 at the cell-cell border. Collectively, our data support the role for Dsg2 in cell adhesion and suggest that ectopic superficial expression of Dsg2 can increase membrane preservation of Dsg1 and limit epidermal blister formation mediated by PF antibodies and exfoliative toxins.

No MeSH data available.


Related in: MedlinePlus