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 offers protection from ETA-induced blister formation. (a) Newborn WT and Inv-Dsg2 Tg mice were injected subcutaneously with 0.5 μg ETA in PBS. Visible blisters were observed in WT but not Tg mice, 6–8 hours after ETA treatment. (b) Mice were sacrificed, and their skin was processed for histological analysis, revealing slightly more extensive blisters in the WT mice (n = 14), as compared to Tg mice (n = 23), in response to ETA. Top panels show 3X magnification, and lower panels show 40X magnification of the site of blister formation. (c) The extent of blistering was graded based on the following semiquantitative scale: 0: no blisters, 1+: minor blisters at the edge; 2+: localized blisters <50%; 3+: extensive blisters >50%; and 4+: very extensive blisters >75%. Each dot represents one mouse. The average blister scores were 2.6 ± 1.2 for WT and 1.7 ± 1.3 for Tg. These values were statistically significant, P ≤  .038260921 (2-tailed unequal variance) or ≤  .01913046 (1-tailed unequal variance). (d) The back skin biopsies were homogenized in Laemmli buffer, proteins were resolved with SDS-PAGE and immunoblotted for Dsg1 (27B2), Dsg2-Flag (Flag), and Actin (for equal loading). Western blotting demonstrates that ETA cleaved Dsg1 (arrowhead), but not Dsg2. Note. antibody 27B2 was raised against the cytoplasmic epitope of human Dsg1, and recognizes mouse Dsg1-a, -β, and -γ. Thus, the full-length signal is most likely ETA-resistant Dsg1-γ.
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fig2: Superficial expression of Dsg2 offers protection from ETA-induced blister formation. (a) Newborn WT and Inv-Dsg2 Tg mice were injected subcutaneously with 0.5 μg ETA in PBS. Visible blisters were observed in WT but not Tg mice, 6–8 hours after ETA treatment. (b) Mice were sacrificed, and their skin was processed for histological analysis, revealing slightly more extensive blisters in the WT mice (n = 14), as compared to Tg mice (n = 23), in response to ETA. Top panels show 3X magnification, and lower panels show 40X magnification of the site of blister formation. (c) The extent of blistering was graded based on the following semiquantitative scale: 0: no blisters, 1+: minor blisters at the edge; 2+: localized blisters <50%; 3+: extensive blisters >50%; and 4+: very extensive blisters >75%. Each dot represents one mouse. The average blister scores were 2.6 ± 1.2 for WT and 1.7 ± 1.3 for Tg. These values were statistically significant, P ≤  .038260921 (2-tailed unequal variance) or ≤  .01913046 (1-tailed unequal variance). (d) The back skin biopsies were homogenized in Laemmli buffer, proteins were resolved with SDS-PAGE and immunoblotted for Dsg1 (27B2), Dsg2-Flag (Flag), and Actin (for equal loading). Western blotting demonstrates that ETA cleaved Dsg1 (arrowhead), but not Dsg2. Note. antibody 27B2 was raised against the cytoplasmic epitope of human Dsg1, and recognizes mouse Dsg1-a, -β, and -γ. Thus, the full-length signal is most likely ETA-resistant Dsg1-γ.

Mentions: It is well established that ETA cleaves Dsg1 and causes epidermal blisters in the upper layers of the epidermis, where Dsg1 is highly expressed [16]. Mice treated with purified ETA develop blisters similar to those seen in patients infected with S. aureus. To determine whether Dsg2 could compensate for the loss of Dsg1, we treated neonatal WT and Tg mice with purified ETA. In response to subcutaneous injection of ETA, we observed dramatic gross blisters in WT, but not Tg, mice (Figure 2(a)). However, the results from the histologic analysis were less definitive, since some Tg mice developed extensive blisters while others showed a resistance to blister formation (Figure 2(b), top panels).


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 offers protection from ETA-induced blister formation. (a) Newborn WT and Inv-Dsg2 Tg mice were injected subcutaneously with 0.5 μg ETA in PBS. Visible blisters were observed in WT but not Tg mice, 6–8 hours after ETA treatment. (b) Mice were sacrificed, and their skin was processed for histological analysis, revealing slightly more extensive blisters in the WT mice (n = 14), as compared to Tg mice (n = 23), in response to ETA. Top panels show 3X magnification, and lower panels show 40X magnification of the site of blister formation. (c) The extent of blistering was graded based on the following semiquantitative scale: 0: no blisters, 1+: minor blisters at the edge; 2+: localized blisters <50%; 3+: extensive blisters >50%; and 4+: very extensive blisters >75%. Each dot represents one mouse. The average blister scores were 2.6 ± 1.2 for WT and 1.7 ± 1.3 for Tg. These values were statistically significant, P ≤  .038260921 (2-tailed unequal variance) or ≤  .01913046 (1-tailed unequal variance). (d) The back skin biopsies were homogenized in Laemmli buffer, proteins were resolved with SDS-PAGE and immunoblotted for Dsg1 (27B2), Dsg2-Flag (Flag), and Actin (for equal loading). Western blotting demonstrates that ETA cleaved Dsg1 (arrowhead), but not Dsg2. Note. antibody 27B2 was raised against the cytoplasmic epitope of human Dsg1, and recognizes mouse Dsg1-a, -β, and -γ. Thus, the full-length signal is most likely ETA-resistant Dsg1-γ.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig2: Superficial expression of Dsg2 offers protection from ETA-induced blister formation. (a) Newborn WT and Inv-Dsg2 Tg mice were injected subcutaneously with 0.5 μg ETA in PBS. Visible blisters were observed in WT but not Tg mice, 6–8 hours after ETA treatment. (b) Mice were sacrificed, and their skin was processed for histological analysis, revealing slightly more extensive blisters in the WT mice (n = 14), as compared to Tg mice (n = 23), in response to ETA. Top panels show 3X magnification, and lower panels show 40X magnification of the site of blister formation. (c) The extent of blistering was graded based on the following semiquantitative scale: 0: no blisters, 1+: minor blisters at the edge; 2+: localized blisters <50%; 3+: extensive blisters >50%; and 4+: very extensive blisters >75%. Each dot represents one mouse. The average blister scores were 2.6 ± 1.2 for WT and 1.7 ± 1.3 for Tg. These values were statistically significant, P ≤  .038260921 (2-tailed unequal variance) or ≤  .01913046 (1-tailed unequal variance). (d) The back skin biopsies were homogenized in Laemmli buffer, proteins were resolved with SDS-PAGE and immunoblotted for Dsg1 (27B2), Dsg2-Flag (Flag), and Actin (for equal loading). Western blotting demonstrates that ETA cleaved Dsg1 (arrowhead), but not Dsg2. Note. antibody 27B2 was raised against the cytoplasmic epitope of human Dsg1, and recognizes mouse Dsg1-a, -β, and -γ. Thus, the full-length signal is most likely ETA-resistant Dsg1-γ.
Mentions: It is well established that ETA cleaves Dsg1 and causes epidermal blisters in the upper layers of the epidermis, where Dsg1 is highly expressed [16]. Mice treated with purified ETA develop blisters similar to those seen in patients infected with S. aureus. To determine whether Dsg2 could compensate for the loss of Dsg1, we treated neonatal WT and Tg mice with purified ETA. In response to subcutaneous injection of ETA, we observed dramatic gross blisters in WT, but not Tg, mice (Figure 2(a)). However, the results from the histologic analysis were less definitive, since some Tg mice developed extensive blisters while others showed a resistance to blister formation (Figure 2(b), top panels).

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