Exfoliatin

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Exfoliatin is a Staphylococcus aureus exotoxin [1] that causes a blistering of the skin known as staphylococcal scalded skin syndrome, usually in infants. [2]

Exfoliatins are glutamate-specific serine proteases highly specific to desmoglein I, a cadherin (adhesion protein) in the desmosomes of the stratum granulosum that facilitates intercellular adhesion between keratinocytes. The resulting vesicle is an intraepidermal cleft located above the basal cells (suprabasal), between the stratum corneum and stratum spinosum. Desmoglein-1 is similarly involved in Pemphigus foliaceus, an auto-immune skin condition. A very similar non-infectious condition is seen in the autoimmune skin disorder pemphigus vulgaris in which there is an IgG antibody against the cadherin desmoglein 3.

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<span class="mw-page-title-main">Desmosome</span> Cell junction involved in cell-to-cell adhesion

A desmosome, also known as a macula adherens, is a cell structure specialized for cell-to-cell adhesion. A type of junctional complex, they are localized spot-like adhesions randomly arranged on the lateral sides of plasma membranes. Desmosomes are one of the stronger cell-to-cell adhesion types and are found in tissue that experience intense mechanical stress, such as cardiac muscle tissue, bladder tissue, gastrointestinal mucosa, and epithelia.

<span class="mw-page-title-main">Cadherin</span>

Cadherins (named for "calcium-dependent adhesion") are cell adhesion molecules important in forming adherens junctions that let cells adhere to each other. Cadherins are a class of type-1 transmembrane proteins, and they depend on calcium (Ca2+) ions to function, hence their name. Cell-cell adhesion is mediated by extracellular cadherin domains, whereas the intracellular cytoplasmic tail associates with numerous adaptors and signaling proteins, collectively referred to as the cadherin adhesome.

<span class="mw-page-title-main">Pemphigus</span> Blistering autoimmune diseases

Pemphigus is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. The name is derived from the Greek root pemphix, meaning "pustule".

<span class="mw-page-title-main">Desquamation</span> Medical condition

Desquamation occurs when the outermost layer of a tissue, such as the skin, is shed. The term is from Latin desquamare 'to scrape the scales off a fish'.

<span class="mw-page-title-main">Staphylococcal scalded skin syndrome</span> Medical condition

Staphylococcal scalded skin syndrome (SSSS) is a dermatological condition caused by Staphylococcus aureus.

Nikolsky's sign is a clinical dermatological sign, named after Pyotr Nikolsky (1858–1940), a Russian physician who trained and worked in the Russian Empire. The sign is present when slight rubbing of the skin results in exfoliation of the outermost layer. A typical test would be to place the eraser of a pencil on the roof of a lesion and spin the pencil in a rolling motion between the thumb and forefinger. If the lesion is opened, then the Nikolsky's sign is present/positive.

<span class="mw-page-title-main">Pemphigus vulgaris</span> Medical condition

Pemphigus vulgaris is a rare chronic blistering skin disease and the most common form of pemphigus. Pemphigus was derived from the Greek word pemphix, meaning blister. It is classified as a type II hypersensitivity reaction in which antibodies are formed against desmosomes, components of the skin that function to keep certain layers of skin bound to each other. As desmosomes are attacked, the layers of skin separate and the clinical picture resembles a blister. These blisters are due to acantholysis, or breaking apart of intercellular connections through an autoantibody-mediated response. Over time the condition inevitably progresses without treatment: lesions increase in size and distribution throughout the body, behaving physiologically like a severe burn.

The desmogleins are a family of desmosomal cadherins consisting of proteins DSG1, DSG2, DSG3, and DSG4. They play a role in the formation of desmosomes that join cells to one another.

<span class="mw-page-title-main">Desmoglein-1</span> Protein found in humans

Desmoglein-1 is a protein that in humans is encoded by the DSG1 gene. Desmoglein-1 is expressed everywhere in the skin epidermis, but mainly it is expressed in the superficial upper layers of the skin epidermis.

<span class="mw-page-title-main">Desmoglein-3</span> Protein found in humans

Desmoglein-3 is a protein that in humans is encoded by the DSG3 gene. In the skin epidermis Desmoglein-3 is expressed in the basal lower layers of the epidermis, and dominates in terms of expression on mucosal surfaces compared to Desmoglein-1.

<span class="mw-page-title-main">Desmoglein-2</span> Protein found in humans

Desmoglein-2 is a protein that in humans is encoded by the DSG2 gene. Desmoglein-2 is highly expressed in epithelial cells and cardiomyocytes. Desmoglein-2 is localized to desmosome structures at regions of cell-cell contact and functions to structurally adhere adjacent cells together. In cardiac muscle, these regions are specialized regions known as intercalated discs. Mutations in desmoglein-2 have been associated with arrhythmogenic right ventricular cardiomyopathy and familial dilated cardiomyopathy.

<span class="mw-page-title-main">Plakoglobin</span> Mammalian protein found in Homo sapiens

Plakoglobin, also known as junction plakoglobin or gamma-catenin, is a protein that in humans is encoded by the JUP gene. Plakoglobin is a member of the catenin protein family and homologous to β-catenin. Plakoglobin is a cytoplasmic component of desmosomes and adherens junctions structures located within intercalated discs of cardiac muscle that function to anchor sarcomeres and join adjacent cells in cardiac muscle. Mutations in plakoglobin are associated with arrhythmogenic right ventricular dysplasia.

<span class="mw-page-title-main">Desmoglein-4</span> Protein found in humans

Desmoglein-4 is a protein that in humans is encoded by the DSG4 gene.

Desmocollins are a subfamily of desmosomal cadherins, the transmembrane constituents of desmosomes. They are co-expressed with desmogleins to link adjacent cells by extracellular adhesion. There are seven desmosomal cadherins in humans, three desmocollins and four desmogleins. Desmosomal cadherins allow desmosomes to contribute to the integrity of tissue structure in multicellular living organisms.

Pemphigus foliaceus is an autoimmune of the skin. Pemphigus foliaceus causes a characteristic inflammatory attack at the subcorneal layer of epidermis, which results in skin lesions that are scaly or crusted erosions with an erythematous (red) base. Mucosal involvement is absent even with widespread disease.

<span class="mw-page-title-main">Bullous impetigo</span> Medical condition

Bullous impetigo is a bacterial skin infection caused by Staphylococcus aureus that results in the formation of large blisters called bullae, usually in areas with skin folds like the armpit, groin, between the fingers or toes, beneath the breast, and between the buttocks. It accounts for 30% of cases of impetigo, the other 70% being non-bullous impetigo.

<i>Staphylococcus</i> Genus of Gram-positive bacteria

Staphylococcus is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. Staphylococcus species are facultative anaerobic organisms.

Cell–cell interaction refers to the direct interactions between cell surfaces that play a crucial role in the development and function of multicellular organisms. These interactions allow cells to communicate with each other in response to changes in their microenvironment. This ability to send and receive signals is essential for the survival of the cell. Interactions between cells can be stable such as those made through cell junctions. These junctions are involved in the communication and organization of cells within a particular tissue. Others are transient or temporary such as those between cells of the immune system or the interactions involved in tissue inflammation. These types of intercellular interactions are distinguished from other types such as those between cells and the extracellular matrix. The loss of communication between cells can result in uncontrollable cell growth and cancer.

<i>Staphylococcus hyicus</i> Species of bacterium

Staphylococcus hyicus is a Gram-positive, facultatively anaerobic bacterium in the genus Staphylococcus. It consists of clustered cocci and forms white circular colonies when grown on blood agar. S. hyicus is a known animal pathogen. It causes disease in poultry, cattle, horses, and pigs. Most notably, it is the agent that causes porcine exudative epidermitis, also known as greasy pig disease, in piglets. S. hyicus is generally considered to not be zoonotic, however it has been shown to be able to cause bacteremia and sepsis in humans.

References

  1. Exfoliatins at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
  2. " exfoliatin " at Dorland's Medical Dictionary