Alpha-smooth muscle actin (SMA), an actin isoform that contributes to cell-generated mechanical tension, is normally restricted to cells of vascular smooth muscle, but SMA can also be expressed in certain non-muscle cells, most notably myofibroblasts.
What is alpha SMA a marker for?
α-Smooth muscle actin (α-SMA) is used as a marker for a subset of activated fibrogenic cells, myofibroblasts, which are regarded as important effector cells of tissue fibrogenesis. α-SMA is not a functional marker of fibrogenic cells in skeletal muscle fibrosis associated with muscular dystrophy.
What cells express alpha smooth muscle actin?
Myofibroblasts. Myofibroblasts express α-smooth muscle actin (α-SMA) and have contractile and secretory properties that are central to controlling tissue architecture [6]. They express a panel of markers that have been correlated with the site of origin.
What does SMA stain for?
Smooth. Muscle Actin stains smooth muscle cells in vessel walls, gut wall, and myometrium. Myoepithelial cells in breast and salivary glands are also stained as they also contain. actin. This MAb is reportedly useful for identifying tumors arising from smooth.
What is SMA positive?
If your results show a high amount of SMA antibodies, it probably means you have the type 1 form of autoimmune hepatitis. A lower amount may mean you have the type 2 form of the disease.
What is actin function?
Actin participates in many important cellular processes, including muscle contraction, cell motility, cell division and cytokinesis, vesicle and organelle movement, cell signaling, and the establishment and maintenance of cell junctions and cell shape. …
Where is alpha smooth muscle actin found?
Alpha-smooth muscle actin, a differentiation marker of smooth muscle cells, is present in microfilamentous bundles of pericytes. J Histochem Cytochem.
What is SMA in a tumor?
Alpha-smooth muscle actin (α-SMA) is an isoform of actin, positive in myofibroblasts and is an epithelial to mesenchymal transition (EMT) marker. EMT is a process by which tumor cells develop to be more hostile and able to metastasize.
What are benign smooth muscle tumors called?
A leiomyoma, also known as a fibroid, is a benign smooth muscle tumor that very rarely becomes cancer (0.1%). They can occur in any organ, but the most common forms occur in the uterus, small bowel, and the esophagus.
Is SMA an autoimmune disease?
SMAs attack smooth muscle tissues in the liver and other parts of the body. If SMAs are found in your blood, it is likely you have autoimmune hepatitis. Autoimmune hepatitis is a disease in which the immune system attacks liver tissues.
How long can you live with SMA?
Life expectancy Most children with type 1 SMA will only live a few years. However, people who’ve been treated with new SMA drugs have seen promising improvements in their quality of life — and life expectancy. Children with other types of SMA can survive long into adulthood and live healthy, fulfilling lives.
What is muscle actin?
actin, protein that is an important contributor to the contractile property of muscle and other cells. It exists in two forms: G-actin (monomeric globular actin) and F-actin (polymeric fibrous actin), the form involved in muscle contraction.
Is α-smooth muscle actin a marker for fibrosis?
However, the precise fibroblast subsets that drive fibrosis have been poorly understood. In the absence of well-characterized markers, α-smooth muscle actin (αSMA) is often used to identify pathologic fibroblasts, and some authors have equated αSMA(+) cells with contractile myofibroblasts and proposed that these cells are the major source of ECM.
Is alpha-actin a marker of cardiac fibroblast activity?
Smooth muscle alpha-actin (αSMA) is the definitive marker for the activated cardiac fibroblast population known as the myofibroblast ( Frangogiannis et al., 2000 ), but this actin isoform is also abundant in vascular smooth muscle cells ( Skalli et al., 1989 ).
How do subsets of fibroblasts contribute to tissue fibrosis?
Subsets of fibroblasts contribute to tissue fibrosis in multiple ways, including generating contractile force to activate integrin-bound, latent TGFβ and secreting excess amounts of col … Fibrosis is a common pathological sequela of tissue injury or inflammation, and is a major cause of organ failure.
What are myofibroblasts and what do they do?
Myofibroblasts express α-smooth muscle actin (α-SMA) and have contractile and secretory properties that are central to controlling tissue architecture. They express a panel of markers that have been correlated with the site of origin.
