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.
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 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 Alpha SMA stain for?
Alpha-SMA, together with vimentin, E-cadherin, and fibronectin are the markers for the epithelial to mesenchymal transition (EMT) process.
What do myofibroblasts do?
Myofibroblasts are the mesenchymal cell type responsible for wound healing and tissue repair across all organs and various physiological states, including cancer [31].
What is Pericyte?
Pericytes, spatially isolated contractile cells on capillaries, have been reported to control cerebral blood flow physiologically, and to limit blood flow after ischaemia by constricting capillaries and then dying.
Do endothelial cells express smooth muscle actin?
Cardiac microvascular endothelial cells express α-smooth muscle actin and show low NOS III activity.
What is smooth muscle made of?
Smooth muscle is a type of muscle that contracts without any voluntary control, and it is made of a thin form of layers, which is made up of spindle-shaped, unstriated cells with only one nucleus and present in inner organs walls like bladder, intestine, stomach, blood vessels, etc.
What is ACTA2 gene?
The ACTA2 gene provides instructions for making a protein called smooth muscle alpha (α)-2 actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing (contraction) of muscles. Smooth muscle α-2 actin is found in smooth muscle cells.
What cells express alpha SMA?
Myofibroblasts are conventionally identified by co-expression of collagen I and α-SMA [27–30], although α-SMA is also expressed by smooth muscle cells. α-SMA has been used not only as a differentiation marker but also as a functional marker for myofibroblasts [31–33].
Do fibroblasts express SMA?
In contrast, when cardiac fibroblasts are cultured in collagen pads, they acquire a round, or dendritic morphology and express low levels of α-SMA (<5% of the levels in high-tension fibroblasts), exhibiting disassembly of the stress fibers (Figure 2A–B).
Which filaments control the contraction of smooth muscle cells?
Smooth muscle cytoplasm contains large amounts of actin and myosin. Actin and myosin act as the main proteins involved in muscle contraction. Actin filaments attach to dense bodies spread throughout the cell.
What does desmin positive mean?
If the cells in your sample produce desmin, your pathology report will describe the cells as positive or reactive. If they do not produce desmin, your report will describe the cells as negative or non-reactive.
What is muscle specific actin?
Muscle specific actin (MSA) is a highly conserved, ubiquitous protein found in muscle and some non-muscle cells. Actins can be divided into three subsets, alpha actins found in muscle tissue cells, beta and gamma actins found in non-muscle cells and a small subset of gamma actins also found in muscle tissue cells.
What is the molecular weight of beta actin?
approximately 42 kD The molecular weight (MW) of beta-actin is approximately 42 kD.
What is the difference between fibroblast and myofibroblast?
Fibroblasts participate in the repair process by differentiating into activated myofibroblasts, which help maintain the inflammatory response to injury [28, 37, 38]. Myofibroblasts are large cells with a highly active endoplasmic reticulum, and they can produce and secrete cytokines [37]. …
Where are myofibroblasts found in the body?
Location. Myofibroblasts were first identified in granulation tissue during skin wound healing. Typically, these cells are found in granulation tissue, scar tissue (fibrosis) and the stroma of tumours. They also line the gastrointestinal tract, wherein they regulate the shapes of crypts and villi.
How are myofibroblasts activated?
Being contractile cells, myofibroblasts sense and modulate stiffness within the ECM through focal adhesions via integrin binding. Moreover, recent data suggest that mechanical stiffness alone, independent of TGF-β signalling, can induce myofibroblast activation in the setting of fibrosis [186].
How can I increase my pericytes?
This can be achieved by increasing PDGF-BB signalling from endothelial cells to PDGFRβ receptors on pericytes (mirroring the loss of BBB function which occurs when PDGFRβ signalling is reduced transgenically [6, 11, 29]), by increasing TGFβ signalling to increase pericyte number, or by modulating Ang2 and Tie2 function …
How do pericytes work?
Pericytes control the flow of blood through blood vessels by extending their long projections around the contracting or relaxing endothelial vessel. Pericytes also contribute to the development, remodeling, architecture, and permeability of the vasculature.
How do you identify pericyte?
To confirm pericyte identity through their juxtaposition with capillaries, pericyte markers can be co-localized with vascular markers such as fluorescently conjugated lectins (e.g., FITC-tomato lectin) or EC markers (e.g., CD31) (Robertson et al., 2015).
How do the endothelial cells regulate vascular smooth muscle contractility?
Endothelial cells secrete vasoactive agents and ROS that modulate the vessel diameter by influencing vascular smooth muscle cell function. The muscular media of vessels is innervated by the autonomic nervous system and its contractile state is regulated by hormones, vasoactive peptides, and ROS.
What are endothelial cells?
The endothelium is a thin membrane that lines the inside of the heart and blood vessels. Endothelial cells release substances that control vascular relaxation and contraction as well as enzymes that control blood clotting, immune function and platelet (a colorless substance in the blood) adhesion.
What are the types of endothelial cells?
Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries.
How are smooth and actin myosin arranged?
Smooth muscle cells lack sarcomeres. Instead, actin filaments are arranged obliquely in the cytoplasm. Some filaments have their plus ends anchored at points in the plasma membrane termed dense plaques, whereas other filaments have plus ends anchored in dense bodies in the cytosol.
What does smooth muscle look like under a microscope?
Smooth muscle, also called involuntary muscle, muscle that shows no cross stripes under microscopic magnification. It consists of narrow spindle-shaped cells with a single, centrally located nucleus. Smooth muscle tissue, unlike striated muscle, contracts slowly and automatically.
What is unique about smooth muscle?
Smooth muscles are unique in their largely involuntary response, and in their structure. Smooth muscles have a much stronger ability to contract than skeletal muscles, and are able to maintain contraction longer. … visceral smooth muscle – all cells work together at the same time as one unit.
What causes multisystemic smooth muscle dysfunction?
MSMDS is a rare genetic disease mainly caused by the mutation of the ACTA2 gene p.R179H. Early genetic diagnosis should be performed for children presenting with congenital fixed dilated pupils and patent ductus arteriosus.
What chromosome is the human actin in the cardiac muscle found?
We show here that the gene coding for the cardiac muscle actin, which is closely related to the skeletal muscle actin (1.1% amino acid replacements), is located on mouse chromosome 17.
What is the myofibroblast?
Myofibroblasts are large cells with ruffled membranes and highly active endoplasmic reticulum (Figure 1B). Myofibroblasts are not part of normal cardiac tissue and appear only following cardiac injury.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.