scholarly journals Substrate Elastic Modulus Regulates the Morphology, Focal Adhesions, and α-Smooth Muscle Actin Expression of Retinal Müller Cells

2015 ◽  
Vol 56 (10) ◽  
pp. 5974 ◽  
Author(s):  
Shao-Chong Bu ◽  
Roel Kuijer ◽  
Roelofje J. van der Worp ◽  
Sander M. van Putten ◽  
Olaf Wouters ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Elastic Modulus ◽  
Smooth Muscle Actin ◽  
Focal Adhesions ◽  
Müller Cells ◽  
Muller Cells ◽  
Muscle Actin ◽  
Actin Expression

scholarly journals Focal adhesion features during myofibroblastic differentiation are controlled by intracellular and extracellular factors

2001 ◽  
Vol 114 (18) ◽  
pp. 3285-3296 ◽  
Author(s):  
Vera Dugina ◽  
Lionel Fontao ◽  
Christine Chaponnier ◽  
Jury Vasiliev ◽  
Giulio Gabbiani
Keyword(s):  
Smooth Muscle ◽  
Focal Adhesion ◽  
Smooth Muscle Actin ◽  
Three Dimensional ◽  
Focal Adhesions ◽  
Laser Scanning Microscopy ◽  
Stress Fibers ◽  
Muscle Actin ◽  
Cultured Fibroblasts ◽  
Actin Expression

Transforming growth factor β (TGFβ), the most established promoter of myofibroblast differentiation, induces ED-A cellular fibronectin and α-smooth muscle actin expression in fibroblastic cells in vivo and in vitro. ED-A fibronectin exerts a permissive action for α-smooth muscle actin expression. A morphological continuity (called fibronexus), a specialized form of focal adhesion, has been described between actin stress fibers that contain α-smooth muscle actin, and extracellular fibronectin, which contains the ED-A portion, in both cultured fibroblasts and granulation tissue myofibroblasts. We have studied the development of these focal adhesions in TGFβ-treated fibroblasts using confocal laser scanning microscopy, three-dimensional image reconstruction and western blots using antibodies against focal adhesion proteins. The increase in ED-A fibronectin expression induced by TGFβ was accompanied by bundling of ED-A fibronectin fibers and their association with the terminal portion of α-smooth muscle actin-positive stress fibers. In parallel, the focal adhesion size was importantly increased, and tensin and FAK were neoexpressed in focal adhesions; moreover, vinculin and paxillin were recruited from the cytoplasmic pool into focal adhesions. We have evaluated morphometrically the length and area of focal adhesions. In addition, we have evaluated biochemically their content of associated proteins and of α-smooth muscle actin after TGFβ stimulation and on this basis suggest a new focal adhesion classification, that is, immature, mature and supermature.When TGFβ-induced α-smooth muscle actin expression was blocked by soluble recombinant ED-A fibronectin, we observed that the fragment was localised into the fibronectin network at the level of focal adhesions and that focal adhesion supermaturation was inhibited. The same effect was also exerted by the ED-A fibronectin antibody IST-9. In addition, the antagonists of actin-myosin contractility BDM and ML-7 provoked the dispersion of focal adhesions and the decrease of α-smooth muscle actin content in stress fibers of pulmonary fibroblasts, which constitutively show large focal adhesions and numerous stress fibers that contain α-smooth muscle actin. These inhibitors also decreased the incorporation of recombinant ED-A into fibronectin network. Our data indicate that a three-dimensional transcellular structure containing both ED-A fibronectin and α-smooth muscle actin plays an important role in the establishment and modulation of the myofibroblastic phenotype. The organisation of this structure is regulated by intracellularly and extracellularly originated forces.

scholarly journals α-Smooth muscle actin expression predicts the outcome of Kasai portoenterostomy in biliary atresia

2019 ◽  
Vol 25 (2) ◽  
pp. 101 ◽  
Author(s):  
Priya Ramachandran ◽  
AshithaK Unny ◽  
Mukul Vij ◽  
Mohamed Safwan ◽  
MuthukrishnanSaravana Balaji ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Biliary Atresia ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Kasai Portoenterostomy ◽  
Actin Expression
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