scholarly journals α-Smooth muscle actin is constitutively expressed in the lens epithelial cells of several species

2006 ◽  
Vol 83 (4) ◽  
pp. 999-1001 ◽  
Author(s):  
Claudia M. Garcia ◽  
Gina P. Kwon ◽  
David C. Beebe
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Lens Epithelial Cells ◽  
Muscle Actin

Extracellular matrixes influence a-smooth muscle actin expression in cultured porcine lens epithelial cells

1999 ◽  
Vol 19 (3) ◽  
pp. 260-263 ◽  
Author(s):  
Daijiro Kurosaka ◽  
Katsuhiko Kato ◽  
Takeshi Oshima ◽  
Hiroyo Kurosaka ◽  
Mami Yoshino ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Lens Epithelial Cells ◽  
Muscle Actin ◽  
Actin Expression

MKL1 mediates TGF-β1-induced α-smooth muscle actin expression in human renal epithelial cells

2008 ◽  
Vol 294 (5) ◽  
pp. F1116-F1128 ◽  
Author(s):  
Gerard Elberg ◽  
Lijuan Chen ◽  
Dorit Elberg ◽  
Michael D. Chan ◽  
Charlotte J. Logan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Primary Cultures ◽  
Muscle Actin ◽  
Mesenchymal Transition ◽  
Endogenous Expression ◽  
Tgf Β1 ◽  
Stimulation Of

Transforming growth factor-β1 (TGF-β1) is known to induce epithelial-mesenchymal transition in the kidney, a process involved in tubulointerstitial fibrosis. We hypothesized that a coactivator of the serum response factor (SRF), megakaryoblastic leukemia factor-1 (MKL1), stimulates α-smooth muscle actin (α-SMA) transcription in primary cultures of renal tubular epithelial cells (RTC), which convert into myofibroblasts on treatment with TGF-β1. Herein, we study the effect of MKL1 expression on α-SMA in these cells. We demonstrate that TGF-β1 stimulation of α-SMA transcription is mediated through CC(A/T)6-rich GG elements known to bind to SRF. These elements also mediate the MKL1 effect that dramatically activates α-SMA transcription in serum-free media. MKL1 fused to green fluorescent protein localizes to the nucleus and induces α-SMA expression regardless of treatment with TGF-β1. Using proteasome inhibitors, we also demonstrate that the proteolytic ubiquitin pathway regulates MKL1 expression. These data indicate that MKL1 overexpression is sufficient to induce α-SMA expression. Inhibition of endogenous expression of MKL1 by small interfering RNA abolishes TGF-β1 stimulation of α-SMA expression. Therefore, MKL1 is also absolutely required for TGF-β1 stimulation of α-SMA expression. Western blot and immunofluorescence analysis show that overexpressed and endogenous MKL1 are located in the nucleus in non-stimulated RTC. Chromatin immunoprecipitation assay demonstrates that TGF-β1 induces binding of endogenous SRF and MKL1 to the α-SMA promoter in chromatin. Since MKL1 constitutes a potent factor regulating α-SMA expression, modulation of endogenous MKL1 expression or activity may have a profound effect on myofibroblast formation and function in the kidney.

Feline Cystic Thymoma: A Clinicopathologic, Immunohistologic, and Electron Microscopic Study of 14 Cases

2003 ◽  
Vol 5 (1) ◽  
pp. 27-35 ◽  
Author(s):  
AK Patnaik ◽  
PH Lieberman ◽  
RA Erlandson ◽  
C Antonescu
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Electron Microscopic ◽  
Germinal Centres ◽  
Factor Viii Antigen ◽  
Cell Components ◽  
Microscopic Features

Cystic thymoma was diagnosed in 14 cats in a period of 6 years. The most common clinical sign was laboured breathing. The tumours were characterized by various-sized cystic spaces with central vessels. The epithelial cells varied from oval to spindle to polygonal cells enclosing cystic spaces or in pure epithelial cell components. The nuclei of the neoplastic cells had scattered chromatin and small nucleoli. The cytoplasm was pale eosinophilic. The concentration of mature lymphocytes varied from area to area with rare germinal centres. Immunohistochemically, the epithelial cells stained only with AE1/AE3. The central vessels were positive for vimentin, smooth muscle actin, and factor VIII antigen. Electron microscopy revealed that the cyst walls were lined by epithelial cells that were joined by desmosomes, and the walls were well separated from the cystic spaces by a well-defined basement membrane. The neoplastic epithelial cells contained scattered tonofilaments. Three of the cats had metastasis to the lymph nodes and lungs. Two novel cases of ectopic cystic thymoma have also been described. Results of this study reveal that cystic thymoma is uncommon in cats, and that the histomorphologic, immunohistochemical, and electron microscopic features are similar to those of cystic thymoma in humans.

scholarly journals Specific demonstration of myoepithelial cells by anti-alpha smooth muscle actin antibody.

1988 ◽  
Vol 36 (6) ◽  
pp. 659-663 ◽  
Author(s):  
P Gugliotta ◽  
A Sapino ◽  
L Macrí ◽  
O Skalli ◽  
G Gabbiani ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Salivary Glands ◽  
Smooth Muscle Actin ◽  
Practical Interest ◽  
Myoepithelial Cells ◽  
Basal Cells ◽  
Muscle Actin ◽  
Alpha Smooth Muscle Actin ◽  
Microfilament Bundles

The myoepithelial cells of the sweat, mammary, tracheobronchial, and salivary glands are specifically identified by monoclonal antibody alpha-SM-1, which recognizes alpha smooth muscle actin and not the other actin isoforms. Basal or "reserve" cells in the stratified epithelia and excretory ducts of the salivary glands are negative, as well as all other epithelial cells in various organs. The reaction can be performed in routinely fixed and embedded tissues and is of practical interest in diagnostic histopathology. In immunoelectron cytochemistry, alpha-SM-1 antibody binds to the microfilament bundles in myoepithelial cells of the breast, but does not stain luminal cells and occasional basally located epithelial cells. These basal cells are morphologically and immunocytochemically distinct from the myoepithelial cells, and their nature and significance remain to be clarified.

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