The myofibroblast represents a good candidate for playing an important role in such an interaction; the recently described possibility of modulating myofibroblast behavior using new tools, such as the smoothmuscleactin, provides the opportunity to explore the role of this cell and of the stroma reaction in tumor evolution. The high frequency of stromal MF in known aggressive odontogenic tumors implies that MF can contribute to the biological behavior of these odontogenic lesions. The agents that control stromal MF can be used as an aid to reduce extensive and multilating surgery in cases of remarkably aggressive odontogenic tumors. Based on this study we suggest that the myofibroblast may represent a new important target of antitumor therapy. In conclusion, the old and never fully proven possibility of epithelial/stroma reciprocal induction in many biological and pathological phenomena appears at present more and more likely.
16 | P a g e Significant of mean percentage of myofibroblasts and percentage classification of myofibroblasts between OSCCs and NOM suggest increased presence of these cells in OSCCs and probably their role in tissue invasion process and progression of OSCC. OSCCs had more of spindle pattern of distribution. There is difference in the percentage of myofibroblasts between OSCC and NOM (P-value = 0.036˂0.05) Jeyaraj et al (2015) 31 investigated the presence of myofibroblasts in healthy oral mucosa (32 cases), potentially malignant disorders (PMDs; (n = 32)) and squamous cell carcinoma (SCC; n = 42) by subjecting them to immunohistochemical analysis using alpha SmoothMuscleActin. Among the 42 cases of OSCC, the staining index was negative in 54.7%, low in 21.4% and moderate in 23.8%. The stroma of Verrucous carcinoma, Hyperkeratosis with epithelial dysplasia, 77.5% of the cases of oral Submucous Fibrosis (OSMF) and healthy oral mucosa were devoid of myofibroblasts. There was a significant difference in the expression of myofibroblasts between the groups.
Ameloblastic carcinoma is a relatively aggressive lesion. Early diagnosis and treatment may help in decreasing patient morbidity. Pathologist still find it difficult to differentiate a case of ameloblastoma from ameloblastic carcinoma. Immunohistochemical expression of alpha smoothmuscleactin may help in establishing an early diagnosis and chemotherapeutic agents against stromal myofibroblasts can be used as an adjunct to the surgery in planning the treatment for these locally aggressive and infiltrating lesions.
Mesangial cell proliferation is common in glomerulonephritis but it is unclear if proliferation is associated with any in vivo alteration in phenotype. We investigated whether mesangial of mesangial proliferative nephritis induced with antibody to the Thy-1 antigen present on mesangial cells. At day 3 glomeruli displayed de novo immunostaining for alpha-smoothmuscleactin in a mesangial pattern, correlating with the onset of proliferation, and persisting until day 14. An increase in desmin and vimentin in mesangial regions was also noted. Immunoelectron microscopy confirmed that the actin-positive cells were mesangial cells, and double immunolabeling demonstrated that the smoothmuscleactin-positive cells were actively proliferating. Northern analysis of isolated glomerular RNA confirmed an increase in alpha and beta/gamma actin mRNA at days 3 and 5. Complement depletion or platelet depletion prevented or reduced proliferation, respectively; these maneuvers also prevented smoothmuscleactin and actin gene expression. Studies of five other experimental models of nephritis confirmed that smoothmuscleactin expression is a marker for mesangial cell injury. Thus, mesangial cell proliferation in glomerulonephritis in the rat is associated with a distinct phenotypic change in which mesangial cell assume smoothmuscle cell
This cross-sectional study was approved by the local ethics committee. 80 samples were taken from patients presenting with oral squamous cell carcinomas. All the specimens obtained will be studied using routine Hematoxylin & Eosin staining for histological parameters and Immunohistochemistry for Alpha smoothmuscleactin.
Effects of triiodothyronine (T3) on the expression of cyto- skeletal and myofibrillar proteins in adult rat cardiomyo- cytes (ARC) were followed during two weeks of culture in the presence of 20% T3-depleted (stripped) FCS. Control cultures expressed mainly b -myosin heavy chain (MHC) mRNA. T3 caused a switch to a -MHC expression and a dose-dependent increase of a -smoothmuscle ( a -sm) actin mRNA and protein. In parallel, the number of a -sm actin immunoreactive cells increased from 1% in controls to 29 and 62% in ARC treated with 5 and 100 nM T3. In the pres- ence of T3, cells exhibited a higher beating rate than controls. The distribution of myofibrils in T3-treated cells was re- stricted to the perinuclear area with a sharp boundary. Only 5% of the control cells but 30 and 62% of the T3-treated (5 and 100 nM) ARC showed this restricted myofibrillar phe- notype. Basic fibroblast growth factor (bFGF) which re- stricts myofibrillar growth and upregulates a -sm actin in ARC cultured with normal FCS had no effect on a -sm actin in ARC cultured in stripped FCS, but potentiated the effect of T3. In contrast, insulin-like growth factor I (IGF I), which suppresses a -sm actin and stimulates myofibrillogen- esis in the presence of normal FCS suppressed T3-induced a -sm actin expression in stripped FCS. Thus, T3 appears to be permissive for the action of bFGF and IGF I on a -sm ac- tin expression. ( J. Clin. Invest. 1996. 98:1737–1744.) Key words: myocardium-cytology • myofibrils • cardiac-proteins • actin-isoforms • gene-expression
For detect α-smoothmuscleactin (α-SMA) and smoothmuscle myosin heavy chain (SM-MHC) expression, reverse transcription was per- formed by using a Reverse Transcriptase M- MLV (Takara, Dalian, China). qRT-PCR reaction was performed by using a SYBR® Premix EX TaqTM ⅡPCR Kit (Takara, Japan) on ABI PRISM 7900 Sequence Detection System (Applied Biosystems, Foster City, CA, USA). β-actin was used as internal control. The primers sequenc- es were shown in Table 1. The α-SMA and Table 1. The information of primers for qRT-PCR
enhanced and furthermore PL transformation (measured by expression of iso-alpha smoothmuscleactin and loss of retinylpalmitate) was accelerated. Preincubation of this medium with neutralizing antibodies to TGF beta resulted in (a) the growth inhibitory effect was converted to a growth stimulation and (b) the stimulatory effect on proteoglycan synthesis was abolished. In summary our data indicate that progressive activation of PL on plastic (transformation to MFBlC) leads to an enhanced expression of the TGF alpha- and TGF beta 1-mRNAs and secretion of the corresponding proteins. Medium conditioned by MFBIC stimulates proliferation, transformation, and PG synthesis of untransformed PL. These mechanisms are suggested to be […]
Healing of full-thickness injury to the gastrointestinal tract remains an unresolved topic. It begins with a surgi- cal reapposition of the bowel ends, which is most often the initial step in the repair process. Failure of healing results in dehiscence, leaks, and fistulas, which carry sig- nificant morbidity and mortality. The myofibroblasts play a central role in the process of wound healing [1-5]. They contain smoothmuscle myosin isoforms in addition to a -smoothmuscleactin ( a -SMA), the requisite machinery for contraction and/or motility, respond to proinflamma- tory cytokines with elaboration of matrix proteins and additional growth factors and then disappear by apopto- sis following repair or scar formation [6-11].
Frozen sections (10 μm) were immunostained as previously described . Slides were fixed in 4 % PFA, washed in PBS, permeabilized in 0.3 % Triton/PBS, washed in PBS, blocked in 10 % goat serum, and incubated overnight at 4 °C with primary antibodies in blocking buffer. Additional M.O.M. blocking (Vector Laboratories) steps were performed according to the manufacturer’s instruc- tions when mouse primary antibodies were used. Anti- bodies used included mouse anti-sarcomeric actin (5C5; 1:1000; Sigma-Aldrich), rabbit anti–α-smoothmuscleactin (1:200; Abcam), rabbit anti-MyoD (1:500; Santa Cruz Biotechnology, Inc.), mouse anti-myogenin (F5D; 1:50; Santa Cruz Biotechnology, Inc.), mouse anti-M- cadherin (1:75; Santa Cruz Biotechnology, Inc.), rabbit anti- nNOS (C12H1; 1:500; Cell Signaling Technology), rabbit anti-Ki67 (1:1000; Leica), mouse anti-Ki67 (1:100; BD Pharmingen), and rabbit anti-phospho-Histone H3 (ser10) (1:1000; Millipore). After permeabilization, the following antibodies required an antigen retrieval step of boiling the sections in 10 mM sodium citrate: mouse anti-Pax7 (1:100; Developmental Studies Hybridoma Bank, Iowa City, IA), and rabbit cleaved caspase-3 (Asp175; 1:1000; Cell Signaling Technology). Fluorescent secondary anti- bodies were from Invitrogen and used at 1:1000: goat anti- rabbit Alexa Fluor 488, anti-rabbit Alexa Fluor 568, goat anti-mouse Alexa Fluor 488, and goat anti-mouse IgG1 Alexa Fluor 647. Nuclei were fluorescently labeled with DAPI and mounted with Fluoromount-G anti-fade medium (SouthernBiotech). TUNEL assay was performed using the In Situ Cell Death Detection kit from Roche. For Figs. 4 and 5 and Additional file 2: S2, the transition zone
Abstract: Vascular progenitor cells are desirable in a variety of therapeutic strategies; however, the lineage commitment of endothelial and smoothmuscle cell from a common progenitor is not well-understood. Here, we report the generation of the first dual reporter mouse embryonic stem cell (mESC) lines designed to facilitate the study of vascular endothelial and smoothmuscle devel- opment in vitro. These mESC lines express green fluorescent protein (GFP) under the endothelial promoter, Tie-2, and Discomsoma sp. red fluorescent protein (RFP) under the promoter for alpha-smoothmuscleactin (α-SMA). The lines were then characterized for morphology, marker expression, and pluripotency. The mESC colonies were found to exhibit dome-shaped morphol- ogy, alkaline phosphotase activity, as well as expression of Oct 3/4 and stage-specific embryonic antigen-1. The mESC colonies were also found to display normal karyotypes and are able to generate cells from all three germ layers, verifying pluripotency. Tissue staining confirmed the coexpression of VE (vascular endothelial)-cadherin with the Tie-2 GFP+ expression on endothelial structures and smoothmuscle myosin heavy chain with the α-SMA RFP+ smoothmuscle cells. Lastly, it was verified that the developing mESC do express Tie-2 GFP+ and α-SMA RFP+ cells during differentiation and that the GFP+ cells colocalize with the vascular-like structures sur- rounded by α-SMA-RFP cells. These dual reporter vascular-specific mESC permit visualization and cell tracking of individual endothelial and smoothmuscle cells over time and in multiple dimensions, a powerful new tool for studying vascular development in real time.
Reticulin staining will demonstrate lesional vessels lined by a single layer of endothelial cells, with the pericytes lying outside the basal lamina, although they are often individually surrounded by reticulin and collagen fibers. Lesional cells are immunoreactive for vimentin (variable intensity), factor XIIIa antigen, HLA-DR antigen and QBEND10 (CD34). They do not stain for or react with factor VIII-related antigen, Ulex europaeus I lectin, alpha-smoothmuscleactin, desmin, myoglobin, low-molecular weight cytokeratin, high- molecular weight cytokeratin, or epithelial membrane antigen. 11 Prior to the routine use of
Aortic sinus sections were dewaxed in xylene and rehydrated in an ethanol series. Primary antibodies diluted as appropriate in PBS were: monoclonal mouse anti-human smoothmuscleactin (SMA, Dako M0851, 1:150, 1 h), purified anti-mouse CD206 (Biolegend 123001, rat IgG2ak, 1:100, 1 h RT), (trypsination for antigen retrieval: 0.1% Trypsin (DIFCO 215240) in TBS (Sigma T6664), 10 min, 37uC; 0,5% Triton-X 100) and were followed by biotinylated goat anti-mouse IgG (H+L) (Vector BA9200, 1:500, K –1 h) or polyclonal biotinylated rabbit anti-rat Ig (Dako E0468, 1:500, 1 h RT) and ABC-peroxidase solution (Vektor PK6100, Vectastain Elite ABC Kit; Sigma H1009; 30 min) with 3,39- diaminobenzidine tetrahydrochloride (DAB, Sigma D4418, 10 min) as substrate. Carazzi’s haematoxylin was used for counterstaining.
Hematoxylin/Eosin, Periodic Acid Schiff (PAS) and Alcian Blue histological staining of sections, in situ hybridization and immunohistochemistry used conventional approaches described previously (Kim et al., 2005; Wilkinson and Nieto, 1993). Digoxigenin-labeled Shh, Ihh, Gli1 and Apo1a riboprobes were detected by incubating sections overnight at 4°C with alkaline phosphatase-conjugated sheep digoxigenin antibody diluted 1:2000 in blocking solution; color was developed with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (Roche). The following reagents were used for immunofluorescent and immunohistochemical analysis: a mouse or rat monoclonal antibody against Cdx2 (1:20, Biogenex), H/K-ATPase (2B6, 1:1000, MBL), smoothmuscleactin (1:2000, Sigma), Muc5AC (45M1, 1:150, Novocastra), BrdU (G3G4, 1:100, Developmental Studies Hybridoma Bank; developed under the auspices of the NICHD and maintained by the University of Iowa, USA) and p63 (1:2000); rabbit antisera against Pdx1 (1:6000, a generous gift from C. Wright, Vanderbilt University, TN, USA), CD31 (1:1000, Santa Cruz), Fli1 (1:500, Labvision), Tuj1 (1:2500, Covance), cleaved caspase 3 (1:200, Cell Signaling), GFP (1:1000, Abcam) and Ki67 (1:2000, Vector Lab). Samples were washed and incubated with biotinylated goat anti-mouse, anti-rabbit or anti-rat IgG, followed by avidin-biotin-peroxidase complex (Vector). Reactions were developed with diaminobenzidine (DAB) hydrochloride (Sigma). For b -gal analysis, Shh Cre and Gli1-CreER mice were intercrossed
Liver failure may induce hypoglycemia , and hyperbi- liruninaemia was diagnosed in this horse. No major path- ological change was found at necropsy or histopathology making it unlikely that the hyperbilirubinaemia was caused by liver damage. A more reasonable cause is the reduced food intake. A mild hypertriglyceridemia was also found indicating a catabolic state possibly caused by reduced feed intake, stress and the metabolic demand of the tumour. Hypertriglyceridemia may have contributed to the clinical signs, but was in our opinion not severe enough to explain all the clinical findings. On admission the horse had increased pulse rate and brick coloured Both the tumour associated with the stomach and the nod- ules in the heart showed strong and diffuse positive staining for smoothmuscleactin (mouse monoclonal antihuman smoothmuscleactin visualized by staining with AEC (3- amino-9ethylcarbazole) labelled secondary antibody, Dako Cytomation, Glostrup, Denmark), prompting a diagnosis of a leiomyosarcoma
The exact epitopes identified by antibodies such as HHF35 and CGA7, both of which are said to identify alpha and gamma muscle isoactins, are unknown but HHF35 appears less specific than CGA7 in that it recognises actins of skeletal and cardiac muscle, as well as smoothmuscle (Gown et al. 1985; Tsukada et al. 1987). This relative non-specificity may account for the normal staining with HHF35 in the five patients with absent CGA7 staining in this study. In patient 1, the fact that some reactivity with CGA7 was noted in the circular muscle, probably reflects that gamma smoothmuscle isoactin is present and is immunostained but the weakness of the reaction is accounted for by the deficiency of alpha smoothmuscleactin, proven by the negative 1A4 staining. Immunoreactivity was entirely normal with HHF35, again presumably reflecting the reactivity of this antibody with a whole variety of other actins. A difference in immunoreactivity between the various muscle layers in the same specimen or between specimens from different patients, probably does indicate significant abnormalities in the isoform content, as shown in these seven patients described here (see Table 1). In particular the abnormality detected with 1A4 against alpha smoothmuscleactin is particularly informative due to the high degree of specificity of this antibody.
The fact that the presumed functions of CaD are affected by MAPK and PAK has inspired much interest. Both types of kinases add phosphate groups to residues near the actin- binding sites at the C-terminal region of CaD, thereby decreasing its effectiveness of actin binding, as well as its stabilizing action on the actin cytoskeleton. This may sug- gest that CaD (particularly l-CaD) serves as a converging point for the MAPK and PAK signaling under the stimula- tion of a wide variety of agonists; it also raises the question as how the two types of CaD phosphorylation relate to each other. In this work we have analyzed the cellular conse- quences of the MAPK and PAK actions, individually and in combination, on l-CaD in a dedifferentiated SMC line (A7r5). By using phosphomimetic mutagenesis, we aimed to dissect the effect of MAPK- and PAK-mediated phos- phorylation on CaD. Our results indicate that CaD phos- phorylation is an obligatory step for cell motility, and that MAPK and PAK work independently and additively toward this process. Since only l-CaD is expressed in these cul- tured cells, CaD refers to the non-muscle isoform exclu- sively throughout this work except otherwise specified.
To investigate whether stellate cell activation could be in- hibited in vivo after liver injury had been established, we an- tagonized ET in vivo after the induction of fibrosis. In these experiments, carbon tetrachloride was administered 10 times, and bosentan was instituted 24 h after the final dose of carbon tetrachloride and continued for the next 17 d. In control livers, central–central, central–portal, and portal–portal bridging was extensive. After ET antagonism, bridging was present, but was less prominent. Quantitative analysis demonstrated a reduc- tion in whole-liver collagen content by 58 and 62% (Table III) in the central and portal areas, respectively. Whole-liver type I collagen mRNA expression was similarly reduced (Fig. 5). Likewise, in freshly isolated stellate cells, type I collagen mRNA was reduced (Fig. 5). Smoothmuscle a-actin, assessed by immunoblot and cell counting, was also reduced, confirm- ing the inhibitory effects of bosentan on stellate cell activation (Fig. 6). Finally, in pure cultures of isolated cells that were im- munostained 24 h after isolation, bosentan reduced PCNA la- beling from 40.5610.6% to 17.967.5% of cells.
Disassembly of the actin “mesh” is also facilitated by debranching. Glia maturation factor-γ (GMF-γ) is a 17 kDa member of the ADF/cofilin family that is capable of indu- cing actin depolymerization and debranching . GMF-γ is able to bind to the Arp2/3 complex at the junction of mother filaments and daughter filaments, which induces debranching of the actin meshwork [28, 29]. Subsequently, debranched filaments are severed by gelsolin and de- polymerized by ADF/cofilin, which eventually generate more G-actin pools for subsequent rounds of actin filament polymerization and branching [4, 28, 29]. Knockdown of GMF-γ attenuates the migration of neutrophils and T-lymphocytes [30, 31]. Our recent studies show that GMF- γ is necessary for human airway smoothmuscle cell movement . Contractile stimulation induces c-Abl- dependent GMF-γ phosphorylation at Tyr-104, which regulates airway smoothmuscle cell contraction [2, 33]. Future studies are needed to assess whether GMF-γ phosphorylation at Tyr-104 by c-Abl has a role in regulat- ing the migration and contraction of other cell types.