scholarly journals β-Catenin is required for endothelial-mesenchymal transformation during heart cushion development in the mouse

2004 ◽  
Vol 166 (3) ◽  
pp. 359-367 ◽  
Author(s):  
Stefan Liebner ◽  
Anna Cattelino ◽  
Radiosa Gallini ◽  
Noemi Rudini ◽  
Monica Iurlaro ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Heart Development ◽  
Transcriptional Activity ◽  
Ex Vivo ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Endocardial Cushions ◽  
Smad Phosphorylation ◽  
Mesenchymal Transformation

During heart development endocardial cells within the atrio-ventricular (AV) region undergo TGFβ-dependent epithelial-mesenchymal transformation (EMT) and invade the underlying cardiac jelly. This process gives rise to the endocardial cushions from which AV valves and part of the septum originate. In this paper we show that in mouse embryos and in AV explants TGFβ induction of endocardial EMT is strongly inhibited in mice deficient for endothelial β-catenin, leading to a lack of heart cushion formation. Using a Wnt-signaling reporter mouse strain, we demonstrated in vivo and ex vivo that EMT in heart cushion is accompanied by activation of β-catenin/TCF/Lef transcriptional activity. In cultured endothelial cells, TGFβ2 induces α-smooth muscle actin (αSMA) expression. This process was strongly reduced in β-catenin null cells, although TGFβ2 induced smad phosphorylation was unchanged. These data demonstrate an involvement of β-catenin/TCF/Lef transcriptional activity in heart cushion formation, and suggest an interaction between TGFβ and Wnt-signaling pathways in the induction of endothelial-mesenchymal transformation.

scholarly journals Multidimensional immunolabeling and 4D time-lapse imaging of vital ex vivo lung tissue

2015 ◽  
Vol 309 (4) ◽  
pp. L323-L332 ◽  
Author(s):  
Gerald Burgstaller ◽  
Sarah Vierkotten ◽  
Michael Lindner ◽  
Melanie Königshoff ◽  
Oliver Eickelberg
Keyword(s):  
Smooth Muscle ◽  
Lung Tissue ◽  
Ex Vivo ◽  
Smooth Muscle Actin ◽  
Focal Adhesions ◽  
Cellular Tissue ◽  
Muscle Actin ◽  
Human Lung Tissue

During the last decades, the study of cell behavior was largely accomplished in uncoated or extracellular matrix (ECM)-coated plastic dishes. To date, considerable cell biological efforts have tried to model in vitro the natural microenvironment found in vivo. For the lung, explants cultured ex vivo as lung tissue cultures (LTCs) provide a three-dimensional (3D) tissue model containing all cells in their natural microenvironment. Techniques for assessing the dynamic live interaction between ECM and cellular tissue components, however, are still missing. Here, we describe specific multidimensional immunolabeling of living 3D-LTCs, derived from healthy and fibrotic mouse lungs, as well as patient-derived 3D-LTCs, and concomitant real-time four-dimensional multichannel imaging thereof. This approach allowed the evaluation of dynamic interactions between mesenchymal cells and macrophages with their ECM. Furthermore, fibroblasts transiently expressing focal adhesions markers incorporated into the 3D-LTCs, paving new ways for studying the dynamic interaction between cellular adhesions and their natural-derived ECM. A novel protein transfer technology (FuseIt/Ibidi) shuttled fluorescently labeled α-smooth muscle actin antibodies into the native cells of living 3D-LTCs, enabling live monitoring of α-smooth muscle actin-positive stress fibers in native tissue myofibroblasts residing in fibrotic lesions of 3D-LTCs. Finally, this technique can be applied to healthy and diseased human lung tissue, as well as to adherent cells in conventional two-dimensional cell culture. This novel method will provide valuable new insights into the dynamics of ECM (patho)biology, studying in detail the interaction between ECM and cellular tissue components in their natural microenvironment.

Follicle development in cryopreserved bitch ovarian tissue grafted to immunodeficient mouse

2012 ◽  
Vol 24 (3) ◽  
pp. 461 ◽  
Author(s):  
L. Commin ◽  
S. Buff ◽  
E. Rosset ◽  
C. Galet ◽  
A. Allard ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Histological Analysis ◽  
Smooth Muscle Actin ◽  
Ovarian Tissue ◽  
Follicular Development ◽  
Slow Freezing ◽  
Angiogenic Factor ◽  
Muscle Actin ◽  
Once Daily

The present study evaluated: (1) in vivo follicular development in canine ovarian tissue after slow freezing and xenotransplantation; and (2) the use of erythropoietin (EPO) as an angiogenic factor to optimise the transplantation procedure. Frozen–thawed ovarian tissue from five bitches was grafted into severe combined immunodeficient (SCID) mice (n = 47) treated with or without EPO (500 IU kg–1, once daily for 3 days) (Groups A and B, respectively) and analysed after 0, 1, 8 or 16 weeks. Follicle grade, follicle density, follicle morphology and stromal cells density were assessed by histological analysis, whereas vascularisation of the graft was quantified by immunohistochemistry with anti-α-smooth muscle actin antibody. Despite a massive loss of follicles after grafting, secondary follicle density was higher at 8 and 16 weeks than at 1 week regardless of EPO treatment. EPO significantly improved early follicle morphology and stromal cell density after 8 weeks and blood vessel density at 16 weeks after transplantation (P < 0.05). Intact secondary follicles with more than three granulosa cells layers were observed 16 weeks after transplantation. The results suggest that canine ovarian tissue can be successfully preserved by our slow-freezing protocol because the tissue showed follicular growth after xenotransplantation. EPO treatment did not lessen the massive loss of follicles after transplantation.

Regulation of apoptosis in the endocardial cushions of the developing chick heart

2002 ◽  
Vol 282 (6) ◽  
pp. C1348-C1360 ◽  
Author(s):  
William M. Keyes ◽  
Esmond J. Sanders
Keyword(s):  
Heart Development ◽  
Time Course ◽  
Nuclear Staining ◽  
Caspase 9 ◽  
Endocardial Cushions ◽  
Similar Time ◽  
Cleavage Fragment ◽  
Protein Levels ◽  
Developing Heart

During the early stages of heart development, there are two main foci of cell death: outflow tract (OT) and atrioventricular (AV) endocardial cushions. These tissues contribute to the septa and valves of the mature heart and receive cell populations from neural crest (NC) cell migration and epicardial cell invasion. We examined embryonic chick hearts for expression, in the cushions, of bcl-2 family members, caspase-9, and the caspase substrate poly(ADP-ribose) polymerase. Antiapoptotic bcl-2 is expressed heavily in the OT and AV regions throughout embryonic days (ED) 4–7, with a decrease in levels at ED 4 and 5 in OT and AV cushions, respectively. Proapoptotic bax predominantly associated with the prongs of the NC-derived aorticopulmonary (AP) septum but was expressed throughout the AV cushions. Proapoptotic bak also associated with the prongs of the AP septum in the OT, while protein levels were upregulated at ED 4–5 and 4–6 in OT and AV cushions, respectively. Bid expression showed a similar time course. We found the 10-kDa cleavage fragment of active caspase-9 at ED 4–8 and 5–8 in OT and AV cushions, respectively, and the 24-kDa cleavage fragment of poly(ADP-ribose) polymerase throughout ED 3–8 and 7–8 in OT and AV cushions, respectively. Caspase-3 cleavage occurred throughout the time period examined. Using cushion cell cultures, we found that inhibitors of caspases-3 and -9 and a universal caspase inhibitor significantly reduced apoptosis, as did retroviral overexpression of bcl-2 using an RCAS expression vector. Premigratory NC cells were fluorescently labeled in vivo with 1,1-didodecyl-3,3,3′,3′-tetramethylindocarbocyanine. Subsequent nuclear staining of cushion cells with 4,6-diamidino-2-phenylindole revealed the presence of apoptotic nuclei in the NC cells in the OT cushions and in the prongs of the AP septum. These results demonstrate a developmentally regulated role for the bcl-2 and the caspase families of molecules in the endocardial cushions of the developing heart and lend support to the possibility that some of the dying cells in the cushions are derived from the NC.

scholarly journals Explanting Is anEx VivoModel of Renal Epithelial-Mesenchymal Transition

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Catherine E. Winbanks ◽  
Ian A. Darby ◽  
Kristen J. Kelynack ◽  
Dodie Pouniotis ◽  
Gavin J. Becker ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
De Novo ◽  
Epithelial Mesenchymal Transition ◽  
Ex Vivo ◽  
Rat Kidney ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Alpha Smooth Muscle Actin ◽  
Mesenchymal Transition ◽  
Renal Tubulointerstitial Fibrosis

Recognised by theirde novoexpression of alpha-smooth muscle actin (SMA), recruitment of myofibroblasts is key to the pathogenesis of fibrosis in chronic kidney disease. Increasingly, we realise that epithelial-mesenchymal transition (EMT) may be an important source of these cells. In this study we describe a novel model of renal EMT. Rat kidney explants were finely diced on gelatin-coated Petri dishes and cultured in serum-supplemented media. Morphology and immunocytochemistry were used to identify mesenchymal (vimentin+, α-smooth muscle actin (SMA)+, desmin+), epithelial (cytokeratin+), and endothelial (RECA+) cells at various time points. Cell outgrowths were all epithelial in origin (cytokeratin+) at day 3. By day 10, 50 ± 12% (mean ± SE) of cytokeratin+ cells double-labelled for SMA, indicating EMT. Lectin staining established a proximal tubule origin. By day 17, cultures consisted only of myofibroblasts (SMA+/cytokeratin−). Explanting is a reproducibleex vivomodel of EMT. The ability to modify this change in phenotype provides a useful tool to study the regulation and mechanisms of renal tubulointerstitial fibrosis.

scholarly journals Hyperoxia-induced neonatal rat lung injury involves activation of TGF-β and Wnt signaling and is protected by rosiglitazone

2009 ◽  
Vol 296 (6) ◽  
pp. L1031-L1041 ◽  
Author(s):  
Chiranjib Dasgupta ◽  
Reiko Sakurai ◽  
Ying Wang ◽  
Pinzheng Guo ◽  
Namasivayam Ambalavanan ◽  
...  
Keyword(s):  
Lung Injury ◽  
Wnt Signaling ◽  
Transforming Growth Factor ◽  
Very Low Birth Weight ◽  
Morphological Changes ◽  
Smooth Muscle Actin ◽  
Neonatal Rat ◽  
Respiratory Morbidity ◽  
Rat Lung

Despite tremendous technological and therapeutic advances, bronchopulmonary dysplasia (BPD) remains a leading cause of respiratory morbidity in very low birth weight infants, and there are no effective preventive and/or therapeutic options. We have previously reported that hyperoxia-induced neonatal rat lung injury might be prevented by rosiglitazone (RGZ). Here, we characterize 1) perturbations in wingless/Int (Wnt) and transforming growth factor (TGF)-β signaling, and 2) structural aberrations in lung morphology following 7-day continuous in vivo hyperoxia exposure to neonatal rats. We also tested whether treatment of neonatal pups with RGZ, concomitant to hyperoxia, could prevent such aberrations. Our study revealed that hyperoxia caused significant upregulation of Wnt signaling protein markers lymphoid enhancer factor 1 (Lef-1) and β-catenin and TGF-β pathway transducers phosphorylated Smad3 and Smad7 proteins in whole rat lung extracts. These changes were also accompanied by upregulation of myogenic marker proteins α-smooth muscle actin (α-SMA) and calponin but significant downregulation of the lipogenic marker peroxisome proliferator-activated receptor-γ (PPARγ) expression. These molecular perturbations were associated with reduction in alveolar septal thickness, radial alveolar count, and larger alveoli in the hyperoxia-exposed lung. These hyperoxia-induced molecular and morphological changes were prevented by systemic administration of RGZ, with lung sections appearing near normal. This is the first evidence that in vivo hyperoxia induces activation of both Wnt and TGF-β signal transduction pathways in lung and of its near complete prevention by RGZ. Hyperoxia-induced arrest in alveolar development, a hallmark of BPD, along with these molecular changes strongly implicates these proteins in hyperoxia-induced lung injury. Administration of PPARγ agonists may thus be a potential strategy to attenuate hyperoxia-induced lung injury and subsequent BPD.

scholarly journals Combination of 13-Cis Retinoic Acid and Lovastatin: Marked Antitumor Potential In Vivo in a Pheochromocytoma Allograft Model in Female Athymic Nude Mice

Endocrinology ◽  
2014 ◽  
Vol 155 (7) ◽  
pp. 2377-2390 ◽  
Author(s):  
Svenja Nölting ◽  
Alessio Giubellino ◽  
Yasin Tayem ◽  
Karen Young ◽  
Michael Lauseker ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Retinoic Acid ◽  
Smooth Muscle Actin ◽  
Treated Group ◽  
Muscle Actin ◽  
Tumor Mass ◽  
Viable Tumor ◽  
Over Time

Currently, there are no reliably effective therapeutic options for metastatic pheochromocytoma (PCC) and paraganglioma. Moreover, there are no therapies that may prevent the onset or progression of tumors in patients with succinate dehydrogenase type B mutations, which are associated with very aggressive tumors. Therefore, we tested the approved and well-tolerated drugs lovastatin and 13-cis-retinoic acid (13cRA) in vitro in an aggressive PCC mouse cell line, mouse tumor tissue-derived (MTT) cells, and in vivo in a PCC allograft nude mouse model, in therapeutically relevant doses. Treatment was started 24 hours before sc tumor cell injection and continued for 30 more days. Tumor sizes were measured from outside by caliper and sizes of viable tumor mass by bioluminescence imaging. Lovastatin showed antiproliferative effects in vitro and led to significantly smaller tumor sizes in vivo compared with vehicle treatment. 13cRA promoted tumor cell growth in vitro and led to significantly larger viable tumor mass and significantly faster increase of viable tumor mass in vivo over time compared with vehicle, lovastatin, and combination treatment. However, when combined with lovastatin, 13cRA enhanced the antiproliferative effect of lovastatin in vivo. The combination-treated mice showed slowest tumor growth of all groups with significantly slower tumor growth compared with the vehicle-treated mice and significantly smaller tumor sizes. Moreover, the combination-treated group displayed the smallest size of viable tumor mass and the slowest increase in viable tumor mass over time of all groups, with a significant difference compared with the vehicle- and 13cRA-treated group. The combination-treated tumors showed highest extent of necrosis, lowest median microvessel density and highest expression of α-smooth muscle actin. The combination of high microvessel density and low α-smooth muscle actin is a predictor of poor prognosis in other tumor entities. Therefore, this drug combination may be a well-tolerated novel therapeutic or preventive option for malignant PCC.

scholarly journals Mutation in the Trapα/Ssr1 Gene, Encoding Translocon-Associated Protein α, Results in Outflow Tract Morphogenetic Defects

2006 ◽  
Vol 26 (20) ◽  
pp. 7760-7771 ◽  
Author(s):  
K. Mesbah ◽  
A. Camus ◽  
C. Babinet ◽  
J. Barra
Keyword(s):  
Heart Development ◽  
Proximal Part ◽  
Double Outlet Right Ventricle ◽  
Outflow Tract ◽  
Endoplasmic Reticulum Membrane ◽  
Messenger Rnas ◽  
Endocardial Cushions ◽  
Gene Encoding ◽  
Mutant Cells

ABSTRACT Translocon-associated protein complex (TRAP) is thought to be required for efficient protein-specific translocation across the endoplasmic reticulum membrane. We created a mutation in the Trapα gene that leads to the synthesis of a truncated TRAPα protein fused to ShBle-β-galactosidase. Analysis of Trapα cDNAs reveals that among three different messenger RNAs expressed in the mouse, one of them encodes a slightly larger protein that differs in its C-terminal end. This mRNA, specific for skeletal muscle and heart, is only expressed after birth. Homozygous Trapα mutant pups die at birth, likely as a result of severe cardiac defects. Indeed, the septation of the proximal part of the outflow tract is absent, resulting in a double-outlet right ventricle. Studies of protein secretion in transfected embryonic fibroblasts reveal that the TRAP complex does not function properly in homozygous mutant cells and confirm, in vivo, the involvement of TRAP in substrate-specific translocation. Our results provide the first in vivo demonstration that a member of the TRAP complex plays a crucial role in mammalian heart development and suggest that TRAPα could be involved in translocation of factors necessary for maturation of endocardial cushions.

The correlation of in vivo burn scar contraction with the level of α-smooth muscle actin expression

Burns ◽  
2011 ◽  
Vol 37 (8) ◽  
pp. 1367-1377 ◽  
Author(s):  
Xue-Qing Wang ◽  
Olena Kravchuk ◽  
Clay Winterford ◽  
Roy M. Kimble
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Burn Scar ◽  
Actin Expression ◽  
Scar Contraction
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