Abstract 251: Development of a Transgenic Goat Model with Cardiac-Specific Overexpression of Transforming Growth Factor-β1 to Study the Relationship Between Atrial Fibrosis and Atrial Fibrillation

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Irina A Polejaeva ◽  
Justin Hall ◽  
Qinggang Meng ◽  
Xinchang Zhou ◽  
Benjamin R Sessions ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Large Animal ◽  
Atrial Pacing ◽  
Atrial Fibrosis ◽  
Transgenic Goat ◽  
Large Animal Models ◽  
Fetal Fibroblasts ◽  
Tgf Β1

Studies on patients, large animal models and transgenic mouse models have shown a strong association of atrial fibrosis with atrial fibrillation (AF). However, it is unclear whether there is a causal relationship between atrial fibrosis and AF or whether these events appear as a result of independent pathological changes in the heart. We are testing the hypothesis that goats that overexpress TGF-β1 (transforming growth factor beta1) specifically in cardiac myocytes will develop atrial fibrosis that in turn will lead to AF. Many aspects of AF-related remodeling have been studied comprehensively in goat models. However, these AF models are typically mechanically induced (eg, the rapid atrial pacing model). This unique transgenic goat model has the potential to offer insights into the role of fibrosis in AF initiation and progression without the confounding effects of mechanical AF induction. Somatic cell nuclear transfer (SCNT or cloning) was used to produce TGF-β1 transgenic pregnancies. First, pcDNA3.1DV5-MHC-TGF-β1cys33ser vector was constructed by subcloning the MHC-TGF-β1 fragment from the plasmid pUC-BM20-MHC-TGF-β1 into the pcDNA3.1D V5 vector. The NeonTM transfection system was used to electroporate primary goat fetal fibroblasts. After two weeks of G418 selection, the resulting G418 resistant colonies were screened by PCR to confirm transgene integration into goat genomic DNA. PCR positive cells were used for SCNT. Cloned embryos (n=264) were cultured for 12-60 h in vitro and then transferred into synchronized recipient females (n=15). Confirmation of pregnancy was done by ultrasonography on day 30 post-transfer. At the time of this abstract submission, 40% (6/15) of recipients were confirmed to be pregnant as determined by the presence of a heartbeat. The range for the stage of gestation is between day-60 and day-120. The first delivery date is April 28, 2012. Several reports documented no pregnancy losses after 30 days of gestation in goats. Therefore, we expect that most if not all of these pregnancies will result in delivery of live offspring. To our knowledge, this will be the first transgenic goat model generated for cardiovascular research.

30 GENERATION OF CLONED TRANSGENIC GOATS WITH CARDIAC SPECIFIC OVEREXPRESSION OF TRANSFORMING GROWTH FACTOR β1

2013 ◽  
Vol 25 (1) ◽  
pp. 162 ◽  
Author(s):  
Q. Meng ◽  
J. Hall ◽  
H. Rutigliano ◽  
X. Zhou ◽  
B. R. Sessions ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Transforming Growth Factor Β1 ◽  
Transgenic Goat ◽  
First Polar Body ◽  
Fetal Fibroblasts ◽  
Transgenic Goats ◽  
Tgf Β1

Transforming growth factor β1 (TGF-β1) has a potent profibrotic function and is central to signaling cascades involved in interstitial fibrosis, which plays a critical role in the pathobiology of cardiomyopathy and contributes to diastolic and systolic dysfunction. In addition, fibrotic remodeling is responsible for generation of re-entry circuits that promote arrhythmias (Bujak and Frangogiannis 2007 Cardiovasc. Res. 74, 184–195). Due to the small size of the heart, functional electrophysiology of transgenic mice is problematic. Large transgenic animal models have the potential to offer insights into conduction heterogeneity associated with fibrosis and the role of fibrosis in cardiovascular diseases. The goal of this study was to generate transgenic goats overexpressing an active form of TGFβ-1 under control of the cardiac-specific α-myosin heavy chain promoter (α-MHC). A pcDNA3.1DV5-MHC-TGF-β1cys33ser vector was constructed by subcloning the MHC-TGF-β1 fragment from the plasmid pUC-BM20-MHC-TGF-β1 (Nakajima et al. 2000 Circ. Res. 86, 571–579) into the pcDNA3.1D V5 vector. The Neon transfection system was used to electroporate primary goat fetal fibroblasts. After G418 selection and PCR screening, transgenic cells were used for SCNT. Oocytes were collected by slicing ovaries from an abattoir and matured in vitro in an incubator with 5% CO2 in air. Cumulus cells were removed at 21 to 23 h post-maturation. Oocytes were enucleated by aspirating the first polar body and nearby cytoplasm by micromanipulation in Hepes-buffered SOF medium with 10 µg of cytochalasin B mL–1. Transgenic somatic cells were individually inserted into the perivitelline space and fused with enucleated oocytes using double electrical pulses of 1.8 kV cm–1 (40 µs each). Reconstructed embryos were activated by ionomycin (5 min) and DMAP and cycloheximide (CHX) treatments. Cloned embryos were cultured in G1 medium for 12 to 60 h in vitro and then transferred into synchronized recipient females. Pregnancy was examined by ultrasonography on day 30 post-transfer. A total of 246 cloned embryos were transferred into 14 recipients that resulted in production of 7 kids. The pregnancy rate was higher in the group cultured for 12 h compared with those cultured 36 to 60 h [44.4% (n = 9) v. 20% (n = 5)]. The kidding rates per embryo transferred of these 2 groups were 3.8% (n = 156) and 1.1% (n = 90), respectively. The PCR results confirmed that all the clones were transgenic. Phenotype characterization [e.g. gene expression, electrocardiogram (ECG), and magnetic resonance imaging (MRI)] is underway. We demonstrated successful production of transgenic goat via SCNT. To our knowledge, this is the first transgenic goat model produced for cardiovascular research. This work was supported by the Utah Science Technology and Research Initiative, Utah Multidisciplinary Arrhythmia Consortium.

scholarly journals Blockade of Exosome Release Suppresses Atrial Fibrillation by Alleviating Atrial Fibrosis in Canines With Prolonged Atrial Pacing

2021 ◽  
Vol 8 ◽  
Author(s):  
Yajun Yao ◽  
Shanqing He ◽  
Youcheng Wang ◽  
Zhen Cao ◽  
Dishiwen Liu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Transforming Growth Factor ◽  
Canine Model ◽  
Transforming Growth Factor Β1 ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Atrial Pacing ◽  
Atrial Fibrosis ◽  
Exosome Biogenesis ◽  
Underlying Mechanisms ◽  
Tgf Β1

Background: Clinical studies have shown that exosomes are associated with atrial fibrillation (AF). However, the roles and underlying mechanisms remain unclear. Hence, this study aimed to investigate the function of exosomes in AF development.Methods: Twenty beagles were randomly divided into the sham group (n = 6), the pacing group (n = 7), and the pacing + GW4869 group (n = 7). The pacing and GW4869 groups underwent rapid atrial pacing (450 beats/min) for 7 days. The GW4869 group received intravenous GW4869 injection (an inhibitor of exosome biogenesis/release, 0.3 mg/kg, once a day) during pacing. Electrophysiological measurements, transmission electron microscopy, nanoparticle tracking analysis, western blotting, RT-PCR, Masson's staining, and immunohistochemistry were performed in this study.Results: Rapid atrial pacing increased the release of plasma and atrial exosomes. GW4869 treatment markedly suppressed AF inducibility and reduced the release of exosomes. After 7 days of pacing, the expression of transforming growth factor-β1 (TGF-β1), collagen I/III, and matrix metalloproteinases was enhanced in the atrium, and the levels of microRNA-21-5p (miR-21-5p) were upregulated in both plasma exosomes and the atrium, while the tissue inhibitor of metalloproteinase 3 (TIMP3), a target of miR-21-5p, showed a lower expression in the atrium. The administration of GW4869 abolished these effects.Conclusions: The blockade of exosome release with GW4869 suppressed AF by alleviating atrial fibrosis in a canine model, which was probably related to profibrotic miR-21-5p enriched in exosomes and its downstream TIMP3/TGF-β1 pathway.

scholarly journals A Review of the Molecular Mechanisms Underlying Cardiac Fibrosis and Atrial Fibrillation

2021 ◽  
Vol 10 (19) ◽  
pp. 4430
Author(s):  
Grażyna Sygitowicz ◽  
Agata Maciejak-Jastrzębska ◽  
Dariusz Sitkiewicz
Keyword(s):  
Atrial Fibrillation ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Signalling Pathways ◽  
Ang Ii ◽  
Atrial Fibrosis ◽  
Genes Encoding ◽  
Tgf Β1

The cellular and molecular mechanism involved in the pathogenesis of atrial fibrosis are highly complex. We have reviewed the literature that covers the effectors, signal transduction and physiopathogenesis concerning extracellular matrix (ECM) dysregulation and atrial fibrosis in atrial fibrillation (AF). At the molecular level: angiotensin II, transforming growth factor-β1, inflammation, and oxidative stress are particularly important for ECM dysregulation and atrial fibrotic remodelling in AF. We conclude that the Ang-II-MAPK and TGF-β1-Smad signalling pathways play a major, central role in regulating atrial fibrotic remodelling in AF. The above signalling pathways induce the expression of genes encoding profibrotic molecules (MMP, CTGF, TGF-β1). An important mechanism is also the generation of reactive oxygen species. This pathway induced by the interaction of Ang II with the AT2R receptor and the activation of NADPH oxidase. Additionally, the interplay between cardiac MMPs and their endogenous tissue inhibitors of MMPs, is thought to be critical in atrial ECM metabolism and fibrosis. We also review recent evidence about the role of changes in the miRNAs expression in AF pathophysiology and their potential as therapeutic targets. Furthermore, keeping the balance between miRNA molecules exerting anti-/profibrotic effects is of key importance for the control of atrial fibrosis in AF.

Growth factor expression pattern of homologous feeder layer for culturing buffalo embryonic stem cell-like cells

2012 ◽  
Vol 24 (8) ◽  
pp. 1098 ◽  
Author(s):  
Ruchi Sharma ◽  
Aman George ◽  
Nitin M. Kamble ◽  
Manmohan S. Chauhan ◽  
Suresh Singla ◽  
...  
Keyword(s):  
Stem Cell ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Embryonic Stem ◽  
Transforming Growth Factor Β1 ◽  
Activin A ◽  
Feeder Layer ◽  
Es Cell ◽  
Fetal Fibroblasts ◽  
Tgf Β1

The present study examined the expression profile of buffalo fetal fibroblasts (BFF) used as a feeder layer for embryonic stem (ES) cell-like cells. The expression of important growth factors was detected in cells at different passages. Mitomycin-C inactivation increased relative expression levels of ACTIVIN-A, TGF-β1, BMP-4 and GREMLIN but not of fibroblast growth factor-2 (FGF-2). The expression level of ACTIVIN-A, transforming growth factor-β1 (TGF-β1), bone morphogenetic protein-4 (BMP-4) and FGF-2 was similar in buffalo fetal fibroblast (BFF) cultured in stem cell medium (SCM), SCM + 1000 IU mL–1 leukemia inhibitory factor (LIF), SCM + 5 ng mL–1 FGF-2 or SCM + LIF + FGF-2 for 24 h whereas GREMLIN expression was higher in FGF-2-supplemented groups. In spent medium, the concentration of ACTIVIN-A was higher in FGF-2-supplemented groups whereas that of TGF-β1 was similar in SCM and LIF + FGF-2, which was higher than when either LIF or FGF-2 was used alone. Following culture of ES cell-like cells on a feeder layer for 24 h, the TGF-β1 concentration was higher with LIF+FGF-2 than with LIF or FGF-2 alone which, in turn, was higher than that in SCM. In the LIF + FGF-2 group, the concentration of TGF-β1 was lower and that of ACTIVIN-A was higher in spent medium at 24 h than at 48 h of culture. These results suggest that BFF produce signalling molecules that may help in self-renewal of buffalo ES cell-like cells.

Eicosapentaenoic acid prevents atrial fibrillation associated with heart failure in a rabbit model

2011 ◽  
Vol 300 (5) ◽  
pp. H1814-H1821 ◽  
Author(s):  
Kazuhisa Kitamura ◽  
Rei Shibata ◽  
Yukiomi Tsuji ◽  
Masayuki Shimano ◽  
Yasuya Inden ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Eicosapentaenoic Acid ◽  
Transforming Growth Factor ◽  
Rabbit Model ◽  
Transforming Growth Factor Β1 ◽  
Atrial Remodeling ◽  
Atrial Fibrosis ◽  
Erk Phosphorylation ◽  
Tgf Β1

Atrial fibrillation (AF) is associated with morbidity and mortality of heart failure. Eicosapentaenoic acid (EPA), which is contained in fish oil, was shown to reduce the risk of cardiovascular diseases. We investigated the effects of EPA on AF associated with heart failure in a rabbit model. Rabbits were subjected to ventricular tachypacing (VTP) for 4 wk with or without EPA treatment. Continuous VTP induced heart failure status in these rabbits. The duration of AF (DAF) induced by burst pacing was analyzed by electrophysiological studies. VTP resulted in increased DAF following burst pacing. EPA treatment attenuated increased DAF. Atrial fibrosis increased in response to VTP, accompanied by extracellular signal-regulated kinase (ERK) phosphorylation and transforming growth factor-β1 (TGF-β1) expression in the atrium. Treatment with EPA attenuated atrial fibrosis, ERK phosphorylation, and TGF-β1 expression in response to VTP. EPA treatment increased adiponectin as an anti-inflammatory adipokine and decreased tumor necrosis factor-α as a proinflammatory adipokine in the atrium and epicardial adipose tissues. EPA attenuated VTP-induced AF promotion and atrial remodeling, which was accompanied by modulating the profiles of adipokine production from epicardial adipose tissue. EPA may be useful for prevention and treatment of AF associated with heart failure.

scholarly journals Myocardial fibrosis and atrial fibrillation

2018 ◽  
pp. 71-76 ◽  
Author(s):  
S. V. Grigoryan ◽  
L. G. Azarapetyan ◽  
K. G. Adamyan
Keyword(s):  
Atrial Fibrillation ◽  
Growth Factor ◽  
Structural Changes ◽  
Transforming Growth Factor ◽  
Matrix Metalloproteases ◽  
Diagnostic Methods ◽  
Atrial Fibrosis ◽  
Non Invasive ◽  
Level Measurement

Atrial fibrillation is the most prevalent arrhythmia, and tends to progress. Any structural changes in the heart may lead to its progressive remodelling with increased deposition of connective tissue and fibrosis. Predominance of collagen types I and III synthesis over its degradation leads to accumulation of fibers and to fibrosis. Increase of atrial fibrosis is usually found on autopsy and biopsy. There is relation revealed, of atrial fibrosis grade and postsurgery atrial fibrillation. The mechanisms participating in the structural remodelling and progression of atrial fibrosis are not studied well enough, but there is known role of renin-angiotensinaldosterone system, transforming growth factor, inflammation and matrix metalloproteases. As an alternative, one should consider non-invasive diagnostic methods: magnetic resonance imaging of the heart and biomarkers level measurement. Hyperactivation of the renin-angiotensin-aldosterone system facilitates structural remodelling of the heart and progression of atrial fibrosis. Hyperexpression of the transforming growth factor leads to selective atrial fibrosis, heterogeneity of excitation conduction and fibrillation onset. Matrix metalloproteases are the marker of extracellular degradation. Study of fibrosis biomarkers makes it to increase significantly the efficacy of atrial fibrillation course prediction.

scholarly journals MG53/CAV1 regulates transforming growth factor-β1 signaling-induced atrial fibrosis in atrial fibrillation

Cell Cycle ◽  
2020 ◽  
Vol 19 (20) ◽  
pp. 2734-2744
Author(s):  
Meixia Zhang ◽  
Hechuan Wang ◽  
Xiaowen Wang ◽  
Mengjun Bie ◽  
Kai Lu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Atrial Fibrosis

scholarly journals Platelets Promote Ang II (Angiotensin II)-Induced Atrial Fibrillation by Releasing TGF-β1 (Transforming Growth Factor-β1) and Interacting With Fibroblasts

Hypertension ◽  
2020 ◽  
Vol 76 (6) ◽  
pp. 1856-1867
Author(s):  
Yang Liu ◽  
Haichen Lv ◽  
Ruopeng Tan ◽  
Xiangbo An ◽  
Xiao-Hui Niu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Platelet Activation ◽  
Transforming Growth Factor ◽  
Platelet Inhibition ◽  
Transforming Growth Factor Β1 ◽  
Ang Ii ◽  
Atrial Fibrosis ◽  
Electrical Transmission ◽  
Platelet Accumulation ◽  
Tgf Β1

Hypertension is a risk factor of atrial fibrillation (AF), and a certain number of patients with hypertension were found with an enlarged left atrium. Platelet activation is found in patients with hypertension or pressure overload/Ang II (angiotensin II)-induced hypertensive animal models and contribute to ventricular fibrosis. Whether hypertension-induced atrial fibrosis is mediated by platelets remains unknown. Our previous experimental data showed that platelet-derived TGF-β1 (transforming growth factor-β1) was reduced in patients with hypertensive AF. The present study is to investigate whether platelet-derived TGF-β1 promotes Ang II-induced atrial fibrosis and AF. Platelet activation and atrial platelet accumulation were measured in sinus rhythm controls, normotensive AF, and patients with hypertensive AF. Ang II (1500 ng/kg per minute, 3 weeks) infused mice with pharmacological (clopidogrel) and genetic platelet inhibition (TGF-β1 deletion in platelets) were used. Platelet activation, atrial structural remodeling, atrial electrical transmission, AF inducibility, inflammation, and fibrosis were measured in mice. We found that circulating platelets were activated in patients with hypertensive AF. A large amount of platelet was accumulated in the atriums of patients with hypertensive AF. Both clopidogrel treatment and platelet-specific deletion of TGF-β1 attenuated Ang II-induced structural remodeling, atrial electrical transmission, AF inducibility, as well as atrial inflammation and fibrosis than mice without interventions. Furthermore, clopidogrel blocked atrial platelet accumulation and platelet-fibroblast conjugation. Platelets promoted atrial fibroblast differentiation in cell culture. Profibrotic actions of platelets are largely via activation of atrial fibroblasts by releasing TGF-β1 and inducing platelet-fibroblast conjugation, and platelet inhibition is sufficient to inhibit atrial fibrosis and AF inducibility.

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