Abstract 121: Interleukin 11 Mediates Wnt/β-catenin-dependent Fibrotic Response Of Human Cardiac Fibroblasts

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Edyta Dzialo ◽  
Marcin Czepiel ◽  
Maciej Siedlar ◽  
Gabriela Kania ◽  
Przemyslaw Blyszczuk
Keyword(s):  
Smooth Muscle ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Neutralizing Antibody ◽  
Cell Culture Supernatant ◽  
Muscle Actin ◽  
Alpha Smooth Muscle Actin ◽  
Wnt Proteins ◽  
Human Cardiac Fibroblasts

Wnt proteins family represents secreted glycoproteins implicated in the number of fibrotic cardiac pathologies. The transcriptional activity of Wnts is broad and involves β-catenin-dependent or β-catenin-independent responses. In this study, we examined the effect of exogenous Wnt3a (β-catenin-dependent) and Wnt5a (β-catenin-independent) in TGF-β-activated human cardiac fibroblasts. Furthermore, we assessed the hypothesis that Wnt3a could regulate IL-11 production and analyzed its contribution to profibrotic response in cardiac fibroblasts.By employing a full genome transcriptomics, we analyzed transformation of human cardiac fibroblasts induced by TGF-β in the presence of Wnt3a or Wnt5a produced by cell culture supernatant of L-Wnt3a, L-Wnt5a or control L-cells. Stimulation with Wnt3a of TGF-β-activated fibroblasts resulted in induction of 66 genes, specifically involved in myofibroblast differentiation including ACTA2 (encoding alpha smooth muscle actin; αSMA) ACTG2 (encoding gamma smooth muscle actin; γSMA) and VCL (encoding vinculin). In contrast to Wnt3a, treatment with Wnt5a upregulated expression of only 2 genes in TGF-β-activated cells. Additionally, in the presence of TGF-β, Wnt3a enhanced phosphorylation of TAK1 and production and secretion of IL-11. Importantly, in the absence of TGF-β, Wnt3a did not promote fibroblast-to-myofibroblast transition, TAK1 phosphorylation and IL-11 production. To determine, if Wnt3a-dependent production of IL-11 could contribute to profibrotic response we blocked IL-11 activity with anti-IL-11 neutralizing antibody in cardiac fibroblasts activated with TGF-β and Wnt3a. We found that neutralizing anti-IL11 antibody effectively suppressed production of αSMA, γSMA, fibronectin and pro-collagen I alpha 1, both on mRNA and protein levels. In line with these findings, blockade of IL-11 suppressed contractile properties of TGF-β/Wnt3a-activated cardiac fibroblasts. In conclusion, Wnt3a and Wnt5a differentially regulate gene expression of TGF-β-activated cardiac. Activation of the Wnt/β-catenin pathway promotes fibroblast-to-myofibroblast transition by enhancing production of profibrotic IL-11. It seems that identifying the profibrotic Wnt/β-catenin-IL11 mechanism in cardiac fibroblasts might represent a promising strategy in development of new therapies against cardiac fibrosis.

scholarly journals Ivabradine Reduces α-Smooth Muscle Actin Expression, Proliferation and Collagen Production in Human Cardiac Fibroblasts

2014 ◽  
Vol 106 (2) ◽  
pp. 759a
Author(s):  
Priyanthi Dias ◽  
Manoraj Navaratnarajah ◽  
Samha Alayoubi ◽  
Christopher Kane ◽  
Leanne E. Felkin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Collagen Production ◽  
Human Cardiac Fibroblasts ◽  
Actin Expression

scholarly journals A deep learning approach to identify and segment alpha-smooth muscle actin stress fiber positive cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Hillsley ◽  
Javier E. Santos ◽  
Adrianne M. Rosales
Keyword(s):  
Smooth Muscle ◽  
Deep Learning ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Stress Fiber ◽  
Stress Fibers ◽  
Actin Stress Fiber ◽  
Muscle Actin ◽  
Alpha Smooth Muscle Actin

AbstractCardiac fibrosis is a pathological process characterized by excessive tissue deposition, matrix remodeling, and tissue stiffening, which eventually leads to organ failure. On a cellular level, the development of fibrosis is associated with the activation of cardiac fibroblasts into myofibroblasts, a highly contractile and secretory phenotype. Myofibroblasts are commonly identified in vitro by the de novo assembly of alpha-smooth muscle actin stress fibers; however, there are few methods to automate stress fiber identification, which can lead to subjectivity and tedium in the process. To address this limitation, we present a computer vision model to classify and segment cells containing alpha-smooth muscle actin stress fibers into 2 classes (α-SMA SF+ and α-SMA SF-), with a high degree of accuracy (cell accuracy: 77%, F1 score 0.79). The model combines standard image processing methods with deep learning techniques to achieve semantic segmentation of the different cell phenotypes. We apply this model to cardiac fibroblasts cultured on hyaluronic acid-based hydrogels of various moduli to induce alpha-smooth muscle actin stress fiber formation. The model successfully predicts the same trends in stress fiber identification as obtained with a manual analysis. Taken together, this work demonstrates a process to automate stress fiber identification in in vitro fibrotic models, thereby increasing reproducibility in fibroblast phenotypic characterization.

scholarly journals The AP-1 Transcription Factor Fosl-2 Regulates Autophagy in Cardiac Fibroblasts during Myocardial Fibrogenesis

2021 ◽  
Vol 22 (4) ◽  
pp. 1861
Author(s):  
Jemima Seidenberg ◽  
Mara Stellato ◽  
Amela Hukara ◽  
Burkhard Ludewig ◽  
Karin Klingel ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Beclin 1 ◽  
Type I ◽  
Alpha Smooth Muscle Actin

Background: Pathological activation of cardiac fibroblasts is a key step in development and progression of cardiac fibrosis and heart failure. This process has been associated with enhanced autophagocytosis, but molecular mechanisms remain largely unknown. Methods and Results: Immunohistochemical analysis of endomyocardial biopsies showed increased activation of autophagy in fibrotic hearts of patients with inflammatory cardiomyopathy. In vitro experiments using mouse and human cardiac fibroblasts confirmed that blockade of autophagy with Bafilomycin A1 inhibited fibroblast-to-myofibroblast transition induced by transforming growth factor (TGF)-β. Next, we observed that cardiac fibroblasts obtained from mice overexpressing transcription factor Fos-related antigen 2 (Fosl-2tg) expressed elevated protein levels of autophagy markers: the lipid modified form of microtubule-associated protein 1A/1B-light chain 3B (LC3BII), Beclin-1 and autophagy related 5 (Atg5). In complementary experiments, silencing of Fosl-2 with antisense GapmeR oligonucleotides suppressed production of type I collagen, myofibroblast marker alpha smooth muscle actin and autophagy marker Beclin-1 in cardiac fibroblasts. On the other hand, silencing of either LC3B or Beclin-1 reduced Fosl-2 levels in TGF-β-activated, but not in unstimulated cells. Using a cardiac hypertrophy model induced by continuous infusion of angiotensin II with osmotic minipumps, we confirmed that mice lacking either Fosl-2 (Ccl19CreFosl2flox/flox) or Atg5 (Ccl19CreAtg5flox/flox) in stromal cells were protected from cardiac fibrosis. Conclusion: Our findings demonstrate that Fosl-2 regulates autophagocytosis and the TGF-β-Fosl-2-autophagy axis controls differentiation of cardiac fibroblasts. These data provide a new insight for the development of pharmaceutical targets in cardiac fibrosis.

Expression of alpha-smooth muscle actin, TGF-β1 and TGF-β type II receptor during connective tissue contraction

1997 ◽  
Vol 33 (8) ◽  
pp. 622-627 ◽  
Author(s):  
M. Reza Ghassemifar ◽  
Roy W. Tarnuzzer ◽  
Nasser Chegini ◽  
Erkki Tarpila ◽  
Gregory S. Schultz ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Connective Tissue ◽  
Smooth Muscle Actin ◽  
Type Ii ◽  
Muscle Actin ◽  
Alpha Smooth Muscle Actin ◽  
Tissue Contraction ◽  
Tgf Β1
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