Abstract 445: A Pro-Fibrotic Role of Interleukin-4 in Cardiac Remodeling and Dysfunction

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Hongmei Peng ◽  
Oscar Carretero ◽  
Xiao-Ping Yang ◽  
Pablo Nakagawa ◽  
Jiang Xu ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Interleukin 4 ◽  
Ang Ii ◽  
Collagen Production ◽  
And Function ◽  
First Time ◽  
Mini Pump

Elevated interleukin-4 (IL-4) levels are positively related to cardiac fibrosis in heart failure and hypertension. Using Balb/c exhibiting high circulating IL-4, Balb/c- Il4 tm2Nnt (IL-4 knockout with Balb/c background, IL-4 -/- ) and C57BL/6 mice, as well as cultured cardiac fibroblasts (CFs), we hypothesized that 1) high levels of IL-4 result in cardiac fibrosis, making the heart susceptible to angiotensin II (Ang II)-induced damage, and 2) IL-4 potently stimulates collagen production by CFs. Each strain (9- to 12-week old male) received vehicle or Ang II (1.4 mg/kg/day, s.c. via osmotic mini-pump) for 8 weeks. Cardiac fibrosis and function were determined by histology and echocardiography, respectively. Compared to C57BL/6, Balb/c mice had doubled interstitial collagen in the heart, enlarged left ventricle and decreased cardiac function along with elevated cardiac IL-4 protein (1.00±0.08 in C57BL/6 vs 2.61±0.46 in Balb/c, p <0.05); all those changes were significantly attenuated in IL-4 -/- (Table 1). Ang II further deteriorated cardiac fibrosis and dysfunction in Balb/c; these detrimental effects were attenuated in IL-4 -/- , although the three strains had a similar level of hypertension. In vitro study revealed that IL-4Rα was constitutively expressed in CFs (Western blot), and IL-4 potently stimulated collagen production by CFs (hydroxproline assay, from 18.89±0.85 to 38.81±3.61 μg/mg at 10 ng/ml, p <0.01). Our study demonstrates for the first time that IL-4, as a potent pro-fibrotic cytokine in the heart, contributes to cardiac fibrotic remodeling and dysfunction. Thus IL-4 may be a potential therapeutic target for cardiac fibrosis and dysfunction.

Abstract 15671: Adipocyte-derived Exosomal Lncrna Nbr2 Promotes Diabetic Myocardial Fibrosis Through Regulating the Ikba/nf-kb Pathway

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Yue Guo ◽  
Xingfeng Xu ◽  
Lingling Wu ◽  
Xiaodong Zhuang ◽  
Xinxue Liao
Keyword(s):  
Myocardial Fibrosis ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Epigenetic Mechanism ◽  
Ang Ii ◽  
Intramyocardial Injection ◽  
Underlying Mechanisms ◽  
Human Cardiac Fibroblasts ◽  
And Function

Introduction: The activation of NF-κB is the dominant process that correlates with the pathogenesis of diabetic cardiomyopathy (DCM). Recently, accumulating evidence shows that long noncoding RNAs (lncRNAs) play crucial roles in sustaining the NF-κB pathway. However, the underlying mechanisms remain unclear. In this study, we identified the upregulated expressed lncRNA NBR2 in adipocyte-derived exosomes (AdEXO) and investigated its regulatory role in diabetic myocardial fibrosis. Hypothesis: We hypothesized that AdEXO-NBR2 promotes diabetic myocardial fibrosis through regulating the IκBα/NF-κB pathway. Methods: We examined the effect of exosomes from diabetic (db/db) mice-derived adipocytes on ANG-II-induced cardiac fibrosis and function in non-diabetic (C57BL/6J mice). In the invitro study, HG (33mmol/L)-stimulated AdEXO were cultured with adult human cardiac fibroblasts (aHCFs). Differentially expressed lncRNAs in AdEXO were screened using lncRNA sequencing. Results: Intramyocardial injection of diabetic AdEXO in the non-diabetic heart significantly exacerbated myocardial fibrosis, as evidenced by poorer cardiac function and enhancer collagen deposition. Whereas administration of a exosomes biogenesis inhibitor mitigated cardiac fibrosis in diabetic mice. We found lncRNA-NBR2 is a common molecule significantly increased in diabetic AdEXO and HG-stimulated non-diabetic AdEXO. After four weeks of ANG II infusion, EXO-db/dbWT-injected mice displayed fibrosis in the heart. However, interestingly, mice receiving NBR2-deficient db/db-EXO showed a decrease in cardiac fibrosis. Similarly, AdEXO-NBR2 promoted aHCFs proliferation and transformation capabilities in vitro. Mechanistically, NBR2 was loaded to AdEXO by directly interacting with heterogeneous nuclear ribonucleoprotein K (hnRNPK). Subsequently, AdEXO-NBR2 was internalized by aHCFs and epigenetically downregulated IκBα expression by recruitment of hnRNPK/SETDB1 and increasing the H3K9 trimethylation level in the IκBα promoter, ultimately activating the NF-κB pathway. Conclusions: Our findings highlight a novel epigenetic mechanism of AdEXO lncRNA-mediated diabetic cardiac fibrosis and identify NBR2 as a therapeutic target of DCM.

scholarly journals Long Non-Coding RNA 554 Promotes Cardiac Fibrosis via TGF-β1 Pathway in Mice Following Myocardial Infarction

2020 ◽  
Vol 11 ◽  
Author(s):  
Bihui Luo ◽  
Zhiyu He ◽  
Shijun Huang ◽  
Jinping Wang ◽  
Dunzheng Han ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Non Coding Rna ◽  
Novel Target ◽  
And Function ◽  
Tgf Β1

Rationale: Cardiac fibrosis is observed in nearly every form of myocardial disease. Long non-coding RNAs (lncRNAs) have been shown to play an important role in cardiac fibrosis, but the detailed molecular mechanism remains unknown.Object: We aimed at characterizing lncRNA 554 expression in murine cardiac fibroblasts (CFs) after myocardial infarction (MI) to identify CF-enriched lncRNA and investigate its function and contribution to cardiac fibrosis and function.Methods and Results: In this study, we identified lncRNA NONMMUT022554 (lncRNA 554) as a regulator of MI-induced cardiac fibrosis. We found that lncRNA 554 was significantly up-regulated in the mouse hearts following MI. Further study showed that lncRNA 554 was predominantly expressed in cardiac fibroblasts, indicating a potential role of lncRNA 554 in cardiac fibrosis. In vitro knockdown of lncRNA 554 by siRNA suppressed fibroblasts migration and expression of extracellular matrix (ECM); while overexpression of lncRNA 554 promoted expression of ECM genes. Consistently, lentivirus mediated in vivo knockdown of lncRNA 554 could inhibit cardiac fibrosis and improve cardiac function in mouse model of MI. More importantly, TGF-β1 inhibitor (TEW-7197) could reverse the pro-fibrotic function of lncRNA 554 in CFs. This suggests that the effects of lncRNA 554 on cardiac fibrosis is TGF-β1 dependent.Conclusion: Collectively, our study illustrated the role of lncRNA 554 in cardiac fibrosis, suggested that lncRNA 554 might be a novel target for cardiac fibrosis.

scholarly journals miR-21 is upregulated, promoting fibrosis and blocking G2/M in irradiated rat cardiac fibroblasts

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10502
Author(s):  
Huan Guo ◽  
Xinke Zhao ◽  
Haixiang Su ◽  
Chengxu Ma ◽  
Kai Liu ◽  
...  
Keyword(s):  
Myocardial Fibrosis ◽  
Target Genes ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Differentially Expressed Gene ◽  
Stem Loop ◽  
Cardiac Morbidity ◽  
Increased Risk ◽  
And Function

Background Radiation exposure of the thorax is associated with a greatly increased risk of cardiac morbidity and mortality even after several decades of advancement in the field. Although many studies have demonstrated the damaging influence of ionizing radiation on cardiac fibroblast (CF) structure and function, myocardial fibrosis, the molecular mechanism behind this damage is not well understood. miR-21, a small microRNA, promotes the activation of CFs, leading to cardiac fibrosis. miR-21 is overexpressed after irradiation; however, the relationship between increased miR-21 and myocardial fibrosis after irradiation is unclear. This study was conducted to investigate gene expression after radiation-induced CF damage and the role of miR-21 in this process in rats. Methods We sequenced irradiated rat CFs and performed weighted correlation network analysis (WGCNA) combined with differentially expressed gene (DEG) analysis to observe the effect on the expression profile of CF genes after radiation. Results DEG analysis showed that the degree of gene changes increased with the radiation dose. WGCNA revealed three module eigengenes (MEs) associated with 8.5-Gy-radiation—the Yellow, Brown, Blue modules. The three module eigengenes were related to apoptosis, G2/M phase, and cell death and S phase, respectively. By blocking with the cardiac fibrosis miRNA miR-21, we found that miR-21 was associated with G2/M blockade in the cell cycle and was mainly involved in regulating extracellular matrix-related genes, including Grem1, Clu, Gdf15, Ccl7, and Cxcl1. Stem-loop quantitative real-time PCR was performed to verify the expression of these genes. Five genes showed higher expression after 8.5 Gy-radiation in CFs. The target genes of miR-21 predicted online were Gdf15 and Rsad2, which showed much higher expression after treatment with antagomir-miR-21 in 8.5-Gy-irradiated CFs. Thus, miR-21 may play the role of fibrosis and G2/M blockade in regulating Grem1, Clu, Gdf15, Ccl7, Cxcl1, and Rsad2 post-irradiation.

scholarly journals Downregulation of S100A4 Alleviates Cardiac Fibrosis via Wnt/β -Catenin Pathway in Mice

2018 ◽  
Vol 46 (6) ◽  
pp. 2551-2560 ◽  
Author(s):  
LiJun Qian ◽  
Jian Hong ◽  
YanMei Zhang ◽  
MengLin Zhu ◽  
XinChun Wang ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Group A ◽  
Ischemic Diseases ◽  
Fibrotic Diseases ◽  
Signaling Activation

Background/Aims: Cardiac fibrosis is a pathological change leading to cardiac remodeling during the progression of myocardial ischemic diseases, and its therapeutic strategy remains to be explored. S100A4, a calcium-binding protein, participates in fibrotic diseases with an unclear mechanism. This study aimed to investigate the role of S100A4 in cardiac fibrosis. Methods: Cardiac fibroblasts from neonatal C57BL/6 mouse hearts were isolated and cultured. Myocardial infarction was induced by ligating the left anterior descending coronary artery (LAD). The ligation was not performed in the sham group. A volume of 5×105pfu/g adenovirus or 5 µM/g ICG-001 was intramyocardially injected into five parts bordering the infarction zone or normal region. We used Western blotting, quantitative RT-PCR, immunofluorescence, immunohistochemistry and Masson’s trichrome staining to explore the function of S100A4. Results: We found significant increases of S100A4 level and cardiac fibrosis markers, and β-catenin signaling activation in vitro and in vivo. In addition, knockdown of S100A4 significantly reduced cardiac fibrosis and β-catenin levels. Moreover, the expression of S100A4 decreased after ICG-001 inhibited β-catenin signal pathway. Conclusion: Downregulation of S100A4 alleviates cardiac fibrosis via Wnt/β -catenin pathway in mice. S100A4 may be a therapeutic target of cardiac fibrosis.

Abstract 220: miR-486 Mediates the Benefits of Exercise in Attenuating Cardiac Fibrosis

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Dongchao Lv ◽  
Yihua Bei ◽  
Qiulian Zhou ◽  
Qi Sun ◽  
Tianzhao Xu ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Mrna Level ◽  
Neonatal Rat ◽  
Cardiac Growth ◽  
Non Coding Rnas ◽  
Exercise Induced ◽  
Proliferation Assays

MicroRNAs (miRNAs, miRs), a novel group of small non-coding RNAs, play important roles in cardiac fibrosis. Exercise-induced physiological cardiac growth is associated with hypertrophy and proliferation of cardiomyocytes. In addition, exercise has been shown to inhibit cardiac fibrosis. However, relative little is known about whether exercise could attenuating cardiac fibrosis via targeting miRNA. miR-486 is a muscle enriched miRNAs, however, its role in heart is relative unclear. The current study aimed to investigate the role of miR-486 in exercise-induced cardiac growth in a 3-week swimming training murine model as well as in the function of cardiac fibroblasts and production of extracellular matrix (ECM) using neonatal rat cardiac fibroblasts in primary culture. Our data showed that exercised mice displayed increased about three-fold expression of miR-486 in hearts as measured by microarray analysis and qRT-PCRs. EdU proliferation assays demonstrated that miR-486 mimics decreased (5.90%±0.57% vs 4.02%±0.27% in nc-mimics vs miR-486-mimics, respectively), while miR-486 inhibitor increased the proliferation of cardiac fibroblasts in vitro (5.87%±0.16% vs 9.60%±0.58% in nc-inhibitor vs miR-486-inhibitor, respectively). Although downregulation of miR-486 had no regulatory effect on α-sma and collagen-1 gene expression in cardiac fibroblasts, overexpression of miR-486 significantly reduced the mRNA level of α-sma (1.01±0.08 vs 0.28±0.04 in nc-mimics vs miR-486-mimics, respectively) and collagen-1(1.02±0.12 vs 0.58±0.09 in nc-mimics vs miR-486-mimics, respectively), indicative of attenuated activation of fibroblasts and reduced production of ECM. These data reveal that miR-486 is essentially involved in the proliferation and activation of cardiac fibroblasts, and might be a key regulator mediating the benefit of exercise in preventing cardiac fibrosis.

Differential response of cardiac fibroblasts from young adult and senescent rats to ANG II

2003 ◽  
Vol 284 (4) ◽  
pp. H1454-H1459 ◽  
Author(s):  
K. Shivakumar ◽  
David E. Dostal ◽  
Kenneth Boheler ◽  
Kenneth M. Baker ◽  
Edward G. Lakatta
Keyword(s):  
Young Adult ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Receptor Subtype ◽  
Mrna Levels ◽  
Ang Ii ◽  
Adult Rats ◽  
Collagen Production ◽  
Age Related

The intracardiac ANG II-forming pathway is activated in the senescent myocardium, raising the possibility of enhanced ANG II effects on cardiac fibroblasts. This study established an in vitro model of cultured cardiac fibroblasts from aged rats to examine if the response of these cells to ANG II is modified in the aged heart. Levels of mRNA encoding renin, angiotensinogen, and the AT1 receptor subtype in cardiac fibroblasts from young adult and senescent rats were quantified by RT-PCR, net collagen production by a hydroxyproline-based assay, and transforming growth factor (TGF)-β levels using a commercial kit. In cardiac fibroblasts from young adult rats, ANG II significantly enhanced AT1mRNA levels, net collagen production, and TGF-β production. In fibroblasts from the aged myocardium, ANG II downregulated AT1 mRNA expression, had a less pronounced effect on net collagen production, and had no effect on TGF-β production. Such age-related modification of the response of cardiac fibroblasts to ANG II may counteract the effects of augmented intracardiac ANG II production in the senescent heart, limiting fibrogenesis.

scholarly journals Intermittent hypoxia mediated by TSP1 dependent on STAT3 induces cardiac fibroblast activation and cardiac fibrosis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Qiankun Bao ◽  
Bangying Zhang ◽  
Ya Suo ◽  
Chen Liu ◽  
Qian Yang ◽  
...  
Keyword(s):  
Intermittent Hypoxia ◽  
Cardiac Fibrosis ◽  
Synergistic Effects ◽  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Ang Ii ◽  
Fibroblast Activation ◽  
Obstructive Sleep

Intermittent hypoxia (IH) is the predominant pathophysiological disturbance in obstructive sleep apnea (OSA), known to be independently associated with cardiovascular diseases. However, the effect of IH on cardiac fibrosis and molecular events involved in this process are unclear. Here, we tested IH in angiotensin II (Ang II)-induced cardiac fibrosis and signaling linked to fibroblast activation. IH triggered cardiac fibrosis and aggravated Ang II-induced cardiac dysfunction in mice. Plasma thrombospondin-1 (TSP1) content was upregulated in both IH-exposed mice and OSA patients. Moreover, both in vivo and in vitro results showed IH-induced cardiac fibroblast activation and increased TSP1 expression in cardiac fibroblasts. Mechanistically, phosphorylation of STAT3 at Tyr705 mediated the IH-induced TSP1 expression and fibroblast activation. Finally, STAT3 inhibitor S3I-201 or AAV9 carrying a periostin promoter driving the expression of shRNA targeting Stat3 significantly attenuated the synergistic effects of IH and Ang II on cardiac fibrosis in mice. This work suggests a potential therapeutic strategy for OSA-related fibrotic heart disease.

Stat5a/b contribute to interleukin 7–induced B-cell precursor expansion, but abl- andbcr/abl-induced transformation are independent of Stat5

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2277-2283 ◽  
Author(s):  
Veronika Sexl ◽  
Roland Piekorz ◽  
Richard Moriggl ◽  
Juerg Rohrer ◽  
Michael P. Brown ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Interleukin 4 ◽  
Target Cells ◽  
Interleukin 7 ◽  
And Function ◽  
Deficient Mice

Abstract The cytokines interleukin 7 (IL-7) and interleukin 4 (IL-4) regulate lymphoid differentiation and function and activate the transcription factor Stat5. Using mice deficient for the 2 highly related transcription factors, Stat5a and Stat5b (Stat5a/b−/−), we investigated the role of Stat5 for B-cell differentiation, expansion, and function. Peripheral blood B cells of Stat5-deficient mice are significantly reduced, but no proliferation defects in response to various mitogenic stimuli are found. Also, IgM and IgG1 antibody production and immunoglobulin class switching are not affected. Pre- and pro-B cells of Stat5-deficient animals were found to have reduced responses to IL-7. Pro- and pre-B cells are the target cells of the abloncogene and numerous studies have suggested that Stat5a/b is essential for transformation by derivatives of the Abelson(abl) gene. To assess the role of Stat5a/b in transformation, we have evaluated the ability of variousabl derivatives to transform cells from Stat5a/b-deficient mice in vitro or in vivo. We demonstrate that the absence of Stat5a/b is not essential for the induction of lymphoid or myeloid tumors in vivo or on the ability to transform bone marrow cells in vitro.

scholarly journals CREG ameliorates the phenotypic switching of cardiac fibroblasts after myocardial infarction via modulation of CDC42

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Dan Liu ◽  
Xiaoxiang Tian ◽  
Yanxia Liu ◽  
Haixu Song ◽  
Xiaoli Cheng ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Phenotypic Switching ◽  
Littermate Control ◽  
Border Regions ◽  
Phenotype Switching

AbstractPhenotype switching of cardiac fibroblasts into myofibroblasts plays important role in cardiac fibrosis following myocardial infarction (MI). Cellular repressor of E1A-stimulated genes (CREG) protects against vascular and cardiac remodeling induced by angiotensin-II. However, the effects and mechanisms of CREG on phenotype switching of cardiac fibroblasts after MI are unknown. This study aimed to investigate the role of CREG on the phenotype switching of cardiac fibroblasts following MI and its mechanism. Our findings demonstrated that, compared with littermate control mice, cardiac function was deteriorated in CREG+/− mice on day 14 post-MI. Fibrosis size, αSMA, and collagen-1 expressions were increased in the border regions of CREG+/− mice on day 14 post-MI. Conversely, exogenous CREG protein significantly improved cardiac function, inhibited fibrosis, and reduced the expressions of αSMA and collagen-1 in the border regions of C57BL/6J mice on day 14. In vitro, CREG recombinant protein inhibited αSMA and collagen-1 expression and blocked the hypoxia-induced proliferation and migration of cardiac fibroblasts, which was mediated through the inhibition of cell division control protein 42 (CDC42) expression. Our findings could help in establishing new strategies based on the clarification of the role of the key molecule CREG in phenotype switching of cardiac fibroblasts following MI.

The physical interaction of Mcm10 with Cdc45 modulates their DNA-binding properties

2013 ◽  
Vol 454 (2) ◽  
pp. 333-343 ◽  
Author(s):  
Roberta Di Perna ◽  
Valentina Aria ◽  
Mariarosaria De Falco ◽  
Vincenzo Sannino ◽  
Andrei L. Okorokov ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Binding ◽  
Replication Fork ◽  
Physical Interaction ◽  
Eukaryotic Dna ◽  
And Function ◽  
First Time ◽  
Dna Binding Properties

The eukaryotic DNA replication protein Mcm10 (mini-chromosome maintenance 10) associates with chromatin in early S-phase and is required for assembly and function of the replication fork protein machinery. Another essential component of the eukaryotic replication fork is Cdc45 (cell division cycle 45), which is required for both initiation and elongation of DNA replication. In the present study we characterize, for the first time, the physical and functional interactions of human Mcm10 and Cdc45. First we demonstrated that Mcm10 and Cdc45 interact in cell-free extracts. We then analysed the role of each of the Mcm10 domains: N-terminal, internal and C-terminal (NTD, ID and CTD respectively). We have detected a direct physical interaction between CTD and Cdc45 by both in vitro co-immunoprecipitation and surface plasmon resonance experiments. On the other hand, we have found that the interaction of the Mcm10 ID with Cdc45 takes place only in the presence of DNA. Furthermore, we found that the isolated ID and CTD domains are fully functional, retaining DNA-binding capability with a clear preference for bubble and fork structures, and that they both enhance Cdc45 DNA-binding affinity. The results of the present study demonstrate that human Mcm10 and Cdc45 directly interact and establish a mutual co-operation in DNA binding.

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