scholarly journals The Stiffness of Cardiac Fibroblast Substrates Exerts a Regulatory Influence on Collagen Metabolism via α2β1 Integrin, FAK and Src Kinases

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3506
Author(s):  
Małgorzata Gałdyszyńska ◽  
Paulina Radwańska ◽  
Jacek Szymański ◽  
Jacek Drobnik
Keyword(s):  
Cardiac Fibroblasts ◽  
Substrate Inhibition ◽  
Mechanical Strain ◽  
Collagen Metabolism ◽  
Collagen Content ◽  
Substrate Stiffness ◽  
Type I ◽  
Src Kinases ◽  
Downstream Signaling ◽  
Regulatory Influence

Information about mechanical strain in the extracellular space is conducted along collagen fibers connected with integrins and then transmitted within cells. An aim of the study is to verify the hypothesis that the stiffness of cardiac human fibroblast substrates exerts a regulatory effect on collagen metabolism via integrin α2β1 and downstream signaling. The experiments were performed on human cardiac fibroblasts cultured on stiff or soft polyacrylamide gels. Extracellular and intracellular collagen content, metalloproteinase-1 (MMP-1), metalloproteinase-9 (MMP-9) and expression of the α1 chain of the procollagen type I gene (Col1A1) were elevated in cultures settled on soft substrate. The substrate stiffness did not modify tissue inhibitors of matrix metalloproteinase capacity (TIMPs 1–4). Integrin α2β1 inhibition (TC-I 15) or α2 subunit silencing resulted in augmentation of collagen content within the culture. Expression of Col1A1 and Col3A1 genes was increased in TC-I 15-treated fibroblasts. Total and phosphorylated levels of both FAK and Src kinases were elevated in fibroblasts cultured on stiff substrate. Inhibition of FAK (FAK kinase inhibitor 14) or Src kinase (AZM 47527) increased collagen content within the culture. The substrate stiffness exerted a regulatory influence on collagen metabolism via integrin α2β1 and its downstream signaling (FAK and Src kinases) in cardiac fibroblasts.

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.

scholarly journals Decreased Substrate Stiffness Promotes a Hypofibrotic Phenotype in Cardiac Fibroblasts

2021 ◽  
Vol 22 (12) ◽  
pp. 6231
Author(s):  
Rachel C. Childers ◽  
Pamela A. Lucchesi ◽  
Keith J. Gooch
Keyword(s):  
Nuclear Translocation ◽  
Cardiac Fibroblasts ◽  
Volume Overload ◽  
Substrate Stiffness ◽  
Aortocaval Fistula ◽  
Failure Model ◽  
Tissue Stiffness ◽  
Mechanical Memory ◽  
Heart Failure Model ◽  
Control Sham

A hypofibrotic phenotype has been observed in cardiac fibroblasts (CFs) isolated from a volume overload heart failure model, aortocaval fistula (ACF). This paradoxical phenotype results in decreased ECM synthesis despite increased TGF-β presence. Since ACF results in decreased tissue stiffness relative to control (sham) hearts, this study investigates whether the effects of substrate stiffness could account for the observed hypofibrotic phenotype in CFs isolated from ACF. CFs isolated from ACF and sham hearts were plated on polyacrylamide gels of a range of stiffness (2 kPa to 50 kPa). Markers related to cytoskeletal and fibrotic proteins were measured. Aspects of the hypofibrotic phenotype observed in ACF CFs were recapitulated by sham CFs on soft substrates. For instance, sham CFs on the softest gels compared to ACF CFs on the stiffest gels results in similar CTGF (0.80 vs. 0.76) and transgelin (0.44 vs. 0.57) mRNA expression. The changes due to stiffness may be explained by the observed decreased nuclear translocation of transcriptional regulators, MRTF-A and YAP. ACF CFs appear to have a mechanical memory of a softer environment, supported by a hypofibrotic phenotype overall compared to sham with less YAP detected in the nucleus, and less CTGF and transgelin on all stiffnesses.

Type I and III collagen content and fibre distribution in normal human skin during ageing

1987 ◽  
Vol 117 (4) ◽  
pp. 419-428 ◽  
Author(s):  
C.R. LOVELL ◽  
K.A. SMOLENSKI ◽  
V.C. DUANCE ◽  
N.D. LIGHT ◽  
S. YOUNG ◽  
...  
Keyword(s):  
Human Skin ◽  
Collagen Content ◽  
Type I ◽  
Normal Human Skin ◽  
Fibre Distribution ◽  
Normal Human

PPARβ/δ activation inhibits angiotensin II-induced collagen type I expression in rat cardiac fibroblasts

2007 ◽  
Vol 460 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Huijie Zhang ◽  
Rongbiao Pi ◽  
Ruifang Li ◽  
Ping Wang ◽  
Futian Tang ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Collagen Type ◽  
Cardiac Fibroblasts ◽  
Collagen Type I ◽  
Type I

Abstract 58: AT2 Receptor Agonism Regulates TIMP1/MMP9 Axis in the Heart Preventing Cardiac Fibrosis and Improving Heart Function After Experimental Myocardial Infarction

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Dilyara Lauer ◽  
Svetlana Slavic ◽  
Manuela Sommerfeld ◽  
Christa Thöne-Reineke ◽  
Yuliya Sharkovska ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Left Ventricle ◽  
Late Stage ◽  
Heart Function ◽  
Cardiac Fibroblasts ◽  
Collagen Content ◽  
Vehicle Group ◽  
At2 Receptor ◽  
Down Regulation ◽  
Tgf Β1

Aims: A selective nonpeptide agonist for the angiotensin AT2 receptor compound 21 (C21) improved cardiac functions 7 days after myocardial infarction (MI). Here, we aimed to investigate what are the cellular mechanisms underlying cardiac protection in the late stage after MI. Methods and Results: MI was induced in Wistar rats by permanent ligation of the left coronary artery. Treatment with C21 (0.03mg/kg i.p. daily) started 6h after MI and continued for 6 weeks. Hemodynamic parameters were measured via transthoracic Doppler echocardiography and intracardiac Samba catheter. The expression of MMP9, TIMP1, TGF-β1 and collagen content were determined in left ventricle. Anti-proteolytic effects were additionally studied in primary cardiac fibroblasts. C21 significantly improved systolic and diastolic function 6 weeks after MI in comparison with the vehicle group as shown by ejection fraction (71.2±4.7 % vs. 53.4±7.0%; p<0.001), fractional shortening (40.8±2.3% vs. 30.9±3.1%; p<0.05), LVIDs (4.4±0.5mm vs. 5.2±0.8mm; p<0.05), LV EDP (16.9±1.2mmHg vs. 22.1±1.4mmHg; p<0.05), E/A ratio, dP/dt max and dP/dt min (p<0.05). Moreover, C21 improved arterial stiffness parameter (AIx) (18±1.2% vs. 25%±1.8, p<0.05) and reduced collagen content (15%; p<0.05) in postinfarcted myocardium. TIMP1 protein expression in the left ventricle was strongly up-regulated (17.7-fold; p<0.05) whereas MMP9 and TGF-β1 were significantly down-regulated (1.5-fold, p<0.05; 3.4-fold p<0.001, respectively) in the treated group. In cardiac fibroblasts, C21 primarily induced TIMP1 expression followed by attenuated MMP9 secretion and TGF-β1 down-regulation. Conclusion: C21 improves heart function in the late stage after MI and prevents cardiac remodeling. Activation of TIMP1 and subsequent inhibition of MMP9-mediated proteolysis as well as down-regulation of TGF-β1 followed by decreased collagen accumulation may attenuate disintegration of the extracellular matrix and reduce fibrosis.

scholarly journals Activated myofibroblasts promote cardiac hypertrophy and systolic dysfunction independently of cardiac fibrosis in experimental autoimmune myocarditis

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
K Tkacz ◽  
A Jazwa-Kusior ◽  
F Rolski ◽  
E Dzialo ◽  
K Weglarczyk ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Dilated Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Systolic Dysfunction ◽  
Heart Weight ◽  
Type I ◽  
Autoimmune Myocarditis ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

Abstract Background/Introduction Heart-specific inflammation – myocarditis is a common cause dilated cardiomyopathy which is characterized by pathological tissue remodeling, ventricular stiffening, cardiomyopathy and heart failure. In experimental autoimmune myocarditis (EAM) susceptible mice immunized with alpha myosin heavy chain (αMyHC) and complete Freund's adjuvant (CFA) develop acute myocarditis driven by autoreactive CD4+ T cells that is followed by progressive fibrosis, cardiomyopathy and systolic dysfunction. Purpose The aim of the study was to investigate the role of cardiac fibroblasts and myofibroblasts in myocarditis and post-inflammatory dilated cardiomyopathy in mouse model of EAM. Methods EAM was induced in BALB/c mice by immunization with αMyHC/CFA. We used reporter mice expressing EGFP under collagen type I promoter (Coll-EGFP) and RFP under a control of α-smooth muscle actin (αSMA) promoter (αSMA-RFP) and transgenic αSMA-TK mice with ganciclovir-inducible ablation of proliferating myofibroblasts. Cardiac cells were quantified using flow cytometry. Cardiac fibroblasts (CD45-CD31-EGFP+) were sorted from healthy and myocarditis-positive (day 21) mice using BD FACSAria™ II Cell Sorter and analyzed for the whole genome transcriptomics by RNA sequencing. Echocardiography was performed on Vevo 2100 Imaging System. Cardiac fibrosis was assessed by Trichrome Massons's staining and hydroxyproline assay, whereas cardiac hypertrophy by analysing cross-sectional cardiomyocyte area. Profibrotic gene expression was assessed by qRT-PCR. Results The total number of cardiac fibroblasts (CD45-CD31-EGFP+) and the subset of myofibroblasts (CD45-CD31-EGFP+RFP+) remained unchanged at inflammatory (d21) and fibrotic stages (d40). Analysis of differentially expressed genes (min. 2x fold change, p value &lt;0.05) pointed out activation of immune processes (mainly chemokine production), response to stress, cytoskeletal and extracellular matrix re-organization in cardiac fibroblasts in response to myocarditis. αSMA-TK mice treated with ganciclovir (from day 21) showed comparable percent of fibrotic area, but significantly reduced heart weight, decreased cardiomyocyte hypertrophy and improved ejection fraction and cardiac output at day 40 comparing to PBS-treated mice. Ganciclovir-treated mice showed also attenuated cardiac Acta2 and Srf but markedly enhanced Mmp2 expression. Conclusions In EAM model cardiac fibroblasts actively participate in proinflammatory and profibrotic responses, while activated myofibroblasts contribute to dilated cardiomyopathy development independently of cardiac fibrosis. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Science Centre (Poland)

scholarly journals Matrix metalloproteinase-degraded type I collagen is associated with APOE/TOMM40 variants and preclinical dementia

2020 ◽  
Vol 6 (5) ◽  
pp. e508
Author(s):  
Man-Hung Eric Tang ◽  
Joseph P.M. Blair ◽  
Cecilie Liv Bager ◽  
Anne-Christine Bay-Jensen ◽  
Kim Henriksen ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Matrix Metalloproteinase ◽  
Gene Cluster ◽  
Type I Collagen ◽  
Early Death ◽  
Collagen Metabolism ◽  
Type I ◽  
Age Related ◽  
Genome Wide ◽  
A Genome

ObjectiveDysregulation of type I collagen metabolism has a great impact on human health. We have previously seen that matrix metalloproteinase–degraded type I collagen (C1M) is associated with early death and age-related pathologies. To dissect the biological impact of type I collagen dysregulation, we have performed a genome-wide screening of the genetic factors related to type I collagen turnover.MethodsPatient registry data and genotypes have been collected for a total of 4,981 Danish postmenopausal women. Genome-wide association with serum levels of C1M was assessed and phenotype-genotype association analysis performed.ResultsTwenty-two genome-wide significant variants associated with C1M were identified in the APOE-C1/TOMM40 gene cluster. The APOE-C1/TOMM40 gene cluster is associated with hyperlipidemia and cognitive disorders, and we further found that C1M levels correlated with tau degradation markers and were decreased in women with preclinical cognitive impairment.ConclusionsOur study provides elements for better understanding the role of the collagen metabolism in the onset of cognitive impairment.

scholarly journals Telmisartan improves myocardial remodeling by inhibiting leptin autocrine activity and activating PPARγ

2020 ◽  
Vol 245 (7) ◽  
pp. 654-666
Author(s):  
Hui Chen ◽  
Min Li ◽  
Lei Liu ◽  
Danjun Zhu ◽  
Gang Tian
Keyword(s):  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Cardiac Fibroblasts ◽  
Left Ventricular ◽  
Collagen Metabolism ◽  
Myocardial Remodeling ◽  
Ang Ii ◽  
Metabolism Disorder ◽  
Ppar Γ ◽  
Stat3 Phosphorylation

The mechanism responsible for myocardial remodeling in hypertensive left ventricular hypertrophy (LVH) is complex. This study was designed to investigate the role of telmisartan in improving myocardial remodeling in hypertensive LVH and to explore the molecular mechanisms underlying the effects of telmisartan on hypertensive LVH. Hypertensive LVH was established in eight-week-old male Sprague–Dawley (SD) rats by abdominal aortic constriction. Telmisartan was intragastrically administered six weeks after surgery. Telmisartan improved cardiac dysfunction and myocardial fibrosis and reduced myocardial renin-angiotensin-aldosterone system (RAAS) activity and leptin levels in hypertensive LVH rats. To assess the mechanism underlying hypertensive LVH, cardiac fibroblasts were treated in vitro with angiotensin II (Ang II) or leptin, plus various inhibitors. Ang II stimulated leptin synthesis and secretion in cardiac fibroblasts by promoting AP-1 nuclear translocation via the AT1R-ROS-ERK1/2 pathway. Leptin induced collagen metabolism disorder in cardiac fibroblasts via the JAK2/STAT3 pathway. Telmisartan improved collagen metabolism disorder by inhibiting leptin induced by local Ang II in an autocrine manner. Telmisartan also improved Ang II-induced collagen metabolism disorder by inhibiting STAT3 phosphorylation, a leptin downstream signal, by activating PPAR-γ. Telmisartan therefore improved myocardial remodeling in hypertensive LVH rats by acting as an AT1R antagonist, inhibiting leptin autocrine activity induced by local Ang II and by acting as a PPAR-γ agonist, inhibiting downstream leptin activation of STAT3 phosphorylation. These findings indicate the crosstalk between local myocardial RAAS and leptin and suggest a molecular mechanism by which telmisartan improves myocardial remodeling in hypertensive LVH. Impact statement This study shows the crosstalk between local myocardial RAAS and leptin in hypertensive LVH rats; that Ang II induces myocardial remodeling by stimulating leptin autocrine activity by promoting AP-1 nuclear translocation via the AT1R-ROS-ERK1/2 pathway; and that telmisartan improves myocardial remodeling by inhibiting local Ang II-induced leptin autocrine activity and by inhibiting the leptin downstream signal STAT3 phosphorylation by activating PPAR-γ. These findings reveal novel molecular mechanisms by which telmisartan improves myocardial remodeling and could help to identify therapeutic targets for hypertensive LVH.

scholarly journals Effect of magnesium ions/Type I collagen promote the biological behavior of osteoblasts and its mechanism

2019 ◽  
Author(s):  
Xiaojing Nie ◽  
Xirao Sun ◽  
Chengyue Wang ◽  
Jingxin Yang
Keyword(s):  
Type I Collagen ◽  
Bone Development ◽  
Critical Role ◽  
Biological Behavior ◽  
Type I ◽  
Alizarin Red ◽  
Downstream Signaling ◽  
Proliferation And Differentiation ◽  
Main Component ◽  
Rhodamine B Isothiocyanate

Abstract Type I collagen (Col I) is a main component of extracellular matrix (ECM). Its safety, biocompatibility, hydrophilicity and pyrogen immunogenicity make it suitable for tissues engineering applications. Mg2+ also control a myriad of cellular processes, including the bone development by enhancing the attachment and differentiation of osteoblasts and accelerating mineralization to enhance bone healing. In our studies, Mg2+ bind collagen to promote the proliferation and differentiation of osteoblasts through the expression of integrins and downstream signaling pathways. In order to clarify the biological behavior effect of 10 mM Mg2+/Col I coating, we performed 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP), 4′6-diamidino-2-phenylindole (DAPI), Alizarin red staining and Rhodamine B-isothiocyanate (RITC)-labeled phalloidin experiments and found that 10 mM Mg2+ group, Col I-coating group, 10 mM Mg2+/Col I-coating group, respectively, promoted the proliferation and differentiation of osteoblasts, especially 10 mM Mg2+/Col I-coating group. We detected the mRNA expression of osteogenic-related genes (Runx2, ALP and OCN, OPN and BMP-2) and the protein expression of signaling pathway (integrin α2, integrin β1, FAK and ERK1/2), these results indicated that 10 mM Mg2+/Col I coating play an critical role in up-regulating the MC3T3-E1 cells activity. The potential mechanisms of this specific performance may be through activating via integrin α2β1-FAK-ERK1/2 protein-coupled receptor pathway.

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