scholarly journals The Role of the Dynamic Lung Extracellular Matrix Environment on Fibroblast Morphology and Inflammation

Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Tillie-Louise Hackett ◽  
Noamie R. T. F. Vriesde ◽  
May AL-Fouadi ◽  
Leila Mostaco-Guidolin ◽  
Delaram Maftoun ◽  
...  

The extracellular matrix (ECM) supports lung tissue architecture and physiology by providing mechanical stability and elastic recoil. Over the last several decades, it has become increasingly clear that the stiffness of the ECM governs many cellular processes, including cell-phenotype and functions during development, healing, and disease. Of all the lung ECM proteins, collagen-I is the most abundant and provides tensile strength. In many fibrotic lung diseases, the expression of collagen is increased which affects the stiffness of the surrounding environment. The goal of this study was to assess the effect on fibroblast morphology, cell death, and inflammation when exposed to 2D and 3D low (0.4 mg/mL) versus high (2.0 mg/mL) collagen-I-matrix environments that model the mechanics of the breathing lung. This study demonstrates that human fetal lung fibroblasts (HFL1), grown in a 3D collagen type-I environment compared to a 2D one, do not form cells with a myofibroblast morphology, express less F-actin stress fibers, exhibit less cell death, and significantly produce less pro-inflammatory IL-6 and IL-8 cytokines. Exposure to mechanical strain to mimic breathing (0.2 Hz) led to the loss of HFL1 fibroblast dendritic extensions as well as F-actin stress fibers within the cell cytoskeleton, but did not influence cytokine production or cell death. This dynamic assay gives researchers the ability to consider the assessment of the mechanodynamic nature of the lung ECM environment in disease-relevant models and the potential of mechano-pharmacology to identify therapeutic targets for treatment.

1995 ◽  
Vol 269 (1) ◽  
pp. L52-L58 ◽  
Author(s):  
C. A. Partridge

Incubation of bovine pulmonary microvascular endothelial (BPMVE) cells in low O2 content (95% N2-5% CO2) for 4 h increased monolayer permeability to dextran almost twofold and also increased the incidence of intercellular gaps and intracellular actin stress fibers. Hypoxic incubation decreased the extracellular matrix contents of fibronectin and vitronectin, proteins that serve as anchorage points for the endothelial cells. This state was reversed after 24 h of hypoxic incubation, and the BPMVE monolayer permeability to dextran was less than that of normoxic controls. The monolayer had fewer intercellular gaps and stress fibers, and the extracellular matrix contained increased amounts of fibronectin, vitronectin, and type I collagen. These alterations stimulated by 24 h of hypoxic incubation were resolved within 4 h of reoxygenation in room air supplemented with 5% CO2. These studies indicate that incubation of endothelial monolayers in hypoxic conditions first increases and then decreases monolayer permeability, through increased and decreased formation of intercellular gaps.


2000 ◽  
Vol 122 (3) ◽  
pp. 210-215 ◽  
Author(s):  
Byung-Soo Kim ◽  
David J. Mooney

Cyclic mechanical strain has been demonstrated to enhance the development and function of engineered smooth muscle (SM) tissues, but appropriate scaffolds for engineering tissues under conditions of cyclic strain are currently lacking. These scaffolds must display elastic behavior, and be capable of inducing an appropriate smooth muscle cell (SMC) phenotype in response to mechanical signals. In this study, we have characterized several scaffold types commonly utilized in tissue engineering applications in order to select scaffolds that exhibit elastic properties under appropriate cyclic strain conditions. The ability of the scaffolds to promote an appropriate SMC phenotype in engineered SM tissues under cyclic strain conditions was subsequently analyzed. Poly(L-lactic acid)-bonded polyglycolide fiber-based scaffolds and type I collagen sponges exhibited partially elastic mechanical properties under cyclic strain conditions, although the synthetic polymer scaffolds demonstrated significant permanent deformation after extended times of cyclic strain application. SM tissues engineered with type I collagen sponges subjected to cyclic strain were found to contain more elastin than control tissues, and the SMCs in these tissues exhibited a contractile phenotype. In contrast, SMCs in control tissues exhibited a structure more consistent with the nondifferentiated, synthetic phenotype. These studies indicate the appropriate choice of a scaffold for engineering tissues in a mechanically dynamic environment is dependent on the time frame of the mechanical stimulation, and elastic scaffolds allow for mechanically directed control of cell phenotype in engineered tissues. [S0148-0731(00)00103-5]


2020 ◽  
Vol 133 (23) ◽  
pp. jcs248278 ◽  
Author(s):  
Ana M. Diaz-Espinosa ◽  
Patrick A. Link ◽  
Delphine Sicard ◽  
Ignasi Jorba ◽  
Daniel J. Tschumperlin ◽  
...  

ABSTRACTMatrix resorption is essential to the clearance of the extracellular matrix (ECM) after normal wound healing. A disruption in these processes constitutes a main component of fibrotic diseases, characterized by excess deposition and diminished clearance of fibrillar ECM proteins, such as collagen type I. The mechanisms and stimuli regulating ECM resorption in the lung remain poorly understood. Recently, agonism of dopamine receptor D1 (DRD1), which is predominantly expressed on fibroblasts in the lung, has been shown to accelerate tissue repair and clearance of ECM following bleomycin injury in mice. Therefore, we investigated whether DRD1 receptor signaling promotes the degradation of collagen type I by lung fibroblasts. For cultured fibroblasts, we found that DRD1 agonism enhances extracellular cleavage, internalization and lysosomal degradation of collagen I mediated by cathepsin K, which results in reduced stiffness of cell-derived matrices, as measured by atomic force microscopy. In vivo agonism of DRD1 similarly enhanced fibrillar collagen degradation by fibroblasts, as assessed by tissue labeling with a collagen-hybridizing peptide. Together, these results implicate DRD1 agonism in fibroblast-mediated collagen clearance, suggesting an important role for this mechanism in fibrosis resolution.This article has an associated First Person interview with the first author of the paper.


2011 ◽  
Vol 300 (4) ◽  
pp. C907-C918 ◽  
Author(s):  
Matilde Alique ◽  
Laura Calleros ◽  
Alicia Luengo ◽  
Mercedes Griera ◽  
Miguel Ángel Iñiguez ◽  
...  

Glomerular diseases are characterized by a sustained synthesis and accumulation of abnormal extracellular matrix proteins, such as collagen type I. The extracellular matrix transmits information to cells through interactions with membrane components, which directly activate many intracellular signaling events. Moreover, accumulating evidence suggests that eicosanoids derived from cyclooxygenase (COX)-2 participate in a number of pathological processes in immune-mediated renal diseases, and it is known that protein kinase B (AKT) may act through different transcription factors in the regulation of the COX-2 promoter. The present results show that progressive accumulation of collagen I in the extracellular medium induces a significant increase of COX-2 expression in human mesangial cells, resulting in an enhancement in PGE2 production. COX-2 overexpression is due to increased COX-2 mRNA levels. The study of the mechanism implicated in COX-2 upregulation by collagen I showed focal adhesion kinase (FAK) activation. Furthermore, we observed that the activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway by collagen I and collagen I-induced COX-2 overexpression was abolished by PI3K and AKT inhibitors. Additionally, we showed that the cAMP response element (CRE) transcription factor is implicated. Finally, we studied COX-2 expression in an animal model, NG-nitro-l-arginine methyl ester hypertensive rats. In renal tissue and vascular walls, COX-2 and collagen type I content were upregulated. In summary, our results provide evidence that collagen type I increases COX-2 expression via the FAK/PI3K/AKT/cAMP response element binding protein signaling pathway.


2020 ◽  
Author(s):  
A. E. Hafner ◽  
N. G. Gyori ◽  
C. A. Bench ◽  
L. K. Davis ◽  
A. Šarić

One of the most robust examples of self-assembly in living organisms is the formation of collagen architectures. Collagen type I molecules are a crucial component of the extracellular-matrix where they self-assemble into fibrils of well defined striped patterns. This striped fibrilar pattern is preserved across the animal kingdom and is important for the determination of cell phenotype, cell adhesion, and tissue regulation and signalling. The understanding of the physical processes that determine such a robust morphology of self-assembled collagen fibrils is currently almost completely missing. Here we develop a minimal coarse-grained computational model to identify the physical principles of the assembly of collagen-mimetic molecules. We find that screened electrostatic interactions can drive the formation of collagen-like filaments of well-defined striped morphologies. The fibril pattern is determined solely by the distribution of charges on the molecule and is robust to the changes in protein concentration, monomer rigidity, and environmental conditions. We show that the fibril pattern cannot be easily predicted from the interactions between two monomers, but is an emergent result of multi-body interactions. Our results can help address collagen remodelling in diseases and ageing, and guide the design of collagen scaffolds for biotechnological applications.Statement of SignificanceCollagen type I protein is the most abundant protein in mammals. It is a crucial component of the extracellular-matrix where it robustly self-assembles into fibrils of specific striped architectures that are crucial for the correct collagen function. The molecular features that determine such robust fibril architectures are currently not well understood. Here we develop a minimal coarse-grained model to connect the design of collagen-like molecules to the architecture of the resulting self-assembled fibrils. We find that the pattern of charged residues on the surface of molecules can drive the formation of collagen-like fibrils and fully control their architectures. Our findings can help understand changes in collagen architectures observed in diseases and guide the design of synthetic collagen scaffolds.


2001 ◽  
Vol 281 (4) ◽  
pp. C1291-C1299 ◽  
Author(s):  
Brant E. Isakson ◽  
Richard L. Lubman ◽  
Gregory J. Seedorf ◽  
Scott Boitano

The alveolar epithelium consists of two cell types, alveolar type I (AT1) and alveolar type II (AT2) cells. We have recently shown that 7-day-old cultures of AT2 cells grown on a type I collagen/fibronectin matrix develop phenotypic characteristics of AT1 cells, display a distinct connexin profile, and coordinate mechanically induced intercellular Ca2+ changes via gap junctions (25). In this study, we cultured AT2 cells for 7 days on matrix supplemented with laminin-5 and/or in the presence of keratinocyte growth factor. Under these conditions, cultured AT2 cells display AT2 type morphology, express the AT2-specific marker surfactant protein C, and do not express AT1-specific cell marker aquaporin 5, all consistent with maintenance of AT2 phenotype. These AT2-like cells also coordinate mechanically induced intercellular Ca2+ signaling, but, unlike AT1-like cells, do so by using extracellular nucleotide triphosphate release. Additionally, cultured cells that retain AT2 cell-specific markers express connexin profiles different from cultured cells with AT1 characteristics. The parallel changes in intercellular Ca2+ signaling with cell differentiation suggest that cell signaling mechanisms are an intrinsic component of lung alveolar cell phenotype. Because lung epithelial injury is accompanied by extracellular matrix and growth factor changes, followed by extensive cell division, differentiation, and migration of AT2 progenitor cells, we suggest that similar changes may be vital to the lung recovery and repair process in vivo.


2002 ◽  
Vol 87 (12) ◽  
pp. 5751-5759 ◽  
Author(s):  
Maryam Kabir-Salmani ◽  
Shigetatsu Shiokawa ◽  
Yoshihiro Akimoto ◽  
Habib Hasan-Nejad ◽  
Keiji Sakai ◽  
...  

Abstract IGF-I and IGF-II were appeared to play major roles in the adhesive and migratory events that are considered to be crucial in the implantation process. The purpose of this study was to determine the effects of IGF-I on trophoblast adhesion to extracellular matrix. Trophoblast cells obtained from early gestation at artificial abortion were incubated with the indicated doses of IGF-I at the indicated times. Trophoblast cells were treated with IGF-I in the presence or absence of RGD peptide and an antibody against α-subunit of IGF-I receptor (αIR3). Morphometric and morphological changes were studied using light and electron microscopy. Furthermore, vinculin, actin stress fibers, phosphorylated focal adhesion kinase (FAK), phosphotyrosine, and paxillin were immunolocalized in trophoblast cells after IGF-I treatment in the presence or absence of αIR3. Immunoprecipitation and anti-phosphotyrosine immunoblotting were carried out to detect the phosphorylated FAK and phosphorylated paxillin contents of the IGF-I-treated and untreated trophoblast cells. The results showed that IGF-I promoted trophoblast adhesion to fibronectin substrate in a time- and dose-dependent manner, and addition of RGD peptide and αIR3 monoclonal antibody abolished the effects of IGF-I in these cells. Morphological studies exhibited an increase in the lamellipodia formation upon IGF-I treatment, and confocal images of immunofluorescent staining revealed localization of phosphorylated FAK, paxillin, and vinculin at focal adhesions as well as redistribution of actin microfilaments and formation of actin stress fibers inside the cell. Western blotting, using antiphosphotyrosine demonstrated proteins with molecular masses of 125 kDa (FAK) and 68 kDa (paxillin) present in the IGF-I-treated cells, which were lacking in the control groups. In conclusion, these findings suggest that IGF-I can stimulate lamellipodia formation and promote adhesion of trophoblast cells to extracellular matrix by activating their adhesion molecules that must be activated within the implantation window.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Kristin M. French ◽  
Joshua T. Maxwell ◽  
Srishti Bhutani ◽  
Shohini Ghosh-Choudhary ◽  
Marcos J. Fierro ◽  
...  

Cardiac progenitor cells (CPCs) have rapidly advanced to clinical trials, yet little is known regarding their interaction with the microenvironment. Signaling cues present in the microenvironment change with development and disease. This work aims to assess the influence of two distinct signaling moieties on CPCs: cyclic biaxial strain and extracellular matrix. We evaluate four endpoints for improving CPC therapy: paracrine signaling, proliferation, connexin43 expression, and alignment. Vascular endothelial growth factor A (about 900 pg/mL) was secreted by CPCs cultured on fibronectin and collagen I. The application of mechanical strain increased vascular endothelial growth factor A secretion 2–4-fold for CPCs cultured on poly-L-lysine, laminin, or a naturally derived cardiac extracellular matrix. CPC proliferation was at least 25% higher on fibronectin than that on other matrices, especially for lower strain magnitudes. At 5% strain, connexin43 expression was highest on fibronectin. With increasing strain magnitude, connexin43 expression decreased by as much as 60% in CPCs cultured on collagen I and a naturally derived cardiac extracellular matrix. Cyclic mechanical strain induced the strongest CPC alignment when cultured on fibronectin or collagen I. This study demonstrates that culturing CPCs on fibronectin with 5% strain magnitude is optimal for their vascular endothelial growth factor A secretion, proliferation, connexin43 expression, and alignment.


2002 ◽  
Vol 196 (10) ◽  
pp. 1387-1392 ◽  
Author(s):  
Ute M. Liegibel ◽  
Ulrike Sommer ◽  
Pascal Tomakidi ◽  
Ulrike Hilscher ◽  
Loes van den Heuvel ◽  
...  

Adhesion of bone cells to the extracellular matrix is a crucial requirement for osteoblastic development and function. Adhesion receptors connect the extracellular matrix with the cyto-skeleton and convey matrix deformation into the cell. We tested the hypothesis that sex hormones modulate mechanoperception of human osteoblastic cells (HOB) by affecting expression of adhesion molecules like fibronectin and the fibronectin receptor. Only dihydrotestosterone (DHT), but not 17β-estradiol, stimulated fibronectin (137%) and fibronectin receptor (252%) protein expression. The effects of deformation strain on HOB metabolism were investigated in a FlexerCell® strain unit. Cyclically applied strain (2.5% elongation) increased DNA synthesis (125%) and interleukin-6 (IL-6) production (170%) without significantly affecting alkaline phosphatase (AP) activity, type I collagen (PICP), or osteoprotegerin (OPG) secretion. 10 nM DHT pretreatment abolished the mitogenic response of HOB to strain and increased AP activity (119%), PICP (163%), and OPG production (204%). In conclusion, mechanical strain stimulates bone remodeling by increasing HOB mitosis and IL-6 production. DHT enhances the osteoanabolic impact of deformation strain by increasing bone formation via increased AP activity and PICP production. At the same time, bone resorption is inhibited by decreased IL-6 and increased OPG secretion into the bone microenvironment.


2021 ◽  
Vol 9 (1) ◽  
pp. e002091
Author(s):  
Cécile Guillon ◽  
Sandra Ferraro ◽  
Sophie Clément ◽  
Marielle Bouschbacher ◽  
Dominique Sigaudo-Roussel ◽  
...  

IntroductionDiabetes is a worldwide health problem that is associated with severe complications. Advanced Glycation End products (AGEs) such as Nε-(carboxymethyl)lysine, which result from chronic hyperglycemia, accumulate in the skin of patients with diabetes. The effect of AGEs on fibroblast functionality and their impact on wound healing are still poorly understood.Research design and methodsTo investigate this, we treated cultured human fibroblasts with 0.6 mM glyoxal to induce acute glycation. The behavior of fibroblasts was analyzed by time-lapse monolayer wounding healing assay, seahorse technology and atomic force microscopy. Production of extracellular matrix was studied by transmission electronic microscopy and western blot. Lipid metabolism was investigated by staining of lipid droplets (LDs) with BODIPY 493/503.ResultsWe found that the proliferative and migratory capacities of the cells were greatly reduced by glycation, which could be explained by an increase in fibroblast tensile strength. Measurement of the cellular energy balance did not indicate that there was a change in the rate of oxygen consumption of the fibroblasts. Assessment of collagen I revealed that glyoxal did not influence type I collagen secretion although it did disrupt collagen I maturation and it prevented its deposition in the extracellular matrix. We noted a pronounced increase in the number of LDs after glyoxal treatment. AMPK phosphorylation was reduced by glyoxal treatment but it was not responsible for the accumulation of LDs.ConclusionGlyoxal promotes a change in fibroblast behavior in favor of lipogenic activity that could be involved in delaying wound healing.


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