scholarly journals The extracellular matrix protein agrin is essential for epicardial epithelial-to-mesenchymal transition during heart development

Development ◽  
2021 ◽  
Vol 148 (9) ◽  
Author(s):  
Xin Sun ◽  
Sophia Malandraki-Miller ◽  
Tahnee Kennedy ◽  
Elad Bassat ◽  
Konstantinos Klaourakis ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Heart Development ◽  
Matrix Protein ◽  
Wilms Tumor ◽  
Embryonic Stem ◽  
Focal Adhesions ◽  
Extracellular Matrix Protein ◽  
Mesenchymal Transition ◽  
Epicardial Cells

ABSTRACT During heart development, epicardial cells residing within the outer layer undergo epithelial-mesenchymal transition (EMT) and migrate into the underlying myocardium to support organ growth and morphogenesis. Disruption of epicardial EMT results in embryonic lethality, yet its regulation is poorly understood. Here, we report epicardial EMT within the mesothelial layer of the mouse embryonic heart at ultra-high resolution using scanning electron microscopy combined with immunofluorescence analyses. We identified morphologically active EMT regions that associated with key components of the extracellular matrix, including the basement membrane-associated proteoglycan agrin. Deletion of agrin resulted in impaired EMT and compromised development of the epicardium, accompanied by downregulation of Wilms’ tumor 1. Agrin enhanced EMT in human embryonic stem cell-derived epicardial-like cells by decreasing β-catenin and promoting pFAK localization at focal adhesions, and promoted the aggregation of dystroglycan within the Golgi apparatus in murine epicardial cells. Loss of agrin resulted in dispersal of dystroglycan in vivo, disrupting basement membrane integrity and impairing EMT. Our results provide new insights into the role of the extracellular matrix in heart development and implicate agrin as a crucial regulator of epicardial EMT.

scholarly journals The extracellular matrix protein agrin is essential for epicardial epithelial-to-mesenchymal transition during heart development

2020 ◽  
Author(s):  
Xin Sun ◽  
Sophia Malandraki-Miller ◽  
Tahnee Kennedy ◽  
Elad Bassat ◽  
Konstantinos Klaourakis ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Golgi Apparatus ◽  
Basement Membrane ◽  
Heart Development ◽  
Focal Adhesions ◽  
Embryonic Heart ◽  
Extracellular Matrix Protein ◽  
Mesenchymal Transition ◽  
Epicardial Cells

AbstractDuring embryonic heart development, epicardial cells residing within the outer layer of the heart undergo epithelial-mesenchymal transition (EMT) and migrate into the myocardium to support and stimulate organ growth and morphogenesis. Disruption of epicardial EMT results in aberrant heart formation and embryonic lethality. Despite being an essential process during development, the regulation of epicardial EMT is poorly understood. Here we report EMT on the epicardial surface of the embryonic heart at subcellular resolution using scanning electron microscopy (SEM). We identified high- and low-EMT regions within the mesothelial layer of the epicardium and an association with key components of the extracellular matrix (ECM). The ECM basement membrane-associated proteoglycan agrin was found to localize in the epicardium in regions actively undergoing EMT. Deletion of agrin resulted in impaired EMT and compromised development of the epicardium, accompanied by down-regulation of the epicardial EMT regulator WT1. Agrin enhanced EMT in human embryonic stem cell-derived epicardial-like cells by decreasing β-catenin and promoting pFAK localization at focal adhesions. In addition, agrin promoted the aggregation of its receptor dystroglycan to the Golgi apparatus in murine epicardial cells and loss of agrin resulted in dispersal of dystroglycan throughout the epicardial cells in embryos, disrupting basement membrane integrity and impairing EMT. Our results provide new insights into the role of the ECM in heart development, and implicate agrin as a critical regulator of EMT, functioning to ensure dystroglycan connects signals between the ECM and activated epicardial cells.Summary statementThe basement membrane-associated proteoglycan agrin regulates epicardial epithelia-to-mesenchyme transition (EMT) through dystroglycan localizing on the Golgi apparatus. This ensures ECM and cytoskeletal connectivity and mechanical integrity of the transitioning epicardium and has important implications for the role of the extracellular matrix (ECM) in heart development.

Hypoxia – as a Possible Regulator of the Activity of Epicardial Mesothelial Cells After Myocardial Infarction

Kardiologiia ◽  
2021 ◽  
Vol 61 (6) ◽  
pp. 59-68
Author(s):  
K. V. Dergilev ◽  
Z. I. Tsokolaeva ◽  
Yu. D. Vasilets ◽  
I. B. Beloglazova ◽  
B. N. Kulbitsky ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Extracellular Matrix ◽  
Matrix Protein ◽  
Mesothelial Cells ◽  
Immunofluorescent Staining ◽  
Extracellular Matrix Protein ◽  
Hypoxic Exposure ◽  
Mesenchymal Transition ◽  
Epicardial Cells

Aim      To study the effect of hypoxia on the activity of epithelial-mesenchymal transition (EMT) in epicardial cells, which provides formation of a specialized microenvironment.Material and methods   This study used a model of experimental myocardial infarction created by ligation of the anterior descendent coronary artery. The activity of epicardial cells after a hypoxic exposure was studied with the hypoxia marker, pimonidazole, bromodeoxyuridine, immunofluorescent staining of heart cryosections, and in vitro mesothelial cell culture.Results The undamaged heart maintained the quiescent condition of mesothelial cells and low levels of their proliferation, extracellular matrix protein production, and of the EMT activity. Acute ischemic injury induced moderate hypoxia in the epicardial/subepicardial region. This caused a global rearrangement of this region due to the initiation of EMT in cells, changes in the cell composition, and accumulation of extracellular matrix proteins. We found that the initiation of EMT in mesothelial cells may result in the formation of smooth muscle cell precursors, fibroblasts, and a population of Sca-1+ cardiac progenitor cells, which may both participate in construction of new blood vessels and serve as a mesenchymal link for the paracrine support of microenvironmental cells. In in vitro experiments, we showed that 72‑h hypoxia facilitated activation of EMT regulatory genes, induced dissembling of intercellular contacts, cell uncoupling, and increased cell plasticity.Conclusion      The epicardium of an adult heart serves as a “reparative reserve” that can be reactivated by a hypoxic exposure. This creates a basis for an approach to influence the epicardium to modulate its activity for regulating reparative processes.

scholarly journals Chlorination and oxidation of the extracellular matrix protein laminin and basement membrane extracts by hypochlorous acid and myeloperoxidase

Redox Biology ◽  
2019 ◽  
Vol 20 ◽  
pp. 496-513 ◽  
Author(s):  
Tina Nybo ◽  
Simon Dieterich ◽  
Luke F. Gamon ◽  
Christine Y. Chuang ◽  
Astrid Hammer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Matrix Protein ◽  
Hypochlorous Acid ◽  
Extracellular Matrix Protein

scholarly journals Baicalein inhibits fibronectin-induced epithelial–mesenchymal transition by decreasing activation and upregulation of calpain-2

2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Yan Chen ◽  
Lin Chen ◽  
Duanyang Hong ◽  
Zongyue Chen ◽  
Jingyu Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Extracellular Matrix ◽  
Cellular Response ◽  
Matrix Protein ◽  
Epithelial Mesenchymal Transition ◽  
T Antigen ◽  
Extracellular Matrix Protein ◽  
Mesenchymal Transition ◽  
Calpain 2 ◽  
E Cadherin

AbstractThe extracellular matrix protein fibronectin (FN) facilitates tumorigenesis and the development of breast cancer. Inhibition of the FN-induced cellular response is a potential strategy for breast cancer treatment. In the present study, we investigated the effects of the flavonoid baicalein on FN-induced epithelial–mesenchymal transition (EMT) in MCF-10A breast epithelial cells and in a transgenic mouse MMTV-polyoma middle T antigen breast cancer model (MMTV-PyMT). Baicalein inhibited FN-induced migration, invasion, and F-actin remodeling. Baicalein also suppressed FN-induced downregulation of the epithelial markers E-cadherin and ZO-1 and upregulation of the mesenchymal markers N-cadherin, vimentin, and Snail. Further investigation revealed that calpain-2 was involved in baicalein suppression of FN-induced EMT. Baicalein significantly decreased FN-enhanced calpain-2 expression and activation by suppressing its plasma membrane localization, substrate cleavage, and degradation of its endogenous inhibitor calpastatin. Overexpression of calpain-2 in MCF-10A cells by gene transfection partially blocked the inhibitory effect of baicalein on FN-induced EMT changes. In addition, baicalein inhibited calpain-2 by decreasing FN-increased intracellular calcium ion levels and extracellular signal-regulated protein kinases activation. Baicalein significantly decreased tumor onset, growth, and pulmonary metastasis in a spontaneous breast cancer MMTV-PyMT mouse model. Baicalein also reduced the expression of FN, calpain-2, and vimentin, but increased E-cadherin expression in MMTV-PyMT mouse tumors. Overall, these results revealed that baicalein markedly inhibited FN-induced EMT by inhibiting calpain-2, thus providing novel insights into the pharmacological action and mechanism of baicalein. Baicalein may therefore possess therapeutic potential for the treatment of breast cancer though interfering with extracellular matrix–cancer cell interactions.

scholarly journals Recombinant Extracellular Matrix Protein Fragments Support Human Embryonic Stem Cell Chondrogenesis

2018 ◽  
Vol 24 (11-12) ◽  
pp. 968-978 ◽  
Author(s):  
Aixin Cheng ◽  
Stuart A. Cain ◽  
Pinyuan Tian ◽  
Andrew K. Baldwin ◽  
Paweena Uppanan ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Human Embryonic Stem Cell ◽  
Matrix Protein ◽  
Embryonic Stem ◽  
Extracellular Matrix Protein ◽  
Protein Fragments

scholarly journals Simulated Microgravity Influences VEGF, MAPK, and PAM Signaling in Prostate Cancer Cells

2020 ◽  
Vol 21 (4) ◽  
pp. 1263 ◽  
Author(s):  
Trine Engelbrecht Hybel ◽  
Dorothea Dietrichs ◽  
Jayashree Sahana ◽  
Thomas J. Corydon ◽  
Mohamed Z. Nassef ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Cell Culture ◽  
Extracellular Matrix ◽  
Matrix Protein ◽  
Simulated Microgravity ◽  
Focal Adhesions ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Matrix Protein ◽  
Vegf Mrna

Prostate cancer is one of the leading causes of cancer mortality in men worldwide. An unusual but unique environment for studying tumor cell processes is provided by microgravity, either in space or simulated by ground-based devices like a random positioning machine (RPM). In this study, prostate adenocarcinoma-derived PC-3 cells were cultivated on an RPM for time periods of 3 and 5 days. We investigated the genes associated with the cytoskeleton, focal adhesions, extracellular matrix, growth, survival, angiogenesis, and metastasis. The gene expression of signaling factors of the vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK), and PI3K/AKT/mTOR (PAM) pathways was investigated using qPCR. We performed immunofluorescence to study the cytoskeleton, histological staining to examine the morphology, and a time-resolved immunofluorometric assay to analyze the cell culture supernatants. When PC-3 cells were exposed to simulated microgravity (s-µg), some cells remained growing as adherent cells (AD), while most cells detached from the cell culture flask bottom and formed multicellular spheroids (MCS). After 3-day RPM exposure, PC-3 cells revealed significant downregulation of the VEGF, SRC1, AKT, MTOR, and COL1A1 gene expression in MCS, whereas FLT1, RAF1, MEK1, ERK1, FAK1, RICTOR, ACTB, TUBB, and TLN1 mRNAs were not significantly changed. ERK2 and TLN1 were elevated in AD, and FLK1, LAMA3, COL4A5, FN1, VCL, CDH1, and NGAL mRNAs were significantly upregulated in AD and MCS after 3 days. After a 5-day culture in s-µg, the PC-3 cells showed significant downregulations of VEGF mRNA in AD and MCS, and FN1, CDH1, and LAMA3 in AD and SCR1 in MCS. In addition, we measured significant upregulations in FLT1, AKT, ERK1, ERK2, LCN2, COL1A1, TUBB, and VCL mRNAs in AD and MCS, and increases in FLK1, FN1, and COL4A5 in MCS as well as LAMB2, CDH1, RAF1, MEK1, SRC1, and MTOR mRNAs in AD. FAK1 and RICTOR were not altered by s-µg. In parallel, the secretion rate of VEGFA and NGAL proteins decreased. Cytoskeletal alterations (F-actin) were visible, as well as a deposition of collagen in the MCS. In conclusion, RPM-exposure of PC-3 cells induced changes in their morphology, cytoskeleton, and extracellular matrix protein synthesis, as well as in their focal adhesion complex and growth behavior. The significant upregulation of genes belonging to the PAM pathway indicated their involvement in the cellular changes occurring in microgravity.

scholarly journals ApoE (Apolipoprotein E) in Brain Pericytes Regulates Endothelial Function in an Isoform-Dependent Manner by Modulating Basement Membrane Components

2020 ◽  
Vol 40 (1) ◽  
pp. 128-144 ◽  
Author(s):  
Yu Yamazaki ◽  
Mitsuru Shinohara ◽  
Akari Yamazaki ◽  
Yingxue Ren ◽  
Yan W. Asmann ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Cell Phenotype ◽  
Dependent Manner ◽  
Barrier Formation ◽  
Brain Pericytes ◽  
Membrane Components ◽  
And Function

Objective: The ε4 allele of the APOE gene ( APOE4 ) is the strongest genetic risk factor for Alzheimer disease when compared with the common ε3 allele. Although there has been significant progress in understanding how apoE4 (apolipoprotein E4) drives amyloid pathology, its effects on amyloid-independent pathways, in particular cerebrovascular integrity and function, are less clear. Approach and Results: Here, we show that brain pericytes, the mural cells of the capillary walls, differentially modulate endothelial cell phenotype in an apoE isoform-dependent manner. Extracellular matrix protein induction, tube-like structure formation, and barrier formation were lower with endothelial cells cocultured with pericytes isolated from apoE4-targeted replacement (TR) mice compared with those from apoE3-TR mice. Importantly, aged apoE4-targeted replacement mice had decreased extracellular matrix protein expression and increased plasma protein leakages compared with apoE3-TR mice. Conclusions: ApoE4 impairs pericyte-mediated basement membrane formation, potentially contributing to the cerebrovascular effects of apoE4.

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