scholarly journals Involvement of Urokinase-Type Plasminogen Activator Receptor in the Formation of a Profibrotic Microenvironment in the Epicardial Region

2021 ◽  
Vol 17 (6) ◽  
pp. 49-55
Author(s):  
K. V. Dergilev ◽  
Z. I. Tsokolayeva ◽  
I. B. Beloglazova ◽  
Yu. D. Vasilets ◽  
D. O. Traktuyev ◽  
...  

The study of the mechanisms of development and progression of fibrosis is one of the key directions of modern cardiology. Our work suggests that the urokinase receptor (uPAR) is involved in the regulation of mesothelial cell activity and epicardial fibrosis development, which, when interacting with specific ligands and intermediate proteins, can activate intracellular signaling, trigger the cascade of proteolytic reactions, including local plasmin formation and activation of matrix metalloproteinases, providing matrix remodeling.Objective: to perform a comparative study of fibrogenic activity of the epicardium in the hearts of uPAR-/- and wild-type animals and evaluate the effect of cardiac microenvironment factors on the migration activity of epicardial mesothelial cells.Material and methods. We used histological and immunofluorescent staining, microarray analysis of proinflammatory cytokine levels, and a method for assessing the migratory properties of epicardial cells.Results. Results. We found that compared to wild-type animals, uPAR-/- animals show significant thickening of the epicardial area (2.46+0.77 (uPAR-/- mice) and 1.02+0.17 (Wt mice) relative units, P=0.033) accompanied by accumulation of extracellular matrix proteins. Deficiency of uPAR gene leads to formation of proinflammatory microenvironment in the heart (increased levels of proinflammatory factors such as IL-1, IL-13, IL-17, RANTES and MIP1), increased migratory activity of epicardial mesothelial cells, accumulation of TCF21+fibroblast/myofibroblast precursors (29.8+13.7 (uPAR-/- mouse) and 3.03+0.8 (Wt mouse) cells per visual field,P=0.02), as well as development of subepicardial fibrosis.Conclusion. These findings suggest that uPAR is a promising candidate for the developing targeted agents to prevent the development and progression of cardiac fibrosis.

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Shirong Cao ◽  
Shu Li ◽  
Yating Wang ◽  
Jiani Shen ◽  
Yi Zhou ◽  
...  

Increased high mobility group box 1 (HMGB1) in dialysis effluence is associated with the presence of peritoneal dialysis-related peritonitis in patients and peritoneal dysfunction in acute peritonitis mice model, but it remains unclear whether HMGB1 is involved in peritoneal mesothelial cell injury and functions via molecular posttranslational modifications by acetylation in this process. Here we first showed correlation between HMGB1 acetylation level in dialysis effluence of patients and occurrence of Gram-negative peritonitis. The increased level of acetylated HMGB1 was similarly observed under the lipopolysaccharides (LPS) treatment in both human peritoneal mesothelial cell line (HMrSV5) and mice visceral peritoneum tissue. Overexpression of wild-type, but not hypoacetylation mutant of HMGB1, enhanced LPS-induced apoptosis in HMrSV5 cells, which was accompanied by elevated protein levels of BAX and cleaved-caspase 3 compared to the control. Pretreatment of HMrSV5 cell with JNK inhibitor attenuated LPS-induced HMGB1 acetylation. Consistently, primary peritoneal mesothelial cells from Jnk1-/- mice showed a lower protein contents of acetylated HMGB1, fewer apoptosis, and decreased protein expression of BAX and cleaved-caspase3 after LPS exposure, as compared to those from wild-type mice. In conclusion, our data demonstrated HMGB1 promotes LPS-induced peritoneal mesothelial cells apoptosis, which is associated with JNK1-mediated upregulation of HMGB1 acetylation.


2020 ◽  
Vol 117 (41) ◽  
pp. 25543-25552 ◽  
Author(s):  
Jiaming Xue ◽  
Simone Patergnani ◽  
Carlotta Giorgi ◽  
Joelle Suarez ◽  
Keisuke Goto ◽  
...  

Asbestos causes malignant transformation of primary human mesothelial cells (HM), leading to mesothelioma. The mechanisms of asbestos carcinogenesis remain enigmatic, as exposure to asbestos induces HM death. However, some asbestos-exposed HM escape cell death, accumulate DNA damage, and may become transformed. We previously demonstrated that, upon asbestos exposure, HM and reactive macrophages releases the high mobility group box 1 (HMGB1) protein that becomes detectable in the tissues near asbestos deposits where HMGB1 triggers chronic inflammation. HMGB1 is also detectable in the sera of asbestos-exposed individuals and mice. Searching for additional biomarkers, we found higher levels of the autophagy marker ATG5 in sera from asbestos-exposed individuals compared to unexposed controls. As we investigated the mechanisms underlying this finding, we discovered that the release of HMGB1 upon asbestos exposure promoted autophagy, allowing a higher fraction of HM to survive asbestos exposure. HMGB1 silencing inhibited autophagy and increased asbestos-induced HM death, thereby decreasing asbestos-induced HM transformation. We demonstrate that autophagy was induced by the cytoplasmic and extracellular fractions of HMGB1 via the engagement of the RAGE receptor and Beclin 1 pathway, while nuclear HMGB1 did not participate in this process. We validated our findings in a novel unique mesothelial conditional HMGB1-knockout (HMGB1-cKO) mouse model. Compared to HMGB1 wild-type mice, mesothelial cells from HMGB1-cKO mice showed significantly reduced autophagy and increased cell death. Autophagy inhibitors chloroquine and desmethylclomipramine increased cell death and reduced asbestos-driven foci formation. In summary, HMGB1 released upon asbestos exposure induces autophagy, promoting HM survival and malignant transformation.


1984 ◽  
Vol 52 (02) ◽  
pp. 102-104 ◽  
Author(s):  
L J Nicholson ◽  
J M F Clarke ◽  
R M Pittilo ◽  
S J Machin ◽  
N Woolf

SummaryA technique for harvesting mesothelial cells is described. This entails collagenase digestion of omentum after which the cells can be cultured. The technique has been developed using the rat, but has also been successfully applied to human tissue. Cultured rat mesothelial cells obtained in this way have been examined by scanning electron microscopy. Rat mesothelial cells grown on plastic film have been exposed to blood in an in vitro system using a Baumgartner chamber and have been demonstrated to support blood flow. No adhering platelets were observed on the mesothelial cell surface. Fibroblasts similarily exposed to blood as a control were washed off the plastic.


Author(s):  
Hadis Shakeri ◽  
Jente R.A. Boen ◽  
Sofie De Moudt ◽  
Jhana O. Hendrickx ◽  
Arthur J.A. Leloup ◽  
...  

Endothelial cells (ECs) secrete different paracrine signals that modulate the function of adjacent cells; two examples of these paracrine signals are nitric oxide (NO) and neuregulin-1 (NRG1), a cardioprotective growth factor. Currently, it is undetermined whether one paracrine factor can compensate for the loss of another. Herein, we hypothesized that NRG1 can compensate for endothelial NO synthase (eNOS) deficiency. Methods. We characterized eNOS null and wild type (WT) mice by cardiac ultrasound and histology and we determined circulating NRG1 levels. In a separate experiment, 8 groups of mice were divided into 4 groups of eNOS null mice and wild type (WT) mice; half of the mice received angiotensin II (Ang II) to induce a more severe phenotype. Mice were randomized to daily injections with NRG1 or vehicle for 28 days. Results. eNOS deficiency increased NRG1 plasma levels, indicating that ECs increase their NRG1 expression when NO production is deleted. eNOS deficiency also increased blood pressure, lowered heart rate, induced cardiac fibrosis, and affected diastolic function. In eNOS null mice, Ang II administration increased cardiac fibrosis, but also induced cardiac hypertrophy and renal fibrosis. NRG1 administration prevented the cardiac and renal hypertrophy and fibrosis caused by Ang II infusion and eNOS deficiency. Moreover, Nrg1 expression in the myocardium is shown to be regulated by miR-134. Conclusion. This study indicates that administration of endothelium-derived NRG1 can compensate for eNOS deficiency in the heart and kidneys.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ritu Pandey ◽  
Muhan Zhou ◽  
Shariful Islam ◽  
Baowei Chen ◽  
Natalie K Barker ◽  
...  

AbstractWe investigated biomarker CEACAM6, a highly abundant cell surface adhesion receptor that modulates the extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDA). The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) RNA-Seq data from PDA patients were analyzed for CEACAM6 expression and evaluated for overall survival, association, enrichment and correlations. A CRISPR/Cas9 Knockout (KO) of CEACAM6 in PDA cell line for quantitative proteomics, mitochondrial bioenergetics and tumor growth in mice were conducted. We found CEACAM6 is over-expressed in primary and metastatic basal and classical PDA subtypes. Highest levels are in classical activated stroma subtype. CEACAM6 over-expression is universally a poor prognostic marker in KRAS mutant and wild type PDA. High CEACAM6 expression is associated with low cytolytic T-cell activity in both basal and classical PDA subtypes and correlates with low levels of T-REG markers. In HPAF-II cells knockout of CEACAM6 alters ECM-cell adhesion, catabolism, immune environment, transmembrane transport and autophagy. CEACAM6 loss increases mitochondrial basal and maximal respiratory capacity. HPAF-II CEACAM6−/− cells are growth suppressed by >65% vs. wild type in mice bearing tumors. CEACAM6, a key regulator affects several hallmarks of PDA including the fibrotic reaction, immune regulation, energy metabolism and is a novel therapeutic target in PDA.


2004 ◽  
Vol 72 (10) ◽  
pp. 5662-5667 ◽  
Author(s):  
Nicola J. Mason ◽  
Jim Fiore ◽  
Takashi Kobayashi ◽  
Katherine S. Masek ◽  
Yongwon Choi ◽  
...  

ABSTRACT The production of interleukin-12 (IL-12) is critical to the development of innate and adaptive immune responses required for the control of intracellular pathogens. Many microbial products signal through Toll-like receptors (TLR) and activate NF-κB family members that are required for the production of IL-12. Recent studies suggest that components of the TLR pathway are required for the production of IL-12 in response to the parasite Toxoplasma gondii; however, the production of IL-12 in response to this parasite is independent of NF-κB activation. The adaptor molecule TRAF6 is involved in TLR signaling pathways and associates with serine/threonine kinases involved in the activation of both NF-κB and mitogen-activated protein kinase (MAPK). To elucidate the intracellular signaling pathways involved in the production of IL-12 in response to soluble toxoplasma antigen (STAg), wild-type and TRAF6−/− mice were inoculated with STAg, and the production of IL-12(p40) was determined. TRAF6−/− mice failed to produce IL-12(p40) in response to STAg, and TRAF6−/− macrophages stimulated with STAg also failed to produce IL-12(p40). Studies using Western blot analysis of wild-type and TRAF6−/− macrophages revealed that stimulation with STAg resulted in the rapid TRAF6-dependent phosphorylation of p38 and extracellular signal-related kinase, which differentially regulated the production of IL-12(p40). The studies presented here demonstrate for the first time that the production of IL-12(p40) in response to toxoplasma is dependent upon TRAF6 and p38 MAPK.


2015 ◽  
Vol 34 (4) ◽  
pp. 325-335 ◽  
Author(s):  
Masanao Yokohira ◽  
Nozomi Hashimoto ◽  
Toshitaka Nakagawa ◽  
Yuko Nakano ◽  
Keiko Yamakawa ◽  
...  

The present study was conducted to examine the chronic effects of potassium octatitanate fibers (trade name TISMO; chemical formula K2O·6TiO2) on the mouse lung and thoracic cavity. This method of infusion was employed to examine the direct effects of the fibers to the pleura. In the present study, 52- and 65-week experiments were employed to examine the long-term chronic effects after infusion of fiber-shaped TISMO into the thoracic cavities of A/J mice. Following this infusion, TISMO fibers were observed in the alveoli, indicating penetration through the visceral pleura. The additional histopathological detection of TISMO fibers in the liver, spleen, kidneys, ovary, heart, bone marrow, and brain of TISMO-infused mice indicated migration of the fibers out from the thoracic cavity. Atypical mesothelial cells with severe pleural proliferation were observed, but malignant mesotheliomas were not detected. This study demonstrated that intrathoracic infusion of TISMO fiber did not cause malignant mesothelioma but did cause severe chronic inflammation and proliferation of pleural mesothelial cells.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Pao-Hsien Chu

Aims: With aging and stresses, the myocardium undergoes structural remodeling and often leading to fibrosis. Main Methods: To examine whether lumican, one of the class II small leucine-rich proteoglycans, has a role in cardiac remodeling and fibrosis, we analyzed the basic cardiac phenotypes of lumican-null (Lum-/-) mice in both youth and elder, and then used the isoproterenol-induced cardiac fibrosis model to study the roles of extra-cellular matrix and apoptosis in cardiac remodeling. Key Findings: Higher mortality resulted from significantly impaired systolic function, and an increase of atrial natriuretic peptide secreted by the ventricles in response to excessive stretching of myocytes of Lum-/- mice in comparison to wild type littermates. In addition, Lum-/- mice exhibited higher level of TGF-β, collagen I/III, and membrane-type matrix metalloproteinase-1 (MT1-MMP, or MMP-14) during cardiac remodeling. Significance: Our data implicates that the lumican protein plays an important role in the pathogenesis of cardiac fibrosis.


2007 ◽  
Vol 27 (2_suppl) ◽  
pp. 110-115 ◽  
Author(s):  
Susan Yung ◽  
Chan Tak Mao

♦ Background The introduction of peritoneal dialysis (PD) as a modality of renal replacement therapy has provoked much interest in the biology of the peritoneal mesothelial cell. Mesothelial cells isolated from omental tissue have immunohistochemical markers that are identical to those of mesothelial stem cells, and omental mesothelial cells can be cultivated in vitro to study changes to their biologic functions in the setting of PD. ♦ Method The present article describes the structure and function of mesothelial cells in the normal peritoneum and details the morphologic changes that occur after the introduction of PD. Furthermore, this article reviews the literature of mesothelial cell culture and the limitations of in vitro studies. ♦ Results The mesothelium is now considered to be a dynamic membrane that plays a pivotal role in the homeostasis of the peritoneal cavity, contributing to the control of fluid and solute transport, inflammation, and wound healing. These functional properties of the mesothelium are compromised in the setting of PD. Cultures of peritoneal mesothelial cells from omental tissue provide a relevant in vitro model that allows researchers to assess specific molecular pathways of disease in a distinct population of cells. Structural and functional attributes of mesothelial cells are discussed in relation to long-term culture, proliferation potential, age of tissue donor, use of human or animal in vitro models, and how the foregoing factors may influence in vitro data. ♦ Conclusions The ability to propagate mesothelial cells in culture has resulted, over the past two decades, in an explosion of mesothelial cell research pertaining to PD and peritoneal disorders. Independent researchers have highlighted the potential use of mesothelial cells as targets for gene therapy or transplantation in the search to provide therapeutic strategies for the preservation of the mesothelium during chemical or bacterial injury.


1987 ◽  
Vol 7 (3) ◽  
pp. 148-156 ◽  
Author(s):  
Lazaro Gotloib ◽  
Abshalom Shostack ◽  
Phina Bar-Sella ◽  
Ricardo Cohen

This study reconstructs the whole sequence of mesothelial injury and regeneration in patients on longterm peritoneal dialysis. Our observations indicate that peritoneal dialysis induces a process of continuous mesothelial injury and regeneration. New mesothelial cells seem to originate from wandering mesothelial cells of the peritoneal fluid, as well as from mesothelial cell precursors localized in the sub-mesothelial connective tissue.


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