scholarly journals Matrix Stiffness Affects Glycocalyx Expression in Cultured Endothelial Cells

Author(s):  
Marwa Mahmoud ◽  
Limary Cancel ◽  
John M. Tarbell

Rationale: The endothelial cell glycocalyx (GCX) is a mechanosensor that plays a key role in protecting against vascular diseases. We have previously shown that age/disease mediated matrix stiffness inhibits the glycocalyx glycosaminoglycan heparan sulfate and its core protein Glypican 1 in human umbilical vein endothelial cells, rat fat pad endothelial cells and in a mouse model of age-mediated stiffness. Glypican 1 inhibition resulted in enhanced endothelial cell dysfunction. Endothelial cell culture typically occurs on stiff matrices such as plastic or glass. For the study of the endothelial GCX specifically it is important to culture cells on soft matrices to preserve GCX expression. To test the generality of this statement, we hypothesized that stiff matrices inhibit GCX expression and consequently endothelial cell function in additional cell types: bovine aortic endothelial cells, mouse aortic endothelial cell and mouse brain endothelial cells.Methods and Results: All cell types cultured on glass showed reduced GCX heparan sulfate expression compared to cells cultured on either soft polyacrylamide (PA) gels of a substrate stiffness of 2.5 kPa (mimicking the stiffness of young, healthy arteries) or on either stiff gels 10 kPa (mimicking the stiffness of old, diseased arteries). Specific cell types showed reduced expression of GCX protein Glypican 1 (4 of 5 cell types) and hyaluronic acid (2 of 5 cell types) on glass vs soft gels.Conclusion: Matrix stiffness affects GCX expression in endothelial cells. Therefore, the study of the endothelial glycocalyx on stiff matrices (glass/plastic) is not recommended for specific cell types.

2010 ◽  
Vol 298 (1) ◽  
pp. C66-C74 ◽  
Author(s):  
Nica M. Borradaile ◽  
J. Geoffrey Pickering

Polyploid endothelial cells are found in aged and atherosclerotic arteries. However, whether increased chromosome content has an impact on endothelial cell function is unknown. We show here that human aortic endothelial cells become tetraploid as they approach replicative senescence. Furthermore, accumulation of tetraploid endothelial cells was accelerated during growth in high glucose. Interestingly, induction of polyploidy was completely prevented by modest overexpression of the NAD+ regenerating enzyme, nicotinamide phosphoribosyltransferase (Nampt). To determine the impact of polyploidy on endothelial cell function, independent of replicative senescence, we induced tetraploidy using the spindle poison, nocodazole. Global gene expression analyses of tetraploid endothelial cells revealed a dysfunctional phenotype characterized by a cell cycle arrest profile (decreased CCNE2/A2, RBL1, BUB1B; increased CDKN1A) and increased expression of genes involved in inflammation ( IL32, TNFRSF21/10C, PTGS1) and extracellular matrix remodeling ( COL5A1, FN1, MMP10/14). The protection from polyploidy conferred by Nampt was not associated with enhanced poly(ADP-ribose) polymerase-1 or sirtuin (SIRT) 2 activity, but with increased SIRT1 activity, which reduced cellular reactive oxygen species and the associated oxidative stress stimulus for the induction of polyploidy. We conclude that human aortic endothelial cells are prone to chromosome duplication that, in and of itself, can induce characteristics of endothelial dysfunction. Moreover, the emergence of polyploid endothelial cells during replicative aging and glucose overload can be prevented by optimizing the Nampt-SIRT1 axis.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1918
Author(s):  
Yunzhou Dong ◽  
Beibei Wang ◽  
Kui Cui ◽  
Xiaofeng Cai ◽  
Sudarshan Bhattacharjee ◽  
...  

Background: The endothelial epsin 1 and 2 endocytic adaptor proteins play an important role in atherosclerosis by regulating the degradation of the calcium release channel inositol 1,4,5-trisphosphate receptor type 1 (IP3R1). In this study, we sought to identify additional targets responsible for epsin-mediated atherosclerotic endothelial cell activation and inflammation in vitro and in vivo. Methods: Atherosclerotic ApoE−/− mice and ApoE−/− mice with an endothelial cell-specific deletion of epsin 1 on a global epsin 2 knock-out background (EC-iDKO/ApoE−/−), and aortic endothelial cells isolated from these mice, were used to examine inflammatory signaling in the endothelium. Results: Inflammatory signaling was significantly abrogated by both acute (tumor necrosis factor-α (TNFα) or lipopolysaccharide (LPS)) and chronic (oxidized low-density lipoprotein (oxLDL)) stimuli in EC-iDKO/ApoE−/− mice and murine aortic endothelial cells (MAECs) isolated from epsin-deficient animals when compared to ApoE−/− controls. Mechanistically, the epsin ubiquitin interacting motif (UIM) bound to Toll-like receptors (TLR) 2 and 4 to potentiate inflammatory signaling and deletion of the epsin UIM mitigated this interaction. Conclusions: The epsin endocytic adaptor proteins potentiate endothelial cell activation in acute and chronic models of atherogenesis. These studies further implicate epsins as therapeutic targets for the treatment of inflammation of the endothelium associated with atherosclerosis.


2002 ◽  
Vol 283 (2) ◽  
pp. L297-L304 ◽  
Author(s):  
Larissa A. Shimoda ◽  
Laura E. Welsh ◽  
David B. Pearse

Endothelial barrier dysfunction is typically triggered by increased intracellular Ca2+concentration. Membrane-permeable analogs of guanosine 3′,5′-cyclic monophosphate (cGMP) prevent disruption of endothelial cell integrity. Because membrane potential ( E m), which influences the electrochemical gradient for Ca2+ influx, is regulated by K+ channels, we investigated the effect of 8-bromo-cGMP on E m and inwardly rectifying K+ (KIR) currents in bovine pulmonary artery and microvascular endothelial cells (BPAEC and BMVEC), using whole cell patch-clamp techniques. Both cell types exhibited inward currents at potentials negative to −50 mV that were abolished by application of 10 μM Ba2+, consistent with KIR current. Ba2+ also depolarized both cell types. 8-Bromo-cGMP (10−3 M) depolarized BPAEC and BMVEC and inhibited KIR current. Pretreatment with Rp-8-cPCT-cGMPS or KT-5823, protein kinase G (PKG) antagonists, did not prevent current inhibition by 8-bromo-cGMP. These data suggest that 8-bromo-cGMP induces depolarization in BPAEC and BMVEC due, in part, to PKG-independent inhibition of KIR current. The depolarization could be a protective mechanism that prevents endothelial cell barrier dysfunction by reducing the driving force for Ca2+ entry.


Author(s):  
Samina Momtaz ◽  
Belen Molina ◽  
Luwanika Mlera ◽  
Felicia Goodrum ◽  
Jean M. Wilson

AbstractHuman cytomegalovirus (HCMV), while highly restricted for the human species, infects an unlimited array of cell types in the host. Patterns of infection are dictated by the cell type infected, but cell type-specific factors and how they impact tropism for specific cell types is poorly understood. Previous studies in primary endothelial cells showed that HCMV infection induces large multivesicular-like bodies that incorporate viral products including dense bodies and virions. Here we define the nature of these large vesicles using a recombinant virus where UL32, encoding the pp150 tegument protein, is fused in frame with green fluorescent protein (GFP, TB40/E-UL32-GFP). Cells were fixed and labeled with antibodies against subcellular compartment markers and imaged using confocal and super-resolution microscopy. In fibroblasts, UL32-GFP-positive vesicles were marked with classical markers of MVBs, including CD63 and lysobisphosphatidic acid (LBPA), both classical MVB markers, as well as the clathrin and LAMP1. Unexpectedly, UL32-GFP-positive vesicles in endothelial cells were not labeled by CD63, and LBPA was completely lost from infected cells. We defined these UL32-positive vesicles in endothelial cells using markers for the cis-Golgi (GM130), lysosome (LAMP1), and autophagy (LC3B). These findings suggest that virus-containing MVBs in fibroblasts are derived from the canonical endocytic pathway and takeover classical exosomal release pathway. Virus containing MVBs in HMVECs are derived from the early biosynthetic pathway and exploit a less characterized early Golgi-LAMP1-associated non-canonical secretory autophagy pathway. These results reveal striking cell-type specific membrane trafficking differences in host pathways that are exploited by HCMV.ImportanceHuman cytomegalovirus (HCMV) is a herpesvirus that, like all herpesvirus, that establishes a life long infection. HCMV remains a significant cause of morbidity and mortality in the immunocompromised and HCMV seropositivity is associated with increased risk vascular disease. HCMV infects many cells in the human and the biology underlying the different patterns of infection in different cell types is poorly understood. Endothelial cells are important target of infection that contribute to hematogenous spread of the virus to tissues. Here we define striking differences in the biogenesis of large vesicles that incorporate virions in fibroblasts and endothelial cells. In fibroblasts, HCMV is incorporated into canonical MVBs derived from an endocytic pathway, whereas HCMV matures through vesicles derived from the biosynthetic pathway in endothelial cells. This work defines basic biological differences between these cell types that may impact the outcome of infection.


Author(s):  
Emmi Helle ◽  
Minna Ampuja ◽  
Alexandra Dainis ◽  
Laura Antola ◽  
Elina Temmes ◽  
...  

Cell-cell interactions are crucial for organ development and function. In the heart, endothelial cells engage in bidirectional communication with cardiomyocytes regulating cardiac development and growth. We aimed to elucidate the organotypic development of cardiac endothelial cells and cardiomyocyte and endothelial cell crosstalk using human induced pluripotent stem cells (hiPSC). Single-cell RNA sequencing was performed with hiPSC-derived cardiomyocytes (hiPS-CMs) and endothelial cells (hiPS-ECs) in mono- and co-culture. The presence of hiPS-CMs led to increased expression of transcripts related to vascular development and maturation, cardiac development, as well as cardiac endothelial cell and endocardium-specific genes in hiPS-ECs. Interestingly, co-culture induced the expression of cardiomyocyte myofibrillar genes and MYL7 and MYL4 protein expression was detected in hiPS-ECs. Major regulators of BMP- and Notch-signaling pathways were induced in both cell types in co-culture. These results reflect the findings from animal studies and extend them to human endothelial cells, demonstrating the importance of EC-CM interactions during development.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Jennifer S Esser ◽  
Susanne Rahner ◽  
Meike Deckler ◽  
Christoph Bode ◽  
Martin Moser

Introduction: Bone morphogenetic proteins (BMP) play a key role in vascular development. Previously, we have identified BMP endothelial cell precursor-derived regulator (BMPER), an extracellular BMP modulator, to increase the angiogenic activity of endothelial cells in a concentration-dependent manner. In this project we now investigate how the BMPER effect is mediated by key molecules of angiogenesis. Methods and Results: To assess the effect of BMPER on angiogenesis-related molecules we performed an angiogenesis antibody array with BMPER-stimulated human umbilical venous endothelial cells (HUVECs) and vice versa with BMPER-silenced HUVECs compared to control conditions, respectively. We detected increased protein expression of the anti-angiogenic thrombospondin-1 (TSP-1) 48 hours after siBMPER transfection and, consistently, decreased TSP-1 expression after stimulation with BMPER (60 ng/ml; 39% ± 7.3 N=4). Furthermore, the pro-angiogenic protein bFGF was increased after BMPER stimulation, which was confirmed by realtime-PCR and western blot analysis (288.8% ± 74.8 N=3). Additionally, we detected increased FGF receptor-1 protein expression (137.7% ± 0.4 N=3) as well as FGF signaling pathway activation. Next, we investigated the interaction of BMPER and the FGF signaling pathway in endothelial cell function. BMPER stimulation increased HUVEC angiogenic activity in matrigel, migration and spheroid assays and concomitant inhibition of FGF signaling by an anti-bFGF antibody effectively inhibited the pro-angiogenic BMPER effect. Silencing of BMPER decreased the expression of FGFR1 and, accordingly, stimulation of BMPER-silenced cells with bFGF showed decreased angiogenic endothelial cell activity (65%) compared to control. The angiogenic activity of bFGF was also reduced in C57BL/6_Bmper +/- mice as assessed in the matrigel plug assay. Ex vivo aortic ring assays of C57BL/6_Bmper +/- mice confirmed a specific effect for bFGF but not for VEGF. Conclusion: In summary, BMPER inhibits the expression of the anti-angiogenic TSP-1 and increased the expression as well as activation of the pro-angiogenic FGF signaling pathway, which overall lead to the promotion of angiogenesis.


1999 ◽  
Vol 276 (2) ◽  
pp. H530-H534 ◽  
Author(s):  
Jenny Sörensson ◽  
Göran L. Matejka ◽  
Maria Ohlson ◽  
Börje Haraldsson

The serum protein orosomucoid (α1-acid glycoprotein) is needed to maintain the high capillary permselectivity required for normal homeostasis. It is not known how the protein executes its action, but it seems to contribute to the charge barrier. Moreover, recent studies suggest that the endothelial glycocalyx is essential for the charge barrier. The main site of orosomucoid synthesis is the liver, but we wanted to explore the possibility that orosomucoid was synthesized in endothelial cells. Primary cultures of human microvascular endothelial cells (HMVEC) from dermal tissue were established. Human liver cells were used as positive controls, and total RNA was prepared from both cell types. Reverse transcription-polymerase chain reaction (RT-PCR) was performed and demonstrated orosomucoid expression. After RT-PCR, the identities of the PCR products were confirmed by sequencing. RNase protection assay performed on total RNA from the HMVEC confirmed the results from the RT-PCR, i.e., orosomucoid mRNA is expressed by endothelial cells. Synthesis of orosomucoid in both liver and endothelial cells was demonstrated by immunoprecipitation. In conclusion, endothelial cells normally produce orosomucoid, which is essential for capillary charge selectivity. We suggest that orosomucoid exerts its effect by interacting with other components of the endothelial glycocalyx.


2002 ◽  
Vol 283 (3) ◽  
pp. F578-F582 ◽  
Author(s):  
Laszlo Wagner ◽  
Janet D. Klein ◽  
Jeff M. Sands ◽  
Chris Baylis

Our laboratory previously reported that uremic levels of urea inhibitl-arginine (l-Arg) transport into endothelial cells. The present study further investigated this effect. We measuredl-Arg transport in cultured bovine aortic endothelial cells with normal or high urea (25 mM). The urea transport inhibitor phloretin abolished the inhibitory effect of urea on l-Arg transport, suggesting a role for urea transporters (UTs). We screened bovine aortic endothelial cells and several other endothelial cell types for the presence of UTs by using Western blot analysis. UT-B was present in all endothelial cells, irrespective of species or location of derivation, whereas UT-A distribution was variable and sparse. UT-B was also abundant in rat aorta, mesenteric blood vessels, and spinotrapezius muscle, whereas UT-A distribution was, again, variable and sparse. Chronic elevation of urea had variable, inconsistent effects on UT abundance. This study showed that urea must enter endothelial cells, probably by UT-B, to inhibit l-Arg transport. In view of the wide distribution of UT-B in rat vasculature, elevated blood urea nitrogen may lead to endothelial l-Arg deficiency in vivo.


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