Involvement of functional autoantibodies against vascular receptors in systemic sclerosis

BackgroundSystemic sclerosis (SSc) features autoimmunity, vasculopathy and tissue fibrosis. The renin-angiotensin and endothelin systems have been implicated in vasculopathy and fibrosis. A role for autoantibody-mediated receptor stimulation is hypothesised, linking three major pathophysiological features consistent with SSc.MethodsSerum samples from 478 patients with SSc (298 in the study cohort and 180 from two further independent cohorts), 372 healthy subjects and 311 control-disease subjects were tested for antibodies against angiotensin II type 1 receptor (AT1R) and endothelin-1 type A receptor (ETAR) by solid phase assay. Binding specificities were tested by immunoprecipitation. The biological effects of autoantibodies in microvascular endothelial cells in vitro were also determined, as well as the quantitative differences in autoantibody levels on specific organ involvements and their predictive value for SSc-related mortality.ResultsAnti-AT1R and anti-ETAR autoantibodies were detected in most patients with SSc. Autoantibodies specifically bound to respective receptors on endothelial cells. Higher levels of both autoantibodies were associated with more severe disease manifestations and predicted SSc-related mortality. Both autoantibodies exert biological effects as they induced extracellular signal-regulated kinase 1/2 phosphorylation and increased transforming growth factor β gene expression in endothelial cells which could be blocked with specific receptor antagonists.ConclusionsFunctional autoimmunity directed at AT1R and ETAR is common in patients with SSc. AT1R and ETAR autoantibodies could contribute to disease pathogenesis and may serve as biomarkers for risk assessment of disease progression.

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Transforming Growth Factor β1 (TGF-β1) Promotes Endothelial Cell Survival during In Vitro Angiogenesis via an Autocrine Mechanism Implicating TGF-α Signaling

Molecular and Cellular Biology ◽

10.1128/mcb.21.21.7218-7230.2001 ◽

2001 ◽

Vol 21 (21) ◽

pp. 7218-7230 ◽

Cited By ~ 145

Author(s):

Francesc Viñals ◽

Jacques Pouysségur

Keyword(s):

Endothelial Cells ◽

Growth Factor ◽

Cell Survival ◽

Network Formation ◽

Egf Receptor ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β1 ◽

In Vitro Angiogenesis ◽

Tgf Β1

ABSTRACT Mouse capillary endothelial cells (1G11 cell line) embedded in type I collagen gels undergo in vitro angiogenesis. Cells rapidly reorganize and form capillary-like structures when stimulated with serum. Transforming growth factor β1 (TGF-β1) alone can substitute for serum and induce cell survival and tubular network formation. This TGF-β1-mediated angiogenic activity depends on phosphatidylinositol 3-kinase (PI3K) and p42/p44 mitogen-activated protein kinase (MAPK) signaling. We showed that specific inhibitors of either pathway (wortmannin, LY-294002, and PD-98059) all suppressed TGF-β1-induced angiogenesis mainly by compromising cell survival. We established that TGF-β1 stimulated the expression of TGF-α mRNA and protein, the tyrosine phosphorylation of a 170-kDa membrane protein representing the epidermal growth factor (EGF) receptor, and the delayed activation of PI3K/Akt and p42/p44 MAPK. Moreover, we showed that all these TGF-β1-mediated signaling events, including tubular network formation, were suppressed by incubating TGF-β1-stimulated endothelial cells with a soluble form of an EGF receptor (ErbB-1) or tyrphostin AG1478, a specific blocker of EGF receptor tyrosine kinase. Finally, addition of TGF-α alone poorly stimulated angiogenesis; however, by reducing cell death, it strongly potentiated the action of TGF-β1. We therefore propose that TGF-β1 promotes angiogenesis at least in part via the autocrine secretion of TGF-α, a cell survival growth factor, activating PI3K/Akt and p42/p44 MAPK.

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Endothelial Cells Require STAT3 for Protection against Endotoxin-induced Inf lammation

Journal of Experimental Medicine ◽

10.1084/jem.20030077 ◽

2003 ◽

Vol 198 (10) ◽

pp. 1517-1525 ◽

Cited By ~ 105

Author(s):

Arihiro Kano ◽

Michael J. Wolfgang ◽

Qian Gao ◽

Joerg Jacoby ◽

Gui-Xuan Chai ◽

...

Keyword(s):

Endothelial Cells ◽

Transforming Growth Factor ◽

Endotoxic Shock ◽

Transforming Growth Factor Β ◽

Organ Damage ◽

Interleukin 10 ◽

Interferon Γ ◽

Protective Function ◽

Lps Challenge

Endothelial cells (ECs) are believed to be an important component in the protection from lipopolysaccharide (LPS)-induced endotoxic shock. However, the cellular and molecular mechanism is not well defined. Here, we report that signal transducer and activator of transcription (STAT) 3 is an essential regulator of the antiinflammatory function of ECs in systemic immunity. Because STAT3 deficiency results in early embryonic lethality, we have generated mice with a conditional STAT3 deletion in endothelium (STAT3E−/−). STAT3E−/− mice are healthy and fertile, and isolated ECs initiate normal tube formation in vitro. Conditional endothelial but not organ-specific (i.e., hepatocyte or cardiomyocyte) STAT3 knockout mice show an increased susceptibility to lethality after LPS challenge. The LPS response in STAT3E−/− mice shows exaggerated inflammation and leukocyte infiltration in multiple organs combined with elevated activity of serum alanine aminotransferase and aspartate aminotransferase, indicating organ damage. Concomitantly, proinflammatory cytokines are produced at an exaggerated level and for a prolonged period. This defect cannot be explained by lack of antiinflammatory cytokines, such as interleukin 10 and transforming growth factor β. Instead, we have shown that a soluble activity derived from endothelia and dependent on STAT3 is critical for suppression of interferon γ. These data define STAT3 signaling within endothelia as a critical antiinflammatory mediator and provide new insight to the protective function of ECs in inflammation.

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Protective Effects of Eicosapentaenoic Acid on the Glomerular Endothelium via Inhibition of EndMT in Diabetes

Journal of Diabetes Research ◽

10.1155/2021/2182225 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Toshinori Yasuzawa ◽

Tomomi Nakamura ◽

Shigeru Ueshima ◽

Akira Mima

Keyword(s):

Endothelial Cells ◽

Eicosapentaenoic Acid ◽

Transforming Growth Factor ◽

Protective Effects ◽

Plasminogen Activator Inhibitor 1 ◽

Renal Protection ◽

Mesangial Expansion ◽

Mesenchymal Transition ◽

Pai 1

Diabetes-induced endothelial pathologies are hypothesized to lead to the progression of diabetic kidney disease (DKD). The endothelial to mesenchymal transition (EndMT) possibly induces fibrosis, leading to glomerulosclerosis in the kidney. Furthermore, this could lead to albuminuria in diabetic nephropathy due to glomerular endothelial dysfunction. Eicosapentaenoic acid (EPA), purified from fish oil, decreases inflammatory cytokine levels in glomerulonephritis. Here, we aimed at finding whether ethyl eicosapentaenoate (EPA-E) exerts renal protective effects via EndMT inhibition. To find out whether EPA inhibits EndMT in vitro, the changes in CD31 expression were studied in cultured mouse endothelial cells. The addition of the conditioned medium from the adipocyte culture significantly decreased the protein levels of CD31, while the addition of EPA-E partially reversed this inhibition. Further, EndMT inhibition by EPA-E treatment might occur via the inhibition of the protein kinase Cβ (PKCβ)/transforming growth factor-β (TGF-β)/plasminogen activator inhibitor-1 (PAI-1) signaling and not via microRNAs. Streptozotocin-induced diabetic mice fed a high-fat diet (60% from fat) exhibited mesangial expansion and albuminuria. Induction of EPA-E ameliorated the mesangial expansion and decreased albuminuria without affecting blood pressure, triglyceride and free fatty acid levels, and intraperitoneal glucose. These findings suggest that EPA-E exerts renal protective effects on endothelial cells, by normalizing EndMT followed by the PKCβ/TGF-β/PAI-1 signaling. Thus, EPA-E has the potential for imparting renal protection by regulating EndMT in DKD.

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Endothelial cell integrin alpha5beta1 expression is modulated by cytokines and during migration in vitro

Journal of Cell Science ◽

10.1242/jcs.112.4.569 ◽

1999 ◽

Vol 112 (4) ◽

pp. 569-578 ◽

Cited By ~ 1

Author(s):

G. Collo ◽

M.S. Pepper

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Growth Factor ◽

Transforming Growth Factor ◽

Integrin Subunit ◽

Subunit Expression ◽

Synergistic Induction ◽

Co Addition ◽

Extracellular Matrix Interactions

Alterations in endothelial cell-extracellular matrix interactions are central to the process of angiogenesis. We have investigated the effect of wound-induced two-dimensional migration, basic fibroblast growth factor (bFGF), transforming growth factor-beta1 (TGF-beta1) and leukemia inhibitory factor (LIF) on expression of the alpha5beta1 integrin in endothelial cells. In multiple-wounded monolayers of bovine microvascular endothelial (BME) cells, an increase in mRNA and total protein for both alpha5 and beta1 subunits was observed, and this could be correlated with a reduction in cell density but not proliferation, both of which are induced following wounding. Although as previously reported, the alpha5 subunit was increased when cells were exposed to TGF-beta1 alone, co-addition of bFGF and TGF-beta1 resulted in a striking synergistic induction of alpha5, with no significant changes in the expression of beta1. In contrast, the alpha5 subunit was decreased by LIF in bovine aortic endothelial but not in BME cells. These findings suggest that quantitative alterations in alpha5 and beta1 integrin subunit expression modulate the adhesive and migratory properties of endothelial cells during angiogenesis.

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Topically Applied Etamsylate: A New Orphan Drug for HHT-Derived Epistaxis (Antiangiogenesis through FGF Pathway Inhibition)

TH Open ◽

10.1055/s-0039-1693710 ◽

2019 ◽

Vol 03 (03) ◽

pp. e230-e243 ◽

Cited By ~ 1

Author(s):

Virginia Albiñana ◽

Guillermo Giménez-Gallego ◽

Angela García-Mato ◽

Patricia Palacios ◽

Lucia Recio-Poveda ◽

...

Keyword(s):

Clinical Trial ◽

Endothelial Cells ◽

Growth Factor ◽

Orphan Drug ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Life Threatening ◽

Vascular Dysplasia ◽

Pathway Inhibition

AbstractHereditary hemorrhagic telangiectasia (HHT) is a vascular dysplasia characterized by recurrent and spontaneous epistaxis (nose bleeds), telangiectases on skin and mucosa, internal organ arteriovenous malformations, and dominant autosomal inheritance. Mutations in Endoglin and ACVRL1/ALK1, genes mainly expressed in endothelium, are responsible in 90% of the cases for the pathology. These genes are involved in the transforming growth factor-β(TGF-β) signaling pathway. Epistaxis remains as one of the most common symptoms impairing the quality of life of patients, becoming life-threatening in some cases. Different strategies have been used to decrease nose bleeds, among them is antiangiogenesis. The two main angiogenic pathways in endothelial cells depend on vascular endothelial growth factor and fibroblast growth factor (FGF). The present work has used etamsylate, the diethylamine salt of the 2,5-dihydroxybenzene sulfonate anion, also known as dobesilate, as a FGF signaling inhibitor. In endothelial cells, in vitro experiments show that etamsylate acts as an antiangiogenic factor, inhibiting wound healing and matrigel tubulogenesis. Moreover, etamsylate decreases phosphorylation of Akt and ERK1/2. A pilot clinical trial (EudraCT: 2016–003982–24) was performed with 12 HHT patients using a topical spray of etamsylate twice a day for 4 weeks. The epistaxis severity score (HHT-ESS) and other pertinent parameters were registered in the clinical trial. The significant reduction in the ESS scale, together with the lack of significant side effects, allowed the designation of topical etamsylate as a new orphan drug for epistaxis in HHT (EMA/OD/135/18).

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N-Acetylcysteine and Sulodexide Reduce the Prothrombotic Effect of Uremic Serum on the Venous Endothelial Cells

Kidney & Blood Pressure Research ◽

10.1159/000499879 ◽

2019 ◽

Vol 44 (2) ◽

pp. 277-285

Author(s):

Patrycja Sosinska-Zawierucha ◽

Beata Mackowiak ◽

Andrzej Breborowicz

Keyword(s):

Gene Expression ◽

Renal Failure ◽

Endothelial Cells ◽

Ex Vivo ◽

Secretory Activity ◽

Serum Samples ◽

Uremic Serum ◽

Uremic Patients ◽

End Stage

Background/Aims: Thromboembolic episodes are a frequent problem in end stage renal failure patients. The pathomechanism of the disorder is complex, including bioincompatibility of renal replacement therapy, endothelial dysfunction, increased blood level of procoagulant factors and uremic toxins. We studied changes in the functional properties of venous endothelial cells (VEC) in the presence of uremic serum and evaluated their possible modulation by N-acetylcysteine (NAC) or sulodexide (SUL). Methods: Serum samples from 12 uremic patients treated with hemodialysis were studied ex vivo on in vitro cultured VEC. In separate experiments, NAC 1 mmol/L or SUL 0.5 LRU/mL were added to uremic serum samples. Both changes in the gene expression and secretory activity of VEC were studied. Results: Uremic serum increased the expression of the following genes: IL6 +97%, p < 0.002; VEGF +28%, p < 0.002; vWF +47%, p < 0.002; PECAM +76%, p < 0.002; ICAM-1 +275%, p < 0.002; t-PA +96%, p < 0.002. Changes in gene expression were reflected by the increased secretory activity of VEC treated with the uremic serum. Exposure of VEC to uremic serum supplemented with NAC or SUL resulted in weaker stimulation of the studied genes’ expression. Also, secretion of the studied solutes, with the exception of ICAM-1, was reduced in the presence of NAC: IL6 –34%, p < 0.01; VEGF –40%, p < 0.005; vWF –25%, p < 0.001; t-PA –47%, p < 0.01, and MMP9 –37%, p < 0.001. SUL reduced the uremic serum-induced secretion of all solutes: IL6 –24%, p < 0.05; ICAM-1 –43%, p < 0.01; VEGF –38%, p < 0.01; vWF –23%, p < 0.01; t-PA –49%, p < 0.01, and MMP9 –25%, p < 0.05. Conclusions: Uremic serum induces prothrombotic changes in VEC, which may cause a predisposition to thrombotic disorders in patients with renal failure. NAC and SUL reduce the effects of the uremic serum in VEC, which suggests their potential therapeutic application in uremic patients.

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In Vitro ELISA and Cell-Based Assays Confirm the Low Immunogenicity of VNAR Therapeutic Constructs in a Mouse Model of Human RA: An Encouraging Milestone to Further Clinical Drug Development

Journal of Immunology Research ◽

10.1155/2020/7283239 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Obinna C. Ubah ◽

Andrew J. Porter ◽

Caroline J. Barelle

Keyword(s):

Mouse Model ◽

Solid Phase ◽

Molecular Architecture ◽

Serum Samples ◽

Complete Control ◽

Drug Levels ◽

Trough Serum ◽

The Impact

Anti-drug antibodies (ADAs), specific for biotherapeutic drugs, are associated with reduced serum drug levels and compromised therapeutic response. The impact of ADA on the bioavailability and clinical efficacy of blockbuster anti-hTNF-α monoclonal antibodies is well recognised, especially for adalimumab and infliximab treatments, with the large and complex molecular architecture of classical immunoglobulin antibody drugs, in part, responsible for the immunogenicity seen in patients. The initial aim of this study was to develop solid-phase enzyme-linked immunosorbent assays (ELISA) and an in vitro cell-based method to accurately detect ADA and estimate its impact on the preclinical in vivo efficacy outcomes of two novel, nonimmunoglobulin VNAR fusion anti-hTNF-α biologics (Quad-X™ and D1-NDure™-C4) and Humira®, a brand of adalimumab. Serum drug levels and the presence of ADA were determined in a transgenic mouse model of polyarthritis (Tg197) when Quad-X™ and Humira® were dosed at 1 mg/kg and D1-NDure™-C4 was dosed at 30 mg/kg. The serum levels of the Quad-X™ and D1-NDure™-C4 modalities were consistently high and comparable across all mice within the same treatment groups. In 1 mg/kg and 3 mg/kg Quad-X™- and 30 mg/kg D1-NDure™-C4-treated mice, an average trough drug serum concentration of 8 μg/mL, 50 μg/mL, and 350 μg/mL, respectively, were estimated. In stark contrast, Humira® trough serum concentrations in the 1 mg/kg treatment group ranged from <0.008 μg/mL to 4 μg/mL with trace levels detected in 7 of the 8 animals treated. Trough serum Humira® and Quad-X™ concentrations in 3 mg/kg treatment samples were comparable; however, the functionality of the detected Humira® serum was significantly compromised due to neutralising ADA. The impact of ADA went beyond the simple and rapid clearance of Humira®, as 7/8 serum samples also showed no detectable capacity to neutralise hTNF-α-mediated cytotoxicity in a murine fibrosarcoma (L929) cell assay. The neutralisation capacity of all the VNAR constructs remained unchanged at the end of the experimental period (10 weeks). The data presented in this manuscript goes some way to explain the exciting outcomes of the previously published preclinical in vivo efficacy data, which showed complete control of disease at Quad-X™ concentrations of 0.5 mg/kg, equivalent to 10x the in vivo potency of Humira®. This independent corroboration also validates the robustness and reliability of the assay techniques reported in this current manuscript, and while it comes with the caveat of a mouse study, it does appear to suggest that these particular VNAR constructs, at least, are of low inherent immunogenicity.

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Characterization of a new monoclonal antibody (PG-M3) directed against the aminoterminal portion of the PML gene product: immunocytochemical evidence for high expression of PML proteins on activated macrophages, endothelial cells, and epithelia

Blood ◽

10.1182/blood.v85.7.1871.bloodjournal8571871 ◽

1995 ◽

Vol 85 (7) ◽

pp. 1871-1880 ◽

Cited By ~ 67

Author(s):

L Flenghi ◽

M Fagioli ◽

L Tomassoni ◽

S Pileri ◽

M Gambacorta ◽

...

Keyword(s):

Monoclonal Antibody ◽

Endothelial Cells ◽

Transforming Growth Factor Beta ◽

Transforming Growth Factor ◽

Retinoic Acid Receptor ◽

Chromosomal Translocation ◽

Peptide Sequence ◽

Nuclear Staining

PG-M3 is a new monoclonal antibody (MoAb) specifically directed against a peptide sequence located in the aminoterminal region of the human PML protein. PML gene fuses with the retinoic acid receptor alpha (RAR alpha) gene during the t(15; 17) chromosomal translocation of acute promyelocytic leukemia (APL). The epitope recognized by PG-M3 is species-specific and fixative-resistant and is shared by most PML isoforms and PML/RAR alpha fusion proteins. PML is consistently located within the nucleus, although a minority of cells (about 20%), both in vitro and in vivo, show positivity for PML also in the cytoplasm. The nuclear staining pattern of PG-M3 varies from speckled (cells other than APL) to micropunctate (APL cells). Although two physiologically expressed PML isoforms are detectable by immunocytochemistry only or predominantly in the cytoplasm of transfected cells, the cytoplasmic localization of PML is a property also shared by the PML isoforms that predominantly localize to the nuclei. Immunohistologic analysis of normal human tissues with the PG-M3 MoAb showed variable PML expression, with the highest levels of the protein in postmitotic, differentiated cell types, such as endothelial cells, epithelia, and tissue macrophages, especially activated ones. In keeping with this in vivo finding, PML appears strongly upregulated in the U937 promonocyte cell line after exposure to agents that induce monocyte/macrophage activation (interferon gamma) or maturation (vitamin D3 and transforming growth factor beta 1).

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In Vitro Cytological Responses against Laser Photobiomodulation for Periodontal Regeneration

International Journal of Molecular Sciences ◽

10.3390/ijms21239002 ◽

2020 ◽

Vol 21 (23) ◽

pp. 9002

Author(s):

Yujin Ohsugi ◽

Hiromi Niimi ◽

Tsuyoshi Shimohira ◽

Masahiro Hatasa ◽

Sayaka Katagiri ◽

...

Keyword(s):

Gene Expression ◽

Endothelial Cells ◽

Laser Irradiation ◽

Biological Effects ◽

Periodontal Regeneration ◽

Chronic Inflammatory Disease ◽

Periodontal Ligament Cells ◽

Positive Effects ◽

Periodontal Tissues

Periodontal disease is a chronic inflammatory disease caused by periodontal bacteria. Recently, periodontal phototherapy, treatment using various types of lasers, has attracted attention. Photobiomodulation, the biological effect of low-power laser irradiation, has been widely studied. Although many types of lasers are applied in periodontal phototherapy, molecular biological effects of laser irradiation on cells in periodontal tissues are unclear. Here, we have summarized the molecular biological effects of diode, Nd:YAG, Er:YAG, Er,Cr:YSGG, and CO2 lasers irradiation on cells in periodontal tissues. Photobiomodulation by laser irradiation enhanced cell proliferation and calcification in osteoblasts with altering gene expression. Positive effects were observed in fibroblasts on the proliferation, migration, and secretion of chemokines/cytokines. Laser irradiation suppressed gene expression related to inflammation in osteoblasts, fibroblasts, human periodontal ligament cells (hPDLCs), and endothelial cells. Furthermore, recent studies have revealed that laser irradiation affects cell differentiation in hPDLCs and stem cells. Additionally, some studies have also investigated the effects of laser irradiation on endothelial cells, cementoblasts, epithelial cells, osteoclasts, and osteocytes. The appropriate irradiation power was different for each laser apparatus and targeted cells. Thus, through this review, we tried to shed light on basic research that would ultimately lead to clinical application of periodontal phototherapy in the future.

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Donor antibodies to HNA-3a implicated in TRALI reactions prime neutrophils and cause PMN-mediated damage to human pulmonary microvascular endothelial cells in a two-event in vitro model

Blood ◽

10.1182/blood-2006-05-025106 ◽

2006 ◽

Vol 109 (4) ◽

pp. 1752-1755 ◽

Cited By ~ 93

Author(s):

Christopher C. Silliman ◽

Brian R. Curtis ◽

Patricia M. Kopko ◽

Samina Y. Khan ◽

Marguerite R. Kelher ◽

...

Keyword(s):

Endothelial Cells ◽

In Vitro Model ◽

Microvascular Endothelial Cells ◽

Pulmonary Microvascular Endothelial Cells ◽

Biologic Response ◽

Event Model ◽

Microvascular Endothelial ◽

Vitro Model ◽

Related Mortality

Abstract Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. Antibodies to HNA-3a are commonly implicated in TRALI. We hypothesized that HNA-3a antibodies prime neutrophils (PMNs) and cause PMN-mediated cytotoxicity through a two-event pathogenesis. Isolated HNA-3a+ or HNA-3a− PMNs were incubated with plasma containing HNA-3a antibodies implicated in TRALI, and their ability to prime the oxidase was measured. Human pulmonary microvascular endothelial cells (HMVECs) were activated with endotoxin or buffer, HNA-3a+ or HNA-3a− PMNs were added, and the coculture was incubated with plasma ± antibodies to HNA-3a. PMN-mediated damage was measured by counting viable HMVECs/mm2. Plasma containing HNA-3a antibodies primed the fMLP-activated respiratory burst of HNA-3a+, but not HNA-3a−, PMNs and elicited PMN-mediated damage of LPS-activated HMVECs when HNA-3a+, but not HNA-3a−, PMNs were used. Thus, antibodies to HNA-3a primed PMNs and caused PMN-mediated HMVEC cytotoxicity in a two-event model identical to biologic response modifiers implicated in TRALI.

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