The F11 receptor (F11R/JAM-A) in atherothrombosis: Overexpression of F11R in atherosclerotic plaques

2007 ◽  
Vol 97 (02) ◽  
pp. 272-281 ◽  
Author(s):  
Anna Babinska ◽  
Bani Azari ◽  
Moro Salifu ◽  
Ruijie Liu ◽  
Xian-Cheng Jiang ◽  
...  

SummaryF11R is the gene name for an adhesion protein, called the F11-receptor, aka JAM-A, which under normal physiological conditions is expressed constitutively on the surface of platelets and localized within tight junctions of endothelial cells (EC). Previous studies of the interactions between human platelets and EC suggested that F11R/JAM-A plays a crucial role in inflammatory thrombosis and atherosclerosis. The study reported here obtained in-vivo confirmation of this conclusion by investigating F11R/JAM-A protein and mRNA in patients with aortic and peripheral vascular disease and in an animal model of atherosclerosis. Molecular and immunofluorescence determinations revealed very high levels of F11R/JAM-A mRNA and F11R/JAM-A protein in atherosclerotic plaques of cardiovascular patients. Similar results were obtained with 12-week-old atherosclerosis-prone apoE-/- mice, an age in which atherosclerotic plaques are well established. Enhanced expression of the F11R/JAM-A message in cultured EC from human aortic and venous vessels was observed following exposure of the cells to cytokines. Determinations of platelet adhesion to cultured EC inflamed by combined cytokine treatment in the presence of F11R/JAM-A – antagonists provided data indicating that de novo expression of F11R/JAM-A on the luminal surface of inflamed EC has an important role in the conversion of EC to a thrombogenic surface. Further studies of these interactions under flow conditions and under in-vivo settings could provide a final proof of a causal role for F11R/JAM-A in the initiation of thrombosis. Based on our invitro and in-vivo studies to date, we propose that therapeutic drugs which antagonize the function of F11R/JAM-A should be tested as novel means for the prevention and treatment of atherosclerosis, heart attacks and stroke.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mylène Tajan ◽  
Marc Hennequart ◽  
Eric C. Cheung ◽  
Fabio Zani ◽  
Andreas K. Hock ◽  
...  

AbstractMany tumour cells show dependence on exogenous serine and dietary serine and glycine starvation can inhibit the growth of these cancers and extend survival in mice. However, numerous mechanisms promote resistance to this therapeutic approach, including enhanced expression of the de novo serine synthesis pathway (SSP) enzymes or activation of oncogenes that drive enhanced serine synthesis. Here we show that inhibition of PHGDH, the first step in the SSP, cooperates with serine and glycine depletion to inhibit one-carbon metabolism and cancer growth. In vitro, inhibition of PHGDH combined with serine starvation leads to a defect in global protein synthesis, which blocks the activation of an ATF-4 response and more broadly impacts the protective stress response to amino acid depletion. In vivo, the combination of diet and inhibitor shows therapeutic efficacy against tumours that are resistant to diet or drug alone, with evidence of reduced one-carbon availability. However, the defect in ATF4-response seen in vitro following complete depletion of available serine is not seen in mice, where dietary serine and glycine depletion and treatment with the PHGDH inhibitor lower but do not eliminate serine. Our results indicate that inhibition of PHGDH will augment the therapeutic efficacy of a serine depleted diet.


Author(s):  
Anjali P ◽  
Vimalavathini R

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease which mainly targets synovial membrane during its disease pathogenesis. Available therapeutic drugs for the treatment of RA provide only symptomatic relief and are associated with severe side effects. Herbal plants comprise many active biological compounds that cure the disease with minimal adverse effects. Pyrenacantha volubilis is a climber and member of Icacinaceae family. Gas chromatography- mass spectrometry (GC-MS) analysis of ethanolic extracts of leaves of Pyrenacantha volubilis (EEPV) reveals the presence of 2-isopropyl-5-methylcyclohexyl 3-(1-(4- chlorophenyl)-3-oxobutyl)-coumarin-4-yl carbonate and 1-naphthalenepropanol, alpha-ethyldecahydro-5- (hydroxymethyl)-alpha,5,8A-trimethyl-2-methyl phytoconstitutents. Hence these compounds were docked with various pathological mediators of RA using Autodock 4.2. The docking results unveils that these compounds had better binding energy against inflammatory, oxidative stress and receptor for advanced glycation end products (RAGE) mediators that plays a pivotal role in the progression of RA. However, this study warrants further in- vitro and in-vivo studies to be carried out to establish the anti-inflammatory and anti-arthritic activity of selected phytoconstitutents.


2019 ◽  
Vol 133 (11) ◽  
pp. 1215-1228 ◽  
Author(s):  
Yu Sun ◽  
Juan Guan ◽  
Yunfeng Hou ◽  
Fei Xue ◽  
Wei Huang ◽  
...  

Abstract Background: Although junctional adhesion molecule-like protein (JAML) has recently been implicated in leukocyte recruitment during inflammation and wound repair, its role in atherosclerosis remains to be elucidated. Methods and results: First, we showed that JAML was strongly expressed in atherosclerotic plaques of cardiovascular patients. Similar results were obtained with atherosclerotic plaques of ApoE−/− mice. Co-immunofluorescence staining showed that JAML was mainly expressed in macrophages. Enhanced expression of JAML in cultured macrophages was observed following exposure of the cells to oxLDL. The functional role of JAML in atherosclerosis and macrophages function was assessed by interference of JAML with shRNA in vivo and siRNA in vitro. Silencing of JAML in mice significantly attenuated atherosclerotic lesion formation, reduced necrotic core area, increased plaque fibrous cap thickness, decreased macrophages content and inflammation. In addition, histological staining showed that JAML deficiency promoted plaques to stable phenotype. In vitro, JAML siRNA treatment lowered the expression of inflammatory cytokines in macrophages treated with oxLDL. The mechanism by which JAML mediated the inflammatory responses may be related to the ERK/NF-κB activation. Conclusions: Our results demonstrated that therapeutic drugs which antagonize the function of JAML may be a potentially effective approach to attenuate atherogenesis and enhance plaque stability.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1595-1595
Author(s):  
Randall M Rossi ◽  
Marlene Balys ◽  
Dean Franklin ◽  
Valerie Grose ◽  
Richard I Fisher ◽  
...  

Abstract Previous studies in our lab have shown that the PKC-beta inhibitor, enzastaurin (LY317615), when used to treat a panel of human diffuse large cell lymphoma (DLCL) lines, was able to induce cell death in vitro and substantially reduce tumor growth in xenograft assays. These findings support the hypothesis that activation of PKC contributes to tumor cell survival and proliferation, which has been implicated in the pathogenesis of human B cell lymphomas. Specifically, PKC-beta activation is increased in tumor cells from patients with poor prognosis DLCL, suggesting that PKC-beta may be a target for therapeutic intervention. In the present study, we have explored the interaction of enzastaurin with a panel of well characterized therapeutic agents to evaluate whether its anti-tumor activity can potentially be enhanced. Drugs were chosen for analysis based either on known single agent activity in lymphoma, or by preclinical evaluation indicating potential synergy with enzastaurin. For in vitro culture assays (48–72 hr treatment), the addition of gemcitabine, rapamycin, or bortezomib, increased the cytotoxicity of enzastaurin from 2 to 7 fold. This effect was evident with multiple human DLCL cell lines, (OCI-Ly3, 7, 10, 19, and SUDHL-4, and 6), as well as two independent primary DLCL cultures. For in vivo studies, subcutaneous transplantation of the DLCL cell line OCI-Ly19, (previously engineered to express luciferase which allows for real time in vivo imaging), or a primary DLCL isolate, into immune deficient NOD/SCID mice formed reproducible tumors. Recipient animals were separated into uniform cohorts when the tumors were of <=500 cubic mm in size. The animals were then simultaneously or sequentially treated with enzastaurin, (150 mg/kg b.i.d. via oral gavage) and a secondary drug, either gemcitabine, (2.5 or 5.0 mg/kg 1x/3 days IP), bortezomib, (0.4 mg/kg twice weekly IP), rapamycin, (1.0 mg/kg, daily IP), or rituxan, (5 mg/kg, weekly IP). Imaging and analysis of tumor volumes showed that addition of either rituxan or rapamycin provided no additional benefit in comparison to enzastaurin alone during the course of treatment. In contrast, the combination of either gemcitabine or bortezomib with enzastaurin demonstrated significantly reduced tumor volumes in comparison to enzastaurin alone (17% to 38% greater decrease with enzastaurin + gemcitabine, and 50% greater decrease in tumor volume with enzastaurin + bortezomib). These data suggest that the use of enzastaurin in combination with existing therapeutic drugs (gemcitabine or bortezomib) has the potential to limit tumor size/growth while lowering dose levels and thereby reducing potential side effects associated with traditional treatments.


2013 ◽  
Vol 59 (12) ◽  
pp. 1708-1721 ◽  
Author(s):  
Emma Raitoharju ◽  
Niku Oksala ◽  
Terho Lehtimäki

BACKGROUND MicroRNAs (miRNA, miR) are noncoding RNAs that regulate gene expression by hindering translation. miRNA expression profiles have been shown to differ in vivo and in vitro in many cellular processes associated with cardiovascular diseases (CVDs). The progression of CVDs has also been shown to alter the blood miRNA profile in humans. CONTENT We summarize the results of animal and cell experiments concerning the miRNA profile in the atherosclerotic process and the changes which occur in the blood miRNA profile of individuals with CVD. We also survey the relationship of these CVD-related miRNAs and their expression in the human advanced atherosclerotic plaque, thereby providing more insight into miRNA function in human atherosclerotic lesions. The miRNAs miR-126, -134, -145, -146a, -198, -210, -340*, and -92a were found to be expressed differently in the blood of individuals affected and unaffected by CVD. These differences paralleled those seen in tissue comparisons of miRNA expression in advanced atherosclerotic plaques and healthy arteries. Furthermore, several miRNAs associated with atherosclerosis in in vitro studies (such as miR-10a, -126, -145, -146a/b, -185, -210, and -326) were expressed in plaques in a similar pattern as was predicted by the in vitro experiments. The clinical implications of miRNAs in atherosclerosis as biomarkers and as possible drug targets are also reviewed. SUMMARY miRNA profiles in in vitro and in vivo studies as well as in human peripheral blood are quite representative of the miRNA expression in human atherosclerotic plaques. miRNAs appear promising in terms of future clinical applications.


2007 ◽  
Vol 6 (7) ◽  
pp. 1137-1149 ◽  
Author(s):  
Talibah Metcalf ◽  
Hanke van der Wel ◽  
Ricardo Escalante ◽  
Leandro Sastre ◽  
Christopher M. West

ABSTRACT Like the cyst walls of other protists, the spore coat of Dictyostelium discoideum is formed de novo to protect the enclosed dormant cell from stress. Spore coat assembly is initiated by exocytosis of protein and polysaccharide precursors at the cell surface, followed by the infusion of nascent cellulose fibrils, resulting in an asymmetrical trilaminar sandwich with cellulose filling the middle layer. A molecular complex consisting of cellulose and two proteins, SP85 and SP65, is associated with the inner and middle layers and is required for proper organization of distinct proteins in the outer layer. Here we show that, unlike SP85 and other protein precursors, which are stored in prespore vesicles, SP65 is, like cellulose, synthesized just in time. By tagging the SP65 locus with green fluorescent protein, we find that SP65 is delivered to the cell surface via largely distinct vesicles, suggesting that separate delivery of components of the cellulose-SP85-SP65 complex regulates its formation at the cell surface. In support of previous in vivo studies, recombinant SP65 and SP85 are shown to interact directly. In addition, truncation of SP65 causes a defect of the outer layer permeability barrier as seen previously for SP85 mutants. These observations suggest that assembly of the cellulose-SP85-SP65 triad at the cell surface is biosynthetically regulated both temporally and spatially and that the complex contributes an essential function to outer layer architecture and function.


2021 ◽  
pp. 1-12
Author(s):  
M.C. Nino ◽  
L. Reddivari ◽  
C. Osorio ◽  
I. Kaplan ◽  
A.M. Liceaga

The use of insects in traditional medicine and unveiling the chemical structure of the bright pigments in butterfly wings led to the discovery of bioactive phenolic compounds in the insect bodies. These metabolites have been found not only due to the insect absorption and metabolisation of the plant-derived phenolic present in their diet, but also from the ability of insects to synthesise phenolic compounds de novo through the sclerotisation process. Plant phenolics are secondary metabolites involved in the protection of tissues against UV radiation, herbivores, and pathogens, as well as pigmentation of fruits and flowers. These bioactive compounds exhibit antioxidant, anti-inflammatory, anticancer, and antimicrobial activities, demonstrated through in vitro and in vivo studies. This bioactive potential is thought to occur due to their chemical characteristics that allow them to stabilise reactive oxygen species (ROS), chelate prooxidant metal ions, interact with key enzymes and signal cascades involved in biological pathways. Bioactivity of plant phenolics and both in vitro, in vivo studies, suggest that the dietary compounds absorbed by the insect maintain their chemical and bioactive properties. Further characterisation of the phenolic composition in edible insects and evaluation of their bioactive capacity as well as their bioavailability, could result in discovering additional health benefits of entomophagy apart from macro-nutritional (e.g. protein) content.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 711-711
Author(s):  
Anagh Anant Sahasrabuddhe ◽  
Xiaofei Chen ◽  
Kaiyu Ma ◽  
Rui Wu ◽  
Richa Kapoor ◽  
...  

Abstract Introduction: Diffuse large B cell lymphoma (DLBCL) is the most common form of malignant lymphoma and may arise de novo, or through transformation from a pre-existing low-grade B cell lymphoma such as follicular lymphoma (FL). However, the post-translational mechanisms and deregulated pathways underlying the pathogenesis of disease evolution are not fully understood. Methods: We employed integrated functional and structural genomics and mass spectrometry (MS)-driven proteomics which implicated a possible novel tumor suppressor role for a conserved E3 ubiquitin ligase FBXO45 in DLBCL pathogenesis. We generated conditional knockout mice targeting loss of Fbxo45 in germinal center (GC) B-cells using the Cg1-Cre-loxP system and an assortment of CRISPR-mediated knockouts of FBXO45 in B cell lymphoma cells (FL518, BJAB, U2932). We engineered B cell lines (BJAB, U2932) to inducibly express FLAG-tagged FBXO45 to identify candidate substrates of FBXO45 using liquid chromatography-tandem MS. In vitro biochemical and in vivo studies using a variety of genetically-modified lines in xenograft studies in immunodeficient mice were performed to validate observations from proteogenomic studies. Whole genome sequencing (WGS) and genomic copy number studies were interrogated to investigate structural alterations targeting FBXO45 in primary human lymphoma samples. Results: Conditional targeting of Fbxo45 in GCB-cells in transgenic mice resulted in abnormal germinal center formation with increased number and size of germinal centers. Strikingly, targeted deletion of Fbxo45 in GCB-cells resulted in spontaneous B cell lymphomas with (22/22);100%) penetrance and none of the wild-type (WT) littermates (0/20; 0%) developed lymphoma at 24 months. Macroscopic examination revealed large tumor masses, splenomegaly, and lymphadenopathy at different anatomic locations including ileocecal junction, mesenteric, retroperitoneal and cervical lymph nodes and thymus. Next generation sequencing of immunoglobulin heavy chain genes revealed monoclonal or oligoclonal B cell populations. Using proteomic analysis of affinity-purified FBXO45-immunocomplexes and differential whole proteome analysis from GCB-cells of Fbxo45 wt/wt vs Fbxo45 fl/fl mice, we discovered that FBXO45 targets the RHO guanine exchange factor GEF-H1 for ubiquitin-mediated proteasomal degradation. FBXO45 exclusively interacts with GEF H1 among 8 F-box proteins investigated and silencing of FBXO45 using three independent shRNA and CRISPR-Cas9-mediated knockouts in B-cell lymphoma cell lines promotes RHOA and MAPK activation, B cell growth and enhances proliferation. GEF-H1 is stabilized by FBXO45 depletion and GEF-H1 ubiquitination by FBXO45 requires phosphorylation of GEF-H1. Importantly, FBXO45 depletion and expression of a GEF-H1 mutant that is unable to bind FBXO45 results in GEF-H1 stabilization, promotes hyperactivated RHO and MAPK signaling and B-cell oncogenicity in vitro and in vivo. Notably, this phenotype is reverted by co-silencing of GEF-H1. Inducible ectopic expression of FBXO45 triggers accelerated turnover of GEF H1 and decreased RHOA signaling. Genomic analyses revealed recurrent loss targeting FBXO45 in transformed DLBCL (25%), de novo DLBCL (6.6%) and FL (2.3%). In keeping with our observation of prolonged hyperactivation of pERK1/2 consequent to FBXO45 ablation, in vitro and in vivo studies using B-cell lymphoma cell lines and xenografts demonstrated increased sensitivity to pharmacologic blockade with the MAP2K1/2 (ERK1/2) inhibitor Trametinib. Conclusions: Our findings define a novel FBXO45-GEF-H1-MAPK signalling axis, which plays an important role in DLBCL pathogenesis. Our studies carry implications for potential exploitation of this pathway for targeted therapies. Disclosures Siebert: AstraZeneca: Speakers Bureau. Lim: EUSA Pharma: Honoraria.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Alexandra C Finney ◽  
Jonette M Green ◽  
Mohammad A Rana ◽  
Steven D Funk ◽  
James G Traylor ◽  
...  

Eph receptors, the largest mammalian subfamily of receptor tyrosine kinases, regulate inflammation and tissue remodeling. The EphA2 receptor shows enhanced expression in atherosclerosis, and deletion of EphA2 in atherosclerosis-prone ApoE knockout mice attenuates lesion formation. We now show that EphA2 knockout mice exhibit reduced late stage plaque progression associated with diminished smooth muscle content. While EphA2 is absent in quiescent vascular smooth muscle cells in vitro and in vivo , dedifferentiation to a synthetic phenotype significantly upregulates EphA2 expression. Deletion of EphA2, a known oncogene, reduces markers of proliferation in atherosclerotic plaques, and EphA2 knockdown similarly reduces vascular smooth muscle proliferation in culture with associated reductions in serum-induced ERK and Akt signaling. In addition to proliferation, EphA2 knockout mice show significantly reduced collagen content in their atherosclerotic plaques, and EphA2 knockdown reduces smooth muscle matrix deposition in vitro . Together these data suggest a potential role for EphA2 in smooth-muscle driven vascular fibroproliferative remodeling, representing the first link between EphA2 signaling and smooth muscle function.


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