Overexpression Of Intercellular Adhesion Molecule-1 Research Articles

STAT3 in acute myeloid leukemia facilitates natural killer cell-mediated surveillance.

Acute myeloid leukemia (AML) is a heterogenous disease characterized by the clonal expansion of myeloid progenitor cells. Despite recent advancements in the treatment of AML, relapse still remains a significant challenge, necessitating the development of innovative therapies to eliminate minimal residual disease. One promising approach to address these unmet clinical needs is natural killer (NK) cell immunotherapy. To implement such treatments effectively, it is vital to comprehend how AML cells escape the NK-cell surveillance. Signal transducer and activator of transcription 3 (STAT3), a component of the Janus kinase (JAK)-STAT signaling pathway, is well-known for its role in driving immune evasion in various cancer types. Nevertheless, the specific function of STAT3 in AML cell escape from NK cells has not been deeply investigated. In this study, we unravel a novel role of STAT3 in sensitizing AML cells to NK-cell surveillance. We demonstrate that STAT3-deficient AML cell lines are inefficiently eliminated by NK cells. Mechanistically, AML cells lacking STAT3 fail to form an immune synapse as efficiently as their wild-type counterparts due to significantly reduced surface expression of intercellular adhesion molecule 1 (ICAM-1). The impaired killing of STAT3-deficient cells can be rescued by ICAM-1 overexpression proving its central role in the observed phenotype. Importantly, analysis of our AML patient cohort revealed a positive correlation between ICAM1 and STAT3 expression suggesting a predominant role of STAT3 in ICAM-1 regulation in this disease. In line, high ICAM1 expression correlates with better survival of AML patients underscoring the translational relevance of our findings. Taken together, our data unveil a novel role of STAT3 in preventing AML cells from escaping NK-cell surveillance and highlight the STAT3/ICAM-1 axis as a potential biomarker for NK-cell therapies in AML.

Fibrinogen promotes gallbladder cancer cell metastasis and extravasation by inducing ICAM1 expression.

Fibrinogen plays an important role in tumor progression. Here, we explored the role of fibrinogen in gallbladder cancer (GBC) metastasis. The plasma fibrinogen level in M1 GBC patients was higher than in M0 GBC patients, indicating that fibrinogen may participate in GBC metastasis. Treatment of GBC cell lines with fibrinogen promoted metastasis and induced the expression of intercellular adhesion molecule 1 (ICAM1). ICAM1 overexpression promoted metastasis and knockdown inhibited it. The cell adhesion and transendothelial migration of GBC cells were enhanced by fibrinogen treatment and ICAM1 overexpression. In addition, the medium of fibrinogen-treated and overexpression-ICAM1 NOZ cells exhibited enhanced macrophages recruitment. This may work in concert to promote angiogenesis. Immunohistochemistry results on clinical specimens showed that higher fibrinogen levels, higher ICAM1 expression, higher blood vessel density, and higher macrophage levels were present simultaneously. Collectively, this study indicates fibrinogen promotes metastasis and extravasation by inducing ICAM1 expression to enhance tumor cell migration, cell adhesion, transendothelial migration and promote angiogenesis and increase vascular endothelial permeability.

Abstract 5072: A novel antibody drug conjugateengineered for chromosome instable gastric cancer

Abstract Gastric cancer (GC) ranks the fifth common cancer worldwide. Patients with GC suffer from a low 5-y survival rate due to the lack of effective treatments. Based on the genomic and molecular characteristics of GC, the Cancer Genome Atlas (TCGA) classified GC into four molecular subtypes: microsatellite-instable (MSI), Epstein-Barr virus-positive (EBV), chromosomal-instable (CIN), and genomically stable (GS). CIN tumors usually occur at gastroesophageal junction and normally belong to intestinal type of Lauren classification, which are characterized by DNA anueploidy, abnormal chromosomal copy numbers, and the frequent mutation of gene TP53, leading to chromosomal instability. CIN represents the most prevalent GC subtype (>50%) with a poor prognosis, highlighting a significant and unmet medical need for developing effective CIN-targeted therapeutics. Antibody drug conjugates (ADCs) are a new class of targeted therapeutics, composed of a humanized monoclonal antibody and small molecular cytotoxic drugs via chemical linkers. In this study, we designed and engineered a novel ADC targeting chromosome instable gastric cancer (CINGC). We first explored intercellular adhesion molecule-1 (ICAM1) as a novel molecular target for CINGC by characterizing its overexpression levels in a panel of human GINGC cell lines. ICAM1 is a cell surface transmembrane glycoprotein with functions of regulating cell-cell adhesion, signaling, and transendothelial migration of leukocytes to sites of inflammation. Many malignant tumors including GC were found to aberrantly overexpress ICAM1 on the surfaces of tumor cells. The high overexpression of ICAM1 on CINGC cells was validated by using flow cytometry (FCM) quantitatively and immunofluorescence (IF) staining qualitatively. To correlate it with clinically relevant GC tumor tissues, immunohistochemical (IHC) staining of ICAM1 was then conducted to determine the high expression of tumor tissue compared with para cancer tissue. The antigen-mediated endocytosis of ICAM1 monoclonal antibody was further detected by FCM quantitatively and IF visually. All the results showed that ICAM1 was an promising molecular target for CINGC, therefore, it was selected to engineer CINGC-targeted ADCs. We engineered a panel of ADC formulations with different linkers and cytotoxic payloads. We identified an optimal ADC formulation for CINGC by screening their cytotoxicity against CINGC cells in vitro in comparison with first line chemodrugs including 5-FU and oxaliplatin, which efficacy was validated by measuring its inhibitory activity on tumor growth, progression and metastasis via CINGC xenograft models. In conclusion, a novel ICAM1 ADC was designed and engineered to selectively recognize and ablate CINGC cells in vitro and in vivo. Our engineered new ADC offers the possibility of improving the clinical outcome and life quality of CINGC patients and expanding the scope of clinical use of drugs. Citation Format: Xinyan Wang, Li Yuan, Xiaoqing Guan, Shili Yao, Bing Zhu, Chun Liu, Tong Yang, Peng Guo, Jiangjiang Qin, Xiangdong Cheng. A novel antibody drug conjugateengineered for chromosome instable gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5072.

Therapeutic role of eicosapentaenoic and arachidonic acid in benzo(a) pyrene-induced toxicity in HUVEC endothelial cells

Endothelial cells are characterized by intense metabolic activity and control of homeostasis. Exposure to benzo(a)pyrene (BaP) plays an important role in the etiology of atherosclerosis. The study aimed to determine the effect of arachidonic (ARA), and eicosapentaenoic acid (EPA) on pro-inflammatory gene and protein levels in human umbilical vein endothelial cells (HUVEC) exposed to BaP. Cyclooxygenase-2 (COX-2), aryl hydrocarbon receptor (AHR), and glutathione S transferase Mu1 (GSTM1) proteins expression were analyzed by Western blot. Prostaglandin synthase 2 (PTGS2), AHR, GSTM1, phospholipase A2 (PLA2G4A), cytochrome P450 CYP1A1, intercellular adhesion molecule-1 (ICAM-1), endothelial nitric-oxide synthase (NOS3), and vascular adhesion molecule-1 gene expression (VCAM-1) was analyzed in Real time-qPCR. Phospholipase A2 activity was measured using the ELISA technique, and CYP1A1 activity was analyzed in luminescence assay.The highest amount of COX-2, the most increased activity of CYP1A1 and cPLA2, and overexpression of GSTM1, CYP1A1, ICAM-1, and VCAM-1 gene was observed in HUVEC cells treated with BaP. After co-treatment with BaP and ARA or EPA, an increase of GSTM1 level was observed. Incubation of endothelial cells with ARA or EPA and BaP resulted in lower CYP1A1 and cPLA2 activities and lower expression of VCAM-1 and ICAM-1 genes. Significant overexpression of AHR, GSTM1, CYP1A1, PTGS2, PLA2G4A, and NOS3 genes was noted in cells treated with EPA and BaP.Our data suggest a beneficial effect of EPA and ARA on endothelial function. Thus, it justifies further research on the participation of fatty acids in the regulation of physiological and pathological processes in endothelial cells.

RelB promotes the migration and invasion of prostate cancer DU145 cells via exosomal ICAM1 in vitro

RelB confers the aggressiveness to prostate cancer (PC) cells. Exosomes modulate the oncogenesis and progression of PC. We aimed to identify the downstream molecule in the exosomes, by which RelB increases the aggressiveness of DU145. Totally, 137 upregulated and 55 downregulated exosomal proteins were identified from RelB-knockdown DU145 cells by Liquid Chromatography-Mass Spectrometry. UALCAN, GeneMANIA and tissue microarray analysis revealed that intercellular adhesion molecule-1 (ICAM1) was positively related to and co-expressed with RelB in PC. Luciferase reporter assay revealed that RelB bound directly to the promoter of ICAM1. ICAM1 overexpression enhanced the migration and invasion abilities of DU145 cells. Exposure to exosomes derived from ICAM1 overexpressing cells (hICAM1-exo) strengthened the aggressiveness of RelB-knockdown cells, especially the migration and invasion capabilities. Mechanistically, the expression of ICAM1, Integrin β1, MMP9 and uPA were upregulated in RelB-knockdown cells upon hICAM1-exo treatment. Exosomal ICAM1 is the key molecule regulated by RelB, which increased the aggressiveness of DU145. The study suggests that cell-cell communication via exosomal ICAM1 is a novel mechanism by which RelB promotes PC progression.

Dauricine Attenuates Vascular Endothelial Inflammation Through Inhibiting NF-κB Pathway.

Endothelial cells are the fundamental components of blood vessels that regulate several physiological processes including immune responses, angiogenesis, and vascular tone. Endothelial dysfunction contributes to the development of various diseases such as acute lung injury, and endothelial inflammation is a vital part of endothelial dysfunction. Dauricine is an extract isolated from Menispermum dauricum DC, a traditional Chinese medical plant that can be used for pharyngitis. In this work, we found that IL-1β-induced overexpression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin was inhibited by dauricine in primary human umbilical vein endothelial cells (HUVECs). Correspondingly, adhesion of human acute monocytic leukemia cell line (THP-1) to HUVECs was decreased by dauricine. Further studies showed that dauricine inhibited the activation of nuclear factor-κB (NF-κB) pathway in HUVECs stimulated with IL-1β. In vivo, dauricine protected mice from lipopolysaccharide (LPS)-induced acute lung injury. In lung tissues, the activation of NF-κB pathway and the expression of its downstream genes (ICAM-1, VCAM-1, and E-selectin) were decreased by dauricine, consistent with what was found in vitro. In summary, we concluded that dauricine could alleviate endothelial inflammation by suppressing NF-κB pathway, which might serve as an effective candidate for diseases related with endothelial inflammation.

Circ_0003204 knockdown protects endothelial cells against oxidized low-density lipoprotein-induced injuries by targeting the miR-491-5p-ICAM1 pathway.

Emerging evidence indicates that circular RNA (circRNA) is implicated in the development of atherosclerosis (AS). This study investigated the effect of circ_0003204 on endothelial cell function and explored the functional mechanism of circ_0003204 in AS progression. AS cell models were constructed by treating human umbilical vein endothelial cells (HUVEC) with oxidized low-density lipoprotein (ox-LDL). The expression of circ_0003204 was detected by quantitative real-time PCR (qPCR). The releases of pro-inflammatory factors were determined by ELISA. Cell viability was checked by CCK-8 assay. Cell apoptosis was monitored by flow cytometry assay. The ability of angiogenesis was assessed by tube formation assay. The protein levels of cell development- and apoptosis-related markers were measured by western blot. The binding relationship between miR-491-5p and circ_0003204 or intercellular adhesion molecule 1 (ICAM1) was verified by dual-luciferase reporter assay or RIP assay. The expression of circ_0003204 was strengthened in ox-LDL-treated HUVECs. Circ_0003204 knockdown inhibited ox-LDL-induced inflammation and cell apoptosis, and promoted ox-LDL-depleted cell viability and tube formation ability in HUVECs. MiR-491-5p was a target of circ_0003204, and miR-491-5p directly bound to ICAM1 3'UTR. Accordingly, circ_0003204 positively regulated ICAM1 expression by targeting miR-491-5p. Rescue experiments presented that miR-491-5p inhibition reversed the effects of circ_0003204 knockdown, and ICAM1 overexpression abolished the effects of miR-491-5p restoration. Circ_0003204 knockdown protects HUVECs against ox-LDL-induced injuries by targeting the miR-491-5p-ICAM1 pathway, hinting that circ_0003204 inhibition might prevent AS development.

The adhesion molecule ICAM-1 in diffuse large B-cell lymphoma post-rituximab era: relationship with prognostic importance and rituximab resistance.

Intercellular adhesion molecule-1 (ICAM-1) is a cell-surface receptor contributing to lymphocyte homing, adhesion and activation. The prognostic significance of the protein is unknown in diffuse large B-cell lymphoma (DLBCL) in post-rituximab era. We detected expression of ICAM-1 immunohistochemically in 102 DLBCL tissue samples. Overexpression of ICAM-1 was found in 28 (27.5%) cases. In patients with low ICAM-1 expression levels, the addition of rituximab to CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy resulted in an improved overall response rate, progression-free survival (PFS) and overall survival (OS) (P=0.019, 0.01, 0.02). In pre-clinical models, we found that chronic exposure of cell lines to rituximab led to downregulation of ICAM-1 and acquirement of a rituximab resistant phenotype. In vitro exposure of rituximab resulted in rapid aggregation of B-cells regardless of the ICAM-1 expression levels. MTT assay showed knockdown of ICAM-1 could cause rituximab resistance. Neutralization of ICAM-1 did not affect rituximab activity in vitro and in vivo. Our data illustrated that in post-rituximab era, R-CHOP significantly improved the ORR, PFS and OS in ICAM-1 negative subset patients. Downregulation of ICAM-1 may contribute to rituximab resistance, and that rituximab, by promoting cell-cell aggregation, may sensitize cells to the cytotoxic effects of chemotherapy agents.

Desert Hedgehog-Driven Endothelium Integrity Is Enhanced by Gas1 (Growth Arrest-Specific 1) but Negatively Regulated by Cdon (Cell Adhesion Molecule-Related/Downregulated by Oncogenes).

Evidences accumulated within the past decades identified hedgehog signaling as a new regulator of endothelium integrity. More specifically, we recently identified Dhh (desert hedgehog) as a downstream effector of Klf2 (Kruppel-like factor 2) in endothelial cells (ECs). The purpose of this study is to investigate whether hedgehog coreceptors Gas1 (growth arrest-specific 1) and Cdon (cell adhesion molecule-related/downregulated by oncogenes) may be used as therapeutic targets to modulate Dhh signaling in ECs. Approach and Results: We demonstrated that both Gas1 and Cdon are expressed in adult ECs and relied on either siRNAs- or EC-specific conditional knockout mice to investigate their role. We found that Gas1 deficiency mainly phenocopies Dhh deficiency especially by inducing VCAM-1 (vascular cell adhesion molecule 1) and ICAM-1 (intercellular adhesion molecule 1) overexpression while Cdon deficiency has opposite effects by promoting endothelial junction integrity. At a molecular level, Cdon prevents Dhh binding to Ptch1 (patched-1) and thus acts as a decoy receptor for Dhh, while Gas1 promotes Dhh binding to Smo (smoothened) and as a result potentiates Dhh effects. Since Cdon is upregulated in ECs treated by inflammatory cytokines, including TNF (tumor necrosis factor)-α and Il (interleukin)-1β, we then tested whether Cdon inhibition would promote endothelium integrity in acute inflammatory conditions and found that both fibrinogen and IgG extravasation were decreased in association with an increased Cdh5 (cadherin-5) expression in the brain cortex of EC-specific Cdon knockout mice administered locally with Il-1β. Altogether, these results demonstrate that Gas1 is a positive regulator of Dhh in ECs while Cdon is a negative regulator. Interestingly, Cdon blocking molecules may then be used to promote endothelium integrity, at least in inflammatory conditions.

Myocardial Infarction-associated Transcript Knockdown Inhibits Cell Proliferation, Migration, and Invasion Through miR-490-3p/Intercellular Adhesion Molecule 1 Axis in Oxidized Low-density Lipoprotein-induced Vascular Smooth Muscle Cells.

Emerging evidence has demonstrated that long noncoding RNAs are related to the pathogenesis of atherosclerosis. We aimed to investigate the roles and molecular mechanisms of myocardial infarction-associated transcript (MIAT) in the proliferation, migration, and invasion of oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs). Quantitative real-time polymerase chain reaction was conducted to determine the levels of MIAT, microRNA490-3p (miR-490-3p), and intercellular adhesion molecule 1 (ICAM1). Cell Counting Kit-8 assay was performed to assess cell proliferation. Transwell assay was used to evaluate cell migration and invasion. Western blot assay was performed to measure the protein levels of proliferating cell nuclear antigen, N-cadherin, matrix metalloprotein-9, and ICAM1. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to verify the relationship between miR-490-3p and MIAT or ICAM1. MIAT was elevated in atherosclerosis patients' serum and ox-LDL-induced VSMCs. MIAT knockdown suppressed cell proliferation, migration, and invasion in ox-LDL-stimulated VSMCs. MIAT acted as a sponge of miR-490-3p, and miR-490-3p deficiency overturned the inhibition of MIAT knockdown on VSMC proliferation, migration, and invasion. ICAM1 was a direct target of miR-490-3p, and ICAM1 silencing repressed the proliferation, migration, and invasion of ox-LDL-stimulated VSMCs. Moreover, ICAM1 overexpression reversed the impacts of MIAT knockdown on ox-LDL-induced VSMC proliferation, migration, and invasion. MIAT knockdown could depress cell proliferation, migration, and invasion through miR-490-3p/ICAM1 axis in ox-LDL-induced VSMCs.

Shiga Toxin Selectively Upregulates Expression of Syndecan-4 and Adhesion Molecule ICAM-1 in Human Glomerular Microvascular Endothelium.

Hemolytic uremic syndrome (HUS) is a severe renal disease that is often preceded by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC). The exact mechanism of Stx-mediated inflammation on human glomerular microvascular endothelial cells (HGMVECs) during HUS is still not well understood. In this study, we investigated the effect of Stx1 on the gene expression of proteins involved in leucocyte-mediated and complement-mediated inflammation. Our results showed that Stx1 enhances the mRNA and protein expression of heparan sulfate proteoglycan (HSPG) syndecan-4 in HGMVECs pre-stimulated with tumor necrosis factor α (TNFα). CD44 was upregulated on mRNA but not on protein level; no effect on the mRNA expression of other tested HSPGs glypican-1 and betaglycan was observed. Furthermore, Stx1 upregulated the mRNA, cell surface expression, and supernatant levels of the intercellular adhesion molecule-1 (ICAM-1) in HGMVECs. Interestingly, no effect on the protein levels of alternative pathway (AP) components was observed, although C3 mRNA was upregulated. All observed effects were much stronger in HGMVECs than in human umbilical endothelial cells (HUVECs), a common model cell type used in endothelial studies. Our results provide new insights into the role of Stx1 in the pathogenesis of HUS. Possibilities to target the overexpression of syndecan-4 and ICAM-1 for STEC-HUS therapy should be investigated in future studies.

ICAM-1 promotes the abnormal endothelial cell phenotype in chronic thromboembolic pulmonary hypertension.

Pulmonary endothelial cells play a key role in the pathogenesis of Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Increased synthesis and/or the release of intercellular adhesion molecule-1 (ICAM-1) by pulmonary endothelial cells of patients with CTEPH has been recently reported, suggesting a potential role for ICAM-1 in CTEPH. We studied pulmonary endarterectomy specimens from 172 patients with CTEPH and pulmonary artery specimens from 97 controls undergoing lobectomy for low-stage cancer without metastasis. ICAM-1 was overexpressed in vitro in isolated and cultured endothelial cells from endarterectomy specimens. Endothelial cell growth and apoptosis resistance were significantly higher in CTEPH specimens than in the controls (p < 0.001). Both abnormalities were abolished by pharmacological inhibition of ICAM-1 synthesis or activity. The overexpression of ICAM-1 contributed to the acquisition and maintenance of abnormal EC growth and apoptosis resistance via the phosphorylation of SRC, p38 and ERK1/2 and the overproduction of survivin. Regarding the ICAM-1 E469K polymorphism, the KE heterozygote genotype was significantly more frequent in CTEPH than in the controls, but it was not associated with disease severity among patients with CTEPH. ICAM-1 contributes to maintaining the abnormal endothelial cell phenotype in CTEPH.

Combining vascular targeting and the local first pass provides 100-fold higher uptake of ICAM-1-targeted vs untargeted nanocarriers in the inflamed brain

New advances in intra-arterial (IA) catheters offer clinically proven local interventions in the brain. Here we tested the effect of combining local IA delivery and vascular immunotargeting. Microinjection of tumor necrosis factor alpha (TNFα) in the brain parenchyma causes cerebral overexpression of Inter-Cellular Adhesion Molecule-1 (ICAM-1) in mice. Systemic intravenous injection of ICAM-1 antibody (anti-ICAM-1) and anti-ICAM-1/liposomes provided nearly an order of magnitude higher uptake in the inflamed vs normal brain (from ~0.1 to 0.8%ID/g for liposomes). Local injection of anti-ICAM-1 and anti-ICAM-1/liposomes via carotid artery catheter provided an additional respective 2-fold and 5-fold elevation of uptake in the inflamed brain vs levels attained by IV injection. The uptake in the inflamed brain of respective untargeted IgG counterparts was markedly lower (e.g., uptake of anti-ICAM-1/liposomes was 100-fold higher vs IgG/liposomes). These data affirm the specificity of the combined effect of the first pass and immunotargeting. Intravital real-time microscopy via cranial window revealed that anti-ICAM-1/liposomes, but not IgG/liposomes bind to the lumen of blood vessels in the inflamed brain within minutes after injection. This straightforward framework provides the basis for translational efforts towards local vascular drug targeting to the brain.

Hyperfibrinogenemia-mediated astrocyte activation

Fibrinogen (Fg)-containing plaques are associated with memory loss during various inflammatory neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, stroke, and traumatic brain injury. However, mechanisms of its action in neurovascular unit are not clear. As Fg is a high molecular weight blood protein and cannot translocate far from the vessel after extravasation, we hypothesized that it may interact with astrocytes first causing their activation. Cultured mouse cortical astrocytes were treated with Fg in the presence or absence of function-blocking anti-mouse intercellular adhesion molecule 1 (ICAM-1) antibody, or with medium alone (control). Expressions of ICAM-1 and tyrosine receptor kinase B (TrkB) as markers of astrocyte activation, and phosphorylation of TrkB (pTrkB) were assessed. Fg dose-dependently increased activation of astrocytes defined by their shape change, retraction of processes, and enhanced expressions of ICAM-1 and TrkB, and increased pTrkB. Blocking of ICAM-1 function ameliorated these Fg effects. Data suggest that Fg interacts with astrocytes causing overexpression of ICAM-1 and TrkB, and TrkB phosphorylation, and thus, astrocyte activation. Since TrkB is known to be involved in neurodegeneration, interaction of Fg with astrocytes and the resultant activation of TrkB can be a possible mechanism involved in memory reduction, which were observed in previous studies and were associated with formation of complexes of Fg deposited in extravascular space with proteins such as Amyloid beta or prion, the proteins involved in development of dementia.

Therapeutic Effects of a Novel Phenylphthalimide Analog for Corneal Neovascularization and Retinal Vascular Leakage.

PurposeNeovascularization (NV) and retinal vascular leakage are major causes of impaired vision in ocular diseases. The purpose of this study was to identify novel phenylphthalimide analogs with therapeutic effects on NV and vascular leakage and to explore the mechanism of action.MethodsAntiangiogenic activities of novel phenylphthalimide analogs were assessed in vitro by using VEGF ELISA and endothelial cell proliferation assay. Their efficacies on retinal vascular leakage were evaluated using rat models of oxygen-induced retinopathy (OIR) and streptozotocin (STZ)-induced diabetes. The in vivo antiangiogenic activity was evaluated using topical administration in the alkali burn-induced corneal NV model. The expression of VEGF and intercellular adhesion molecule-1 (ICAM-1) were measured using ELISA.ResultsThalidomide and three novel analogs all showed inhibitory effects on endothelial cell proliferation and VEGF expression in vitro. Through intravitreal injection, all of the compounds reduced retinal vascular leakage in the OIR and STZ-induced diabetic models. Among these compounds, (2,6-diisopropylphenyl)-5-amino-1H-isoindole-1,3-dione (DAID) displayed the most potent efficacy and reduced retinal vascular leakage in a dose-dependent manner in both the OIR and STZ-diabetes models. Topical administration of DAID also inhibited alkali burn-induced corneal NV. Furthermore, DAID attenuated the overexpression of VEGF and ICAM-1 in the retina of the OIR model. Intravitreal injection of DAID did not result in any detectable side effects, as shown by electroretinogram and retinal histological analysis.ConclusionsDAID is a novel phenylphthalimide analog with potent effects on NV and retinal vascular leakage through downregulation of VEGF and inflammatory factors and has therapeutic potential.

Salt Intake and Immunity.

Increased salt intake has been associated with cardiovascular disease,1 and it has been suggested that reductions in dietary salt could substantially reduce cardiovascular events and medical costs and, therefore, should be a public health target.2 The relationship between salt intake and cardiovascular diseases involves the complex interplay of several factors that include age, sex, the renin–angiotensin–aldosterone and kallikrein–kinin systems, sympathetic nervous system activity, endothelial function, and redox balance.3 In addition, it is now recognized that the immune system plays an active role in the development and progression of hypertension, and salt intake not only drives hemodynamic changes but is also associated with changes in the immune responses. Here we review the evidence that indicates that salt intake modulates immune function and salt-driven proinflammatory reactivity induces vascular endothelial dysfunction, immune cell activation, and cytokine secretion, all of which are central characteristics of hypertensive cardiovascular disease. Endothelial dysfunction is one of the central characteristics of hypertension and is associated with overexpression of leukocyte adhesion molecules and local inflammation. In spontaneously hypertensive rats, overexpression of ICAM-1 (intercellular adhesion molecule-1), MCP-1 (monocyte chemotactic protein-1), and macrophage adhesion ligand-1 (a cell-surface protein expressed in most leukocytes) has been demonstrated in association with increased monocyte endothelial adhesiveness. These findings play a role in end-organ damage.4–7 Takahashi et al4 studied changes in leukocyte adhesiveness induced by sodium intake in Dahl salt–sensitive rats. They examined adhesion of leukocytes to retinal vessels using acridine orange fluoroscopy and scanning laser ophthalmoscope and followed the expression of adhesion molecules in the kidney. After only 3 days of a diet with 8% NaCl, before hypertension developed, leukocyte adhesion was increased in association with increments in mRNA synthesis of MCP-1 and ICAM-1 in the kidney. Anti-CD18 antibodies inhibited these early effects of high salt intake and …

Danshenol A inhibits TNF-\u03b1-induced expression of intercellular adhesion molecule-1 (ICAM-1) mediated by NOX4 in endothelial cells

ICAM-1 overexpression and subsequent adhesion of leukocytes to endothelial cells play critical roles in the early stage of atherosclerosis. Danshenol A (DA) is an abietane-type diterpenoid isolated from traditional Chinese herb Salvia miltiorrhiza Bunge. The mechanisms under its regulation of adhesion of molecular expression are explored. Here, the effect of DA on TNF-α-induced ICAM-1 expression was investigated in endothelial cells. TNF-α-induced ICAM-1 expression and subsequent adhesion of monocytes, as well as elevated reactive oxygen species (ROS) generation and NOX4 expression were all significantly reversed by DA, siNOX4 and NOX4 inhibitor GKT137831. Furthermore, TNF-α-induced ICAM-1 expression, which was increased via IKKβ/IκBα-mediated activation of NF-κB p65, was also inhibited by DA. Interestingly, NOX4 overexpression suppressed the ICAM-1 expression, and this finding may be ascribed to the activation of Nrf-2. Additionally, NF-κB inhibitor PDTC, siNOX4, or DA can decrease the TNF-α-induced ICAM-1 expression and suppress the adhesion of monocytes. In all, DA inhibited TNF-α-induced ICAM-1 expression and subsequent monocyte adhesion to endothelial cells through the NOX4-dependent IKKβ/NF-κB pathway. Besides, NOX4 played dual role in regulating ICAM-1 expression via diverse signal pathway. This novel bioactivity will make DA a good candidate to be further explored for therapeutic or preventive application for atherosclerosis.

Human Airway Epithelial Cells Direct Significant Rhinovirus Replication in Monocytic Cells by Enhancing ICAM1 Expression.

Human rhinovirus (RV) is the major cause of common cold, and it also plays a significant role in asthma and asthma exacerbation. The airway epithelium is the primary site of RV infection and production. In contrast, monocytic cells (e.g., monocytes and macrophages) are believed to be nonpermissive for RV replication. Instead, RV has been shown to modulate inflammatory gene expressions in these cells via a replication-independent mechanism. In the study presented here, replication of RV16 (a major-group RV) was found to be significantly enhanced in monocytes when it was cocultivated with airway epithelial cells. This effect appeared to be mediated by secretory components from epithelial cells, which stimulated RV16 replication and significantly elevated the expression of a number of proinflammatory cytokines. The lack of such an effect on RV1A, a minor-group RV that enters the cell by a different receptor, suggests that intercellular adhesion molecule 1 (ICAM1), the receptor for major-group RVs, may be involved. Indeed, conditioned media from epithelial cells significantly increased ICAM1 expression in monocytes. Consistently, ICAM1 overexpression and ICAM1 knockdown enhanced and blocked RV production, respectively, confirming the role of ICAM1 in this process. Thus, this is the first report demonstrating that airway epithelial cells direct significant RV16 replication in monocytic cells via an ICAM1-dependent mechanism. This finding will open a new avenue for the study of RV infection in airway disease and its exacerbation.

A high-salt diet enhances leukocyte adhesion in association with kidney injury in young dahl salt-sensitive rats

Salt-sensitive hypertension is associated with severe organ damage. Generating oxygen radicals is an integral component of salt-induced kidney damage, and activated leukocytes are important in oxygen radical biosynthesis. We hypothesized that a high-salt diet causes the upregulation of immune-related mechanisms, thereby contributing to the susceptibility of Dahl salt-sensitive rats to hypertensive kidney damage. For verifying the hypothesis, we investigated leukocytes adhering to retinal vessels when Dahl salt-sensitive rats were challenged with a high-salt (8% NaCl) diet using acridine orange fluoroscopy and a scanning laser ophthalmoscope. The high-salt diet increased leukocyte adhesion after 3 days and was associated with a significant increase in mRNA biosynthesis of monocyte chemotactic protein-1 and intercellular adhesion molecule-1 (ICAM-1) -related molecules in the kidney. Losartan treatment did not affect increased leukocyte adhesion during the early, pre-hypertensive phase of high salt loading; however, losartan attenuated the adhesion of leukocytes during the hypertensive stage. Moreover, the inhibition of leukocyte adhesion in the pre-hypertensive stage by anti-CD18 antibodies decreased tethering of leukocytes and was associated with the attenuation of functional and morphological kidney damage without affecting blood pressure elevation. In conclusion, a high-salt challenge rapidly increased leukocyte adhesion through the over-expression of ICAM-1. Increased leukocyte adhesion in the pre-hypertensive stage is responsible for subsequent kidney damage in Dahl salt-sensitive rats. Immune system involvement may be a key component that initiates kidney damage in a genetic model of salt-induced hypertension.

Downregulation of microRNA-155 ameliorates high glucose-induced endothelial injury by inhibiting NF-κB activation and promoting HO-1 and NO production

Abstract Background High glucose-associated endothelial cell injury plays an important role in the pathogenesis of diabetic vascular complications. This study was undertaken to explore the role of miR-155 in high glucose-induced endothelial dysfunction and the underlying molecular mechanisms. Methods Human umbilical vein endothelial cells (HUVECs) were divided into four groups: control group (5.5 mmol/L glucose), HG group (33.3 mmol/L glucose), HG + miR-155 inhibitor and HG + inhibitor-control group. Gene and protein expression levels were determined by Real-time PCR and Western blot, respectively. Cell viability was measured by MTT assay. Cell apoptosis and production of ROS were determined by flow cytometric analyses. The target relationship of miR-155 and gene mRNA were assessed by Dual-Luciferase reporter assay. Results High glucose treatment upregulated the expression of miR-155 significantly. MiR-155 inhibition promoted cell viability and reduced apoptosis, prevented the overexpression of cleaved-Caspase-3, cleaved-Caspase-9 and Bax, promoted the expression of Bcl-2, downregulated the overexpression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), suppressed reactive oxygen species (ROS) production, inhibited the NF-κB signaling, activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling, promoted the endothelial NOS (eNOS)/NO expression in the high glucose-treated HUVECs. We subsequently demonstrated that miR-155 targeted the 3′-untranslated region (UTR) of eNOS, but neither Nrf2 nor HO-1. Conclusions Taken together, the data suggest that downregulation of miR-155 ameliorates high glucose-associated injury in HUVECs, and it may related with the inhibition of ROS/NF-κB signaling and the upregulation of HO-1 and NO.