Induction Of Intercellular Adhesion Molecule-1 Research Articles

Brief research report: ETS-1 blockade increases ICAM-1 expression in activated human retinal endothelial cells

Intercellular adhesion molecule 1 (ICAM-1) is a central cell adhesion molecule for retinal transendothelial migration of the leukocytes in non-infectious posterior uveitis. Inhibiting ICAM1 gene transcription reduces induction of ICAM-1 in inflamed retinal endothelium. Based on published literature implicating transcription factor ETS-1 as an activator of ICAM1 gene transcription, we investigated the effect of ETS-1 blockade on ICAM-1 levels in cytokine-stimulated human retinal endothelial cells. We first examined ICAM1 and ETS1 transcript expression in human retinal endothelial cells exposed to tumor necrosis factor-alpha (TNF-α) or interleukin-1beta (IL-1β). ICAM1 and ETS1 transcripts were increased in parallel in primary human retinal endothelial cell isolates (n = 5) after a 4-hour stimulation with TNF-α or IL-1β (p ≤ 0.012 and ≤ 0.032, respectively). We then assessed the effect of ETS-1 blockade by small interfering (si)RNA on cellular ICAM1 transcript and membrane-bound ICAM-1 protein. ETS1 transcript was reduced by greater than 90% in cytokine-stimulated and non-stimulated human retinal endothelial cell monolayers following a 48-hour treatment with two ETS-1-targeted siRNA, in comparison to negative control non-targeted siRNA (p ≤ 0.0002). The ETS-1 blockade did not reduce ICAM1 transcript expression nor levels of membrane-bound ICAM-1 protein, rather it increased both for a majority of siRNA-treatment and cytokine-stimulation conditions (p ≤ 0.018 and ≤ 0.004, respectively). These unexpected findings indicate that ETS-1 blockade increases ICAM-1 transcript and protein levels in human retinal endothelial cells. Thus ETS-1-targeting would be expected to promote rather than inhibit retinal transendothelial migration of leukocytes in non-infectious posterior uveitis.

Induction of ICAM1 in Brain Vessels is Implicated in an Early AD Pathogenesis by Modulating Neprilysin.

Intercellular adhesion molecule 1 (ICAM1) is a vessel adhesion protein induced during brain vascular inflammation, which could be closely linked with the development of Alzheimer's disease (AD). This study investigated the effect of ICAM1 on amyloid-degrading enzymes (ADEs) in endothelial cells and their potential involvement in inflammation and AD progression. TNF-α treatment increased ICAM1 in human brain microvascular endothelial cells (HBMVECs) but decreased the neprilysin (NEP) protein level. Knock-down of ICAM1 using siRNA enhanced NEP, which increased the degradation of amyloid-β. In the brains of 4-month-old AD transgenic mice (APPswe/PSEN1dE9), there were significantly higher levels of ICAM1 expression and amyloid deposits but lower levels of NEP and insulin-degrading enzymes (IDE), demonstrating an inverse correlation of ICAM1 with NEP and IDE expression. Further studies demonstrated significantly increased GFAP protein levels in the brain, specifically localized near blood vessels, of both TNF-α-injected and 4-month-old AD transgenic mice. Taken together, the induction of ICAM1 in endothelial cells suppresses NEP expression, accelerating the accumulation of amyloid-β in blood vessels. It also enhances leukocyte adhesion to blood vessels stimulating the migration of leukocytes into the brain, subsequently triggering brain inflammation.

ICAM-1 on the luminal surface of endothelial cells is induced to a greater extent in mouse retina than in other tissues in diabetes.

Induction of intercellular adhesion molecule-1 (ICAM-1) has been implicated in the development of macrovascular and microvascular diseases such as diabetic retinopathy. Lesions of diabetic retinopathy are unique to the retina but the reason for this is unclear, as all tissues are exposed to the same hyperglycaemic insult. We tested whether diabetes induces ICAM-1 on the luminal surface of endothelial cells to a greater extent in the retina than in other tissues and the role of vision itself in that induction. Experimental diabetes was induced in C57Bl/6J, P23H opsin mutant and Gnat1-/- × Gnat2-/- double knockout mice using streptozotocin. The relative abundance of ICAM-1 on the luminal surface of endothelial cells in retina and other tissues was determined by conjugating anti-ICAM-1 antibodies to fluorescent microspheres (2μm), injecting them intravenously and allowing them to circulate for 30min. After transcardial perfusion, quantification of microspheres adherent to the endothelium in tissues throughout the body was carried out by fluorescent microscopy or flow cytometry. Mice injected with lipopolysaccharide (LPS) were used as positive controls. The difference in leucostasis between retinal and non-retinal vasculature was evaluated. Diabetes significantly increased ICAM-1-mediated adherence of microspheres to retinal microvessels by almost threefold, independent of sex. In contrast, diabetes had a much smaller effect on endothelial ICAM-1 in other tissues, and more tissues showed a significant induction of endothelial ICAM-1 with LPS than with diabetes. The diabetes-induced increase in endothelial ICAM-1 in retinal vasculature was inhibited by blocking phototransduction in photoreceptor cells. Diabetes significantly increased leucostasis in the retina by threefold compared with a non-ocular tissue (cremaster). The diabetes-induced upregulation of ICAM-1 on the luminal surface of the vascular endothelium varies considerably among tissues and is highest in the retina. Induction of ICAM-1 on retinal vascular endothelial cells in diabetes is influenced by vision-related processes in photoreceptor cells. The unique presence of photoreceptors in the retina might contribute to the greater susceptibility of this tissue to vascular disease in diabetes.

Syntheses and structure-activity relationship study of santamarine, douglanine, dihydrosantamarine and four series of 1-/3-oxygenated eudesman-12,6α-olides

Herein, we report the syntheses and structure-activity relationships of Santamarine, Douglanine, dihydrosantamarine, 1-oxygenated and 3-oxygenated eudesman-12,6α-lactones. The anti-inflammatory and anti-cancer activities were measured by the inhibition on induction of intercellular adhesion molecule (ICAM-1), killing function of cytotoxic T lymphocytes (CTLs), and cytotoxic activities to cell lines (VA-13, HepG-2, and WI-38), respectively. α-Methylene-γ-lactones 13 with a 1-oxo-2-en moiety showed significant inhibition toward ICAM-1(IC50 12.8 μM), the killing function of CTLs (IC50 11.0 μM) and the VA-13 cell line (IC50 2.84 μM), 21 with α-bromo-ketone moiety showed significant inhibition to VA-13(IC50 1.85 μM). Both 13 ((cell viability)/(inhibitory activity of ICAM-1) = 6.0-fold, WI-38/VA-13 = 1.28-fold) and 21 (WI-38/VA-13 = 1.28-fold) were within safety satisfaction. To conclude, the α,β-unsaturated-ketone and α-bromo-ketone moieties were essential for α-methylene-eudesman-12,6α-olides' anti-inflammatory and anti-cancer activities.

CpG-ODN instillation boosts ICAM-1 expression in an orthotopic murine UCC model: immunohistochemical evaluation of the local response to immunostimulatory DNA

Immunostimulatory CpG oligodeoxynucleotides (CpG-ODN) have been verified as an effective antineoplastic agent for intravesical application in a murine orthotopic C57-BL6 /MB-49 urothelial cell carcinoma (UCC). To date, many details in the mode of action have remained unclear. Preceding studies pointed towards a Th1-weighted response. The aim of this work was to identify the local lymphocyte subsets in murine tumour-bearing bladders and to examine effects on the expression of Intercellular Adhesion Molecule 1 (ICAM-1) after treatment with CpG-ODN. Different instillation schedules were applied in an established orthotopic C57-BL6 /MB49 UCC model. After 13 days, fresh frozen sections of the harvested bladders were immunohistochemically examined for the infiltration density of lymphocytes expressing CD 3, CD4, CD8 and CD19. In a second series of the same animal model, healthy and tumour-bearing bladders were exposed to CpG-ODN or PBS and later stained for the expression of ICAM-1. CpG-ODN instillation led to augmented T-cell infiltration (represented by CD3). Further T-cell subdifferentiation between T-helper cells (CD4) and cytotoxic T cells (CD 8a) did not show a perceptible variety between groups. The B-cell population (CD19) was found to decrease over the course of treatment. In the second series, treatment provoked a strong expression of ICAM-1 by infiltrating leukocytes, endothelial cells and particularly by the cancer cells themselves. The previously observed augmented lymphocyte density was classified as T-cell infiltration. The decline of the B-cell concentration over the course of treatment suggests a Th2 suppression in favour of a Th-1 polarisation. These findings support the assumption that a cell-mediated immune response is the mode of action underlying the antineoplastic CpG-ODN capacities. The marked upregulation of ICAM-1 expression, especially on tumour cells, suggests a crucial role of this membrane protein for the initiation and maintenance of anticancer immune response. CpG-ODN might be a prospective alternative to established instillation therapies. With a view to the current BCG shortage and the well-known toxicities, an amplification of the topic therapy armamentarium could be achievable. The now described capability of ICAM-1 induction on carcinoma cells and, by association, the reversal of escape strategies to cancer immunity may also make the agent interesting as an adjuvant for modern checkpoint inhibition.

Synthesis of 6-epi-tuberiferin and the biological activities of tuberiferin, dehydrobrabrachylaenolide, 6-epi-tuberiferin, and their synthetic intermediates

Tuberiferin, 6-epi-tuberifelin, dehydrobrachylaenolide and two series of eudesmanolides, eudesmane-12,6 α-lactones and eudesmane-12,6β-lactones, were synthesized for the studies of the structure–activity relationships to explore novel anti-inflammatory, anti-cancer and crop disease prevention agents. The anti-inflammatory activities were tested by the inhibitory on the induction of inter-cellular adhesion molecule (ICAM-1), the permeation of leucocyte into inflammatory air pouch of murine, the killing function of cytotoxic T-lymphocytes (CTL), production of IL-1; The anti-cancer activities were established on the cytotoxic activities to six kinds of cell lines (P388, CCRF-CEM, VA-13, HepG2, QG-56, and WI-38). Results showed that Dehydrobrachylaenolide (an exo-endo cross conjugated dienone and α-methylene γ-lactone) was the most effective compound inhibiting ICAM-1 (IC50 3.0 μM) and the cell line VA-13 (IC50 0.45 μM); Compound 20 with an α-bromo-ketone moiety embraced the most potent inhibitory activity towards the permeation of leucocyte into inflammatory air pouches of murine in vivo (inhibitory ratio 54% at 10 mg); Compound 25 with an α-bromo-ketone and α-methylene trans-γ-lactone) showed the most significant inhibitory activity on the killing function of CTL (IC50 18 μM), as well as the cell lines of CCRF-CEM (IC50 1.1 μM) and P388 (IC50 1.21 μM) ; Tuberiferin (an α,β-unsaturated ketone and α- methylene γ-lactone) was on the top effective inhibitory on the production of IL-1; Compounds 19 with an α-bromo-ketone and α-methylene cis-γ-lactone exhibited the most potent inhibitory of QG-56 (IC50 12.5 μM); Compound 29 with an α-bromo-α,β-unsaturated ketone and α-methylene γ-lactone) showed significant inhibitory for HepG2 (IC50 1.23 μM) , though potently inhibited WI 38 (IC50 0.31 μM) as well. A conclusion may be reached that the α-Methylene γ-lactone moiety, exo-endo cross conjugated dienone moiety, and α-bromo-ketone withα-methylene moiety might be essential for eudesmanolides in the expression of their anti-inflammatory, anti-tumour biological activities. Similarly, the above mentioned key moieties are also responsible for the preventive activity of crop disease controlling.

Adiponectin and Its Role in Inflammatory Process of Obesity

Obesity is a chronic, low degree systemic inflammatory status. Microarray examination shows a disturbance in the expression of cytokine, chemokine, complementary protein and half of the other acute phase components in obese patients. Adiponectin is the hormone that increases insulin sensitivity, while its level decreases under condition of fatty tissue enlargement that occurs in obesity. Excessive weight causes the adipocyte cells and adipose tissues produce various types of mediators. The inflammatory process is the main cause of metabolic diseases, and the main role of adipose tissue in the inflammatory process is determined by the production of pro-inflammatory mediators and anti-inflammatory mediators. Adiponectin has an important anti-inflammatory effect on obesity. Adiponectin has an important anti-inflammatory effect on obesity. Adiponectin works on macrophage and monocyte to inhibit the production of pro-inflammatory cytokine and increase the expression of interleukin (IL)-10 and IL-1 receptor antagonists. Adiponectin reduces induction of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 endothelial adhesion by TNF-α or resistin. In obese patients, it is characterized by resistance to adiponectin alongside a decrease and the possibility of adiponectin loss in the receptor population in liver and muscles, leading to low adiponectin level.Keywords: adiponectin, obesity, inflammation

Meningitic Escherichia coli-induced upregulation of PDGF-B and ICAM-1 aggravates blood-brain barrier disruption and neuroinflammatory response

BackgroundBlood-brain barrier (BBB) disruption and neuroinflammation are considered key mechanisms of pathogenic Escherichia coli invasion of the brain. However, the specific molecules involved in meningitic E. coli-induced BBB breakdown and neuroinflammatory response remain unclear. Our previous RNA-sequencing data from human brain microvascular endothelial cells (hBMECs) revealed two important host factors: platelet-derived growth factor-B (PDGF-B) and intercellular adhesion molecule-1 (ICAM-1), which were significantly upregulated in hBMECs after meningitic E. coli infection. Whether and how PDGF-B and ICAM-1 contribute to the development of E. coli meningitis are still unclear.MethodsThe western blot, real-time PCR, enzyme-linked immunosorbent assay, immunohistochemistry, and immunofluorescence were applied to verify the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in vivo and in vitro. Evan’s blue assay and electric cell-substrate impedance sensing assay were combined to identify the effects of PDGF-B on BBB permeability. The CRISPR/Cas9 technology, cell-cell adhesion assay, and electrochemiluminescence assay were used to investigate the role of ICAM-1 in neuroinflammation subversion.ResultsWe verified the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in mouse as well as monolayer hBMECs models. Functionally, we showed that the increase of PDGF-B may directly enhance the BBB permeability by decreasing the expression of tight junction proteins, and the upregulation of ICAM-1 contributed to neutrophils or monocytes recruitment as well as neuroinflammation subversion in response to meningitic E. coli infection.ConclusionsOur findings demonstrated the roles of PDGF-B and ICAM-1 in mediating bacterial-induced BBB damage as well as neuroinflammation, providing new concepts and potential targets for future prevention and treatment of bacterial meningitis.

Decreased serum levels of immunoglobulin M and increased complement 3 in Egyptian vitiligo patients

Background Vitiligo is a common, acquired, depigmenting disorder that results from loss of functional melanocytes in the skin and mucous membranes. It is occasionally associated with autoantibodies against the melanocyte-specific proteins such as tyrosine-related protein-1 tyrosine-related protein-2. These antibodies could induce melanocyte damage in vitro by a complement-mediated mechanism and antibody-dependent cellular cytotoxicity might play an active role in the stimulation and inappropriate expression of HLA-DR and induction of intercellular adhesion molecule-1 on melanocytes. Objective Our aim was to assess the serum levels of different immunoglobulins (Ig) in addition to C3 and C4 in vitiligo patients and to determine their correlation with different clinical aspects of the disease. Patients and methods Serum levels of IgG, IgA, and IgM as well as C3 and C4 were estimated in 24 vitiligo patients and 24 healthy controls using the Radial Immuno-Diffusion (immunoprecipitation) technique. Results Serum IgM levels were found to be significantly decreased and C3 levels were significantly increased among patients compared with the controls. No significant difference was found in the serum levels of IgA, IgG, or C4 between both groups. Also, a significant positive correlation was found between serum IgA levels and the age of the patients, as well as between C3 and C4 and a family history of vitiligo. Conclusion Changes in Ig serum levels might be a cause or an effect in the pathogenesis of vitiligo, as well as alterations in the complement system. These ffindings suggest that altered immunity is to be considered in the therapeutic management of these patients.

Advanced Atherosclerosis with Leriche Syndrome, in a Patient with Carney Complex.

Carney complex (CNC) is a rare autosomal dominant syndrome. Spotty skin pigmentation is the major clinical manifestation of CNC, followed by cardiac myxomas, benign tumors that usually present with features from the classical triad of obstructive cardiac, embolic and non-specific constitutional symptoms (NCS). NCS are caused by the overproduction of interleukin-6 (IL-6), a pro-inflammatory cytokine which mediates the induction of intercellular adhesion molecule 1 (ICAM-1) and promotes endothelial dysfunction and atherosclerosis. Thus, myxomas may be directly linked to an increased risk of atherosclerotic events. We report here a case of a 74-year-old woman with left atrial myxoma, skin pigmentary abnormalities, thyroid disorder and extensive atherosclerosis, with non-embolic occlusion of infrarenal abdominal aorta.

RGC-32 (Response Gene to Complement 32) Deficiency Protects Endothelial Cells From Inflammation and Attenuates Atherosclerosis.

The objective of this study is to determine the role and underlying mechanisms of RGC-32 (response gene to complement 32 protein) in atherogenesis. RGC-32 was mainly expressed in endothelial cells of atherosclerotic lesions in both ApoE-/- (apolipoprotein E deficient) mice and human patients. Rgc-32 deficiency (Rgc32-/-) attenuated the high-fat diet-induced and spontaneously developed atherosclerotic lesions in ApoE-/- mice without affecting serum cholesterol concentration. Rgc32-/- seemed to decrease the macrophage content without altering collagen and smooth muscle contents or lesional macrophage proliferation in the lesions. Transplantation of WT (wild type) mouse bone marrow to lethally irradiated Rgc32-/- mice did not alter Rgc32-/--caused reduction of lesion formation and macrophage accumulation, suggesting that RGC-32 in resident vascular cells, but not the macrophages, plays a critical role in the atherogenesis. Of importance, Rgc32-/- decreased the expression of ICAM-1 (intercellular adhesion molecule-1) and VCAM-1 (vascular cell adhesion molecule-1) in endothelial cells both in vivo and in vitro, resulting in a decrease in TNF-α (tumor necrosis factor-α)-induced monocyte-endothelial cell interaction. Mechanistically, RGC-32 mediated the ICAM-1 and VCAM-1 expression, at least partially, through NF (nuclear factor)-κB signaling pathway. RGC-32 directly interacted with NF-κB and facilitated its nuclear translocation and enhanced TNF-α-induced NF-κB binding to ICAM-1 and VCAM-1 promoters. RGC-32 mediates atherogenesis by facilitating monocyte-endothelial cell interaction via the induction of endothelial ICAM-1 and VCAM-1 expression, at least partially, through NF-κB signaling pathway.

Abstract 211: Response Gene to Complement 32 Deficiency Protects Endothelial Cell From Inflammation and Attenuates Atheroslcerosis

Response gene to complement 32 (RGC-32) is involved in diet-induced obesity and hepatic steatosis. Therefore, we hypothesized that RGC-32 plays a role in atherosclerosis. Our current study showed that RGC-32 expression was dramatically induced in endothelial cells (ECs) of the atherosclerotic lesions from both apolipoprotein E-deficient (ApoE -/- ) mice and diseased human arteries. RGC-32 deficiency (Rgc32 -/- ) significantly attenuated the high-fat diet-induced and spontaneously developed atherogenesis in ApoE -/- mice without affecting the serum lipid profiles. In addition, Rgc32 -/- decreased the macrophage content without affecting fibrous cap size. Rgc32 -/- in bone marrow cells had no effect on atherosclerosis development, and Rgc32 -/- mice transplanted with wild-type (WT) bone marrow cells exhibited decreased atherosclerotic lesion area and macrophage infiltration, suggesting that RGC-32 in resident vascular cells plays a critical role in the atherogenesis. Rgc32 -/- decreased the expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in ECs both in vivo and in vitro , resulting in a decreased monocyte-EC interaction. Mechanistically, RGC-32 regulated ICAM-1 and VCAM-1 transcription via activation of nuclear factor (NF)-κB. It appeared that RGC-32 interacted with NF-κB, which facilitated NF-κB binding to ICAM-1 and VCAM-1 promoters. Indeed, blockade of NF-κB activity by its selective inhibitor ammonium pyrrolidinedithiocarbamate blocked RGC-32-induced ICAM-1 and VCAM-1 expression. In conclusion, RGC-32 promoted atherogenesis by inducing monocyte-EC interaction through NF-κB-dependent induction of endothelial ICAM-1 and VCAM-1 expression.

Uterine natural killer cell partnerships in early mouse decidua basalis

Interactions of the ligand/receptor pair LFA- 1(CD11a/ CD18) and ICAM-1(CD54) initiate and control the cell-cell interactions of leukocytes and interactions of leukocytes with parenchymal cells in all phases of the immune response. Induction of the intercellular adhesion molecule 1 (ICAM-1) on the surface of epidermal keratinocytes has been proposed as an important regulator of contact-dependent aspects of cutaneous inflammation. Ultraviolet radiation (UVR) also modifies cutaneous inflammation, producing both up- and down-regulation of contact hypersensitivity. We have found that UVR has a biphasic effect on the induction of keratinocyte CD54. Using immunofluorescence and FACS techniques to quantitate cell-surface CD54 staining, we have shown that UVR (100 mJ/cm2 of UVB) significantly (p <0.01) inhibits keratinocyte CD54 induction by gamma interferon 24 h after irradiation. However, at 48, 72, and 96 h after UVR (10 to 100 mJ/cm2), CD54 expression is significantly induced (p <0.01 to p < 0.00 1) to levels even greater than are induced by gamma interferon (20 U/ml). In addition, at 48, 72, or 96 h following UVR (30-100 mJ/cm2) the gamma-interferon – induced CD54 expression on human keratinocytes is also strongly (p < 0.05 to p <0.001) enhanced. In this cell-culture system, gamma interferon and TNF-α are both strong CD54 inducers and are synergistic but GM-CSF, TFG-β, and IL-1 have no direct CD54-inducing effects. Thus the effects of UVR on CD54 induction are biphasic, producing inhibition at 24 h and induction at 48, 72, and 96 h. This effect on CD54 may contribute to the biphasic effect of UVR on delayed hypersensitivity in vivo. The early inhibition of ICAM-1 by UVR may also contribute to the therapeutic effects of UVR. We also speculate that the late induction of ICAM-1 by UVR might be an important step in the induction of photosensitive diseases such as lupus erythema tosus.

Sphingosine 1-Phosphate-Induced ICAM-1 Expression via NADPH Oxidase/ROS-Dependent NF-κB Cascade on Human Pulmonary Alveolar Epithelial Cells.

The intercellular adhesion molecule-1 (ICAM-1) expression is frequently correlated with the lung inflammation. In lung injury, sphingosine-1-phosphate (S1P, bioactive sphingolipid metabolite), participate gene regulation of adhesion molecule in inflammation progression and aggravate tissue damage. To investigate the transduction mechanisms of the S1P in pulmonary epithelium, we demonstrated that exposure of HPAEpiCs (human pulmonary alveolar epithelial cells) to S1P significantly induces ICAM-1 expression leading to increase monocyte adhesion on the surface of HPAEpiCs. These phenomena were effectively attenuated by pretreatments with series of inhibitors such as Rottlerin (PKCδ), PF431396 (PYK2), diphenyleneiodonium chloride (DPI), apocynin (NADPH oxidase), Edaravone (ROS), and Bay11-7082 (NF-κB). Consistently, knockdown with siRNA transfection of PKCδ, PYK2, p47phox, and p65 exhibited the same results. Pretreatment with both Gq-coupled receptor antagonist (GPA2A) and Gi/o-coupled receptor antagonist (GPA2) also blocked the upregulation of ICAM-1 protein and mRNA induced by S1P. We observed that S1P induced PYK2 activation via a Gq-coupled receptor/PKCδ-dependent pathway. In addition, S1P induced NADPH oxidase activation and intracellular ROS generation, which were also reduced by Rottlerin or PF431396. We demonstrated that S1P induced NF-κB p65 phosphorylation and nuclear translocation in HPAEpiCs. Activated NF-κB was blocked by Rottlerin, PF431396, APO, DPI, or Edaravone. Besides, the results of monocyte adhesion assay indicated that S1P-induced ICAM-1 expression on HPAEpiCs can enhance the monocyte attachments. In the S1P-treated mice, we found that the levels of ICAM-1 protein and mRNA in the lung fractions, the pulmonary hematoma and leukocyte count in bronchoalveolar lavage fluid were enhanced through a PKCδ/PYK2/NADPH oxidase/ROS/NF-κB signaling pathway. We concluded that S1P-accelerated lung damage is due to the ICAM-1 induction associated with leukocyte recruitment.

NSun2 Deficiency Protects Endothelium From Inflammation via mRNA Methylation of ICAM-1

Vascular endothelial inflammation, including the expression of intercellular adhesion molecule 1 (ICAM-1), is a key event in vascular diseases. However, the mechanisms underlying the regulation of ICAM-1 are largely unknown. To investigate the mechanisms on the regulation of ICAM-1 by NOP2/Sun domain family, member 2 (NSun2)-mediated mRNA methylation and the impact of NSun2-ICAM-1 regulatory process in vascular inflammation and allograft arteriosclerosis. By using in vitro, in cells, and in vivo methylation assays, we showed that the tRNA methyltransferase NSun2 methylated the ICAM-1 mRNA. Methylation by NSun2 promoted the translation of ICAM-1, thereby increasing the adhesion of leukocytes to endothelial cells. Tumor necrosis factor-α or homocysteine activated the methyltransferase activity of NSun2 by repressing the phosphorylation of NSun2 by Aurora-B. The levels of ICAM-1 induction and of leukocyte adhesion to vascular endothelium observed with homocysteine treatment in wild-type rats were markedly decreased in NSun2(-/-) rats. In a rat model of aortic allograft, the lack of donor NSun2 impaired the formation of allograft arteriosclerosis. NSun2 upregulates the expression of ICAM-1 by methylating ICAM-1 mRNA. This regulatory process impacts on vascular inflammation and allograft arteriosclerosis.

Celecoxib increases lung cancer cell lysis by lymphokine-activated killer cells via upregulation of ICAM-1.

The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Using lung cancer cell lines (A549, H460) and metastatic cells derived from a lung cancer patient, the present study investigates the impact of celecoxib on the expression of intercellular adhesion molecule 1 (ICAM-1) and cancer cell lysis by lymphokine-activated killer (LAK) cells. Celecoxib, but not other structurally related selective COX-2 inhibitors (i.e., etoricoxib, rofecoxib, valdecoxib), was found to cause a substantial upregulation of ICAM-1 protein levels. Likewise, ICAM-1 mRNA expression was increased by celecoxib. Celecoxib enhanced the susceptibility of cancer cells to be lysed by LAK cells with the respective effect being reversed by a neutralizing ICAM-1 antibody. In addition, enhanced killing of celecoxib-treated cancer cells was reversed by preincubation of LAK cells with an antibody to lymphocyte function associated antigen 1 (LFA-1), suggesting intercellular ICAM-1/LFA-1 crosslink as crucial event within this process. Finally, celecoxib elicited no significant increase of LAK cell-mediated lysis of non-tumor bronchial epithelial cells, BEAS-2B, associated with a far less ICAM-1 induction as compared to cancer cells. Altogether, our data demonstrate celecoxib-induced upregulation of ICAM-1 on lung cancer cells to be responsible for intercellular ICAM-1/LFA-1 crosslink that confers increased cancer cell lysis by LAK cells. These findings provide proof for a novel antitumorigenic mechanism of celecoxib.

Lauric acid abolishes interferon-gamma (IFN-γ)-induction of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression in human macrophages

Abstract Objective To investigate the effect of different concentrations of lauric acid on Intercellular Adhesion Molecule-1 (ICAM-1) and Vascular Cell Adhesion Molecule-1 (VCAM-1) expression in IFN-γ stimulated human monocytic THP-1 cell line. Methods THP-1 cell were cultured using Roswell Park Memorial Institute medium supplemented with 10% fetal bovine serum. THP-1 monocytes were firstly differentiated into macrophages by using phorbol-12-myristate-13-acetate. IFN-γ response test was performed and total cellular RNA was extracted using TRI Reagent ® LS before q-RT-PCR was carried out. Subsequently, IFN-γ treated THP-1 macrophages were stimulated with increasing doses of lauric acid for another 24 h, before q-RT-PCR. Results The mRNA expression levels of ICAM-1 and VCAM-1 were normalized to β-actin and relatived to the untreated cells. The expressions of ICAM-1 and VCAM-1 were significantly induced in cells treated with 10 ng/mL of IFN-γ. This showed that IFN-γ could up-regulate inflammatory process and may cause atheroma formation. MTT assay was carried out to investigate the effect of lauric acid on undifferentiated and differentiated THP-1 cells. Although lauric acid did not have any significant impact on undifferentiated and differentiated THP-1 cell viability, the normalized fold expressions of ICAM-1 and VCAM-1 in IFN-γ-treated THP-1 macrophages were decreased significantly in a dose dependent manner with the presence of increasing doses of lauric acid. Conclusions This study successfully proved that lauric acid was able to antagonize the up-regulatory effect of IFN-γ on ICAM-1 and VCAM-1 expressions in THP-1 macrophages. This indicates that lauric acid may be an anti-inflammatory therapeutic and prophylaxis agent for atherosclerosis.

Cannabinoids increase lung cancer cell lysis by lymphokine-activated killer cells via upregulation of ICAM-1

Cannabinoids have been shown to promote the expression of the intercellular adhesion molecule 1 (ICAM-1) on lung cancer cells as part of their anti-invasive and antimetastatic action. Using lung cancer cell lines (A549, H460) and metastatic cells derived from a lung cancer patient, the present study addressed the impact of cannabinoid-induced ICAM-1 on cancer cell adhesion to lymphokine-activated killer (LAK) cells and LAK cell-mediated cytotoxicity. Cannabidiol (CBD), a non-psychoactive cannabinoid, enhanced the susceptibility of cancer cells to adhere to and subsequently be lysed by LAK cells, with both effects being reversed by a neutralizing ICAM-1 antibody. Increased cancer cell lysis by CBD was likewise abrogated when CBD-induced ICAM-1 expression was blocked by specific siRNA or by antagonists to cannabinoid receptors (CB1, CB2) and to transient receptor potential vanilloid 1. In addition, enhanced killing of CBD-treated cancer cells was reversed by preincubation of LAK cells with an antibody to lymphocyte function associated antigen-1 (LFA-1) suggesting intercellular ICAM-1/LFA-1 crosslink as crucial event within this process. ICAM-1-dependent pro-killing effects were further confirmed for the phytocannabinoid Δ9-tetrahydrocannabinol (THC) and R(+)-methanandamide (MA), a hydrolysis-stable endocannabinoid analogue. Finally, each cannabinoid elicited no significant increase of LAK cell-mediated lysis of non-tumor bronchial epithelial cells, BEAS-2B, associated with a far less pronounced (CBD, THC) or absent (MA) ICAM-1 induction as compared to cancer cells. Altogether, our data demonstrate cannabinoid-induced upregulation of ICAM-1 on lung cancer cells to be responsible for increased cancer cell lysis by LAK cells. These findings provide proof for a novel antitumorigenic mechanism of cannabinoids.

Estrogen receptor inhibits mineralocorticoid receptor transcriptional regulatory function.

The steroid hormone aldosterone (aldo) contributes to cardiovascular disease in animal models and in humans. Aldo activates the mineralocorticoid receptor (MR), a hormone-activated transcription factor, and indeed, pharmacological MR inhibition improves cardiovascular outcomes. Because the incidence of cardiovascular disease is lower in premenopausal women, we hypothesized that estrogen (E2) signaling through the estrogen receptor (ER) may protect the vasculature by inhibiting the detrimental effects of aldo signaling through the MR. We demonstrate that E2-activated ER inhibits MR-mediated gene transcription from the mouse mammary tumor virus reporter in human embryonic kidney-293 cells. In contrast, aldo-activated MR does not affect ER-mediated gene transcription. The ERα N terminus (amino acids 1-253) containing part of the DNA-binding domain is sufficient to inhibit MR genomic function, although point mutations reveal that DNA binding, ligand-independent activation, and rapid nongenomic ERα signaling are not required for this effect. Furthermore, ERα and MR are part of a complex in cell lysates, with amino acids 1-233 of the ERα N terminus being sufficient to complex with the MR. Overall, the ability of ERα to inhibit MR-mediated gene transcription correlates with the ability of ERα segments to both localize to the nucleus and complex with the MR. In cultured vascular endothelial cells expressing ERα, E2 inhibits aldo induction of the vascular MR target gene intercellular adhesion molecule-1 (ICAM-1). ICAM-1 induction by endothelial MR is known to promote vascular inflammation that could contribute to the mechanism of aldo-induced atherosclerosis. E2 also inhibits aldo induction of ICAM-1 protein and prevents aldo-enhanced leukocyte adhesion to endothelial cells. These studies support a new model in which E2-activated ER in endothelial cells forms a complex with MR in the nucleus to modulate MR regulation of the proinflammatory gene ICAM-1. Estrogen inhibition of MR regulation of genes that contribute to cardiovascular disease may be a new mechanism by which premenopausal women are protected from cardiovascular disease.

Rg3-enriched Korean Red Ginseng improves vascular function in spontaneously hypertensive rats

BackgroundPanax ginseng has distinct and impressive health benefits, such as improved blood pressure and immune system functioning. Rg3-enriched Korean Red Ginseng (REKRG) isolated from Korean Red Ginseng contains a high percentage of Rg3. MethodsIn this study, we examined the effects of REKRG on endothelial cell nitric oxide synthase (eNOS) activation and adhesion molecules in endothelial cells and vascular function in rats. ResultsREKRG dose-dependently increased eNOS phosphorylation and nitric oxide (NO) production in endothelial cells. In addition, REKRG markedly inhibited the tumor necrosis factor-α (TNF-α)-mediated induction of intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 expressions in endothelial cells. REKRG improved endothelium-dependent vasorelaxation in the Wistar-Kyoto (WKY) rat and spontaneously hypertensive rats (SHRs) compared with controls. Furthermore, REKRG treatment for 6 weeks increased serum NO levels and reduced the mean aortic intima-media thickness compared with controls. ConclusionTaken together, these results suggest that REKRG increased vascular function and improved immune system functioning. Therefore, REKRG is a very useful food for preventing or improving various cardiovascular diseases.