Down-regulation Of ICAM-1 Research Articles

Differences in sensitivity to tumor-specific CTLs between primary and metastatic esophageal cancer cell lines derived from the same patient

MHC antigens and adhesion molecules, such as the intracellular adhesion molecule (ICAM-I), play an important role in cellular immune response. We examined the expression patterns of these molecules in both primary and metastatic esophageal carcinoma cells from the same patient and evaluated the cellular immune responses against these cells. In the esophageal cancer patient (H122), tumor cell lines were established from primary and subcutaneous metastatic lesions. We compared the expression of cell surface molecules on the metastatic tumor cell line (H122SC) with that on the primary tumor cell line (H122ESO) using flow cytometry. Moreover, we analyzed the differences in cellular immune responses against these cell lines, which expressed similar levels of the Tara antigen, using the Tara antigen-specific CTL clone. H122SC ICAM-1 expression was significantly lower in H122ESO, and the Tara antigen-specific CTL clone produced lower levels of TNF in response to H122SC than H122ESO. ICAM-1 transfection into the H122SC rendered these cells as sensitive to the CTL clone as the H122ESO. The metastatic tumor cells displayed lower regulated ICAM-1 expression levels and were less sensitive to specific CTLs. ICAM-1 downregulation may be one mechanism by which tumor cells escape immunologic surveillance.

Zerumbone Attenuates the Severity of Acute Necrotizing Pancreatitis and Pancreatitis-Induced Hepatic Injury

This paper investigated the potential effects of zerumbone pretreatment on an acute necrotizing pancreatitis rat model induced by sodium taurocholate. The pancreatitis injury was evaluated by serum AMY, sPLA2, and pancreatic pathological score. Pancreatitis-induced hepatic injury was measured by ALT, AST, and hepatic histopathology. The expression of I-κBα and NF-κB protein was evaluated by western blot and immunohistochemistry assay while ICAM-1 and IL-1β mRNA were examined by RT-PCR. The results showed that AMY, sPLA2, ALT, and AST levels and histopathological assay of pancreatic and hepatic tissues were significantly reduced following administration of zerumbone. Applying zerumbone also has been shown to inhibit NF-κB protein and downregulation of ICAM-1 and IL-1β mRNA. The present paper suggests that treatment of zerumbone on rat attenuates the severity of acute necrotizing pancreatitis and pancreatitis-induced hepatic injury, via inhibiting NF-κB activation and downregulating the expression of ICAM-1 and IL-1β.

The effects of sPLA2-IIA in human umbilical vein endothelial cells

BackgroundSecretory phospholipase A2 group IIA (sPLA2-IIA) appears to be an important inflammatory mediator of cardiovascular disease and may play a pivotal role in the pathophysiology of AS. To understand whether...

Retroviral expression of MIR2 decreases both surface MHC class I and the alloimmune CTL response

The immune response to allogeneic cells in tissue-engineered constructs is a major barrier to their successful application in the treatment of many human diseases. Specifically, the T cell-mediated immune response, initiated through the recognition of cell surface MHCI molecules, is the primary cause of acute cellular allograft rejection. In this study, we altered expression of MHCI through viral immunomodulatory mechanisms to examine whether allogeneic cells could be made to 'mimic' viral evasion of a host CTL response. We demonstrate the successful application of a retroviral vector in vitro to overexpress the Kaposi's sarcoma-associated herpesvirus immunomodulatory protein, MIR2, in human monocyte-like myeloid progenitor cells. This approach led to differential downregulation of cell surface MHCI, ICAM-1 and B7-2 molecules. We also demonstrate that downregulation of immunoactive molecules has the functional effect of significantly reducing T cell-mediated cytotoxicity without altering NK-mediated cytotoxicity in vitro. These results provide proof-of-concept that viral immune evasion strategies allow cell-based tissue-engineered constructs to delay or even prevent acute cellular immune rejection in vivo. Importantly, this methodology could facilitate the development of universal donor cells for tissue engineering applications.

FK506 causes cellular and functional defects in human natural killer cells

The role of NK cells in allogeneic HCT has been increasingly appreciated, particularly in the GVL effect. Although FK506 has been used widely to prevent GVHD, its action was considered to be primarily through activated T cells. In this study, we provide direct evidence for the first time that human NK cells are immediate targets of FK506. Our in vivo data from patients undergoing peripheral blood stem cell transplantation or BMT showed a reduced number of NK cells with down-regulated CD25 expression in their peripheral blood compartment. Likewise, FK506 caused profound inhibition of NK cell proliferation in vitro and suppressed NK cytotoxicity and cytokine secretion in response to IL-2. These defects were accompanied by impaired cell clustering and selective down-regulation of adhesion molecules, ICAM-1, CD2, CD49d, and CD58. Furthermore, FK506 specifically inhibited expression of NKG2D, CD48, and DNAM1 receptors without affecting that of 2B4, NKp30, NKp44, and NKp46. As a result, natural cytotoxicity against K562 tumor targets was impaired, while leaving redirected ADCC via 2B4 intact. Finally, FK506-treated NK cells showed impaired IL-2R signaling and inhibition of STAT3. Collectively, these signaling impairments and selective down-regulation of NK receptors by FK506 may underlie the proliferative and functional defects of NK cells. Thus, our data provide a new insight into the mechanism of immunosuppression by FK506, which should be considered to interpret the outcome of graft transplantation.

Down-regulation of adhesion molecules and matrix metalloproteinases by ZK 156979 in inflammatory bowel diseases

Intracellular adhesion molecules and matrix metalloproteinases (MMPs) are up-regulated in intestinal mucosa of patients with inflammatory bowel diseases (IBD), i.e. ulcerative colitis (UC) or Crohn's disease (CD). Our aim was to verify whether the vitamin D analogue ZK 156979 (ZK) down-regulates adhesion molecules, and decreases MMPs production by PBMC of IBD patients. ICAM-1 and LFA-1 levels increase, when PBMC were incubated with PHA or LPS or TNF-alpha, and decrease when these substances were used in combination with ZK. MMPs activity increases incubating the cells with PHA or LPS or TNF-alpha. MMP-9 decreases when ZK was used in association, while MMP-2 decreases only when ZK was used in combination with anti-TNF-alpha. Our results suggest that the down-regulation of ICAM-1 and LFA-1 on PBMC and the inhibition of MMP-9 activity by ZK could provide a potential role of this low calcemic vitamin D derivative in future strategies in IBD therapy.

HUVEC ICAM-1 and VCAM-1 Synthesis in Response to Potentially Athero-Prone and Athero-Protective Mechanical and Nicotine Chemical Stimuli

Previous mechano-transduction studies have investigated the endothelial cell (EC) morphological response to mechanical stimuli; generally consisting of a wall shear stress (WSS) and a cyclic tensile hoop strain (THS). More recent studies have investigated the EC biochemical response (intercellular adhesion molecule, ICAM-1, and vascular cellular adhesion molecule, VCAM-1, expression) to idealized mechanical stimuli. However, current literature is lacking in the area of EC biochemical response to combinations of physiological WSS and THS mechanical stimuli. The objective of this study is to investigate the EC response to physiological WSS and THS stimuli and to compare this response to that of ECs exposed to idealized steady WSS and cyclic THS of the same magnitudes. This study also investigated the EC response to a nicotine chemical stimulus combined with a suspected athero-prone physiological mechanical stimulus. A bioreactor was designed to apply a range of combinations of physiological WSS and THS waveforms. The bioreactor was calibrated and validated using computational fluid dynamics and video extensometry techniques. The bioreactor was used to investigated the biochemical response exhibited by human umbilical vein endothelial cells (HUVECs) exposed to physiological athero-protective (first bioreactor test case, pulsatile WSS combined with pulsatile THS) and athero-prone (second bioreactor test case, oscillating WSS combined with pulsatile THS) mechanical environments. The final testing environment (third bioreactor test case) combined a nicotine chemical stimulus with the mechanical stimuli of the second bioreactor test case. In first and second bioreactor test cases, the addition of a pulsatile THS to the WSS resulted in opposite trends of ICAM-1 down-regulation and up-regulation, respectively. This outcome suggests that the effect of the additional pulsatile THS depends on the state of the applied WSS waveform. Similarly, in first and second bioreactor test cases, the addition of a pulsatile THS to the WSS resulted in a VCAM-1 up-regulation. However, it has been previously shown that the addition of a cyclic THS to a high- or low-steady WSS resulted in a VCAM-1 down-regulation, indicating that the EC response to idealized mechanical stimuli (steady WSS and cyclic THS) is not comparable to physiological mechanical stimuli (unsteady WSS and pulsatile THS), even though in both situations the average magnitude of WSS and THS applied were similar. In third bioreactor test case, a nicotine chemical stimulus induced a substantial VCAM-1 up-regulation and a moderate ICAM-1 up-regulation. The addition of the mechanical stimuli of the second bioreactors test case resulted in a greater VCAM-1 up-regulation than what was expected, considering the observations of the previous second bioreactor test case alone. This study found that the EC biochemical response to physiological mechanical stimuli is not comparable to the previously observed EC response to idealized mechanical stimuli, even though in both environments the mechanical stimuli were of a similar magnitude. Also, the level of VCAM-1 expressed by the nicotine stimulated ECs showed an elevated level of sensitivity to the athero-prone mechanical stimuli.

Protective effect of resin adsorption on septic plasma-induced tubular injury

IntroductionA pro-apoptotic effect of circulating mediators on renal tubular epithelial cells has been involved in the pathogenesis of sepsis-associated acute kidney injury (AKI). Adsorption techniques have been showed to efficiently remove inflammatory cytokines from plasma. The aim of this study was to evaluate the efficiency of the hydrophobic resin Amberchrom CG161 M to adsorb from septic plasma soluble mediators involved in tubular injury.MethodsWe enrolled in the study 10 critically ill patients with sepsis-associated AKI and we evaluated the effects of their plasma on granulocyte adhesion, apoptosis and functional alterations of cultured human kidney tubular epithelial cells. We established an in vitro model of plasma adsorption and we studied the protective effect of unselective removal of soluble mediators by the Amberchrom CG161 M resin on septic plasma-induced tubular cell injury.ResultsPlasma from septic patients induced granulocyte adhesion, apoptosis and altered polarity in tubular cells. Plasma adsorption significantly decreased these effects and abated the concentrations of several soluble mediators. The inhibition of granulocyte adhesion to tubular cells was associated with the down-regulation of ICAM-1 and CD40. Resin adsorption inhibited tubular cell apoptosis induced by septic plasma by down-regulating the activation of caspase-3, 8, 9 and of Fas/death receptor-mediated signalling pathways. The alteration of cell polarity, morphogenesis, protein reabsorption and the down-regulation of the tight junction molecule ZO-1, of the sodium transporter NHE3, of the glucose transporter GLUT-2 and of the endocytic receptor megalin all induced by septic plasma were significantly reduced by resin adsorption.ConclusionsSeptic plasma induced a direct injury of tubular cells by favouring granulocyte adhesion, by inducing cell apoptosis and by altering cell polarity and function. All these biological effects are related to the presence of circulating inflammatory mediators that can be efficiently removed by resin adsorption with a consequent limitation of tubular cell injury.

Cytoskeletal structure regulates endothelial cell immunogenicity independent of fluid shear stress

The cardiovascular disease atherosclerosis is directly linked to the functions of endothelial cells (ECs), which are affected by fluid shear stress (FSS). High, unidirectional FSS causes EC elongation with aligned cytoskeletal components and nonimmunogenic EC functions that protect against atherosclerosis. In contrast, low, oscillatory FSS is associated with cobblestone-shaped ECs with randomly oriented cytoskeletons and proinflammatory EC functions that promote atherosclerosis. Whether EC shape plays a role in EC immunogenic functions, independent of FSS, has not been previously determined. The goal of this study was to determine the effect of EC elongation and cytoskeletal alignment on the expression of inflammatory genes and functions. With the use of micropatterned lanes, EC elongation and cytoskeletal alignment were achieved in the absence of FSS. EC gene expression of key inflammation markers determined that the elongation and cytoskeletal alignment of micropattern-elongated ECs (MPECs) alone significantly downregulated VCAM-1 while having no effect on E-selectin and ICAM-1. The positive control of FSS-elongated ECs promoted E-selectin and VCAM-1 downregulation and upregulation of ICAM-1. Functionally, monocytic U937 cells formed weaker interactions on the surface of MPECs compared with cobblestone ECs. Interestingly, MPEC expression of the known FSS-dependent transcription factor krüppel-like factor 2 (KLF2), which promotes a nonimmunogenic EC phenotype, was significantly upregulated in MPECs compared with cobblestone ECs. Cytoskeletal regulation of KLF2 expression was shown to be dependent on microtubules. Therefore, the cellular elongation and cytoskeletal alignment of MPECs regulated immunogenic gene expression and functions and may act synergistically with FSS to create an EC surface with reduced inflammatory capability.

Dicer-regulated microRNAs 222 and 339 promote resistance of cancer cells to cytotoxic T-lymphocytes by down-regulation of ICAM-1

The RNase III endonuclease Dicer plays a key role in generation of microRNAs (miRs). We hypothesized that Dicer regulates cancer cell susceptibility to immune surveillance through miR processing. Indeed, Dicer disruption up-regulated intercellular cell adhesion molecule (ICAM)-1 and enhanced the susceptibility of tumor cells to antigen-specific lysis by cytotoxic T-lymphocytes (CTLs), while expression of other immunoregulatory proteins examined was not affected. Blockade of ICAM-1 inhibited the specific lysis of CTLs against Dicer-disrupted cells, indicating a pivotal role of ICAM-1 in the interaction between tumor cells and CTL. Both miR-222 and -339 are down-regulated in Dicer-disrupted cells and directly interacted with the 3' untranslated region (UTR) of ICAM-1 mRNA. Modulation of Dicer or these miRs inversely correlated with ICAM-1 protein expression and susceptibility of U87 glioma cells to CTL-mediated cytolysis while ICAM-1 mRNA levels remained stable. Immunohistochemical and in situ hybridization analyses of 30 primary glioblastoma tissues demonstrated that expression of Dicer, miR-222, or miR-339 was inversely associated with ICAM-1 expression. Taken together, Dicer is responsible for the generation of the mature miR-222 and -339, which suppress ICAM-1 expression on tumor cells, thereby down-regulating the susceptibility of tumor cells to CTL-mediated cytolysis. This study suggests development of novel miR-targeted therapy to promote cytolysis of tumor cells.

Multi-Axial Mechanical Stimulation of HUVECs Demonstrates That Combined Loading is not Equivalent to the Superposition of Individual Wall Shear Stress and Tensile Hoop Stress Components

Over the past 25 years, many laboratory based bioreactors have been used to study the cellular response to hemodynamic forces. The vast majority of these studies have focused on the effect of a single isolated hemodynamic force, generally consisting of a wall shear stress (WSS) or a tensile hoop strain (THS). However, investigating the cellular response to a single isolated force does not accurately represent the true in vivo situation, where a number of forces are acting simultaneously. This study used a novel bioreactor to investigate the cellular response of human umbilical vein endothelial cells (HUVECs) exposed to a combination of steady WSS and a range of cyclic THS. HUVECs exposed to a range of cyclic THS (0-12%), over a 12 h testing period, expressed an upregulation of both ICAM-1 and VCAM-1. HUVECs exposed to a steady WSS (0 dynes/cm2 and 25 dynes/cm2), over a 12 h testing period, also exhibited an ICAM-1 upregulation but a VCAM-1 downregulation, where the greatest level of WSS stimulus resulted in the largest upregulation and downregulation of ICAM-1 and VCAM-1, respectively. A number of HUVEC samples were exposed to a high steady WSS (25 dynes/cm2) combined with a range of cyclic THS (0-4%, 0-8%, and 0-12%) for a 12 h testing period. The initial ICAM-1 upregulation, due to the WSS alone, was downregulated with the addition of a cyclic THS. It was observed that the largest THS (0-12%) had the greatest reducing effect on the ICAM-1 upregulation. Similarly, the initial VCAM-1 downregulation, due to the high steady WSS alone, was further downregulated with the addition of a cyclic THS. A similar outcome was observed when HUVEC samples were exposed to a low steady WSS combined with a range of cyclic THS. However, the addition of a THS to the low WSS did not result in an expected ICAM-1 downregulation. In fact, it resulted in a trend of unexpected ICAM-1 upregulation. The unexpected cellular response to the combination of a steady WSS and a cyclic THS demonstrates that such a response could not be determined by simply superimposing the cellular responses exhibited by ECs exposed to a steady WSS and a cyclic THS that were applied in isolation.

Phosphodiesterase-4 Inhibition Reduces Ischemic/Reperfusion Liver Injury in a Mouse Model for Sickle Cell Disease.

Ischemic/reperfusion (I/R) injury plays a critical role in the pathogenesis of several clinical manifestations of sickle cell disease (SCD) and it results from complex interactions between cells and plasma factors. Hepatic dysfunction has been described in SCD and the pathophysiology of liver I/R damage in SCD is only partially known. The liver is highly vascular organ with high metabolic rate, susceptible to stress-induced by hypoxia. Here, we studied the effects of acute and chronic hypoxia on liver function and pathology in transgenic sickle mice (SAD mice). We evaluated the following parameters at baseline, at 4, 48 and 168 hours (hrs) of exposure to hypoxia (8% oxygen) followed by 2 hrs reoxygenation (21% oxygen): complete blood counts with retic, red cell density, serum AST and ALT levels, liver pathology and expression by RT-PCR of the following genes: TNF-a, IL-1b as inflammatory response markers; TgfB1 (involved in control cell growth and extracellular matrix formation), mmp9 (marker of hepatic matrix remodeling), NfKb (transcription effector involved in liver cell death and regeneration), Icam1 (endothelial damage and vascular remodeling marker), in addition to heme oxygenase-1 (Homx1), eNOS (Nos3) and iNOS (Nos2). SAD mice at baseline exhibitedliver infiltrates of inflammatory cells, no thrombi and a mild hepatic injury (pathological score: 1.4±0.02; n=5);up-regulation of TgfB1, Icam1, Nos3 and down-regulation of Nfkb compared to normoxic WT mice.One SAD mice died at 48 hrs hypoxia and 2 SAD mice died at 96 hrs hypoxia. In SAD mice I/R induced:increased red cell density at 48 and 168 hrs of hypoxia;increased peripheral neutrophil count at 48 and 168 hrs;increased retic count at 168 hrs;increased serum levels of AST/ALT;increased liver cell inflammatory infiltrate at 48 hrs (n=5) and 168 hrs (n=6);increased pathological score at 48 hrs (2.3±0.02 n=5) and at 168 hrs (3.2±0.05 n=6; P<0.05).In SAD mice I/R induced changes in the expression of the following genes: 4hrs: up-regulation of Nfkb, Ilb1, Nos2 and down-regulation of Tgfb1, Icam1, homx1 and Nos3; 48 hrs: up-regulation of Icam1, Nos2, Tnfa and down-regulation of TgfB1, Nos3, homx1, Nfkb, Ilb1; 168 hrs: up-regulation of TgfB1, Icam1, Nos 3, homx1, Nfkb, Ilb1, Nos2 and down-regulation of Nos2. In WT mice I/R inducedincreased neutrophils and retic count at 168 hrs;increased serum levels of AST/ALT at 48 and 168 hrs;increased liver cell inflammatory infiltrate at 168 hrs (n=7) and pathological score at 168 hrs andmodulation of the following genes at 4hrs: up-regulation of Nfkb, Icam1, Ilb1, Nos2, mmp9 and down-regulation of TgfB1 and homx1; at 48 hrs: up-regulation of TgfB1, Icam1, homx1, Nos2, Tnfa, mmp9 and down-regulation of Ilb1; at 168 hrs: up-regulation of Icam1, Nfkb, Nos 3, Nos2, Tnfa, mmp9 and down-regulation of Il1b, homox1, TnfB1.Then, we investigated the effects of a PDE-4 inhibitor (Rolipram) on hepatic I/R injury in sickle cell SAD mice, since cAMP cell content has been recently described to be crucial in I/R liver damage and PDE-4 is a key regulator of cAMP metabolism. In SAD mice, Rolipram reduced the hypoxia induced peripheral neutrophilia and serum AST/ALT increase, prevented the I/R liver injury as supported by reducing cell inflammatory infiltrate, pathological score (1.8±0.02, n= 6, P<0.05) and the modulation of the following genes: TgfB1, Icam1, Nos3, Ilb1, Tnfa and mmp9 These data suggest that the inhibition of PDE-4 protects from I/R related sickle cell liver injury, most likely by inducing over-expression of Nos3, reducing vascular activation, modulating matrix remodeling and immune-inflammatory response.

Vitamin D derivatives induce apoptosis and downregulate ICAM-1 levels in peripheral blood mononuclear cells of inflammatory bowel disease patients

Lymphocytes are crucial in the pathogenesis of inflammatory bowel disease (IBD) and are an important target for drug development. Our aim was to verify whether 2 vitamin D derivatives, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and EB 1089, could induce cell apoptosis and affect cell-cell interaction by regulating adhesion molecule levels. Peripheral blood mononuclear cell (PBMC) proliferation was studied by [3H]thymidine incorporation and apoptosis was determined using an enzyme-linked immunosorbent assay (ELISA) kit. (Poly(ADP-ribose)polymerase (PARP) cleavage, caspase-3, and ICAM-1 protein levels were determined by Western blot analysis. Our results indicate that 1,25(OH)2D3 or EB 1089 or anti-TNF-alpha (infliximab) induce apoptosis in PBMC obtained from healthy subjects. In IBD patients apoptosis is induced by vitamin D derivatives and by anti-TNF-alpha only in CD patients. Caspase-3 activation and PARP cleavage are registered when PBMC were treated with vitamin D derivatives. ICAM-1 levels remarkably increase when PBMC was incubated with lipopolysaccharide (LPS) or TNF-alpha. The treatment with the vitamin D derivatives, alone or in combination with LPS or TNF-alpha, significantly decreases ICAM-1 levels both in healthy subjects and IBD patients. In HUVEC cocultured with PBMC, previously incubated with LPS or TNF-alpha associated with 1,25(OH)2D3, ICAM-1 levels decrease both in healthy subjects and IBD patients. 1,25(OH)2D3 and EB 1089 inhibit PBMC proliferation, induce apoptosis in PBMC of healthy subjects and IBD patients, and affect ICAM-1 expression on PBMC and on HUVEC cocultured with PBMC, suggesting that the ICAM-1 downregulation could provide a new target for controlling the recruitment of leukocytes at the sites of inflammation in IBD.

Celecoxib decreases expression of the adhesion molecules ICAM‐1 and VCAM‐1 in a colon cancer cell line (HT29)

We investigated the ability of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, to modulate expression of ICAM-1 and VCAM-1 in the colon cancer cell line HT29. We analysed the effect of celecoxib on ICAM-1 and VCAM-1 protein and mRNA expression in HT29 cells. Experiments were performed in the presence of mitogen-activated protein kinases (MAPK) inhibitors to evaluate the involvement of these kinases in this phenomenon. We evaluated adhesion of HT29 cells to FCS-coated plastic wells in the presence of celecoxib or MAPK inhibitors. Furthermore, we studied the effect of celecoxib on apoptosis. Celecoxib down-regulated ICAM-1 and VCAM-1 expression in HT29 cells in a time- and dose-dependent way. Celecoxib reduced activation of p38 and p55 c-Jun terminal NH(2) kinase (JNK) MAPKs, but did not affect p46 JNK or p42/44 MAPK phosphorylation. Pretreatment with SB202190 or SP600125, specific inhibitors of p38 and JNK MAPKs, respectively, reduced ICAM-1 and VCAM-1 expression in HT29 cells dose-dependently. Adhesion of HT29 cells to FCS-coated plastic wells was inhibited dose-dependently by celecoxib, and also by SB202190 and SP600125. Celecoxib showed a pro-apoptotic effect, inducing Bax and BID but down-regulating Bcl-2. Our findings show that celecoxib caused down-regulation of ICAM-1 and VCAM-1, affecting the adhesive properties of HT29 cells in a COX-2 independent way, inhibiting p38 and p55 MAPKs and activating a pro-apoptotic pathway.

2′‐O‐Lysylaminohexyl Oligonucleotides: Modifications for Antisense and siRNA

A novel type of oligonucleotide has been developed, characterized by the attachment of a lysyl moiety to a 2'-O-aminohexyl linker. A protected lysine building block was tethered to 2'-O-aminohexyluridine, and the product was converted into the corresponding phosphoramidite. Up to six modified nucleosides were incorporated in dodecamer DNA and RNA oligonucleotides using standard phosphoramidite chemistry. Each of the building blocks contributes one positive charge to the oligonucleotide instead of the negative charge of a wild-type nucleotide. Thermal denaturation profiles indicated a stabilizing effect of 2'-O-lysylaminohexyl chains that was more pronounced in RNA duplexes. Incubation of the oligonucleotides with 5'-exonuclease revealed an exceptionally high stability against enzymatic degradation. Incorporation of up to three modifications into functional antisense and siRNA oligonucleotides targeted at ICAM-1 showed that the gene-silencing activity was higher with an increasing number of lysylaminohexyl nucleotides. Compared with wild-type antisense or siRNA, compounds with three modifications led to equal or higher ICAM-1 downregulation.

Preliminary evidence of the efficacy of probiotic eye-drop treatment in patients with vernal keratoconjunctivitis

Probiotics have been shown to improve allergic inflammation. The aim of this study was to evaluate the efficacy of Lactobacillus Acidophilus eye-drops in controlling signs and symptoms of vernal keratoconjunctivitis (VKC). Seven patients (mean age 11.8 +/- 4.3; five M, two F) with mild to moderate VKC were included in the study. Lactobacillus Acidophilus diluted in saline solution (2 x 10(8) CFU/ml) was administrated as eye-drops four times daily for 4 weeks in both eyes. Clinical signs (conjunctival hyperemia, chemosis, secretion, Trantas dots, superficial punctuate keratitis) and symptoms (itching, photophobia, burning, tearing) were evaluated and scored from 0 to 3 at baseline, after 2 and 4 weeks of treatment. Total sign (TSS) and symptom (TSyS) scores were calculated. Conjunctival impression cytology was performed in three patients at baseline and after 4 weeks of treatment, in order to evaluate the expression of ICAM-1 and TLR-4. In the six out of seven patients who completed the study, symptoms were significantly improved after both 2 weeks (TSyS: baseline 6.7 +/- 0.9 vs 4.1 +/- 1.2; p = 0.017) and 4 weeks (TSyS: baseline 6.7 +/- 0.9 vs 3.6 +/- 1.2, p = 0.011) of treatment. A significant improvement of clinical signs was observed after 4 weeks of treatment (TSS: baseline 7.5 +/- 1.6 vs 3.9 +/- 1.7, p = 0.034) but not after 2 weeks of treatment (TSS: baseline 7.5 +/- 1.6 vs 5.3 +/- 1.5; NS). In particular, photophobia was significantly reduced (2 +/- 0.6 vs 1 +/- 0.3; p = 0.023) at 2 weeks, while at 4 weeks the scores for itching (1.8 +/- 0.3 vs 1 +/- 0.3), tearing (1.6 +/- 0.4 vs 0.8 +/- 0.2), conjunctival hyperemia (2.3 +/- 0.2 vs 1.4 +/- 0.5) and chemosis (1.2 +/- 0.4 vs 0.4 +/- 0.4) were significantly lower compared to baseline. A down-regulation of ICAM-1 and TLR-4 was observed in two patients showing clinical improvement after 4 weeks of treatment. Our open pilot study showed that 1-month treatment with probiotic eye-drops improves signs and symptoms in patients with VKC. Additional double-blind controlled clinical trials with a larger sample of patients are needed to confirm the effects of topical Lactobacilli on VKC patients.

Inhibition of Heart Allograft Rejection With Mitomycin C???Treated Donor Dendritic Cells

We showed previously that dendritic cells (DCs) treated with mitomycin C (MMC) tolerize allogeneic T cells in vitro and this might be mediated by downregulation of CD80, CD86, and ICAM-1. Here we analyze the suppression of the T-cell response induced by MMC-DCs in vivo. Rats injected with allogeneic DCs developed a strong lymph node reaction, whereas MMC-DCs induced no reaction. The same effect was obtained when CD80, CD86, and ICAM-1 expressed by DCs were blocked with antibodies. One injection of donor MMC-DCs strongly prolonged heart allograft survival in a donor-specific manner. Suppression of rejection was also achieved when donor DCs were pretreated with a combination of anti-CD80, anti-CD86, and anti-ICAM-1 antibodies, showing that downregulation of these molecules confers the DCs inhibitory properties. We conclude that allogeneic MMC-DCs specifically inhibit the T-cell response in vivo and that downregulation of CD80, CD86, and ICAM-1 is a potential mechanism of this effect.

The Effect of Intraportal Prostaglandin E1 on Adhesion Molecule Expression, Inflammatory Modulator Function, and Histology in Canine Hepatic Ischemia/Reperfusion Injury

Prostaglandin E1 (PGE1) is known to protect the liver from I/R, however, the mechanism of cytoprotection is not well understood. This study investigates the effect of intraportal infusion of PGE1 in a warm liver ischemia/reperfusion (I/R) model on cytokines, adhesion molecules and liver structure. Twenty dogs underwent laparotomy under general anesthesia. PGE1 (0.02 microg\kg\min) was perfused through the portal vein in the PGE1 group (n = 10), or a similar volume of Ringer's solution in the control group (n = 10) for 15 min. Liver ischemia was induced by hepatic artery and portal vein occlusion and PGE1 was infused via the portal vein for 60 min. The occlusion was released and PGE1 infusion recommenced for 30 min. Blood and liver biopsies were sampled at baseline, 60 min ischemia, and 30 min reperfusion and assessed for transaminases, cytokines, adhesion molecules, and electron microscopy. PGE1 infusion significantly reduced transaminases TNF-alpha, sICAM-1, sP-selectin, and sE-selectin on ischemia and reperfusion. PGE1 reduced hepatocytic degeneration, portal and central ICAM-1 expression, central and sinusoidal VCAM-1 expression, portal and central P-selectin expression, and portal and sinusoidal E-selectin expression on reperfusion. Intraportal PGE1 infusion reduced I/R injury and was associated with down-regulation of ICAM-1, VCAM-1, P-selectin, and E-selectin on reperfusion.

MARCH-IX mediates ubiquitination and downregulation of ICAM-1

The membrane associated RING-CH (MARCH) family of genes encode a novel group of RING-type ubiquitin E3 ligases. Overexpression of one of these family members, MARCH-IX, leads to a downregulation of cell surface major histocompatibility complex (MHC) class I and CD4. Here, we identify MARCH-IX as the first ubiquitin E3 ligase to control expression of the critical cell adhesion molecule ICAM-1. MARCH-IX expression causes ubiquitination and downregulation of ICAM-1 and a short alternative transcript of MARCH-IX lacking the RING-CH domain, termed MARCH-IX RINGless, is shown to act as a positive regulator of MARCH-IX activity.

Transient supplementation of superoxide dismutase protects endothelial cells against Plasmodium falciparum-induced oxidative stress

The pathogenesis of cerebral malaria, a major complication of Plasmodium falciparum infection, relies on mechanisms such as cytokine production and cytoadherence of parasitized red blood cells (PRBCs) on microvascular endothelial cells. In this way parasites avoid spleen clearance by sequestration in post-capillary venules of various organs including the brain. Infected erythrocytes adhesion has also been shown to have molecular signaling consequences providing insight on how tissue homeostasis could be comprised by endothelium perturbation. Our previous work demonstrated that PRBCs adhesion to human lung endothelial cells (HLEC) induces caspases activation, oxidative stress and apoptosis. Cytoplasmic Cu/Zn superoxide dismutase (SOD1), which provides the first line of defense against oxidative stress within a cell, is now used as a treatment of numerous diseases including traumatic brain injury and ischemic stroke. In this report, we demonstrated that transient supplementation of SOD1 protects endothelial cells against P. falciparum induced oxidative stress and apoptosis. We also showed a significant decrease in PRBCs cytoadherence through a downregulation of ICAM-1 and an induction of iNOS. Protection of endothelium via antioxidant delivery may constitute a relevant strategy in cerebral malaria treatment.