Increase In Intercellular Adhesion Molecule-1 Research Articles

MiR-486-5p protects against rat ischemic kidney injury and prevents the transition to chronic kidney disease and vascular dysfunction.

Acute kidney injury (AKI) increases the risk for progressive chronic kidney disease (CKD). MicroRNA (miR)-486-5p protects against kidney ischemia reperfusion (IR) injury in mice, although its longterm effects on the vasculature and development of CKD are unknown. We studied whether miR-486-5p would prevent the AKI to CKD transition in rat, and affect vascular function.Methods:Adult male rats were subjected to bilateral kidney IR followed by i.v. injection of liposomal-packaged miR-486-5p (0.5 mg/kg). Kidney function and histologic injury were assessed after 24 h and 10 weeks. Kidney endothelial protein levels were measured by immunoblot and immunofluorescence, and mesenteric artery reactivity was determined by wire myography.Results:In rats with IR, miR-486-5p blocked kidney endothelial cell increases in intercellular adhesion molecule-1 (ICAM-1), reduced neutrophil infiltration and histologic injury, and normalized plasma creatinine (p<0.001). However, miR-486-5p attenuated IR-induced kidney endothelial nitric oxide synthase (eNOS) expression (p<0.05). At 10 weeks, kidneys from rats with IR alone had decreased peritubular capillary density and increased interstitial collagen deposition (p<0.0001), and mesenteric arteries showed impaired endothelium-dependent vasorelaxation (p<0.001). These changes were inhibited by miR-486-5p. Delayed miR-486-5p administration (96 h, 3 weeks after IR) had no impact on kidney fibrosis, capillary density, or endothelial function.Conclusion:In rats, administration of miR-486-5p early after kidney IR prevents injury, and protects against CKD development and systemic endothelial dysfunction. These protective effects are associated with inhibition of endothelial ICAM-1 and occur despite reduction in eNOS. miR-486-5p holds promise for the prevention of ischemic AKI and its complications.

Hypoxia-sensitive cells trigger NK cell activation via the KLF4-ASH1L-ICAM-1 axis, contributing to impairment in the rat epididymis

Male infertility is a global health problem especially prevalent in high-altitude regions. The epididymis is essential for sperm maturation, but the influence of environmental cues on its reshaping remains poorly understood. Here, we use single-cell transcriptomics to track the cellular profiles of epidydimal cells in rats raised under normoxia or extended hypoxia. The results show that hypoxia impairs epididymal function, evident in reduced epithelial cells, compromised blood-epididymis barrier integrity, and increased natural killer cells. Through combined analysis of gene-regulatory networks and cell-cell interaction maps, we identify epididymal hypoxia-sensitive cells that communicate with natural killer (NK) cells via increased intercellular adhesion molecule 1 (ICAM-1) driven by KLF4 recruitment of the histone methyltransferase ASL1L to the Icam1 promoter. Taken together, our study offers a detailed blueprint of epididymal changes during hypoxia and defines a KLF4-ALSH1L-ICAM-1 axis contributing to NK cell activation, yielding a potential treatment targeting hypoxia-induced infertility.

APOL1 promotes endothelial cell activation beyond the glomerulus

Apolipoprotein L1 (APOL1) high-risk genotypes are associated with increased risk of chronic kidney disease (CKD) in people of West African ancestry. Given the importance of endothelial cells (ECs) in CKD, we hypothesized that APOL1 high-risk genotypes may contribute to disease via EC-intrinsic activation and dysfunction. Single cell RNA sequencing (scRNA-seq) analysis of the Kidney Precision Medicine Project dataset revealed APOL1 expression in ECs from various renal vascular compartments. Utilizing two public transcriptomic datasets of kidney tissue from African Americans with CKD and a dataset of APOL1-expressing transgenic mice, we identified an EC activation signature; specifically, increased intercellular adhesion molecule 1 (ICAM-1) expression and enrichment in leukocyte migration pathways. Invitro, APOL1 expression in ECs derived from genetically modified human induced pluripotent stem cells and glomerular ECs triggered changes in ICAM-1 and platelet endothelial cell adhesion molecule 1 (PECAM-1) leading to an increase in monocyte attachment. Overall, our data suggest the involvement of APOL1 as an inducer of EC activation in multiple renal vascular beds with potential effects beyond the glomerular vasculature.

Methamphetamine Induces the Release of Proadhesive Extracellular Vesicles and Promotes Syncytia Formation: A Potential Role in HIV-1 Neuropathogenesis.

Despite the success of combinational antiretroviral therapy (cART), the high pervasiveness of human immunodeficiency virus-1 (HIV)-associated neurocognitive disorders (HAND) poses a significant challenge for society. Methamphetamine (meth) and related amphetamine compounds, which are potent psychostimulants, are among the most commonly used illicit drugs. Intriguingly, HIV-infected individuals who are meth users have a comparatively higher rate of neuropsychological impairment and exhibit a higher viral load in the brain than infected individuals who do not abuse meth. Effectively, all cell types secrete nano-sized lipid membrane vesicles, referred to as extracellular vesicles (EVs) that can function as intercellular communication to modulate the physiology and pathology of the cells. This study shows that meth treatments on chronically HIV-infected promonocytic U1 cells induce the release of EVs that promote cellular clustering and syncytia formation, a phenomenon that facilitates HIV pathogenesis. Our analysis also revealed that meth exposure increased intercellular adhesion molecule-1 (ICAM-1) and HIV-Nef protein expression in both large (10 K) and small (100 K) EVs. Further, when meth EVs are applied to uninfected naïve monocyte-derived macrophages (MDMs), we saw a significant increase in cell clustering and syncytia formation. Furthermore, treatment of MDMs with antibodies against ICAM-1 and its receptor, lymphocyte function-associated antigen 1 (LFA1), substantially blocked syncytia formation, and consequently reduced the number of multinucleated cells. In summary, our findings reveal that meth exacerbates HIV pathogenesis in the brain through release of proadhesive EVs, promoting syncytia formation and thereby aiding in the progression of HIV infection in uninfected cells.

Curcumin Mitigates TNFα-Induced Caco-2 Cell Monolayer Permeabilization Through Modulation of NF-κB, ERK1/2, and JNK Pathways.

This work studies the capacity of curcumin to inhibit tumor necrosis alpha (TNFα)-induced inflammation, oxidative stress, and loss of intestinal barrier integrity, characterizing the underlying mechanisms. Caco-2 cell monolayers are incubated with TNFα (10ng mL-1 ), in the absence or presence of curcumin. TNFα causes an increase in interleukin (IL)-6 and IL-8 release, which is inhibited by curcumin in a dose-dependent manner (half-maximal inhibitory concentration (IC50 ) = 3.4 µM for IL-6). Moreover, TNFα leads to: i) increased intercellular adhesion molecule 1 (ICAM-1) and NLRP3 inflammasome expression; ii) increased cell monolayer permeability and decreased levels of tight junction proteins; iii) increased cellular and mitochondrial oxidant production; iv) decreased mitochondrial membrane potential and complex I-III activity; v) activation of redox-sensitive pathways, i.e., nuclear factor-kappa B (NF-κB), extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinases (JNK); and vi) increased myosin light-chain kinase (MLCK) expression and phosphorylation levels of myosin light-chain protein MLC. Curcumin (2-8 µM) inhibits all these TNFα-triggered undesirable outcomes, mostly showing dose-dependent effects. The inhibition of NF-κB, ERK1/2, and JNK activation could be in part involved in the capacity of curcumin to mitigate intestinal inflammation, oxidant production, activation of redox-sensitive pathways, and prevention of monolayer permeabilization. These results support an action of dietary curcumin in sustaining gastrointestinal tract physiology.

Effects of Bovine Colostrum with or without Egg on In Vitro Bacterial-Induced Intestinal Damage with Relevance for SIBO and Infectious Diarrhea.

Small intestinal bacterial overgrowth (SIBO) occurs commonly, is difficult to treat, and frequently recurs. Bovine colostrum (BC) and chicken eggs contain immunoglobulins and other components that possess antimicrobial, immunoregulatory, and growth factor activities; however, it is not known if they have the ability to reduce injury caused by the presence of bacteria associated with SIBO (Streptococcus, Escherichia coli, Staphylococcus, Bacteroides, Klebsiella, Enterococcus, and Proteus) and infectious diarrhea (enteropathogenic Escherichia coli, Salmonella). We examined the effects of BC, egg, or the combination, on bacterial growth and bacteria-induced changes in transepithelial electrical resistance (TEER) and bacterial translocation across confluent Caco-2 monolayers. BC, egg, or the combination did not affect bacterial growth. Adding bacteria to monolayers reduced TEER and (with minor variations among species) increased bacterial translocation, increased monolayer apoptosis (increased caspase-3 and Baxα, reduced Bcl2), increased intercellular adhesion molecule 1 (ICAM-1), and reduced cell adhesion molecules zonulin1 (ZO1) and claudin-1. BC, egg, or the combination reduced these effects (all p < 0.01) and caused additional increases in vascular endothelial growth factor (VEGF) and Heat Shock Protein 70 (Hsp70) expression. We conclude that BC ± egg strengthens mucosal integrity against a battery of bacteria relevant for SIBO and for infectious diarrhea. Oral BC ± egg may have clinical value for these conditions, especially SIBO where eradication of precipitating organisms may be difficult to achieve.

Altered levels of immune cell adhesion molecules are associated with memory impairment in schizophrenia and healthy controls

Increased cytokines and increased intercellular adhesion molecule-1 (ICAM1) found in the schizophrenia prefrontal cortex and in the blood may relate to cognitive deficits. Endothelial ICAM1 regulates immune cell trafficking into the brain by binding to integrins located on the surface of leukocytes. Whether the circulating levels of the main ICAM1 adhesion partners, lymphocyte-function associated antigen-1 (LFA1) and complement receptor 3 (CR3), both integrins, are altered in schizophrenia is unknown. Gene expressions of ICAM1, LFA1 and CR3 were measured in leukocytes from 86 schizophrenia patients and 77 controls. Participants were also administered cognitive testing to determine the extent to which cognitive ability was related to molecular measures of leukocyte adhesion. This cohort was previously stratified into inflammatory subgroups based on circulating cytokine mRNAs; thus, gene expressions were analysed by diagnosis and by inflammatory subgroups. Previously measured plasma ICAM1 protein was elevated in “high inflammation” schizophrenia compared to both “high” and “low inflammation” controls while ICAM1 mRNA was unchanged in leukocytes. LFA1 mRNA was decreased and CR3 mRNA was increased in leukocytes from people with schizophrenia compared to controls. LFA1 mRNA levels were positively correlated with working memory and elevated soluble ICAM1 was negatively correlated with verbal memory in schizophrenia. Altogether, some of the cognitive deficits in schizophrenia may be associated with altered expression of molecules that regulate immune cell trafficking.

Nitric oxide synthase mediates cerebellar dysfunction in mice exposed to repetitive blast-induced mild traumatic brain injury

We investigated the role of nitric oxide synthase (NOS) in mediating blood-brain barrier (BBB) disruption and peripheral immune cell infiltration in the cerebellum following blast exposure. Repetitive, but not single blast exposure, induced delayed-onset BBB disruption (72 hours post-blast) in cerebellum. The NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) administered after blast blocked BBB disruption and prevented CD4+ T-cell infiltration into cerebellum. L-NAME also blocked blast-induced increases in intercellular adhesion molecule-1 (ICAM-1), a molecule that plays a critical role in regulating blood-to-brain immune cell trafficking. Blocking NOS-mediated BBB dysfunction during this acute/subacute post-blast interval (24–71 hours after the last blast) also prevented sensorimotor impairment on a rotarod task 30 days later, long after L-NAME cleared the body. In postmortem brains from Veterans/military Servicemembers with blast-related TBI, we found marked Purkinje cell dendritic arbor structural abnormalities, which were comparable to neuropathologic findings in the blast-exposed mice. Taken collectively, these results indicate that blast provokes delayed-onset of NOS-dependent pathogenic cascades that can later emerge as behavioral dysfunction. These results also further implicate the cerebellum as a brain region vulnerable to blast-induced mTBI.

Increased Lymphangiogenesis and Lymphangiogenic Growth Factor Expression in Perivascular Adipose Tissue of Patients with Coronary Artery Disease.

Experimental and human autopsy studies have associated adventitial lymphangiogenesis with atherosclerosis. An analysis of perivascular lymphangiogenesis in patients with coronary artery disease is lacking. Here, we examined lymphangiogenesis and its potential regulators in perivascular adipose tissue (PVAT) surrounding the heart (C-PVAT) and compared it with PVAT of the internal mammary artery (IMA-PVAT). Forty-six patients undergoing coronary artery bypass graft surgery were included. Perioperatively collected C-PVAT and IMA-PVAT were analyzed using histology, immunohistochemistry, real time PCR, and PVAT-conditioned medium using cytokine arrays. C-PVAT exhibited increased PECAM-1 (platelet endothelial cell adhesion molecule 1)-positive vessel density. The number of lymphatic vessels expressing lymphatic vessel endothelial hyaluronan receptor-1 or podoplanin was also elevated in C-PVAT and associated with higher inflammatory cell numbers, increased intercellular adhesion molecule 1 (ICAM1) expression, and fibrosis. Significantly higher expression of regulators of lymphangiogenesis such as vascular endothelial growth factor (VEGF)-C, VEGF-D, and VEGF receptor-3 was observed in C-PVAT compared to IMA-PVAT. Cytokine arrays identified angiopoietin-2 as more highly expressed in C-PVAT vs. IMA-PVAT. Findings were confirmed histologically and at the mRNA level. Stimulation of human lymphatic endothelial cells with recombinant angiopoietin-2 in combination with VEGF-C enhanced sprout formation. Our study shows that PVAT surrounding atherosclerotic arteries exhibits more extensive lymphangiogenesis, inflammation, and fibrosis compared to PVAT surrounding a non-diseased vessel, possibly due to local angiopoietin-2, VEGF-C, and VEGF-D overexpression.

MicroRNA-200a/200b Modulate High Glucose-Induced Endothelial Inflammation by Targeting O-linked N-Acetylglucosamine Transferase Expression.

Background and Aims: Increased O-linked N-acetylglucosamine (O-GlcNAc) modification of proteins by O-GlcNAc transferase (OGT) is associated with diabetic complications. Furthermore, oxidative stress promotes endothelial inflammation during diabetes. A previous study reported that microRNA-200 (miR-200) family members are sensitive to oxidative stress. In this study, we examined whether miR-200a and miR-200b regulate high-glucose (HG)-induced OGT expression in human aortic endothelial cells (HAECs) and whether miRNA-200a/200b downregulate OGT expression to control HG-induced endothelial inflammation.Methods: HAECs were stimulated with high glucose (25 mM) for 12 and 24 h. Real-time polymerase chain reaction (PCR), western blotting, THP-1 adhesion assay, bioinformatics predication, transfection of miR-200a/200b mimic or inhibitor, luciferase reporter assay, and transfection of siRNA OGT were performed. The aortic endothelium of db/db diabetic mice was evaluated by immunohistochemistry staining.Results: HG upregulated OGT mRNA and protein expression and protein O-GlcNAcylation levels (RL2 antibody) in HAECs, and showed increased intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin gene expression; ICAM-1 expression; and THP-1 adhesion. Bioinformatics analysis revealed homologous sequences between members of the miR-200 family and the 3′-untranslated region (3′-UTR) of OGT mRNA, and real-time PCR analysis confirmed that members of miR-200 family were significantly decreased in HG-stimulated HAECs. This suggests the presence of an impaired feedback restraint on HG-induced endothelial protein O-GlcNAcylation levels because of OGT upregulation. A luciferase reporter assay demonstrated that miR-200a/200b mimics bind to the 3′-UTR of OGT mRNA. Transfection with miR-200a/200b mimics significantly inhibited HG-induced OGT mRNA expression, OGT protein expression; protein O-GlcNAcylation levels; ICAM-1, VCAM-1, and E-selectin gene expression; ICAM-1 expression; and THP-1 adhesion. Additionally, siRNA-mediated OGT depletion reduced HG-induced protein O-GlcNAcylation; ICAM-1, VCAM-1, and E-selectin gene expression; ICAM-1 expression; and THP-1 adhesion, confirming that HG-induced endothelial inflammation is partially mediated via OGT-induced protein O-GlcNAcylation. These results were validated in vivo: tail-vein injection of miR-200a/200b mimics downregulated endothelial OGT and ICAM-1 expression in db/db mice.Conclusion: miR-200a/200b are involved in modulating HG-induced endothelial inflammation by regulating OGT-mediated protein O-GlcNAcylation, suggesting the therapeutic role of miR-200a/200b on vascular complications in diabetes.

Selenoprotein S Attenuates Tumor Necrosis Factor-α-Induced Dysfunction in Endothelial Cells.

Endothelial dysfunction, partly induced by inflammatory mediators, is known to initiate and promote several cardiovascular diseases. Selenoprotein S (SelS) has been identified in endothelial cells and is associated with inflammation; however, its function in inflammation-induced endothelial dysfunction has not been described. We first demonstrated that the upregulation of SelS enhances the levels of nitric oxide and endothelial nitric oxide synthase in tumor necrosis factor- (TNF-) α-treated human umbilical vein endothelial cells (HUVECs). The levels of TNF-α-induced endothelin-1 and reactive oxygen species are also reduced by the upregulation of SelS. Furthermore, SelS overexpression blocks the TNF-α-induced adhesion of THP-1 cells to HUVECs and inhibits the increase in intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. Moreover, SelS overexpression regulates TNF-α-induced inflammatory factors including interleukin-1β, interleukin-6, interleukin-8, and monocyte chemotactic protein-1 and attenuates the TNF-α-induced activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways. Conversely, the knockdown of SelS with siRNA results in an enhancement of TNF-α-induced injury in HUVECs. These findings suggest that SelS protects endothelial cells against TNF-α-induced dysfunction by inhibiting the activation of p38 MAPK and NF-κB pathways and implicates it as a possible modulator of vascular inflammatory diseases.

The effect of weight change over a 2-year period on inflammatory status in postmenopausal women.

Body fat distribution has been shown to be a predictor of adhesion molecule and inflammatory marker expression albeit the effect of modest weight change on concentrations of adhesion molecules and inflammatory markers in postmenopausal women are not fully understood. The primary aim was to investigate the effects of weight change on adhesion molecules and inflammatory markers over 24 months in postmenopausal women. Body composition was assessed in 254 healthy postmenopausal women using dual-energy X-ray absorptiometry (DXA). Adhesion molecules and inflammatory markers were analysed by multiplex ELISA. Participants weight gain/loss at 24 months was defined as any value that was either above/below the weight value recorded at baseline. Postmenopausal women with an average weight loss of 3% had significantly decreased leptin concentrations by 18% at 24 months (P < 0.01). A 4% increase in body weight or a 9% increase in FMI significantly increased intercellular adhesion molecule-1 (ICAM-1), tumour necrosis factor-α (TNF-α) and leptin concentrations in postmenopausal women at 24 months (P < 0.01). Modest weight loss in postmenopausal women has a lowering effect on leptin concentrations over 24 months which may improve inflammatory status whilst modest weight gain increases ICAM-1, leptin and TNF-α, markers which are associated with a pro-inflammatory state and vascular complications.

Combination of tadalafil and diltiazem attenuates renal ischemia reperfusion-induced acute renal failure in rats.

Life threatening conditions characterized by renal ischemia/reperfusion (RIR) such as kidney transplantation, partial nephrectomy, renal artery angioplasty, cardiopulmonary bypass and aortic bypass surgery, continue to be among the most frequent causes of acute renal failure. The current study investigated the possible protective effects of tadalafil alone and in combination with diltiazem in experimentally-induced renal ischemia/reperfusion injury in rats. Possible underlying mechanisms were also investigated such as oxidative stress and inflammation. Rats were divided into sham-operated and I/R-operated groups. Anesthetized rats (urethane 1.3g/kg) were subjected to bilateral ischemia for 30min by occlusion of renal pedicles, then reperfused for 6h. Rats in the vehicle I/R group showed a significant (p˂0.05) increase in kidney malondialdehyde (MDA) content; myeloperoxidase (MPO) activity; TNF-α and IL-1β contents. In addition significant (p˂0.05) increase in intercellular adhesion molecule-1(ICAM-1) content, BUN and creatinine levels, along with significant decrease in kidney superoxide dismutase (SOD) activity. In addition, marked diffuse histopathological damage and severe cytoplasmic staining of caspase-3 were detected. Pretreatment with combination of tadalafil (5mg/kg bdwt) and diltiazem (5mg/kg bdwt) resulted in reversal of the increased biochemical parameters investigated. Also, histopathological examination revealed partial return to normal cellular architecture. In conclusion, pretreatment with tadalafil and diltiazem combination protected against RIR injury.

High glucose induces human endothelial dysfunction through an Axl-dependent mechanism

The receptor tyrosine kinase Axl and its ligand growth arrest-specific protein 6 (Gas6) are involved in the diabetic vascular disease. The aim of this study was to explore the role of Gas6/Axl system in high glucose (HG)-induced endothelial dysfunction. We investigated the effect of various glucose concentrations on Axl signaling in human microvascular endothelial cells (HMEC-1 s). Human plasma Gas6 value inversely correlated with glucose status, endothelial markers. HG decreased Gas6/Axl expression and increased intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression in HMEC-1 s. HG significantly decreased HMEC-1 s cell viability and tube formation and promoted monocyte-EC adhesion. Down-regulation of Akt phosphorylation was found in HG culture. Axl transfection significantly reversed HG-induced Akt phosphorylation, VCAM-1 expression and endothelial dysfunction. We also found additive changes in Axl-shRNA-infected HMEC-1 cells in HG culture. Furthermore, Axl overexpression in HMEC-1 s significantly reversed HG-induced vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) expression. In addition, significantly lower Axl and VEGFR2 expression in arteries were found in diabetic patients as compared with non-diabetic patients. This study demonstrates that HG can alter Gas6/Axl signaling and may through Akt and VEGF/VEGFR2 downstream molecules and suggests that Gas6/Axl may involve in HG-induced EC dysfunction.

Determination of Atherosclerosis markers changes after HIIT and ginger consumption in response to acute exercise in overweight women

The purpose of this study was to determine the effects of ten weeks of high intensity interval training (HIIT) with ginger supplementation on the systemic inflammatory response to acute HIIT exercise.Twenty four sedentary overweight women randomly assigned into three groups’ including HIIT + ginger (n=8), HIIT + placebo (n=8) and ginger (n=8). Sixteen women performed ten weeks of HIIT while the supplement consuming groups daily took 3 gm. of ginger pills and the HIIT + placebo group took placebo. Serum samples were collected at rest and immediately post-acute exercise, before and after the training. Two-way repeated measures ANOVA, paired t test, one-way ANOVA and post hoc benferoni were used to analyze data. Results indicated that three groups similarly affect the Monocyte Chemo tactic proetein-1 (MCP-1), Interlukine-10 (IL-10) changes in response to acute exercise (p>0.05) but showed significant increase in intercellular adhesion molecule-1 (ICAM-1) in HIIT + placebo group in comparison with HIIT + ginger group (p=0.02) in second acute exercise. The combination of HIIT and ginger consumption may induce a modest inflammatory attenuation of atherosclerosis factors in response to acute exercise and improvement in Vo2max and PBF results rather than ginger and training alone, in young sedentary overweight women.

Melanoma upregulates ICAM-1 expression on endothelial cells through engagement of tumor CD44 with endothelial E-selectin and activation of a PKCα-p38-SP-1 pathway.

Cancer metastasis involves multistep adhesive interactions between tumor cells (TCs) and endothelial cells (ECs), but the molecular mechanisms of intercellular communication in the tumor microenvironment remain elusive. Using static and flow coculture systems in conjunction with flow cytometry, we discovered that certain receptors on the ECs are upregulated on melanoma cell adhesion. Direct contact but not separate coculture between human umbilical endothelial cells (HUVECs) and a human melanoma cell line (Lu1205) increased intercellular adhesion molecule 1 (ICAM-1) and E-selectin expression on HUVECs by 3- and 1.5-fold, respectively, compared with HUVECs alone. The nonmetastatic cell line WM35 failed to promote ICAM-1 expression changes in HUVECs on contact. Enzyme-linked immunosorbent assay (ELISA) revealed that EC-TC contact has a synergistic effect on the expression of the cytokines interleukin (IL)-8, IL-6, and growth-related oncogene α (Gro-α). By using E-selectin cross-linking and beads coated with CD44 immunopurified from Lu1205 cells, we showed that CD44/selectin ligation was responsible for the ICAM-1 up-regulation on HUVECs. Protein kinase Cα (PKC-α) activation was found to be the downstream target of the CD44/selectin-initiated signaling, as ICAM-1 elevation was inhibited by siRNA targeting PKCα or a dominant negative form of PKCα (PKCα DN). Western blot analysis and electrophoretic mobility shift assays (EMSAs) showed that TC-EC contact mediated p38 phosphorylation and binding of the transcription factor SP-1 to its regulation site. In conclusion, CD44/selectin binding signals ICAM-1 up-regulation on the EC surface through a PKCα-p38-SP-1 pathway, which further enhances melanoma cell adhesion to ECs during metastasis.

High glucose induces human endothelial dysfunction through an Axl-dependent mechanism.

BackgroundThe receptor tyrosine kinase Axl and its ligand growth arrest-specific protein 6 (Gas6) are involved in the diabetic vascular disease. The aim of this study was to explore the role of Gas6/Axl system in high glucose (HG)-induced endothelial dysfunction.MethodsWe investigated the effect of various glucose concentrations on Axl signaling in human microvascular endothelial cells (HMEC-1 s).ResultsHuman plasma Gas6 value inversely correlated with glucose status, endothelial markers. HG decreased Gas6/Axl expression and increased intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression in HMEC-1 s. HG significantly decreased HMEC-1 s cell viability and tube formation and promoted monocyte-EC adhesion. Down-regulation of Akt phosphorylation was found in HG culture. Axl transfection significantly reversed HG-induced Akt phosphorylation, VCAM-1 expression and endothelial dysfunction. We also found additive changes in Axl-shRNA-infected HMEC-1 cells in HG culture. Furthermore, Axl overexpression in HMEC-1 s significantly reversed HG-induced vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) expression. In addition, significantly lower Axl and VEGFR2 expression in arteries were found in diabetic patients as compared with non-diabetic patients.ConclusionsThis study demonstrates that HG can alter Gas6/Axl signaling and may through Akt and VEGF/VEGFR2 downstream molecules and suggests that Gas6/Axl may involve in HG-induced EC dysfunction.

Glucocorticoid-Induced Tumor Necrosis Factor Receptor Family-Related Ligand Triggering Upregulates Vascular Cell Adhesion Molecule-1 and Intercellular Adhesion Molecule-1 and Promotes Leukocyte Adhesion

The interaction of glucocorticoid-induced tumor necrosis factor receptor-family related (GITR) protein with its ligand (GITRL) modulates different functions, including immune/inflammatory response. These effects are consequent to intracellular signals activated by both GITR and GITRL. Previous results have suggested that lack of GITR expression in GITR(-/-) mice decreases the number of leukocytes within inflamed tissues. We performed experiments to analyze whether the GITRL/GITR system modulates leukocyte adhesion and extravasation. For that purpose, we first evaluated the capability of murine splenocytes to adhere to endothelial cells (EC). Our results indicated that adhesion of GITR(-/-) splenocytes to EC was reduced as compared with wild-type cells, suggesting that GITR plays a role in adhesion and that this effect may be due to GITRL-GITR interaction. Moreover, adhesion was increased when EC were pretreated with an agonist GITR-Fc fusion protein, thus indicating that triggering of GITRL plays a role in adhesion by EC regulation. In a human in vitro model, the adhesion to human EC of HL-60 cells differentiated toward the monocytic lineage was increased by EC pretreatment with agonist GITR-Fc. Conversely, antagonistic anti-GITR and anti-GITRL Ab decreased adhesion, thus further indicating that GITRL triggering increases the EC capability to support leukocyte adhesion. EC treatment with GITR-Fc favored extravasation, as demonstrated by a transmigration assay. Notably, GITRL triggering increased intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression and anti-ICAM-1 and anti-VCAM-1 Abs reversed GITR-Fc effects. Our study demonstrates that GITRL triggering in EC increases leukocyte adhesion and transmigration, suggesting new anti-inflammatory therapeutic approaches based on inhibition of GITRL-GITR interaction.

Tumor necrosis factor-α, monocyte chemoattractant protein-1 and intercellular adhesion molecule-1 increase during the development of a 2,4-dinitrofluorobenzene-induced immediate-type dermatitis in rats

Due to the steadily increasing incidence of atopic dermatitis, there is a great medical need for new therapies and improved animal models. To provide more detailed analysis of a Sprague-Dawley rat dermatitis model. Sprague-Dawley rats were actively sensitized by intraperitoneal injections of dinitrophenylated ovalbumin (DNP-OVA) plus alum. Skin reactions were elicited by repeated epicutaneous challenge with 2,4-dinitrofluorobenzene (DNFB). The ear thickness exhibited a significant increase from the first challenge. A relatively steep increase in ear thickness was observed at the fifth DNFB application. After the fifth DNFB application, total serum immunoglobulin (Ig) E and IgG1 levels reached a plateau at 1h compared with the normal group. The peak production of tumor necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1 was found at 1h, while that of intercellular adhesion molecule (ICAM)-1 was found at 24h. Infiltration of CD4+T cells, CD8+T cells, eosinophils and mast cells increased in the skin lesion. The indices such as thickness and inflammatory cell infiltration in the lesional skin were increased by repeated hapten application; TNF-α, MCP-1 and ICAM-1 increased with the development of the dermatitis.

Essential role of cooperative NF-κB and Stat3 recruitment to ICAM-1 intronic consensus elements in the regulation of radiation-induced invasion and migration in glioma

Although radiotherapy improves survival in patients, glioblastoma multiformes (GBMs) tend to relapse with augmented tumor migration and invasion even after ionizing radiation (IR). Aberrant nuclear factor-κB (NF-κB) and signal transducer and activator of transcription factor 3 (Stat3) activation and interaction have been suggested in several human tumors. However, possible NF-κB/Stat3 interaction and the role of Stat3 in maintenance of NF-κB nuclear retention in GBM still remain unknown. Stat3 and NF-κB (p65) physically interact with one another in the nucleus in glioma tumors. Most importantly, glutathione S-transferase pull-down assays identified that Stat3 binds to the p65 transactivation domain and is present in the NF-κB DNA-binding complex. Irradiation significantly elevated nuclear phospho-p65/phospho-Stat3 interaction in correlation with increased intercellular adhesion molecule-1 (ICAM-1) and soluble-ICAM-1 levels, migration and invasion in human glioma xenograft cell lines 4910 and 5310. Chromatin immunopreicipitation and promoter luciferase activity assays confirmed the critical role of adjacent NF-κB (+399) and Stat3 (+479) binding motifs in the proximal intron-1 in elevating IR-induced ICAM-1 expression. Specific inhibition of Stat3 or NF-κB with Stat3.siRNA or JSH-23 severely inhibited IR-induced p65 recruitment onto ICAM-1 intron-1 and suppressed migratory properties in both the cell lines. On the other hand, Stat3C- or IR-induced Stat3 promoter recruitment was significantly decreased in p65-knockdown cells, thereby suggesting the reciprocal regulation between p65 and Stat3. We also observed a significant increase in NF-κB enrichment on ICAM-1 intron-1 and ICAM-1 transactivation in Stat3C overexpressing cells. In in vivo orthotopic experiments, suppression of tumor growth in Stat3.si+IR-treated mice was associated with the inhibition of IR-induced p-p65/p-Stat3 nuclear colocalization and ICAM-1 levels. To our knowledge, this is the first study showing the crucial role of NF-κB/Stat3 nuclear association in IR-induced ICAM-1 regulation and implies that targeting NF-κB/Stat3 interaction may have future therapeutic significance in glioma treatment.