Intercellular Adhesion Molecule-1 Immunoreactivity Research Articles

Up-regulation of intestinal nuclear factor kappa B and intercellular adhesion molecule-1 following traumatic brain injury in rats

Nuclear factor kappa B (NF-kappaB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-kappaB is activated and intercellular adhesion molecule-1 (ICAM-1) expressed in the gut following traumatic brain injury (TBI). The aim of current study was to investigate the temporal pattern of intestinal NF-kappaB activation and ICAM-1 expression following TBI. Male Wistar rats were randomly divided into six groups (6 rats in each group) including controls with sham operation and TBI groups at hours 3, 12, 24, and 72, and on d 7. Parietal brain contusion was adopted using weight-dropping method. All rats were decapitated at corresponding time point and mid-jejunum samples were taken. NF-kappaB binding activity in jejunal tissue was measured using EMSA. Immunohistochemistry was used for detection of ICAM-1 expression in jejunal samples. There was a very low NF-kappaB binding activity and little ICAM-1 expression in the gut of control rats after sham surgery. NF-kappaB binding activity in jejunum significantly increased by 160% at 3 h following TBI (P<0.05 vs control), peaked at 72 h (500% increase) and remained elevated on d 7 post-injury by 390% increase. Compared to controls, ICAM-1 was significantly up-regulated on the endothelia of microvessels in villous interstitium and lamina propria by 24 h following TBI and maximally expressed at 72 h post-injury (P<0.001). The endothelial ICAM-1 immunoreactivity in jejunal mucosa still remained strong on d 7 post-injury. The peak of NF-kappaB activation and endothelial ICAM-1 expression coincided in time with the period during which secondary mucosal injury of the gut was also at their culmination following TBI. TBI could induce an immediate and persistent up-regulation of NF-kappaB activity and subsequent up-regulation of ICAM-1 expression in the intestine. Inflammatory response mediated by increased NF-kappaB activation and ICAM-1 expression may play an important role in the pathogenesis of acute gut mucosal injury following TBI.

Adhesion molecule expression in vivo on extraocular muscles (EOM) in thyroid-associated ophthalmopathy (TAO).

TAO is an autoimmune condition characterized by mononuclear cell infiltration of the extraocular muscles (EOM) and/or the orbital fat/connective tissue with associated deposition of glycosaminoglycans (GAG) in the interstitial spaces. In this study, the presence and distribution of the vascular adhesion molecules intercellular adhesion molecule-1 (ICAM-1), endothelial-leucocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1) and the leucocyte integrins CD11a/CD18, CD11b/CD18, CD11c/CD18 were investigated. Nineteen EOM biopsies were collected from 17 patients with early (n = 6) and late (n = 13) TAO as well as from 12 non-TAO control patients. Consecutive cryostat sections of these biopsies were immunostained with MoAbs to the above-mentioned molecules and haematoxylin and eosin. Primary antibody binding was visualized using an avidin-biotin system. In early untreated TAO specimens, the interstitial and perimysial connective tissue surrounding EOM fibres and numerous mononuclear cells stained strongly for ICAM-1. In contrast, the vascular endothelial cells (ulex lectin-positive) stained strongly for ELAM-1 (E-selectin), VCAM-1 as well as ICAM-1. In late disease, the same distribution of immunoreactivity for ICAM-1, ELAM-1 and VCAM-1 was observed, but with significantly lower staining. The leucocyte integrins (CD11a, CD11b, CD11c) were again expressed at significantly higher levels in early TAO specimens compared with late TAO specimens and were minimal or absent in the EOM biopsies harvested from control patients. In conclusion, increased expression of adhesion molecules studied correlated with early active disease and was reduced in later stages.

Effects of HIV gp120 on endothelium-dependent relaxation and eNOS expression

Introduction: Clinical studies indicate that HIV infection is associated with high incidence of cardiovascular disease. However, the mechanisms are unknown. The objective of this study was to investigate the effects of HIV gp120 on vasomotor function of porcine coronary arteries and eNOS expression. Methods: Coronary arteries were isolated from fresh porcine hearts and cut into rings, which were studied in 7 groups (TNF-α, gp120, TNF-α plus gp120, TNF-α plus gp120 and anti-gp120 antibody, TNF-α plus gp120 and anti-ICAM-1 antibody, or negative control). Vasomotor function was analyzed with myograph tension system in response to vasoreactive drugs (U46619, bradykinin or sodium nitroprusside). eNOS and ICAM-1 mRNA and eNOS protein levels were determined using RT-PCR and western blot or immunochemistry, respectively. Human coronary artery endothelial cells (HCAECs) were also included for eNOS and ICAM-1 expression. Results: Porcine coronary artery rings treated with TNF-α alone for 8 hrs or gp120 alone for 16 hrs did not show any changes of vasomotor function. However, the rings treated with TNF-α plus gp120 showed a 34.18% reduction of endothelium-dependent vasorelaxation in response to bradykinin as compared to controls (P < 0.05). Anti-gp120 or anti-ICAM-1 antibody blocked this effect of TNF-α and gp120 treated vessels. The vessel contractivity (U46619) or endothelium-independent vasorelaxation did not show changes in all treated vessels. Only TNF-α plus gp120 group significantly reduced eNOS/GAPDH mRNA ratios by 28.86% as compared to controls (P < 0.05). eNOS protein levels were also substantially decreased in this group. ICAM-1 immunoreactivity was increased in all TNF-α treated vessels. Furthermore, HCAECs showed consistent data with pig vessels in response these treatments. Conclusions: These data demonstrate that HIV gp120 reduces endothelium-dependent vasorelaxation and eNOS expression in both porcine coronary arteries and HCAECs pre-treated with TNF-α; and blocking of ICAM-1 or gp120 reverses these effects. This study suggests that ICAM-1 may be an important mediator of gp120 induced endothelial cell injury.

ICAM-1 expression is upregulated in reflux nephropathy.

Reflux nephropathy (RN) is a major cause of end-stage renal failure in children and young adults. Intercellular adhesion molecule-1 (ICAM-1), a cell surface glycoprotein, has a role in the regulation of interaction among immune cells. It has been demonstrated that increased levels of tubular ICAM-1 correlate with an extent of tubular damage in diabetic nephropathy. We hypothesized that ICAM-1 local synthesis is altered in reflux nephropathy and therefore designated this study to investigate ICAM-1 expression in RN. The kidney specimens from six patients with severe reflux nephropathy secondary to primary vesicoureteral reflux were obtained at the time of nephrectomy. Control materials included normal kidney specimens obtained from three adult patients during partial nephrectomy for an incidentaloma. Fluorescent immunohistochemistry was carried out using monoclonal antibodies to ICAM-1 utilizing confocal laser scanning microscopy. Reverse transcriptase polymerase chain reaction (RT-PCR) was performed to evaluate the relative amount of ICAM-1. In the control kidneys, there was lack of ICAM-1 immunoreactivity in the interstitium and proximal tubules and moderate immunoreactivity in the glomerulus. In the refluxing kidney there was strong ICAM-1 immunoreactivity in the glomerulus, interstitium and proximal tubules. The RT-PCR showed strong ICAM-1 mRNA expression in the refluxing kidneys and absent or weak ICAM-1 expression in the controls. Our findings of increased expression of ICAM-1 in the severe reflux nephropathy kidney suggests that ICAM-1 may play a role in the pathogenesis of renal parenchymal damage associated with RN.

Immunohistochemical analysis of anti-Hu-associated paraneoplastic encephalomyelitis.

The precise immune mechanisms of neuronal death in anti-Hu-associated paraneoplastic encephalomyelitis (PEM) are unclear. We performed an immunohistochemical study on postmortem brain tissue from 11 patients with anti-Hu-associated PEM to further characterize the immune reaction and to ascertain possible mechanisms of neuronal death. To analyze inflammatory infiltrates, antibodies against lymphocyte subpopulations (CD3, CD20, CD4, CD8), macrophage and activated microglia (CD68), major histocompatibility complex (MHC) classes I and II (HLA-ABC and HLA-DR), and the intercellular adhesion molecules (ICAM) -1 and -3 were used. Cell death mechanisms were defined using antibodies against the cytotoxic protein TIA-1, the C9neo component of complement, the Fas receptor (CD95) and its ligand, the apoptosis effector activated caspase-3, and the apoptosis inhibitor Bcl-2. A great number of T cells expressing the cytotoxic protein TIA-1 was observed, mainly in clusters around neurons. ICAM-1 immunoreactivity was increased in the neuropil and reactive astrocytes in areas of inflammation within the central nervous system and in satellite cells of pathological dorsal root ganglia surrounding apparently normal sensory neurons. By contrast, Fas, FasL, C9neo, and activated caspase-3 immunoreactivities were negative in pathological areas. Bcl-2 immunoreactivity was found in satellite cells, but not in sensory neurons of normal and pathological dorsal root ganglia. Our data point out to an induction of a cytotoxic, non-apoptotic, neuronal death in anti-Hu-associated PEM. The increased ICAM-1 immunoreactivity may favor the infiltration of lymphocytes in the pathological areas.

Adhesion molecules in human pancreatic cancer.

Adhesion molecules are cell surface glycoproteins that are important in cell-to-cell and cell-to-extracellular matrix interactions. In the present study, we analyzed the adhesion molecules ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1), and ELAM-1 (endothelial leukocyte adhesion molecule-1) in human pancreatic cancer. ICAM-1, VCAM-1, and ELAM-1 were analyzed in 20 pancreatic cancer specimens and 20 normal pancreatic tissues. mRNA expression encoding ICAM-, VCAM-1, and ELAM-1 was assessed with Northern blot analysis. The distribution and localization of ICAM-1, VCAM-1, and ELAM-1 was determined in the pancreatic specimens by immunohistochemistry. Northern blot analysis revealed a 5.4-fold increase of ICAM-1 (P<0.01) and a 3.7-fold increase in VCAM-1 (P<0.01) mRNA expression in cancer samples in comparison with normal controls. In contrast, ELAM-1 mRNA levels did not show significant differences between the cancer and the normal tissues. Immunohistochemical analysis of cancer tissues showed strong immunostaining for ICAM-1 and VCAM-1, and faint immunostaining for ELAM-1 in the pancreatic cancer cells. Fibrotic or noncancerous pancreatic tissue adjacent to the cancer mass was devoid of any immunoreactivity for ICAM-1, ELAM-1, and VCAM-1. In contrast, the normal pancreas exhibited no immunoreactivity of ICAM-1, ELAM-1, and VCAM-1. Enhanced expression of ICAM-1 and VCAM-1 in human pancreatic cancers suggests a role in tumor pathogenesis. The increase of these adhesion molecules might influence the detachment of cancer cells in the primary tumor, might contribute to cancer cell migration and the spread of cancer cells to distant organs, or both.

Expression of cell adhesion molecules, their ligands and tumour necrosis factor alpha in the liver of patients with metastatic gastrointestinal carcinomas.

The expression of the following cell adhesion molecules, their beta1 and beta2 integrin ligands and the cytokine tumour necrosis factor-alpha (TNF-alpha) was investigated by light and electron microscope immunohistochemistry in the liver tissue in 20 patients with colorectal and gastric cancer also presenting with liver metastases: intercellular adhesion molecule-1 (ICAM-1), vascular endothelial adhesion molecule-1 (VCAM-1), E-selectin, leucocyte function-associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1), and very late antigen-4 (VLA-4). We have found a parallel enhancement of the adhesion molecules and of TNF-alpha in liver sinusoids surrounding metastases. The expression of ICAM-1 was enhanced on sinusoidal cells in all zones of the acinus. VCAM-1 immune reactivity was diffuse but less intensive in the lobule. E-selectin expression was observed in sinusoidal cells attached to metastases. In tumour metastases the expression of ICAM-1, VCAM-1, and E-selectin was visible on the tumour vascular endothelium. Tumour infiltrating host cells sowing positive immunoreactivity for ICAM-1, VCAM-1, LFA-1, Mac-1, and VLA-4 were located mainly at the boundary between liver parenchyma and the metastasis. At the ultrastructural level, ICAM-1-positive immune deposits were observed on the cellular membrane and in some transport vesicles of gastric metastatic cells. Further, the expression of all adhesion molecules was confirmed to sinusoidal endothelial cells and tumour vessels. It is concluded that the enhanced expression of adhesion molecules in liver sinusoids could be a marker for the assessment of the ability of sinusoidal endothelial cells to control the recruitment of leukocytes and monocytes to the metastatic site. They could also direct the adhesion of new circulating tumour cells to sinusoidal endothelium.

Fluvastatin inhibits O2- and ICAM-1 levels in a rat model with aortic remodeling induced by pressure overload.

Upregulation of intercellular adhesion molecule-1 (ICAM-1) expression is suggested to play an important role in the pathogenesis of vascular remodeling. The aim of the present study was to investigate the effects of the 3-hydroxy-3-methylglutaryl (HMG) CoA reductase inhibitor fluvastatin on superoxide anion (O2-) production and ICAM-1 expression in a rat model with vascular remodeling induced by pressure overload. Two weeks after aortic banding, marked increases in O2- production and ICAM-1 protein levels were observed in the aorta. O2- formation and ICAM-1 immunoreactivity were mainly increased in the endothelium and adventitia of the aorta in banded rats. Oral administration of fluvastatin prevented both these changes and the development of perivascular fibrosis and increased the expression of endothelial nitric oxide synthase. Cholesterol and lipid peroxide levels in serum did not change in the banded rats. Thus the beneficial effects of fluvastatin seen in this study as well as its cholesterol-lowering effect may contribute to attenuate the atherosclerotic process.

Leukocyte recruitment and neuroglial activation during facial nerve regeneration in ICAM-1-deficient mice: effects of breeding strategy.

Intercellular adhesion molecule 1 (ICAM-1) is a widely expressed glycoprotein involved in leukocyte extravasation and the interaction of lymphocytes with antigen-presenting cells. We examined these aspects of ICAM-1 function in the central nervous system after axonal injury in wild-type and ICAM-1-deficient mice. ICAM-1 immunoreactivity in the normal mouse facial nucleus was restricted to the vascular endothelium. Transection of the facial nerve led to a fast upregulation of ICAM-1 on activated microglia in the axotomized facial nucleus and the infiltration of ICAM-1-positive lymphocytes. Labeling elsewhere was unchanged. In homozygous ICAM-1 mutant mice, ICAM-1 was absent from endothelial cells and lymphocytes, but low levels of ICAM-1 were detected on cell membranes of reactive microglial cells. Comparison of wild-type animals with homozygously bred, ICAM-1-deficient mice showed a reduction of astrocytic and microglial activation, massive late axonal sprouting, and decreased lymphocyte infiltration. These experiments were repeated in F1 progeny of heterozygous mice on a C57BL/6 background. Neuroglial activation and lymphocyte infiltration in F1 homozygously deficient mice was unaffected compared with wild-type siblings. The invading ICAM-1-deficient lymphocytes also adhered to the ICAM-1-positive phagocytotic microglial cells in the ICAM-1 mutants. No change in the recruitment of macrophages and granulocytes into the crushed facial nerve, and no effect on axonal regeneration occurred. These data argue against the requirement of endothelial ICAM-1 in the recruitment of leukocytes into the crushed peripheral nerve or the axotomized facial motor nucleus and stress the importance of adequately matched controls in studying the effects of gene deletion in experimental animals.

Sequential upregulation of cell adhesion molecules in degenerating rat basal forebrain cholinergic neurons and in phagocytotic microglial cells

To study the functional role of adhesion molecules in neurodegenerative events in vivo, the basal forebrain cholinergic lesion-induced expression of the intercellular adhesion molecule (ICAM)-1 and leukocyte function-associated antigen (LFA)-1 was studied by double immunocytochemistry and Western blot analysis. A single intracerebroventricular application of the cholinergic immunotoxin, 192IgG-saporin, produced a selective cholinergic cell loss in rat basal forebrain nuclei detectable by gradual loss of choline acetyltransferase (ChAT)-immunoreactive cells starting 3 days but being nearly complete 7 days after injection of the toxin. The degeneration of cholinergic neurons was accompanied by a striking appearance of activated microglial cells in the lesioned areas. Four days following injection of 192IgG-saporin, ICAM-1 immunoreactivity was predominantly observed in ChAT-positive neurons and partly in activated microglia in the basal forebrain nuclei, while LFA-1 expression at this time point was restricted to neurons. However, 7 days after cholinergic lesion, only a few, shrunken neuronal somata were found to be immunoreactive for ICAM-1 and LFA-1, while activated microglial cells demonstrated strong immunoreactivity for ICAM-1 and LFA-1 in the lesioned forebrain areas, persisting up to 14 days after lesion while no immunoreactivity was observed in neurons at this time point. Western blot analysis demonstrated increased ICAM-1 level in the basal forebrain already detectable 4 days after surgery but being more pronounced 7 days post lesion. The data suggest that ICAM-1 and LFA-1 may act as intercellular recognition signals by which degenerating cholinergic neurons actively participate in the sequence of events leading to their targeting and elimination by phagocytotic microglia.

Biological Implications of Circulating Soluble Intercellular Adhesion Molecule-1 in Colorectal Cancer Patients

Background: Intercellular adhesion molecule-1 (ICAM-1) is assumed to play a role in cell-cell and cell- extracellular matrix interactions. We evaluated the relationship between local expression of ICAM-1 and the circulating level of sICAM-1, and clarified its biological implications. Methods: Serum concentrations of sICAM-1 in 94 colorectal cancer patients were determined. Tissue concentrations of sICAM-1 in the tumor, colorectal adenoma, and the normal mucosa were also determined. The expression of ICAM-1 in the tumor was evaluated immunohistochemically. Results: The serum concentration of sICAM-1 in the patients was significantly higher than that in the controls, and the tumor size was the independent pathological factor that was associated with the serum ICAM-1 level. ICAM-1 immunoreactivity was seen intensively in the stromal cells in the tumor. The tissue concentration of sICAM-1 in the normal mucosa was significantly lower than that in the adenoma and the early carcinoma. The tissue concentration of sICAM-1 in the advanced carcinoma significantly decreased in association with the increase in tumor size. This fluctuation of ICAM-1 expression in the tumor was also associated with the metastatic potential even at an early stage of the disease. Conclusions: The tissue concentration of sICAM-1 increased during tumorigenesis and at an early stage of carcinoma, and decreased in association with progression of the disease. Serum sICAM-1 level reflected the fluctuation of ICAM-1 expression in the tumor. Evaluation of serum concentration of sICAM-1 may be associated with tumor load and can reflect disease progression in colorectal cancer patients.

Melatonin ameliorates autoimmune encephalomyelitis through suppression of intercellular adhesion molecule-1

Melatonin (N-acetyl-5-methoxytryptamine), a pineal neurohormone, is a hydroxyl radical scavenger and antioxidant, and plays an important role in the immune system. We studied the effect of exogenous melatonin on the pathogenesis of experimental autoimmune encephalomyelitis (EAE). EAE was induced in Lewis rats by immunization with rat spinal cord homogenates. Subsequent oral administration of melatonin at 5 mg/kg significantly reduced the clinical severity of EAE paralysis compared with administration of the vehicle alone (p<0.01). Infiltration of ED1+ macrophages and CD4+ T cells into spinal cords occurred both in the absence and presence of melatonin treatment, but melatonin-treated rats had less spinal cord infiltration of inflammatory cells than did the control group. ICAM-1 immunoreactivity in the blood vessels of EAE lesions was decreased in melatonin-treated rats compared to vehicle-treated rats. These findings suggest that exogenous melatonin ameliorates EAE via a mechanism involving reduced expression of ICAM-1 and lymphocyte function associated antigen-1a in autoimmune target organs.

Expression of cystic fibrosis transmembrane conductance regulator in liver tissue from patients with cystic fibrosis

The authors examined the expression of cystic fibrosis transmembrane conductance regulator (CFTR) and its relationship to histopathological changes in cystic fibrosis (CF) liver tissue. Immunohistochemistry was used to examine expression of CFTR, intercellular adhesion molecule-1 (ICAM-1) and liver cell-type markers in liver cryosections in 11 patients with CF-associated liver disease, and non-CF controls with (n = 17) and without (n = 3) liver disease. In CF patients prominent inflammatory infiltrates were not found, yet hepatic stellate cells were identified within fibrotic areas around bile ducts. Proliferating bile ducts displayed ICAM-1 immunoreactivity in 3 cases, but bile ducts were otherwise negative. In 2 patients homozygous for R764X and for 1112delT no CFTR immunoreactivity was detected. Bile-duct epithelial cells in patients carrying the ΔF508 mutation displayed aberrant cytoplasmic immunolocalization of CFTR, as determined with confocal laser scanning microscopy, in contrast to the distinct CFTR expression at the luminal surface seen in controls. No clear relationship between CFTR expression and fibrosis or inflammation was evidenced in CF patients. In conclusion, these findings are consistent with an impairment of ΔF508 CFTR processing in intrahepatic biliary epithelium. ICAM-1 expression on bile-duct epithelial cells and inflammatory infiltrates were rare findings in CF liver tissue, indicating that immunological mechanisms are unlikely to be involved in initiation of CF-associated liver disease. (Hepatology 2000;32:334-340.)

Intercellular adhesion molecule-1 and hair follicle regression.

Although the intercellular adhesion molecule-1 (ICAM-1) is recognized for its pivotal role in inflammation and immune responses, its role in developmental systems, such as the cyclic growth (anagen) and regression (catagen) of the hair follicle, remains to be explored. Here we demonstrate that ICAM-1 expression in murine skin is even more widespread and more developmentally regulated than was previously believed. In addition to endothelial cells, selected epidermal and follicular keratinocyte subpopulations, as well as interfollicular fibroblasts, express ICAM-1. Murine hair follicles express ICAM-1 only late during morphogenesis. Thereafter, morphologically identical follicles markedly differ in their ICAM-1 expression patterns, which become strikingly hair cycle-dependent in both intra- and extrafollicular skin compartments. Minimal ICAM-1 and leukocyte function-associated (LFA-1) protein and mRNA expression is observed during early anagen and maximal expression during late anagen and catagen. Keratinocytes of the distal outer root sheath, fibroblasts of the perifollicular connective tissue sheath, and perifollicular blood vessels exhibit maximal ICAM-1 immunoreactivity during catagen, which corresponds to changes of LFA-1 expression on perifollicular macrophages. Finally, ICAM-1-deficient mice display significant catagen acceleration compared to wild-type controls. Therefore, ICAM-1 upregulation is not limited to pathological situations but is also important for skin and hair follicle remodeling. Collectively, this suggests a new and apparently nonimmunological function for ICAM-1-related signaling in cutaneous biology.

Vascular factors are critical in selective neuronal loss in an animal model of impaired oxidative metabolism.

Thiamine deficiency (TD) models the cellular and molecular mechanisms by which chronic oxidative deficits lead to death of select neurons in brain. Region- and cell-specific oxidative stress and vascular changes accompany the TD-induced neurodegeneration. The current studies analyzed the role of oxidative stress in initiating these events by testing the role of intercellular adhesion molecule-1 (ICAM-1) and endothelial nitric oxide synthase (eNOS) in the selective neuronal loss that begins in the submedial thalamic nucleus of mice. Oxidative stress to microvessels is known to induce eNOS and ICAM-1. TD increased ICAM-1 immunoreactivity in microvessels within the submedial nucleus and adjacent regions 1 day prior to the onset of neuronal loss. On subsequent days, the pattern of ICAM-1 induction overlapped that of neuronal loss, and of induction of the oxidative stress marker heme oxygenase-1 (HO-1). The intensity and extent of ICAM-1 and HO-1 induction progressively spread in parallel with the neuronal death in the thalamus. Targeted disruption of ICAM-1 or eNOS gene, but not the neuronal NOS gene, attenuated the TD-induced neurodegeneration and HO-1 induction. TD induced ICAM-1 in eNOS knockout mice, but did not induce eNOS in mice lacking ICAM-1. These results demonstrate that in TD, an ICAM-1-dependent pathway of eNOS induction leads to oxidative stress-mediated death of metabolically compromised neurons. Thus, TD provides a useful model to help elucidate the role of ICAM-1 and eNOS in the selective neuronal death in diseases in which oxidative stress is implicated.

Labour-associated Expression of Intercellular Adhesion Molecule-1 (ICAM-1) in Placental Endothelial Cells Indicates Participation of Immunological Processes in Parturition

Inflammatory cytokines induce or upregulate de novo expression of cell adhesion molecules on endothelial and epithelial cells. In order to demonstrate inflammatory reactions within placental tissues in association with normal term as well as non-infection-induced preterm labour, the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and endothelial leucocyte adhesion molecule-1 (ELAM-1) was examined by immunohistochemical methods in both trophoblastic villi (n=123) and umbilical cord (n=61). As a result, ICAM-1 immunoreactivity was exclusively localized in the endothelial cells of the fetal vascular system, while VCAM-1 and ELAM-1 were not detected. Whereas ICAM-1 was not expressed in early pregnancy (9–12 weeks of gestation), it could be weakly detected at the end of pregnancy in cases of elective caesarean delivery in the absence of labour, and was significantly more strongly expressed in cases of vaginal delivery after spontaneous onset of normal term labour. Significantly increased immunoreactivity of ICAM-1 within umbilical cord tissues was also found in association with uncontrollable preterm labour in the absence of intrauterine infection which was excluded after histological examination of fetal membranes, umbilical cord and chorionic plate. We conclude that ICAM-1 expression in the endothelium of the fetal vascular system is associated with the presence of labour and reflects participation of immune–inflammatory reactions in labour-promoting mechanisms.

Ultrastructural localization of adhesion molecules in the healthy and inflamed choroid plexus of the mouse.

The functional expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and MAdCAM-1 in the choroid plexus is indicative of a role of this structure in the communication of the immune system with the central nervous system (CNS). In order to gain further insight into the possible functions of adhesion molecules expressed in the choroid plexus, we investigated the exact ultrastructural localization of VCAM-1, ICAM-1 and MAdCAM-1 on semithin and ultrathin cryosections of the choroid plexus of healthy mice and of mice suffering from experimental autoimmune encephalomyelitis (EAE). In the healthy choroid plexus VCAM-1 and ICAM-1, but not MAdCAM-1, could be detected on the apical surface of the choroid plexus epithelial cells. During EAE, immunoreactivity for VCAM-1 and ICAM-1 was dramatically increased. Additionally, apical expression of MAdCAM-1 was observed on individual choroid plexus epithelial cells during EAE. At the same time, VCAM-1, ICAM-1 or MAdCAM-1 were never present on the endothelial cells of the fenestrated capillaries within the choroid plexus. The polar expression of VCAM-1, ICAM-1 and MAdCAM-1 on the apical surface of choroid plexus epithelial cells, which form the blood-cerebrospinal fluid barrier, implies a previously unappreciated function of this barrier in the immunosurveillance of the CNS.

In situ expression of E-selectin and intercellular adhesion molecule-1 in chronic inflammatory diseases of the gastrointestinal tract.

The study of cell adhesion molecules contributes to our understanding of the inflammatory mechanisms which include the endothelial activation of newly formed or pre-existing vessels, the increase of inflammatory cells' adhesive capability and their migration into perivascular tissues. The aim of the present study was to investigate the local presence and the extent of expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) in the mucosa of patients with chronic gastritis, chronic inflammatory bowel disease, and controls, as well as to identify possible correlations between in situ expression of the above adhesion molecules and degree of inflammatory activity or therapeutic response. In cryostat tissue sections we examined the immunohistochemical expression and localization of E-selectin and the intercellular adhesion molecule-1 (ICAM-1). Our specimens consisted of 27 cases of chronic gastritis, 42 cases of ulcerative colitis, and 15 cases of Crohn's disease. E-selectin was expressed in capillary endothelia as well as on neutrophils, located either in the lamina propria or in the glandular epithelia or lumina. This marker's expression was associated with the active phase of ulcerative colitis (p<0.0005) and possibly of chronic gastritis (p=0.06). ICAM-1 immunolabelling was localized in endothelia and chronic inflammatory components which had passed through the vascular walls. This marker's immunoreactivity was generally increased in all our specimens compared to normal mucosa and generally tended to correlate with chronic phases of the inflammatory process (p<0.10). E-selectin regulates the accumulation of neutrophils in the early stages of the inflammatory process and is thus associated at least with the active phase of ulcerative colitis. Whether any post-therapy alteration of E-selectin immunopositivity seems to indicate a good response to drug therapy is well worth investigating in ulcerative colitis patients. ICAM-1 immunoreactivity in lymphoplasmacytic infiltrates might serve as a marker of chronic immune stimulation, which is potentially responsible for the persistence of the inflammatory disorders.

Thrombolysis with tissue plasminogen activator alters adhesion molecule expression in the ischemic rat brain.

We tested the hypothesis that treatment of embolic stroke with recombinant human tissue plasminogen activator (rhtPA) alters cerebral expression of adhesion molecules. Male Wistar rats were subjected to middle cerebral artery occlusion by a single fibrin-rich clot. P-selectin, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) immunoreactivity was measured at 6 or 24 hours after embolic stroke in control rats and in rats treated with rhtPA at 1 or 4 hours after stroke. To examine the therapeutic efficacy of combined rhtPA and anti-ICAM-1 antibody treatment at 4 hours after embolization, ischemic lesion volumes were measured in rats treated with rhtPA alone, rats treated with rhtPA and anti-ICAM-1 antibody, and nontreated rats. Administration of rhtPA at 1 hour after embolization resulted in a significant reduction of adhesion molecule vascular immunoreactivity after embolization in the ipsilateral hemisphere compared with corresponding control rats. However, when rhtPA was administered to rats at 4 hours after embolization, significant increases of adhesion molecule immunoreactivity in the ipsilateral hemisphere were detected. A significant increase of ICAM-1 immunoreactivity was also detected in the contralateral hemisphere at 24 hours after ischemia. A significant reduction in lesion volume was found in rats treated with the combination of rhtPA and anti-ICAM-1 antibody compared with rats treated only with rhtPA. The present study suggests that the time of initiation of thrombolytic therapy alters vascular immunoreactivity of inflammatory adhesion molecules in the ischemic brain and that therapeutic benefit can be obtained by combining rhtPA and anti-ICAM-1 antibody treatment 4 hours after stroke.

The expression of cellular adhesion molecules is upregulated and co-localized with the oxidative stress in the early course of experimental acute pancreatitis

Using a novel method to demonstrate histologically the production of oxygen free radicals (OFR-s), this study investigates the possible role of cellular adhesion molecules (CAM-s) -in relation to the oxidative stressduring the early course of acute necrotizing pancreatitis (ANP). Similarly to other inflammatory pathologies, injury to the pancreatic acini supposedly results in the expression/upregulation of CAM-s on the periacinar endothelial cells as well as release of proinflammatory mediators. The adherent lenkocytes, mostly neutrophils (PMN), become activated and release OFR-s, microbicidal enzymes and more mediators to strengthen the inflammatory response. An uncontrolled inflammatory cascade may become locally and systemically deleterious. We have developed a novel technique to detect the presence and localization of OFR-s in vivo, using the cerium capture method. Reaction of OFR-s with CeC13 leads to cerium-perhydroxide precipitation. These deposits can be detected histologically by their laser reflecting properties using confocal laser scanning microscopy (CLSM) in the reflectance mode (RM). METHODS: ANP was induced in Wistar rats by retrograde infusion of taurocholate into the pancreatic duct. At different time points (1, 2, 24h) the animals were re-laparotomized and perfused with CeC13 (20mM in Hartmann solution) through the abdominal aorta, then sacrificed. Normal rats received a CeCI 3 perfusion in the same fashion and were used as controls. Pancreata were snap frozen in liquid nitrogen. Indirect immunofluorescence (FITC fluorochrome) was performed on serial frozen sections to label E-selectin, P-selectin, ICAM-1, VCAM-1, and PECAM molecules. Nuclei were colored by propidium-iodide. Simultaneous observation of CAM expression, cerium reflectance and cell type definition was performed by CLSM using multichannel detection. RESULTS: The capillaries in the pancreata of normal animals showed weak, sparse P-selectin and ICAM-1 positivity, with a constitutive expression of PECAM. Reflectance signals were negligible. At the early time points (1, 2h) of pancreatitis the tissue architecture was found to be relatively well preserved, an increase in endothelial P-selectin, and ICAM-1 immunoreactivity was observed. Strong, shining reflectance could be detected in the pancreatic microvasculature, as well as cloud-like signals over certain groups of acini. Numerous leukocytes adherent to CAM positive capillary walls were seen, however they presented small, focal, mostly intracellular reflectance signals, which were often localized at the contact points between the CAM-s and leukocytes. At 24h the samples were characterized by intense PMN infiltration, heterogeneous necrosis, strong, mostly perinecrotic P-selectin, and ICAM-1, but moderately increased E-selectin, and VCAM-1 expression. Large numbers of adherent, or already transmigrated PMN-s showed abundant intraand pericellular reflectance signals. CONCLUSION: Pancreatic endothelial CAM-s are upregulated early in ANP, and may play a role -in addition to cytokinesin the activation of adhering leukocytes. At the earliest time points the major source of OFR seems to be the pancreatic cell (xanthine-oxidase), later the activated PMN-s, thereby possibly contributing to local and distant organ damage. The CAM over-expression showed a significant spatial co-localization with the oxidative stress. The work of G. Telek was supported by a grant from IRMAD Foundation, France.